Step 4-H

Two-phase Report

Examine the Mach II Two-phase Report.   The Mach II performs the direct integration of the VdP integral to determine the maximum fluid flux.  The results are shown both numerically and graphically. The Mach II,

takes the user input physical property data for the nozzle at three different points to perform a regression analysis to generate pseudo-equations of state for the specific volume of vapor, the liquid and vapor viscosities, and mass fractions as a function of pressure, so that these equations can be integrated over the pressure range to determine the mass flux(G), as the fluid expands and/or flashes as it moves through the relief nozzle.  The fluid will expand and /or flash building momentum and velocity until it reaches a maximum at sonic(choke) conditions or it reaches the end of the pipe or nozzle.  At this point the fluid has reached its maximum fluid flux, (Gmax).  The user can see both numerically and graphically how the fluid flux and velocity will continue to increase to a maximum at a point of discontinuity as seen on the graph (undefined), which occurs at the choke.  This sets the basis for the two-phase relief design.  The required orifice size can then be simply calculated as Areq. = Wtp/Gmax.   The inlet and outlet piping design is determined based on the nozzle flow.  The inlet / outlet pipe, can only see the flow that is limited by the relief nozzle.  Go to the "Report Inlet / Outlet  Piping", to view these results.

Pressure at choke                                                                                219.6 psia

specific volume at choke                                                                   0.05721  ft3/lb

Mass flux at choke(Gmax)                                                                 49,670.9   lbs/in2 -hr

Download two-phase Report