Handbook detailing innovative technologies for small hydropower ...

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Pilot station of micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion ..... information processing and presentation method.
D5.4 HANDBOOK OF INNOVATIVE TECHNOLOGIES TO PROMOTE SHP WORK PACKAGE 5 - COMMON STRATEGIES TO IMPROVE SHP IMPLEMENTATION Final Version 1 Date 25.08.2011

R. Magureanu (POLI-B), S. Ambrosi (POLI-B), B. Popa (POLI-B), Bostan Ion (MOLD), Dulgheru Valeriu (MOLD), Bostan Viorel (MOLD), Sochirean Anatol (MOLD)

INDEX PREFACE ............................................................................................................................................. 5  1. LIST OF ABBREVIATIONS.............................................................................................................. 6  2. INTRODUCTION .............................................................................................................................. 7  3. SMART MEASUREMENTS FOR SMALL HYDROPOWER PLANTS (RO) ................................... 8  4. INNOVATIVE TECHNOLOGIES TO PRODUCE SHP (MOLD) ..................................................... 24  4.1. IDENTIFICATION AND EVALUATION OF POTENTIAL SITES FOR SHP IMPLEMENTATION (ON RIVER PRUT) .. 24  5. ELABORATION OF INNOVATIVE TECHNOLOGIES TO PRODUCE SHP.................................. 31  5.1. ELABORATION OF FLOATING MICRO HYDROPOWER PLANTS FOR RIVER WATER KINETIC ENERGY CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY ....................................................................... 31  5.1.1. Conceptual diagrams ................................................................................................................ 31  5.1.2. Micro hydro power plant for river water kinetic energy conversion into electrical Micro hydro power plant (figure 26) [9] ................................................................................................................... 33  5.1.3. Design of the hydrodynamic rotor ............................................................................................. 38  5.2. INDUSTRIAL PROTOTYPES OF MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR .................... 58  5.2.1. Pilot station of micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into mechanical energy (MHCF D4x1,5 M) ...................................................................... 58  5.2.2. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical and mechanical energy (MHCF D4x1,5ME) ........................................................................ 62  5.2.3. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical and mechanical energy at small speeds (MHCF D4x1,5ME) ............................................. 65  5.2.4. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical energy (MHCF D4x1,5E) ..................................................................................................... 67  6. SUMMARY AND CONCLUSIONS ................................................................................................. 70  ANNEX ............................................................................................................................................... 71  7. REFERENCES ............................................................................................................................... 75 

Figure index FIGURE 1 - MAP OF ROMANIA WITH MAIN RIVERS, MAJOR, MEDIUM AND SMALL HYDRO PLANTS ..................... 8  FIGURE 2 - RIVER ARGES WITH MAJOR AND SMALL HYDRO PLANTS ............................................................. 8  FIGURE 3 - H/Q AND Η/Q CHARACTERISTICS FOR SMALL HYDRO TURBINES ................................................. 9  FIGURE 4 - MIHAILESTI SMALL HYDRO PLANT WITH ONE FRANCIS AND TWO KAPLAN TURBINES ..................... 9  FIGURE 5 - MEASUREMENT DIAGRAM FOR MIHAILESTI SHP ..................................................................... 10  FIGURE 6 - ARBITER SYSTEMS – POWER SENTINEL PHASOR MEASUREMENT UNIT ................................... 10  FIGURE 7 – WIDE AREA MONITORING SYSTEM (WAMS) .......................................................................... 11  FIGURE 8 - DATA COLLECTED FROM PHASOR MEASUREMENT UNIT 1 AT MIHAILESTI SHP; A) VOLTAGES, B) CURRENTS, C) RMS DATA, D) PHASORS ......................................................................................... 12  FIGURE 9 - THE PMUS IN ELPROS NETWORK AND REPRESENTATION OF VOLTAGES, PHASORS, FREQUENCY IN ALL FOUR ACQUISITION POINTS .................................................................................................... 13  FIGURE 10 - DATA COLLECTED FROM MIHAILESTI PMU ON THE OUTPUT 20KV OUTPUT LINE...................... 14  FIGURE 11 - NATIONAL INSTRUMENTS COMPACT RIO PROGRAMMABLE AUTOMATION CONTROLLER .......... 15  FIGURE 12 – POWER MONITORING APPLICATION SCREENSHOTS ............................................................. 18  FIGURE 13 - DIAGRAM FOR THE DIFFERENTIAL PROTECTION USING A COMPACT RIO EQUIPMENT .............. 19  FIGURE 14 - ZIGBEE NETWORK ............................................................................................................. 20  FIGURE 15 - SEA ZIGBEE MODULE ........................................................................................................ 20  2

FIGURE 16 - DIGI XBEE MODULE .......................................................................................................... 20  FIGURE 17 - DATA MONITORING APPLICATION .......................................................................................... 21  FIGURE 18 - CARLO GAVAZZI ENERGY MANAGEMENT SMART POWER QUALITY TRANSDUCER ................... 22  FIGURE 19 – SCREENSHOTS OF SCADA POWER MONITORING APPLICATION ........................................... 23  FIGURE 20 – MAP OF ENERGETIC POTENTIAL ON PRUT: ........................................................................... 24  FIGURE 21 – FP 201 GLOBAL WATER FLOW PROBE. .............................................................................. 25  FIGURE 22 – ALIMENTATION SCHEME FOR PRUT RIVER FROM RIGHT AND LEFT BANKS WITH TRIBUTARIES WATERS. ........................................................................................................................................ 26  FIGURE 23 – MEASUREMENTS OF THE FLOW SPEED ON PRUT RIVER. ....................................................... 28  FIGURE 24 – CONCEPTUAL DIAGRAM OF THE WATER WHEEL WITH RECTILINEAR PROFILE OF BLADES. ......... 32  FIGURE 25– CONCEPTUAL DIAGRAM OF THE WATER ROTOR WITH HYDRODYNAMIC PROFILE OF BLADES WITH ITS ORIENTATION TOWARDS THE WATER STREAMS. ........................................................................... 32  FIGURE 26 – FLOATABLE MICRO HYDROPOWER PLANT WITH BLADES ORIENTATION MECHANISM.................. 34  FIGURE 27– POSITIONING OF BLADES TOWARDS THE WATER CURRENTS. .................................................. 34  FIGURE 28 – FLOATING MICRO HYDROPOWER PLANT WITH ELECTRIC GENERATOR AND HYDRAULIC PUMP. .. 35  FIGURE 29 – FLOATING MICRO HYDROPOWER PLANT WITH INFLUENCE COMPENSATION OF WATER CURRENTS FLOW DIRECTION CHANGE............................................................................................................... 36  FIGURE 30 – MICRO HYDROPOWER PLANT WITH INCREASED TRANSVERSE STABILITY. ................................ 37  FIGURE 31 – FLUID CYCLIC MOTION AROUND PROFILE C. ....................................................................... 41  FIGURE 32 – DIGITIZATION OF PROFILE C. ............................................................................................. 41  FIGURE 33 – BOUNDARY ELEMENT E j . .................................................................................................. 42  FIGURE 34 – SYMMETRIC HYDRODYNAMIC PROFILES: NACA 0012, 0016, 63018 AND 67015. ................. 45  FIGURE 35 – HYDRODYNAMIC LIFT CL AND DRAG CD COEFFICIENTS DEPENDANT ON THE ENTERING ANGLE FOR NACA 0012, 0016, 63018 AND 67015 PROFILES. ................................................................... 46  FIGURE 36 - HYDRODYNAMIC LIFT CL AND DRAG CD COEFFICIENTS DEPENDANT ON THE ENTERING ANGLE FOR NACA 0016 PROFILE. ........................................................................................................... 47  FIGURE 37 – BLADE POSITION AND WORKING AREAS. .............................................................................. 47  FIGURE 38– MODULE, TANGENTIAL COMPONENT AND NORMAL COMPONENT OF THE HYDRODYNAMIC FORCE OF A ROTOR BLADE DEPENDING ON THE ANGLE OF POSITIONING. ....................................................... 47  FIGURE 39 – MOMENT Tr ,i DEVELOPED BY THE ROTOR BLADE DEPENDING ON THE ANGLE OF POSITIONING. 48 

FIGURE 40 – TOTAL MOMENT Tr DEVELOPED BY 5 BLADES AT ROTOR SHAFT DEPENDING ON THE ANGLE OF POSITIONING. ................................................................................................................................. 48  FIGURE 41 – TOTAL MOMENT Tr AT ROTOR SHAFT DEPENDING ON THE ANGLE OF POSITIONING FOR VARIOUS VELOCITIES OF THE WATER FLOW .................................................................................................... 48  FIGURE 42 – NUMBER OF TURNS CM , ref DEPENDING ON THE ENTERING ANGLE FOR NACA 0016 PROFILE 48 

FIGURE 43 – LOCATION OF THE BLADE FIXING POINT. ............................................................................... 49  FIGURE 44 – MOMENT DEVELOPED BY THE BLADE Tr ,i DEPENDING ON THE POSITIONING ANGLE FOR VARIOUS VALUES OF THE ENTERING ANGLE

FIGURE 45 – TOTAL MOMENT Tr ENTERING ANGLE

  15o , 17 o , 18o , 20o. .............................................................. 49 

DEPENDING ON THE POSITIONING ANGLE FOR VARIOUS VALUES OF THE

  15 , 17 o , 18o , 20o. ..................................................................................... 49  o

FIGURE 46 – TOTAL MOMENT Tr 

DEVELOPED AT THE 3-, 4- AND 5-BLADE ROTOR SHAFT DEPENDING ON THE

POSITIONING ANGLE. ...................................................................................................................... 50  FIGURE 47 – NACA 0016 HYDRODYNAMIC RACK PROFILE STANDARD. ..................................................... 51  FIGURE 48 – NACA 0016 HYDRODYNAMIC RACK PROFILE STANDARD AND THE OPTIMISED PROFILE. .......... 51  FIGURE 49 – BLADES PROTOTYPING 5-AXIS MACHINE .............................................................................. 51  FIGURE 50 – FLOATING STABILITY ANALYSIS. ........................................................................................... 52  FIGURE 51 – MIGRATION TRAJECTORY OF THE CENTRAL POINT OF APPLICATION OF THE ARCHIMEDES FORCES FOR THE 3-BLADE (A) AND 5-BLADE ROTOR (B). ................................................................................ 53  FIGURE 52 – DEPENDENCE OF DISTANCE E OF THE CENTRAL POINT OF APPLICATION OF THE ARCHIMEDES FORCES ON THE POSITIONING ANGLE  OF THE 3-BLADE ROTOR (A) AND OF 5-BLADE ROTOR (B). ...... 54 

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o

FIGURE 53 – VELOCITY FIELD AROUND NACA 0016 PROFILE AT THE ENTERING ANGLE 18 . ...................... 54  FIGURE 54 – POINT OF SEPARATION FOR THE FLOW VELOCITIES 1 M/S (A) AND 2 M/S (B)............................ 55  FIGURE 55 – 3-BLADE HYDRODYNAMIC ROTOR. ....................................................................................... 55  FIGURE 56 – 5-BLADE HYDRODYNAMIC ROTOR. ....................................................................................... 55  FIGURE 57 – MULTIBLADE ROTOR CONNECTED KINEMATICALLY TO THE ELECTRIC (GENERATOR 1) ENERGY OR MECHANICAL HYDRAULIC PUMP 2) ENERGY PRODUCTION UNITS......................................................... 56  FIGURE 58 – ROTORS WITH 3- (A) AND 5-BLADES (B) WITH HYDRODYNAMIC PROFILE, MANUFACTURED IN THE LABORATORY OF THE CENTRE FOR RENEWABLE ENERGY CONVERSION SYSTEMS DESIGN, TUM. ..... 56  FIGURE 59 – GENERATED POWER AT ROTOR SHAFT. ................................................................................ 58  FIGURE 60 – MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER KINETIC ENERGY 3 CONVERSION INTO MECHANICAL ENERGY FOR WATER PUMPING (FLOW RATE Q = 40M /H, PUMPING HEIGHT H =10...15 M) .................................................................................................................... 59  FIGURE 61 – KINEMATICS OF MICRO HYDROPOWER PLANT MHCF D4X1,5 M. .......................................... 60  FIGURE 62 – TORQUE T1 AT THE HYDRODYNAMIC ROTOR SHAFT WITH NACA 0016 PROFILE BLADES. ....... 60  FIGURE 63 – INDUSTRIAL PROTOTYPE OF THE MICROHYDROPOWER STATION FOR THE RIVER KINETIC ENERGY CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGIES (DIAMETER OF ROTOR D = 4M, SUBMERSED HEIGHT OF THE BLADE H = 1,4M, LENGTH OF BLADE L =1,3M) (MHCF D4X1,5 ME). .......................... 62  FIGURE 64 – INDUSTRIAL PROTOTYPE OF THE MICROHYDROPOWER STATION FOR THE RIVER KINETIC ENERGY CONVERSION INTO MECHANICAL ENERGY INSTALLED ON THE RIVER PRUT, V. STOIENEŞTI, CANTEMIR. . 62  FIGURE 65 – MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER KINETIC ENERGY CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY (ROTOR DIAMETER D = 4 M, SUBMERGED HEIGHT OF BLADE H = 1,4 M, LENGTH OF BLADE CHORD L = 1,3 M) (MHCF D4X1,5 ME) .................... 64  FIGURE 66 – KINEMATICS OF MICRO HYDROPOWER PLANT MHCF D4X1,5 ME. ........................................ 65  FIGURE 67 – MICRO HYDROPOWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER KINETIC ENERGY CONVERSION INTO ELECTRICAL AND MECHANICAL ENERGY USED FOR WATER PUMPING (ROTOR DIAMETER D = 4 M, SUBMERGED HEIGHT OF BLADE H = 1,4 M, LENGTH OF BLADE CHORD L = 1,3 M). .................. 66  FIGURE 68 – UNIT OF THREE-STAGE HYDRAULIC PUMP DRIVING MECHANISM PSS 40-10/50...................... 67  FIGURE 69 – UNIT OF LOW SPEED ELECTRIC GENERATOR DRIVING MECHANISM (MCHF D4X1,5E). ........... 67  FIGURE 70 – MICRO HYDRO POWER PLANT WITH HYDRODYNAMIC ROTOR FOR RIVER WATER KINETIC ENERGY CONVERSION INTO ELECTRICAL ENERGY (5-BLADE ROTOR DIAMETER D = 4 M, SUBMERGED HEIGHT OF BLADE H = 1,4 M, LENGTH OF BLADE CHORD L = 1,3 M). .................................................................... 68  FIGURE 72 – INDUSTRIAL PROTOTYPE OF THE MICROHYDROPOWER STATION FOR THE RIVER KINETIC ENERGY CONVERSION INTO ELECTRICAL ENERGY (DIAMETER OF ROTOR D = 4M, SUBMERSED HEIGHT OF THE BLADE H = 1,4M, LENGTH OF BLADE L =1,3M) (MHCF D4X1,5 E)..................................................... 69  FIGURE 71 – TORQUE T1 AT THE SHAFT OF 5-BLADE HYDRODYNAMIC ROTOR WITH NACA 0016 PROFILE .. 69  FIGURE 73 – FREE FLOW TURBINE, VERDANT POPWER ........................................................................... 71  FIGURE 74 – FREE FLOW TURBINE, UEK CORPORATION UNDERWATER ELECTRIC KITE ............................ 72  FIGURE 75 – FREE FLOW TURBINE, SWAN TURBINE ................................................................................. 73  FIGURE 76 – FREE FLOW TURBINE, GORLOV HELICAL TURBINE ................................................................ 74  FIGURE 77 – FREE FLOW TURBINE, MILLAU VLH ..................................................................................... 74 

Table index TABLE 1 – WATER FLOW VELOCITY ON PRUT RIVER IN DIFFERENT AREAS. ................................................. 30 

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Preface The present work is an outcome of the project “SEE HYDROPOWER, targeted to improve water resource management for a growing renewable energy production”, in the frame of the South-EastEurope Transnational Cooperation Programme, co-funded by the European Regional Development Fund (www.seehydropower.eu). The project is based on the European Directive on the promotion of Electricity from Renewable Energy Sources respect to the Kyoto protocol targets, that aims to establish an overall binding target of 20% share of renewable energy sources in energy consumption to be achieved by each Member State, as well as binding national targets by 2020 in line with the overall EU target of 20%. Objectives of the SEE HYDROPOWER deal with the promotion of hydro energy production in SEE countries, by the optimization of water resource exploitation, in a compatible way with other water users following environmental friendly approaches. Therefore, it gives a strong contribution to the integration between the Water Frame and the RES-e Directives. Main activities of the project concerns the definition of policies, methodologies and tools for a better water & hydropower planning and management; the establishment of common criteria for preserving water bodies; to assess strategies to improve hydropower implementation, such as small hydropower; testing studies in pilot catchments of partner countries; promotion and dissemination of project outcomes among target groups all over the SEE Region countries. In particular, the report “Handbook of innovative technologies to promote SHP”, which is part of the Work Package 5 – Common strategies to improve SHP implementation, is presented here.

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1. List of abbreviations SHP

Small Hydropower Plant

PMU

Phasor Measurement Unit

WAMS

Wide Area System Monitoring

Sp

Pumping Station,

SpA

Pumping Station for Water Supply,

SpC

Pumping Station for Sewage,

SpM

Pumping station for Irrigation,

Spm

Mobile Pumping Station,

SE

Water Cleaning Plant;

STA

Water Treatment Plant,

BA

Storage Pool

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2. Introduction Handbook of Innovative Technologies presents, on one hand, a monitoring system of the hydraulic, mechanical and electrical parameters related to a SHP and, on the other hand, it presents a new concept with regard to the possibility to catch the kinetic energy of a water stream. Therefore, the first part shows the monitoring system of the SHP parameters implemented to a SHP on Arges river (one of the well hydropower developed rivers in Romania) – Mihailesti SHP, one of the most important also from the standpoint of the fact that it has a strategic importance for the company Hidroelectrica, its owner. There are presented the equipment of the monitoring system, their arrangement within the power house, the connection between the equipment, and the information processing and presentation method. The system consists in modern equipment, is portable and can be placed in any small hydropower plant. Several small hydropower plants, having implemented this monitoring system, can be interconnected and managed from a dispatcher center. Received parameters can be collected within a data base and the hydropower plant operation can be analyzed. The most important issue is that the different failures, that can occur, can be analyzed and interpreted accurately, especially the electrical failures and that cannot be other way interpreted. The second part presents potential sites for SHP implementation on Prut river (located at the border between Romania and Moldavia), providing details on the kinetic energy potential of rivers. This is due to the fact that the innovative technology refers to the possibility of catching the river kinetic energy and of its conversion into electrical energy, by means of kinetic turbines. The micro hydropower plant is a complex technical system that includes constructive components with distinct functions: rotor-turbine that draws off a part of the water kinetic energy at its interaction with the water flow; mechanical transmissions for the transformation of the converted energy; pumps and generators for useful power generation, etc. The conversion efficiency of the micro hydroelectric power plant depends on the performances of each component. Starting with the idea and up to the functional prototype in situ the main steps are as follows: the design of the functional concept of the micro hydroelectric power plant; the theoretical research of the factor of influence on the water kinetic energy conversion efficiency; the particular research and design of the working element for the water kinetic energy conversion efficiency; the research and design of the units participating in the transformation of converted energy into useful energy; the manufacturing and separate experimental research on the units; the design and manufacturing of the micro hydroelectric power pilot-plant; the experimental research on the units as integral technical system and the evaluation of the similarity of functional and constructive parameters that have been theoretically and experimentally determined; the introduction of partial modifications in the project documentation; the development of the execution technologies and manufacturing of the micro hydroelectric power plant, as a final industrial product. In the Annex there are presented new technologies developed for the catchment of the water kinetic energy.

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3. Smart Measurements for Small Hydropower Plants (RO) Romania is rich not only in concentrated sources on energy but also on distributed ones represented by internal rivers flowing through long valleys several hundred kilometers long, Figure 1. (1)

Figure 1 - Map of Romania with main rivers, major, medium and small hydro plants

In our case, on the studied river Arges, Figure 2, where were built a number of Small Hydro Plants, (SHP), based on different types of water turbines, Figure 3. Function of the head, available flow and power of the turbines, the best solution was chosen from Francis, Kaplan and Cross Flow (Banki) type. (2)

Figure 2 - River Arges with major and small hydro plants 8

Banki

Pelton

Kaplan

Francis

Figure 3 - H/Q and η/Q characteristics for small hydro turbines

As a first step for building an advanced Synchronous Measurements System on Arges River, was the pilot project at SHP Mihailesti, 20 Km outside Bucharest, Figure 4.

Figure 4 - Mihailesti small hydro plant with one Francis and two Kaplan turbines

This SHP belongs to Hidroelectrica SA and is composed of two, 5 MW/6KV Kaplan Turbine / Synchronous Generator Groups and one 450 KW/400V Francis Turbine/ Induction-Generator Group, Figure 5, all of them operating in parallel through step-up voltage transformers with output of 20KV, 50Hz.

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Figure 5 - Measurement diagram for Mihailesti SHP

Figure 6 - Arbiter Systems – Power Sentinel Phasor Measurement Unit

Through an underground feeder the generated electrical energy is sent to a distribution substation owned by ENEL SA Romania from where through a step-up transformers at 110 KV is sent by an aerial line to a 110/400 KV station belonging to TRANSELECTRICA SA, in Romanian National Grid and from there also to European neighbors, Figure 7.

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Figure 7 – Wide Area Monitoring System (WAMS)

Due to the fact that monitoring area covers large distances and even for lengths of lines of 300 Km, the information travelling with the speed of light needs 1 ms to be transferred from one point to another. This corresponds to a delay of 18 electrical degrees for a 50 Hz power line. Taking into consideration the latencies added by Ethernet network (at least 4 -5 ms) the overall delay in data transfer can reach a value close to 90 electrical degrees, which make it impossible to be used in differential protection or in remote control. In the case of distributed data acquisition in an electrical system the data obtained cannot be used properly as they are based on different individual local clocks. Synchronous measurement represents the only solution to solve this problem and is used successfully in transport power systems. Optimization of distribution networks needs the real time knowledge of actual steady state operation and dynamic transitions. In order to achieve this target a synchronization technique has to be used and all the measurements have to be time tagged. Such a commercial equipment which fulfils these request built on IEEE standard C37,118-TM 2005, is called Phasor Measurement Unit (PMU), and is basically a data acquisition system of three phase voltages and currents sampled at 10 KHz, based on these data are calculated the frequency, the per-phase rms values, active and reactive power, active and reactive energy, harmonics and THD, all this data is sent via different communication protocols, including internet, to the solicitant. The precise time is obtained from Global Positioning Satellites, (GPS), as Coordinated Universal Time (UTC). Such a distributed system is called: a Wide Area Measurement Systems (WAMS) and represents the optimum way to solve also the power transfer and distribution problems. These systems are intended for monitoring of wide networks by extensive measurement of synchronous phasors in important network points. WAMS consist of a network of GPS synchronized Phasor Measurement Units (PMUs), system of tagged data transfer collected using various types of communication, similar to that of SCADA systems. Using specialized software a server rearranges all the information to the same moments of time and distributes the synchronized data through Internet to all stake holders. The PMU used in this project is an Arbiter Systems Power Sentinel which, offers as output in UTC time, the three phase voltages and currents with 1 KHz sample time and all other results calculated in numerical form, Figure 8. (3)

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a)

b)

c)

d)

Figure 8 - Data Collected From Phasor Measurement Unit 1 at Mihailesti SHP; a) Voltages, b) Currents, c) RMS Data, d) Phasors

Our Lab is connected to a Continental and UK network with a server in Slovenia. [www.elpros.si (4)]. In Figure 9 a) is a map of continental Europe where the PMUs are placed: Ljubljana, Slovenia; Dortmund, Germany; Almelo, Nederland, and Bucharest with the low voltage, frequency and phasors data. In Figure 9 b) are presented the charts of low voltage, phase angle variation and frequency in these four locations.

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a)

b) Figure 9 - The PMUs in ELPROS network and representation of voltages, phasors, frequency in all four acquisition points

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a)

b) Figure 10 - Data collected from Mihailesti PMU on the output 20KV output line

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In Figure 10 is presented in detail the data collected from the PMU installed at Mihailesti: a) Positive sequence voltage, frequency; b) phase current magnitude, active power, reactive power. Developing digital measurements control and protection for a power system, and verifying its stability, it is necessary to estimate in real time the system parameters, and based on them to simulate the dynamic of system operation. For the control of the synchronous generators from SHP Mihailesti is necessary to use as reaction the state variables, which have to be synchronously measured or observed. In order to realize this operation with a single data acquisition equipment was chosen a Reconfigurable Control and Monitoring System, a NI Compact RIO Programmable Automation Controller (Figure 11) GPS synchronized, for which we developed the necessary software in LabVIEW graphical programming language (5). The NI CompactRIO system contains a real-time controller floating-point processor (RT) and an embedded user-programmable fixed point FPGA (field programmable gate array) chip providing direct access to input/output (I/O) modules which contain built-in signal conditioning and isolation. The program in the FPGA runs at 50 us loop rate while that in the RT processor at 5ms only.

Figure 11 - National Instruments Compact RIO Programmable Automation Controller

For our application were chosen two 5 A, four phase current acquisition modules and one voltage acquisition module with 300V inputs. The acquisition modules have a resolution of 24 bits and a maximum sampling rate of 50 ksamples/s. As in the previous case the sampling is done at 10 ksamples/s and a rms currents and voltages, powers, THD and phasors can be done for every cycle, in fixed point by the mean of a FPGA emulating the Power Sentinel PMU presented above but even with superior performances. The system is not using prefabricated embedded software as in the previous case but the one developed by the authors. More than that, the real time data for currents and voltages sampled at 10 kHz are re-sampled at 1 KHz and can be accessed via Internet. The preliminary results recorded during a lab test using a 3x400V supply and a pure resistive load are presented in Figure 12.

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a)

Voltage, Current waveforms; Frequency

b)

RMS Data

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c)

d)

Power

RMS Voltage, Current charts

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e)

f)

Voltage, Current Phasors

Voltage, Current Harmonics

Figure 12 – Power Monitoring Application Screenshots

The System can be used also for power transformers Differential Protection. In Figure 13 is presented such a protection for a 20/110 KV transformer. The short circuit must be detected as 18

soon as possible and the transformer disconnected from the AC Grid, otherwise the effects can be disastrous. A Compact RIO controller with two current acquisition modules with four current inputs each and two voltage modules with three inputs each is used in this case. In normal situation, the sum of the rated primary, the secondary currents plus the homo-polar one has to be equal with the magnetization current which generally is less than 10% of the rated current. If this condition is not fulfilled, it means that a short circuit is inside and the transformer should be disconnected. A redundant solution is to measure the active powers on the two entries of the transformer and if they have contrary senses, means that total power is dissipated inside the transformer due to a short circuit.

Figure 13 - Diagram for the Differential Protection using a Compact Rio Equipment

One alternative for the acquisition of slow varying signals (temperature, flow, etc.) is to use a wireless connection between the sensor and controller/measurement unit. Using a wireless acquisition system instead of a wired one can be less costly in the case of retrofitting a hydro plant. In our study we had chosen the ZigBee technology. ZigBee wireless network can provide a medium range communication (about one hundred meters) with fast connection of nodes to the network and low power usage. For example a data acquisition node can be put in sleep state and at a specified interval powers up, connects to the network, acquires the signal and sends it to the coordinator, than goes back to sleep mode. A ZigBee network can be formed in three ways: star, mesh and tree topology, or any combination of them. In Figure 14 is presented a network formed using mesh and star topology.

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Figure 14 - ZigBee Network

In order to test this type of communication in SHP monitoring and control the Compact RIO controller was equipped with a SEA GMBh ZigBee Module (Figure 15) acting as coordinator.

Figure 15 - SEA ZigBee Module

As end-points the Digi Xbee PRO modules from DIGI were chosen. These modules include four ADC channels with a sampling rate of about two samples per second.

Figure 16 - DIGI XBee Module One of these modules was connected to a temperature sensor, while the other to a light sensor. In Errore.

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L'origine riferimento non è stata trovata. It is shown a screenshot of the application which records the data received from both of them.

Figure 17 - Data monitoring application

The smaller power generators used are of induction types, generators which practically do not influence the system operation and the transient data are not necessary to be recorded. For this reason for the monitoring of the Francis group installed at Mihailesti SHP, was chosen the Carlo Gavazzi Energy Management Modular Smart Power Quality Transducer (Figure 18) (6). This transducers computes all power related data, which is acquired and recorded on a server every second by custom developed SCADA software. This software includes also a WEB interface so all the data can be visualized remotely. Screenshots of the developed application are presented in Figure 19.

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Figure 18 - Carlo Gavazzi Energy Management Smart Power Quality Transducer

a)

Main Screen

b)

Online Values

c)

Voltage Chart

d)

Current Chart

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e)

g)

i)

Active Power

Reactive Power

Current Total Harmonic Distortion

f)

h)

Total Power

Voltage Total Harmonic Distortion

j)

Frequency

Figure 19 – Screenshots of SCADA Power Monitoring Application

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4. Innovative technologies to produce SHP (MOLD) 4.1. Identification and evaluation of potential sites for SHP implementation (on river Prut) A special area of interest consists in a more detailed study of the kinetic energy potential of rivers of Moldova - Nistru, Prut and Raut, rivers with potential sites for SHP implementation. Given the importance of SHP implementation for Republic of Moldova, the Centre for Development of Renewable Energy Conversion Systems (CESCER) has been created at the Technical University of Moldova. In order to perform the research on the rivers kinetic hydropower potential CESCER was equipped with a measuring water velocity device Flow Probe FP201. First measurements were made on the Prut River (figure 20) [1,4]. The choice of the sites was dictated by the following considerations: – Prut river is the border river between Republic of Moldova and Romania, which in 2007 became a part of the European Union; on both sides of the Prut river towns are located fairly dense, which may allow expansion of field research in regional projects funded by the European Union. Prut, the first tributary of the Danube, starts on the north - east coasts of the Carpathians at a height of 1580m and flows through geographic plateau of Moldova. The total length of the river is 950km with a water catchment area of 28,400km2 and an average flow of 86m3/s. The distance of 900km from its mouth, Prut river is a natural border between Republic of Moldova, Romania and Ukraine. Prut river section from its source through the mountains region has a relatively high flow. Downriver the town of Chernivtsi (Ukraine) begins the portion of the river with an average flow discharge through a floodplain with width 5–6km. The river banks are low and floodable. River flow in the middle is strong and during the floods the river channel changes.

Figure 20 – Map of energetic potential on Prut: – Stoieneşti village, the site of micro hydro power station; – Areas with a measured flow speed v>1m/s.

Average flow region extends to Ungheni having a length of 380km. Descending portion of the Prut River, from Ungheni to the river’s mouth has a length of 396km. In this region Prut flows through several unimportant valleys with an average width of 10–12km. On a large portion of low flow discharge the river often floods. During the flooding on certain portions of the river multiple channels are formed and during

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the low flow periods drainage channels are subjected to erosion. Also, in this region, landslides occur often, sometimes quite serious, for example, in 1981, near the village Taxobeni a landslide almost covered the whole river channel. Sinuosity of the river is high, with an average sinuosity index equaling 2. River bed has an irregular pattern, sometimes covered with gravel, with sporadic stone accumulations or even boulders. The river’s banks vegetation mainly consists of trees and bushes. Temperature instability characterizes the freezing temperature of the river during the winter. On most of the river temporary plates of ice can be observed. Stable ice cover was observed 2–3 times in a ten year period. The ice usually begin to form in late November and breaks on average in late February. Average ice thickness is 0.26 to 0.35m, and during very cold winters can reach up to 60cm. On the average the river is navigable for a period of 266 days, 50–60 days of which correspond to the flooding period, and 190–210 days correspond to the average flow discharge period.

Average annual air temperature in mountainous areas of the river basin is about +7°C. In the hilly region of the basin average air temperature is +10ºC. Absolute Maximum is +40ºC, while absolute minimum is –31°C. In the mountainous area of the river the annual rainfall reaches the level of 800mm. In the other parts of the river, the rainfall varies from 600 to 300 mm. Most of the rainfall season is in spring–summer. Rainfall is the main source of water in the Prut River region. The water level in the river increases especially in the summer. Water level oscillations on Prut river depend mostly on the fluctuations of precipitations throughout the year with some of them being recorded even in the winter months (not often). Spring floods are caused by snow melt in the mountain region as well as rains and usually end in February–April. Summer floods are more important quantitatively, with powerful overflows in July and August. According to the records provided by Republic of Moldova State Hidrometeorological Service (HidroMeteo) the highest topological level of the river portion in Republic of Moldova is at 55m (nearby Criva village). The kinetic hydropower potential can be explored on the part of the Prut River between Criva village in the north to Giurgiulesti village in the south. In order to perform the water flow speed measurements a Global Water Flow Probe FP 201 Digital Velocity Meter (produced by IRIS Instruments, USA) has been used (figure 21) [1,4]. Its telescopic design allows the maximal and average flow speed measurements at different depths. FP201 Meter is calibrated and certified by Global Water Instrumentation Inc. Prut River leaves the mountain region at Deleatin, where the valley widens to molasses Neogene formations, farther downstream enters the plateau area, being supplied with water on both sides by its Figure 21 – FP 201 Global Water Flow Probe. tributary streams (figure 22) [1]. In its wide valley up to the border with Republic of Moldova, there is a strong alluvial meadow with an abundance of good quality groundwater. Upriver from entering the Republic of Moldova, the river collects a number of important tributaries from the Beschido-Maramures Carpathians, such as Prutetul, Liucica, Pistinka, Rybnitsa and Ceremusul or Ceremsan (the largest mountain tributary, composed of Ceremusul Negru and

25

Ceremesul Alb). The left bank does not have important Carpathians tributaries, but in turn develops more extensive associated rivers from Podolo–Moldav Plateau to the south (Turkey, Cerneava, Sovita, Sada, Rarancea, Rakitna and Ringaci). In order to select the potential sites for micro hydro power station installation the following conditions must be fulfilled: – the average water flow speed should be greater than 1m/s – the presence of nearby villages and economic agents, potential consumers of converted energy; – necessity of a minimal capital investment for the construction of the anchoring system for micro hydro power station. In order to detect and evaluate the possible sites the following actions have been made: – a comprehensive analysis of the data provided by HidroMeteo Service; – several expeditions in order to perform measurements on Prut River. 967 km r. Ceremos (2558) 800

or. Iaremcia or. Kolomaia r. Cerneava (351) or. Cernauti

600

sto. Lipcani r. Lopatinca (265) r. Racovet (795) r. Ciugur (724)

r. Baseu (930)

r. Camenca (1230) 400

or. Ungheni

r. Jijia (5800)

r. Narova (358) r. Gura-Lapusna (483) 200

r. Elanului (554)

r. Sarata(706)

or. Leova or. Cahul

r. Chineja (764) Km2

24000

16000

8000

0

8000

16000

Malul drept

Malul stang

Figure 22 – Alimentation scheme for Prut river from right and left banks with tributaries waters.

Using the data provided by HidroMeteo Service and other sourses, the following locations have been initially identified as portions of Prut river with the flow speed greater than 1m/s: Criva – Costeşti Sector: Lipcani, Şireuţi; Costeşti – Ungheni Sector: Avrameni, Cobani, Taxobeni; Ungheni – Leova Sector: Ungheni, Costuleni, Bărboieni, Grozeşti, Pogăneşti; Leova – Giugiuleşti Sector: Châşliţa – Prut, Colibaşi, Stoieneşti, Leca, Antoneşti. 26

Ungheni Sector. In Ungheni, nearby water intakes and pumping stations there have been recorded average flow speeds 0.75–1.05m/s at a distance of 2.5–4.5m from river banks and depth of up to 1.5m. The measurements have been made between villages Măcăreşti–Frăsineşti (Ungheni district) and Bălăureşti (Nisporeni district). Grozeşti, Zberoaia, Bălăureşti Sector. The narrowest place of the river in this sector is located form village Frăsineşti downriver to village Bărboieni, where the flow speeds of approximately 2m/s have been recorded. Because of this narrowing during the increased flow discharge periods the floods often occur. In order to prevent flooding a bypass channel was built on the opposite bank. Electrical energy converted from the kinetic energy of water can be consumed by the nearby border guard station. In the village Grozesti there were identified three possible sites with an increased flow speed, two of them near the pumping stations and the other one located nearby the water supply pumping station (currently out of use due to the lack of electricity). Also, areas with higher flow speeds (1.2– 1.4m/s) are located in the downriver areas of the village Grozesti. In the village Bălăureşti relatively high flow speeds were recorded in the area of river bends, where small bypass channels with a length up to a hundred meters can be build. Also, the site of nearby irrigation pumping station, located on the river bank, can be considered. Cahul – Giurgiuleşti Sector. Prut river portion from the village Giurgiulesti (mouth of the river) up to village Manta (Cahul district) there was investigated in the following locations: villages ChişliţaPrut, Slobozia Mare Văleni, Branza, Colibaşi, Vadul-lui-Isaac. Average flow speeds of 1.1–1.2m/s were recorded in the village Branza (at hydrometric station) downriver the mark nr.14. The river width at the measurement sites is approximately 40–60m. The observation and measurement of the flow speeds were performed in the places with potential consumers of either converted energy or water for irrigation and water supply purposes. Along the river banks were located pumping stations and water intake pipes. Measurements were made from river bank, river docks and boat (see figure 23). The methodology of hydrometric observations and measurements. Water flow speed was measured with Flow Probe FP 201 device from the river bank shore at a distance of 3–5m, from a raft (in Leova, Ungheni, Taxobeni, Costesti, Bădrajii Vechi), from a river dock at a distance up to 15m from the bank (Duruitoarea and Stoieneşti) and from a boat at a distance of 25m (Colibaşi).

27

Measuring depth of water flow speed was limited to 1.5 m, equal to the possible submersion height of the micro hydro power station blades. Water depth at the distance of 5m from the river banks in different places at the time of measurements varied between 1.8 to 3.8m. Investigations on the Prut River were made from its mouth on the Danube (village Giurgiulesti) upriver to the border with Ukraine (village Criva) over a distance of 685km in the locations shown in Table 1. From the observations and measurements it was found that higher than average water flow speeds are registered at the bends and in narrow places and some rare rapids. At the beginning and the end of measurements of the depth or flow speed the

Figure 23 – Measurements of the flow speed on Prut river.

water level was measured that was correlated with previously recorded data from the hydrometric stations located in the area of interest. In Table 1 there were included sites on Prut River (nearby villages and cities) close to houses, gardens, agricultural lands, pumping stations, water storage tanks and other objectives, which may be potential consumers of energy converted from the kinetic river energy. In order to select potential sites for the installation of micro hydro power stations additional investigations were performed in the following sectors: Sector: mouth of Jijia river–village Stoieneşti. River floodplain is weakly sinusoidal with a width of 7–8.5km, and in the village Tochile-Raducani has a width of 5.2km. Floodplain on both sides, up the village Pogăneşti is dammed. Downriver Sarata-Razesi village in the floodplain there are located small ponds and swampy areas, nearby the river banks dense forest changes in a bushy area. The soil consists predominantly of clay and sands. The river channel is strongly sinusoidal, at short distances smaller than 2-5km there are located sandbanks. Predominant width of the river is 50–70m, 2km downriver the village Sarata, the river width is 120m and in Broscăeşti village its width is 40m. The river depth varies from 0.7 up to 7.3m, with prevailing depth of 3–5m. The river banks are steep with a height of 3–4m. The vegetation mostly consists of forests and bushes. Sector: village Stoieneşti–Prut mouth on Danube. On this sector 160 km long, the floodplain is weakly sinusoidal with an average width of 7–8.5 km, at times increasing up to 12 km. Left slope of the floodplain is convex with a height of 80–120m. In the village Branza left slope tends towards a more pronounced convexity and it is covered by steppe vegetation. Between village Zărneşti and city Cahul there were terraces with steep steps, with a width of 1–1.5km and length 6–12km. The slope and terraces are well formed mainly with clay soils. Between villages Slobozia Mare and Cucoara the river channel is highly sinusoidal. Plain is mostly unbranched. Nearby village Branza there is an island with a length of 24m, width 6m, height 1m. The width of the river is predominantly 60–80m, the largest width being 104m in the village Crihana. Predominant river depth is 2–4m, the largest being 15m (2km upriver village Zărneşti).

28

Nr. crt. 1

2

speed , m/s 3

Border marks 4

1

Giurgiuleşti

0.8/1.0

1329-1334

2 3 4 5 6 7 8

Châşliţa – Prut Slobozia Mare Văleni Brânza Colibaşi Cahul Goteşti

1.0/1.2 0.7/0.9 0.8/1.1 0.9/1.1 1.0 /1.3 0.8/1.1 0.9/1.2

1323 1320 1299/1300 1296/1297 1291-1294 1270

9

Stoieneşti

1.1/1.3

10 11 12

Cantemir Leca Antoneşti

0.8/1.1 1.0/1.2 1.1/1.3

13

Leova

0.9/1.1

1188-1192

14 15 16 17 18 19

Sârma Tochile–Răducani Sărata – Răzeşi Pogăneşti Cioara Dancu,Călmăţui

0.8/1.0 0.9/1.1 0.8/1.0 1.0/1.3 0.8/1.1 0.9/1.2

1181 1175, 1178 1168-1174 1160-1167 1156-1159 1153-1155

20

Leuşeni

0.8/1.1

1145-1152

21 22

Drănceni (Rom) Cotul Morii

0.7/1.0 0.8/1.1

1137

23

Bălăureşti

0.9/1.2

1125-1126

24

Zberoaia

0.8/1.1

1120

25

Grozeşti

1.0/1.3

1117, 1118

26

Bărboieni (sus)

1.1/1.5

1110, 1111

27 1 28

Frăsineşti 2 Măcăreşti

0.7/1.0 3 0.7/1.0

1109 4 1107

29

Costuleni

1.2/1.5

1101

30

Valea Mare

0.8/1.1

1097

31

Ungheni

1.0/1.3

1077-1079

32

Sculeni

0.8/1.1

1045/1051

33 34 35

Medeleni Gherman Taxobeni

0.9/1.1 0.9/1.0 1.1/1.4

1055 1042-1044 1035-1037

Location, village

Nearby reference points 5 SpM, Spm, customs, bridge Bypass channel Bypass channel Rapids, SpM Spm SpM, Spm, BA SpA+inlet, bridge SpM, Sp2, BA Spm–dock, bridge, customs SpA+inlet

SpA,SpC,SE, raft

Remark 6 Border guard station Border guard station Hydrometric station Boat measures Border guard station Border guard station

Border guard station, hydrometric station

SpM Border guard station SpM, steep bend Sp1, Sp2 SpM, steep bend SpM, steep bend, costums Bend Steep bank, Sp Sp1+BA,Sp2+BA, bend Bend Sp1,Sp2,SpA, meanders Narrow width, meanders Bend, bypass channe 5 Meanders Narrow width, meanders Sp9, Sp10, SE (Ungheni city) SpA, STA, raft, bridge Sp, bypass channel, customs, bridge Sp3, Sp4, meanders Sp5+inlet, Sp6(hill) SPA(Făleşti city), raft

Border guard station Hydrometric station Border guard station

Landslides Border guard station 6

Border guard station Border guard station, punct hidrometric Border guard station

Border guard station

29

36 37 38 39 40

Horeşti, Unteni Valea Rusului Călineşti Chetriş Bisericani

0.7/1.0 0.8/1.2 0.7/1.0 0.8/1.1 0.9/1.2

1031-1034 1027, 1028

41

Cobani

1.1/1.4

988

42 43

Avrameni Brăneşti CHE Costeşti, downriver

1.1/1.5 0.9/1.1

984 982

45

CHE Costeşti, upriver

0

46 47

Duruitoarea Bădrajii Vechi

0.1/0.2 0.2/0.3

48

Bădrajii Noi

0.3/0.5

49 50

Viişoara Lopatnic

0.6/0.8 0.7/1.0

51

Bogdăneşti

0.9/1.1

52 53

Gremeşti Teţcani

0.9/1.2 0.8/1.1

54

Pererâta

0.9/1.2

55

Şireuţi

1.0/1.2

44

56 57 58

0.9/1.2

Lipcani 1.1/1.3 Drepcăuţi 0.9/1.1 Criva 0.8/1.0 Table 1 – Water flow

1007 1003

Sp, bend SpM+BA Sp1, Sp2, Sp3 SpM+priză SpA (Sugar factory Glodeni) Steep bend Sp1, Sp2+BA, 2 turbines, small BA

Landslides Border guard station Border guard station Bridge r. Camenca Border guard station Border guard station Hydrometric station Border guard station

BA, dam, Sp, Border guard station customs BA, dock Tributary r.Ciuhur 960/961 Inlet SpAC+ST, AP Dam r.Racovăţ, Sp Border guard station, 956 Border guard station pond, plate bank 953/954 Bypass channel Hydrometric station 952/953 Bypass channel Tributary r.Lopatinca Steep banks both 951 Border guard station sides 948 Steep bank, quarry 945 Mal abrupt, forrest Tributary r.Vilia 938/939, Steep bank, bypass, 942 bend Steep banks, Hydrometric station 934-936 meanders 933 Steep banks, bridge 926 Forrest 924 Railway Northern point of Moldova velocity on Prut river in different areas.

Legend to Table 1: Sp – Pumping Station, SpA – Pumping Station for Water Supply, SpC – Pumping Station for Sewage, SpM – Pumping station for Irrigation, Spm – Mobile Pumping Station, SE – Water Cleaning Plant; STA – Water Treatment Plant, BA – Storage Pool. Flow speed in m/s is specified as follows: numerator at the depth of 1m; denominator at the water surface.

30

5. Elaboration of innovative technologies to produce SHP 5.1. Elaboration of floating micro hydropower plants for river water kinetic energy conversion into electrical and mechanical energy This issue is quite important for the execution of the renewable energy conversion system, for instance, - of the micro hydroelectric power plant for the conversion of the river water kinetic energy into electrical or mechanical energy using the hydrodynamic effects. The micro hydropower plant is a complex technical system that includes constructive components with distinct functions: rotor-turbine that draws off a part of the water kinetic energy at its interaction with the water flow; mechanical transmissions for the transformation of the converted energy; pumps and generators for useful power generation, etc. The conversion efficiency of the micro hydroelectric power plant depends on the performances of each component. The main phases (in successive order) are as follows: - design of the functional concept of the micro hydroelectric power plant; - theoretical research of the factor of influence on the water kinetic energy conversion efficiency; - particular research and design of the working element for the water kinetic energy conversion efficiency; - research and design of the units participating in the transformation of converted energy into useful energy; - manufacturing and separate experimental research on the units; - design and manufacturing of the micro hydroelectric power pilot-plant; - experimental research on the units as integral technical system and the evaluation of the similarity of functional and constructive parameters that have been theoretically and experimentally determined; - introduction of partial modifications in the project documentation; - development of the execution technologies and manufacturing of the micro hydroelectric power plant, as a final industrial product. The functional and constructive parameters of the hydrodynamic rotor, multiplier, generator and hydraulic pumps, adopted within the carried out research separately on each working element, demand experimental research of their functioning as an integral system, in real conditions. The experimental research on the units of the micro hydroelectric power plant as an integral system aims at the increase of the conversion efficiency of the water flow kinetic energy into useful energy by introducing the relevant constructive modifications in the project documentation of the final industrial product.

5.1.1. Conceptual diagrams To avoid the construction of dams, it is possible to use the river kinetic energy by utilizing water flow turbines. This type of turbines can be mounted easily and are simple in operation. Their maintenance costs are rather convenient. The stream velocity of 1m/s represents an energy density of 500W/m2 of the flow passage. Still, only part of this energy can be extracted and converted into useful electrical or mechanical energy, depending on the type of rotor and blades. Velocity is important, in particular, because the doubling of water velocity leads to an 8 times increase of the energy density. The section of Prut River is equivalent to 60 m2 and its mean velocity in the zones of exploration is (1-1,3) m/s, which is equivalent to approximately (30-65) kW 31

of theoretical energy. Taking into account the fact that the turbine can occupy only a part of the riverbed, the generated energy could be much smaller. There are various conceptual solutions, but the issue of increasing the conversion efficiency of the water kinetic energy stands in the attention of the researchers. The analysis of the constructive diversion of micro hydroelectric power plants, examined previously, does not satisfy completely from the point of view of water kinetic energy conversion efficiency. The maximum depth of blade’s immersion is about 2/3 of the blade height h in a classical hydraulic wheel with horizontal axle (Figure 24) [1,2,4]. Thus, only this surface of the blade participates at the transformation of water kinetic energy into mechanical one. As well, the preceding blade covers approximately 2/3 of the Figure 24 – Conceptual diagram of the water wheel with rectilinear profile of blade surface plunged into the water to the utmost blades. (h’’ 2/3h’), that reduces sensitively the water stream pressure on the blade. The blade, following the one that is plunged into the water to its utmost, is covered completely by it and practically does not participate in the water kinetic energy conversion. Therefore the efficiency of such hydraulic wheels is small. Insistent searches of authors have led to the design and licensing of some advanced technical solutions for outflow micro hydroelectric power plants. They are based on the hydrodynamic effect, generated by the hydrodynamic profile of blades and by the optimal blades’ orientation towards water streams with account of energy conversion at each rotation phase of the turbine rotor (Figure 25) [1, 2, 4]. To achieve this, it was necessary to carry out considerable multicriteria theoretical research on the selection of the optimal hydrodynamic profile of blades and the design of the orientation mechanism of blades towards the water streams. The main advantages of these types of micro hydroelectric power plants are: - reduced impact on the environment; - civil engineering works are not necessary; - the river does not change its natural stream; - possibility to produce floating turbines by utilizing local knowledge. Another important advantage is the fact that it is possible to install a series of micro hydro power plants at small distances (about 30-50m) along the river course. The influence of turbulence caused by the neighboring plants is excluded. Figure 25– Conceptual diagram of the water

The results of investigations conducted by the rotor with hydrodynamic profile of blades authors (on the water flow velocity in the selected with its orientation towards the water streams. location for micro hydro power plant mounting, on the geological prospects of the river banks in the location of installing the anchor foundation and on the energy demands of the potential consumer) represent the initial data for the conceptual development of the micro hydro power plants and the working element.

32

The conceptual development of the plant structures with hydrodynamic profile of the blades was performed on the basis of three conceptual diagrams: - Micro hydropower plant with pintle and blades fixed on the vertical axles anchored by steel structure; - floatable micro hydro power plant with pintle and blades fixed on the vertical axles; - floatable micro hydro power plant with horizontal axis and blades fixed on the horizontal axles. In order to increase the conversion factor of water kinetic energy (Betz coefficient), a number of structural diagrams of floatable micro hydro power plants has been developed and patented [8-14]. The micro hydropower plants comprise a rotor with vertical axis and vertical blades with hydrodynamic profile in normal section. The blades are connected by an orientation mechanism towards the water streams direction. The rotational motion of the rotor with vertical axis is multiplied by a mechanical transmissions system and is transmitted to an electric generator or to a hydraulic pump. The mentioned nodes are fixed on a platform installed on floating bodies. The platform is connected to the shore by a hinged metal truss and by a stress relieving cable. The selection of the optimal blades hydrodynamic profile is very important for functional optimization of micro hydro power plants. It will allow increasing the conversion factor (Betz coefficient) due to the hydrodynamic buoyant force. As well, conversion increase is achieved by ensuring the optimal position of blades towards the water streams at various phases of rotor revolution, employing an orientation mechanism of blades. Thus, practically all blades (even those blades which move against the water currents) participate in the generation of the summary torque. Moving in the water currents direction, for torque generation the blades use both the hydrodynamic forces and the water pressure exercised on the blade surfaces. Moving against the water currents direction the blades use only the hydrodynamic lift force for torque generation. Due to the fact that the relative velocity of blades concerning the water currents is twice bigger, practically, at their motion against the water currents, the hydrodynamic lift force is relatively big, and the generated torque is commensurable to the one generated by the water pressure. This effect makes the basis of all patented technical solutions. Next, six technical solutions of micro hydro power plants are presented, comprising various basic nodes and conversion principles that have been patented. These technical solutions allow essential increasing of the river water kinetic energy conversion coefficient. Full description of the most representative technical solutions and brief description of the conceptual diagrams of micro hydro power plants properties are given below.

5.1.2. Micro hydro power plant for river water kinetic energy conversion into electrical Micro hydro power plant (figure 26) [9] The turbine 1 comprises blades 2, executed with the hydrodynamic profile and mounted on the axles 3, fixed by their upper part on the extreme ends of the bars 4, with the possibility to rotate around their axles. The position of the blades 2 at angle  to the direction of water flow is ensured by the controlling mechanism 5. Platform 6 is consolidated additionally by a winch 7 fixed on the truss that is mounted unshiftable on the shore pillar 8. The turbine 1 and the blades 2 are placed in the river water flow. The floating bodies 9 and the hollow blades 2 themselves control the position of turbine 1 and blades 2 concerning the water level.

33

Figure 26 – Floatable micro hydropower plant with blades orientation mechanism.

The multi-blade rotor is connected cinematically and coaxially to the electric generator 11 by the multiplier 10. The winch 7 is used for turbine 1 maintenance which fact requires its removal from the water. The blade 2 (figure 27) is positioned under angle α towards the water flow; it changes

depending on the blade position to the water flow direction. The components of force F, acting on the blade, are determined from the relationships:

Fx  C x 

  v2

S , 2   v2 , S Fy  C y  2

(1)

where: ρ is water density; v is the water flow linear velocity; s is the blade surface; Cx, Cy are lift and drag (resistance) coefficients of the blade profile. Coefficients Cx and Cy depend on the blade entering angle α (the angle between the blade and the water flow direction) and on the profile shape. The angle is determined either experimentally or by numerical calculations.

Figure 27– Positioning of blades towards the water currents.

The torque developed by one blade is described by the equation;

d d M  F   (cos  Fy  sin  Fx ) , 2 2

(2)

where Fτ is the projection of force F on the tangent drawn to the path of motion of the blade axis.

The summary torque includes the general component of the resistance force Fh. The torque moment generated by the turbine consists of the torques generated by each separate blade. Currently only one blade will not generate positive moment (it will generate a negative moment – the resistance one). Thus, the torque generated by the proposed turbine will be essentially bigger 34

than the torque produced by the existing turbines for the same geometrical (blades dimensions) and kinematical parameters of water. The proposed micro hydro power plant allows the transformation of the water flow kinetic energy into mechanical or electrical energy with an increased utilization coefficient of water energy. In the floating micro hydro power plant (figure 28) [10] an additional centrifugal pump 2 is mounted on the resistance structure 1. It is connected cinematically to the multi-blade rotor spindle 3 by belt transmissions 4 and 5. The electric generator 6 is connected to the multi-blade rotor spindle by belt transmissions 4 and 7. As well, the resistance structure 1 is connected to the shore by the metal truss 8 and supporting cables with cross-ties 9.

Figure 28 – Floating micro hydropower plant with electric generator and hydraulic pump.

In the floating micro hydro power plant (figure 29, a) [11] the rotor 1 contains an odd number of blades 2 that are fitted with the possibility of rotation on vertical axes O'–O' (Figure 29,b) mounted on the extreme end of each horizontal bar 3. On frame 4, in the front part (through which water flows pass) a rigid bar 5 is installed on which, in front of the hydro turbine relative to the water flow direction, a sensor 6 is fixed that determines the water flow direction and connects to the rotation gear 7. The water flow moves in the direction of vector V0 (figure 29, b). Angle γ is the entering angle of the blades formed by the hydrodynamic surface string and the working lines of the water flow vector V0V0. The angle depends on the form of the hydrodynamic surface and on the position in the plane surface. By changing the water flow direction due to the change of water discharge and river bed, the water currents will divert by angle  modifying the entering angle γ. To meet the angle of attack, optimal in terms of conversion, it is necessary to correct the position of all blades by angle ±. When changing the water flow direction, the positioning of all blades 2 is corrected simultaneously by angle ± using the rotation mechanism 7:

1,2 =  ± .

(3)

35

Figure 29 – Floating micro hydropower plant with influence compensation of water currents flow direction change.

In the floating micro hydro power plant (figure 30) [8,13] a technical solution is proposed ensuring the transverse stability of platform 1 of the floating micro hydro power plant that is mounted on floating bodies 2 and 3, placed on the same side (shore side of the rotor spindle 4). Due to the fact that the rotor 4 blades 5 are hollow, the hydrostatic Archimedes force of the blades 5 fulfills the role of the floating bodies (figure 30,a, b). The analysis of the application points motion path of the Archimedes force Fa (point N in fig. 30, c) has shown that the distance from this point to the plane that crosses the rotor spindle 4 (O1-O1, figure 38, b) will differentiate depending on the positioning angle of the rotor. Thus, these distances, for the blades that are placed in the upper semiplane defined by axis O1O1-OO differ from the distances of those blades placed in the lower semiplane. The migration of the points of application of the Archimedes force causes the pitching moment: Mr=Mas-Mad,

(4)

where MΣas is the summary moment developed by the Archimedes forces that react on the blades currently located in the upper semiplane; MΣad is the summary moment developed by the Archimedes forces that react on the blades currently located in the lower semiplane. The summary moments developed by the Archimedes forces that react on the blades are determined by the relations: MΣas = ΣFai · lsi and MΣad = ΣFai ·ldi

(5)

where Fai is the Archimedes forces that react on the blades 5 currently located in the upper semiplane; lsi is the distance from the point of application of the Archimedes force that reacts on the blades 5 currently located in the upper semiplane;

36

Figure 30 – Micro hydropower plant with increased transverse stability.

37

ldi is the distance from the point of application of Archimedes force that reacts on the blades 5 currently located in the lower semiplane. Distances lsi and ldi are calculated from the relation:

l 2  R 2  cM2  2 RcM cos(   ) ,

(6)

Where R is the rotor radius 4; CM is the distance from the point of application of the Archimedes force and the blade fixing point to the turbine rotor; α is the angle formed by the blade chord and the water flow direction; φ is the angle formed by the rotor lever and the perpendicular direction on the watercourse. To compensate the pitching moment Mr, the rotor spindle 10 is settled in plane O1'  O1' at distance e compared to the longitudinal axial plane of the floating bodies O1-O1 . Distance e is calculated from the relation: n

e

y i 1

i

,

(7)

n

where n is the number of rotor blades, and yi is the distance from the centre of application of Archimedes force on blade i up to the longitudinal axial plane (figure 30, c). For each distance, yi is calculated by the relation: 360o (8) ), yi  cM cos   R sin(  (i  1) n where R is the rotor radius; CM is the distance from the point of application of the Archimedes force and the blade fixing point to the turbine impeller, OiNi in figure 30,c; n is the number of rotor blades. So, the distance e is calculated by the relation:

e  cM  cos  ,

(9)

where α is the angle formed by the blade chord and the water flow direction. Conclusion: To ensure the floating stability of the micro hydro power plants the rotor is mounted on the main structure with displacement e against the water stream. Thus, the micro hydro power plants designed to be anchored on the left bank cannot be anchored on the right bank.

5.1.3. Design of the hydrodynamic rotor 5.1.3.1. Theoretical justification of the hydrodynamic profile selection of the blade in normal section Let consider the symmetrical profile of the blade placed in a fluid stream that moves uniformly at  velocity V  (figure 31). In the fixing point O' of the symmetrical blade with lever OO′ let consider two coordinate systems, that is: the system O'xy with axis O'y oriented in the direction of the  velocity vector V  , and axis O'x - normal for this direction; and the system O'x′y′ with axis O'y′ 38

oriented to the lever direction O'O, and axis O'x′ - normal for this direction. Point A corresponds to the rear edge, and point B corresponds to the entering edge. The entering angle  is the angle



between the chord AB of the profile and the direction of the velocity vector V  , and the positioning angle φ is the angle formed by the velocity vector direction and lever O'O

Figure 31 – Hydrodynamic profile blade.



The components of the hydrodynamic force F in the directions O'x and O'y are named the lift force and the resistance force: 1 FL  CL V2 S p , 2

(10)

1 FD  CD V2 S p , 2

(11)

where ρ is fluid density, V∞ is flow velocity, Sp=ch (c is the length of chord AB, and h is the blade height) represents the area of the blade lateral surface, and CL and CD are hydrodynamic dimensionless coefficients, called the lift coefficient and drag coefficient. The hydrodynamic coefficients CL and CD are functions of the entering angle α , Reynolds number Re and the hydrodynamic shape of the blade profile. The components of the hydrodynamic force in the coordinate system O'x′y′ are Fx   FL sin   FD cos  , Fy  FL cos   FD sin .

(12)

The torque moment of the rotor spindle OO′ developed by blade i is

Tr ,i  Fx  OO ,

(13)

and the summary torque moment developed by blades is Npal

Tr   Tri ,

(14)

i 1

where Npal is the number of rotor blades.

39

Generally, the hydrodynamic force has no point of application in the origin of the blade axes system O′ so as it produces a resulting moment. The produced moment is determined by comparing it to a certain point of reference. The point situated at distance ¼ of the chord from the entering edge B will be considered as point of reference. The moment, also called the pitching moment, is calculated according to formula 1 M  CM V2 cS p , 2

(15)

where CM is the profile number of turns.

5.1.3.2. Determination of the hydrodynamic coefficients CL and CM. Plane potential (cyclic) motion The profile chord is considered unitary for simplicity. Initially, the fluid is considered incompressible and non-viscous, and its motion –plane and cyclic. In the case of an incompressible fluid in plane motion the velocity components V   u , v  in point P(x,y) are given by the relations: u ( x, y ) 

  , v ( x, y )  , x y

(16)

where Ф is the potential (cyclic) motion that is obtained by overlapping the velocity uniform flow  V   (V cos  ,V sin  ) with a distribution of sources and a distribution of vortexes placed on the profile C. In other words the potential is decomposed like:

      S  V ,

(17)

where the potential of the uniform flow is demonstrated by the formula:

   V x cos   V y sin  ,

(18)

the potential of the intensity source distribution γ(s) is given by formula S 



C

q(s) ln(r )ds, 2

(19)

and the potential of intensity vortex distribution q(s) is given by formula:

 (s) (20)  ds.  2 C In the relations (19, 20) s represents the measured distance of profile C, and (r, θ) are the polar coordinates of point P'(x,y) reported to the point on the contour corresponding to distance s (figure 32). V   

40

Figure 31 – Fluid cyclic motion around profile

C.

Therefore the potential in point P'(x,y) is given by formula:  ( P ')  V x cos   V y sin  



C

q( s)  ( s)  ds. ln(r )ds   2 2 C

(21)

To calculate the cyclic motion potential Ф the collocation method is used, namely: the boundary of profile C is approximated by a closed polygon N

C   Ej, j 1

sides Ej having their points (vertex) Pj and Pj+1 placed on C. The numbering of points starts from the rear edge on the lower side in the direction of the entering edge, passing further to the upper side (Fig. 33). It is considered that the intensity of vortexes γ(s) distributed on profile C is constant at the boundary having value γ, and the intensity of sources q(s) distributed on the profile is constant at each boundary element Ej having value qj, where j=1,…, N. Specifying the above, equation (21) becomes: N  qj     V x cos   V y sin        ds, ln(r )  2  j 1 E j  2

(22)

The unknown being  and q j , j  1, , N .

Figure 32 – Digitization of profile

C.

Let consider the boundary element Ej with points Pj and Pj+1 (Fig. 34). The normal and tangent unit vectors of the element Ej are given in formulas: n j  ( sin  j , cos  j ), (23)  j  (cos  j ,sin  j ), where sin  j 

y j 1  y j lj

,

cos j 

x j 1  x j lj

.

41

Figure 33 – Boundary element E j .

The unknown γ and qj, where j=1,…, N from the relation (22), are determined from the boundary conditions and Kutta condition. In the case of non-viscous fluid, the boundary condition is the sliding condition at the profile boundary that is watertight and rigid, that, in the particular case of plane and potential motion of the incompressible fluid, is written as follows:

  V  n  0,

(24)

 where n is the normal of the profile. It is necessary to satisfy the condition (24) in the points of





collocation. Points M j x j , y j – the centers of sides Ej , are selected as points of collocation: xj 

x j  x j 1 2

, yj 

y j  y j 1 2

, j  1, , N .

Velocity components in the point of collocation Mj are written by: u j  u ( x j , y j ), v j  v( x j , y j ).

Thus, condition (21) delivers N algebraic relations:

ui sin  i  vi cos  i  0, i  1, , N

(25)

that are used to determine those N+1 unknown γ and qj, where j=1,…, N. Kutta condition will deliver the final relation, namely:     (26) V    V  , E1

EN



where  is the tangent versor of the boundary element. In our notations, condition (26) takes the form:

u1 cos 1  v1 sin 1  u N cos  N  vN sin  N .

(27)

Velocity components in point M i are determined by the contributions of velocities induced by the distribution of sources and vortexes on each boundary element Ej:

42

N

N

ui  V cos    q j uijs    uijv , j 1

j 1

N

N

(28)

vi  V sin    q v    v , s j ij

j 1

j 1

v ij

where uijs , vijs , uijv , vijv are so-called induction (influence) coefficients. For instance, uijs represents the component of velocity direction x in point Mi, induced by the unitary intensity source distribution from the element E j . The induction coefficients can be calculated in the following way:  ij 1  ri , j 1  ln  sin  j ,  cos  j   2  rij  2  ij 1  ri , j 1  vijs   ln  cos  j ,  sin  j   2  rij  2 ij 1  ri , j 1  uijv  cos  j  ln   sin  j , 2 2  rij  ij 1  ri , j 1  vijs  sin  j  ln   cos  j , 2 2  rij  uijs  

(29)

where βij is the angle formed by sides Pj M i and M i Pj 1 , for i≠j, and βij = π, i,j=1,…,N, and rij is the distance between points Mi and Pj. Let substitute expressions (28) and (29) in the boundary conditions (25) and in Kutta condition (27) to obtain the linear system N+1 of equations with N+1 unknowns: γ and qj, where j=1,…,N : N

A q ij

j 1

j

 Ai , N 1  bi , i  1, N ,

N

A

N 1, j

j 1

(30)

q j  AN 1, N 1  bN 1 ,

where coefficients Aij and bi, i, j = 1,…, N+1 are calculated by formulas: Aij 

 ri , j 1  1 1  sin   ij  ln  cos   ij  ij , i, j  1, , N ,  r  2 2  ij 

Ai , N 1 

1 2

AN 1, j



  ri , j 1    sin  ij   ij , i  1, , N ,   rij 

 cos    ln  N

ij

 1   sin  1 j  1, j  sin   Nj   N , j 2  j 1

r  r   cos  1 j  ln  1, j 1   cos   Nj  ln  N , j 1   ,  r   r   1, j   N , j   r1, j 1   rN , j 1  1 N  AN 1, N 1  sin  1 j  ln    sin   Nj  ln    2 j 1   r1, j   rN , j 

  cos  1 j  1 j  cos   Nj   Nj  , 

43

bi  V sin i    , i  1, , N , bN 1  V cos(1   )  V sin( N   ),

and ij  i   j . The linear system (30) will give the searched values: γ and qj, where j=1,…, N, that will help further to calculate the tangential components of velocity in the points of collocation Mi ,i = 1,…, N. Let remind that the normal component of velocity in the points of collocation is null. The below relation gives the tangential component:

u i  ui cos  i  vi sin  i .

Let substitute the relation (28) in the above relation to obtain: N N N N     u i   V cos    q j uijs    uijv  cos i   V sin    q j vijs    vijv  sin i . j 1 j 1 j 1 i 1    

Consequently, the following relations will be obtained for the tangential components of velocity:  ri , j 1   qi  sin   ij  ij  cos   ij  ln    j 1 2   rij    N

u i  cos i    V  

 j 1 2 N



(31)

   ri , j 1  sin   ij  ln    cos   ij  ij  .    rij 

Bernoulli equation p  1 V 2  p  1 V 2 implies that 2

2

1 1 p  p  V 2  V 2 . 2 2

Thus, the local coefficient of pressure can be rewritten as follows: Cp 

p  p V2 1 .   1  V2 V2   2

(32)

Accordingly, the local pressure coefficient on the discretized contour profile can be calculated from the relation 2

u  C p ,i  1    i  ,  V 

(33)

where components u i are supplied by formula (31). The hydrodynamic forces that react on the boundary element Ej are obtained from the relations relations: f xj  C p , j  y j 1  y j  ,

(34)

f yj  C p , j  x j 1  x j  ,









and the pitching moments reported to the point of reference xref , yref  c ,0 , are calculated by

4

formula:  y  yj cm, j   f xj  j 1 2 

  x j 1  x j c   .   f yj  2 4  

(35)

44

The total force is the sum of contributions of each boundary element: N

Fx   f xj ,

(36)

j 1 N

Fy   f yj , j 1

and the lift coefficient and the moment coefficient are calculated as follows:

CL   Fx sin   Fy cos  ,

(37)

N

CM   cm, j .

(38)

j 1

5.1.3.3. Selection of the optimal hydrodynamic profile of blades The optimization of the hydrodynamic blade turbine performance demands blade optimal hydrodynamic profile. The numerical calculation methods, previously described, are used to calculate the coefficients CL ,ref and CD ,ref for the symmetrical profiles from the library of NACA aerodynamic profiles with a chord length cref = 1 m. It should be remarked that the calculation method converges for the entering angles α that do not exceed 20o  25o dependent on the selected profile and the corresponding Reynolds number (Re = 1300000). For the entering angles exceeding this critical value, the rates corresponding to a flat (plane) profile are considered. Some of the considered profiles are shown in figure 35: NACA 0012, 0016, 63018 and 67015. Figure 36 shows the hydrodynamic lift C L , ref and drag CD , ref coefficients depending on the entering angle. Taking into account the data from Fig. 36, the NACA 0016 hydrodynamic profile is being selected as the reference profile. Subsequently, this profile will be optimized in order to increase the turbine performance. Profil NACA 0016

0.3

0.3

0.2

0.2

0.1

0.1 Y (m)

Y (m)

Profil NACA 0012

0 -0.1

0 -0.1

-0.2

-0.2

-0.3

-0.3 0.2

0.4 0.6 X (m)

0.8

1

0.2

0.3

0.3

0.2

0.2

0.1

0.1

0 -0.1

0

-0.2

-0.3

-0.3 0.4 0.6 X (m)

0.8

1

-0.1

-0.2

0.2

0.8

Profil NACA 67015

Y (m)

Y (m)

Profil NACA 63018

0.4 0.6 X (m)

0.2

0.4 0.6 X (m)

0.8

Figure 34 – Symmetric hydrodynamic profiles: NACA 0012, 0016, 63018 and 67015.

45

Profil: NACA 0012

2

1.5

CL CD

CL, CD

CL, CD

1.5

1

0.5

0

0

15

30 45 60 75 Unghiul de atac, (Deg)

0

90

Profil: NACA 63018

15

30 45 60 75 Unghiul de atac, (Deg)

90

Profil NACA 67015

2

1.5 CL, CD

1.5 CL, CD

1

0.5

2

1

0.5

0

Profil: NACA 0016

2

1

0.5

15

30 45 60 75 Unghiul de atac, (Deg)

90

0

15

30 45 60 75 Unghiul de atac, (Deg)

90

Figure 35 – Hydrodynamic lift CL and drag CD coefficients dependant on the entering angle for NACA 0012, 0016, 63018 and 67015 profiles.

5.1.3.4. The torque moment and the forces applied on the multi-blade hydrodynamic rotor The hydrodynamic coefficients for the NACA 0016 reference profile with chord length, for instance, c  1,3 m. , are calculated below. The coefficients corresponding to the profile with the chord length 1.3 m are calculated from the relations:

46

CL  CL ,ref 1,3 ,

Coeficientii CL si CD in functie de unghiul de atac. Profil: NACA 0016 2.5

CD  CD ,ref 1,3 .

Numarul Reynolds1300000

2

C

The values of the lift and drag coefficients dependant on the entering angle α are shown in figure 37. Taking into account these values, the angle   18o is selected as the working entering angle.

L

1.75

CD

1.5

CL, CD

(39)

CM  CM ,ref  (1,3) 2 ,

Lungimea palei1.3 m 2.25

1.25 1 0.75

The blade changes its entering angle during its motion depending on the position 0.25 (figure 38). Thus, in sector I the entering 0 angle (angle formed by the blade and water 0 10 20 30 40 50 60 70 80 90 Unghiul de atac, (Deg) flow) is 18˚; in sector II the entering angle shifts from 18˚ up to -18˚, but the blade Figure 36 - Hydrodynamic lift CL and drag CD does not contribute to the total moment coefficients dependant on the entering angle for developed at the rotor shaft. In this sector, NACA 0016 profile. extended up to approximately 60˚, the blade is carried freely by the water flow and its re-positioning takes place at an angle of -18˚ at the end of sector III. The entering angle is -18˚ in sector III. In sectors IV-VI the hydrodynamic effect is minimal and the blade has to be re-positioned from angle -18˚ to angle 18. In order to use the kinetic energy in the sectors IV-VI it is proposed to re-position the blade from -18˚ to 90˚ in sector IV; in sector V the blade remains under an angle of 90˚, and in sector VI the entering angle returns to 18˚. Knowing the values of the hydrodynamic coefficients C L and CD , the lift force FL and drag 0.5

Fortele care actioneaza pe pala , Profil:NACA 0016 4000

Modulul rezultantei Componenta tangentiala Componenta normala

3500 3000 2500 2000 1500 Fortele, (N)

1000 500 0 −500 −1000 −1500 −2000 −2500 −3000 −3500 −4000

Figure 37 – Blade position and working areas.

Profil: NACA 0016

Raza rotorului = 2 m

Viteza fluxului de apa = 1 m/s

Numarul palelor = 5

Unghiul de atac = 18 Deg

Inaltimea palei = 1.4 m Lungimea palei = 1.3 m

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

Figure 38– Module, tangential component and normal component of the hydrodynamic force of a rotor blade depending on the angle of positioning.

force FD are calculated by the formulas (10) and (11), and the formula (12) supplies the hydrodynamic force that reacts on the blade (figure 39).

47



The module of the hydrodynamic force F that reacts on the blade, and its tangential and normal components Fx and Fy, depending on the positioning angle (angle of sight) are shown in Fig. 39. The following constructive parameters of the rotor (impeller) were considered: Rotor (Impeller) radius R  2 m; Height of the submersible blade H  1, 4 m; Blade length (chord) c  1,3 m; Working entering angle   18o ; Number of blades N pal  5. Figure 40 shows the moment Tr ,i developed by the blade depending on the positioning angle; the moment is calculated by the formula (13). Figure 41 shows the total (sum) moment at the rotor (impeller) shaft TrΣ developed by all blades depending on the positioning angle. The total moment is calculated by the formula (14). Figure 42 shows the total moment TrΣ depending on the positioning angle for three values of water flow velocity V∞: 1 m/s, 1.3 m/s and 1.6 m/s. The graph of the number of turns CM,ref depending on the entering angle α is shown in figure 43. Momentul dezvoltat de o pala functie de unghiul de pozitionare

Momentul total la arborele rotorului functie de unghiul de pozitionare

7000 14000

6000 5000

12000

4000 10000

Moment, (N⋅ m)

Moment, (N ⋅ m)

3000 2000 1000 0

8000

6000

−1000 Profil: NACA 0016

Raza rotorului = 2 m

Viteza fluxului de apa = 1 m/s

Numarul palelor = 5

Profil: NACA 0016 4000

−2000 −3000 Unghiul de atac = 18 Deg

Numarul palelor = 5

Unghiul de atac = 18 Deg

Inaltimea palei = 1.4 m

2000

Inaltimea palei = 1.4 m

Raza rotorului = 2 m

Viteza fluxului de apa = 1 m/s

Lungimea palei = 1.3 m

−4000 Lungimea palei = 1.3 m −5000

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare (Deg)

300

330

360

Figure 39 – Moment Tr ,i developed by the rotor blade depending on the angle of positioning. 4

4.5

0

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare (Deg)

300

330

360

Figure 40 – Total moment Tr developed by 5 blades at rotor shaft depending on the angle of positioning.

Momentul total la diferite viteze

x 10

1 m/s 1.3 m/s 1.6 m/s

4 3.5

Moment, (N⋅ m)

3 2.5 2 1.5 1 0.5 0

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

Figure 41 – Total moment Tr at rotor shaft depending on the angle of positioning for various velocities of the water flow

Figure 42 – Number of turns CM ,ref depending on the entering angle for NACA 0016 profile

48

Taking into account the fact that the hydrodynamic force is not applied in the blade fixed coordinate system O (figure 44) this force produces a moment of torsion called the pitching moment. This moment is determined given the point of reference. Point P will be considered as the point of reference situated at ¼ distance of the chord from the entering edge B (figure 44). For the working values of the entering angle α = 18˚ it is obtained CM,ref = -0.026. Thus, from the relation (40) results that CM = 0.0439. The moment of torsion compared to the point P is 1 (40) M  CM V2 cS p  39,92 N  m, 2 where V∞ = 1 m/s, c = 1.3 m and H = 1.4 m. In the system of coordinates Oxy , the components of the hydrodynamic forces are delivered by the relation (12). Applying the values FL and FD obtained previously we have: Fx  1601, 2 N , (41) Fy  413,8 N . Then

OP  M

Fx  0,0249 m  25 mm.

(42)

In order to ensure the stability of the blade motion, the fixing point W should be selected in the interval 25 mm  O W  H , where H min  H  H max . Values Hmin and Hmax are taken under the condition that the frictional force, appearing in the kinematical couples of the orientation mechanism, must be minimal.

Figure 43 – Location of the blade fixing point.

To determine the optimal working entering angle it is necessary to calculate the value of the moment developed by one blade and the total moment for several values of the entering angle, namely:   15o , 17o , 18o , 20o , (figure 45-46). In this context the entering angle for the blade with hydrodynamic profile NACA 0016 is   18o. 4

Momentul dezvoltat de o pala la diferite unghiuri de atac 1.7

5000

15 Deg 17 Deg 18 Deg 20 Deg

4000

Momentul total la diferite unghiuri de atac

x 10

15 Deg 17 Deg 18 Deg 20 Deg

1.6 1.5 1.4 1.3

Moment, (N ⋅ m)

Moment, (N ⋅ m)

3000

2000

1.2 1.1 1 0.9

1000

0.8 0.7

0

0.6 0.5

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

330

Figure 44 – Moment developed by the blade Tr ,i depending on the positioning angle for various values of the entering angle   15o , 17 o , 18o , 20o.

Figure 45 – Total moment Tr depending on the positioning angle for various values of the entering angle   15o , 17 o , 18o , 20o.

49

Also, the performance of 3-, 4- and 5-blades rotor was analysed. The total moment developed by the rotor shaft was calculated and the results are presented in figure 47. 4

1.7

Momentul total la diferite configuratii

x 10

3 pale 4 pale 5 pale

1.6 1.5 1.4

Moment, (N ⋅ m)

1.3 1.2 1.1 1 0.9 0.8 0.7 0.6 0.5

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

Figure 46 – Total moment Tr  developed at the 3-, 4- and 5-blade rotor shaft depending on the positioning angle.

5.1.3.5. Optimisation of NACA 0016 hydrodynamic profile In order to maximize the moment of torsion produced by the micro hydro power plant rotor, the optimization of the hydrodynamic profile will be considered. The moment of torsion depends on the lift and drag hydrodynamic forces given by formulas (10) and (11). The hydrodynamic forces through the hydrodynamic coefficients depend on the entering angle α, Re number and the shape of the hydrodynamic profile. The hydrodynamic shape of the profile was selected from the NACA library of 4 and 5 figures having as parameters (with account of the profile symmetry) only the maximal thickness. The entering angle constitutes the second parameter. The optimization aims at maximizing the lift force and, at the same time, does not allow the pitching moment and the resistance force to take very big values. The following issue of optimization should be considered: Maximize C L  C L ( ,  ) with constraints imposed to the coefficients CD and CM ,

(43)

where θ is the maximum thickness and α is the entering angle. The values of the inferior and superior borders are determined, as follows: the negative maximum value for the pitching coefficient will correspond to the solution for the entering angle 0. The maximum value for the resistance coefficient will correspond to the solution for the entering angle α = 18˚. Also, restrictions have been added to the optimization parameters 10%    20% and 0o    20o . To find the optimal values of function f  f ( x1 , , xn ) an iterative method is used: As long as the demanded accuracy is not reached the solution will be, Bi si  f ( xi ) ,

xi 1  xi   i si ,

(44) 50

where  i are the multipliers and Bi are the definite positive approximations of the Hessian function f . The partial derivation of function f related to the component i is approximated with the help of the finite difference formulas: f ( x  hei )  f ( x  hei ) f , ( x)  xi 2h

(45)

where ei is the basis vector. The optimization is done by the MATLAB optimization soft: “Sequential quadratic programming algorithm with a line search and a BFGS Hessian update”. The quadratic sub-tasks are solved by modified projection method. The gradient of function CL  CL ( ,  ) is calculated by the finite difference formulas with the constant pitch h  10 4 . NACA 0016 profile was considered as the initial profile (figure 48). The result of optimization is presented in Fig. 49. The results of the carried out research were published in [1 - 5].

Figure 47 – NACA 0016 hydrodynamic rack profile standard.

Figure 48 – NACA 0016 hydrodynamic rack profile standard and the optimised profile.

In order to optimize the hydrodynamic profiles of the blades a prototyping 5-axis machine has been purchased (figure 50). For the manufacturing of the prototypes of hydrodynamic blades in the framework of the current project several special modules are at purchasing stage. The purchased equipment will allow the prototyping, manufacturing and testing of the profiles sugested by modelling and computer simulations.

Figure 49 – Blades prototyping 5-axis machine

51

5.1.3.6. Floating stability of the micro hydropower plant The micro hydro power plant is posted in the river water flow. The position of blades compared to the water level is ensured by the Archimedes forces that react on the floating blades. The blade cavity generates the Archimedes force determined by the relation

FA  Vg ,

(46),

where  is the water density, V is the interior volume of the blade and g is the gravitational acceleration. The analysis of the path of motion (motion trajectory) of the points of application of the Archimedes force FA (points Ni, i = 1, 2, 3, figure 51) has shown that the distance from these points to the rotor axis O will oscillate depending on the positioning angle  . Thus, for the blades located in the superior semi-plane defined by the straight line OO΄ these distances are different from the respective distances of the blades located in the inferior semi-plane. This fact leads to the appearance of the pitching moment with respect to the axis of longitudinal symmetry of the floating bodies:

Figure 50 – Floating stability analysis.

M r  M ,S  M ,I ,

(47)

where M  ,S is the total moment developed by the Archimedes forces that react on the blades, currently located in the superior semi-plane, and M  ,I is the total moment developed by the Archimedes forces that react on the blades currently located in the inferior semi-plane. The total moments developed by the Archimedes forces that react on the blades currently located in the superior and the inferior semi-plane are determined by the relation

M , S   FA,i  DA,i ,

(48)

where FA,i are the Archimedes forces that react on the blades; D A,i are the distances from the point of application of the Archimedes forces to the rotor spindle, and the summarization is done for all blades located in the superior semi-plane. Similarly, (49) M  , I   FA,i  DA,i . Distances D A,i are calculated by the formula: DA2,i  R 2  cA2  2 RcA cos(  i ),

(50)

where R is the rotor radius; c A is the distance between the point of application of the Archimedes forces and the point of blade fixing to the rotor lever;  is the angle formed by the blade chord

52

AB and the direction of the water flowing, and i is the angle formed by the rotor lever and the direction OO . To compensate the pitching moment M r it is proposed to locate the rotor spindle in the plane shifted at distance e compared to the plane of longitudinal symmetry of the floating bodies. Distance e is calculated by the relation: N pal

e

y

i

i 1

N pal

(51)

,

where N pal is the number of rotor blades and yi is the distance from the central point of application of the Archimedes force on the blade i till the plane of longitudinal symmetry (figure 51). For each blade, distance yi is calculated by the relation: yi  c A cos   R sin(  (i  1)

360o ). n

(52)

Let introduce (52) into (52) and obtain:

e  c A cos 

(53)

The point of application of the Archimedes force on each blade is the centre of gravity (mass point) of the applied hydrodynamic profile, in our case NACA 0016 profile. The central point of application of the Archimedes force system that reacts on a number N pal of the submersible blades will describe a migration trajectory generated by the rotor revolution. The migration trajectory generated by a complete revolution of 3- and 5-blade rotor represents closed curves described in figure 52 (a) and figure 52 (b). One point on the closed curve represents the position of the central point of application of the Archimedes force system corresponding to a concrete angular position of the rotor. To identify the technical solution ensuring the floating stability of the micro hydro power plant it is Traiectoria de migrare a punctului c Traiectoria de migrare a punctului c necessary to estimate the values of the 0.37 0.38 distance between the 0.36 0.36 central point of 0.35 0.34 application of the 0.34 0.32 Archimedes force 0.33 0.3 system and the 0.32 0.28 longitudinal symmetry 0.31 0.26 axis of the floating A

Y, (m)

Y, (m)

A

0.24

0.3

0.22

0.29

−0.03 −0.01

0.01

0.03

0.05 0.07 X, (m)

0.09

0.11

0.13

−0.01

0

0.01

0.02

0.03 0.04 X, (m)

0.05

0.06

0.07

Figure 51 – Migration trajectory of the central point of application of the Archimedes forces for the 3-blade (a) and 5-blade rotor (b).

bodies Figure 53 (a, b). shows

53

Distanta e

the distance e depending on the positioning angle φ of the 3-blade (a) and 5blade (b) rotor. It has been stated that in the case of 3-blade rotor, distance e takes values comprising

Distanta e

0.36

0.36

0.35

0.34

0.3296 0.34 e, (m)

e, (m)

0.32 0.3

0.3296

0.33 0.32

0.28 0.31 0.26

0.3

0.24

0.29

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

36

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

emin  0, 238 m and emax  0,363 m .

Figure 52 – Dependence of distance e of the central point of application of the Archimedes forces on the positioning angle  of the 3-blade rotor (a) and of 5-blade rotor (b).

And in the case of 5-blade rotor: emin  0, 289 m , and emax  0,363 m . Let calculate the mean value of distance e depending on the positioning angle φ: for 3- and 5-blade rotors the same mean distance emed  0,33 m is obtained. Conclusions: 1. To ensure the floating stability of the micro hydro power plant it is necessary that the spindle of 3- and 5-blade rotor shifts from the axis of longitudinal symmetry of the floating bodies at rate emed  0,33 m in the direction opposite to the water flow. 2. Micro hydro power plants anchored on the left bank differ from those anchored on the right bank by the spatial truss constructions and, in particular, by the constructional elements of the hydrodynamic rotor shifted at rate emed  0,33 m.

5.1.3.7. Turbulence and stability of the hydrodynamic rotor Figure 54 shows the field of fluid velocities around NACA 0016 profile at entering angle 18˚ and the Reynolds number calculated from the relation [2]:   Re 

 cV cV  ,  

(54)

where the fluid density is o   998, 4 kg m3 at 20 C, the kinematical viscosity is   1, 012 106 m2 s , and the length of the profile chord is c  1,3 m . For the fluid flow rate

V  1 m s , 1,5 m s , 2 m s Figure 53 – Velocity field around NACA 0016 profile at the entering

the following values of the

o

angle 18 .

54

Reynolds number Re = 1284600, 1798400 and 2312300 are obtained. The transition and separation of the boundary layer on the inferior and superior surfaces of the blade profile is shown in figure 55. Points T.U. and T.L. stand for the points of separation from the laminar flow to the turbulent flow on the inferior Cinf and superior Csup surfaces of the blade (figure 52). Respectively, points S.U. and S.L. represent the points of separation on the inferior and superior surface. In all cases it was observed that transition from the laminar flow to the turbulent flow takes place in the proximity of the point of stagnation, and the separation of flow from the profile surface is foreseen at an approximate 40-50% distance of the blade chord length. The transition from the laminar flow to the turbulent flow as well as the separation of the turbulent boundary layer will take place in the proximity of the rear edge on the inferior surface.

a.

b.

Figure 54 – Point of separation for the flow velocities 1 m/s (a) and 2 m/s (b).

5.1.3.8. Design and manufacturing of the hydrodynamic rotor The hydrodynamic rotor has been designed in the Autodesk MotionInventor software (figure 56 - 3 blades rotor, and figure 57 - 5 blades rotor). The 4 1 2 hydrodynamic rotor is the main working element of the micro hydropower plant, which converts kinetic energy of the water flow and transmit it via the kinematical linkage to the production units of electrical (generator 1) energy or mechanical (hydraulic pump 2) energy (figure 58). From the point of view of its design, the rotor comprises the main shaft 1 (figures 56, 57), the casing with radial bars 2, on which 3 ends the hydrodynamic profile blades 3 are mounted with the help of node 4. The main Figure 55 – 3-blade hydrodynamic rotor.

shaft 1 and the casing with the bars 2 are mounted removable. The hydrodynamic rotor is a spatial structure, strained complex with the bending and twisting moments. The casing with radial bars are made of aluminium alloy plates with calculated dimensions able to ensure design positioning (calculated) of blades with minimal deviations (the deflexion of blade axles till 5 mm, the angle of twist of the radial bars  1o).

1

2

4

3 Figure 56 – 5-blade hydrodynamic rotor. 55

Figure 57 – Multiblade rotor connected kinematically to the electric (generator 1) energy or mechanical hydraulic pump 2) energy production units.

The technical solutions adopted in the final construction of the hydrodynamic rotor have resulted into computer simulated research, by utilising ANSYS CFX 5.7, sub programmes in the package of mathematic modelling MathCAD, etc., by applying possible loading in real conditions. The node 4 allows the changing of blade 3 positioning towards their axis of rotation, aiming at the insurance of the optimal pitching moment (the technical solution contains Know-How elements). Figure 59 shows 3-blade (a) and, respectively, 5-blade (b) rotors, the diameter of blade location is D = 4 m. The shape and dimensions of the hydrodynamic profile of blades have been justified within the carried out research [1,2].

Pilot station destination. The micro hydro power plant is a complex system, which includes the main working element – the hydrodynamic rotor, destined for the conversion of a part of the river water kinetic energy potential into useful energy, and the units with distinct functions, such as the multiplier, generator, hydraulic pump etc. The results of research on the construction and functional parameters of the mentioned units, shown separately from each other regardless of their functional interdependence as an integral system, are presented in [1,2]. To carry out research on the functional parameters, in field conditions, of all units participating in the process of conversion of flowing water kinetic energy into useful energy as an integral technical system, the pilot plant design was developed in MotionInventor AutoDesk design environment,

Figure 58 – Rotors with 3- (a) and 5-blades (b) with hydrodynamic profile, manufactured in the laboratory of the Centre for Renewable Energy Conversion Systems Design, TUM.

using the developed conceptual diagrams [1,2] and the results of theoretical research findings, of computer modelling and simulation of hydrodynamic profile blade interaction with the fluid (water). The pilot station is intended for research and verification of the technical solutions adopted at each stage of unit development, in real conditions, and, if necessary, changes will be made at the design stage of the industrial prototypes of micro hydro power plants. Pilot station positioning. The pilot station is installed on the river Prut, v. Stoieneşti, district Cantemir, under the following positioning conditions: - Rotor axis is perpendicular to the water mirror; 56

- Longitudinal axis of spatial housing is perpendicular to the water flow velocity vector; - Level of blades submersion meets the project rate (h = 1.4 m). Perpendicularity of the hydrodynamic rotor shaft to the water mirror is ensured by changing the buoyancy of four floating bodies, and the perpendicularity of the longitudinal axis of the spatial housing to the water flow stream vector is ensured through supporting cables secured to the anchoring rods. The submersion level of blades with hydrodynamic profile h = 1.4 m is maintained by changing the buoyancy of the four equal floating bodies. Structural and functional parameters of hydrodynamic rotor, planetary multiplier, generator and low speed centrifugal pumps, determined separately for each working body, needs to be checked by experimental investigations in real conditions of their operation in an integral technical system. In this context, the time table of experimental research on the pilot station in field conditions includes: 1. study of diversity of water flow speed cadastre within the boundaries of rotor effective section (the width of the rotor blades and level of submersion) and assessment of the water flow energy potential; 2. study of the influence of force factors on the stability of the hydrodynamic profile blades positioning (angle of attack ) and the kinetostatic analysis of the blades positioning mechanism; 3. study of energy and kinetic conversion efficiency parameters (for the electric generator terminals and the input shaft of hydraulic pumps); 4. study of kinematic parameters of hydrodynamic rotor and mechanical losses in the kinematic chain (linkage); 5. setting the influence of structural and functional parameters of hydrodynamic rotor on the hydrodynamic effects and water turbulence flow mode under field conditions; 6. study of functional characteristics of electrical generator and centrifugal pumps. The experimental research of the integral technical system - hydrodynamic rotor coupled kinematically with component units of micro hydro power plants aims at increasing efficiency of water flow kinetic energy conversion into useful energy by identifying and, where necessary, introducing in the technical documentation of partial structural changes and, sometimes, of conceptual and technical solutions adopted previously. When developing industrial prototypes of micro hydropower plants for river water kinetic energy conversion the following criteria and requirements were taken into account: - Exclusion of dam construction and of the negative impact on the environment, implicitly; - Lowest cost; - Simplicity of construction and operation; - Increased reliability at dynamic overload in operating conditions; - Resistant composite materials, including conditions of high humidity; - Automatic adjustment of the micro hydropower plant platform position in conditions of water level changing. The technical solutions adopted in the process of micro hydropower plants design result from theoretical and experimental research presented in [1,2]. To justify the constructive and functional parameters, additional numerical modelling and simulations were performed, using ANSYS software CFX5.7, and the sub-software developed by the authors for MathCAD, Autodesk MotionInventor, etc., namely, simulation of the “fluid – blade” interaction and floating stability, hydrodynamic optimization of the blade profile in order to increase kinetic energy conversion efficiency of river water at its different velocities using 3-, 4- and 5-blades rotor. The efficient operation of micro hydropower plants by individual customers for particular destination depends on their constructive configuration choices and on the functional characteristics of component units

57

participating in the conversion of flowing water kinetic energy into useful energy. To meet the objectives and consumer demands for micro hydro power plants, and also to increase the efficiency of conversion of flowing water kinetic potential in the certain river area, the authors have developed the following structural and functional concepts based on modular assembly: 1. micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into mechanical energy for water pumping (MHCF D4x1,5 M); 2. micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electric and mechanical energy (MHCF D4x1,5 ME); 3. micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into mechanical energy at low speeds (MHCF D4x1,5 ME); 4. micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electric energy (MHCF D4x1,5 E). The micro hydropower plants designed modularly, allow change of destination and of functional characteristics by replacing some units with others (generator, pump, blades with other hydrodynamic profile, 3- and 5- blade rotor).

Figure 59 – Generated power at rotor shaft.

The micro hydropower plants possess similar resistance in structure construction calculated for strength and rigidity to dynamic applications. Buoyancy and maintainance of hydropower plant rotor axis perpendicularity at variable river water level is ensured by patented technical solutions [8-14]. Continuous orientation mechanism of the blades at the constant entering angle relative to the direction of fluid stream contains Know-how elements and is not described here. The main working body, which depends mainly on the amount of kinetic energy converted into useful energy, is the blade with hydrodynamic NACA 0016 profile, developed on the basis of carried research [1,2]. Two types of 3- and 5-blade rotors were designed for the described micro hydropower plants. Installed capacity of micro hydropower plants with diameter D = 4 m, submerged height of blades h = 1,4 m and the length of blade chord l = 1,3 m at water flow velocity V = 1...2 m/s can be in the boundaries P = 2...19 kW (see [figure 60]).

5.2. Industrial prototypes of micro hydropower plant with hydrodynamic rotor 5.2.1. Pilot station of micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into mechanical energy (MHCF D4x1,5 M) This model of hydro power plant is designed to convert river water kinetic energy into mechanical energy used to pump water into irrigation and sewerage systems, and supply industrial water etc. with the flow rate Q = 40 m3/h at the height pumping H = (10 – 15) m.

58

Static description of the microhydro power plant. The blades 1 (figure 61) are connected to the hydrodynamic rotor 2 by roller friction bearings to ensure their orientation under a certain entering angle .

1.1. Blade with hydrodynamic 0016 NACA profile; 2 – 3-blade rotor; 3 – planetary multiplier with multiplying ratio i=112; 4 – belt drive with multiplying ratio i = 1,9; 5 - permanent magnet generator (characteristics – see p. 5.4); 6. centrifugal pump PSS40–10/50 (characteristics – pump flow rate Q=40m3/h at pumping height (10...15)m; 7 –plastic pontoons; 8 – guide; 9 – spatial housing. Figure 60 – Micro hydropower plant with hydrodynamic rotor for river kinetic energy conversion into mechanical energy for water pumping (flow rate Q = 40m3/h, pumping height H =10...15 m) (MHCF D4x1,5 M)

59

Functioning principle. The river flowing water with the energy potential dependent on the flow velocity drives the hydrodynamic profile blades 1 (figure 62), oriented continuously by the entering The hydrodynamic rotor 2 is mounted on the input shaft of the planetary multiplier 3 through an auxiliary shaft, which is fixed on the bearings. The belt pulleys of the transmission 4 are mounted on the output shaft of the planetary multiplier - the big one, and the small one - on the input shaft of the centrifugal pump 5. The hydrodynamic rotor 2 and blades 1, the multiplier 3, the centrifugal pump 5 and guides 6 are mounted on the spatial housing 7, installed on the pontoons 8.

Figure 61 – Kinematics of micro hydropower plant MHCF D4x1,5 M. under the hydrodynamic forces and reporting rotational motion with angular frequency 1 and torque T1 to the rotor 2. The summary torque T1 , developed by the hydrodynamic forces and applied to the 3blade rotor shaft at water flow velocities 1.3, 1.6 and 1.8 m/s and at the entering angle of blades  = 18o , is presented in figure 63.

x 10

Momentul sumar T la diferite viteze, Profil:NACA 0016 v0=1.3 m/s v =1.6 m/s 0

3.5

v0=1.8 m/s 3 2.5

T, (n⋅ m)

For rotor diameter D = 4 m, the submerged height of blades h=1,4 m and length of blade chord l = 1,3 m, the torque is: T1 = 11938 Nm for water flow velocity V = 1,3 m/s; T1 = 18084 Nm for V = 1,3 m/s; T1 = 22887 Nm for V = 1,8 m/s. The calculations of kinematics and lifting capacity of all constructive elements as well as of all functional and energy parameters

4

4

The micro hydropower rotor 2 comprises three blades oriented at an entering angle , which is dependent on the water flow velocity. In the areas of blades 1 location, inefficient from the point of view of river kinetic energy conversion, under hydrodynamic forces the blades 1 are repositioned at an angle of 90o to the currents of water or are carried by the water unhampered to the angle  = 0. Thus, the respective positioning of blades allows the increase of water kinetic energy rate converted into useful energy. As result, the water currents transmit a part of their kinetic energy to the blades 1, stressing them

22887 N⋅ m

2

18084 N⋅ m

1.5 11938 N⋅ m 1 0.5 0

valoare medie

0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

Figure 62 – Torque T1 at the hydrodynamic rotor shaft with NACA 0016 profile blades. 60

of micro hydropower plant have been carried out for the torque value T1 = 18084 Nm. Rotor 2, rigidly coupled by means of auxiliary shaft with the input shaft of the multiplier 3, transmits rotational motion to the last with angular frequency 1 and torque T1. The multiplier reproduces the rotor 2 revolutions up to n2  301 i1 (min 1 ), where i1 represents the multiplying ratio of the multiplier  (i1=112). Rotational motion at angular frequency 2   n2 ( s 1 ) is transmitted from the multiplier 30

input shaft via a transmission belt 4 of the centrifugal pump input shaft with multiplying ratio i1 = 2,25. As result, the input shaft of the centrifugal pump swivels with angular frequency 3 = 1i1i2 (s-1) and is stressed at torque:

T1 1  2 r ,( Nm ) , i1  i2 where: 1 is the multiplier mechanical efficiency (1 = 0,9); 2 - is belt transmission mechanical efficiency (1 = 0,95); r - mechanical efficiency of hydrodynamic rotor bearings (1 = 0,99). T3 

According to the experimental research presented in [1,2] the mechanical efficiency of centrifugal pump is 1 = 0,72 at rated speed frequency

n3 

303



 500 min 1 .

The mechanical efficiency of the micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into mechanical energy, with account of all mechanical losses in the linkage (at the hydraulic pump shaft) is:

  123r  0,9  0,95  0,99  0,846.

Accordingly, the micro hydropower plant (MHCF D4x1,5 M) ensures the transformation into useful energy of 84,6% of the kinetic energy potential of the flowing water transmitted to the hydrodynamic rotor.

61

Figure 63 – Industrial prototype of the microhydropower station for the river kinetic energy conversion into electrical and mechanical energies (diameter of rotor d = 4m, submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 ME).

According with obtained results the industrial prototype of the microhydropower station for the river kinetic energy conversion into electrical and mechanical energies (diameter of rotor d = 4m, submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 ME) was produced (figure 64). Now is installed on the river Prut, v. Stoieneşti, Cantemir for testing in real conditions (figure 65).

Figure 64 – Industrial prototype of the microhydropower station for the river kinetic energy conversion into mechanical energy installed on the river Prut, v. Stoieneşti, Cantemir.

5.2.2. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical and mechanical energy (MHCF D4x1,5ME) The micro hydropower plant MHCF D4x1,5 ME for river water kinetic energy conversion into electrical and mechanical energy (figure 66) is polyfunctional and can be utilised for electrical lighting of streets, heating, water pumping in drip irrigation systems, and also for draining agricultural lands adjacent to rivers. Rigging the NACA 0016 profile blades 1 in the hydrodynamic rotor 2 and its attachment to the multiplier input shaft 3 is done similar to micro hydropower plant MHCF D4x1, 5 M. Kinematic and construction peculiarities of MHCF D4x1,5 ME are as follows: rotational movement of the 62

hydrodynamic rotor 2 (Figure 67) with an angular frequency (velocity) 1, by means of multiplier 3 and belt transmission 4 with effective multiplying ratio i = 212.8, is multiplied to the operating angular frequency of the permanent magnet low speed generator 5:

3=1i1 (s-1). Torque T3, applied to rotor 5, is:

T3 

T1 1  2 r ,( Nm ) , i

where: 1 is multiplier mechanical efficiency (1 = 0,9); 2 – is belt transmission mechanical efficiency (1 = 0,95); r – mechanical efficiency of hydrodynamic rotor bearings (1 = 0,99). i – effective multiplying ratio equal to the multiplying ratios product of the planetary multiplier and belt transmission

63

1. Blade with hydrodynamic NACA 0016 profile; 2 – 3-blade rotor; 3 – planetary multiplier with multiplying ratio i=112; 4 – belt drive with multiplying ratio i = 1,9; 5 - permanent magnet generator (characteristics – see p. 5.4); 6. centrifugal pump CH – 400 (characteristics – pump flow rate Q=(20-40)m3/h at pumping height 15...32m); 7 –plastic pontoons; 8 – guide; 10 – space housing. Figure 65 – Micro hydropower plant with hydrodynamic rotor for river kinetic energy conversion into electrical and mechanical energy (rotor diameter D = 4 m, submerged height of blade h = 1,4 m, length of blade chord l = 1,3 m) (MHCF D4x1,5 ME) The electric energy produced by the permanent magnet generator 5 (figure 67) can be utilised to satisfy the energy needs of the private consumers and, as well, to supply the centrifugal pump 6 (model CH 400) with electrical energy in order to pump water in drip irrigation systems or for drainage of agricultural land adjacent to river (with relocation of the centrifugal pump 6). In the case of electric energy production, with account of mechanical losses both in the micro hydropower plant linkage and in the permanent magnet generator, the efficiency of energy utilisation at generator’s terminals is,

   1 2 r g  0,9  0,95  0,99  0,87  0,736 ,

And in the case of water pumping (at the centrifugal pump shaft) the efficiency is:

   1 2 r g me  0,9  0,95  0,99  0,87  0,91  0,67 , 64

where: g is the generator efficiency; me is the efficiency of the hydraulic pump electromotor. Thus, the micro hydropower plant MHCF D4x1,5 ME ensures the transformation into useful energy of 73,6% and 67% of the energy potential of flowing water, picked up by the hydrodynamic rotor, in producing electrical energy and, respectively, in water pumping. Water current Figure 66 – Kinematics of micro hydropower plant MHCF D4x1,5 ME.

5.2.3. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical and mechanical energy at small speeds (MHCF D4x1,5ME) Micro hydropower plant MHCF D4x1,5 ME (figure 68) is designed to convert river water kinetic energy into electrical and mechanical energy, by utilising low speed permanent magnet generator 5 (n = 375 min-1) and three-stage low speed centrifugal pump (PSS 40-10/50 (n = 500 min-1) 7 designed, in particular, for the micro hydropower plant and manufactured at „Hidrotehnica” S.A., Chişinău. Research results and functional characteristics of the low speed pump are presented in [1,2]. Kinematics and functional principle of the micro hydropower plant are analogic to the micro hydropower plant presented above (figure 67). Constructive peculiarities of this micro hydropower plant refer, in particular, to the driving mechanism unit of the centrifugal pump (fig. 69) and to the supply of the pump low speed electromotor 2 from the permanent magnet low speed generator 5 (figure 68). This design configuration can be used both to meet the needs of irrigation by pumping water at relatively low heights (10 ... 15) m (e.g. over the river dam) and to perform the draining works of the land adjacent to the river. When the micro hydropower plant is used for draining works, the centrifugal pump driving mechanism (Fig. 70) is relocated from the spatial housing of the micro hydropower plant to the floating platform in the flooded area of agricultural land adjacent to the river.

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1. Blade with hydrodynamic NACA 0016 profile; 2 – 3-blade rotor; 3 – planetary multiplier with multiplying ratio i=112; 4 – belt drive with multiplying ratio i = 1,9; 5 permanent magnet generator (characteristics – see p. 5.4); 6. asynchronous electromotor; 7 – centrifugal pump PSS-40-10/50 (characteristics Q and H – see p.5.4.3); 8 – plastic pontoons; 9 – guide; 10 – spatial housing. Figure 67 – Micro hydropower plant with hydrodynamic rotor for river kinetic energy conversion into electrical and mechanical energy used for water pumping (rotor diameter D = 4 m, submerged height of blade h = 1,4 m, length of blade chord l = 1,3 m).

Three-stage centrifugal pump PSS 40-10/50 1 (fig. 69) is coupled to the electromotor 2 through the toroidal coupling 3 and the housing 4 for the transmission of the reactive torque. Taking into account the mechanical losses both in the linkage and in the electric generator, the kinetic energy efficiency transmitted by the water flow to the hydrodynamic rotor at the permanent magnet generator terminals makes up:

  1 2 r  g  0,9  0,95  0,99  0,87  0,736 ,

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and at the inlet shaft of the hydraulic pump PSS40–10/50 it is:

Figure 68 – Unit of three-stage hydraulic pump driving mechanism PSS 40-10/50.

Figure 69 – Unit of low speed electric generator driving mechanism (MCHF D4x1,5E).

  1 2 r  g m.e.  0,9  0,95  0,99  0,87  0,81  0,596. The micro hydropower plant (MHCF D4x1,5 ME) with the given configuration ensures the transformation of 73,6% of river water energy potential into useful energy and only 59,6% - at water pumping. Relatively small efficiency at water pumping is due to a more reduced efficiency of the low speed electromotor.

5.2.4. Micro hydropower plant with hydrodynamic rotor for river water kinetic energy conversion into electrical energy (MHCF D4x1,5E) The micro hydro power plant (figure 54) is designed to convert river water kinetic energy into electrical energy only. The construction peculiarities are as follows: the hydraulic rotor comprises five blades 1; the permanent magnet generator 3 (figure 53) is assembled coaxially with a

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planetary multiplier 1 through toroidal coupling 2 and housing 4 for taking over the reactive moment of torsion.

1. Blade with hydrodynamic NACA 0016 profile; 2 – 5 blade rotor; 3 – planetary multiplier with multiplying ratio i=112; 4 – permanent magnet generator (characteristics – see p. 5.3); 5 – plastic pontoons; 6 – guide; 7 – spatial housing.

Figure 70 – Micro hydro power plant with hydrodynamic rotor for river water kinetic energy conversion into electrical energy (5-blade rotor diameter D = 4 m, submerged height of blade h = 1,4 m, length of blade chord l = 1,3 m).

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Efficiency of the kinetic energy transmitted by the water flow to the hydraulic rotor can be considered (at the permanent magnet generator terminals):

   1  r  g  0,9  0,99  0,87  0,775 .

4

5

x 10

Momentul sumar T la diferite viteze, Profil:NACA 0016

4.5 4 38137 N⋅ m 3.5 3

T, (n⋅ m)

Dependence of summary torque T1 applied to the 5-blade rotor shaft depending on water flow velocity (V = 1,3...1,8) m/s is presented in figure 72. Kinematic and lifting capacity calculations of all structural elements, including functional parameters and technical characteristics of micro hydropower plants have been carried out for the torque value T1 = 19893 Nm, corresponding to the water flow velocity V = 1,3 m/s (maximum velocity specified for Prut, Dniester and Raut rivers).

30133 N⋅ m

2.5 2

19893 N⋅ m

1.5 v0=1.3 m/s

1 Valoare medie

v =1.6 m/s 0

0.5 0

v0=1.8 m/s 0

30

60

90

120 150 180 210 240 270 Unghiul de pozitionare, (Deg)

300

330

360

Figure 71 – Torque T1 at the shaft of 5-blade hydrodynamic rotor with NACA 0016 profile

In conclusion, we state that micro hydropower plant MHCF D4x1, 5E ensures the transformation of 77.5% of the flowing water potential energy into useful electrical energy transmitted to the hydrodynamic rotor. According with obtained research results the industrial prototype of the microhydropower station for the river kinetic energy conversion into electrical and mechanical energies (diameter of rotor d = 4m, submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 E) was produced (figure 73).

Figure 72 – Industrial prototype of the microhydropower station for the river kinetic energy conversion into electrical energy (diameter of rotor d = 4m, submersed height of the blade h = 1,4m, length of blade l =1,3m) (MHCF D4x1,5 E)

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6. Summary and Conclusions The paper presents a modern monitoring system of the hydraulic, mechanical and electrical parameters related to a SHP and also a new concept with regard to the possibility of catching the kinetic energy of a water stream. The monitoring system of the SHP parameters has been implemented to a SHP on Arges river, here being presented the equipment of the monitoring system, their arrangement within the power house, the connection between the equipment, and the information processing and presentation method. The paper presents also the fact that several small hydropower plants, having implemented this monitoring system, can be interconnected and managed from a dispatcher center. The most important issue is that the different failures, that can occur, can be analyzed and interpreted accurately, especially the electrical failures and that cannot be other way interpreted. As innovative technology for the catchment of the water kinetic energy it is presented a kinetic turbine, completely new, of last generation, fully designed and manufactured by the technical University of Moldavia and tested in situ in Prut river (located at the border between Romania and Moldavia). In the Annex there are presented new technologies developed for the catchment of the water kinetic energy.

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Annex FREE FLOW TURBINE – VERDANT POWER -a three-blade horizontal-axis turbine designed to capture energy from both river and tidal currents -the turbines are installed and operate fully under water, invisible from the shore -spun slowly and steadily by underwater currents, the turbine’s rotor drives a gearbox, which in turn drives a grid-connected generator -the gearbox and generator are encased in a waterproof streamlined nacelle mounted on a pylon -the pylon assembly has internal yaw bearings allowing it to pivot the turbine with the direction of the river’s currents -the pylon is bolted via an adjustable adapter to a pile fixed to the river bottom -the turbine will operate below 1 m/s but for economic efficiency it recommends velocities greater than of 2 m/s and water depths of at least 6.5 m

Figure 73 – Free flow turbine, Verdant Popwer

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FREE FLOW TURBINE – UEK Corporation Underwater Electric Kite -the system employs two axial-flow turbines in a “side-by-side” configuration. Each turbine consists of five blades that dive a single internal generator housed within the nacelle. -the system incorporates an augmenter ring that is integral with rear edge of the shroud. The augmenter ring extends outwardly with respect to the axial alignment of the turbine shafts and deflects the flow of water about the shroud. This creates a low pressure zone of the rear of the shroud that “pulls” water through the turbine blades at a velocity greater than that of the normal surrounding flow of water. -the unit is positively buoyant and is secured to the river bed by a single anchorage system using a cable bridle. When flown as a kite the angle of attack is altered by a patented ballasting system that shifts a weight forward and back in the keel. Keeping a controlled operational depth, the units are not affected by the surface effect of the large waves or navigation. Lateral positioning controls permit the units to stay in the core of current. -the turbine is designed to operate in river, tidal or ocean currents -various models exist from 2 m to 5 m and operate in extremely low velocities of 0.2 m/s or less

Figure 74 – Free flow turbine, UEK Corporation Underwater Electric Kite

FREE FLOW TURBINE – SWAN TURBINE -the unit is a three-bladed axial flow turbine -a gearless low speed generator offers a high efficiency over a range of speeds with minimal maintenance demands through the use of novel structural electromagnetic topologies -a simple, robust and serviceable yawing mechanism is used for maximum flow capture

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Figure 75 – Free flow turbine, Swan turbine

FREE FLOW TURBINE – GORLOV HELICAL -a cross-axis turbine consisting of one or more helical blades that run along an imaginary cylindrical surface of rotation like a screw thread -the helical airfoil blades provide a reaction thrust perpendicular to the leading edges of the blades that can pull them faster than the fluid flow itself -the GHT allows a large mass of slow water to flow through, capturing its kinetic energy and utilizing a very simple rotor -it can be assembled vertically, horizontally or in any other cross-axis combination using common shaft and generator for an array of multiple turbines -generating capacity is proportional to the number of modules -in its vertical orientation the generator and gearing can easily be positioned above water -the standard unit is 1 m diameter by 2.5 m in length -it starts producing power at approximately 0.6 m/s.

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Figure 76 – Free flow turbine, Gorlov helical turbine

FREE FLOW TURBINE – MILLAU VLH (VERY LOW HEAD TURBINE) -installed capacity 410 kW -commissioned on March 19, 2007 -a DN 4500 (runner diameter 4.5 m). -the 410 kW max nominal power at grid was reached at the nominal speed of 37 rpm -very smooth, vibration-free and silent operation (one must touch the machine to find out whether it is operating)

Figure 77 – Free flow turbine, Millau VLH

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7. References References (RO) 1. Cojocar, Mihai. Hidroconstructia 2005. 2005. 2. Pavel, Dorin. Masini Hidraulice. Bucuresti : Editura Energetica de stat, 1965. 3. Arbiter Systems. Model 1133A Power Sentinel GPS-Synchronized Power Quality/Revenue Standard Operation Manual. 4. www.elpros.si. UniFusion. ELPROS. [Online] ELPROS. http://www.elpros.si/eng/UF_base.htm. 5. National Instruments. NI cRIO-9022 Operating Instructions and Specifications. 6. Carlo Gavazzi. PQT H Smart Modular Network Power Quality Transducer - Instruction Manual. 7. Boyle, Godfrey. Renewable Energy - Power for a Sustainable Future. s.l. : Oxford University Press. 8. Silviu, Folea. LabVIEW - Practical Applications and Solutions. s.l. : InTech, Croatia, 2011. 9. Alexandru Fransua, Razvan Magureanu. Electrical machines and Drive Systems. s.l. : Technical Press, Oxford, UK, 1984. 10. Aquatic Renewable Energy Technologies – AQUARET, Leonardo da Vinci, Project No: IRL/06/B/F/PP153111, 2006, www.aquaret.com.

11. Websites: www.vlh-turbine.com, www.swanturbines.co.uk, www.uekus.com, www.verdantpower.com, www.gcktechnology.com, en.wikipedia.org

References (MOLD) Monographs: 1. I. Bostan, V. Dulgheru, I. Sobor, V. Bostan, A. Sochirean. Renewable energy conversion systems: / - Ch. : Tehnica-Info, 2007. – 592pp. 2. Bostan, V. Dulgheru, V. Bostan, R. Ciupercă. Anthology of inventions: renewable energy conversion systems: / - Ch.: Bons Offices SRL, 2009. – 458pp. 3. Jula A., Mogan Gh., Bostan I., Dulgheru V. et al. ECOMECA – ECO- mechanical engineering. Braşov, Publ. House of „Transilvania” University, Braşov, p.324. 4. BOSTAN, I.; GHEORGHE, A.; DULGHERU, V.; BOSTAN, V.; SOCHIREANU, A.; DICUSARĂ, I. Conversion of Renewable Kinetic Energy of Water: synthesis, Theoretical Modeling, and Experimental Evaluation. Energy Security: International and Local Issues, Theoretical Perspectives, and Critical Energy Infrastructures (NATO Science for Peace and Security Series - C: Environmental Security). 2011. Published by Springer, p. 125-177. ISBN 978-94-007-0718-4 Article: 5. Bostan I., Dulgheru V., Sobor I., Bostan V., Sochirean A. Valorisation of renewable energy // ENERG VI: Energy, Environment, Economy, Resources, Globalization. Publ. AGIR, Bucureşti. P. 152-205. ISBN 978973-720-263-5. 6. Bostan I., Bostan V., Dulgheru V. Microhidro stations / Seminar addressed to hydropower stakeholders in Moldova - SEE HYDROPOWER - clear water, clean energy (SEE - South East Europe) 24.03.2010. 7. Dulgheru V. Utilisation of renewable energy sources - wind, solar and hydro in the Republic of Moldova. Meridian Ingineresc, nr. 3, 2009. P. 63-69. 8. Bostan I., Dulgheru V. Renewable energy conversion systems – one of basic element for sustenable st development of society. // Pro-Active Partnership in Creativity for the Next Generation. Proceedings: 32 ARA Congress. - Sibiu, 2009. - P. 78-82. 75

Patents: 9. PATENT 2981 (MD), CIB B 63 B 35/44; E 02 B 17/00. Hydraulic station / I. BOSTAN, V. Dulgheru, V. Bostan. R. Ciupercă. Publ. BOPI – 2006. - Nr. 2. 10. PATENT 2991 (MD), CIB F03 B 7/00. Hydroelectric station / I. BOSTAN, V. Dulgheru, V. Bostan, O. Ciobanu, A. Sochireanu. Publ. BOPI – 2006. - Nr. 2. 11. PATENT 2992 (MD), CIB F 03 B 7/00. Hydraulic station / I. BOSTAN, V. Dulgheru, A. Sochireanu, V. Bostan, O. Ciobanu, R. Ciobanu. Publ. BOPI – 2006. - Nr. 2. 12. PATENT 2993 (MD), CIB F 03 B 7/00; F 03 B 13/00. Hydraulic turbine / I. BOSTAN, V. Dulgheru, V. Bostan, A. Sochireanu, N. Trifan. Publ. BOPI – 2006. - Nr. 2. 13. PATENT 3104 (MD), CIB F 03 B 7/00: F 16 H 1/00. Hydraulic station / I. BOSTAN, V. Dulgheru, V. Bostan, A. Sochireanu, O. Ciobanu; R. Ciobanu, I. Dicusară. Publ. BOPI–2006. -Nr. 7. 14. PATENT 3845 (MD), CIB F 03 B 13/00; F 03 B 7/00; F 03 B 13/10; ; F 03 B 13/22; ; F 03 B 17/06. Hydraulic station / I. BOSTAN, V. Dulgeru, V. Bostan, A. Sochireanu, O. Ciobanu, R. Ciobanu. Publ. BOPI – 2009. - Nr. 2. 15. PATENT 3846 (MD), CIB F 03 B 13/00; F 03 B 7/00; F 03 B 13/18; ; F 03 B 13/22; ; F 03 B 17/06. Hydraulic station with horizontal axle / I. BOSTAN, A. Gheorghe, V. Dulgheru, V. Bostan, A. Sochireanu, O. Ciobanu, R. Ciobanu. Publ. BOPI – 2009. - Nr. 2. Presentation on the International Salon of Research and Innovations 16. Bostan Ion, Dulgheru Valeriu, Sobor Ion, Bostan Viorel, Sochireanu Anatol, Crudu Radu, Guţu Marin, Ciobanu Oleg, Ciobanu Radu, Trifan Nicolae. Industrial prototype of mini hidropower station for flow water kinetic energy conversion. Salon des Inventions, Geneva,- Palexpo, 6 au 10 avril 2010 (Silver medal). 17. Bostan Ion, Dulgheru Valeriu, Sobor Ion, Bostan Viorel, Sochireanu Anatol, Crudu Radu, Guţu Marin, Ciobanu Oleg, Ciobanu Radu,Trifan Nicolae. Industrial prototype of mini hidropower station for flow water kinetic energy conversion. XIIIth Moskow International Salon of Research and Innovations ARHIMED-2010. 30.03..02.04.2010 (Gold medal). 18. Bostan I. (MD), Dulgheru V. (MD), Bostan V. (MD), Ciobanu O. (MD), Ciobanu R. (MD), Sochireanu A. (MD), Dicusară I. (MD), Trifan N. (MD). Industrial prototype of mini hidropower station for flow water kinetic energy conversion into electrica land mechanical energy. (DIPLOMĂ şi Medalia de aur. Premiul Special al Asociaţiei Inventatorilor din Zagreb). EUROINVENT"-European Exhibition of Creativity and Innovation-Iaşi, România. 07..09.05.2010 (Gold medal). 19. Bostan Ion, Dulgheru Valeriu, Bostan Viorel, Sochireanu Anatol, Ciobanu Oleg, Ciobanu Radu, Dicusară Ion, Trifan Nicolae. Industrial prototype of mini hidropower station for flow water kinetic energy conversion into electrica land mechanical energy. International Salon of Research and Innovations, INVENTICA 2010, XIVth edition, 9- 11 June 2010 (Gold medal). 20. Bostan Ion, Dulgheru Valeriu, Bostan Viorel, Sochireanu Anatol, Ciobanu Oleg, Ciobanu Radu, Dicusară Ion, Trifan Nicolae. Industrial prototype of mini-hydropower station for flow water kinetic energy conversion. EURECA 2009, Bruxel (Gold medal). 21. DIPLOMA. Awarded to: I. Bostan, V. Dulgheru, V. Bostan, A. Sochirean, O. Ciobanu, R. Ciobanu, N. Trifan for the “Floatable micro-hydropower station”. PRIZE ENVIRONMENT PROTECTION. „EUROINVENT’2009” - Iaşi, 9/05/2009. 22. I. Bostan, V. Dulgheru, V. Bostan, A. Sochirean, O. Ciobanu, R. Ciobanu, Nicolae Trifan for the “Floatable micro-hydropower station with adjustable blades”. „EUROINVENT’2009”.- Iaşi, 9/05/2009. (Gold medal). 23. I. Bostan, I. Vişa, V. Dulgheru, V. Bostan, A. Sochireanu, O. Ciobanu, N. Trifan. Micro-hydropower station for the rivers water kinetic energy conversion” // - Cluj-Napoca, 2009 The International Salon of Research and Innovations “PROINVENT’ 2009”. The DIPLOMA of EXCELLENCE and PROINVENT medal. 24. I. Bostan, A.Greorghe, V. Dulgheru, V. Bostan, A. Sochireanu, V. Cartofeanu, O. Ciobanu, R. Ciobanu, I. Dicusară, N. Trifan. Flotable micro-hydropower station with self-oriented hydrodynamic blades” // - ClujNapoca, 2011 The International Salon of Research and Innovations “PROINVENT’ 2011”. The DIPLOMA of EXCELLENCE and (Gold medal).

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Authors Contact Razvan Magureanu (POLI-B) [email protected] Telephone: +40 722228514 Fax: +40 214029342 Sergiu Ambrosi (POLI-B) [email protected] Telephone: +40 721761481 Fax: +40 214029342 Bogdan Popa (POLI-B) e-mail: [email protected] Telephone: +40 214029189 Fax: +40 214029189 Bostan Ion, Dulgheru Valeriu, Bostan Viorel, Sochirean Anatol (MOLD) e-mail:[email protected]

www.seehydropower.eu Project Contact Ing. Maximo Peviani [email protected] Telephone: +39 035 55771 (switchboard)

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