Patent ID: 8166774
Filing Date: 2012-05-01
Classification: F25B,F28D

Abstract:
1. A heat transfer system including a first fluid-air heat exchanger unit ( 3 ) with a first tube element ( 3 a ) and a second tube element ( 3 b ) connected in series with the first tube element ( 3 a ), a main compressor (K) connected to the first tube element ( 3 a ) for compressing a refrigerant supplied to the first tube element ( 3 a ) to system operating pressure and thereby increasing its temperature to an operating temperature at which the refrigerant is supplied to said first tube element ( 3 a ), a compressor-expansion stage unit ( 2 ) arranged between the first and second tube elements ( 3 a , 3 b ) and including a compression stage ( 14 ) connected to the first tube element ( 3 a ) for re-compressing the refrigerant from the first tube element ( 3 a ) in which the refrigerant has been cooled and lost pressure, before the refrigerant re-pressurized and reheated is supplied to the second tube element ( 3 b ), and an expansion stage ( 15 ) connected to the second tube element ( 3 b ) for receiving the refrigerant which has been cooled in the second tube unit ( 3 b ) and decompressing it to a low system pressure while recuperating expansion energy therefrom, the expansion stage ( 15 ) being operatively connected to the compression stage ( 14 ) for transferring the energy recuperated in the expansion stage ( 15 ) to the compression stage ( 14 ) for operating the compression stage and for efficient cooling of the refrigerant, the expansion stage ( 15 ) being connected to a second heat exchanger unit (W 2 ) in which the refrigerant is heated again before being supplied directly, that is without intermediate heat exchanger to the main compressor (K), the compression stage ( 14 ) and the expansion stage ( 15 ) being arranged in a common housing ( 16 ) including a compression stage wheel arrangement ( 14 a , 14 b ) and an expansion stage wheel arrangement ( 15 a , 15 b ) and an insulating separation wall ( 21 ) slidably supported in the housing ( 16 ) between the compression stage wheel arrangement ( 14 a , 14 b ) and the expansion stage wheel arrangement ( 15 a , 15 b ) and in contact with the compressor and expansion stage wheel arrangements ( 14 a , 14 b ; 15 a , 15 b ); wherein the compression stage ( 14 ) and the expansion stage ( 15 ) bare a common shaft ( 17 ) carrying a compression stage wheel ( 14 a ) and an expansion stage wheel ( 15 a ), and one of the compression stage wheel ( 14 a ) and the expansion stage wheel ( 15 a ) is axially slidably supported on the common shaft ( 17 ); and a support element ( 23 ) provided axially in contact with the shaft ( 17 ) and the compressor wheels ( 14 a 14 b ) by a compression spring ( 25 ) disposed between the support element ( 23 ) and the housing lid ( 16 d ) supported in the housing ( 16 ) and biased toward the compression stage wheel ( 14 a , 14 b ).