![]() ![]() The liquid level first increases and then drops. The blue line is the wet area and the red line is the fire heat input. ![]() On the vessel strip chart, the black line is the liquid level percentage in the vessel. Let us start the simulator and see what's going to happen.Ĭurrently two strip charts are shown. Suddenly the vessel is exposed to a fire. Initially it is at 34.5 F and 400 psia, with a liquid level of 60%. The vessel is horizontal with a diameter of 5 ft and a length of 20 ft. The PSV orifice size is E with a set pressure of 500 psia. In this example, VMGSim Dynamics is selected to do this demo.Īs you see on the PFD, there is one vessel and one PSV. Latent heat is changing through the reliving periodĪ proper way to size PSV fire case is to use a dynamic process simulator, since the relieving process is dynamic, not steady state. ![]() By the way, the wet area might increase at the beginning Assume constant wet area, which is not true.Common mistakes of 99% engineers are making: The calculation sequence seems easy, but it is actually extremely difficult when you get into the details. You use API 521 to calculate the fire heat input by calculating the wet area, then you get the latent heat from a process simulator, finally you get the reliving mass flow and you follow API 520 to size the PSV area. Are you one of 99% engineers who size PSV fire case the wrong way? Sizing PSV fire case seems extremely easy on the surface. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |