中文摘要：

节能是解决我国能源问题的关键，针对制冷行业，提高制冷循环的效率便是关键。采用膨胀机代替节流阀是其中一种有效方式。本文针对大中型制冷与热泵系统，设计了R22双转子单级膨胀机；对膨胀机进行了多工况仿真计算；最后介绍了膨胀机的相关试验。对于大中型制冷与热泵系统而言，采用膨胀机代替节流阀可逐步走向实用，在膨胀机得到广泛应用的情况下回收的膨胀功可以作为分布式能源系统下的分散能源来使用。

英文摘要：

Energy conservation is the key solution to solve the energy status of China. For the refrigeration industry, improve the system efficiency of refrigeration cycle is the key. One effective way is to use an expander to replace a throttle valve. In this paper, a R22 two rolling piston one stage expander is designed to use in the large and medium-sized refrigeration and heat pump systems. Then the simulation and test of the designed expander is introduced. For the large and medium-sized refrigeration and heat pump systems, to use an expander to replace a throttle valve could be gradually practical, and the recovered expansion work can be served as a decentralize energy under distributed energy systems.