Heat exchanger designs using variable geometries and configurations

Abstract

A heat exchanger may include at least one fluid passageway adjacent a heat transfer plate and a plurality of heat transfer elements positioned in the at least one fluid passageway and joined with the heat transfer plate. The heat transfer elements may be positioned with first spacings therebetween at an inlet end of the at least one fluid passageway. The heat transfer elements may be positioned with second spacings therebetween at an outlet end of the at least one fluid passageway. The first spacings may be smaller than the second spacings.

We claim: 
     
         1 . A heat exchanger comprising:
 at least one fluid passageway adjacent a heat transfer plate; and   a plurality of heat transfer elements positioned in the at least one fluid passageway and joined with the heat transfer plate,   the heat transfer elements being positioned with first spacings therebetween at an inlet end of the at least one fluid passageway,   the heat transfer elements being positioned with second spacings therebetween at an outlet end of the at least one fluid passageway, and   the first spacings being smaller than the second spacings.   
     
     
         2 . The heat exchanger of  claim 1  wherein intermediate heat transfer elements are interposed between the inlet end and the outlet end and are positioned with varying spacings therebetween, said varying spacings progressively increasing in the direction of inlet end to outlet end of the at least one fluid passageway. 
     
     
         3 . The heat exchanger of  claim 1  wherein all of the heat transfer elements are fins oriented orthogonally to the heat transfer plate. 
     
     
         4 . The heat exchanger of  claim 3 :
 wherein the fins have a first thickness at the inlet end of the at least one fluid passageway;   wherein the fins have a second thickness at the outlet end of the at least one fluid passageway; and   wherein the first thickness is greater than the second thickness.   
     
     
         5 . The heat exchanger of  claim 3 :
 wherein the heat transfer plate varies in thickness between the inlet end and the outlet end of the at least one fluid passageway; and   wherein the at least one fluid passageway varies in height between the inlet end and the outlet end of the fluid passageway.   
     
     
         6 . The heat exchanger of  claim 3  wherein fillets are present at joining locations of the fins and the at least one heat transfer plate. 
     
     
         7 . The heat exchanger of  claim 6 :
 wherein the fillets have a first radius at the joining locations of the fins at the inlet end of the heat transfer plate;   wherein the fillets have a second radius at the joining locations of the fins at the outlet end of the heat transfer plate; and   wherein the first radius is greater than the second radius.   
     
     
         8 . The heat exchanger of  claim 1 :
 wherein the at least one transfer plate has a first thickness at the inlet end of the fluid passageway and has a second thickness at the outlet end of the fluid passageway; and   wherein the first thickness of the heat transfer plate is greater than the second thickness of the heat transfer plate.   
     
     
         9 . Apparatus for cooling bleed air extracted from an aircraft engine comprising:
 at least one fluid passageway adjacent a heat transfer plate;   a plurality of fins positioned in the at least one fluid passageway and joined with the heat transfer plate; and   at least one de-icing channel formed in the at least one fluid passageway,   wherein none of the fins are present in the at least one de-icing passageway,   wherein the at least one de-icing channel extends from an inlet end to an outlet end of the at least one fluid passageway, and   wherein a length of the at least one de-icing channel is greater than a length of the at least one fluid passageway.   
     
     
         10 . The apparatus of  claim 9 :
 wherein fillets are present at joining locations of the fins and the at least one heat transfer plate;   wherein the fillets have a first radius at the joining locations of the fins at an inlet end of the heat transfer plate;   wherein the fillets have a second radius at the joining locations of the fins at an outlet end of the heat transfer plate; and   wherein the first radius is greater than the second radius.   
     
     
         11 . The apparatus of  claim 9  wherein the at least one de-icing passageway has a serpentine configuration 
     
     
         12 . The apparatus of  claim 9  wherein the heat transfer plate comprises a flow channeling segment and a main heat transfer segment. 
     
     
         13 . The apparatus of  claim 12  wherein curved fins are joined to the flow channeling segment. 
     
     
         14 . The apparatus of  claim 9  further comprising:
 a plurality of the fluid passageways each fluidly isolated from one another by a one of the heat transfer plates so that first fluid passageways are interposed between second fluid passageways and so that adjacent ones of the first and second fluid passageways are thermally coupled to one another ; 
 wherein the fins are oriented parallel to fluid flow in a first direction within the first fluid passageways; 
 wherein the fins are oriented parallel to fluid flow in a second direction within the second fluid passageways; and 
 wherein the fluid flow in the first direction is orthogonal to the fluid flow in the second direction. 
 
     
     
         15 . The apparatus of  claim 14  wherein each of the first fluid passageways contains at least one of the de-icing passageways. 
     
     
         16 . The apparatus of  claim 14  wherein fillets are present at joining locations of the fins and the heat transfer plates. 
     
     
         17 . A method for cooling bleed air comprising the steps:
 passing bleed air through first fluid passageways of a heat exchanger, the second fluid passageways being thermally coupled with the first fluid passageways; and   passing ambient air through second fluid passageways of the heat exchanger;   wherein the step of passing bleed air through the first fluid passageways comprises,
 a) passing bleed air around first fins having a first thickness at an inlet end of the first fluid passageways so the first fins absorb heat at a maximum temperature differential of the heat exchanger, and 
 b) passing bleed air around second fins having a second thickness, less than the first thickness, at an outlet end of the first fluid passageways so that the second fins produce less bleed air pressure drop than the first fins. 
   
     
     
         18 . The method of  claim 17  further comprising the step of passing the bleed air around curved fins at the inlet end of the first fluid passageways to channel bleed air flow through the heat exchanger. 
     
     
         19 . The method of  claim 17  further comprising passing bleed air through de-icing channels within the first fluid passageways along paths that are longer than the first fluid passageways. 
     
     
         20 . The method of  claim 19  wherein the step of passing bleed air through de-icing channels comprises passing the bleed air along serpentine paths.