Schematic diagram of the reciprocating pump water station

What are the reasons for the high control temperature of the cylinder cooling water? Is it to avoid medium liquefaction?

I think it’s more reasonable to ask the question in reverse

Due to the high temperature of the cylinders, the required temperature of the cooling water also needs to increase accordingly. Gas liquefaction is not an issue here; it’s mainly done to protect the equipment

Friction between the packing and the piston rod generates heat, and the medium compressed by the compressor leaks into the packing box; both of these factors raise the temperature of the packing box. Cooling water is used to lower this temperature. The packing has certain radial and axial gaps within the packing box, and it is able to provide pressure-reducing sealing in these appropriate gaps. It is essential to ensure that the packing rings operate within a specific temperature range; otherwise, the packing may deform due to excessive heat, the gaps may shrink, or it may stick to the piston rod, resulting in leakage at the packing seal. Based on the compressor performance curve, the efficiency of the compressor is related to the temperature of the gas being compressed. Increasing the number of stages and reducing the temperature of the gas being compressed can effectively improve the compressor’s efficiency; therefore, there is an inter-stage cooler after each stage – its purpose is first to lower the temperature and second to create the conditions necessary for the gas-liquid separator that follows. The piston moves back and forth within the cylinder; friction between the piston rings, the support rings, and the inner wall of the cylinder generates heat. At the same time, the gas molecules under compression also rub against each other, which causes the gas temperature to rise as heat is released. This too constitutes an energy loss for the compressor. To reduce this energy loss and improve compression efficiency, it is necessary to cool the gas, as well as the piston, the piston rings, and the support rings. There must be a certain gap between these components for them to function properly. If the temperature rises, the piston rings and support rings may stick inside their respective grooves, which accelerates their wear and can even lead to gas leakage from the piston, damage to the cylinder, and reduced efficiency in performing work.

The main concern is that the light hydrocarbons in the gas may condense; if liquid slugging occurs in the cylinder, it can damage the equipment