LIQUID SLUGGING IN RECIPROCATING COMPRESSOR

The refrigerant typically enters the compressor in super-heated vapor state, although in some specific operating conditions the refrigerant might enter in liquid state. This usually happens during a defrost cycle or cold compressor start up. In some cases, the liquid refrigerant might be injected deliberately into the compression chamber in order to increase the cooling capacity. However, in most of the cases the liquid state of the refrigerant entering the cylinder increases the risk of a failure due to significant pressure elevation. In order to avoid liquid slugging in reciprocating compressor, the suction flow path must be redesigned. This paper presents a study on two-phase flow of refrigerant applying numerical simulation. The effect of suction muffler design and boundary conditions on slugging are discussed.