Vehicle air-conditioning system
The vehicle air conditioning system addresses inefficiencies in desorption by controlling air flow rate based on temperature, ensuring effective desorption and reduced heating loss.
Patent Information
- Application Number
- JP2024128139
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2026-02-16
AI Technical Summary
Existing vehicle air conditioning systems face inefficiencies in the desorption of adsorption target substances during the regeneration mode, as increasing air flow rate does not effectively manage temperature changes, leading to difficulties in desorption.
A vehicle air conditioning system with a control unit that adjusts air flow rate based on the temperature of the adsorption section, reducing flow rate when the temperature reaches a certain percentage of the desorption temperature and increasing it when necessary to maintain efficient desorption.
The system efficiently desorbs adsorption target substances by controlling air flow rate in response to temperature changes, maximizing regeneration efficiency while minimizing heating loss.
Smart Images

Figure 2026025402000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a vehicle air conditioning system. [Background technology]
[0002] There is a growing demand for improved cabin environments in automobiles and other vehicles. Specific demands include reducing CO2 emissions in the cabin to suppress driver drowsiness, controlling cabin humidity, and removing odorous components, allergy-inducing substances, and other harmful volatile components from the cabin. Ventilation is an effective solution to these demands, but it can significantly reduce heating energy in winter, resulting in reduced energy efficiency. This energy loss, particularly in battery electric vehicles (BEVs), poses a significant problem: the driving range is significantly reduced.
[0003] As a method for solving the above problems, Patent Document 1 proposes a vehicle air conditioning system (vehicle interior purification system) that includes a honeycomb structure having an outer peripheral wall and partition walls arranged inside the outer peripheral wall that partition a plurality of cells that form flow paths extending from one end face to the other end face, with at least the partition walls being made of a material that has PTC (Positive Temperature Coefficient) properties, and an air conditioning device (heater element) that has a pair of electrodes provided at predetermined positions on the honeycomb structure and has adsorption sections (functional material-containing layers) on the surfaces of the partition walls that adsorb substances to be adsorbed (such as water vapor and CO2). [Prior art documents] [Patent documents]
[0004] [Patent Document 1] International Publication No. 2023 / 074202 Summary of the Invention [Problem to be solved by the invention]
[0005] However, simply using the air conditioning device of Patent Document 1 does not allow for efficient desorption of the adsorption target substance during the regeneration mode, in which the adsorption section that has adsorbed the adsorption target substance is heated. For example, although the amount of desorption of the adsorption target substance tends to increase by increasing the flow rate of air flowing through the air conditioning device, the temperature of the adsorption section decreases, making it difficult for the adsorption target substance to desorb from the adsorption section. For this reason, simply increasing the flow rate of air flowing through the air conditioning device does not allow for efficient desorption of the adsorption target substance.
[0006] The present invention has been made to solve the above-mentioned problems, and aims to provide a vehicle air conditioning system that can efficiently desorb adsorption target substances in the adsorption section regeneration mode. [Means for solving the problem]
[0007] As a result of extensive research into vehicle air conditioning systems equipped with air conditioning devices, the inventors discovered that, in a regeneration mode in which the adsorption section is heated, controlling the air flow rate in accordance with the temperature of the adsorption section makes it possible to efficiently desorb the target substance, leading to the completion of the present invention. That is, the present invention is exemplified as follows.
[0008] <1> an air conditioning duct through which air from the vehicle compartment or outside the vehicle can circulate; an air conditioning device disposed in the air conditioning duct, the air conditioning device having an adsorption unit having an adsorbent capable of adsorbing and desorbing a target substance to be adsorbed, and a heating means capable of heating the adsorption unit; a control unit capable of controlling the flow rate of the air flowing through the air conditioning duct and the heating of the adsorption unit; Equipped with In a regeneration mode in which the adsorption section is heated, the control section controls the flow rate of the air in accordance with the temperature of the adsorption section.
[0009] <2> the control of the air flow rate by the control unit includes reducing the air flow rate when the temperature of the adsorption unit reaches −30 to 250% of the desorption temperature. <1> The vehicle air conditioning system according to claim 1.
[0010] <3> The control of the air flow rate by the control unit is performed when the adsorption unit is at or above a desorption temperature. <1> The vehicle air conditioning system according to claim 1.
[0011] <4> The control of the air flow rate by the control unit includes reducing the air flow rate when the temperature of the adsorption unit reaches 0 to 250% of the desorption temperature. <3> The vehicle air conditioning system according to claim 1.
[0012] <5> The control of the air flow rate by the control unit includes reducing the air flow rate when the temperature of the adsorption unit reaches 20 to 250% of the desorption temperature. <3> The vehicle air conditioning system according to claim 1.
[0013] <6> The control of the air flow rate by the control unit includes increasing the air flow rate when the temperature of the adsorption unit reaches 260 to 380% of the desorption temperature. <1> ~ <5> 10. A vehicle air conditioning system according to claim 9, wherein:
[0014] <7> the control of the air flow rate by the control unit includes increasing the air flow rate when the adsorption unit is at or above a desorption temperature to be higher than the air flow rate when the adsorption unit is below the desorption temperature. <1> ~ <6> 10. A vehicle air conditioning system according to claim 9, wherein:
[0015] <8> The air conditioning device is a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that serve as the air flow paths 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 wall of the honeycomb structure that is parallel to the extending direction of the cells; Equipped with <1> ~ <7> 10. A vehicle air conditioning system according to claim 9, wherein:
[0016] <9> the temperature of the adsorption layer is determined by determining in advance a relationship between the temperature of the adsorption layer and at least one condition parameter selected from the temperature of the honeycomb structure, the resistance value of the honeycomb structure, the current value of the honeycomb structure, the heating time of the honeycomb structure, the temperature of the air that has passed through the honeycomb structure, and the amount of components contained in the air that has passed through the honeycomb structure, and measuring the condition parameter. <8> The vehicle air conditioning system according to claim 1.
[0017] <10> Further comprising a power source for applying a voltage to the pair of electrodes. <8> or <9> The vehicle air conditioning system according to claim 1.
[0018] <11> In the honeycomb structure, at least the partition walls are made of a material having PTC properties. <8> ~ <10> 10. A vehicle air conditioning system according to claim 9, wherein:
[0019] <12> The adsorbent is capable of adsorbing and desorbing one or more types selected from moisture, carbon dioxide, and volatile components. <1> ~ <11> 10. A vehicle air conditioning system according to claim 9, wherein:
[0020] <13> The air conditioning duct is branched downstream of the air conditioning device into a first flow path that introduces the air into the vehicle compartment and a second flow path that discharges the air to the outside of the vehicle, and further includes a valve that can switch the flow of the air between the first flow path and the second flow path. <1> ~ <12> 10. A vehicle air conditioning system according to claim 9, wherein:
[0021] <14> The control unit is capable of controlling the valve, the control unit is capable of executing an air conditioning mode in which the valve is switched so that the air flows through the first flow path, and a regeneration mode in which the valve is switched so that the air flows through the second flow path and the adsorption unit is heated. <13> The vehicle air conditioning system according to claim 1. [Effects of the Invention]
[0022] According to the present invention, it is possible to provide a vehicle air conditioning system that can efficiently desorb the adsorption target substance in the regeneration mode of the adsorption unit. [Brief explanation of the drawings]
[0023] [Figure 1] 1 is a schematic diagram illustrating the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2A] 10 is a graph showing the relationship between a typical control pattern of air flow velocity and the temperature of the adsorption section in a regeneration mode. [Figure 2B] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 2C] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 2D] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 2E] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 2F] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 2G] 10 is a graph showing the relationship between another control pattern of the air flow rate and the temperature of the adsorption section in the regeneration mode. [Figure 3A] 1 is a schematic diagram of a cross section parallel to a flow path direction of an air conditioning device used in a vehicle air conditioning system according to an embodiment of the present invention. [Figure 3B] 3B is a schematic cross-sectional view of the air conditioning device of FIG. 3A taken along line aa'. FIG. DETAILED DESCRIPTION OF THE INVENTION
[0024] The vehicle air conditioning system of the present invention comprises an air conditioning duct through which air can flow from the vehicle compartment or outside the vehicle; an air conditioning device disposed in the air conditioning duct and having an adsorption unit having an adsorbent capable of adsorbing and desorbing a target substance for adsorption and a heating means capable of heating the adsorption unit; and a control unit capable of controlling the flow rate of air flowing through the air conditioning duct and the heating of the adsorption unit. In a regeneration mode in which the adsorption unit is heated, the control unit controls the flow rate of the air in accordance with the temperature of the adsorption unit. By configuring the vehicle air conditioning system in this way, the target substance for adsorption can be efficiently desorbed in the regeneration mode of the adsorption unit. As a result, the regeneration efficiency of the adsorption unit can be maximized while suppressing heating loss in the regeneration mode of the adsorption unit.
[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments, and it should be understood that modifications and improvements made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention are also within the scope of the present invention.
[0026] A vehicle air conditioning system according to an embodiment of the present invention can be suitably used in various vehicles, such as automobiles. Examples of vehicles include, but are not limited to, automobiles and trains. Examples of automobiles include, but are not limited to, gasoline-powered vehicles, diesel-powered vehicles, gas-fueled vehicles using CNG (compressed natural gas) or LNG (liquefied natural gas), fuel cell vehicles, electric vehicles, and plug-in hybrid vehicles. A vehicle air conditioning system according to an embodiment of the present invention can be suitably used in vehicles without internal combustion engines, such as electric vehicles and trains.
[0027] FIG. 1 is a schematic diagram showing the overall configuration of a vehicle air conditioning system according to an embodiment of the present invention. 1, a vehicle air conditioning system 100 according to an embodiment of the present invention includes an air conditioning duct 10, an air conditioning device 20, and a control unit 30. The vehicle air conditioning system 100 may further include a power supply 40, a valve 50, and a ventilator 60.
[0028] Air from the vehicle interior or outside the vehicle can flow through the air conditioning duct 10. The air conditioning duct 10 branches downstream of the air conditioning device 20 into a first flow path 10a that introduces air into the vehicle interior and a second flow path 10b that discharges air outside the vehicle. The valve 50 can switch the air flow between the first flow path 10a and the second flow path 10b.
[0029] The air conditioning device 20 is disposed inside the air conditioning duct 10. The number of air conditioning devices 20 disposed inside the air conditioning duct 10 may be one or more. When a plurality of air conditioning devices 20 are provided, they may be disposed in parallel or in series with respect to the flow of air circulating inside the air conditioning duct 10. The air conditioning device 20 has an adsorption section having an adsorbent capable of adsorbing and desorbing a substance to be adsorbed, and a heating means capable of heating the adsorption section.
[0030] The control unit 30 can control the flow rate of air flowing through the air conditioning duct 10 and the heating of the adsorption unit of the air conditioning device 20. Specifically, the control unit 30 can control the flow rate (flow rate) of air by adjusting the rotation speed of a fan 60 electrically connected to the control unit 30. The control unit 30 can also control whether or not to heat the adsorption unit of the air conditioning device 20 by controlling a power source 40 electrically connected to the heating means of the air conditioning device 20. The control unit 30 is also connected to a valve 50 and can control the open / close state of the valve 50.
[0031] In the vehicle air conditioning system 100 having the above-described structure, air from the vehicle compartment or outside the vehicle flows into the air conditioning device 20 through the air conditioning duct 10, both in a regeneration mode in which the adsorption unit of the air conditioning device 20 is heated and in an air conditioning (adsorption) mode in which the adsorption unit of the air conditioning device 20 is not heated. In the adsorption mode, the adsorption target substances in the air are captured (adsorbed) by the adsorption unit of the air conditioning device 20, and the air with reduced amounts of the adsorption target substances flows into the vehicle compartment through the first flow path 10a. On the other hand, in the regeneration mode, as the adsorption unit of the air conditioning device 20 is heated, the adsorption target substances captured by the adsorption unit are desorbed, and the air containing the adsorption target substances flows out of the vehicle through the second flow path 10b.
[0032] In the regeneration mode in which the adsorption unit is heated, the control unit 30 controls the air flow rate according to the temperature of the adsorption unit. Specifically, when the temperature of the adsorption unit is low, the air flow rate is reduced, making it easier to increase the temperature of the adsorption unit and preventing the adsorption target substance from becoming difficult to desorb from the adsorption unit. Furthermore, when the temperature of the adsorption unit is high, the air flow rate is increased, promoting desorption of the adsorption target substance. By controlling the air flow rate according to the temperature of the adsorption unit in this way, the air flow rate can be increased while preventing the temperature of the adsorption unit from decreasing excessively, making it possible to efficiently desorb the adsorption target substance.
[0033] FIG. 2A shows a graph illustrating the relationship between a typical control pattern of the air flow rate in the regeneration mode and the temperature of the adsorption section. As shown in FIG. 2A, if the air flow rate is kept constant from the start of the regeneration mode until time T1, the temperature of the adsorption unit rises. Because the temperature of the adsorption unit is high at time T1, the air flow rate is increased from time T1 to time T2, thereby promoting desorption of the target substance from the adsorption unit. Because the temperature of the adsorption unit is reduced at time T2 due to the increased air flow rate, the air flow rate is reduced from time T2 to time T3, thereby raising the temperature of the adsorption unit and preventing the target substance from desorbing from the adsorption unit. Because the temperature of the adsorption unit is high at time T3, similar to time T1, the air flow rate is increased from time T3 to time T4, thereby promoting desorption of the target substance from the adsorption unit. Because the temperature of the adsorption unit is reduced at time T4, similar to time T2, the air flow rate is reduced from time T4 to time T5, thereby raising the temperature of the adsorption unit and preventing the target substance from desorbing from the adsorption unit. Repeating this control allows for efficient desorption of the target substance.
[0034] The control of the air flow rate by the control unit 30 preferably includes reducing the air flow rate when the temperature of the adsorption unit reaches -30 to 250% of the desorption temperature. Specifically, in the graph shown in FIG. 2A, this includes reducing the air flow rate when the temperatures P2 and P4 of the adsorption unit at times T2 and T4 reach -30 to 250% of the desorption temperature. For example, when the desorption temperature is 100°C, this includes reducing the air flow rate when the temperatures P2 and P4 of the adsorption unit reach 70 to 250°C. Controlling the air flow rate in this manner can prevent the adsorption target substance from becoming difficult to desorb while sufficiently ensuring the effect of promoting desorption of the adsorption target substance. Here, in this specification, the "desorption temperature" refers to the temperature at which the substance to be adsorbed can be desorbed from the adsorption section. Therefore, the desorption temperature is determined depending on the substance to be adsorbed. For example, if the substance to be adsorbed is moisture, the desorption temperature is the temperature at which moisture can be desorbed. The desorption temperature of moisture is typically 100°C ± 40°C, although it depends on the structure of the air conditioning device 20.
[0035] The air flow velocity can be controlled by controlling the rotation speed of the fan 60. Specifically, the air flow velocity can be reduced by reducing the rotation speed of the fan 60. Conversely, the air flow velocity can be increased by increasing the rotation speed of the fan 60.
[0036] When the air flow rate is decreased and increased, the control pattern of the air flow rate is not particularly limited. Here, graphs showing the relationship between other control patterns of the air flow rate in the regeneration mode and the temperature of the adsorption section are shown in Figures 2B to 2G. In the temperature range of the adsorption unit where the air flow rate is reduced (e.g., between temperatures P2 and P3 and between temperatures P4 and P5 in FIG. 2A), the air flow rate may be gradually reduced (FIGS. 2A to 2D) or may be rapidly reduced and then maintained constant (FIGS. 2E to 2G). Similarly, in the temperature range of the adsorption unit where the air flow rate is increased (e.g., between temperatures P1 and P2 and between temperatures P3 and P4 in FIG. 2A), the air flow rate may be gradually increased (FIGS. 2A to 2D) or may be rapidly increased and then maintained constant (FIGS. 2E to 2G).
[0037] When the air flow velocity is reduced, the lower limit of the air flow velocity is not particularly limited and may be 0 m / s (a state in which no air flows) (e.g., FIG. 2C). However, since an air flow velocity of 0 m / s makes it difficult to discharge the desorbed substance to be adsorbed, it is preferable that the state in which the air flow velocity is 0 m / s be as short as possible. From the viewpoint of increasing the amount of desorption of the substance to be adsorbed, the lower limit of the air flow velocity is preferably 0.04 m / s, more preferably 0.05 m / s. When the air flow velocity is increased, the upper limit of the air flow velocity is not particularly limited, but is preferably 1.50 m / sec, and more preferably 1.40 m / sec.
[0038] The control of the air flow rate by the control unit 30 is preferably performed when the adsorption unit is at or above the desorption temperature (FIGS. 2C to 2G). By controlling the air flow rate when the adsorption unit is at or above the desorption temperature, it is possible to stably prevent the adsorption target substance from becoming difficult to desorb.
[0039] When the air flow rate is controlled when the adsorption section is at or above the desorption temperature, it is preferable to include reducing the air flow rate when the adsorption section reaches a temperature of 0 to 250% of the desorption temperature, and more preferably to include reducing the air flow rate when the adsorption section reaches a temperature of 20 to 250% of the desorption temperature. By controlling the air flow rate in this manner, it is possible to more stably prevent the substance to be adsorbed from becoming difficult to desorb.
[0040] The control of the air flow rate by the control unit 30 preferably includes increasing the air flow rate when the temperature of the adsorption unit reaches 260 to 380% of the desorption temperature. Specifically, in the graph shown in FIG. 2A, this includes increasing the air flow rate when the temperatures P1, P3, and P5 of the adsorption unit at times T1, T3, and T5 reach 260 to 380% of the desorption temperature. For example, when the desorption temperature is 100°C, this includes increasing the air flow rate when the temperatures P1, P3, and P5 of the adsorption unit reach 260 to 380°C. Controlling the air flow rate in this manner can further enhance the effect of promoting desorption of the adsorption target substance.
[0041] The control of the air flow rate by the control unit 30 preferably includes increasing the air flow rate when the adsorption unit is at or above the desorption temperature more than the air flow rate when the adsorption unit is below the desorption temperature. When the adsorption section is below the desorption temperature, the amount of the substance to be adsorbed is small, whereas when the adsorption section is at or above the desorption temperature, the amount of the substance to be adsorbed is large. Therefore, by controlling the air flow rate as described above, the effect of promoting desorption of the substance to be adsorbed can be improved.
[0042] Each component of the vehicle air conditioning system 100 will be described in detail below.
[0043] (1. Air conditioning duct 10) The air conditioning duct 10 is a flow path through which air can flow from the vehicle interior or outside the vehicle. The upstream side of the air conditioning duct 10 is connected to the vehicle interior or an outside air inlet. The air conditioning duct 10 allows air to flow in from the vehicle interior or outside the vehicle, and also allows air that has passed through the air conditioning device 20 to flow into the vehicle interior or out of the vehicle. Therefore, it is preferable that the air conditioning duct 10 be branched downstream of the air conditioning device 20 into a first flow path 10a that allows air to flow into the vehicle interior and a second flow path 10b that discharges air to the outside of the vehicle.
[0044] The air conditioning duct 10 may include a valve 50 capable of switching the air flow between the first flow path 10a and the second flow path 10b. The valve 50 is not particularly limited as long as it is electrically driven and has the function of switching the flow path, and a solenoid valve, an electric valve, or the like may be used. For example, the valve 50 may include an opening / closing door supported on a rotating shaft and an actuator such as a motor that rotates the rotating shaft. The actuator may be configured to be controllable by the control unit 30.
[0045] (2. Air Conditioning Device 20) Fig. 3A is a schematic cross-sectional view of an air conditioning device used in a vehicle air conditioning system according to an embodiment of the present invention, taken along a line a-a'. 3A and 3B, the air conditioning device 20 includes a honeycomb structure 21 having an outer peripheral wall 23 and partition walls 26 disposed inside the outer peripheral wall 23 and defining a plurality of cells 25 that serve as air flow paths extending from a first end face 24a to a second end face 24b, an adsorbent-containing adsorbent layer 27 provided on the surface of the partition wall 26, and a pair of electrodes 28a, 28b provided on the first end face 24a and the second end face 24b of the honeycomb structure 21. The air conditioning device 20 may also include terminals 29 connected to the pair of electrodes 28a, 28b.
[0046] (2-1. Honeycomb structure 21) The shape of the honeycomb structure 21 is not particularly limited. For example, the outer shape of a cross section perpendicular to the flow path direction (the direction in which the cells 25 extend) of the honeycomb structure 21 can be a polygon such as a quadrangle (rectangle, square), pentagon, hexagon, heptagon, or octagon, a circle, or an oval shape (egg, ellipse, oval, rounded rectangle, etc.). The end faces (first end face 24a and second end face 24b) have the same shape as the cross section. When the cross section and end faces are polygonal, the corners may be chamfered.
[0047] The shape of the cells 25 is not particularly limited, but may be a polygon such as a square, pentagon, hexagon, heptagon, or octagon, a circle, or an oval in a cross section perpendicular to the flow path direction of the honeycomb structure 21. These shapes may be used alone or in combination of two or more. Among these shapes, a square or hexagon is preferable. By providing cells 25 of such a shape, pressure loss during air flow can be reduced.
[0048] The honeycomb structure 21 may be a honeycomb bonded body having a plurality of honeycomb segments and a bonding layer bonding the outer peripheral side surfaces of the plurality of honeycomb segments together. By using the honeycomb bonded body, it is possible to increase the total cross-sectional area of the cells 25, which is important for ensuring the air flow rate (flow velocity), while suppressing the occurrence of cracks. The bonding layer can be formed using a bonding material. The bonding material is not particularly limited, but a paste made by adding a solvent such as water to a ceramic raw material can be used. The bonding material may contain a material having PTC properties, or may contain the same material as the outer peripheral wall 23 and the partition walls 26. In addition to the role of bonding the honeycomb segments together, the bonding material can also be used as an outer peripheral coating material after the honeycomb segments are bonded.
[0049] From the viewpoints of ensuring the strength of the honeycomb structure 21, reducing pressure loss when air passes through the cells 25, ensuring the amount of functional material carried, and ensuring the contact area with the air flowing within the cells 25, it is desirable to suitably combine the thickness of the partition walls 26, the cell density, and the cell pitch (or the opening rate of the cells 25). 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 24a or second end face 24b) of the honeycomb structure 21 (the total area of the partition walls 26 and cells 25 excluding the outer wall 23). In this specification, the cell pitch refers to a value calculated by the following calculation: First, the area per cell is calculated by dividing the area of one end face (first end face 24a or second end face 24b) of the honeycomb structure 21 (the total area of the partition walls 26 and the cells 25 excluding the outer peripheral wall 23) by the number of cells. Next, the square root of the area per cell is calculated, and this is defined as the cell pitch. In this specification, the opening ratio of the cells 25 is a value obtained by dividing the total area of the cells 25 partitioned by the partition walls 26 in a cross section perpendicular to the flow direction of the honeycomb structure 21 by the area of one end face (the first end face 24a or the second end face 24b) (the total area of the partition walls 26 and the cells 25 excluding the outer peripheral wall 23). Note that when calculating the opening ratio of the cells 25, the pair of electrodes 28a, 28b and the adsorption layer 27 are not taken into consideration.
[0050] In an embodiment advantageous from the viewpoint of carrying a sufficient amount of functional material, the thickness of the partition walls 26 is 0.300 mm or less, and the cell density is 100 cells / cm. 2In a preferred embodiment, the thickness of the partition walls 26 is 0.200 mm or less, and the cell density is 70 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 26 is 0.130 mm or less, and the cell density is 65 cells / cm. 2 or less, and the cell pitch is 1.3 mm or more.
[0051] 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 walls 26 is preferably 0.010 mm or more, more preferably 0.020 mm or more, and even more preferably 0.030 mm or more. From the viewpoint of ensuring the strength of the honeycomb structure 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 30 cells / cm. 2 Preferably, 35 cells / cm or more. 2 More preferably, 40 cells / cm or more. 2 More preferably, it is equal to or greater than this. From the viewpoint of ensuring the strength of the honeycomb structure 21, maintaining low electrical resistance, and increasing the surface area to promote reaction, adsorption, and desorption, the upper limit of the cell pitch is preferably 2.0 mm or less, more preferably 1.8 mm or less, and even more preferably 1.6 mm or less.
[0052] In an embodiment that is advantageous from the viewpoint of achieving both a reduction in pressure loss and maintaining strength, the thickness of the partition walls 26 is 0.08 to 0.36 mm, and the cell density is 2.54 to 140 cells / cm. 2 In a preferred embodiment, the thickness of the partition walls 26 is 0.09 to 0.35 mm, and the cell density is 15 to 100 cells / cm. 2 In a more preferred embodiment, the thickness of the partition walls 26 is 0.14 to 0.30 mm, and the cell density is 20 to 90 cells / cm. 2 The aperture ratio of the cell 25 is 0.85 or more.
[0053] From the viewpoint of ensuring the strength of the honeycomb structure 21, the upper limit of the opening ratio of the cells 25 is preferably 0.94 or less, more preferably 0.92 or less, and further preferably 0.90 or less.
[0054] The thickness of the peripheral wall 23 is not particularly limited, but is preferably determined based on the following points: First, from the viewpoint of reinforcing the honeycomb structure 21, the thickness of the peripheral wall 23 is preferably 0.05 mm or more, more preferably 0.06 mm or more, and even more preferably 0.08 mm or more. On the other hand, from the viewpoint of increasing the electrical resistance to suppress the initial current and reducing the pressure loss when air flows through, the thickness of the peripheral wall 23 is preferably 1.0 mm or less, more preferably 0.5 mm or less, even more preferably 0.4 mm or less, and even more preferably 0.3 mm or less. In this specification, the thickness of the peripheral wall 23 refers to the length in the normal direction of the side surface of the honeycomb structure 21 from the boundary between the peripheral wall 23 and the outermost cell 25 or partition wall 26 to the side surface of the honeycomb structure 21 in a cross section perpendicular to the flow direction of the honeycomb structure 21.
[0055] The length of the honeycomb structure 21 in the flow path direction and the cross-sectional area perpendicular to the flow path direction are not particularly limited and may be adjusted according to the required size of the air conditioning device 20. For example, when the honeycomb structure 21 is used in a compact air conditioning device 20 while ensuring a predetermined function, the length of the honeycomb structure 21 in the flow path direction is set to 2 to 20 mm, and the cross-sectional area perpendicular to the flow path direction is set to 10 cm. 2 The upper limit of the cross-sectional area perpendicular to the flow path direction is not particularly limited, but may be, for example, 300 cm 2 The following is the result.
[0056] The partition walls 26 constituting the honeycomb structure 21 are made of a material that can generate heat when electricity is applied thereto, and specifically, are preferably made of a material having PTC characteristics. If necessary, the peripheral wall 23 may also be made of a material having PTC characteristics, like the partition walls 26. With this configuration, the adsorption layer 27 can be directly heated by heat transfer from the heat-generating partition walls 26 (and the peripheral wall 23, if necessary). Furthermore, materials having PTC characteristics have the property that, when their temperature rises and exceeds the Curie point, their resistance value rises sharply, making it difficult for electricity to flow through them. Therefore, when the partition walls 26 (and the peripheral wall 23, if necessary) reach a high temperature, the current flowing through them is limited, thereby suppressing excessive heat generation in the honeycomb structure 21. Therefore, it is also possible to suppress thermal deterioration of the adsorption layer 27 due to excessive heat generation.
[0057] From the viewpoint of obtaining appropriate heat generation, the lower limit of the volume resistivity at 25°C of a material having PTC characteristics is preferably 0.5 Ω·cm or more, more preferably 1 Ω·cm or more, and even more preferably 5 Ω·cm or more. From the viewpoint of generating heat at a low driving voltage, the upper limit of the volume resistivity at 25°C of a material having PTC characteristics 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 at 25°C of a material having PTC characteristics is measured in accordance with JIS K6271:2008.
[0058] From the viewpoint of being able to generate heat when electrically applied and having PTC characteristics, the outer peripheral wall 23 and the partition walls 26 are preferably made of a material whose main component is barium titanate (BaTiO3). Furthermore, this material is more preferably a ceramic made of a material whose main component is barium titanate (BaTiO3)-based crystal particles in which part of the Ba is substituted with a rare earth element. In this specification, the term "main component" refers to a component that accounts for more than 50 mass% of the total components. The content of BaTiO3-based crystal particles can be determined by fluorescent X-ray analysis. Other crystal particles can also be measured using a similar method.
[0059] The composition formula of BaTiO3-based crystal particles in which part of Ba is replaced by rare earth elements is (Ba 1-x A x )TiO3, where A represents one or more rare earth elements and x is 0.0001≦x≦0.010. A is not particularly limited as long as it is a rare earth element, but is preferably one or more selected from the group consisting of La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Er, Y, and Yb, and more preferably La. x is preferably 0.001 or more, more preferably 0.0015 or more, from the viewpoint of preventing the electrical resistance at room temperature from becoming too high. On the other hand, x is preferably 0.009 or less, from the viewpoint of preventing the electrical resistance at room temperature from becoming too high due to insufficient sintering. The content of BaTiO3-based crystal particles in the ceramic, in which Ba is partially substituted with a rare earth element, is not particularly limited as long as it is an amount that serves as the main component, but is preferably 90 mass% or more, more preferably 92 mass% or more, and even more preferably 94 mass% or more. The upper limit of the content of BaTiO3-based crystal particles is not particularly limited, but is generally 99 mass%, preferably 98 mass%.
[0060] From the viewpoint of reducing the environmental impact, it is desirable that the materials used for the outer peripheral wall 23 and the partition wall 26 be substantially free of lead (Pb). Specifically, the Pb content of the outer peripheral wall 23 and the partition wall 26 is preferably 0.01% by mass or less, more preferably 0.001% by mass or less, and even more preferably 0% by mass. A low Pb content allows, for example, air heated by contact with the partition wall 26 during heat generation to be safely applied to living organisms such as humans. The Pb content of the outer peripheral wall 23 and the partition wall 26, calculated as 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).
[0061] The Curie points of the materials constituting the outer peripheral wall 23 and the partition walls 26 are preferably in the temperature range at which the resistance value thereof is at least twice the resistance value at room temperature (25°C). If the Curie points are in this temperature range, the current flowing through these materials is limited when the air-conditioning device 20 becomes hot, thereby efficiently suppressing excessive heat generation in the air-conditioning device 20. Therefore, thermal degradation of the adsorption layer 27 caused by excessive heat generation can be suppressed. The lower limit of the Curie point of the material constituting the outer peripheral wall 23 and the partition walls 26 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 27. The upper limit of the Curie point is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and particularly preferably 150°C or lower, from the viewpoint of safety as a part placed in or near the vehicle interior.
[0062] The Curie point of the material forming the outer peripheral wall 23 and the partition walls 26 can be adjusted by the type and amount of the shifter added. For example, the Curie point of barium titanate (BaTiO) is approximately 120°C, but by substituting part of the Ba and Ti with one or more of Sr, Sn, and Zr, the Curie point can be shifted to a lower temperature.
[0063] In this specification, the Curie point is measured by the following method: A sample is attached to a sample holder for measurement and placed in a measurement chamber (e.g., MINI-SUBZERO MC-810P, manufactured by Espec Corporation). The change in the sample's electrical resistance relative to temperature is measured as the temperature rises from 10°C using a DC resistance meter (e.g., Multimeter 3478A, manufactured by Hewlett-Packard Japan, LLC). The Curie point is determined by the temperature at which the resistance value, based on the electrical resistance-temperature plot obtained from the measurement, is twice the resistance value at room temperature (25°C).
[0064] (2-2. Pair of electrodes 28a, 28b) The positions of the pair of electrodes 28a, 28b are not particularly limited, but as shown in Fig. 3A, they can be provided on the first end face 24a and the second end face 24b of the honeycomb structure 21. Furthermore, the pair of electrodes 28a, 28b may be provided on the outer wall 23 parallel to the direction in which the cells 25 of the honeycomb structure 21 extend. By applying a voltage between the pair of electrodes 28a and 28b, it becomes possible to cause the honeycomb structure 21 to generate heat by Joule heat.
[0065] The pair of electrodes 28a, 28b is not particularly limited, and may be, for example, a metal or alloy containing at least one selected from Cu, Ag, Al, Ni, and Si. Alternatively, an ohmic electrode capable of making ohmic contact with the outer peripheral wall 23 and / or the partition wall 26 having PTC characteristics may be used. The ohmic electrode may contain, for example, 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 as a dopant for n-type semiconductors. The pair of electrodes 28a, 28b may have a single-layer structure or a stacked structure of two or more layers. When the pair of electrodes 28a, 28b has a stacked structure of two or more layers, the materials of the layers may be the same or different.
[0066] The thickness of the pair of electrodes 28a, 28b can be set appropriately depending on the method for forming the pair of electrodes 28a, 28b. Examples of methods for forming the pair of electrodes 28a, 28b include metal deposition methods such as sputtering, vapor deposition, electrolytic deposition, and chemical deposition. The pair of electrodes 28a, 28b can also be formed by applying an electrode paste and then baking it, or by thermal spraying. Furthermore, the pair of electrodes 28a, 28b may also be formed by joining metal or alloy plates.
[0067] The thickness of the pair of electrodes 28a, 28b is preferably about 5 to 30 μm for baking of electrode paste, about 100 to 1000 nm for dry plating such as sputtering and vapor deposition, about 10 to 100 μm for thermal spraying, and about 5 to 30 μm for wet plating such as electrolytic deposition and chemical deposition. Furthermore, when joining metal or alloy plates, the thickness is preferably about 5 to 100 μm.
[0068] (2-3. Terminal 29) Terminal 29 is connected to the pair of electrodes 28a, 28b and is provided on at least a portion of the pair of electrodes 28a, 28b. Providing terminal 29 facilitates connection to an external power source. Terminal 29 is connected to a conductor that is connected to the external power source.
[0069] The material of terminal 29 is not particularly limited, but may be, for example, a metal. As the metal, a single metal or an alloy may be used, but from the viewpoints of corrosion resistance, electrical resistivity, and linear expansion coefficient, an alloy containing at least one selected from the group consisting of Cr, Fe, Co, Ni, Cu, Al, and Ti is preferable, and stainless steel, an Fe-Ni alloy, and phosphor bronze are more preferable.
[0070] The size and shape of the terminal 29 are not particularly limited. For example, as shown in Fig. 3A, the terminal 29 may be provided over the entire pair of electrodes 28a, 28b on the outer peripheral wall 23. The terminal 29 may also be provided over a portion of the pair of electrodes 28a, 28b on the outer peripheral wall 23, or may be provided so as to extend outward beyond the outer edges of the pair of electrodes 28a, 28b on the outer peripheral wall 23. The terminal 29 may also be provided over a portion of the pair of electrodes 28a, 28b on the partition wall 26, or may be provided so as to cover some of the cells 25. The thickness of the terminal 29 is not particularly limited, but is, for example, 0.01 to 10 mm, typically 0.05 to 5 mm.
[0071] The method of connecting the terminal 29 and the pair of electrodes 28a, 28b is not particularly limited as long as they are electrically connected, and they can be connected by, for example, diffusion bonding, a mechanical pressure mechanism, welding, or the like.
[0072] (2-4.Adsorption layer 27) The adsorption layer 27 is a layer containing an adsorbent. The adsorption layer 27 can be provided on the surface of the partition wall 26 (in the case of the outermost cell 25, the partition wall 26 and the outer wall 23 that define the outermost cell 25). By providing the adsorption layer 27 in this manner, the adsorption target substance can be easily adsorbed during the adsorption process, and the adsorption layer 27 can be easily heated in the regeneration mode, so that the desired function of the adsorption layer 27 can be regenerated.
[0073] The adsorption layer 27 is capable of adsorbing and desorbing the substance to be adsorbed. Specifically, the adsorption layer 27 is preferably capable of adsorbing and desorbing one or more substances selected from moisture, carbon dioxide, and volatile components. For example, the adsorption layer 27 can contain one or more adsorbents capable of adsorbing these components. Furthermore, if one adsorbent is capable of adsorbing all of moisture, carbon dioxide, and volatile components, the adsorption layer 27 can adsorb moisture, carbon dioxide, and volatile components by containing only that adsorbent. The inclusion of such an adsorbent can provide an air purification effect.
[0074] The adsorbent contained in the adsorption layer 27 preferably has a function of being able to adsorb the substance to be adsorbed at temperatures between -20 and 40°C and desorb it at high temperatures of 60°C or higher. Examples of adsorbents include, but are not limited to, aluminosilicates, silica gel, silica, graphene oxide, polymer adsorbents, polystyrene sulfonic acid, zeolites, activated carbon, alumina, low-crystalline clay, amorphous aluminum silicate complexes, and metal organic frameworks (MOFs). These may be used alone or in combination of two or more.
[0075] The aluminosilicate is preferably a porous clay mineral such as AFI-type, CHA-type or BEA-type zeolite, allophane, imogolite, etc. The aluminosilicate is preferably amorphous.
[0076] As the silica gel, it is preferable to use type A silica gel. The polymer adsorbent is preferably one having a polyacrylic acid polymer chain, such as sodium polyacrylate. The metal-organic framework is a crystalline hybrid material containing metal ions and organic molecules (organic ligands). The metal ions are preferably hydrophilic metal ions (e.g., aluminum ions).
[0077] Volatile components contained in the air inside a vehicle cabin 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.
[0078] The adsorption layer 27 may contain a catalyst. By containing a catalyst, it is possible to promote oxidation-reduction reactions and the like, thereby purifying carbon dioxide and / or volatile components. Examples of catalysts having such functions include metal catalysts such as Pt, Pd, and Ag, and oxide catalysts such as CeO2 and ZrO2. One type of catalyst may be used alone, or two or more types may be used in combination. Furthermore, the catalyst may be used in combination with the above-mentioned functional materials.
[0079] The thickness of the adsorption layer 27 is not particularly limited and may be determined depending on the size of the cells 25. For example, from the viewpoint of ensuring sufficient contact with air, the thickness of the adsorption layer 27 is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 30 μm or more. On the other hand, from the viewpoint of preventing the adsorption layer 27 from peeling off from the partition walls 26 and the outer peripheral wall 23, the thickness of the adsorption layer 27 is preferably 400 μm or less, more preferably 380 μm or less, and even more preferably 350 μm or less.
[0080] The thickness of the adsorption layer 27 is measured by the following procedure. An arbitrary cross section parallel to the flow path direction of the honeycomb structure 21 is cut out, and a cross-sectional image at approximately 50 magnification is obtained using a scanning electron microscope or the like. This cross section is also set to pass through the center of gravity of the cross section perpendicular to the flow path direction of the honeycomb structure 21. For each adsorption layer 27 visible in the cross-sectional image, the thickness is calculated by dividing the cross-sectional area by the length of the cell 25 in the flow path direction. This calculation is performed for all adsorption layers 27 visible in the cross-sectional image, and the overall average value is taken as the thickness of the adsorption layer 27.
[0081] From the viewpoint of exhibiting the desired function in the air-conditioning device 20, the amount of the adsorption layer 27 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 a value determined by the outer dimensions of the honeycomb structure 21.
[0082] (2-5. Method for manufacturing air conditioning device 20) The method for manufacturing the air-conditioning device 20 is not particularly limited and can be carried out in accordance with a known method. The method for manufacturing the air-conditioning device 20 will be exemplified below. The method for manufacturing the honeycomb structure 21 constituting the air-conditioning device 20 includes a molding step and a firing step. In the molding step, a clay containing ceramic raw materials including BaCO3 powder, TiO2 powder, and powder of a rare earth nitrate or hydroxide is molded to produce a honeycomb molded body with a relative density of 60% or more. The ceramic raw material can be obtained by dry mixing each powder to obtain a desired composition. The clay can be obtained by adding a dispersion medium, a binder, a plasticizer, and a dispersant to a ceramic raw material and kneading the mixture. The clay may contain additives such as a sifter, a metal oxide, a property improver, and a conductive powder, as needed. The blending amount of components other than the ceramic raw materials is not particularly limited as long as it is an amount that allows the relative density of the honeycomb formed body to be 60% or more.
[0083] Here, in this specification, the "relative density of the honeycomb formed body" means the ratio of the density of the honeycomb formed body to the true density of the entire ceramic raw material. Specifically, it can be calculated by the following formula. Relative density (%) of honeycomb formed body = Density of honeycomb formed body (g / cm 3 ) / true density of the entire ceramic raw material (g / cm 3 ) x 100 The density of the honeycomb formed body can be measured by the Archimedes method using pure water as a medium. The true density of the entire ceramic raw material is calculated by multiplying the total mass (g) of each raw material by the total volume (cm) of each raw material. 3 ) can be calculated by dividing by
[0084] Examples of the dispersion medium include water and a mixed solvent of water and an organic solvent such as alcohol, with water being particularly preferred.
[0085] Examples of binders include organic binders such as methyl cellulose, hydroxypropoxyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, and polyvinyl alcohol. It is particularly preferable to use a combination of methyl cellulose and hydroxypropoxyl cellulose. While one binder may be used alone or two or more binders may be used in combination, it is preferable that the binder does not contain an alkali metal element.
[0086] Examples of the plasticizer include polyoxyalkylene alkyl ether, polycarboxylic acid polymer, and alkyl phosphate ester.
[0087] The dispersant may be a surfactant such as polyoxyalkylene alkyl ether, ethylene glycol, dextrin, fatty acid soap, polyalcohol, etc. The dispersant may be used alone or in combination of two or more.
[0088] The honeycomb formed body can be produced by extrusion molding of a clay. In extrusion molding, a die having a desired overall shape, cell shape, partition wall thickness, cell density, etc. can be used.
[0089] 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 this range, it is possible to densify the honeycomb formed body and reduce its electrical resistance at room temperature. The upper limit of the relative density of the honeycomb formed body is not particularly limited, but is generally 80%, preferably 75%.
[0090] The honeycomb molded body can be dried before the firing step. The drying method is not particularly limited, and for example, a conventionally known drying method such as hot air drying, microwave drying, dielectric drying, reduced pressure drying, vacuum drying, freeze drying, etc. Among these, a drying method that combines hot air drying with microwave drying or dielectric drying is preferred because it can dry the entire molded body quickly and uniformly.
[0091] The firing step involves holding the temperature at 1150 to 1250°C, then raising the temperature to a maximum temperature of 1360 to 1430°C at a rate of 20 to 600°C / hour, and holding the temperature for 0.5 to 10 hours. By holding the honeycomb formed body at a maximum temperature of 1360 to 1430°C for 0.5 to 10 hours, a honeycomb structure 21 containing, as a main component, BaTiO3-based crystal particles in which part of Ba has been substituted with a rare earth element can be obtained. Furthermore, by maintaining the temperature at 1150 to 1250°C, Ba2TiO4 crystal particles generated during the firing process can be easily removed, and the honeycomb structure 21 can be made dense. Furthermore, by setting the heating rate from 1150 to 1250°C to the maximum temperature of 1360 to 1430°C at 20 to 600°C / hour, 1.0 to 10.0 mass% of Ba6Ti 17 O 40 Crystal grains can be generated in the honeycomb structure 21.
[0092] The holding time at 1150 to 1250°C is not particularly limited, but is preferably 0.5 to 10 hours. By holding for such a time, Ba2TiO4 crystal particles formed during the firing process can be stably and easily removed.
[0093] The firing step preferably includes holding the mixture at 900 to 950°C for 0.5 to 5 hours during heating. Holding the mixture at 900 to 950°C for 0.5 to 5 hours allows BaCO3 to efficiently decompose, making it easier to obtain a honeycomb structure 21 having a predetermined composition.
[0094] Before the firing step, a degreasing step may be carried out to remove the binder. The degreasing step is preferably carried out in an air atmosphere to completely decompose the organic components. Furthermore, the firing step is preferably carried out in an air atmosphere from the viewpoint of controlling electrical properties and reducing manufacturing costs. The firing furnace used in the firing step and degreasing step is not particularly limited, but an electric furnace, a gas furnace, or the like can be used.
[0095] A pair of electrodes 28a, 28b are formed on the honeycomb structure 21 obtained in this manner. The pair of electrodes 28a, 28b can be formed by a metal deposition method such as sputtering, vapor deposition, electrolytic deposition, or chemical deposition. The pair of electrodes 28a, 28b can also be formed by applying an electrode paste and then baking it. Furthermore, the pair of electrodes 28a, 28b can also be formed by thermal spraying. The pair of electrodes 28a, 28b may be formed of a single layer, or may be formed of multiple electrode layers with different compositions. Representative methods for forming the pair of electrodes 28a, 28b will be described below.
[0096] First, an electrode slurry containing an electrode material, an organic binder, and a dispersion medium is prepared and applied to the first end face 24a or the second end face 24b of the honeycomb structure 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 on the outer periphery of the honeycomb structure 21 is removed by blowing and wiping. Thereafter, the slurry is dried to form a pair of electrodes 28a, 28b on the first end face 24a or the second end face 24b of the honeycomb structure 21. Drying can be performed while heating the honeycomb structure 21 to a temperature of, for example, about 120 to 600°C. The series of steps of coating, slurry removal, and drying may be carried out only once, but by repeating these steps multiple times, a pair of electrodes 28a, 28b of a desired thickness can be provided.
[0097] Next, terminals 29 are placed at predetermined positions of the pair of electrodes 28a, 28b, and the pair of electrodes 28a, 28b are connected to terminal 29. The method for connecting the pair of electrodes 28a, 28b to terminal 29 can be the method described above. The terminals 29 may be disposed after the adsorption layer 27 described below is formed.
[0098] Next, an adsorption layer 27 is formed on the surfaces of the partition walls 26 and the like of the honeycomb structure 21 . The method for forming the adsorption layer 27 is not particularly limited, and it can be formed, for example, by the following process. The honeycomb structure 21 is immersed in a slurry containing an adsorbent, an organic binder, and a dispersion medium for a predetermined period of time, and excess slurry on the end faces and outer periphery of the honeycomb structure 21 is removed by blowing and wiping. 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. Thereafter, the slurry is dried to form the adsorption layer 27 on the surface of the partition wall 26. The drying can be performed while heating the honeycomb structure 21 to a temperature of, for example, about 120 to 600°C. The series of steps of immersion, slurry removal, and drying may be carried out only once, but by repeating the steps multiple times, an adsorption layer 27 of a desired thickness can be provided on the surface of the partition wall 26 or the like.
[0099] (3.Power supply 40) The power supply 40 is used to apply a voltage to the air conditioning device 20 (particularly to the pair of electrodes 28a, 28b). The power supply 40 is electrically connected to the control unit 30, and adjusts the state of voltage application to the pair of electrodes 28a, 28b in accordance with instructions from the control unit 30. The power source 40 is not particularly limited, and a battery or the like can be used.
[0100] (4. Ventilator 60) The ventilator 60 is arranged in the air conditioning duct 10 to introduce air from the vehicle interior or outside the vehicle into the air conditioning device 20. The position of the ventilator 60 is not particularly limited, and may be, for example, upstream of the air conditioning device 20 as shown in FIG. Furthermore, the ventilator 60 is electrically connected to the control unit 30, and controls the air flow rate by adjusting the rotation speed in accordance with instructions from the control unit 30.
[0101] (5. Control unit 30) The control unit 30 is connected to a power source 40, a valve 50, a ventilator 60, etc., and can control these. Specifically, by controlling the power source 40, the control unit 30 controls the state of voltage application to the pair of electrodes 28a, 28b of the air-conditioning device 20, and can adjust the heating state of the honeycomb structure 21. The control unit 30 can also control the valve 50 so that air flows through the first flow path 10a or the second flow path 10b. Furthermore, the control unit 30 can control the flow rate of air flowing through the air-conditioning duct 10 by adjusting the rotation speed of the ventilator 60.
[0102] The control unit 30 is not particularly limited, but is generally an ECU (Engine (electronic) Control Unit). The ECU includes a CPU that executes various arithmetic processes, a ROM that stores programs and data required for the control, a RAM that temporarily stores the results of the CPU calculations, and an input / output port for inputting and outputting signals to and from the outside.
[0103] The control unit 30 can execute an air conditioning mode in which the valve 50 is switched so that air flows through the first flow path 10a, and a regeneration mode in which the valve 50 is switched so that air flows through the second flow path 10b and the adsorption unit (adsorption layer 27) is heated. That is, the control unit 30 can execute an air conditioning mode in which the applied voltage from the power supply 40 is turned off and the valve 50 is switched so that air flows through the first flow path 10a, and a regeneration mode in which the applied voltage from the power supply 40 is turned on and the valve 50 is switched so that air flows through the second flow path 10b. By executing the air conditioning mode and the regeneration mode in this manner, the adsorption process and the regeneration process can be performed efficiently.
[0104] The control unit 30 controls the air flow rate by adjusting the rotation speed of the fan 60 according to the temperature of the adsorption unit (adsorption layer 27). The temperature of the adsorption layer 27 is preferably determined by measuring the condition parameter, which is determined in advance based on a relationship between the temperature of the adsorption layer 27 and at least one condition parameter selected from the temperature of the honeycomb structure 21, the resistance value of the honeycomb structure 21, the current value of the honeycomb structure 21, the heating time of the honeycomb structure 21, the temperature of the air that has passed through the honeycomb structure 21, and the amount of components contained in the air that has passed through the honeycomb structure 21. Although it is difficult to directly measure the temperature of the adsorption layer 27 in the vehicle air conditioning system 100, the temperature of the adsorption layer 27 can be determined by measuring the condition parameter as described above.
[0105] In the air conditioning mode, the control unit 30 performs the control as described above to capture (adsorb) the adsorption target substance in the air circulating from the vehicle interior or outside the vehicle. At this time, the honeycomb structure 21 of the air conditioning device 20 is not heated. Specifically, air from the vehicle interior or outside the vehicle flows into the air conditioning device 20 through the air conditioning duct 10, and the adsorption target substance contained in the air is captured (adsorbed). Then, the air with the adsorption target substance captured is returned to the vehicle interior through the first flow path 10a.
[0106] In the regeneration mode, the control unit 30 performs the control as described above to regenerate the adsorption layer 27 of the air conditioning device 20. At this time, the honeycomb structure 21 of the air conditioning device 20 is heated. Specifically, air from the vehicle compartment or outside the vehicle flows into the air conditioning device 20 through the air conditioning duct 10, and while passing through the air conditioning device 20, the adsorption target substances captured in the adsorption layer 27 are desorbed. Then, the air containing moisture is discharged to the outside of the vehicle through the second flow path 10b.
[0107] From the viewpoint of stably performing the above control, it is desirable that the air conditioning device 20 be located close to the vehicle interior. Therefore, from the viewpoint of preventing electric shock, etc., it is preferable that the driving voltage of the air conditioning device 20 is 60 V or less. The honeycomb structure 21 used in the air conditioning device 20 has low electrical resistance at room temperature, so that the honeycomb structure 21 can be heated at this low driving voltage. The lower limit of the driving voltage is not particularly limited, but is preferably 10 V or more. If the driving voltage is less than 10 V, the current when heating the honeycomb structure 21 will be large, and therefore the conductor wires will need to be thicker. [Explanation of symbols]
[0108] 10 Air conditioning ducts 10a First flow path 10b Second flow path 20 Air Conditioning Devices 21 Honeycomb structure 23 Outer wall 24a 1st end face 24b 2nd end face 25 cells 26 Bulkhead 27 Adsorption layer 28a, 28b Pair of electrodes 29 terminals 30 Control Unit 40 Power supply 50 valves 60 Ventilator 100 Vehicle air conditioning system
Claims
1. an air conditioning duct through which air from the vehicle compartment or outside the vehicle can circulate; an air conditioning device disposed in the air conditioning duct, the air conditioning device having an adsorption unit having an adsorbent capable of adsorbing and desorbing a target substance to be adsorbed, and a heating means capable of heating the adsorption unit; a control unit capable of controlling the flow rate of the air flowing through the air conditioning duct and the heating of the adsorption unit; Equipped with In a regeneration mode in which the adsorption section is heated, the control section controls the flow rate of the air in accordance with the temperature of the adsorption section.
2. 2. The vehicle air conditioning system according to claim 1, wherein the control of the air flow velocity by the control unit includes reducing the air flow velocity when the temperature of the adsorption unit reaches −30 to 250% of the desorption temperature.
3. The vehicle air conditioning system according to claim 1 , wherein the control unit controls the air flow velocity when the adsorption unit is at or above a desorption temperature.
4. 4. The vehicle air conditioning system according to claim 3, wherein the control of the air flow velocity by the control unit includes reducing the air flow velocity when the temperature of the adsorption unit reaches 0 to 250% of the desorption temperature.
5. 4. The vehicle air conditioning system according to claim 3, wherein the control of the air flow velocity by the control unit includes reducing the air flow velocity when the temperature of the adsorption unit reaches 20 to 250% of the desorption temperature.
6. 6. The vehicle air conditioning system according to claim 1, wherein the control of the air flow rate by the control unit includes increasing the air flow rate when the temperature of the adsorption unit reaches 260 to 380% of the desorption temperature.
7. 6. The vehicle air conditioning system according to claim 1, wherein the control of the air flow rate by the control unit includes increasing the air flow rate when the adsorption unit is at or above a desorption temperature to be higher than the air flow rate when the adsorption unit is below the desorption temperature.
8. The air conditioning device is a honeycomb structure having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that serve as air flow paths 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 wall of the honeycomb structure that is parallel to the direction in which the cells of the honeycomb structure extend; The vehicle air conditioning system according to any one of claims 1 to 5, comprising:
9. 9. The vehicle air conditioning system according to claim 8, wherein the temperature of the adsorption layer is determined by determining in advance the relationship between the temperature of the adsorption layer and at least one condition parameter selected from the temperature of the honeycomb structure, the resistance value of the honeycomb structure, the current value of the honeycomb structure, the heating time of the honeycomb structure, the temperature of the air that has passed through the honeycomb structure, and the amount of components contained in the air that has passed through the honeycomb structure, and measuring the condition parameter.
10. The vehicle air conditioning system according to claim 8 , further comprising a power source for applying a voltage to the pair of electrodes.
11. 9. The vehicle air conditioning system according to claim 8, wherein at least the partition walls of the honeycomb structure are made of a material having PTC properties.
12. 6. The vehicle air conditioning system according to claim 1, wherein the adsorbent is capable of adsorbing and desorbing one or more kinds selected from the group consisting of moisture, carbon dioxide, and volatile components.
13. 6. The vehicle air conditioning system according to claim 1, wherein the air conditioning duct branches downstream of the air conditioning device into a first flow path that introduces the air into the vehicle compartment and a second flow path that exhausts the air to the outside of the vehicle, and further comprises a valve that can switch the flow of the air between the first flow path and the second flow path.
14. The control unit is capable of controlling the valve, 14. The vehicle air conditioning system according to claim 13, wherein the control unit is capable of executing an air conditioning mode in which the valve is switched so that the air flows through the first flow path, and a regeneration mode in which the valve is switched so that the air flows through the second flow path and the adsorption unit is heated.
Citation Information
Patent Citations
Heater element and cabin-cleaning system
WO2023074202A1