Two-phase refrigerant distribution system for parallel tube evaporator coils

Abstract

A parallel tube heat exchanger receiving two-phase refrigerant flow from a common manifold is provided with an eductor nozzle in one end of the manifold so as to cause the flow of refrigerant to pass along one leg of the manifold and down another leg thereof so as to reenter the upstream end of the first leg by way of a crossover tube. In this way, the two-phase refrigerant flow to the parallel tubes is more uniformly distributed. In one embodiment of the invention, the manifold is a unitary tube with a centrally disposed, longitudinally extending partition to define two longitudinally extending chambers that fluidly communicate by gaps at the ends of the central partition.

1 . A heat exchanger having a plurality of parallel tubes for receiving two-phase refrigerant flow from a common manifold, comprising: 
 a plurality of tubes aligned in substantially parallel relationship for simultaneously conducting the flow of two-phase refrigerant downstream from inlet ends thereof;    a manifold having first and second passes for serially conducting the flow of two-phase refrigerant along the length of said first pass and then along the length of said second pass to an entrance of said first pass;    said plurality of tubes being fluidly interconnected at their entrance ends to said second pass for receiving two-phase refrigerant flow therefrom; and    an inducer nozzle fluidly connected with said first pass, said nozzle having inlet and discharge ends and being connected by a source of two-phase refrigerant at its inlet end for providing motive flow of two-phase refrigerant into said first pass.    
   
   
       2 . A heat exchanger as set forth in  claim 1  wherein said first and second passes are substantially parallel to each other.  
   
   
       3 . A heat exchanger as set forth in  claim 1  wherein said first and second passes are fluidly connected by a return bend.  
   
   
       4 . A heat exchanger as set forth in  claim 1  wherein said tubes are substantially orthogonal to said manifold.  
   
   
       5 . A heat exchanger as set forth in  claim 1  wherein said inducer nozzle is disposed at one end of said first pass.  
   
   
       6 . A heat exchanger as set forth in  claim 5  wherein said inducer nozzle is co-axially orientated with respect to said first pass.  
   
   
       7 . A heat exchanger as set forth in  claim 1  wherein said manifold is a unitary structure with a longitudinally extending divider disposed therein to define upper and lower chambers.  
   
   
       8 . A heat exchanger as set forth in  claim 7  wherein said divider does not extend the full length of the manifold but leaves gaps at each end thereof between the ends of the divider and the respective ends of the manifold.