Specific fluid property changes on the refrigerant side of the cryogenic tank
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Our company uses a mixed refrigerant process; the main refrigerants are C1-C5 and nitrogen. These refrigerants re-enter the cold box at its bottom through shut-off valves. What physical changes occur to these five types of refrigerants as they pass through the shut-off valves?
First, you need to check whether all five types of refrigerants pass through the throttle valve; in some cases, only the light components go through it, while the heavy components bypass the throttle valve and are sent directly to the phase change area. You should consult the detailed piping diagram of the cryogenic tank. The main change is an isenthalpic cooling process in which the substance changes from gas to liquid before the valve, while after the valve it undergoes an isobaric expansion process that absorbs heat, leading to cooling and vaporization; the overall relationship corresponds to the refrigeration process depicted on a pressure-enthalpy diagram.