Hi, I am a junior process engineer of LNG power plant or off shore.
And nowadays I am calculating some PSVs on the liquid line.
But I don't know the relief temperature values exactly.
I already saw API and ASME, but there is nothing to satisfy my curiosity.
I am going to show you my questions as below;
Fluid: LNG
Set Pressure: 10 barg
Set Temperature: -163'C
Relieving Pressure: 11 barg (10% of Set Pressure, normal case)
and Relieving Temperature: ???
I saw a lot of comment of this problem and they say T1=Tn*(P1/Pn) but I don't understand this formula and another opinion is
relieving temperature will be determined by the relieving pressure cause of the saturated temperature of that pressure.
So in case of above condition, when LNG relief to the air at 11 barg, at that time the saturate temperature will be abt.-80'C.
(Commonly 1atm LNG will be evaporate at -161.8'C, so at 11 barg, evaporation temperature will be -80'C)
then the relieving temperature is -80'C?
I have some calculation sheets of PSV and the fluid is air. At that time the relieving temperature is 0'C. Why?
I am going to black hole when I try to figure it out. Please Help ME.