Vapor-compression refrigeration apparatus with backup air-cooled heat sink and auxiliary refrigerant heater

Abstract

Apparatus and method are provided for cooling an electronic component. The apparatus includes a refrigerant evaporator in thermal communication with a component(s) to be cooled, and a refrigerant loop coupled in fluid communication with the evaporator for facilitating flow of refrigerant through the evaporator. The apparatus further includes a compressor in fluid communication with a refrigerant loop, an air-cooled heat sink coupled to the refrigerant evaporator, for providing backup cooling to the electronic component in a backup, air cooling mode, and a controllable refrigerant heater coupled to the heat sink. The refrigerant heater is in thermal communication across the heat sink with refrigerant passing through the refrigerant evaporator, and is controlled in a primary, refrigeration cooling mode to apply an auxiliary heat load to refrigerant passing through the refrigerant evaporator to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state.

1 . An apparatus for facilitating cooling of an electronic component, the apparatus comprising:
 a refrigerant evaporator in thermal communication with the electronic component, the refrigerant evaporator comprising at least one channel therein for accommodating flow of refrigerant therethrough;   a refrigerant loop coupled in fluid communication with the at least one channel of the refrigerant evaporator for facilitating flow of refrigerant therethrough;   a compressor coupled in fluid communication with the refrigerant loop;   an air-cooled heat sink coupled to the refrigerant evaporator and providing backup cooling to the electronic component in a backup, air cooling mode; and   a controllable refrigerant heater coupled to the air-cooled heat sink and in thermal communication across the air-cooled heat sink with refrigerant passing through the refrigerant evaporator, the controllable refrigerant heater being controlled in a primary, refrigeration cooling mode to apply an auxiliary heat load to refrigerant passing through the refrigerant evaporator to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state.   
     
     
         2 . The apparatus of  claim 1 , wherein the refrigerant evaporator comprises a first main surface and a second main surface, the first main surface and the second main surface extending substantially parallel, and wherein the electronic component is in thermal communication with the refrigerant evaporator across the first main surface thereof and the air-cooled heat sink is in thermal communication with the refrigerant evaporator across the second main surface thereof. 
     
     
         3 . The apparatus of  claim 2 , wherein the refrigerant evaporator further comprises a plurality of heat conduction structures facilitating conducting heat from the electronic component to the air-cooled heat sink in the backup, air cooling mode, the plurality of heat conduction structures further facilitating conduction of the auxiliary heat load to refrigerant passing through the refrigerant evaporator in the primary, refrigeration cooling mode. 
     
     
         4 . The apparatus of  claim 2 , wherein the air-cooled heat sink comprises a heat sink base coupled to the second main surface of the refrigerant evaporator and a plurality of thermally conductive heat sink fins extending from the heat sink base. 
     
     
         5 . The apparatus of  claim 4 , wherein the controllable refrigerant heater couples at least partially to at least one thermally conductive heat sink fin of the plurality of thermally conductive heat sink fins of the air-cooled heat sink, and is in thermal communication with refrigerant passing through the refrigerant evaporator across, at least in part, the at least one thermally conductive heat sink fin. 
     
     
         6 . The apparatus of  claim 5 , wherein the controllable refrigerant heater comprises a heater block and a plurality of thermally conductive heater fins extending therefrom, and wherein the controllable refrigerant heater is coupled to the air-cooled heat sink with the plurality of thermally conductive heater fins interdigitated with the plurality of thermally conductive heat sink fins. 
     
     
         7 . The apparatus of  claim 6 , further comprising a thermal interface material disposed between at least two opposing surfaces of the interdigitated plurality of thermally conductive heater fins and plurality of thermally conductive heat sink fins. 
     
     
         8 . The apparatus of  claim 6 , wherein the plurality of thermally conductive heat sink fins extend in a first direction and the plurality of thermally conductive heater fins extend in a second direction, the first direction and the second direction being perpendicular directions. 
     
     
         9 . The apparatus of  claim 5 , wherein the controllable refrigerant heater comprises a heater block including multiple grooves sized and positioned to partially accommodate therein multiple thermally conductive heat sink fins of the plurality of thermally conductive heat sink fins of the air-cooled heat sink, and wherein the controllable refrigerant heater is in thermal communication with refrigerant passing through the refrigerant evaporator across, at least in part, the multiple thermally conductive heat sink fins. 
     
     
         10 . The apparatus of  claim 5 , wherein the controllable refrigerant heater comprises at least one heater slat coupled in thermal communication with at least one thermally conductive heat sink fin of the air-cooled heat sink, the at least one heater slat comprising a flat heater disposed within a thermally conductive housing. 
     
     
         11 . The apparatus of  claim 4 , wherein the controllable refrigerant heater comprises a plurality of heater slats, each heater slat comprising a flat heater disposed within a thermally conductive housing, and at least one heater slat of the plurality of heater slats being disposed between two adjacent thermally conductive heat sink fins of the plurality of thermally conductive heat sink fins of the air-cooled heat sink. 
     
     
         12 . The apparatus of  claim 1 , further comprising a controller coupled to the controllable refrigerant heater for automatically controlling the auxiliary heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant evaporator, wherein the controller periodically monitors a current heat load of the electronic component and, responsive thereto, automatically determines whether the current heat load of the electronic component is above a specified heat load, and responsive to the current heat load of the electronic component being above the specified heat load, automatically sets the auxiliary heat load applied by the controllable refrigerant heater to zero, and responsive to the current heat load of the electronic component being below the specified heat load, automatically sets the auxiliary heat load applied by the controllable refrigerant heater to the refrigerant passing through the refrigerant evaporator to the specified heat load less the current heat load of the electronic component. 
     
     
         13 . The apparatus of  claim 1 , further comprising a controller coupled to the controllable refrigerant heater for automatically controlling the auxiliary heat load applied by the controllable refrigerant heater to refrigerant in the refrigerant loop, and a refrigerant temperature sensor and a refrigerant pressure sensor for monitoring a temperature and a pressure of refrigerant, respectively, within the refrigerant loop, and wherein the controller automatically adjusts auxiliary heat load applied by the controllable refrigerant heater with reference to the monitored temperature of refrigerant and pressure of refrigerant within the refrigerant loop, and wherein the auxiliary heat load applied by the controllable refrigerant heater is automatically incrementally increased responsive to refrigerant entering the compressor being superheated by less than a specified delta temperature threshold, and is automatically incrementally decreased responsive to refrigerant entering the compressor being superheated by greater than the specified delta temperature threshold. 
     
     
         14 . A cooled electronic system comprising:
 an electronic component; and   an apparatus for cooling the electronic component, the apparatus comprising:
 a refrigerant evaporator in thermal communication with the electronic component, the refrigerant evaporator comprising at least one channel therein for accommodating flow of refrigerant therethrough; 
 a refrigerant loop coupled in fluid communication with the at least one channel of the refrigerant evaporator for facilitating flow of refrigerant therethrough; 
 a compressor coupled in fluid communication with the refrigerant loop; 
 an air-cooled heat sink coupled to the refrigerant evaporator and providing backup cooling to the electronic component in a backup, air cooling mode; and 
 a controllable refrigerant heater coupled to the air-cooled heat sink and in thermal communication across the air-cooled heat sink with refrigerant passing through the refrigerant evaporator, the controllable refrigerant heater being controlled in a primary, refrigeration cooling mode to apply an auxiliary heat load to refrigerant passing through the refrigerant evaporator to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state. 
   
     
     
         15 . The cooled electronic system of  claim 14 , wherein the refrigerant evaporator comprises a first main surface and a second main surface, the first main surface and the second main surface extending substantially parallel, and wherein the electronic component is in thermal communication with the refrigerant evaporator across the first main surface thereof and the air-cooled heat sink is in thermal communication with the refrigerant evaporator across the second main surface thereof. 
     
     
         16 . The cooled electronic system of  claim 15 , wherein the refrigerant evaporator further comprises a plurality of heat conduction structures facilitating conducting heat from the electronic component to the air-cooled heat sink in the backup, air cooling mode, the plurality of heat conduction structures further facilitating conduction of the auxiliary heat load to refrigerant passing through the refrigerant evaporator in the primary, refrigeration cooling mode. 
     
     
         17 . The cooled electronic system of  claim 15 , wherein the air-cooled heat sink comprises a heat sink base coupled to the second main surface of the refrigerant evaporator and a plurality of thermally conductive heat sink fins extending from the heat sink base, and wherein the controllable refrigerant heater couples at least partially to at least one thermally conductive heat sink fin of the plurality of thermally conductive heat sink fins of the air-cooled heat sink, and is in thermal communication with refrigerant passing through the refrigerant evaporator across, at least in part, the at least one thermally conductive heat sink fin. 
     
     
         18 . The cooled electronic system of  claim 17 , wherein the controllable refrigerant heater comprises a heater block and a plurality of thermally conductive heater fins extending therefrom, and wherein the controllable refrigerant heater is coupled to the air-cooled heat sink with the plurality of thermally conductive heater fins interdigitated with the plurality of thermally conductive heat sink fins. 
     
     
         19 . The cooled electronic system of  claim 18 , wherein the plurality of thermally conductive heat sink fins extend in a first direction and the plurality of thermally conductive heater fins extend in a second direction, the first direction and the second direction being perpendicular directions. 
     
     
         20 . The cooled electronic system of  claim 17 , wherein the controllable refrigerant heater comprises a heater block including multiple grooves sized and positioned to partially accommodate therein multiple thermally conductive heat sink fins of the plurality of thermally conductive heat sink fins of the air-cooled heat sink, and wherein the controllable refrigerant heater is in thermal communication with refrigerant passing through the refrigerant evaporator across, at least in part, the multiple thermally conductive heat sink fins. 
     
     
         21 . The cooled electronic system of  claim 17 , wherein the controllable refrigerant heater comprises at least one heater slat coupled in thermal communication with at least one thermally conductive heat sink fin of the air-cooled heat sink, the at least one heater slat comprising a flat heater disposed within a thermally conductive housing. 
     
     
         22 . A method of facilitating cooling of an electronic component, the method comprising:
 coupling in thermal communication a refrigerant evaporator to the electronic component, the refrigerant evaporator comprising at least one channel therein for accommodating flow of refrigerant therethrough;   providing a refrigerant loop in fluid communication with the at least one channel of the refrigerant evaporator for facilitating flow of refrigerant therethrough;   coupling a compressor in fluid communication with the refrigerant loop;   coupling an air-cooled heat sink to the refrigerant evaporator for providing backup cooling to the electronic component in a backup, air cooling mode; and   coupling a controllable refrigerant heater to the air-cooled heat sink, the controllable refrigerant heater being in thermal communication across the air-cooled heat sink with refrigerant passing through the refrigerant evaporator, and being controlled in a primary, refrigeration cooling mode, to apply an auxiliary heat load to refrigerant passing through the refrigerant evaporator to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state.   
     
     
         23 . The method of  claim 22 , wherein the refrigerant evaporator comprises a first main surface and a second main surface, the first main surface and the second main surface extending substantially parallel, and wherein coupling in thermal communication the refrigerant evaporator to the electronic component comprises coupling the electronic component in thermal communication with the refrigerant evaporator across the first main surface thereof, and coupling the air-cooled heat sink to the refrigerant evaporator comprises coupling the air-cooled heat sink in thermal communication with the refrigerant evaporator across the second main surface thereof. 
     
     
         24 . The method of  claim 23 , wherein the air-cooled heat sink comprises a heat sink base coupled to the second main surface of the refrigerant evaporator and a plurality of thermally conductive heat sink fins extending from the heat sink base, and wherein coupling the controllable refrigerant heater to the air-cooled heat sink comprises coupling the controllable refrigerant heater at least partially to at least one thermally conductive heat sink fin of the plurality of thermally conductive heat sink fins of the air-cooled heat sink, wherein the controllable refrigerant heater is in thermal communication with refrigerant passing through the refrigerant evaporator across, at least in part, the at least one thermally conductive heat sink fin.