Vehicle air conditioning system and method for controlling same

Abstract

Provided are: a vehicle air-conditioning system using a heat pump cycle, which has excellent heating efficiency and immediate heating properties in cold weather, is capable of removing moisture and the like in the air in the cabin, and is capable of being reduced in size; and a method for controlling the vehicle air-conditioning system. An air conditioning system for a vehicle is provided with: an air conditioning duct through which air can flow; a humidity control device disposed in the air conditioning channel; a heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device; and a control unit that controls the humidity control device and the heat pump cycle in accordance with the operation mode. The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed on the inner side of the outer peripheral wall and defining a plurality of cells, the plurality of cells extending from a first end surface to a second end surface to form a flow path, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition wall. The control unit includes a heating mode in which air is heated by the humidity control device at the start of a heating operation mode of the heat pump cycle.

Description

Technical Field

[0001] The present invention relates to a vehicle air conditioning system and a control method therefor. Background Art

[0002] In various vehicles such as automobiles, the demand for improving the cabin environment is increasing. As specific demands, examples include reducing CO2 in the cabin to suppress the driver's drowsiness, humidifying the cabin, and removing harmful volatile components such as odor components and allergy-inducing components in the cabin. As an effective countermeasure against such demands, ventilation can be cited. However, ventilation is a major cause of a large amount of heater energy loss in winter, resulting in a decrease in energy efficiency in winter. In particular, in an electric vehicle (BEV: Battery Electric Vehicle), there is a problem that the cruising range is significantly reduced due to its energy loss.

[0003] As a method for solving the above problems, Patent Documents 1 and 2 disclose a vehicle air conditioning system in which components to be removed such as moisture (water vapor) and CO2 in the air in the cabin are captured by a functional material such as an adsorbent material, and then, by heating, the components to be removed react or are released and discharged to the outside of the vehicle to regenerate the functional material. In the above vehicle air conditioning system, it is required that the air comes into contact with the functional material as much as possible to ensure the capture performance of the components to be removed, and in addition, the functional material can be heated to a specified temperature to promote the regeneration of the functional material. Regarding regeneration, for example, a method of removing the components to be removed adsorbed on the functional material by an oxidation reaction, a method of discharging the components to be removed adsorbed on the functional material by desorption, etc. are used for regeneration. However, in each case, the functional material needs to be heated to an appropriate temperature according to the type of the adsorbed components to be removed.

[0004] Patent Document 3 discloses a heater member having a columnar honeycomb structure with an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of compartments. The plurality of compartments form flow paths from a first end face to a second end face. The partition walls have PTC characteristics, the average thickness of the partition walls is 0.13 mm or less, and the opening ratio of the first end face and the second end face is 0.81 or more. This heater member is used for heating in a vehicle compartment and can increase the heating area due to its honeycomb structure, so it is an efficient heating mechanism. Therefore, it can be considered that if such a heater member is used as a carrier for a functional material, it can contribute to shortening the regeneration time of the functional material. In particular, it can be considered that this heater member can be heated by energization and has PTC (Positive Temperature Coefficient) characteristics. Thus, it can easily heat the functional material. On the other hand, it can also suppress overheating and thereby suppress the thermal degradation of the functional material. In addition, since the possibility of reaching an excessively high temperature is avoided, even if the initial resistance is set small to accelerate the heating speed, safety can be ensured and the temperature can be raised in a short time.

[0005] On the other hand, from the viewpoints of improving heating efficiency and reducing power consumption, an air conditioning system using a heat pump cycle is known. However, this air conditioning system has insufficient heating efficiency, i.e., insufficient warmth, in cold weather such as below freezing. Therefore, it has been proposed to use a PTC heater also as an auxiliary heat source (for example, Patent Document 4).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2020 - 104774

[0009] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2020 - 111282

[0010] Patent Document 3: International Publication No. 2020 / 036067

[0011] Patent Document 4: International Publication No. 2011 / 016264 Summary of the Invention

[0012] In a vehicle air conditioning system using a heat pump cycle, from the viewpoint of heating efficiency in cold weather, i.e., warmth, it is preferable to mount a PTC heater as an auxiliary heat source. From the viewpoint of removing moisture and the like in the air in the vehicle compartment, it is preferable to mount a humidity control device. However, when both the PTC heater and the humidity control device are mounted on the vehicle air conditioning system, the vehicle air conditioning system becomes larger.

[0013] The present invention is implemented to solve the above-described problems, and an object thereof is to provide a vehicle air conditioning system using a heat pump cycle and a control method thereof, which have excellent heating efficiency and immediate warming property in cold weather, can remove moisture in the air in the vehicle compartment, and can be miniaturized.

[0014] The inventors of the present invention have intensively studied a vehicle air conditioning system using a heat pump cycle, and as a result, found that by disposing a specific humidity control device in the air conditioning passage and heating the air through the humidity control device at the start of the heating operation mode of the heat pump cycle, the heating efficiency and immediate warming property in cold weather can be improved. Therefore, a PTC heater is not required and miniaturization can be achieved, thus completing the present invention. That is, the present invention is illustrated as follows.

[0015] [1] A vehicle air conditioning system, comprising:

[0016] an air conditioning passage through which air can flow;

[0017] a humidity control device disposed in the air conditioning passage;

[0018] a heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device; and

[0019] a control unit that controls the humidity control device and the heat pump cycle according to an operation mode,

[0020] The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surfaces of the partition walls,

[0021] The control unit includes a heating mode in which the air is heated through the humidity control device at the start of the heating operation mode of the heat pump cycle.

[0022] [2] The vehicle air conditioning system according to [1], wherein

[0023] the heating of the air by the humidity control device is performed during a period from the start of the heating operation mode of the heat pump cycle to 10 minutes.

[0024] [3] The vehicle air conditioning system according to [1] or [2], wherein

[0025] the heating of the air by the humidity control device stops at a stage where the heating COP of the heat pump cycle reaches a specified value of 1.0 or more.

[0026] [4] The vehicle air conditioning system according to any one of [1] to [3], wherein,

[0027] The air conditioning passage has an inflow path for the air to flow into the passenger compartment and an outflow path for the air to flow out of the vehicle between the humidity control device and the condenser, and a valve capable of switching the flow of the air is provided between the inflow path and the outflow path.

[0028] The condenser is disposed within the inflow path.

[0029] [5] The vehicle air conditioning system according to [4], wherein,

[0030] The heating mode of the humidity control device is as follows: the valve is controlled so that the air flows into the inflow path, and a voltage is applied to the humidity control device and the air is circulated.

[0031] [6] The vehicle air conditioning system according to [4] or [5], wherein,

[0032] The humidity control device further includes at least one operating mode selected from a dehumidifying mode and a regeneration mode.

[0033] In the dehumidifying mode, the valve is controlled so that the air flows into the inflow path, and the air is circulated through the humidity control device, thereby performing dehumidification.

[0034] In the regeneration mode, the valve is controlled so that the air flows out to the outflow path, and the humidity control device is heated and the air is circulated, thereby regenerating the moisture absorption layer.

[0035] [7] The vehicle air conditioning system according to any one of [1] to [6], wherein,

[0036] The heat pump cycle further includes: a compressor that compresses and ejects a refrigerant.

[0037] The heating operation mode of the heat pump cycle includes: introducing the refrigerant ejected from the compressor into the condenser to heat the air.

[0038] [8] The vehicle air conditioning system according to any one of [1] to [7], wherein,

[0039] The humidity control device further includes a pair of electrodes, and the pair of electrodes are provided on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall of the honeycomb structure parallel to the direction in which the compartments extend.

[0040] [9] The vehicle air conditioning system according to any one of [1] to [8], wherein,

[0041] The moisture absorption layer can adsorb not only moisture but also carbon dioxide and / or volatile components.

[0042]

[10] A control method for a vehicle air conditioning system, the vehicle air conditioning system comprising:

[0043] An air conditioning passage through which air can flow;

[0044] A humidity control device disposed in the air conditioning passage; and

[0045] A heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device,

[0046] The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition walls,

[0047] In the vehicle air conditioning system, there is a heating mode in which the air is heated by the humidity control device at the start of the heating operation mode of the heat pump cycle.

[0048]

[11] The control method for a vehicle air conditioning system according to

[10] , wherein,

[0049] The heating of the air by the humidity control device is performed during the period from the start of the heating operation mode of the heat pump cycle to 10 minutes.

[0050]

[12] The control method for a vehicle air conditioning system according to

[10] or

[11] , wherein,

[0051] The heating of the air by the humidity control device stops at a stage where the heating COP of the heat pump cycle reaches a specified value of 1.0 or more.

[0052]

[13] The control method for a vehicle air conditioning system according to any one of

[10] to

[12] , wherein,

[0053] The air conditioning passage has an inflow path for the air to flow into the vehicle compartment and an outflow path for the air to flow out of the vehicle between the humidity control device and the condenser, and a valve capable of switching the flow of the air is provided between the inflow path and the outflow path.

[0054] The condenser is disposed in the inflow path.

[0055]

[14] The control method of the vehicle air conditioning system according to

[13] , wherein

[0056] The heating mode of the humidity control device is as follows: the valve is controlled so that the air flows into the inflow path, and a voltage is applied to the humidity control device and the air is circulated.

[0057]

[15] The control method of the vehicle air conditioning system according to

[13] or

[14] , wherein

[0058] The humidity control device further includes at least one operating mode selected from a dehumidification mode and a regeneration mode.

[0059] In the dehumidification mode, the valve is controlled so that the air flows into the inflow path, and the air is circulated through the humidity control device, thereby performing dehumidification.

[0060] In the regeneration mode, the valve is controlled so that the air flows out to the outflow path, and the humidity control device is heated and the air is circulated, thereby regenerating the moisture absorption layer.

[0061]

[16] The control method of the vehicle air conditioning system according to any one of

[10] to

[15] , wherein

[0062] The heat pump cycle further includes a compressor that compresses and ejects a refrigerant.

[0063] The heating operation mode of the heat pump cycle includes: introducing the refrigerant ejected from the compressor into the condenser to heat the air.

[0064] Advantageous Effects of the Invention

[0065] According to the present invention, it is possible to provide a vehicle air conditioning system using a heat pump cycle and a control method thereof, which have excellent heating efficiency and immediate warming property in cold weather, can remove moisture in the air in the vehicle compartment, and can be miniaturized. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1AIt is a schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention, and is a diagram showing the working state in a heating / heating operation mode.

[0067] Figure 1B It is a schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention, and is a diagram showing the working state in a dehumidifying / cooling operation mode.

[0068] Figure 1C It is a schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention, and is a diagram showing the working state in a dehumidifying / cooling operation mode.

[0069] Figure 1D It is a schematic configuration diagram of a vehicle air conditioning system according to an embodiment of the present invention, and is a diagram showing the working state in a regeneration / non-cooling heating operation mode.

[0070] Figure 2A It is a schematic diagram of a cross section parallel to the flow path direction of a humidity control device used in a vehicle air conditioning system according to an embodiment of the present invention.

[0071] Figure 2B It is Figure 2A a schematic diagram of the cross section of the a-a' line in the humidity control device.

[0072] Symbol description

[0073] 10... air conditioning passage, 11... inflow path, 12... outflow path, 13... valve, 20... humidity control device, 21... outer peripheral wall, 22a... first end face, 22b... second end face, 23... compartment, 24... partition wall, 25... honeycomb structure, 26... moisture absorption layer, 27a, 27b... pair of electrodes, 28... terminal, 30... heat pump cycle, 31... condenser, 32... evaporator, 33... compressor, 34... outdoor heat exchanger, 35a, 35b... expansion valve, 36a - 36e... shut-off valve, 40... control unit, 50... power supply, 60... ventilator, 70... air mixing door. Detailed implementation mode

[0074] The vehicle air conditioning system of the present invention includes: an air conditioning passage through which air can flow; a humidity control device disposed in the air conditioning passage; a heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device; and a control unit that controls the humidity control device and the heat pump cycle according to an operation mode. The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition walls. The control unit includes a heating mode in which air is heated by the humidity control device at the start of the heating operation mode of the heat pump cycle. By adopting such a configuration, the vehicle air conditioning system of the present invention has excellent heating efficiency and quick warm-up property in cold weather. Therefore, it is not necessary to install a PTC heater, and miniaturization can be achieved. In addition, since the vehicle air conditioning system is provided with a humidity control device, it can also remove moisture and the like in the air in the vehicle compartment.

[0075] In addition, regarding the control method of the vehicle air conditioning system of the present invention, it includes a heating mode in which air is heated by the humidity control device at the start of the heating operation mode of the heat pump cycle in the vehicle air conditioning system. The vehicle air conditioning system includes: an air conditioning passage through which air can flow; a humidity control device disposed in the air conditioning passage; and a heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device. The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition walls. By adopting such a configuration, the control method of the vehicle air conditioning system of the present invention can improve the heating efficiency and quick warm-up property in cold weather even though no PTC heater is installed. In addition, regarding the control method of the vehicle air conditioning system, since it is provided with a humidity control device, it can also remove moisture and the like in the air in the vehicle compartment.

[0076] Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that solutions obtained by appropriately changing and improving the following embodiments based on the common knowledge of those skilled in the art without departing from the gist of the present invention also fall within the scope of the present invention.

[0077] <Vehicle air conditioning system>

[0078] The vehicle air conditioning system according to an embodiment of the present invention is used for various vehicles such as automobiles. The vehicle is not particularly limited, and examples thereof include automobiles and electric trains. The automobile is not particularly limited, and examples thereof include gasoline vehicles, diesel vehicles, gaseous fuel vehicles using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. The vehicle air conditioning system according to an embodiment of the present invention can be particularly preferably used for vehicles without an internal combustion engine such as electric vehicles and electric trains.

[0079] Figures 1A to 1D It is a schematic configuration diagram of the vehicle air conditioning system according to an embodiment of the present invention and is a diagram showing the working states in each operation mode. In particular, Figure 1A is the heating / heating operation mode, Figure 1B and Figure 1C is the dehumidification / cooling operation mode, Figure 1D is the regeneration / unrefrigerated heating operation mode. It should be noted that for the dehumidification / heating operation mode, its diagram is the same as Figure 1A and is thus omitted. Figure 2A It is a schematic diagram of a cross section parallel to the flow path direction of the humidity control device used in the vehicle air conditioning system according to an embodiment of the present invention. Figure 2B is Figure 2A a cross-sectional schematic diagram of the a-a' line in the humidity control device.

[0080] The vehicle air conditioning system according to an embodiment of the present invention includes: an air conditioning passage 10, a humidity control device 20, a heat pump cycle 30, and a control unit 40. In addition, the vehicle air conditioning system may further include: a power supply 50, a ventilator 60, and an air mixing door 70.

[0081] Hereinafter, each of the above-described constituent elements will be described in detail.

[0082] (1. Air conditioning passage 10)

[0083] The air conditioning passage 10 is a pipe through which air from the passenger compartment or outside the vehicle can flow.

[0084] The shape, size, etc. of the air conditioning passage 10 may be appropriately adjusted according to the type of vehicle and the like, and are not particularly limited.

[0085] The air conditioning passage 10 preferably has an inflow path 11 for air to flow into the passenger compartment and an outflow path 12 for air to flow out of the vehicle between the humidity control device 20 and the condenser 31 of the heat pump cycle 30.

[0086] A valve 13 capable of switching the flow of air is preferably provided between the inflow path 11 and the outflow path 12.

[0087] The valve 13 can be arranged at the branch of the inflow path 11 and the outflow path 12. Regarding the switching of the valve 13, for example, the control unit 40 and the valve 13 are electrically connected by wires or wirelessly, and the control unit 40 operates the opening and closing of the valve 13, thereby enabling the switching of the valve 13.

[0088] As the valve 13, as long as it has the function of being electrically driven and switching the flow path, there is no particular limitation, and an electromagnetic valve and an electric valve can be cited. For example, the valve 13 can be cited as: an opening and closing door supported on a rotating shaft, and an actuator such as a motor that rotates the rotating shaft. The actuator is configured to be controllable by the control unit 40.

[0089] (2. Humidity control device 20)

[0090] The humidity control device 20 is arranged in the air conditioning passage 10. The humidity control device 20 includes: a honeycomb structure 25 having an outer peripheral wall 21 and partition walls 24, the partition walls 24 being arranged inside the outer peripheral wall 21 and partitioning to form a plurality of compartments 23, the plurality of compartments 23 extending from the first end face 22a to the second end face 22b to form a flow path, and at least the partition walls 24 being made of a material having PTC characteristics; and a moisture absorption layer 26 formed on the surface of the partition walls 24. The humidity control device 20 may further include: a pair of electrodes 27a, 27b for applying a voltage to the honeycomb structure 25 and terminals 28 connected to the pair of electrodes 27a, 27b.

[0091] When air from the vehicle compartment or outside the vehicle flows into the humidity control device 20 through the air conditioning passage 10, during the passage through the humidity control device 20, moisture in the air is captured (removed) by the moisture absorption layer 26. And the air with reduced moisture can flow into the vehicle compartment through the inflow path 11.

[0092] On the other hand, the performance of the moisture absorption layer 26 gradually decreases as the amount of moisture captured increases. Therefore, the moisture absorption layer 26 must be regenerated. The regeneration process of the moisture absorption layer 26 is as follows: a voltage is applied to the pair of electrodes 27a, 27b by a power supply 50 controlled by the control unit 40 to heat the honeycomb structure 25. Since the moisture absorption layer 26 is directly heated by the heating of the honeycomb structure 25, the moisture captured by the moisture absorption layer 26 can efficiently detach or react from the moisture absorption layer 26 and be released to the outside of the vehicle via the outflow path 12.

[0093] (2-1. Honeycomb structure 25)

[0094] The shape of the honeycomb structure 25 is not particularly limited. For example, the outer shape of the cross section of the honeycomb structure 25 orthogonal to the flow path direction (the direction in which the compartments 23 extend) can be a polygon such as a quadrilateral (rectangle, square), pentagon, hexagon, heptagon, octagon, etc., a circle, a shape with an arc (oval, ellipse, oblong, rounded rectangle, etc.), and the like. It should be noted that the end faces (the first end face 22a and the second end face 22b) have the same shape as this cross section. In addition, when the cross section and the end face are polygons, the corners can be chamfered.

[0095] The shape of the compartment 23 is not particularly limited. In the cross section of the honeycomb structure 25 orthogonal to the flow path direction, it can be a polygon such as a quadrilateral, pentagon, hexagon, heptagon, octagon, etc., a circle, or a shape with an arc. These shapes can be single or a combination of two or more. In addition, among these shapes, a quadrilateral or a hexagon is preferred. By providing the compartment 23 with such a shape, the pressure loss during air flow can be reduced.

[0096] The honeycomb structure 25 can be a honeycomb bonded body having a plurality of honeycomb cells and a bonding layer that indirectly bonds the outer peripheral side surfaces of the plurality of honeycomb cells to each other. By using the honeycomb bonded body, the generation of cracks can be suppressed, and the total cross-sectional area of the compartments 23, which is very important for ensuring the air flow rate, can be increased.

[0097] It should be noted that a bonding material can be used to form the bonding layer. As the bonding material, there is no particular limitation, and a material made by adding a solvent such as water to a ceramic material to form a paste-like material can be used. The bonding material can contain a material having PTC characteristics, or can contain the same material as the outer peripheral wall 21 and the partition wall 24. In addition to the function of bonding the honeycomb cells to each other, the bonding material can also be used as an outer peripheral coating material after the honeycomb cells are bonded.

[0098] From the viewpoints of ensuring the strength of the honeycomb structure 25, reducing the pressure loss when air passes through the compartments 23, ensuring the loading amount of the moisture absorption layer 26, and ensuring the contact area with the air flowing in the compartments 23, etc., it is preferable to well combine the thickness of the partition wall 24, the compartment density, and the compartment pitch (or the opening ratio of the compartments 23).

[0099] In this specification, the compartment density is a value obtained by dividing the number of compartments by the area of one end face (the first end face 22a or the second end face 22b) of the honeycomb structure 25 (the total area of the partition wall 24 and the compartments 23 excluding the outer peripheral wall 21).

[0100] In this specification, the compartment pitch refers to the value obtained through the following calculation. First, the area of one end face (the first end face 22a or the second end face 22b) of the honeycomb structure 25 (the total area of the partition walls 24 and the compartments 23 excluding the peripheral wall 21) is divided by the number of compartments to calculate the area of each compartment. Next, the square root of the area of each compartment is calculated and set as the compartment pitch.

[0101] In this specification, the opening ratio of the compartment 23 is the value obtained by dividing the total area of the compartments 23 partitioned by the partition walls 24 by the area of one end face (the first end face 22a or the second end face 22b) of the honeycomb structure 25 (the total area of the partition walls 24 and the compartments 23 excluding the peripheral wall 21) in a cross-section orthogonal to the flow path direction. It should be noted that when calculating the opening ratio of the compartment 23, the pair of electrodes 27a, 27b and the dehumidifying layer 26 are not considered.

[0102] In an advantageous embodiment from the viewpoint of supporting a sufficient amount of the moisture-absorbing layer 26, the thickness of the partition wall 24 is 0.300 mm or less, the compartment density is 100 compartments / cm 2 or less, and the compartment pitch is 1.0 mm or more. In a preferred embodiment, the thickness of the partition wall 24 is 0.200 mm or less, the compartment density is 70 compartments / cm 2 or less, and the compartment pitch is 1.2 mm or more. In a more preferred embodiment, the thickness of the partition wall 24 is 0.130 mm or less, the compartment density is 65 compartments / cm 2 or less, and the compartment pitch is 1.3 mm or more.

[0103] From the viewpoints of ensuring the strength of the honeycomb structure 25 and maintaining the resistance at a low level, the lower limit of the thickness of the partition wall 24 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and further preferably 0.030 mm or more.

[0104] From the viewpoints of ensuring the strength of the honeycomb structure 25, maintaining the resistance at a low level, and increasing the surface area to promote reactions, adsorption, and desorption, the lower limit of the compartment density is preferably 30 compartments / cm 2 or more, more preferably 35 compartments / cm 2 or more, and further preferably 40 compartments / cm 2 or more.

[0105] From the viewpoints of ensuring the strength of the honeycomb structure 25, maintaining the resistance at a low level, and increasing the surface area to promote reactions, adsorption, and desorption, the upper limit of the compartment pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and further preferably 1.6 mm or less.

[0106] In an advantageous embodiment from the viewpoint of simultaneously reducing the pressure loss and maintaining the strength, the thickness of the partition wall 24 is 0.08 to 0.36 mm, the compartment density is 2.54 to 140 compartments / cm 2 , and the opening ratio of the compartment 23 is 0.70 or more. In a preferred embodiment, the thickness of the partition wall 24 is 0.09 to 0.35 mm, the compartment density is 15 to 100 compartments / cm 2 , and the opening ratio of the compartment 23 is 0.80 or more. In a more preferred embodiment, the thickness of the partition wall 24 is 0.14 to 0.30 mm, the compartment density is 20 to 90 compartments / cm 2 , and the opening ratio of the compartment 23 is 0.85 or more.

[0107] From the viewpoint of ensuring the strength of the honeycomb structure 25, the upper limit of the opening ratio of the compartment 23 is preferably 0.94 or less, more preferably 0.92 or less, and further preferably 0.90 or less.

[0108] The thickness of the outer peripheral wall 21 is not particularly limited, and is preferably determined based on the following viewpoints. First, from the viewpoint of strengthening the honeycomb structure 25, the thickness of the outer peripheral wall 21 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and further preferably 0.08 mm or more. On the other hand, from the viewpoints of increasing the resistance to suppress the initial current and reducing the pressure loss during air flow, the thickness of the outer peripheral wall 21 is preferably 1.0 mm or less, more preferably 0.5 mm or less, further preferably 0.4 mm or less, and still further preferably 0.3 mm or less.

[0109] In this specification, the thickness of the outer peripheral wall 21 means: in a cross section of the honeycomb structure 25 orthogonal to the flow path direction, the length in the normal direction of the side surface from the boundary between the outer peripheral wall 21 and the outermost peripheral side compartment 23 or partition wall 24 to the side surface of the honeycomb structure 25.

[0110] The length of the honeycomb structure 25 in the flow path direction and the cross-sectional area orthogonal to the flow path direction can be adjusted according to the size of the required humidity control device 20, and are not particularly limited. For example, in the case of a humidity control device 20 that ensures a specified function and is compact, in the honeycomb structure 25, the length in the flow path direction can be set to 2 to 20 mm, and the cross-sectional area orthogonal to the flow path direction can be set to 10 cm 2 or more. It should be noted that the upper limit value of the cross-sectional area orthogonal to the flow path direction is not particularly limited, for example, it is 300 cm 2 or less.

[0111] The partition wall 24 constituting the honeycomb structure 25 is made of a material that can generate heat by energization, specifically, a material having PTC characteristics. If necessary, the outer peripheral wall 21 may also be made of a material having PTC characteristics in the same manner as the partition wall 24. By adopting such a configuration, it is possible to directly heat the moisture absorption layer 26 by heat transfer from the heat-generating partition wall 24 (and the outer peripheral wall 21 if necessary). In addition, a material having PTC characteristics has the following property: when the temperature rises and exceeds the Curie point, the resistance value rises sharply, making it difficult for current to flow. Therefore, when the partition wall 24 (and the outer peripheral wall 21 if necessary) reaches a high temperature, the current flowing through them is restricted, and thus, excessive heat generation of the honeycomb structure 25 is suppressed. Therefore, thermal deterioration of the moisture absorption layer 26 caused by excessive heat generation can also be suppressed.

[0112] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity of the material having PTC characteristics at 25°C is preferably 0.5 Ω·cm or more, more preferably 1 Ω·cm or more, and further preferably 5 Ω·cm or more. From the viewpoint of causing it to generate heat at a low driving voltage, the upper limit of the volume resistivity of the material having PTC characteristics at 25°C is preferably 30 Ω·cm or less, more preferably 18 Ω·cm or less, and further preferably 16 Ω·cm or less. In this specification, the volume resistivity of the material having PTC characteristics at 25°C is measured in accordance with JIS K6271:2008.

[0113] From the viewpoint of being able to generate heat by energization and having PTC characteristics, the outer peripheral wall 21 and the partition wall 24 are preferably made of a material mainly composed of barium titanate (BaTiO3). In addition, this material is more preferably a ceramic made of a material mainly composed of BaTiO3-based crystalline particles in which a part of Ba is replaced by a rare earth element. It should be noted that in this specification, "main component" means a component that occupies a proportion of more than 50% by mass in the overall composition. The content of BaTiO3-based crystalline particles can be determined by fluorescence X-ray analysis. For other crystalline particles, they can also be measured in the same manner as this method.

[0114] The composition formula of BaTiO3-based crystalline particles in which a part of Ba is replaced by a rare earth element can be expressed as (Ba 1-x A x )TiO3. In the composition formula, A represents one or more rare earth elements, and 0.0001 ≤ x ≤ 0.010.

[0115] A may be any rare earth element without particular limitation, and is preferably at least one selected from the group consisting of La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Er, Y, and Yb, and more preferably La. From the viewpoint of suppressing excessive resistance at room temperature, x is preferably 0.001 or more, and more preferably 0.0015 or more. On the other hand, from the viewpoint of suppressing excessive resistance at room temperature due to insufficient sintering, x is preferably 0.009 or less.

[0116] The content of BaTiO3-based crystalline particles in the ceramic, in which a part of Ba is replaced with a rare earth element, may be any amount as long as it is the main component, without particular limitation, and is preferably 90% by mass or more, more preferably 92% by mass or more, and further preferably 94% by mass or more. It should be noted that the upper limit value of the content of BaTiO3-based crystalline particles is not particularly limited and is usually 99% by mass, preferably 98% by mass.

[0117] The content of the BaTiO3-based crystalline particles can be measured by fluorescent X-ray analysis. For other crystalline particles, they can also be measured in the same manner as this method.

[0118] From the viewpoint of reducing the environmental load, the materials for the outer peripheral wall 21 and the partition wall 24 preferably contain substantially no lead (Pb). Specifically, in the outer peripheral wall 21 and the partition wall 24, the Pb content is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and further preferably 0% by mass. By having a small Pb content, air that is heated by contacting the partition wall 24 during heating, for example, can be safely blown toward a living being such as a human. It should be noted that in the outer peripheral wall 21 and the partition wall 24, the Pb content in terms of PbO conversion is preferably less than 0.03% by mass, more preferably less than 0.01% by mass, and further preferably 0% by mass. The content of lead can be determined by ICP-MS (inductively coupled plasma mass spectrometry).

[0119] The Curie point of the materials constituting the outer peripheral wall 21 and the partition wall 24 is preferably in the temperature range when the resistance value at room temperature (25 °C) becomes twice or more the resistance value. If the Curie point is in such a temperature range, when the humidity control device 20 reaches a high temperature, the current flowing through them is restricted, and thus, excessive heating of the humidity control device 20 can be efficiently suppressed. Therefore, thermal degradation of the moisture absorption layer 26 caused by excessive heating can be suppressed.

[0120] From the viewpoint of efficiently heating the moisture absorption layer 26, the lower limit of the Curie point of the material constituting the outer peripheral wall 21 and the partition wall 24 is preferably 80°C or higher, more preferably 100°C or higher, further preferably 110°C or higher, and particularly preferably 125°C or higher. In addition, from the viewpoint of the safety of the components placed in or near the vehicle compartment, the upper limit of the Curie point is preferably 200°C or lower, more preferably 190°C or lower, further preferably 180°C or lower, and particularly preferably 150°C or lower.

[0121] The Curie point of the material constituting the outer peripheral wall 21 and the partition wall 24 can be adjusted by the type and addition amount of the displacement agent. For example, the Curie point of barium titanate (BaTiO3) is about 120°C, and by replacing a part of Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to the low temperature side.

[0122] In this specification, the Curie point is measured by the following method. The specimen is installed in the specimen holder for measurement and assembled in the measurement tank (e.g., MINI-SUBZERO MC-810P manufactured by Espec Corporation), and the change in the resistance of the specimen with respect to the temperature change during heating from 10°C is measured using a DC resistance meter (e.g., multimeter 3478A manufactured by YOKOGAWA HEWLETT PACKARD, LTD). Based on the measured resistance-temperature graph, the temperature at which the resistance value becomes twice the resistance value at room temperature (20°C) is set as the Curie point.

[0123] (2 - 2. A pair of electrodes 27a, 27b)

[0124] The positions of the pair of electrodes 27a, 27b can be set on the first end face 22a and the second end face 22b as shown. In addition, the positions of the pair of electrodes 27a, 27b can also be set on the outer peripheral wall 21 parallel to the extending direction of the compartment 23. Figure 2A

[0125] By applying a voltage between the pair of electrodes 27a, 27b, the honeycomb structure 25 can be heated by Joule heat.

[0126] ​The pair of electrodes 27a and 27b is not particularly limited. For example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si can be used. Additionally, an ohmic electrode that can make ohmic contact with the outer peripheral wall 21 having PTC characteristics and / or the partition wall 24 can be used. As the ohmic electrode, for example, an ohmic electrode containing at least one selected from Al, Au, Ag, and In as the base metal and at least one selected from Ni, Si, Zn, Ge, Sn, Se, and Te for n-type semiconductors as the dopant can be used. Further, the pair of electrodes 27a and 27b can have a single-layer structure or a laminated structure of two or more layers. When the pair of electrodes 27a and 27b has a laminated structure of two or more layers, the materials of each layer can be of the same type or different types.

[0127] The thickness of the pair of electrodes 27a and 27b can be appropriately set according to the formation method of the pair of electrodes 27a and 27b. Examples of the formation method of the pair of electrodes 27a and 27b include metal deposition methods such as sputtering, evaporation plating, electrolytic deposition, and chemical deposition. Additionally, the pair of electrodes 27a and 27b can be formed by a method of sintering after coating an electrode paste or by cladding. Further, the pair of electrodes 27a and 27b can be made by joining a metal plate or an alloy plate.

[0128] Regarding the thickness of the pair of electrodes 27a and 27b, for example, in the sintering of the electrode paste, the thickness is preferably about 5 to 30 μm, in dry plating such as sputtering and evaporation plating, the thickness is preferably about 100 to 1000 nm, in cladding, the thickness is preferably about 10 to 100 μm, and in wet plating such as electrolytic deposition and chemical deposition, the thickness is preferably about 5 to 30 μm. Additionally, in the joining of a metal plate or an alloy plate, it is preferable to set their thickness to about 5 to 100 μm.

[0129] (2 - 3. Terminal 28)

[0130] The terminal 28 is connected to the pair of electrodes 27a and 27b, and the terminal 28 is provided on at least a part of the pair of electrodes 27a and 27b. By providing the terminal 28, the connection to an external power source becomes easy. The terminal 28 is connected to a wire connected to the power source 50.

[0131] The material of the terminal 28 is not particularly limited. For example, it can be a metal. As the metal, a simple metal and an alloy, etc. can be used. From the viewpoints of corrosion resistance, resistivity, and linear expansion rate, for example, an alloy containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti is preferably used, and stainless steel, Fe-Ni alloy, and phosphor bronze are more preferably used.

[0132] The size and shape of the terminal 28 are not particularly limited. For example, as Figure 2A shown, the terminal 28 can be provided on the entirety of a pair of electrodes 27a and 27b on the outer peripheral wall 21. Additionally, the terminal 28 can be provided on a part of a pair of electrodes 27a and 27b on the outer peripheral wall 21, or can be provided to extend more outward than the outer edges of a pair of electrodes 27a and 27b on the outer peripheral wall 21. Further, the terminal 28 can be provided on a part of a pair of electrodes 27a and 27b on the partition wall 24, or can be provided to block a part of the compartment 23.

[0133] In addition, the thickness of the terminal 28 is not particularly limited, for example, it is 0.01 to 10 mm, typically 0.05 to 5 mm.

[0134] Regarding the connection method between the terminal 28 and the pair of electrodes 27a and 27b, as long as it is electrically connected, it is not particularly limited. For example, it can be connected by diffusion bonding, a mechanical pressing mechanism, welding, etc.

[0135] (2 - 4. Moisture-absorbing layer 26)

[0136] The moisture-absorbing layer 26 can be provided on the surface of the partition wall 24 (in the case of the outermost compartment 23, the partition wall 24 and the outer peripheral wall 21 that demarcate the outermost compartment 23). By providing the moisture-absorbing layer 26 in this way, it is easy to heat the moisture-absorbing layer 26 during the regeneration process. Therefore, the moisture-absorbing function brought by the moisture-absorbing layer 26 can be regenerated.

[0137] The moisture-absorbing layer 26 contains a moisture-absorbing material.

[0138] The moisture-absorbing material preferably has the function of being able to adsorb moisture (water vapor) at -20 to 40°C and desorb it at a high temperature of 60°C or higher. Examples of moisture-absorbing materials having such a function include: aluminosilicates, silica gels, silica, graphene oxide, polymer moisture-absorbing materials, polystyrenesulfonic acid, and metal-organic frameworks (MOF: Metal Organic Framework). These materials can be used alone or in combination of two or more.

[0139] As the aluminosilicate, it is preferable to use porous clay minerals such as zeolites of the AFI type, CHA type, or BEA type, allophane, and filamentous allophane. Additionally, the aluminosilicate is preferably amorphous.

[0140] As the silica gel, it is preferable to use type A silica gel.

[0141] As the polymer moisture-absorbing material, it is preferably a material having a polyacrylic acid-based polymer chain. For example, as the polymer moisture-absorbing material, sodium polyacrylate, etc. can be used.

[0142] The metal-organic structure is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). The metal ions are preferably hydrophilic metal ions (such as aluminum ions).

[0143] The moisture absorption layer 26 may contain a functional material other than the moisture absorption material, or a catalyst. As the functional material other than the moisture absorption material, any material capable of enabling it to exhibit the desired function may be used, and there is no particular limitation. Adsorbing materials, etc. may be used. The adsorbing material preferably has a function of adsorbing at least one selected from carbon dioxide and volatile components. The moisture absorption layer 26 containing the above-mentioned adsorbing material can adsorb not only moisture but also carbon dioxide and / or volatile components. In addition, by using a catalyst, the component to be removed can be purified. Further, for the purpose of improving the capturing function of the adsorbing material for capturing the component to be removed, etc., the adsorbing material and the catalyst may be used in combination.

[0144] Examples of the adsorbing material include zeolite, silica gel, activated carbon, alumina, silica, low-crystalline clay, amorphous aluminosilicate complex, etc. Some of these components can also function as moisture absorption materials. The adsorbing material may be used alone or in combination of two or more.

[0145] As the catalyst, it preferably has a function of promoting redox reactions. Examples of the catalyst having such a function include metal catalysts such as Pt, Pd, Ag, and oxide catalysts such as CeO2, ZrO2, etc. The catalyst may be used alone or in combination of two or more.

[0146] The volatile components contained in the air in the vehicle compartment are, for example, volatile organic compounds (VOCs), or odor components other than VOCs, etc. Specific examples of the volatile components include ammonia, acetic acid, isovaleric acid, nonenal, formaldehyde, toluene, xylene, p-dichlorobenzene, ethylbenzene, styrene, chlorpyrifos, di-n-butyl phthalate, tetradecane, bis(2-ethylhexyl) phthalate, diazinon, acetaldehyde, N-methylcarbamate-2-(1-methylpropyl)phenyl ester, etc.

[0147] The thickness of the moisture absorption layer 26 may be determined according to the size of the compartment 23, and there is no particular limitation. For example, from the viewpoint of sufficiently ensuring contact with air, the thickness of the moisture absorption layer 26 is preferably 20 μm or more, more preferably 25 μm or more, and still more preferably 30 μm or more. On the other hand, from the viewpoint of suppressing peeling of the moisture absorption layer 26 from the partition wall 24 or the outer peripheral wall 21, the thickness of the moisture absorption layer 26 is preferably 400 μm or less, more preferably 380 μm or less, and still more preferably 350 μm or less.

[0148] The thickness of the moisture-absorbing layer 26 is measured as follows. Cut out: an arbitrary cross-section parallel to the flow path direction of the honeycomb structure 25, and obtain a cross-sectional image at about 50 times magnification using a scanning electron microscope or the like. In addition, this cross-section is passed through the center of gravity position in the cross-section orthogonal to the flow path of the honeycomb structure 25. For each moisture-absorbing layer 26 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length in the flow path direction of the compartment 23. This calculation is performed for all the moisture-absorbing layers 26 visible in this cross-sectional image, and the overall average value is set as the thickness of the moisture-absorbing layer 26.

[0149] From the viewpoint of the moisture-absorbing material or the like exerting the desired function in the humidity control device 20, the amount of the moisture-absorbing layer 26 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and still more preferably 150 to 350 g / L with respect to the volume of the honeycomb structure 25. It should be noted that the volume of the honeycomb structure 25 is a value determined according to the external dimensions of the honeycomb structure 25.

[0150] (2 - 5. Manufacturing method of the humidity control device 20)

[0151] The manufacturing method of the humidity control device 20 is not particularly limited and can be carried out according to a known method. Hereinafter, a method for manufacturing the humidity control device 20 will be illustratively described.

[0152] The manufacturing method of the honeycomb structure 25 constituting the humidity control device 20 includes a molding step and a firing step.

[0153] In the molding step, a green body of a ceramic raw material containing powders including BaCO3 powder, TiO2 powder, and a nitrate or hydroxide of a rare earth is molded to produce a honeycomb green body having a relative density of 60% or more.

[0154] Each powder can be dry-mixed in a desired composition to obtain a ceramic raw material.

[0155] A green body can be obtained by adding a dispersion medium, a binder, a plasticizer, and a dispersant to the ceramic raw material and kneading them. Additives such as a displacement agent, a metal oxide, a property improver, and a conductive powder can be contained in the green body as needed.

[0156] The blending amount of the components other than the ceramic raw material is not particularly limited as long as it is an amount that makes the relative density of the honeycomb green body reach 60% or more.

[0157] Here, the "relative density of the honeycomb green body" in this specification means the ratio of the density of the honeycomb green body to the true density of the entire ceramic raw material. Specifically, it can be obtained by the following formula.

[0158] Relative density (%) of the honeycomb formed body = Density of the honeycomb formed body (g / cm 3 ) / True density of the entire ceramic raw material (g / cm 3 ) × 100

[0159] The density of the honeycomb formed body can be measured by the Archimedes method using pure water as the medium. In addition, the true density of the entire ceramic raw material can be obtained by dividing the total mass value (g) of each raw material by the total actual volume value (cm 3 ) of each raw material.

[0160] As the dispersion medium, examples include: water, or a mixed solvent of water and an organic solvent such as alcohol, etc., and water can be particularly preferably used.

[0161] As the binder, examples include: organic binders such as methyl cellulose, hydroxypropoxy cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, etc. It is particularly preferred to use a combination of methyl cellulose and hydroxypropoxy cellulose. The binder can be used alone or in combination of two or more, however, it is preferably free of alkali metal elements.

[0162] As the plasticizer, examples include: polyoxyethylene alkyl ether, polycarboxylic acid-based polymer, alkyl phosphate ester, etc.

[0163] As the dispersant, surfactants such as polyoxyethylene alkyl ether, ethylene glycol, dextrin, fatty acid soap, polyhydric alcohol, etc. can be used. The dispersant can be used alone or in combination of two or more.

[0164] The honeycomb formed body can be produced by extruding the blank. During extrusion molding, a die having a desired overall shape, compartment shape, partition wall thickness, compartment density, etc. can be used.

[0165] The relative density of the honeycomb formed body obtained by extrusion molding is 60% or more, preferably 65% or more. By controlling the relative density of the honeycomb formed body within such a range, the honeycomb formed body can be densified and the resistance at room temperature can be reduced. It should be noted that the upper limit value of the relative density of the honeycomb formed body is not particularly limited, usually 80%, preferably 75%.

[0166] The honeycomb formed body can be dried before the firing process. As the drying method, there is no particular limitation, for example, conventionally known drying methods such as hot air drying, microwave drying, induction drying, vacuum drying, freeze drying, etc. can be used. Among them, in terms of being able to dry the entire formed body quickly and uniformly, a drying method combining hot air drying and microwave drying or induction drying is preferred.

[0167] The firing process includes: after holding at 1150 - 1250°C, heating it to a maximum temperature of 1360 - 1430°C at a heating rate of 20 - 600°C per hour, and holding for 0.5 - 10 hours.

[0168] By holding the honeycomb formed body at the maximum temperature of 1360 - 1430°C for 0.5 - 10 hours, a honeycomb structure 25 mainly composed of BaTiO3 - based crystal particles obtained by replacing a part of Ba with a rare earth element can be obtained.

[0169] In addition, by holding at 1150 - 1250°C, the Ba2TiO4 crystal particles generated during the firing process are easily removed, and thus, the honeycomb structure 25 can be densified.

[0170] Furthermore, by setting the heating rate from 1150 - 1250°C to the maximum temperature of 1360 - 1430°C to 20 - 600°C per hour, 1.0 - 10.0 mass% of Ba6Ti 17 O 40 crystal particles can be generated in the honeycomb structure 25.

[0171] The holding time at 1150 - 1250°C is not particularly limited, and is preferably 0.5 - 10 hours. By setting the holding time like this, the Ba2TiO4 crystal particles generated during the firing process are easily and stably removed.

[0172] The firing process preferably includes holding at 900 - 950°C for 0.5 - 5 hours during heating. By holding at 900 - 950°C for 0.5 - 5 hours, BaCO3 decomposes efficiently, and it is easy to obtain a honeycomb structure 25 having a specified composition.

[0173] It should be noted that, before the firing process, a degreasing process for removing the binder can be performed. The atmosphere of the degreasing process is preferably an air atmosphere in order to completely decompose the organic components.

[0174] In addition, from the viewpoints of controlling electrical characteristics and manufacturing costs, the atmosphere of the firing process is also preferably an air atmosphere.

[0175] As the firing furnace for the firing process or the degreasing process, there is no particular limitation, and an electric furnace, a gas furnace, etc. can be used.

[0176] A pair of electrodes 27a and 27b are formed on the honeycomb structure 25 obtained in this way. The pair of electrodes 27a and 27b can be formed by a metal deposition method such as sputtering, evaporation, electrolytic deposition, or chemical deposition. In addition, the pair of electrodes 27a and 27b can also be formed by sintering after applying electrode paste. Furthermore, the pair of electrodes 27a and 27b can be formed by cladding. The pair of electrodes 27a and 27b can be composed of a single layer or multiple electrode layers with different compositions. Hereinafter, representative formation methods of the pair of electrodes 27a and 27b will be described.

[0177] First, an electrode paste containing an electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 22a or the second end face 22b of the honeycomb structure 25. As the dispersion medium, 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 can be used. The excess paste on the outer periphery of the honeycomb structure 25 is removed by blowing and wiping. Then, by drying the paste, a pair of electrodes 27a and 27b can be formed on the first end face 22a or the second end face 22b of the honeycomb structure 25. Drying can be performed while heating the heater member to a temperature of about 120 to 600 °C, for example. The series of processes of application, paste removal, and drying can be performed only once, or can be repeated multiple times to form a pair of electrodes 27a and 27b with a desired thickness.

[0178] Next, when the terminal 28 is provided, the terminal 28 is arranged at a specified position of the pair of electrodes 27a and 27b, and the pair of electrodes 27a and 27b and the terminal 28 are connected. As the connection method between the pair of electrodes 27a and 27b and the terminal 28, the above-described method can be used.

[0179] It should be noted that the provision of the terminal 28 can also be performed after forming the moisture absorption layer 26 described below.

[0180] Next, a moisture absorption layer 26 is formed on the surfaces of the partition walls 24 etc. of the honeycomb structure 25.

[0181] The method for forming the moisture absorption layer 26 is not particularly limited. For example, it can be formed by the following steps. The honeycomb structure 25 is immersed in a slurry containing a moisture absorption material, an organic binder, and a dispersion medium for a specified time, and the excess slurry on the end faces and outer periphery of the honeycomb structure 25 is removed by blowing and wiping. As the dispersion medium, 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 can be used. Thereafter, by drying the slurry, the moisture absorption layer 26 can be formed on the surface of the partition wall 24. Drying can be carried out in a state where the honeycomb structure 25 is heated to a temperature of, for example, about 120 to 600°C. The series of steps of impregnation, slurry removal, and drying can be carried out only once, or can be repeated multiple times to provide a moisture absorption layer 26 with a desired thickness on the surface of the partition wall 24 and the like.

[0182] (3. Heat pump cycle 30)

[0183] The heat pump cycle 30 includes a condenser 31 disposed in the air conditioning passage 10 on the downstream side of the humidity control device 20. In particular, the condenser 31 is disposed in the inflow path 11 of the air conditioning passage 10.

[0184] The condenser 31 can perform heat exchange between the heat of the refrigerant and the air. Specifically, the condenser 31 can release heat through the high-temperature and high-pressure refrigerant flowing inside, and heat the air passing around the condenser 31.

[0185] The heat pump cycle 30 may further include an evaporator 32 disposed in the air conditioning passage 10 on the downstream side of the humidity control device 20. In particular, the evaporator 32 is disposed in the inflow path 11 of the air conditioning passage 10.

[0186] The evaporator 32 can perform heat exchange between the cold of the refrigerant and the air. Specifically, the evaporator 32 can absorb heat through the low-temperature and low-pressure refrigerant flowing inside, and cool the air passing around the evaporator 32.

[0187] The heat pump cycle 30 may further include: a compressor 33, an outdoor heat exchanger 34, expansion valves 35a, 35b, and stop valves 36a to 36e, and the above-described respective components are connected by a refrigerant flow path (refrigerant pipe).

[0188] The compressor 33 has the function of compressing and discharging the refrigerant. The compressor 33 is configured such that the suction part is connected to the outdoor heat exchanger 34 via a refrigerant flow path, and the discharge part is connected to the condenser 31 via a refrigerant flow path. The compressor 33 is driven by the control unit 40 to compress the refrigerant, and thus discharges the high-temperature and high-pressure refrigerant to the condenser 31.

[0189] It should be noted that a known device such as a gas-liquid separator may be provided between the compressor 33 and the outdoor heat exchanger 34.

[0190] The outdoor heat exchanger 34 has the function of exchanging the heat of the refrigerant with the heat of the external atmosphere. The outdoor heat exchanger 34 can mainly absorb heat from the external atmosphere through the low-temperature and low-pressure refrigerant flowing inside during the heating operation mode, and vaporize the refrigerant by absorbing heat from the external atmosphere. In addition, the outdoor heat exchanger 34 can mainly release heat to the external atmosphere through the high-temperature and high-pressure refrigerant flowing inside during the cooling operation mode, and cool the refrigerant by releasing heat to the external atmosphere.

[0191] The expansion valves 35a and 35b are throttle valves whose opening degrees can be adjusted by the control unit 40. In particular, for the expansion valve 35a, during the heating operation mode, after decompressing and expanding the refrigerant discharged from the condenser 31, the low-temperature and low-pressure refrigerant is discharged to the outdoor heat exchanger 34. In addition, for the expansion valve 35b, during the cooling operation mode, after decompressing and expanding the refrigerant from the outdoor heat exchanger 34, the low-temperature and low-pressure refrigerant is discharged to the evaporator 32.

[0192] The stop valves 36a to 36e are provided to control the refrigerant flow path. The stop valves 36a to 36e are controlled to open and close by the control unit 40.

[0193] (4. Control Unit 40)

[0194] The control unit 40 controls the humidity control device 20 and the heat pump cycle 30 according to the operation mode. Therefore, the control unit 40 is electrically connected to the humidity control device 20 and the heat pump cycle 30. Specifically, the control unit 40 is connected to the power supply 50 for applying voltage to a pair of electrodes 27a and 27b of the humidity control device 20. By controlling the power supply 50, the heating state of the honeycomb structure 25 can be adjusted. In addition, the control unit 40 is electrically connected to the stop valves 36a to 36e of the heat pump cycle 30. By opening and closing the stop valves 36a to 36e, the refrigerant flow path can be controlled. In addition, the control unit 40 is electrically connected to the expansion valves 35a and 35b of the heat pump cycle 30. By adjusting the opening degrees of the expansion valves 35a and 35b, the degree of decompression of the refrigerant can be controlled.

[0195] In addition to being electrically connected to the humidity control device 20 and the heat pump cycle 30, the control unit 40 is also electrically connected to the valve 13, the ventilator 60, the air mixing door 70, etc., and can control them.

[0196] The control unit 40 is not particularly limited and is usually an ECU (Engine (electronic) Control Unit). The ECU includes: a CPU that performs various arithmetic processes, a ROM that stores programs or data required for its control, a RAM that temporarily stores arithmetic results in the CPU, and an input / output port for inputting or outputting signals to and from the outside.

[0197] (5. Power supply 50)

[0198] The power supply 50 is used to apply a voltage to the pair of electrodes 27a, 27b. The power supply 50 is electrically connected to the control unit 40 and adjusts the voltage application state to the pair of electrodes 27a, 27b according to an instruction from the control unit 40.

[0199] The power supply 50 is not particularly limited, and a storage battery or the like can be used.

[0200] (6. Ventilator 60)

[0201] The ventilator 60 is provided to make air flow through the air conditioning passage 10. The ventilator 60 is not particularly limited, and a known ventilator can be used.

[0202] The position of the ventilator 60 is not particularly limited. For example, it can be provided on the upstream side of the humidity control device 20. However, it can also be provided on the downstream side of the condenser 31.

[0203] (7. Air mixing door 70)

[0204] The air mixing door 70 is configured to rotate between a heating position that opens a heating path toward the condenser 31 and a cooling position that opens a cooling path that bypasses the condenser 31 in the air conditioning passage 10. In addition, for the air mixing door 70, by rotating between the heating position and the cooling position, the ratio between the air passing through the condenser 31 and the air bypassing the condenser 31 can be adjusted, and thus the temperature of the air flowing into the vehicle interior can be adjusted.

[0205] In the vehicle air conditioning system according to the embodiment of the present invention, the operation mode of the humidity control device 20 includes a heating mode in which air is heated by the humidity control device 20. In addition, the operation mode of the humidity control device 20 can further include a dehumidification mode and a regeneration mode. The operation mode of the humidity control device 20 can be selected according to a switch operation performed by the driver, a humidity change known by various monitoring units, etc.

[0206] (A) Heating mode

[0207] The heating mode is a mode executed in cold weather such as below freezing point. The heating mode is carried out as follows: As shown, the control valve 13 is adjusted to allow air to flow into the inflow path 11, and a voltage is applied to the humidifying device 20 to allow air to flow through. By executing such a heating mode, the humidifying device 20 can function instead of the conventional PTC heater used as an auxiliary heat source. Therefore, in cold weather, the heating efficiency and instant heating performance are improved. Figure 1A It should be noted that the humidity in the atmosphere in cold weather is relatively low. Therefore, even if the heating mode of the humidifying device 20 is executed at the start of the heating operation mode of the heat pump cycle 30, the humidity inside the vehicle is unlikely to rise.

[0208] The heating mode (heating of air by the humidifying device 20) is preferably carried out during the period from the start of the heating operation mode of the heat pump cycle 30 to 10 minutes. By executing the heating mode during this period, heating can be efficiently performed in cold weather and power consumption can be reduced. From the viewpoint of stably ensuring this effect, the heating mode is preferably within 8 minutes from the start of the heating operation mode of the heat pump cycle 30, and more preferably within 5 minutes.

[0209] The heating mode (heating of air by the humidifying device 20) is preferably stopped at the stage when the heating COP of the heat pump cycle 30 reaches a specified value of 1.0 or more. By stopping heating at this stage, heating can be efficiently performed in cold weather and power consumption can be reduced.

[0210] Here, the heating COP refers to the energy consumption efficiency of heating (Coefficient of Performance), which is an index indicating the energy-saving performance of heating. The heating COP can be obtained by dividing the heating capacity (kW) by the heating power consumption (kW).

[0211] In addition, the stage when the heating COP reaches a specified value of 1.0 or more refers to the stage when the heating COP reaches a set value of 1.0 or more (such as 1.1, 1.2, 1.3, etc.).

[0212] From the viewpoint of stably ensuring the above effects, the set value of the heating COP of the heat pump cycle 30 at which heating is stopped is preferably 2.0 or less, and more preferably 1.5 or less.

[0213] (B) Dehumidifying mode

[0214] Regarding the dehumidifying mode, as shown in

[0215] and Figure 1B and Figure 1CAs shown, the control valve 13 is configured to allow air to flow into the inflow path 11, and the air flows through the humidity control device 20, thereby performing dehumidification. By executing such a dehumidification mode, the air from the passenger compartment or outside the vehicle can be quickly dehumidified. It should be noted that Figure 1A similarly, if no voltage is applied to the humidity control device 20, the dehumidification mode is established.

[0216] (C) Regeneration mode

[0217] Regarding the regeneration mode, as Figure 1D shown, the control valve 13 is configured to allow air to flow out to the outflow path 12, and a voltage is applied to the humidity control device 20 to heat it and allow air to flow through, thereby regenerating the moisture absorption layer 26. By executing such a regeneration mode, the moisture absorption layer 26 of the humidity control device 20 can be quickly regenerated.

[0218] In the vehicle air conditioning system according to the embodiment of the present invention, the operation modes of the heat pump cycle 30 may include a heating operation mode and a refrigeration operation mode. The operation mode of the heat pump cycle 30 can be selected according to the switch operation performed by the driver, the temperature change detected by various monitoring units, and the like.

[0219] (A) Heating operation mode

[0220] Regarding the heating operation mode, as Figure 1A shown, the stop valves 36a to 36c are opened and the stop valves 36d to 36e are closed, thereby forming a flow path in which the refrigerant sequentially flows through the compressor 33, the condenser 31, the expansion valve 35a, and the outdoor heat exchanger 34. It should be noted that Figure 1A in this, the flow path through which the refrigerant flows in the heating operation mode is indicated by a thick line.

[0221] The refrigerant compressed by the compressor 33 enters the condenser 31 as a high-temperature and high-pressure refrigerant, exchanges heat with the air flowing in the air conditioning passage 10, and releases heat. The refrigerant leaving the condenser 31 is decompressed and expanded by the expansion valve 35a, becomes a low-temperature and low-pressure refrigerant, and then exchanges heat with the outside atmosphere in the outdoor heat exchanger 34 to absorb heat, and returns to the compressor 33.

[0222] When implementing this heating operation mode, the air flowing in the air conditioning passage 10 is heated by the condenser 31, and the heated air flows into the passenger compartment. The temperature of the air flowing into the passenger compartment can be adjusted by controlling the opening degree of the air mixing door 70.

[0223] This heating operation mode can be implemented when the operation mode of the humidity control device 20 is the heating mode or the dehumidification mode.

[0224] (B) First refrigeration operation mode

[0225] Regarding the first refrigeration operation mode, as Figure 1B shown, open the stop valves 36a, 36d, 36e, and close the stop valves 36b, 36c. Thus, a refrigerant flow path is formed in which the refrigerant sequentially flows through the compressor 33, the outdoor heat exchanger 34, the expansion valve 35b, and the evaporator 32. It should be noted that Figure 1B in, the thick line indicates the flow path for the refrigerant to flow in this refrigeration operation mode.

[0226] The refrigerant compressed by the compressor 33 and becoming high-temperature and high-pressure exchanges heat with the external atmosphere in the outdoor heat exchanger 34 and releases heat, thereby being cooled. The refrigerant leaving the outdoor heat exchanger 34 is decompressed and expanded by the expansion valve 35b, becomes a low-temperature and low-pressure refrigerant, enters the evaporator 32, and exchanges heat with the air flowing in the air conditioning passage 10 to absorb heat. The refrigerant leaving the evaporator 32 returns to the compressor 33.

[0227] When this refrigeration operation mode is implemented, the air flowing in the air conditioning passage 10 is cooled by the evaporator 32, and the cooled air flows into the passenger compartment. This refrigeration operation mode is particularly useful for the situation where it is desired to quickly cool the interior of the passenger compartment (forced refrigeration operation mode).

[0228] This refrigeration operation mode can be implemented when the operation mode of the humidity control device 20 is the dehumidification mode.

[0229] (C) Second refrigeration operation mode

[0230] Regarding the second refrigeration operation mode, as Figure 1C shown, open the stop valves 36a, 36c, 36e, and close the stop valves 36b, 36d. Thus, a refrigerant flow path is formed in which the refrigerant sequentially flows through the compressor 33, the condenser 31, the expansion valve 35a, the outdoor heat exchanger 34, the expansion valve 35b, and the evaporator 32. It should be noted that Figure 1C in, the thick line indicates the flow path for the refrigerant to flow in this refrigeration operation mode.

[0231] In the refrigerant flow path under this refrigeration operation mode, a condenser 31 and an expansion valve 35a are also arranged on the downstream side of the compressor 33. Moreover, in this refrigeration operation mode, by controlling the opening degree of the air mixing door 70, the cooling of the air by the evaporator 32 and the heating of the air by the condenser 31 can be adjusted. Therefore, the temperature of the air can be controlled to the optimal temperature.

[0232] This refrigeration operation mode can be implemented when the operation mode of the humidity control device 20 is the dehumidification mode.

[0233] The humidity control device 20 is preferably arranged close to the vehicle compartment. Therefore, from the viewpoint of preventing electric shock and the like, the driving voltage of the humidity control device 20 is preferably 60 V or less. The honeycomb structure 25 used in the humidity control device 20 has a low resistance at room temperature, and thus, the honeycomb structure 25 can be heated at such a low driving voltage. It should be noted that the lower limit of the driving voltage is not particularly limited, and is preferably 10 V or more. If the driving voltage is less than 10 V, the current when the honeycomb structure 25 is heated becomes large, and thus, the wire needs to be thickened.

[0234] <Method for Controlling Vehicle Air Conditioning System>

[0235] Regarding the method for controlling the vehicle air conditioning system according to the embodiment of the present invention, in the vehicle air conditioning system having the above configuration, there is a heating mode in which air is heated by the humidity control device 20 at the start of the heating operation mode of the heat pump cycle 30. By adopting such a configuration, the humidity control device 20 can be made to function instead of the conventional PTC heater used as an auxiliary heat source, and thus, the heating efficiency and the quick warm-up property are improved in cold weather.

[0236] The heating of the air by the humidity control device 20 (heating mode) is preferably performed during the period from the start of the heating operation mode of the heat pump cycle 30 to 10 minutes. By performing the heating mode during this period, it is possible to heat the air efficiently in cold weather and reduce power consumption.

[0237] The heating of the air by the humidity control device 20 (heating mode) is preferably stopped at a stage where the heating COP of the heat pump cycle 30 reaches a specified value of 1.0 or more. By stopping the heating at this stage, it is possible to heat the air efficiently in cold weather and reduce power consumption.

[0238] In the vehicle air conditioning system, it is preferable to have an inflow path 11 for air to flow into the vehicle compartment and an outflow path 12 for air to flow out of the vehicle outside between the humidity control device 20 and the condenser 31, and a valve 13 capable of switching the flow of air is provided between the inflow path 11 and the outflow path 12, and the condenser 31 is arranged in the inflow path 11. By adopting such a configuration, it is possible to execute the heating mode, the dehumidifying mode, and the regeneration mode based on the humidity control device 20, and the refrigeration operation mode and the heating operation mode based on the heat pump cycle 30.

[0239] The heating mode of the humidity control device 20 is preferably performed as follows: the valve 13 is controlled so that air flows into the inflow path 11, and a voltage is applied to the humidity control device 20 and air is made to flow through. By performing control in this way, it is possible to heat the air efficiently in cold weather and reduce power consumption.

[0240] In a vehicle air conditioning system, the humidity control device 20 preferably further includes at least one operating mode selected from a dehumidification mode and a regeneration mode. In the dehumidification mode, the valve 13 is controlled so that air flows into the inflow path 11, and the air is circulated through the humidity control device 20 to perform dehumidification. In the regeneration mode, the valve 13 is controlled so that air flows out to the outflow path 12, and the humidity control device 20 is heated and air is circulated to regenerate the moisture absorption layer 26. By adopting such a configuration, it is possible to easily implement the dehumidification mode and the regeneration mode based on the humidity control device 20.

[0241] In a vehicle air conditioning system, the heat pump cycle 30 preferably further includes a compressor 33 that compresses and discharges a refrigerant. The heating operation mode of the heat pump cycle 30 includes introducing the refrigerant discharged from the compressor 33 into the condenser 31 to heat air. By adopting such a configuration, it is possible to easily implement the heating operation mode of the heat pump cycle 30.

Claims

1. An air conditioning system for a vehicle, comprising: An air conditioning passage through which air can flow; A humidity control device disposed in the air conditioning passage; A heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device; And A control unit that controls the humidity control device and the heat pump cycle according to an operation mode, The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition walls, The control unit includes a heating mode in which the air is heated by the humidity control device at the start of the heating operation mode of the heat pump cycle.

2. The air conditioning system for a vehicle according to claim 1, wherein The heating of the air by the humidity control device is performed during a period from the start of the heating operation mode of the heat pump cycle to 10 minutes.

3. The air conditioning system for a vehicle according to claim 1 or 2, wherein The heating of the air by the humidity control device stops when the heating COP of the heat pump cycle reaches a specified value of 1.0 or more.

4. The air conditioning system for a vehicle according to claim 1 or 2, wherein The air conditioning passage has an inflow path for the air to flow into the vehicle compartment and an outflow path for the air to flow out of the vehicle outside between the humidity control device and the condenser, and a valve capable of switching the flow of the air is provided between the inflow path and the outflow path, The condenser is disposed in the inflow path.

5. The air conditioning system for a vehicle according to claim 4, wherein The heating mode of the humidity control device is performed as follows: controlling the valve so that the air flows into the inflow path, and applying a voltage to the humidity control device and allowing the air to flow through.

6. The air conditioning system for a vehicle according to claim 4, wherein The humidity control device further includes at least one operation mode selected from a dehumidification mode and a regeneration mode, In the dehumidification mode, the valve is controlled so that the air flows into the inflow path, and the air is allowed to flow through the humidity control device, thereby performing dehumidification, In the regeneration mode, the valve is controlled so that the air flows out to the outflow path, and the humidity control device is heated and the air is allowed to flow through, thereby regenerating the moisture absorption layer.

7. The air conditioning system for a vehicle according to claim 1 or 2, wherein The heat pump cycle further includes: a compressor that compresses and discharges a refrigerant, The heating operation mode of the heat pump cycle includes: introducing the refrigerant discharged from the compressor into the condenser to heat the air.

8. The air conditioning system for a vehicle according to claim 1 or 2, wherein The humidity control device further includes a pair of electrodes, which are disposed on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall of the honeycomb structure parallel to the direction in which the compartments extend.

9. The vehicle air conditioning system according to claim 1 or 2, wherein The moisture absorption layer can not only adsorb moisture, but also adsorb carbon dioxide and / or volatile components.

10. A control method for a vehicle air conditioning system, the vehicle air conditioning system comprising: An air conditioning passage through which air can flow; A humidity control device disposed in the air conditioning passage; And A heat pump cycle including a condenser disposed in the air conditioning passage on the downstream side of the humidity control device, The humidity control device includes: a honeycomb structure having an outer peripheral wall and partition walls, the partition walls being disposed inside the outer peripheral wall and partitioning to form a plurality of compartments, the plurality of compartments extending from a first end face to a second end face to form flow paths, and at least the partition walls being made of a material having PTC characteristics; and a moisture absorption layer formed on the surface of the partition walls, In the vehicle air conditioning system, there is a heating mode in which the air is heated by the humidity control device at the start of the heating operation mode of the heat pump cycle.

11. The control method for a vehicle air conditioning system according to claim 10, wherein The heating of the air by the humidity control device is performed during a period from the start of the heating operation mode of the heat pump cycle to 10 minutes.

12. The control method for a vehicle air conditioning system according to claim 10 or 11, wherein The heating of the air by the humidity control device stops at a stage where the heating COP of the heat pump cycle reaches a specified value of 1.0 or more.

13. The control method for a vehicle air conditioning system according to claim 10 or 11, wherein The air conditioning passage has an inflow path for the air to flow into the vehicle compartment and an outflow path for the air to flow out of the vehicle outside between the humidity control device and the condenser, and a valve capable of switching the flow of the air is provided between the inflow path and the outflow path, The condenser is disposed in the inflow path.

14. The control method for a vehicle air conditioning system according to claim 13, wherein The heating mode of the humidity control device is performed as follows: the valve is controlled so that the air flows into the inflow path, and a voltage is applied to the humidity control device and the air is made to flow through.

15. The control method for a vehicle air conditioning system according to claim 13, wherein The humidity control device further includes at least one operation mode selected from a dehumidification mode and a regeneration mode, In the dehumidification mode, the valve is controlled so that the air flows into the inflow path, and the air is made to flow through the humidity control device, thereby performing dehumidification, In the regeneration mode, the valve is controlled such that the air flows out to the outflow path, and the humidity control device is heated and the air is circulated, thereby regenerating the moisture absorption layer.

16. The control method of the vehicle air conditioning system according to claim 10 or 11, wherein the heat pump cycle further includes a compressor that compresses and discharges the refrigerant, the heating operation mode of the heat pump cycle includes introducing the refrigerant discharged from the compressor into the condenser to heat the air.

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