Formed microchannel heat exchanger

Abstract

A heat exchanger includes a plurality of heat exchange layers stacked in a stackwise direction. Each of the layers includes a first plate and a second plate, each of the first plate and the second plate includes a portion of a first enclosed header, a second enclosed header and at least one flow channel that extends between the first enclosed header and the second enclosed header. The first plate and the second plate are fixedly attached to one another to completely define the first enclosed header, the second enclosed header, and the at least one flow channel. An inlet header is in fluid communication with the first enclosed header of each of the plurality of heat exchange layers to direct a flow of fluid to the heat exchange layers. An outlet header is in fluid communication with the second enclosed header of each of the plurality of heat exchange layers to direct the flow of fluid from the heat exchange layers. The heat exchanger also includes a plurality of fins with each positioned between adjacent heat exchange layers.

1 - 18 . (canceled) 
     
     
         19 . A heat exchanger comprising:
 a plurality of heat exchange layers arranged in a stackwise direction, each of the heat exchange layers including an inlet and an outlet;   an inlet header fluidly coupled to the plurality of heat exchange layers, the inlet header having an outer wall with a central axis extending along a longitudinal length thereof and an inner wall disposed within the outer wall to define a first space therebetween, the outer wall coupled to at least one of the plurality of heat exchange layers to provide fluid communication between the first space and the inlet; and   a filler plug disposed within the inner wall to define a second space therebetween, the second space in fluid communication with an inlet conduit to receive a flow of fluid, the second space having a flow cross sectional area normal to the central axis, the flow cross sectional area varying along the length of the central axis.   
     
     
         20 . The heat exchanger of  claim 19 , wherein the inner wall includes a plurality of ribs that cooperate with the outer wall of the inlet header to divide the first space into a plurality of separate annular spaces. 
     
     
         21 . The heat exchanger of  claim 20 , wherein the number of annular spaces is equal to the number of heat exchange layers. 
     
     
         22 . The heat exchanger of  claim 19 , wherein the filler plug includes a portion having a non-circular cross-section taken normal to the longitudinal axis, the filler plug cross-section varying along the length of the central axis. 
     
     
         23 . The heat exchanger of  claim 19 , wherein the inner wall includes an inlet aperture near a first end, the inlet aperture arranged to receive the flow of fluid, and wherein the flow cross sectional area of the second space decreases as the distance from the inlet increases. 
     
     
         24 . The heat exchanger of  claim 20  wherein a portion of each rib engages with the outer wall of the inlet header. 
     
     
         25 . The heat exchanger of  claim 20  further comprising an outlet aperture formed through the inner wall proximate each of the annular spaces. 
     
     
         26 . The heat exchanger of  claim 19 , wherein each of the heat exchange layers include a first plate and a second plate, each of the first and the second plates includes a portion of a first enclosed header, a second enclosed header and at least one flow channel that extends between the first enclosed header and the second enclosed header, the first plate and the second plate attached to one another to define the first enclosed header, the second enclosed header, and the flow channel. 
     
     
         27 . The heat exchanger of  claim 26  further comprising an outlet header in fluid communication with the second enclosed header of at least one of the plurality of heat exchange layers. 
     
     
         28 . The heat exchanger of  claim 27 , wherein the outlet header includes an inner wall and an outer wall spaced apart from one another to form an outer annual flow area. 
     
     
         29 . The heat exchanger of  claim 28  further comprising a filler plug positioned inward of the inner wall of the outlet header. 
     
     
         30 . The heat exchanger of  claim 29 , wherein the filler plug includes a non-circular cross-section that varies along a length thereof. 
     
     
         31 . The heat exchanger of  claim 29  further comprising an inner annual flow area defined by a space between the filler plug and the inner wall of the outlet header. 
     
     
         32 . The heat exchanger of  claim 31  wherein the inner annual flow area decreases from one end to an opposing end of the outlet header. 
     
     
         33 . The heat exchanger of  claim 28 , wherein the inner wall of the outlet header includes a plurality of ribs positioned along a longitudinal length thereof. 
     
     
         34 . The heat exchanger of  claim 33 , wherein each of the ribs protrude outward to engage with the outer wall of the outlet header to divide the outer annual flow area into a plurality of separate annular spaces. 
     
     
         35 . The heat exchanger of  claim 34  further comprising an outlet aperture formed through the inner wall proximate each of the annular spaces. 
     
     
         36 . The heat exchanger of  claim 27  further comprising at least one fin positioned between adjacent heat exchange layers; and
 wherein the at least one flow channel directs the fluid between the inlet header and the outlet header and the at least one fin direct a second fluid in a direction that is substantially normal to a flow direction of the fluid. 
 
     
     
         37 . The heat exchanger of  claim 26 , wherein the at least one flow channel extends in a substantially U-shape configuration from the first enclosed header to the second enclosed header disposed adjacent to one another at a same end of the heat exchange layer. 
     
     
         38 . The heat exchanger of  claim 37 , wherein the at least one U-shaped flow channel defines a first flow leg that directs flow in a first direction and a second flow leg that directs the flow in a second direction opposite the first direction. 
     
     
         39 . The heat exchanger of  claim 38  further comprising a thermal break positioned between the first flow leg and the second flow leg in a heat exchange layer. 
     
     
         40 . The heat exchanger of  claim 26 , wherein the first plate is substantially the same as the second plate.