Pressure relief valve

January 12, 2009, 01:37

We are doing some testing on pressure relief valve for pressurized oil. Our test engineer reported the heating of the PRV during operation. I am surprised since there should be cooling during the release of the pressurized oil. As the process is very fast and we assume it is adiabatic it is a case of adiabatic cooling. Isn't it?

Your explanation will help me to understand the process.

Thanks

January 12, 2009, 09:40

I assume the pressurized oil is (almost) incompressible. So there is no real cooling as with a compressible gas undergoing an adiabatic expansion. When the oil contains dissolved gas which is released during depressurization this will have a slight cooling effect. But when dealing with an incompressible fluid you will get heating due to friction.

January 13, 2009, 01:06

Thanks Bart for the explanation. I will dig into it further.

January 12, 2009, 01:37	Pressure relief valve	#1
carno Guest Posts: n/a	We are doing some testing on pressure relief valve for pressurized oil. Our test engineer reported the heating of the PRV during operation. I am surprised since there should be cooling during the release of the pressurized oil. As the process is very fast and we assume it is adiabatic it is a case of adiabatic cooling. Isn't it? Your explanation will help me to understand the process. Thanks

January 12, 2009, 09:40	Re: Pressure relief valve	#2
Bart Guest Posts: n/a	I assume the pressurized oil is (almost) incompressible. So there is no real cooling as with a compressible gas undergoing an adiabatic expansion. When the oil contains dissolved gas which is released during depressurization this will have a slight cooling effect. But when dealing with an incompressible fluid you will get heating due to friction.

January 13, 2009, 01:06	Re: Pressure relief valve	#3
carno Guest Posts: n/a	Thanks Bart for the explanation. I will dig into it further.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Fluent natural ventilation pressure boundary condition	pierresandre	FLUENT	24	November 8, 2011 15:32
How to simulate valve using pressure BC??	Luk_Fiz	CFX	4	August 16, 2010 19:27
Pressure enigma.	Sara	Main CFD Forum	22	July 30, 2009 05:46
Neumann pressure BC and velocity field	Antech	Main CFD Forum	0	April 25, 2006 03:15
Hydrostatic pressure in 2-phase flow modeling (CFX4.2)	HB &DS	CFX	0	January 9, 2000 14:19