Cooling system for high density heat load

A cooling system for transferring heat from a heat load to an environment, the cooling system comprising:

• a first cooling cycle containing a two-phase working fluid;
• and
• a second cooling cycle thermally connected to the first cooling cycle;
• wherein the first cooling cycle comprises:
• a pump configured to increase the pressure of the working fluid without substantially increasing the enthalpy of the working fluid;
• an air-to-fluid heat exchanger in fluid communication with the pump and in thermal communication with the heat load;
• a second heat exchanger having a first fluid path for the working fluid in fluid communication with the air-to-fluid heat exchanger and the pump, and a second fluid path comprising a portion of the second cooling cycle;
• wherein the first and second fluid paths are in thermal communication with one another;
• wherein the heat load causes at least a portion of the two-phase working fluid to change phase from a liquid to a gas within the air-to-fluid heat exchanger;
• and
• wherein the second cooling cycle comprises a chilled water system in thermal communication with the environment and wherein the second cooling cycle is controlled to maintain a temperature of the two-phase working fluid entering the air-to-fluid heat exchanger above a dew point of air flowing through the air-to-fluid heat exchanger.

A cooling system for transferring heat from a heat load to an environment, the cooling system comprising:

• a working fluid pump configured to increase the pressure of a two-phase working fluid without substantially increasing the enthalpy of the working fluid;
• an air-to-fluid heat exchanger connected to the pump and having a fluid path in thermal communication with the heat load;
• a second heat exchanger having first and second fluid paths in thermal communication with one another, wherein the first fluid path provides fluid communication from the air-to-fluid heat exchanger to the pump, and wherein the second fluid path is adapted to thermally connect the air-to-fluid heat exchanger in the first fluid path to a chilled water cooling system that is in thermal communication with the environment;
• wherein air passing through the air-to-fluid heat exchanger transfers heat from the heat load and causes at least a portion of the working fluid to change phase from a liquid to a gas;
• and
• a controller operatively coupled to the chilled water cooling system and configured to maintain a temperature of the working fluid between the second heat exchanger and the air-to-fluid heat exchanger above a dew point temperature of the air passing through the air-to-fluid heat exchanger so that the cooling system removes only sensible heat from the air and thereby prevents condensation on the air-to-fluid heat exchanger.

A heat transfer system, comprising:

• a first heat transfer subsystem adapted to circulate there through a first working fluid, wherein the first working fluid is selected from the group consisting of:
• chlorofluorocarbons, hydrofluorocarbons and hydrochlorofluorocarbons, comprising:
• at least one air-to-fluid heat exchanger in thermal communication with a heat load;
• a pump configured to increase the pressure of the first working fluid without substantially increasing the enthalpy of the first working fluid;
• and
• at least a portion of a second heat exchanger;
• a second heat transfer subsystem comprising:
• at least a second portion of the second heat exchanger and
• a third heat exchanger;
• the second heat transfer subsystem adapted to circulate a second working fluid there through, wherein the second working fluid is selected from the group consisting of:
• water, water-ethylene glycol, and water-propylene glycol;
• and
• wherein air passing through the air-to-fluid heat exchanger causes at least a portion of the first working fluid to undergo a phase change from a liquid to a gas in the first heat transfer subsystem;
• and
• a system controller operatively coupled to the second subsystem and configured to prevent condensation on the air-to-fluid heat exchanger by maintaining the first working fluid leaving the second heat exchanger above a dew point temperature of the air passing through the air-to-fluid heat exchanger.

A cooling system for removing heat from a high density heat load, comprising:

• a first heat transfer system comprising:
• a two-phase working fluid;
• a plurality of air-to-fluid heat exchangers configured to transfer heat from the load to the working fluid so that at least a portion of the working fluid changes phase from a liquid to a gas within at least one of the air-to-fluid heat exchangers;
• a working fluid flow regulator associated with at least one of the plurality of air-to-fluid heat exchangers and configured to limit the maximum working fluid flow to each air-to-fluid heat exchanger
• a working fluid receiver configured to hold working fluid based on working fluid temperature or cooling system load;
• a pump configured to increase the pressure of the working fluid without substantially increasing the enthalpy of the working fluid;
• and
• a first portion of a fluid-to-fluid heat exchanger;
• wherein all of the first heat transfer system is arranged in fluid communication;
• a second heat transfer system comprising:
• a second portion of the fluid-to-fluid heat exchanger;
• a single-phase working fluid;
• a pump;
• and
• wherein all of the second heat transfer system is arranged in fluid communication;
• wherein the first heat transfer system is thermally coupled to the second heat transfer system by the fluid-to-fluid heat exchanger;
• and
• a cooling system controller monitoring the dew point temperature of air flowing through the air-to-fluid heat exchanger, and operatively connected to the second heat transfer system to prevent condensation on the air-to fluid heat exchangers by maintaining the first heat transfer system working fluid entering the air-to-fluid heat exchangers at a temperature above the dew point temperature of the air flow.