Boiling heat transfer device

Abstract

A boiling heat transfer device of the present invention includes: a heat receiving portion that boils a liquefied refrigerant to convert it to vapor, and contacts with a device to be cooled and cools the device to be cooled; a vapor tube that connects to an upper portion of the heat receiving portion and conveys the vapor generated by the heat receiving portion; a heat dissipating portion that condenses the vapor conveyed from the vapor tube to convert it to a liquefied refrigerant and dissipates heat to an atmosphere; and a liquid tube that returns to the heat receiving portion the liquefied refrigerant condensed by the heat dissipating portion. At least a portion of a cross-sectional area of a flow passage of the vapor in the heat receiving portion gradually decreases from a lower portion of the heat receiving portion toward the upper portion of the heat receiving portion.

1 . A boiling heat transfer device comprising:
 a heat receiving portion that boils a liquefied refrigerant to convert it to a vapor, and contacts with a device to be cooled and cools the device to be cooled;   a vapor tube that connects to an upper portion of the heat receiving portion and conveys the vapor generated by the heat receiving portion;   a heat dissipating portion that condenses the vapor conveyed from the vapor tube to convert it to a liquefied refrigerant and dissipates heat to an atmosphere; and   a liquid tube that returns to the heat receiving portion the liquefied refrigerant condensed by the heat dissipating portion,   at least a portion of a cross-sectional area of a :flow passage of the vapor in the heat receiving portion gradually decreasing from a lower portion of the heat receiving portion toward the upper portion of the heat receiving portion.   
     
     
         2 . The boiling heat transfer device according to  claim 1 , wherein the vapor tube is drawn out from the heat receiving portion side in a parallel direction to a direction of gravity, and is bent in a direction close to horizontal toward the heat dissipating portion. 
     
     
         3 . The boiling heat transfer device according to  claim 1 , wherein the vapor tube has a first end portion connected with the heat receiving portion and a second end portion connected with the heat dissipating portion, and an orientation of a center axis of the vapor tube is approximately parallel to a direction of gravity in a vicinity of the first end portion and approximately perpendicular to the direction of gravity in a vicinity of the second end portion. 
     
     
         4 . A boiling heat transfer device comprising:
 a heat receiving portion that boils a liquefied refrigerant to convert it to vapor, and contacts with a device to be cooled and cools the device to be cooled;   a vapor tube that conveys the vapor generated by the heat receiving portion;   a heat dissipating portion that condenses the vapor conveyed from the vapor tube to convert it to a liquefied refrigerant and dissipates heat to an atmosphere; and   a liquid tube that returns to the heat receiving portion the liquefied refrigerant condensed by the heat dissipating portion,   the vapor tube being drawn out from the heat receiving portion side in a parallel direction to a direction of gravity and being bent in a direction close to horizontal toward the heat dissipating portion.   
     
     
         5 . The boiling heat transfer device according to  claim 3 , wherein the vapor tube starts to bend immediately after a connection portion with the heat receiving portion. 
     
     
         6 . The boiling heat transfer device according to  claim 1 , where in the heat receiving portion and the heat dissipating portion are installed in a lateral direction with respect to a direction of gravity. 
     
     
         7 . A boiling heat transfer device comprising:
 a heat receiving portion that boils a liquefied refrigerant to convert it to vapor, and contacts with a device to be cooled and cools the device to be cooled;   a vapor tube that conveys the vapor generated by the heat receiving portion;   a heat dissipating portion that condenses the vapor conveyed from the vapor tube to convert it to a liquefied refrigerant and dissipates heat to an atmosphere; and   a liquid tube that returns to the heat receiving portion the liquefied refrigerant condensed by the heat dissipating portion,   height of a liquid surface of the liquefied refrigerant in the heat receiving portion being higher than height of a bottom surface of the heat dissipating portion.   
     
     
         8 . The boiling heat transfer device according to  claim 1 , wherein the liquid tube is drawn out from a bottom portion of the heat dissipating portion, and the liquefied refrigerant that passes through the liquid tube is directly returned to the liquefied refrigerant in the heat receiving portion. 
     
     
         9 . The boiling heat transfer device according to  claim 1 , wherein the heat receiving portion has a main body portion that has a box shape and a cover portion that covers the main body portion, and an outer shape of the cover portion is a truncated cone or a truncated pyramid. 
     
     
         10 . The boiling heat transfer device according to  claim 1 , wherein the device to be cooled is disposed in a center portion directly below the heat receiving portion, and the vapor tube opens at an upper center of the heat receiving portion. 
     
     
         11 . The boiling heat transfer device according to  claim 1 , wherein at least one of a connection portion between a vapor outflow portion of the heat receiving portion and a main body portion of the heat receiving portion, and a connection portion between the main body portion of the heat receiving portion and the cover portion of the heat receiving portion is formed in a streamlined shape. 
     
     
         12 . The boiling heat transfer device according to  claim 1 , wherein a plurality of boiling promotion fins are provided in the heat receiving portion. 
     
     
         13 . The boiling heat transfer device according to  claim 12 , wherein the boiling promotion fins include a porous material. 
     
     
         14 . The boiling heat transfer device according to  claim 1 , wherein a nozzle for pouring in refrigerant is provided at an upper side corner portion of the heat dissipating portion.