Device Having Enhanced Heat Transfer in Natural Convection by Means of Liquid Metals and Partitioned Domains

Abstract

A heat transfer device comprises: an outer wall, a first end wall connected to a first end of the outer wall, and a second end wall connected to a second end of the outer wall, wherein the outer wall, first end wall, and second end wall define a cavity; at least one partition wall located in the cavity, each partition wall being spaced inward from the first and second end walls; and a working fluid in the cavity, the working fluid being selected from liquid metals and liquid metal alloys, wherein the fluid has a final melting point at or below an operating temperature of the device, wherein the heat transfer device transfers heat from a heat source adjacent the first end wall to the working fluid such that convection is induced within the working fluid that increases heat transfer from the heat source toward the second end wall.

What is claimed is: 
     
         1 . A heat transfer device comprising:
 an outer wall, a first end wall connected to a first end of the outer wall, and a second end wall connected to an opposite second end of the outer wall, wherein the outer wall, the first end wall, and the second end wall define a cavity;   at least one partition wall located in the cavity, each partition wall being spaced inward from the first end wall and the second end wall; and   a working fluid contained in the cavity, the working fluid being selected from liquid metals and liquid metal alloys, wherein the working fluid has a final melting point at or below an operating temperature of the heat transfer device,   wherein the heat transfer device transfers heat from a heat source adjacent the first end wall to the working fluid such that convection is induced within the working fluid that increases heat transfer from the heat source toward the second end wall.   
     
     
         2 . The device of  claim 1  wherein:
 the working fluid is selected from the group consisting of gallium, mercury, sodium, and eutectic alloys. 
 
     
     
         3 . The device of  claim 1  wherein:
 the working fluid is selected from the group consisting of gallium, mercury, sodium, a eutectic alloy of gallium, indium, and tin, and a eutectic alloy of bismuth, lead, tin, and cadmium. 
 
     
     
         4 . The device of  claim 1  wherein:
 the working fluid comprises gallium. 
 
     
     
         5 . The device of  claim 1  wherein:
 the working fluid has a final melting point of 100° C. or below. 
 
     
     
         6 . The device of  claim 1  wherein:
 the working fluid has a final melting point of 80° C. or below. 
 
     
     
         7 . The device of  claim 1  wherein:
 the working fluid has a final melting point of 40° C. or below. 
 
     
     
         8 . The device of  claim 1  wherein:
 the at least one partition wall extends laterally between a first inner surface of the outer wall and a second inner surface of the outer wall. 
 
     
     
         9 . The device of  claim 1  wherein:
 the outer wall has a cylindrical shape such that the cavity has a height and a diameter. 
 
     
     
         10 . The device of  claim 9  wherein:
 a height-to-diameter ratio of the cavity is 3 or greater. 
 
     
     
         11 . The device of  claim 9  wherein:
 the at least one partition wall extends laterally along the diameter of the cavity between a first inner surface of the outer wall and a second inner surface of the outer wall. 
 
     
     
         12 . The device of  claim 9  wherein:
 each partition wall is spaced inward from the first end wall and the second end wall by a gap distance, and 
 a gap distance-to-height ratio (δ) is in a range of 0.001 to 0.3. 
 
     
     
         13 . The device of  claim 9  wherein:
 each partition wall is spaced inward from the first end wall and the second end wall by a gap distance, and 
 a gap distance-to-height ratio (δ) is in a range of 0.02 to 0.6. 
 
     
     
         14 . The device of  claim 9  wherein:
 a diameter-to-height ratio (AR) of the cavity is in a range of 0.1 to 10. 
 
     
     
         15 . The device of  claim 9  wherein:
 a diameter-to-height ratio (AR) of the cavity is in a range of 4 to 6. 
 
     
     
         16 . The device of  claim 1  wherein:
 a Rayleigh number (Ra) of the working fluid is in a range of 10 5 -10 8 . 
 
     
     
         17 . The device of  claim 1  wherein:
 a Rayleigh number (Ra) of the working fluid is in a range of 10 5 -10 7 . 
 
     
     
         18 . The device of  claim 1  wherein:
 the at least one partition wall is spaced inward from the first end wall by a first gap distance, 
 the at least one partition wall is spaced inward from the second end wall by a second gap distance, and 
 a gap ratio (a) of the second gap distance to the first gap distance is not 1. 
 
     
     
         19 . The device of  claim 18  wherein:
 the gap ratio (a) in a range of 0.5 to 1.5. 
 
     
     
         20 . The device of  claim 18  wherein:
 the gap ratio (a) in a range of 0.7 to 0.8. 
 
     
     
         21 . The device of  claim 1  further comprising:
 the heat source, 
 wherein the heat source is positioned adjacent the first end wall such that the first end wall has a first temperature higher than a second temperature of the second end wall, and the first end wall is located at a lower level than the second end wall. 
 
     
     
         22 . The device of  claim 21  wherein:
 the heat source is selected from engines, electrochemical devices, power electronics, computer components, and heating, ventilation, and air conditioning systems. 
 
     
     
         23 . The device of  claim 1  wherein:
 the outer wall has a polygonal shape. 
 
     
     
         24 . A method for cooling a heat source, the method comprising:
 (a) providing a heat transfer device comprising: (i) an outer wall, a first end wall connected to a first end of the outer wall, and a second end wall connected to an opposite second end of the outer wall, wherein the outer wall, the first end wall, and the second end wall define a cavity, (ii) at least one partition wall located in the cavity, each partition wall being spaced inward from the first end wall and the second end wall; and (iii) a working fluid contained in the cavity, the working fluid being selected from liquid metals and liquid metal alloys, wherein the working fluid has a final melting point at or below an operating temperature of the heat transfer device;   (b) thermally coupling the first end wall of the heat transfer device with a heat source; and   (c) cooling the heat source by transferring heat from the heat source to the working fluid such that convection is induced within the working fluid that increases heat transfer from the heat source toward the second end wall.   
     
     
         25 . The method of  claim 24  wherein:
 the working fluid is selected from the group consisting of gallium, mercury, sodium, and eutectic alloys. 
 
     
     
         26 . The method of  claim 24  wherein:
 the working fluid is selected from the group consisting of gallium, mercury, sodium, a eutectic alloy of gallium, indium, and tin, and a eutectic alloy of bismuth, lead, tin, and cadmium. 
 
     
     
         27 . The method of  claim 24  wherein:
 the working fluid comprises gallium. 
 
     
     
         28 . The method of  claim 24  wherein:
 the working fluid has a final melting point of 100° C. or below. 
 
     
     
         29 . The method of  claim 24  wherein:
 the at least one partition wall extends laterally between a first inner surface of the outer wall and a second inner surface of the outer wall. 
 
     
     
         30 . The method of  claim 24  wherein:
 the outer wall has a cylindrical shape such that the cavity has a height and a diameter, 
 a height-to-diameter ratio of the cavity is 3 or greater, 
 each partition wall is spaced inward from the first end wall and the second end wall by a gap distance, 
 a gap distance-to-height ratio (δ) is in a range of 0.001 to 0.3, and 
 a diameter-to-height ratio (AR) of the cavity is in a range of 0.1 to 10. 
 
     
     
         31 . The method of  claim 24  wherein:
 a Rayleigh number (Ra) of the working fluid is in a range of 10 5 -10 8 . 
 
     
     
         32 . The method of  claim 24  wherein:
 the at least one partition wall is spaced inward from the first end wall by a first gap distance, 
 the at least one partition wall is spaced inward from the second end wall by a second gap distance, 
 a gap ratio (α) of the second gap distance to the first gap distance is not 1, and 
 the gap ratio (α) in a range of 0.5 to 1.5. 
 
     
     
         33 . The method of  claim 24  wherein:
 the heat source is positioned adjacent the first end wall such that the first end wall has a first temperature higher than a second temperature of the second end wall, and the first end wall is located at a lower level than the second end wall. 
 
     
     
         34 . The method of  claim 24  wherein:
 the outer wall has a polygonal shape.