Ammonia refrigerating unit, working fluid composition to be used in said unit, and lubrication of ammonia compressor

摘要

A refrigerator working fluid composition comprising an ammonia refrigerant and a lubricating oil which has a remarkably good compatibility therewith, and a method of lubricating a refrigerating unit suitable when the above composition is used. The composition comprises a mixture of ammonia with one or more polyether compounds represented by the general formula (I): R1-[-O-(PO)m-(EO)n-R2]x wherein R1 represents C1-C6 hydrocarbon group; R2 represents C1-C6 alkyl; PO represents oxypropylene; EO represents oxyethylene; x represents an integer of 1 to 40; m represents a positive integer; and n represents 0 or a positive integer. The refrigerating unit comprises circulating the above composition in a circulatory cycle and constituting a refrigeration or heat pump cycle. The method of lubricating an ammonia refrigerant compressor comprises the use of a lubricating oil comprising one or more ether compounds of general formula (I).