Pressure Reliefs for Heat Exchanger
Pressure Reliefs for Heat Exchanger
(OP)
I have a shell and tube heat exchanger, designed to handle a glycol solution at 200 Deg. F on the shell side, and water at 190 Deg. F on the tube side. Both flow paths have isolation valves on their inlet and outlet piping, so they could be isolated and thermal expansion of the liquid come into play.
My question is whether a pressure relief valve is required, and if so, what formula to use in its sizing?
Thanks
My question is whether a pressure relief valve is required, and if so, what formula to use in its sizing?
Thanks





RE: Pressure Reliefs for Heat Exchanger
If it is only to be for thermal expansion, the expanded volume (liquid, vapor, or both) must be relieved within the time taken for the temperature rise to occur.
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RE: Pressure Reliefs for Heat Exchanger
Secondly , one could estimate the size of a thermal releif valve as follows:
volumetric capacity, dV/dt =m*{dv/dT},p * dT/dt
where m= mass of liquid initially in tubes at lowest practical temperature
{dv/dT},p = partial derivative of specific volume with respect to temperature at constant pressure- see thermo book
dT/dt= max rate of change of fluid temp due to heat transfer from shell to coldes practical fluid in tubes= q,max/(m*Cp)
RE: Pressure Reliefs for Heat Exchanger
Patricia Lougheed
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RE: Pressure Reliefs for Heat Exchanger