CPC F25B 49/027 (2013.01) [F25B 9/008 (2013.01); F25B 39/00 (2013.01); F25B 49/02 (2013.01); F25D 17/02 (2013.01); F25B 39/04 (2013.01); F25B 2339/047 (2013.01); F25B 2400/22 (2013.01); F25B 2700/195 (2013.01); F25B 2700/21161 (2013.01)] | 17 Claims |
1. A refrigeration system for a temperature-controlled storage device, comprising:
a refrigeration circuit configured to circulate a refrigerant, the refrigeration circuit comprising a compressor, a condenser, an expansion device, and an evaporator;
a cooling circuit separate from the refrigeration circuit and configured to circulate a coolant through the condenser to provide cooling for the refrigerant, the cooling circuit comprising a pump, a control valve, and a chiller in fluid communication with the condenser via the coolant; and
a controller operatively coupled to the control valve, the controller configured to:
identify a temperature differential setpoint, wherein the temperature differential setpoint is a target value of a difference between an inlet temperature of the coolant provided to the condenser by the cooling circuit and a condensing temperature of the refrigerant in the condenser;
monitor the inlet temperature of the coolant provided to the condenser by the cooling circuit;
determine the condensing temperature of the refrigerant in the condenser;
calculate an actual temperature differential ΔT by calculating a difference between the inlet temperature of the coolant provided to the condenser and the condensing temperature of the refrigerant in the condenser; and
provide a signal to the control valve to modulate a flow of the coolant through the condenser to drive the actual temperature differential ΔT to the temperature differential setpoint,
wherein the refrigerant is carbon dioxide (CO2); and
wherein the controller is configured to:
at least partially open the control valve to increase the flow of the coolant through the condenser when the actual temperature differential ΔT is higher than the temperature differential setpoint; and
at least partially close the control valve to decrease the flow of the coolant through the condenser when the actual temperature differential ΔT is lower than the temperature differential setpoint.
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