Integrated multi-circuit microchannel heat exchanger

Abstract

A microchannel heat exchanger has at least two manifolds, with the at least two manifolds communicating with a respective one of a first and second plurality of heat exchange tube banks. The first and second plurality of heat exchange tube banks are intertwined within a single microchannel heat exchanger core.

What is claimed is: 
     
         1 . A microchannel heat exchanger comprising:
 at least two manifolds, with said at least two manifolds communicating with a respective one of a first and second plurality of heat exchange tubes; and   said first and second plurality of heat exchange tubes providing microchannel heat exchangers within a single heat exchanger core.   
     
     
         2 . The microchannel heat exchanger as set forth in  claim 1 , wherein the microchannel heat exchanger has a heat transfer surface area with said at least two manifolds each communicating to a separate one of said first and second plurality of heat transfer tubes, which extend through said heat transfer surface area along a first direction, with said first and second plurality of heat transfer tubes being generally parallel to each other, and said heat transfer area having a second direction that is generally perpendicular to said first direction, and heat exchange tubes from said first and second plurality of tubes being intertwined along said second direction. 
     
     
         3 . The microchannel heat exchanger as set forth in  claim 2 , wherein said at least two manifolds are spaced on opposed sides of said heat transfer surface area. 
     
     
         4 . The microchannel heat exchanger as set forth in  claim 1 , wherein said at least two manifolds are connected to said plurality of heat transfer tubes by connecting refrigerant tubes that extend from said at least two manifolds to be connected to said heat exchange tubes in the plane perpendicular to said heat transfer surface area. 
     
     
         5 . The microchannel heat exchanger as set forth in  claim 1 , wherein there are at least four of said manifolds, with each of said manifolds communicating with separate heat exchange tubes. 
     
     
         6 . The microchannel heat exchanger as set forth in  claim 5 , wherein there is at least one of said at least four manifolds positioned on each of two lateral sides of said heat transfer surface area. 
     
     
         7 . The microchannel heat exchanger as set forth in  claim 1 , wherein said at least two manifolds are one of inlet manifolds and outlet manifolds. 
     
     
         8 . The microchannel heat exchanger as set forth in  claim 1 , wherein each of said plurality of heat transfer tubes has a plurality of separate refrigerant channels extending into a plane of said heat transfer area, and wherein said plurality of refrigerant channels of said heat exchange tubes has a hydraulic diameter less than 5 mm, and preferably less than 3 mm. 
     
     
         9 . The microchannel heat exchanger as set forth in  claim 1 , wherein each of said connecting refrigerant tubes is connected to several heat transfer tubes. 
     
     
         10 . The microchannel heat exchanger as set forth in  claim 1 , wherein said heat exchange tubes are bent or formed to fit into said at least two manifolds. 
     
     
         11 . The microchannel heat exchanger as set forth in  claim 1 , wherein said first and second plurality of heat exchange tubes include different numbers of heat exchange tubes. 
     
     
         12 . The microchannel heat exchanger as set forth in  claim 1 , wherein there is a single refrigerant pass from an inlet manifold to an outlet manifold. 
     
     
         13 . The microchannel heat exchanger as set forth in  claim 1 , wherein there are multiple passes between an inlet manifold and an outlet manifold, with each of said inlet and outlet manifolds being subdivided to provide intermediate manifold chambers. 
     
     
         14 . The microchannel heat exchanger as set forth in  claim 1 , wherein said at least two manifolds are connected to separate independent refrigerant circuits of a refrigerant system. 
     
     
         15 . The microchannel heat exchanger as set forth in  claim 1 , wherein said at least two manifolds are connected to a single refrigerant circuit of a refrigerant system.