Refrigeration system with condenser temperature differential setpoint control

A cooling circuit for a temperature-controlled storage device, comprising:

• a pump configured to circulate a coolant through the cooling circuit;
• a condenser configured to transfer heat from a refrigerant flowing through the heat exchanger to the coolant flowing through the heat exchanger;
• a fluid control valve operable to modulate a flow rate of the coolant through the heat exchanger;
• and
• a controller configured to:
• identify a setpoint value for a temperature differential between a saturation temperature of the refrigerant as it condenses in the heat exchanger and a temperature of the coolant as it enters the heat exchanger;
• and
• operate the fluid control valve to maintain the saturation temperature of the refrigerant as it condenses in the heat exchanger equal to a sum of the setpoint value and the temperature of the coolant as it enters the heat exchanger.

A method for controlling a refrigeration system that includes a refrigeration circuit, a cooling circuit, and a heat exchanger coupled to the refrigeration circuit and the cooling circuit, the method comprising:

• identifying, by a controller for the refrigeration system, a coolant temperature differential setpoint;
• monitoring, by the controller, a temperature of a coolant provided to the heat exchanger by the cooling circuit;
• determining, by the controller, a condensing temperature of a refrigerant provided to the heat exchanger by the refrigeration circuit;
• calculating, by the controller, a setpoint condensing temperature for the refrigerant by adding the coolant temperature differential setpoint to the temperature of the coolant provided to the heat exchanger;
• and
• operating, by the controller, a control valve of the cooling circuit to modulate a flow of the coolant through the heat exchanger to achieve the setpoint condensing temperature for the refrigerant.