Air conditioning device

Abstract

The purpose of the present invention is to suppress performance degradation of a heat exchanger with time in an air-conditioning device provided with the heat exchanger. An HVAC system (1) is provided with: a heat exchanger (3) that exchanges heat between exhaust gas discharged to the outside of a vehicle compartment and outside air introduced into the inside of the vehicle compartment; and a housing (5) in which are formed an exhaust passage (5A) that guides exhaust gas to the exhaust gas introduction port (3A) of the heat exchanger (3), an outside air passage (5B) that guides outside air to the outside air introduction port (3B) of the heat exchanger (3), a return air passage (5C) that bypasses the heat exchanger (3) and circulates return air in the vehicle interior, and a discharge port (5D) that discharges the exhaust gas that has passed through the heat exchanger (3) to the outside of the vehicle interior. Furthermore, the HVAC system (1) is provided with: a filter (7) disposed on the upstream side of the exhaust introduction port (3A) and the outside air introduction port (3B) of the heat exchanger (3) so as to straddle at least the exhaust passage (5A) and the outside air passage (5B) among the exhaust passage (5A), the outside air passage (5B), and the return air passage (5C); and a damper (9) that adjusts the amount of external air introduced into the vehicle interior by changing the aperture ratio of the external air passage (5B) and the air return passage (5C) on the upstream side of the filter (7).

Description

Technical Field

[0001] This invention relates to an air conditioning device for regulating the air inside a vehicle. Background Technology

[0002] In automobiles and other vehicles, air conditioning devices such as HVAC (Heating, Ventilation, and Air Conditioning) systems are installed to maintain a comfortable interior environment. As described in Japanese Patent Application Publication No. 2016-155516 (Patent Document 1), the air conditioning device includes a heat exchanger that improves energy efficiency by exchanging heat between outside air introduced into the vehicle interior and inside air exhausted to the outside during ventilation. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2016-155516 Summary of the Invention The problem to be solved by the present invention

[0004] However, in the air conditioning device described in Patent Document 1, since external air containing foreign matter such as dust and internal air are directly introduced into the heat exchanger, the blockage of the heat exchanger will worsen over time, which may lead to a decrease in the performance of the heat exchanger.

[0005] Therefore, the object of the present invention is to suppress the performance degradation of the heat exchanger over time in an air conditioning device equipped with a heat exchanger. Methods for solving problems

[0006] The air conditioning system includes: a heat exchanger for exchanging heat between exhaust gas discharged from the vehicle interior to the vehicle exterior and outside air introduced from the vehicle exterior to the vehicle interior; and a housing having an exhaust passage that directs exhaust gas to an exhaust inlet of the heat exchanger, an outside air passage that directs outside air to an outside air inlet of the heat exchanger, a return air passage that bypasses the heat exchanger and recirculates return air from the vehicle interior, and an exhaust outlet that discharges exhaust gas after passing through the heat exchanger to the vehicle exterior. In addition to the heat exchanger and housing, the air conditioning system also includes: a filter disposed integrally across the exhaust passage, the outside air passage, and the return air passage on the upstream side of the exhaust inlet and the outside air inlet of the heat exchanger; and a damper that, on the upstream side of the filter, changes the opening ratio of the outside air passage and the return air passage to adjust the amount of outside air introduced into the vehicle interior. Invention Effects

[0007] According to the present invention, in an air conditioning device equipped with a heat exchanger, it is possible to suppress the performance degradation of the heat exchanger over time. Attached Figure Description

[0008] Figure 1 This is a schematic diagram illustrating an example of an HVAC (Heating, Ventilation and Air Conditioning) system. Figure 2 This is a three-dimensional schematic diagram illustrating an example of a static heat exchanger. Figure 3 This is an illustration of the operation of the summer external air intake mode. Figure 4 This is a diagram illustrating the action of the summer hybrid mode. Figure 5 This is a diagram illustrating the operation of the summer cycle. Figure 6 This is an illustration of the operation of the external air intake mode in winter. Figure 7 This is a diagram illustrating the action of the mixed mode in winter. Figure 8 This is a diagram illustrating the operation of the winter cycle. Detailed Implementation

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. Figure 1 This section describes an example of an HVAC system 1 to which this embodiment can be applied. It should be noted that the HVAC system 1 described below is merely an example of how this embodiment can be applied and should not be construed as being limited by this configuration. Therefore, those skilled in the art can certainly make any changes and modifications within the technical scope of this embodiment. Furthermore, the HVAC system 1 is given as an example of an air conditioning device.

[0010] HVAC system 1 includes: a heat exchanger 3 for exchanging heat between exhaust gas discharged from the vehicle interior to the vehicle exterior and outside air introduced from the vehicle exterior to the vehicle interior; a housing 5 for housing the heat exchanger 3; and a filter 7 for removing foreign matter such as dust contained in the exhaust gas, outside air, and return air from the vehicle interior.

[0011] Heat exchanger 3 can be used, for example, as a total heat exchanger that recovers the total heat (sensible heat, temperature) and latent heat (humidity) lost due to ventilation. If heat exchanger 3 is used as a total heat exchanger, temperature and humidity are exchanged between exhaust gas discharged from the vehicle interior to the exterior and outside air introduced from the exterior to the interior. Therefore, in winter, the outside air is heated by the exhaust gas, and in summer, the outside air is cooled by the exhaust gas, thereby reducing the air conditioning load. The following description assumes a stationary type heat exchanger 3, but a rotary type heat exchanger 3, as described later, is also possible.

[0012] like Figure 2 As shown, the heat exchanger 3 is constructed, for example, by stacking a partition member 3C formed by coating a fibrous substrate with a polymer adsorbent and a wave-shaped spacer member 3D in one direction. The heat exchanger 3 is configured such that the direction of external airflow and the direction of exhaust flow alternately differ by 90° between each layer. Therefore, the exhaust inlet 3A and the external air inlet 3B of the heat exchanger 3 are formed on adjacent sides, respectively. The polymer adsorbent coated on the partition member 3C is, for example, composed of a sodium polyacrylate crosslinker. Such a polymer adsorbent absorbs moisture rapidly, can release the retained moisture at a relatively low temperature, and can retain moisture for a long time. Therefore, the partition member 3C formed by coating a fibrous substrate with a polymer adsorbent has good heat transfer and moisture permeability.

[0013] The housing 5 has, at designated locations, an exhaust passage 5A that directs exhaust gas to the exhaust inlet 3A of the heat exchanger 3, an external air passage 5B that directs external air to the external air inlet 3B of the heat exchanger 3, a return air passage 5C that bypasses the heat exchanger 3 and recirculates return air from the vehicle interior, and an outlet 5D equipped with a rubber shutter SH that discharges exhaust gas from the heat exchanger 3 to the outside of the vehicle interior. Partitions are formed between the exhaust passage 5A, the external air passage 5B, and the return air passage 5C, and between the heat exchanger 3 and the return air passage 5C, to prevent mixing of the exhaust gas, external air, and return air flowing through each passage. Furthermore, a return air inlet 5E that directs return air from the vehicle interior into the return air passage 5C is formed at a designated location upstream of the return air passage 5C in the housing 5.

[0014] In the housing 5, a damper 9 is disposed (received) near the upstream end of the partition wall separating the external air passage 5B and the return air passage 5C. This damper 9 adjusts the amount of external air introduced into the vehicle interior by interlocking the opening ratios of the external air passage 5B and the return air passage 5C. The damper 9 is operated, for example, by an actuator (not shown) such as a stepper motor, in the external air introduction state (where external air is introduced). Figure 1Between the state shown and the return air circulation state, the opening ratio of the external air passage 5B and the return air passage 5C is changed continuously or in stages.

[0015] In the housing 5, the downstream side of the heat exchanger 3 merges with the downstream side of the return air passage 5C to form a narrow passage 5F. An electric fan 11 is arranged on the downstream side of this narrow passage 5F. The fan 11 supplies air including at least one of the exhaust gas after passing through the heat exchanger 3 and the return air after passing through the return air passage 5C. The fan 11 can be, for example, an electric blower.

[0016] A supply air passage 5G is formed downstream of the fan 11, guiding the supply air delivered by the fan 11 into the vehicle interior. An evaporator 13 is disposed on the supply air passage 5G downstream of the fan 11, forming the refrigerant circuit of the HVAC system 1. Furthermore, a portion of the supply air passage 5G downstream of the evaporator 13 is divided into two parts along the direction of air flow. In one part, for example in the illustrated example, a heater core 15 is disposed below, heating the supply air passing through the evaporator 13 and cooling it to near 0°C. Additionally, an air mixing valve 17 is disposed upstream of the heater core 15, adjusting the flow rate of the supply air through the heater core 15 to regulate the temperature of the supply air introduced into the vehicle interior. Here, the air mixing valve 17 is configured to be operated, for example by an actuator such as a stepper motor (not shown), to continuously or intermittently adjust the flow rate of the supply air through the heater core 15 between approximately 0% and approximately 100%.

[0017] In addition, Figure 1 The component BH, indicated by a double-dotted line on the left, is the bulkhead that separates the front of the vehicle from the passenger compartment (this is also true in other diagrams). Therefore, the area to the left of the bulkhead BH represents the outside of the passenger compartment, and the area to the right of the bulkhead BH represents the inside of the passenger compartment.

[0018] The filter 7 is a component that removes foreign matter such as dust contained in the exhaust gas and outside air introduced into the heat exchanger 3, and is replaceably installed in the HVAC system 1. That is, the filter 7 removes foreign matter along with the operation of the HVAC system 1, and therefore gradually becomes clogged over time. Therefore, the filter 7 can be easily replaced relative to the HVAC system 1. Moreover, the filter 7 is arranged as a whole across the exhaust passage 5A, the outside air passage 5B, and the return air passage 5C of the housing 5, upstream of the exhaust port 3A and the outside air passage 3B of the heat exchanger 3.

[0019] Next, the operation of this HVAC system 1 will be explained. In the summer when the air conditioning is on, if the driver or passengers switch the air conditioning system to outside air intake mode, then... Figure 3 As shown, the damper 9 operates by closing the return air passage 5C, making the opening ratio of the external air passage 5B approximately 100%, while the opening ratio of the return air passage 5C is approximately 0%. In the summer external air intake mode, with the operation of the fan 11, external air passes sequentially through the external air passage 5B, filter 7, and heat exchanger 3, then through the narrow passage 5F located downstream of them and the fan 11, becoming supplied air and being introduced into the supply air passage 5G. Furthermore, in the summer external air intake mode, according to the set temperature of the air conditioning system, the air mixing door 17 adjusts the flow rate of the air supplied through the heater core 15 to bring the temperature inside the vehicle close to the set temperature.

[0020] If outside air is introduced into the vehicle interior, the pressure inside the vehicle increases, and the pressure of the internal air becomes higher than that of the outside air. Utilizing this pressure difference, exhaust gas is introduced into exhaust passage 5A through the exhaust channel (not shown). After being introduced into exhaust passage 5A, the exhaust gas passes through filter 7 and heat exchanger 3, then pushes open the baffle SH formed in the exhaust outlet 5D of housing 5, and is discharged outside the vehicle. Here, as the exhaust gas, which is colder than the outside air, passes through heat exchanger 3, the outside air is cooled by the heat exchanger 3, thus reducing the air conditioning load.

[0021] In this summer external air intake mode, after foreign matter is removed by the filter 7, external air is introduced into the heat exchanger 3 located downstream of the filter 7. Therefore, the foreign matter introduced into the heat exchanger 3 is eliminated or greatly reduced, which can suppress the aggravation of blockage in the heat exchanger 3, thereby suppressing the performance degradation of the heat exchanger over time.

[0022] In the summer when air conditioning is used, if the driver or passengers switch the air conditioning system to hybrid mode, then... Figure 4 As shown, the damper 9 operates in an intermediate position between the external air intake state and the return air recirculation state, with the opening ratios of the external air passage 5B and the return air passage 5C each approximately 50%. In the summer mixed mode, with the operation of the fan 11, external air passes sequentially through the external air passage 5B, filter 7, and heat exchanger 3, while return air from the vehicle interior passes sequentially through the return air passage 5C and filter 7. Then, the external air and return air pass through the narrow passage 5F located downstream of it and the fan 11, becoming supply air, and are introduced into the supply air passage 5G. In addition, in the summer mixed mode, similar to the summer external air intake mode, the air mixing door 17 adjusts the flow rate of the supply air through the heater core 15 according to the set temperature of the air conditioning system, so that the temperature inside the vehicle interior is close to the set temperature.

[0023] If outside air is introduced into the vehicle interior, the pressure inside the vehicle increases, and the pressure of the internal air becomes higher than that of the outside air. Utilizing this pressure difference, exhaust gas is introduced into exhaust passage 5A through the exhaust channel (not shown). After passing through exhaust passage 5A, the exhaust gas passes through filter 7 and heat exchanger 3, then pushes open the baffle SH formed in the exhaust port 5D of housing 5, and is discharged outside the vehicle. Here, the exhaust gas, which is colder than the outside air, cools the outside air as it passes through heat exchanger 3, thus reducing the air conditioning load.

[0024] In this summer mixed mode, outside air is filtered through filter 7 to remove impurities before being introduced into heat exchanger 3, which is located downstream of filter 7. Therefore, the absence or significant reduction of impurities introduced into heat exchanger 3 inhibits further blockage and thus prevents performance degradation over time. Furthermore, return air introduced into return air passage 5C is filtered through filter 7 to remove impurities before returning to the vehicle interior via narrow passage 5F, fan 11, and supply air passage 5G. Therefore, even if dust or other impurities mix with the interior air, the cleanliness of the vehicle interior can be maintained.

[0025] In the summer when air conditioning is used, if the driver or passengers switch the air conditioning system to recirculation mode, then... Figure 5 As shown, the damper 9 operates by closing the external air passage 5B, making the opening ratio of the external air passage 5B approximately 0%, while the opening ratio of the return air passage 5C is approximately 100%. In summer circulation mode, with the operation of the fan 11, the return air passes through the filter 7, then through the narrow passage 5F located downstream of the filter 7 and the fan 11, becoming supply air and being introduced into the supply air passage 5G. Furthermore, in summer circulation mode, according to the set temperature of the air conditioning system, the air mixing door 17 adjusts the flow rate of the supply air through the heater core 15 to bring the temperature inside the vehicle close to the set temperature.

[0026] In the summer circulation mode, heat exchange between the exhaust and the outside air does not occur through the heat exchanger 3, but the return air from the cabin is returned to the cabin after foreign objects are removed by the filter 7, thus maintaining the cleanliness of the cabin.

[0027] In winter, when the vehicle is using heating, if the driver or passengers switch the air conditioning system to outside air intake mode, then... Figure 6As shown, the damper 9 operates by closing the return air passage 5C, making the opening ratio of the external air passage 5B approximately 100%, while the opening ratio of the return air passage 5C is approximately 0%. In the winter external air intake mode, with the operation of the fan 11, external air passes sequentially through the external air passage 5B, filter 7, and heat exchanger 3, then passes through the narrow passage 5F located downstream of them and the fan 11, becoming supplied air and being introduced into the supply air passage 5G. In addition, in the summer external air intake mode, according to the set temperature of the air conditioning system, the air mixing door 17 adjusts the flow rate of the air supplied through the heater core 15 to bring the temperature inside the vehicle close to the set temperature.

[0028] If outside air is introduced into the vehicle interior, the pressure inside the interior rises, and the pressure of the internal air becomes higher than that of the outside air. Utilizing this pressure difference, exhaust gas is introduced into exhaust passage 5A through the exhaust channel (not shown). After passing through filter 7 and heat exchanger 3, the exhaust gas introduced into exhaust passage 5A pushes open the baffle SH formed in the exhaust outlet 5D of housing 5 and is discharged outside the vehicle. Here, the exhaust gas, which is hotter than the outside air, heats the outside air as it passes through heat exchanger 3, thus reducing the air conditioning load.

[0029] In this winter external air intake mode, after foreign matter is removed by the filter 7, external air is introduced into the heat exchanger 3 located downstream of the filter 7. Therefore, the foreign matter introduced into the heat exchanger 3 is eliminated or greatly reduced, which can suppress the aggravation of blockage in the heat exchanger 3, thereby suppressing the performance degradation of the heat exchanger over time.

[0030] In winter, when the vehicle is using heating, if the driver or passengers switch the air conditioning system to mixed mode, then... Figure 7 As shown, the damper 9 operates in an intermediate position between the external air intake state and the return air recirculation state, with the opening ratios of the external air passage 5B and the return air passage 5C each approximately 50%. In the winter mixed mode, with the operation of the fan 11, external air passes sequentially through the external air passage 5B, filter 7, and heat exchanger 3, while return air from the vehicle interior passes sequentially through the return air passage 5C and filter 7. Then, the external air and return air pass through the narrow passage 5F located downstream and the fan 11, becoming supply air, and are introduced into the supply air passage 5G. In addition, in the winter mixed mode, similar to the winter external air intake mode, the air mixing door 17 adjusts the flow rate of the supply air through the heater core 15 according to the set temperature of the air conditioning system, so that the temperature inside the vehicle interior is close to the set temperature.

[0031] When outside air is introduced into the vehicle interior, the pressure inside the interior rises, making the pressure of the interior air higher than that of the outside air. Utilizing this pressure difference, exhaust gas is introduced into exhaust passage 5A through the exhaust channel (not shown). After passing through filter 7 and heat exchanger 3, the exhaust gas pushed open the baffle SH formed in the exhaust outlet 5D of the housing 5 and was discharged outside the vehicle. Here, the exhaust gas, which is hotter than the outside air, heats the outside air as it passes through heat exchanger 3, thus reducing the air conditioning load.

[0032] In this winter mixed mode, outside air, after being filtered by filter 7 to remove impurities, is introduced into heat exchanger 3 located downstream of filter 7. Therefore, the elimination or significant reduction of impurities introduced into heat exchanger 3 suppresses further blockage and thus prevents performance degradation over time. Furthermore, the return air introduced into return air passage 5C, after being filtered by filter 7 to remove impurities, returns to the vehicle interior via narrow passage 5F, fan 11, and supply air passage 5G. Therefore, even if dust or other impurities mix with the interior air, the cleanliness of the vehicle interior can be maintained.

[0033] In winter, when the vehicle is using heating, if the driver or passengers switch the air conditioning system to recirculation mode, then... Figure 8 As shown, the damper 9 operates by closing the external air passage 5B, making the opening ratio of the external air passage 5B approximately 0%, while the opening ratio of the return air passage 5C is approximately 100%. In winter circulation mode, with the operation of the fan 11, the return air passes through the filter 7, then through the narrow passage 5F located downstream of the filter 7 and the fan 11, becoming supply air and being introduced into the supply air passage 5G. Furthermore, in winter circulation mode, according to the set temperature of the air conditioning system, the air mixing door 17 adjusts the flow rate of the air supplied through the heater core 15 to bring the temperature inside the vehicle close to the set temperature.

[0034] In winter recirculation mode, heat exchange between exhaust and outside air does not occur through heat exchanger 3, but the return air from the cabin is returned to the cabin after foreign objects are removed by filter 7, thus maintaining the cleanliness of the cabin.

[0035] As explained above, regardless of whether it is the summer or winter external air intake mode, mixing mode, or recirculation mode, the external air or exhaust air introduced into the heat exchanger 3 is cleaned of foreign matter by the filter 7 located upstream of the heat exchanger 3. Therefore, in the HVAC system 1, the clogging of the heat exchanger 3 over time can be suppressed, thereby extending maintenance intervals, for example. Furthermore, the filter 7 of the HVAC system 1 is typically replaced at a prescribed interval, so even if foreign matter accumulates in the filter 7, it can be considered within acceptable limits.

[0036] Here, the control system of HVAC system 1 will be described. The control system of the HVAC system 1 according to the first embodiment includes: a concentration sensor for detecting the CO2 concentration (carbon dioxide concentration) of the return air flowing in the return air passage 5C of the housing 5; and a control unit for controlling the position of the damper 9 based on the output signal of the concentration sensor. Here, the control unit may be, for example, any one of the following: a microcomputer with built-in computing device, storage device, input / output device and communication device, or LSI (Large Scale Integration), IC (Integrated Circuit), or control circuit composed of resistors and capacitors (hereinafter the same).

[0037] An example is described where the control unit repeatedly executes damper control processing when the air conditioning system is switched to mixed or recirculating mode upon starting HVAC system 1. Furthermore, in the case where the control unit is a microcomputer, the application program for executing the damper control processing is pre-stored in a storage device.

[0038] In the first step, the control unit reads the CO2 concentration from the concentration sensor.

[0039] In the second step, the control unit determines whether the CO2 concentration read from the concentration sensor is above a specified concentration. Here, the specified concentration is the threshold at which the passenger's alertness is considered to have decreased; for example, it can be set to 3000 ppm. Then, when the control unit determines that the CO2 concentration is above the specified concentration (yes), the process proceeds to the third step. On the other hand, when the control unit determines that the CO2 concentration is below the specified concentration (no), the damper control process of this control cycle ends.

[0040] In the third step, the control unit outputs a control signal to an actuator (not shown) such as a stepper motor that changes the position of the damper 9, thereby increasing the opening ratio of the external air passage 5B of the housing 5 and decreasing the opening ratio of the return air passage 5C, thus increasing the amount of external air introduced into the vehicle interior. Then, after controlling the damper 9, the control unit ends the damper control processing of this control cycle.

[0041] By installing such damper control processing in the control unit, when the CO2 concentration of the return air flowing in the return air passage 5C of the housing 5 (i.e., the interior air of the vehicle compartment) reaches a predetermined concentration or higher, the amount of outside air introduced into the vehicle compartment is increased. Therefore, the CO2 concentration inside the vehicle compartment is maintained below the predetermined concentration, thereby preventing a decrease in the alertness of the driver and passengers. Furthermore, when the mode is switched to the outside air introduction mode, since fresh outside air is continuously or intermittently introduced into the vehicle compartment, there is no need to control the damper 9.

[0042] The control system of the HVAC system 1 in the second embodiment includes: a temperature and humidity sensor for detecting the temperature and humidity of the return air flowing in the return air passage 5C of the housing 5; an external air temperature sensor for detecting the temperature of the external air; and a control unit for controlling the position of the damper 9 based on the output signals of the temperature and humidity sensor and the external air temperature sensor.

[0043] An example of damper control processing repeatedly executed by the control unit when the air conditioning system is switched to mixed or recirculating mode upon startup of HVAC system 1 will be described. Furthermore, in the case where the control unit is a microcomputer, the application program for performing the damper control processing is pre-stored in a storage device.

[0044] In the first step, the control unit reads the temperature and humidity from the temperature and humidity sensor. In the second step, the control unit reads the outside air temperature from the outside air temperature sensor.

[0045] In the third step, the control unit calculates the dew point temperature based on the temperature and humidity readings from the temperature and humidity sensors. Specifically, the control unit uses a prescribed formula, a saturated water vapor pressure gauge, and an air curve to determine the temperature of saturated water vapor, which is set as the water vapor pressure determined by the temperature and relative humidity of the return air flowing in the return air passage 5C of the housing 5 (i.e., the interior air inside the vehicle compartment). The dew point temperature is then calculated from this.

[0046] In the fourth step, the control unit determines whether the dew point temperature is above the outside air temperature. Then, if the control unit determines that the dew point temperature is above the outside air temperature (yes), the process proceeds to the fifth step. On the other hand, if the control unit determines that the dew point temperature is below the outside air temperature (no), the damper control process of this control cycle ends.

[0047] In the fifth step, the control unit outputs a control signal to an actuator (not shown) such as a stepper motor that changes the position of the damper 9, thereby increasing the opening ratio of the external air passage 5B of the housing 5 and decreasing the opening ratio of the return air passage 5C, thus increasing the amount of external air introduced into the vehicle interior. Then, after controlling the damper 9, the control unit ends the damper control processing of this control cycle.

[0048] By installing such damper control processing in the control unit, when the dew point temperature of the return air flowing in the return air passage 5C of the housing 5 (i.e., the interior air inside the vehicle cabin) becomes higher than the outside air temperature, the amount of outside air introduced into the vehicle cabin is increased. Therefore, the dew point temperature inside the vehicle cabin can be maintained below the outside air temperature, for example, preventing condensation and blurring of the windshield. Furthermore, when the mode is switched to outside air introduction mode, fresh outside air is continuously or intermittently introduced into the vehicle cabin, making condensation less likely on the windshield, thus eliminating the need to control the damper 9.

[0049] Furthermore, it is readily understood that, for those skilled in the art, new implementation methods can be generated by omitting a portion of the technical ideas of the various embodiments described above, or by appropriately combining a portion of them with each other, or by replacing a portion of them with well-known technologies.

[0050] As an example, HVAC system 1 can also be configured as an internal or external air inlet that can be detachably installed in the HVAC unit. Furthermore, filter 7 is not limited to a configuration that spans the entire exhaust passage 5A, external air passage 5B, and return air passage 5C; it can also be configured to span at least exhaust passage 5A and external air passage 5B. Explanation of reference numerals in the attached figures:

[0051] 1: HVAC system (air conditioning unit); 3: heat exchanger; 3A: exhaust inlet; 3B: external air inlet; 5: housing; 5A: exhaust passage; 5B: external air passage; 5C: return air passage; 5D: exhaust outlet; 7: filter; 9: damper.

Claims

1. An air conditioning device, wherein, The air conditioning device includes: A heat exchanger that exchanges heat between exhaust gas discharged from the vehicle interior to the vehicle exterior and outside air introduced from the vehicle exterior to the vehicle interior. The housing has an exhaust passage that directs the exhaust gas to the exhaust inlet of the heat exchanger, an external air passage that directs the external air to the external air inlet of the heat exchanger, a return air passage that bypasses the heat exchanger and circulates the return air from the vehicle interior, and an exhaust outlet that discharges the exhaust gas after passing through the heat exchanger to the outside of the vehicle interior. A filter is configured on the upstream side of the exhaust inlet and the external air inlet of the heat exchanger in such a way that it spans at least the exhaust passage and the external air passage of the exhaust passage, the external air passage and the return air passage; as well as The damper, located upstream of the filter, changes the opening ratio of the external air passage and the return air passage, thereby adjusting the amount of external air introduced into the vehicle interior.

2. The air conditioning device according to claim 1, wherein, The heat exchanger is a total heat exchanger.

3. The air conditioning device according to claim 1, wherein, The air conditioning device also includes: A concentration sensor detects the carbon dioxide concentration in the return gas flowing in the return gas channel; and The control unit is configured to control the damper so that the carbon dioxide concentration detected by the concentration sensor is less than a predetermined concentration.

4. The air conditioning device according to claim 1, wherein, The air conditioning device also includes: A temperature and humidity sensor detects the temperature and humidity of the return air flowing in the return air channel; External air temperature sensor to detect the external air temperature; as well as The control unit is configured to calculate the dew point temperature based on the temperature and humidity detected by the temperature and humidity sensor, and control the damper so that the dew point temperature is lower than the outside air temperature detected by the outside air temperature sensor.

5. The air conditioning device according to claim 1, wherein, The air conditioning unit is configured to be detachably installed at the internal and external air inlets of the HVAC unit.

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