TITLE : HIGH PRESSURE STEAM TURBINE GOVERNING VALVE

BY : E. N. Jal MRAeS (CEng), Senior Engineer.
COMPANY : GEC ALSTHOM, Aerodynamics Group, Large Steam Turbines, Newbold Road, Rugby. Warwickshire. CV21 2NH. ENGLAND.

DETAILS :

• Three-dimensional steady-state compressible viscous flow.
• BFC grid; high-Reynolds Number k-e turbulence model.

NOTES :

• Evaluation of the flow structure within the valve is an important issue for the valve designer. Thus development of a computational model to accurately predict this is a beneficial tool.
• Validation of the model was conducted against flow visualisation and pressure measurements of an experimental 3/4 scale test-rig, at several valve lift openings of 60%, 80% and 100% (fully open).
• Comparison of the mass flow and total pressure loss between the predicted and test measurements are within 1-2% for the 60% and 80% lift cases and within 5-10% for the 100% lift case.

  The pictures (courtesy of GEC ALSTHOM T. G. Ltd.) are as follows:

  1. 3D perspective view of the computational grid geometry. 2. Flow structure at the symmetry plane for the 60% valve lift case. 3. Flow structure at the symmetry plane for the 100% valve lift case. 4. 3D streamlines within the valve for the 60% valve lift case. 5. Pressure distribution along the chest wall (60% lift case). 6. Pressure distribution along the valve head (60% lift case).

  For information about GEC ALSTHOM, Large Steam Turbines, contact :-

  Mr Eric Jal, Senior Engineer, GEC ALSTHOM Turbine Generators Ltd, Aerodynamics Group, Large Steam Turbines, Newbold Road, Rugby. Tel : 01788 - 531774 Warwickshire. CV21 2NH Fax : 01788 - 531309

  GEC ALSTHOM : High Pressure Steam Turbine Governing Valve1
  GEC ALSTHOM : High Pressure Steam Turbine Governing Valve2
  GEC ALSTHOM : High Pressure Steam Turbine Governing Valve3
  GEC ALSTHOM : High Pressure Steam Turbine Governing Valve4
  GEC ALSTHOM : High Pressure Steam Turbine Governing Valve5 Pressure Distribution Along Chest Wall (60% Lift) GEC ALSTHOM : High Pressure Steam Turbine Governing Valve6 Pressure Distribution Along Valve Head (60% Lift)