Counter-flow heat exchanger for battery thermal management applications

Abstract

A heat exchanger for thermal management of battery units made-up of plurality of battery cells or battery cell containers housing one or more battery cells. The heat exchanger has a main body portion defining at least one primary heat transfer surface for surface-to-surface contact with a corresponding surface of at least one of the battery cells or containers. A plurality of alternating first and second fluid flow passages are formed within the main body portion each defining a flow direction, the flow direction through the first fluid flow passages being generally opposite to the flow direction through the second fluid flow passages providing a counter-flow heat exchanger. In some embodiments the heat exchanger has two pairs of inlet and outlet manifolds, the heat exchanger providing a single-pass, counter-flow arrangement. In other embodiments the first and second fluid flow passages are interconnected by turn portions forming a U-flow, counter-flow heat exchanger.

What is claimed is: 
     
         1 . A heat exchanger for thermal management of a battery unit having a plurality of battery cell containers each housing one or more battery cells, comprising:
 a main body portion having opposed ends and defining at least one primary heat transfer surface for surface-to-surface contact with a corresponding surface of at least one of the battery cell containers;   a plurality of first fluid flow passages formed within the main body portion, each of the first fluid flow passages having a first end and a second end, the first end and the second end of the first fluid flow passages defining a first flow direction through the first fluid flow passages, wherein the first fluid flow passages are substantially planar;   a plurality of second fluid flow passages formed within the main body portion, each of the second fluid flow passages having a first end and a second end, the first end and the second end of the second fluid flow passages defining a second flow direction through the second fluid flow passages, wherein the second fluid flow passages are substantially planar;   wherein the first ends of the first fluid flow passages are interconnected by an inlet header region;   wherein, for each of the plurality of second fluid flow passages, the first end of the second fluid flow passages, which is located on an opposite side of the main body portion from the inlet header region, is fluidly connected to the second end of one of the first fluid flow passages via a turn portion;   wherein the second fluid flow passage terminates at the second end of the second fluid flow passage; and   wherein the first flow direction of the first fluid flow passages is opposite to the second flow direction of the second fluid flow passages.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the first fluid flow passages and the second fluid flow passages are alternating laterally across the main body portion. 
     
     
         3 . The heat exchanger of  claim 1 , wherein at least some of the first fluid flow passages and the second fluid flow passages are alternating laterally across the main body portion. 
     
     
         4 . The heat exchanger of  claim 1 , wherein the second ends of the second flow passages are located closer to the center of the main body portion compared with the inlet header region. 
     
     
         5 . The heat exchanger of  claim 1 , further comprising an inlet manifold in fluid communication with the inlet header region and an outlet manifold in fluid communication with the second ends of the second fluid flow passages. 
     
     
         6 . The heat exchanger of  claim 5 , wherein the inlet manifold and the outlet manifold are arranged perpendicular to the first flow direction of the first fluid flow passages and are located at one end of the main body portion of the heat exchanger. 
     
     
         7 . The heat exchanger of  claim 1 , wherein the main body portion has a base plate and a cover plate. 
     
     
         8 . The heat exchanger of  claim 7 , wherein the second ends of the second fluid flow passages are staggered with respect to the first ends of the first fluid flow passages such that the second ends of the second fluid flow passages are inwardly disposed from a width of the main body portion. 
     
     
         9 . The heat exchanger of  claim 7 , wherein the first fluid flow passages, the second fluid flow passages, the turn portion, and the inlet header region are formed within the base plate. 
     
     
         10 . The heat exchanger of  claim 7 , wherein each of the first fluid flow passages and the second fluid flow passages, collectively referred to as flow passages, are spaced apart from adjacent flow passages by a flow divider. 
     
     
         11 . The heat exchanger of  claim 10 , wherein the flow divider acts as a brazing surface for sealing together the base plate and the cover plate. 
     
     
         12 . The heat exchanger of  claim 7 , wherein the cover plate comprises a fluid routing slot that provides fluid communication with the inlet header region and a series of fluid flow openings that provides fluid communication with the second ends of the second fluid flow passages, wherein the fluid flow openings have increasing diameters across a width of the cover plate. 
     
     
         13 . A heat exchanger for thermal management of a battery unit, comprising:
 a rectangular main body portion having a first surface defining a planar, primary heat transfer surface, the first surface extending between a first width and a second width;   an inlet header region located near the first width of the rectangular main body portion;   a first plurality of flow channels extending through the rectangular main body portion from the inlet header region to the second width of the rectangular main body portion;   a plurality of turn portions fluidly connected to each of the first plurality of flow channels located near the second width of the rectangular main body portion;   a second plurality of flow channels extending through the rectangular main body portion from the second width of the rectangular main body portion and ending at a closed outlet end, wherein each of the second plurality of flow channels is fluidly connected to one of the turn portions.   
     
     
         14 . The heat exchanger of  claim 13 , wherein the turn portion is U-shaped. 
     
     
         15 . The heat exchanger of  claim 13 , wherein the second plurality of flow channels is longitudinally staggered with respect to the first plurality of flow channels, and wherein the turn portion turns a fluid travelling in the first plurality of flow channels 180 degrees and into the second plurality of flow channels. 
     
     
         16 . The heat exchanger of  claim 13 , further comprising a manifold section, the manifold section comprising: 
       a plurality of inlet and outlet channels formed within the manifold section each extending from a first open end disposed in the first end surface of the manifold section to a second end disposed within the manifold section;
 a first manifold comprising a row of spaced apart fluid flow openings formed in an upper surface of the manifold section and extending into the manifold section establishing fluid communication with the second end of one of the plurality of inlet channels or the plurality of outlet channels; and 
 a second manifold comprising at least one fluid flow opening formed in the upper surface of the manifold section and extending into the manifold section establishing fluid communication with the second end of the other one of the plurality of inlet channels or the plurality of outlet channels; 
 wherein the row of spaced apart fluid flow openings extends parallel to and is inwardly disposed with respect to the at least one fluid flow opening of the second manifold. 
 
     
     
         17 . A heat exchanger for thermal management of a battery unit having a plurality of battery cell containers each housing one or more battery cells, comprising:
 a base plate;   a plurality of planar first fluid flow passages formed within the base plate, each of the first fluid flow passages extending between spaced apart first and second ends;   a plurality of planar second fluid flow passages formed within the base plate, each of the second fluid flow passages extending between spaced apart first and second ends;   wherein a first flow direction of the first fluid flow passages is opposite to a second flow direction of the second fluid flow passages;   
       wherein the plurality of first fluid flow passages and the plurality of second fluid flow passages are defined by U-shaped flow channels having a pair of elongate fluid branches that are interconnected at one end by a turn portion such that the second ends of the first fluid flow passages are connected to and in fluid communication with the first ends of the second fluid flow passages; and
 a cover plate arranged over top of and in sealing engagement with the base plate enclosing the plurality of first fluid flow passages and the plurality of second fluid flow passages therebetween, the cover plate having a central, generally planar portion defining a primary heat transfer surface. 
 
     
     
         18 . The heat exchanger of  claim 17 , further comprising:
 at least one series of fluid flow openings at a first end of the cover plate;   an inlet manifold with a fluid opening in fluid communication with at least the first ends of the plurality of first fluid flow passages; and   an outlet manifold with a fluid opening in fluid communication with at least the second ends of the second fluid flow passages;   wherein the fluid flow openings are arranged inward from at least one of the inlet manifold fluid opening or the outlet manifold fluid opening; and   wherein one of the inlet manifold and the outlet manifold is offset with respect to the fluid flow openings.   
     
     
         19 . The heat exchanger of  claim 18 , wherein the U-shaped flow channels forming the first and second fluid flow passages are formed by a plurality of U-shaped depressions formed in the central, generally planar portion of the base plate, wherein one of the elongate fluid branches of each U-shaped depression terminates at an open free end, the open free ends of adjacent U-shaped U-shaped depressions being interconnected by an inlet header region formed in the base plate, the inlet header region being in fluid communication with the inlet manifold. 
     
     
         20 . The heat exchanger of  claim 18 , wherein the U-shaped flow channels forming the first and second fluid flow passages are formed by a plurality of U-shaped embossments formed in the central, generally planar portion of the base plate, the U-shaped embossments having two elongate branches that are interconnected at one end thereof by an end portion, wherein each U-shaped embossment comprises one of the first fluid flow passages and one of the second fluid flow passages.