Heat Exchangers and Systems Thereof

Abstract

Improved heat exchangers and methods of manufacturing the heat exchangers are provided. The methods include modification of surface(s) of the heat exchanger in an integrated manner during manufacturing, to impart desired properties such as decreased corrosion, pressure drop, and water retention, and increased anti-frosting performance.

1 . A method for manufacturing a heat exchanger, comprising integrating modification of one or more substrate surface of the heat exchanger with manufacture of the heat exchanger,
 wherein one or more substrate surface a heat exchanger is modified with a surface modification material, and   wherein the surface modification is performed prior to completion of manufacture of the complete heat exchanger structure.   
     
     
         2 . The method according to  claim 1 , wherein said modification of one or more substrate surface comprises:
 (a) depositing the surface modification material on the one or more substrate surface of the heat exchanger;   (b) treating the deposited surface modification material to remove moisture, an anionic compound, a binder, and/or a solvent; and   (c) optionally, depositing a second layer of material onto the surface modification material to provide one or more functional properties to the surface.   
     
     
         3 . The method according to  claim 2 , wherein the surface modification changes the wettability, ultraviolet (UV) protection, corrosion resistance, surface energy modulation, and/or aesthetic modification, in comparison to an identical substrate surface that does not comprise the surface modification. 
     
     
         4 . The method according to  claim 1 , wherein the heat exchanger is a microchannel heat exchanger (MCHE). 
     
     
         5 . The method according to  claim 1 , wherein the substrate surface comprises a surface of a manifold, a fin, a tube, and/or a microchannel. 
     
     
         6 . The method according to  claim 1 , wherein said modification of one or more substrate surface comprises an additive barrier coating method, a conversion coating method, or a combination thereof. 
     
     
         7 . The method according to  claim 1 , wherein the manufacturing method comprises a brazing step and a step for attachment of fluidic interconnects, and wherein the surface modification is conducted either (a) after brazing and prior to attachment of the fluidic interconnects, or (b) prior to brazing. 
     
     
         8 . (canceled) 
     
     
         9 . The method according to  claim 1 , wherein the manufacturing method comprises a brazing step, wherein flux material is applied to the substrate surface prior to brazing, and wherein the surface modification and flux brazing are conducted concomitantly. 
     
     
         10 . The method according to  claim 9 , wherein either (a) the surface modification material comprises a metal oxide, and wherein, during brazing, the flux material interacts with the substrate surface to remove native surface oxide and interacts with the surface modification material to remove at least a portion of the metal oxide comprised in the surface modification material, or (b) during brazing, the flux material interacts with the substrate surface to remove native surface oxide and does not interact with the surface modification material. 
     
     
         11 . (canceled) 
     
     
         12 . The method according to  claim 1 , wherein the surface modification material is an inorganic material. 
     
     
         13 . The method according to  claim 12 , wherein
 (a) the surface modification material comprises a metal and/or a metalloid,   (b) the inorganic material comprises one or more element that forms alloys with aluminum, and/or   (c) the surface modification material forms alloys with aluminum that melt below 660° C.   
     
     
         14 . The method according to  claim 13 , wherein the surface modification material comprises a metal and/or metalloid, and wherein the metal and/or metalloid comprises a transition metal, a post-transition metal, a lanthanide, an actinide, an alkaline earth metal, an alkali metal, and/or another metal. 
     
     
         15 . (canceled) 
     
     
         16 . The method according to  claim 13 , the inorganic material comprises one or more element that forms alloys with aluminum, and wherein one or more element comprises silicon, zinc, magnesium, manganese, indium, copper, germanium, calcium, cerium or a combination thereof. 
     
     
         17 . (canceled) 
     
     
         18 . The method according to  claim 1 , wherein the surface modification material (a) forms a nanostructured material on the substrate surface, (b) acts as a braze, flux, barrier coating, functional coating, or a combination thereof during manufacture of the heat exchanger, and/or (c) is involved in the adhesion of parts of the heat exchanger. 
     
     
         19 .- 20 . (canceled) 
     
     
         21 . The method according to  claim 18 , wherein the surface modification material is involved in the adhesion of parts of the heat exchanger, and wherein the parts are adhered by brazing, ceramic bonding, or a combination thereof. 
     
     
         22 . The method according to  claim 21 , wherein the parts are adhered at a temperature lower than 660° C. 
     
     
         23 . The method according to  claim 22  wherein the substrate comprises a metal alloy, a ceramic, a polymer, or a combination thereof. 
     
     
         24 . A heat exchanger that is manufactured according to  claim 1 . 
     
     
         25 . The heat exchanger according to  claim 24 , wherein the heat exchanger is a microchannel heat exchanger (MCHE). 
     
     
         26 . The heat exchanger according to  claim 24 , wherein the surface modification material (a) reduces the condensate droplet adhesion force and in turn the wettability of the surface, (b) provides improved heat exchanger performance in comparison to a heat exchanger that comprises an identical substrate surface that does not comprise the surface modification material, (c) provides improved corrosion resistance in comparison to a heat exchanger that comprises an identical substrate surface that does not comprise the surface modification material, (d) provides a reduced amount of holdup liquid in the heat exchanger in comparison to a heat exchanger that comprises an identical substrate surface that does not comprise the surface modification material, (e) reduces the amount of water, condensate, frost, or ice that is maintained within the heat exchanger body during operation in comparison to a heat exchanger that comprises an identical substrate surface that does not comprise the surface modification material, and/or (f) reduces the amount of debris or fouling material which is maintained within the heat exchanger body during operation in comparison to an uncoated heat exchanger surface. 
     
     
         27 .- 28 . (canceled) 
     
     
         29 . A system comprising a heat exchanger according to  claim 24 , wherein the system comprises an air conditioning system, a refrigeration system, a filter element, or a heat pump. 
     
     
         30 .- 32 . (canceled) 
     
     
         33 . A system comprising a refrigeration unit that comprises: a compressor; an evaporator coil; a condenser coil; a working fluid expansion device; and an enclosure,
 wherein at least one of the evaporator coil and the condenser coil comprises one or more microchannel coil(s),   wherein a surface of at least one of said microchannel coil(s) comprises a coating of a surface modification material that comprises a metal oxide and/or metal hydroxide, and   wherein the enclosure comprises a housing that protects the refrigeration unit and maintains a desired temperature range within an area in which the system controls the temperature, wherein the temperature is controlled across variable seasonal temperature conditions in the surrounding environment outside of the area in which the system controls the temperature.   
     
     
         34 . A system comprising a heat pump system that comprises: a compressor; a first microchannel coil; a second microchannel coil; a working fluid expansion device; and an enclosure; comprising both a heating and cooling mode,
 wherein the first and/or the second microchannel coil comprises a coating of a surface modification material that comprises a metal oxide, and   wherein the enclosure comprises a housing that protects the heat pump system and maintains a desired a temperature range within an area in which the system controls the temperature, wherein the temperature is controlled across variable seasonal temperature conditions in the surrounding environment outside of the area in which the system controls the temperature.   
     
     
         35 . (canceled) 
     
     
         36 . The system according to  claim 33 , wherein (a) said coating of surface modification material comprises a thickness of less than about 20 microns, (b) said coating of surface modification material comprises iron, manganese, magnesium, cerium, tin, zinc, or a combination thereof, and/or (c) the surface modification results in a contact angle greater than 120° or less than 30° on said microchannel coil surface, which reduces the aggregation of water, condensate, frost, or ice on the microchannel coil surface in comparison to an identical microchannel coil surface that does not comprises the surface modification. 
     
     
         37 .- 39 . (canceled) 
     
     
         40 . A method for coating a microchannel heat exchanger with a surface modification material, comprising:
 (a) optionally, etching one or more surface of a heat exchanger;   (b) immersing said heat exchanger in a bath comprising a metal salt;   (c) optionally, immersing said heat exchanger in a solution of a fluorinated-terminated or alkyl-terminated compound or alkane; and   (d) allowing said heat exchanger to dry.   
     
     
         41 . (canceled) 
     
     
         42 . The system according to  claim 34 , wherein (a) said coating of surface modification material comprises a thickness of less than about 20 microns, (b) said coating of surface modification material comprises iron, manganese, magnesium, cerium, tin, zinc, or a combination thereof, and/or (c) the surface modification results in a contact angle greater than 120° or less than 30° on said microchannel coil surface, which reduces the aggregation of water, condensate, frost, or ice on the microchannel coil surface in comparison to an identical microchannel coil surface that does not comprises the surface modification.