System and method for controlling the cooling of variable heat loads in heat generating devices

Abstract

The present invention offers an improvement over prior art cooling systems by accounting for rapid changes in thermal load. The circulation rate of refrigerant in a cooling cycle is set so that the two phase mixture exiting the cold plate evaporator device stays within a saturation dome of all mixtures between a saturated liquid and a saturated vapor. Furthermore, the two phase mixture exiting the cold plate evaporator device is allowed to move within the saturation dome so that the exit quality of the two phase mixture leaving the cold plate evaporator device changes with the heat load being removed. In this way, rapid changes in heat load are removed from the component or components in contact with the cold plate evaporator device without having to change the circulation rate of refrigerant in the cycle. Only the exit quality of the vapor leaving the cold plate/evaporator changes.

1 . A pumped liquid multiphase cooling cycle method for controlling the cooling of variable heat loads in heat generating devices, comprising the steps of:
 providing at least one component generating heat and required to be cooled;   providing at least one cold plate evaporator device in thermal contact with the at least one component;   providing a liquid refrigerant pump having at least an inlet;   providing a vaporizable refrigerant circulated by the liquid refrigerant pump to the at least one cold plate evaporator device, whereby the refrigerant is at least partially evaporated by the heat generated by the at least one component, creating a vapor;   providing a condenser for condensing the partially evaporated refrigerant vapor, creating a single liquid phase;   providing a first liquid conduit for receiving the vaporizable refrigerant from the liquid refrigerant pump, said first liquid conduit connected to the at least one cold plate evaporator device;   providing a second conduit from the at least one cold plate evaporator device, said second conduit connected to the condenser;   providing a liquid return line from the condenser to the inlet of the refrigerant pump; and   allowing a two phase liquid vapor mixture exiting the cold plate evaporator device to adjust within a saturation dome defined by the pumped liquid multiphase cooling cycle whereby exit quality of the two phase liquid vapor mixture leaving the cold plate evaporator device changes with the variable heat loads being removed by the cold plate evaporator device.   
   
   
       2 . A method as claimed in  claim 1  further comprising the step of containing an additional volume in the pumped liquid multiphase cooling cycle to provide for storage of liquid refrigerant when liquid refrigerant is displaced in the cold plate evaporator device and the condenser by vapor during the cooling operation. 
   
   
       3 . A method as claimed in  claim 1  wherein the at least one cold plate evaporator device comprises at least two cold plate evaporator devices. 
   
   
       4 . A method as claimed in  claim 3  wherein the at least two cold plate evaporator devices are in series flow. 
   
   
       5 . A method as claimed in  claim 3  wherein the at least two cold plate evaporator devices are in parallel flow. 
   
   
       6 . A pumped liquid multiphase cooling cycle system for controlling the cooling of variable heat loads in heat generating devices, comprising:
 at least one component generating heat and required to be cooled;   at least one cold plate evaporator device in thermal contact with the at least one component;   a liquid refrigerant pump having at least an inlet;   a vaporizable refrigerant circulated by the liquid refrigerant pump to the at least one cold plate evaporator device, whereby the refrigerant is at least partially evaporated by the heat generated by the at least one component, creating a vapor;   a condenser for condensing the partially evaporated refrigerant vapor, creating a single liquid phase;   a first liquid conduit for receiving the vaporizable refrigerant from the liquid refrigerant pump, said first liquid conduit connected to the at least one cold plate evaporator device;   a second conduit from the at least one cold plate evaporator device, said second conduit connected to the condenser;   a liquid return line from the condenser to the inlet of the refrigerant pump; and   a saturation dome defined by the pumped liquid multiphase cooling cycle, the saturation dome containing a saturated liquid point, a saturated vapor point, and all mixtures between, whereby the two phase liquid vapor mixture exiting the cold plate evaporator device is allowed to move within the saturation dome so exit quality of the two phase liquid vapor mixture leaving the cold plate evaporator device changes with the variable heat loads being removed by the cold plate evaporator device.   
   
   
       7 . A system as claimed in  claim 6  further comprising an additional volume contained in the pumped liquid multiphase cooling cycle to provide for storage of liquid refrigerant when liquid refrigerant is displaced in the cold plate evaporator device and the condenser by vapor during the cooling operation. 
   
   
       8 . A system as claimed in  claim 6  wherein the at least one cold plate evaporator device comprises at least two cold plate evaporator devices. 
   
   
       9 . A system as claimed in  claim 8  wherein the at least two cold plate evaporator devices are in series flow. 
   
   
       10 . A system as claimed in  claim 8  wherein the at least two cold plate evaporator devices are in parallel flow.