Flat Tube Single Serpentine Co2 Heat Exchanger

Abstract

A refrigeration system includes 0 compressor for driving 0 refrigerant along flow path in at least a first mode of system; a first heat exchanger along the flow path downstream of the compressor in the first mode; a second heat exchanger along the flow path upstream the compressor in the first mode; and a pressure regulator or expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein at least one of the first heat exchanger and the second heat exchanger comprises a flat tube heat exchanger.

1 . A refrigeration system comprising:
 a compressor for driving a refrigerant along a flow path in at least a first mode of system operation;   a first heat exchanger along the flow path downstream of the compressor in the first mode;   a second heat exchanger along the flow path upstream of the compressor in the first mode; and   a pressure regulator or expansion device in the flow path downstream of the first heat exchanger and upstream of the second heat exchanger in the first mode, wherein at least one of the first heat exchanger and the second heat exchanger comprises a flat tube heat exchanger.   
   
   
       2 . The system of  claim 1  wherein the flat tube heat exchanger comprises a conduit having a substantially rectangular outside shape and at least one internal flow port for carrying refrigerant flow. 
   
   
       3 . The system of  claim 2  wherein the rectangular outside shape has a short side and a long side, and wherein the flow paths are arranged with the short side facing a flow of heat exchange fluid. 
   
   
       4 . The system of  claim 3 , wherein the short side has a length of between about 0.5 and about 4.0 mm, and the long side has a length of between about 12.7 and about 101.6 mm. 
   
   
       5 . The system of  claim 2 , wherein the conduit has a flow hydraulic diameter of between about 0.1 and about 3.0 mm. 
   
   
       6 . The system of  claim 1  wherein the flat tube heat exchanger comprises a flat tube in a serpentine configuration defining a plurality of substantially parallel flow paths. 
   
   
       7 . The system of  claim 6  wherein the flat tube heat exchanger is positioned having the substantially parallel flow paths arranged in a substantially vertical plane. 
   
   
       8 . The system of  claim 7 , wherein the fins are present in a fin density of up to about 20 fins per inch. 
   
   
       9 . The system of  claim 6 , wherein the serpentine configuration has a tube pitch of between about 5 and about 50 mm. 
   
   
       10 . The system of  claim 1 , wherein the first heat exchanger comprises a plurality of rows of flat tube heat exchanger, and wherein the rows have a row pitch of between about 12.7 and about 50 mm. 
   
   
       11 . The system of  claim 1  further comprising fins extending from the flat tube heat exchanger across a flow path for heat exchange medium. 
   
   
       12 . The system of  claim 1  further comprising fins extending from the flat tube heat exchanger and having slots or louvers to allow drainage of condensation on the heat exchanger and fins. 
   
   
       13 . The system of  claim 1  wherein the flat tube heat exchanger has a single inlet and a single refrigerant outlet. 
   
   
       14 . The system of  claim 1  wherein the flat tube heat exchanger comprises flat tubes made of copper or aluminum. 
   
   
       15 . The system of  claim 1  wherein the flat tube heat exchanger comprises multiple rows of flat tube heat exchanger components arranged along a flow path of heat exchange fluid so as to provide counter flow heat exchange between refrigerant in the flat tube heat exchanger and heat exchange fluid. 
   
   
       16 . The system of claim ˜1 wherein:
 the refrigerant comprises, in major mass part, CO 2 ; and   the first and second heat exchangers are refrigerant-air heat exchangers.   
   
   
       17 . The system of  claim 1 , wherein the system is adapted to operate under a transcritical vapor compression mode. 
   
   
       18 . A beverage cooling device comprising the system of  claim 1 .