Coating wear sensor assembly for monitoring deterioration of heat exchanger coating

Abstract

A heat exchanger assembly includes a coated core and an electronic coating wear sensor assembly mounted adjacent to the coated core for monitoring depletion of a coating layer of the core. The coating wear sensor assembly is electrically insulated from the coated core to ensure that an electric circuit of the coating wear sensor assembly does not affect deterioration of the core. The sensor assembly has a pair of spaced electrodes electrically insulated from each other by an insulating spacer forming a coating sample area coated with a sample layer of the coating material that provides conductive bridge between the electrodes. The coating sample area is coated with the same coating composition of the same thickness as the heat exchanger core in order to replicate the same rate coating degradation. The coating wear sensor assembly is connected to a sensing circuit that outputs to a coating condition diagnostic unit.

What is claimed is:  
     
         1 . A heat exchanger assembly comprising: 
 a heat exchanger including a first tank, a second tank and a heat exchanger core extending between the first tank and the second tank for providing a fluid communication therebetween;    said heat exchanger core coated with a coating layer of a coating material; and    an electronic coating wear sensor assembly for detecting a deterioration of said coating layer, said coating wear sensor assembly having at least one pair of spaced electrodes electrically insulated from each other by an insulating spacer,    a surface of said sensor assembly adjacent to said electrodes forms a coating sample area coated with a sample layer of said coating material, said sample layer of said coating material provides a conductive bridge between said electrodes;    said coating sample area of said coating wear sensor assembly is electrically insulated from said coating layer of said heat exchanger core.    
     
     
         2 . The heat exchanger assembly as defined in  claim 1 , wherein said coating material is a catalytic coating composition provided for reducing airborne pollutant elements that pass through said heat exchanger core.  
     
     
         3 . The heat exchanger assembly as defined in  claim 1 , wherein a thicness of said sample layer of said coating material on said coating sample area is substantially the same as a thicness of said coating layer of said coating material on said heat exchanger core.  
     
     
         4 . The heat exchanger assembly as defined in  claim 1 , wherein said coating sample area of said coating wear sensor assembly is mounted adjacent to said heat exchanger core.  
     
     
         5 . The heat exchanger assembly as defined in  claim 1 , wherein said coating wear sensor assembly is a resistance measuring sensor provided to measure an electrical resistance of said coating sample layer of said coating material.  
     
     
         6 . The heat exchanger assembly as defined in  claim 1 , wherein said coating wear sensor assembly comprises a sensor body and a fastener assembly provided for securing said sensor body to said heat exchanger core, said sensor body includes said at least one pair of said spaced electrodes and defines said coating sample area, said fastener assembly includes a fastener member having a shaft extending through said heat exchanger core and a retainer secured to said shaft for clamping said core between said sensor body and said retainer.  
     
     
         7 . The heat exchanger assembly as defined in  claim 6 , wherein said fastener member is formed integral with said sensor body.  
     
     
         8 . The heat exchanger assembly as defined in  claim 6 , wherein said shaft of said fastener member has a threaded outer peripheral surface adapted to threadedly engage said retainer.  
     
     
         9 . The heat exchanger assembly as defined in  claim 6 , wherein said threaded shaft of said fastener assembly is made of a heat conductive material and functions as a heat-conducting conduit that carries a thermal energy from said heat exchanger core to said coating sample area for substantially equalizing a temperature of said coating sample area with a temperature of said heat exchanger core.  
     
     
         10 . The heat exchanger assembly as defined in  claim 1 , wherein said coating wear sensor assembly further including a heat-conducting conduit that carries a thermal energy from said heat exchanger core to said coating sample area for substantially eqilizing a temperature of said coating sample area with a temperature of said heat exchanger core.  
     
     
         11 . The heat exchanger assembly as defined in  claim 6 , further including a canopy cover providing a coating spray protection during a coating process to said shaft of said fastener member keeping it free from said coating material and insulated from said coating sample area.  
     
     
         12 . The heat exchanger assembly as defined in  claim 6 , wherein said sensor body of said electronic coating wear sensor assembly includes at least one pair of substantially disk-shaped electrodes separated by a substantially disk-shaped insulator spacer, and 
 wherein circumferentially outer peripheral surfaces of said electric electrodes and said insulator spacer form said coating sample surface.    
     
     
         13 . The heat exchanger assembly as defined in  claim 12 , wherein said sensor body of said electronic coating wear sensor assembly further includes an insulator cover disposed between said sensor body and said heat exchanger core for electrically isolating said coating sample surface of said sensor assembly from said heat exchanger core and preventing stray current from passing through said heat exchanger core and functions as a canopy cover that provides a coating spray protection during a coating process to said shaft of said fastener member keeping it free from said coating material and insulated from said coating sample area.  
     
     
         14 . The heat exchanger assembly as defined in  claim 11 , wherein said canopy cover is in the form of an insulator cover disposed between said sensor body and said heat exchanger core.  
     
     
         15 . The heat exchanger assembly as defined in  claim 6 , wherein said sensor body of said electronic coating wear sensor assembly has a substantially cup-shaped body and a fastener shaft coaxially extending from said cup-shaped body for securing said sensor assembly to said heat exchanger core.  
     
     
         16 . The heat exchanger assembly as defined in  claim 15 , wherein said fastener shaft is formed integrally with said cup-shaped body.  
     
     
         17 . The heat exchanger assembly as defined in  claim 6 , wherein said sensor body of said electronic coating wear sensor assembly has a substantially box-shaped body and a fastener shaft coaxially extending from said box-shaped body for securing said sensor assembly to said heat exchanger core.  
     
     
         18 . The heat exchanger assembly as defined in  claim 17 , wherein said fastener shaft is formed integrally with said cup-shaped body.  
     
     
         19 . The heat exchanger assembly as defined in  claim 6 , wherein said sensor body of said electronic coating wear sensor assembly including a bottom wall and a sidewall extending from said bottom wall.  
     
     
         20 . The heat exchanger assembly as defined in  claim 19 , wherein said coating sample area is formed on said bottom wall of said sensor body.  
     
     
         21 . The heat exchanger assembly as defined in  claim 19 , wherein said coating sample area is formed on said sidewall of said sensor body.  
     
     
         22 . The heat exchanger assembly as defined in  claim 1 , wherein said fastener assembly of said coating wear sensor assembly includes a fastener sleeve extending through said heat exchanger core and a push pin provided to penetrate into said fastener sleeve for radially expanding said fastener sleeve thereby firmly engaging said heat exchanger core and securing said coating wear sensor assembly thereto.  
     
     
         23 . The heat exchanger assembly as defined in  claim 1 , wherein said coating wear sensor assembly further includes a sensing circuit provided for monitoring an electrical resistance change of said sample layer of said coating material on said coating sample area and for providing an interpretive output to a coating condition diagnostic unit.  
     
     
         24 . The heat exchanger assembly as defined in  claim 1 , further including an ID tag provided to identify a date of applying said coating layer to said heat exchanger assembly and a composition of said coating material.