Patent ID: 8424326

Claim:
A refrigerant vapor compression system comprising: a primary refrigerant circuit including a refrigerant compression device, a refrigerant heat rejection heat exchanger downstream of said compression device, a refrigerant heat absorption heat exchanger downstream of said refrigerant heat rejection heat exchanger, and a primary expansion device disposed in the refrigerant circuit downstream of said refrigerant heat rejection heat exchanger and upstream of said refrigerant heat absorption heat exchanger; a flash tank disposed in the refrigerant circuit downstream of said refrigerant heat rejection heat exchanger and upstream of said primary expansion device, said flash tank defining a separation chamber wherein refrigerant in a liquid state collects in a lower portion of said separation chamber and refrigerant in a vapor state in a portion of said separation chamber above the liquid refrigerant; a secondary expansion device disposed in the refrigerant circuit in operative association with and upstream with of said flash tank; a refrigerant vapor injection line establishing refrigerant flow communication between an upper portion of said separation chamber and an intermediate pressure stage of said compression device and a suction pressure portion of said primary refrigerant circuit; and a refrigerant liquid injection line establishing refrigerant flow communication between a lower portion of said separation chamber and an intermediate pressure stage of said compression device and a suction pressure portion of said primary refrigerant circuit.