Compact high temperature heat exchanger, such as a recuperator

Abstract

A heat exchanger for transferring heat energy between a first working fluid and a second working fluid. The heat exchanger can include a first sheet contoured to define a plurality of first fins and having an upper end and a lower end, a second sheet contoured to define a plurality of second fins and being positioned between the upper end of the first sheet and the lower end of the first sheet, and a housing formed from a third sheet and at least partially enclosing the first sheet and the second sheet.

1 . A heat exchanger for transferring heat energy between a first working fluid and a second working fluid, the heat exchanger comprising: 
 a pair of first fins formed from a single sheet and at least partially defining a flow path for the first working fluid; and    a second fin positioned between the pair of first fins and at least partially defining a flow path for the second working fluid, the flow path of the first working fluid being separated from the flow path of the second working fluid.    
   
   
       2 . The heat exchanger of  claim 1 , wherein a flow direction of the first working fluid through the heat exchanger is substantially counter to a flow direction of the second working fluid.  
   
   
       3 . The heat exchanger of  claim 1 , wherein the second fin is formed from a corrugated sheet.  
   
   
       4 . The heat exchanger of  claim 3 , wherein the pair of first fins are corrugations formed along the sheet.  
   
   
       5 . The heat exchanger of  claim 1 , wherein an end of the second fin is secured to one of the pair of first fins and an other end of the second fin is secured to an other of the pair of first fins.  
   
   
       6 . The heat exchanger of  claim 1 , wherein a pair of second fins are positioned along the flow path of the second working fluid, the second fin being one of the pair of second fins.  
   
   
       7 . The heat exchanger of  claim 6 , wherein the pair of second fins are formed from a single sheet.  
   
   
       8 . The heat exchanger of  claim 7 , wherein the pair of second fins are corrugations formed along the sheet.  
   
   
       9 . The heat exchanger of  claim 7 , wherein the pair of first fins have an upper end and a lower end, and wherein the second sheet is positioned between the upper end of the pair of fins and the lower end of the pair of first fins.  
   
   
       10 . The heat exchanger of  claim 1 , wherein the pair of first fins are formed from a first corrugated sheet, wherein the second fin is formed from a second corrugated sheet, and wherein a housing is formed from a third sheet, the housing at least partially enclosing the first sheet and the second sheet.  
   
   
       11 . The heat exchanger of  claim 10 , wherein the first sheet and the third sheet substantially enclose the flow path for the first working fluid, and wherein the first sheet, the second sheet, and the third sheet together at least partially enclose the flow path for the second working fluid.  
   
   
       12 . The heat exchanger of  claim 10 , wherein the second sheet is nested in the first sheet between the pair of first fins.  
   
   
       13 . A heat exchanger for transferring heat energy between a first working fluid and a second working fluid, the heat exchanger comprising: 
 a first corrugated sheet having a pair of peaks and separating a flow path for the first working fluid from a flow path for the second working fluid; and    a second corrugated sheet positioned between the pair of peaks of the first corrugated sheet.    
   
   
       14 . The heat exchanger of  claim 13 , wherein a flow direction of the first working fluid along the flow path is substantially counter to a flow direction of the second working fluid along the flow path.  
   
   
       15 . The heat exchanger of  claim 13 , wherein the second sheet has a pair of peaks, and wherein the pair of peaks of the second sheet are secured to one of the pair of peaks of the first sheet.  
   
   
       16 . The heat exchanger of  claim 13 , wherein a side of the second sheet is secured to one of the pair of peaks of the first sheet and an other side of the second sheet is secured to an other of the pair of peaks of the first sheet.  
   
   
       17 . The heat exchanger of  claim 13 , wherein the first sheet has a lower end, wherein the pair of peaks of the first sheet provide an upper end, and wherein the second sheet is positioned between the upper end and the lower end of the first sheet.  
   
   
       18 . The heat exchanger of  claim 13 , wherein a housing is formed from a third sheet, the housing at least partially enclosing the first sheet and the second sheet.  
   
   
       19 . The heat exchanger of  claim 18 , wherein the first sheet and the third sheet substantially enclose the flow path for the first working fluid, and wherein the first sheet, the second sheet, and the third sheet together at least partially enclose the flow path for the second working fluid.  
   
   
       20 . The heat exchanger of  claim 13 , wherein the second sheet is nested in the first sheet between the pair of peaks of the first sheet.  
   
   
       21 . A method of assembling a heat exchanger, the method comprising the acts of: 
 corrugating a first sheet to define a pair of peaks and to at least partially define a flow path for a first working fluid and a flow path for a second working fluid;    corrugating a second sheet; and    nesting the second sheet in the first sheet between the pair of peaks and along the flow path for the second working fluid.    
   
   
       22 . The method of  claim 21 , wherein nesting the second sheet between the pair of peaks includes securing an end of the second sheet to one of the pair of the peaks of the first sheet and securing an other end of the second sheet to an other of the pair of peaks of the first sheet.  
   
   
       23 . The method of  claim 21 , further comprising securing a third sheet to the peaks of the first sheet to at least partially enclose the first flow path.  
   
   
       24 . The method of  claim 23 , wherein securing the third sheet to the peaks of the first sheet includes at least partially enclosing the second flow path between the peaks of the first sheet and the third sheet.  
   
   
       25 . The method of  claim 21 , wherein corrugating the first sheet includes defining a second pair of peaks, and further comprising corrugating a third sheet and nesting the third sheet in the first sheet between the second pair of peaks.  
   
   
       26 . The method of  claim 21 , wherein nesting the second sheet between the pair of peaks includes positioning the second sheet between an upper end of the first sheet and a lower end of the first sheet.  
   
   
       27 . A heat exchanger for transferring heat energy between a first working fluid and a second working fluid, the heat exchanger comprising: 
 a first sheet contoured to define a plurality of first fins and having an upper end and a lower end;    a second sheet contoured to define a plurality of second fins and being positioned between the upper end of the first sheet and the lower end of the first sheet; and    a housing formed from a third sheet and at least partially enclosing the first sheet and the second sheet.    
   
   
       28 . The heat exchanger of  claim 27 , wherein the housing defines an inlet and an outlet for a Mow path for the first working fluid and defines an inlet and an outlet for a flow path for the second working fluid.  
   
   
       29 . The heat exchanger of  claim 28 , wherein the second sheet is positioned along the flow path of the second working fluid.  
   
   
       30 . The heat exchanger of  claim 28 , wherein a flow direction of the first working fluid is substantially counter to a flow direction of the second working fluid.  
   
   
       31 . The heat exchanger of  claim 27 , wherein the second sheet is nested in the first sheet between two of the plurality of first fins.  
   
   
       32 . The heat exchanger of  claim 27 , wherein the plurality of first fins are corrugations formed along the first sheet.  
   
   
       33 . The heat exchanger of  claim 27 , wherein a side of the first sheet is secured to one of the plurality of first fins and an other side of the second sheet is secured to an other of the plurality of first fins.  
   
   
       34 . The heat exchanger of  claim 27 , wherein the plurality of second fins are corrugations formed along the second sheet.