Patent ID: 6898941

Claim:
A transcritical vapor compression system comprising: a compression device to compress a refrigerant to a high pressure; a heat rejecting heat exchanger for cooling said refrigerant; an expansion machine for reducing said refrigerant to a low pressure and for recovering energy, said refrigerant flowing through said expansion machine at an expansion machine flowrate, and adjustment of said expansion machine flowrate regulating said high pressure in the system; and a heat accepting heat exchanger for evaporating said refrigerant; and a recompression device linked to said expansion machine to recompress a portion of said refrigerant exiting said expansion machine, and said portion of said refrigerant is injected at a high pressure component of the system, wherein said portion of said refrigerant flows through said recompression device at a recompression flowrate, and said recompression flowrate is regulated to control said expansion machine flowrate.