Thermal management systems

Abstract

An evaporator includes a cold plate configured to extract heat from one or more heat loads in proximity to the evaporator. The cold plate includes a housing, and a plurality of channels disposed through the housing, with at least one of the plurality of channels being a meandered channel.

What is claimed is: 
     
         1 . An evaporator, comprising:
 a cold plate configured to extract heat from one or more heat loads in proximity to the evaporator, the cold plate comprising:
 a housing, and 
 a plurality of channels disposed through the housing, with at least one of the plurality of channels being a meandered channel. 
   
     
     
         2 . The evaporator of  claim 1 , wherein the meandered channel has at least one curved region in the meandered channel. 
     
     
         3 . The evaporator of  claim 1 , wherein the meandered channel has one curved region in the meandered channel and the meandered channel has a net internal angle greater than zero degrees and up to 360 degrees. 
     
     
         4 . The evaporator of  claim 1 , wherein the meandered channel has more than one curved region in the meandered channel and the meandered channel has a net internal angle between and including zero degrees up to but not including 360 degrees. 
     
     
         5 . The evaporator of  claim 2 , wherein the at least one curved region in the meandered channel is defined as a first section of the channel that forms a non-zero degree angle along the length of the channel with respect to a second section of the channel. 
     
     
         6 . The evaporator of  claim 1 , wherein the cold plate is a first cold plate and the evaporator comprises a plurality of cold plates including the first cold plate. 
     
     
         7 . The evaporator of  claim 6 , wherein each of the plurality of cold plates includes at least one meandered channel. 
     
     
         8 . The evaporator of  claim 6 , wherein at least one of the plurality of cold plates includes the at least one meandered channel. 
     
     
         9 . The evaporator of  claim 6 , further comprising:
 a plurality of inlet headers fluidly coupled to inlets of the plurality of cold plates; and   a plurality of exit headers fluidly coupled to outlets of the plurality of cold plates.   
     
     
         10 . The evaporator of  claim 9 , further comprising an inlet distributer, comprising:
 an inlet configured to receive refrigerant fluid; and   a plurality of outlets, each of the plurality of outlets fluidly coupled to a corresponding one of the plurality of inlet headers.   
     
     
         11 . The evaporator of  claim 9 , further comprising:
 an exit collector having a plurality of inlets configured to receive refrigerant fluid from the plurality of exit headers.   
     
     
         12 . A thermal management system, comprising:
 an evaporator that comprises at least one cold plate configured to extract heat from one or more heat loads in proximity to the evaporator, the cold plate comprising a housing and a plurality of channels disposed through the housing, with at least one of the plurality of channels being a meandered channel;   a receiver configured to store refrigerant fluid, the receiver disposed in a refrigerant fluid path with the evaporator; and   an expansion valve positioned between the receiver and the evaporator in the refrigerant fluid path, the expansion valve configured to expand the refrigerant fluid from the receiver and deliver a mixed liquid/vapor refrigerant to the evaporator.   
     
     
         13 . The thermal management system of  claim 12 , wherein the meandered channel comprises at least one curved region in the meandered channel. 
     
     
         14 . The thermal management system of  claim 12 , wherein the meandered channel comprises one curved region in the meandered channel and the meandered channel has a net internal angle greater than zero degrees up to 360 degrees. 
     
     
         15 . The thermal management system of  claim 13 , wherein the at least one curved region in the meandered channel is defined as a first section of the channel that forms a non-zero degree angle along the length of the channel with respect to a second section of the channel. 
     
     
         16 . The thermal management system of  claim 12 , wherein the cold plate is a first cold plate and the evaporator comprises a plurality of cold plates including the first cold plate and each of the plurality of cold plates includes at least one meandered channel. 
     
     
         17 . The thermal management system of  claim 12 , wherein the evaporator further comprises:
 a plurality of inlet headers coupled to inlets of the plurality of cold plates; and   a plurality of exit headers, coupled to outlets of the plurality of cold plates.   
     
     
         18 . The thermal management system of  claim 16 , wherein the evaporator further comprises:
 an inlet distributer comprising an inlet configured to receive the refrigerant fluid and a plurality of outlets, each of the plurality of outlets fluidly coupled to a corresponding one of the plurality of inlet headers; and   an exit collector comprising a plurality of inlets configured to receive the refrigerant fluid from the plurality of exit headers.   
     
     
         19 . The thermal management system of  claim 12 , wherein the refrigerant fluid path is an open-circuit refrigerant fluid path, the system further comprising:
 a back-pressure regulator coupled to an outlet of the evaporator and configured to control vapor pressure upstream of the back-pressure regulator.   
     
     
         20 . The thermal management system of  claim 18 , wherein the refrigerant fluid path further includes a closed-circuit refrigerant fluid path, and the system further comprises:
 a compressor configured to receive refrigerant vapor from the evaporator and compress the refrigerant vapor; and   a condenser configured to condense the compressed refrigerant vapor from the compressor.   
     
     
         21 . The thermal management system of  claim 12 , wherein the expansion valve is configured to perform a constant-enthalpy expansion of the liquid refrigerant fluid to generate the refrigerant fluid mixture. 
     
     
         22 . The thermal management system of  claim 12 , wherein the refrigerant fluid comprises ammonia. 
     
     
         23 . A method of operating an evaporator, comprising:
 transporting refrigerant fluid through a plurality of channels in a cold plate according to a required mass velocity range and a required mass flow rate demand, with at least one channel of the plurality of channels being a meandered channel;   transferring refrigerant through the plurality of channels to absorb an amount of heat from a heat load to provide at an evaporator outlet a preset exit vapor quality; and   maintaining a heat load temperature band of the heat load, while thermally conducting the heat from the heat load to the plurality of refrigerant channels within the cold plate.   
     
     
         24 . The method of  claim 23 , wherein the meandered channel has at least one curved region in the meandered channel. 
     
     
         25 . The method of  claim 23 , wherein the meandered channel has one curved region in the meandered channel and the meandered channel has a net internal angle greater than zero degrees up to 360 degrees. 
     
     
         26 . The method of  claim 24 , wherein the at least one curved region in the meandered channel is defined as a first section of the channel that forms a non-zero degree angle along the length of the channel with respect to a second section of the channel.