Vehicle Air Conditioning Systems

Abstract

To provide an air conditioning system for a vehicle capable of suppressing fogging of window glass in a vehicle interior even if humidity in the vehicle interior rises suddenly. [Solution] An air conditioning system for a vehicle comprising: a humidity control device 10 capable of adsorbing and desorbing moisture; an air conditioning duct 20 in which the humidity control device 10 is arranged and through which air can flow from the vehicle compartment or outside the vehicle, the air conditioning duct 20 having a first flow path 20a downstream of the humidity control device 10 for introducing air into the vehicle compartment and a second flow path 20b for discharging air outside the vehicle; a valve 30 capable of switching the flow of air between the first flow path 20a and the second flow path 20b; a fan 40 capable of adjusting the flow rate of air flowing through the air conditioning duct 20; and a control unit 50 capable of controlling the humidity control device 10, the valve 30 and the fan 40.

Description

[Technical field]

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

[0002] There is an increasing demand for improved cabin environments in various vehicles such as automobiles. Specific demands include reducing CO2 in the cabin to suppress driver drowsiness, controlling humidity in the cabin, and removing harmful volatile components such as odorous components and allergy-inducing components from the cabin. Ventilation is an effective measure to meet such demands, but ventilation causes a large loss of heater energy in winter, leading to a decrease in energy efficiency in winter. In particular, electric vehicles (BEVs: Battery Electric Vehicles) have the problem that the energy loss significantly reduces the driving range.

[0003] As a method for solving the above problems, a vehicle interior purification system (vehicle air conditioning system) has been proposed, which includes a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that form flow paths extending from one end face to the other end face, the partition walls being made of a material having PTC characteristics; a pair of electrodes consisting of a first electrode provided on one end face and a second electrode provided on the other end face; and a heater element (humidity control device) having a functional material-containing layer provided on the surface of the partition wall; an inlet pipe connecting the vehicle interior to an inlet end face of the heater element, and an outlet pipe having a first path (first flow path) connecting the outlet end face of the heater element to the vehicle interior, the outlet pipe having the first path connecting the outlet end face of the heater element to the vehicle interior and a second path (second flow path) connecting the outlet end face of the heater element to the outside of the vehicle, and a switching valve capable of switching the flow of air flowing through the outlet pipe between the first path and the second path. [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] In the vehicle air conditioning system described in Patent Document 1, when the humidity control device is in adsorption mode (a process in which moisture and the like is adsorbed by the functional material-containing layer), the humidity inside the vehicle cabin may suddenly rise due to an increase in the number of passengers, the bringing in of rain or snow from outside the vehicle, etc. Under such circumstances, if the outside temperature is low, fogging is likely to occur on the window glass inside the vehicle cabin.

[0006] The present invention has been made to solve the above-mentioned problems, and has an object to provide a vehicle air conditioning system that can suppress fogging of the window glass inside the vehicle cabin even if the humidity inside the vehicle cabin suddenly increases. [Means for solving the problem]

[0007] As a result of extensive research into a vehicle air conditioning system equipped with a humidity control device, the inventors discovered that the above problems can be solved by controlling the ventilator to adjust the air flow rate so that the temperature Ta of the window glass in the vehicle compartment is higher than the dew point temperature Tb in the vehicle compartment when the adsorption mode is performed, and thus completed the present invention. That is, the present invention is exemplified as follows.

[0008] <1> A humidity control device capable of adsorbing and desorbing moisture; an air conditioning duct in which the humidity control device is disposed and through which air from a vehicle compartment or outside the vehicle can flow, the air conditioning duct having a first flow path downstream of the humidity control device for introducing the air into the vehicle compartment and a second flow path for discharging the air to the outside of the vehicle; a valve capable of switching the flow of the air between the first flow path and the second flow path; a fan capable of adjusting a flow rate of the air flowing through the air conditioning duct; a control unit capable of controlling the humidity control device, the valve, and the ventilator; Equipped with The control unit, when executing an adsorption mode in which the valve is switched so that the air flows into the first flow path and the humidity control device adsorbs the moisture, controls the ventilator to adjust the flow rate of the air so that a temperature Ta of the window glass in the vehicle compartment is higher than a dew point temperature Tb in the vehicle compartment.

[0009] <2> The control unit further controls a time of the adsorption mode when the adsorption mode is executed. <1> The vehicle air conditioning system according to claim 1 .

[0010] <3> The vehicle further includes a thermometer for measuring a temperature Ta of a window glass in the vehicle interior, and a dew point meter for measuring a dew point temperature Tb in the vehicle interior. <1> or <2> The vehicle air conditioning system according to claim 1 .

[0011] <4> The temperature Ta of the window glass in the vehicle interior is calculated by the following formula (1): <1> or <2> The vehicle air conditioning system according to claim 1 .

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[0012] <5> The temperature Ta of the window glass in the vehicle interior is calculated by the following formula (2): <1> or <2> The vehicle air conditioning system according to claim 1 .

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[0013] <6> The Tc is measured by a thermometer disposed in the vehicle interior. <4> or <5> The vehicle air conditioning system according to claim 1 .

[0014] <7> The To is measured by a temperature gauge disposed outside the vehicle. <4> ~ <6> 13. A vehicle air conditioning system according to claim 12,

[0015] <8> The Hco is calculated by the following formula (3) when the vehicle speed is 5 m / s or more, and by the following formula (4) when the vehicle speed is less than 5 m / s. <4> The vehicle air conditioning system according to claim 1 . Hco=7.1×U A 0.78 (3) Hco=5.57+3.94U A (4) In the formula, U A is the vehicle speed [m / sec].

[0016] <9> The Hci is calculated by the following formula (5) when the flow velocity of the air on the passenger compartment side of the window glass is 5 m / sec or more, and by the following formula (6) when the flow velocity of the air on the passenger compartment side of the window glass is less than 5 m / sec. <4> ~ <8> 13. A vehicle air conditioning system according to claim 12, Hci=7.1×U B 0.78 (5) Hci=5.57+3.94U B (6) In the formula, U B is the air flow velocity on the passenger compartment side of the window glass [m / sec].

[0017] <10> The dew point temperature Tb in the vehicle interior is calculated by the following formula (7): <1> , <2> and <4> ~ <9> 13. A vehicle air conditioning system according to claim 12,

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[0018] <11> The dew point temperature Tb in the vehicle interior is calculated by the following formula (8): <1> , <2> and <4> ~ <9> 13. A vehicle air conditioning system according to claim 12,

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[0019] <12> The Wa is calculated based on a relationship between a flow rate of the air flowing into the humidity control device and an inflow time, which is obtained in advance. <10> or <11> The vehicle air conditioning system according to claim 1 .

[0020] <13> The AHi is measured by a hygrometer disposed in the air conditioning duct upstream of the humidity control device. <10> The vehicle air conditioning system according to claim 1 .

[0021] <14> The humidity control device has an adsorption section containing an adsorbent capable of adsorbing the moisture at or below a predetermined temperature and desorbing the adsorbed moisture when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption section. <1> ~ <13> 13. A vehicle air conditioning system according to claim 12,

[0022] <15> The humidity control device 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 passages extending from a first end face to a second end face; an adsorption layer containing the adsorbent provided on the surface of the partition; and A pair of electrodes provided on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall parallel to the extending direction of the cells of the honeycomb structure. Equipped with <14> The vehicle air conditioning system according to claim 1 .

[0023] <16> In the honeycomb structure, at least the partition walls are made of a material having PTC characteristics. <15> The vehicle air conditioning system according to claim 1 .

[0024] <17> The humidity control device includes a flow path of the air and a flow path of a heating medium adjacent to the flow path of the air, and the adsorption unit is provided in the flow path of the air. <14> The vehicle air conditioning system according to claim 1 .

[0025] <18> The humidity control device 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 passages extending from a first end face to a second end face; an adsorption layer containing the adsorbent provided on the surface of the partition; and A heater provided on the upstream side of the honeycomb structure Equipped with <14> The vehicle air conditioning system according to claim 1 .

[0026] <19> The adsorbent is capable of adsorbing and desorbing carbon dioxide and / or volatile components in addition to the moisture. <14> ~ <18> 13. A vehicle air conditioning system according to claim 12, Effect of the Invention

[0027] According to the present invention, it is possible to provide a vehicle air conditioning system capable of suppressing fogging of window glass in the vehicle compartment even if the humidity in the vehicle compartment rises suddenly. [Brief description of the drawings]

[0028] [Figure 1] 1 is a schematic diagram illustrating an overall configuration of a vehicle air conditioning system according to an embodiment of the present invention; [Diagram 2]10 is a graph showing an example of a method for controlling a temperature Ta of a window glass in a vehicle compartment to be higher than a dew-point temperature Tb in the vehicle compartment when an adsorption mode is executed. [Figure 3A] 1 is a schematic diagram of a cross section parallel to a flow path direction of a typical humidity control device used in a vehicle air conditioning system according to an embodiment of the present invention. [Figure 3B] 3B is a schematic cross-sectional view of the humidity control device of FIG. 3A taken along line aa'. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] The vehicle air conditioning system of the present invention includes a humidity control device capable of adsorbing and desorbing moisture; an air conditioning duct in which the humidity control device is disposed and through which air from the vehicle interior or the outside of the vehicle can flow, the air conditioning duct having a first flow path for introducing air into the vehicle interior and a second flow path for discharging air to the outside of the vehicle downstream of the humidity control device; a valve capable of switching the flow of air between the first flow path and the second flow path; a ventilator capable of adjusting the flow rate of air flowing through the air conditioning duct; and a control unit capable of controlling the humidity control device, the valve, and the ventilator. When an adsorption mode is executed in which the valve is switched so that air flows into the first flow path and moisture is adsorbed by the humidity control device, the control unit controls the ventilator to adjust the flow rate of air so that the temperature Ta of the window glass in the vehicle interior is higher than the dew point temperature Tb in the vehicle interior. By configuring the vehicle air conditioning system of the present invention as described above, even if the humidity in the vehicle interior rises suddenly, the amount of moisture adsorbed by the humidity control device can be increased by adjusting the flow rate of air. Therefore, even if the humidity in the vehicle interior rises suddenly, fogging of the window glass in the vehicle interior can be suppressed.

[0030] Hereinafter, the 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 to the following embodiments, which are made based on the ordinary knowledge of a person skilled in the art, fall within the scope of the present invention, without departing from the spirit of the present invention. In this specification, the terms "upstream side" and "downstream side" are based on the flow of air circulating through the vehicle air conditioning system.

[0031] The vehicle air conditioning system according to the embodiment of the present invention can be suitably used in various vehicles. Examples of the vehicle include, but are not limited to, automobiles and trains. Examples of the automobile include, but are not limited to, gasoline vehicles, diesel vehicles, gas-fueled 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 suitably used in vehicles that do not have an internal combustion engine, such as electric vehicles and trains.

[0032] FIG. 1 is a schematic diagram showing the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. 1, a vehicle air conditioning system according to an embodiment of the present invention includes a humidity control device 10, an air conditioning duct 20, a valve 30, a fan 40, and a control unit 50. In addition, the vehicle air conditioning system may further include a power source 60.

[0033] The humidity control device 10 is capable of adsorbing and desorbing moisture. The air conditioning duct 20 has the humidity control device 10 disposed therein, and allows air to flow from the vehicle cabin or outside the vehicle. The air conditioning duct 20 has a first flow path 20a downstream of the humidity control device 10 for introducing air into the vehicle cabin, and a second flow path 20b for discharging air to the outside of the vehicle. The valve 30 is capable of switching the flow of air between the first flow path 20a and the second flow path 20b. The fan 40 is capable of adjusting the flow rate of air flowing through the air conditioning duct 20 . The control unit 50 is capable of controlling the humidity adjustment device 10 , the valve 30 and the fan 40 .

[0034] In the vehicle air conditioning system having the above structure, when air from the vehicle interior or outside the vehicle flows through the air conditioning duct 20, moisture (water vapor) can be adsorbed or desorbed in the humidity control device 10. When the humidity control device 10 adsorbs moisture, the humidity control device 10 is set to an adsorption mode in which the humidity control device 10 is not heated. In the adsorption mode, air from which moisture has been reduced or removed in the humidity control device 10 can be allowed to flow into the vehicle interior by switching the valve 30 so that the air flows through the first flow path 20a. On the other hand, when moisture is desorbed in the humidity control device 10, the humidity control device 10 is set to a regeneration mode in which the humidity control device 10 is heated. In the regeneration mode, air containing moisture desorbed from the humidity control device 10 can be discharged outside the vehicle by switching the valve 30 so that the air flows through the second flow path 20b. The adsorption mode and the regeneration mode are repeatedly executed. At this time, the amount of moisture adsorbed by the humidity control device 10 in the adsorption mode can be increased by sufficiently desorbing the moisture adsorbed by the humidity control device 10 in the regeneration mode. Examples of a method for sufficiently desorbing the moisture adsorbed by the humidity control device 10 in the regeneration mode include increasing the flow rate of air flowing into the humidity control device 10 and extending the time of the regeneration mode.

[0035] When the adsorption mode is executed in which the valve 30 is switched so that the air flows into the first flow path 20a and the humidity control device 10 adsorbs moisture, the control unit 50 controls the ventilator 40 to adjust the air flow rate so that the temperature Ta of the window glass in the vehicle interior is higher than the dew point temperature Tb in the vehicle interior. By adjusting the air flow rate in this manner, fogging of the window glass in the vehicle interior can be suppressed even if the humidity in the vehicle interior increases suddenly. Specifically, when the dew point temperature Tb in the vehicle interior approaches the temperature Ta of the window glass in the vehicle interior, the rotation speed of the ventilator 40 is increased to increase the air flow rate. The dew point temperature Tb in the vehicle interior is more affected by changes in the air flow rate than the temperature Ta of the window glass in the vehicle interior, so by increasing the air flow rate, the dew point temperature Tb in the vehicle interior is significantly lower than the temperature Ta of the window glass in the vehicle interior. Specifically, by increasing the air flow rate, the amount of moisture adsorbed by the humidity control device 10 increases and the proportion of moisture in the air flowing into the vehicle cabin decreases, so that the dew point temperature Tb inside the vehicle cabin can be maintained lower than the temperature Ta of the window glass inside the vehicle cabin.

[0036] The control unit 50 can further control the time of the adsorption mode when the adsorption mode is executed. Since it may take time to reduce the humidity in the vehicle interior depending on the number of passengers and the amount of rain or snow brought in from outside the vehicle, by controlling the time of the adsorption mode, the temperature Ta of the window glass in the vehicle interior can be controlled to always be higher than the dew point temperature Tb in the vehicle interior. Therefore, fogging of the window glass in the vehicle interior can be stably suppressed depending on the number of passengers and the amount of rain or snow brought in from outside the vehicle.

[0037] The vehicle air conditioning system according to the embodiment of the present invention may further include a thermometer for measuring the temperature Ta of the window glass in the vehicle compartment, and a dew point meter for measuring the dew point temperature Tb in the vehicle compartment. With this configuration, the window glass temperature Ta and the dew point temperature Tb in the vehicle compartment can be measured. The thermometer and the dew point meter are connected to the control unit 50. The thermometer and dew point meter are not particularly limited, and commercially available ones can be used.

[0038] In the vehicle air conditioning system according to the embodiment of the present invention, instead of arranging a thermometer and a dew point meter to measure the temperature Ta and the dew point temperature Tb of the window glass in the vehicle interior, a predetermined formula may be used to calculate the temperature Ta and the dew point temperature Tb of the window glass in the vehicle interior. A method for calculating the temperature Ta and the dew point temperature Tb of the window glass in the vehicle interior will be described below.

[0039] The temperature Ta of the window glass in the vehicle interior can be calculated by the following formula (1).

[0040]

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[0041] In equation (1), Tc is the temperature of the air inside the vehicle cabin [℃], To is the temperature of the air outside the vehicle [℃], and Hci is the heat transfer coefficient of the window glass on the vehicle cabin side [W / m 2 K], and Hco is the heat transfer coefficient of the window glass on the outside of the vehicle [W / m 2 K], and Kg is the heat transfer coefficient of the window glass [W / m 2 K].

[0042] The Hco in formula (1) may be a fixed value assuming an average vehicle speed in the high-speed phase of the WLTC (Worldwide-harmonized Light vehicles Test Cycle) mode test. 2 The temperature Ta of the window glass in the vehicle compartment may be calculated based on the time when the temperature T of the window glass in the vehicle compartment is equal to or greater than the temperature T of the window glass in the vehicle compartment. In this case, the temperature Ta of the window glass in the vehicle compartment is calculated by the following formula (2).

[0043]

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[0044] In equation (2), Tc is the temperature of the air inside the vehicle cabin [℃], To is the temperature of the air outside the vehicle [℃], and Hci is the heat transfer coefficient of the window glass on the vehicle cabin side [W / m 2 K], and Kg is the heat transfer coefficient of the window glass [W / m 2 K].

[0045] In formulas (1) and (2), Tc can be measured by a thermometer placed in the vehicle cabin. This thermometer is generally installed in the vehicle cabin, so there is no need to install a separate thermometer. In other words, the value of the air temperature in the vehicle cabin measured by this generally installed thermometer can be used as Tc.

[0046] In formulas (1) and (2), To can be measured by a thermometer placed outside the vehicle. This thermometer is generally installed outside the vehicle, so there is no need to install a separate thermometer. In other words, the value of the temperature of the air outside the vehicle measured by this generally installed thermometer can be used as To.

[0047] In formula (1), Hco can be calculated by the following formula (3) when the vehicle speed is 5 m / sec or more, and by the following formula (4) when the vehicle speed is less than 5 m / sec. Hco=7.1×U A 0.78 (3) Hco=5.57+3.94U A (4) In formulas (3) and (4), U A is the vehicle speed [m / sec]. The vehicle speed can be measured using a speedometer that is generally installed in the vehicle.

[0048] In formulas (1) and (2), Hci can be calculated by the following formula (5) when the air flow velocity on the passenger compartment side of the window glass is 5 m / s or more, and by the following formula (6) when the air flow velocity on the passenger compartment side of the window glass is less than 5 m / s. Hci=7.1×U B 0.78 (5) Hci=5.57+3.94U B (6) In the formula, U B is the air flow velocity on the passenger compartment side of the window glass [m / s]. The air flow velocity on the passenger compartment side of the window glass is the flow rate of air blown into the passenger compartment side of the window glass [m 3 / sec] is the cross-sectional area of ​​the window glass on the passenger compartment side [m 2 ] can be calculated by dividing it by

[0049] The dew point temperature Tb in the vehicle interior can be calculated by the following formula (7).

[0050]

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[0051] In formula (7), Wa is the moisture absorption amount [g / sec] of the humidity control device 10, and Q is the flow rate [m 3 / sec], and AHi is the absolute humidity [g / m 3 ] and Tc is the air temperature inside the vehicle cabin [℃].

[0052] AHi in formula (7) may be a fixed value that is determined in advance under the most severe conditions under which fogging of the window glass is likely to occur. Specifically, since fogging of the window glass is likely to occur under conditions of high humidity inside the vehicle cabin, it is assumed that the absolute humidity of the air flowing into the humidity control device 10 is 10 [g / m 3 In this case, the dew-point temperature Tb in the vehicle interior is calculated by the following formula (8).

[0053]

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[0054] In formula (8), Wa is the moisture absorption amount [g / sec] of the humidity control device 10, and Q is the flow rate [m 3 / sec], and Tc is the air temperature inside the vehicle cabin [℃].

[0055] In formulas (7) and (8), Wa may be calculated from the humidity difference by measuring the humidity with hygrometers disposed upstream and downstream of the humidity control device 10, but it is preferable to calculate Wa based on a relationship between the flow rate and inflow time of air flowing into the humidity control device 10, which is determined in advance. That is, it is preferable to determine in advance the relationship between the flow rate and inflow time of air flowing into the humidity control device 10 and Wa when the adsorption mode is being performed, and to calculate Wa from the flow rate and inflow time of air flowing into the humidity control device 10 based on the relationship. Calculating Wa in this way eliminates the need to place hygrometers upstream and downstream of the humidity control device 10, which leads to simplification of the vehicle air conditioning system.

[0056] In formula (7), AHi can be measured by a hygrometer arranged in the air conditioning duct 20 on the upstream side of the humidity control device 10. The hygrometer is connected to the control unit 50. The hygrometer is not particularly limited, and a commercially available one can be used.

[0057] In formulas (7) and (8), Tc can be measured by a thermometer placed in the vehicle cabin. This thermometer is generally provided in the vehicle cabin, so there is no need to provide a separate thermometer. In other words, the value of the air temperature in the vehicle cabin measured by this generally provided thermometer can be used as Tc.

[0058] FIG. 2 shows a graph illustrating an example of a method for controlling the temperature Ta of the window glass in the vehicle compartment to be higher than the dew point temperature Tb in the vehicle compartment when the adsorption mode is executed. As shown in FIG. 2, when the adsorption mode is executed with the flow rate Q of air flowing into the humidity control device 10 constant, the humidity in the vehicle cabin increases due to the influence of an increase in the number of passengers, rain or snow brought in from outside the vehicle, etc., and the dehumidification by the humidity control device 10 becomes insufficient, and the humidity in the vehicle cabin increases, and the dew point temperature Tb in the vehicle cabin approaches the temperature Ta of the window glass in the vehicle cabin (time 0 to P1). When the dew point temperature Tb in the vehicle cabin exceeds the temperature Ta of the window glass in the vehicle cabin, the window glass is likely to fog up. Therefore, the flow rate Q of the air flowing into the humidity control device 10 is increased to increase the moisture absorption amount Wa of the humidity control device 10. As a result, the moisture content of the air in the vehicle cabin decreases, and the dew point temperature Tb in the vehicle cabin can be reduced (after time P1). At this time, the temperature Ta of the window glass in the vehicle cabin also decreases slightly, but the rate of decrease is smaller than the rate of decrease of the dew point temperature Tb in the vehicle cabin. Therefore, by controlling the flow rate Q of the air flowing into the humidity control device 10 as described above, the dew point temperature Tb in the vehicle compartment can be maintained lower than the temperature Ta of the window glass in the vehicle compartment.

[0059] As described above, the flow rate Q of air flowing into the humidity control device 10 affects the temperature Ta of the window glass in the vehicle cabin and the dew point temperature Tb in the vehicle cabin when the adsorption mode is being executed. Specifically, when the flow rate Q of air flowing into the humidity control device 10 increases, the temperature Ta of the window glass in the vehicle cabin and the dew point temperature Tb in the vehicle cabin decrease when the adsorption mode is being executed. In particular, when the flow rate Q of air flowing into the humidity control device 10 increases, the dew point temperature Tb in the vehicle cabin decreases more significantly than the temperature Ta of the window glass in the vehicle cabin. Therefore, by controlling the flow rate Q of air flowing into the humidity control device 10, the temperature Ta of the window glass in the vehicle cabin can be controlled to be higher than the dew point temperature Tb in the vehicle cabin. The flow rate Q of the air flowing into the humidity control device 10 is not particularly limited and may be adjusted according to the type of humidity control device 10 used. 3 / sec] or more, and 0.0050 [m 3 / sec] or more is more preferable.

[0060] Each component of the vehicle air conditioning system will now be described in detail.

[0061] (1. Humidity Control Device 10) The humidity control device 10 is not particularly limited as long as it is capable of adsorbing and desorbing moisture, but it is preferable that the humidity control device 10 has an adsorption section containing an adsorbent capable of adsorbing moisture at or below a predetermined temperature and desorbing the adsorbed moisture when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption section. A humidity control device 10 having such characteristics can easily achieve adsorption and desorption of moisture. Furthermore, the number of humidity control devices 10 arranged in the air conditioning duct 20 may be one or more. When a plurality of humidity control devices 10 are provided, they may be arranged in parallel or in series with respect to the flow of air circulating in the air conditioning duct 20.

[0062] Fig. 3A is a schematic diagram of a cross section parallel to the flow path direction of a typical humidity control device used in a vehicle air conditioning system according to an embodiment of the present invention, and Fig. 3B is a schematic diagram of a cross section taken along line a-a' in the humidity control device of Fig. 3A. 3A and 3B includes a honeycomb structure 11 having an outer peripheral wall 12, partition walls 15 disposed inside the outer peripheral wall 12 and defining a plurality of cells 14 that serve as air passages extending from a first end face 13a to a second end face 13b, an adsorption layer 16 containing an adsorbent provided on the surface of the partition wall 15, and a pair of electrodes 17a, 17b provided on the first end face 13a and the second end face 13b of the honeycomb structure 11. Although not shown, the pair of electrodes 17a, 17b may be provided on the outer peripheral wall 12 parallel to the direction in which the cells 14 of the honeycomb structure 11 extend. Terminals 18 can be connected to the pair of electrodes 17a, 17b.

[0063] (1-1. Honeycomb structure 11) The shape of the honeycomb structure 11 is not particularly limited. For example, the outer shape of a cross section perpendicular to the flow path direction (the direction in which the cells 14 extend) of the honeycomb structure 11 can be a polygon such as a quadrangle (rectangle, square), pentagon, hexagon, heptagon, or octagon, a circle, or an oval shape (egg, ellipse, oval, rounded rectangle, etc.). The end faces (first end face 13a and second end face 13b) have the same shape as the cross section. When the cross section and the end faces are polygonal, the corners may be chamfered.

[0064] The shape of the cells 14 is not particularly limited, but may be a polygon such as a square, pentagon, hexagon, heptagon, or octagon, a circle, or an oval in a cross section perpendicular to the flow path direction of the honeycomb structure 11. These shapes may be used alone or in combination of two or more. Among these shapes, a square or hexagon is preferable. By providing cells 14 of such a shape, the pressure loss during air flow can be reduced.

[0065] The honeycomb structure 11 may be a honeycomb bonded body having a plurality of honeycomb segments and a bonding layer bonding the peripheral side surfaces of the plurality of honeycomb segments together. By using the honeycomb bonded body, it is possible to increase the total cross-sectional area of ​​the cells 14, which is important for ensuring the air flow rate (flow velocity), while suppressing the occurrence of cracks. The bonding layer can be formed using a bonding material. The bonding material is not particularly limited, but a paste made by adding a solvent such as water to a ceramic raw material can be used. The bonding material may contain a material having a PTC characteristic, or may contain the same material as the outer peripheral wall 12 and the partition wall 15. 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 bonding the honeycomb segments.

[0066] From the standpoints of ensuring the strength of the honeycomb structure 11, reducing the pressure loss when air passes through the cells 14, ensuring the amount of adsorbent carried, and ensuring the contact area with the air flowing within the cells 14, it is desirable to suitably combine the thickness of the partition walls 15, the cell density, and the cell pitch (or the opening ratio of the cells 14). In this specification, cell density is a value obtained by dividing the number of cells by the area of ​​one end face (first end face 13a or second end face 13b) of the honeycomb structure 11 (the total area of ​​the partition walls 15 and cells 14 excluding the outer wall 12). 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 13a or second end face 13b) of the honeycomb structure 11 (the total area of ​​the partition walls 15 and the cells 14 excluding the outer peripheral wall 12) by the number of cells. Next, the square root of the area per cell is calculated, and this is defined as the cell pitch. In this specification, the opening ratio of the cells 14 is a value obtained by dividing the total area of ​​the cells 14 partitioned by the partition walls 15 in a cross section perpendicular to the flow direction of the honeycomb structure 11 by the area of ​​one end face (the first end face 13a or the second end face 13b) (the total area of ​​the partition walls 15 and the cells 14 excluding the outer peripheral wall 12). Note that the pair of electrodes 17a, 17b and the adsorption layer 16 are not taken into consideration when calculating the opening ratio of the cells 14.

[0067] In an embodiment advantageous from the viewpoint of carrying a sufficient amount of functional material, the thickness of the partition wall 15 is 0.300 mm or less, and the cell density is 100 cells / cm 2 In a preferred embodiment, the thickness of the partition wall 15 is 0.200 mm or less, and the cell density is 70 cells / cm. 2 In a more preferred embodiment, the thickness of the partition wall 15 is 0.130 mm or less, and the cell density is 65 cells / cm. 2 and the cell pitch is 1.3 mm or more.

[0068] From the viewpoint of ensuring the strength of the honeycomb structure 11 and keeping the electrical resistance low, the lower limit of the thickness of the partition walls 15 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and further preferably 0.030 mm or more. From the viewpoints of ensuring the strength of the honeycomb structure 11, keeping the electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is 30 cells / cm. 2 Preferably, 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 viewpoints of ensuring the strength of the honeycomb structure 11, maintaining low electrical resistance, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and even more preferably 1.6 mm or less.

[0069] In an embodiment that is advantageous from the viewpoint of achieving both a reduction in pressure loss and a maintenance of strength, the thickness of the partition wall 15 is 0.08 to 0.36 mm, and the cell density is 2.54 to 140 cells / cm. 2 In a preferred embodiment, the thickness of the partition walls 15 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 15 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm. 2 , the aperture ratio of the cell 14 is 0.85 or more.

[0070] From the viewpoint of ensuring the strength of the honeycomb structure 11, the upper limit of the opening ratio of the cells 14 is preferably 0.94 or less, more preferably 0.92 or less, and further preferably 0.90 or less.

[0071] The thickness of the peripheral wall 12 is not particularly limited, but is preferably determined based on the following viewpoints. First, from the viewpoint of reinforcing the honeycomb structure 11, the thickness of the peripheral wall 12 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and even more preferably 0.08 mm or more. On the other hand, from the viewpoint of increasing the electrical resistance to suppress the initial current, and from the viewpoint of reducing the pressure loss during air circulation, the thickness of the peripheral wall 12 is preferably 1.0 mm or less, more preferably 0.5 mm or less, even more preferably 0.4 mm or less, and even more preferably 0.3 mm or less. In this specification, the thickness of the peripheral wall 12 refers to the length in the normal direction of the side surface of the honeycomb structure 11 from the boundary between the peripheral wall 12 and the most peripheral cell 14 or partition wall 15 to the side surface of the honeycomb structure 11 in a cross section perpendicular to the flow direction of the honeycomb structure 11.

[0072] The length of the honeycomb structure 11 in the flow path direction and the cross-sectional area perpendicular to the flow path direction are not particularly limited and may be adjusted according to the required size of the humidity control device 10. For example, when used in a compact humidity control device 10 while ensuring a predetermined function, the honeycomb structure 11 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.

[0073] The partition walls 15 constituting the honeycomb structure 11 are made of a material capable of generating heat when electricity is applied thereto, and specifically, are preferably made of a material having a PTC characteristic. If necessary, the outer peripheral wall 12 may also be made of a material having a PTC characteristic like the partition walls 15. With this configuration, it is possible to directly heat the adsorption layer 16 by heat transfer from the partition walls 15 (and the outer peripheral wall 12, if necessary). In addition, a material having a PTC characteristic has a characteristic that, when the temperature rises and exceeds the Curie point, the resistance value rises rapidly and electricity becomes difficult to flow. Therefore, when the partition walls 15 (and the outer peripheral wall 12, if necessary) become hot, the current flowing through them is limited, and excessive heat generation of the honeycomb structure 11 is suppressed. Therefore, it is also possible to suppress thermal deterioration of the adsorption layer 16 caused by excessive heat generation.

[0074] From the viewpoint of obtaining an appropriate heat generation, the lower limit of the volume resistivity of the material having the PTC characteristics at 25°C 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 of the material having the PTC characteristics at 25°C 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 of the material having the PTC characteristics at 25°C is measured in accordance with JIS K6271:2008.

[0075] From the viewpoint of being able to generate heat when electricity is applied and having PTC characteristics, the outer peripheral wall 12 and the partition wall 15 are preferably made of a material mainly composed of barium titanate (BaTiO3). This material is more preferably a ceramic made of a material mainly composed of barium titanate (BaTiO3)-based crystal particles in which part of Ba is replaced with a rare earth element. In this specification, the term "main component" means 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 in the same manner.

[0076] 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 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 suppressing 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 suppressing the electrical resistance at room temperature from becoming too high due to insufficient sintering. The content of BaTiO3-based crystal particles in the ceramics, in which a part of Ba is replaced by a rare earth element, is not particularly limited as long as it is the 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%.

[0077] From the viewpoint of reducing the environmental load, it is desirable that the material used for the outer peripheral wall 12 and the partition wall 15 does not substantially contain lead (Pb). Specifically, the Pb content of the outer peripheral wall 12 and the partition wall 15 is preferably 0.01 mass% or less, more preferably 0.001 mass% or less, and even more preferably 0 mass%. With a low Pb content, for example, air heated by contacting the partition wall 15 during heat generation can be safely applied to living organisms such as humans. In addition, the Pb content of the outer peripheral wall 12 and the partition wall 15 is preferably less than 0.03 mass%, more preferably less than 0.01 mass%, and even more preferably 0 mass%, calculated as PbO. The lead content can be determined by ICP-MS (inductively coupled plasma mass spectrometry).

[0078] The Curie points of the materials constituting the outer peripheral wall 12 and the partition walls 15 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 such a temperature range, the current flowing through them is limited when the humidity control device 10 becomes hot, so that excessive heat generation in the humidity control device 10 is efficiently suppressed. Therefore, the thermal deterioration of the adsorption layer 16 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the material constituting the outer peripheral wall 12 and the partition wall 15 is preferably 80° C. or higher, more preferably 100° C. or higher, even more preferably 110° C. or higher, and particularly preferably 125° C. or higher, from the viewpoint of efficient heating of the adsorption layer 16. Meanwhile, 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 the vehicle interior or in the vicinity of the vehicle interior.

[0079] The Curie point of the material constituting the outer peripheral wall 12 and the partition walls 15 can be adjusted by the type and amount of the shifter added. For example, the Curie point of barium titanate (BaTiO3) is about 120°C, but by substituting a part of Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to the lower temperature side.

[0080] In this specification, the Curie point is measured by the following method. A sample is attached to a sample holder for measurement and placed in a measurement tank (e.g., MINI-SUBZERO MC-810P, manufactured by Espec Corporation). The change in electrical resistance of the sample relative to the temperature change when the temperature is raised from 10°C is measured using a DC resistance meter (e.g., multimeter 3478A, manufactured by Hewlett-Packard Japan, LLC). The temperature at which the resistance value is twice the resistance value at room temperature (25°C) based on the electrical resistance-temperature plot obtained by the measurement is taken as the Curie point.

[0081] (1-2.Adsorption layer 16) Adsorbent bed 16 is a bed containing an adsorbent. The adsorption layer 16 can be provided on the surface of the partition wall 15 (in the case of the outermost cell 14, the partition wall 15 and the outer peripheral wall 12 that define the outermost cell 14). By providing the adsorption layer 16 in this manner, moisture can be easily adsorbed in the adsorption mode, and the adsorption layer 16 can be easily heated in the regeneration mode, making it easier to desorb moisture from the adsorption layer 16.

[0082] The adsorbent contained in the adsorption layer 16 is capable of adsorbing and desorbing moisture. In addition, the adsorbent is preferably capable of adsorbing and desorbing carbon dioxide and / or volatile components in addition to moisture. By using such an adsorbent, the humidity control device 10 can obtain not only a moisture absorption effect but also a purification effect.

[0083] The adsorbent contained in the adsorption layer 16 preferably has a function capable of adsorbing moisture and the like at -20 to 60°C and desorbing moisture and the like at a temperature exceeding 60°C. Examples of the adsorbent include, but are not limited to, aluminosilicate, silica gel, silica, graphene oxide, polymer adsorbent, polystyrene sulfonic acid, zeolite, activated carbon, alumina, low crystalline clay, amorphous aluminum silicate complex, and metal organic framework (MOF). These may be used alone or in combination of two or more.

[0084] As the aluminosilicate, it is preferable to use a porous clay mineral such as AFI-type, CHA-type or BEA-type zeolite, allophane, imogolite, etc. In addition, it is preferable that the aluminosilicate is amorphous.

[0085] 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, for example, 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).

[0086] The volatile components contained in the air in the vehicle cabin include, for example, volatile organic compounds (VOCs) and odor components other than VOCs. Specific examples of the 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.

[0087] The adsorption layer 16 may further contain a catalyst. By containing a catalyst, it is possible to promote oxidation-reduction reactions and the like, and purify carbon dioxide and / or volatile components. Examples of catalysts having such functions include metal catalysts such as Pt, Pd, and Ag, and oxide catalysts such as CeO2 and ZrO2. One type of catalyst may be used alone, or two or more types may be used in combination. The catalyst may also be used in combination with the above-mentioned functional materials.

[0088] The thickness of the adsorption layer 16 is not particularly limited and may be determined depending on the size of the cells 14. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the adsorption layer 16 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. On the other hand, from the viewpoint of preventing the adsorption layer 16 from peeling off from the partition walls 15 and the outer peripheral wall 12, the thickness of the adsorption layer 16 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.

[0089] The thickness of the adsorption layer 16 is measured by the following procedure. An arbitrary cross section parallel to the flow path direction of the honeycomb structure 11 is cut out, and a cross-sectional image of about 50 times is obtained using a scanning electron microscope or the like. This cross section is also set to pass through the center of gravity of the cross section perpendicular to the flow path direction of the honeycomb structure 11. For each adsorption layer 16 visible from the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 14 in the flow path direction. This calculation is performed for all adsorption layers 16 visible from the cross-sectional image, and the overall average value is regarded as the thickness of the adsorption layer 16.

[0090] From the viewpoint of exhibiting a desired function in the humidity control device 10, the amount of the adsorption layer 16 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and even more preferably 150 to 350 g / L, relative to the volume of the honeycomb structure 11. The volume of the honeycomb structure 11 is a value determined by the outer dimensions of the honeycomb structure 11.

[0091] (1-3. Pair of electrodes 17a, 17b) The positions of the pair of electrodes 17a, 17b are not particularly limited, but as shown in Fig. 3A, they can be provided on the first end face 13a and the second end face 13b of the honeycomb structure 11. In addition, the pair of electrodes 17a, 17b may be provided on the outer peripheral wall 12 parallel to the extension direction of the cells 14 of the honeycomb structure 11. By applying a voltage between the pair of electrodes 17a and 17b, it becomes possible to cause the honeycomb structure 11 to generate heat by Joule heat.

[0092] The pair of electrodes 17a, 17b is not particularly limited, and may be, for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si. An ohmic electrode capable of making ohmic contact with the outer peripheral wall 12 and / or the partition wall 15 having PTC characteristics may also be used. The ohmic electrode may be, for example, an ohmic electrode containing 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 for n-type semiconductors as a dopant. The pair of electrodes 17a, 17b may have a single-layer structure or a laminated structure of two or more layers. When the pair of electrodes 17a, 17b has a laminated structure of two or more layers, the materials of the layers may be the same or different.

[0093] The thickness of the pair of electrodes 17a, 17b can be appropriately set depending on the method for forming the pair of electrodes 17a, 17b. Examples of the method for forming the pair of electrodes 17a, 17b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. The pair of electrodes 17a, 17b can also be formed by applying an electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 17a, 17b may be formed by joining metal or alloy plates.

[0094] The thickness of the pair of electrodes 17a, 17b 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. In addition, in joining metal or alloy plates, the thickness is preferably about 5 to 100 μm.

[0095] (1-4. Terminal 18) The terminal 18 is connected to the pair of electrodes 17a, 17b and is provided on at least a part of the pair of electrodes 17a, 17b. The provision of the terminal 18 facilitates connection to an external power source. The terminal 18 is connected to a conductor connected to the external power source.

[0096] The material of the terminal 18 is not particularly limited, and may be, for example, a metal. As the metal, a simple metal or an alloy may be adopted, 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, Fe-Ni alloy, and phosphor bronze are more preferable.

[0097] The size and shape of the terminal 18 are not particularly limited. For example, as shown in Fig. 3A, the terminal 18 can be provided on the entire pair of electrodes 17a, 17b on the outer peripheral wall 12. The terminal 18 may be provided on a part of the pair of electrodes 17a, 17b on the outer peripheral wall 12, or may be provided so as to extend outward beyond the outer edge of the pair of electrodes 17a, 17b on the outer peripheral wall 12. Furthermore, the terminal 18 may be provided on a part of the pair of electrodes 17a, 17b on the partition wall 15, or may be provided so as to cover some of the cells 14. The thickness of the terminal 18 is not particularly limited, but is, for example, 0.01 to 10 mm, and typically 0.05 to 5 mm.

[0098] The method of connecting the terminal 18 and the pair of electrodes 17a, 17b is not particularly limited as long as they are electrically connected, and they can be connected by, for example, diffusion bonding, a mechanical pressure mechanism, welding, or the like.

[0099] (1-5. Method for manufacturing the humidity control device 10) The method for producing the humidity control device 10 is not particularly limited and can be carried out in accordance with a known method. Hereinafter, an example of the method for producing the humidity control device 10 will be described. The method for manufacturing the honeycomb structure 11 constituting the humidity control device 10 includes a molding step and a firing step. In the forming step, a clay containing ceramic raw materials including BaCO3 powder, TiO2 powder, and powder of rare earth nitrate or hydroxide is formed to produce a honeycomb formed body having a relative density of 60% or more. The ceramic raw material can be obtained by dry mixing each powder so as 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 necessary. The blending amount of components other than the ceramic raw materials is not particularly limited as long as the blending amount is such that the relative density of the honeycomb formed body is 60% or more.

[0100] 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 ceramic raw material (g / cm 3 ) x 100 The density of the honeycomb molded 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 3 ) can be calculated by dividing it by

[0101] The dispersion medium may be water or a mixed solvent of water and an organic solvent such as alcohol, with water being particularly preferred.

[0102] Examples of the binder include organic binders such as methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. In particular, it is preferable to use methyl cellulose and hydroxypropoxyl cellulose in combination. The binder may be used alone or in combination of two or more kinds, but it is preferable that the binder does not contain an alkali metal element.

[0103] Examples of the plasticizer include polyoxyalkylene alkyl ethers, polycarboxylic acid polymers, and alkyl phosphate esters.

[0104] 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 kinds.

[0105] The honeycomb formed body can be produced by extruding a clay. In the extrusion molding, a die having a desired overall shape, cell shape, partition wall thickness, cell density, etc. can be used.

[0106] The relative density of the honeycomb molded body obtained by extrusion molding is 60% or more, preferably 65% ​​or more. By controlling the relative density of the honeycomb molded body within this range, it is possible to densify the honeycomb molded body and reduce the electrical resistance at room temperature. The upper limit of the relative density of the honeycomb molded body is not particularly limited, but is generally 80%, preferably 75%.

[0107] 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 quickly and uniformly dry the entire molded body.

[0108] The firing step involves holding the material at 1150-1250° C., then increasing the temperature to a maximum temperature of 1360-1430° C. at a rate of 20-600° C. / hour, and holding the temperature for 0.5-10 hours. By holding 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 11 containing as a main component BaTiO3-based crystal grains in which a portion of Ba has been substituted with a rare earth element. Moreover, by maintaining the temperature at 1150 to 1250° C., Ba2TiO4 crystal particles generated during the firing process are easily removed, so that the honeycomb structure 11 can be made dense. Furthermore, by setting the heating rate from 1150-1250°C to the maximum temperature of 1360-1430°C at 20-600°C / hour, 1.0-10.0 mass% of Ba6Ti 17 O 40 Crystal grains can be generated in the honeycomb structure 11 .

[0109] The holding time at 1150 to 1250° C. is not particularly limited, but is preferably 0.5 to 10 hours. By setting the holding time in this range, Ba2TiO4 crystal particles formed during the firing process can be stably and easily removed.

[0110] 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 11 having a predetermined composition.

[0111] 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 in order to completely decompose the organic components. Moreover, it is preferable that the firing step be performed in an air atmosphere from the viewpoints of controlling electrical characteristics and reducing manufacturing costs. The firing furnace used in the firing step and the degreasing step is not particularly limited, but an electric furnace, a gas furnace, or the like can be used.

[0112] A pair of electrodes 17a, 17b are formed on the honeycomb structure 11 thus obtained. The pair of electrodes 17a, 17b can be formed by a metal deposition method such as sputtering, vapor deposition, electrolytic deposition, or chemical deposition. The pair of electrodes 17a, 17b can also be formed by applying an electrode paste and then baking it. Furthermore, the pair of electrodes 17a, 17b can also be formed by thermal spraying. The pair of electrodes 17a, 17b may be formed of a single layer, but may also be formed of multiple electrode layers with different compositions. A representative method for forming the pair of electrodes 17a, 17b will be described below.

[0113] First, an electrode slurry containing an electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 13a or the second end face 13b of the honeycomb structure 11. The dispersion medium may be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Excess slurry on the outer periphery of the honeycomb structure 11 is removed by blowing and wiping. Thereafter, the slurry is dried to form a pair of electrodes 17a, 17b on the first end face 13a or the second end face 13b of the honeycomb structure 11. Drying may be performed while heating the honeycomb structure 11 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 the steps multiple times, a pair of electrodes 17a, 17b having a desired thickness can be provided.

[0114] Next, terminals 18 are placed at predetermined positions of the pair of electrodes 17a, 17b, and the pair of electrodes 17a, 17b are connected to terminals 18. The method for connecting the pair of electrodes 17a, 17b to terminals 18 can be the method described above. The terminals 18 may be disposed after the adsorption layer 16 described below is formed.

[0115] Next, an adsorption layer 16 is formed on the surfaces of the partition walls 15 and the like of the honeycomb structure 11 . The method for forming the adsorption layer 16 is not particularly limited, but for example, the adsorption layer 16 can be formed by the following process. The honeycomb structure 11 is immersed in a slurry containing an adsorbent, a binder, and a dispersion medium for a predetermined time, and excess slurry on the end face and outer periphery of the honeycomb structure 11 is removed by blowing and wiping. The binder may be an organic binder or an inorganic binder, or a combination thereof. The dispersion medium may be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Thereafter, the slurry is dried to form the adsorption layer 16 on the surface of the partition wall 15, etc. The drying can be performed while heating the honeycomb structure 11 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, an adsorption layer 16 of a desired thickness can be provided on the surface of the partition wall 15 or the like.

[0116] (1-6. Other humidity control devices 10) The humidity control device 10 includes an air flow path and a heating medium flow path adjacent to the air flow path, and an adsorption section may be provided in the air flow path. Examples of the humidity control device 10 having such a structure include a plate-fin type heat exchanger in which a plurality of fins are provided on a pipe, and an aerofin type heat exchanger in which an adsorption layer 16 is formed on the surface of the fin. In the humidity control device 10 having the above-mentioned structure, air flows between the fins, and a heating medium flows through the pipes. The flow of the heating medium heats the fins, and therefore the adsorption layer 16 provided on the surface of the fins can be heated. The humidity control device 10 having the above-mentioned structure can be manufactured by using a commercially available plate-fin type heat exchanger or aerofin type heat exchanger and forming the adsorption layer 16 on the fin surfaces. The method for forming the adsorption layer 16 may be the method described above.

[0117] The humidity control device 10 may include a honeycomb structure 11 having an outer peripheral wall 12 and partition walls 15 disposed inside the outer peripheral wall 12 and defining a plurality of cells 14 that serve as air passages extending from a first end face 13a to a second end face 13b, an adsorption layer 16 containing an adsorbent provided on the surface of the partition wall 15, and a heater provided upstream of the honeycomb structure 11. The structure of this humidity control device 10 corresponds to the structure in FIG. 3A from which the pair of electrodes 17a, 17b and the terminal 18 are removed. In the humidity control device 10 having the heating structure described above, the adsorption layer 16 provided on the surface of the partition wall 15 can be heated by circulating air heated by a heater through the cells 14 of the honeycomb structure 11.

[0118] The humidity control device 10 having the above-mentioned heating structure does not require the honeycomb structure 11 itself to generate heat by passing an electric current through it, and therefore can be formed from various materials such as metals and ceramics. However, the honeycomb structure 11 may be made of a material that can generate heat by passing an electric current through it. Moreover, the humidity control device 10 having the above-mentioned heating structure can be produced in accordance with the method described above or a known method.

[0119] (2. Air conditioning duct 20) The air conditioning duct 20 is a flow path through which air from the vehicle interior or outside the vehicle can flow. The upstream side of the air conditioning duct 20 is connected to the vehicle interior or an outside air inlet. The air conditioning duct 20 allows air to flow from the vehicle interior or outside the vehicle, and allows air that has passed through the humidity control device 10 to flow into the vehicle interior or to be discharged outside the vehicle. Therefore, the air conditioning duct 20 has a structure branched into a first flow path 20a that allows air to flow into the vehicle interior and a second flow path 20b that allows air to be discharged outside the vehicle on the downstream side of the humidity control device 10.

[0120] (3. Valve 30) The valve 30 can switch the flow of air between the first flow path 20a and the second flow path 20b. The valve 30 can be provided at a branch point of the air conditioning duct 20 between the first flow path 20a and the second flow path 20b. The valve 30 is not particularly limited as long as it is electrically driven and has the function of switching the air flow path, and a solenoid valve, an electric valve, or the like can be used. For example, the valve 30 can be a butterfly valve equipped with an opening / closing door supported on a rotating shaft and an actuator such as a motor that rotates the rotating shaft. The actuator can be configured to be controllable by the control unit 50. Also, a flap valve that controls opening and closing by a flap valve, or a slide valve that controls opening and closing by the movement of a sliding body (valve) may be used.

[0121] (4. Ventilator 40) The ventilator 40 is for introducing air from the vehicle compartment or outside the vehicle into the humidity control device 10, and is disposed in the air conditioning duct 20. The position of the ventilator 40 is not particularly limited, and may be, for example, upstream of the humidity control device 10 as shown in FIG. Moreover, the fan 40 is electrically connected to the control unit 50, and can control the air flow rate by adjusting the rotation speed according to instructions from the control unit 50.

[0122] (5.Power supply 60) The power supply 60 is for applying a voltage to the humidity control device 10 (particularly, the pair of electrodes 17a, 17b). The power supply 60 is electrically connected to the control unit 50, and adjusts the state of voltage application to the pair of electrodes 17a, 17b according to instructions from the control unit 50. The power source 60 is not particularly limited, and a battery or the like can be used.

[0123] (6. Control unit 50) The control unit 50 controls the humidity control device 10 and the valve 30. The control unit 50 can also control the fan 40. The control unit 50 is electrically connected to the humidity control device 10 and the fan 40 via a power source 60. The control unit 50 controls the power source 60 to control the state of voltage application to the pair of electrodes 17a, 17b of the humidity control device 10, and can adjust the heating state of the honeycomb structure 11. The control unit 50 can also control the valve 30 so that air flows through the first flow path 20a or the second flow path 20b. Furthermore, the control unit 50 can control the flow rate of air flowing through the air conditioning duct 20 by adjusting the rotation speed of the fan 40.

[0124] The control unit 50 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.

[0125] The control unit 50 can execute an adsorption mode in which the valve 30 is switched so that air flows into the first flow path 20a, and a regeneration mode in which the humidity control device 10 is heated and the valve 30 is switched so that air flows into the second flow path 20b. In the adsorption mode, moisture in the air flowing from the vehicle interior or outside is adsorbed, and the air from which the moisture has been reduced or removed is returned to the vehicle interior through the first flow path 20a. In the regeneration mode, moisture adsorbed in the adsorption layer 16 is desorbed, and the air is discharged outside the vehicle through the second flow path 20b.

[0126] From the viewpoint of stably performing the above control, it is desirable to place the humidity control device 10 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 10 is 60 V or less. Since the honeycomb structure 11 used in the humidity control device 10 has low electrical resistance at room temperature, it is possible to heat the honeycomb structure 11 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 the honeycomb structure 11 is heated will be large, and therefore it is necessary to use thicker conductors. EXAMPLES

[0127] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0128] <Preparation 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 specified 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. Polyoxyalkylene alkyl ether was used as the plasticizer and dispersant.

[0129] 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: Rectangular Shape of cell cross section perpendicular to flow direction: Square Partition thickness: 0.100mm Outer wall thickness: 0.2mm Cell density: 80 cells / cm 2 Cell pitch: 1.1mm Cross-sectional area perpendicular to the direction of extension of the flow passage of the honeycomb structure: 12000 mm 2 Length of the honeycomb structure in the direction of flow: 10 mm Volume resistivity of the material that composes the outer wall and partition at 25°C: 15 Ω cm Curie point of the material constituting the outer wall and partition wall: 110°C

[0130] 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.

[0131] 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, and then the electrode slurry was dried to form an electrode on the surface of the first end face. In addition, the same electrode slurry was used to apply the electrode slurry to the second end face and dry it to form an electrode on the second end face.

[0132] Next, the honeycomb structure with the pair of electrodes formed thereon was immersed in a slurry containing zeolite (adsorbent), an organic binder and water, and any slurry adhering to excess areas (such as the outer periphery) was removed by blowing and wiping. The structure was then dried at a temperature of approximately 550°C to form an adsorption layer 150 μm thick on the surface of the partition wall and the surface of the outer wall facing the cells.

[0133] The humidity control device obtained as described above was placed in an air conditioning duct to construct an air conditioning system as shown in FIG. In this air conditioning system, the occurrence of fogging on the vehicle interior window glass was visually evaluated assuming an environment in which fogging is likely to occur when the air temperature inside the vehicle cabin is 20°C and the air temperature outside the vehicle is 0°C. First, the temperature of the air inside the vehicle, Tc, is set to 20[℃], the temperature of the air outside the vehicle, To, is set to 0[℃], and the heat transfer coefficient of the window glass on the vehicle interior side, Hci, is set to 6[W / m 2 K], and the heat transfer coefficient Hco of the outside of the window glass is 43.3 [W / m 2 K], and the heat transfer coefficient of the window glass is 200 [W / m 2 The temperature Ta of the window glass inside the vehicle cabin was calculated using equation (1) as 2.9 [°C]. Next, the flow rate of air flowing into the humidity control device Q [m 3 The dew point temperature Tb inside the vehicle cabin was calculated using formula (7) while changing the air flow rate (A / sec) as shown in Table 1. The moisture absorption amount Wa of the humidity control device was calculated from the air flow rate and inflow time of the air flowing into the humidity control device based on a relationship between the flow rate and inflow time of the air flowing into the humidity control device when the adsorption mode is being executed and Wa, which was previously obtained. The inflow time of the air flowing into the humidity control device was set to 30 [seconds]. The absolute humidity AHi of the air flowing into the humidity control device was set to 7.1 [g / m 3 ], and the air temperature Tc inside the vehicle was set to 20[℃]. The above evaluation results are shown in Table 1. The evaluation results for window glass fogging were expressed as follows: no fogging at all, indicated by ⊚; slight fogging but not to a degree that caused any problems, indicated by ◯; and significant fogging, indicated by x.

[0134] [Table 1]

[0135] As shown in Table 1, when the air flow rate was controlled so that the temperature Ta of the window glass in the vehicle cabin was higher than the dew point temperature Tb in the vehicle cabin, the occurrence of fogging on the window glass could be suppressed.3 By setting the air flow rate at 0.0050 [m / sec] or more, the occurrence of fogging on the window glass can be suppressed. 3 / sec] or more, the occurrence of fogging on the window glass could be stably suppressed.

[0136] As can be seen from the above results, the present invention can provide a vehicle air conditioning system that is capable of suppressing fogging of the window glass inside the vehicle compartment even if the humidity inside the vehicle compartment rises suddenly. [Explanation of symbols]

[0137] 10 Humidity Control Device 11 Honeycomb structure 12 Peripheral wall 13a First end surface 13b Second end surface 14 Cells 15 Bulkhead 16 Adsorption layer 17a, 17b Pair of electrodes 18 Terminals 20 Air conditioning duct 20a First flow path 20b Second flow path 30 Valve 40 Ventilator 50 Control section 60 power supply

Claims

1. A humidity control device capable of adsorbing and desorbing moisture; an air conditioning duct in which the humidity control device is disposed and through which air from a vehicle compartment or outside the vehicle can flow, the air conditioning duct having a first flow path downstream of the humidity control device for introducing the air into the vehicle compartment and a second flow path for discharging the air to the outside of the vehicle; a valve capable of switching the flow of the air between the first flow path and the second flow path; a fan capable of adjusting a flow rate of the air flowing through the air conditioning duct; a control unit capable of controlling the humidity control device, the valve, and the ventilator; Equipped with the control unit controls the ventilator to adjust a flow rate of the air so that a temperature Ta of a window glass in the vehicle interior is higher than a dew point temperature Tb in the vehicle interior when an adsorption mode is executed in which the valve is switched so that the air flows into the first flow path and the humidity control device adsorbs the moisture, The dew point temperature Tb in the vehicle compartment is calculated by the following equation (7). [0010] In the formula, Wa is the moisture absorption amount of the humidity control device [g / sec], Q is the flow rate of the air flowing into the humidity control device [m3 / sec], AHi is the absolute humidity of the air flowing into the humidity control device [g / m3], and Tc is the temperature of the air in the vehicle cabin [°C].

2. A humidity control device capable of adsorbing and desorbing moisture; an air conditioning duct in which the humidity control device is disposed and through which air from a vehicle compartment or outside the vehicle can flow, the air conditioning duct having a first flow path downstream of the humidity control device for introducing the air into the vehicle compartment and a second flow path for discharging the air to the outside of the vehicle; a valve capable of switching the flow of the air between the first flow path and the second flow path; a fan capable of adjusting a flow rate of the air flowing through the air conditioning duct; a control unit capable of controlling the humidity control device, the valve, and the ventilator; Equipped with the control unit controls the ventilator to adjust a flow rate of the air so that a temperature Ta of a window glass in the vehicle interior is higher than a dew point temperature Tb in the vehicle interior when an adsorption mode is executed in which the valve is switched so that the air flows into the first flow path and the humidity control device adsorbs the moisture, The dew point temperature Tb in the vehicle compartment is calculated by the following equation (8). [0025] In the formula, Wa is the moisture absorption amount of the humidity control device [g / sec], Q is the flow rate of the air flowing into the humidity control device [m 3 / sec], and Tc is the temperature of the air in the vehicle cabin [°C].

3. The vehicle air conditioning system according to claim 1 , wherein the control unit further controls a time period during which the adsorption mode is performed.

4. 3. The vehicle air conditioning system according to claim 1, further comprising a thermometer for measuring a temperature Ta of a window glass in the vehicle compartment, and a dew point meter for measuring a dew point temperature Tb in the vehicle compartment.

5. 3. The vehicle air conditioning system according to claim 1, wherein the temperature Ta of the window glass in the vehicle compartment is calculated by the following formula (1): Ta=Ta+Ta+Ta / Ta+ ... [0030] In the formula, Tc is the temperature of the air inside the vehicle compartment [°C], To is the temperature of the air outside the vehicle [°C], and Hci is the heat transfer coefficient of the window glass on the vehicle compartment side [W / m 2 K], and Hco is the heat transfer coefficient of the window glass on the outside of the vehicle [W / m 2 K], and Kg is the overall heat transfer coefficient of the window glass [W / m 2 K].

6. 3. The vehicle air conditioning system according to claim 1, wherein the temperature Ta of the window glass in the vehicle compartment is calculated by the following formula (2): [0045] In the formula, Tc is the temperature of the air inside the vehicle compartment [°C], To is the temperature of the air outside the vehicle [°C], and Hci is the heat transfer coefficient of the window glass on the vehicle compartment side [W / m 2 K], and Kg is the overall heat transfer coefficient of the window glass [W / m 2 K].

7. The vehicle air conditioning system according to claim 5 , wherein the temperature Tc is measured by a thermometer disposed in the passenger compartment.

8. 6. The vehicle air conditioning system according to claim 5, wherein the temperature To is measured by a thermometer disposed outside the vehicle.

9. 6. The vehicle air conditioning system according to claim 5, wherein Hco is calculated by the following formula (3) when the vehicle speed is 5 m / sec or more, and by the following formula (4) when the vehicle speed is less than 5 m / sec. Hco=7.1×U A 0.78 ・・・(3) Hco=5.57+3.94U A ・・・(4) In the formula, U A is the vehicle speed [m / sec].

10. 6. The vehicle air conditioning system according to claim 5, wherein Hci is calculated by the following formula (5) when the flow velocity of the air on the passenger compartment side of the window glass is 5 m / s or more, and by the following formula (6) when the flow velocity of the air on the passenger compartment side of the window glass is less than 5 m / s. Hci=7.1×U B 0.78 ・・・(5) Hci=5.57+3.94U B ・・・(6) In the formula, U B is the flow velocity of the air on the passenger compartment side of the window glass [m / sec].

11. 3. The vehicle air conditioning system according to claim 1, wherein the Wa is calculated based on a relationship between a flow rate of the air flowing into the humidity control device and an inflow time, the relationship being determined in advance.

12. 2. The vehicle air conditioning system according to claim 1, wherein the AHi is measured by a hygrometer disposed in the air conditioning duct upstream of the humidity control device.

13. 3. The vehicle air conditioning system according to claim 1, wherein the humidity control device has an adsorption section containing an adsorbent capable of adsorbing the moisture at or below a predetermined temperature and desorbing the adsorbed moisture when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption section.

14. The humidity control device 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 passages extending from a first end face to a second end face; an adsorption layer containing the adsorbent provided on the surface of the partition; and A pair of electrodes provided on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall parallel to the extending direction of the cells of the honeycomb structure. The vehicle air conditioning system of claim 13, comprising:

15. 15. The vehicle air conditioning system according to claim 14, wherein at least the partition walls of the honeycomb structure are made of a material having a PTC characteristic.

16. The vehicle air conditioning system according to claim 13, wherein the humidity control device includes a flow path for the air and a flow path for the heating medium adjacent to the flow path for the air, and the adsorption portion is provided in the flow path for the air.

17. The humidity control device 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 passages extending from a first end face to a second end face; an adsorption layer containing the adsorbent provided on the surface of the partition; and A heater provided on the upstream side of the honeycomb structure The vehicle air conditioning system of claim 13, comprising:

18. The vehicle air conditioning system according to claim 13, wherein the adsorbent is capable of adsorbing and desorbing carbon dioxide and / or a volatile component in addition to the moisture.

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