Heat exchanger, fluorination method of heat exchanger or its components and manufacturing method of heat exchanger

Abstract

The heat exchanger according to the present invention includes a heat exchanger component in which a fluoride layer 10 is formed at the surface layer portion. It is preferable that the fluoride layer 10 falls within the range of from 2 nm to 10 μm in thickness. It is preferable that the component is at least one of a fin and a plate. Furthermore, it is preferable that the fluoride layer 10 is formed on a substrate via an intermediate layer 2. It is preferable that the intermediate layer 2 includes an anodized oxide layer 3 and/or a nickel plated layer 4. The heat exchanger is excellent in corrosion resistance against water, vapor and the like The heat exchanger is preferably used, especially, for a fuel cell.

What is claimed is:  
     
         1 . A heat exchanger including a heat exchanger component having a surface layer portion in which a fluoride layer is formed.  
     
     
         2 . The heat exchanger as recited in  claim 1 , wherein a thickness of said fluoride layer falls within the range of from 2 nm to 10 μm.  
     
     
         3 . The heat exchanger as recited in  claim 1 , wherein said heat exchanger is a fin-plate type heat exchanger, and wherein said component is at least one of a fin and a plate.  
     
     
         4 . The heat exchanger as recited in  claim 1 , wherein said heat exchanger uses water as heat medium.  
     
     
         5 . The heat exchanger as recited in  claim 1 , wherein said beat exchanger is used under a water environment, a vapor environment, or a fuel gas environment of a fuel cell.  
     
     
         6 . The heat exchanger as recited in  claim 1 , wherein a layer containing catalyst is formed on a surface of said fluoride layer.  
     
     
         7 . The heat exchanger as recited in  claim 1 , wherein said heat exchanger is for use in a fuel cell.  
     
     
         8 . The heat exchanger as recited in  claim 1 , wherein said heat exchanger is a fin-plate type heat exchanger for a fuel tell to be used under a fuel gas environment of a fuel cell, and wherein a layer containing catalyst for accelerating a reaction of carbon monoxide contained in the fuel gas and oxygen.  
     
     
         9 . The heat exchanger as recited in  claim 1 , wherein a substrate of said component is substantially made of aluminum or its alloy.  
     
     
         10 . The heat exchanger as recited in  claim 1 , wherein said fluoride layer is formed on a surface of a substrate of said component.  
     
     
         11 . The heat exchanger as recited in  claim 10 , wherein said fluoride layer is substantially made of fluoride generated by performing fluorination processing of said surface of said substrate.  
     
     
         12 . The heat exchanger as recited in  claim 1 , wherein said fluoride layer is formed on a surface of an intermediate layer formed on a surface of a substrate of said component.  
     
     
         13 . The heat exchanger as recited in  claim 12 , wherein said fluoride layer is substantially made of fluoride generated by performing fluorination processing of said surface of said intermediate layer.  
     
     
         14 . The heat exchanger as recited in  claim 12  or  13 , wherein said intermediate layer includes a layer which is substantially made of oxide generated by performing forcible oxidation of said surface of said substrate.  
     
     
         15 . The heat exchanger as recited in  claim 12  or  13 , wherein said intermediate layer includes an anodized oxide layer formed by anodizing said surface of said substrate.  
     
     
         16 . The heat exchanger as recited in  claim 1 , wherein said fluoride layer is formed on a surface of an anodized oxide layer formed by anodizing a surface of a substrate of said component and substantially made of fluoride generated by performing fluorination processing of said surface of said anodized oxide layer.  
     
     
         17 . The heat exchanger as recited in  claim 1 , wherein said fluoride layer is formed on a surface of a plated layer containing nickel formed on a surface of a substrate of said component and substantially made of fluoride generated by performing fluorination processing of said surface of said plated layer.  
     
     
         18 . The heat exchanger as recited in  claim 17 , wherein said plated layer is substantially made of electroless nickel plating.  
     
     
         19 . The heat exchanger as recited in  claim 17 , wherein said plated layer is substantially made of electroless nickel-phosphorus alloy plated layer.  
     
     
         20 . The heat exchanger as recited in  claim 1 , wherein said fluoride layer is formed on a surface of a plated layer constituting an intermediate layer including an anodized oxide layer formed by anodizing a surface of a substrate of said component and said plated layer formed on a surface of said anodized oxide layer and containing nickel, and substantially made of fluoride generated by performing fluorination processing of said surface of said plated layer.  
     
     
         21 . The heat exchanger as recited in  claim 20 , wherein said plated layer is substantially made of electroless nickel plating.  
     
     
         22 . The heal exchanger as recited in  claim 20 , wherein said plated layer is substantially made of electroless nickel-phosphorus alloy plating.  
     
     
         23 . A method of fluorinating a heat exchanger or its component, comprising: 
 heating a heat exchanger or its component in an atmosphere containing a fluorination processing gas to thereby form a fluoride layer in a surface layer portion of said heat exchanger or its component.    
     
     
         24 . The method of fluorinating a heat exchanger or its component as recited in  claim 23 , wherein said fluorination processing gas is at least one gas selected from the group consisting of a fluorine gas, a chlorine trifluoride gas and a nitrogen fluoride gas, wherein an inert gas is used as a base gas of said atmosphere, and wherein concentration of said fluorine gas or that of said fluoride gas is set so as to fall within the range of from 5 to 80 mass %.  
     
     
         25 . The method of fluorinating a heat exchanger or its component as recited in  claim 24 , wherein said concentration of said fluorine gas or that of said fluoride gas is set so as to fall within the range of from 10 to 60 mass %.  
     
     
         26 . The method of fluorinating a heat exchanger or its component as recited in  claim 23 , wherein said heating is performed under a heat processing condition that a holding temperature is 100° C. or more and a holding time is 5 hours or more.  
     
     
         27 . A method of fluorinating a heat exchanger or its component, comprising: 
 implanting an ionized fluorine into at least a part of a surface of a heat exchanger or its component to thereby form a fluoride layer on a surface layer portion of said heat exchanger or its component.    
     
     
         28 . A method of manufacturing a heat exchanger, comprising: 
 a heating step for heating a heat exchanger component in an atmosphere containing a fluorination processing gas; and    a fixing step for fixing said component processed by said heating step to a predetermined position of a desired heat exchanger.    
     
     
         29 . The method of manufacturing a heat exchanger as recited in  claim 28 , further comprising a catalyst containing layer forming step for forming a layer containing catalyst on a surface of said component processed by said heating step.  
     
     
         30 . A method of manufacturing a heat exchanger, comprising: 
 a fluorine implanting step for implanting an ionized fluorine into at least a part of a surface of a heat exchanger component; and    a fixing step for fixing said component processed by said fluorine implanting step to a predetermined position of a desired heat exchanger.    
     
     
         31 . The method of manufacturing a heat exchanger according to  claim 30 , further comprising a catalyst containing layer forming step for forming a layer containing catalyst on a portion of said surface of said component processed by said fluorine implanting stop to which said fluorine is implanted.  
     
     
         32 . A method of manufacturing a heat exchanger, comprising: 
 a heating step for heating a heat exchanger assembly in an atmosphere containing a fluorination processing gas, wherein said heat exchanger assembly is formed by assembling a plurality of heat exchanger components and integrally brazing said plurality of heat exchanger components in an assembled state.    
     
     
         33 . The method of manufacturing a heat exchanger as recited in  claim 32 , further comprising a catalyst containing layer forming step for forming a layer containing catalyst on a surface of said assembly processed by said heating step.  
     
     
         34 . A method of manufacturing a heat exchanger, comprising: 
 a fluorine implanting step for implanting an ionized fluorine into at least a part of a surface of a heat exchanger assembly, wherein said heat exchanger assembly is formed by assembling a plurality of heat exchanger components and integrally brazing said plurality of heat exchanger components in an assembled state.    
     
     
         35 . The method of manufacturing a heat exchanger as recited in  claim 34 , further comprising a catalyst containing layer forming step for forming a layer containing catalyst on a portion of said surface of said assembly processed by said fluorine implanting step to which said fluorine is implanted.