Patent ID: 8511103

Claim:
A method of operating a vapor compression system comprising: providing a first fluid circuit comprising a first compressor, a condenser and an evaporator; providing a second fluid circuit connected to the first fluid circuit between the condenser and evaporator to receive fluid from the first fluid circuit, the second fluid circuit comprising a vessel configured and positioned to receive fluid from the first fluid circuit and a second compressor configured and positioned to receive vapor from the vessel and to discharge compressed vapor to the first fluid circuit; monitoring a plurality of operating parameters of the first fluid circuit; calculating an operating condition setpoint for the vessel based on the monitored plurality of operating parameters; monitoring an operating condition of the vessel corresponding to the calculated operating condition setpoint; comparing the calculated operating condition setpoint to the monitored operating condition; and adjusting the capacity of the second compressor in response to the comparison of the calculated operating condition setpoint and the monitored operating condition.