Vehicle air conditioner

Abstract

[Problem] To provide a new means with which it is possible to dehumidify the air in the cabin of a vehicle such as an automobile. [Solution] A vehicle air conditioner comprises: a housing through which air circulates; an air intake port through which the air is taken into the housing; an air discharge port through which the air is discharged from the housing; a heat exchanger that functions as a cooler and a heater; a conductive member that is disposed upstream from the heat exchanger in the housing and that allows the air to pass therethrough; and a corona discharge unit that is disposed upstream from the conductive member in the housing and that electrically charges water contained in the air by generating a corona discharge. The conductive member is at ground potential via a conductor electrically connected to the conductive member, and the charged water condenses on the surface of the conductive member. As a result, dehumidification of the air is realized.

Description

Vehicle air conditioner

[0001] The present invention relates to a vehicle air conditioner.

[0002] Generally, vehicles such as automobiles are equipped with a vehicle air conditioner for adjusting the temperature and humidity inside the vehicle cabin. Such a vehicle air conditioner is configured to generate conditioned air at a predetermined temperature by dehumidifying and cooling the air blown by a blower fan with an evaporator and heating a part of the cooled air with a heater core.

[0003] In addition, in vehicles such as automobiles, in winter or during the rainy season, in order to prevent the window from becoming cloudy due to condensation, the heat in the cabin is released to the outside, or the dehumidifying function of the air conditioner is used to dehumidify the air inside the cabin. An air conditioning device for dehumidification is described in, for example, Patent Document 1.

[0004] Japanese Unexamined Patent Application Publication No. 2013 - 14234

[0005] An object of the present invention is to provide a novel means for dehumidifying the air inside the cabin of a vehicle such as an automobile.

[0006] One aspect of the present invention is a vehicle air conditioner for mounting and using on a vehicle, comprising a housing through which air flows, an air inlet for taking in the air into the housing, an air outlet for discharging the air from the housing, a heat exchanger functioning as a cooler and a heater, a conductive member that allows air to pass through and is disposed upstream of the housing with respect to the heat exchanger, and a corona discharge unit disposed upstream of the housing with respect to the conductive member for charging water contained in the air by generating a corona discharge. The conductive member is electrically grounded through a conductor electrically connected to the conductive member, and the charged water condenses on the surface of the conductive member.

[0007] FIG. 1 is a cross-sectional view showing an example of the configuration of an HVAC system according to an embodiment of the vehicle air conditioner of the present invention. FIG. 2A is a diagram showing the configuration of the corona discharge unit fabricated in Experimental Example 1 described later. FIG. 2B is a diagram showing the arrangement form of each member when the dehumidification test was carried out in Experimental Example 1 described later.

[0008] The embodiments of the present invention will be described below with reference to the attached drawings, but the technical scope of the present invention is not limited to the following forms. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant explanations are omitted. Also, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from the actual ratios. In this specification, "X to Y" indicating a range means "X or more and Y or less". Unless otherwise specified, operations and measurements of physical properties, etc., are performed under conditions of room temperature (20 to 25°C) / relative humidity 40 to 50%.

[0009] <Vehicle Air Conditioning System> Figure 1 is a cross-sectional view showing an example of the configuration of an HVAC (Heating, Ventilation, and Air Conditioning) system 10 according to one embodiment of the vehicle air conditioning system of the present invention. The HVAC system is a car air conditioning unit that adjusts the temperature, airflow, and air outlets of the air to keep the cabin of a car comfortable, for example. Air conditioning systems such as HVAC systems installed in automobiles are usually located inside the dashboard.

[0010] In this embodiment, the HVAC system 10 includes a housing 100 through which air flows, an air intake port 110 for taking air into the housing 100, and an air outlet port 120 for discharging air from the housing 100.

[0011] The HVAC system 10 further includes, inside the housing 100, a corona discharge section 230, a wire mesh 210 (an example of a "conductive member"), and a heat exchanger 220, arranged from upstream to downstream of the housing 100. The heat exchanger 220 combines the functions of a chiller (cooler) and a heater (heater), and therefore the HVAC system 10 has an evaporator-less structure. Here, the air permeability of the wire mesh 210 is configured to be greater than the air permeability of the heat exchanger 220.

[0012] The corona discharge unit 230 has the function of charging water contained in the air by generating electrons through corona discharge, and normally the water becomes negatively charged. This charged water condenses on the surface of the wire mesh 210. A water outlet 130 for discharging the condensed water is provided at the bottom of the housing 100. A wire mesh removal section 140 that can be opened and closed is provided at the top of the housing 100 for removing the wire mesh 210. When the wire mesh removal section 140 is opened while corona discharge is occurring in the corona discharge unit 230, the corona discharge is controlled to stop. This eliminates the risk of electric shock when removing the wire mesh. Here, in this specification, "up" and "down" refer to positions in the direction along the vertical line.

[0013] The housing 100 is provided with a pair of grooves (not shown) for supporting the wire mesh 210, and the wire mesh 210 is fixed to the housing 100 by fitting its side edges into these grooves. The wire mesh 210 is grounded to the body earth by being electrically connected to the vehicle body conductive part 300 via an electrical wire 212 (an example of a "conductor") which is electrically connected to the wire mesh 210. Because the wire mesh 210 is grounded to the body earth in this way, water that has been charged by contact with electrons generated by corona discharge is attracted to the wire mesh 210 by Coulomb force. The electrical wire 212 is electrically connected to the upper edge of the wire mesh 210.

[0014] In this embodiment, the wire mesh 210 is made of aluminum, the electrical wiring 212 is made of copper, and the vehicle body conductive part 300 is made of iron. In other words, these components are made of different conductive materials. Furthermore, corrosion-resistant treatment is applied to the conductive parts between the aluminum wire mesh 210 and the copper electrical wiring 212, and between the copper electrical wiring 212 and the iron vehicle body conductive part 300.

[0015] Next, the operation of the HVAC system will be explained. When the HVAC system 10 is in operation, outside air is first drawn into the housing 100 from the air intake 110. The drawn-in air usually contains water in the form of liquid (water droplets) or gaseous (water vapor). When electrons are generated by corona discharge in the corona discharge section 230, the water in the air comes into contact with these electrons and becomes charged (usually negatively). Meanwhile, the wire mesh 210 installed inside the housing 100 is electrically connected to the vehicle body conductive section 300 and is grounded to the body earth. As a result, the charged water is attracted to the wire mesh 210 by Coulomb force and adheres to its surface. The water vapor that adheres is then cooled by the wire mesh 210 and condenses. In this way, the water in the air drawn into the housing 100 is recovered. The air from which water has been collected is adjusted to an appropriate temperature by the chiller or heater function of the heat exchanger 220 located downstream of the wire mesh 210, and is discharged from the air outlet 120 into the cabin (not shown). The amount of water vapor contained in the air flowing into the cabin is reduced by passing through the HVAC system 10. Thus, dehumidification of the air inside the cabin is achieved.

[0016] Traditionally, dehumidifying the cabin air during winter or the rainy season involved turning on the A / C (air conditioning) even when the heating was on to activate the car's air conditioning compressor and cool the evaporator and other cooling components, or adjusting the airflow to direct the airflow directly onto the windows. In contrast, the vehicle air conditioning system according to this embodiment has an evaporator-less structure, eliminating the need to overcool the cooling components. This allows for dehumidification without placing an excessive load on the onboard air conditioning system, resulting in reduced power consumption and further improvements in fuel efficiency and / or electricity efficiency. Furthermore, while conventional dehumidification using cooling components only condenses water in the air by randomly contacting the cooling component, this embodiment utilizes Coulomb force to attract more water to the wire mesh (conductive material), thereby condensing it. This also results in superior dehumidification efficiency.

[0017] It should be noted that a technology is known for using corona discharge to charge water in the air, moving it to a grounded cylindrical wire by Coulomb force, and recovering it by condensation (MJ Zeng, ZG Qu, JF Zhang, Separation and Purification Technology 305 (2023) 122465). However, the applications of airborne water recovery (fog collection) proposed in that document are limited to large-scale systems such as collecting drinking water, irrigation water, and afforestation water in drought-prone areas, water recovery by applying it to cooling towers of power plants, and fog removal systems to improve visibility on roads and airports. There is no consideration whatsoever for applying this technology to dehumidifying the air inside the cabin of vehicles such as automobiles.

[0018] In this embodiment, wire mesh is used as the conductive member. However, it is not limited to wire mesh; any conductive member that allows air to pass through can be used. In particular, it is preferable that the conductive member has a mesh-like structure, such as wire mesh. This configuration allows the conductive member to be constructed using inexpensive and lightweight materials. Furthermore, in this embodiment, as described above, the air permeability of the conductive member is set to be greater than that of the heat exchanger. This configuration has the advantage of allowing more air to come into contact with the heat exchanger and accelerating the dripping of water that has adhered to and condensed on the conductive member. In addition, it is preferable that the surface of the conductive member is treated with a conductive water-repellent coating. This prevents galvanic corrosion of the conductive member while further accelerating the dripping of condensed water.

[0019] In this embodiment, the conductive member (wire mesh) is grounded to the body earth by electrically connecting with the vehicle body conductive part 300 via a conductor (electrical wiring) that is electrically connected to the conductive member (wire mesh). By achieving grounding of the conductive member with this configuration, water charged by contact with electrons can be reliably attracted to the conductive member. Here, "vehicle body conductive part" refers to a part of the vehicle body formed of a conductive material. This vehicle body conductive part constitutes the outer edge of the vehicle, the boundary between the engine room and the cabin (passenger compartment), etc. The vehicle body conductive part does not necessarily have to be constructed as a single unit; if it is divided into multiple parts, it is sufficient that it has a structure that has such low impedance that it can be considered to be short-circuited with each other.

[0020] In this embodiment, the conductive member (wire mesh) and the conductor (electrical wiring) are composed of different conductive materials, and the conductor (electrical wiring) and the conductive part of the vehicle body are composed of different conductive materials. Each conductive part is treated with corrosion protection. There are no particular restrictions on the specific conductive materials that constitute the conductive member, the conductor, and the conductive part of the vehicle body, but those skilled in the art can make appropriate selections in consideration of common technical knowledge, taking into account conductivity and contribution to weight reduction. When the constituent materials of both conductive parts (the conductive part between the conductive member and the conductor, or the conductive part between the conductor and the conductive part of the vehicle body) are different from each other, it is preferable that corrosion protection be applied to the conductive part. This can effectively prevent electrolytic corrosion of the conductive part. Regarding specific forms of such corrosion protection, conventionally known knowledge can be appropriately referred to, but examples include a method of applying a corrosion protectant (sealant) to the conductive part, or a method of constructing the conductive part using a waterproof connector.

[0021] On the other hand, it is also a preferred embodiment that the constituent materials of both components constituting the conductive portion (the conductive portion between the cooler and the conductor, or the conductive portion between the conductor and the conductive portion of the vehicle body) are identical to each other. With such a configuration, the potential difference between the two constituent materials becomes almost zero, and the occurrence of electrolytic corrosion can be effectively prevented.

[0022] In this embodiment, the conductor (electrical wiring) is electrically connected to the upper edge of the conductive member (wire mesh). This electrically connected conductor to the edge of the conductive member is preferable because it prevents an increase in airflow resistance when air passes through the conductive member (wire mesh) due to the presence of the conductive portion between the conductor and the conductive member. Furthermore, from the viewpoint of preventing electrolytic corrosion of the conductive portion due to contact with condensed water, it is preferable that the conductor is electrically connected to the upper or side edge of the conductive member, more preferably to the upper part when the conductive member is divided vertically in half, and even more preferably to the upper edge of the conductive member. From another viewpoint, it is also preferable that the conductor is electrically connected to the conductive member on the upstream side of the housing. With this configuration, the conductive portion between the conductor and the conductive member is less likely to come into contact with condensed water in the conductive member, thereby preventing electrolytic corrosion of the conductive portion. Furthermore, if the groove described above is made of a conductive material, the conductor (electrical wiring) may be electrically connected to the conductive member (wire mesh) through this groove. In other words, the conductive member (wire mesh) may be electrically connected to the conductor through the groove. In this case, grounding of the conductive member (wire mesh) is completed simply by fitting the side of the conductive member (wire mesh) into the groove.

[0023] In this embodiment, a water outlet is provided at the bottom of the housing to discharge the condensed water. This prevents the water condensed in the conductive member from accumulating inside the air conditioning unit. As a result, the growth of bacteria caused by the condensed water and the generation of unpleasant odors can be effectively prevented. The specific configuration of such a water outlet is not particularly limited, and conventionally known knowledge can be referred to as appropriate. Note that the installation of a water outlet is not mandatory and may be omitted in some cases.

[0024] Furthermore, in this embodiment, the upper part of the housing 100 is provided with an openable and closable wire mesh removal section 140 (conductive member removal section) for removing the wire mesh 210. This makes it possible to more effectively prevent the growth of bacteria caused by water condensed by dehumidification and the generation of unpleasant odors that result from it. Conventionally, since the coolers such as evaporators built into HVAC systems are fixed to the housing via piping, it was not possible to remove and clean only the coolers. In contrast, with the HVAC system according to this embodiment, as described above, it is possible to remove and clean the conductive member (wire mesh), which has the advantage of keeping the inside of the housing very hygienic.

[0025] There are no particular restrictions on the specific configuration of the corona discharge section that generates corona discharge, and conventionally known knowledge may be referenced as appropriate. Corona discharge is a discharge phenomenon that occurs when a high voltage is applied between electrodes. This phenomenon can be efficiently induced depending on the shape and arrangement of the electrodes, and any of the following types of electrodes may be used: needle electrodes, wire electrodes, plate electrodes, mesh electrodes, etc. As for the materials used to construct the electrodes, durable metals that are resistant to oxidation and corrosion, such as stainless steel or tungsten, may be used. Furthermore, there are no particular restrictions on the high-voltage generator that generates the high voltage, and conventionally known knowledge may be referenced as appropriate. As an example, the magnitude of the voltage applied to the electrodes by the high-voltage generator is in the range of several hundred volts to several kV.

[0026] The following items are also included in the scope of the present invention: Item 1: A vehicle air conditioning system for use mounted on a vehicle, comprising: a housing through which air flows; an air intake port for taking the air into the housing; an air outlet for discharging the air from the housing; a heat exchanger that functions as a cooler and a heater; an air-permeable conductive member disposed upstream of the housing relative to the heat exchanger; and a corona discharge unit disposed upstream of the housing relative to the conductive member for charging water contained in the air by generating corona discharge, wherein the conductive member is electrically grounded via a conductor that is electrically conductive with the conductive member, and the charged water condenses on the surface of the conductive member; Item 2: The vehicle air conditioning system according to Item 1, wherein the conductor is electrically grounded to the body earth by being electrically conductive with a conductive part of the vehicle body; Item 3: The vehicle air conditioning system according to Item 1 or 2, wherein the conductive member and the conductor are made of different conductive materials, and the conductive portion between the conductive member and the conductor is treated with corrosion protection; Item 4: The vehicle air conditioning system according to any one of items 1 to 3, wherein the conductor is electrically conductive to the edge of the conductive member; Item 5: The vehicle air conditioning system according to any one of items 1 to 4, wherein the housing has a pair of grooves for supporting the conductive member by fitting the side edge of the conductive member into them; Item 6: The vehicle air conditioning system according to item 5, wherein the conductive member is electrically conductive to the conductor via the grooves; Item 7: The vehicle air conditioning system according to any one of items 1 to 6, wherein the air permeability of the conductive member is greater than the air permeability of the heat exchanger; Item 8: The vehicle air conditioning system according to any one of items 1 to 7, wherein the surface of the conductive member is treated with a conductive water-repellent coating; Item 9: The vehicle air conditioning system according to any one of items 1 to 8, wherein the conductive member has a mesh-like structure; Item 10: The housing has an openable and closable conductive member removal section at the top for removing the conductive member, The vehicle air conditioning system according to any one of items 1 to 9, wherein the corona discharge stops when the conductive member outlet is opened while the corona discharge is occurring.

[0027] The embodiments of the present invention will be described in more detail below using experimental examples (dehumidification tests), but the technical scope of the present invention is not limited by the experimental examples below.

[0028] [Experimental Example 1] First, the corona discharge section 230 shown in Figure 2A was fabricated. Specifically, linear electrodes 234 made of stainless steel (0.2 mm in diameter, approximately 50 cm in length) were arranged in a zigzag pattern on the surface of a plastic substrate 232, and one end of the electrodes was connected to a high-voltage generator 236 (Spellman SL30N10).

[0029] The corona discharge section 230, prepared as described above, was placed approximately 10 mm away from one main surface of a wire mesh (mesh spacing 0.8 mm, mesh wire diameter 0.1 mm) 210 made of stainless steel with a grid-like mesh. One end of a copper electrical wire 212 was electrically connected to the upper edge of the wire mesh 210, and the other end of the electrical wire 212 was grounded.

[0030] The laminate of the wire mesh 210 and corona discharge section 230, prepared as described above, was arranged together with the heat exchanger 220 as shown in Figure 2B. A voltage of 10 kV was then applied to the linear electrode 234 using a high-voltage generator 236 to generate a corona discharge. In this state, steam generated using a humidifier 400 (ultrasonic humidifier, humidification spray volume 90 mL / hr) was sprayed onto the corona discharge section 230 side of the laminate for 3 minutes, and the amount of water removed from the laminate in 3 minutes was measured. In this experiment, since the removal of water was observed dripping from the wire mesh, the amount of water removed was measured by weighing the total amount of water that dripped from the wire mesh and the water that adhered to the wire mesh during the 3 minutes from the start of spraying. As a result, the amount of water removed in this experiment was 1.98 g.

[0031] [Experimental Example 2] The experiment was conducted using the same method as in Experimental Example 1, except that corona discharge was not generated. As a result, the amount of water removed in this experimental example was 0.19 g.

[0032] From the above results, it can be seen that, according to the configuration of a vehicle air conditioning system according to one embodiment of the present invention, dehumidification can be achieved very efficiently by utilizing corona discharge.

[0033] 10 HVAC system (vehicle air conditioning system), 100 housing, 110 air intake, 120 air exhaust, 130 water outlet, 140 wire mesh outlet (conductive material outlet), 210 wire mesh (conductive material), 212 electrical wiring (conductor), 220 heat exchanger, 230 corona discharge section, 232 substrate, 234 linear electrode, 236 high voltage generator, 300 vehicle body conductive section, 400 humidifier.

Claims

1. A vehicle air conditioning system for use mounted on a vehicle, comprising: a housing through which air flows; an air intake port for taking the air into the housing; an air outlet for discharging the air from the housing; a heat exchanger that functions as a cooler and a heater; an air-permeable conductive member positioned upstream of the housing relative to the heat exchanger; and a corona discharge unit positioned upstream of the housing relative to the conductive member for charging water contained in the air by generating corona discharge, wherein the conductive member is electrically grounded via a conductor that is electrically connected to the conductive member, and the charged water condenses on the surface of the conductive member.

2. The vehicle air conditioning system according to claim 1, wherein the conductor is grounded to the body earth by electrically connecting with the conductive part of the vehicle body.

3. The vehicle air conditioning system according to claim 1 or 2, wherein the conductive member and the conductor are made of different conductive materials, and the conductive portion between the conductive member and the conductor is treated with a corrosion-preventive coating.

4. The vehicle air conditioning system according to claim 1 or 2, wherein the conductor is electrically conductive to the edge of the conductive member.

5. The vehicle air conditioning device according to claim 1 or 2, wherein the housing has a pair of grooves for supporting the conductive member by fitting the side edges of the conductive member into them.

6. The vehicle air conditioning device according to claim 5, wherein the groove is made of a conductive material, and the conductive member is electrically connected to the conductor via the groove.

7. The vehicle air conditioning system according to claim 1 or 2, wherein the air permeability of the conductive member is greater than that of the heat exchanger.

8. The vehicle air conditioning system according to claim 1 or 2, wherein the surface of the conductive member is treated with a conductive water-repellent coating.

9. The vehicle air conditioning system according to claim 1 or 2, wherein the conductive member has a mesh-like structure.

10. The vehicle air conditioning system according to claim 1 or 2, wherein the housing has an openable and closable conductive member removal section at the top for removing the conductive member, and when the conductive member removal section is opened while corona discharge is occurring, the corona discharge stops.

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