Loop-type thermosiphon and stirling refrigerator

Abstract

A loop-type thermosiphon capable of stable operation regardless of fluctuation of heat load and a Stirling refrigerator using the same are provided. The loop-type thermosiphon transferring heat from a high-temperature heat source using a working fluid includes a evaporator having a heat absorption portion and evaporating the working fluid by depriving the high-temperature heat source of heat through the heat absorption portion, a condenser located above the high-temperature heat source and condensing the working fluid that has evaporated in the evaporator, and a pipe connecting the evaporator and the condenser so as to form a loop. In the loop-type thermosiphon, the working fluid that has passed through the condenser is brought in contact with the heat absorption portion before it is pooled in a liquid pool for the working fluid in the evaporator, so as to exchange heat with the same

1 . A loop-type thermosiphon transferring heat from a cylindrical high-temperature heat source using a working fluid comprising: 
 an annular evaporator having a heat absorption portion attached to said high-temperature heat source and evaporating said working fluid by depriving said high-temperature heat source of heat through the heat absorption portion;    a condenser located above said high-temperature heat source and condensing the working fluid that has evaporated in said evaporator; and    a pipe connecting said evaporator and said condenser so as to form a loop; wherein    said working fluid that has passed through said condenser and has been condensed is made to fall on contact with said heat absorption portion.    
   
   
       2 . The loop-type thermosiphon according to  claim 1 , wherein 
 in said evaporator has the heat absorption portion provided so as to receive said high-temperature heat source said working fluid condensed in said condenser is introduced so as to fall on a top portion.    
   
   
       3 . The loop-type thermosiphon according to  claim 1 , wherein 
 a flow resistance of said pipe guiding the working fluid that has evaporated in said evaporator to said condenser is made smaller than a flow resistance of said pipe guiding the working fluid condensed in said condenser to said evaporator.    
   
   
       4 . The loop-type thermosiphon according to  claim 1 , wherein 
 in accordance with an amount of heat transfer from said high-temperature heat source, if the amount of heat transfer is large, the flow resistance of the pipe from said condenser to said evaporator is made smaller, and if the amount of heat transfer is small, the flow resistance of the pipe from said condenser to said evaporator is made larger.    
   
   
       5 . The loop-type thermosiphon according to  claim 1 , wherein 
 a contained amount of the working fluid refers to such a contained amount that ⅓ to ⅔ of a total volume of a possible volume of liquid pool in said condenser at an operation temperature, a volume of the pipe and a volume of the evaporator is filled with a liquid of said working fluid and a remaining volume of said total volume is filled with saturated vapor of said working fluid.    
   
   
       6 . The loop-type thermosiphon according to  claim 1 , wherein 
 a natural refrigerant is used as the working fluid.    
   
   
       7 . The loop-type thermosiphon according to  claim 1 , wherein 
 any one of carbon dioxide, water, hydrocarbon, ammonia, ethanol, and a mixture thereof is used as the working fluid.    
   
   
       8 . The loop-type thermosiphon according to  claim 1 , wherein 
 a mixture containing ethanol by at most 60% is used as the working fluid.    
   
   
       9 . A Stirling refrigerator provided with a Stirling cooler wherein 
 said Stirling cooler includes the loop-type thermosiphon according to  claim 1 ,    said evaporator exchanges heat with a high-temperature portion of said Stirling cooler, and said condenser is located above said high-temperature portion.