Heat exchange structure of loop type heat pipe

Abstract

The present invention provides a heat exchange structure of a loop type heat pipe, which has a closed loop formed by connecting an evaporation portion, a vapor passageway, a condensation portion, and a fluid return passageway in series in this order. Appropriate amount of liquid is filled in the loop. The flow resistance of the vapor passageway is smaller than that of the fluid return passageway. When the evaporation portion is heated and the condensation portion radiates heat, all the fluids in the loop will stably flow toward the same direction, and pass through any position of the loop. Therefore, non-condensing gas existing in the loop will have little influence to the loop and flow along the loop, thereby letting the loop have good uniformity of temperature and large amount of heat transfer rate.

I claim:  
     
         1 . A heat exchange structure of a loop type heat pipe having a closed loop, said loop being formed by connecting an evaporation portion, a vapor passageway, a condensation portion, and a fluid return passageway in series in this order, liquid being filled in said loop, said fluid return passageway and said vapor passageway being independent passageways, the flow resistance in said fluid return passageway being larger than that in said vapor passageway; whereby when fluid is heated in said evaporation portion to form vapor flow, which flows to said condensation portion to condense into liquid, the condensed liquid, left vapor without condensing, and non-condensing gas in said loop will flow unidirectionally toward said fluid return passageway, return to said evaporation portion, and then flow into said vapor passageway under asymmetric guidance of heat flow in said loop, hence forming circulative flow in said loop.  
     
     
         2 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said evaporation portion is a pipeline and/or said condensation portion is a pipeline.  
     
     
         3 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said evaporation portion is formed of a heat spreader, said heat spreader being connected to said vapor passageway and said fluid return passageway, said heat spreader having a connected passageway connected with said vapor passageway and said fluid return passageway.  
     
     
         4 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said evaporation portion is thermally connected with a heat exchange device to be cooled, said heat exchange device to be cooled being a heat spreader of a heat source, a set of fins, a water sleeve, or an condensation portion of another loop.  
     
     
         5 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said vapor passageway is composed of more than two pipelines connected in parallel.  
     
     
         6 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said condensation portion is formed of a connection block, said connection block being connected to said vapor passageway and said fluid return passageway, said connection block having a connected passageway connected with said vapor passageway and said fluid return passageway.  
     
     
         7 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said condensation portion is connected with a heat exchange device, said heat exchange device being a set of heat-radiating fins, a heat radiator, a cooling water sleeve, or an evaporation portion of another loop.  
     
     
         8 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein liquid-shutting phenomenon is formed in said fluid return passageway with liquid.  
     
     
         9 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein said fluid return passageway is composed of more than two pipelines connected in parallel.  
     
     
         10 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein the requirement that the flow resistance of said fluid return passageway be larger than that of said vapor passageway is accomplished by reducing the cross-sectional area of said fluid return passageway or lengthening the length thereof or both.  
     
     
         11 . The heat exchange structure of a loop type heat pipe as claimed in  claim 1 , wherein a capillary tissue is disposed in said fluid return passageway to obtain a larger flow resistance and to simultaneously guide the condensed liquid by capillarity to return to said evaporation portion.  
     
     
         12 . The heat exchange structure of a loop type heat pipe as claimed in  claim 11 , wherein the amount of fluid can fill the whole said capillary tissue and up to 90% of the volume of said loop.  
     
     
         13 . The heat exchange structure of a loop type heat pipe as claimed in  claim 11 , wherein said capillary tissue can further extend to said evaporation portion and/or said condensation portion, and said capillary tissue is ceramic, sintered powder, foaming metal, a knitted net, a sintered net, a grooved plate, a fiber bundle, or a spiral wire.