1 / 35

Design Analysis of Parts of Francis Turbine

Design Analysis of Parts of Francis Turbine. P M V Subbarao Professor Mechanical Engineering Department. Provision of Features to Blend some Reaction into Impulse…. Spiral Casing. Spiral Casing : The fluid enters from the penstock to a spiral casing which completely surrounds the runner.

kwelch
Download Presentation

Design Analysis of Parts of Francis Turbine

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Design Analysis of Parts of Francis Turbine P M V Subbarao Professor Mechanical Engineering Department Provision of Features to Blend some Reaction into Impulse…

  2. Spiral Casing • Spiral Casing : The fluid enters from the penstock to a spiral casing which completely surrounds the runner. • This casing is known as scroll casing or volute. • The cross-sectional area of this casing decreases uniformly along the circumference to keep the fluid velocity constant in magnitude along its path towards the stay vane/guide vane.

  3. Design of Spiral Casing dpenstock Rcasing Q Risv How to select Q ?

  4. Spiral Casing for 35 MW Vertical Francis Turbine

  5. Design of Spiral Casing dpenstock Rcasing Q Risv Select a suitable value of discharge per unit: Q But maximum allowable value is 10 m/s Maximum allowable head loss in Penstock =2 to 4% of available head

  6. At any angle q, the radius of casing is: A full spiral is generally recommended for high head 300m, semi-spiral is recommended for low head < 50m. In general k =1.0, however corrected using CFD.

  7. Flow Distribution Analysis of Casing Stay vanes or Guide vanes

  8. Static Pressure Distribution in Casing.

  9. Mega Civil Works for Mechanical Power Generation

  10. Parts of A Francis Turbine

  11. Geometrical Description of A Francis Turbine Parts

  12. Stay Vanes & Guide Vanes • The basic Purpose of the stay vanes & guide vanes is to convert a part of pressure energy of the fluid at its entrance to the kinetic energy and then to direct the fluid on to the runner blades at the angle appropriate to the design. • Moreover, the guide vanes are pivoted and can be turned by a suitable governing mechanism to regulate the flow while the load changes. • The guide vanes are also known as wicket gates. • The guide vanes impart a tangential velocity and hence an angular momentum to the water before its entry to the runner. • The guide vanes are constructed using an optimal aerofoil shape, in order to optimize off-design performance.

  13. Design of Guide Wheel (Stator): Low Specific Speed

  14. Design of Guide Wheel (Stator): High Specific Speed

  15. Design of the Guide VanesDiameter of guide vane shaft D1 D2

  16. Bgi Bsi rinlet Guide Vane rinlet Stay Vane Design of the Details of Stay & Guide Vane Wheels Theory of Relatively free Whirling flow: • The inlet angle can be calculated by assuming a free vortex from the flow coming from the spiral casing

  17. Pressure drop versus Flow Rate Pressure drop versus discharge

  18. Global Symmetric Flow Domain through Statinary Vanes

  19. Operational Configurations of Guide Vanes

  20. The correlation between the turbinedischarge and the guide vane opening angle.

  21. Pressure drop versus guide vane angle

  22. Design of the Guide Vanes How to choose the guide vane maximum angle a0 at full load ? ao

  23. Design of the Guide VanesLevel of Overlapping of the guide vanes

  24. Design of Guide Vanes . L: length of vane L=15 to 30% of Dgo

  25. Runner inlet (Φ0.870m) Guide vane outlet for designα) (Φ0.913m) Closed Position Max. Opening Position

  26. Bg0 rri Dg0 Design of the Guide Vane Outlet Angle • The outlet angle can be calculated by assuming a free vortex from the flow in the gap between the runner and the guide vanes

  27. Design of the Guide VanesHow to choose the number of vanes • The number of guide vanes has to be different from the number of runner vanes.

  28. Water particle Water from spiral casing

  29. Number of guide vanes

  30. Number of Guide Vanes

  31. The Runner

  32. Mean Velocity triangles Across Runner

  33. Velocity triangles rri Uri Vwi bi ai Vfi Vri Vai rre Ure Vwe be ae Vfe Vre Vae

  34. The transposition of the profiles for all the 11 streamlines

  35. Vwi Vri Vfi Vai Vwi Vri Ub Vai Vfi Ub Vwi Ub Vfi Vri Vai

More Related