Encyclopaedia Index
    
TITLE:    VENTILATION IN A GAS TURBINE PLANT - A HAZARD ANALYSIS STUDY
    BY:       P J Phelps & D R Glynn, FLOWSOLVE.  Tel: +44 181 944 0940
    FOR:      IVO GENERATION SERVICES / REGIONAL POWER GENERATORS LTD
   - Hazard analysis study for a gas-turbine power plant.
   
 - Accidental gas release may contact hot surfaces, resulting in an
       explosion.
   
 - Ventilation provided to dilute and disperse hazardous gas releases.
   
 - Safety requirement is that ventilation must keep critical gas
       concentration envelope below a defined size.
   
 - Aim of CFD study is to assist in evaluation of alternative
       ventilation strategies to ensure compliance.
 
     (1)  GEOMETRY
   - The next panel shows the geometry.
   
 - Air enters through the green rectangular regions from the adjoining
       accessory compartment.
   
 - Turbine casing and exhaust box are hot.
   
 - Assumed leak location is shown.
   
 - Model features - 3D steady, cartesian grid, ASAP, buoyancy.
 
GEOMETRY
    
 (2)  VELOCITY VECTORS ON VERTICAL PLANE THROUGH LEAK
     The buoyant plume driven by the hot casing dominates the flow.
VELOCITY VECTORS
    
 (3)  CRITICAL CONCENTRATION CONTOUR ENVELOPE
     The isosurface of gas concentration at 50% of LEL (lower explosive
     limit) is shown, for a given ventilation strategy.
     The volume contained within this envelope is evaluated automatically
     by the model, for comparison with the safety requirement.
CRITICAL CONCENTRATION CONTOUR ENVELOPE
        For further details see the May 1997 issue of Phoenics News.
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