System including a heat exchanger with different cryogenic fluids therein and method of using the same

Abstract

A system can include a heat transfer structure and a heat exchanger. The heat transfer structure is to cool an object, and the heat exchanger is to cool a portion of the heat transfer structure. The system can be cooled significantly faster than a conventional system that uses conductive cooling. The system has no or less liquid cryogen that would be vaporized as compared to a conventional system that immerses the object to be cooled within a bath of liquid cryogen or has a substantial mass of liquid cryogen within a cooling loop.

1 . A system comprising:
 a coldhead;   a first heat exchanger operable to receive a first cryogenic fluid and coupled to the coldhead;   a vessel designed to be operated at a cryogenic temperature; and   a heat transfer structure including a closed loop and further including a first portion disposed within the first heat exchanger and a second portion disposed, wherein:
 the closed loop is operable to contain a second cryogenic fluid that would be disposed therein; and 
 the first heat exchanger is designed such that the first cryogenic fluid and the second cryogenic fluid would be spaced apart from each other. 
   
   
   
       2 . The system of  claim 1 , wherein:
 the system is designed such that the first cryogenic fluid would have a different phase state as compared to the second cryogenic fluid;   the system is designed such that the first cryogenic fluid would have a different composition as compared to the second cryogenic fluid; or   any combination thereof.   
   
   
       3 . The system of  claim 1 , wherein the first heat exchanger is operable to receive the first fluid cryogen as a liquid cryogen from the coldhead. 
   
   
       4 . The system of  claim 1 , further comprising a wetsock coupled to the coldhead, wherein the coldhead is disposed within the wetsock. 
   
   
       5 . The system of  claim 1 , further comprising a reservoir coupled to the first heat exchanger, wherein the reservoir has a capacity sufficient to receive spillover from the first cryogenic fluid during a typical operating state. 
   
   
       6 . The system of  claim 1 , further comprising a second heat exchanger, wherein the second heat exchanger is coupled to the coldhead and the first heat exchanger. 
   
   
       7 . The system of  claim 6 , further comprising a thermal switch including a first terminal and a second terminal, wherein:
 the first terminal is coupled to the first heat exchanger; and   the second terminal is coupled to the second heat exchanger.   
   
   
       8 . A superconducting system comprising:
 a vessel;   a superconducting element disposed within the vessel;   a first heat exchanger disposed within the vessel; and   a heat transfer structure disposed within the vessel and thermally coupled to the superconducting element and the first heat exchanger.   
   
   
       9 . The superconducting system of  claim 8 , wherein the first heat exchanger is operable to cool a first fluid with a second fluid, wherein the first fluid includes gaseous He, and the second fluid includes gaseous He and liquid He. 
   
   
       10 . The superconducting system of  claim 8 , wherein the first heat exchanger lies at an elevation higher than a lowest point of the heat transfer structure. 
   
   
       11 . The superconducting system of  claim 10 , wherein the heat transfer structure is configured to allow a fluid to flow within the heat transfer structure by natural convection when the superconducting system would be operating at steady state. 
   
   
       12 . The superconducting system of  claim 8 , further comprising:
 a coldhead operable to condense a first gaseous cryogen into a liquid cryogen; and   a wetsock coupled to the first heat exchanger, wherein the first heat exchanger is operable to receive the liquid cryogen when the coldhead would be operating.   
   
   
       13 . The superconducting system of  claim 12 , further comprising:
 a second heat exchanger;   a thermal switch connected to the first heat exchanger and the second heat exchanger; and   a reservoir connected to the first heat exchanger.   
   
   
       14 . A method of using a system comprising:
 providing a first cryogenic fluid;   cooling a second cryogenic fluid with the first cryogenic fluid, wherein the first cryogenic fluid and the second cryogenic fluid remain spaced apart from each other;   flowing the second cryogenic fluid disposed within a heat transfer structure that is coupled to a cooled object; and   cooling the cooled object to a cryogenic temperature using the second cryogenic fluid.   
   
   
       15 . The method of  claim 14 , further comprising condensing a gaseous cryogen within the first cryogenic fluid into a liquid cryogen. 
   
   
       16 . The method of  claim 15 , wherein cooling the second cryogenic fluid comprises contacting the heat transfer structure with the liquid cryogen. 
   
   
       17 . The method of  claim 14 , wherein cooling the cooled object is performed while a superconducting element is disposed within the vessel. 
   
   
       18 . The method of  claim 17 , further comprising operating the superconducting element, wherein:
 operating the superconductor element is performed while a first pressure within the vessel is less than atmospheric pressure; and   flowing the second gaseous cryogen is performed at a second pressure less than atmospheric pressure.   
   
   
       19 . The method of  claim 18 , wherein the first pressure is at least three orders of magnitude lower than the second pressure. 
   
   
       20 . The method of  claim 18 , further comprising closing a thermal switch between a first heat exchanger and a second heat exchanger. 
   
   
       21 . The method of  claim 20 , further comprising opening the thermal switch after flowing the second gaseous cryogen before the superconducting element is in its typical operating state. 
   
   
       22 . The method of  claim 14 , further comprising flowing the first cryogenic fluid from a reservoir to a heat exchanger. 
   
   
       23 . The method of  claim 22 , further comprising flowing a liquid cryogen from the heat exchanger to the reservoir.