Vehicle air-conditioning system and method for using humidity control device

Abstract

To provide a vehicle air-conditioning system capable of efficiently adsorbing moisture.SOLUTION: A vehicle air-conditioning system 100 includes: an air-conditioning duct 10 through which air can flow; a humidity control device 20 including a honeycomb structure 21 having an outer peripheral wall 23 and partition walls 26 which are provided inside the outer peripheral wall 23 and demarcate a plurality of cells 25 each serving as an air flow path extending from a first end surface 24a to a second end surface 24b, and a moisture absorption layer 27 provided on a surface of each of the partition walls 26, the humidity control device 20 being disposed in the air-conditioning duct 10; and a control section 30 capable of controlling a flow velocity of the air flowing through the cells 25 of the humidity control device 20. The control section 30 includes controlling the flow velocity of the air flowing in the humidity control device 20 to 0.23-1.40 m / s in a moisture absorption process of the humidity control device 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle air conditioning system and a method for using a humidity control device. [Background technology]

[0002] There is a growing demand for improved cabin environments in automobiles and other vehicles. Specific examples of such demands include humidity control within the vehicle cabin. Ventilation is an effective solution to this demand, 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 significant problem of reduced driving range.

[0003] As a method for solving the above problem, Patent Document 1 proposes a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall that define a plurality of cells that form flow paths extending from one end face to the other end face, with at least the partition walls being made of a material that has PTC (Positive Temperature Coefficient) properties, and a heater element having a pair of electrodes provided at predetermined positions on the honeycomb structure and a functional material-containing layer that adsorbs water vapor and the like on the surface of the partition walls. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2023 / 074202 Summary of the Invention [Problem to be solved by the invention]

[0005] However, simply using the heater element of Patent Document 1 is not enough to efficiently adsorb moisture (water vapor). The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle air conditioning system capable of efficiently adsorbing moisture, and a method for using a humidity control device. [Means for solving the problem]

[0006] As a result of extensive research into vehicle air conditioning systems equipped with humidity control devices, the inventors discovered that the amount of moisture adsorption can be improved by controlling the flow rate of air flowing into the humidity control device, and thus completed the present invention. That is, the present invention is exemplified as follows.

[0007] [1] An air conditioning duct through which air can flow; 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 the air flow path extending from a first end face to a second end face; and a humidity control device disposed in the air conditioning duct, the humidity control device comprising: a moisture absorptive layer provided on a surface of the partition walls; a control unit capable of controlling a flow rate of the air flowing through the cells of the humidity control device; Equipped with The vehicle air conditioning system includes the control unit controlling the flow velocity of the air flowing into the humidity control device to 0.23 to 1.40 m / sec during the moisture absorption process of the humidity control device.

[0008] [2] The vehicle air conditioning system according to [1], wherein the control unit controls the flow velocity of the air flowing into the humidity control device to 0.24 to 1.30 m / s during the moisture absorption process of the humidity control device.

[0009] [3] The vehicle air conditioning system according to [1], wherein the control unit controls the flow rate of the air flowing into the humidity control device to 0.25 to 1.20 m / s during the moisture absorption process of the humidity control device.

[0010] [4] The vehicle air conditioning system according to [1], wherein the control unit controls the flow velocity of the air flowing into the humidity control device to 0.26 to 1.10 m / s during the moisture absorption process of the humidity control device.

[0011] [5] The vehicle air conditioning system according to any one of [1] to [4], wherein the control unit performs the moisture absorption process of the humidity control device for 0.16 to 6 minutes.

[0012] [6] The vehicle air conditioning system according to any one of [1] to [5], wherein the control unit controls the flow velocity of the air flowing into the humidity control device to 0.06 to 0.30 m / s during the regeneration process of the humidity control device.

[0013] [7] The vehicle air conditioning system according to [6], wherein the control unit controls the flow velocity of the air flowing into the humidity control device to 0.08 to 0.20 m / s during the regeneration process of the humidity control device.

[0014] [8] The vehicle air conditioning system according to [6] or [7], wherein the control unit performs the regeneration process of the humidity control device for 0.16 to 4 minutes.

[0015] [9] A humidity control device that is disposed in an air conditioning duct and includes 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, and a moisture absorption layer provided on a surface of the partition walls, A method for using a humidity control device, comprising controlling the flow rate of the air flowing into the humidity control device to 0.23 to 1.40 m / sec during moisture absorption processing by the humidity control device.

[0016]

[10] A method for using the humidity control device according to [9], comprising controlling the flow rate of the air flowing into the humidity control device to 0.24 to 1.30 m / sec during the moisture absorption process of the humidity control device.

[0017]

[11] A method for using the humidity control device according to [9], comprising controlling the flow rate of the air flowing into the humidity control device to 0.25 to 1.20 m / sec during the moisture absorption process of the humidity control device.

[0018]

[12] A method for using the humidity control device according to [9], comprising controlling the flow rate of the air flowing into the humidity control device to 0.26 to 1.10 m / sec during the moisture absorption process of the humidity control device.

[0019]

[13] A method for using the humidity control device according to any one of [9] to

[12] , comprising subjecting the humidity control device to the moisture absorption treatment for 0.16 to 6 minutes.

[0020]

[14] A method for using a humidity control device according to any one of [9] to

[13] , comprising controlling the flow rate of the air flowing into the humidity control device to 0.06 to 0.30 m / sec during regeneration of the humidity control device.

[0021]

[15] A method for using the humidity control device according to

[14] , comprising controlling the flow rate of the air flowing into the humidity control device to 0.08 to 0.20 m / sec during the regeneration treatment of the humidity control device.

[0022]

[16] A method for using the humidity control device according to

[14] or

[15] , comprising carrying out the regeneration treatment of the humidity control device for 0.16 to 4 minutes. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a vehicle air conditioning system capable of efficiently adsorbing moisture, and a method for using a humidity control device. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram illustrating the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2A]1 is a schematic diagram of a cross section parallel to the flow path direction of a humidity control device used in a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2B] 2B is a schematic cross-sectional view of the humidity control device of FIG. 2A taken along line aa'. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0025] The vehicle air conditioning system of the present invention includes: an air conditioning duct through which air can flow; a humidity control device disposed in the air conditioning duct, the humidity control device having a honeycomb structure including 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, and a moisture absorptive layer disposed on the surface of the partition wall; and a control unit capable of controlling the flow rate of air flowing through the cells of the humidity control device. The control unit controls the flow rate of air flowing into the humidity control device to 0.23 to 1.40 m / sec during the moisture absorption process of the humidity control device. This configuration of the vehicle air conditioning system of the present invention allows the moisture absorptive layer of the humidity control device to efficiently adsorb moisture. This maximizes the moisture adsorption function of the moisture absorptive layer of the humidity control device.

[0026] Furthermore, a method for using a humidity control device of the present invention includes a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall that define a plurality of cells that serve as air flow paths extending from a first end face to a second end face, and a moisture absorptive layer disposed on the surface of the partition wall, the humidity control device being placed in an air conditioning duct, and includes controlling the flow velocity of air flowing into the humidity control device to 0.23 to 1.40 m / sec during a moisture absorption process of the humidity control device. By configuring the humidity control device in this way, the method for using the humidity control device of the present invention allows the moisture absorptive layer of the humidity control device to efficiently adsorb moisture. Therefore, the moisture adsorption function of the moisture absorptive layer of the humidity control device can be maximized.

[0027] 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.

[0028] <Vehicle air conditioning system> 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.

[0029] 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 humidity control device used in the 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 a-a' in the humidity control device of Fig. 2A.

[0030] 1, a vehicle air conditioning system 100 according to an embodiment of the present invention includes an air conditioning duct 10, a humidity control device 20, and a control unit 30. The vehicle air conditioning system 100 may further include a power source 40, a valve 50, and a fan 60.

[0031] Air from the vehicle interior or outside the vehicle can flow through the air conditioning duct 10. The air conditioning duct 10 can have, downstream of the humidity control device 20, a first path 10a through which air flows into the vehicle interior and a second path 10b through which air is discharged outside the vehicle.

[0032] The humidity control device 20 is disposed inside the air conditioning duct 10. The number of humidity control devices 20 disposed inside the air conditioning duct 10 may be one or more. When a plurality of humidity control devices 20 are provided, they may be disposed in parallel or in series with respect to the flow of air circulating inside the air conditioning duct 10. 2A and 2B, the humidity control device 20 includes a honeycomb structure 21 having an outer peripheral wall 23 and partition walls 26 disposed inside the outer peripheral wall 23 and defining a plurality of cells 25 that serve as air flow paths extending from a first end face 24a to a second end face 24b, and a moisture absorbing layer 27 provided on the surface of the partition wall 26. The honeycomb structure 21 may also be provided with a pair of electrodes 28a, 28b and a terminal 29 connected to the pair of electrodes 28a, 28b.

[0033] The control unit 30 can control the flow rate of air flowing through the cells 25 of the humidity control device 20. Specifically, the control unit 30 controls the flow rate of air by controlling the rotation speed of a fan 60 electrically connected to the control unit 30. The control unit 30 is also connected to a power source 40, a valve 50, etc., and can control these.

[0034] In the vehicle air conditioning system 100 having the above-described structure, during the moisture absorption process and regeneration process of the humidity control device 20, air from the vehicle compartment or outside the vehicle flows into the humidity control device 20 through the air conditioning duct 10. During the moisture absorption process of the humidity control device 20, moisture in the air is captured (adsorbed) by the moisture absorption layer 27 of the humidity control device 20, and the air with reduced moisture flows into the vehicle compartment through the first path 10a. On the other hand, during the regeneration process of the humidity control device 20, as the honeycomb structure 21 of the humidity control device 20 is heated, the moisture captured by the moisture absorption layer 27 is desorbed, and the moisture-containing air flows out of the vehicle through the second path 10b. The moisture absorption process and regeneration process of the humidity control device 20 are repeatedly performed until the humidity in the vehicle compartment reaches an appropriate range.

[0035] In the moisture absorption process of the humidity control device 20, the control unit 30 controls the flow velocity of the air flowing into the humidity control device 20 to 0.23 to 1.40 m / s, preferably 0.24 to 1.30 m / s, more preferably 0.25 to 1.20 m / s, and even more preferably 0.26 to 1.10 m / s. By controlling the flow velocity to such a value, the moisture absorption layer 27 of the humidity control device 20 can efficiently absorb moisture while providing dry air that is less likely to fogging up windows for a long period of time. On the other hand, if the air flow velocity is less than 0.23 m / s, the amount of moisture absorbed is reduced, requiring the humidity control device 20 to perform the moisture absorption process for a long period of time and making it difficult to provide dry air that is less likely to fogging up windows. On the other hand, if the air flow velocity exceeds 1.40 m / s, the amount of moisture absorbed becomes excessive, resulting in early saturation, and therefore shortening the time for which dry air that is less likely to fogging up windows can be provided. Furthermore, it may be necessary to increase the size of the ventilator 60 in order to increase the air flow rate, the noise level may increase due to the increased rotation speed of the ventilator 60, and the pressure loss may increase, which may result in stricter characteristics being required of surrounding components such as the air conditioning duct 10.

[0036] The time for the moisture absorption process of the humidity control device 20 is not particularly limited, but is preferably 0.16 to 6 minutes, more preferably 0.33 to 5 minutes, and even more preferably 0.5 to 4 minutes. By controlling the time for the moisture absorption process within this range, it is possible to ensure the amount of moisture adsorbed while also making it easier to prevent wasteful moisture absorption process due to saturation of the amount of moisture adsorbed. On the other hand, if the moisture absorption process of the humidity control device 20 is shorter than 0.16 minutes, it is difficult to ensure the amount of moisture adsorbed. Furthermore, if the moisture absorption process of the humidity control device 20 exceeds 6 minutes, the amount of moisture adsorbed is likely to saturate.

[0037] In the regeneration process of the humidity control device 20, the control unit 30 preferably controls the flow velocity of the air flowing into the humidity control device 20 to 0.06 to 0.30 m / s. By controlling the flow velocity at such a rate, moisture adsorbed in the moisture absorption layer 27 of the humidity control device 20 can be efficiently desorbed. Furthermore, by controlling the flow velocity at such a rate, it is not necessary to perform two-stage flow velocity adjustment, making it easier to control the regeneration process. From the viewpoint of stably ensuring these effects, it is more preferable that the control unit 30 controls the flow velocity of the air to 0.08 to 0.20 m / s. On the other hand, if the flow velocity of the air exceeds 0.30 m / s, the humidity control device 20 is more likely to be cooled by the circulating air, making it difficult for moisture to desorb from the moisture absorption layer 27. On the other hand, if the flow velocity of the air is less than 0.06 m / s, there is less contact with the circulating air, making it difficult for moisture to desorb from the moisture absorption layer 27.

[0038] The time for the regeneration process of the humidity control device 20 is not particularly limited, but is preferably 0.16 to 4 minutes, more preferably 0.33 to 4 minutes, and even more preferably 0.5 to 3 minutes. By controlling the regeneration process time within this range, it is possible to ensure the amount of moisture desorbed while also making it easier to prevent waste in the regeneration process due to saturation of the amount of moisture desorbed. On the other hand, if the regeneration process of the humidity control device 20 is shorter than 0.16 minutes, it is difficult to ensure the amount of moisture desorbed. Furthermore, if the regeneration process of the humidity control device 20 exceeds 4 minutes, the amount of moisture desorbed is likely to saturate.

[0039] Each component of the vehicle air conditioning system 100 will be described in detail below.

[0040] (1. Air conditioning duct 10) The air conditioning duct 10 is a flow path through which air can flow. The upstream side of the air conditioning duct 10 is connected to the vehicle compartment or an outside air inlet. The air conditioning duct 10 introduces air from the vehicle compartment or outside the vehicle, and also causes air that has passed through the humidity control device 20 to flow into the vehicle compartment or out of the vehicle. Therefore, it is preferable that the air conditioning duct 10 be branched downstream of the humidity control device 20 into a first path 10a that introduces air into the vehicle compartment and a second path 10b that discharges air outside the vehicle.

[0041] The air conditioning duct 10 may include a valve 50 capable of switching the air flow between the first path 10a and the second path 10b. The valve 50 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 may be used. For example, the valve 50 may include an opening / closing door supported on a rotating shaft and an actuator such as a motor that rotates the rotating shaft. The actuator may be configured to be controllable by the control unit 30.

[0042] (2. Humidity Control Device 20) (2-1. Honeycomb structure 21) The shape of the honeycomb structure 21 is not particularly limited. For example, the outer shape of a cross section perpendicular to the flow path direction (the direction in which the cells 25 extend) of the honeycomb structure 21 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 24a and second end face 24b) have the same shape as the cross section. When the cross section and end faces are polygonal, the corners may be chamfered.

[0043] The shape of the cells 25 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 21. 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 25 of such a shape, pressure loss during air flow can be reduced.

[0044] The honeycomb structure 21 may be a honeycomb bonded body having a plurality of honeycomb segments and a bonding layer bonding the outer peripheral side surfaces of the plurality of honeycomb segments together. By using the honeycomb bonded body, it is possible to increase the total cross-sectional area of ​​the cells 25, which is important for ensuring the air flow rate, 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 ceramic material with a solvent such as water added to form a paste can be used. The bonding material may contain a material having PTC properties, or may contain the same material as the outer peripheral wall 23 and the partition walls 26. In addition to the role of bonding the honeycomb segments together, the bonding material can also be used as an outer peripheral coating material after the honeycomb segments are bonded.

[0045] From the viewpoints of ensuring the strength of the honeycomb structure 21, reducing pressure loss when air passes through the cells 25, ensuring the amount of functional material carried, and ensuring the contact area with the air flowing within the cells 25, it is desirable to suitably combine the thickness of the partition walls 26, the cell density, and the cell pitch (or the opening rate of the cells 25). In this specification, cell density is a value obtained by dividing the number of cells by the area of ​​one end face (first end face 24a or second end face 24b) of the honeycomb structure 21 (the total area of ​​the partition walls 26 and cells 25 excluding the outer wall 23). In this specification, the cell pitch refers to a value calculated by the following calculation: First, the area per cell is calculated by dividing the area of ​​one end face (first end face 24a or second end face 24b) of the honeycomb structure 21 (the total area of ​​the partition walls 26 and the cells 25 excluding the outer peripheral wall 23) 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 25 is a value obtained by dividing the total area of ​​the cells 25 partitioned by the partition walls 26 in a cross section perpendicular to the flow direction of the honeycomb structure 21 by the area of ​​one end face (the first end face 24a or the second end face 24b) (the total area of ​​the partition walls 26 and the cells 25 excluding the outer peripheral wall 23). Note that when calculating the opening ratio of the cells 25, the pair of electrodes 28a, 28b and the moisture absorption layer 27 are not taken into consideration.

[0046] In an embodiment advantageous from the viewpoint of carrying a sufficient amount of functional material, the thickness of the partition walls 26 is 0.300 mm or less, and the cell density is 100 cells / cm. 2In a preferred embodiment, the thickness of the partition walls 26 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 26 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.

[0047] From the viewpoint of ensuring the strength of the honeycomb structure 21 and keeping the electrical resistance low, the lower limit of the thickness of the partition walls 26 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 viewpoint of ensuring the strength of the honeycomb structure 21, 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, 35 cells / cm or more. 2 More preferably, 40 cells / cm or more. 2 More preferably, it is equal to or greater than this. From the viewpoint of ensuring the strength of the honeycomb structure 21, 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 even more preferably 1.6 mm or less.

[0048] 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 walls 26 is 0.08 to 0.36 mm, and the cell density is 2.54 to 140 cells / cm. 2 In a preferred embodiment, the thickness of the partition walls 26 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 26 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm. 2 The aperture ratio of the cell 25 is 0.85 or more.

[0049] From the viewpoint of ensuring the strength of the honeycomb structure 21, the upper limit of the opening ratio of the cells 25 is preferably 0.94 or less, more preferably 0.92 or less, and further preferably 0.90 or less.

[0050] The thickness of the peripheral wall 23 is not particularly limited, but is preferably determined based on the following points: First, from the viewpoint of reinforcing the honeycomb structure 21, the thickness of the peripheral wall 23 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 reducing the pressure loss when air flows through, the thickness of the peripheral wall 23 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 outer wall 23 refers to the length in the normal direction of the side surface from the boundary between the outer wall 23 and the outermost cell 25 or partition wall 26 to the side surface of the honeycomb structure 21 in a cross section perpendicular to the flow path direction.

[0051] The length of the honeycomb structure 21 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 humidity control device 20. For example, when used in a compact humidity control device 20 while ensuring a predetermined function, the honeycomb structure 21 has a length in the flow path direction of 2 to 20 mm and a cross-sectional area perpendicular to the flow path direction of 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.

[0052] The partition walls 26 constituting the honeycomb structure 21 are made of a material that can generate heat when electricity is applied thereto, and specifically, are preferably made of a material having PTC characteristics. If necessary, the peripheral wall 23 may also be made of a material having PTC characteristics, like the partition walls 26. With this configuration, the moisture absorption layer 27 can be directly heated by heat transfer from the heat-generating partition walls 26 (and the peripheral wall 23, if necessary). Furthermore, materials having PTC characteristics have the property that, when their temperature rises and exceeds the Curie point, their resistance value rises sharply, making it difficult for electricity to flow through them. Therefore, when the partition walls 26 (and the peripheral wall 23, if necessary) reach a high temperature, the current flowing through them is limited, thereby suppressing excessive heat generation in the honeycomb structure 21. Therefore, it is also possible to suppress thermal deterioration of the moisture absorption layer 27 due to excessive heat generation.

[0053] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity at 25°C of a 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 a 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 a material having PTC characteristics is measured in accordance with JIS K6271:2008.

[0054] From the viewpoint of being able to generate heat when electrically applied and having PTC characteristics, the outer peripheral wall 23 and the partition walls 26 are preferably made of a material whose main component is barium titanate (BaTiO3). Furthermore, this material is more preferably a ceramic made of a material whose main component is barium titanate (BaTiO3)-based crystal particles in which part of the Ba is substituted with a rare earth element. In this specification, the term "main component" refers to a component that accounts for more than 50 mass% of the total components. The content of BaTiO3-based crystal particles can be determined by fluorescent X-ray analysis. Other crystal particles can also be measured using a similar method.

[0055] The composition formula of BaTiO3-based crystal particles in which part of Ba is replaced by rare earth elements is (Ba 1-x A x )TiO3, where A represents one or more rare earth elements and x is 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 the electrical resistance at room temperature from becoming too high due to insufficient sintering. The content of BaTiO3-based crystal particles in the ceramic, in which Ba is partially substituted with a rare earth element, is not particularly limited as long as it is an amount that serves as the main component, but is preferably 90 mass% or more, more preferably 92 mass% or more, and even more preferably 94 mass% or more. The upper limit of the content of BaTiO3-based crystal particles is not particularly limited, but is generally 99 mass%, preferably 98 mass%.

[0056] From the viewpoint of reducing the environmental impact, it is desirable that the materials used for the outer peripheral wall 23 and the partition wall 26 be substantially free of lead (Pb). Specifically, the Pb content of the outer peripheral wall 23 and the partition wall 26 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 26 during heat generation to be safely applied to living organisms such as humans. The Pb content of the outer peripheral wall 23 and the partition wall 26, 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).

[0057] The Curie points of the materials constituting the outer peripheral wall 23 and the partition walls 26 are preferably in the temperature range in which the resistance value becomes at least twice the resistance value at room temperature (25°C). If the Curie points are in this temperature range, the current flowing through them is limited when the humidity control device 20 becomes hot, so that excessive heat generation in the humidity control device 20 is efficiently suppressed. Therefore, thermal degradation of the moisture absorbing layer 27 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the material constituting the outer peripheral wall 23 and the partition walls 26 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, from the viewpoint of efficiently heating the moisture absorbing layer 27. 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, from the viewpoint of safety as a part placed in or near the vehicle interior.

[0058] The Curie point of the material forming the outer peripheral wall 23 and the partition walls 26 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.

[0059] 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 chamber (e.g., MINI-SUBZERO MC-810P, manufactured by Espec Corporation). The change in the sample's electrical resistance relative to temperature is measured as the temperature rises from 10°C using a DC resistance meter (e.g., Multimeter 3478A, manufactured by Hewlett-Packard Japan, LLC). The Curie point is determined by the temperature at which the resistance value, based on the electrical resistance-temperature plot obtained from the measurement, is twice the resistance value at room temperature (25°C).

[0060] (2-2. Pair of electrodes 28a, 28b) The positions of the pair of electrodes 28a, 28b are not particularly limited, but may be provided on the first end face 24a and the second end face 24b as shown in Fig. 2A. The pair of electrodes 28a, 28b may also be provided on a pair of outer peripheral walls 23 parallel to the direction in which the cells 25 extend. By applying a voltage between the pair of electrodes 28a and 28b, it becomes possible to cause the honeycomb structure 21 to generate heat by Joule heat.

[0061] The pair of electrodes 28a, 28b 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 23 and / or the partition wall 26 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 28a, 28b may have a single-layer structure or a stacked structure of two or more layers. When the pair of electrodes 28a, 28b has a stacked structure of two or more layers, the materials of the layers may be the same or different.

[0062] The thickness of the pair of electrodes 28a, 28b can be set appropriately depending on the method for forming the pair of electrodes 28a, 28b. Examples of methods for forming the pair of electrodes 28a, 28b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. The pair of electrodes 28a, 28b can also be formed by applying an electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 28a, 28b may also be formed by joining metal or alloy plates.

[0063] The thickness of the pair of electrodes 28a, 28b is preferably about 5 to 30 μm for baking of electrode paste, about 100 to 1000 nm for dry plating such as sputtering and vapor deposition, about 10 to 100 μm for thermal spraying, and about 5 to 30 μm for wet plating such as electrolytic deposition and chemical deposition. Furthermore, when joining metal or alloy plates, the thickness is preferably about 5 to 100 μm.

[0064] (2-3. Terminal 29) Terminal 29 is connected to the pair of electrodes 28a, 28b and is provided on at least a portion of the pair of electrodes 28a, 28b. Providing terminal 29 facilitates connection to an external power source. Terminal 29 is connected to a conductor that is connected to the external power source.

[0065] The material of terminal 29 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 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.

[0066] The size and shape of the terminal 29 are not particularly limited. For example, as shown in Fig. 2A, the terminal 29 may be provided over the entire pair of electrodes 28a, 28b on the outer peripheral wall 23. The terminal 29 may also be provided over a portion of the pair of electrodes 28a, 28b on the outer peripheral wall 23, or may be provided so as to extend outward beyond the outer edges of the pair of electrodes 28a, 28b on the outer peripheral wall 23. The terminal 29 may also be provided over a portion of the pair of electrodes 28a, 28b on the partition wall 26, or may be provided so as to cover some of the cells 25. The thickness of the terminal 29 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.

[0067] The method of connecting the terminal 29 and the pair of electrodes 28a, 28b 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.

[0068] (2-4. Moisture absorption layer 27) The moisture absorbing layer 27 is a layer containing a moisture absorbing material, and has the function of absorbing moisture (water vapor). The moisture absorbing layer 27 can be provided on the surface of the partition wall 26 (in the case of the outermost cell 25, the partition wall 26 and the outer wall 23 that define the outermost cell 25). By providing the moisture absorbing layer 27 in this manner, moisture can be easily adsorbed during moisture absorption treatment, and the moisture absorbing layer 27 can be easily heated during regeneration treatment, so that the desired function of the moisture absorbing layer 27 can be regenerated.

[0069] The moisture absorbent material contained in the moisture absorption layer 27 preferably has a function of being able to adsorb moisture at temperatures between -20 and 40°C and desorb it at high temperatures of 60°C or higher. The moisture absorbent is not particularly limited, but examples thereof include aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbent, polystyrene sulfonic acid, and metal organic framework (MOF). These may be used alone or in combination of two or more.

[0070] The aluminosilicate is preferably a porous clay mineral such as AFI-type, CHA-type or BEA-type zeolite, allophane, imogolite, etc. The aluminosilicate is preferably amorphous.

[0071] As the silica gel, it is preferable to use type A silica gel. The polymer adsorbent is preferably one having a polyacrylic acid polymer chain, such as sodium polyacrylate. The metal-organic framework is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). The metal ions are preferably hydrophilic metal ions (e.g., aluminum ions).

[0072] It is preferable that the moisture absorption layer 27 be capable of adsorbing carbon dioxide and / or volatile components in addition to moisture. Specifically, the moisture absorption layer 27 can further contain an adsorbent capable of adsorbing carbon dioxide and / or volatile components in addition to a moisture absorbent capable of adsorbing moisture. Furthermore, if the moisture absorbent capable of adsorbing moisture can also adsorb carbon dioxide and / or volatile components, by containing only the moisture absorbent, it is possible to adsorb carbon dioxide and / or volatile components in addition to moisture. By containing such an adsorbent or using such a moisture absorbent, it is possible to obtain an air purification effect in addition to an air dehumidification effect. The adsorbent preferably has a function of being able to adsorb carbon dioxide and / or volatile components at temperatures between -20 and 40°C and desorb them at high temperatures of 60°C or higher. Examples of adsorbents having such functions include zeolite, silica gel, activated carbon, alumina, silica, low-crystalline clay, and amorphous aluminum silicate complexes. The type of adsorbent may be appropriately selected depending on the type of component to be removed. One type of adsorbent may be used alone, or two or more types may be used in combination.

[0073] Volatile components contained in the air inside a 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.

[0074] The moisture absorption layer 27 may contain a catalyst. By containing a catalyst, oxidation-reduction reactions and the like can be promoted, thereby purifying 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.

[0075] The thickness of the moisture absorbing layer 27 is not particularly limited and may be determined depending on the size of the cells 25. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the moisture absorbing layer 27 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 moisture absorbing layer 27 from peeling off from the partition walls 26 and the outer peripheral wall 23, the thickness of the moisture absorbing layer 27 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.

[0076] The thickness of the moisture absorption layer 27 is measured by the following procedure. An arbitrary cross section parallel to the flow path direction of the honeycomb structure 21 is cut out, and a cross-sectional image at approximately 50x 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 of the honeycomb structure 21. For each moisture absorption layer 27 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 25 in the flow path direction. This calculation is performed for all moisture absorption layers 27 visible in the cross-sectional image, and the overall average value is taken as the thickness of the moisture absorption layer 27.

[0077] From the viewpoint of exhibiting the desired function in the humidity control device 20, the amount of the moisture absorption layer 27 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 21. The volume of the honeycomb structure 21 is a value determined by the outer dimensions of the honeycomb structure 21.

[0078] (2-5. Manufacturing Method of Humidity Control Device 20) The method for producing the humidity control device 20 is not particularly limited and can be carried out in accordance with a known method. The method for producing the humidity control device 20 will be exemplified below. The method for manufacturing the honeycomb structure 21 that constitutes the humidity control device 20 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 material can be obtained by dry mixing each powder to obtain a desired composition. The clay can be obtained by adding a dispersion medium, a binder, a plasticizer, and a dispersant to a ceramic raw material and kneading the mixture. The clay may contain additives such as a sifter, a metal oxide, a property improver, and a conductive powder, as needed. The blending amount of components other than the ceramic raw materials is not particularly limited as long as it is an amount that allows the relative density of the honeycomb formed body to be 60% or more.

[0079] 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 ) x 100 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 is 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

[0080] 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.

[0081] 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.

[0082] Examples of the plasticizer include polyoxyalkylene alkyl ether, polycarboxylic acid polymer, and alkyl phosphate ester.

[0083] 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.

[0084] 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.

[0085] 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%.

[0086] 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.

[0087] The firing step involves holding the temperature at 1150 to 1250°C, then raising the temperature to a maximum temperature of 1360 to 1430°C at a 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 21 containing, as a main component, BaTiO3-based crystal particles in which part of Ba has been substituted with a rare earth element can be obtained. Furthermore, by maintaining the temperature at 1150 to 1250°C, Ba2TiO4 crystal particles generated during the firing process can be easily removed, and the honeycomb structure 21 can be made dense. Furthermore, by setting the heating rate from 1150 to 1250°C to the 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 21.

[0088] 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 formed during the firing process can be stably and easily removed.

[0089] The firing step preferably includes holding the mixture at 900 to 950°C for 0.5 to 5 hours during heating. Holding the mixture at 900 to 950°C for 0.5 to 5 hours allows BaCO3 to efficiently decompose, making it easier to obtain a honeycomb structure 21 having a predetermined composition.

[0090] Before the firing step, a degreasing step may be carried out to remove the binder. The degreasing step is preferably carried out in an air atmosphere to completely decompose the organic components. Furthermore, the firing step is preferably carried out in an air atmosphere from the viewpoint of controlling electrical properties and reducing manufacturing costs. The firing furnace used in the firing step and degreasing step is not particularly limited, but an electric furnace, a gas furnace, or the like can be used.

[0091] A pair of electrodes 28a, 28b are formed on the honeycomb structure 21 obtained in this manner. The pair of electrodes 28a, 28b can be formed by a metal deposition method such as sputtering, vapor deposition, electrolytic deposition, or chemical deposition. The pair of electrodes 28a, 28b can also be formed by applying an electrode paste and then baking it. Furthermore, the pair of electrodes 28a, 28b can also be formed by thermal spraying. The pair of electrodes 28a, 28b may be formed of a single layer, or may be formed of multiple electrode layers with different compositions. Representative methods for forming the pair of electrodes 28a, 28b will be described below.

[0092] First, an electrode slurry containing an electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 24a or the second end face 24b of the honeycomb structure 21. 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 outer periphery of the honeycomb structure 21 is removed by blowing and wiping. Thereafter, the slurry is dried to form a pair of electrodes 28a, 28b on the first end face 24a or the second end face 24b of the honeycomb structure 21. Drying can be performed while heating the honeycomb structure 21 to a temperature of, for example, about 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 28a, 28b of a desired thickness can be provided.

[0093] Next, terminals 29 are placed at predetermined positions of the pair of electrodes 28a, 28b, and the pair of electrodes 28a, 28b are connected to terminal 29. The method for connecting the pair of electrodes 28a, 28b to terminal 29 can be the same as that described above. The terminal 29 may be installed after the moisture absorbing layer 27 described below is formed.

[0094] Next, the moisture absorbing layer 27 is formed on the surfaces of the partition walls 26 and the like of the honeycomb structure 21 . The method for forming the moisture absorption layer 27 is not particularly limited, and it can be formed, for example, by the following process. The honeycomb structure 21 is immersed in a slurry containing a moisture absorbent, an organic binder, and a dispersion medium for a predetermined period of time, and excess slurry on the end faces and outer periphery of the honeycomb structure 21 is removed by blowing and wiping. 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. Thereafter, the slurry is dried to form the moisture absorption layer 27 on the surface of the partition wall 26. The drying can be performed while heating the honeycomb structure 21 to a temperature of, for example, about 120 to 600°C. The series of steps of immersion, slurry removal, and drying may be carried out only once, but by repeating the steps multiple times, a moisture absorbing layer 27 of a desired thickness can be provided on the surface of the partition wall 26 or the like.

[0095] (3.Power supply 40) The power supply 40 is used to apply a voltage to the humidity control device 20 (particularly to the pair of electrodes 28a, 28b). The power supply 40 is electrically connected to the control unit 30, and adjusts the state of voltage application to the pair of electrodes 28a, 28b in accordance with instructions from the control unit 30. The power source 40 is not particularly limited, and a battery or the like can be used.

[0096] (4. Ventilator 60) The ventilator 60 is arranged in the air conditioning duct 10 to allow air from the vehicle compartment or outside the vehicle to flow into the humidity control device 20. The position of the ventilator 60 is not particularly limited, and may be, for example, upstream of the humidity control device 20 as shown in FIG. The ventilator 60 is electrically connected to the control unit 30, and controls the flow rate of the air by adjusting the rotation speed according to instructions from the control unit 30.

[0097] (5. Control unit 30) The control unit 30 is connected to a power source 40, a valve 50, a ventilator 60, etc., and can control these. Specifically, by controlling the power source 40, the control unit 30 can control the state of voltage application to the pair of electrodes 28a, 28b of the humidity control device 20, and adjust the heating state of the honeycomb structure 21. The control unit 30 can also control the valve 50 so that air flows through the first path 10a or the second path 10b. Furthermore, the control unit 30 can control the flow rate of air flowing through the air conditioning duct 10 by adjusting the rotation speed of the ventilator 60.

[0098] The control unit 30 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.

[0099] The control unit 30 controls the humidity control device 20 to perform the following operations: in the moisture absorption process, turning off the voltage applied from the power supply 40 and switching the valve 50 so that the air flowing through the air conditioning duct 10 passes through the first path 10a (i.e., moisture absorption mode); and in the regeneration process, turning on the voltage applied from the power supply 40 and switching the valve 50 so that the air flowing through the air conditioning duct 10 passes through the second path 10b (i.e., regeneration mode). By executing the moisture absorption mode and the regeneration mode in this manner, the moisture absorption process and the regeneration process can be performed efficiently.

[0100] In the moisture absorption mode, the control unit 30 performs the control as described above to absorb moisture from the air coming from the vehicle interior or outside the vehicle. At this time, the honeycomb structure 21 of the humidity control device 20 is not heated. Specifically, air coming from the vehicle interior or outside the vehicle flows into the humidity control device 20 through the air conditioning duct 10, and moisture contained in the air is captured (adsorbed). Then, the air with the captured moisture is returned to the vehicle interior through the first path 10a.

[0101] In the regeneration mode, the control unit 30 performs the control as described above to regenerate the moisture absorption layer 27 of the humidity control device 20. At this time, the honeycomb structure 21 of the humidity control device 20 is heated. Specifically, air from the vehicle compartment or outside the vehicle flows into the humidity control device 20 through the air conditioning duct 10, and while passing through the humidity control device 20, the air desorbs moisture trapped in the moisture absorption layer 27. Then, the moisture-laden air is discharged to the outside of the vehicle through the second path 10b.

[0102] In the regeneration mode, it is preferable to heat the moisture absorption layer 27 to a temperature equal to or higher than the desorption temperature depending on the type of moisture absorbent material in order to promote desorption of moisture trapped in the moisture absorption layer 27. For example, it is preferable to heat the moisture absorption layer 27 to 70 to 150°C, more preferably to 80 to 140°C, and even more preferably to 90 to 130°C.

[0103] From the viewpoint of stably performing the above control, it is desirable that the humidity control device 20 be placed in a position close to the vehicle interior. Therefore, from the viewpoint of preventing electric shock, etc., it is preferable that the driving voltage of the humidity control device 20 is 60 V or less. The honeycomb structure 21 used in the humidity control device 20 has low electrical resistance at room temperature, so that the honeycomb structure 21 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 21 will be large, and therefore the conductor wires will need to be thicker.

[0104] <How to use the humidity control device> A method for using a humidity control device according to an embodiment of the present invention includes controlling the flow velocity of air flowing into the humidity control device 20, which is disposed in an air conditioning duct 10, to 0.23 to 1.40 m / s, preferably 0.24 to 1.30 m / s, more preferably 0.25 to 1.20 m / s, and even more preferably 0.26 to 1.10 m / s, during the moisture absorption process of the humidity control device 20. By controlling the flow velocity to such a value, moisture can be efficiently adsorbed in the moisture absorption layer 27 of the humidity control device 20, while dry air that is less likely to fogging up windows can be supplied for a long period of time. On the other hand, if the air flow velocity is less than 0.23 m / s, the amount of moisture adsorbed by the humidity control device 20 is reduced, which requires a longer moisture absorption process of the humidity control device 20 and makes it difficult to supply dry air that is less likely to fogging up windows. On the other hand, if the air flow velocity exceeds 1.40 m / s, the amount of moisture adsorbed becomes excessive, resulting in early saturation, shortening the time for which dry air that is less likely to fogging up windows can be supplied. Furthermore, it may be necessary to increase the size of the ventilator 60 in order to increase the air flow rate, the noise level may increase due to the increased rotation speed of the ventilator 60, and the pressure loss may increase, which may result in stricter characteristics being required for surrounding components such as the air conditioning duct 10.

[0105] The time for the moisture absorption process of the humidity control device 20 is not particularly limited, but is preferably 0.16 to 6 minutes, more preferably 0.33 to 5 minutes, and even more preferably 0.5 to 4 minutes. By controlling the time for the moisture absorption process within this range, it is possible to ensure the amount of moisture adsorbed while also making it easier to prevent wasteful moisture absorption process due to saturation of the amount of moisture adsorbed. On the other hand, if the moisture absorption process of the humidity control device 20 is shorter than 0.16 minutes, it is difficult to ensure the amount of moisture adsorbed. Furthermore, if the moisture absorption process of the humidity control device 20 exceeds 6 minutes, the amount of moisture adsorbed is likely to saturate.

[0106] The regeneration process of the humidity control device 20 preferably includes controlling the flow velocity of the air flowing into the humidity control device 20 to 0.06 to 0.30 m / sec. By controlling the flow velocity to such a value, moisture adsorbed in the moisture absorption layer 27 of the humidity control device 20 can be efficiently desorbed. From the viewpoint of stably ensuring this effect, it is more preferable to include controlling the air flow velocity to 0.08 to 0.20 m / sec. On the other hand, if the air flow velocity exceeds 0.30 m / sec, the humidity control device 20 is more likely to be cooled by the circulating air, making it difficult for moisture to be desorbed from the moisture absorption layer 27. On the other hand, if the air flow velocity is less than 0.06 m / sec, there is less contact with the circulating air, making it difficult for moisture to be desorbed from the moisture absorption layer 27.

[0107] The time for the regeneration process of the humidity control device 20 is not particularly limited, but is preferably 0.16 to 4 minutes, more preferably 0.33 to 4 minutes, and even more preferably 0.5 to 3 minutes. By controlling the regeneration process time within this range, it is possible to ensure the amount of moisture desorbed while also making it easier to prevent waste in the regeneration process due to saturation of the amount of moisture desorbed. On the other hand, if the regeneration process of the humidity control device 20 is shorter than 0.16 minutes, it is difficult to ensure the amount of moisture desorbed. Furthermore, if the regeneration process of the humidity control device 20 exceeds 4 minutes, the amount of moisture desorbed is likely to saturate.

[0108] The humidity control device 20 used in the method of using a humidity control device according to the embodiment of the present invention is as described above, and a detailed description thereof will be omitted. [Example]

[0109] 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.

[0110] <Fabrication of humidity control device> BaCO3 powder, TiO2 powder, and La(NH3)3·6H2O powder were prepared as ceramic raw materials. These powders were weighed so that the desired composition would be obtained after firing, and then 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 in 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, and polyoxyalkylene alkyl ether was used as the plasticizer and dispersant.

[0111] 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 shape shown below after firing. Cross section and end face shape of honeycomb structure perpendicular to the flow direction: square Shape of the cell cross section perpendicular to the flow direction: square Partition thickness: 0.1mm Outer 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 direction: 6000 mm 2 Length of honeycomb structure in the flow direction: 10 mm Volume resistivity of the material that makes up the outer wall and partition wall at 25°C: 15 Ω·cm Curie point of the material that makes up the outer wall and partition wall: 110°C

[0112] 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.

[0113] 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. The same electrode slurry was also used to form an electrode on the second end face by applying the same electrode slurry to the second end face and drying it.

[0114] Next, the honeycomb structure with the pair of electrodes formed thereon was immersed in a slurry containing zeolite (moisture-absorbing material), an organic binder, and water. Any excess slurry adhering to the outer periphery or other areas was removed by blowing and wiping, and the structure was then dried at a temperature of approximately 550°C to form a moisture-absorbing layer 150 μm thick on the surface of the partition wall and the surface of the outer wall facing the cell.

[0115] The humidity control device obtained as described above was placed in an air conditioning duct to construct a vehicle air conditioning system as shown in Figure 1. This vehicle air conditioning system was evaluated as follows.

[0116] <Moisture absorption performance 1 (moisture absorption rate)> The vehicle air conditioning system was subjected to the regeneration mode and then the moisture absorption mode. The regeneration mode 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 at a flow rate of 0.07 m / s while applying a voltage of 12 V from a DC power supply to the humidity control device for 4 minutes. The moisture absorption mode was performed by circulating air under the same conditions through the air conditioning duct for 5 minutes at the flow rate shown in Table 1 without applying voltage to the humidity control device. In the regeneration mode, the absolute humidity [g / m 3 ] was measured using a humidity sensor, and the amount of moisture released [g] was calculated using the following formula. Moisture release rate [g] = (absolute humidity at the outlet of the humidity control device [g / m 3 ]-Absolute humidity at the inlet of the humidity control device [g / m 3 ])×Flow rate [m 3 / min] x playback mode time [min] In addition, in the moisture absorption mode, the absolute humidity [g / m 3 ] was measured using a humidity sensor, and the amount of moisture absorbed [g] was calculated using the following formula. Moisture absorption amount [g] = (absolute humidity at the inlet of the humidity control device [g / m 3 ]-Absolute humidity at the outlet of the humidity control device [g / m 3 ])×Flow rate [m 3 / min] x adsorption mode time [min] Next, the moisture absorption rate [%] in the moisture absorption mode was calculated by dividing the moisture absorption amount [g] by the moisture release amount [g] and multiplying the result by 100. The results are shown in Table 1.

[0117] [Table 1]

[0118] As shown in Table 1, Nos. 1-3 and 1-4 (Examples), in which the flow rate of air flowing into the humidity control device during the humidity absorption process (moisture absorption mode) was controlled to 0.23 to 1.40 m / s, had higher moisture absorption rates than Nos. 1-1, 1-2 and 1-5 (Comparative Examples), in which the air flow rate was controlled outside the above range.

[0119] <Moisture absorption performance 2 (effective moisture absorption rate)> The vehicle air conditioning system was put into a regeneration mode and then into a moisture absorption mode. The regeneration mode was performed by starting the fan to circulate air at a temperature of 25°C and a relative humidity of 40% through the air conditioning duct at a flow rate of 0.07 m / s, while applying a voltage of 12 V from the DC power supply to the humidity control device for 4 minutes. The moisture absorption mode was performed without applying voltage to the humidity control device, while the temperature was 25°C and the absolute humidity was 8 g / m. 3 The test was carried out by passing the air through the air conditioning duct at the flow rate shown in Table 1 for 4 minutes. In moisture absorption mode, the absolute humidity at the outlet of the humidity control device is measured by a humidity sensor and set to 4 g / m 3 The time that the humidity could be maintained below 4 g / m was measured. 3The percentage [%] of time that the humidity can be maintained below 4 g / m (hereinafter referred to as the "effective moisture absorption rate") was calculated. 3 The following ranges are absolute humidity levels that prevent windows from fogging up, and if the effective moisture absorption rate is 30% or higher, dry air that prevents windows from fogging up can be supplied for a long period of time. The results are shown in Table 2.

[0120] [Table 2]

[0121] As shown in Table 2, Nos. 2-3 to 2-10 (Examples), in which the flow rate of air flowing into the humidity control device during the humidity absorption process (moisture absorption mode) of the humidity control device was controlled to 0.23 to 1.40 m / s, had an effective moisture absorption rate of 30% or more, and the time during which dry air that was less likely to fog up the windows could be supplied was extended. In contrast, in Nos. 2-1 and 2-2 (comparative examples) in which the flow rate of the air flowing into the humidity control device during the moisture absorption process (moisture absorption mode) of the humidity control device was less than 0.23 m / s, the absolute humidity was 4 g / m 3 Furthermore, in the humidity control device Nos. 2-11 and 2-12 (comparative examples), in which the flow velocity of the air flowing into the humidity control device during the moisture absorption process (moisture absorption mode) of the humidity control device exceeded 1.40 m / s, the absolute humidity could not be reduced to 4 g / m 3 Although the following was possible, the amount of moisture adsorbed quickly saturated, causing the effective moisture absorption rate to fall below 30%, shortening the time during which dry air that is less likely to fog up the windows can be supplied.

[0122] <Regeneration performance 1 (moisture release rate)> The vehicle air conditioning system was subjected to a moisture absorption mode and then a regeneration mode. The moisture absorption mode 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 at a flow rate of 1.10 m / s for 3 minutes. The regeneration mode was performed by applying a voltage of 12 V from a DC power supply to the humidity control device and circulating air under the same conditions through the air conditioning duct at the flow rate shown in Table 1 for 6 minutes. In the regeneration mode and moisture absorption mode, the absolute humidity [g / m3 The moisture absorption amount [g] in the moisture absorption mode and the moisture release amount [g] in the regeneration mode were calculated in the same manner as above. The moisture release amount [g] was then divided by the moisture absorption amount [g] and multiplied by 100 to calculate the moisture release rate [%] in the regeneration mode. The results are shown in Table 3.

[0123] [Table 3]

[0124] As shown in Table 3, No. 3-4 (Example), in which the flow rate of air flowing into the humidity control device was controlled to 0.06 to 0.30 m / s during the humidity control device regeneration process (regeneration mode), had a higher moisture release rate than Nos. 3-1 to 3-3 and 3-5 (Comparative Examples), in which the air flow rate was controlled outside the above range.

[0125] <Regeneration performance 2 (moisture release rate)> The test was conducted under the same conditions as above, except that the regeneration treatment time was changed to 2 minutes, and the moisture release rate [%] in the regeneration mode was calculated. The results are shown in Table 4.

[0126] [Table 4]

[0127] As shown in Table 4, Nos. 4-2 to 4-5 (Examples), in which the flow rate of air flowing into the humidity control device was controlled to 0.06 to 0.30 m / s during the humidity control device regeneration process (regeneration mode), had a higher moisture release rate than Nos. 4-1 and 4-6 to 4-9 (Comparative Examples), in which the air flow rate was controlled outside the above range.

[0128] As can be seen from the above results, the present invention can provide a vehicle air conditioning system capable of efficiently adsorbing moisture, and a method for using a humidity control device. [Explanation of symbols]

[0129] 10 Air conditioning duct 10a Route 1 10b 2nd pathway 20 Humidity Control Device 21 Honeycomb structure 23 Outer wall 24a 1st end face 24b 2nd end face 25 cells 26 Bulkhead 27 Moisture absorption layer 28a, 28b Pair of electrodes 29 terminals 30 Control Unit 40 Power supply 50 valves 60 Ventilator 100 Vehicle air conditioning system

Claims

1. an air conditioning duct through which air can circulate; a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells that serve as the air flow path extending from a first end face to a second end face, and a humidity control device disposed in the air conditioning duct, the humidity control device including a moisture absorption layer provided on a surface of the partition walls; a control unit capable of controlling a flow rate of the air flowing through the cells of the humidity control device; Equipped with The control unit controls the flow rate of the air flowing into the humidity control device to 0.23 to 1.40 m / sec during the moisture absorption process of the humidity control device.

2. 2. The vehicle air conditioning system according to claim 1, wherein the control unit controls a flow velocity of the air flowing into the humidity control device to 0.24 to 1.30 m / sec during the moisture absorption process of the humidity control device.

3. 2. The vehicle air conditioning system according to claim 1, wherein the control unit controls a flow velocity of the air flowing into the humidity control device to 0.25 to 1.20 m / sec during the moisture absorption process of the humidity control device.

4. 2. The vehicle air conditioning system according to claim 1, wherein the control unit controls a flow velocity of the air flowing into the humidity control device to 0.26 to 1.10 m / sec during the moisture absorption process of the humidity control device.

5. 5. The vehicle air conditioning system according to claim 1, wherein the control unit performs the moisture absorption process of the humidity control device for 0.16 to 6 minutes.

6. The control unit includes controlling the flow rate of the air flowing into the humidity control device to 0.06 to 0.30 m / s during the regeneration process of the humidity control device. The vehicle air conditioning system according to any one of claims 1 to 4.

7. 7. The vehicle air conditioning system according to claim 6, wherein the control unit controls a flow velocity of the air flowing into the humidity control device to 0.08 to 0.20 m / sec during the regeneration process of the humidity control device.

8. 7. The vehicle air conditioning system according to claim 6, wherein the control unit performs the regeneration process of the humidity control device for 0.16 to 4 minutes.

9. A humidity control device is provided in an air conditioning duct, the humidity control device comprising: a honeycomb structure having an outer peripheral wall; and partition walls disposed inside the outer peripheral wall to define a plurality of cells that serve as air flow paths extending from a first end face to a second end face; and a moisture absorptive layer provided on a surface of the partition walls, A method for using a humidity control device, comprising controlling the flow rate of the air flowing into the humidity control device to 0.23 to 1.40 m / sec during moisture absorption processing of the humidity control device.

10. 10. The method for using the humidity control device according to claim 9, further comprising controlling the flow rate of the air flowing into the humidity control device to 0.24 to 1.30 m / sec during the moisture absorption process of the humidity control device.

11. 10. The method for using the humidity control device according to claim 9, further comprising controlling the flow rate of the air flowing into the humidity control device to 0.25 to 1.20 m / sec during the moisture absorption process of the humidity control device.

12. 10. The method for using a humidity control device according to claim 9, further comprising controlling the flow rate of the air flowing into the humidity control device to 0.26 to 1.10 m / sec during the moisture absorption process of the humidity control device.

13. A method for using the humidity control device according to any one of claims 9 to 12, comprising performing the moisture absorption treatment of the humidity control device for 0.16 to 6 minutes.

14. A method for using the humidity control device according to any one of claims 9 to 12, comprising controlling the flow rate of the air flowing into the humidity control device to 0.06 to 0.30 m / s during the regeneration process of the humidity control device.

15. The method for using the humidity control device according to claim 14, comprising controlling the flow rate of the air flowing into the humidity control device to 0.08 to 0.20 m / sec during the regeneration treatment of the humidity control device.

16. The method for using the humidity control device according to claim 14, comprising carrying out the regeneration treatment of the humidity control device for 0.16 to 4 minutes.

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