In the case of two- phase flow discharge, pressure safety valves (PSV) design becomes difficult due to complex thermal-fluid dynamic phenomena that occur between the two phases. Currently, there are two main types of prediction models, the Homogeneous Equilibrium Model (HEM) and the Homogeneous Non Equilibrium model (HNE), used for developing methods to calculate the theoretical mass flux Gt; this value has to be corrected by an experimental coefficient kd, termed as two-phase "discharge coefficient", for obtaining the actual two phase mass flow-rate value Wr. Generally, for each method a different way of calculating kdis proposed, but various studies are looking for a general correlation that considers all the two-phase flow aspects. This paper will compare some experimental results obtained with a steam-water system and a small PSV (orifice diameter (φor=6 mm) with the predictions of three methods, an HEM, an HNE and a more recent method, called HNE-DS, proposed by the ISO working group on PSV sizing. Copyright © 2010, AIDIC Servizi S.r.l.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)