Vehicle air conditioning system

Abstract

This vehicle air conditioning system comprises: an air conditioning device10 that has an adsorption part having an adsorbent capable of adsorbing and desorbing moisture, and a heating means capable of heating the adsorption part; an air conditioning duct 20 through which air from a cabin or outside of a vehicle can flow, and in which the air conditioning device 10 is disposed inside, the air conditioning duct 20 having, on a downstream side of the air conditioning device 10, a first flow path 20a for allowing air to flow into the cabin and a second flow path 20b for discharging air to the outside of the vehicle; and a valve 30 capable of switching a flow of air between the first flow path 20a and the second flow path 20b. The distance between the air conditioning device 10 and the valve 30 is 5 to 310 mm.

Description

Vehicle air conditioning systems

[0001] The present invention relates to a vehicle air conditioning system.

[0002] There is a growing demand for improved cabin environments in various vehicles, including automobiles. Specific requirements include reducing CO2 emissions in the cabin to suppress driver drowsiness, controlling humidity in the cabin, and removing harmful volatile components, such as odorous components and allergy-inducing components, from the cabin. Ventilation is an effective solution to these requirements, but ventilation can significantly reduce heating energy in winter, resulting in reduced energy efficiency. This energy loss, particularly in battery electric vehicles (BEVs), poses a problem of significantly reduced driving range.

[0003] To solve the above problems, a vehicle interior purification system (vehicle air conditioning system) has been proposed, which includes: a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells that form flow paths extending from one end face to the other end face, wherein at least the partition walls are made of a material having PTC characteristics; a heater element (air conditioning device) having a pair of electrodes consisting of a first electrode provided on one end face and a second electrode provided on the other end face; and a functional material-containing layer provided on the surface of the partition wall; an inlet pipe connecting the vehicle interior to an inlet end face of the heater element; and an outlet pipe having a first path (first flow path) connecting the outlet end face of the heater element to the vehicle interior, wherein the outlet pipe has the first path connecting the outlet end face of the heater element to the vehicle interior and a second path (second flow path) connecting the outlet end face of the heater element to the outside of the vehicle, and a switching valve capable of switching the flow of air flowing through the outlet pipe between the first path and the second path.

[0004] International Publication No. 2023 / 074202

[0005] The vehicle air conditioning system described in Patent Document 1 applies a voltage to a pair of electrodes to heat the heater element and desorb water vapor and CO2 adsorbed from the functional material-containing layer during the regeneration process of the air conditioning device (a process for desorbing water vapor, CO2, and other adsorbed substances from the functional material-containing layer). The desorbed air is then discharged outside the vehicle through the second flow path of the outlet pipe. In this case, if the distance between the valve that switches between the first and second flow paths and the air conditioning device is short, the valve is prone to thermal degradation. This requires the valve to be constructed using expensive heat-resistant materials, which increases costs. While increasing the distance between the valve and the air conditioning device would reduce the thermal degradation of the valve, this would increase the length of the air conditioning duct, which would likely interfere with other components and reduce the ease of installation of the vehicle air conditioning system in the vehicle. Furthermore, a longer air conditioning duct (air flow path) increases pressure loss, which increases the load on the ventilator. Furthermore, during the regeneration process of the air conditioning device, water vapor condenses in the air conditioning duct between the air conditioning device and the valve, making it easier for water droplets to adhere, and there is a risk that water droplets may enter the vehicle cabin during the air conditioning process of the air conditioning device (the process of adsorbing water vapor, CO2, etc. using the functional material-containing layer).

[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle air conditioning system that can improve mountability in a vehicle while suppressing thermal deterioration of the valve, increased pressure loss, and intrusion of water droplets into the passenger compartment.

[0007] As a result of extensive research into vehicle air conditioning systems equipped with air conditioning devices, the inventors discovered that the above problems can be solved by controlling the distance between the air conditioning device and the valve that switches the flow path within a predetermined range, and thus completed the present invention. That is, the present invention is exemplified as follows.

[0008] <1> An air conditioning system for a vehicle, comprising: an air conditioning device having an adsorption section having an adsorbent capable of adsorbing and desorbing moisture, and a heating means capable of heating the adsorption section; an air conditioning duct through which air can flow from a vehicle interior or outside the vehicle and in which the air conditioning device is disposed, the air conditioning duct having, downstream of the air conditioning device, a first flow path for introducing the air into the vehicle interior and a second flow path for discharging the air to the outside of the vehicle; and a valve capable of switching the flow of the air between the first flow path and the second flow path, wherein the distance between the air conditioning device and the valve is 5 to 310 mm.

[0009] <2> The vehicle air conditioning system according to <1>, wherein the distance between the air conditioning device and the valve is 7 to 300 mm.

[0010] <3> The vehicle air conditioning system according to <1> or <2>, wherein the air conditioning device comprises: a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that serve as air flow paths extending from a first end face to a second end face; an adsorption layer containing the adsorbent disposed on a surface of the partition wall; and a pair of electrodes disposed on the first end face and the second end face of the honeycomb structure or on the outer peripheral wall parallel to an extension direction of the cells of the honeycomb structure.

[0011] <4> The vehicle air conditioning system according to <3>, further comprising a power source for applying a voltage to the pair of electrodes.

[0012] <5> The vehicle air conditioning system according to <3> or <4>, wherein at least the partition walls of the honeycomb structure are made of a material having PTC properties.

[0013] <6> The vehicle air conditioning system according to any one of <1> to <5>, wherein the adsorbent is capable of adsorbing and desorbing one or more types selected from carbon dioxide and volatile components.

[0014] <7> The vehicle air conditioning system according to any one of <1> to <6>, further comprising a control unit that controls the air conditioning device and the valve, wherein the control unit is capable of executing an air conditioning mode in which the valve is switched so that the air flows into the first flow path, and a regeneration mode in which the air conditioning device is heated and the valve is switched so that the air flows into the second flow path.

[0015] According to the present invention, it is possible to provide a vehicle air conditioning system that can improve mountability in a vehicle while suppressing thermal deterioration of the valve, an increase in pressure loss, and the intrusion of water droplets into the vehicle compartment.

[0016] 2A is a schematic diagram of an overall configuration of a vehicle air conditioning system according to an embodiment of the present invention, and is a schematic diagram of a cross section parallel to the flow path direction of a typical air conditioning device used in the vehicle air conditioning system according to an embodiment of the present invention.

[0017] The vehicle air conditioning system of the present invention includes an air conditioning device having an adsorption section with an adsorbent capable of adsorbing and desorbing moisture and a heating means capable of heating the adsorption section; an air conditioning duct through which air can flow from the vehicle interior or the exterior and in which the air conditioning device is disposed, the air conditioning duct having a first flow path downstream of the air conditioning device for introducing air into the vehicle interior and a second flow path for discharging air to the exterior; and a valve capable of switching the air flow between the first flow path and the second flow path. The distance between the air conditioning device and the valve is 5 to 310 mm. The vehicle air conditioning system of the present invention, configured as described above, can improve mountability in a vehicle while suppressing thermal degradation of the valve, increased pressure loss, and intrusion of water droplets into the vehicle interior. Specifically, because the distance between the air conditioning device and the valve is not too short, thermal degradation of the valve is suppressed, allowing the use of a valve made of inexpensive materials with low heat resistance. Furthermore, because the distance between the air conditioning device and the valve is not too long, interference with other vehicle components is reduced, improving mountability of the vehicle air conditioning system in a vehicle. In addition, since pressure loss is less likely to increase, the load on the ventilator can be reduced.Furthermore, during the regeneration process of the air conditioning device, water vapor is less likely to condense and form water droplets in the air conditioning duct between the air conditioning device and the valve, which prevents water droplets from entering the vehicle cabin during the air conditioning process of the air conditioning device.

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention are also within the scope of the present invention.

[0019] A vehicle air conditioning system according to an embodiment of the present invention can be suitably used in various vehicles, such as automobiles. Examples of vehicles include, but are not limited to, automobiles and trains. Examples of automobiles include, but are not limited to, gasoline-powered vehicles, diesel-powered vehicles, gas-fueled vehicles using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. A vehicle air conditioning system according to an embodiment of the present invention can be suitably used in vehicles without internal combustion engines, such as electric vehicles and trains.

[0020] Fig. 1 is a schematic diagram of the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. Fig. 2A is a schematic diagram of a cross section parallel to the flow path direction of a typical air conditioning device used in a vehicle air conditioning system according to an embodiment of the present invention. Fig. 2B is a schematic diagram of a cross section taken along line aa' in the air conditioning device of Fig. 2A.

[0021] As shown in FIG. 1 , a vehicle air conditioning system according to an embodiment of the present invention includes an air conditioning device 10, an air conditioning duct 20, and a valve 30. The vehicle air conditioning system may further include a power source 40, a ventilator 50, and a control unit 60. The air conditioning device 10 includes an adsorption unit having an adsorbent capable of adsorbing and desorbing moisture, and a heating unit capable of heating the adsorption unit. The air conditioning duct 20 allows air from the vehicle cabin or outside the vehicle to flow therethrough, and the air conditioning device 10 is disposed therein. The air conditioning duct 20 further includes, downstream of the air conditioning device 10, a first flow path 20a for introducing air into the vehicle cabin and a second flow path 20b for discharging air to the outside of the vehicle. The valve 30 is capable of switching the air flow between the first flow path 20a and the second flow path 20b.

[0022] In a vehicle air conditioning system having the above-described structure, when air from the vehicle interior or outside the vehicle flows through the air conditioning duct 20, moisture (water vapor) can be adsorbed or desorbed in the air conditioning device 10. When adsorbing moisture in the air conditioning device 10, the air conditioning device 10 is set to an adsorption mode (air conditioning mode) in which the heating means of the air conditioning device 10 is not activated. Air from which moisture has been reduced or removed in the air conditioning device 10 (adsorption unit) can be allowed to flow into the vehicle interior by switching the valve 30 so that the air flows through the first flow path 20a. On the other hand, when desorbing moisture in the air conditioning device 10, the air conditioning device 10 is set to a desorption mode (regeneration mode) in which the heating means of the air conditioning device 10 is activated, heating the adsorption unit. The moisture-containing air desorbed from the air conditioning device 10 (adsorption unit) can be discharged outside the vehicle by switching the valve 30 so that the air flows through the second flow path 20b.

[0023] The distance D1 between the air conditioning device 10 and the valve 30 is 5 to 310 mm. By setting the distance D1 between the air conditioning device 10 and the valve 30 to 5 mm or more, thermal degradation of the valve 30 is suppressed, making it possible to use a valve made of inexpensive materials with low heat resistance. Furthermore, by setting the distance D1 between the air conditioning device 10 and the valve 30 to 310 mm or less, the mountability of the vehicle air conditioning system in a vehicle is improved. Furthermore, since pressure loss is less likely to increase, the load on the ventilator 50 can be reduced, and water droplets can be prevented from entering the vehicle cabin during air conditioning processing by the air conditioning device 10. From the perspective of stably ensuring these effects, the distance D1 between the air conditioning device 10 and the valve 30 is preferably 7 to 300 mm, and more preferably 7 to 290 mm. Here, in this specification, the "distance D1 between the air conditioning device 10 and the valve 30" refers to the shortest distance between the air conditioning device 10 and the valve 30 when the valve 30 is switched so that air flows into the second flow path 20b. Therefore, the position of the valve 30 for calculating the "distance D1 between the air conditioning device 10 and the valve 30" is the position of the component of the valve 30 that is closest to the air conditioning device 10 when the valve 30 is switched so that air flows into the second flow path 20b.

[0024] Each component of the vehicle air conditioning system will be described in detail below.

[0025] (1. Air Conditioning Device 10) The air conditioning device 10 is not particularly limited as long as it has an adsorption section having an adsorbent capable of adsorbing and desorbing moisture, and a heating means capable of heating the adsorption section. Furthermore, the number of air conditioning devices 10 arranged in the air conditioning duct 20 may be one or more. When multiple air conditioning devices 10 are provided, they may be arranged in parallel or in series with respect to the flow of air circulating within the air conditioning duct 20. Note that when multiple air conditioning devices 10 are arranged in series, the "distance D1 between the air conditioning device 10 and the valve 30" means the distance between the air conditioning device 10 on the most downstream side and the valve 30.

[0026] FIG. 2A is a schematic cross-sectional view of a typical air conditioning device used in a vehicle air conditioning system according to an embodiment of the present invention, taken along line a-a'. FIG. 2B is a schematic cross-sectional view of the air conditioning device of FIG. 2A taken along line a-a'. The air conditioning device 10 shown in FIGS. 2A and 2B includes a honeycomb structure 11 having an outer peripheral wall 12 and partition walls 15 disposed inside the outer peripheral wall 12 to define a plurality of cells 14 that serve as air flow paths extending from a first end face 13a to a second end face 13b. The honeycomb structure 11 also includes an adsorbent-containing adsorbent layer 16 disposed on the surface of the partition wall 15. The pair of electrodes 17a, 17b may be disposed on the outer peripheral wall 12 parallel to the extension direction of the cells 14 of the honeycomb structure 11. Terminals 18 can be connected to the pair of electrodes 17a, 17b.

[0027] (1-1. Honeycomb structure 11) The shape of the honeycomb structure 11 is not particularly limited. For example, the outer shape of a cross section perpendicular to the flow path direction (direction in which the cells 14 extend) of the honeycomb structure 11 can be a polygon such as a quadrangle (rectangle, square), pentagon, hexagon, heptagon, or octagon, a circle, or an oval shape (egg, ellipse, oval, rounded rectangle, etc.). The end faces (first end face 13a and second end face 13b) have the same shape as the cross section. Furthermore, when the cross section and the end faces are polygonal, the corners may be chamfered.

[0028] The shape of the cells 14 is not particularly limited, but may be a polygon such as a square, pentagon, hexagon, heptagon, or octagon, a circle, or an oval in a cross section perpendicular to the flow path direction of the honeycomb structure 11. These shapes may be used alone or in combination of two or more. Among these shapes, a square or hexagon is preferable. By providing cells 14 of such a shape, pressure loss during air flow can be reduced.

[0029] The honeycomb structure 11 may be a honeycomb bonded body having a plurality of honeycomb segments and a bonding layer bonding the peripheral side surfaces of the plurality of honeycomb segments together. Using a honeycomb bonded body makes it possible to increase the total cross-sectional area of ​​the cells 14, which is important for ensuring the air flow rate (flow velocity) while suppressing the occurrence of cracks. The bonding layer can be formed using a bonding material. The bonding material is not particularly limited, but a paste made by adding a solvent such as water to a ceramic raw material can be used. The bonding material may contain a material having PTC properties or may contain the same material as the peripheral wall 12 and the partition walls 15. In addition to bonding the honeycomb segments together, the bonding material can also be used as a peripheral coating material after the honeycomb segments are bonded.

[0030] From the viewpoints of ensuring the strength of the honeycomb structure 11, reducing pressure loss when air passes through the cells 14, ensuring the amount of adsorbent carried, and ensuring the contact area with the air flowing through the cells 14, it is desirable to suitably combine the thickness of the partition walls 15, the cell density, and the cell pitch (or the opening ratio of the cells 14). In this specification, the cell density refers to a value obtained by dividing the number of cells by the area of ​​one end face (the first end face 13 a or the second end face 13 b) of the honeycomb structure 11 (the total area of ​​the partition walls 15 and the cells 14 excluding the outer peripheral wall 12). In this specification, the cell pitch refers to a value obtained by the following calculation. First, the area per cell is calculated by dividing the area of ​​one end face (the first end face 13 a or the second end face 13 b) of the honeycomb structure 11 (the total area of ​​the partition walls 15 and the cells 14 excluding the outer peripheral wall 12) by the number of cells. Next, the square root of the area per cell is calculated, and this is defined as the cell pitch. In this specification, the opening ratio of the cells 14 is a value obtained by dividing the total area of ​​the cells 14 partitioned by the partition walls 15 in a cross section perpendicular to the flow direction of the honeycomb structure 11 by the area of ​​one end face (the first end face 13 a or the second end face 13 b) (the total area of ​​the partition walls 15 and the cells 14 excluding the outer peripheral wall 12). Note that when calculating the opening ratio of the cells 14, the pair of electrodes 17 a, 17 b and the adsorption layer 16 are not taken into consideration.

[0031] In an embodiment advantageous from the viewpoint of carrying a sufficient amount of functional material, the thickness of the partition wall 15 is 0.300 mm or less, and the cell density is 100 cells / cm 2 In a preferred embodiment, the thickness of the partition walls 15 is 0.200 mm or less, and the cell density is 70 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 15 is 0.130 mm or less, and the cell density is 65 cells / cm. 2 or less, and the cell pitch is 1.3 mm or more.

[0032] From the viewpoints of ensuring the strength of the honeycomb structure 11 and keeping the electrical resistance low, the lower limit of the thickness of the partition walls 15 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and even more preferably 0.030 mm or more. From the viewpoints of ensuring the strength of the honeycomb structure 11, keeping the electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is 30 cells / cm. 2 Preferably, the number of cells per square centimeter is 35 or more. 2 More preferably, 40 cells / cm or more. 2 From the viewpoints of ensuring the strength of the honeycomb structure 11, maintaining low electrical resistance, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and further preferably 1.6 mm or less.

[0033] In an embodiment that is advantageous from the viewpoint of achieving both a reduction in pressure loss and maintaining strength, the thickness of the partition wall 15 is 0.08 to 0.36 mm, and the cell density is 2.54 to 140 cells / cm. 2 , the opening ratio of the cells 14 is 0.70 or more. In a preferred embodiment, the thickness of the partition walls 15 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 15 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm. 2 The aperture ratio of the cell 14 is 0.85 or more.

[0034] From the viewpoint of ensuring the strength of the honeycomb structure 11, the upper limit of the opening ratio of the cells 14 is preferably 0.94 or less, more preferably 0.92 or less, and even more preferably 0.90 or less.

[0035] The thickness of the peripheral wall 12 is not particularly limited, but is preferably determined based on the following viewpoints. First, from the viewpoint of reinforcing the honeycomb structure 11, the thickness of the peripheral wall 12 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and even more preferably 0.08 mm or more. On the other hand, from the viewpoint of increasing the electrical resistance to suppress the initial current and from the viewpoint of reducing the pressure loss during air flow, the thickness of the peripheral wall 12 is preferably 1.0 mm or less, more preferably 0.5 mm or less, even more preferably 0.4 mm or less, and even more preferably 0.3 mm or less. In this specification, the thickness of the peripheral wall 12 refers to the length from the boundary between the peripheral wall 12 and the outermost cell 14 or partition wall 15 to the side surface of the honeycomb structure 11 in the normal direction of the side surface in a cross section perpendicular to the flow path direction of the honeycomb structure 11.

[0036] The length of the honeycomb structure 11 in the flow path direction and the cross-sectional area perpendicular to the flow path direction are not particularly limited and may be adjusted according to the required size of the air conditioning device 10. For example, when the honeycomb structure 11 is used in a compact air conditioning device 10 while ensuring a predetermined function, the length of the honeycomb structure 11 in the flow path direction is set to 2 to 20 mm, and the cross-sectional area perpendicular to the flow path direction is set to 10 cm. 2 The upper limit of the cross-sectional area perpendicular to the flow path direction is not particularly limited, but may be, for example, 300 cm 2 The following is the result.

[0037] The partition walls 15 constituting the honeycomb structure 11 are made of a material capable of generating heat when an electric current is applied thereto, and specifically, are preferably made of a material having a PTC characteristic. If necessary, the peripheral wall 12 may also be made of a material having a PTC characteristic, like the partition walls 15. This configuration allows the adsorption layer 16 to be directly heated by heat transfer from the heat-generating partition walls 15 (and, if necessary, the peripheral wall 12). Furthermore, materials having a PTC characteristic have the property that, when their temperature rises and exceeds the Curie point, their resistance value rises rapidly, making it difficult for electricity to flow. Therefore, when the partition walls 15 (and, if necessary, the peripheral wall 12) become hot, the current flowing through them is limited, thereby suppressing excessive heat generation in the honeycomb structure 11. This also makes it possible to suppress thermal deterioration of the adsorption layer 16 due to excessive heat generation.

[0038] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity at 25°C of the material having PTC characteristics is preferably 0.5 Ω cm or more, more preferably 1 Ω cm or more, and even more preferably 5 Ω cm or more. From the viewpoint of generating heat at a low driving voltage, the upper limit of the volume resistivity at 25°C of the material having PTC characteristics is preferably 30 Ω cm or less, more preferably 18 Ω cm or less, and even more preferably 16 Ω cm or less. In this specification, the volume resistivity at 25°C of the material having PTC characteristics is measured in accordance with JIS K6271:2008.

[0039] From the viewpoint of being able to generate heat when electrically connected and having PTC characteristics, the outer peripheral wall 12 and the partition walls 15 are preferably made of a material primarily composed of barium titanate (BaTiO). Furthermore, this material is more preferably a ceramic material primarily composed of barium titanate (BaTiO)-based crystal particles in which a portion of the Ba is substituted with a rare earth element. In this specification, the term "major component" refers to a component that accounts for more than 50 mass% of the total components. The content of BaTiO-based crystal particles can be determined by fluorescent X-ray analysis. Other crystal particles can also be measured in a similar manner.

[0040] The composition formula of BaTiO3-based crystal particles in which part of Ba is replaced with a rare earth element is (Ba 1-x A x )TiO3. In the composition formula, A represents one or more rare earth elements, and 0.0001≦x≦0.010. A is not particularly limited as long as it is a rare earth element, but is preferably one or more selected from the group consisting of La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Er, Y, and Yb, and more preferably La. x is preferably 0.001 or more, more preferably 0.0015 or more, from the viewpoint of preventing the electrical resistance at room temperature from becoming too high. On the other hand, x is preferably 0.009 or less, from the viewpoint of preventing insufficient sintering, which results in an excessively high electrical resistance at room temperature. The content of BaTiO3-based crystal particles in which a portion of Ba is substituted with a rare earth element in the ceramic is not particularly limited as long as it is the main component, but is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 94% by mass or more. The upper limit of the content of BaTiO3-based crystal particles is not particularly limited, but is generally 99% by mass, and preferably 98% by mass.

[0041] From the viewpoint of reducing environmental impact, it is desirable that the materials used for the outer peripheral wall 12 and the partition wall 15 be substantially free of lead (Pb). Specifically, the Pb content of the outer peripheral wall 12 and the partition wall 15 is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass. A low Pb content allows, for example, air heated by contact with the partition wall 15 during heat generation to be safely applied to living organisms such as humans. The Pb content of the outer peripheral wall 12 and the partition wall 15, calculated as PbO, is preferably less than 0.03% by mass, more preferably less than 0.01% by mass, and even more preferably 0% by mass. The lead content can be determined by ICP-MS (inductively coupled plasma mass spectrometry).

[0042] The Curie points of the materials constituting the outer peripheral wall 12 and the partition walls 15 are preferably within a temperature range in which the resistance value thereof is at least twice the resistance value at room temperature (25°C). If the Curie points are within this temperature range, the current flowing through these materials is limited when the air conditioning device 10 becomes hot, thereby efficiently suppressing excessive heat generation in the air conditioning device 10. Therefore, thermal degradation of the adsorption layer 16 due to excessive heat generation can be suppressed. From the viewpoint of efficiently heating the adsorption layer 16, the lower limit of the Curie points of the materials constituting the outer peripheral wall 12 and the partition walls 15 is preferably 80°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, and particularly preferably 125°C or higher. Furthermore, from the viewpoint of safety as a component placed in or near the vehicle interior, the upper limit of the Curie point is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and particularly preferably 150°C or lower.

[0043] The Curie point of the material forming the outer peripheral wall 12 and the partition walls 15 can be adjusted by the type and amount of the shifter added. For example, the Curie point of barium titanate (BaTiO) is approximately 120° C., but by substituting part of the Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to a lower temperature.

[0044] In this specification, the Curie point is measured by the following method. A sample is attached to a sample holder for measurement and placed in a measurement tank (e.g., MINI-SUBZERO MC-810P, manufactured by Espec Corporation), and the change in the electrical resistance of the sample relative to the temperature change when the temperature is raised from 10°C is measured using a DC resistance meter (e.g., Multimeter 3478A, manufactured by Hewlett-Packard Japan, LLC). The Curie point is determined as the temperature at which the resistance value is twice the resistance value at room temperature (25°C) based on the electrical resistance-temperature plot obtained by the measurement.

[0045] (1-2. Adsorption Layer 16) The adsorption layer 16 is a layer containing an adsorbent. The adsorption layer 16 can be provided on the surface of the partition walls 15 (in the case of the outermost cells 14, the partition walls 15 and the outer wall 12 that define the outermost cells 14). By providing the adsorption layer 16 in this manner, it becomes easier to adsorb the adsorption target substance, such as moisture or CO2, in the adsorption mode, and it also becomes easier to heat the adsorption layer 16 in the desorption mode, making it easier to desorb the adsorption target substance from the adsorption layer 16.

[0046] The temperature of the adsorption layer 16 is preferably determined by measuring the condition parameter after determining in advance the relationship between the temperature of the adsorption layer 16 and at least one condition parameter selected from the temperature of the honeycomb structure 11, the resistance value of the honeycomb structure 11, the current value of the honeycomb structure 11, the heating time of the honeycomb structure 11, the temperature of the air that has passed through the honeycomb structure 11, and the amount of components contained in the air that has passed through the honeycomb structure 11. Although it is difficult to directly measure the temperature of the adsorption layer 16 in a vehicle air conditioning system, the temperature of the adsorption layer 16 can be determined by measuring the condition parameter as described above.

[0047] The adsorbent contained in the adsorption layer 16 is capable of adsorbing and desorbing moisture. Preferably, the adsorbent is capable of adsorbing and desorbing not only moisture but also one or more species selected from carbon dioxide and volatile components. By using such an adsorbent, the air conditioning device 10 can not only dehumidify the air but also purify it.

[0048] The adsorbent contained in the adsorption layer 16 preferably has the function of being able to adsorb moisture and the like at temperatures between −20 and 60° C. and desorb moisture and the like at temperatures exceeding 60° C. Examples of adsorbents include, but are not limited to, aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbents, polystyrene sulfonic acid, zeolite, activated carbon, alumina, low-crystalline clay, amorphous aluminum silicate complexes, and metal organic frameworks (MOFs). These may be used alone or in combination of two or more.

[0049] As the aluminosilicate, it is preferable to use porous clay minerals such as AFI-type, CHA-type or BEA-type zeolite, allophane, imogolite, etc. Furthermore, it is preferable that the aluminosilicate is amorphous.

[0050] As the silica gel, it is preferable to use type A silica gel. As the polymer adsorbent, it is preferable to use one having a polyacrylic acid polymer chain. For example, sodium polyacrylate can be used as the polymer adsorbent. The metal organic framework is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). It is preferable that the metal ions are hydrophilic metal ions (e.g., aluminum ions).

[0051] The volatile components contained in the air in the vehicle cabin include, for example, volatile organic compounds (VOCs) and odor components other than VOCs. Specific examples of volatile components include ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, diazinon, acetaldehyde, and N-methylcarbamate-2-(1-methylpropyl)phenyl.

[0052] The adsorption layer 16 may further contain a catalyst. By containing a catalyst, it is possible to promote oxidation-reduction reactions and the like to purify carbon dioxide and / or volatile components. Examples of catalysts having such functions include metal catalysts such as Pt, Pd, and Ag, and oxide catalysts such as CeO2 and ZrO2. One type of catalyst may be used alone, or two or more types may be used in combination. Furthermore, the catalyst may be used in combination with the above-mentioned functional materials.

[0053] The thickness of the adsorption layer 16 is not particularly limited and may be determined depending on the size of the cells 14. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the adsorption layer 16 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. On the other hand, from the viewpoint of preventing the adsorption layer 16 from peeling off from the partition walls 15 and the outer peripheral wall 12, the thickness of the adsorption layer 16 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.

[0054] The thickness of the adsorption layer 16 is measured by the following procedure. An arbitrary cross section parallel to the flow path direction of the honeycomb structure 11 is cut out, and a cross-sectional image at approximately 50 magnification is obtained using a scanning electron microscope or the like. This cross section is also set to pass through the center of gravity of the cross section perpendicular to the flow path direction of the honeycomb structure 11. For each adsorption layer 16 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 14 in the flow path direction. This calculation is performed for all adsorption layers 16 visible in the cross-sectional image, and the overall average value is taken as the thickness of the adsorption layer 16.

[0055] From the viewpoint of exhibiting the desired function in the air-conditioning device 10, the amount of the adsorption layer 16 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and even more preferably 150 to 350 g / L relative to the volume of the honeycomb structure 11. The volume of the honeycomb structure 11 is a value determined by the outer dimensions of the honeycomb structure 11.

[0056] (1-3. Pair of electrodes 17a, 17b) The positions of the pair of electrodes 17a, 17b are not particularly limited, but as shown in Fig. 2A, they can be provided on the first end face 13a and the second end face 13b of the honeycomb structure 11. Furthermore, the pair of electrodes 17a, 17b may be provided on the outer peripheral wall 12 parallel to the extension direction of the cells 14 of the honeycomb structure 11. By applying a voltage between the pair of electrodes 17a, 17b, it becomes possible to cause the honeycomb structure 11 to generate heat by Joule heat.

[0057] The pair of electrodes 17a, 17b is not particularly limited, and may be, for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si. Alternatively, an ohmic electrode capable of making ohmic contact with the outer peripheral wall 12 and / or the partition wall 15 having PTC characteristics may be used. The ohmic electrode may contain, for example, at least one selected from Al, Au, Ag, and In as a base metal and at least one selected from Ni, Si, Zn, Ge, Sn, Se, and Te as a dopant for n-type semiconductors. The pair of electrodes 17a, 17b may have a single-layer structure or a stacked structure of two or more layers. When the pair of electrodes 17a, 17b has a stacked structure of two or more layers, the materials of the layers may be the same or different.

[0058] The thickness of the pair of electrodes 17a, 17b can be set appropriately depending on the method for forming the pair of electrodes 17a, 17b. Examples of methods for forming the pair of electrodes 17a, 17b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. The pair of electrodes 17a, 17b can also be formed by applying an electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 17a, 17b may be formed by joining metal or alloy plates.

[0059] The thickness of the pair of electrodes 17a, 17b is preferably about 5 to 30 μm in the case of baking an electrode paste, about 100 to 1000 nm in the case of dry plating such as sputtering and vapor deposition, about 10 to 100 μm in the case of thermal spraying, and about 5 to 30 μm in the case of wet plating such as electrolytic deposition and chemical deposition. In addition, when joining metal or alloy plates, the thickness is preferably about 5 to 100 μm.

[0060] (1-4. Terminal 18) The terminal 18 is connected to the pair of electrodes 17a, 17b and is provided on at least a part of the pair of electrodes 17a, 17b. Providing the terminal 18 makes it easy to connect to an external power source. The terminal 18 is connected to a conductor that is connected to the external power source.

[0061] The material of the terminal 18 is not particularly limited, but may be, for example, a metal. As the metal, a single metal or an alloy may be used, but from the viewpoints of corrosion resistance, electrical resistivity, and linear expansion coefficient, an alloy containing at least one element selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti is preferable, and stainless steel, an Fe—Ni alloy, and phosphor bronze are more preferable.

[0062] The size and shape of the terminal 18 are not particularly limited. For example, as shown in FIG. 2A , the terminal 18 may be provided over the entire pair of electrodes 17a, 17b on the outer peripheral wall 12. The terminal 18 may also be provided over a portion of the pair of electrodes 17a, 17b on the outer peripheral wall 12, or may be provided so as to extend outward beyond the outer edges of the pair of electrodes 17a, 17b on the outer peripheral wall 12. The terminal 18 may also be provided over a portion of the pair of electrodes 17a, 17b on the partition wall 15, or may be provided so as to cover some of the cells 14. The thickness of the terminal 18 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.

[0063] The method of connecting the terminal 18 and the pair of electrodes 17a, 17b is not particularly limited as long as they are electrically connected, and they can be connected by, for example, diffusion bonding, a mechanical pressure mechanism, welding, or the like.

[0064] (1-5. Manufacturing Method of Air Conditioning Device 10) The manufacturing method of the air conditioning device 10 is not particularly limited and can be performed according to known methods. An exemplary method for manufacturing the air conditioning device 10 will be described below. The manufacturing method of the honeycomb structure 11 constituting the air conditioning device 10 includes a molding step and a firing step. In the molding step, a clay containing ceramic raw materials including BaCO3 powder, TiO2 powder, and powder of a rare earth nitrate or hydroxide is molded to produce a honeycomb molded body with a relative density of 60% or more. The ceramic raw materials can be obtained by dry-mixing the powders to achieve the desired composition. The clay can be obtained by adding a dispersion medium, a binder, a plasticizer, and a dispersant to the ceramic raw materials and kneading them. The clay may contain additives such as a sifter, a metal oxide, a property improver, or a conductive powder, as needed. The amount of components other than the ceramic raw materials is not particularly limited as long as the honeycomb molded body has a relative density of 60% or more.

[0065] Here, in this specification, the "relative density of the honeycomb formed body" means the ratio of the density of the honeycomb formed body to the true density of the entire ceramic raw material. Specifically, it can be calculated by the following formula: Relative density of honeycomb formed body (%) = Density of honeycomb formed body (g / cm 3 ) / true density of the entire ceramic raw material (g / cm 3 The density of the honeycomb formed body can be measured by the Archimedes method using pure water as a medium. The true density of the entire ceramic raw material can be calculated by multiplying the total mass (g) of each raw material by the total actual volume (cm) of each raw material. 3 ) can be calculated by dividing by

[0066] Examples of the dispersion medium include water and a mixed solvent of water and an organic solvent such as alcohol, with water being particularly preferred.

[0067] Examples of binders include organic binders such as methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. It is particularly preferable to use a combination of methyl cellulose and hydroxypropoxyl cellulose. While one binder may be used alone or two or more binders may be used in combination, it is preferable that the binder does not contain an alkali metal element.

[0068] Examples of the plasticizer include polyoxyalkylene alkyl ether, polycarboxylic acid polymer, and alkyl phosphate ester.

[0069] The dispersant may be a surfactant such as polyoxyalkylene alkyl ether, ethylene glycol, dextrin, fatty acid soap, polyalcohol, etc. The dispersant may be used alone or in combination of two or more.

[0070] The honeycomb formed body can be produced by extrusion molding of a clay. In extrusion molding, a die having a desired overall shape, cell shape, partition wall thickness, cell density, etc. can be used.

[0071] The relative density of the honeycomb formed body obtained by extrusion molding is 60% or more, preferably 65% ​​or more. By controlling the relative density of the honeycomb formed body within this range, it is possible to densify the honeycomb formed body and reduce its electrical resistance at room temperature. The upper limit of the relative density of the honeycomb formed body is not particularly limited, but is generally 80%, preferably 75%.

[0072] The honeycomb molded body can be dried before the firing step. The drying method is not particularly limited, and for example, a conventionally known drying method such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, freeze drying, etc. Among these, a drying method that combines hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire molded body quickly and uniformly.

[0073] The firing process includes holding the honeycomb formed body at 1150 to 1250°C, then raising the temperature to a maximum temperature of 1360 to 1430°C at a heating rate of 20 to 600°C / hour, and holding the temperature for 0.5 to 10 hours. By holding the honeycomb formed body at a maximum temperature of 1360 to 1430°C for 0.5 to 10 hours, a honeycomb structure 11 containing, as a main component, BaTiO3-based crystal particles in which a portion of Ba is substituted with a rare earth element can be obtained. Furthermore, by holding the honeycomb formed body at 1150 to 1250°C, Ba2TiO4 crystal particles generated during the firing process can be easily removed, thereby densifying the honeycomb structure 11. Furthermore, by setting the heating rate from 1150 to 1250°C to a maximum temperature of 1360 to 1430°C at 20 to 600°C / hour, 1.0 to 10.0 mass% of Ba6Ti 17 O 40 Crystal grains can be generated in the honeycomb structure 11 .

[0074] The holding time at 1150 to 1250°C is not particularly limited, but is preferably 0.5 to 10 hours. By holding for such a time, Ba2TiO4 crystal particles generated during the firing process can be stably and easily removed.

[0075] The firing step preferably includes holding the mixture at 900 to 950°C for 0.5 to 5 hours during heating. By holding the mixture at 900 to 950°C for 0.5 to 5 hours, BaCO3 is efficiently decomposed, making it easier to obtain a honeycomb structure 11 having a predetermined composition.

[0076] A degreasing step for removing the binder may be carried out before the firing step. The atmosphere for the degreasing step is preferably an air atmosphere in order to completely decompose the organic components. The atmosphere for the firing step is also preferably an air atmosphere from the viewpoint of controlling the electrical properties and reducing the manufacturing cost. The firing furnace used for the firing step and the degreasing step is not particularly limited, but an electric furnace, a gas furnace, or the like can be used.

[0077] A pair of electrodes 17a, 17b are formed on the honeycomb structure 11 obtained in this manner. The pair of electrodes 17a, 17b can be formed by a metal deposition method such as sputtering, vapor deposition, electrolytic deposition, or chemical deposition. The pair of electrodes 17a, 17b can also be formed by applying an electrode paste and then baking it. Furthermore, the pair of electrodes 17a, 17b can also be formed by thermal spraying. The pair of electrodes 17a, 17b may be formed of a single layer, or may be formed of multiple electrode layers with different compositions. Below, a typical method for forming the pair of electrodes 17a, 17b will be described.

[0078] First, an electrode slurry containing an electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 13a or the second end face 13b of the honeycomb structure 11. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, Texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Excess slurry on the periphery of the honeycomb structure 11 is removed by blowing and wiping. The slurry is then dried to form a pair of electrodes 17a, 17b on the first end face 13a or the second end face 13b of the honeycomb structure 11. Drying can be performed while heating the honeycomb structure 11 to a temperature of, for example, approximately 120 to 600°C. The series of steps of coating, slurry removal, and drying may be carried out only once, but by repeating these steps multiple times, a pair of electrodes 17a, 17b of a desired thickness can be provided.

[0079] Next, terminals 18 are placed at predetermined positions of the pair of electrodes 17a, 17b, and the pair of electrodes 17a, 17b are connected to the terminals 18. The above-mentioned methods can be used to connect the pair of electrodes 17a, 17b to the terminals 18. The placement of the terminals 18 may be performed after the adsorption layer 16 described below is formed.

[0080] Next, an adsorption layer 16 is formed on the surfaces of the partition walls 15 and the like of the honeycomb structure 11. The method for forming the adsorption layer 16 is not particularly limited, but it can be formed, for example, by the following process. The honeycomb structure 11 is immersed in a slurry containing an adsorbent, a binder, and a dispersion medium for a predetermined period of time, and excess slurry from the end faces and outer periphery of the honeycomb structure 11 is removed by blowing and wiping. The binder may be an organic binder, an inorganic binder, or a combination thereof. The dispersion medium may be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, Texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. The slurry is then dried to form the adsorption layer 16 on the surfaces of the partition walls 15 and the like. Drying can be performed while heating the honeycomb structure 11 to a temperature of, for example, about 120 to 600° C. A series of steps of immersion, slurry removal, and drying may be performed only once, but by repeating the steps multiple times, an adsorption layer 16 of a desired thickness can be provided on the surfaces of the partition walls 15 and the like.

[0081] (2. Air Conditioning Duct 20) The air conditioning duct 20 is a flow path through which air from the vehicle cabin or outside the vehicle can flow. The upstream side of the air conditioning duct 20 is connected to the vehicle cabin or an outside air inlet. The air conditioning duct 20 allows air to flow in from the vehicle cabin or outside the vehicle, and also allows air that has passed through the air conditioning device 10 to flow into the vehicle cabin or to be discharged outside the vehicle. Therefore, the air conditioning duct 20 has a structure that branches into a first flow path 20a downstream of the air conditioning device 10 that allows air to flow into the vehicle cabin and a second flow path 20b that discharges air outside the vehicle.

[0082] The size of the air conditioning duct 20 (the portion where the air conditioning device 10 is disposed) is not particularly limited, but the inner circumferential length of the cross section of the air conditioning duct 20 is, for example, 10 to 100 cm. Also, the inner circumferential length of the cross section of the first flow path 20a and the second flow path 20b is, for example, 3 to 97 cm.

[0083] (3. Valve 30) The valve 30 can switch the air flow between the first flow path 20a and the second flow path 20b. The valve 30 can be provided at the branch point between the first flow path 20a and the second flow path 20b in the air conditioning duct 20. The valve 30 is not particularly limited as long as it is electrically driven and has the function of switching the flow path, and a solenoid valve, an electric valve, or the like can be used. For example, the valve 30 can be a butterfly valve including an opening / closing door supported on a rotating shaft and an actuator such as a motor that rotates the rotating shaft. The actuator can be configured to be controllable by the control unit 60. Alternatively, a flap valve that controls opening and closing using a flap valve or a slide valve that controls opening and closing by moving a sliding body (valve) can be used. Note that when the distance D1 between the air conditioning device 10 and the valve 30 is short, it is preferable to use a slide valve.

[0084] (4. Power Source 40) The power source 40 is used to apply a voltage to the air conditioning device 10 (particularly the pair of electrodes 17a, 17b). The power source 40 is electrically connected to the control unit 60, and adjusts the state of voltage application to the pair of electrodes 17a, 17b in accordance with instructions from the control unit 60. The power source 40 is not particularly limited, and a battery or the like can be used.

[0085] (5. Ventilator 50) The ventilator 50 is arranged in the air conditioning duct 20 to allow air from the vehicle cabin or outside the vehicle to flow into the air conditioning device 10. The location of the ventilator 50 is not particularly limited, and may be, for example, upstream of the air conditioning device 10 as shown in FIG. 1 or downstream of the air conditioning device 10. The ventilator 50 is electrically connected to the control unit 60, and controls the air flow rate by adjusting the rotation speed in accordance with instructions from the control unit 60.

[0086] (6. Control Unit 60) The control unit 60 controls the air conditioning device 10 and the valve 30. The control unit 60 can also control the fan 50. The control unit 60 is electrically connected to the air conditioning device 10 and the fan 50 via the power source 40. By controlling the power source 40, the control unit 60 can control the state of voltage application to the pair of electrodes 17a, 17b of the air conditioning device 10 and adjust the heating state of the honeycomb structure 11. The control unit 60 can also control the valve 30 so that air flows through the first flow path 20a or the second flow path 20b. Furthermore, the control unit 60 can control the flow rate of air flowing through the air conditioning duct 20 by adjusting the rotation speed of the fan 50.

[0087] The control unit 60 is not particularly limited, but is generally an ECU (Engine (electronic) Control Unit). The ECU includes a CPU that executes various arithmetic processes, a ROM that stores programs and data required for the control, a RAM that temporarily stores the results of the CPU calculations, and an input / output port for inputting and outputting signals to and from the outside.

[0088] The control unit 60 can execute an air-conditioning mode in which the valve 30 is switched so that air flows through the first flow path 20a, and a regeneration mode in which the air-conditioning device 10 is heated and the valve 30 is switched so that air flows through the second flow path 20b. In the air-conditioning mode, moisture in air circulating from the vehicle interior or outside is adsorbed, and the air with reduced or removed moisture is returned to the vehicle interior through the first flow path 20a. In the regeneration mode, moisture adsorbed in the adsorption layer 16 is desorbed, and the air is discharged outside the vehicle through the second flow path 20b.

[0089] From the viewpoint of stably performing the above control, it is desirable that the air conditioning device 10 be located close to the vehicle interior. Therefore, from the viewpoint of preventing electric shock, etc., it is preferable that the driving voltage of the air conditioning device 10 is 60 V or less. The honeycomb structure 11 used in the air conditioning device 10 has low electrical resistance at room temperature, so that the honeycomb structure 11 can be heated at this low driving voltage. The lower limit of the driving voltage is not particularly limited, but is preferably 10 V or more. If the driving voltage is less than 10 V, the current when heating the honeycomb structure 11 will be large, so that thicker conductors will be required.

[0090] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0091] <Preparation of Air Conditioning Device> BaCO3 powder, TiO2 powder, and La(NH3)3.6H2O powder were prepared as ceramic raw materials. These powders were weighed to achieve the desired composition after firing and dry-mixed to obtain a mixed powder. Dry mixing was carried out for 30 minutes. Next, water, binder, plasticizer, and dispersant were added in appropriate amounts in the range of 3 to 30 parts by mass total to 100 parts by mass of the obtained mixed powder, and kneaded to obtain a clay body with a relative density of 64.8% after extrusion molding. Methylcellulose was used as the binder. Polyoxyalkylene alkyl ether was used as the plasticizer and dispersant.

[0092] Next, the obtained clay was put into an extrusion molding machine and extrusion-molded using a predetermined die so as to obtain a honeycomb structure having the following shape after firing: Cross section and end face shape of honeycomb structure perpendicular to the flow channel direction: square Cross section shape of cell perpendicular to the flow channel direction: square Partition wall thickness: 0.13 mm Peripheral wall thickness: 0.2 mm Cell density: 80 cells / cm 2 Cell pitch: 1.1 mm Cross-sectional area of ​​honeycomb structure perpendicular to the flow path direction: 10,000 mm 2 Length of honeycomb structure in the flow path direction: 10 mm Volume resistivity of material constituting the outer wall and partition walls at 25°C: 15 Ω·cm Curie point of material constituting the outer wall and partition walls: 110°C

[0093] Next, the obtained honeycomb molded body was subjected to dielectric drying and hot air drying, and then degreased in an air atmosphere in a firing furnace (450°C x 4 hours), and then fired in an air atmosphere to obtain a honeycomb structure. The firing was performed by holding at 950°C for 1 hour, then increasing the temperature to 1200°C and holding at 1200°C for 1 hour, then increasing the temperature to 1400°C (maximum temperature) at a heating rate of 200°C / hour, and holding at 1400°C for 2 hours.

[0094] Next, a pair of electrodes was formed on both end faces (first end face and second end face) of the obtained honeycomb structure. First, an electrode slurry containing aluminum (electrode material), ethyl cellulose, and diethylene glycol monobutyl ether (organic binder) was prepared and applied to the first end face. The electrode slurry was then dried to form an electrode on the surface of the first end face. Using the same electrode slurry, an electrode was also formed on the second end face by applying the same electrode slurry to the second end face and drying it.

[0095] Next, the honeycomb structure on which the pair of electrodes had been formed was immersed in a slurry containing zeolite (adsorbent), an inorganic binder, and water, and any excess slurry adhering to areas (such as the outer periphery) was removed by blowing and wiping.The structure was then dried at a temperature of about 550°C to form an adsorption layer 150 μm thick on the surface of the partition wall and the surface of the outer wall facing the cell.

[0096] The air conditioning device obtained as described above was placed in an air conditioning duct so that the distance from the valve was the distance shown in Table 1, and a vehicle air conditioning system such as that shown in Figure 1 was constructed. The inner circumferential length of the cross section of the air conditioning duct (the portion where the air conditioning device was placed) was 46 cm, and the inner circumferential lengths of the cross sections of the first flow path and the second flow path were 23 cm. Furthermore, a polypropylene slide valve was used as the valve. The following evaluations were performed on this vehicle air conditioning system.

[0097] (Valve Thermal Degradation) A regeneration process for the air conditioning device was performed on a vehicle air conditioning system, and the air temperature was measured at the most upstream position of the valve. The regeneration process for the air conditioning device involved applying a 12 V voltage from a DC power supply to the air conditioning device, while circulating air at a temperature of 25°C and a relative humidity of 40% at a flow rate of 0.1 m / s for 3 minutes. In this evaluation, air temperatures below 80°C were designated A, air temperatures between 80°C and 90°C were designated B, air temperatures between 90°C and 100°C were designated C, and air temperatures above 100°C were designated D. The lower the air temperature, the greater the effect of suppressing valve thermal degradation. However, air temperatures below 100°C (A, B, and C) were sufficient to suppress valve thermal degradation.

[0098] (Pressure Loss) A moisture adsorption process was performed on a vehicle air conditioning system using an air conditioning device, and the pressure loss was measured. The moisture adsorption process was performed by starting a fan and circulating air at a temperature of 25°C and a relative humidity of 40% through the air conditioning duct at a flow rate of 1.00 m / s for 3 minutes. Pressure loss was measured using pressure gauges placed upstream of the air conditioning device and within the first flow path of the air conditioning duct. The pressure loss was calculated based on the following formula: Pressure Loss = Py - Pz, where Py is the pressure at a position upstream of the air conditioning device, and Pz is the pressure at a position within the first flow path. In this evaluation, a pressure loss of less than 140 Pa was designated A, a pressure loss of 140 Pa or more but less than 170 Pa was designated B, a pressure loss of 170 Pa or more but less than 200 Pa was designated C, and a pressure loss of 200 Pa or more was designated D. If the pressure loss is less than 200 Pa (A, B, and C), it can be said that the pressure loss is small.

[0099] (Water Droplet Intrusion) A vehicle air conditioning system was subjected to a moisture adsorption process using an air conditioning device, followed by a regeneration process and another moisture adsorption process. The moisture adsorption process was performed by starting the fan and circulating air at a temperature of 25°C and a relative humidity of 40% through the air conditioning duct for 3 minutes at a flow rate of 1.00 m / s. The air conditioning device regeneration process was performed by applying a 12 V voltage from a DC power supply to the air conditioning device and circulating air at a temperature of 25°C and a relative humidity of 40% for 3 minutes at a flow rate of 0.1 m / s. The state of water droplet adhesion within the first flow path of the air conditioning duct was then evaluated. In this evaluation, A indicates no water droplet adhesion, B indicates water droplet adhesion in a region of 20% or less of the piping length (the distance between the air conditioning device and the valve), C indicates water droplet adhesion in a region of more than 20% but not more than 30% of the piping length, and D indicates water droplet adhesion in a region of more than 30% of the piping length. If the water droplets adhere to an area of ​​30% or less of the piping length, there is almost no intrusion of water droplets into the casing, and therefore A, B and C are considered to be acceptable.

[0100] (Mountability) Since mountability depends on the distance between the air conditioning device and the valve, if the distance is 50 mm or less, it is rated as A, if the distance is more than 50 mm and less than 290 mm, it is rated as B, if the distance is more than 290 mm and less than 310 mm, it is rated as C, and if the distance is more than 310 mm, it is rated as D. Note that mountability can be said to be good if the distance is 310 mm or less (A, B, and C).

[0101] The results are shown in Table 1.

[0102]

[0103] As shown in Table 1, when the distance between the air conditioning device and the valve was in the range of 5 to 310 mm, the results for thermal degradation, pressure loss, water intrusion, and mountability of the valve were good. In contrast, when the distance between the air conditioning device and the valve was less than 5 mm, the results for thermal degradation of the valve were poor, and when the distance between the air conditioning device and the valve was more than 310 mm, the results for pressure loss, water intrusion, and mountability were poor.

[0104] As can be seen from the above results, the present invention can provide a vehicle air conditioning system that can improve installation ease in a vehicle while suppressing thermal degradation of the valve, increased pressure loss, and intrusion of water droplets into the vehicle cabin.

[0105] REFERENCE SIGNS LIST 10 Air conditioning device 11 Honeycomb structure 12 Outer peripheral wall 13a First end face 13b Second end face 14 Cell 15 Partition wall 16 Adsorption layer 17a, 17b Pair of electrodes 18 Terminal 20 Air conditioning duct 20a First flow path 20b Second flow path 30 Valve 40 Power source 50 Ventilator 60 Control unit

Claims

1. An air conditioning system for a vehicle comprising: an air conditioning device having an adsorption section having an adsorbent capable of adsorbing and desorbing moisture, and a heating means capable of heating the adsorption section; an air conditioning duct through which air can flow from the vehicle interior or outside the vehicle and in which the air conditioning device is disposed, the air conditioning duct having, downstream of the air conditioning device, a first flow path for introducing the air into the vehicle interior and a second flow path for discharging the air outside the vehicle; and a valve capable of switching the flow of the air between the first flow path and the second flow path, wherein the distance between the air conditioning device and the valve is 5 to 310 mm.

2. The vehicle air conditioning system according to claim 1, wherein the distance between the air conditioning device and the valve is 7 to 300 mm.

3. The vehicle air conditioning system according to claim 1 or 2, wherein the air conditioning device comprises: a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall and defining a plurality of cells that serve as air flow paths extending from a first end face to a second end face; an adsorption layer containing the adsorbent provided on the surface of the partition wall; and a pair of electrodes provided on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall parallel to the extension direction of the cells of the honeycomb structure.

4. The vehicle air conditioning system according to claim 3, further comprising a power source for applying a voltage to the pair of electrodes.

5. The vehicle air conditioning system according to claim 3, wherein at least the partition walls of the honeycomb structure are made of a material having PTC properties.

6. The vehicle air conditioning system according to claim 1 or 2, wherein the adsorbent is capable of adsorbing and desorbing one or more species selected from carbon dioxide and volatile components.

7. A vehicle air conditioning system as described in claim 1 or 2, further comprising a control unit that controls the air conditioning device and the valve, wherein the control unit is capable of executing an air conditioning mode in which the valve is switched so that the air flows into the first flow path, and a regeneration mode in which the air conditioning device is heated and the valve is switched so that the air flows into the second flow path.

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