Sterilization device for coolers

Abstract

To provide a sterilization device for a cooler that can suppress the growth of mold and bacteria and sterilize the cooling part of the cooler. [Solution] This is a sterilization device for a cooler, characterized in that it comprises a plasma generation unit (102) that generates plasma and has a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer, an AC power supply unit (104) that applies an AC voltage to the pair of electrode layers, a cooling unit (108) that supplies cool air to a space, and a filter (110) that is provided upstream of the cooling unit (108) in the air flow, and the plasma generation unit (102) is positioned between the filter (110) and the cooling unit (108).

Description

[Technical Field]

[0001] The present invention relates to a sterilizer for a cooler. [Background technology]

[0002] In recent years, a technique called dielectric barrier discharge (DBD) has been developed in plasma processing technology, making it possible to generate low-temperature plasma at atmospheric pressure. As a result, the range of applications of plasma processing has expanded, and it is increasingly being used in a variety of applications. The purposes of plasma processing include sterilization, deodorization, surface modification, and decomposition of chemical substances. Furthermore, the substances that can be subjected to plasma processing can be solid, liquid, or gaseous.

[0003] Various plasma processing apparatuses have been developed to perform continuous plasma processing while flowing air. For example, Patent Document 1 discloses a plasma generating apparatus in which plasma generating units, each having a flat plate-shaped first electrode and a second electrode facing each other across a gap, are stacked in two or more layers. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-190472 Summary of the Invention [Problem to be solved by the invention]

[0005] Condensation in the cooling portion of a cooler (e.g., air conditioner) can lead to the growth of mold and bacteria. This mold and bacteria growth can cause unpleasant odors. Therefore, it is desirable to reduce mold and bacteria in the cooling portion of a cooler. The cooling portion of a cooler refers to the cooling portion of, for example, an automobile air conditioner, a home air conditioner, an office air conditioner, etc.

[0006] The present invention has been made in consideration of the above points, and aims to provide a sterilization device for a cooler that can suppress the growth of mold and bacteria and sterilize them in the cooling part of the cooler. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the present invention provides a plasma generating unit that generates plasma and has a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer, a power supply unit that applies an AC voltage to the pair of electrode layers, a cooling unit that supplies cool air to a space, and a filter that is provided upstream of the cooling unit in the air flow, and is characterized in that the plasma generating unit is arranged between the filter and the cooling unit.

[0008] According to the present invention, plasma-treated gas generated by the plasma generating unit is circulated along the air flow, whereby it collides with bacteria in the air and is sterilized, and by spraying it onto the cooling unit, it is possible to reduce the activity of bacteria, mold, etc. adhering to the multiple fins of the cooling unit 108 and thereby reduce their occurrence. As a result, the present invention provides a cooler sterilization device that can inhibit the occurrence of and sterilize mold and bacteria in the cooling portion of the cooler. Note that, in the present invention, the phrase "the plasma generating unit is disposed between the filter and the cooling unit" includes cases where the plasma generating unit is provided in the filter itself and cases where the plasma generating unit is provided in the cooling unit itself.

[0009] In the present invention, it is preferable that the cooler casing has a frame that supports the filter, and the plasma generating section is attached to the frame.

[0010] Furthermore, in the present invention, it is preferable that the cooling unit has a plurality of fins for controlling the flow of air, and the plasma generating part is attached to at least one of the fins.

[0011] Furthermore, in the present invention, it is preferable that the filter comprises an exterior filter that takes in outside air, and that the cooler casing is provided with an interior filter that takes in air circulating within the vehicle cabin.

[0012] Furthermore, in the present invention, it is preferable that the plasma generating part has flexibility.

[0013] Furthermore, in the present invention, it is preferable that the plasma generating unit and the power supply unit are each covered with a highly flame-retardant material.

[0014] Furthermore, in the present invention, it is preferable that a humidity sensor and a temperature sensor are disposed near the cooling unit.

[0015] Furthermore, in the present invention, it is preferable that the cooler has a control unit to which detection signals from the humidity sensor and the temperature sensor are input, and that this control unit controls the cooler to operate continuously or intermittently according to the moisture concentration around the cooling unit after the operation of the cooler is stopped.

[0016] Furthermore, in the present invention, it is preferable that the control unit sets the plasma generation time in the plasma generating unit based on detection signals from the humidity sensor and the temperature sensor. [Effects of the Invention]

[0017] According to the present invention, it is possible to obtain a sterilization device for a cooler that can inhibit the growth of mold and bacteria and sterilize the cooling portion of the cooler. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 2] FIG. 2 is a perspective view for explaining a plasma generating unit. [Figure 3] FIG. 2 is a cross-sectional view for explaining a plasma generating unit. [Figure 4]FIG. 10 is a perspective view for explaining a plasma generating unit according to a first modified example. [Figure 5] FIG. 10 is a perspective view for explaining a plasma generating unit according to a second modified example. [Figure 6] FIG. 10 is a cross-sectional view illustrating a plasma generating unit according to a third modified example. [Figure 7] 1 is a schematic diagram showing a cooler sterilization apparatus according to a first embodiment of the present invention; [Figure 8] FIG. 10 is a schematic diagram showing a cooler sterilization apparatus according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a partial phantom side view showing a sterilization apparatus for a cooler according to a third embodiment of the present invention. [Figure 10] FIG. 10 is a partial phantom perspective view of the cooler sterilizer shown in FIG. [Figure 11] FIG. 10 is a schematic diagram showing a sterilization apparatus for a cooler according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present invention will be described in detail, but the embodiments of the present invention are not limited to the embodiments described below. Each embodiment and modified example can be applied in appropriate combination. Furthermore, directions such as "upper" and "lower" in the description are used for convenience of explanation and do not limit the directions of the present invention.

[0020] The cooler sterilization apparatus of this embodiment is configured to continuously plasma treat gas and is equipped with a plasma generating unit having a multilayer structure having a dielectric layer, an electrode layer, and a mask layer (optional), and an AC power supply unit (power supply unit) capable of applying an AC voltage between a pair of electrode layers. In dielectric barrier discharge, a dielectric layer is provided between two electrode layers, and by applying an AC voltage between the two electrode layers, plasma can be generated within the dielectric layer sandwiched between the two electrode layers. First, the plasma generating unit will be described.

[0021] <Basic structure of the plasma generation unit> As shown in Figures 1 and 2, the plasma generating unit 10 includes a dielectric layer 11, an upper electrode 12, a lower electrode 13, an upper mask layer 14, and a lower mask layer 15. The plasma generating unit 10 is a thin-film member and is flexible. For convenience, the dielectric layer 11 is expressed as a single dielectric, but it may also be a laminate of one or more dielectrics containing air (air layers). The mask layer is provided to protect the electrodes and improve the ease of assembling the electrodes, and may be omitted. Furthermore, by appropriately selecting the thickness and position of the mask layer, excessive electric field concentration on the electrodes can be prevented, thereby extending the life of the electrodes.

[0022] As shown in FIGS. 1 to 3, the dielectric layer 11 is a layer member disposed between the upper electrode 12 and the lower electrode 13. The material of the dielectric layer 11 is an insulating material with a large breakdown voltage so that discharge does not easily occur between the upper electrode 12 and the lower electrode 13. Furthermore, since the material of the dielectric layer 11 will be exposed to the generated plasma, it is preferable that the material be durable against the active substances generated in the plasma. The material of the dielectric layer 11 is preferably a material selected mainly from glass, ceramics, and synthetic resins. The term "mainly" means that the component composition is 50 mass % or more (the same applies hereinafter).

[0023] Examples of glass include soda-lime glass (soda glass), borosilicate glass, quartz glass, lead glass, oxide glass, etc. Examples of ceramics include alumina, silica, titanium oxide, zinc oxide, etc.

[0024] Synthetic resins include thermoplastic resins and thermosetting resins. Examples of thermoplastic resins include general-purpose resins such as polyolefin, polystyrene, polyvinyl acetate, polyurethane, polylactic acid, ABS resin, AS resin, acrylic resin, polyvinyl chloride, and polyvinylidene chloride; engineering plastics such as polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polyester, and cyclic polyolefin; polyphenylene sulfide, polysulfone, polyethersulfone, polyarylate, liquid crystal polymer, polyetheretherketone, polyimide, polyamideimide, polyetherimide, fluorine-based resin, unsaturated polyester resin, and polyurethane resin. Among these synthetic resins, silicone-based resins, polyimide-based resins, and Teflon®-based resins, which have excellent durability, are particularly preferred. The thickness of the dielectric layer 11 is not particularly limited, but is preferably 0.1 mm to 5.0 mm, more preferably 0.1 mm to 3.0 mm, and even more preferably 0.1 mm to 1.0 mm, in order to achieve lightweight and compactness.

[0025] As shown in FIGS. 2 and 3, the upper electrode (electrode layer) 12 and the lower electrode (electrode layer) 13 are layer members disposed on the front and back of the dielectric layer 11. The upper electrode 12 and the lower electrode 13 are each provided with a through-hole 16 penetrating in the thickness direction. In this embodiment, the through-holes 16 are oval in plan view, and five through-holes 16 are formed, but the shape and number are not limited. The through-holes 16 may be omitted, but providing the through-holes 16 as in this embodiment makes it easier to generate plasma and facilitates the creation of a power supply circuit. Furthermore, contact with gas at the through-holes 16 enables plasma processing of the gas.

[0026] The upper electrode (electrode layer) 12 and the lower electrode (electrode layer) 13 are formed of a conductive material, and may be a metal plate (including metal foil), a conductive paint, a conductive polymer, a conductive film, etc. The thickness of the upper electrode 12 and the lower electrode 13 is not particularly limited, but is preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm, respectively, in order to provide a flexible, lightweight, and compact processing device.

[0027] The dielectric layer 11, the upper electrode 12, and the lower electrode 13 may be laminated without using an adhesive, or may be bonded with an adhesive. The adhesive is preferably a material that is durable against active substances generated in plasma. Examples of adhesives include epoxy, acrylic, urethane, phenol, urea, silicone, cyanoacrylate, rubber, and vinyl acetate adhesives. Among these, silicone adhesives and UV-curable epoxy adhesives are preferred from the viewpoint of durability, with polyamide adhesives, polyimide adhesives, and silicone adhesives being more preferred. The thickness of the adhesive is preferably 0.01 to 0.2 mm, and more preferably 0.01 to 0.1 mm.

[0028] As shown in FIG. 3 , the upper mask layer 14 and the lower mask layer 15 are components disposed on the outer sides of the upper electrode 12 and the lower electrode 13, respectively. More specifically, the upper mask layer 14 is disposed on the upper surface of the upper electrode 12. The lower mask layer 15 is disposed on the lower surface of the lower electrode 13. The upper mask layer 14 and the lower mask layer 15 are each provided with through holes 17. In this embodiment, the through holes 17 are oval and five in number are formed, but the shape and number are not limited thereto. The through holes 17 may be omitted, but for ease of manufacturing, it is preferable that the through holes 17 are the same as the through holes 16, although this is not limitative.

[0029] As shown in Figures 2 and 3, through hole 17 has the same shape as through hole 16, and they communicate with each other. It is not necessary that through hole 17 and through hole 16 have the same shape. Through holes 16, 17, dielectric layer 11 is exposed to the outside. In other words, the surface of dielectric layer 11 is exposed to the outside at multiple locations where through holes 16, 17 are formed. In addition, hole walls (cross-sectional portions) 16a, 17a of through holes 16, 17 are also exposed to the outside. Furthermore, through holes 16, 17 may be provided on only one side.

[0030] The upper mask layer 14 and the lower mask layer 15 are formed of an insulating material. The hardness of the upper mask layer 14 and the lower mask layer 15 is preferably equal to or less than that of the upper electrode 12 and the lower electrode 13. If the plasma generation unit 10 is manufactured using a thin material, it may be difficult to handle. However, providing the upper mask layer 14 and the lower mask layer 15 improves ease of handling. The upper mask layer 14 and the lower mask layer 15 also protect the thin conductor from mechanical and physical shocks during manufacture and use, as well as deterioration caused by the surrounding environment. Furthermore, they provide mechanical protection against scratches that may occur during manufacture. Considering that the plasma generation unit 10 will be installed on an object to be attached, the upper mask layer 14 and the lower mask layer 15 preferably have a hardness that allows for easy installation along the object and also improves ease of handling. Furthermore, by dividing the dielectric layer 11 into two, the upper and lower structures of the plasma generating unit 10 can be made symmetrical. Manufacturing can be easily achieved by assembling the upper and lower structures and bonding them together in the center. In this case, the dielectric layer 11 is divided into three layers: the upper layer, the lower layer, and the adhesive layer, but can be considered electrically as a single dielectric.

[0031] The thicknesses of the upper mask layer 14 and the lower mask layer 15 are not particularly limited, but in order to provide a flexible, lightweight, and compact processing device, they are preferably 5 μm to 1.0 mm, more preferably 5 μm to 0.2 mm, and even more preferably 5 μm to 0.1 mm. The thicknesses of the upper mask layer 14 and the lower mask layer 15 may be set as appropriate, but in this embodiment they are formed to be larger than the thicknesses of the upper-layer electrode 12 and the lower-layer electrode 13.

[0032] The plasma generating unit 10 is very thin and flexible, which can make it difficult to handle during assembly. Furthermore, the upper electrode 12 and the lower electrode 13 are made of conductive materials, such as conductive metals and conductive dielectrics. Metals, for example, can be corroded by liquids and gases. For example, the upper electrode 12 and the lower electrode 13 are oxidized by highly oxidizing gases and corroded by sulfuric acid and hydrochloric acid. Resin-based conductive materials can also be deteriorated by humidity and acid. Furthermore, the plasma generating unit 10 is designed to be installed according to the shape of the target object. However, if only the upper electrode 12 and the lower electrode 13 are installed without the upper mask layer 14 and the lower mask layer 15, thin metal electrodes can wrinkle or create gaps between the electrodes and the dielectric layer 11. Gaps between the upper electrode 12 and the lower electrode 13 and the dielectric layer 11 can cause abnormal or partial discharges.

[0033] In this regard, according to this embodiment, the upper mask layer 14 and the lower mask layer 15 can protect the upper electrode 12 and the lower electrode 13, and the plasma generation unit 10 can be easily handled, improving workability and assembly. Furthermore, the provision of the upper mask layer 14 and the lower mask layer 15 allows the plasma generation unit 10 to be installed on an object without forming wrinkles or gaps. Furthermore, in the case of a multi-stage structure, the upper mask layer 14 and the lower mask layer 15 also serve as part of the dielectric that constitutes the barrier discharge, making it less likely that abnormal discharge will occur even if gaps are formed during installation.

[0034] The outer edges of upper layer electrode 12 and lower layer electrode 13 may be sealed with an insulator (not shown) to prevent deterioration over time due to exposure to the outside world and to prevent discharge from occurring via the outer edges other than through-hole 16. When a resin or the like is used as the mask layer, the mask layer has the effect of spreading thinly over not only upper layer electrode 12 and lower layer electrode 13 but also the upper and lower surfaces of dielectric 11.

[0035] Similarly, the outer edges of the upper mask layer 14 and the lower mask layer 15 may be sealed with an insulator (not shown) to prevent their outer edges from being exposed to the outside world and reacting with external substances to deteriorate over time, and to prevent discharge from occurring through the outer edges other than the through holes 17.

[0036] Furthermore, an insulating layer (not shown) may be provided on the outside of the upper mask layer 14 and the lower mask layer 15 .

[0037] When the longitudinal direction of the through holes 16 and 17 is parallel to the gas flow direction, the resistance to the gas flow is small and the gas flows smoothly. On the other hand, when the longitudinal direction of the through holes 16 and 17 is perpendicular to the gas flow direction, the resistance to the gas flow is large, the gas flow is disturbed, and the gas is agitated.

[0038] The shape, number, and direction of the through holes 16, 17 relative to the gas flow can be selected appropriately depending on the purpose of the plasma processing, the effect of the plasma processing, etc. The shapes of the through holes may be different between the front and back sides of the plasma generating unit 10. Alternatively, the through holes may be provided on the front side of the plasma generating unit 10 and not on the back side.

[0039] <First Modification of Plasma Generation Unit> 4 is a perspective view for explaining a plasma generating unit according to a first modified example. The plasma generating unit 10A according to the first modified example differs from the basic structure described above in that it does not have an upper mask layer 14. As in the plasma generating unit according to the first modified example, the mask electrode (mask electrode layer) may be provided only on one side of the plasma generating unit 10A.

[0040] <Second Modification of Plasma Generation Unit> FIG. 5 is a perspective view illustrating a plasma generating unit according to a second modified example. The plasma generating unit 10B according to the second modified example differs from the basic structure described above in that it does not include the upper mask layer 14 and the lower mask layer 15. The upper mask layer 14 and the lower mask layer 15 may be omitted, as in the plasma generating unit 10B according to the second modified example. That is, by configuring the plasma generating unit 10B with only the dielectric layer 11, the upper electrode 12, and the lower electrode 13, it is possible to further reduce the size and the number of parts. Furthermore, by thinning the dielectric layer 11, the upper electrode 12, and the lower electrode 13, the electrodes themselves can be made flexible, allowing them to be manufactured to fit curved surfaces.

[0041] Furthermore, as in the first and second modified examples, by omitting both or one of the upper mask layer 14 and the lower mask layer 15, the upper electrode 12 and the lower electrode 13 can be brought into direct contact with the gas, and the plasma and gas can be brought into contact at the ends of the electrodes, making it possible to easily extract the plasma gas (active species).

[0042] <Third Modification of Plasma Generation Unit> FIG. 6 is a cross-sectional view illustrating a plasma generating unit according to a third modified example. The plasma generating unit 10C according to the third modified example differs from the basic structure described above in that it does not include an upper mask layer 14 and a lower mask layer 15. Furthermore, the plasma generating unit 10C according to the third modified example does not have a monolithic dielectric layer, but is composed of an upper dielectric layer 18 and a lower dielectric layer 19, which are separated vertically and arranged facing each other. However, since air is also considered a type of dielectric, the upper dielectric layer 18, the air layer 20, and the lower dielectric layer 19 can be considered as a single dielectric layer 11, resulting in the same structure as the plasma generating unit 10B. An upper electrode 12 is provided on the upper surface of the upper dielectric layer 18, and a lower electrode 13 is provided on the lower surface of the lower dielectric layer 19. An air layer 20 is provided between the upper dielectric layer 18 and the lower dielectric layer 19. In the third modified example, plasma can also be generated in the air layer 20. For convenience, this embodiment does not show supports with pillars, grooves, protrusions, or the like that structurally support the air layer 20, which is made of air. These may be either conductive or insulating, provided they are positioned a sufficient distance from the electrodes, but insulating materials are preferred. Furthermore, structures may be placed to divide, control, or change the flow rate of fluid passing through the interior. Furthermore, if these structures are made of a dielectric material, they can control the electric field to suppress electric field concentration in specific areas, or conversely, intentionally concentrate the electric field.

[0043] First Embodiment Next, a cooler sterilization apparatus according to a first embodiment of the present invention will be described. Figure 7 is a schematic diagram showing the configuration of a cooler sterilization apparatus according to a first embodiment of the present invention. A cooler sterilization apparatus 100 according to a first embodiment of the present invention (hereinafter simply referred to as the sterilization apparatus 100) comprises a plasma generation section 102, an AC power supply section (power supply section) 104, a cooling unit 108 that constitutes a cooler 106 and supplies cool air to a space (for example, the interior of a vehicle or a car), and a filter (air filter) 110 that is provided upstream of the cooling unit 108 in the air flow.

[0044] The sterilization apparatus 100 also has a casing 112 with an air flow (see the white arrow A in Figure 7), and the filter 110, the plasma generating unit 102, and the cooling unit 108 are arranged in this order in the direction of the air flow, spaced a predetermined distance apart.

[0045] The plasma generating unit 102 may be any of the plasma generating units 10, 10A, 10B, and 10C shown in Figures 1 to 6. In this embodiment, the plasma generating unit 10 shown in Figures 1 to 3 will be described in detail below as an example.

[0046] In this embodiment, the plasma generating unit 102 (10) is configured as a module with a built-in plasma electrode, and can be easily retrofitted to the sterilization apparatus 100. The plasma electrode has a curved or flat shape and is disposed in the air passageway through the casing 112. By selecting an appropriate dielectric layer 11 sandwiched between the plasma electrodes, the plasma electrode itself can be used as a fin for changing the direction of air in the air passageway. Furthermore, the upper mask layer 14 and the lower mask layer 15 constituting the plasma electrode may be provided depending on the method, material, thickness, usage environment, purpose of use, manufacturing method, etc. of the plasma electrode, or may be omitted to obtain the same effect.

[0047] Furthermore, the electrodes and mask layer each have through-holes 16 and 17 (see FIGS. 2 and 3 ) formed of slits with arc-shaped cross sections at both ends in the extension direction. However, these may be circular, triangular, or rectangular in plan view. Furthermore, a mesh-like shape with wider gaps, which is an extension of the circular shape, may also be used. In this embodiment, from the perspective of preventing electric field concentration, it is appropriate for all shapes to have rounded corners, but this is not a requirement for operation. Furthermore, the shape and material properties (dielectric constant) of the mask layer may be changed to prevent electric field concentration at the corners. Furthermore, by minimizing the conductive portion and widening the gap area, as in a mesh-like shape, the area in contact with gases such as air can be increased. At the same time, under certain conditions, such as a design aimed at minimizing the device size, the design of the AC power supply unit 104 that drives these plasma electrodes may be simplified, but this does not pose any particular problems in the operation of this embodiment. Furthermore, in this embodiment, since lower layer electrode 13 is attached toward the inside of casing 112, it is not necessary to provide through-hole 16 in lower layer electrode 13. Note that the same effects can be obtained even when through-hole 16 is provided in lower layer electrode 13 (see FIG. 3).

[0048] 7, the plasma generating unit 102 is disposed approximately in the center between the filter 110 and the cooling unit 108 along the air flow direction, but this is not limitative. The plasma generating unit 102 may be disposed between the filter 110 and the cooling unit 108 along the air flow direction.

[0049] The filter 110 is made of, for example, a mesh-like air filter, and is disposed in the air flow upstream of the cooling unit 108. The filter 110 is mounted in the casing 112 so as to extend in a direction substantially perpendicular to the air flow.

[0050] The cooling unit 108 includes an evaporator having multiple fins, a fan, and the like, and is supported within a casing 112. Specifically, it includes an air intake port, a fan, an outer filter, an inner filter, a heat exchanger (cooler), an air outlet, a flow path, and the like, all of which are not shown.

[0051] The AC power supply unit 104 is not particularly limited as long as it can apply an AC voltage of a predetermined voltage at a predetermined frequency to each electrode of the plasma generation unit 102, and any known power supply device can be used. The frequency of the AC voltage is preferably 50 Hz to 30 MHz, and more preferably 50 Hz to 100 kHz. The AC voltage is preferably 0.1 to 50 kV, and more preferably 0.2 to 10 kV.

[0052] Furthermore, the plasma generating unit 102 and the AC power supply unit 104 may be each preferably covered with a highly flame-retardant material (not shown), metal, glass, etc. In this embodiment, by covering the plasma generating unit 102 and the AC power supply unit 104, it is possible to prevent the fire from spreading to other areas even if an electrical failure or trouble occurs.

[0053] Furthermore, a humidity sensor 114 and a temperature sensor 116 are disposed near the cooling unit 108. Detection signals from the humidity sensor 114 and the temperature sensor 116 are input to the control unit 118. After the operation of the cooler 106 stops, the control unit 118 can control the cooler 106 to operate continuously or intermittently in accordance with the moisture concentration around the cooling unit 108.

[0054] Furthermore, the control unit 118 can set the plasma generation time in the plasma generation unit 102 based on the detection signals from the humidity sensor 114 and the temperature sensor 116 .

[0055] <Action and effect> Next, the effects of the sterilization apparatus 100 according to this embodiment will be described. First, AC power supply unit 104 is switched from an off state to an on state to apply an AC voltage between upper electrode 12 and lower electrode 13. When an AC voltage is applied between upper electrode 12 and lower electrode 13 with dielectric layer 11 therebetween, plasma is generated in the vicinity of the upper surface of upper electrode 12 and the lower surface of lower electrode 13. In addition, active oxygen species are generated at the contact surfaces between the plasma-treated gas and upper electrode 12 and lower electrode 13.

[0056] The plasma-treated gas kills microorganisms present in the gas and decomposes chemical substances due to the active oxygen species generated by the plasma, thereby sterilizing and deodorizing the gas.

[0057] Furthermore, active oxygen species remain in the plasma-treated gas. Therefore, by circulating the plasma-treated gas generated by the sterilization apparatus 100 of this embodiment along the air flow, it collides with bacteria in the air and is sterilized. Furthermore, by spraying the plasma-treated gas onto the cooling unit 108, it is possible to reduce the activity of bacteria, mold, and the like adhering to the multiple fins of the cooling unit 108 and thereby reduce their occurrence. Note that the plasma generation unit 102 needs to be operated for a while after the cooler 106 is stopped, but it does not need to be operated continuously, and PWM (Pulse Wide Modulation) control, which repeatedly turns on and off as necessary, may be used.

[0058] Functions achieved by plasma treating gas using the sterilization apparatus 100 of this embodiment include sterilization, virus inactivation, deodorization, surface modification, and decomposition of chemical substances. The mechanism by which these functions are achieved is thought to be that reactive oxygen species (ROS) such as singlet oxygen, hydrogen peroxide, OH radicals, superoxide anions, peroxide radicals, and ozone are generated in the gas by plasma treatment, and these kill target microorganisms or decompose and modify chemical substances through oxidation reactions, etc. Examples of microorganisms include various bacteria, viruses, and molds.

[0059] By utilizing these functions, the sterilization apparatus 100 of this embodiment can be used for purposes such as deodorization, odor removal, sterilization, disinfection, and air purification in many industrial fields, including medicine (fiberscopes, endoscopes, various small cameras, etc.), housing, civil engineering, construction, agriculture, fisheries, livestock farming, food processing, transportation, storage, and retail.

[0060] Second Embodiment Next, a cooler sterilization apparatus 200 according to a second embodiment of the present invention will be described. From the second embodiment onwards, the explanation will focus on the parts that differ from the first embodiment. In addition, in the second embodiment onwards, the same components as those in the first embodiment will be described using the same reference numerals.

[0061] As shown in Figure 8, the cooler sterilizer 200 according to this embodiment differs from the first embodiment in that it has a frame (holder) 202 that supports the filter 110 within the casing 112, and the plasma generating unit 102 is attached to this frame 202. Note that in this embodiment, the plasma generating unit 102 is incorporated into the frame 202 of the filter 110, but this is not limiting. For example, the plasma generating unit 102 may be incorporated into the filter 110. Furthermore, the same effect can be obtained by incorporating the plasma generating unit 102 into the cooling unit 108. In other words, "the plasma generating unit is disposed between the filter and the cooling unit" includes incorporating the plasma generating unit 102 into the filter 110 and incorporating the plasma generating unit 102 into the cooling unit 108.

[0062] Furthermore, as an assembly method, for example, the plasma generating unit 102 may be directly attached to a member that holds or positions the filter 110, or a fin-like structure may be placed at the position of the plasma generating unit 102 behind the filter 110. By placing the plasma generating unit 102 behind the filter 110 or in front of the cooling unit 108 in the air flow direction, dust and other particles are not taken in by the filter 110, and mold, bacteria, and the like that occur in the condensation areas of the cooling unit 108 can be efficiently removed.

[0063] Third Embodiment Next, a cooler sterilizer 300 according to a third embodiment of the present invention will be described. As shown in Figures 9 and 10, the cooler sterilizer 300 according to this embodiment is provided with plate-shaped multi-stage fins 304 that can control the wind direction (air flow) using a pair of support shafts 302a, 302b provided on both the left and right sides as rotation axes. These fins 304 are provided, for example, inside or at the outlet of the cooling unit 108. This embodiment differs from the first embodiment in that the plasma generation unit 102 is incorporated into at least one of the multi-stage fins 304.

[0064] In this embodiment, a total of five fins 304 stacked in the vertical direction are shown, but this is not limited to this. Also, in this embodiment, the plasma generation unit 102 is arranged in the fin 304 located in the center in the vertical direction among the five fins 304, but this is not limited to this.

[0065] <Fourth embodiment> Next, a cooler sterilization apparatus 400 according to a fourth embodiment of the present invention will be described. As shown in Figure 11, the cooler sterilization apparatus 400 according to this embodiment differs from the first embodiment in that the filter 110 is composed of an exterior filter 402 that takes in external air (fresh air) and an interior filter 404 that is disposed in the casing 112 and takes in air circulating in the vehicle cabin (not shown). In Figure 11, the outline arrow B indicates the flow of outside air, and the outline arrow C indicates the flow of air circulating inside the vehicle.

[0066] In this embodiment, the plasma generating unit 102 is disposed close to the cooling unit 108 to avoid interference with the vehicle interior filter 404. The air inside the vehicle circulates within the vehicle and is repeatedly taken into the cooling unit 108.

[0067] Although the embodiments and modifications of the present invention have been described above, appropriate design changes are possible within the scope of the present invention. [Explanation of symbols]

[0068] Sterilizer for 100, 200, 300, 400 coolers 102 Plasma generation unit 104 AC power supply section 106 Cooler 108 Cooling Unit 110 Filters 112 Casing 114 Humidity Sensor 116 Temperature Sensor 118 Control Unit 202 Frame 304 Fins 402 Exterior filter 404 Car Filter A. Air flow B. External air flow C. Flow of circulating air inside the vehicle

Claims

1. a plasma generating unit that generates plasma and includes a dielectric layer and a pair of electrode layers provided on both sides of the dielectric layer; a power supply unit that applies an AC voltage to the pair of electrode layers; a cooling unit that supplies cool air to the space; a filter provided upstream of the cooling unit in the air flow; Equipped with The sterilization apparatus for a cooler, wherein the plasma generating unit is disposed between the filter and the cooling unit.

2. The sterilization apparatus for a cooler according to claim 1, a frame that supports the filter in a cooler casing; The sterilization device for a cooler, wherein the plasma generating unit is attached to the frame.

3. The sterilization apparatus for a cooler according to claim 1, The cooling unit has a plurality of fins for controlling air flow; The sterilization device for a cooler, wherein the plasma generating unit is attached to at least one of the fins.

4. The sterilization apparatus for a cooler according to claim 1, a cooler casing for supporting the filter and the cooling unit; The filter is an exterior filter that takes in outside air, The sterilization device for a cooler is characterized in that an interior filter that takes in air circulating within the vehicle interior is disposed in the cooler casing.

5. The sterilization apparatus for a cooler according to claim 1, The sterilization device for a cooler, wherein the plasma generating unit is flexible.

6. The sterilization apparatus for a cooler according to claim 1, The sterilization device for a cooler, wherein the plasma generating unit and the power supply unit are each covered with a highly flame-retardant material.

7. The sterilization apparatus for a cooler according to claim 1, A sterilization device for a cooler, characterized in that a humidity sensor and a temperature sensor are arranged near the cooling unit.

8. The sterilization apparatus for a cooler according to claim 7, The cooling unit is provided in a cooler, the cooler has a control unit to which detection signals from the humidity sensor and the temperature sensor are input, The control unit controls the cooler to operate continuously or intermittently after the cooler has stopped operating, depending on the moisture concentration around the cooling unit.

9. The sterilizer for a cooler according to claim 8, The sterilization apparatus for a cooler, wherein the control unit sets a plasma generation time in the plasma generation unit based on detection signals from the humidity sensor and the temperature sensor.

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