Vapor-compression refrigeration apparatus with refrgierant bypass and controlled heat load

Abstract

Apparatus and method are provided for cooling an electronic component. The apparatus includes a refrigerant evaporator in thermal communication with the 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 the refrigerant loop, a refrigerant bypass pipe coupled to the refrigerant loop in parallel fluid communication with the evaporator, and a control valve for controlling refrigerant flow through the evaporator. The control valve is controlled to maintain temperature of the component(s) within a specified temperature range. The apparatus further includes a controllable refrigerant heater associated with the refrigerant bypass pipe for providing an adjustable heat load on refrigerant in the bypass pipe to ensure that refrigerant 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;   a refrigerant bypass pipe coupled to the refrigerant loop in parallel fluid communication with the refrigerant evaporator;   a control valve for controlling refrigerant flow through the at least one channel of the refrigerant evaporator, the control valve being controlled to maintain temperature of the electronic component within a specified temperature range; and   a controllable refrigerant heater to heat refrigerant in the refrigerant loop, the controllable refrigerant heater being controlled to selectively heat refrigerant in the refrigerant loop 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 controllable refrigerant heater is coupled to the refrigerant bypass pipe to controllably heat refrigerant passing through the refrigerant bypass pipe to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state. 
     
     
         3 . The apparatus of  claim 1 , wherein the control valve is controlled to maintain temperature of the electronic component within the specified temperature range responsive to a changing electronic component heat load. 
     
     
         4 . The apparatus of  claim 1 , further comprising a temperature sensor for monitoring a temperature associated with the electronic component, and a controller coupled to the temperature sensor and the control valve, the controller automatically, incrementally opening the control valve further responsive to the monitored temperature of the electronic component being below to a first specified temperature, and automatically, incrementally closing the control valve further responsive to the monitored temperature of the electronic component being above a second specified temperature, wherein the first specified temperature is higher than the second specified temperature. 
     
     
         5 . The apparatus of  claim 1 , wherein the control valve comprises an electronically-controlled, three-way valve, and wherein the refrigerant bypass pipe couples at one end in fluid communication with the refrigerant loop through the electronically-controlled, three-way valve, wherein variation in refrigerant flow through the at least one channel of the refrigerant evaporator results in variation of refrigerant flow through the refrigerant bypass pipe, and wherein the controllable refrigerant heater is coupled to the refrigerant bypass pipe. 
     
     
         6 . The apparatus of  claim 1 , further comprising a fixed expansion orifice in fluid communication with the refrigerant loop for expanding refrigerant passing therethrough, the fixed expansion orifice being disposed at a refrigerant inlet to the refrigerant evaporator. 
     
     
         7 . The apparatus of  claim 1 , further comprising a controller coupled to the controllable refrigerant heater for automatically controlling a heat load applied by the controllable refrigerant heater to refrigerant in the refrigerant loop. 
     
     
         8 . The apparatus of  claim 7 , wherein the controllable refrigerant heater is coupled to the refrigerant bypass pipe, and the controller automatically adjusts heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe responsive to a change in heat load of the electronic component. 
     
     
         9 . The apparatus of  claim 8 , 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 heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe to zero, and responsive to the current heat load of the electronic component being below the specified heat load, automatically sets the heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe to the specified heat load less the current heat load of the electronic component. 
     
     
         10 . The apparatus of  claim 7 , further comprising 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 heat load applied by the controllable refrigerant heater with reference to the monitored temperature of refrigerant and pressure of refrigerant within the refrigerant loop, wherein heat load applied by the controllable refrigerant heater is automatically increased responsive to refrigerant entering the compressor being superheated by less than a specified delta temperature threshold, and is automatically decreased responsive to refrigerant entering the compressor being superheated by greater than the specified delta temperature threshold. 
     
     
         11 . A cooled electronic system comprising:
 an electronic component; and   an apparatus for facilitating cooling of 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; 
 a refrigerant bypass pipe coupled to the refrigerant loop in parallel fluid communication with the refrigerant evaporator; 
 a control valve for controlling refrigerant flow through the at least one channel of the cold plate, the control valve being controlled to maintain temperature of the electronic component within a specified temperature range; and 
 a controllable refrigerant heater to heat refrigerant in the refrigerant loop, the controllable refrigerant heater being controlled to selectively heat refrigerant in the refrigerant loop to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state. 
   
     
     
         12 . The cooled electronic system of  claim 11 , wherein the controllable refrigerant heater is coupled to the refrigerant bypass pipe to controllably heat refrigerant passing through the refrigerant bypass pipe to ensure that refrigerant in the refrigerant loop entering the compressor is in a superheated thermodynamic state. 
     
     
         13 . The cooled electronic system of  claim 11 , further comprising a temperature sensor for monitoring a temperature associated with the electronic component, and a controller coupled to the temperature sensor and the control valve, the controller automatically, incrementally opening the control valve further responsive to the monitored temperature of the electronic component being below to a first specified temperature, and automatically, incrementally closing the control valve further responsive to the monitored temperature of the electronic component being above a second specified temperature, wherein the first specified temperature is higher than the second specified temperature. 
     
     
         14 . The cooled electronic system  claim 11 , wherein the control valve comprises an electronically-controlled, three-way valve, and wherein the refrigerant bypass pipe couples at one end in fluid communication with the refrigerant loop through the electronically-controlled, three-way valve, wherein variation in refrigerant flow through the at least one channel of the refrigerant evaporator results in variation of refrigerant flow through the refrigerant bypass pipe, and wherein the controllable refrigerant heater is coupled to the refrigerant bypass pipe. 
     
     
         15 . The cooled electronic system of  claim 11 , further comprising a fixed expansion orifice in fluid communication with the refrigerant loop for expanding refrigerant passing therethrough, the fixed expansion orifice being disposed at a refrigerant inlet to the refrigerant evaporator. 
     
     
         16 . The cooled electronic system of  claim 11 , further comprising a controller coupled to the controllable refrigerant heater for automatically controlling a heat load applied by the controllable refrigerant heater to refrigerant in the refrigerant loop. 
     
     
         17 . The cooled electronic system of  claim 16 , wherein the controllable refrigerant heater is coupled to the refrigerant bypass pipe, and the controller automatically adjusts heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe responsive to a change in heat load of the electronic component. 
     
     
         18 . The cooled electronic system of  claim 17 , 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 heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe to zero, and responsive to the current heat load of the electronic component being below the specified heat load, automatically sets the heat load applied by the controllable refrigerant heater to refrigerant passing through the refrigerant bypass pipe to the specified heat load less the current heat load of the electronic component. 
     
     
         19 . The cooled electronic system of  claim 16 , further comprising 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 heat load applied by the controllable refrigerant heater with reference to the monitored temperature of refrigerant and pressure of refrigerant within the refrigerant loop, wherein heat load applied by the controllable refrigerant heater is automatically increased responsive to refrigerant entering the compressor being superheated by less than a specified delta temperature threshold, and is automatically decreased responsive to refrigerant entering the compressor being superheated by greater than the specified delta temperature threshold. 
     
     
         20 . 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;   providing a refrigerant bypass pipe coupled to the refrigerant loop in parallel fluid communication with the refrigerant evaporator;   providing a control valve for controlling refrigerant flow through the at least one channel of the refrigerant evaporator, the control valve being controlled to maintain temperature of the electronic component within a specified temperature range; and   associating a controllable refrigerant heater in thermal communication with refrigerant in the refrigerant loop, the controllable refrigerant heater being controlled to selectively heat refrigerant in the refrigerant loop to ensure that refrigerant entering the compressor is in a superheated thermodynamic state.