Microchannel heat exchanger with varying fin density

Abstract

A heat exchanger of a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a plurality of microchannel tubes, where each microchannel tube of the plurality of microchannel tubes is configured to direct refrigerant therethrough, and a plurality of fin sets, where each fin set of the plurality of fin sets is disposed between corresponding adjacent microchannel tubes of the plurality of microchannel tubes. Additionally, each fin set of the plurality of fin sets includes a respective fin density based on a location of the respective fin set along a height of the heat exchanger.

1 - 20 . (canceled) 
     
     
         21 . A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a plurality of heat exchangers comprising a first heat exchanger and a second heat exchanger arranged in a V-shape configuration, wherein each heat exchanger of the plurality of heat exchangers comprises:
 a plurality of microchannel tubes, wherein each microchannel tube of the plurality of microchannel tubes is configured to direct a working fluid therethrough; 
 a plurality of fin sets, wherein each fin set of the plurality of fin sets is disposed between corresponding adjacent microchannel tubes of the plurality of microchannel tubes, and each fin set of the plurality of fin sets comprises a respective fin density corresponding to a location of the respective fin set along a height of the heat exchanger; 
 an inlet at a first end of the height of the heat exchanger; and 
 an outlet at a second end of the height of the heat exchanger, opposite the first end; and 
   a fan disposed adjacent the respective first end of the respective height of each of the first heat exchanger and the second heat exchanger, wherein the fan is configured to force air across the first heat exchanger and the second heat exchanger,   wherein, in each heat exchanger of the plurality of heat exchangers, the plurality of fin sets comprises:
 a first fin set having a first fin density, wherein the first fin set is disposed proximate to the inlet; and 
 a second fin set having a second fin density, wherein the second fin set is disposed proximate to the outlet, and the first fin density is greater than the second fin density. 
   
     
     
         22 . The HVAC&R system of  claim 21 , wherein each heat exchanger of the plurality of heat exchangers comprises a first header and a second header, the first header comprises the inlet and the outlet, each microchannel tube of the plurality of microchannel tubes comprises a plurality of ports configured to direct the working fluid from the first header to the second header or from the second header to the first header. 
     
     
         23 . The HVAC&R system of  claim 22 , wherein the plurality of fin sets comprises a third fin set having a third fin density disposed between first fin set and the second fin set, relative to the height of the heat exchanger, the third fin density is less than the first fin density, and the third fin density is greater than the second fin density. 
     
     
         24 . The HVAC&R system of  claim 23 , wherein each heat exchanger of the plurality of heat exchangers is a two-pass heat exchanger comprising a first pass and a second pass, the first pass is configured to direct the working fluid from the first header to the second header, and the second pass is configured to direct the working fluid from the second header to the first header. 
     
     
         25 . The HVAC&R system of  claim 24 , wherein the first pass comprises a first set of microchannel tubes of the plurality of microchannel tubes and a second set of microchannel tubes of the plurality of microchannel tubes, the second pass comprises a third set of microchannel tubes of the plurality of microchannel tubes, the first set of plurality of microchannel tubes is configured to direct a first portion of the working fluid from the first header to the second header, the second set of plurality of microchannel tubes is configured to direct a second portion of the working fluid from the first header to the second header, and the third set of plurality of microchannel tubes is configured to direct a combined flow of the first portion of the working fluid and the second portion of the working fluid from the second header to the first header. 
     
     
         26 . The HVAC&R system of  claim 25 , wherein the first fin set extends between adjacent microchannel tubes of the first set of microchannel tubes, the third fin set extends between adjacent microchannel tubes of the second set of microchannel tubes, and the second fin set extends between adjacent microchannel tubes of the third set of microchannel tubes. 
     
     
         27 . The HVAC&R system of  claim 21 , wherein each heat exchanger of the plurality of heat exchangers comprises:
 a first section comprising a first set of microchannel tubes of the plurality of microchannel tubes arrayed along a first portion of the height of the heat exchanger, wherein the first section comprises the first fin set;   a second section comprising a second set of microchannel tubes of the plurality of microchannel tubes arrayed along a second portion of the height of the heat exchanger, wherein the second section comprises the second fin set; and   a third section comprising a third set of microchannel tubes of the plurality of microchannel tubes arrayed along a third portion of the height of the heat exchanger, wherein the third section comprises a third fin set having a third fin density,   wherein the third section is disposed between the first section and the second section, relative to the height of the heat exchanger, the third fin density is less than the first fin density, the third fin density is greater than the second fin density, and the first section, the second section, and the third section cooperatively define the height of the heat exchanger.   
     
     
         28 . The HVAC&R system of  claim 21 , wherein a common distance extends between adjacent microchannel tubes of the plurality of microchannel tubes. 
     
     
         29 . A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a plurality of heat exchangers comprising a first heat exchanger and a second heat exchanger arranged in a V-shape configuration, wherein each heat exchanger of the plurality of heat exchangers comprises:
 a plurality of microchannel coils arranged along a height of the heat exchanger, wherein each microchannel coil of the plurality of microchannel coils extends along a length of the heat exchanger; 
 a plurality of fin sets, wherein each fin set of the plurality of fin sets is disposed between a corresponding pair of adjacent microchannel coils of the plurality of microchannel coils, and the plurality of fin sets comprises a first fin set having a first fin density, a second fin set having a second fin density less than the first fin density, and a third fin set having a third fin density less than the second fin density; 
 an inlet disposed at a first end of the height of the heat exchanger; and 
 an outlet disposed at a second end, opposite the first end, of the height of the heat exchanger; and 
   a fan positioned adjacent the respective first end of the respective height of each of the first heat exchanger and the second heat exchanger, wherein the fan is configured to force air across the first heat exchanger and the second heat exchanger,   wherein the first fin set is disposed proximate to the first end of the height of the heat exchanger, the third fin set is disposed proximate to the second end of the height of the heat exchanger, and the second fin set is disposed between the first fin set and the third fin set relative to the height of the heat exchanger.   
     
     
         30 . The HVAC&R system of  claim 29 , wherein each heat exchanger of the plurality of heat exchangers comprises:
 a first header and a second header, wherein the first header comprises the inlet and the outlet;   a first section comprising a first set of microchannel coils of the plurality of microchannel coils arrayed along a first distance of the height of the heat exchanger and extending from the first header to the second header, wherein the first section comprises the first fin set;   a second section comprising a second set of microchannel coils of the plurality of microchannel coils arrayed along a second distance of the height of the heat exchanger and extending from the first header to the second header, wherein the second section comprises the second fin set; and   a third section comprising a third set of microchannel coils of the plurality of microchannel coils arrayed along a third distance of the height of the heat exchanger and extending from the first header to the second header, wherein the third section comprises the third fin set.   
     
     
         31 . The HVAC&R system of  claim 30 , wherein the first distance of the height is greater than the second distance of the height, and the second distance of the height is greater than the third distance of the height. 
     
     
         32 . The HVAC&R system of  claim 31 , wherein a first ratio of the first distance of the height and the first fin density is 0.9-0.95, a second ratio of the second distance of the height and the second fin density is 0.9-1, a third ratio of the third distance of the height and the third fin density is 0.85-0.9, or any combination thereof. 
     
     
         33 . The HVAC&R system of  claim 29 , wherein the air comprises ambient air,
 and the heat exchanger is configured to reject heat from a working fluid directed through the plurality of microchannel coils to the ambient air.   
     
     
         34 . The HVAC&R system of  claim 29 , wherein a first fin length of each fin of the first fin set is less than a second fin length of each fin of the second fin set, and the second fin length of each fin of the second fin set is less than a third fin length of each fin of the third fin set. 
     
     
         35 . A heating, ventilation, air conditioning, and refrigeration (HVAC&R) system, comprising:
 a plurality of heat exchangers comprising a first heat exchanger and a second heat exchanger arranged in a V-shape configuration, wherein each heat exchanger of the plurality of heat exchangers comprises:
 a first section extending along a height of the heat exchanger, wherein the first section comprises a plurality of first microchannel tubes and a plurality of first fin sets disposed between corresponding adjacent first microchannel tubes of the plurality of first microchannel tubes, wherein each first fin set of the plurality of first fin sets comprises a first fin density; 
 a second section extending along the height, wherein the second section comprises a plurality of second microchannel tubes and a plurality of second fin sets disposed between corresponding adjacent second microchannel tubes of the plurality of second microchannel tubes, wherein each second fin set of the plurality of second fin sets comprises a second fin density, and wherein the second fin density is less than the first fin density; 
 a first header and a second header, wherein each first microchannel tube of the plurality of first microchannel tubes extends from the first header to the second header, and each second microchannel tube of the plurality of second microchannel tubes extends from the first header to the second header; 
 an inlet disposed at a first end of the height; and 
 an outlet disposed at a second end of the height, opposite the first end, 
 wherein the first section is disposed proximate to the first end, and the second section is disposed proximate to the second end; and 
   a fan disposed adjacent the respective first end of each of the first heat exchanger and the second heat exchanger, wherein the fan is configured to force air across the first heat exchanger and the second heat exchanger.   
     
     
         36 . The HVAC&R system of  claim 35 , wherein a first distance of the first section along the height of the heat exchanger is greater than a second distance of the second section along the height of the heat exchanger. 
     
     
         37 . The HVAC&R system of  claim 35 , wherein each heat exchanger of the plurality of heat exchangers comprises a third section extending along the height between the first section and the second section, the third section comprises a plurality of third microchannel tubes and a plurality of third fin sets disposed between corresponding adjacent third microchannel tubes of the plurality of third microchannel tubes, each third microchannel tube of the plurality of third microchannel tubes extends from the first header to the second header, each third fin set of the plurality of third fin sets comprises a third fin density, the third fin density is less than the first fin density, and the third fin density is greater than the second fin density. 
     
     
         38 . The HVAC&R system of  claim 37 , wherein the first header comprises the inlet and the outlet. 
     
     
         39 . The HVAC&R system of  claim 38 , wherein the first header is configured to receive a flow of working fluid via the inlet, each first microchannel tube of the plurality of first microchannel tubes is configured to direct a first portion of the flow of working fluid from the first header to the second header, each third microchannel tube of the plurality of third microchannel tubes is configured to direct a second portion of the flow of working fluid from the first header to the second header, and each second microchannel tube of the plurality of second microchannel tubes is configured to direct a combined flow of the first portion of the flow of working fluid and the second portion of the flow of working fluid from the second header to the first header. 
     
     
         40 . The HVAC&R system of  claim 37 , wherein the first fin density is based on a first distance of the first section along the height of the heat exchanger, the second fin density is based on a second distance of the second section along the height of the heat exchanger, and the third fin density is based on a third distance of the third section along the height of the heat exchanger.