Heat exchanger

Abstract

A heat exchanger element for a heat exchanger includes a curved thermally conductive sheet having a curved end and a pair of legs extending contiguously from the curved end. The sheet has a substantially horizontal base edge along a lower edge of the sheet when, in an operational position, the curved end and the pair of legs are substantially horizontally aligned relative to one another. The base edge lays on a horizontal floor surface of a fluid filled cavity in a fluid reservoir when the sheet is operably positioned in the operational position in the cavity. The curved end and the pair of legs form substantially vertically extending walls. A plurality of horizontal tubes are mounted in the sheet so as to extend substantially horizontally in a vertically spaced apart array of tubes spaced apart along a height of the walls when the sheet is in the operational position. Each tube is mounted in a corresponding sleeve formed in the sheet. Each sleeve is sized to snugly encase a corresponding tube in heat conducting contact between the tube and the sleeve.

1 . A heat exchanger apparatus comprising:
 at least one heat exchanger element, each element including a curved thermally conductive sheet having a curved end and a pair of legs extending contiguously from said curved end, said sheet having a substantially horizontal base edge along a lower edge of said sheet when, in an operational position, said curved end and said pair of legs are substantially horizontally aligned relative to one another so that said base edge lays on a horizontal floor surface of a fluid filled cavity in a fluid reservoir when said sheet is operably positioned in said operational position in the cavity, said curved end and said pair of legs forming substantially vertically extending walls extending substantially vertically upwardly from said base edge,   a plurality of horizontal tubes mounted in said sheet so as to extend substantially horizontally, in a vertically spaced apart array of tubes spaced apart along a height of said walls when said sheet is in said operational position,   wherein each tube of said plurality of tubes is mounted in a corresponding sleeve formed in said sheet, each said sleeve sized to snugly encase a corresponding said tube in heat conducting contact between said tube and said sleeve,   wherein said array of tubes are interconnected by interconnecting tubes at adjacent ends of said plurality of horizontal tubes so as form a substantially spiraling flow path for a heat exchanger fluid flowing through said array and said interconnecting tubes,   wherein, with said sheet in said operational position, heat energy is exchanged between said array and said sheet via said sleeves, and wherein the heat energy from said sleeves and said sheet is exchanged between a first heat exchange fluid flowing down along said flow path through said array and said interconnecting tubes, and a passive second heat exchange fluid in which said apparatus is immersed, and wherein said passive second heat exchange fluid is thereby circulated over said sheet by convection along the surfaces said walls of said sheet.   
   
   
       2 . The apparatus of  claim 1  wherein said interconnecting tubes are substantially horizontal and said sheet is substantially u-shaped in plain view. 
   
   
       3 . The apparatus of  claim 1  wherein said interconnecting tubes are inclined and said sheet is substantially U-shaped. 
   
   
       4 . The apparatus of  claim 1  wherein said interconnecting tubes are substantially vertical and said sheet is substantially u-shaped. 
   
   
       5 . The apparatus of  claim 1  further comprising inlet and outlet headers, and wherein said at least one heat exchanger element is a plurality of said heat exchanger elements mounted in a parallel gang to said headers in fluid communication therewith. 
   
   
       6 . The apparatus of  claim 5  wherein said array includes at least three said tubes in said array. 
   
   
       7 . The apparatus of  claim 1  wherein said sheet is substantially aluminum sheet. 
   
   
       8 . The apparatus of  claim 7  wherein said sleeves are formed by crimping said sheet around said tubes so as to closely conformally wrap sleeve forming segments of said sheet around said tubes in close contact therewith. 
   
   
       9 . The apparatus of  claim 8  wherein seams are formed along said sleeves where said sleeve forming segments of said sheet are crimped so as to be substantially closed about said tubes, and wherein said seams are sealed closed by heat conductive sealant. 
   
   
       10 . The apparatus of  claim 9  wherein said seams are sealed by welding said seams closed.