氨作为制冷剂使用已有一百多年的历史,因而有丰富的实践经验,目前仍大量地应用于往复式或螺杆式压缩机的重工业装置中,它已显示出的主要优点是低分子重量和高蒸发热焓,另外的一些优点至今还没完全开拓,这应归于它常被人们所夸大了的毒性和易燃性。而实际上,合理的设计能够容易地控制这些毒性和易燃性。最先的实用型制冷机建造于上世纪中页,它所使用的工质是乙醚,但它只适用于很低的压力和很低的易燃极限值,所以作为制冷剂是不太合适的。无水氨在1867年引入 Ammonia has been used for more than 100 years as a refrigerant and has a wealth of practical experience and is still used extensively in heavy industrial plants for reciprocating or screw compressors. The main advantage it has shown is its low molecular weight And high enthalpy of evaporation, a number of additional advantages have not yet been completely exploited, due to the toxicity and flammability that it has often been overstated. In fact, reasonable design can easily control these toxicities and flammability. The first practical refrigerator was built in the middle of last century and it uses diethyl ether as its working medium. However, it is only suitable for very low pressures and low flammability limits, so it is not suitable as a refrigerant . Anhydrous ammonia was introduced in 1867