一、引言随着科学技术的发展,各种形式的制冷设备进入了千家万户。制冷设备的质量问题已引起人们的关注。制冷机的冷却速度是评价制冷设备性能优劣的重要指标之一。为此,国家颁发了严格的标准(简称国标)。生产厂家如何在实施国标的同时,又兼顾工厂的经济效益,则是一个具有普遍意义的研究课题, I. Introduction With the development of science and technology, various forms of refrigeration equipment have entered every household. The quality of refrigeration equipment has aroused people’s attention. Chiller cooling rate is one of the important indicators to evaluate the performance of refrigeration equipment. To this end, the country issued a strict standard (referred to as the national standard). How to implement the national standard manufacturer, but also take into account the economic benefits of the factory, it is a research topic of general significance,