Vehicle air conditioning system

Abstract

To provide a vehicle air conditioning system that can suppress fogging of the vehicle's windows even when the humidity inside the vehicle rises rapidly. [Solution] A vehicle air conditioning system 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 placed and through which air from the vehicle interior or outside the vehicle can flow, the air conditioning duct 20 having a first flow path 20a for bringing air into the vehicle interior and a second flow path 20b for discharging air outside the vehicle downstream of the humidity control device 10; a valve 30 capable of switching the airflow between the first flow path 20a and the second flow path 20b; a ventilator 40 capable of adjusting the flow rate of air circulating through the air conditioning duct 20; and a control unit 50 capable of controlling the humidity control device 10, the valve 30 and the ventilator 40.

Description

[Technical Field]

[0001] This invention relates to an air conditioning system for vehicles. [Background technology]

[0002] There is a growing demand for improved cabin environments in various vehicles, including automobiles. Specific requirements include reducing CO2 in the cabin to suppress driver drowsiness, humidifying the cabin, and removing harmful volatile components such as odor and allergy-inducing substances. While ventilation is an effective measure to meet these demands, it significantly reduces heater energy in winter, leading to decreased energy efficiency. This is particularly problematic for electric vehicles (BEVs), as this energy loss drastically reduces their driving range.

[0003] As a method to solve the above problems, a cabin air conditioning system has been proposed, comprising: a honeycomb structure having an outer wall and partition walls disposed inside the outer wall that partition a plurality of cells forming a flow path extending from one end face to the other, wherein at least the partition walls are made of a material having PTC properties; a pair of electrodes consisting of a first electrode provided on one end face and a second electrode provided on the other end face; and a functional material-containing layer provided on the surface of the partition wall; an inlet pipe connecting the cabin and the 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 and the cabin, wherein the outlet pipe has a first path connecting the outlet end face of the heater element and the cabin and a second path (second flow path) connecting the outlet end face of the heater element and the outside of the vehicle, and a switching valve is provided that can switch the airflow through the outlet pipe between the first path and the second path. [Prior art documents] [Patent Documents]

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the adsorption mode (a process of adsorbing moisture, etc. in the functional material-containing layer) of the humidity control device in the vehicle air conditioning system described in Patent Document 1 is executed, the humidity inside the vehicle may rapidly increase due to factors such as an increase in the number of passengers, rain or snow brought in from outside the vehicle. When the outside air temperature is low under such circumstances, the window glass inside the vehicle is likely to become cloudy.

[0006] The present invention has been made to solve the above problems, and an object thereof is to provide a vehicle air conditioning system capable of suppressing clouding of the window glass inside the vehicle even when the humidity inside the vehicle rapidly increases.

Means for Solving the Problems

[0007] As a result of intensive research on a vehicle air conditioning system provided with a humidity control device, the inventors of the present invention have found that by controlling a blower to adjust the air flow rate so that the temperature Ta of the window glass inside the vehicle is higher than the dew point temperature Tb inside the vehicle when the adsorption mode is executed, the above problems can be solved, and the present invention has been completed. 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 inside and through which air from inside the vehicle compartment or outside the vehicle can flow, the air conditioning duct having a first flow path for flowing the air into the vehicle compartment and a second flow path for discharging the air to the outside of the vehicle on the downstream side of the humidity control device, A valve capable of switching the air flow between the first flow path and the second flow path, A blower capable of adjusting the 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 blower Equipped with, A vehicle air conditioning system in which, when executing an adsorption mode in which the control unit switches the valve so that the air flows into the first flow path and adsorbs the moisture onto the humidity control device, the control unit controls the ventilator to adjust the airflow rate so that the temperature Ta of the window glass inside the vehicle is higher than the dew point temperature Tb inside the vehicle.

[0009] <2> The control unit further controls the duration of the adsorption mode when the adsorption mode is being executed. <1> The vehicle air conditioning system described in [reference].

[0010] <3> The vehicle further comprises a thermometer for measuring the temperature Ta of the window glass inside the vehicle and a dew point meter for measuring the dew point temperature Tb inside the vehicle. <1> or <2> The vehicle air conditioning system described in [reference].

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

number

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

number

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

[0014] <7> The To is the vehicle air conditioning system according to any one of <4> to <6>, measured by a thermometer disposed outside the vehicle.

[0015] <8> The Hco is the vehicle air conditioning system according to <4>, 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. 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 / s].

[0016] <9> The Hci is the vehicle air conditioning system according to any one of <4> to <8>, calculated by the following formula (5) when the air flow velocity on the vehicle interior side of the window glass is 5 m / s or more and by the following formula (6) when the air flow velocity on the vehicle interior 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 [m / s] on the vehicle interior side of the window glass.

[0017] <10> The dew point temperature Tb in the vehicle interior is calculated by the following formula (7), and is the vehicle air conditioning system according to any one of <1>, <2>, and <4> to <9>.

Number

[0018] <11> The dew point temperature Tb inside the vehicle is calculated by the following equation (8): <1> , <2> and <4> ~ <9> A vehicle air conditioning system as described in any one of the following.

number

[0019] <12> The Wa is calculated based on a predetermined relationship between the flow rate and flow time of the air flowing into the humidity control device. <10> or <11> The vehicle air conditioning system described in [reference].

[0020] <13> The AHi is measured by a hygrometer placed in the air conditioning duct upstream of the humidity control device. <10> The vehicle air conditioning system described in [reference].

[0021] <14> The humidity control device includes an adsorption section containing an adsorbent that adsorbs moisture at a predetermined temperature or below and allows the adsorbed moisture to be released when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption section. <1> ~ <13> A vehicle air conditioning system as described in any one of the following.

[0022] <15> The humidity control device is a honeycomb structure having an outer periphery wall and partition walls disposed inside the outer periphery wall, which divide and form 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 is provided on the surface of the partition wall, and A pair of electrodes provided on the first and second end faces of the honeycomb structure, or on the outer peripheral wall parallel to the direction in which the cells of the honeycomb structure extend. Equipped with, <14> The vehicle air conditioning system described in [reference].

[0023] <16> The honeycomb structure is composed of a material in which at least the partition walls have PTC properties. <15> The vehicle air conditioning system described in [reference].

[0024] <17> The humidity control device comprises an air passage and a heating medium passage adjacent to the air passage, and the adsorption portion is provided in the air passage. <14> The vehicle air conditioning system described in [reference].

[0025] <18> The humidity control device is a honeycomb structure having an outer periphery wall and partition walls disposed inside the outer periphery wall, which divide and form 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 is provided on the surface of the partition wall, and A heater provided on the upstream side of the honeycomb structure. Equipped with, <14> The vehicle air conditioning system described in [reference].

[0026] <19> The adsorbent is capable of adsorbing and desorbing carbon dioxide and / or volatile components in addition to moisture. <14> ~ <18> A vehicle air conditioning system as described in any one of the following. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide a vehicle air conditioning system that can suppress fogging of the windows inside the vehicle even when the humidity inside the vehicle rises rapidly. [Brief explanation of the drawing]

[0028] [Figure 1] This is a schematic diagram of the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2]This graph shows an example of a method for controlling the temperature Ta of the window glass inside the vehicle to be higher than the dew point temperature Tb inside the vehicle when the adsorption mode is running. [Figure 3A] This is a schematic diagram of a typical cross-section of a humidity control device used in a vehicle air conditioning system according to an embodiment of the present invention, parallel to the flow path direction. [Figure 3B] Figure 3A is a schematic diagram of the cross-section of the humidity control device along the line a-a'. [Modes for carrying out the invention]

[0029] The vehicle air conditioning system of the present invention comprises: a humidity control device capable of adsorbing and desorbing moisture; an air conditioning duct through which air from the vehicle interior or outside the vehicle can flow, with the humidity control device located inside, and having a first flow path for introducing air into the vehicle interior and a second flow path for discharging air outside the vehicle downstream of the humidity control device; a valve capable of switching the airflow between the first and second flow paths; 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 the control unit switches the valve so that air flows through the first flow path to perform an adsorption mode in which moisture is adsorbed by the humidity control device, it controls the ventilator to adjust the airflow rate so that the temperature Ta of the window glass inside the vehicle interior becomes higher than the dew point temperature Tb inside the vehicle interior. With the above configuration, the vehicle air conditioning system of the present invention can increase the amount of moisture adsorbed by the humidity control device by adjusting the airflow rate, even if the humidity inside the vehicle interior rises rapidly. Therefore, fogging of the window glass inside the vehicle interior can be suppressed even if the humidity inside the vehicle interior rises rapidly.

[0030] The embodiments of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications, improvements, etc., to the following embodiments, based on the ordinary knowledge of those skilled in the art, without departing from the spirit of the invention, also fall within the scope of the present invention. In this specification, "upstream" and "downstream" refer to the airflow through the vehicle's air conditioning system.

[0031] The vehicle air conditioning system according to the embodiment of the present invention can be suitably used in various types of vehicles. Vehicles are not particularly limited, but include automobiles and trains. Automobiles are not particularly limited, but include 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 is particularly suitable for vehicles without internal combustion engines, such as electric vehicles and trains.

[0032] Figure 1 is a schematic diagram of the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. As shown in Figure 1, an embodiment of the vehicle air conditioning system of the present invention comprises a humidity control device 10, an air conditioning duct 20, a valve 30, a ventilator 40, and a control unit 50. The vehicle air conditioning system may further include a power supply 60.

[0033] The humidity control device 10 is capable of adsorbing and desorbing moisture. The air conditioning duct 20 has a humidity control device 10 located inside, and allows air from the vehicle interior or outside to flow through it. Downstream of the humidity control device 10, it has a first flow path 20a for bringing air into the vehicle interior and a second flow path 20b for discharging air outside the vehicle. The valve 30 can switch the airflow between the first flow path 20a and the second flow path 20b. The ventilator 40 can adjust the airflow rate of the air circulating through the air conditioning duct 20. The control unit 50 can control the humidity control device 10, the valve 30, and the ventilator 40.

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

[0035] When the control unit 50 switches the valve 30 so that air flows into the first flow path 20a and performs the adsorption mode in which moisture is adsorbed onto the humidity control device 10, it controls the ventilator 40 to adjust the airflow rate so that the temperature Ta of the window glass inside the vehicle interior becomes higher than the dew point temperature Tb inside the vehicle interior. By adjusting the airflow rate in this way, fogging of the window glass inside the vehicle interior can be suppressed even if the humidity inside the vehicle interior rises rapidly. Specifically, when the dew point temperature Tb inside the vehicle interior approaches the temperature Ta of the window glass inside the vehicle interior, the rotation speed of the ventilator 40 is increased to increase the airflow rate. Since the dew point temperature Tb inside the vehicle interior is more affected by changes in airflow rate than the temperature Ta of the window glass inside the vehicle interior, increasing the airflow rate causes the dew point temperature Tb inside the vehicle interior to drop significantly lower than the temperature Ta of the window glass inside the vehicle interior. Specifically, by increasing the airflow 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 interior decreases, so that the dew point temperature Tb inside the vehicle interior can be kept lower than the temperature Ta of the window glass inside the vehicle interior.

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

[0037] An embodiment of the present invention of a vehicle air conditioning system may further include a thermometer for measuring the temperature Ta of the window glass inside the vehicle and a dew point meter for measuring the dew point temperature Tb inside the vehicle. With this configuration, the temperature Ta and dew point temperature Tb of the window glass inside the vehicle can be measured. The thermometer and 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 measuring the temperature Ta and dew point temperature Tb of the window glass inside the vehicle by placing a thermometer and a dew point meter, the temperature Ta and dew point temperature Tb of the window glass inside the vehicle may be calculated using a predetermined formula. The method for calculating the temperature Ta and dew point temperature Tb of the window glass inside the vehicle will be described below.

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

[0040]

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[0041] In equation (1), Tc is the temperature of the air inside the vehicle [°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 side [W / m²]. 2 [K] is the heat transfer coefficient on the outside of the car window glass [W / m²], and Hco is the heat transfer coefficient on the outside of the car window glass [W / m²]. 2 [K] is the heat transfer coefficient of window glass [W / m], and Kg is the heat transfer coefficient of window glass [W / m]. 2 It is K].

[0042] In equation (1), Hco may be a fixed value assuming the average vehicle speed during the high-speed phase of the WLTC (Worldwide-harmonized Light vehicles Test Cycle) mode test. Specifically, if Hco is 60.9 [W / m 2 The temperature Ta of the window glass inside the vehicle can also be calculated based on the value when it is [K]. In this case, the temperature Ta of the window glass inside the vehicle is calculated by the following equation (2).

[0043]

number

[0044] In equation (2), Tc is the temperature of the air inside the vehicle [°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 side [W / m²]. 2 [K] is the heat transfer coefficient of window glass [W / m], and Kg is the heat transfer coefficient of window glass [W / m]. 2 It is K].

[0045] In equations (1) and (2), Tc can be measured by a thermometer placed inside the vehicle. Since this thermometer is commonly installed inside the vehicle's interior, it is not necessary to install a separate thermometer. In other words, the value of the air temperature inside the vehicle measured by this commonly installed thermometer can be used as Tc.

[0046] In equations (1) and (2), To can be measured by a thermometer placed outside the vehicle. Since this thermometer is generally installed outside the vehicle, it is not necessary to install a separate thermometer. In other words, the value of the outside air temperature measured by this generally installed thermometer can be used as To.

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

[0048] In equations (1) and (2), Hci can be calculated using equation (5) below when the airflow velocity on the passenger compartment side of the window glass is 5 m / sec or more, and using equation (6) below when the airflow velocity on the passenger compartment side of the window glass is less than 5 m / sec. Hci = 7.1 × U B 0.78 ...(5) Hci = 5.57 + 3.94U B ...(6) In the formula, U B is the airflow velocity [m / sec] on the interior side of the window glass. The airflow velocity on the interior side of the window glass is the flow rate [m 3[ / second] is the cross-sectional area of ​​the air outlet on the interior side of the window glass [m²] 2 It can be calculated by dividing by ].

[0049] The dew point temperature Tb inside the vehicle can be calculated using the following equation (7).

[0050]

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[0051] In equation (7), Wa is the amount of moisture absorbed by the humidity control device 10 [g / sec], and Q is the flow rate of air flowing into the humidity control device 10 [m³]. 3 AHi is the absolute humidity of the air flowing into the humidity control device 10 [g / m³ / second], and AHi is the absolute humidity of the air [g / m³ / second]. 3 ], where Tc is the temperature of the air inside the vehicle [°C].

[0052] In equation (7), AHi may be a fixed value that pre-determines the most severe conditions under which window fogging is likely to occur. Specifically, since window fogging is more likely to occur under high humidity conditions inside the vehicle, the absolute humidity of the air flowing into the humidity control device 10 should be 10 [g / m³]. 3 The dew point temperature Tb inside the vehicle can also be calculated based on the value at ]. In this case, the dew point temperature Tb inside the vehicle is calculated by the following equation (8).

[0053]

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[0054] In equation (8), Wa is the amount of moisture absorbed by the humidity control device 10 [g / sec], and Q is the flow rate of air flowing into the humidity control device 10 [m³]. 3 [ / second], and Tc is the temperature of the air inside the vehicle [°C].

[0055] In equations (7) and (8), Wa may be calculated from the difference in humidity by measuring the humidity by placing hygrometers on the upstream and downstream sides of the humidity control device 10, but it is preferable to calculate it based on the relationship between the flow rate and inflow time of the air flowing into the humidity control device 10, which have been determined in advance. That is, it is preferable to determine in advance the relationship between the flow rate and inflow time of the air flowing into the humidity control device 10 and Wa when the adsorption mode is being executed, and then calculate Wa from the flow rate and inflow time of the air flowing into the humidity control device 10 based on this relationship. By calculating Wa in this way, it is not necessary to place hygrometers on the upstream and downstream sides of the humidity control device 10, which leads to the simplification of the vehicle air conditioning system.

[0056] In equation (7), AHi can be measured by a hygrometer placed in the air conditioning duct 20 upstream of the humidity control device 10. The hygrometer is connected to the control unit 50. There are no particular restrictions on the type of hygrometer used; commercially available models can be used.

[0057] In equations (7) and (8), Tc can be measured by a thermometer placed inside the vehicle. Since this thermometer is generally provided inside the vehicle's interior, it is not necessary to provide a separate thermometer. In other words, the value of the air temperature inside the vehicle measured by this generally provided thermometer can be used as Tc.

[0058] Here, Figure 2 shows a graph illustrating an example of a method for controlling the temperature Ta of the window glass inside the vehicle to be higher than the dew point temperature Tb inside the vehicle when the adsorption mode is being executed. As shown in Figure 2, when the adsorption mode is performed with a constant flow rate Q of air flowing into the humidity control device 10, the dehumidification by the humidity control device 10 becomes insufficient due to factors such as an increase in the number of passengers and the introduction of rain or snow from outside the vehicle, causing the humidity inside the vehicle to rise and the dew point temperature Tb inside the vehicle to approach the temperature Ta of the window glass inside the vehicle (times 0 to P1). When the dew point temperature Tb inside the vehicle exceeds the temperature Ta of the window glass inside the vehicle, fogging of the window glass is likely to occur. Therefore, by increasing the flow rate Q of air flowing into the humidity control device 10, the amount of moisture absorbed by the humidity control device 10 Wa is increased. As a result, the amount of moisture in the air inside the vehicle decreases, and the dew point temperature Tb inside the vehicle can be lowered (from time P1 onward). At this time, the temperature Ta of the window glass inside the vehicle also decreases slightly, but the rate of decrease is smaller than the rate of decrease in the dew point temperature Tb inside the vehicle. Therefore, by controlling the airflow rate Q of the air flowing into the humidity control device 10 as described above, the dew point temperature Tb inside the vehicle can be kept lower than the temperature Ta of the window glass inside the vehicle.

[0059] As described above, the airflow rate Q flowing into the humidity control device 10 affects the window glass temperature Ta and the dew point temperature Tb inside the vehicle when the adsorption mode is in operation. Specifically, when the airflow rate Q flowing into the humidity control device 10 increases, the window glass temperature Ta and the dew point temperature Tb inside the vehicle decrease when the adsorption mode is in operation. In particular, when the airflow rate Q flowing into the humidity control device 10 increases, the dew point temperature Tb inside the vehicle decreases more significantly than the window glass temperature Ta inside the vehicle. Therefore, by controlling the airflow rate Q flowing into the humidity control device 10, it is possible to control the window glass temperature Ta inside the vehicle so that it is higher than the dew point temperature Tb inside the vehicle. The flow rate Q of air flowing into the humidity control device 10 is not particularly limited and can be adjusted according to the type of humidity control device 10 used, but is 0.0033 [m³] 3 Preferably it is 0.0050[m / second] or more. 3 It is more preferable that it be greater than [ / second].

[0060] The following provides a detailed explanation of each component of the vehicle air conditioning system.

[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 it has an adsorption section containing an adsorbent that adsorbs moisture below a predetermined temperature and desorbs the adsorbed moisture when the predetermined temperature is exceeded, and a heating means or heating structure that can heat the adsorption section. With a humidity control device 10 having such features, the adsorption and desorption of moisture can be easily achieved. Furthermore, the number of humidity control devices 10 placed in the air conditioning duct 20 may be one or multiple. If multiple humidity control devices 10 are provided, they may be arranged in parallel or in series with respect to the airflow circulating in the air conditioning duct 20.

[0062] Figure 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. Figure 3B is a schematic diagram of the cross-section along line a-a' in the humidity control device of Figure 3A. The humidity control device 10 shown in Figures 3A and 3B comprises a honeycomb structure 11 having an outer peripheral wall 12 and partition walls 15 disposed inside the outer peripheral wall 12, which divide and form a plurality of cells 14 that serve as airflow channels 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 walls 15; and a pair of electrodes 17a and 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 and 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 also be connected to the pair of electrodes 17a and 17b.

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

[0064] The shape of the cell 14 is not particularly limited, but in a cross-section perpendicular to the flow direction of the honeycomb structure 11, it can be a polygon such as a square, pentagon, hexagon, heptagon, or octagon, or a circle or oval shape. These shapes may be single or a combination of two or more. Among these shapes, square or hexagonal is preferred. By providing cells 14 of such shape, the pressure loss when air flows can be reduced.

[0065] The honeycomb structure 11 may be a honeycomb joint having a plurality of honeycomb segments and a joining layer that joins the outer periphery sides of the plurality of honeycomb segments. By using a honeycomb joint, it is possible to increase the total cross-sectional area of ​​the cells 14, which are important for securing airflow (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 ceramic raw materials can be used. The bonding material may contain a material having PTC properties, or it may contain the same material as the outer periphery wall 12 and the partition wall 15. In addition to its role in bonding the honeycomb segments together, the bonding material can also be used as an outer periphery coating material after the honeycomb segments have been bonded.

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

[0067] In an embodiment advantageous in terms of supporting 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 / cm³. 2 The following conditions apply, and the cell pitch is 1.0 mm or more. In a preferred embodiment, the thickness of the partition wall 15 is 0.200 mm or less, and the cell density is 70 cells / cm³. 2 The following conditions apply, and the cell pitch is 1.2 mm or more. 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 / cm³. 2 The following conditions apply, 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 electrical resistance low, the lower limit of the thickness of the partition wall 15 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and even more preferably 0.030 mm or more. From the viewpoint of ensuring the strength of the honeycomb structure 11, keeping electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is 30 cells / cm². 2 Preferably, it is 35 cells / cm 2 It is more preferable that the rate is 40 cells / cm² or higher. 2 It is even more preferable that the above conditions are met. From the viewpoint of ensuring the strength of the honeycomb structure 11, keeping electrical resistance low, 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 advantageous in terms of achieving both reduced pressure loss and maintained 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 / cm³. 2 The opening ratio of cell 14 is 0.70 or higher. In a preferred embodiment, the thickness of the partition wall 15 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm³. 2 The opening ratio of cell 14 is 0.80 or higher. In a more preferred embodiment, the thickness of the partition wall 15 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm³. 2 The aperture ratio of cell 14 is 0.85 or higher.

[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 even more preferably 0.90 or less.

[0071] The thickness of the outer periphery wall 12 is not particularly limited, but is preferably determined based on the following considerations. First, from the viewpoint of reinforcing the honeycomb structure 11, the thickness of the outer periphery 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 electrical resistance to suppress the initial current and reducing pressure loss when air flows, the thickness of the outer periphery 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 outer peripheral wall 12 refers to the length in the direction normal to the side surface, from the boundary between the outer peripheral wall 12 and the outermost 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 direction and the cross-sectional area perpendicular to the flow direction can be adjusted to the required size of the humidity control device 10 and are not particularly limited. For example, when used in a compact humidity control device 10 while ensuring a predetermined function, the honeycomb structure 11 may have a length of 2 to 20 mm in the flow direction and a cross-sectional area perpendicular to the flow direction of 10 cm². 2 The above is possible. Note that there is no particular upper limit to the cross-sectional area perpendicular to the flow direction, but for example, 300 cm². 2 The following applies:

[0073] The partition walls 15 constituting the honeycomb structure 11 are made of a material capable of generating heat when an electric current is passed through them, and more preferably, they are made of a material having PTC properties. If necessary, the outer peripheral wall 12 may also be made of a material having PTC properties similar to the partition walls 15. With this configuration, the adsorption layer 16 can be directly heated by heat transfer from the heat-generating partition walls 15 (and the outer peripheral wall 12 if necessary). Furthermore, materials with PTC properties have the characteristic that when the temperature rises and exceeds the Curie point, the resistance value increases rapidly and it becomes difficult for electricity 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, so excessive heat generation in the honeycomb structure 11 is suppressed. Consequently, it is also possible to suppress thermal degradation of the adsorption layer 16 caused by excessive heat generation.

[0074] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity of a PTC-type material 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 with a low drive voltage, the upper limit of the volume resistivity of a PTC-type material 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 a PTC-type material at 25°C is measured in accordance with JIS K6271:2008.

[0075] From the viewpoint of being electrically conductive and having PTC characteristics, the outer periphery wall 12 and partition wall 15 are preferably made of a material mainly composed of barium titanate (BaTiO3). Furthermore, it is more preferable that this material is a ceramic made of a material mainly composed of barium titanate (BaTiO3) crystalline particles in which a portion of Ba is replaced with rare earth elements. In this specification, "main component" means a component whose proportion in the total component exceeds 50% by mass. The content of BaTiO3 crystalline particles can be determined by fluorescent X-ray analysis. Other crystalline particles can also be measured in the same manner.

[0076] The compositional formula for BaTiO3-based crystal grains in which some of the Ba is replaced by rare earth elements is (Ba 1-x A x It can be represented as TiO3. In the empirical formula, A represents one or more rare earth elements, and 0.0001 ≤ x ≤ 0.010. A is not particularly limited as long as it is a rare earth element, but is preferably one or more selected from the group consisting of La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Er, Y, and Yb, and is more preferably La. x is preferably 0.001 or more, more preferably 0.0015 or more, from the viewpoint of suppressing excessively high electrical resistance at room temperature. On the other hand, x is preferably 0.009 or less, from the viewpoint of suppressing excessively high electrical resistance at room temperature due to insufficient sintering. The content of BaTiO3-based crystalline particles in ceramics, in which a portion of Ba is substituted with rare earth elements, is not particularly limited as long as it constitutes the main component, but is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 94% by mass or more. The upper limit of the content of BaTiO3-based crystalline particles is not particularly limited, but is generally 99% by mass, preferably 98% by mass.

[0077] From the viewpoint of reducing environmental impact, it is desirable that the materials used for the outer perimeter wall 12 and the partition wall 15 be substantially lead-free (Pb). Specifically, the Pb content of the outer perimeter wall 12 and the partition wall 15 is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass. The low Pb content allows, for example, heated air to be safely directed at living organisms such as humans by contacting the partition wall 15 during heat generation. In addition, the Pb content of the outer perimeter wall 12 and the partition wall 15, when converted to PbO, is preferably less than 0.03% by mass, more preferably less than 0.01% by mass, and even more preferably 0% by mass. The lead content can be determined by ICP-MS (inductively coupled plasma mass spectrometry).

[0078] Preferably, the Curie point of the materials constituting the outer perimeter wall 12 and the partition wall 15 is within the temperature range where the resistance value is more than twice the resistance value at room temperature (25°C). If the Curie point is within such a temperature range, the current flowing through them is limited when the humidity control device 10 becomes hot, so excessive heat generation of the humidity control device 10 is efficiently suppressed. Therefore, thermal degradation of the adsorption layer 16 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the materials 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 efficiently heating the adsorption layer 16. 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 component placed in or near the vehicle compartment.

[0079] The Curie points of the materials constituting the outer perimeter wall 12 and the partition wall 15 can be adjusted by the type and amount of sifter added. For example, the Curie point of barium titanate (BaTiO3) is approximately 120°C, but by substituting some of the Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to a lower temperature.

[0080] In this specification, the Curie point is measured by the following method: The sample is mounted in a sample holder for measurement and placed in a measuring chamber (e.g., MINI-SUBZERO MC-810P, manufactured by ESPEC Corporation). The change in the electrical resistance of the sample with respect to temperature changes as the temperature is raised from 10°C is measured using a DC resistance meter (e.g., Multimeter 3478A, manufactured by Hewlett-Packard Japan, G.K.). The Curie point is defined as the temperature at which the resistance value becomes twice the resistance value at room temperature (25°C) as shown in the electrical resistance-temperature plot obtained from the measurement.

[0081] (1-2.Adsorption layer 16) The adsorption layer 16 is a layer containing an adsorbent. The adsorption layer 16 can be provided on the surface of the partition wall 15 (or, in the case of the outermost cell 14, the partition wall 15 and outer wall 12 that partition the outermost cell 14). By providing the adsorption layer 16 in this way, it becomes easier to adsorb moisture during the adsorption mode, and it becomes easier to heat the adsorption layer 16 during the regeneration mode, thus making it easier to remove moisture from the adsorption layer 16.

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

[0083] Preferably, the adsorbent contained in the adsorption layer 16 has the function of adsorbing moisture and other substances at temperatures between -20 and 60°C, and desorbing moisture and other substances at temperatures above 60°C. Adsorbents are not particularly limited, but include aluminosilicates, silica gel, silica, graphene oxide, polymer adsorbents, polystyrene sulfonic acid, zeolites, activated carbon, alumina, low-crystalline clay, amorphous aluminum silicate composites, and metal-organic frameworks (MOFs). These may be used individually or in combination of two or more.

[0084] As the aluminosilicate, it is preferable to use AFI-type, CHA-type, or BEA-type zeolites; porous clay minerals such as allophane and imogolite. Furthermore, it is preferable that the aluminosilicate is amorphous.

[0085] It is preferable to use type A silica gel as the silica gel. As a polymer adsorbent, one having polyacrylic acid-based polymer chains is preferred. For example, sodium polyacrylate can be used as a polymer adsorbent. Metal-organic structures are crystalline hybrid materials containing metal ions and organic molecules (organic ligands). Preferably, the metal ions are hydrophilic (e.g., aluminum ions).

[0086] The volatile components contained in the air inside a vehicle include, for example, volatile organic compounds (VOCs) and odor components other than VOCs. Specific examples of volatile components include ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, di-2-ethylhexyl phthalate, diazinon, acetaldehyde, and N-methylcarbamate-2-(1-methylpropyl)phenyl.

[0087] The adsorption layer 16 may further contain a catalyst. By including a catalyst, oxidation-reduction reactions can be promoted to purify carbon dioxide and / or volatile components. Examples of catalysts with such functions include metal catalysts such as Pt, Pd, and Ag, and oxide catalysts such as CeO2 and ZrO2. The catalyst may be used alone or in combination of two or more. Furthermore, the catalyst can be used in combination with the functional materials described above.

[0088] The thickness of the adsorption layer 16 can be determined according to the size of the cell 14 and is not particularly limited. 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 suppressing the peeling of the adsorption layer 16 from the partition wall 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 using the following procedure. An arbitrary cross section parallel to the flow direction of the honeycomb structure 11 is cut out, and a cross-sectional image at approximately 50x magnification is obtained using a scanning electron microscope or similar device. This cross section is also taken so that it passes through the centroid position of a cross section perpendicular to the flow direction of the honeycomb structure 11. For each adsorption layer 16 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 14 in the flow direction. This calculation is performed for all adsorption layers 16 visible in the cross-sectional image, and the overall average value is taken as the thickness of the adsorption layer 16.

[0090] From the viewpoint of performing the desired function within 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 determined by the external dimensions of the honeycomb structure 11.

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

[0092] The pair of electrodes 17a and 17b are not particularly limited, but for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si can be used. Alternatively, an ohmic electrode capable of ohmic contact with the outer peripheral wall 12 and / or partition wall 15 having PTC characteristics can be used. For example, an ohmic electrode can be used that contains 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. Furthermore, the pair of electrodes 17a and 17b may have a single-layer structure or a multilayer structure of two or more layers. If the pair of electrodes 17a and 17b have a multilayer structure of two or more layers, the material of each layer may be the same type or different types.

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

[0094] The thickness of the pair of electrodes 17a and 17b is preferably about 5 to 30 μm for electrode paste baking, 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 electroplating and chemical deposition. Furthermore, when joining metal plates or alloy plates, it is preferable that their thickness be about 5 to 100 μm.

[0095] (1-4. Terminal 18) Terminal 18 is connected to a pair of electrodes 17a and 17b and is provided on at least a portion of the pair of electrodes 17a and 17b. Providing terminal 18 facilitates connection to an external power supply. Terminal 18 is connected to a wire connected to the external power supply.

[0096] The material of terminal 18 is not particularly limited, but for example, it can be a metal. As the metal, elemental metals and alloys can be used, but from the viewpoint of corrosion resistance, electrical resistivity and coefficient of linear expansion, it is preferable to use an alloy containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti, 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 Figure 3A, the terminal 18 can be provided over the entire length of the pair of electrodes 17a and 17b on the outer peripheral wall 12. Alternatively, the terminal 18 may be provided on a portion of the pair of electrodes 17a and 17b on the outer peripheral wall 12, or it may be provided so as to extend outward from the outer edge of the pair of electrodes 17a and 17b on the outer peripheral wall 12. Furthermore, the terminal 18 may be provided on a portion of the pair of electrodes 17a and 17b on the partition wall 15, or it may be provided so as to block a portion of the cell 14. Furthermore, the thickness of the terminal 18 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.

[0098] The method of connecting the terminal 18 to the pair of electrodes 17a and 17b is not particularly limited as long as they are electrically connected, and can be done by means of diffusion bonding, a mechanical pressurizing mechanism, welding, etc.

[0099] (1-5. Method for manufacturing the humidity control device 10) The method for manufacturing the humidity control device 10 is not particularly limited and can be carried out in accordance with known methods. The method for manufacturing the humidity control device 10 will be described below as an example. The manufacturing method for the honeycomb structure 11 that constitutes the humidity control device 10 includes a molding step and a firing step. In the molding process, a clay mold containing ceramic raw materials including BaCO3 powder, TiO2 powder, and rare earth nitrate or hydroxide powder is molded to produce a honeycomb molded body with a relative density of 60% or more. Ceramic raw materials can be obtained by dry-mixing each powder to achieve the desired composition. The clay can be obtained by adding a dispersion medium, binder, plasticizer, and dispersant to ceramic raw materials and kneading them together. The clay may also contain additives such as sifters, metal oxides, property improvers, and conductive powders as needed. The amount of components other than ceramic raw materials is not particularly limited, as long as it is such that the relative density of the honeycomb molded body is 60% or more.

[0100] Here, in this specification, "relative density of the honeycomb molded body" means the ratio of the density of the honeycomb molded body to the true density of the entire ceramic raw material. Specifically, it can be calculated by the following formula. Relative density (%) of honeycomb molded material = Density (g / cm³) of honeycomb molded material 3 ) / True density of the entire ceramic raw material (g / cm³) 3 ) × 100 The density of a honeycomb molded body can be measured by the Archimedes method using pure water as the medium. The true density of the entire ceramic material is calculated by adding the mass of each material (g) and then adding the actual volume of each material (cm³). 3 It can be found by dividing by ).

[0101] Examples of dispersion media include water, or a mixed solvent of water and an organic solvent such as alcohol, but water is particularly suitable.

[0102] Examples of binders include organic binders such as methylcellulose, hydroxypropoxylcellulose, hydroxyethylcellulose, carboxymethylcellulose, and polyvinyl alcohol. In particular, the combined use of methylcellulose and hydroxypropoxylcellulose is preferred. The binder may be used alone or in combination of two or more types, but it is preferable that it does not contain alkali metal elements.

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

[0104] Dispersants that can be used include surfactants such as polyoxyalkylene alkyl ethers, ethylene glycol, dextrin, fatty acid soaps, and polyalcohols. Dispersants may be used individually or in combination of two or more types.

[0105] Honeycomb molded bodies can be manufactured by extruding clay. During extrusion molding, a die with the desired overall shape, cell shape, partition thickness, and cell density 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 its 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 process. The drying method is not particularly limited, but conventional known drying methods such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, and freeze drying can be used. Among these, a drying method combining hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire molded body quickly and uniformly.

[0108] The firing process includes maintaining the temperature at 1150-1250°C, then increasing the temperature to a maximum of 1360-1430°C at a heating rate of 20-600°C / hour, and maintaining the temperature for 0.5-10 hours. By holding the honeycomb molded body at a maximum temperature of 1360 to 1430°C for 0.5 to 10 hours, a honeycomb structure 11 mainly composed of BaTiO3-based crystalline grains in which some of the Ba is replaced by rare earth elements can be obtained. Furthermore, by maintaining the temperature at 1150-1250°C, the Ba2TiO4 crystal particles generated during the firing process are more easily removed, thereby densifying the honeycomb structure 11. Furthermore, by setting the heating rate from 1150-1250°C to the maximum temperature of 1360-1430°C to 20-600°C / hour, 1.0-10.0 mass% of Ba6Ti 17 O 40 Crystal particles can be generated in the honeycomb structure 11.

[0109] The holding time at 1150-1250°C is not particularly limited, but is preferably 0.5-10 hours. This holding time makes it easier to stably remove the Ba2TiO4 crystal grains generated during the firing process.

[0110] The firing process preferably includes holding the temperature at 900-950°C for 0.5-5 hours during the heating phase. Holding the temperature at 900-950°C for 0.5-5 hours allows BaCO3 to decompose efficiently, making it easier to obtain a honeycomb structure 11 having a predetermined composition.

[0111] Furthermore, a degreasing process may be performed before the firing process to remove the binder. The atmosphere during the degreasing process is preferably atmospheric air to completely decompose the organic components. Furthermore, the atmosphere during the firing process is preferably an atmospheric environment, from the viewpoint of controlling electrical properties and reducing manufacturing costs. The furnace used in the firing and degreasing processes is not particularly limited, but electric furnaces, gas furnaces, etc., can be used.

[0112] A pair of electrodes 17a and 17b are formed on the honeycomb structure 11 obtained in this manner. The pair of electrodes 17a and 17b can be formed by metal deposition methods such as sputtering, vapor deposition, electrolysis, or chemical deposition. Alternatively, the pair of electrodes 17a and 17b can be formed by applying electrode paste and then baking it. Furthermore, the pair of electrodes 17a and 17b can also be formed by thermal spraying. The pair of electrodes 17a and 17b may consist of a single layer, or it may consist of multiple electrode layers with different compositions. The following describes typical methods for forming the pair of electrodes 17a and 17b.

[0113] First, an electrode slurry containing electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 13a or the second end face 13b of the honeycomb structure 11. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Excess slurry around the outer circumference of the honeycomb structure 11 is removed by blowing and wiping. Then, a pair of electrodes 17a, 17b can be formed on the first end face 13a or the second end face 13b of the honeycomb structure 11 by drying the slurry. Drying can be carried out while heating the honeycomb structure 11 to a temperature of, for example, 120 to 600°C. The series of steps—coating, slurry removal, and drying—may be performed only once, but by repeating them multiple times, a pair of electrodes 17a and 17b of the desired thickness can be provided.

[0114] Next, the terminals 18 are placed at predetermined positions on the pair of electrodes 17a and 17b, and the pair of electrodes 17a and 17b are connected to the terminals 18. The method described above can be used to connect the pair of electrodes 17a and 17b to the terminals 18. Note that the arrangement of the terminals 18 may be performed after the formation of the adsorption layer 16 described below.

[0115] Next, an adsorption layer 16 is formed on the surface of the honeycomb structure 11, such as the partition walls 15. The method for forming the adsorption layer 16 is not particularly limited, but for example, it can be formed by the following steps: 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 from the end faces and outer circumference of the honeycomb structure 11 is removed by blowing and wiping. The binder may be an organic binder, an inorganic binder, or a combination thereof. The dispersion medium 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. After that, the adsorption layer 16 can be formed on the surface of the partition wall 15 or the like by drying the slurry. Drying can be carried out, for example, by heating the honeycomb structure 11 to a temperature of about 120 to 600°C. The series of steps—immersion, slurry removal, and drying—may be performed only once, but by repeating them multiple times, an adsorption layer 16 of the desired thickness can be formed on the surface of the partition wall 15 or the like.

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

[0117] The humidity control device 10 may also include a honeycomb structure 11 having an outer peripheral wall 12 and a partition wall 15 disposed inside the outer peripheral wall 12 that partitions a plurality of cells 14 which form 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. Note that the structure of this humidity control device 10 corresponds to the structure in Figure 3A with the pair of electrodes 17a, 17b and terminal 18 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 the heater through the cells 14 of the honeycomb structure 11.

[0118] The humidity control device 10 having the heating structure described above does not require the honeycomb structure 11 itself to generate heat when an electric current is passed 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 when an electric current is passed through it. Furthermore, the humidity control device 10 having the heating structure described above can be manufactured in accordance with the method described above or known methods.

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

[0120] (3. Valve 30) The valve 30 can switch the airflow between the first flow path 20a and the second flow path 20b. The valve 30 can be installed at the branching point between the first flow path 20a and the second flow path 20b in the air conditioning duct 20. The valve 30 is not particularly limited as long as it is electrically driven and has the function of switching the airflow path, and solenoid valves and electric valves 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. Alternatively, 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 used to draw air from the vehicle interior or outside the vehicle into the humidity control device 10, and is located within the air conditioning duct 20. The location of the ventilator 40 is not particularly limited, but may be upstream of the humidity control device 10 or downstream of the humidity control device 10, as shown in Figure 1, for example. Furthermore, the ventilator 40 is electrically connected to the control unit 50, and the airflow rate can be controlled 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 voltage to the humidity control device 10 (particularly to the pair of electrodes 17a and 17b). The power supply 60 is electrically connected to the control unit 50 and adjusts the voltage applied to the pair of electrodes 17a and 17b according to instructions from the control unit 50. The power source 60 is not particularly limited and can use batteries, etc.

[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 ventilator 40. The control unit 50 is electrically connected to the humidity control device 10 and the ventilator 40 via the power supply 60. By controlling the power supply 60, the control unit 50 can control the voltage applied to the pair of electrodes 17a and 17b of the humidity control device 10, thereby adjusting 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, by adjusting the rotation speed of the ventilator 40, the control unit 50 can control the flow rate of air circulating in the air conditioning duct 20.

[0124] The control unit 50 is not particularly limited, but is generally an ECU (Engine (electronic) Control Unit). The ECU includes a CPU that performs various calculation processes, a ROM that stores programs and data necessary for its control, a RAM that temporarily stores the results of calculations performed by the CPU, and input / output ports for inputting and outputting signals to and from the outside.

[0125] The control unit 50 can perform an adsorption mode in which it switches the valve 30 so that air flows through the first channel 20a, and a regeneration mode in which it heats the humidity control device 10 and switches the valve 30 so that air flows through the second channel 20b. In adsorption mode, moisture from the air flowing in or out of the vehicle is adsorbed, and the air with reduced or removed moisture is returned to the vehicle through the first channel 20a. In regeneration mode, moisture adsorbed on the adsorption layer 16 is desorbed and discharged outside the vehicle through the second channel 20b.

[0126] From the viewpoint of stably performing the above control, it is desirable to position the humidity control device 10 close to the vehicle interior. Therefore, from the viewpoint of preventing electric shock, it is preferable that the drive voltage of the humidity control device 10 be 60V or less. The honeycomb structure 11 used in the humidity control device 10 has low electrical resistance at room temperature, so it is possible to heat the honeycomb structure 11 at this low drive voltage. The lower limit of the drive voltage is not particularly limited, but it is preferable to be 10V or more. If the drive voltage is less than 10V, the current when heating the honeycomb structure 11 will be large, so it will be necessary to use thicker wires. [Examples]

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

[0128] <Fabrication of humidity control devices> BaCO3 powder, TiO2 powder, and La(NH3)3·6H2O powder were prepared as ceramic raw materials. These powders were weighed to obtain a predetermined composition after firing and dry-mixed to obtain a mixed powder. Dry mixing was carried out for 30 minutes. Next, to 100 parts by mass of the obtained mixed powder, water, binder, plasticizer, and dispersant were added in appropriate amounts in the range of 3 to 30 parts by mass in total, so that a ceramic molded body with a relative density of 64.8% after extrusion molding would be obtained, and the mixture was kneaded to obtain clay. Methylcellulose was used as the binder. Polyoxyalkylene alkyl ether was used as the plasticizer and dispersant.

[0129] Next, the obtained clay was fed into an extrusion molding machine and extruded using a predetermined die so that, after firing, it would form a honeycomb structure with the shape shown below. Cross-sectional and end face shapes of the honeycomb structure perpendicular to the flow direction: quadrilateral Shape of the cell cross-section perpendicular to the flow direction: quadrilateral Wall thickness: 0.100 mm Outer wall thickness: 0.2 mm Cell density: 80 cells / cm 2 Cell pitch: 1.1mm Cross-sectional area of ​​the honeycomb structure perpendicular to the direction in which the flow channels extend: 12,000 mm² 2 Length of the flow channel in the honeycomb structure in the direction of extension: 10 mm Volume resistivity of the materials constituting the outer walls and partitions at 25°C: 15 Ω·cm Curie point of materials constituting the outer walls and partition walls: 110°C

[0130] Next, the obtained honeycomb molded body was dielectric-dried and hot-air-dried, then degreased in a firing furnace under an atmospheric atmosphere (450°C for 4 hours), and subsequently fired under an atmospheric atmosphere to obtain a honeycomb structure. The firing was carried out by holding at 950°C for 1 hour, then raising the temperature to 1200°C and holding at 1200°C for 1 hour, and then raising 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 were formed on both end faces (first and second end faces) of the obtained honeycomb structure. First, an electrode slurry containing aluminum (electrode material), ethyl cellulose, and diethylene glycol monobutyl ether (organic binder) was prepared, 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. Similarly, using the same electrode slurry, an electrode was formed on the second end face by applying the electrode slurry and drying it.

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

[0133] The humidity control devices obtained as described above were placed inside the air conditioning ducts, and an air conditioning system as shown in Figure 1 was constructed. In this air conditioning system, assuming an environment where condensation is likely to occur on the windows inside the vehicle, with the indoor air temperature at 20°C and the outdoor air temperature at 0°C, the occurrence of condensation on the indoor windows was visually evaluated. First, let's assume the temperature of the air inside the vehicle (Tc) is 20°C, the temperature of the air outside the vehicle (To) is 0°C, and the heat transfer coefficient (Hci) of the window glass on the vehicle side is 6 [W / m²]. 2 [K], the heat transfer coefficient Hco on the outside of the car window glass is 43.3 [W / m 2 [K], the heat transfer coefficient of window glass is set to 200 [W / m] kg. 2 Assuming K is used, the temperature Ta of the window glass inside the vehicle was calculated using equation (1), and the result was that the temperature Ta of the window glass inside the vehicle was 2.9 [°C]. Next, the flow rate Q[m³] of air flowing into the humidity control device 3 The dew point temperature Tb inside the vehicle was calculated using equation (7) while varying the flow rate [ / second] as shown in Table 1. At this time, the moisture absorption amount Wa of the humidity control device was calculated based on the relationship between the flow rate and inflow time of the air flowing into the humidity control device during adsorption mode execution, which was determined in advance. The inflow time of the air flowing into the humidity control device was set to 30 seconds. Furthermore, the absolute humidity AHi of the air flowing into the humidity control device was set to 7.1 g / m³. 3 The temperature Tc of the air inside the vehicle was set to 20°C. The evaluation results are shown in Table 1. The evaluation results for window fogging are indicated as follows: ◎ indicates no fogging at all, ○ indicates slight fogging that did not cause any problems, and × indicates significant fogging.

[0134] [Table 1]

[0135] As shown in Table 1, controlling the airflow rate so that the temperature Ta of the window glass inside the vehicle interior is higher than the dew point temperature Tb inside the vehicle interior suppressed the occurrence of fogging on the window glass. Specifically, the airflow rate was set to 0.0033 [m³].3 By setting the airflow rate to 0.0050 [m³ / second] or higher, the occurrence of fogging on windowpanes can be suppressed, and in particular, when the airflow rate is 0.0050 [m³ / second] or higher, the occurrence of fogging on windowpanes can be suppressed. 3 By setting the frequency to [ / second] or higher, the occurrence of window fogging was reliably suppressed.

[0136] As can be seen from the above results, the present invention provides a vehicle air conditioning system that can suppress fogging of the windows inside the vehicle even when the humidity inside the vehicle rises rapidly. [Explanation of Symbols]

[0137] 10 Humidity Control Devices 11 Honeycomb structure 12 Peripheral wall 13a First end surface 13b Second end face 14 cells 15 Bulkhead 16 Adsorption layer 17a, 17b A pair of electrodes 18 terminals 20 Air conditioning ducts 20a First channel 20b Second channel 30 valves 40 Ventilator 50 Control Unit 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 inside and air from the vehicle compartment or outside the vehicle can flow through, the air conditioning duct having a first flow path for introducing the air into the vehicle compartment and a second flow path for discharging the air outside the vehicle downstream of the humidity control device, A valve capable of switching the airflow between the first flow path and the second flow path, A ventilator capable of adjusting the flow rate of the air circulating through the air conditioning duct, A control unit capable of controlling the humidity control device, the valve, and the ventilator. Equipped with, A vehicle air conditioning system in which, when executing an adsorption mode in which the control unit switches the valve so that the air flows into the first flow path and adsorbs the moisture onto the humidity control device, the control unit controls the ventilator to adjust the airflow rate so that the temperature Ta of the window glass inside the vehicle is higher than the dew point temperature Tb inside the vehicle.

2. The vehicle air conditioning system according to claim 1, wherein the control unit further controls the duration of the adsorption mode when the adsorption mode is being executed.

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

4. The vehicle air conditioning system according to claim 1, wherein the temperature Ta of the window glass inside the vehicle is calculated by the following formula (1). [Math 1] In the formula, Tc is the temperature of the air inside the vehicle [°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 side [W / m²]. 2 [K] is the heat transfer coefficient on the outside of the window glass [W / m], and Hco is the heat transfer coefficient on the outside of the vehicle [W / m]. 2 K is the thermal conductivity of the window glass [W / m²], where Kg is the thermal conductivity of the window glass [W / m²]. 2 It is K.

5. The vehicle air conditioning system according to claim 1, wherein the temperature Ta of the window glass inside the vehicle is calculated by the following formula (2). [Math 2] In the formula, Tc is the temperature of the air inside the vehicle [°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 side [W / m]. 2 K is the thermal conductivity of the window glass [W / m²], where Kg is the thermal conductivity of the window glass [W / m²]. 2 It is K.

6. The vehicle air conditioning system according to claim 4 or 5, wherein the Tc is measured by a thermometer placed inside the vehicle.

7. The vehicle air conditioning system according to claim 4 or 5, wherein the aforementioned To is measured by a thermometer located outside the vehicle.

8. The vehicle air conditioning system according to claim 4, wherein 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. Hco=7.1×U A 0.78 ・・・(3) Hco=5.57+3.94U A ・・・(4) where U A is the vehicle speed [m / s].

9. The vehicle air conditioning system according to claim 4 or 5, wherein the Hci is calculated by the following formula (5) when the airflow velocity on the vehicle interior side of the window glass is 5 m / s or more, and by the following formula (6) when the airflow velocity on the vehicle interior 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 ceremony, U B is the airflow velocity [m / sec] on the interior side of the window glass.

10. The vehicle air conditioning system according to claim 1, wherein the dew point temperature Tb inside the vehicle interior is calculated by the following formula (7). [Math 3] In the formula, Wa is the amount of moisture absorbed by the humidity control device [g / sec], and Q is the flow rate of the air flowing into the humidity control device [m³]. 3 [g / second], and AHi is the absolute humidity [g / m³] of the air flowing into the humidity control device. 3 ], where Tc is the temperature of the air inside the vehicle cabin [°C].

11. The vehicle air conditioning system according to claim 1, wherein the dew point temperature Tb inside the vehicle is calculated by the following formula (8). 【Number 4】 In the formula, Wa is the amount of moisture absorbed by the humidity control device [g / sec], and Q is the flow rate of the air flowing into the humidity control device [m³]. 3 The value is [ / second], and Tc is the temperature of the air inside the vehicle cabin [°C].

12. The vehicle air conditioning system according to claim 10 or 11, wherein Wa is calculated based on a relationship between the flow rate and flow time of the air flowing into the humidity control device, which has been determined in advance.

13. The vehicle air conditioning system according to claim 10, wherein AHi is measured by a hygrometer placed in the air conditioning duct upstream of the humidity control device.

14. The vehicle air conditioning system according to any one of claims 1 to 5, 10, and 11, wherein the humidity control device has an adsorption section containing an adsorbent that adsorbs moisture at a predetermined temperature or below and allows the adsorbed moisture to be detached when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption section.

15. The humidity control device is a honeycomb structure having an outer periphery wall and partition walls disposed inside the outer periphery wall, which divide and form 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 is provided on the surface of the partition wall, and A pair of electrodes provided on the first and second end faces of the honeycomb structure, or on the outer peripheral wall parallel to the direction in which the cells of the honeycomb structure extend. A vehicle air conditioning system according to claim 14, comprising:

16. The vehicle air conditioning system according to claim 15, wherein at least the partition wall of the honeycomb structure is made of a material having PTC properties.

17. The vehicle air conditioning system according to claim 14, wherein the humidity control device comprises an air passage and a heating medium passage adjacent to the air passage, and the adsorption portion is provided in the air passage.

18. The humidity control device is a honeycomb structure having an outer periphery wall and partition walls disposed inside the outer periphery wall, which divide and form 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 is provided on the surface of the partition wall, and A heater provided on the upstream side of the honeycomb structure. A vehicle air conditioning system according to claim 14, comprising:

19. The vehicle air conditioning system according to claim 14, wherein the adsorbent is capable of adsorbing and desorbing carbon dioxide and / or volatile components in addition to moisture.

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