TURBINE PERFORMANCE CURVES

This presentation deals with CONSTANT HEAD,CONSTANT SPEED,CONSTANT EFFICIENCY & CAVITATION in hydraulic turbines

1. Performance curves for turbines

2. Why?? Or Need?? Turbines are designed for specific conditions of Power , speed ,discharge called as designed conditions But most of time of working turbines are required operated at conditions other than designed conditions Performance curves are important in order to study performance of turbines at such conditions PRATIK ACADEMY,SANGLI 9422378762 2

3. Types of curves Constant Head curves or Main curves Head Maintained Constant Constant speed curves or operating curves Speed Maintain Constant Constant efficiency or isoefficiency curves efficiency maintained constant PRATIK ACADEMY,SANGLI 9422378762 3

4. Constant Head Curves Procedure For obtaining these curves test is carried out with changing only load on turbine in steps & corresponding Power, speed, discharge are measured for a particular gate (or spear rod) opening Repeating the same procedure for different gate opening values After test ,Results are plotted in terms of following 3 graphs Unit discharge Vs Unit speed Unit Power Vs Unit speed Efficiency Vs Unit speed PRATIK ACADEMY,SANGLI 9422378762 4

5. Constant Head curve–For Pelton Wheel PRATIK ACADEMY,SANGLI 9422378762 5

6. Constant Head curve–For Pelton Wheel PRATIK ACADEMY,SANGLI 9422378762 6

7. Constant Head curve–For Pelton Wheel PRATIK ACADEMY, SANGLI 9422378762 7

8. Constant head curves for REACTION TURBINES PRATIK ACADEMY,SANGLI 9422378762 8

9. Constant head curves for Reaction Turbines PRATIK ACADEMY,SANGLI 9422378762 9

10. Constant Speed Curves Procedure This test is carried out maintaining speed constant ( by increasing discharge ) while increasing load in steps After test ,Results are plotted in terms of following 3 graphs Efficiency Vs Discharge Power Vs Discharge Efficiency Vs part load conditions PRATIK ACADEMY,SANGLI 9422378762 10

11. Constant Speed Curves Discharge to overcome friction PRATIK ACADEMY,SANGLI 9422378762 11

12. Constant Speed Curves PRATIK ACADEMY,SANGLI 9422378762 12

13. Efficiency Vs % of Load As % of load increases efficiency also increases At full load conditions efficiency is maximum for almost all turbines KAPLAN ,PELTON maintains high efficiency over large load range Francis and propeller turbines give poor performance at part load conditions PRATIK ACADEMY,SANGLI 9422378762 13

14. ISO-Efficiency Curves These curves are obtained from speed Vs efficiency & Speed Vs Discharge These curves gives zones of constant efficiency and predicting performance of turbine at various efficiencies PRATIK ACADEMY,SANGLI 9422378762 14

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17. PRATIK ACADEMY, SANGLI Dear All , follow below link to find video lecture on “Hydraulic Turbine Performance Curves” https :// www.youtube.com/watch?v=LeQVz0vSBjw&list=PLM38cEkdDRfTXmEB49EiP6WQzCkizLbsx&index=22 Cavitation in Hydraulic Turbines https://www.youtube.com/watch?v=5dqJkkaEotk&list=PLM38cEkdDRfTXmEB49EiP6WQzCkizLbsx&index=23 Please Like and subscribe Our Channel PRATIK ACADEMY,SANGLI 9422378762 17

18. At installation PRATIK ACADEMY,SANGLI 9422378762 18

19. CAVITATION !!! PRATIK ACADEMY,SANGLI 9422378762 19

20. CAVITATION !!! Mean??? Why??? Where??? Effects??? How to avoid?? PRATIK ACADEMY,SANGLI 9422378762 20

21. Formation ,growth and collapse of bubbles of water @ low pressure regions of machine Pressure at section falls below saturation pressure corresponding to given temperature low pressure regions such as turbine outlet and draft tube inlet vibration, noisy operation, hydraulic losses ,erosion of surface controlling discharge pressure ,using high strength materials ,selecting proper speed of turbine PRATIK ACADEMY,SANGLI 9422378762 21