Numerical Simulation of a Counter Rotating Micro-Turbine
Cécile Münch-Alligné Sylvain Richard
Bastien Meier
Vlad Hasmatuchi
François Avellan
Institut Systèmes industriels
Small Hydro in Switzerland P < 10 MW 1’400 small scale hydro power plants 860 MW installed power 3’800 GWh / year
5 % of the electricity production Potential : increasing the production
of 2010 by 40-50% by 2050
Introduction
Case Study
Numerical Setup
Results
Conclusions
2
Institut Systèmes industriels
Objective Recover the energy lost in release valves of water supply network
Water Reservoir
Industrial installation Garage, Garden Bathroom plumbing
Micro-turbine
LMH
Release valve
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
3
Institut Systèmes industriels
Case Study Counter-rotating micro-turbine Concept
LMH
Component
Value
Shroud radius
50 mm
Hub radius
40 mm
Number of blades : runner A
5
Number of blades : runner B
7
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
4
Institut Systèmes industriels
Case Study Counter-rotating micro-turbine Exemple
LMH
Discharge
8.7 l/s
Pressure drop
2 bars
Hydraulic power
1.7 kW
Efficiency
> 0.85
Mechanical power
1.45 kW
Nominal speed
3’000 rpm
Turbine specific speed
0.313
Runner specific speed
0.526
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
5
Institut Systèmes industriels
Numerical Simulation Setup RANS simulations Ansys CFX 13.0 Scheme: 2nd order in space SST turbulence model
Computational domains
LMH
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
6
Institut Systèmes industriels
Numerical Simulation Setup Spatial discretization
Case
Number of nodes
In-line turbine
3.2 M
Turbine with elbows and shafts
4.5 M
Turbine with honeycomb, elbows and shafts.
4.2 M
LMH
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
7
Institut Systèmes industriels
Numerical Simulation Setup Boundary conditions Inlet : constant discharge Outlet : uniform pressure Solid walls : no-slip condition Stator-rotor interface : stage condition Rotor-rotor interface : frozen condition
LMH
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
8
Institut Systèmes industriels
Influence of the Computational Domain a)
c)
b)
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Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
9
Institut Systèmes industriels
Influence of the Computational Domain Q 8.7 l s-1
A B 314.16 rad s-1
Losses in Losses Elbows in Honeycomb
LMH
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
10
Institut Systèmes industriels
Performances
B.E.P
Q
Rs 3 Rs 2 Rh 2
2E 2R 2 P mec Phyd
BEP :
=88% for =0.235, =2.38 expected BEP : for =0.196, =1.59 BEP : Q 10.42 l s-1, H 29.9 m P 2.65 kW
LMH
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
11
Institut Systèmes industriels
Influence of the Relative Rotational Speed Regulation of the turbine in case of discharge variation: B A
1.2 0.8
LMH
f ,
BEP
Laboratory for Hydraulic Machines
Introduction
Case Study
Numerical Setup
Results
Conclusions
12
Institut Systèmes industriels
Unsteady simulations
Introduction
Case Study
Numerical Setup
Results
Conclusions
13
Institut Systèmes industriels
Conclusions New axial turbine to recover energy lost in release valves Multi-stages Two counter rotating runners per stage Medium head
Development using numerical simulations Efficiency : 88 % for BEP operating conditions Regulation using the ratio between the two rotational speeds Introduction
Case Study
Numerical Setup
Results
Conclusions
14
Institut Systèmes industriels
Outlooks Comparison with experiments Test rig with elbow and external generator at EPFL Laboratory Test rig in axial configuration at HES SO Valais
Introduction
Case Study
Numerical Setup
Results
Conclusions
15
Thank You !
LMH
Laboratory for Hydraulic Machines
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