Thermal Stress Reduction for Heat Exchanger

Abstract

A heat exchanger with a first manifold and a second manifold. The heat exchanger includes tubes having first and second ends. The tubes connect to the first manifold at the first end and the second manifold at the second end establishing fluid communication between the manifolds. The tubes are arranged parallel and forming gaps between tubes. The heat exchanger includes fin matrices formed from fins that span the gaps and extend from the first end to the second end. At least two adjacent tubes define an expansion gap that accommodates thermal expansion.

We claim: 
     
         1 . A heat exchanger comprising:
 a first manifold and a second manifold;   a plurality of substantially parallelly aligned tubes having a first end and a second end, the plurality of tubes connected to the first manifold at the first end thereof and connected to the second manifold at the second end thereof such that fluid communication is established between the first manifold and the second manifold;   a plurality of gaps disposed between adjacent tubes of the plurality of tubes; and   a plurality of fin matrices, each of the plurality of fin matrices being formed from a plurality of fins, respective individual fin matrices of the plurality of fin matrices each spanning an individual gap of the plurality of gaps and extending from the first end to the second end of the plurality of tubes, respectively;   wherein at least two adjacent tubes define at least one expansion gap that accommodates thermal expansion of the plurality of tubes.   
     
     
         2 . The heat exchanger of  claim 1 , wherein a portion of the at least one expansion gap adjacent to the first manifold is spanned by a partial fin matrix. 
     
     
         3 . The heat exchanger of  claim 1 , wherein portions of the at least one expansion gap adjacent to the first manifold and second manifold are only partially spanned by partial fin matrices. 
     
     
         4 . The heat exchanger of  claim 1 , wherein at least two sets of adjacent tubes define at least two expansion gaps. 
     
     
         5 . The heat exchanger of  claim 1 , further comprising a first tube set, a second tube set, and a third tube set, each tube set separated by one expansion gap, and at least a portion of the expansion gap is not spanned by a fin matrix. 
     
     
         6 . The heat exchanger of  claim 5 , wherein the first tube set, the second tube set, and the third tube set include substantially the same amount of tubes as each other. 
     
     
         7 . An internal combustion engine comprising a heat exchanger, the heat exchanger comprising:
 a first manifold and a second manifold;   a plurality of tubes having a first end and a second end, the plurality of tubes connected to the first manifold at the first end and connected to the second manifold at the second end such that fluid communication is established between the first manifold and the second manifold;   the plurality of tubes arranged parallel to and aligned with each other forming a plurality of gaps between adjacent tubes; and   a plurality of fin matrices formed from a plurality of fins, the fin matrices spanning the plurality of gaps and extending from the first end to the second end of the plurality of tubes;   wherein at least two adjacent tubes define at least one expansion gap that accommodates thermal expansion of the plurality of tubes.   
     
     
         8 . The internal combustion engine of  claim 7 , wherein a portion of the at least one expansion gap adjacent to the first manifold is spanned by a partial fin matrix. 
     
     
         9 . The internal combustion engine of  claim 7 , wherein portions of the at least one expansion gap adjacent to the first manifold and second manifold are spanned by partial fin matrices. 
     
     
         10 . The internal combustion engine of  claim 7 , wherein at least two sets of adjacent tubes define at least two expansion gaps. 
     
     
         11 . The internal combustion engine of  claim 7 , further comprising a first tube set, a second tube set, and a third tube set, each tube set separated by one expansion gap, and at least a portion of the expansion gap is not spanned by a fin matrix. 
     
     
         12 . The internal combustion engine of  claim 11 , wherein the first tube set, the second tube set, and the third tube set include substantially the same amount of tubes as each other. 
     
     
         13 . A method of manufacturing a heat exchanger, the method comprising:
 arranging a plurality of tubes parallel and aligned with each other forming a plurality of gaps between adjacent tubes;   assembling a plurality of fin matrices in a plurality of the gaps formed between adjacent tubes;   assembling at least one spacer in at least a portion of at least one gap;   arranging the plurality of tubes between a first manifold and a second manifold such that fluid communication is created between the first manifold and the second manifold through the plurality of tubes;   coating at least the fin matrices with a braze material;   heating at least the braze material to at least a first predetermined temperature; and   removing the at least one spacer from the at least one gap, forming at least one expansion gap defined by at least two adjacent tubes, the at least one expansion gap accommodating thermal expansion of the plurality of tubes.   
     
     
         14 . The method of manufacturing a heat exchanger of  claim 13  further comprising allowing the braze material to cool to a second predetermined temperature. 
     
     
         15 . The method of manufacturing a heat exchanger of  claim 13  further comprising assembling a partial fin matrix in the at least one gap in which the at least one spacer is assembled, the partial fin matrix adjacent to the first manifold. 
     
     
         16 . The method of manufacturing a heat exchanger of  claim 13  further comprising assembling two partial fin matrices in the at least one gap in which the at least one spacer is assembled, the two partial fin matrices individually adjacent to the first manifold and second manifold. 
     
     
         17 . The method of manufacturing a heat exchanger of  claim 13 , wherein two spacers are assembled in two gaps formed between adjacent tubes. 
     
     
         18 . The method of manufacturing a heat exchanger of  claim 13 , wherein the at least one spacer assembled in the at least one gap is a made up of a plurality of fins. 
     
     
         19 . The method of manufacturing a heat exchanger of  claim 13  further comprising assembling a first tube set, a second tube set, and a third tube set, each tube set separated by at least one expansion gap. 
     
     
         20 . The method of manufacturing a heat exchanger of  claim 19 , wherein the first tube set, second tube set, and third tube set include substantially the same amount of tubes as one other.