JPH10185357A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent molds or bacteria from developing and propagating and further restrict occurrence of offensive odor without degrading the function of an evaporator 21. SOLUTION: This heat exchanger is operated such that a chlomating process layer 32 is formed at the surface of an evaporator 21. A water-repellent resin film 34 added with in organic anti microbial agent 33 is formed at resin having a superior water-repellent characteristic so as to eliminate adhesion of water droplets of condensate generated an the surface, its antimicrobial characteristic is kept by the anti microbial agent 33, development and propagation of molds or bacteria are prevented under a state in which its durability characteristic is assured and then occurrence of offensive odor is restricted without damaging the function of the evaporator 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used as, for example, an evaporator of a vehicle air conditioner.

[0002]

2. Description of the Related Art Vehicle air conditioners control temperature and humidity.
Ventilation and ventilation are performed, and a ventilator (ventilation function), heater (heating function) and cooler (cooling /
(Dehumidification function). A general air conditioner will be described with reference to FIG. FIG. 3 shows a schematic configuration of a general air conditioner.

A blower 1 is provided downstream of an inside / outside air inlet (not shown), and the blower 1 is driven by a drive motor 2 to blow air. A cooling unit 4 having an aluminum evaporator 3 as a heat exchanger for cooling the air sent from the blower 1 (cooling / dehumidifying function) is provided downstream of the blower 1 in the horizontal direction. It is arranged in the direction.
In the cooling unit 4, cooling and dehumidification are performed by removing heat of air passing horizontally through the evaporator 3.

[0004] An air mix unit 6 having a heater core 5 is provided downstream of the cooling unit 4 in the horizontal direction.
Is for heating air passing through, for example, using high-temperature engine cooling water as a heat source. An air mix damper 7 is mounted on the upstream side of the heater core 5, and the air mix damper 7 is driven by a drive motor (not shown) so that the amount of air passing through the heater core 5 can be adjusted.

[0005] Downstream of the air mix unit 6, a passage 8 is connected to an outlet to a front window or a door window, an outlet to an occupant's upper body, and an outlet to an occupant's feet. The downstream side of the passage 8 is formed so as to be branched into a driver seat side and a passenger seat side, so that air conditioning control can be performed on the driver seat side and the passenger seat side independently.

In the air conditioner described above, after the air sent from the blower 1 in the horizontal direction is cooled by the evaporator 3,
Cooling air in an amount corresponding to the degree of opening of the air mix damper 7 passes through the heater core 5 and is mixed with cooling air that does not pass through the heater core 5 in the air mix unit 6 to reach a predetermined temperature state. Thereafter, cool air or warm air is blown into the vehicle compartment from each outlet as appropriate.

[0007] Since the evaporator 3 cools the air by heat exchange, condensed water is generated on surfaces such as between fins provided at narrow intervals, and water droplets are likely to adhere. The air from the blower 1 is discharged from the evaporator 3
, There is a risk that the water droplets are blown downstream and scattered into the vehicle interior. In addition, in a high humidity state where condensed water adheres, molds, bacteria, and the like are likely to be generated and propagated, causing an unpleasant odor. Therefore, the surface of the evaporator 3 is required to have excellent hydrophilicity with respect to adhesion of water droplets, and is required to have excellent water repellency from the viewpoint of antibacterial properties.

Therefore, conventionally, the surface of the evaporator 3 has been subjected to a surface treatment in consideration of hydrophilicity and antibacterial property (for example, Japanese Patent Laid-Open No. 4-366396). The condition of the surface film of the conventional evaporator 3 will be described with reference to FIG. FIG. 4 shows a sectional state of a surface film of the conventional evaporator 3.

As shown in the figure, a member (for example, a fin) 11 constituting the evaporator 3 made of aluminum has a chromate treatment layer 12 for the purpose of preventing white rust due to corrosion.
Are formed, and a hydrophilic resin film 14 is formed by adding an organic antibacterial agent 13 to a resin having excellent hydrophilicity. Therefore, generation and propagation of mold and bacteria on the surface of the member 11 constituting the evaporator 3 can be prevented.

[0010]

In recent years, in order to secure a space in the horizontal direction, the evaporator 3 is arranged in a horizontal or nearly horizontal state, and the air sent from the blower 1 is blown upward from below. An air conditioner for a vehicle having such a structure has been considered. Even in the air conditioner having such a structure, as shown in FIG. 4, the surface of the evaporator 3 is subjected to a surface treatment in consideration of hydrophilicity and antibacterial property. For this reason, scattering of water droplets is suppressed, and generation and propagation of mold and bacteria are prevented.

By the way, in an air conditioner in which the evaporator 3 is arranged in a horizontal or nearly horizontal state, most of the water droplets adhering to the surface fall by its own weight.
Since water droplets scattered by air sent from the vehicle are very small and the scatter direction is also upward, there is no possibility that the water droplets scatter in the vehicle interior. For this reason, in such an air conditioner, even if the hydrophilicity of the surface is sacrificed to some extent, there is little effect on the scattering of water droplets.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a heat exchanger which maintains antibacterial properties without deteriorating its function and has excellent durability.

[0013]

In order to achieve the above-mentioned object, according to the present invention, a corrosion-resistant film is formed on the surface, and after forming the corrosion-resistant film, a water-repellent resin film containing an inorganic antibacterial agent is formed. It is characterized by having been formed. The water-repellent resin film containing the inorganic antibacterial agent prevents the adhesion of water droplets and maintains the antibacterial property. In addition, since no water adheres, cracks do not occur in the resin and the outflow of the resin can be prevented.

The heat exchanger of the present invention is an evaporator for an air conditioner, wherein the evaporator and the bottom of the air conditioner below the evaporator are inclined in the same direction, and water is discharged to the lowermost part of the bottom. It is characterized by having a discharge port to perform. The water-repellent resin film makes it difficult for water droplets to adhere, flows down due to the inclination of the evaporator or the bottom of the air conditioner, and is discharged from the discharge port.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration of a vehicle air conditioner provided with an evaporator as a heat exchanger according to an embodiment of the present invention, and FIG. 2 shows a cross-sectional state of a surface film of the evaporator. Is shown.

The air conditioner will be described with reference to FIG. FIG.
In the air conditioner shown in (1), the evaporator 21 is disposed so as to be inclined with respect to the horizontal, and the air blown from the blower 22 is sent upward from below. That is, a blower 22 housed in a blower case 23 is provided downstream of an inside / outside air inlet (not shown), and the blower 22 is
4 to drive and blow air. An evaporator 21 made of aluminum is provided downstream of the blower 22 as a heat exchanger for cooling air sent from the blower 22 (cooling / dehumidifying function).
1 is disposed at the lower part of the heater case 25 at an angle of about 20 degrees with respect to the horizontal. The bottom of the heater case 25 is inclined in the same direction as the evaporator 21, and a discharge port 19 is provided at the bottom of the bottom of the heater case 25. The surface of the evaporator 21 is water-repellent,
Further, since the evaporator 21 and the bottom of the heater case 25 are inclined, water droplets generated by the evaporator 21 fall on the bottom of the heater case 25, flow down the inclined surface, and are discharged from the outlet 19, After flowing down the evaporator 21, it may fall from the lowermost part of the evaporator 21 and be discharged from the discharge port 19. For this reason, water is difficult to collect at the bottom of the air conditioner,
It is an environment where mold and bacteria are less likely to be generated and propagated, and it is less likely to generate off-flavors.

The air outflow side of the blower case 23 and the air inflow side of the heater case 25 communicate with each other through a passage 26. The outflow direction (arrow B) of the evaporator 21 with respect to the air blowing direction (arrow A) of the blower 22 is It is in a state going upward substantially orthogonally. In the heater case 25, the heat of the air passing through the evaporator 21 from the bottom to the top is taken away, and the cooling and dehumidification are performed.

A heater core 27 is provided in the heater case 25 above the evaporator 21, and the heater core 2
Numeral 7 is for heating air passing through, for example, using high-temperature engine cooling water as a heat source. An air mix damper 28 is mounted on the upstream side (lower side) of the heater core 27, and the air mix damper 28 is driven by a drive motor (not shown) so that the amount of air passing through the heater core 27 is adjusted. . Air mix damper 28
Is formed so as to be inclined in a shape along the outflow surface of the evaporator 21.

The downstream side (upper side) of the heater case 25 is
It is connected to the branch part 29. A passage 30 leading to the driver's seat side and the passenger's seat side is formed on the downstream side of the branch portion 29, so that the driver's seat side and the passenger's seat side can be independently air-conditioned. The air blowing direction (arrow C) in the branch portion 29 and the passage 30 is bent and becomes a downward direction.

In the above-described air conditioner, the air sent from the blower 22 in the horizontal direction flows into the evaporator 21 in a substantially perpendicular direction and flows upward, and is cooled by the evaporator 21 and sent upward. After that, the amount of cooling air corresponding to the opening degree of the air mix damper 28 passes through the heater core 27, is mixed with the cooling air that does not pass through the heater core 27, is brought to a predetermined temperature state, and is sent to the passage 29. Then, cool air or warm air is appropriately blown into the vehicle interior from each outlet.

Most of the water droplets due to the condensed water generated on the surface of the evaporator 21 by the heat exchange fall by their own weight and are discharged to the outside from a drain (not shown) provided at a lower portion of the heater case 25. A water-repellent resin film containing an inorganic antibacterial agent is formed on the surface of the evaporator 21 in order to promote the dropping of water droplets. The condition of the surface film of the evaporator 21 will be described with reference to FIG.

As shown in the figure, members (for example, fins) 31 constituting the evaporator 21 made of aluminum include:
For the purpose of preventing white rust due to corrosion, a chromate treatment layer 32 is formed as a corrosion resistant film. Further, a water-repellent resin film 34 is formed by adding an inorganic antibacterial agent 33 to a resin having excellent water-repellency. As the inorganic antibacterial agent 33, for example, zeolite, calcium phosphate, or zirconium phosphate having Ag, Cu, Zn, which is an antibacterial metal, supported in a metal state is applied. Further, a material in which Ag, Cu, and Zn, which are antibacterial metals, are supported in a metal state on silica or alumina is also applicable. Further, the antibacterial agent 33 can be formed by supporting Ag, Cu, and Zn, which are antibacterial metals, in an ionic state on zeolite, calcium phosphate, zirconium phosphate, silica, and alumina.

Water droplets due to condensed water generated on the surface of the evaporator 21 are repelled by the water-repellent resin film 34 and almost all fall by their own weight and are discharged. The remaining water droplets are scattered upward by the air sent from the blower 22, but the amount of the scattered water droplets is very small and scatters upward. It does not fly into the cabin because it is heading.

As described above, almost no water droplets adhere to the surface of the evaporator 21.
There is no high humidity, and no mold or bacteria are generated or propagated. Even if water droplets remain on the surface of the fins or the like of the evaporator 21, the antibacterial agent 33 prevents the generation and propagation of mold and bacteria. Further, since water droplets do not adhere to the water-repellent resin film 34, the antibacterial agent 33 does not flow out, and the safety is excellent. In addition, since moisture does not adhere to the surface of the evaporator 21, cracks and the like do not occur in the water-repellent resin film 34, and the durability is excellent.

In the air conditioner provided with the above-described evaporator 21, a chromate treatment layer 32 is formed on the surface of the evaporator 21, and a water-repellent resin obtained by adding an inorganic antibacterial agent 33 to a resin having excellent water repellency. Since the film 34 is formed, water droplets due to condensed water generated on the surface do not adhere to the surface, the antibacterial property is maintained, and mold and bacteria are not generated or propagated. Thereby, the evaporator 2
The generation of an unpleasant odor can be suppressed without impairing the function of (1). In addition, since no water adheres to the surface of the water-repellent resin film 34, cracks and the like do not occur in the water-repellent resin film 34, and the resin does not flow out, resulting in excellent durability.

Since the above-mentioned evaporator 21 is arranged in a substantially horizontal direction, the water-repellent resin film 34 prevents adhesion of water droplets and maintains antibacterial properties. At the same time, most of the water droplets fall due to their own weight. There is no scattering to the downstream side. Thereby, when the air conditioner is operated, generation of an unpleasant odor can be suppressed, and scattering of water droplets into the vehicle interior can be prevented. Further, even if a small amount of water droplets scatter, since the blowing direction downstream of the evaporator 21 is bent, the water droplets in the vehicle cabin can be prevented from being scattered.

In the above embodiment, the heat exchanger of the present invention is used as an evaporator of an air conditioner for a vehicle. However, the heat exchanger of the present invention can be applied to any equipment.

[0028]

According to the heat exchanger of the present invention, a corrosion-resistant film is formed on the surface, and after forming the corrosion-resistant film, a water-repellent resin film containing an inorganic antibacterial agent is formed. The water-repellent resin film eliminates adhesion of water droplets and maintains antibacterial properties. Further, since water does not adhere, cracks and the like do not occur in the resin and there is no outflow of the resin. As a result, it is possible to prevent the generation and propagation of mold and bacteria, and to improve the durability, and to suppress the generation of offensive odor without impairing the function as a heat exchanger.

Further, the heat exchanger of the present invention is used for an evaporator of an air conditioner, and is used in an air conditioner from a horizontal position to a horizontal position.
The evaporator is located in the air conditioner within the range of up to the degree, so that the water-repellent resin film prevents the adhesion of water droplets and maintains antibacterial properties, and most of the condensed water falls by its own weight and scatters to the downstream side There are few things. As a result, it is possible to prevent the generation and propagation of mold, bacteria, and the like, and to suppress the generation of an odor in a state where the water droplets are not scattered to the outside.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a vehicle air conditioner including an evaporator as a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a surface film of an evaporator.

FIG. 3 is a schematic configuration diagram of a general air conditioner.

FIG. 4 is a cross-sectional view of a surface film of a conventional evaporator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 19 Discharge port 21 Evaporator 22 Blower 23 Blower case 24 Drive motor 25 Heater case 26 Passage 27 Heater core 28 Air mix damper 29 Branch 30 Passage 31 Member (fin) 32 Chromate treatment layer 33 Antibacterial agent 34 Water-repellent resin film

Claims (2)

[Claims] 1. A heat exchanger wherein a corrosion-resistant film is formed on a surface, and a water-repellent resin film containing an inorganic antibacterial agent is formed after forming the corrosion-resistant film. 2. The heat exchanger according to claim 1, wherein the heat exchanger is an evaporator of an air conditioner, wherein the evaporator and the bottom of the air conditioner below the evaporator are inclined in the same direction and at the bottom of the bottom. A heat exchanger comprising a discharge port for discharging water.