Heat exchanger for shedding water

Abstract

A microchannel heat exchanger includes a two headers and tubes that extend between the headers. Each tube has an elongated cross-section, the cross-section having a first end and an opposing second end. In one example, each tube is angled such that a line defined between the ends of each tube is angled relative to the horizontal. As the tubes are angled, water that collects on the tubes is directed away from the tubes. In another example, a plate fin directs water away from the tubes. The plate fin includes openings, and a louver including parallel vertical slots is located between each of the openings. Each tube is interference fit in one of the openings of the plate fin, positioning a louver between each tube.

1 . A heat exchanger comprising:
 a first header and a second header; and   a plurality of tubes extending along an axis between the first header and the second header, wherein each of the plurality of tubes has an elongated cross-section taken substantially perpendicular to the axis, a first end and an opposing second end, and each of the plurality of tubes are angled relative to a horizontal such that the first end is higher than the opposing second end.   
     
     
         2 . The heat exchanger as recited in  claim 1  wherein the heat exchanger is an evaporator. 
     
     
         3 . The heat exchanger as recited in  claim 1  wherein the heat exchanger is a microchannel heat exchanger. 
     
     
         4 . The heat exchanger as recited in  claim 1  wherein each of the plurality of tubes includes an outer surface having a flattened portion. 
     
     
         5 . The heat exchanger as recited in  claim 1  wherein the first header and the second header are substantially vertical, each of the plurality of tubes are substantially horizontal, refrigerant flows through a plurality of channels in the plurality of tubes, and air flows over the plurality of tubes in a direction substantially perpendicular to a flow of the refrigerant through the plurality of tubes. 
     
     
         6 . The heat exchanger as recited in  claim 1  further including a plate fin including a plurality of collars each defining an opening, and each of the plurality of tubes is received in one of the plurality of openings. 
     
     
         7 . The heat exchanger as recited in  claim 6  wherein the plate fin includes a louver located between each of the plurality of openings, each of the louvers is located between two of the plurality of tubes, and each of the louvers includes a plurality of parallel vertical slots. 
     
     
         8 . The heat exchanger as recited in  claim 6  wherein each of the plurality of collars includes a v-shaped channel that surrounds each of the plurality of openings. 
     
     
         9 . A refrigeration system comprising:
 a compressor for compressing a refrigerant;   a condenser for cooling a refrigerant;   an expansion device for expanding the refrigeration; and   an evaporator for heating the refrigerant, wherein the evaporator includes a first header and a second header and a plurality of tubes extending along an axis between the first header and the second header, wherein each of the plurality of tubes have an elongated cross-section taken substantially perpendicular to the axis, a first end and an opposing second end, each of the plurality of tubes include a plurality of channels, and each of the plurality of tubes are angled relative to a horizontal such that the first end is higher than the opposing second end.   
     
     
         10 . The refrigeration system as recited in  claim 9  wherein each of the plurality of tubes includes an outer surface having a flattened portion. 
     
     
         11 . The refrigeration system as recited in  claim 9  wherein the first header and the second header are substantially vertical, each of the plurality of tubes are substantially horizontal, refrigerant flows through a plurality of channels in the plurality of tubes, and air flows over the plurality of tubes in a direction substantially perpendicular to a flow of the refrigerant through the plurality of tubes. 
     
     
         12 . The refrigeration system as recited in  claim 9  further including a plate fin including a plurality of collars each defining an opening, and each of the plurality of tubes is received in one of the plurality of openings. 
     
     
         13 . The refrigeration system as recited in  claim 9  wherein the plate fin includes a louver located between each of the plurality of openings, each of the louvers is located between two of the plurality of tubes, and each of the louvers includes a plurality of parallel vertical slots.