Compact heat exchanger design for hybrid cooling equipment with elongated headers and shortened circuits

Abstract

A hybrid condenser or fluid cooler having an indirect heat exchange and a direct heat exchanger, in which tube circuits in the indirect heat exchanger are arranged parallel to the direction of air flow of a crossflow direct heat exchanger. The design features elongated fluid headers combined with multiple shortened circuits, resulting in a compact design that lowers the fluid pressure drop across the heat exchanger. This design creates an increased turbulence in relation to fluid flow, resulting in an increase in thermal performance.

1 . A cooling tower comprising:
 a. a water collection basin,   b. a plenum located above a central portion of said water collection basin,   c. an air mover situated above said plenum,   d. two cross-flow direct heat exchange sections flanking a lower portion of said plenum,   e. two concurrent-flow indirect heat exchange sections flanking an upper portion of said plenum, each of said two indirect heat exchange sections situated above a respective one of said direct heat exchange sections,   f. a water distribution system located above, and configured to selectively distribute water to, said two indirect heat exchange sections,   g. at least one recirculation pump located to draw water collecting in said water collection basin and move it through one or more recirculation pipes to said water distribution system,   h. two side air inlets, each one of said two side air inlets located laterally adjacent a respective one of said two direct heat exchange sections;   i. two top air inlets, each one of said two top air inlets located above a respective one of said two indirect heat exchange sections,   j. wherein said air mover simultaneously,
 i. draws a first flow of air into said cooling tower through said two top air inlets, through said two concurrent-flow indirect heat exchange sections into said plenum, and out of said cooling tower through said air mover, and 
 ii. draws a second flow of air into said cooling tower through said two side air inlets, said two cross-flow direct heat exchange sections, and into said plenum, through said plenum, and out of said cooling tower through said air mover, 
   k. wherein each of said two concurrent-flow indirect heat exchange sections comprise a plurality of tube bundles, each of said plurality of tube bundles comprising an inlet header, an outlet header, and a plurality of serpentine tubes attached at a first end to said inlet header and attached at a second end to said outlet header, each of said plurality of elliptical serpentine tubes comprising a plurality of straight tube segments connected to adjacent ones of said plurality of straight tube segments by tube bends,   l. wherein each of said tube bundles are oriented in said cooling tower so that said longitudinal axes of said plurality of straight tube segments are parallel to said first air flow as said first flow enters said air inlets and through said cross-flow direct heat exchange sections, and   m. wherein a combined length of said inlet headers across a respective one of said two concurrent-flow indirect heat exchange sections is greater than lengths of said plurality of straight tube segments.   
     
     
         2 . The cooling tower of  claim 1 , wherein said serpentine tubes are elliptical or round. 
     
     
         3 . The cooling tower of  claim 1 , wherein said serpentine tubes comprise plate fins, flat fins or spiral fins. 
     
     
         4 . The cooling tower of  claim 1 , wherein said water basin comprises a central section between said plenum and two flanking sections each located beneath a respective one of said two direct heat exchange sections. 
     
     
         5 . The cooling tower of  claim 1 , comprising a single recirculation pump and a single pipe connecting said single recirculation pump and said water distribution system. 
     
     
         6 . The cooling tower of  claim 1 , comprising two recirculation pumps and two pipes connecting a respective one of said two recirculation pumps and a respective section of said water distribution system. 
     
     
         7 . The cooling tower of  claim 1 , wherein said return bends in one of said two concurrent-flow indirect heat exchange sections are located above a respective one of said two side air inlets. 
     
     
         8 . The cooling tower of  claim 1 , wherein said air mover simultaneously,
 draws a first flow of air into said cooling tower through said two top air inlets, down through said two concurrent-flow indirect heat exchange sections into said plenum, and upward and out of said cooling tower through said air mover,   and   draws a second flow of air into said cooling tower through said two side air inlets, across said two cross-flow direct heat exchange sections, and into said plenum, up through said plenum, and out of said cooling tower through said air mover.