Heat Exchanger For Gas, Particularly For Engine Exhaust Gases

Abstract

A heat exchanger uses engine exhaust gases. The heat exchanger comprises a plurality of parallel tubes arranged inside a header and through which the gases to be cooled by exchange of heat with a coolant flow, and fins that disturb the flow of the gas and that are arranged inside each tube. The tubes and the header comprise a plurality of protrusions and respectively, the distribution pattern and dimensions of which are defined according to the dimensions of the tubes and of the header and which are able to guarantee suitable distribution of the compression between the header, the tubes and the fins relative to one another while the heat exchanger is being assembled and brazed in the furnace.

1 . A heat exchanger ( 1 ) for exhaust gases of an engine, the heat exchanger ( 1 ) comprising a plurality of parallel tubes ( 2 ) which are arranged inside a casing ( 3 ) and via which the gases to be cooled by means of heat exchange with a cooling fluid circulate, and fins ( 9 ) which disrupt the flow of gas and which are arranged inside each tube ( 2 ), wherein the tubes ( 2 ) and the casing ( 3 ) comprise a plurality of protuberances ( 10 ) and ( 11 ), respectively, whose distribution pattern and dimensions are defined in accordance with dimensions of the tubes ( 2 ) and the casing ( 3 ), and which are capable of ensuring appropriate distribution of the compression between the casing ( 3 ), the tubes ( 2 ) and the fins ( 9 ) with respect to one another during furnace soldering of the heat exchanger ( 1 ). 
     
     
         2 . The heat exchanger ( 1 ) according to  claim 1 , wherein the protuberances ( 10 ,  11 ) are produced by means of stamping, each protuberance ( 10 ,  11 ) comprising a protruding contact surface ( 12 ) which is substantially planar and circular and a frustoconical side defined by a stamping angle (A) and connection radii (RR) relative to said contact surface ( 12 ) and to the surface of the tube ( 2 ) or the casing ( 3 ) where the protuberance ( 10 ,  11 ) is stamped. 
     
     
         3 . The heat exchanger ( 1 ) according to  claim 2 , wherein the dimensions of the protuberances ( 10 ,  11 ) of the tubes ( 2 ) and the casing ( 3 ), respectively, are defined by their diameter (D) and their height (H) and the stamping angle (A) and the connection radii (RR) at the frustoconical side. 
     
     
         4 . The heat exchanger ( 1 ) according to  claim 1 , wherein the distribution pattern of the protuberances ( 10 ) on the tubes ( 2 ) is defined in accordance with the thickness (T1), the width (W1) and the length (L1) of the tube ( 2 ) itself, the tubes ( 2 ) having a substantially rectangular cross-section and being provided with two opposing flat sides (W1) which are wider than they are high. 
     
     
         5 . The heat exchanger ( 1 ) according to  claim 4 , wherein the protuberances ( 10 ) are arranged on the two opposing flat sides of the tubes ( 2 ), directed towards the outside of the tube ( 2 ) and distributed over one or more longitudinal rows in accordance with the width (W1) of the tube ( 2 ). 
     
     
         6 . The heat exchanger ( 1 ) according to  claim 5 , wherein the protuberances ( 10 ) of the same row on the tubes ( 2 ) are spaced apart by a predetermined distance (DD, DDH) defined by the length (L1) of the tube ( 2 ), and the first protuberance ( 10 ) of the corresponding row is arranged relative to an of the tube ( 2 ) at a predetermined distance (DDE) which is also defined by the length (L1) of the tube ( 2 ). 
     
     
         7 . The heat exchanger ( 1 ) according to  claim 5 , wherein the protuberances ( 10 ) on the tubes ( 2 ) are distributed over two parallel, longitudinal rows which are equidistant relative to a longitudinal axis of symmetry and spaced apart by a predetermined distance (DDV) which is defined in accordance with the width (W1) of the tube ( 2 ). 
     
     
         8 . The heat exchanger ( 1 ) according to  claim 7 , wherein between the two rows of protuberances ( 10 ) on the tubes ( 2 ) there are two reinforcement protuberances ( 10   a ) which are each located relative to the opposing ends of the tube ( 2 ) at a predetermined distance (DDE1, DDE2) defined by the length (L1) of the tube ( 2 ). 
     
     
         9 . The heat exchanger ( 1 ) according to  claim 1 , wherein the distribution pattern of the protuberances ( 11 ) on the casing ( 3 ) is defined in accordance with a width (W1) and thickness (T2) of the tube ( 2 ), a width (W2) and length (L2) of the casing ( 3 ), with the casing ( 3 ) having a substantially rectangular cross-section. 
     
     
         10 . The heat exchanger ( 1 ) according to  claim 9 , wherein the protuberances ( 11 ) are arranged on at least one side of the casing ( 3 ), directed towards the inside of the casing ( 3 ) and distributed in one or more groups of two longitudinal rows in accordance with the width (W2) of the casing ( 3 ). 
     
     
         11 . The heat exchanger ( 1 ) according to  claim 10 , wherein the protuberances ( 11 ) of the same row are spaced apart by a predetermined distance (DD, DDH) which is defined by the length (L2) of the casing ( 3 ) and the first protuberance ( 11 ) of the corresponding row is arranged relative to one of the casing ( 3 ) at a predetermined distance (DDE) which is also defined by the length (L2) of the casing ( 3 ). 
     
     
         12 . The heat exchanger ( 1 ) according to  claim 10 , wherein the protuberances ( 11 ) are distributed in two groups of two parallel, longitudinal rows which are spaced apart by a predetermined distance (DDV) defined in accordance with the width (W2) of the casing ( 3 ), and the two groups of two rows are arranged so as to be equidistant relative to the longitudinal axis of symmetry. 
     
     
         13 . The heat exchanger ( 1 ) according to  claim 12 , wherein between the two rows of protuberances ( 11 ) of each group there are two reinforcement protuberances ( 11   a ) which are each located relative to the opposite ends of the casing ( 3 ) at a predetermined distance (DDE1) which is defined by the length (L2) of the casing ( 3 ). 
     
     
         14 . The heat exchanger ( 1 ) according to  claim 1 , wherein the protuberances ( 10 ,  11 ) may have different shapes such as, circular, cross-like, diamond-like or linear. 
     
     
         15 . The heat exchanger ( 1 ) according to  claim 2 , wherein the distribution pattern of the protuberances ( 10 ) on the tubes ( 2 ) is defined in accordance with the thickness (T1), the width (W1) and the length (L1) of the tube ( 2 ) itself, the tubes ( 2 ) having a substantially rectangular cross-section and being provided with two opposing flat sides (W1) which are wider than they are high.