MULTI-COMPONENT GAS MIXTURES FOR EFFECTIVE COMPRESSOR AND THROTTLING SYSTEMS OF COOLING AT LEVEL OF 65-90 K

Abstract

For a long time the works for creation of compressor and throttling systems of cooling (CTSC) for temperatures of 75-90 K with usage of multi-component gas mixtures have been carried out by SR&DB of ILTPh&E of NASU. For supplying of their durable, reliable and autonomous operation in systems were used the compressors without fluid lubrication of compression cavities. It has allowed to achieve the stable work of throttling unit at cryogenic temperatures and improvement the characteristics of heat-exchange equipments. There has been developed a series of two- and three- step hermetical compressors with clearance- type sealing of pistons which have shown outstanding power characteristics in parrallel with up to 10 thousand and more hours of active work lifetime. With employment of such the compressors and specifically selected multi-component gas mixtures in a simple one- flow throttling cycle, there has been obtained such level of cooling temperatures as 73K and even 65 K. For this class machines of comparatively low refrigerating capacity, i.e., 40–100 W in 80–85 K range of temperatures, specific losses of energy make up only 20–30 W/W. Some results of computational and experimental researches of multi-component gas mixtures for CTSC are given in the present article. By an example of gas mixture for cryostatting temperatures at 80–82 K is demonstrated the influencing of separate parameters of cycle on a system effectiveness. The formation of a two- phase liquid in evaporation heat- exchanger provides the stability of cryostatting temperature, whereby partial liquefaction of gas mixture prior to inlet of counter- flow heat- exchanger, provides high refrigerating capacity of the system.