Vehicle air conditioning device

Abstract

The invention provides an air conditioner for a vehicle, which can improve the blowing efficiency of air in an air conditioner housing, reduce the heat loss caused by the introduction of external air and the discharge of internal air, and suppress the power consumption during the operation of the air conditioner. In an air conditioning device (1) for a vehicle, a first passage (P1) for guiding outside air from an outside air inlet (22) to an evaporator (32) and a second passage (P2) for guiding inside air from an inside air inlet (23) to the evaporator (32) are formed in an air conditioning case (21). A blower (31) is provided in the first passage (P1) and the second passage (P2), and a total heat exchanger (34) is disposed between the blower (31) and the evaporator (32). External air flowing through the first channel (P1) is introduced into the total heat exchanger (34), and at least a part of internal air flowing through the second channel (P2) is introduced into the total heat exchanger (34), so that heat exchange is performed between the external air and the internal air. The heat-exchanged outside air is introduced into the evaporator (32) together with the remaining inside air flowing through the second passage (P2), and the heat-exchanged inside air is discharged to the outside of the vehicle.

Description

Technical Field

[0001] The present invention relates to a vehicle air conditioner for conditioning the air in a vehicle interior. Background Art

[0002] As a previous vehicle air conditioning device, for example, Patent Document 1 discloses a vehicle air conditioning device that reduces heat loss caused by the introduction of external air and improves the heating effect by providing a total heat exchanger. The total heat exchanger absorbs heat from the internal air flowing in the internal air exhaust channel and dissipates heat to the external air introduced from the external air inlet. The internal air exhaust channel exhausts the internal air to the outside of the vehicle.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 10-16531

[0004] However, in the conventional vehicle air conditioning system described above, a total heat exchanger is installed upstream of the blower in the first air supply duct, which draws in outside air, and an evaporator is located downstream of the blower. This arrangement in the first air supply duct results in negative pressure upstream of the blower and positive pressure downstream, resulting in poor blower efficiency. Furthermore, in the second air supply duct, which draws in interior air, the interior air introduced to the blower is blown in both directions, into the vehicle interior and out of the vehicle exterior. This makes it difficult to distribute the interior air in both directions, and there is room for improvement. Summary of the Invention

[0005] The present invention is completed with the above-mentioned problems in mind, and its purpose is to provide a vehicle air conditioning device that can improve the air supply efficiency in the air conditioning casing, reduce heat loss caused by the introduction of external air and the exhaust of internal air, and suppress power consumption during air conditioning operation.

[0006] One embodiment of the present invention for achieving the above-mentioned purpose provides a vehicle air-conditioning device, which includes: an air-conditioning casing, which is formed with an external air inlet for introducing external air and an internal air inlet for introducing internal air on one end side, and is formed with a defroster outlet for blowing air toward the vehicle window glass, and a face outlet and a foot outlet for blowing air toward the passengers in the vehicle cabin on the other end side; a cooling heat exchange portion for cooling the air flowing in the air-conditioning casing; a partition plate, which forms a first channel in the air-conditioning casing for guiding air from the external air inlet to the cooling heat exchange portion, and a second channel for guiding air from the internal air inlet to the cooling heat exchange portion; and an air supply portion, which generates a flow of air from the one end side toward the other end side in the first channel and the second channel. The vehicle air-conditioning device includes an inside-outside air heat exchange portion, which is arranged between the air supply portion and the cooling heat exchange portion, introduces the outside air flowing in the first channel, and introduces at least a part of the inside air flowing in the second channel, and performs heat exchange between the introduced outside air and the inside air. The vehicle air-conditioning device is configured to introduce the outside air after heat exchange in the inside-outside air heat exchange portion and the remaining inside air flowing in the second channel into the cooling heat exchange portion, and discharge the inside air after heat exchange in the inside-outside air heat exchange portion to the outside of the vehicle.

[0007] According to the vehicle air conditioner of the present invention, the air supply efficiency in the air conditioning case can be improved, while heat loss caused by the introduction of external air and the exhaust of internal air can be reduced, thereby suppressing power consumption during air conditioning operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram showing the overall structure of a vehicle air conditioning system according to one embodiment of the present invention. Figure 2 This is a block diagram showing the electrical configuration of a vehicle air conditioner. Figure 3 This is a perspective view schematically showing a total heat exchange element used in a total heat exchanger. Figure 4 This is a diagram showing the flow of air in the initial state when the summer cooling function is turned on. Figure 5 This is a diagram showing the flow of air in the summer when there are two passengers. Figure 6 This is a diagram showing the flow of air in the summer when there are four passengers. Figure 7 It is a diagram showing the flow of air when refrigerant leaks. Figure 8This is a diagram showing the flow of air in winter when there are two passengers and the possibility of condensation is low. Figure 9 This is a diagram showing the flow of air in winter when there are four passengers and the possibility of condensation is low. Figure 10 This is a diagram showing the flow of air in winter when there are two passengers and the possibility of condensation is high. Figure 11 This is a diagram showing the flow of air in winter when there are two passengers and the possibility of condensation is higher. DETAILED DESCRIPTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 and Figure 2 The structure of a vehicle air conditioning device 1 according to one embodiment of the present invention is shown. Figure 1 This is a schematic diagram of the overall structure of the vehicle air conditioning device 1 according to this embodiment. Figure 2 This is a block diagram showing the electrical configuration of the vehicle air conditioner 1 according to the present embodiment.

[0010] The vehicle air conditioning device 1 of this embodiment is mounted on a vehicle such as an automobile and is configured to perform air conditioning in the vehicle interior by blowing conditioned air into the vehicle interior. The vehicle air conditioning device 1 includes an air conditioning unit 2 ( Figure 1 ) and air conditioning control device 5 ( Figure 2 ).

[0011] The air conditioning unit 2 is arranged in the front part of the vehicle interior (not shown) and includes an air conditioning case 21. Figure 1 An outside air inlet 22 and an inside air inlet 23 are formed on the left side of the air conditioner housing 21. The outside air inlet 22 is an intake port for introducing air outside the vehicle (hereinafter referred to as "outside air") into the air conditioner housing 21. The outside air inlet 22 communicates with the space inside the air conditioner housing 21 via an outside air duct 22A. The inside air inlet 23 is an intake port for introducing air inside the vehicle (hereinafter referred to as "inside air") into the air conditioner housing 21. The inside air inlet 23 communicates with the space inside the air conditioner housing 21 via an inside air duct 23A.

[0012] An outside air door 22B and an inside air door 23B are provided at the outside air inlet 22 and the inside air inlet 23, respectively. Furthermore, an inside and outside air door 28 is provided near the outside air inlet 22 in the connecting passage P12, which connects the upstream ends of the first passage P1 and the second passage P2, described later. The outside air door 22B, the inside air door 23B, and the inside and outside air door 28 are driven by corresponding electric actuators 61, 62, and 63, respectively. Figure 2), the electric actuators 61, 62, 63 are operated based on the control signal from the air conditioning control device 5. The outside air door 22B, the inside air door 23B and the inside and outside air door 28 are configured to switch the air inlet mode of the vehicle air conditioning device 1 to the inside air mode, the outside air mode or the inside and outside air mode according to the combination of their respective rotation positions. For example, Figure 1 As shown by the solid line, when the outside air door 22B is in a position to open the outside air inlet 22, the inside air door 23B is in a position to open the inside air inlet 23, and the inside and outside air door 28 is in a position to close the connecting passage P12, the intake mode of the vehicle air conditioning device 1 becomes the inside and outside air mode.

[0013] On the other end side of the air conditioning casing 21 ( Figure 1 A defroster outlet 24, a face outlet 25, and a foot outlet 26 are formed on the right side of the vehicle. The defroster outlet 24 is an outlet for blowing air from the air conditioning casing 21 toward the vehicle's window glass (not shown). The defroster outlet 24 communicates with the space inside the air conditioning casing 21 via a defroster duct 24A. The face outlet 25 is an outlet for blowing air from the air conditioning casing 21 toward the upper body of the passengers in the vehicle. The face outlet 25 communicates with the space inside the air conditioning casing 21 via a face duct 25A. The foot outlet 26 is an outlet for blowing air from the air conditioning casing 21 toward the feet of the passengers in the vehicle. The foot outlet 26 communicates with the space inside the air conditioning casing 21 via a foot duct 26A.

[0014] The face outlet 25 and the foot outlet 26 are provided with a face door 25B and a foot door 26B, respectively. In addition, an outlet switching door 27 is arranged in the space between the defroster outlet 24 and the foot outlet 26. The face door 25B, the foot door 26B and the outlet switching door 27 are driven by their corresponding electric actuators 64, 65 and 66, respectively. Figure 2 ), the electric actuators 64, 65, 66 are operated based on the control signal from the air conditioning control device 5. The face door 25B, the foot door 26B and the outlet switching door 27 are configured to be able to switch the air outlet mode of the vehicle air conditioning device 1 to the defroster mode, the face mode, the foot mode, the face and foot mode, the defroster and foot mode or the closed mode according to the combination of their respective rotation positions. For example, Figure 1 As shown by the solid line, when face door 25B is in a position closing face outlet 25, foot door 26B is in a position opening foot outlet 26, and outlet switching door 27 is in a neutral position away from both defroster outlet 24 and foot outlet 26, the air outlet mode of vehicle air conditioning system 1 is the defroster / foot mode. In this embodiment, face door 25B, foot door 26B, outlet switching door 27, and electric actuators 64-66 correspond to the "air volume adjustment unit" of the present invention.

[0015] A first passage P1, a second passage P2, and a connecting passage P12 are formed in the air conditioning housing 21 and are divided by the inner wall of the air conditioning housing 21 and a plurality of partition plates 29. Figure 1 The first passage P1 is a passage for guiding air from the outside air inlet 22 to the evaporator 32 (cooling heat exchange unit) described later. The second passage P2 is a passage for guiding air from the inside air inlet 23 to the evaporator 32. That is, the space upstream of the evaporator 32 in the air conditioning casing 21 is divided into Figure 1 In the two layers of the first passage P1 located substantially on the upper side and the second passage P2 located substantially on the lower side, the upstream end of the first passage P1 and the upstream end of the second passage P2 are communicated via a connecting passage P12.

[0016] An exhaust port 30 ( Figure 1 The exhaust port 30 communicates with the space inside the air conditioning casing 21 via an exhaust duct 30A. The end of the exhaust duct 30A (not shown) opposite the exhaust port 30 extends to the rear of the vehicle and communicates with the space outside the vehicle. In other words, air introduced into the exhaust duct 30A from the exhaust port 30 of the air conditioning casing 21 passes through the exhaust duct 30A and is discharged into the vehicle interior.

[0017] A blower 31 ( Figure 1 The blower 31 is an electric blower having an electric motor. The blower 31 (electric motor) operates based on a control signal from the air conditioning control device 5 ( Figure 2 ), generating a flow of air from one end of the air conditioning casing 21 toward the other end. Specifically, the blower 31 is configured to blow outside air introduced from the outside air inlet 22 and / or inside air introduced from the inside air inlet 23 into the vehicle interior. In this embodiment, the blower 31 corresponds to the "air supply unit" of the present invention.

[0018] The aforementioned evaporator 32 is provided on the downstream side of the blower 31 in the air-conditioning casing 21. The air (outside air) that has passed through the first passage P1 is introduced into the evaporator 32 via the total heat exchanger 34 described later, and the air (inside air) that has passed through the second passage P2 is introduced into the evaporator 32. Although the evaporator 32 is not shown in the figure here, it is arranged together with the compressor, condenser, liquid separator, expansion valve, etc. in the refrigerant circulation passage for circulating the refrigerant to form a refrigerant circuit (refrigeration cycle). The evaporator 32 is configured to cool the air flowing in the air-conditioning casing 21 by exchanging heat between the air introduced into the evaporator 32 and the refrigerant in accordance with the action of the compressor. That is, the evaporator 32 functions as a cooling heat exchange unit that cools the air flowing in the air-conditioning casing 21. In addition, the evaporator 32 (compressor of the refrigerant circuit) operates based on a control signal from the air-conditioning control device 5 ( Figure 2 ).

[0019] A heater core 33 is provided on the downstream side of the evaporator 32 in the air conditioning housing 21. Figure 1 A bypass passage B ( Figure 1 The bypass passage B is a passage for allowing the air flowing in the air conditioning case 21 to bypass the heater core 33.

[0020] The heater core 33 is a heater that heats the air that flows through the space other than the bypass channel B in the space on the downstream side of the evaporator 32 in the air-conditioning casing 21. Although not particularly limited, in the present embodiment, the heater core 33 is arranged together with a heat medium heating device having a built-in electric heater in a heat medium circulation channel that circulates a heat medium such as water by an electric pump, which is omitted from the illustration. Moreover, the heater core 33 is configured to heat the air by exchanging heat between the heat medium heated by the electric heater of the heat medium heating device and the air flowing in the air-conditioning casing 21 (except the bypass channel B). That is, the heater core 33 functions as a heating heat exchange unit that heats the air flowing in the air-conditioning casing 21 (except the bypass channel B). The heater core 33 (the electric heater and the electric pump of the heat medium heating device) operates based on a control signal from the air-conditioning control device 5 ( Figure 2 ).

[0021] An air mix door 33A is provided on the upstream side of the heater core 33. The air mix door 33A is driven by an electric actuator 67 that operates based on a control signal from the air conditioning control device 5 ( Figure 2 The air mix door 33A adjusts the ratio (air volume ratio) of the flow rate of air passing through the heater core 33 and the flow rate of air passing through the bypass passage B, among the air flowing in the air conditioning case 21 , according to its rotational position.

[0022] The aforementioned total heat exchanger 34 is installed between the blower 31 and the evaporator 32 within the air conditioning casing 21, straddling the downstream end of the first passage P1. Air flowing through the first passage P1 (outside air) is directed into the total heat exchanger 34, and at least a portion of the air flowing through the second passage P2 (inside air) is also directed into the total heat exchanger 34. The total heat exchanger 34 exchanges sensible heat and latent heat between the two types of air (outside air and inside air) being directed. In other words, the total heat exchanger 34 is configured to exchange total heat (temperature and humidity) between the directed outside air and the inside air. In this embodiment, the total heat exchanger 34 serves as the "inside-outside air heat exchange unit" of the present invention.

[0023] Figure 3 3 is a perspective view schematically showing a total heat exchange element used in the total heat exchanger 34. Figure 3 In the total heat exchange element used in the total heat exchanger 34, for example, a partition member 341 formed by applying a polymer adsorbent material to a fibrous base material and a corrugated partition member 342 are stacked in one direction. The total heat exchange element is constructed so that the direction in which external air OA is introduced and discharged as supply air SA and the direction in which return air (internal air) RA is introduced and discharged as exhaust air EA are alternately 90° apart between the layers. The polymer adsorbent used in the partition member 341 is composed of, for example, a cross-linked sodium polyacrylate. Such a polymer adsorbent absorbs moisture quickly, can release the retained moisture at low heating temperatures, and can retain moisture for a long time. Therefore, the partition member 341, formed by applying the polymer adsorbent material to a fibrous base material, has thermal conductivity and moisture permeability.

[0024] In this embodiment, the total heat exchanger 34 is Figure 3 The total heat exchange element is arranged at the downstream end of the first passage P1 in such a manner that the flow direction of the outside air OA-supply air SA side is along the flow direction of the air (outside air) in the first passage P1 in the air conditioning housing 21 ( Figure 1 In other words, the total heat exchanger 34 is Figure 3 The flow direction of the return air (internal air) RA-exhaust air EA in the total heat exchange element is orthogonal to the flow direction of the external air in the first passage P1 in the air conditioning housing 21, and the internal air inlet surface of the total heat exchange element faces the second passage P2 and the exhaust air EA discharge surface faces the exhaust port 30. It is arranged at the downstream end of the first passage P1 ( Figure 1In this configuration, the total heat exchanger 34 efficiently exchanges total heat (temperature and humidity) between the outside air (OA) and the inside air (supply and exhaust air) without mixing. The total heat exchanger 34 in this embodiment has an exchange efficiency of approximately 50%. However, the exchange efficiency of the total heat exchanger 34 is not limited to this.

[0025] On the outside of the inlet surface of the internal air in the total heat exchanger 34 ( Figure 1 The interior air heat exchange adjustment damper 34A is provided in the lower middle portion. The interior air heat exchange adjustment damper 34A is driven by an electric actuator 68 that operates based on a control signal from the air conditioning control device 5 ( Figure 2 The internal air heat exchange adjustment damper 34A adjusts the ratio (air volume ratio) of the flow rate of the air introduced into the total heat exchanger 34 and the flow rate of the air introduced into the evaporator 32 in the air (internal air) flowing in the second passage P2 according to its rotation position. For example, Figure 1 As shown by the solid line, when the inside air heat exchange adjustment damper 34A is located at an angle of approximately 45° relative to the direction of air flow within the second passage P2, the air volume ratio becomes approximately 1:1. In this embodiment, the outside air door 22B, the inside air door 23B, the inside and outside air door 28, the inside air heat exchange adjustment damper 34A, and the electric actuators 61-63, 68 correspond to the "inside and outside air volume adjustment unit" of the present invention.

[0026] Air conditioning control device 5 ( Figure 2 ) is composed of a microcomputer including a CPU, memory such as ROM and RAM, and I / O ports. Furthermore, the air conditioning control device 5 is configured to perform various calculations based on the air conditioning control program stored in the ROM, detection signals from various sensors, and operation signals from various switches. It then outputs control signals to various devices electrically connected to the air conditioning control device 5, such as the aforementioned blower 31, evaporator 32 (the compressor of the refrigerant circuit), heater core 33 (the electric heater and electric pump of the heat medium heating device), and electric actuators 61 to 68, thereby controlling the operation of these devices. In this embodiment, the air conditioning control device 5 corresponds to the "control unit" of the present invention.

[0027] The various sensors connected to the air conditioning control device 5 include, for example, a temperature sensor group 71 and a humidity sensor group 72 installed at various locations inside and outside the air conditioning unit 2, as well as a seat weight sensor 73 and a CO2 concentration sensor 74. The temperature sensor group 71 includes an outside air temperature sensor that detects the temperature of the outside air, an inside air temperature sensor that detects the temperature of the inside air, a temperature sensor that detects the surface temperature of the vehicle's window glass (such as the windshield), and a temperature sensor that detects the temperature of the air near the window glass inside the vehicle. The humidity sensor group 72 includes an outside air humidity sensor that detects the humidity of the outside air, an inside air humidity sensor that detects the humidity of the inside air, and a humidity sensor that detects the humidity of the air near the window glass inside the vehicle. The seat weight sensor 73 detects the weight of each seat installed in the vehicle. The air conditioning control device 5 can determine the number of passengers in the vehicle cabin based on changes in the weight of each seat detected by the seat weight sensor 73. The CO2 concentration sensor 74 detects the concentration of carbon dioxide (CO2) in the vehicle cabin.

[0028] Furthermore, various switches connected to the air conditioning control unit 5 are provided on an operation panel 75 for passenger operation. The operation panel 75 is provided, for example, at the front portion of the vehicle interior. The operation panel 75 includes, for example, an on / off switch for turning the vehicle air conditioning unit 1 on and off, an automatic switch for turning the automatic control of the vehicle air conditioning unit 1 on and off, an A / C switch for turning the cooling function on and off, a heating switch for turning the heating function on and off, an inlet mode switch for switching the inlet mode, an outlet mode switch for switching the outlet mode, and an air volume setting switch for setting the air volume of the blower 31.

[0029] Next, the operation of the vehicle air conditioning device 1 according to this embodiment will be described. Generally speaking, in summer, when the outside temperature rises, when using the cooling function of an air conditioner, it is preferable to set the intake mode to inside air mode to improve cooling efficiency. This allows the conditioned air generated by the air conditioner to circulate within the vehicle interior. When the cooling function is used with 100% inside air circulation, the CO2 concentration within the vehicle interior rises due to passengers' exhalation, necessitating ventilation within the vehicle interior. Specifically, ventilation is achieved by drawing in and cooling high-temperature outside air, supplying it to the vehicle interior, and then exhausting an equal amount of inside air to the outside. The heat loss caused by the introduction of high-temperature outside air and the exhaust of low-temperature inside air associated with this ventilation reduces cooling efficiency. Therefore, the vehicle air conditioner 1 of this embodiment disposes a total heat exchanger 34 between the blower 31 and the evaporator 32. The flow rates of outside air and inside air introduced into the total heat exchanger 34 are controlled according to the CO2 concentration within the vehicle interior. This reduces heat loss caused by the introduction of outside air and the exhaust of inside air, thereby suppressing power consumption during cooling.

[0030] Specifically, in vehicle air conditioning system 1, the various components of vehicle air conditioning system 1 are first activated by turning on the on / off switch of operating panel 75. Then, by turning on the A / C switch on operating panel 75 and setting the air volume setting switch to the desired air volume, or by turning on the automatic switch, the blower 31 and evaporator 32 are activated according to a control signal from air conditioning control unit 5, thereby activating the cooling function. Furthermore, the heating switch is turned off, and heater core 33 does not operate. In the initial state of the cooling function, to improve cooling efficiency, the inlet mode switch is set to inside air mode, or the inlet mode is automatically set to inside air mode by turning on the automatic switch. This causes vehicle air conditioning system 1 to begin cooling operation with 100% inside air circulation.

[0031] Figure 4 The figure shows the air flow in the initial state when the summer cooling function is turned on. By setting the inlet mode to the internal air mode, the electric actuators 61 to 63 are driven according to the control signal from the air conditioning control device 5, and the external air door 22B, the internal air door 23B and the internal and external air door 28 are controlled to Figure 4 That is, the outside air door 22B is in a position to close the outside air inlet 22, the inside air door 23B is in a position to open the inside air inlet 23, and the inside and outside air door 28 is in a position to open the connecting passage P12.

[0032] Furthermore, by setting the outlet mode switch to the face mode, the electric actuators 64 to 66 are driven according to the control signal from the air conditioning control device 5, and the face door 25B, the foot door 26B and the outlet switching door 27 are controlled to Figure 4That is, the face door 25B is in a position to open the face outlet 25, the foot door 26B is in a position to close the foot outlet 26, and the outlet switching door 27 is in a position closest to the defroster outlet 24.

[0033] At this time, the internal air heat exchange adjustment damper 34A corresponding to the total heat exchanger 34 is driven by the electric actuator 68 based on the control signal from the air conditioning control device 5. Figure 4 As shown by the solid line in the middle, it is located along the flow direction of the air in the second passage P2, closing the internal air introduction surface of the total heat exchanger 34. In addition, by driving the electric actuator 67 according to the control signal from the air conditioning control device 5, the air mix door 33A arranged on the upstream side of the heater core 33 is located in a position so that all the air flowing in the air conditioning case 21 passes through the bypass passage B. Furthermore, by driving the blower 31 according to the control signal output from the air conditioning control device 5 according to the air volume setting, for example, 200m 3 Inside air RA at a constant flow rate of / h is introduced into the air-conditioning casing 21 from the inside air inlet 23 via the inside air duct 23A.

[0034] The internal air RA introduced into the air conditioning casing 21 from the internal air inlet 23 is divided into the connecting passage P12 side and the second passage P2 side, becoming the flow of air passing through the connecting passage P12 and the first passage P1, and the flow of air passing through the second passage P2. The air flowing in the first passage P1 is introduced into the evaporator 32 via the total heat exchanger 34, and the air flowing in the second passage P2 is directly introduced into the evaporator 32. The evaporator 32 is driven according to the control signal output from the air conditioning control device 5 according to the temperature setting of the cooling, and the air from the first passage P1 and the second passage P2 is concentratedly cooled. The air cooled by the evaporator 32 passes through the bypass passage B and is discharged from the face outlet 25 as the conditioned air CA at a speed of 200m 3 Thus, in the initial state where the cooling function is turned on, the vehicle air conditioner 1 starts the cooling operation with the interior air circulation 100%.

[0035] In the vehicle air conditioning system 1 of this embodiment, at the start of cooling operation or after a predetermined standby time, the air conditioning control device 5 determines the number of passengers in the vehicle cabin based on changes in the weight of each seat detected by the seat weight sensor 73. The number of passengers in the vehicle cabin is used as a parameter to estimate the extent of the increase in CO2 concentration in the vehicle cabin. Specifically, since CO2 concentration in the vehicle cabin increases primarily through passengers' exhalation, the extent of the increase in CO2 concentration also varies proportionally with the number of passengers in the vehicle cabin or the total weight of the passengers. In this embodiment, this characteristic is utilized to estimate the change in CO2 concentration in the vehicle cabin during cooling based on the number of passengers and to control the ventilation volume. However, the CO2 concentration in the vehicle cabin detected by the CO2 concentration sensor 74 can also be used to control the ventilation volume. In other words, if the vehicle is not equipped with a CO2 concentration sensor, controlling the ventilation volume based on the number of passengers in the vehicle cabin (or the total weight of the passengers) is an effective alternative to controlling the ventilation volume based on CO2 concentration.

[0036] If the number of passengers in the vehicle cabin is determined based on information from the seat weight sensor 73, the air conditioning control device 5 controls the various components of the vehicle air conditioning system 1 to perform ventilation (external air intake and internal air exhaust) in accordance with the number of passengers. In this embodiment, the ventilation rate required for the vehicle cabin during air conditioning operation is set to, for example, 30 cfm (ft2) per passenger, taking into account the increase in CO2 concentration in the vehicle cabin caused by the exhalation of passengers. 3 / min) = 51m 3 / h is set as the control target value. This ventilation rate control target value is based on literature such as Gursaran D. Mathur, "Power Savings by Operating HVAC Unit in Partial Recirculation Mode," Automotive Air-Conditioning Technical Review 2022 - HVAC Systems for Vehicle Electrification. The following describes the specific operation of the vehicle air conditioning system 1 of this embodiment, specifically in the summer, with two and four passengers in the vehicle cabin.

[0037] (Summer, when there are two passengers) Figure 5The figure shows the air flow in the case of two passengers in summer. In the vehicle air conditioning system 1 of this embodiment, if the air conditioning control device 5 determines that there are two passengers based on the information from the seat weight sensor 73, it controls the electric actuators 61, 63, and 68 corresponding to the outside air door 22B, the inside and outside air door 28, and the inside air heat exchange adjustment damper 34A, respectively, so that the air flow is 51m / s. 3 / h×2=102m 3 The ventilation volume of / h is used to introduce outside air and exhaust inside air. Therefore, the outside air door 22B, the inside and outside air door 28 and the inside air heat exchange adjustment damper 34A are adjusted to Figure 5 That is, the outside air door 22B is adjusted so that the flow rate of the outside air OA introduced from the outside air inlet 22 is 102m 3 The internal and external air door 28 is adjusted to the position of closing the connecting passage P12. Through the internal and external air door 28, the internal air inlet 23 is opened at 200m 3 The inside air RA1 introduced at a flow rate of / h flows entirely through the second passage P2. The inside air heat exchange adjustment damper 34A is adjusted so that the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 among the inside air flowing through the second passage P2 is 102m 3 / h, and the flow rate of the internal air RA2-2 delivered to the evaporator 32 is 98m 3 That is, the air conditioning control device 5 controls the ratio of the flow rate of the inside air RA2-1 to the flow rate of the inside air RA2-2 at the inside air heat exchange adjustment damper 34A in proportion to the opening of the outside air door 22B.

[0038] As a specific example of the states of the outside air and inside air, consider a situation where outside air OA at a temperature of 35°C, a relative humidity of 60%, and an absolute humidity of 0.0215 kg / kg is introduced into the air conditioning casing 21 through the outside air inlet 22, and inside air (return air) RA1 at a temperature of 25°C, a relative humidity of 30%, and an absolute humidity of 0.0059 kg / kg is introduced into the air conditioning casing 21 through the inside air inlet 23. Under these conditions, the state of the air flowing through each component of the air conditioning control device 5 changes as shown in Table 1 below. [Table 1]

[0039] Reference Figure 5 The operation of the air conditioning control device 5 in the case of two passengers in summer is described in detail in Table 1. 3The outside air OA introduced into the air conditioning housing 21 at a flow rate of 200 m / h is introduced into the total heat exchanger 34 through the first passage P1. 3 The internal air RA introduced into the air conditioning casing 21 at a flow rate of 102 m / h is divided into two directions by the internal air heat exchange adjustment damper 34A after passing through the second passage P2. 3 The internal air RA2-1 at a flow rate of / h is introduced into the total heat exchanger 34, and 98m 3 The inside air RA2-2 at a flow rate of / h is delivered to the evaporator 32 ( Figure 5 ).

[0040] In the total heat exchanger 34, at the same flow rate (102m 3 Total heat (temperature and humidity) is exchanged between the outside air OA introduced at a rate of 100 mph (100 mph) and the interior air RA2-1. The total heat exchange efficiency in this embodiment is 50%. This total heat exchange reduces the temperature and absolute humidity of the outside air OA, causing the supply air SA (Table 1) at a temperature of 30°C, a relative humidity of 51.4%, and an absolute humidity of 0.0137 kg / kg to be blown out of the total heat exchanger 34 and delivered to the evaporator 32. Furthermore, this total heat exchange increases the temperature and absolute humidity of the interior air RA2-1, causing the exhaust air EA (Table 1) at a temperature of 30°C, a relative humidity of 51.4%, and an absolute humidity of 0.0137 kg / kg to be discharged from the total heat exchanger 34 through the exhaust port 30 and the exhaust duct 30A to the exterior of the vehicle.

[0041] Therefore, from the total heat exchanger 34 at 102m 3 / h of the supply gas SA and the second channel P2 at a rate of 98m 3 The inside air RA2-2 delivered at a flow rate of / h is introduced into the evaporator 32 in a mixed state ( Figure 5 Specifically, the air CA1 (Table 1) at a temperature of 27.5°C, a relative humidity of 42.8%, and an absolute humidity of 0.0098 kg / kg is introduced into the evaporator 32 by mixing the supply air SA and the internal air RA2-2 in different states. The flow rate of the air CA1 introduced into the evaporator 32 is 200 m 3 / h. After being cooled by evaporator 32, air CA1 passes through bypass duct B and is blown out of face outlet 25 as conditioned air CA2. In this embodiment, conditioned air CA2 (Table 1), at a temperature of 5°C, a relative humidity of 100%, and an absolute humidity of 0.0054 kg / kg, is blown toward the upper body of the passenger in the vehicle compartment via face outlet 25 and face duct 25A.

[0042] When the total heat exchanger 34 is used to introduce outside air and exhaust inside air as described above, the specific enthalpy of the air CA1 introduced into the evaporator 32 is 52.7 kJ / kg (total heat exchanger in Table 1: with). On the other hand, under the same conditions, when the total heat exchanger 34 is not used and outside air is introduced and exhausted inside, the temperature of the air CA1 introduced into the evaporator 32 is 30°C, the relative humidity is 51.4%, the absolute humidity is 0.0137 kg / kg, and the specific enthalpy is 65.2 kJ / kg (total heat exchanger in Table 1: without). The specific enthalpy of the conditioned air CA2 blown out of the face outlet 25 in the aforementioned state is 18.6 kJ / kg (Table 1). Using these values ​​to calculate the energy saving effect of the total heat exchanger 34, the result is {1 - (52.7 - 18.6) / (65.2 - 18.6)} = 1 - (34.1 / 46.6) = 26.8%.

[0043] Furthermore, in the vehicle air conditioning system 1 of this embodiment, the upstream side of the blower 31 draws air from the free space (the outside air inlet 22 and the inside air inlet 23) in both the first and second ducts P1 and P2. Furthermore, the outside air and inside air introduced into the blower 31 flow in the same direction. Therefore, the blower 31 can be driven more efficiently compared to the conventional technology described above. Consequently, the vehicle air conditioning system 1 improves the air delivery efficiency within the air conditioning casing 21, reduces heat loss caused by the introduction of outside air and the exhaust of inside air, and effectively reduces power consumption during cooling. Furthermore, in this embodiment, the outside air OA and inside air RA2-1 introduced into the total heat exchanger 34 are set at the same flow rate. However, the flow rate of the inside air RA2-1 can be slightly reduced compared to the flow rate of the outside air OA. In this case, the difference in flow between the outside air OA and inside air RA2-1 is discharged through the ventilation port at the rear of the vehicle. However, increasing the flow rate of the inside air RA2 - 1 compared to the outside air OA requires avoiding the fact that the outside air is introduced into the vehicle interior from the gaps in the vehicle and is not cooled without passing through the evaporator 32 .

[0044] (Summer, when there are four passengers) Figure 6 The figure shows the air flow in the case of four passengers in summer. In the vehicle air conditioning system 1 of this embodiment, if the air conditioning control device 5 determines that there are four passengers based on the information from the seat weight sensor 73, it controls the electric actuators 61, 63, and 68 corresponding to the outside air door 22B, the inside and outside air door 28, and the inside air heat exchange adjustment damper 34A, respectively, so that the air flow is controlled at 51m 3 / h×4=204m 3The ventilation volume of / h is used to introduce outside air and exhaust inside air. Therefore, the outside air door 22B, the inside and outside air door 28 and the inside air heat exchange adjustment damper 34A are adjusted to Figure 6 The difference from the above case with two passengers is that in the case with four passengers, the outside air door 22B is adjusted to a position that opens the outside air inlet 22, and the inside air heat exchange adjustment damper 34A is adjusted to a position that is perpendicular to the flow direction of the inside air in the second passage P2. By such control corresponding to four passengers, the outside air OA is adjusted at 204m 3 / h flow rate is introduced into the air conditioning casing 21 from the external air inlet 22. In addition, the internal air RA1 is 3 / h flow rate is introduced into the air conditioning casing 21 from the internal air inlet 23, and all the internal air RA2 (204m 3 / h) is introduced into the total heat exchanger 34.

[0045] When outside air OA and inside air RA1 of the same temperature and humidity conditions as those in the case of two passengers are introduced into the air conditioning casing 21 , the state of air flowing through each part of the air conditioning control device 5 changes as shown in Table 2 below. [Table 2]

[0046] Reference Figure 6 The operation of the air conditioning control device 5 in the case of four passengers in summer is described in detail in Table 2. Unlike the case of two passengers in summer, the 204m 3 The outside air OA at a flow rate of 1 / h is introduced into the total heat exchanger 34, and 204m 3 The inside air RA2 at a flow rate of / h is introduced into the total heat exchanger 34, and the total heat (temperature and humidity) is exchanged between the outside air OA and the inside air RA2 ( Figure 6 This total heat exchange reduces the temperature and absolute humidity of the outside air OA, while increasing the temperature and absolute humidity of the interior air RA2-1. The state of the supply air SA supplied from the total heat exchanger 34 to the evaporator 32, and the state of the exhaust air EA discharged from the total heat exchanger 34 through the exhaust port 30 and the exhaust duct 30A to the outside of the vehicle, are the same as those described above for the summer with two passengers (Table 2).

[0047] In summer, when there are four passengers, the 3 The supply air SA sent from the total heat exchanger 34 at a flow rate of / h is introduced into the evaporator 32. That is, the air CA1 (=SA) at a temperature of 30°C, a relative humidity of 51.4%, and an absolute humidity of 0.0137 kg / kg is introduced into the evaporator 32 at a flow rate of / h.3 / h flow rate is introduced into evaporator 32. After being cooled by evaporator 32, air CA1 passes through bypass duct B and is blown out of face outlet 25 as conditioned air CA2. The state of conditioned air CA2 blown out of face outlet 25 is the same as that in the summer with two passengers case (Table 2). Thus, even in the summer with four passengers case, the same energy-saving effect as in the summer with two passengers case can be achieved.

[0048] In the present embodiment, the air conditioning control device 5, in addition to performing the aforementioned ventilation (outside air intake and interior air exhaust) based on the number of passengers in the vehicle cabin during cooling, also monitors the CO2 concentration in the vehicle cabin as detected by the CO2 concentration sensor 74 and performs correction control on the ventilation volume based on the number of passengers to keep the CO2 concentration below a reference value. This reference value is pre-set in the air conditioning control device 5 as an upper limit of CO2 concentration that does not pose a risk to passengers, such as 1100 ppm. Specifically, if the CO2 concentration in the vehicle cabin detected by the CO2 concentration sensor 74 approaches or exceeds the reference value, the air conditioning control device 5 corrects the ventilation volume control target value for each passenger, thereby maintaining the vehicle cabin CO2 concentration below the reference value.

[0049] However, when CO2 is used as the refrigerant in the refrigerant circuit (refrigeration cycle) including the evaporator 32, if a refrigerant leak occurs due to a refrigerant circuit anomaly, there is a possibility that the aforementioned correction control of the ventilation volume will reach its limit, and the CO2 concentration in the vehicle interior may significantly exceed the reference value. Therefore, in this embodiment, if the CO2 concentration in the vehicle interior detected by the CO2 concentration sensor 74 exceeds a predetermined threshold value (> the reference value), the air conditioning control device 5 infers that a refrigerant leak has occurred and controls the air in the air conditioning casing 21 to be forcibly discharged to the outside of the vehicle.

[0050] (In case of refrigerant leakage) Figure 7 The figure shows the air flow in the case of refrigerant leakage. As described above, when the CO2 concentration in the vehicle cabin exceeds the threshold value and it is estimated that a refrigerant leak has occurred, the air conditioning control device 5 first controls the electric actuators 64, 65, and 66 corresponding to the front door 25B, the foot door 26B, and the outlet switching door 27, respectively, so that the air outlet mode becomes the closed mode. Figure 7 As shown by the solid line, the face door 25B is adjusted to a position closing the face outlet 25, the foot door 26B is adjusted to a position closing the foot outlet 26, and the outlet switching door 27 is adjusted to a position closest to the defroster outlet 24 side.

[0051] Then, the air conditioning control device 5 controls the electric actuators 61, 62, and 68 corresponding to the outside air door 22B, the inside air door 23B, and the inside air heat exchange adjustment damper 34A, respectively, so that only the outside air OA introduced from the outside air inlet 22 flows through the first passage P1, circulates in the air conditioning case 21, and is discharged to the outside of the vehicle through the exhaust port 30. Figure 7 As shown by the solid line, the outside air door 22B is adjusted to a position that fully opens the outside air inlet 22, and the inside air door 23B is adjusted to a position that closes the inside air inlet 23. Furthermore, the inside air heat exchange adjustment damper 34A is controlled to allow air to flow from the evaporator 32 side to the total heat exchanger 34 side. Specifically, the inside air heat exchange adjustment damper 34A is adjusted to a position that is inclined at approximately 45° relative to the flow direction of air within the second passage P2, thereby controlling the aforementioned air volume ratio to approximately 1:1. The air volume ratio of the inside air heat exchange adjustment damper 34A only needs to be approximately 1:1 and does not need to be strictly 1:1.

[0052] Through the aforementioned control measures to prevent refrigerant leakage, outside air OA introduced from the outside air inlet 22 sequentially passes through the first passage P1, the total heat exchanger 34, the evaporator 32, and the heater core 33. The air then reverses its direction just before the outlet switching door 27, passing through the heater core 33, the evaporator 32, the inside air heat exchange damper 34A, and the total heat exchanger 34 before being discharged from the exhaust port 30 to the exterior of the vehicle. At this point, refrigerant (CO₂) leaking into the air conditioning casing 21 due to, for example, a refrigerant circuit anomaly is also discharged to the exterior of the vehicle along with the outside air OA circulating within the air conditioning casing 21. This prevents increases in the CO₂ concentration within the vehicle cabin caused by refrigerant leakage.

[0053] Furthermore, the aforementioned control for forced ventilation within the air conditioning casing 21 in response to a refrigerant leak is also effective when a refrigerant other than CO2 (e.g., hydrocarbons) is used in the refrigerant circuit (refrigeration cycle) including the evaporator 32. In this case, forced ventilation within the air conditioning casing 21 is performed only when a detection signal from a refrigerant leak sensor installed within the air conditioning casing 21 or a signal notifying of an abnormality in the refrigeration cycle is provided to the air conditioning control device 5.

[0054] Next, the operation of the vehicle air conditioner 1 in winter will be described. Generally speaking, during winter, when the outside temperature drops, setting the intake mode to inside air mode (with inside air circulation) and using the heating function can easily cause condensation on the vehicle's windowpanes due to the higher absolute humidity of the inside air compared to the outside air. While introducing outside air into the vehicle interior is effective in preventing windowpane fogging caused by condensation during heating, heat loss due to this introduction of outside air is a concern. Therefore, the vehicle air conditioning system 1 of this embodiment ensures a ventilation volume sufficient to prevent a similar increase in CO2 concentration within the vehicle interior as during cooling, while controlling the amount of outside air introduced to the minimum required to prevent windowpane fogging. This reduces heat loss due to the introduction of outside air and suppresses power consumption during heating.

[0055] Specifically, in the vehicle air conditioner 1, when the heater core 33 is activated (the evaporator 32 is deactivated) and heating begins, the air conditioning control device 5 determines the number of passengers in the vehicle cabin based on changes in the weight of each seat detected by the seat weight sensor 73, either simultaneously with the start of heating or after a predetermined standby time. Furthermore, the air conditioning control device 5 calculates the dew point temperature of the air near the window pane using the detection values ​​of the temperature and humidity sensors located near the window pane in the temperature sensor group 71 and humidity sensor group 72. The air conditioning control device 5 then controls various components of the vehicle air conditioner 1 to perform ventilation (intake of outside air and exhaust of interior air) in accordance with the number of passengers in the vehicle cabin, while maintaining the dew point temperature below the surface temperature of the window pane. Furthermore, during heating, the air outlet mode is set to, for example, the foot mode.

[0056] (Winter, when there are two passengers and the possibility of condensation is low) Figure 8 The figure shows the air flow in the case of two passengers in winter and low condensation possibility. In the vehicle air conditioning system 1 of this embodiment, if the air conditioning control device 5 determines that there are two passengers based on the information from the seat weight sensor 73 and that the calculated dew point temperature is sufficiently lower than the surface temperature of the window glass to prevent condensation, the electric actuators 61, 63, and 68 corresponding to the outside air door 22B, the inside and outside air door 28, and the inside air heat exchange adjustment damper 34A are controlled so that the air flow is controlled at 51m / s. 3 / h×2=102m 3 / h ventilation volume to introduce external air and exhaust internal air. Figure 8 As shown by the solid line, the outside air door 22B is adjusted so that the flow rate of the outside air OA introduced from the outside air inlet 22 is 102m 3 / h, the inside and outside air door 28 is adjusted to the position of closing the connecting passage P12, and the inside air heat exchange adjustment damper 34A is adjusted to make the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 in the inside air flowing in the second passage P2 be 102m 3 / h, and the flow rate of the inside air RA2-2 sent to the heater core 33 via the evaporator 32 is set to 98m 3 / h middle position.

[0057] As a specific example of the states of the outside air and inside air, consider a situation where outside air OA at a temperature of 5°C, a relative humidity of 50%, and an absolute humidity of 0.0027 kg / kg is introduced into the air conditioning casing 21 through the outside air inlet 22, and inside air (return air) RA1 at a temperature of 25°C, a relative humidity of 30%, and an absolute humidity of 0.0059 kg / kg is introduced into the air conditioning casing 21 through the inside air inlet 23. Under these conditions, the state of the air flowing through each component of the air conditioning control device 5 changes as shown in Table 3 below. [Table 3]

[0058] Reference Figure 8 The operation of the air conditioning control device 5 is described in detail in Table 3 when there are two passengers in winter and the possibility of condensation is low. 3 The outside air OA introduced into the air conditioning casing 21 at a flow rate of 200 m / h is introduced into the total heat exchanger 34 through the first passage P1, similar to the case of two passengers in summer. 3 The internal air RA introduced into the air conditioning casing 21 at a flow rate of 102 m / h is divided into two directions by the internal air heat exchange adjustment damper 34A after passing through the second passage P2. 3 The internal air RA2-1 at a flow rate of / h is introduced into the total heat exchanger 34, and 98m 3 The inside air RA2-2 at a flow rate of / h is delivered to the heater core 33 ( Figure 8 ).

[0059] In the total heat exchanger 34, the same as in the case of two passengers in summer, the same flow rate (102m 3Total heat (temperature and humidity) is exchanged between the outside air OA introduced at a rate of 15°C (15°C / h) and the interior air RA2-1. This causes the temperature and absolute humidity of the outside air OA to rise, and the supply air SA (Table 3), at a temperature of 15°C, a relative humidity of 40.8%, and an absolute humidity of 0.0043 kg / kg, is blown out of the total heat exchanger 34 and delivered to the heater core 33 via the evaporator 32. Furthermore, the temperature and absolute humidity of the interior air RA2-1 decrease, and the exhaust air EA (Table 3), at a temperature of 15°C, a relative humidity of 40.8%, and an absolute humidity of 0.0043 kg / kg, is discharged from the total heat exchanger 34 through the exhaust port 30 and the exhaust duct 30A to the outside of the vehicle.

[0060] Therefore, from the total heat exchanger 34 at 102m 3 / h of the supply gas SA and the second channel P2 at a rate of 98m 3 The inside air RA2-2 delivered at a flow rate of 1 / h is introduced into the heater core 33 ( Figure 8 Specifically, the air CA1 (Table 3) at a temperature of 20°C, a relative humidity of 35.2%, and an absolute humidity of 0.0051 kg / kg is introduced into the heater core 33 via the evaporator 32 by mixing the supply air SA and the inside air RA2-2 in different states. The flow rate of the air CA1 introduced into the heater core 33 is 200 m 3 / h. The air CA1 heated by the heater core 33 is then blown out of the foot outlet 26 as conditioned air CA2. In this embodiment, conditioned air CA2 (Table 3), at a temperature of 50°C, a relative humidity of 6.7%, and an absolute humidity of 0.0051 kg / kg, is blown toward the feet of passengers in the vehicle cabin through the foot outlet 26 and foot duct 26A. Since the dew point temperature of the air near the window glass in the vehicle cabin during this heating is 4.2°C, lower than the outside air temperature of 5°C, fogging of the window glass can be prevented.

[0061] When the total heat exchanger 34 is used to introduce outside air and exhaust inside air as described above, the specific enthalpy of the air CA1 introduced into the heater core 33 via the evaporator 32 is 33.1 kJ / kg, and the specific enthalpy of the conditioned air CA2 blown out of the foot outlet 26 in the aforementioned state is 63.5 kJ / kg (total heat exchanger in Table 3: with). On the other hand, under the same conditions, when the total heat exchanger 34 is not used and outside air is introduced and exhaust inside air is performed, the specific enthalpy of the air CA1 introduced into the heater core 33 via the evaporator 32 is 26 kJ / kg, and the specific enthalpy of the conditioned air CA2 blown out of the foot outlet 26 in the aforementioned state is 61.5 kJ / kg (total heat exchanger in Table 3: without). Using these values ​​to calculate the energy saving effect of the total heat exchanger 34, the result is {1 - (63.5 - 33.1) / (61.5 - 26)} = 1 - (30.4 / 35.5) = 14.4%.

[0062] (Winter, when there are four passengers and the possibility of condensation is low) Figure 9 The figure shows the air flow in the case of four passengers in winter and low condensation possibility. In the vehicle air conditioning system 1 of this embodiment, if the air conditioning control device 5 determines that there are four passengers based on the information from the seat weight sensor 73 and that the calculated dew point temperature is sufficiently lower than the surface temperature of the window glass to prevent condensation, the electric actuators 61, 63, and 68 corresponding to the outside air door 22B, the inside and outside air door 28, and the inside air heat exchange adjustment damper 34A are controlled so that the air flow is controlled at 51m / s. 3 / h×4=204m 3 The ventilation volume of / h is used to introduce outside air and exhaust inside air. Therefore, the outside air door 22B, the inside and outside air door 28 and the inside air heat exchange adjustment damper 34A are adjusted to Figure 9 The difference from the above-mentioned winter situation with two passengers is that in the case of four passengers, the outside air door 22B is adjusted to a position that opens the outside air inlet 22, and the inside air heat exchange adjustment damper 34A is adjusted to a position that is perpendicular to the flow direction of the inside air in the second passage P2. By such control corresponding to four passengers, the outside air OA is adjusted at 204m 3 / h flow rate is introduced into the air conditioning casing 21 from the external air inlet 22. In addition, the internal air RA1 is 3 / h flow rate is introduced into the air conditioning casing 21 from the internal air inlet 23, and all the internal air RA2 (204m 3 / h) is introduced into the total heat exchanger 34.

[0063] When outside air OA and inside air RA1 of the same temperature and humidity conditions as those in the winter with two passengers are introduced into the air conditioning casing 21, the state of air flowing through each part of the air conditioning control device 5 changes as shown in Table 4 below. [Table 4]

[0064] Reference Figure 9 Table 4 describes the operation of the air conditioning control device 5 in detail when there are four passengers in winter. Unlike the above-mentioned case of two passengers in winter, the 204m 3 The outside air OA at a flow rate of 1 / h is introduced into the total heat exchanger 34, and 204m 3 The inside air RA2 at a flow rate of / h is introduced into the total heat exchanger 34, and the total heat (temperature and humidity) is exchanged between the outside air OA and the inside air RA2 ( Figure 9 This total heat exchange increases the temperature and absolute humidity of the outside air OA, while decreasing the temperature and absolute humidity of the interior air RA2-1. The state of the supply air SA delivered from the total heat exchanger 34 via the evaporator 32 to the heater core 33, and the state of the exhaust air EA discharged from the total heat exchanger 34 through the exhaust port 30 and the exhaust duct 30A to the exterior of the vehicle, are the same as those described above for the winter and two-passenger scenario (Table 4).

[0065] In winter, when there are four passengers, only the heat exchanger 34 is heated to 204 m 3 The supply air SA delivered at a flow rate of / h is introduced into the heater core 33 via the evaporator 32. That is, the air CA1 (=SA) at a temperature of 15°C, a relative humidity of 40.8%, and an absolute humidity of 0.0043 kg / kg is heated at 204 m 3 Air CA1 is introduced into the heater core 33 via the evaporator 32 at a flow rate of 1 / h. The heater core 33 then heats the air CA1 and blows it out of the foot outlet 26 as conditioned air CA2. The conditioned air CA2 blowing out of the foot outlet 26 has a temperature of 50°C, a relative humidity of 5.6%, and an absolute humidity of 0.0043 kg / kg (Table 4). During this heating period, the dew point of the air near the windowpanes inside the vehicle is 1.8°C, lower than the outside air temperature of 5°C, thus preventing fogging of the windowpanes. Furthermore, even in the winter with four passengers, the same energy-saving effects as in the winter with two passengers described above are achieved.

[0066] As described above, in the vehicle air conditioning system 1 of this embodiment, when the likelihood of condensation is low during heating, the flow rates of outside air and inside air introduced into the total heat exchanger 34 are maintained at values ​​corresponding to the number of passengers, while ventilation within the vehicle interior (outside air intake and inside air exhaust) is performed while total heat exchange is performed between the outside and inside air. On the other hand, when the likelihood of condensation is high, that is, when the dew point temperature calculated by the air conditioning control device 5 approaches the surface temperature of the window glass, and condensation is about to occur, the position of the inside air heat exchange damper 34A is adjusted, for example, to gradually reduce the flow rate of inside air introduced into the total heat exchanger 34 from a value corresponding to the number of passengers, ultimately reducing the amount of inside air introduced into the total heat exchanger 34 to zero. This maintains the dew point temperature below the surface temperature of the window glass, preventing fogging of the window glass. Here, as an example of a situation with a high likelihood of condensation, the operation of the vehicle air conditioning system 1 in winter with two passengers will be specifically described.

[0067] (Winter, when there are two passengers and there is a high possibility of condensation) Figure 10 The figure shows the air flow in winter when there are two passengers and the possibility of condensation is high. In the vehicle air conditioning system 1 that performs heating operation with a ventilation volume corresponding to two passengers as described above, if the dew point temperature calculated by the air conditioning control device 5 approaches the surface temperature of the window glass and the possibility of condensation increases, the air conditioning control device 5 adjusts the position of the inside air heat exchange adjustment damper 34A so that the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 changes from 102m / s to 102m / s. 3 / h gradually decreases to 0m 3 At this time, in conjunction with the reduction in the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34, the position of the inside air door 23B is also adjusted so that the flow rate of the inside air RA introduced from the inside air inlet 23 is reduced from 200m 3 / h gradually decreases to 98m 3 / h.

[0068] By gradually reducing the flow rate of inside air RA2-1 introduced into the total heat exchanger 34, the amount of latent heat exchanged between the outside air and the inside air in the total heat exchanger 34 is reduced, thereby reducing the absolute humidity of the air delivered to the inside of the vehicle interior. This air with reduced absolute humidity is heated by the heater core 33 and blown into the vehicle interior through the foot outlet 26. This lowers the dew point temperature of the air near the windowpanes within the vehicle interior, making it easier to maintain this dew point temperature below the surface temperature of the windowpanes.

[0069] Specifically, under the conditions of the air shown in Table 3 above, the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 is reduced to 0 m3 / h, the state of the air CA2 blown out from the foot outlet 26 is 50°C, 5.6% relative humidity, and 0.0043 kg / kg absolute humidity. The dew point temperature of the air near the window glass at this time is 1.8°C, and the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 is lower than that of the above-mentioned 102m 3 / h when the dew point temperature (=4.2℃).

[0070] Even if the above-described control to reduce the flow rate of inside air RA2-1 introduced into the total heat exchanger 34 is performed, if the dew point temperature approaches the surface temperature of the window glass, indicating a high probability of condensation, the position of the inside air door 23B is adjusted, etc., to gradually reduce the flow rate of inside air RA1 introduced from the inside air inlet 23, ultimately reducing the amount of inside air introduced from the inside air inlet 23 to zero. Specifically, if the dew point temperature does not fall below the surface temperature of the window glass even if the flow rate of inside air RA2-1 introduced into the total heat exchanger 34 is zero, the air conditioning control device 5 controls the positions of the outside air door 22B, the inside air door 23B, and the inside / outside air door 28 to reduce the ratio (the inside air introduction ratio) of the flow rate of inside air RA1 introduced from the inside air inlet 23 to the flow rate of outside air OA introduced from the outside air inlet 22.

[0071] (Winter, when there are two passengers and the possibility of condensation is higher) Figure 11 The figure shows the air flow in winter when there are two passengers and the possibility of condensation is higher. Specifically, when the possibility of condensation is further increased, the air conditioning control device 5 adjusts the position of the inside air door 23B so that the flow rate of the inside air RA1 introduced from the inside air inlet 23 is changed from 98m 3 / h gradually decreases to 0m 3 At this time, the position of the outside air door 22B is also adjusted to reduce the flow rate of the inside air RA1 introduced from the inside air inlet 23 so that the flow rate of the outside air OA introduced from the outside air inlet 22 increases from 102 m / s to 102 m / s. 3 Gradually increase to 200m / h 3 / h. If the flow rate of the inside air RA1 introduced from the inside air inlet 23 becomes 0m 3 / h, the inside and outside air door 28 is adjusted to the position of opening the connecting passage P12.

[0072] By gradually decreasing the flow rate of inside air RA1 introduced through inside air inlet 23 and gradually increasing the flow rate of outside air OA introduced through outside air inlet 22, the ratio of outside air OA, whose absolute humidity is lower than that of inside air RA1, increases. Consequently, the absolute humidity of the air delivered into the vehicle interior decreases. This air, with its absolute humidity reduced, is heated by heater core 33 and blown into the vehicle interior through foot outlet 26. This lowers the dew point temperature of the air near the windowpanes within the vehicle interior, making it easier to maintain this dew point temperature below the surface temperature of the windowpanes.

[0073] Specifically, in the state of the air shown in Table 3 above, the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 is reduced to 0 m 3 / h, and the flow rate of the inside air RA1 introduced from the inside air inlet 23 is also reduced to 0m 3 When the flow rate of the inside air RA introduced into the inside air inlet 23 is reduced to 3.5% / h, the air CA2 blown out from the foot outlet 26 has a temperature of 50°C, a relative humidity of 3.5%, and an absolute humidity of 0.0027 kg / kg. At this time, the dew point temperature of the air near the window glass drops to -4.0°C. Furthermore, if the dew point temperature approaches the surface temperature of the window glass even after performing the aforementioned control to reduce the flow rate of the inside air RA introduced into the inside air inlet 23, the outlet mode can be switched from the foot mode to the defroster / foot mode or the defroster mode.

[0074] As described above, in the vehicle air conditioning system 1 of this embodiment, a total heat exchanger 34 is disposed between the blower 31 and the evaporator 32. This system introduces outside air OA flowing through the first duct P1 and at least a portion of the inside air (RA2-1) flowing through the second duct P2. Total heat exchange is performed between the introduced outside air OA and the inside air RA2-1, thereby ventilating the vehicle interior by introducing outside air and exhausting inside air. In this vehicle air conditioning system 1, the upstream side of the blower 31 draws air from the free space (the outside air inlet 22 and the inside air inlet 23) in both the first duct P1 and the second duct P2. Furthermore, the outside air and inside air introduced into the blower 31 flow in the same direction. Therefore, compared to the conventional technology described above, the blower 31 can be driven more efficiently. Consequently, the vehicle air conditioning system 1 improves the air supply efficiency within the air conditioning casing 21, reduces heat loss caused by the introduction of outside air and exhaustion of inside air through the total heat exchanger 34, and reduces power consumption during air conditioning operation.

[0075] Furthermore, in the vehicle air conditioning system 1 of this embodiment, the air conditioning control device 5 is configured to adjust the positions of the outside air door 22B, the inside air door 23B, the inside and outside air door 28, and the inside air heat exchange adjustment damper 34A based on the CO2 concentration in the vehicle cabin, which can be estimated from the number of passengers in the vehicle cabin, thereby controlling the flow rates of the outside air OA and the inside air RA2-1 introduced into the total heat exchanger 34. By controlling the amount of total heat (temperature and humidity) exchanged between the outside air OA and the inside air RA2-1 in the total heat exchanger 34 based on the CO2 concentration in the vehicle cabin (the number of passengers), efficient ventilation (outside air intake and inside air exhaust) within the vehicle cabin can be achieved, effectively reducing power consumption during air conditioning operation.

[0076] Furthermore, in the vehicle air conditioning system 1 of this embodiment, the air conditioning control device 5 is configured to control the opening and closing states of the outside air door 22B and the inside air door 23B, and to control the amount of inside air introduced into the total heat exchanger 34 at the inside air heat exchange adjustment damper 34A in proportion to the opening of the outside air door 22B, so as to keep the CO2 concentration in the vehicle cabin below a predetermined reference value. This allows efficient total heat exchange between the outside air OA and the inside air RA2-1 while maintaining a favorable vehicle cabin environment with the CO2 concentration below the reference value. In particular, in the event of refrigerant leakage due to a refrigerant circuit anomaly, forcibly exhausting the air in the air conditioning casing 21 to the outside of the vehicle prevents deterioration of the vehicle cabin environment caused by the refrigerant leakage, thereby ensuring passenger safety.

[0077] Furthermore, in the vehicle air conditioning system 1 of this embodiment, during heating, the air conditioning control device 5 calculates the dew point temperature using the temperature and humidity near the window glass, and controls the flow rates of the outside air OA and inside air RA2-1 introduced into the total heat exchanger 34 so that the dew point temperature is lower than the surface temperature of the window glass. By controlling the flow rates of outside and inside air introduced based on the window glass surface temperature and dew point temperature, condensation on the window glass can be prevented, improving window cleanability. Furthermore, the air conditioning control device 5 controls the positions of the outside air door 22B, inside air door 23B, and inside / outside air door 28 to reduce the inside air introduction ratio if the dew point temperature does not fall below the window glass surface temperature even when the flow rate of the inside air RA2-1 introduced into the total heat exchanger 34 reaches zero. This reliably prevents condensation on the window glass.

[0078] While the embodiments of the present invention have been described above, the present invention is not limited to the aforementioned embodiments and various modifications and alterations are possible based on the technical concepts of the present invention. For example, in the aforementioned embodiment, a total heat exchanger 34 is used to exchange total heat (temperature and humidity) between the outside air OA and the inside air RA2-1. However, a sensible heat exchanger can be used in place of the total heat exchanger 34. When a sensible heat exchanger is used, sensible heat (temperature) is exchanged between the outside air introduced into the sensible heat exchanger and the inside air. In this case, heat loss caused by the introduction of outside air and the discharge of inside air can be reduced, thereby suppressing power consumption during air conditioning operation.

[0079] In the above embodiment, the evaporator 32 is used as the cooling heat exchange unit, and the heater core 33 is used as the heating heat exchange unit. However, for example, a cooler core disposed in the coolant circulation path may be used in place of the evaporator 32. The cooled coolant circulates through this cooler core. Furthermore, a condenser disposed in the refrigerant circulation path similar to the refrigerant circuit (refrigeration cycle) described above may be used in place of the heater core 33. High-temperature refrigerant circulates through this condenser. Description of Reference Numerals

[0080] 1 Vehicle air conditioning system, 2 Air conditioning unit, 5 Air conditioning control unit, 21 Air conditioning case, 22 Outside air inlet, 23 Inside air inlet, 24 Defroster outlet, 25 Face outlet, 26 Foot outlet, 28 Inside / outside air door, 29 Partition panel, 30 Exhaust port, 31 Blower (air supply unit), 32 Evaporator (cooling heat exchange unit), 33 Heater core (heat exchange unit for heating), 33A Air mix door, 34 Total heat exchanger (inside / outside air heat exchange unit), 34A Inside air heat exchange adjustment damper, 61-68 Electric actuator, 71 Temperature sensor group, 72 Humidity sensor group, 73 Seat weight sensor, 74 CO2 concentration sensor, 75 Operation panel, B Bypass duct, P1 First duct, P2 Second duct, P12 Connecting duct, OA Outside air, RA Inside air (return air), SA Supply air, EA Exhaust air, CA Conditioned air

Claims

1. A vehicle air conditioning device, comprising: An air conditioner housing is formed with an outside air inlet for introducing outside air and an inside air inlet for introducing inside air on one end side, and a defroster outlet for blowing air toward a window glass of the vehicle, and a face outlet and a foot outlet for blowing air toward passengers in the vehicle cabin on the other end side; a cooling heat exchange portion for cooling the air flowing in the air conditioning housing; a partition plate forming, within the air conditioning housing, a first passage for guiding air from the outside air inlet to the cooling heat exchange portion, and a second passage for guiding air from the inside air inlet to the cooling heat exchange portion; as well as The air supply unit generates a flow of air from the one end side toward the other end side in the first channel and the second channel, wherein: The vehicle air conditioning device includes an inside-outside air heat exchange unit, which is arranged between the air supply unit and the cooling heat exchange unit, and introduces the outside air flowing in the first passage and at least a portion of the inside air flowing in the second passage, and performs heat exchange between the introduced outside air and the inside air. The vehicle air conditioner is configured to introduce the outside air after heat exchange in the inside-outside air heat exchange portion together with the remaining inside air flowing in the second passage into the cooling heat exchange portion, and discharge the inside air after heat exchange in the inside-outside air heat exchange portion to the outside of the vehicle.

2. The vehicle air conditioning device according to claim 1, comprising: an inside-outside air volume adjustment unit for adjusting the flow rates of the outside air and the inside air introduced into the inside-outside air heat exchange unit; and The control unit is provided with information on the carbon dioxide concentration in the vehicle interior and controls the operation of the inside / outside air volume adjustment unit based on the carbon dioxide concentration.

3. The vehicle air conditioning device according to claim 2, wherein: The inside and outside air volume adjustment unit includes: an external air door for adjusting the flow rate of external air introduced from the external air inlet; an internal air door for adjusting the flow rate of internal air introduced from the internal air inlet; as well as The internal air heat exchange adjustment damper adjusts the ratio of the flow rate of the internal air introduced into the internal air heat exchange portion and the flow rate of the internal air delivered to the cooling heat exchange portion, among the internal air flowing in the second passage. The control unit controls the opening and closing states of the outside air door and the inside air door, and controls the ratio of the inside air heat exchange adjustment damper in proportion to the opening degree of the outside air door so that the carbon dioxide concentration becomes equal to or less than a predetermined reference value.

4. The vehicle air conditioning device according to claim 3, wherein: The vehicle air conditioner includes a blowout amount adjustment unit configured to adjust the flow rates of air blown out from the defroster outlet, the face outlet, and the foot outlet, respectively. In the event of refrigerant leakage in the cooling heat exchange portion, the control portion controls the blowout volume adjustment portion so that the flow rates of air blown out from the defroster outlet, the face outlet, and the foot outlet, respectively, become zero, and the control portion controls the external air door to be in an open state, the internal air door to be in a closed state, and the internal air heat exchange adjustment damper to be in a state in which air can be transported from the cooling heat exchange portion side to the internal and external air heat exchange portion side.

5. The vehicle air conditioning device according to claim 2, wherein: The vehicle air conditioner includes a heating heat exchanger for heating air flowing in the air conditioning casing. The control unit is provided with information indicating the surface temperature of the vehicle's window glass and information indicating the temperature and humidity of the air near the window glass in the vehicle cabin, and controls the operation of the inside and outside air volume adjustment unit so that the dew point temperature calculated using the temperature and humidity near the window glass is lower than the surface temperature of the window glass.

6. The vehicle air conditioning device according to claim 5, wherein When the dew point temperature is not lower than the surface temperature of the window glass even if the flow rate of the internal air introduced into the internal and external air heat exchange unit becomes zero, the control unit controls the operation of the internal and external air volume adjustment unit so that the ratio of the flow rate of the internal air introduced from the internal air inlet to the flow rate of the external air introduced from the external air inlet is reduced.

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