Vehicle air conditioning system

Abstract

The invention provides an air-conditioning system for a vehicle in which water droplets are less likely to adhere to the interior of an air-conditioning channel during regeneration processing. The present invention is provided with: an air-conditioning channel through which air can flow; and a first humidity control unit disposed in the air-conditioning channel, the first humidity control unit having one or more humidity control devices including: a honeycomb structure having an outer peripheral wall and partition walls disposed on the inner side of the outer peripheral wall and defining a plurality of cells, the plurality of cells forming a flow path extending from a first end surface to a second end surface, the flow path extending from the first end surface to the second end surface; at least the partition walls are made of a material having PTC characteristics; a pair of electrodes provided in the honeycomb structure; and a hygroscopic material-containing layer formed on the surface of the partition wall, a second humidity control unit that has one or more humidity control members containing a moisture-absorbing material and is disposed in the air-conditioning passage downstream of the first humidity control unit; and a power supply for applying a voltage to the humidity control device. The total amount of the moisture absorption materials in the second humidity adjusting unit is 0.3-12 times of the total amount of the moisture absorption materials in the first humidity adjusting unit.

Description

Technical Field

[0001] The present invention relates to an air conditioning system for a vehicle. Background Art

[0002] In various vehicles such as automobiles, there is an increasing demand for improving the cabin environment. As a specific demand, humidity control in the cabin can be cited. As an effective countermeasure to such demand, ventilation can be cited. However, ventilation will become the main reason for the loss of a large amount of heater energy in winter, resulting in reduced energy efficiency in winter. In particular, electric vehicles (BEV: Battery Electric Vehicle) have the problem of significantly reducing the cruising range due to their energy loss.

[0003] As a method for solving the above-mentioned problem, Patent Document 1 discloses a vehicle air conditioning system, which is equipped with a desiccant device that adsorbs water vapor contained in the air in the vehicle cabin, and the water vapor adsorbed on the desiccant device is separated by heating. The desiccant device comprises: a desiccant portion that adsorbs water vapor in the air; and a plurality of heating portions that directly heat the upstream and downstream regions of the desiccant portion during regeneration. Regarding the desiccant portion, a prescribed desiccant is carried on a pleated, air-permeable sheet, and the base material may be honeycomb or mesh-shaped. The heating portion is a plate-shaped heater extending in the direction of the air flow, and is in contact with the sheet in the upstream and downstream regions of the desiccant portion, respectively. By adopting such a structure, the entire area of ​​the desiccant portion can be regenerated more evenly.

[0004] On the other hand, Patent Document 2 discloses a heater component, which has a columnar honeycomb structure, the columnar honeycomb structure has an outer peripheral wall and a partition wall, the partition wall is arranged on the inner side of the outer peripheral wall and is divided into a plurality of compartments, the plurality of compartments form a flow path from the first end face to the second end face, the partition wall has a PTC characteristic, the average thickness of the partition wall is less than 0.13 mm, and the opening ratio in the first end face and the second end face is greater than 0.81. Although the heater component is used for heating purposes in a vehicle compartment, it is an efficient heating mechanism because the heating area can be increased by having a honeycomb structure. Therefore, it can be considered that if such a heater component is used as a carrier of a hygroscopic material, it can contribute to shortening the regeneration time of the hygroscopic material. In particular, it can be considered that the heater component can be heated by powering on and has a PTC characteristic, so that the hygroscopic material can be easily heated, and on the other hand, it can also suppress excessive heat generation, thereby suppressing thermal degradation of the hygroscopic material. Furthermore, since the possibility of reaching an excessively high temperature is avoided, even if the initial resistance is set to be small and the heating speed is increased, safety can be ensured and the temperature can be raised in a short time.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2022-80532

[0008] Patent Document 2: International Publication No. 2020 / 036067 Summary of the invention

[0009] In the vehicle air conditioning system of Patent Document 1, when performing a regeneration process to remove water vapor adsorbed on the moisture absorbing device by heating, high-humidity air flows toward the downstream side of the moisture absorbing device, so that water vapor is easily condensed on the downstream side of the moisture absorbing device to form water droplets. As a result, water droplets are easily adsorbed in the air conditioning passage and remain, and are difficult to be discharged outside the vehicle. If the regeneration process is terminated in this state and the moisture absorption process is performed, there is a possibility that water droplets will enter the vehicle compartment.

[0010] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a vehicle air conditioning system in which water droplets are unlikely to adhere to the inside of an air conditioning duct during a regeneration process.

[0011] The inventor of the present invention has conducted intensive research on a vehicle air conditioning system and found that the above-mentioned problem can be solved by providing a predetermined first humidity control unit and a second humidity control unit in an air conditioning passage and controlling the total amount of hygroscopic materials in these humidity control units to a suitable range, thereby completing the present invention. That is, the present invention is exemplified as follows.

[0012] (1) A vehicle air conditioning system comprising:

[0013] an air conditioning passage, the air conditioning passage being capable of providing air circulation;

[0014] A first humidity control unit, the first humidity control unit having one or more humidity control devices, and arranged in the air conditioning passage, the humidity control device comprising: a honeycomb structure having an outer peripheral wall and a partition wall, the partition wall being arranged on the inner side of the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments forming a flow path extending from the first end face to the second end face, at least the partition wall being made of a material having a PTC property; a pair of electrodes, the pair of electrodes being arranged on the honeycomb structure; and a hygroscopic material layer, the hygroscopic material layer being formed on the surface of the partition wall;

[0015] a second humidity control unit including one or more humidity control components including a hygroscopic material and arranged in the air conditioning duct on a downstream side of the first humidity control unit; and

[0016] a power supply, the power supply being used to apply a voltage to the humidity control device,

[0017] The total amount of the hygroscopic material in the second humidity conditioning unit is 0.3 to 12 times the total amount of the hygroscopic material in the first humidity conditioning unit.

[0018] (2) The vehicle air conditioning system according to (1), wherein:

[0019] The humidity regulating component includes: a honeycomb structure having an outer peripheral wall and a partition wall, wherein the partition wall is arranged on the inner side of the outer peripheral wall and divides the structure into a plurality of compartments, wherein the plurality of compartments form a flow path extending from a first end face to a second end face; and a hygroscopic material layer formed on a surface of the partition wall.

[0020] (3) The vehicle air conditioning system according to (2), wherein:

[0021] In the humidity control component, the thickness of the partition wall is 0.06 to 0.40 mm, and the cell density is 30 to 95 cells / cm 2 .

[0022] (4) The vehicle air conditioning system according to any one of (1) to (3), wherein:

[0023] The humidity control member does not have a heater function.

[0024] (5) The vehicle air conditioning system according to any one of (1) to (4), wherein:

[0025] The total amount of the hygroscopic material in the second humidity control unit is 0.5 to 8 times the total amount of the hygroscopic material in the first humidity control unit.

[0026] (6) The vehicle air conditioning system according to any one of (1) to (5), wherein:

[0027] The total amount of the hygroscopic material in the second humidity control unit is 0.6 to 6 times the total amount of the hygroscopic material in the first humidity control unit.

[0028] (7) The vehicle air conditioning system according to any one of (1) to (6), wherein:

[0029] In the humidity control device, the pair of electrodes are provided on the first end surface and the second end surface.

[0030] (8) The vehicle air conditioning system according to any one of (1) to (7), wherein:

[0031] The distance between the first humidity control unit and the second humidity control unit is less than 10 cm.

[0032] (9) The vehicle air conditioning system according to any one of (1) to (8), wherein:

[0033] The air conditioning passage includes a first path for allowing the air to flow into the vehicle cabin and a second path for allowing the air to be discharged to the outside of the vehicle on the downstream side of the second humidity control unit.

[0034] The vehicle air conditioning system further includes a switching valve capable of switching the flow of the air between the first path and the second path.

[0035] (10) The vehicle air conditioning system according to (9), wherein:

[0036] The vehicle air conditioning system further includes a control unit capable of executing a dehumidification mode and a regeneration mode.

[0037] In the dehumidification mode, the switching valve is controlled so as to switch the flow of the air to the first path to dehumidify the interior of the vehicle.

[0038] In the regeneration mode, a voltage is applied from the power supply to the pair of electrodes of the humidity control device, and the switching valve is controlled to switch the flow of the air to the second path to regenerate the moisture absorbing material.

[0039] (11) The vehicle air conditioning system according to any one of (1) to (10), wherein:

[0040] The material having the PTC characteristic contains barium titanate as a main component.

[0041] (12) The vehicle air conditioning system according to any one of (1) to (11), wherein:

[0042] The hygroscopic material-containing layer of the humidity control device further contains: an adsorbent material and / or a catalyst having a function of adsorbing at least one selected from carbon dioxide and volatile components.

[0043] Effects of the Invention

[0044] According to the present invention, it is possible to provide a vehicle air conditioning system in which water droplets are unlikely to adhere to the inside of the air conditioning passage during the regeneration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is an overall schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention.

[0046] Figure 2AIt is a schematic cross-sectional view 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.

[0047] Figure 2B yes Figure 2A Schematic diagram of the cross section of the a-a' line in the humidity control device.

[0048] Figure 3 It is a graph showing the relationship between the regeneration processing time and the relative humidity in the air-conditioning duct when the second humidity control unit is present or absent.

[0049] Figure 4 It is a schematic cross-sectional view parallel to the flow path direction of a humidity control member used in a vehicle air conditioning system according to an embodiment of the present invention.

[0050] Explanation of symbols

[0051] 10…air conditioning passage, 10a…first path, 10b…second path, 20…first humidity control unit, 21…humidity control device, 22…honeycomb structure, 23…peripheral wall, 24a…first end face, 24b…second end face, 25…compartment, 26…next wall, 27a, 27b…a pair of electrodes, 28…a layer containing hygroscopic material, 29…terminal, 30…second humidity control unit, 31…humidity control component, 32…honeycomb structure, 33…peripheral wall, 34a…first end face, 34b…second end face, 35…compartment, 36…next wall, 38…a layer containing hygroscopic material, 40…power supply, 50…switching valve, 60…control unit. DETAILED DESCRIPTION

[0052] The vehicle air conditioning system of the present invention comprises: an air conditioning passage, which can provide air circulation; a first humidity control unit, which has one or more humidity control devices and is arranged in the air conditioning passage, the humidity control device comprising: a honeycomb structure, which has an outer peripheral wall and a partition wall, the partition wall is arranged on the inner side of the outer peripheral wall and is divided into a plurality of compartments, the plurality of compartments form a flow path extending from the first end face to the second end face, at least the partition wall is composed of a material having a PTC (Positive Temperature Coefficient) property; a pair of electrodes, the pair of electrodes are arranged on the honeycomb structure; and a hygroscopic material layer, the hygroscopic material layer is formed on the surface of the partition wall; a second humidity control unit, the second humidity control unit has one or more humidity control components containing hygroscopic material, and is arranged in the air conditioning passage downstream of the first humidity control unit; and a power supply, the power supply is used to apply voltage to the humidity control device, the total amount of hygroscopic material in the second humidity control unit is 0.3 to 12 times the total amount of hygroscopic material in the first humidity control unit. The vehicle air conditioning system of the present invention adopts the above-mentioned structure, whereby a part of the moisture of the high-humidity air generated by the heating of the first humidity control unit during the regeneration process can be temporarily adsorbed in the second humidity control unit on the downstream side and gradually discharged. That is, during the regeneration process, the high-humidity air will not flow to the downstream side of the second humidity control unit at the same time, so it is possible to prevent water droplets from adhering to the air conditioning passage and remaining. In addition, the humidity control performance of the vehicle air conditioning system of the present invention is also good.

[0053] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. The present invention is not limited to the following embodiments, and it should be understood that the following embodiments may be appropriately modified or improved based on the common knowledge of those skilled in the art without departing from the gist of the present invention.

[0054] The vehicle air conditioning system according to the embodiment of the present invention can be preferably used in various vehicles such as automobiles. As the vehicle, there is no particular limitation, and examples thereof include automobiles and electric cars. As the automobile, there is no particular limitation, and examples thereof include: gasoline vehicles, diesel vehicles, gas fuel vehicles using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. The vehicle air conditioning system according to the embodiment of the present invention can be particularly preferably used in: vehicles that do not have an internal combustion engine, such as electric vehicles and electric cars.

[0055] Figure 1 It is an overall schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention. Figure 2A It is a schematic cross-sectional view 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 yes Figure 2A Schematic diagram of the cross section of the a-a' line in the humidity control device.

[0056] like Figure 1 As shown, the vehicle air conditioning system 100 according to the embodiment of the present invention includes an air conditioning duct 10 , a first humidity control unit 20 , a second humidity control unit 30 , and a power source 40 . The vehicle air conditioning system 100 may further include a switching valve 50 and a control unit 60 .

[0057] The air conditioning duct 10 can allow air from the vehicle cabin or the outside of the vehicle to flow in. The air conditioning duct 10 may include a first path 10a for allowing air to flow into the vehicle cabin and a second path 10b for allowing air to be discharged to the outside of the vehicle on the downstream side of the second humidity control unit 30 .

[0058] The first humidity control unit 20 has one or more humidity control devices 21 and is disposed in the air conditioning passage 10. Figure 1 The case where there is one humidity control device 21 is illustrated in FIG.

[0059] The second humidity control unit 30 includes one or more humidity control components 31 and is disposed in the air conditioning duct 10 on the downstream side of the first humidity control unit 20. Figure 1 The case where there is one humidity control member 31 is exemplified.

[0060] The power source 40 can apply a voltage to the humidity control device 21 of the first humidity control unit 20 .

[0061] The switching valve 50 can switch the flow of air between the first path 10 a and the second path 10 b .

[0062] The control unit 60 is connected to the power source 40 , the switching valve 50 , and the like, and can control them.

[0063] like Figure 2A and Figure 2B As shown, the humidity control device 21 includes: a honeycomb structure 22, which has an outer peripheral wall 23 and a partition wall 26, the partition wall 26 is arranged on the inner side of the outer peripheral wall 23 and is divided into a plurality of compartments 25, the plurality of compartments 25 form a flow path extending from the first end face 24a to the second end face 24b, at least the partition wall 26 is made of a material having PTC characteristics; a pair of electrodes 27a, 27b, which are arranged on the honeycomb structure 22; and a hygroscopic material layer 28, which is formed on the surface of the partition wall 26. The humidity control device 21 may further include a terminal 29 connected to the pair of electrodes 27a, 27b.

[0064] In the vehicle air conditioning system 100 having the above-described structure, air from the vehicle cabin or the outside of the vehicle flows into the first humidity control unit 20 through the air conditioning duct 10, and moisture in the air is captured (removed) by the moisture-absorbing material layer 28 of the humidity control device 21 in the first humidity control unit 20. Furthermore, moisture in the air is auxiliary captured (removed) by the humidity control component 31 in the second humidity control unit 30. Then, the air with reduced moisture flows into the vehicle cabin through the first path 10a.

[0065] On the other hand, the performance of the hygroscopic material layer 28 of the humidity control device 21 in the first humidity control unit 20 gradually decreases as the amount of water captured increases, so it is necessary to regenerate them. The regeneration of the hygroscopic material layer 28 of the humidity control device 21 is performed as follows: a voltage is applied to a pair of electrodes 27a, 27b, and the honeycomb structure 22 is heated, thereby performing the regeneration. Since the hygroscopic material layer 28 is directly heated by heating the honeycomb structure 22, the water captured by the hygroscopic material layer 28 is efficiently separated or reacted from the hygroscopic material layer 28 and released. A part of the released water is captured by the humidity control component 31 in the second humidity control unit 30 on the downstream side at the initial stage of the regeneration process, so that the high-humidity air can be suppressed from flowing to the downstream side of the second humidity control unit 30. As a result, it is difficult for the water to become water droplets and adhere to the air conditioning duct 10 on the downstream side of the second humidity control unit 30. As the regeneration process of the hygroscopic material-containing layer 28 proceeds, the humidity control component 31 in the second humidity control unit 30 is also heated by the air heated by the humidity control device 21, and the amount of moisture released from the humidity control component 31 gradually increases. In order to obtain the above-mentioned effect, the total amount of the hygroscopic material in the second humidity control unit 30 needs to be 0.3 to 12 times the total amount of the hygroscopic material in the first humidity control unit 20. If the total amount of the hygroscopic material in the second humidity control unit 30 does not meet this range, the effect cannot be fully obtained. In addition, if the total amount of the hygroscopic material in the second humidity control unit 30 is too much, the humidity control performance may be reduced.

[0066] Here, a graph showing the relationship between the regeneration processing time and the relative humidity in the air conditioning duct 10 when the second humidity control unit 30 is present is shown in FIG. Figure 3 . Figure 3 In the figure, curve A is a case where the second humidity control unit 30 is provided on the downstream side of the first humidity control unit 20 (it should be noted that the total amount of the hygroscopic material in the second humidity control unit 30 is 0.3 to 12 times the total amount of the hygroscopic material in the first humidity control unit 20), and it is the relative humidity in the air conditioning passage 10 on the downstream side of the second humidity control unit 30. In addition, curve B is a case where the second humidity control unit 30 is not provided on the downstream side of the first humidity control unit 20, and it is the relative humidity in the air conditioning passage 10 on the downstream side of the first humidity control unit 20.

[0067] In the case where the second humidity control unit 30 is not provided (curve B), the peak of the relative humidity is high and the peak width is small. Therefore, it can be considered that the air with high relative humidity flows into the air conditioning passage 10 all at once in a short time, and water droplets are easily attached to the air conditioning passage 10. In contrast, in the case where the second humidity control unit 30 is provided (curve A), the peak of the relative humidity is lower and the peak width is larger than that of curve B. It can be considered that the air with suppressed relative humidity gradually flows into the air conditioning passage 10, and water droplets are difficult to attach to the air conditioning passage 10.

[0068] Hereinafter, each component of the vehicle air conditioning system 100 will be described in detail.

[0069] (1. Air conditioning duct 10)

[0070] 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 the external air inlet. The air conditioning duct 10 allows air from the vehicle compartment or the outside of the vehicle to flow in, and allows air that has passed through the first humidity control unit 20 and the second humidity control unit 30 to flow into the vehicle compartment or be discharged to the outside of the vehicle. Therefore, the air conditioning duct 10 preferably has a first path 10a for allowing air to flow into the vehicle compartment and a second path 10b for allowing air to be discharged to the outside of the vehicle on the downstream side of the second humidity control unit 30.

[0071] The air conditioning passage 10 may include a switching valve 50 that can switch the flow of air between the first path 10a and the second path 10b. The switching valve 50 may be a valve that is electrically driven and has the function of switching the flow path, and is not particularly limited. A solenoid valve and an electric valve may be used. For example, the switching valve 50 includes an opening and 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 60.

[0072] The air conditioning duct 10 may include a ventilator (not shown) for allowing the air from the vehicle cabin to flow into the first humidity control unit 20 and the second humidity control unit 30. The position of the ventilator is not particularly limited, and the ventilator may be provided upstream of the first humidity control unit 20, for example.

[0073] (2. First Humidity Control Unit 20)

[0074] The first humidity control unit 20 is a unit including one or more humidity control devices 21 .

[0075] The number of the humidity control devices 21 may be appropriately set according to the required humidity control performance and is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3.

[0076] like Figure 2A and Figure 2B As shown, the humidity control device 21 includes: a honeycomb structure 22 having an outer peripheral wall 23 and a partition wall 26, the partition wall 26 being arranged on the inner side of the outer peripheral wall 23 and partitioning a plurality of compartments 25, the plurality of compartments 25 forming a flow path extending from a first end face 24a to a second end face 24b; a pair of electrodes 27a, 27b, which are arranged on the honeycomb structure 22; and a hygroscopic material-containing layer 28, which is formed on the surface of the partition wall 26. The humidity control device 21 may further include a terminal 29 connected to the pair of electrodes 27a, 27b.

[0077] (2-1. Honeycomb structure 22)

[0078] The shape of the honeycomb structure 22 is not particularly limited. For example, the outer shape of the cross section of the honeycomb structure 22 orthogonal to the flow path direction (the direction in which the compartment 25 extends) can be set to a quadrilateral (rectangle, square), pentagon, hexagon, heptagon, octagon, or other polygon, circle, arc shape (oval, ellipse, oblong, rounded rectangle, etc.), etc. It should be noted that the end face (the first end face 24a and the second end face 24b) is the same shape as the cross section. In addition, when the cross section and the end face are polygonal, the corners can be chamfered.

[0079] The shape of the compartment 25 is not particularly limited. In the cross section of the honeycomb structure 22 orthogonal to the flow path direction, it can be a polygon such as a quadrilateral, pentagon, hexagon, heptagon, octagon, a circle, or a shape with a circular arc. These shapes can be single or a combination of two or more. In addition, among these shapes, a quadrilateral or a hexagon is preferred. By providing a compartment 25 of such a shape, the pressure loss during air circulation can be reduced.

[0080] The honeycomb structure 22 may be a honeycomb bonded body having a plurality of honeycomb units and a bonding layer bonding the outer peripheral sides of the plurality of honeycomb units to each other. By using the honeycomb bonded body, the occurrence of cracks can be suppressed and the total cross-sectional area of ​​the cells 25, which is very important for ensuring air flow, can be increased.

[0081] It should be noted that a bonding material can be used to form a bonding layer. As a bonding material, there is no particular limitation, and a material made into a paste by adding a solvent such as water to a ceramic material can be used. The bonding material can contain a material with PTC properties, and can also contain the same material as the peripheral wall 23 and the next door 26. In addition to having the effect of bonding the honeycomb units to each other, the bonding material can also be used as a peripheral coating material after bonding the honeycomb units.

[0082] From the viewpoints of ensuring the strength of the honeycomb structure 22, reducing the pressure loss when air passes through the cells 25, ensuring the loading amount of functional materials, and ensuring the contact area with the air flowing in the cells 25, it is preferred to well combine the thickness of the partition wall 26, the cell density, and the cell spacing (or the opening ratio of the cells 25).

[0083] In this specification, the cell density is a value obtained by dividing the number of cells by the area of ​​one end surface (first end surface 24a or second end surface 24b) of the honeycomb structure 22 (the total area of ​​the partition walls 26 and the cells 25 excluding the peripheral wall 23).

[0084] In this specification, the cell spacing refers to a value obtained by the following calculation. First, the area of ​​one end face (the first end face 24a or the second end face 24b) of the honeycomb structure 22 (the total area of ​​the partition walls 26 and the cells 25 excluding the peripheral wall 23) is divided by the number of cells to calculate the area of ​​each cell. Next, the square root of the area of ​​each cell is calculated and set as the cell spacing.

[0085] In this specification, the opening ratio of the cell 25 is a value obtained by dividing the total area of ​​the cells 25 divided by the partition walls 26 by the area of ​​one end face (the first end face 24a or the second end face 24b) in the cross section perpendicular to the flow path direction of the honeycomb structure 22 (the total area of ​​the partition walls 26 and the cells 25 excluding the peripheral wall 23). It should be noted that when calculating the opening ratio of the cell 25, the pair of electrodes 27a, 27b and the hygroscopic material-containing layer 28 are not taken into account.

[0086] In an embodiment that is advantageous from the viewpoint of supporting a sufficient amount of functional material, the thickness of the partition wall 26 is 0.300 mm or less, and the cell density is 100 cells / cm 2 In a preferred embodiment, the thickness of the partition wall 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 wall 26 is 0.130 mm or less, and the cell density is 65 cells / cm 2 Below, and the compartment spacing is above 1.3 mm.

[0087] From the viewpoint of ensuring the strength of the honeycomb structure 22 and maintaining the electrical resistance at a low level, 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 further preferably 0.030 mm or more.

[0088] From the viewpoints of ensuring the strength of the honeycomb structure 22, keeping the resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is preferably 30 cells / cm 2 More than 35 cells / cm 2 More preferably, 40 cells / cm 2 above.

[0089] From the viewpoint of ensuring the strength of the honeycomb structure 22, maintaining the electrical resistance at a low level, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell spacing is preferably 2.0 mm or less, more preferably 1.8 mm or less, and further preferably 1.6 mm or less.

[0090] In an embodiment that is advantageous from the viewpoint of simultaneously achieving 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 , the opening ratio of the cell 25 is 0.70 or more. In a preferred embodiment, the thickness of the partition wall 26 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm 2 , the opening ratio of the cell 25 is 0.80 or more. In a more preferred embodiment, the thickness of the partition wall 26 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm 2 , the opening ratio of the compartment 25 is greater than 0.85.

[0091] From the viewpoint of ensuring the strength of the honeycomb structure 22 , 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.

[0092] The thickness of the outer peripheral wall 23 is not particularly limited, and is preferably determined based on the following viewpoints. First, from the viewpoint of strengthening the honeycomb structure 22, the thickness of the outer peripheral wall 23 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and further preferably 0.08 mm or more. On the other hand, from the viewpoint of increasing the resistance to suppress the initial current, and from the viewpoint of reducing the pressure loss during air circulation, the thickness of the outer peripheral wall 23 is preferably 1.0 mm or less, more preferably 0.5 mm or less, further preferably 0.4 mm or less, and further preferably 0.3 mm or less.

[0093] In this specification, the thickness of the outer peripheral wall 23 refers to the length in the normal direction of the side surface of the honeycomb structure 22 from the boundary between the outer peripheral wall 23 and the outermost cell 25 or partition wall 26 in the cross section perpendicular to the flow path direction.

[0094] The length of the honeycomb structure 22 in the flow direction and the cross-sectional area perpendicular to the flow direction can be adjusted according to the required size of the humidity control device 21, and there is no particular limitation. For example, in the case of a compact humidity control device 21 that ensures the specified function, the length of the honeycomb structure 22 in the flow direction can be set to 2 to 20 mm, and the cross-sectional area perpendicular to the flow direction can be set to 10 cm 2 It should be noted that the upper limit of the cross-sectional area perpendicular to the flow path direction is not particularly limited, and is, for example, 300 cm 2 the following.

[0095] The partition walls 26 constituting the honeycomb structure 22 are made of a material that can generate heat by passing electricity, specifically, a material having PTC characteristics. As required, the peripheral wall 23 may also be made of a material having PTC characteristics like the partition walls 26. By adopting such a structure, the hygroscopic material layer 28 can be directly heated by utilizing the heat transfer from the heated partition walls 26 (and the peripheral wall 23 as required). In addition, the material having the PTC characteristic has the following characteristics, namely, when the temperature rises and exceeds the Curie point, the resistance value rises sharply and makes it difficult for the current to flow. Therefore, when the partition walls 26 (and the peripheral wall 23 as required) reach a high temperature, the current flowing through them will be limited, so that the excessive heating of the honeycomb structure 22 is suppressed. Therefore, the thermal degradation of the hygroscopic material layer 28 caused by excessive heating can also be suppressed.

[0096] From the viewpoint of obtaining moderate heat generation, the lower limit of the volume resistivity of the material having the PTC characteristic at 25°C is preferably 0.5Ω·cm or more, more preferably 1Ω·cm or more, and further preferably 5Ω·cm or more. From the viewpoint of making it generate heat at a low driving voltage, the upper limit of the volume resistivity of the material having the PTC characteristic at 25°C is preferably 30Ω·cm or less, more preferably 18Ω·cm or less, and further preferably 16Ω·cm or less. In this specification, the volume resistivity of the material having the PTC characteristic at 25°C is measured in accordance with JIS K6271:2008.

[0097] From the viewpoint of being able to generate heat when powered and having PTC characteristics, the peripheral wall 23 and the partition wall 26 are preferably composed of a material with barium titanate (BaTiO3) as the main component. In addition, the material is more preferably a ceramic composed of a material with barium titanate (BaTiO3)-based crystalline particles in which a part of Ba is replaced by a rare earth element as the main component. It should be noted that the "main component" in this specification refers to a component that occupies a proportion of more than 50% by mass in the overall composition. The content of BaTiO3-based crystalline particles can be solved by fluorescent X-ray analysis. Regarding other crystalline particles, it can also be measured in the same way as this method.

[0098] The composition formula of BaTiO3-based crystal particles in which a part of Ba is replaced by a rare earth element can be expressed as (Ba 1-x A x )TiO3. In the composition formula, A represents one or more rare earth elements, and 0.0001≤x≤0.010.

[0099] A may be a rare earth element, but is not particularly limited, and 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. From the viewpoint of suppressing excessive resistance at room temperature, x is preferably 0.001 or more, and more preferably 0.0015 or more. On the other hand, from the viewpoint of suppressing excessive resistance at room temperature due to insufficient sintering, x is preferably 0.009 or less.

[0100] The content of BaTiO3-based crystalline particles in which a part of Ba is replaced by rare earth elements in the ceramic is the amount of the main component, which is not particularly limited, and is preferably 90% by mass or more, more preferably 92% by mass or more, and further preferably 94% by mass or more. It should be noted that the upper limit of the content of BaTiO3-based crystalline particles is not particularly limited, and is usually 99% by mass, preferably 98% by mass.

[0101] From the viewpoint of reducing the environmental load, the material used for the peripheral wall 23 and the partition wall 26 is preferably substantially free of lead (Pb). Specifically, in the peripheral wall 23 and the partition wall 26, the Pb content is preferably 0.01 mass % or less, more preferably 0.001 mass % or less, and further preferably 0 mass %. With a low Pb content, air heated by contact with the partition wall 26 during heating, for example, can be safely blown toward living things such as humans. It should be noted that in the peripheral wall 23 and the partition wall 26, the Pb content is preferably less than 0.03 mass %, more preferably less than 0.01 mass %, and further preferably 0 mass % in terms of PbO. The lead content can be determined using ICP-MS (inductively coupled plasma mass spectrometry).

[0102] The Curie point of the material constituting the outer peripheral wall 23 and the partition wall 26 is preferably in the temperature range where the resistance value at room temperature (25°C) changes to a resistance value that is more than twice that. If the Curie point is in such a temperature range, when the humidity control device 21 reaches a high temperature, the current flowing through them is limited, so that excessive heat generation of the humidity control device 21 can be effectively suppressed. Therefore, thermal degradation of the hygroscopic material-containing layer 28 caused by excessive heat generation can be suppressed.

[0103] From the viewpoint of efficiently heating the hygroscopic material-containing layer 28, the lower limit of the Curie point of the material constituting the outer peripheral wall 23 and the partition wall 26 is preferably 80° C. or higher, more preferably 100° C. or higher, further preferably 110° C. or higher, and particularly preferably 125° C. or higher. In addition, from the viewpoint of the safety of the components placed in or near the vehicle compartment, the upper limit of the Curie point is preferably 200° C. or lower, more preferably 190° C. or lower, further preferably 180° C. or lower, and particularly preferably 150° C. or lower.

[0104] The Curie point of the material constituting the outer peripheral wall 23 and the partition wall 26 can be adjusted by the type and amount of the shifting agent. For example, the Curie point of barium titanate (BaTiO3) is about 120°C, and the Curie point can be shifted to the low temperature side by replacing a portion of Ba and Ti with one or more of Sr, Sn and Zr.

[0105] In this specification, the Curie point is measured by the following method. The sample is mounted on a sample holder for measurement and assembled in a measurement tank (e.g., MINI-SUBZERO MC-810P manufactured by Espec Co., Ltd.), and the change in the resistance of the sample relative to the temperature change when the temperature is increased from 10°C is measured using a DC resistance meter (e.g., multimeter 3478A manufactured by HEWLETT PACKARD KK). Based on the resistance-temperature graph obtained by the measurement, the temperature at which the resistance value becomes twice the resistance value at room temperature (25°C) is set as the Curie point.

[0106] (2-2. A pair of electrodes 27a, 27b)

[0107] The positions of the pair of electrodes 27a and 27b are not particularly limited. Figure 2A As shown, the electrodes 27a and 27b may be provided on the first end surface 24a and the second end surface 24b. In addition, the electrodes 27a and 27b may be provided on the pair of peripheral walls 23 parallel to the direction in which the compartment 25 extends.

[0108] By applying a voltage between the pair of electrodes 27 a and 27 b , the honeycomb structure 22 can be heated by Joule heat.

[0109] There is no particular limitation on the pair of electrodes 27a and 27b. For example, metals or alloys containing at least one selected from Cu, Ag, Al, Ni and Si can be used. In addition, ohmic electrodes that can make ohmic contact with the peripheral wall 23 and / or the partition wall 26 having PTC characteristics can also be used. The ohmic electrode can be, for example, an ohmic electrode containing at least one selected from Al, Au, Ag and In as a base metal, and containing at least one selected from Ni, Si, Zn, Ge, Sn, Se and Te for n-type semiconductors as a dopant. In addition, a pair of electrodes 27a and 27b can be a single-layer structure or a stacked structure of more than two layers. In the case where a pair of electrodes 27a and 27b have a stacked structure of more than two layers, the materials of each layer can be the same type or different types.

[0110] The thickness of the pair of electrodes 27a, 27b can be appropriately set according to the method for forming the pair of electrodes 27a, 27b. As the method for forming the pair of electrodes 27a, 27b, metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition can be cited. In addition, the pair of electrodes 27a, 27b can also be formed by sintering after applying the electrode paste, or by welding. In addition, the pair of electrodes 27a, 27b can also be made by joining metal plates or alloy plates.

[0111] Regarding the thickness of the pair of electrodes 27a, 27b, for example, in the sintering of the electrode paste, the thickness is preferably about 5 to 30 μm, in the dry plating such as sputtering and evaporation, the thickness is preferably about 100 to 1000 nm, in the welding, the thickness is preferably about 10 to 100 μm, in the wet plating such as electrolytic deposition and chemical deposition, the thickness is preferably about 5 to 30 μm. In addition, in the joining of metal plates or alloy plates, it is preferred that their thickness is set to about 5 to 100 μm.

[0112] (2-3.Terminal 29)

[0113] The terminal 29 is connected to the pair of electrodes 27a and 27b, and is provided at least in part of the pair of electrodes 27a and 27b. The terminal 29 facilitates connection with an external power source. The terminal 29 is connected to a lead wire connected to the external power source.

[0114] The material of the terminal 29 is not particularly limited, and may be metal, for example. As the metal, a single metal or an alloy may be used, and from the viewpoint of corrosion resistance, resistivity, and linear expansion coefficient, for example, an alloy containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti is preferred, and stainless steel, Fe-Ni alloy, and phosphor bronze are more preferred.

[0115] The size and shape of the terminal 29 are not particularly limited. Figure 2A As shown, the terminal 29 can be provided on the entire pair of electrodes 27a, 27b on the peripheral wall 23. In addition, the terminal 29 can be provided on a portion of the pair of electrodes 27a, 27b on the peripheral wall 23, or can be provided to extend further outside than the outer edge of the pair of electrodes 27a, 27b on the peripheral wall 23. In addition, the terminal 29 can be provided on a portion of the pair of electrodes 27a, 27b on the partition wall 26, or can be provided to block a portion of the compartment 25.

[0116] The thickness of the terminal 29 is not particularly limited, and is, for example, 0.01 to 10 mm, and typically 0.05 to 5 mm.

[0117] The method for connecting the terminal 29 and the pair of electrodes 27 a and 27 b is not particularly limited as long as they are electrically connected, and the connection may be performed by, for example, diffusion bonding, a mechanical pressurization mechanism, welding, or the like.

[0118] (2-4. Hygroscopic material layer 28)

[0119] The hygroscopic material-containing layer 28 is a layer containing a hygroscopic material and has a function of absorbing moisture (water vapor).

[0120] The hygroscopic material-containing layer 28 may be provided on the surface of the partition wall 26 (in the case of the outermost compartment 25, the partition wall 26 and the outer peripheral wall 23 that define and form the outermost compartment 25). By providing the hygroscopic material-containing layer 28 in this way, the hygroscopic material-containing layer 28 can be easily heated during the regeneration process, so that the desired function brought by the hygroscopic material-containing layer 28 can be regenerated.

[0121] The hygroscopic material contained in the hygroscopic material-containing layer 28 preferably has a function of being able to adsorb moisture at −20 to 40° C. and to release moisture at a high temperature of 60° C. or higher.

[0122] The hygroscopic material is not particularly limited, and examples thereof include aluminosilicate, silica gel, silicon dioxide, graphene oxide, polymer adsorbents, polystyrene sulfonic acid, and metal organic framework (MOF). These materials may be used alone or in combination of two or more.

[0123] As the aluminosilicate, preferably used are: AFI type, CHA type or BEA type zeolite; porous clay minerals such as allophane and filamentous allophane. In addition, the aluminosilicate is preferably amorphous.

[0124] As the silica gel, type A silica gel is preferably used.

[0125] As the polymer adsorbent, a material having a polyacrylic acid-based polymer chain is preferred. For example, sodium polyacrylate or the like can be used as the polymer adsorbent.

[0126] The metal organic structure is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). The metal ions are preferably hydrophilic metal ions (such as aluminum ions).

[0127] The hygroscopic material-containing layer 28 may contain a functional material having a function of adsorbing carbon dioxide and / or volatile components. By containing such a functional material, in addition to the dehumidification effect of the air, the air purification effect can also be obtained.

[0128] The functional material preferably has a function of being able to adsorb carbon dioxide and / or volatile components at −20 to 40° C. and to release them at a high temperature of 60° C. or higher.

[0129] As functional materials having such functions, zeolite, silica gel, activated carbon, alumina, silicon dioxide, low-crystalline clay, amorphous aluminosilicate complex, etc. can be cited. The type of functional material can be appropriately selected according to the type of the component to be removed. The functional material can be used alone or in combination of two or more.

[0130] It should be noted that the volatile components contained in the air of the vehicle cabin are, for example, volatile organic compounds (VOCs) or odor components other than VOCs, etc. Specific examples of volatile components include ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, p-dichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, diazinon, acetaldehyde, and 2-(1-methylpropyl)phenyl N-methylcarbamate.

[0131] The hygroscopic material-containing layer 28 may contain a catalyst. By containing a catalyst, it is possible to promote redox reactions and purify carbon dioxide and / or volatile components. As catalysts having such functions, metal catalysts such as Pt, Pd, and Ag, oxide catalysts such as CeO2 and ZrO2, etc., can be cited. The catalyst can be used alone or in combination of two or more. In addition, the catalyst can be used in combination with the above-mentioned functional materials.

[0132] The thickness of the hygroscopic material-containing layer 28 may be determined according to the size of the compartment 25 and is not particularly limited. For example, from the viewpoint of sufficiently ensuring contact with air, the thickness of the hygroscopic material-containing layer 28 is preferably 20 μm or more, more preferably 25 μm or more, and further preferably 30 μm or more. On the other hand, from the viewpoint of suppressing the hygroscopic material-containing layer 28 from peeling off from the partition 26 or the peripheral wall 23, the thickness of the hygroscopic material-containing layer 28 is preferably 400 μm or less, more preferably 380 μm or less, and further preferably 350 μm or less.

[0133] The thickness of the hygroscopic material-containing layer 28 is measured according to the following procedure. An arbitrary cross section of the honeycomb structure 22 parallel to the flow path direction is cut out, and a cross-sectional image of about 50 times is obtained using a scanning electron microscope or the like. In addition, the cross section is made to pass through the center of gravity position in the cross section of the honeycomb structure 22 that is orthogonal to the flow path. For each hygroscopic material-containing layer 28 visible from 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 hygroscopic material-containing layers 28 visible from the cross-sectional image, and the overall average value is taken as the thickness of the hygroscopic material-containing layer 28.

[0134] From the viewpoint of exerting the desired function in the humidity control device 21, the amount of the hygroscopic material-containing layer 28 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and further preferably 150 to 350 g / L relative to the volume of the honeycomb structure 22. It should be noted that the volume of the honeycomb structure 22 is a value determined according to the outer dimensions of the honeycomb structure 22.

[0135] (2-5. Method for Manufacturing Humidity Control Device 21)

[0136] The method for manufacturing the humidity control device 21 is not particularly limited, and can be performed according to a known method. Hereinafter, a method for manufacturing the humidity control device 21 will be described illustratively.

[0137] The method for manufacturing the honeycomb structure 22 constituting the humidity control device 21 includes a molding step and a firing step.

[0138] In the molding step, a blank containing a ceramic raw material including BaCO3 powder, TiO2 powder, and powder of a nitrate or hydroxide of a rare earth is molded to produce a honeycomb molded body having a relative density of 60% or more.

[0139] The ceramic raw material can be obtained by dry-mixing the respective powders in a desired composition.

[0140] The green material 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 green material may contain additives such as a displacement agent, a metal oxide, a property improving agent, and a conductor powder as required.

[0141] The blending amount of the components other than the ceramic raw material 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.

[0142] Here, the "relative density of the honeycomb formed body" in the present specification refers to the ratio of the density of the honeycomb formed body to the true density of the entire ceramic raw material. Specifically, it can be solved by the following formula.

[0143] Relative density of honeycomb molded body (%) = Density of honeycomb molded body (g / cm 3 ) / True density of ceramic raw material as a whole (g / cm 3 )×100

[0144] The density of the honeycomb molded body can be measured by the Archimedean method using pure water as the medium. In addition, the true density of the entire ceramic raw material can be obtained by dividing the total mass (g) of each raw material by the total actual volume (cm 3 ) to solve.

[0145] Examples of the dispersion medium include water and a mixed solvent of water and an organic solvent such as alcohol, and water can be particularly preferably used.

[0146] Examples of the binder include organic binders such as methylcellulose, hydroxypropoxycellulose, hydroxyethylcellulose, carboxymethylcellulose, and polyvinyl alcohol. It is particularly preferred to use methylcellulose and hydroxypropoxycellulose in combination. The binder may be used alone or in combination of two or more, but preferably does not contain an alkali metal element.

[0147] Examples of the plasticizer include polyoxyethylene alkyl ethers, polycarboxylic acid-based polymers, and alkyl phosphate esters.

[0148] The dispersant may be a surfactant such as polyoxyethylene alkyl ether, ethylene glycol, dextrin, fatty acid soap, polyol, etc. The dispersant may be used alone or in combination of two or more.

[0149] The honeycomb molded body can be produced by extrusion molding a blank. During the extrusion molding, a die having a desired overall shape, cell shape, cell wall thickness, cell density, etc. can be used.

[0150] 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 to such a range, the honeycomb formed body can be densified and the resistance at room temperature can be reduced. It should be noted that the upper limit of the relative density of the honeycomb formed body is not particularly limited, and is generally 80%, preferably 75%.

[0151] The honeycomb molded body may be dried before the firing step. The drying method is not particularly limited, and for example, conventionally known drying methods such as hot air drying, microwave drying, induction drying, reduced pressure drying, vacuum drying, and freeze drying may be used. Among them, a drying method combining hot air drying with microwave drying or induction drying is preferred in terms of being able to quickly and uniformly dry the entire molded body.

[0152] The sintering process includes: after maintaining at 1150-1250° C., heating it to a maximum temperature of 1360-1430° C. at a heating rate of 20-600° C. / hour, and maintaining it for 0.5-10 hours.

[0153] By maintaining the honeycomb formed body at a maximum temperature of 1360 to 1430° C. for 0.5 to 10 hours, it is possible to obtain a honeycomb structure 22 mainly composed of BaTiO 3 -based crystal particles in which a portion of Ba is substituted with a rare earth element.

[0154] Furthermore, by maintaining the temperature at 1150 to 1250° C., Ba 2 TiO 4 crystal particles generated during the firing process can be easily removed, thereby making it possible to densify the honeycomb structure 22 .

[0155] Furthermore, by setting the heating rate from 1150 to 1250° C. to the maximum temperature of 1360 to 1430° C. to 20 to 600° C. / hour, 1.0 to 10.0 mass % of Ba6Ti can be generated in the honeycomb structure 22. 17 O 40 Crystalline particles.

[0156] The holding time at 1150 to 1250° C. is not particularly limited, but is preferably 0.5 to 10 hours. By setting such a holding time, Ba 2 TiO 4 crystal particles generated during the sintering process can be easily and stably removed.

[0157] The calcining step preferably includes: maintaining the temperature at 900 to 950° C. for 0.5 to 5 hours. By maintaining the temperature at 900 to 950° C. for 0.5 to 5 hours, BaCO 3 is efficiently decomposed, and the honeycomb structure 22 having a predetermined composition is easily obtained.

[0158] Note that a degreasing step for removing the binder may be performed before the calcining step. The atmosphere of the degreasing step is preferably an air atmosphere so that the organic components can be completely decomposed.

[0159] Furthermore, from the viewpoint of controlling electrical characteristics and manufacturing cost, the atmosphere of the firing step is preferably an air atmosphere.

[0160] The firing furnace used in the firing step or the degreasing step is not particularly limited, and an electric furnace, a gas furnace, or the like can be used.

[0161] A pair of electrodes 27a and 27b are formed on the honeycomb structure 22 obtained in this way. A pair of electrodes 27a and 27b can be formed by a metal deposition method such as sputtering, evaporation, electrolytic deposition, and chemical deposition. In addition, a pair of electrodes 27a and 27b can also be formed by sintering after applying an electrode paste. In addition, a pair of electrodes 27a and 27b can also be formed by welding. A pair of electrodes 27a and 27b can be composed of a single layer or a plurality of electrode layers with different compositions. Below, a representative method for forming a pair of electrodes 27a and 27b is described.

[0162] 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 22. 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 22 is removed by blowing and wiping. Thereafter, by drying the slurry, a pair of electrodes 27a, 27b can be formed on the first end face 24a or the second end face 24b of the honeycomb structure 22. The drying can be performed while the honeycomb structure 22 is heated to a temperature of, for example, about 120 to 600°C. A series of steps of coating, slurry removal, and drying may be performed only once, or may be repeated a plurality of times to provide the pair of electrodes 27 a and 27 b having a desired thickness.

[0163] Next, the terminal 29 is disposed at a predetermined position of the pair of electrodes 27a and 27b, and the pair of electrodes 27a and 27b are connected to the terminal 29. As a method for connecting the pair of electrodes 27a and 27b to the terminal 29, the above-mentioned method can be used.

[0164] It should be noted that the terminal 29 may be provided after the hygroscopic material-containing layer 28 described below is formed.

[0165] Next, the hygroscopic material-containing layer 28 is formed on the surfaces of the partition walls 26 and the like of the honeycomb structure 22 .

[0166] The method for forming the hygroscopic material-containing layer 28 is not particularly limited, and it can be formed, for example, by the following process. The honeycomb structure 22 is immersed in a slurry containing a dehumidifying material, an organic binder, and a dispersion medium for a predetermined time, and the excess slurry on the end face and the periphery of the honeycomb structure 22 is removed by blowing and wiping. The dispersion medium can be: water, an organic solvent (for example: 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, by drying the slurry, the hygroscopic material-containing layer 28 can be formed on the surface of the partition wall 26. The drying can be performed while the honeycomb structure 22 is heated to a temperature of, for example, about 120 to 600°C. The series of steps of immersion, slurry removal and drying may be performed only once, or may be repeated a plurality of times to provide the hygroscopic material-containing layer 28 having a desired thickness on the surface of the partition walls 26 and the like.

[0167] (3. Second Humidity Control Unit 30)

[0168] The second humidity control unit 30 is a unit including one or more humidity control members 31 .

[0169] The number of humidity control members 31 may be appropriately set according to the number of humidity control devices 21 disposed in the first humidity control unit 20 on the upstream side, and is not particularly limited, but is preferably 1 to 5, and more preferably 1 to 3.

[0170] The humidity control component 31 is provided to suppress the high-humidity air generated by the heating of the humidity control device 21 in the initial stage of the regeneration process from flowing to the air conditioning passage 10 at the same time, and therefore, it is not necessary to have a heater function. This is because: if the humidity control component 31 is heated to a high temperature in the initial stage of the regeneration process, high-humidity air will also be generated in the humidity control component 31. However, if the humidity control component 31 is not heated or is not heated to a high temperature in the initial stage of the regeneration process, the humidity control component 31 can have a heater function.

[0171] The humidity control component 31 is not particularly limited, and a known humidity control component can be used. As an example of the humidity control component 31, a component obtained by carrying a hygroscopic material on a substrate of various shapes such as a sheet, a mesh, and a honeycomb can be cited. In addition, a component obtained by molding a hygroscopic material into various shapes such as a sheet, a mesh, and a honeycomb, or a component obtained by filling a hygroscopic material of various shapes in a shell can also be used as the humidity control component 31. Among them, the humidity control component 31 preferably has a honeycomb structure like the humidity control device 21.

[0172] Here, a schematic cross-sectional view of the humidity control member 31 having a honeycomb structure parallel to the flow path direction is shown. Figure 4 .

[0173] like Figure 4 As shown, the humidity control component 31 includes: a honeycomb structure 32 having an outer peripheral wall 33 and a partition wall 36, the partition wall 36 being arranged on the inner side of the outer peripheral wall 33 and partitioning a plurality of compartments 35, the plurality of compartments 35 forming a flow path extending from the first end face 34a to the second end face 34b; and a hygroscopic material-containing layer 38 formed on the surface of the partition wall 36. By using the humidity control component 31 having such a structure, the effect of making it difficult for water droplets to adhere to the air conditioning duct 10 during the regeneration process can be stably obtained, and the hygroscopic performance can be improved.

[0174] The detailed configuration of the honeycomb structure 32, such as the shape, is not particularly limited and may be the same as the honeycomb structure 22 used in the humidity control device 21. Therefore, only the features of the honeycomb structure 32 that are different from the honeycomb structure 22 used in the humidity control device 21 will be described below.

[0175] The honeycomb structure 32 is different from the honeycomb structure 22 in that it does not need to be energized to generate heat. Therefore, the outer peripheral wall 33 and the partition wall 36 constituting the honeycomb structure 32 may be made of SiC, metal-bonded SiC, metal-composite SiC, Si3N4, metal-composite Si3N4, cordierite, mullite, spinel, alumina, zirconia, zirconia-reinforced alumina, etc. These materials may be used alone or in combination of two or more.

[0176] Here, as "metal-bonded SiC", metal-impregnated SiC, Si-bonded SiC, SiC obtained by bonding metal Si and other types of metals, etc. can be used. Examples of "other types of metals" include: Al (aluminum), Ni (nickel), Cu (copper), Ag (silver), Be (beryllium), Mg (magnesium), Ti (titanium), etc. In addition, as "metal composite SiC", a substance obtained by mixing and sintering SiC particles and metal powder can be used.

[0177] In the honeycomb structure 32, it is preferred that the thickness of the partition walls 36 is 0.06 to 0.40 mm and the cell density is 30 to 95 cells / cm 2 More preferably, the thickness of the partition wall 36 is 0.08 to 0.25 mm, and the cell density is 40 to 80 cells / cm 2 By controlling the thickness of the partition wall 36 and the cell density within such a range, it is possible to suppress the pressure loss at a low level and improve the moisture absorption performance.

[0178] The type of the hygroscopic material used in the second humidity control unit 30 (humidity control member 31) may be the same as or different from the type of the hygroscopic material used in the humidity control device 21, but is preferably the same in consideration of manufacturability and manufacturing cost.

[0179] The total amount of the hygroscopic material in the second humidity control unit 30 is 0.3 to 12 times the total amount of the hygroscopic material in the first humidity control unit 20. By controlling the total amount of the hygroscopic material in the second humidity control unit 30 to be within such a range, the humidity control performance can be improved, and high-humidity air can be captured in the humidity control member 31 in the second humidity control unit 30 in the initial stage of the regeneration process, thereby preventing the air from flowing to the downstream side of the second humidity control unit 30. From the viewpoint of stably ensuring this effect, the total amount of the hygroscopic material in the second humidity control unit 30 is preferably 0.5 to 8 times the total amount of the hygroscopic material in the first humidity control unit 20, and more preferably 0.6 to 6 times.

[0180] The method for manufacturing the humidity control member 31 is not particularly limited and can be carried out according to a known method. For example, when the humidity control member 31 having a honeycomb structure is used, the method can be carried out in the same manner as the method for manufacturing the honeycomb structure 22 in the humidity control device 21 described above.

[0181] The second humidity control unit 30 is disposed in the air conditioning duct 10 adjacent to the first humidity control unit 20. The second humidity control unit 30 may or may not be in contact with the first humidity control unit 20. When the first humidity control unit 20 and the second humidity control unit 30 are not in contact, the effect of capturing high-humidity air in the humidity control component 31 in the second humidity control unit 30 in the initial stage of the regeneration process and suppressing the air from flowing to the downstream side of the second humidity control unit 30 can be improved.

[0182] When the first humidity control unit 20 and the second humidity control unit 30 are not in contact, the distance between them is preferably 10 cm or less. If the distance is within this range, it is difficult for moisture to remain between the first humidity control unit 20 and the second humidity control unit 30. In addition, the distance between the first humidity control unit 20 and the second humidity control unit 30 is preferably 1 cm or more.

[0183] (4. Power supply 40)

[0184] The power supply 40 is used to apply a voltage to the pair of electrodes 27a and 27b. The power supply 40 is electrically connected to the control unit 60, and adjusts the application state of the voltage applied to the pair of electrodes 27a and 27b according to the instruction from the control unit 60.

[0185] The power source 40 is not particularly limited, and a battery or the like can be used.

[0186] (5. Control unit 60)

[0187] The control unit 60 is connected to the power supply 40, the switching valve 50, etc., and can control them. The control unit 60 controls the power supply 40, thereby controlling the application state of the voltage applied to the pair of electrodes 27a and 27b of the humidity control device 21, and adjusting the heating state of the honeycomb structure 22. In addition, the control unit 60 can control the switching valve 50 in a manner that air flows through the first path 10a or the second path 10b. In addition, the control unit 60 can also be electrically connected to a ventilator (not shown) to control the ventilator.

[0188] The control unit 60 is not particularly limited, but is generally an ECU (Engine (electronic) Control Unit). The ECU includes a CPU that performs various calculations, a ROM that stores programs or data required for its control, a RAM that temporarily stores calculation results in the CPU, and an input / output port for inputting or outputting signals to or from the outside.

[0189] The control unit 60 is preferably capable of executing a dehumidification mode in which the switching valve 50 is controlled to switch the flow of air to the first path 10a to dehumidify the interior of the vehicle, and a regeneration mode in which a voltage is applied from the power supply 40 to a pair of electrodes 27a, 27b of the humidity control device 21 and the switching valve 50 is controlled to switch the flow of air to the second path 10b to regenerate the hygroscopic material. By executing the dehumidification mode and the regeneration mode in this way, the dehumidification process and the regeneration process can be efficiently performed.

[0190] The control unit 60 is configured to switch the switching valve 50 in a manner that allows air to flow through the first path 10a in the dehumidification mode, and start the ventilator. By controlling in this way, the air from the vehicle compartment or the outside of the vehicle is dehumidified. At this time, the humidity control device 21 of the first humidity control unit 20 is not heated. Specifically, the air from the vehicle compartment or the outside of the vehicle passes through the air conditioning duct 10 and flows into the humidity control device 21 of the first humidity control unit 20 and the humidity control component 31 of the second humidity control unit 30 in sequence, and the moisture contained in the air is captured. Then, the dehumidified air passes through the first path 10a and returns to the vehicle compartment.

[0191] The control unit 60 is configured to switch the switching valve 50 so that air flows through the second path 10b in the case of the regeneration mode, apply voltage to the pair of electrodes 27a, 27b, and start the ventilator. By performing control in this way, the hygroscopic material layer 28 of the humidity control device 21 in the first humidity control unit 20 is regenerated. Specifically, the air from the vehicle cabin passes through the air conditioning duct 10 and flows into the humidity control device 21 in the first humidity control unit 20, and the moisture captured in the hygroscopic material layer 28 is separated while passing through the humidity control device 21. In addition, the air heated by the humidity control device 21 heats the humidity control component 31 in the second humidity control unit 30, and the moisture captured in the humidity control component 31 is separated while passing through the humidity control component 31. Then, the air containing moisture passes through the second path 10b and is discharged to the outside of the vehicle.

[0192] In the regeneration mode, in order to promote the desorption of water captured in the hygroscopic material-containing layer 28, it is preferred to heat the hygroscopic material-containing layer 28 to a desorption temperature or higher depending on the type of the hygroscopic material. For example, the hygroscopic material-containing layer 28 is preferably heated to 70 to 150°C, more preferably 80 to 140°C, and even more preferably 90 to 130°C.

[0193] From the viewpoint of stably performing the above-mentioned control, the humidity control device 21 of the first humidity control unit 20 is preferably arranged at a position close to the vehicle compartment. Therefore, from the viewpoint of preventing electric shock, etc., the driving voltage of the humidity control device 21 is preferably 60V or less. The honeycomb structure 22 used in the humidity control device 21 has a low resistance at room temperature, so the honeycomb structure 22 can be heated at this low driving voltage. It should be noted that the lower limit of the driving voltage is not particularly limited, and is preferably above 10V. If the driving voltage is less than 10V, the current when the honeycomb structure 22 is heated becomes larger, so the wire needs to be thicker.

[0194] Example

[0195] Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples at all.

[0196] <Manufacturing of humidity control devices>

[0197] As ceramic raw materials, BaCO3 powder, TiO2 powder and La(NH3)3·6H2O powder are prepared. These powders are weighed in a manner to have a specified composition after firing, and dry mixed to obtain a mixed powder. Dry mixing is performed for 30 minutes. Next, to 100 parts by mass of the obtained mixed powder, appropriate amounts of water, binder, plasticizer and dispersant are added in a range of 3 to 30 parts by mass in total in a manner to obtain a ceramic molded body with a relative density of 64.8% after extrusion molding, and kneading is performed to obtain green clay. Methyl cellulose is used as a binder. Polyoxyethylene alkyl ether is used as a plasticizer and a dispersant.

[0198] Next, the obtained kneaded 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.

[0199] The shape of the cross section and end surface of the honeycomb structure perpendicular to the flow path direction: quadrilateral

[0200] The shape of the cross section of the cell perpendicular to the flow direction: quadrilateral

[0201] Thickness of the wall: 0.1mm

[0202] Thickness of outer wall: 0.2mm

[0203] Compartment density: 80 compartments / cm 2

[0204] Compartment spacing: 1.1mm

[0205] Cross-sectional area of ​​the honeycomb structure perpendicular to the direction in which the flow path extends: 6000 mm 2

[0206] Length of the honeycomb structure in the direction in which the flow path extends: 10 mm

[0207] Volume resistivity of the material constituting the outer wall and partition walls at 25°C: 15Ω·cm

[0208] Curie point of the material constituting the outer wall and partition wall: 110°C

[0209] Next, the obtained honeycomb molded body was subjected to induction drying and hot air drying, and then degreased (450°C × 4 hours) in a firing furnace under an atmospheric atmosphere, and then fired under an atmospheric atmosphere to obtain a honeycomb structure. The firing was performed as follows: after being kept at 950°C for 1 hour, the temperature was increased to 1200°C, and kept at 1200°C for 1 hour, and then the temperature was increased to 1400°C (maximum temperature) at a heating rate of 200°C / hour, and kept at 1400°C for 2 hours.

[0210] Next, a pair of electrodes is formed on the two 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) is prepared, applied to the first end face, and then the electrode slurry is dried to form an electrode on the surface of the first end face. In addition, the same electrode slurry is applied to the second end face and dried to form an electrode on the second end face.

[0211] Next, the honeycomb structure having a pair of electrodes is immersed in a slurry containing zeolite (hygroscopic material), an organic binder, and water, and the slurry attached to excess locations (periphery, etc.) is removed by blowing and wiping, and then dried at a temperature of about 550° C., thereby forming a hygroscopic material-containing layer of a predetermined thickness on the surface of the partition wall and the surface of the peripheral wall facing the compartment. The thickness of the hygroscopic material-containing layer is controlled by adjusting the number of times a series of steps of immersion, slurry removal, and drying are performed.

[0212] <Manufacturing of humidity control parts>

[0213] As a ceramic raw material, a cordierite raw material obtained by mixing alumina, kaolin and talc is used, a binding material including an organic binder, a water-absorbing resin as a pore-forming material, and water as a dispersion medium are mixed with the cordierite raw material to form a raw material composition, and the raw material composition is kneaded to obtain green clay. Next, the obtained green clay is extruded to obtain a honeycomb molded body with cells. The honeycomb molded body is obtained by extrusion molding using a predetermined die in a manner such that the honeycomb structure becomes a shape as shown below after firing.

[0214] The shape of the cross section and end surface of the honeycomb structure perpendicular to the flow path direction: quadrilateral

[0215] The shape of the cross section of the cell perpendicular to the flow direction: quadrilateral

[0216] Thickness of the wall: 0.1mm

[0217] Thickness of outer wall: 0.2mm

[0218] Compartment density: 70 compartments / cm 2

[0219] Cross-sectional area of ​​the honeycomb structure perpendicular to the direction in which the flow path extends: 6000 mm 2

[0220] Length of the honeycomb structure in the direction in which the flow path extends: 10 mm

[0221] Next, the obtained honeycomb molded body was induction dried and hot air dried, and then degreased (450°C x 4 hours) in a firing furnace under air atmosphere, and then fired (1370°C x 6 hours) under air atmosphere to obtain a honeycomb structure.

[0222] Next, the obtained honeycomb structure is immersed in a slurry containing zeolite (hygroscopic material), an organic binder and water, and the slurry attached to the excess position (periphery, etc.) is removed by blowing and wiping, and then dried at a temperature of about 550° C., thereby forming a hygroscopic material-containing layer of a predetermined thickness on the surface of the partition wall and the surface of the peripheral wall facing the compartment. The thickness of the hygroscopic material-containing layer is controlled by adjusting the number of times of a series of steps of immersion, slurry removal, and drying.

[0223] <Examples 1 to 12 and Comparative Example 2>

[0224] In a transparent air conditioning passage, a humidity control device (first humidity control unit) and a humidity control component (second humidity control unit) are arranged from the upstream side, and a DC power supply device is connected to a pair of electrodes of the humidity control device to produce a vehicle air conditioning system. The ratio of the total amount of hygroscopic material in the humidity control component to the total amount of hygroscopic material in the humidity control device (hereinafter sometimes referred to as "the total amount ratio of hygroscopic material") and the distance between the humidity control device and the humidity control component (hereinafter sometimes referred to as "the distance between units") are set as shown in Table 1. In addition, a ventilator is arranged in the air conditioning passage on the upstream side of the humidity control device.

[0225] <Comparative Example 1>

[0226] In a transparent air conditioning passage, starting from the upstream side, only a humidity control device (first humidity control unit) is provided, a pair of electrodes of the humidity control device are connected to a DC power supply device, and a vehicle air conditioning system (existing example) is produced. In addition, a ventilator is arranged in the air conditioning passage on the upstream side of the humidity control device.

[0227] The vehicle air conditioning systems of the examples and comparative examples obtained above were evaluated as follows.

[0228] <Dehumidification performance>

[0229] After the vehicle air conditioning system is in regeneration mode, the dehumidification mode is performed. The regeneration mode is performed as follows: the ventilator is started and air with a temperature of 25°C and a relative humidity of 40% is circulated in the air conditioning passage at a flow rate of 20L / min, and at the same time, a voltage of 12V is applied to the humidity control device from the DC power supply device for 4 minutes. The dehumidification mode is performed as follows: no voltage is applied to the humidity control device, and air with the same conditions is circulated in the air conditioning passage at a flow rate of 300L / min. In addition, in the dehumidification mode, the absolute humidity is recorded by the humidity sensors arranged before and after the humidity control device to calculate the amount of water removed.

[0230] In this evaluation, the result of Comparative Example 1 was used as a reference, and the improvement rate of the results of each embodiment and each comparative example relative to the reference was calculated. The case where the improvement rate was 8% or more was represented as A, the case where the improvement rate was 5% or more and less than 8% was represented as B, the case where the improvement rate was 2% or more and less than 5% was represented as C, and the case where the improvement rate was less than 2% (the same level as Comparative Example 1) was represented as D. It should be noted that if the improvement rate was 2% or more, it can be said that the dehumidification performance was improved compared with the conventional vehicle air conditioning system.

[0231] <Water droplet resistance>

[0232] In the above-mentioned dehumidification performance test, whether or not water droplets adhere to the transparent air-conditioning duct is evaluated by visual observation.

[0233] In this evaluation, the situation where no water droplets are attached to the transparent air conditioning passage is represented as A, the situation where water droplets are attached to the air conditioning passage on the downstream side of the humidity control component is represented as Z, and the situation where water droplets are attached to the air conditioning passage between the humidity control device and the humidity control component is represented as Y.

[0234] Table 1 shows the above evaluation results.

[0235] Table 1

[0236]

[0237] As shown in Table 1, in Examples 1 to 12, the total amount of hygroscopic material in the humidity control component (second humidity control unit) is 0.3 to 12 times the total amount of hygroscopic material in the humidity control device (first humidity control unit), so the dehumidification performance and water droplet adhesion prevention performance are good.

[0238] On the other hand, in Comparative Example 1 (conventional example), since the humidity control member (second humidity control unit) was not provided, the water droplet adhesion prevention performance was insufficient.

[0239] In Comparative Example 2, the total amount of the hygroscopic material in the humidity conditioning member (second humidity conditioning unit) is less than 0.3 times the total amount of the hygroscopic material in the humidity conditioning device (first humidity conditioning unit), so both the dehumidification performance and the water droplet adhesion prevention performance are insufficient.

[0240] From the above results, it is understood that according to the present invention, it is possible to provide a vehicle air conditioning system in which water droplets are unlikely to adhere to the inside of the air conditioning duct during the regeneration process.

Claims

1. A vehicle air conditioning system comprising: an air conditioning passage, the air conditioning passage being capable of providing air circulation; A first humidity control unit, the first humidity control unit having one or more humidity control devices, and arranged in the air conditioning passage, the humidity control device comprising: a honeycomb structure having an outer peripheral wall and a partition wall, the partition wall being arranged on the inner side of the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments forming a flow path extending from the first end face to the second end face, at least the partition wall being made of a material having a PTC property; a pair of electrodes, the pair of electrodes being arranged on the honeycomb structure; and a hygroscopic material layer, the hygroscopic material layer being formed on the surface of the partition wall; a second humidity control unit including one or more humidity control components including a hygroscopic material and arranged in the air conditioning duct on a downstream side of the first humidity control unit; and a power supply, the power supply being used to apply a voltage to the humidity control device, The total amount of the hygroscopic material in the second humidity conditioning unit is 0.3 to 12 times the total amount of the hygroscopic material in the first humidity conditioning unit.

2. The vehicle air conditioning system according to claim 1, wherein: The humidity regulating component includes: a honeycomb structure having an outer peripheral wall and a partition wall, wherein the partition wall is arranged on the inner side of the outer peripheral wall and divides the structure into a plurality of compartments, wherein the plurality of compartments form a flow path extending from a first end face to a second end face; and a hygroscopic material layer formed on a surface of the partition wall.

3. The vehicle air conditioning system according to claim 2, wherein: In the humidity control component, the thickness of the partition wall is 0.06 to 0.40 mm, and the cell density is 30 to 95 cells / cm 2 .

4. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The humidity control member does not have a heater function.

5. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The total amount of the hygroscopic material in the second humidity control unit is 0.5 to 8 times the total amount of the hygroscopic material in the first humidity control unit.

6. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The total amount of the hygroscopic material in the second humidity control unit is 0.6 to 6 times the total amount of the hygroscopic material in the first humidity control unit.

7. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: In the humidity control device, the pair of electrodes are provided on the first end surface and the second end surface.

8. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The distance between the first humidity control unit and the second humidity control unit is less than 10 cm.

9. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The air conditioning passage includes a first path for allowing the air to flow into the vehicle cabin and a second path for allowing the air to be discharged to the outside of the vehicle on the downstream side of the second humidity control unit. The vehicle air conditioning system further includes a switching valve capable of switching the flow of the air between the first path and the second path.

10. The vehicle air conditioning system according to claim 9, wherein: The vehicle air conditioning system further includes a control unit capable of executing a dehumidification mode and a regeneration mode. In the dehumidification mode, the switching valve is controlled so as to switch the flow of the air to the first path to dehumidify the interior of the vehicle. In the regeneration mode, a voltage is applied from the power supply to the pair of electrodes of the humidity control device, and the switching valve is controlled to switch the flow of the air to the second path to regenerate the moisture absorbing material.

11. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The material having the PTC characteristic contains barium titanate as a main component.

12. The vehicle air conditioning system according to any one of claims 1 to 3, wherein: The hygroscopic material-containing layer of the humidity control device further contains: an adsorbent material and / or a catalyst having a function of adsorbing at least one selected from carbon dioxide and volatile components.

Images