3 replies to this topic

[raman123]

Hello,

 

I am a junior engineer and am doing some blowdown and depressurization calculations. I am a bit confused regarding initial conditions for fire case blowdown. I assume that pressure should be the design pressure. Should we take the corresponding temperature from ideal gas law for initial temperature. The vessel is gas filled only. What should be assumption of starting temperature. 

 

RS

[fallah]

RS,

 

The depressurization in case of fire starts at the temperature reached by the system due to the fire heat input which is calculated by relevant simulator while performing the simulation.

[runsaep]

What reflections have the members of cold blowdown of an oil/gas 1.st Stg separator with starting temperature minimum ambient of - 7 deg C , what important  issues do you have to be aware of ? Amongst others, fluid temperatures, wall temperature ?

[runsaep]

A blowdown simulator uses PSV nozzle API 521 equations for the orifice. Is the calculation of minimum temperature inside vessel (gas/liquid/wall) more conservative with nozzle equation than with "pure" orifice equations ? Can you share your thoughts of that ?