design, development & testing of francis turbine model

A THESIS ON

“DESIGN, DEVELOPMENT & TESTING OF FRANCIS TURBINE MODEL” A DISSERTATION SUBMITTED TO SARDAR PATEL UNIVERSITY TOWARDS THE PARTIAL FULFILLMENT OF THE AWARD OF THE DEGREE OF MASTER OF ENGINEERING (MECHANICAL MACHINE DESIGN) PREPARED BY:

MALIK N. HAWAS ID. NO. O7ME506 GUIDED BY

PROF. S . R. PANDYA (HEAD OF DEPARTMENT, MECHANICAL ENGINEERING) DEPT. OF MECHANICAL ENGINEERING A.D.Patel Institute of Technology, New V.V. Nagar INSTITUTE OF SCIENCE AND TECHNOLOGY FOR ADVANCED STUDIES AND RESEARCH [OFFERING POST GRADUATE ENGINEERING PROGRAMMES ON BEHALF OF B.V.M. ENGINEERING COLLEGE]

SARDAR PATEL UNIVERSITY VALLBH VIDYANAGAR-388120 YEAR 2008-2009

CERTIFICATE This is certify that the project work presented in this dissertation entitled “DESIGN, DEVELOPMENT & TESTING OF FRANCIS TURBINE MODEL” submitted by Mr. MALIK N. HAWAS, student of ME (Mechanical Machine Design) having ID. NO. O7-ME-506 has been satisfactorily carried out towards the partial fulfillment of the award of the degree of Master of Engineering in (Mechanical Machine Design) of SARDAR PATEL UNIVERSITY. It is to understand that this approval doesn’t necessarily approve any statement made, opinion expressed or conclusions drawn. It is further certified that the presented dissertation has not been submitted elsewhere for the award of any master degree in engineering.

Guide : Prof. S. R. Pandya, Head, Mechanical Engg. Deptt. ADIT College.

Co-Guide: B. A. Doshi, Head, Head Mechatronics Engg., GCET College.

Co-Ordinator: Prof. (Dr.) M. Y. Vaijnapurkar, Head, Mechanical Engg. Deptt. B.V.M. College.

Prof. (Dr.) Shrivastav, Incharge Director, ISTAR College.

Acknowledgement I find no words to express my sense of obligation an gratitude to Prof. G. R. Kaundinya, Director ISTAR & Head of the Department Machine Design, and necessary help for leading me in right way from the selection of the topic to final shaping of this thesis work in the present form for which I shall remain ever grateful and obliged to him. Also my sense of obligation and gratitude to Prof. S . R. Pandya, Head of Department, Mechanical Engg., ADIT College for his kind guidance. I am also thankful to Dr. Anurag Verma, Principal, GCET College and Dr. M. Y. Vaijnapurkar, Head, Mechanical Engg., BVM Engg. College. I am extremely grateful to co-guide Prof. Bipin A. Doshi, Head Mechatronics Engg., GCET College who has shown me the right direction and take interest in my subject when I was passing through the critical time. I want to extend my thanks to Mr. Balvant Hadia, B.E. Mechanical, for his kind support while making this thesis and the staff members of ISTAR College and also to the staff of Mechanical engineering department of GCET, BVM & ADIT colleges. Finally I want to give my thanks to Dr. Majli, Namaa Hawas, Hazim and all my family who have pray for me to complete my project work. Glory to Allah almighty. Thanks

ABSTRACT The project as the name indicates “Design, Development & Testing of Francis Turbine Model” the flow in the runner of modern Francis turbine is not purely radial but a combination of radial and axial. The flow is inward, that is from the periphery towards the centre. The width of the runner and another parts of Francis turbine depends upon the specific speed. In this thesis specific speed selected is 110 r.p.m to design different parts of Francis turbine 1. Runner 2. Draft tube 3. Spiral casing 4.Guide vane. The high specific speed runner is wider than the one which has a low specific speed because the former has to work with a large amount of water. First step in design of the existing performance by selecting the specific speed and materials all parts of Francis turbine to using this materials the low cost and high efficiency against cavitation a curried in runner also design draft tube to protection from cavitation. Size and cost optimization has been carried out by changing operation fluid and material of the existing performance respectively. We have compared the results of designed Francis turbine existing turbine with results of performance during testing in model size 100mm type 150 during change guide vane (full opening and change opening % ). The application of variable opening of guide vane for fluid and its improvement in performance are with further scope in different aspect of design material and operating fluid. In this thesis we have compared the result design a parts of Francis turbine 3.75 kW compared this result in computer program c++ and drawing figure or graph in Auto CAD. Testing of Francis turbine give the engineer an efficient simple and reliable mechanical means of controlling the efficiency in during working improve out put the means decrease losses in the model Francis turbine.

CONTENT Front Page Certificate Acknowledgement Abstract 1

2

3

Introduction & Theory of Turbine 1.1 Introduction 1.2 Turbo Machines 1.2.1 Types of Water wheels 1.2.2. Reaction water wheel 1.3 Theory of Turbine 1.4 Different type of Francis turbines 1.5 Major components of Modern Francis turbine 1.6 Material selection 1.7 Problem of Cavitation 1.8 Specific speed 1.9 Classification of Hydraulic Turbines 1.10 Definition of Various terms Basic Concepts of Water Francis Turbine 2.1 Introduction 2.2 Theory of turbine 2.3 Classification of Reaction Turbine 2.4 Main components of Radial Flow Reaction Turbine 2.5 Advantages & Disadvantage so Hydroelectric Power plants 2.5.1 Advantages 2.5.2 Disadvantages 2.6 Theory of Francis Water Turbine 2.7 Cavitation Problem in Water turbine 2.7.1 Cavitation Factor 2.8 Hydroelectric Power Plant Technology 2.9 Stages of Velocity triangles 2.10 Design conditions 2.11 General Layout of Hydro-electric Power Plant 2.12 Radial Flow Reaction Turbine 2.12.1 Main parts of Radial flow reaction turbine 2.12.2 Inward radial flow turbine 2.13 Velocity Triangles and work done by water on turbine 2.14 Cost Design & Performance improvement of Francis Turbine 3.1 Modern Francis Turbine 3.2 Different types of Francis turbine

1 1 1 2 2 4 5 6 7 9 9 10 10 12 12 12 12 13 17 17 18 18 20 21 23 25 26 26 27 27 28 29 31 32 32 33

3.3

4

5

Francis Runner 3.3.1 Material of runner 3.4 HCF Loading 3.5 Main components of Modern Francis turbine 3.6 Different types of Draft tubes 3.7 Design of components of Francis turbine 3.7.1 Spiral Casing 3.7.2 Guide Vanes 3.7.3 Francis Runner 3.8 Shape of Francis runner and Evolution of Kaplan runner 3.9 Theory of Draft tube 3.10 Cavitation Performance Improvement & cost optimization by Proper Material Selection 4.1 Method to Avoid Cavitation 4.1.1 Installation of Turbine below tail race 4.1.2 Cavitation-Free runner of Reaction turbine 4.1.3 Use of different materials 4.1.4 Use of machining 4.2 Selection of Speed 4.2.1 Runaway speed 4.3 The Design of a structural element, specified by three things Hydraulic Design of Francis Turbine 5.1 Objective 5.2 Hydraulic Investigation 5.2.1 Runner design 5.2.2 Shape of the Turbine Space 5.3 Flow Without Extraction of Energy 5.4 Position of the Inlet & Outlet Edges of Blade; Increase In Meridional velocities Due to Thickness of the Blade. 5.5 Representation of the Blade Cross Section on Flow Surfaces 5.6 General Hydraulic Design of the Runner of the Francis Turbine 5.7 Actual Design & Construction of Francis Turbine 5.8 Design of Runner & Shaft 5.8.1 Runners with steel plate blades cast in to the disc and rim of the runner 5.8.2 Runners With Blades 5.8.3 Further Construction Common to Both Manufacturing Methods 5.8.4 Shaft 5.9 Cavitation and Material of Runner 5.10 Recalculation of Cavitation Coefficient

34 35 35 36 39 40 40 41 43 44 47 49 52 52 52 52 53 53 53 53 54 67 67 67 67 76 82 84 86 87 89 90 90 94 96 100 101 104

5.11 Sealing of Runner Gaps 5.12 Specific Speed Determined by Design Data 6 Mathematical Calculation of Different Components of Francis Turbine 6.1 Design Inputs 6.2 Runner 6.3 Draft Tube 6.4 Design Guide Vane 6.5 Spiral Casing 7 Performance Characteristics of Francis Turbine based on Practical 7.1 Practical Performed for 100% Gate Opening 7.1.1Objectives 7.1.2 Relevance 7.1.3 Apparatus 7.1.4 Technical Specification 7.1.5 Theory 7.1.6 Procedure 7.1.7 Data 7.1.8 Graphs 7.1.9 Exercise 7.1.10 Sample calculations 7.1.11 Observation, Result tables and Characteristic curves 7.2 Practical Performed for Different Gate Opening 7.2.1 Aim 7.2.2 Sample Calculation 7.2.3 Input Data and result tables for Different Gate openings and its Characteristic curves 7.2.4 Conclusion 8 Conclusion 9 Scope for the Future Work References Appendix - A Appendix - B

105 107 110 110 110 116 118 122 127 127 127 127 127 127 128 128 128 128 128 129 130 133 133 133 135 139 145 147 148 150 157

LIST OF TABLES 1.1 1.2 2.1 2.2 2.3 3.1 3.2 3.3 4.1 5.1 7.1 7.2 7.3 7.4 7.5 7.6 7.7

Materials used for different components Type of specific speed in turbines Relation between impulse & reaction turbine The value of σc Advantage and disadvantage of the hydraulic power plant Practical Data fore 𝐾𝑣𝑖 Practical values for 𝑍𝑜 versus 𝐷𝑜 Vapour Pressure Function of temperature Runaway speed (Nr) in terms of working speed (N) Containing data from pertinent literature Observation table -1 Observation table – 2 Computation table -1 Computation table – 2 Observation for different openings (25%,50%,75%) Computation Table for different openings (25%,50%,75%) – 1 Computation table for different openings (25%,50%,75%) - 2

8 10 14 21 22 41 43 48 54 101 130 130 131 131 135 136 137

LIST OF FIGURES 1.1 1.2 1.3 1.4 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.1 4.2 4.3 4.4

Reaction water turbine The heads of different turbines Outlines of Francis turbine Cavitations main of components of radial flow reaction turbine Inlet and outlet velocity diagrams for Francis turbine A schematic of a Francis water turbine velocity diagram for a Francis turbine The pump-fed power station Connection turbine and generator by control Explained in this chart power production The relation between Flow and head General layout of hydro-electric power plant Main parts of radial reaction turbines Inward radial flow turbine Explained in this chart power production Francis turbine a schematically and notation Outlines of a Francis Turbine Vertical Closed Type Open Flume vertical Francis turbine Layout (a)Traditional runner, (b) X Blade runner Discharge ring “self- venting” runner device (a). left Guide vane, (b). right regulation of Guide vanes Francis turbine runner Installation of Draft tube without loss of head (a) straight Divergent (b)Mouthed Bell Mouthed Draft tube Different types of Draft tube Spiral Casing Guide Vanes and Guide Wheel Construction of Francis Runner Outlines Francis runner with Mechanism for Guide Blade Movement Changes in the Shape of Francis Runner and its Inlet Velocity Triangles with the Variation of Specific Speed Outlet velocity Triangle for all Reaction (Francis as well as Kaplan)Runner Draft tube theory Cavitation factor σ and head H versus specific speed Ns Turbines Efficiency η versus cavitation Factor σ Strength- Density Strength- Density Modulus- Density Modulus- Density

3 5 7 9 13 15 19 20 23 24 24 25 26 28 29 31 32 33 34 35 36 37 37 38 39 40 41 41 43 44 45 46 47 50 51 59 60 61 62

4.5 4.6 4.7 4.8 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 5.10

5.11 5.12 5.13 5.14 5.15 5.16 5.17 5.18 5.19 5.20 5.21 5.22 5.23 5.24 5.25 5.26 5.27 5.28 5.29 6.1 6.2 6.3 6.4 6.5 6.6 6.7

Modulus-Relative Cost Modulus-Relative Cost Strength-Relative Cost Strength-Relative Cost Distribution of the pressure in the streaming liquid Determine the diameter Ds in draft tube Flow surface and inscribe circles The flow surfaces are closer spaced towards Comparing laminar and turbulent flow in pipe Progress of the flow surfaces and rotating space Determine the meridional flow between (A-A, B-B) Illustrates this circumstance The values required for determining the position of the inlet and outlet edge of the blade The determine the values of the inlet and outlet edges of the blade according to the given specific speed we select the specific inlet velocity into the draft tube Cross section of the draft tube The space between guide wheel and the runner The liquid flows through the gap The hub the blade would become meridionally too long The influence of the blade thickness the meridional outlet velocity Data used in design of Francis turbine Data used in design of Francis turbine Runner with steel plate blades Dimensions of the cast-in parts For the dimensions of the cast-in parts Shows such a core box, and the cores made in it The blades and the wetted surfaces of the disc The runner is machined to smooth surface The wheel itself and hub of such a construction Part of the shaft Runner The runner is secured either by a nut Cavitation coefficient Velocity triangles Design of runner Design of runner Design of draft tube Design of guide vane Design of guide vane Design of guide vane Design of casing

63 64 65 66 68 71 71 72 72 73 76 78 79 80

82 82 84 85 86 88 89 91 92 93 93 95 96 97 97 98 98 102 109 114 115 117 119 120 121 124

6.8 6.9 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11

Design of casing Design of casing Graph of Unit speed Vs. Unit discharge Graph of Unit speed Vs Unit power Graph of Unit speed Vs Efficiency Graph of Unit Speed Vs. Unit Power Graph of Unit Speed Vs. Unit Discharge Graph of Unit Speed Vs. Unit Power Francis turbine operating by water from centrifugal pump Francis turbine explained the water inter radial Francis turbine explained the change the guide van by the level Types of draft tube; (a) straight-conical ; (b) bell-mouth; (c) curved Basic dimensions of curved draft tube (a) side view

125 126 131 132 132 138 138 139 141 142 143 144 144

LIST OF SYMBOLS This is a list of common symbols used in this thesis. Specialized used in a subject matter area often attracts fore and post subscripts and superscripts. H – Head (m) Ns – Specific speed R.P.M. B – Width of runner (m) N – Speed in R.P.M. D1 – Diameter of runner (m) ω - Angular velocity (radian/sec) Qmax – Maximum flow-rate of turbine (m3/s) Q1 – Flow-rate under head of 1 meter (m3/s) Qη - Flow-rate at best efficiency (m3/s) 𝑛1′ - Unit speed R.P.M. 𝑄1′ - Unit flow-rate (m3/s) 𝑃1′ - Unit power (kW) R, r – Radius (m) v – Flow Velocity (m/s) z – No. of blades g – Gravitational force (m/s2) γ - Specific weight ρ - Mass Density (kg/m3) n1 – Speed under head of 1 meter R.P.M. L – Length (m) w.p – Water power (kW) B.p – Break power (kW) u – Peripheral or circumferential velocity of water (m/s) Ri – Radius of runner (m) Ra – Radius of spiral casing (m) di – Inlet diameter (m) do – Outlet diameter (m) θ- Angle (degree) Kvm – Coefficient of average velocity Kv1 – Coefficient of velocity Ku0 – Coefficient of peripheral velocity B/D - Ratio T – Torque F – force

k – Ventorineter constant Cd – Coefficient of discharge Cm – Meridional velocity (m/s)

Kcm - Velocity constants β - Blade angle

η - Efficiency (%) ηh – Hydraulic Efficiency (%) ηv – Volumetric Efficiency (%) ηm – Mechanical Efficiency (%) ηo – Overall Efficiency (%) Hth –Theoretic Head (m) Cr – Relative velocity ζ - Slip factor α2 – Absolute velocity at outlet (m/s) C - Absolute velocity (m/s) b3 – Width of volute (m) θ - Include angle (degree) Φt – Tongue angle (degree) Psh – Shaft power (kW) Pm – Motor power (kW) Hi – Inlet head at impeller (m) Ψ - Head coefficient hf – Friction head loss (m) hs – Shock head loss (m) C3 – Volute mean velocity (m/s) Fr – Radial load (kN) Pa – Atmospheric pressure (m of water) Pv – Vapour pressure (m of water) Hs – Total suction head (m of water) Pmech – Mechanical losses Pt – Brake horsepower or net power developed by turbine Ho – Designed head G – Weight and modulus of rigidity Ks – Non – dimensional factor for specific speed Re – Reynolds’ number N1 – Speed reduced to unit head Ph – Hydraulic power (kW) a – area α - Angle between absolute and peripheral velocity; and angular acceleration ν - Kinematic velocity λ - Fraction α, β, γ, φ, Ψ - Angles (in general)