Patent Application
20130104588
The present invention relates to a heat exchanger, and specifically relates to a heat exchanger in which an antibacterial member can be installed at a low cost without using a dedicated fixing member, a decline of heat exchange efficiency caused by the installation of the antibacterial member is kept to a minimum even if it occurs, and flexibility of design can be kept at a high level.
In a heat exchanger, especially in a heat exchanger such as an evaporator provided in an air path in an air-conditioning system, a variety of methods for preventing generation of bacteria and fungi have been suggested hitherto. For example, in Patent document 1, a heat exchanger is disclosed that an antibacterial member impregnated with an antibacterial fungicide agent is placed at an upper end thereof, the antibacterial ingredient is dissolved in water dew generated on a surface of the antibacterial member, and antibacterial functionality is provided by the water dew which contains the antibacterial ingredient and flows down on the surface of the heat exchanger.
However, in the heat exchanger disclosed in Patent Document 1, a position where an antibacterial member is installed is limited to an upper end part of the heat exchanger, and there is a concern that flexibility of design may be reduced by the installation of the antibacterial member. Further, in the embodiment disclosed in Patent Document 1, because a fixing hook or a thermally conductive plate is provided for the special purpose of fixing the antibacterial member, there is a concern that the cost of manufacturing and assembling may increase, and there is a problem that it is difficult to achieve miniaturization and weight reduction of the heat exchanger.
Therefore, an object of the present invention is to provide a heat exchanger in which an antibacterial member can be installed at a low cost without using a dedicated fixing member, a decline of heat exchange efficiency caused by the installation of the antibacterial member is kept to a minimum even if it occurs, and flexibility of design can be kept at a high level comparable to conventional ones in which an antibacterial member is not installed.
In order to solve the above-described object, a heat exchanger according to the present invention is a heat exchanger provided with a heat radiation member containing at least a plurality of tubes which are arranged in a planar manner and through which a heat exchange medium flows, characterized in that a water absorption sheet substrate holding an antibacterial ingredient is partially attached to the heat radiation member so that the antibacterial ingredient can diffuse along a surface of the heat radiation member through water which has been absorbed by the water absorption sheet substrate.
According to such a heat exchanger, because a water absorption sheet substrate which is capable of absorbing and releasing water is used as a member holding an antibacterial ingredient, water can be released out of the sheet quickly after the antibacterial ingredient is dissolved in water which is absorbed temporarily, and the antibacterial ingredient rapidly diffuses over a wide range along the surface of the heat radiation member. Further, because the water containing the antibacterial ingredient is released successively after the antibacterial ingredient is dissolved in the water being absorbed in the water absorption sheet substrate due to the ease in releasing water, the water absorption sheet substrate does not have to be configured as a wide member having a great capability of keeping water and may be placed partially at a position in which heat exchange performance is not affected. Therefore, a decline of heat exchange efficiency of the heat exchanger itself is prevented, or is kept to a minimum even if it exists.
Because the water absorption sheet substrate according to the present invention can absorb and release water easily, the diffusion of the antibacterial ingredient can be realized in various embodiment. For example, when a filmy aqueous layer is formed on the surface of the heat radiation member, and part of the aqueous layer comes in contact with the water absorption sheet substrate, the antibacterial ingredient becomes dissolved and diffuses in the aqueous layer, and the antibacterial ingredient has an effect on the entire aqueous layer. Further, when a water flow path is formed on the surface of the heat radiation member, by placing the water absorption sheet substrate in the upstream, water in which the antibacterial ingredient is dissolved flows in the flow path formed on the surface of the heat radiation member, and the diffusion of the antibacterial ingredient on the surface of the heat radiation member is achieved. Where, the above-described water current flowing in the flow path may be a continuous water current or a discrete water current (for example, drops which dribbles down the surface of the heat radiation member intermittently, etc.).
Because the water absorption sheet substrate can realize the diffusion of antibacterial ingredient in various means as described above, it is possible to choose an setting method appropriate to the use of the heat exchanger. Further, because it is formed in a sheet shape, the setting space can be kept small, a processing of size and shape matching with the setting location is easy, the flexibility of design of the heat exchanger can be kept at a high level as in the conventional case of having no antibacterial member, and a rise in manufacturing cost and an effect on peripheral equipments of the heat exchanger which are caused by the installation of the water absorption sheet substrate is suppressed.
In the water absorption sheet substrate according to the present invention, condensation water condensed on the surface of the heat radiation member can be used as water for diffusing antibacterial ingredient, although it is not particularly limited. By using the flow path of the condensation water to diffuse antibacterial ingredient, it becomes unnecessary to form a new path for diffusing antibacterial ingredient and a rise in manufacturing cost of the heat exchanger is suppressed.
The water absorption sheet substrate is not limited about a setting embodiment specifically. For example, when the water absorption sheet substrate is attached to part of the surface of the tube array, the water absorption sheet substrate may be fixed on the surface of the tube array by adhesion or fastening, or a fixing member may be used for fastening the substrate onto the surface of the tube array. However, from the viewpoint of easiness of the setting work and reduction of component cost, it is preferred that the water absorption sheet substrate is attached to the surface of the tube array non-adhesively without any additional dedicated fixing member. For example, such a setting embodiment is exemplified by a layout wherein an water absorption sheet substrate is placed between an insulation seal member and tubes in a heat exchanger, in which the insulation seal member is provided around an end part of the surface of the tube array.
Further, the heat radiation member according to the present invention is not limited to the above-described tubes and, for example, an end plate provided at an end part of the tubes in the tube array direction, a header connected with the ends of tubes, fins provided among the tubes, etc. can be included in the heat exchanger.
In such a heat radiation member other than the tubes, as mentioned above, it is also preferred that the water absorption sheet substrate is attached to the heat radiation member without any additional dedicated fixing member non-adhesively. For example, such a setting embodiment is exemplified by a layout wherein an water absorption sheet substrate is placed between a seal member and an end plate in a heat exchanger, in which the end plate as a heat radiation member is placed at an end part of tubes in a tube array direction and the seal member is placed on at least part of the surface of the end plate.
A position where the water absorption sheet substrate is installed is not limited specifically. For example, when the water absorption sheet substrate is placed at an lower end part of the heat exchanger, the antibacterial ingredient can diffuse in an upward direction through aqueous layer formed on the surface of the tubes as mentioned above. Further, the water absorption sheet substrate can be placed at an upper end part of the heat exchanger so that a flow path of moisture formed on the surface of the tubes can be used as a diffusion path of the antibacterial ingredient as mentioned above.
From the viewpoint of excellent ability of absorbing and releasing moisture, it is preferred that a material of water absorption sheet substrate according to the present invention comprises a nonwoven fabric or a mesh, although is not limited specifically.
For example, the above-described water absorption sheet substrate may have a configuration that at least 2 water absorption sheet members are stacked, and that an antibacterial sheet holding antibacterial ingredient is located between the stacked water absorption sheet members. Because such a configuration can be constituted merely by the water absorption sheet members and the antibacterial sheet, the costs of manufacturing, processing and components of the water absorption sheet substrate can be reduced.
An inorganic antibacterial ingredient, an organic antibacterial ingredient, a natural antibacterial ingredient, etc. can be cited as the antibacterial ingredient according to the present invention, for example, although it is not limited specifically.
The above-described inorganic antibacterial ingredient can be exemplified by a metal ion such as Ag, Cu, Zn, Ti, a compound consisting of the metal ion, etc., although it is not limited specifically. By using such an inorganic antibacterial ingredient, a water absorption sheet substrate which has little effect on human body and has excellent safety can be provided. Further, because the above-described metal ions have high solubility in water, the antibacterial ingredient can diffuse on the surface of the tubes quickly.
The above-described organic antibacterial ingredient can be exemplified by pyridione, thiabendazole, etc., although it is not limited specifically. Such an organic antibacterial ingredient which can be synthesized chemically is inexpensive and makes it possible to reduce the manufacturing cost of the water absorption sheet substrate.
For example, the above-described natural antibacterial ingredient can be exemplified by catechin, chitosan, allyl isothiocyanate, ozone, etc., although it is not limited specifically. Such a natural antibacterial ingredient has little effect on human body and environment, and makes it possible to provide a water absorption sheet substrate which puts little load on the environment.
A method for keeping hold of ozone can be exemplified by a method of holding ozone by making water absorption sheet substrate absorb ozone-dissolving water, for example.
Although the uses of a heat exchanger according to the present invention are not particularly limited, this heat exchanger is preferably applicable to an evaporator which is provided in a refrigeration circuit and in which water dew forms on a surface of tubes, and is especially suitable for an evaporator provided in a refrigeration circuit for automobile air-conditioning systems where the installation space is strictly limited and high flexibility of design is required.
According to a heat exchanger in the present invention, a heat exchanger which is capable of antibacterial function can be realized at a low cost while maintaining flexibility of design.
Hereinafter, embodiments of the present invention will be explained referring to figures.
Hereinafter, desirable embodiments of the present invention will be explained as referring to figures.
Where, the water absorption sheet substrate is provided at a lower end part of the heat exchanger in
In
Insulation seal member 6 is provided at a position close to an end part of the array surface of tubes 2 and at a position on the surface of header 3. Water absorption sheet substrate 7 intervenes between insulation seal member 6 and tubes 2 non-adhesively.
In
Because the other configurations are similar to the embodiment depicted in
As shown in
As mentioned above, because water absorption sheet substrate 7 can be easily processed into suitable size and shape for the installation space and is space-saving, water absorption sheet substrate 7 can be provided at a plurality of positions as keeping flexibility of design of heat exchanger 1 at high level, and a rise in the cost of manufacturing and an effect on peripheral equipments of heat exchanger 1 caused by the installation of water absorption sheet substrate 7 are kept to a minimum.
In heat exchanger 1 of
When heat exchanger 1 as an evaporator operates, tubes 2 are cooled by heat of evaporation of a refrigerant (a heat exchange medium) circulating in tubes 2, heat exchange (air cooling) with air flowing through tube 2 is performed and condensation water 8 may condense dew on a surface of tubes 2.
Because condensation water 8 is cooled and does not evaporate easily, when quantity of condensation increases, membrane-like aqueous layer 9 consisting of condensation 8 is formed on the surface of tubes 2.
When aqueous layer 9 grows in size and a lower end of aqueous layer 9 comes in contact with water absorption sheet substrate 7, antibacterial ingredient 10 held by water absorption sheet substrate 7 dissolves in aqueous layer 9 and diffuses on the surface of tubes 2.
If antibacterial ingredient 10 is nonvolatile, when heat exchanger 1 stops and condensation water 8 and aqueous layer 9 evaporate, antibacterial ingredient 10 that has diffused remains on the surface of tubes 2. And when heat exchanger operates again and aqueous layer 9 consisting of condensation water 8 is formed, antibacterial ingredient 10 diffuses on the surface of tubes 2 again.
Therefore, by using a chemically stable nonvolatile ingredient as antibacterial ingredient 10, antibacterial ingredient 10 stays on the surface of tubes 2 and sustainable antibacterial function on the entire surface of tubes 2 can be provided.
In heat exchanger 1 of
When heat exchanger 1 as an evaporator operates, tube 2 is cooled by the heat of evaporation of a refrigerant circulating in tube 2, and condensation water 8 may be condensed on the surface of tube 2.
When condensation water 8 that condenses at a position close to the upper end part of tube 2 comes into contact with water absorption sheet substrate 7, antibacterial compound held by water absorption sheet substrate 7 dissolves in condensation water 8.
Because water absorption sheet substrate 7 is provided at a position close to the upper end of tube 2 and is capable of releasing moisture easily, condensation water 8a containing antibacterial compound 10 is released from water absorption sheet substrate 7 by gravity at once and flows upon the surface of tube 2 in a downward direction, and antibacterial compound 10 diffuses over the entire surface of tube 2.
As is the case with above-described
Therefore, by using a chemically stable volatile compound as antibacterial compound 10, antibacterial compound 10 is kept on the surface of tube 2 and the persistent antibacterial capability can be provided over the entire surface of tubes 2.
The present invention is applicable to any kind of heat exchangers and, in particular, is suitable to be used as an evaporator provided in a refrigeration circuit.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2010/002291 | 3/30/2010 | WO | 00 | 12/11/2012 |
