Abstract: In the conventional mono-component refrigeration with propylene，ethylene or methane and the latest multi-component mixed refrigeration of ethylene plants，the superheated extent of returning refrigerant vapor to be compressed varied from null or a big value to am appropriate degree are discussed. The restrictions between superheated extent and its implementing elements，such as the type of heat exchanger used，the temperature control of outlet vapor and the addition intermediate cooler of refrigerant compressor are presented. Its influences on the introduction of inter-stage suction drums，the optimized design of liquid quench line and liquid drain system are analyzed further.

摘要： 介绍了乙烯装置上传统的丙烯、乙烯和甲烷单组分制冷以及近年出现的混合制冷中，返回压缩的气相冷剂过热度设定情况。评述了它们跟所使用换热设备的型号、出口温度的控制方式与中间冷却器的设置等实施要素的相互制约关系；并就过热度对段间吸入罐的引入、淬冷线和排液系统的优化设计方面的影响进行了分析。