Dempster, William and Elmayyah, Wael (2012) Two-phase discharge flow prediction in safety valves. In: 13th International Conference on Pressure Vessel Technology, 2012-05-20 - 2012-05-23, London.
Dempster_WM_Pure_Two_phase_discharge_flow_prediction_in_safety_valves_May_2012.pdf - Draft Version
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Safety Relief Valves (SRV) are necessary elements in the protection of any pressurised system and the prediction of the expected discharge flows is an important consideration for the valve sizing to ensure that rupture pressures do not occur. The high speed flows that occur inside the SRV are complex particularly when a two-phase flow is involved and lead to a less capable protection device which result in larger valves compared to single phase flows. In this paper the ability of a CFD based two phase mixture model to predict the critical flows of air and water through a safety valve is examined. An industrial refrigeration safety relief valve of ¼” inlet bore size has been tested experimentally over a pressure range of 6-15 barg and air mass qualities from 0.1-1 when discharging to near atmospheric conditions for a fully open condition. A two-dimensional mixture model consisting of mixture mass, momentum, and energy equations, combined with a liquid mass equation and the standard k- ε turbulence model for mixture turbulent transport has been used to predict the two phase flows through the valve. The mixture model results have been compared with the Homogenous Equilibrium Model (HEM) commonly used for in valve sizing in non flashing two phase flow conditions. The accuracy of the models over the two phase flow range are quantified and discussed.
|Item type:||Conference or Workshop Item (Paper)|
|Keywords:||safety relief valves, two phase discharge, prediction, CFD, Mechanical engineering and machinery, Mechanical Engineering, Mechanics of Materials, Fluid Flow and Transfer Processes, Modelling and Simulation|
|Subjects:||Technology > Mechanical engineering and machinery|
|Department:||Faculty of Engineering > Mechanical and Aerospace Engineering|
|Depositing user:||Pure Administrator|
|Date Deposited:||05 Dec 2012 10:11|
|Last modified:||11 Dec 2015 18:10|
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