Some issues with calculating safety valves using SW6
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This post was last edited by wingfj on 2018-11-14 at 14:06. Seeking advice on using SW6 to calculate safety valves. 1. Does the medium density under discharge conditions refer to the density at the discharge pressure or at atmospheric pressure? 2. There are 2 feed pipes; should the inner diameter be taken as the larger value, or as the sum of the diameters of the two feed pipes?
I think 1 refers to the density of the medium under pressure release. 2. Considering the most dangerous scenario, it is necessary to take into account the situation where air enters through both intake pipes simultaneously, but the diameter of the two intake pipes is not simply added together.
1. Medium density under pressure relief； 2. The diameter should be obtained by adding the cross-sectional areas of the two diameters and then calculating the overall diameter ； The mass flow rate and flow velocity at the calculated relief pressure of the safety valve.
1. Density under pressure relief: PM = ρRt
1. Discharge conditions refer to the temperature, pressure, and discharge diameter at the time of discharge; obviously, the two main factors relevant here are the first two, as explained in point 4#. 2. The latter two items represent the amount of medium that enters the container per unit of time (for example, in terms of volume), which is essentially the discharge rate of the safety valve. Therefore, whether there are 2 or 3 inlets, the values entered can be average values; theoretically, however, their product should equal the amount of medium received by the container per unit of time (again, in terms of volume). :)
1 Density at vented pressure 2 Pipe diameter calculated based on equivalent cross-sectional area