CAD tools to systemize small low - head turbines: an efficient key for SHP development MHyLab (Mini hydraulics Laboratory) Vincent DENIS
Hidroenergia, Crieff, 9th June 2006 03/08/2006
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Procedures to design a small turbine : the standardisation y Subdivision of the range of application of one type of turbine in several sub-ranges. y Design of a limited number of turbines calculated a precise point in the sub-range. y Adaptation of these turbines to the sites to be equipped. y No additional laboratory tests performed. y No possibilities to know the effect of the adaptations. 03/08/2006
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Risks of non tested designs y Guaranteed performances not upheld y Operation under an exaggerated blade-opening to reach the required output y No control on cavitation ÆHydro mechanical troubles ÆMechanical breaks
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Systemisation: principles y Simplification of hydraulic shapes, and use of commercially available parts Æ turbine simple to manufacture + at low cost. y Measure of the impact (efficiency & cavitation) of these simplifications on the test bench. y Parameterisation of all hydraulic shapes, function of the site's data. y Development of mathematical and computer tools to design the turbine specific to the site to equip Æ reduction of the turbine deliverytime. 03/08/2006
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MHyLab's method : systemisation For high-heads turbines, transfer from laboratory to industry validated by more than 30 schemes
Laboratory tests for low head and high-head turbines
1rst step: models tested in our laboratory Last step: CAD tools 03/08/2006
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The SEARCH LHT program y Objectives : To develop, optimise, and test a novel systematic concept of small hydroelectric units that satisfy the criteria of simplicity, performance and reliability for heads between 3 and 30 m and for up to 1 MW power. y Duration : 2001-2006 y Framework : 5th FPRD y Financing : DG TREN, OFES, Partners
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II. Systemisation for low-head turbines and CAD tools Low-head sites: y Often more complicated than high-head ones Constraints: y Cavitation, y Integration to the existing infrastructure y Recovery of kinetic energy in the draft tube y Construction & civil engineering costs in front of the electricity production 03/08/2006
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Procedure developed through the SEARCH LHT programme y Collection of the site's data y Calculation of the main turbine characteristics y Generation of the efficiencies guarantees y Generation of 2 D drawings of the hydraulic profile y Generation of 3 D drawings of the runner blades for CNC manufacturing 03/08/2006
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Excel dimensioning programmes To define the optimal dimensioning point with: y A number of turbines y A number of blades (adjustable or not) y A fixed guide vane opening y A nominal discharge y A rotation speed (synchronous or not) y A runner diameter y A maximal efficiency at a certain discharge y A maximal suction height 03/08/2006
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phi^ (Hsmax) phi^(De) phi^(N nat)
1.1 phi^(Hs max) 1.1 phi^(De) 1.1 phi^ (N nat)
1.2 phi^ (Hsmax) 1.2 phi^(De) 1.2 phi^ (N nat)
1.3phi^ (Hsmax) 1.3 phi^(De) 1.3 phi^(Nnat)
1.4 phi^(Hsmax) 1.4 phi^(De) 1.4 phi ^(N nat) 700
7.0 6.5 1.4 phi^(Hsmax); 6.4
600
5.5 500
5.0 4.5 4.0
400
1.4 phi ^(N nat); 345
3.5 1.4 phi ^(N nat); 288 300
3.0 2.5
phi^(N nat)
2.0
200
phi^(N nat); 227
1.5
phi^(De); 1.11
phi^(De); 1.02 100
1.0 1.4 phi^(De)
1.4 phi^(De); 0.91
0.5
0
0.0 30
32.5
35
37.5
40
42.5
45
47.5
50
Wicket gate opening (째) 03/08/2006
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N, rotation speed (rpm)
maximal suction height, Hs max (m) external runner diameter, De (m)
6.0
Evolution of the guaranteed efficiency vs discharge for a 2.2. m3/s 4.5 m head site 90.0 85.0 80.0 75.0 65.0 maximal discharge
Turbine efficiency Ρ [%]
70.0 60.0 55.0 50.0 45.0
Turbine with adjustable blades
40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0
2.30
2.20
2.10
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0.0
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Discharge Q [m /s] 03/08/2006
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Evolution of the output vs discharge for a 2.2 m3/s 4.5 m head site Maximal installation discharge
100.0 90.0
Mechanical output P [kW]
80.0 70.0 Turbine with adjustable blades
60.0 50.0 40.0 30.0 20.0 10.0
2.30
2.20
2.10
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
0.90
0.80
0.70
0.60
0.50
0.40
0.30
0.20
0.10
0.00
0.0
Discharge Q [m3/s] 03/08/2006
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Other results from the Excel programmes y Evolution of the blade opening regarding the discharge y The torques on the blade trunnion to dimension the control system to adjust the blade position y The turbine behaviour at runaway speed.
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Drawing of the hydraulic profiles: the square-cross section inlet y Base: runner diameter Composed of: y 2 quarters if a standard elbow as lower part y A pipe curved to the required radius as higher part y Guiding blades made of curved standard metal sheets Parameters: y Angle adjustable to the turbine axis y Round-offs radius of the square crosssection 03/08/2006
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Other developed inlets Inlet used for a siphon turbine Inlet used for an open flume turbine
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Drawing of the hydraulic profiles: guide vanes Base: runner diameter Parameters: y Thickness of the vanes from standard metal sheet y Guide vane angle: from 20 to 50째
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Drawing of the hydraulic profiles: the draft tube To recover most of the kinetic energy in the draft tube, speed at the draft tube outlet: < 2 m/s Base: runner diameter & discharge Parameters: y Length of the cone-shaped draft tube y With or without elbow, y Circular or not outlet section 03/08/2006
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Integration of the turbine to an existing site Square-section inlet
Draft tube without elbow
Hn = 4.5 Qmax = 2.2 m3/s Direct integration of the turbine into the existing infrastructure 03/08/2006
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Integration of the turbine to the site (new HPP)
2 open flume turbines Qmax = 3.5 m3/s Important civil works
Draft tube without elbow
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Drawing of the hydraulic profiles: the runner Blade profile defined to reach: y high efficiencies, y wide operation areas without any cavitation problems, y high resistance to torques.
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Drawing of the hydraulic profiles: the blades y 3 D Catia file y Manufactured using CNC Ă&#x2020; Blades strictly similar to the ones tests in laboratory
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First applications of the SEARCH LHT project
Farettes, Switzerland 4 –blades turbine 7.7 m 2.7 m3/s 178 kW 03/08/2006
St-Bueil, France, 8 –blade sturbine 27 m, 1.5 m3/s, 350 kW 22
Conclusions y A new family of low head turbines (3 to 30 m) as been developed within the SEARCH LHT project. y CAD tools developed by MHyLab allows a fast and efficient custom design solution. y Technology available now ! 03/08/2006
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