COLD AIR REFRIGERATING MACHINES WITH MECHANICAL, THERMAL AND MATERIAL REGENERATION
The cold air refrigerating machines are practically of the same age as the vaporisation-
compression-type refrigerating machines, however, the former ones were put in actual 
operation only during the past decades. As the principal reason for it, their lower economi-
cal efficiency can be considered. However, the vaporisation-compression-type refrigerating 
machines cause heavy pollution to the environment (gap of ozone layer problem), there-
fore the interest in the cold air refrigerating machines has been greatly aroused lately. In 
the paper, the operation, theory and application possibilities of the cold air refrigerating 
machines are dealt with, especially considering the air- conditioning of motor vehicles. 
The improvement of the economy of cold air refrigerating machines is especially paid 
great attention in this paper. In addition, the possibilities of applying heat exchangers, 
as well as the cooling process of the operating-medium during compression with the help 
of liquid charge are examined.