JP2012073014A - Exchanger tube and fin for fin-and-tube heat exchanger, fin-and-tube heat exchanger using the same, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exchanger tube and a fin which can be assembled together by a jointing method that maintains preferable heat contact between the fin and exchanger tube without impairing a function of a hydrophilic coat or water-repelling coat of a pre-coated fin, a fin-and-tube heat exchanger using them, and a manufacturing method for the same.SOLUTION: The outer surface of the flat multi-hole tube 14 made of an aluminum or alloy of the same is coated with a coating layer made of an adhesive resin that melts or reacts at a temperature of 100 to 200°C. The adhesive resin fills a gap between the flat multi-hole tube 14 and the inner surface of an attachment hole 16 of the fin 12 made of an aluminum or alloy of the same, thereby fixing them to constitute the fin-and-tube heat exchanger 10.

Description

  TECHNICAL FIELD The present invention relates to heat transfer tubes and fins for fin-and-tube heat exchangers, fin-and-tube heat exchangers using the same, and manufacturing methods thereof, and in particular, air conditioners such as home air conditioners and packaged air conditioners. The present invention relates to a heat transfer tube and a fin that are preferably used for a fin-and-tube heat exchanger in a machine, a fin-and-tube heat exchanger using them, and a method for advantageously producing the same.

  Conventionally, in addition to air conditioning equipment such as home air conditioners, automotive air conditioners, and packaged air conditioners, refrigerators, heat pump water heaters, and the like have used heat exchangers that operate as evaporators or condensers, among them. In home indoor air conditioners and commercial packaged air conditioners, fin-and-tube heat exchangers having a structure in which fins are assembled to heat transfer tubes are most commonly used.

  In recent years, heat exchangers using natural refrigerants with low global warming potential have been developed in place of conventional chlorofluorocarbon refrigerants from the viewpoint of protecting the ozone layer and preventing global warming. However, hot water heaters using refrigerants mainly composed of carbon dioxide gas have attracted attention and have been developed. However, fin-and-tube heat exchangers similar to the above are also used in such heat exchangers. It is used.

  By the way, such a fin-and-tube heat exchanger generally has a structure in which heat transfer tubes are inserted in a direction perpendicular to a plurality of fins (outer surface fins) and the plurality of fins and the heat transfer tubes are joined. Has been put to practical use. In the heat exchanger having such a structure, the refrigerant is circulated in the heat transfer tube, while air as a heat exchange fluid is caused to flow along the plurality of fins in a direction perpendicular to the heat transfer tube. Thus, heat exchange is performed between the refrigerant and the air.

  The fins constituting the fin-and-tube heat exchanger are generally made of a plate material made of aluminum or an aluminum alloy, and the surface of the fins is not flat but slits or A material that has been processed into a shape having a heat transfer promoting effect, such as a louver, is often used.

  As is well known, as a heat transfer tube used in the fin-and-tube heat exchanger, a circular tube having a circular shape in a cross section perpendicular to the tube axis is used, and a flat tube inside is also used. A flat multi-hole tube having a structure in which a plurality of partitions are divided into a plurality of flow paths is generally employed. And among them, in the circular cross-sectional shape (round tube), copper, copper alloy, or aluminum or aluminum alloy is often used as the material, and many grooves, for example, A so-called inner-grooved heat transfer tube in which a large number of spiral grooves are formed so as to extend with a predetermined lead angle with respect to the tube axis, and inner fins having a predetermined height are formed between the grooves. Many are used. Moreover, as for the flat multi-hole tube, those obtained by port hole extrusion of aluminum or an aluminum alloy are generally used.

  And as a typical joining method of the fin and the heat transfer tube in such a fin-and-tube heat exchanger, a heat transfer tube inserted into a mounting hole provided in the fin is expanded by a mechanical tube or a hydraulic tube. The pipe expansion method in which the inner surface of the mounting hole and the outer peripheral surface of the heat transfer tube are in close contact with each other, or the gap between the outer peripheral surface of the heat transfer tube inserted into the fin mounting hole and the mounting hole is filled with brazing material The brazing method of performing is well known. Among such joining methods, when the heat transfer tube has a circular cross-sectional shape, a mechanical tube expansion method that can quickly and surely bring the heat transfer tube and the aluminum fin into close contact is often employed. Yes. On the other hand, when the heat transfer tube is a flat multi-hole tube, since it is difficult to expand using such a mechanical tube expansion method, a brazing method is often employed. For example, as clarified in Japanese Utility Model Laid-Open No. 5-25173 (Patent Document 1), a clad material coated with a brazing material on one side is used as a plate fin, and the cross-sectional shape of the heat transfer tube is the same. A plurality of through holes are opened, heat transfer tubes are inserted horizontally into the through holes, and are integrally brazed by a processing method such as vacuum brazing, so that the plate fins and the heat transfer tubes are integrated. .

  On the other hand, when the fin-and-tube heat exchanger is operated for use in an air conditioner such as a home air conditioner or a packaged air conditioner, condensation may occur on the fin surface. When such dew condensation occurs, the resistance (air flow resistance) when air passes between the fins is increased, which may cause the performance of the heat exchanger to deteriorate. Therefore, in Japanese Patent Laid-Open No. 10-103858 (Patent Document 2) and Japanese Patent Laid-Open No. 2002-322418 (Patent Document 3), the surface of the heat exchanger fin material made of an aluminum plate is made of a hydrophilic or water-repellent resin. A technique for forming a coating film has been clarified. That is, with such a coating film made of hydrophilic or water-repellent resin, the condensed water generated on the fin surface is made into a uniform water film, smoothly dropped and discharged, and the resistance to ventilation due to the condensed water is lowered, and the heat exchanger Therefore, it is possible to maintain the performance.

  By the way, as a method of forming a resin coating film as described above on the fin surface, a fin material (pre-coated fin material) on which a coating film has been formed in advance is processed into a predetermined fin shape, assembled to a heat transfer tube,・ A pre-coating method for forming an and tube type heat exchanger, or a fin and tube type heat exchanger assembled to form a fin and tube type heat exchanger, and then the entire heat exchanger is melted with resin There is a post-coating method in which a coating film is formed on the fin surface by an immersion method or the like. Among them, in the dipping method, it is difficult to apply a uniform coating film on the fin surface, and under the present situation where the fin interval is becoming narrower, the resin melted between the fins in the dipping method. However, it is considered that a precoat method excellent in quality is preferable because it is difficult to spread and sometimes difficult to implement.

  However, depending on the method of joining the fin and the heat transfer tube, the coating film pre-coated on the fin may not function. That is, a brazing method often employed when the heat transfer tube constituting the fin-and-tube heat exchanger is a flat multi-hole tube, for example, the vacuum brazing disclosed in Patent Document 1 described above. In addition, since it is carried out at 500 ° C. or higher, the plate fin itself is exposed to the temperature, and the heat resistance temperature of the resin coating film pre-coated on the plate fin (200 ° C. or lower) As a result, the precoated resin coating film does not function as a surface treatment material.

  Therefore, as a method for joining the fin and the heat transfer tube (flat multi-hole tube) without exposing the fin to such a high temperature, [0005] of Japanese Patent Laid-Open No. 2003-313153 (Patent Document 4) is elongated. Instead of providing a flat hole in the plate fin, a so-called knitting method has been clarified in which a U-shaped slit is formed in the width direction from one end of the plate fin and a flat tube is press-fitted into the slit. Furthermore, in JP-A-8-247678 (Patent Document 5) and JP-A-2002-139282 (Patent Document 6), a joining method using a resin (adhesive resin) containing an adhesive component is also disclosed. Yes.

  However, in these joining methods, for example, a clicking method as disclosed in Patent Document 4, as described in [0005] of Patent Document 4, a plate-type heat with slit fins is used. Since the exchangers are troublesome to handle each plate fin, they have not been mass-produced until now, and practical use and mass production have not yet been established. Also, the clearance between the outer diameter of the heat transfer tube and the heat transfer tube insertion hole of the plate fin can be assembled with little or no clearance, but in this case, the heat transfer tube and the plate fin are in sufficient contact on a macroscopic basis. Microscopically, there are many fine voids, but it cannot be said that thermal contact is sufficient.

  On the other hand, even in the bonding method using a resin containing an adhesive component, the details are not disclosed in the above-mentioned Patent Documents 5 and 6, and the heat resistance of the resin coating film pre-coated on the fin surface described above is not disclosed. No suitable adhesive has yet been found to join the fin and the heat transfer tube (flat multi-hole tube) without exposing the fin above the temperature.

  In addition, after assembling the heat transfer tube and the plate fin, it is possible to inject adhesive resin into the contact surface, but evenly adhere to the gap between the heat transfer tube and plate fin so assembled. Filling the resin was technically difficult and it was difficult to ensure that they were in good thermal contact.

Japanese Utility Model Publication No. 5-25173 Japanese Patent Laid-Open No. 10-103858 JP 2002-322418 A Japanese Patent Laid-Open No. 2003-313153 JP-A-8-247678 JP 2002-139282 A

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is that in the fin-and-tube heat exchanger of the air conditioner, the hydrophilic coating of the pre-coated fins. An object of the present invention is to provide a heat transfer tube or fin that can be assembled by a bonding method that favorably keeps the thermal contact between the fin and the heat transfer tube without impairing the function of the film or the water repellent coating film. Further, in the present invention, a fin-and-tube heat exchanger for an air conditioner manufactured using such heat transfer tubes and fins for a fin-and-tube heat exchanger and the manufacture thereof Providing a method to do this is also a problem to be solved.

  In the present invention, in order to solve such problems, a fin-and-tube heat exchanger transmission fitted into and assembled with an assembly hole provided in a fin made of aluminum or an alloy thereof. An adhesive coating made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or more and 200 ° C. or less is formed on the outer surface of a multi-hole tube made of aluminum or an alloy thereof as a heat tube, and the adhesive coating A fin-and-tube heat exchanger heat transfer tube, characterized in that it is configured to be fixed to the fin while filling a gap between the fin and the inner surface of the assembly hole by the film, This is the gist.

  Further, in the present invention, a flat multi-hole tube made of aluminum or an alloy thereof is fitted into the assembly hole to form a fin-and-tube heat exchanger fin to be assembled, and is made of aluminum or an alloy thereof. An adhesive coating made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower is formed on at least the inner surface of the assembly hole of the fin, and the flat multi-hole tube is formed by the adhesive coating. A fin-and-tube type heat exchanger fin, characterized in that it can be fixed to the flat multi-hole tube while filling the gap between them, is also the gist thereof.

  Further, in the present invention, a fin-and-tube heat exchanger is assembled by fitting a flat multi-hole tube made of aluminum or an alloy thereof into an assembly hole provided in a fin made of aluminum or an alloy thereof. An adhesive coating film made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower is provided on the outer surface of the flat multi-hole tube and / or the inner surface of at least the assembly hole of the fin. The flat multi-hole tube and the fin are fixed to each other while the gap between the flat multi-hole tube and the inner surface of the assembly hole of the fin is filled with the adhesive coating film. The gist of the fin-and-tube heat exchanger is also used.

  In the present invention, in order to advantageously obtain the fin-and-tube heat exchanger as described above, a temperature of 100 ° C. or more and 200 ° C. or less is applied to the outer surface of the flat multi-hole tube made of aluminum or an alloy thereof. After the application of the adhesive resin that melts or reacts in the step, the adhesive resin is formed by holding the adhesive resin at a temperature lower than the melting / reaction temperature of the adhesive resin and drying the adhesive resin. A step of preparing a multi-hole tube, and the flat multi-hole tube is fitted into an assembly hole provided in a fin made of aluminum or an alloy thereof obtained by applying a hydrophilic paint or a water-repellent paint to the surface. A step of producing an attachment body, and the assembly body is maintained at a temperature not lower than the melting / reaction temperature of the adhesive resin constituting the adhesive coating film and not higher than 200 ° C. to soften the adhesive resin, Of the fins Filling the space between the inner surface of the attachment hole and the outer surface of the flat multi-hole tube and curing or solidifying the adhesive resin to complete an integrated fin-and-tube heat exchanger. The manufacturing method of the fin-and-tube heat exchanger which is characterized also has the gist thereof.

  Furthermore, in the present invention, after an adhesive resin having a melting temperature or a reaction temperature of 100 ° C. or higher and 200 ° C. or lower is applied, the adhesive resin is held at a temperature lower than the melting / reaction temperature of the adhesive resin. A step of preparing a fin made of aluminum or an alloy thereof having an adhesive coating film formed by drying at least on the inner surface of the assembly hole, and a flat multi-hole tube made of aluminum or an alloy thereof, A step of producing an assembly by fitting in the assembly hole, and maintaining the assembly at a temperature not lower than the melting / reaction temperature of the adhesive resin constituting the adhesive coating film and not higher than 200 ° C .; The adhesive resin is softened and filled between the inner surface of the assembly hole of the fin and the outer surface of the flat multi-hole tube, and the adhesive resin is hardened or solidified to form an integrated fin Also a method of manufacturing a fin-and-tube heat exchanger, characterized in that a step of completing the command-tube heat exchanger, and the gist thereof.

  Therefore, according to the heat transfer tube or fin for a fin-and-tube heat exchanger configured according to the present invention as described above, the predetermined surface formed on the outer surface of the flat multi-hole tube or at least the inner surface of the assembly hole of the fin The adhesive coating made of an adhesive resin fills the gap between the inner surface of the fin assembly hole and the outer surface of the flat multi-hole tube so that the fin can be fixed to the flat multi-hole tube.・ Because heat transfer tubes and fins for AND-tube heat exchangers are configured, it is possible to effectively reduce the contact thermal resistance between fins and flat multi-hole tubes, and to improve heat exchange performance Become.

  In addition, since the adhesive coating film formed on the surface of the flat multi-hole tube is formed of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower, a hydrophilic coating is applied to the fin surface. Even if a film or a water-repellent coating film is pre-coated, a fin-and-tube heat exchanger tube that can be fixed by assembling the fins and heat transfer tubes while keeping the function of the coatings good. It can be formed.

  A fin-and-tube heat exchanger heat transfer tube in which a predetermined adhesive coating film is formed on the outer surface of such a flat multi-hole tube, or a predetermined adhesive coating at least on the inner surface of the assembly hole of the fin. In a fin-and-tube heat exchanger manufactured using a fin-and-tube heat exchanger fin formed with a film, the contact thermal resistance between the fin and the flat multi-hole tube is low. Since it is possible to demonstrate high heat exchange performance, the effect of the hydrophilic coating film and water-repellent coating film formed on the fin surface is exhibited well. Condensation water on the fin surface that is generated when the exchanger is operated is smoothly discharged from the fin surface by these coating films, effectively suppressing the increase in ventilation resistance due to such condensation water, and stable and high heat exchange performance Maintain It is to become possible.

  Furthermore, in the present invention, in order to produce the fin-and-tube heat exchanger described above, the melting temperature or the reaction temperature is 100 on the outer surface of the flat multi-hole tube and / or on the inner surface of at least the assembly hole of the fin. After forming an adhesive coating film made of an adhesive resin at a temperature of from ℃ to 200 ℃, the flat multi-hole tube is fitted into an assembly hole provided in the fin, and an assembly in which these two are assembled is assembled. Then, the assembly is held at a temperature not lower than the melting / reaction temperature of the adhesive resin and not higher than 200 ° C. to soften the adhesive resin so as to be flowable. The adhesive resin is filled between the inner surface and the outer surface of the flat multi-hole tube, and the adhesive resin is cured or solidified to integrate the fin and the flat multi-hole tube. Fin and tube heat exchange By fixing the fins to the heat transfer tubes (flat multi-hole tubes), the fins and heat transfer tubes can be secured without performing brazing processing that exposes them to high temperatures. Therefore, it is possible to advantageously manufacture a fin-and-tube heat exchanger in which the functions of the hydrophilic coating film and water-repellent coating film formed on the fin surface are kept good. It will be.

  Further, in such a manufacturing method, by using a fin having a hydrophilic coating or a water-repellent coating applied to the surface in advance, the fin and the heat transfer tube are assembled, and then the hydrophilic coating or Compared to the post-coating method that forms a coating film of water-repellent paint, it is not necessary to prepare a paint tank that can immerse the entire heat exchanger, so manufacturing costs can be advantageously reduced. In addition, the coating film formed on the fin has a feature that can improve the quality.

  Furthermore, after assembling the fin and the heat transfer tube, it is not necessary to apply a hydrophilic paint or a water-repellent paint to the fin, or to apply an adhesive or the like for fixing the fin and the heat transfer tube. The fin interval can be advantageously reduced, and as a result, effects such as miniaturization of the heat exchanger and improvement of the heat exchange performance are also exhibited.

It is a perspective explanatory view showing an example of a fin and tube type heat exchanger according to the present invention. It is a perspective explanatory view which shows the fin which comprises the fin and tube type heat exchanger shown by FIG. FIG. 2 is an explanatory cross-sectional view showing an enlarged joint portion between a fin and a flat multi-hole tube of the fin-and-tube heat exchanger shown in FIG. 1. It is sectional explanatory drawing which shows the form of the surface treatment of the fin material used in the Example. It is a perspective explanatory view showing roughly the fin and tube type heat exchanger for heat exchange performance evaluation used in the example. FIG. 6 is a schematic cross-sectional view showing the arrangement of heat transfer tubes in the fin-and-tube heat exchanger shown in FIG. 5.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

  First, FIG. 1 schematically shows one embodiment of a fin-and-tube heat exchanger using a heat transfer tube for a fin-and-tube heat exchanger according to the present invention in the form of a perspective view. ing. In the heat exchanger 10, two flat multi-hole tubes 14 and 14 are slits provided in the fins 12 with respect to the plurality of fins 12 arranged in parallel to each other and at a predetermined distance. It is formed by being inserted into and fixed to the assembly hole 16.

  More specifically, the fin 12 is formed of a metal material made of aluminum or an aluminum alloy, as in the prior art, and has a rectangular plate shape as shown in FIG. The surface is coated with a hydrophilic resin or a water repellent resin to form a coating layer 18 having a predetermined thickness. In addition, an assembly hole 16 into which the flat multi-hole tube 14 is assembled is provided in the fin 12 so as to extend from one end of the rectangular fin 12 in the width direction of the fin 12 (left and right in FIG. 2). As formed. Further, a collar portion 20 having a predetermined height is formed integrally with the fin 12 around the assembly hole 16.

  On the other hand, as is well known, the flat multi-hole tube 14 is formed by extrusion or the like using a metal material made of aluminum or an aluminum alloy. Here, the seven holes 15 extending in the tube axis direction are formed. A multi-hole tube having a flat shape is formed.

  And, according to the present invention, the outer surface of the flat multi-hole tube 14 and / or the inner surface of at least the assembly hole 16 of the fin 12 is melted or reacted at a temperature of 100 ° C. or more and 200 ° C. or less. For example, as shown in FIG. 3, an adhesive coating layer 22 having a predetermined thickness is formed on the outer surface of the flat multi-hole tube 14 by applying an adhesive resin. The adhesive resin referred to here is interposed between the metal material constituting the fin 12 and the metal material constituting the flat multi-hole tube 14, and both the metal materials are physically or mechanically fixed. Among the resins having adhesiveness capable of maintaining the state, the resin softens and flows by being maintained at a temperature equal to or higher than the melting temperature, and the resin is solidified or cured by cooling, and heat By holding the plastic resin, hot melt adhesive resin, or a temperature higher than the reaction temperature, a chemical reaction or polymerization reaction of the contained substance occurs, the resin is cured, and the adhesiveness is improved. Examples of the resin having characteristics include a thermosetting resin, a reactive resin, and a reactive adhesive. Among them, as heat-reactive adhesive resins that are advantageously used, specifically, epoxy, cyanoacrylate, polyurethane, acrylic, polyvinyl alcohol, or a combination thereof, or thermoplasticity thereof A combination with a resin is appropriately selected and used. Further, the thickness of the coating layer 22 is appropriately determined according to the size of the flat multi-hole tube 14 and the fin 12 in the thickness necessary for fixing the fin 12 and the flat multi-hole tube 14. However, it is preferably about 1 to 10 μm.

  In the case where the adhesive coating layer 22 as described above is formed on the fin 12, the fin 12 is formed so as to include at least the inner surface of the assembly hole 16 of the fin 12. Even if it is formed on the entire surface, there is no problem. In that case, the adhesive coating layer 22 is formed so as not to adversely affect the properties of the coating layer 18 formed on the fins 12. Further, after such an adhesive coating layer 22 is formed on the fin 12, the slit-like assembly hole 16 can be formed by processing.

  Then, using such flat multi-hole tube 14 and fins 12, a plurality of such fins 12 are separated from each other in parallel and at a constant distance in a state where the assembly holes 16 formed in each of them are aligned. Since the flat multi-hole tube 14 is fitted in the assembled assembly hole 16 and assembled, the target heat transfer tube for the fin-and-tube heat exchanger is configured. is there. At this time, the outer surface of the flat multi-hole tube 14 and the inner surface of the assembly hole 16 of the fin 12, that is, the inner surface of the collar portion 20 formed so as to rise integrally from the periphery of the assembly hole 16 As shown in FIG. 3, the gap between the coating film layer 22 formed on the outer peripheral surface of the flat multi-hole tube 14 (or the adhesive coating film layer formed on the inner surface of at least the assembly hole 16 of the fin 12. ) And are fixed to form an integral fin-and-tube heat exchanger tube. And each both ends of the flat multi-hole tube 14 which comprises such a heat transfer tube for fin and tube type heat exchangers are connected to the header which is not illustrated here, respectively, and seven of the flat multi-hole tube 14 are included. Since the holes 15, that is, the seven flow paths through which the refrigerant extending in the tube axis direction circulates, are combined on the inlet side and the outlet side of the refrigerant to constitute the fin-and-tube heat exchanger 10. is there.

  Therefore, according to the fin-and-tube heat exchanger 10 configured in accordance with the present invention, it is formed on the outer surface of the flat multi-hole tube 14 or on the inner surface of at least the assembly hole 16 of the fin 12. A gap between the inner surface of the assembly hole 16 of the fin 12 and the outer surface of the flat multi-hole tube 14 is filled with the coating layer (22) made of an adhesive resin. From the place where 12 is fixed, it becomes possible to effectively reduce the contact heat resistance between the fin 12 and the flat multi-hole tube 14, thereby advantageously improving the heat exchange performance of the heat exchanger 10. It can be done.

  The adhesive resin constituting the coating layer (22) formed on the outer surface of the flat multi-hole tube 14 or on the inner surface of at least the assembly hole 16 of the fin 12 has a melting temperature or reaction temperature of 100 ° C. or higher. Therefore, after the fin 12 and the flat multi-hole tube 14 are assembled, the adhesive resin applied to the outer surface of the flat multi-hole tube 14 or the fin 12 is reacted and cured to be firmly integrated. The fin-and-tube heat exchanger can be completed. In the manufacturing process until the fin 12 and the flat multi-hole tube 14 are assembled, such as a step of drying the resin after applying the adhesive resin to the outer surface of the flat multi-hole tube 14 or the fin 12, 100 When the melting temperature or reaction temperature of the adhesive resin forming the coating layer 22 is less than 100 ° C., the flattened flat hole tube 14 may be flattened before assembling. There is a possibility that the adhesive resin applied to the outer surface of the multi-hole tube 14 may solidify, react, or harden, and finally a fin-and-tube heat exchanger that is firmly integrated may be completed. There is a risk that it cannot be performed, and therefore, the melting temperature or reaction temperature of the adhesive resin needs to be 100 ° C. or higher.

  Furthermore, since the melting temperature or reaction temperature of the adhesive resin forming the coating layer 22 is set to 200 ° C. or lower, the hydrophilic coating film or the water-repellent coating film formed on the surface of the fin 12 is used. The flat multi-hole tube 14 and the fins 12 can be assembled and fixed to each other while maintaining the functions well, and the fin-and-tube heat exchanger 10 can be formed. That is, after the flat multi-hole tube 14 is inserted into the assembly hole 16 provided in the fin 12 made of aluminum or aluminum alloy having a hydrophilic resin or water-repellent resin applied to the surface thereof, they are heated. Then, the adhesive resin for forming the coating layer 22 applied to the outer surface of the flat multi-hole tube 14 is liquefied or softened, and the inner surface (collar portion 20) of the assembly hole 16 and the outer surface of the flat multi-hole tube 14 are removed. After filling the gap between the surfaces with the adhesive resin, the hydrophilic coating film or the water-repellent coating film precoated on the surface of the fin 12 is thermally decomposed at the temperature at which the adhesive resin is cured or solidified. Since the temperature can be suppressed to 200 ° C. or lower, which is lower than the temperature that causes the above, the possibility of causing the performance deterioration of the hydrophilic coating film or the water-repellent coating film can be effectively avoided. In consideration of maintaining the functions of the hydrophilic coating film or the water-repellent coating film even better, the upper limit of the reaction temperature of the adhesive resin constituting the coating film layer 22 may be 150 ° C. or less. preferable.

  And since the effect of the hydrophilic coating film and water-repellent coating film formed on the surface of the fin 12 is thus satisfactorily exhibited, dew condensation water generated on the surface of the fin 12 when the heat exchanger 10 is operated. Can be discharged smoothly from the surface of the fins 12 by these coating films, and the increase in ventilation resistance due to the condensed water can be effectively suppressed, so that the heat exchanger 10 has a stable and high heat exchange performance. Can be maintained.

  By the way, the fin-and-tube heat exchanger 10 having such a configuration is advantageously manufactured by adopting the following method. That is, first, the melting temperature or reaction temperature is 100 ° C. or more and 200 ° C. or less on the outer surface of the flat multi-hole tube 14 formed by subjecting aluminum or an alloy thereof to a known processing method such as porthole extrusion. After the adhesive resin is applied, the adhesive resin is dried by maintaining the temperature below the melting temperature or reaction temperature of the adhesive resin, and the coating layer 22 having a predetermined thickness is formed on the outer surface of the flat multi-hole tube 14. Prepare what formed.

  On the other hand, by applying a pressing process or the like to an aluminum plate or an aluminum alloy plate on which a coating layer having a predetermined thickness is formed by applying a hydrophilic paint or a water-repellent paint on the surface of the flat multi-hole tube 14. A fin 12 having a predetermined shape in which an assembly hole 16 and a collar portion 20 corresponding to the outer shape are integrally formed is prepared. Then, a plurality of such fins 12 are arranged in parallel to each other at a predetermined interval so that the respective assembly holes 16 coincide with each other, and sequentially pass through the assembly holes 16 of the plurality of fins 12. Thus, the flat multi-hole pipe 14 prepared previously is inserted, and an assembly is produced. At this time, there is a slight gap between the inner surface of the assembly hole 16 of the fin 12, in other words, between the inner surface of the collar portion 20 and the outer surface of the flat multi-hole tube 14.

  Next, the assembly resin is softened by holding the assembly at a temperature of not lower than the melting / reaction temperature of the adhesive resin applied to the outer surface of the flat multi-hole tube 14 and not higher than 200 ° C. By filling the entire gap existing between the inner surface of the assembly hole 16 and the outer surface of the flat multi-hole tube 14 and hardening or solidifying the adhesive resin, the fin 12 and the flat multi-hole as shown in FIG. A fin-and-tube heat exchanger integrated with the hole tube 14 is completed.

  By adopting such a manufacturing method, the heat transfer tube (flat multi-hole tube 14) and the fin 12 are assembled and fixed without performing brazing processing in which the fin or the heat transfer tube is exposed to a high temperature. Since they can be fixed at a low temperature, the fin-and-tube heat exchanger in which the functions of the hydrophilic coating film and the water-repellent coating film formed on the surface of the fin 12 are kept good. 10 can be advantageously manufactured.

  Moreover, in this manufacturing method, since the fin by which the hydrophilic coating material and the water-repellent coating material were apply | coated previously on the surface is used, the coating film formed in a fin can be made high quality. Furthermore, since it is not necessary to form a hydrophilic paint or water-repellent paint film on the fin surface after assembling the fin and the heat transfer tube, the manufacturing cost of the heat exchanger can be advantageously reduced and the fin spacing can be reduced. As a result, it is possible to reduce the size of the heat exchanger and to improve the heat exchange performance.

  As described above, one of the representative embodiments of the present invention and the manufacturing method thereof have been described in detail, but these are merely examples, and the present invention is specific to such embodiments. It should be understood that the description is not to be construed as limiting in any way.

  For example, in the above-described embodiment, the adhesive coating film (coating layer 22) made of an adhesive resin is formed on the outer surface of the flat multi-hole tube 14, but instead of the outer surface of the flat multi-hole tube 14, fins The fin-and-tube heat exchanger 10 may be configured by forming an adhesive coating layer made of an adhesive resin on the inner surface of at least the 12 assembly holes 16. Such an adhesive coating layer can be formed on either the flat multi-hole tube 14 or the fin 12 or on the flat multi-hole tube 14 or the fin 12 as a matter of course.

In addition, the adhesive resin constituting such an adhesive coating film (coating layer 22) can contain a particulate inorganic material having good thermal conductivity to the extent that fluidity is not impaired. It is. This is because the resin containing the adhesive component usually has poor thermal conductivity, and therefore, filling the gap between the fin and the heat transfer tube with the resin containing the adhesive component means that air exists in the gap. Although the thermal conductivity is better than that in the case where it is present, it does not exhibit sufficient thermal conductivity. Therefore, it is possible to further improve the thermal conductivity by mixing a material having good thermal conductivity into the adhesive resin. Examples of the inorganic material mixed in the adhesive resin include fine silica (SiO ₂ ), alumina (Al ₂ O ₃ ), carbon powder, and the like. However, if too much inorganic material is mixed, when the adhesive resin is heated, the melted adhesive resin will not flow sufficiently, and it will conform to the gap formed between the fin and the heat transfer tube. (To be filled) will be insufficient. Moreover, when using a metal material, it is desirable that the natural potential is the same as that of the fins or higher than that of the fins. By doing so, preferential corrosion of the bonded portion can be prevented.

  Furthermore, you may mix | blend a hardening | curing agent with this adhesive resin. Such a curing agent to be blended is not particularly limited, and for example, one or more of blocked isocyanate, phenol resin, amino resin and the like can be used. Furthermore, by blending two or more kinds of curing agents having different reaction rates, it is possible to adjust the curing rate during heating, thereby preventing dripping of the adhesive coating layer due to gravity. It will be. Further, the curing agent may be blended in a state where it is contained in microcapsules having a particle diameter of 1 to 1000 μm using gelatin, gum arabic, urethane resin or the like as a film agent. In this case, the curing of the resin other than the joint where pressure is applied is suppressed, and the bending of the heat exchanger after bonding can be easily performed. Furthermore, an anaerobic curing agent combining acrylic diester and N, N-dimethylaniline or the like can be blended. In this case as well, only the site where oxygen is blocked by close contact during assembly is cured. Therefore, the heat exchanger after bonding can be easily bent. Moreover, a humidity hardening | curing agent can also be mix | blended and, in this case, intensity | strength can be raised further at the time of the water-immersion airtight test after assembling a heat exchanger, or an evaporation operation.

  In addition, it is desirable to use a highly flexible resin for such an adhesive resin. This is because, even when the heat exchanger is deformed such as L-bending after being formed in the heat exchanger, the adhesion between the flat multi-hole tube and the fin can be maintained and the low adhesive heat resistance can be maintained. It is.

  It is also possible to form a lubricating layer such as carnauba wax, polyethylene wax, lubricating oil, polyethylene glycol or the like on the surface of the flat multi-hole tube. By forming such a lubricating layer, it becomes possible to improve the slipperiness when inserting a flat multi-hole tube into the fin, and to improve the productivity of the fin-and-tube heat exchanger. Features that can be obtained.

  Moreover, you may further mix | blend organic fine particles, such as PTFE and polyethylene, with adhesive resin, for example. Also in this case, it becomes possible to improve the slipperiness at the time of inserting the flat multi-hole tube into the fin, and the productivity of the heat exchanger can be improved. Further, by using particles having a melting point of 200 ° C. or less as the organic fine particles to be blended in such a manner, it is possible to suppress a decrease in adhesive strength.

  Furthermore, you may mix | blend 1 type, or 2 or more types of low melting metal fine particles with melting | fusing point of 200 degrees C or less, such as Sn-Bi type | system | group and Sn-Ag-Cu-Bi type | system | group, for example in adhesive resin. Also in this case, it becomes possible to improve the slipperiness at the time of inserting the flat multi-hole tube into the fin, and the productivity of the heat exchanger can be improved. And, in the case of heating, the low melting point metal fine particles are melted and integrated, whereby the bonding strength and the heat transfer can be improved. In this case, a flux component such as glutaric acid or adipic acid can be blended in the adhesive coating film at the same time, and the oxide film of the low melting point metal fine particles can be removed by heating with such a flux component. And integration can be promoted more.

  Note that the adhesive resin may have two or more layers. For example, by forming a resin layer with a low melting point on the top coat that is easy to flow and forming a resin layer on the undercoat using a resin that has a small difference in linear expansion coefficient from the aluminum material, it is possible to secure an adhesive area during heating and heat It is possible to maintain both adhesion when using the exchanger.

  Moreover, it is also possible to mix | blend magnetic ER fluid with adhesive resin. In this case, by applying a magnetic force from above during heating, it is possible to effectively prevent the adhesive coating film softened during heating from drooping downward due to weight.

  Further, the adhesive resin may contain a lubricant, a thixotropic agent, an antioxidant, a storage stabilizer, and an antistatic agent.

  Furthermore, the adhesive resin (coating layer 22) formed on the surface of the flat multi-hole tube 14 binds to an active functional group such as a hydroxyl group remaining on the hydrophilic coating on the fin surface. May be. In that case, the fin and the heat transfer tube can be more firmly fixed, and the contact thermal resistance can be effectively reduced.

  The flatness of the flat multi-hole tube 14 is preferable because the smaller the difference in the width direction, the more uniformly the fins can come into contact with the fins. However, in order to reduce the flatness, the cost increases such as addition of a correction process. Rmax is preferably in the range of 2 μm to 100 μm. Moreover, if it is a flat tube, it may not be a multi-hole tube, For example, the flat tube with which the hole which lets a refrigerant | coolant pass is one hole may be sufficient.

  The coating film formed on the surface of the fin 12 can be formed of a single layer of hydrophilic resin or water-repellent resin coating. It is possible to form a coating film of the outermost layer among the coating films of the plurality of layers as a coating film of a hydrophilic resin or a water repellent resin. For example, when forming a multi-layer coating film as such, first, on the surface of the aluminum plate, epoxy resin, urethane resin, polyester resin, acrylic resin, melamine resin, vinyl chloride resin, etc. It is preferable to form a coating film having corrosion resistance and comprising a coating film of a hydrophilic resin or a water-repellent resin as the outermost layer. By forming such a corrosion-resistant coating film, the corrosion resistance of the fins 12 made of an aluminum material can be advantageously improved.

  Furthermore, the adhesive resin may be used on the fin surface to which minute irregularities are provided by particles such as acrylic acid, polyalkylene glycol, and silica. In this case, the adhesive force can be improved by the anchor effect due to the increase in the bonding area of the fin surface.

  Furthermore, it is preferable that a film obtained by chemical film treatment (chemical conversion treatment) such as chromate treatment with phosphoric acid chromate or the like is formed on the surface of the fin 12 as a base treatment layer. That is, an aluminum plate (substrate) and a hydrophilic resin coating film formed on the surface thereof by forming such a base treatment layer on the surface of the fin substrate made of aluminum or aluminum alloy forming the fins 12. In addition, it is possible to effectively improve the adhesion to water-repellent resin coatings and corrosion-resistant coatings.

  In addition, although not listed one by one, the present invention is implemented in a mode to which various changes, modifications, improvements and the like are added based on the knowledge of those skilled in the art. It goes without saying that any one of them falls within the scope of the present invention without departing from the spirit of the invention.

  Hereinafter, representative examples of the present invention will be shown to clarify the present invention more specifically, but the present invention is not limited by the description of such examples. It goes without saying.

  First, in order to constitute a fin-and-tube heat exchanger according to the present invention, an aluminum alloy (JIS A3003) is extruded as a heat transfer tube to exhibit a cross-sectional shape as shown in FIG. An extruded flat multi-hole tube (14) of 16 mm, thickness: 2 mm, 7 holes was prepared. Then, a mixture (paint) of a 20% aqueous solution of polyvinyl alcohol having an average polymerization degree of 600 and a saponification degree of 88% and a blocked isocyanate 40% aqueous solution in a ratio of 1: 9 is prepared and impregnated with felt. After being coated at room temperature by bringing it into contact with the surface of the extruded flat multi-hole tube (14), it was held at 100 ° C. for 15 minutes, and on the outer surface of the extruded flat multi-hole tube (14), a film thickness of 10 μm A coating film made of an adhesive resin that was uniform and had good adhesion was formed. The paint has a reaction temperature of 140 ° C. and softens at 120 ° C., which is lower than the reaction temperature.

  On the other hand, as an aluminum fin material for forming the fin material, a plate material of pure aluminum (JIS A1050) having a plate thickness of 0.1 mm was prepared. The surface of the fin material was subjected to a surface treatment consisting of three layers as shown in FIG. That is, first, a chemical conversion film 32 made of phosphoric acid chromate was formed on the surface of the aluminum substrate by subjecting the aluminum material substrate 30 to a phosphoric acid chromate dipping treatment. Next, an epoxy resin was applied on the chemical conversion film 32 using a roll coater and heated at a temperature of 220 ° C. for 10 seconds to form a corrosion-resistant coating film 34 having a thickness of 1 μm. Further, after air cooling, a hydrophilic coating film made of polyvinyl alcohol resin is applied to the surface of the corrosion-resistant coating film 34 and heated at a temperature of 220 ° C. for 10 seconds, whereby a hydrophilic film having a thickness of 1.5 μm is obtained. The coating film 36 was formed to form an aluminum fin material. The hydrophilic coating film 36 made of polyvinyl alcohol resin undergoes thermal decomposition at 170 ° C. or higher, causing a decrease in performance as a hydrophilic coating film.

  Furthermore, two U-shaped slit-shaped assembly holes into which the flat multi-hole pipe (14) is inserted as shown in FIG. 2 by subjecting such an aluminum fin material to known press processing or the like. A fin material (12) was prepared by processing into a rectangular fin shape having a longitudinal length of 30 mm and a lateral length of 22 mm on which (16, 16) was formed. The width of the assembly hole (16) is 15 mm, and the inner width of the collar portion (20) erected around the assembly hole (16) is the thickness of the previously prepared flat multi-hole tube: It was set to 2.01 mm, which is slightly larger than 2 mm.

  And the fin and tube type heat exchanger (10) as shown in FIG. 1 was produced using the flat multi-hole pipe (14) and the fin material (12) prepared in this way. That is, first, ten fin materials are arranged in parallel with each other and with a predetermined fin interval in a state in which the positions of the respective assembly holes (16) coincide with each other, and then, in the assembly holes (16). A flat multi-hole tube (14) was inserted to produce an assembly. At this time, the clearance (gap) between the inner surface of the assembly hole (16) (the inner surface of the collar portion) and the outer surface of the flat multi-hole tube (14) is 5 μm. Then, the assembly is placed in an oven and held at 150 ° C. for 15 minutes to melt the coating film made of the adhesive resin applied to the outer surface of the flat multi-hole tube (14). The gap formed between the inner surface of the assembly hole (16) and the outer surface of the flat multi-hole tube (14) is filled, and the adhesive resin is reacted and cured so that the fin material (12) and the flat surface are flattened. The multi-hole tube (14) was fixed to produce a fin-and-tube heat exchanger (10) according to the present invention, which was used as the heat exchanger of Example 1.

  Further, using the same fin material as described above, a mixture of a 20% aqueous solution of polyvinyl alcohol having an average polymerization degree of 600 and a saponification degree of 88% and a blocked isocyanate 40% aqueous solution in a 1: 9 ratio (coating material) ) And was held at 100 ° C. for 15 minutes to obtain a fin material coated with an adhesive resin. A fin-and-tube heat exchanger as in Example 2 was produced using the fin material on which the adhesive coating film was formed and the same flat multi-hole tube as in Example 1. That is, in the same manner as in the heat exchanger of the first embodiment, ten fin materials are arranged, flat multi-hole tubes are fitted into the assembly holes, and they are assembled, whereby the heat exchanger of the second embodiment. Got.

  On the other hand, the same fin material as in Example 1 is prepared, and further, the heat transfer tube is formed of the same material as in Example 1 with no adhesive resin applied to the outer surface, and the width and thickness are the same. A flat multi-hole tube having the same dimensions was prepared, and a fin-and-tube heat exchanger as a comparative example was produced. That is, similarly to the heat exchanger of Example 1, ten fin materials are arranged, a flat multi-hole tube is inserted into the assembly hole, and they are assembled, whereby the heat exchanger of Comparative Example 1 is assembled. Was made. In the heat exchanger of Comparative Example 1, the clearance between the fin assembly hole and the flat multi-hole tube is 5 μm, and no adhesive resin is interposed in the gap. Further, after manufacturing a pair of heat exchangers having a clearance of 5 μm between the assembly hole and the flat multi-hole tube similar to the heat exchanger of Comparative Example 1, the heat exchanger is brazed in a furnace at 590 ° C. By attaching the fin and the flat multi-hole tube, a heat exchanger of Comparative Example 2 was prepared.

  Regarding the heat exchangers of Examples 1 and 2 and Comparative Examples 1 and 2 thus produced, fins and heat transfer tubes (flat multi-hole tubes) in a state after completion of assembly as fin-and-tube heat exchangers The joining state of was confirmed. As a result, in the heat exchangers of Example 1 and Example 2, the heat transfer tube and the fin were fixed with an adhesive resin, and the bonding state was good. Moreover, also in the heat exchanger of the comparative example 2, the heat exchanger tube and the fin were fixed by brazing, and the joining state was favorable. On the other hand, in the heat exchanger of Comparative Example 1, the heat transfer tubes and the fins were not fixed, there was backlash, and the joined state was not good.

  Furthermore, as an evaluation of the hydrophilicity of the fins, one fin was taken out from each heat exchanger, and the water droplet contact angle was measured. As a result, the fins of Examples 1 and 2 and Comparative Example 1 all have a water droplet contact angle of 15 °, and it was confirmed that the function of the hydrophilic coating film formed on the fin surface was maintained. . On the other hand, in the fin of Comparative Example 2, the hydrophilic coating film was altered and disappeared by heating at 590 ° C. during brazing, and the hydrophilic performance was not exhibited at all.

  In addition, in order to evaluate the heat exchange performance between the fins and the heat transfer tubes, the heat transfer tubes are circular cross-sectional tubes, and the heat transfer tubes are arranged in two rows and 14 stages, and the fins having the shape as shown in FIG.・ A tube-type heat exchanger was manufactured. That is, as the fin material, an aluminum fin material having a hydrophilic coating film formed on the surface thereof, which is the same as in Example 1, was prepared, and this was formed into a rectangular heat transfer tube having a length of 300 mm and a width of 25.4 mm. Were prepared to be processed into a fin shape in which 28 assembly holes for assembling were provided at predetermined intervals. In addition, a fin collar that is erected with a predetermined height from the periphery of the hole is integrally formed in the assembly hole portion. The inner diameter of the collar portion was set to 7.2 mm.

  On the other hand, as a heat transfer tube, an extruded smooth tube formed by extruding an aluminum alloy (JIS A3003), having an outer diameter of 7.0 mm and a wall thickness of the tube wall of 0.47 mm, and a circular cross section. Two types were prepared, one having a coating film made of the same adhesive resin as in Example 1 and the other having no coating film formed thereon.

Then, the fins and heat transfer tubes thus prepared are assembled, and the heat transfer tubes having the shape shown in FIG. 5 are arranged in 14 rows and two rows of 300 mm × 300 mm × 25.4 mm.・ Tube type heat exchangers were manufactured by adopting the following two types of fixing methods for fixing heat transfer tubes and fins, respectively. In each of these two heat exchangers, the number of fins is 214, the fin interval is 1.4 mm, and the intervals (P ₁ , P ₂ ) of the heat transfer tubes are as shown in FIG. The interval between the heat transfer tubes constituting the tube: P ₁ was 21 mm, and the interval between the heat transfer tubes in the first row and the second row: P ₂ was 12 mm.

  Next, as a first method, a heat transfer tube having an outer diameter of 7.0 mm obtained by applying a resin to aluminum fins having a collar inner diameter of 7.2 mm is used as in a fin-and-tube heat exchanger according to the present invention. After inserting and assembling, put in an oven and hold at 140 ° C. for 5 minutes to melt the resin containing the adhesive component, and the resin containing the adhesive component between the inner surface of the fin assembly hole and the outer surface of the heat transfer tube Charged. Then, it cooled to room temperature and solidified resin. Thereafter, the heat transfer tube was fixed to the aluminum fin by mechanical expansion with a tube expansion rate of 6.0%. The heat exchanger produced in this manner was designated as Test Example 1. On the other hand, as a second method, after inserting a heat transfer tube with an outer diameter of 7.0 mm with no resin applied to the outer surface of an aluminum fin with a collar inner diameter of 7.2 mm, mechanical expansion with a tube expansion ratio of 6.0% is performed. The heat transfer tube was fixed to the aluminum fin. And the heat exchanger produced in this way was made into Test Example 2.

  Thereafter, using the heat exchangers of Test Example 1 and Test Example 2 prepared in this way, hot water of 50 ° C. was flowed in the first row, and cold water of 20 ° C. was flowed in the second row to counteract the hot water and The cold water flow rate was changed, and the thermal resistance was calculated by subtracting the thermal resistance on the water side by the Wilson plot method. The test heat exchanger was installed in a vacuum vessel, and evaluation was performed while suppressing the influence of heat transfer by natural convection generated in the test part.

  As a result, the heat exchange of Test Example 2, which is a conventional fin-and-tube heat exchanger in which the heat transfer tube and the aluminum fins are fixed only by mechanical expansion without applying adhesive resin to the surface of the heat transfer tube When the performance is 100, the heat exchange performance ratio of the test example 1 in which the adhesive coating film according to the present invention is formed is 110. As a result, the gap between the heat transfer tube and the fin is filled with the adhesive resin. Thus, it was confirmed that the contact thermal resistance can be reduced and the heat exchange performance can be improved.

  Further, as an evaluation of the adhesive coating film made of an adhesive resin formed on the surface of the fin-and-tube heat exchanger heat transfer tube or the fin-and-tube heat exchanger fin according to the present invention, Various types of resins constituting the film and various blending ratios of these resins and curing agents were prepared as shown in Table 1 below, and the shear strength and tackiness were evaluated for each.

The shear strength was evaluated in accordance with “Test method for tensile shear strength of adhesive” in JIS-K-6850. That is, first, an aluminum alloy plate having a thickness of 0.5 mm was prepared, and the aluminum resin plate was cut into a length of 100 mm and a width of 10 mm, and each resin shown in Table 1 was applied to the surface. After the application, the test pieces 1 to 8 having a coating film made of an adhesive resin having a predetermined thickness formed on the surface thereof were dried by holding at 100 ° C. for 15 minutes. Then, each of the test pieces prepared as described above is taken out two by two, overlapped so that the area of the overlapping portion is 0.5 cm ^2, and then heated at 150 ° C. for 20 minutes. Two test pieces were bonded at the overlapped portion. And the test piece bonded in that way was set in a testing machine, the test piece was pulled at a speed of 20 mm / min, and the shear strength was measured. The results are also shown in Table 1 below.

  In addition, for the evaluation of tackiness, after drying the adhesive resin applied to the surface of each test piece, touch it with the hand, and according to the tactile sensation, “O” indicates that there is no tack, and there is a slight stickiness. Was evaluated as “C”, and those having stickiness to pull the yarn were evaluated as “x”, and the results are also shown in Table 1 below.

  Here, in Table 1 below, PVA used as a resin is a 30% aqueous solution of polyvinyl alcohol having a saponification degree of 90% or more, and urethane is an ether type, Tg: 90 ° C., viscosity: 90 Ps / Acrylic is a 30% aqueous solution having an ester copolymer type, Tg: 75 ° C, and solution viscosity: 5000 cPs / 25 ° C. Moreover, the epoxy resin A is a 40% aqueous solution of a bisphenol A type epoxy resin having a number average molecular weight of 10,000, and the epoxy resin B is a 40% aqueous solution of a bisphenol A type epoxy resin having a number average molecular weight of 5000. The filler is an Al filler having a particle size of 20 μm, and the blocked isocyanate is Fixer # 212 manufactured by Murayama Chemical Laboratory.

As apparent from the results in Table 1, the shear strengths of the test pieces 1 to 8 all exceed 10 kgf / 0.5 cm ² , and the adhesive resin applied to the surface of each test piece is sufficient for bonding. It can be confirmed that it exhibits strength. That is, when a fin-and-tube heat exchanger is formed using a flat multi-hole tube or fin in which these resins are applied to the surface and an adhesive coating film is formed, The hole tube can be firmly fixed. In addition, with regard to tackiness, although some stickiness was confirmed in the test piece 1 and the test piece 4, it was confirmed that the other test pieces were not tacky. That is, even if these resins are applied to the surfaces of flat multi-hole tubes and fins, dried, and laminated with a state where an adhesive coating film of a predetermined thickness is formed, flat multi-hole tubes and Without causing problems such as fins sticking together, it is possible to advantageously improve the manufacturability when manufacturing fin-and-tube heat exchangers using flat multi-hole tubes and fins. It becomes possible.

DESCRIPTION OF SYMBOLS 10 Heat exchanger 12 Fin 14 Flat multi-hole pipe 16 Assembly hole 18 Coating layer 20 Color part 22 Coating layer

Claims (5)

A heat transfer tube for a fin-and-tube heat exchanger to be assembled by being fitted into an assembly hole provided in a fin made of aluminum or an alloy thereof,
An adhesive coating film made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower is formed on the outer surface of the multi-hole tube made of aluminum or an alloy thereof, A heat transfer tube for a fin-and-tube heat exchanger, characterized in that the fin-and-tube heat exchanger can be fixed to the fin while filling a gap between the inner surface of the fin assembly holes. A flat multi-hole tube made of aluminum or an alloy thereof is fitted into the assembly hole to form a fin-and-tube heat exchanger fin to be assembled.
An adhesive coating made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower is formed on at least the inner surface of the assembly hole of the fin made of aluminum or an alloy thereof. A fin for a fin-and-tube heat exchanger, which is configured to be fixed to the flat multi-hole tube while filling a gap between the flat multi-hole tube. By inserting a flat multi-hole tube made of aluminum or an alloy thereof into an assembly hole provided in the fin made of aluminum or an alloy thereof, a fin-and-tube heat exchanger assembled is obtained.
An adhesive coating made of an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower is provided on the outer surface of the flat multi-hole tube and / or the inner surface of at least the assembly hole of the fin. A fin-and-tube characterized in that the flat multi-hole tube and the fin are fixed to each other while filling a gap between the flat multi-hole tube and the inner surface of the assembly hole of the fin.・ Tube type heat exchanger. After applying an adhesive resin that melts or reacts at a temperature of 100 ° C. or higher and 200 ° C. or lower to the outer surface of a flat multi-hole tube made of aluminum or an alloy thereof, the temperature is kept below the melting / reaction temperature of the adhesive resin. And, by drying the adhesive resin, preparing a flat multi-hole tube in which an adhesive coating film is formed,
A step of fitting the flat multi-hole tube into an assembly hole provided in a fin made of aluminum or an alloy thereof formed by applying a hydrophilic paint or a water-repellent paint on the surface;
The assembly is held at a temperature not lower than the melting / reaction temperature of the adhesive resin constituting the adhesive coating and not higher than 200 ° C. to soften the adhesive resin, Filling the outer surface of the flat multi-hole tube and curing or solidifying the adhesive resin to complete an integrated fin-and-tube heat exchanger;
A method for manufacturing a fin-and-tube heat exchanger. It is formed by applying an adhesive resin having a melting temperature or a reaction temperature of 100 ° C. or more and 200 ° C. or less, and then holding the adhesive resin at a temperature lower than the melting / reaction temperature of the adhesive resin and drying the adhesive resin. A step of preparing a fin made of aluminum or an alloy thereof having an adhesive coating film at least on the inner surface of the assembly hole;
Inserting a flat multi-hole tube made of aluminum or an alloy thereof into an assembly hole of the fin to produce an assembly; and
The assembly is held at a temperature not lower than the melting / reaction temperature of the adhesive resin constituting the adhesive coating and not higher than 200 ° C. to soften the adhesive resin, Filling the outer surface of the flat multi-hole tube and curing or solidifying the adhesive resin to complete an integrated fin-and-tube heat exchanger;
A method for manufacturing a fin-and-tube heat exchanger.

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