Vehicle air conditioning system

Abstract

This invention provides a vehicle air conditioning system that can suppress excessive dehumidification and the decrease in energy efficiency during dehumidification. [Solution] This is a vehicle air conditioning system comprising: a flow path 10 through which air can flow; a humidity control device 20 disposed within the flow path 10 and capable of adsorbing and desorbing moisture; an HVAC unit 30 including an evaporator 31 disposed within the flow path 10 downstream of the humidity control device 20; and a control unit 40 capable of controlling the humidity control device 20 and the HVAC unit 30. The control unit 40 performs dehumidification by the evaporator 31 during cooling and dehumidification by the humidity control device 20 during heating.

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 demands include reducing CO2 emissions inside the vehicle 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 (for example, Patent Document 1) 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.

[0004] On the other hand, as an air conditioning system capable of providing heating and cooling for vehicles, an air conditioning system equipped with an HVAC (Heating, Ventilation and Air Conditioning) unit utilizing a heat pump cycle has been proposed (for example, Patent Documents 2 and 3). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] International Publication No. 2023 / 074202 [Patent Document 2] Patent No. 6746742 [Patent Document 3] Japanese Patent Publication No. 2016-097817 [Overview of the initiative] [Problems that the invention aims to solve]

[0006] In vehicle air conditioning systems equipped with humidity control devices and HVAC units, both the humidity control device and the evaporator of the HVAC unit have dehumidifying functions. Therefore, when dehumidification is performed by both the evaporator and the humidity control device, there are problems such as excessive dehumidification of the vehicle interior and a decrease in energy efficiency.

[0007] This invention was made to solve the above-mentioned problems and aims to provide a vehicle air conditioning system that can suppress excessive dehumidification and a decrease in energy efficiency during dehumidification. [Means for solving the problem]

[0008] The present inventors have diligently researched vehicle air conditioning systems equipped with a humidity control device and an HVAC unit, and as a result have found that the above problems can be solved by performing dehumidification by the evaporator of the HVAC unit during cooling and dehumidification by the humidity control device during heating, thereby completing the present invention. That is, the present invention is illustrated as follows.

[0009] <1> A flow path through which air can circulate, A humidity control device disposed within the aforementioned flow path and capable of adsorbing and desorbing moisture, An HVAC unit including an evaporator disposed in the flow path downstream of the humidity control device, A control unit capable of controlling the humidity control device and the HVAC unit Equipped with, The control unit is a vehicle air conditioning system that performs dehumidification by the evaporator during cooling and dehumidification by the humidity control device during heating.

[0010] <2> The aforementioned flow path branches upstream of the evaporator into a first flow path in which the humidity control device is located and a second flow path in which the humidity control device is not located. The system is configured such that the air flows through the second channel during cooling and through the first channel during heating. <1> The vehicle air conditioning system described in [reference].

[0011] <3> A ventilator is further provided in the first flow path upstream of the humidity control device. <2> The vehicle air conditioning system described in [reference].

[0012] <4> The humidity control device further includes a first valve capable of switching the airflow between the first channel and the second channel, upstream of the humidity control device. <2> The vehicle air conditioning system described in [reference].

[0013] <5> The humidity control device is located within the HVAC unit. <1> ~ <4> A vehicle air conditioning system as described in any one of the following.

[0014] <6> The humidity control device is located upstream of the HVAC unit. <1> ~ <4> A vehicle air conditioning system as described in any one of the following.

[0015] <7> It is further equipped with a sensor that measures the outside temperature of the vehicle. When the outside temperature is equal to or higher than a predetermined set temperature, the control unit performs cooling, and when the outside temperature is lower than the predetermined set temperature, the control unit performs heating. The vehicle air conditioning system according to any one of <1> to <6>, wherein the set temperature is 0 to 15°C.

[0016] <8> The evaporator of the HVAC unit is connected to a heat pump cycle. The vehicle air conditioning system according to any one of <1> to <7>.

[0017] <9> The flow path branches, downstream of the humidity control device, into a third flow path for allowing the air to flow into the vehicle interior and a fourth flow path for allowing the air to flow out of the vehicle exterior. The vehicle air conditioning system according to any one of <1> to <8>, further comprising a second valve capable of switching the air flow between the third flow path and the fourth flow path.

[0018] <10> The humidity control device has an adsorption part containing an adsorbent that adsorbs moisture at a predetermined temperature or lower and desorbs the adsorbed moisture when the temperature exceeds the predetermined temperature, and heating means or a heating structure capable of heating the adsorption part. The vehicle air conditioning system according to any one of <1> to <9>.

[0019] <11> The humidity control device has a honeycomb structure including an outer peripheral wall and partition walls disposed inside the outer peripheral wall and partitioning a plurality of cells serving as the air flow path extending from a first end face to a second end face. An adsorption layer containing the adsorbent provided on the surface of the partition wall, and A pair of electrodes provided on the first end face and the second end face of the honeycomb structure, or on the outer peripheral wall parallel to the direction in which the cells of the honeycomb structure extend. The vehicle air conditioning system according to <10>, comprising the above.

[0020] <12> The honeycomb structure is composed of a material in which at least the partition wall has PTC characteristics. The vehicle air conditioning system according to <11>.

[0021] <13> 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. <10> The vehicle air conditioning system described in [reference].

[0022] <14> 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, <10> The vehicle air conditioning system described in [reference]. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a vehicle air conditioning system that can suppress excessive dehumidification and a decrease in energy efficiency during dehumidification. [Brief explanation of the drawing]

[0024] [Figure 1] This is a schematic diagram of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of another vehicle air conditioning system according to an embodiment of the present invention. [Figure 3] This is a schematic diagram of another vehicle air conditioning system according to an embodiment of the present invention. [Figure 4] This is a schematic diagram of another vehicle air conditioning system according to an embodiment of the present invention. [Figure 5] This is a schematic diagram of another vehicle air conditioning system according to an embodiment of the present invention. [Figure 6A] 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 6B] Figure 6A is a schematic diagram of the cross-section of the humidity control device along the line a-a'. [Figure 7]This is a schematic diagram of a heat pump cycle. [Modes for carrying out the invention]

[0025] The vehicle air conditioning system of the present invention comprises: a flow path through which air can circulate; a humidity control device disposed within the flow path and capable of adsorbing and desorbing moisture; an HVAC unit including an evaporator disposed in the flow path downstream of the humidity control device; and a control unit capable of controlling the humidity control device and the HVAC unit. The control unit performs dehumidification by the evaporator during cooling and dehumidification by the humidity control device during heating. Since the evaporator cools and dehumidifies the air, energy efficiency can be increased by performing dehumidification by the evaporator during cooling. On the other hand, during heating, it is necessary to heat the air cooled by the evaporator, so energy efficiency is low. Also, when the air temperature falls below freezing point, the evaporator freezes and air flow becomes difficult, so the evaporator temperature is usually set to 2-5°C, and dehumidification is not possible at temperatures below that. Therefore, energy efficiency can be increased by performing dehumidification by the humidity control device during heating. The humidity control device can dehumidify regardless of the air temperature. On the other hand, the humidity control device may generate heat when performing dehumidification, so energy efficiency is low during cooling. Therefore, by having the above-described configuration, the vehicle air conditioning system of the present invention can suppress excessive dehumidification and a decrease in energy efficiency during dehumidification.

[0026] 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.

[0027] The vehicle air conditioning system according to the embodiment of the present invention can be used in various vehicles such as automobiles. 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 use in vehicles without internal combustion engines, such as electric vehicles and trains.

[0028] Figures 1 to 5 are schematic diagrams of a vehicle air conditioning system according to an embodiment of the present invention. The vehicle air conditioning system shown in Figures 1 to 5 comprises a flow path 10 through which air can flow, a humidity control device 20 located within the flow path 10, an HVAC unit 30 including an evaporator 31 located in the flow path downstream of the humidity control device 20, and a control unit 40 capable of controlling the humidity control device 20 and the HVAC unit 30. Here, Figures 1 and 2 show configurations in which the humidity control device 20 is located inside the HVAC unit 30. Figures 3 to 5 show configurations in which the humidity control device 20 is located outside the HVAC unit 30, specifically, configurations in which the humidity control device 20 is located upstream of the HVAC unit 30. Furthermore, the vehicle air conditioning system according to the embodiments of the present invention is not limited to these embodiments, and the position of the humidity control device 20 can be changed, etc., as long as it does not impede the effects of the present invention. Also, in this specification, the terms upstream and downstream refer to the direction of air flow.

[0029] In a vehicle air conditioning system having the structure described above, dehumidification is performed by the evaporator 31 during cooling and by the humidity control device 20 during heating. By performing dehumidification by the evaporator 31 during cooling, the air can also be cooled by the evaporator 31, thereby improving energy efficiency during cooling. Furthermore, by performing dehumidification by the humidity control device 20 during heating, efficient dehumidification and heating of the air can be performed even when the air temperature is low, thereby improving energy efficiency during heating. Therefore, it is possible to suppress excessive dehumidification and the decrease in energy efficiency during dehumidification. Herein, in this specification, "cooling" means cooling in the HVAC unit 30, and more specifically, means cooling the air by the evaporator 31 of the HVAC unit 30. Therefore, it is preferable that the evaporator 31 of the HVAC unit 30 is connected to a heat pump cycle. Furthermore, "heating" means heating in the HVAC unit 30, and more specifically, means heating the air by the condenser 32 of the HVAC unit 30. Therefore, it is preferable that the condenser 32 of the HVAC unit 30 is connected to a heat pump cycle. Furthermore, in this specification, dehumidification by the humidity control device 20 means adsorbing moisture from the air by circulating air (internal air and / or external air) through the humidity control device 20.

[0030] The flow path 10 is preferably configured to branch upstream of the evaporator 31 into a first flow path 11 where the humidity control device 20 is located and a second flow path 12 where the humidity control device 20 is not located, with air flowing through the second flow path 12 during cooling and air flowing through the first flow path 11 during heating. With this configuration, during cooling, air does not flow to the humidity control device 20, so dehumidification can be performed by the evaporator 31 alone. Also, during heating, air flows to the humidity control device 20, so dehumidification can be performed by the humidity control device 20. However, air may also be allowed to flow through the second flow path 12 during cooling. In this case, dehumidification by the humidity control device 20 is performed in the initial stage during cooling, but as time passes, the dehumidification effect of the humidity control device 20 saturates, so dehumidification can be performed by the evaporator 31 alone.

[0031] In the vehicle air conditioning system shown in Figures 1, 3, and 5, it is preferable to further provide a ventilator 50 in the first flow path 11 upstream of the humidity control device 20. This configuration allows for the selective circulation of air within the first flow path 11. Furthermore, it is preferable that the vehicle air conditioning system shown in Figures 1 and 3 also includes a ventilator 50 within the second airflow channel 12. This configuration allows for selective airflow within the second airflow channel 12. In the vehicle air conditioning system shown in Figure 5, air can be selectively circulated within the second airflow channel 12 by activating the ventilator 50 of the HVAC unit 30.

[0032] In the vehicle air conditioning system shown in Figures 2 and 4, it is preferable to further provide a first valve 60 upstream of the humidity control device 20, which can switch the airflow between the first flow path 11 and the second flow path 12. By providing the first valve 60, air can be selectively circulated to either the first flow path 11 or the second flow path 12. In this case, as shown in Figures 2 and 4, a ventilator 50 may be provided upstream of the first valve 60.

[0033] An embodiment of the present invention provides a vehicle air conditioning system that further includes a sensor for measuring the outside temperature, and the control unit 40 performs cooling when the outside temperature is above a predetermined set temperature, and heating when the outside temperature is below a predetermined set temperature, preferably with a set temperature of 0 to 15°C. With this configuration, the energy efficiency during dehumidification in heating and cooling can be stably improved. Furthermore, the sensor used to measure the outside temperature of the vehicle can be the one that comes with the vehicle.

[0034] The flow path 10 is preferably further provided with a second valve 61 that can switch the airflow between the third flow path 13 and the fourth flow path 14, downstream of the humidity control device 20, which allows air to flow into the vehicle and out of the vehicle.

[0035] The following provides a detailed explanation of each of the above components and other components.

[0036] (1. Flow channel 10) The airflow path 10 is a region through which air can flow and consists of the housing of the HVAC unit 30 and ducts (piping). For example, in the vehicle air conditioning system shown in Figures 1 and 2, the airflow path 10 consists of the housing of the HVAC unit 30. Also, the vehicle air conditioning system shown in Figures 3 to 5 consists of the housing of the HVAC unit 30 and ducts 15. The shape and size of the flow path 10 are not particularly limited and can be adjusted as appropriate depending on the type of HVAC unit 30 and the duct 15 connected to it.

[0037] (2. Humidity control device 20) The humidity control device 20 is placed within the flow path 10. The humidity control device 20 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 20 having such features, the adsorption and desorption of moisture can be easily achieved. Furthermore, the number of humidity control devices 20 placed in the flow path 10 may be one or multiple. If multiple humidity control devices 20 are provided, they may be arranged in parallel or in series with respect to the airflow circulating in the flow path 10.

[0038] Figure 6A 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 6B is a schematic diagram of the cross-section along line a-a' in the humidity control device of Figure 6A. The humidity control device 20 shown in Figures 6A and 6B comprises a honeycomb structure 21 having an outer peripheral wall 22 and partition walls 25 disposed inside the outer peripheral wall 22, which divide and form a plurality of cells 24 that serve as air passages extending from a first end face 23a to a second end face 23b; an adsorption layer 26 containing an adsorbent provided on the surface of the partition walls 25; and a pair of electrodes 27a and 27b provided on the first end face 23a and the second end face 23b of the honeycomb structure 21. Although not shown, the pair of electrodes 27a and 27b may be provided on the outer peripheral wall 22 parallel to the direction in which the cells 24 of the honeycomb structure 21 extend. Terminals 28 can also be connected to the pair of electrodes 27a and 27b. The pair of electrodes 27a and 27b can be electrically connected to the control unit 40 via a power supply (not shown). Therefore, the humidity control device 20 can adjust the voltage applied to the pair of electrodes 27a and 27b according to instructions from the control unit 40. The power supply is not particularly limited and can be a battery or the like.

[0039] (2-1. Honeycomb structure 21) The shape of the honeycomb structure 21 is not particularly limited. For example, the outer shape of the cross-section of the honeycomb structure 21 perpendicular to the flow direction (the direction in which the cells 24 extend) can be a polygon such as a quadrilateral (rectangle, square), pentagon, hexagon, heptagon, or octagon, or a circle, oval (egg, ellipse, oblong, rounded rectangle, etc.). The end faces (first end face 23a and second end face 23b) have the same shape as the cross-section. Furthermore, if the cross-section and end faces are polygonal, the corners may be chamfered.

[0040] The shape of the cell 24 is not particularly limited, but in a cross-section perpendicular to the flow direction of the honeycomb structure 21, 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 24 of such shape, the pressure loss when air flows can be reduced.

[0041] The honeycomb structure 21 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 24, 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 22 and the partition wall 25. 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.

[0042] From the viewpoint of ensuring the strength of the honeycomb structure 21, reducing pressure loss when air passes through the cells 24, ensuring the amount of adsorbent carried, and ensuring the contact area with the air flowing inside the cells 24, it is desirable to suitably combine the thickness of the partition wall 25, the cell density, and the cell pitch (or the opening ratio of the cells 24). 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 23a or second end face 23b) of the honeycomb structure 21 (the total area of ​​the partition walls 25 and cells 24 excluding the outer peripheral wall 22). 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 21 (first end face 23a or second end face 23b) (the total area of ​​the partition wall 25 and cells 24 excluding the outer perimeter wall 22) 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 24 is the value obtained by dividing the total area of ​​cells 24 partitioned by partition walls 25 in a cross section perpendicular to the flow direction of the honeycomb structure 21 by the area of ​​one end face (first end face 23a or second end face 23b) (the total area of ​​partition walls 25 and cells 24 excluding the outer peripheral wall 22). Note that the pair of electrodes 27a, 27b and the adsorption layer 26 are not considered when calculating the aperture ratio of cell 24.

[0043] In an embodiment advantageous in terms of supporting a sufficient amount of functional material, the thickness of the partition wall 25 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 25 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 25 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.

[0044] From the viewpoint of ensuring the strength of the honeycomb structure 21 and keeping the electrical resistance low, the lower limit of the thickness of the partition wall 25 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and still more preferably 0.030 mm or more. From the viewpoints of ensuring the strength of the honeycomb structure 21, keeping the electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the lower limit of the cell density is preferably 30 cells / cm 2 or more, more preferably 35 cells / cm 2 or more, and still more preferably 40 cells / cm 2 or more. From the viewpoints of ensuring the strength of the honeycomb structure 21, keeping the electrical resistance low, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and still more preferably 1.6 mm or less.

[0045] In an advantageous embodiment from the viewpoint of achieving both reduction of pressure loss and maintenance of strength, the thickness of the partition wall 25 is 0.08 to 0.36 mm, the cell density is 2.54 to 140 cells / cm 2 , and the aperture ratio of the cell 24 is 0.70 or more. In a preferred embodiment, the thickness of the partition wall 25 is 0.09 to 0.35 mm, the cell density is 15 to 100 cells / cm 2 , and the aperture ratio of the cell 24 is 0.80 or more. In a more preferred embodiment, the thickness of the partition wall 25 is 0.14 to 0.30 mm, the cell density is 20 to 90 cells / cm 2 , and the aperture ratio of the cell 24 is 0.85 or more.

[0046] From the viewpoint of ensuring the strength of the honeycomb structure 21, the upper limit of the aperture ratio of the cell 24 is preferably 0.94 or less, more preferably 0.92 or less, and still more preferably 0.90 or less.

[0047] The thickness of the outer periphery wall 22 is not particularly limited, but is preferably determined based on the following considerations. First, from the viewpoint of reinforcing the honeycomb structure 21, the thickness of the outer periphery wall 22 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 initial current and reducing pressure loss when air flows, the thickness of the outer periphery wall 22 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 22 refers to the length in the direction normal to the side surface, from the boundary between the outer peripheral wall 22 and the outermost cell 24 or partition wall 25 to the side surface of the honeycomb structure 21, in a cross section perpendicular to the flow direction of the honeycomb structure 21.

[0048] The length of the honeycomb structure 21 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 20 and are not particularly limited. For example, when used in a compact humidity control device 20 that ensures a predetermined function, the honeycomb structure 21 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 can be applied. The upper limit of the cross-sectional area of ​​the honeycomb structure 21 perpendicular to the flow direction is not particularly limited, but for example, 300 cm². 2 The following applies:

[0049] The partition walls 25 constituting the honeycomb structure 21 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 22 may also be made of a material having PTC properties similar to the partition walls 25. With this configuration, the adsorption layer 26 can be directly heated by heat transfer from the heat-generating partition walls 25 (and optionally the outer peripheral wall 22). Furthermore, materials having 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 25 (and optionally the outer peripheral wall 22) become hot, the current flowing through them is limited, so excessive heat generation in the honeycomb structure 21 is suppressed. Consequently, it is also possible to suppress thermal degradation of the adsorption layer 26 caused by excessive heat generation.

[0050] 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.

[0051] From the viewpoint of being electrically conductive and having PTC characteristics, the outer periphery wall 22 and the partition wall 25 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)-based 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-based crystalline particles can be determined by fluorescent X-ray analysis. Other crystalline particles can also be measured in the same manner.

[0052] 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.

[0053] From the viewpoint of reducing environmental impact, it is desirable that the materials used for the outer perimeter wall 22 and the partition wall 25 be substantially lead-free (Pb). Specifically, the Pb content of the outer perimeter wall 22 and the partition wall 25 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 heat-generating partition wall 25. In addition, the Pb content of the outer perimeter wall 22 and the partition wall 25, 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).

[0054] Preferably, the Curie point of the materials constituting the outer perimeter wall 22 and the partition wall 25 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 20 becomes hot, so excessive heat generation of the humidity control device 20 is efficiently suppressed. Therefore, thermal degradation of the adsorption layer 26 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the materials constituting the outer peripheral wall 22 and the partition wall 25 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 26. 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.

[0055] The Curie points of the materials constituting the outer perimeter wall 22 and the partition wall 25 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.

[0056] 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.

[0057] (2-2.Adsorption layer 26) The adsorption layer 26 is a layer containing an adsorbent. The adsorption layer 26 can be provided on the surface of the partition wall 25 (or, in the case of the outermost cell 24, the partition wall 25 and outer wall 22 that partition the outermost cell 24). By providing the adsorption layer 26 in this way, it becomes easier to adsorb moisture during the moisture absorption mode, and it becomes easier to heat the adsorption layer 26 during the regeneration mode, thus making it easier to remove moisture from the adsorption layer 26.

[0058] The adsorbent contained in the adsorption layer 26 is capable of adsorbing and desorbing moisture. Preferably, the adsorbent is also 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 20 but also a purification effect can be obtained.

[0059] Preferably, the adsorbent contained in the adsorption layer 26 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.

[0060] 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.

[0061] 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).

[0062] 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.

[0063] The adsorption layer 26 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.

[0064] The thickness of the adsorption layer 26 can be determined according to the size of the cell 24 and is not particularly limited. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the adsorption layer 26 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 26 from the partition wall 25 and the outer peripheral wall 22, the thickness of the adsorption layer 26 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.

[0065] The thickness of the adsorption layer 26 is measured using the following procedure. An arbitrary cross section parallel to the flow direction of the honeycomb structure 21 is cut out, and a cross-sectional image at approximately 50x magnification is obtained using a scanning electron microscope or 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 21. For each adsorption layer 26 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 24 in the flow direction. This calculation is performed for all adsorption layers 26 visible in the cross-sectional image, and the overall average value is taken as the thickness of the adsorption layer 26.

[0066] From the viewpoint of performing the desired function within the humidity control device 20, the amount of the adsorption layer 26 is preferably 50 to 500 g / L, more preferably 100 to 400 g / L, and even more preferably 150 to 350 g / L, relative to the volume of the honeycomb structure 21. The volume of the honeycomb structure 21 is determined by the external dimensions of the honeycomb structure 21.

[0067] In the regeneration mode of the adsorption layer 26, it is preferable to heat the adsorption layer 26 to a temperature above the desorption temperature, depending on the type of adsorbent, in order to promote the desorption of moisture trapped in the adsorption layer 26. For example, it is preferable to heat the adsorption layer 26 to 70-150°C, more preferably to 80-140°C, and even more preferably to 90-130°C.

[0068] (2-3. A pair of electrodes 27a, 27b) The positions of the pair of electrodes 27a and 27b are not particularly limited, but as shown in Figure 6A, they can be provided on the first end face 23a and the second end face 23b of the honeycomb structure 21. Alternatively, the pair of electrodes 27a and 27b may be provided on the outer peripheral wall 22 of the honeycomb structure 21 that is parallel to the direction in which the cells 24 extend. By applying a voltage between the pair of electrodes 27a and 27b, it is possible to generate heat in the honeycomb structure 21 by Joule heating.

[0069] The pair of electrodes 27a and 27b 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 22 and / or partition wall 25 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 27a and 27b may have a single-layer structure or a multilayer structure of two or more layers. If the pair of electrodes 27a and 27b have a multilayer structure of two or more layers, the material of each layer may be the same type or different types.

[0070] The thickness of the pair of electrodes 27a and 27b can be appropriately set depending on the method of forming the pair of electrodes 27a and 27b. Methods for forming the pair of electrodes 27a and 27b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. Alternatively, the pair of electrodes 27a and 27b can be formed by applying electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 27a and 27b may be formed by joining metal plates or alloy plates.

[0071] The thickness of the pair of electrodes 27a and 27b 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.

[0072] (2-4. Terminal 28) Terminal 28 is connected to a pair of electrodes 27a and 27b and is provided on at least a portion of the pair of electrodes 27a and 27b. Providing terminal 28 facilitates connection to an external power supply. Terminal 28 is connected to a wire connected to the external power supply.

[0073] The material of terminal 28 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.

[0074] The size and shape of the terminal 28 are not particularly limited. For example, as shown in Figure 6A, the terminal 28 can be provided over the entire length of the pair of electrodes 27a and 27b on the outer peripheral wall 22. Alternatively, the terminal 28 may be provided on a portion of the pair of electrodes 27a and 27b on the outer peripheral wall 22, or it may be provided so as to extend outward from the outer edge of the pair of electrodes 27a and 27b on the outer peripheral wall 22. Furthermore, the terminal 28 may be provided on a portion of the pair of electrodes 27a and 27b on the partition wall 25, or it may be provided so as to block a portion of the cell 24. Furthermore, the thickness of the terminal 28 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.

[0075] The method of connecting terminal 28 to the pair of electrodes 27a and 27b 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.

[0076] (2-5. Method for manufacturing the humidity control device 20) The method for manufacturing the humidity control device 20 is not particularly limited and can be carried out in accordance with known methods. The method for manufacturing the humidity control device 20 will be described below as an example. The manufacturing method for the honeycomb structure 21 constituting the humidity control device 20 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.

[0077] 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 ).

[0078] Examples of dispersion media include water, or a mixed solvent of water and an organic solvent such as alcohol, but water is particularly suitable.

[0079] 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.

[0080] Examples of plasticizers include polyoxyalkylene alkyl ethers, polycarboxylic acid polymers, and alkyl phosphate esters.

[0081] 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.

[0082] 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.

[0083] 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%.

[0084] 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.

[0085] 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 21 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 21. 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 21.

[0086] 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.

[0087] 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 21 having a predetermined composition.

[0088] 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.

[0089] A pair of electrodes 27a and 27b are formed on the honeycomb structure 21 obtained in this manner. The pair of electrodes 27a and 27b can be formed by metal deposition methods such as sputtering, vapor deposition, electrolysis, or chemical deposition. Alternatively, the pair of electrodes 27a and 27b can be formed by applying electrode paste and then baking it. Furthermore, the pair of electrodes 27a and 27b can also be formed by thermal spraying. The pair of electrodes 27a and 27b 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 27a and 27b.

[0090] First, an electrode slurry containing electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 23a or the second end face 23b of the honeycomb structure 21. The dispersion medium can be water, an organic solvent (e.g., toluene, xylene, ethanol, n-butanol, ethyl acetate, butyl acetate, terpineol, dihydroterpineol, texanol, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether), or a mixture thereof. Excess slurry around the outer circumference of the honeycomb structure 21 is removed by blowing and wiping. Then, a pair of electrodes 27a, 27b can be formed on the first end face 23a or the second end face 23b of the honeycomb structure 21 by drying the slurry. Drying can be carried out while heating the honeycomb structure 21 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 27a and 27b of the desired thickness can be provided.

[0091] Next, the terminals 28 are placed at predetermined positions on the pair of electrodes 27a and 27b, and the pair of electrodes 27a and 27b are connected to the terminals 28. The method described above can be used to connect the pair of electrodes 27a and 27b to the terminals 28. Note that the arrangement of terminals 28 may be performed after the formation of the adsorption layer 26 described below.

[0092] Next, an adsorption layer 26 is formed on the surface of the honeycomb structure 21, such as the partition walls 25. The method for forming the adsorption layer 26 is not particularly limited, but for example, it can be formed by the following steps: The honeycomb structure 21 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 21 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 26 can be formed on the surface of the partition wall 25 or the like by drying the slurry. Drying can be carried out, for example, by heating the honeycomb structure 21 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 26 of the desired thickness can be formed on the surface of a partition wall 25 or the like.

[0093] (2-6. Other humidity control devices 20) The humidity control device 20 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 20 having such a structure include a plate fin type heat exchanger or an elo fin type heat exchanger in which an adsorption layer 26 is formed on the surface of the fins, with multiple fins provided on a pipe. In the humidity control device 20 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 26 provided on the surface of the fins can be heated. A humidity control device 20 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 26 on the surface of the fins. The method for forming the adsorption layer 26 can be the method described above.

[0094] The humidity control device 20 may also include a honeycomb structure 21 having an outer peripheral wall 22 and partition walls 25 disposed inside the outer peripheral wall 22 that partition a plurality of cells 24 which form air passages extending from a first end face 23a to a second end face 23b, an adsorption layer 26 containing an adsorbent provided on the surface of the partition walls 25, and a heater provided upstream of the honeycomb structure 21. Note that the structure of this humidity control device 20 corresponds to the structure in Figure 6A with the pair of electrodes 27a, 27b and terminal 28 removed. In the humidity control device 20 having the heating structure described above, the adsorption layer 26 provided on the surface of the partition wall 25 can be heated by circulating air heated by the heater through the cells 24 of the honeycomb structure 21.

[0095] The humidity control device 20 having the heating structure described above does not require the honeycomb structure 21 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 21 may be made of a material that can generate heat when an electric current is passed through it. Furthermore, the humidity control device 20 having the heating structure described above can be manufactured in accordance with the method described above.

[0096] (3. HVAC Unit 30) The HVAC unit 30 includes an evaporator 31 located in the flow path 10 downstream of the humidity control device 20. The evaporator 31 can cool and dehumidify the air flowing through the HVAC unit 30. The HVAC unit 30 may include a capacitor 32 to heat the air flowing through the HVAC unit 30. The location of the capacitor 32 is not particularly limited, but for example, it may be located in the flow path 10 downstream of the evaporator 31.

[0097] The HVAC unit 30 may include a defroster opening 33a, a foot opening 33b, and a face opening 33c downstream of the evaporator 31 and condenser 32, which are open towards the interior of the vehicle. It may also include a defroster door 34a for adjusting the amount of air blown out from the defroster opening 33a, a foot door 34b for adjusting the amount of air blown out from the foot opening 33b, and a face door 34c for adjusting the amount of air blown out from the face opening 33c.

[0098] In the vehicle air conditioning systems shown in Figures 1, 2, and 5, the HVAC unit 30 may include a ventilator 50 (blower). Specifically, in the vehicle air conditioning system shown in Figure 1, the HVAC unit 30 may include a ventilator 50 in both the first flow path 11 where the humidity control device 20 is located and the second flow path 12 where the humidity control device 20 is not located. In the vehicle air conditioning system shown in Figure 2, the HVAC unit 30 may include a ventilator 50 in the flow path 10 upstream of the first flow path 11 and the second flow path 12. In the vehicle air conditioning system shown in Figure 5, the HVAC unit 30 may include a ventilator 50 in the flow path upstream of the evaporator 31. The ventilator 50 is not particularly limited, and any known type can be used.

[0099] On the other hand, in the vehicle air conditioning system shown in Figures 3 and 4, a ventilator 50 is provided in the flow path 10 within a duct 15 separate from the HVAC unit 30. Also, in the vehicle air conditioning system shown in Figure 5, a ventilator 50 is provided in the flow path 10 within the duct 15 in addition to the HVAC unit 30. Specifically, in the vehicle air conditioning system shown in Figure 3, in the flow path 10 within the duct 15 upstream of the HVAC unit 30, a ventilator 50 can be included in both the first flow path 11 where the humidity control device 20 is located and the second flow path 12 where the humidity control device 20 is not located. Also, in the vehicle air conditioning system shown in Figure 4, in the flow path 10 within the duct 15 upstream of the HVAC unit 30, a ventilator 50 can be included in the flow path 10 upstream of the first flow path 11 and the second flow path 12. Also, in the vehicle air conditioning system shown in Figure 5, a ventilator 50 can be included in the first flow path 11 upstream of the humidity control device 20.

[0100] In the vehicle air conditioning system shown in Figures 1, 2, and 5, the HVAC unit 30 may include an interior air supply port 51a for supplying air from inside the vehicle (interior air), an exterior air supply port 51b for supplying air from outside the vehicle (outside air), and a damper 52 for adjusting the flow rates of the interior and outside air. On the other hand, in the case of the vehicle air conditioning system shown in Figures 3 and 4, the duct 15 upstream of the HVAC unit 30 may include an interior air supply port 51a for supplying air from inside the vehicle (interior air), an exterior air supply port 51b for supplying air from outside the vehicle (outside air), and a damper 52 for adjusting the flow rates of the interior and outside air.

[0101] The HVAC unit 30 may include an air mix door 39 between the evaporator 31 and the condenser 32. The air mix door 39 is configured to rotate within the flow path 10 of the HVAC unit 30 between a heating position that opens a heating path toward the condenser 32 and a cooling position that opens a cooling path that bypasses the condenser 32. By rotating the air mix door 39 between the heating and cooling positions, the ratio of air passing through the condenser 32 to air bypassing the condenser 32 can be adjusted, thereby controlling the temperature of the air flowing into the vehicle.

[0102] The evaporator 31 and condenser 32 of the HVAC unit 30 can be connected to a heat pump cycle. Figure 7 shows a schematic diagram of the heat pump cycle connected to the evaporator 31 and the condenser 32. In the heat pump cycle, the evaporator 31 can exchange heat between the cold energy of the refrigerant and the air. Specifically, the evaporator 31 can absorb heat from the low-temperature, low-pressure refrigerant flowing through the heat pump cycle, cooling the air in the flow path 10 that passes around the evaporator 31. The condenser 32 can also exchange heat between the warm energy of the refrigerant and the air. Specifically, the condenser 32 can dissipate heat from the high-temperature, high-pressure refrigerant flowing through the heat pump cycle, heating the air in the flow path 10 that passes around the condenser 32.

[0103] The heat pump cycle may further include a compressor 35, an outdoor heat exchanger 36, expansion valves 37a, 37b, and shut-off valves 38a to 38d, with each of these components connected via a refrigerant flow path.

[0104] The compressor 35 has the function of compressing and discharging the refrigerant. The compressor 35's suction section is connected to the outdoor heat exchanger 36, and its discharge section is connected to the condenser 32 via a refrigerant flow path. The compressor 35 is driven by the control unit 40 and compresses the refrigerant, thereby discharging high-temperature, high-pressure refrigerant to the condenser 32. Furthermore, known devices such as a gas-liquid separator may be provided between the compressor 35 and the heat exchanger.

[0105] The outdoor heat exchanger 36 has the function of exchanging heat between the refrigerant and the outside air. The outdoor heat exchanger 36 can absorb heat from the outside air by the low-temperature, low-pressure refrigerant circulating inside, mainly when the heating operation mode is running, and vaporizes the refrigerant by absorbing heat from the outside air. In addition, the outdoor heat exchanger 36 can release heat to the outside air by the high-temperature, high-pressure refrigerant circulating inside, and cools the refrigerant by releasing heat to the outside air.

[0106] The expansion valves 37a and 37b are throttle valves whose opening degree can be adjusted by the control unit 40. In particular, when the heating operation mode is running, the expansion valve 37a depressurizes and expands the refrigerant discharged from the condenser 32, and then discharges the low-temperature, low-pressure refrigerant to the outdoor heat exchanger 36. Similarly, when the cooling operation mode is running, the expansion valve 37b depressurizes and expands the refrigerant from the outdoor heat exchanger 36, and then discharges the low-temperature, low-pressure refrigerant to the evaporator 31.

[0107] The shut-off valves 38a to 38d are provided to control the flow path of the refrigerant. The opening and closing of the shut-off valves 38a to 38d are controlled by the control unit 40.

[0108] (4. Control Unit 40) The control unit 40 controls the humidity control device 20 and the HVAC unit 30 (including the heat pump cycle) according to the operating mode. Therefore, the control unit 40 is electrically connected to the humidity control device 20 and the HVAC unit 30. In other words, the control unit 40 can control the humidity control device 20 to perform either a dehumidification mode or a regeneration mode. The control unit 40 can also control the HVAC unit 30 to perform either a heating operation mode or a cooling (dehumidification) operation mode.

[0109] The control unit 40 is electrically connected to the shut-off valves 38a to 38d of the heat pump cycle, and can control the flow path of the refrigerant by opening and closing the shut-off valves 38a to 38d. The control unit 40 is also electrically connected to the expansion valves 37a and 37b of the heat pump cycle, and can control the degree of refrigerant pressure reduction by adjusting the opening of the expansion valves 37a and 37b. Furthermore, the control unit 40 is electrically connected to the air mix door 39, the ventilator 50, the first valve 60, the second valve 61, etc., and can control these as well.

[0110] The control unit 40 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.

[0111] In a vehicle air conditioning system according to an embodiment of the present invention, the control unit 40 can execute a dehumidification mode and a regeneration mode as operating modes for the humidity control device 20.

[0112] <Dehumidification mode> In the vehicle air conditioning system shown in Figures 1 and 3, a ventilator 50 located in the first flow path 11 is activated, and the first valve 60 is controlled so that air flows into the first flow path 11, and the second valve 61 is controlled so that air flows into the third flow path 13, thereby circulating air to the humidity control device 20 and dehumidifying it. Furthermore, in the vehicle air conditioning system shown in Figures 2 and 4, the ventilator 50 is activated, and the first valve 60 is controlled so that air flows into the first passage 11, and the second valve 61 is controlled so that air flows into the third passage 13, thereby circulating air to the humidity control device 20 and dehumidifying it. Furthermore, in the vehicle air conditioning system shown in Figure 5, the ventilator 50 in the HVAC unit 30 is activated, and the second valves 61 are controlled so that air flows into the third flow path 13, thereby dehumidifying the air by circulating it through the humidity control device 20. At this time, the ventilator 50 located in the first flow path 11 may also be activated. Note that in dehumidification mode, the humidity control device 20 is not heated.

[0113] <Playback Mode> In the vehicle air conditioning system shown in Figures 1, 3, and 5, a ventilator 50 located in the first flow path 11 is activated, and the first valve 60 is controlled so that air flows into the first flow path 11, and the second valve 61 is controlled so that air flows out into the fourth flow path 14, thereby circulating air to the humidity control device 20. By heating the humidity control device 20 at this time, moisture adsorbed on the humidity control device 20 is removed, allowing the humidity control device 20 to be regenerated. Furthermore, in the vehicle air conditioning system shown in Figures 2 and 4, the ventilator 50 is activated, and the first valve 60 is controlled so that air flows into the first passage 11, and the second valve 61 is controlled so that air flows out into the fourth passage 14, thereby circulating air to the humidity control device 20. By heating the humidity control device 20 at this time, moisture adsorbed on the humidity control device 20 is removed, allowing the humidity control device 20 to be regenerated.

[0114] In a vehicle air conditioning system according to an embodiment of the present invention, the control unit 40 can execute a heating operation mode and a cooling operation mode as operating modes for the HVAC unit 30.

[0115] <Heating operation mode> In heating operation mode, shut-off valves 38a and 38b are opened, and shut-off valves 38c and 38d are closed to form a flow path through which the refrigerant flows sequentially through the compressor 35, condenser 32, expansion valve 37a, and outdoor heat exchanger 36. The refrigerant compressed by the compressor 35 enters the condenser 32 as a high-temperature, high-pressure refrigerant, and dissipates heat by exchanging heat with the air circulating in the flow path 10 of the HVAC unit 30. The refrigerant that leaves the condenser 32 is depressurized and expanded in the expansion valve 37a, becoming a low-temperature, low-pressure refrigerant. After that, it exchanges heat with the outside air in the outdoor heat exchanger 36, absorbs heat, and returns to the compressor 35. When this heating operation mode is activated, the air flowing through the passage 10 in the HVAC unit 30 is heated by the condenser 32, and the heated air can be flowed 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 mix door 39.

[0116] <Cooling operation mode> In cooling operation mode, shut-off valves 38c and 38d are opened and shut-off valves 38a and 38b are closed to form a flow path through which the refrigerant flows sequentially through the compressor 35, outdoor heat exchanger 36, expansion valve 37b, and evaporator 31. The refrigerant, compressed by the compressor 35 to become high temperature and high pressure, is cooled by exchanging heat with the outside air in the outdoor heat exchanger 36. The refrigerant that leaves the outdoor heat exchanger 36 is depressurized and expanded in the expansion valve 37b, becoming low temperature and low pressure, and enters the evaporator 31, where it exchanges heat with the air circulating in the flow path 10 of the HVAC unit 30 and absorbs heat. The refrigerant that leaves the evaporator 31 returns to the compressor 35. When this cooling operation mode is activated, the air circulating in the flow path 10 of the HVAC unit 30 is cooled by the evaporator 31, and the cooled air flows into the passenger compartment.

[0117] In the vehicle air conditioning system according to an embodiment of the present invention, when the control unit 40 executes the cooling operation mode of the HVAC unit 30, dehumidification is performed by the evaporator 31. At this time, the control unit 40 does not need to actively perform dehumidification by the humidity control device 20. Therefore, in the vehicle air conditioning system shown in Figures 1 and 3, it is sufficient to activate the ventilator 50 located in the second flow path 12 so that air flows into the second flow path 12. Alternatively, the ventilators 50 located in the first flow path 11 and the second flow path 12 may be activated so that air flows into both the first flow path 11 and the second flow path 12 (however, the second valve 61 is controlled so that air flows into the third flow path 13). Furthermore, in the vehicle air conditioning system shown in Figure 5, it is sufficient to activate the ventilator 50 in the HVAC unit 30 and block the flow in the first flow path 11 with the second valve 61. Alternatively, in addition to the ventilator 50 in the HVAC unit 30, the ventilator 50 located in the first flow path 11 may be activated so that air flows into both the first flow path 11 and the second flow path 12 (however, the second valve 61 is controlled so that air flows into the third flow path 13). When air flows into both the first flow path 11 and the second flow path 12, dehumidification is performed by the humidity control device 20 in the initial stage, but as time passes, the dehumidification effect of the humidity control device 20 saturates, and thereafter dehumidification by the humidity control device 20 is not performed. Furthermore, in the vehicle air conditioning system shown in Figures 2 and 4, the ventilator 50 may be activated and the first valve 60 may be controlled so that air flows into the second flow path 12.

[0118] In the vehicle air conditioning system according to an embodiment of the present invention, when the control unit 40 executes the heating operation mode of the HVAC unit 30, the dehumidification mode of the humidity control device 20 is also executed. Therefore, in the vehicle air conditioning system shown in Figures 1 and 3, the ventilator 50 located in the first flow path 11 is activated, and the first valve 60 is controlled so that air flows into the first flow path 11, and the second valve 61 is controlled so that air flows into the third flow path 13, thereby circulating air to the humidity control device 20. Similarly, in the vehicle air conditioning system shown in Figures 2 and 4, the ventilator 50 is activated, and the first valve 60 is controlled so that air flows into the first flow path 11, and the second valve 61 is controlled so that air flows into the third flow path 13, thereby circulating air to the humidity control device 20. Furthermore, in the vehicle air conditioning system shown in Figure 5, the ventilator 50 in the HVAC unit 30 is activated, and the second valve 61 is controlled so that air flows into the third flow path 13, thereby circulating air to the humidity control device 20. At this time, the ventilator 50 in the first flow path 11 may also be activated. [Explanation of Symbols]

[0119] 10 channels 11. First channel 12 Second channel 13 Third channel 14. Fourth channel 15 ducts 20 Humidity Control Devices 21 Honeycomb structure 22 Outer wall 23a First end surface 23b 2nd end face 24 cells 25 Bulkhead 26 Adsorption layer 27a, 27b A pair of electrodes 28 terminals 30 HVAC units 31 Evaporator 32 Capacitors 33a Defroster opening 33b Foot opening 33c Face opening 34a Defroster Door 34b Footdoor 34c face door 35 Compressor 36 Outdoor heat exchanger 37a, 37b Expansion valve 38a~38d Shut-off valves 39 Air Mix Door 40 Control Unit 50 Ventilator 51a Indoor air supply port 51b Outside air supply port 52 dampers 60. Valve No. 1 61. Second valve

Claims

1. A flow path through which air can circulate, A humidity control device disposed within the aforementioned flow path and capable of adsorbing and desorbing moisture, An HVAC unit including an evaporator disposed in the flow path downstream of the humidity control device, A control unit capable of controlling the humidity control device and the HVAC unit Equipped with, The control unit is a vehicle air conditioning system that performs dehumidification by the evaporator during cooling and dehumidification by the humidity control device during heating.

2. The flow path branches upstream of the evaporator into a first flow path in which the humidity control device is located and a second flow path in which the humidity control device is not located. The vehicle air conditioning system according to claim 1, wherein the air flows through the second flow path during cooling and through the first flow path during heating.

3. The vehicle air conditioning system according to claim 2, further comprising a ventilator in the first flow path upstream of the humidity control device.

4. The vehicle air conditioning system according to claim 2, further comprising a first valve upstream of the humidity control device, which is capable of switching the airflow between the first flow path and the second flow path.

5. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the humidity control device is located within the HVAC unit.

6. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the humidity control device is located upstream of the HVAC unit.

7. It is further equipped with a sensor that measures the outside temperature of the vehicle. The control unit performs cooling when the outside temperature is above a predetermined set temperature, and heating when the outside temperature is below a predetermined set temperature. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the set temperature is 0 to 15°C.

8. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the evaporator of the HVAC unit is connected to a heat pump cycle.

9. The aforementioned flow path branches downstream of the humidity control device into a third flow path that allows the air to flow into the vehicle and a fourth flow path that allows the air to flow out of the vehicle. The vehicle air conditioning system according to any one of claims 1 to 4, further comprising a second valve capable of switching the airflow between the third flow path and the fourth flow path.

10. The vehicle air conditioning system according to any one of claims 1 to 4, wherein the humidity control device has an adsorption portion containing an adsorbent that adsorbs moisture at a predetermined temperature or below and desorbs the adsorbed moisture when the temperature exceeds the predetermined temperature, and a heating means or heating structure capable of heating the adsorption portion.

11. 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 10, comprising:

12. The vehicle air conditioning system according to claim 11, wherein at least the partition wall of the honeycomb structure is made of a material having PTC properties.

13. The vehicle air conditioning system according to claim 10, 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.

14. 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 10, comprising:

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