Topping cycle for a sub-ambient cooling system

A cooling system for a heat-generating structure, the cooling system comprising:

• a heat exchanger in physical contact and conductive thermal communication with a heat-generating structure, the heat exchanger having an inlet and an outlet, the inlet operable to receive fluid coolant substantially in the form of a liquid into the heat exchanger, and the outlet operable to dispense fluid coolant at least partially in the form of a vapor out of the heat exchanger;
• a first structure which directs a flow of the fluid coolant substantially in the form of a liquid to the heat exchanger, thermal energy communicated from the heat-generating structure to the fluid coolant causing the fluid coolant substantially in the form of a liquid to boil and vaporize in the heat exchanger so that the fluid coolant absorbs at least a portion of the thermal energy from the heat-generating structure as the fluid coolant changes state;
• a condenser heat exchanger that receives a flow of the fluid coolant at least partially in the form of a vapor from the heat exchanger and transfers at least a portion of the thermal energy within the fluid coolant to a heat sink;
• and
• a second condenser that assists the condenser heat exchanger in transferring at least a portion of the thermal energy within the fluid coolant away from the fluid coolant, the second condenser selectively activated when the heat sink reaches an undesirable temperature.

A cooling system for a heat-generating structure, the cooling system comprising:

• a heat exchanger in physical contact and conductive thermal communication with a heat-generating structure, the heat exchanger having an inlet and an outlet, the inlet operable to receive fluid coolant substantially in the form of a liquid into the heat exchanger, the outlet operable to dispense fluid coolant at least partially in the form of a vapor out of the heat exchanger, and the heat exchanger operating at a sub-ambient temperature;
• a first structure which directs a flow of the fluid coolant substantially in the form of a liquid to the heat exchanger, thermal energy communicated from the heat-generating structure to the fluid coolant causing the fluid coolant substantially in the form of a liquid to boil and vaporize in the heat exchanger so that the fluid coolant absorbs at least a portion of the thermal energy from the heat-generating structure as the fluid coolant changes state;
• a condenser heat exchanger that receives a flow of the fluid coolant at least partially in the form of a vapor from the heat exchanger and transfers at least a portion of the thermal energy within the fluid coolant to an ambient fluid;
• and
• a second condenser that assists the condenser heat exchanger in transferring at least a portion of the thermal energy within the fluid coolant away from the fluid coolant, the second condenser selectively activated when the ambient fluid reaches an undesirable temperature.