Patent ID: 8312737

Claim:
A refrigeration system comprising: a compressor; a heat rejection heat exchanger downstream of the compressor along a refrigerant primary flowpath; an expansion device downstream of the heat rejection heat exchanger along the refrigerant primary flowpath; and a heat absorption heat exchanger downstream of the expansion device along the refrigerant primary flowpath; and a single economizer heat exchanger unit between the heat rejection heat exchanger and the expansion device along the refrigerant primary flowpath and comprising: a first portion configured to provide heat transfer from the primary flowpath to a first economizer flowpath; and a second portion configured to provide heat transfer from the primary flowpath to a second economizer flowpath, wherein: the compressor has a first cylinder, a second cylinder, and a third cylinder; the first economizer flowpath branches from the primary flowpath between the economizer heat exchanger and the expansion device and returns to the primary flowpath between the first and second cylinders and extends through: a second expansion device; and the economizer first portion; and the second economizer flowpath branches from the primary flowpath between the economizer heat exchanger and the expansion device and returns to the primary flowpath between the second cylinder and the heat rejection heat exchanger and extends through: a third expansion device; the economizer second portion; and the third cylinder.