Thermal relief mechanism for combination-type heat exchangers

Abstract

A multi-fluid heat exchanger ( 10 ) is provided for transferring heat between a common fluid and a first fluid in one core section ( 22 ), and between the common fluid and a second fluid in another core section ( 28 ) of the heat exchanger ( 10 ). The core sections ( 22,28 ) are located in a series arrangement with respect to the flow of the common fluid through the heat exchanger ( 10 ) by folding the heat exchanger ( 10 ), with the core sections ( 22,28 ) being connected by folded portions ( 20 ) of the header pipes ( 12,14 ) that direct the first and second fluid flows to the interiors of the core sections ( 22,28 ).

1 . A multi-fluid heat exchanger for transferring heat between a common fluid and a first fluid in one part of the heat exchanger and between the common fluid and a second fluid in another part of the heat exchanger, the heat exchanger comprising:
 a pair of spaced, elongated header pipes to direct the first and second fluids to and from the heat exchanger, each of the header pipes including a first fluid manifold for the first fluid and a second fluid manifold for the second fluid with the first and second fluid manifolds connected by a folded portion of the elongate header pipe;   a first core section to transfer heat between the common fluid and the first fluid as the common and first fluids pass through the first core section, the first core section extending between the header pipes and connected at opposite sides to the first fluid manifold in each header to transfer the first fluid between the header pipes and the first core section; and   a second core section to transfer heat between the common fluid and the second fluid as the common and second fluids pass through the second core section, the second core section extending between the header pipes and connected at opposite sides to the second fluid manifold in each header to transfer the second fluid between the header pipes and the second core section, the second core section positioned downstream from the first core section with respect to a flow direction of the common fluid through the first and second core sections to receive the common fluid after it has passed through the first core section.   
   
   
       2 . The multi-fluid heat exchanger of  claim 1  further comprising a structural support on one of said header pipes and connected to both the first and second fluid manifolds at a location spaced from said folded portion. 
   
   
       3 . The multi-fluid heat exchanger of  claim 1  wherein the first and second manifolds of each header pipe are separated from each other by a cut portion located adjacent the folded portion. 
   
   
       4 . The multi-fluid heat exchanger of  claim 1  wherein each of the header pipes comprises a cylindrical tube having a plurality of tube receiving openings spaced along a length of the header pipe to receive ends of heat exchange tubes from the first and second cores. 
   
   
       5 . The multi-fluid heat exchanger of  claim 4  wherein each of the first and second cores comprises a plurality of parallel, spaced, flattened tubes, each of the tubes having a first end and a second end, with the first end received in one of the header pipes and the second end received in the other header pipe to direct the corresponding one of the first and second fluids between the first and second header pipes through an interior of the tube. 
   
   
       6 . The multi-fluid heat exchanger of  claim 5  wherein each of the first and second cores further comprises corrugated fins extending between adjacent pairs of said tubes. 
   
   
       7 . The multi-fluid heat exchanger of  claim 1  further comprising a third core section to transfer heat between the common fluid and a third fluid as the common and third fluids pass through the third core section, the third core section extending between the header pipes and connected at opposite sides to a third fluid manifold in each header to transfer the third fluid between the header pipes and the third core section, the third fluid manifold connected to one of the first and second fluid manifolds by another folded portion of the elongate header pipe, the third core section positioned relative to at least one of the first and second core sections so that the common fluid passes through the third core section and the at least one of the first and second core sections in series fashion. 
   
   
       8 . A multi-fluid heat exchanger for transferring heat between a first fluid and a common fluid in one part of the heat exchanger and between a second fluid and the common fluid in a second part of the heat exchanger, the heat exchanger comprising:
 a first elongated header pipe having a plurality tube receiving openings spaced along a length of the first header pipe;   a second elongate header pipe having a plurality of tube receiving openings spaced along a length of the second header pipe;   a first core section comprising a plurality of parallel, spaced tubes, each of the tubes having a first end and a second end, with the first end received in a corresponding one of the tube receiving openings of the first header pipe and the second end received in a corresponding one of the tube receiving openings of the second header pipe to direct the first fluid between the first and second header pipes through an interior of the tube;   a second core section comprising a plurality of parallel, spaced tubes, each of the tubes having a first end and a second end, with the first end received in a corresponding one of the tube receiving openings of the first header pipe and the second end received in a corresponding one of the tube receiving openings of the second header pipe to direct the second fluid between the first and second header pipes through an interior of the tube; and   each of the header pipes having a folded portion at a location between the first and second cores to locate the second core downstream from the first core with respect to a flow path of the common fluid through the first and second cores.   
   
   
       9 . The multi-fluid heat exchanger of  claim 8  wherein each of the header pipes comprises a cut adjacent the folded portion between the first and second manifolds. 
   
   
       10 . The multi-fluid heat exchanger of  claim 8  wherein each of the header pipes comprises a cylindrical tube having the tube receiving holes formed therein. 
   
   
       11 . The multi-fluid heat exchanger of  claim 8  further comprising a structural support on one of said header pipes and connected to both the first and second fluid manifolds at a location spaced from said folded portion. 
   
   
       12 . The multi-fluid heat exchanger of  claim 8  wherein the tubes of at least one of the cores are flattened tubes and the at least one of the cores further comprises corrugated fins extending between each adjacent pair of flattened tubes. 
   
   
       13 . The multi-fluid heat exchanger of  claim 7  further comprising a third core section to transfer heat between the common fluid and a third fluid as the common and third fluids pass through the third core section, the third core section extending between the header pipes and connected at opposite sides to a third fluid manifold in each header to transfer the third fluid between the header pipes and the third core section, the third fluid manifold connected to one of the first and second fluid manifolds by another folded portion of the elongate header pipe, the third core section positioned relative to at least one of the first and second core sections so that the common fluid passes through the third core section and the at least one of the first and second core sections. 
   
   
       14 . A method of making a multi-fluid heat exchanger for transferring heat between a first fluid and a common fluid in one part of the heat exchanger and between a second fluid and the common fluid in a second part of the heat exchanger, the method comprising the steps of:
 a) providing a heat exchanger with first and second core sections extending between a pair of elongated header pipes, with each of the header pipes having a first fluid manifold for the first core section and a second fluid manifold for the second core section;   b) providing a cut portion in each of the header pipes at a location between the first and second fluid manifolds, the cut portion leaving at least part of the header pipe connecting the first and second fluid manifolds of the header; and   c) folding the heat exchanger at the cut portion so that the at least part of the header pipe is deformed and the first and second core portions are located in series with respect to a flow path for the common fluid through the first and second core portions.   
   
   
       15 . The method of  claim 14  further comprising the step of connecting the first and second manifolds of at least one of the header pipes to each other at a location spaced from the cut portion after step c). 
   
   
       16 . The method of  claim 14  further comprising the step of brazing the first and second core sections and the pair of elongated header pipes as an assembly prior to step c). 
   
   
       17 . The method of  claim 14  further comprising the step of brazing the first and second core sections and the pair of elongated header pipes as an assembly prior to step b). 
   
   
       18 . The method of  claim 14  further comprising the steps of:
 d) providing the heat exchanger with a third core section extending between the pair of elongate header pipes, with each of the header pipes having a third fluid manifold for the third core section;   e) providing an additional cut portion in each of the header pipes at a location between the third fluid manifold and one of the first and second fluid manifolds, the additional cut portion leaving at least part of the header pipe connecting the third fluid manifold and the one of the first and second fluid manifolds of the header; and   f) folding the heat exchanger at the additional cut portion so that the at least part of the header pipe connecting the third fluid manifold and the one of the first and second fluid manifolds is deformed and the third core section is located in series with at least one of the first and second core sections with respect to a flow path for the common fluid through the third core section and the at least one of the first and second core sections.   
   
   
       19 . A method of making a pair of heat exchangers for transferring heat between a first fluid and a common fluid in one of the heat exchangers and between a second fluid and the common fluid in the other of the heat exchangers, the method comprising the steps of:
 a) providing a heat exchanger with first and second core sections extending between a pair of elongated header pipes, with each of the pipes having a first fluid manifold for the first core section and a second fluid manifold for the second core section; and   b) completely severing each of the header pipes at a location between the first and second fluid manifolds to form the pair of heat exchangers, with one heat exchanger comprising the first fluid manifolds and the first core section, and the other heat exchanger comprising the second fluid manifolds and the second core section.   
   
   
       20 . The method of  claim 19  further comprising the step of securing the pair of heat exchangers to each other so that the first and second core portions are located in series with respect to a flow path for the common fluid through the pair of heat exchangers after step b).