Filter regeneration control method and air conditioning system

Abstract

The present invention provides a filter regeneration control method and air conditioning system that can effectively remove substances adsorbed on the filter during filter regeneration while reducing the energy required for filter heating. [Solution] In the filter regeneration control method, the filter 21 is heated to a first temperature that evaporates the gas components originating from the interior of the vehicle interior that have been adsorbed onto the filter 21 if less than a predetermined time has passed since the start of vehicle use. If more than a predetermined time has passed, the filter 21 is heated to a second temperature that is higher than the first temperature, and evaporates the gas components originating from people, such as occupants in the vehicle interior 22 and items (food and pets) that occupants have brought into the vehicle, that have been adsorbed onto the filter 21.

Description

Technical Field

[0001] The present invention relates to a filter regeneration control method and an air conditioning system.

Background Art

[0002] Conventionally, as an air conditioning system for improving the air conditioning environment in a vehicle interior, there is an air conditioning system that performs filter regeneration control for removing substances adsorbed on a filter for air purification.

[0003] For example, the air conditioning system described in Patent Document 1 includes an outside air pollution degree acquisition unit that acquires data indicating the outside air pollution degree, which is the pollution degree of outside air that is the air outside the vehicle, a filter pollution degree acquisition unit that acquires data indicating the filter pollution degree, which is the pollution degree of a filter for removing target substances contained in the outside air, an outside air purification control for purifying the outside air using the filter, and a control unit that selectively performs filter regeneration control for removing the filter pollution.

[0004] This control unit is configured to determine whether to execute filter regeneration control based on the filter pollution degree and the pollution degree of the outside air.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above air conditioning system, when the pollution degree of the filter becomes a certain level or more due to the adsorption of target substances contained in the outside air taken in from outside the vehicle onto the filter, filter regeneration control is executed to improve the collection performance of the filter.

[0007] Here, when an air conditioning system performs cooling or heating while circulating internal air, the substances adsorbed on the filter include components of interior-derived gases (e.g., toluene) originating from the interior materials of the vehicle interior, and components of human-derived gases (e.g., 3-mercapto-3-methyl-1-butanol) emitted from the occupants and items they bring into the vehicle (food, pets, etc.). Furthermore, the boiling points of human-derived gases tend to be higher than those of interior-derived gases.

[0008] In this case, when controlling the regeneration of the filter, if the heating temperature of the filter is set low, specifically, if the filter is heated to a temperature above the boiling point of the components of the gas originating from the interior but below the boiling point of the components of the gas originating from humans, the components of the gas originating from the interior can be evaporated and removed, but the components of the gas originating from humans cannot be removed.

[0009] On the other hand, if the filter is always heated to a high temperature at the boiling point of the human-derived gas components during filter regeneration, both the interior-derived gas components and the human-derived gas components can be removed. However, in the initial stages of vehicle use, the concentration of interior-derived gases is higher than the concentration of human-derived gases, resulting in excessively high energy requirements for filter heating. This leads to increased energy consumption and thermal degradation of the filter.

[0010] This invention has been made in view of the above circumstances, and aims to provide a filter regeneration control method and an air conditioning system that can effectively remove substances adsorbed on the filter during filter regeneration and reduce the energy required for filter heating. [Means for solving the problem]

[0011] To solve the aforementioned problems, the present invention provides a filter regeneration control method for an air conditioning system equipped with a filter that purifies the air inside a vehicle's cabin, in which a substance adsorbed on the filter is removed by heating the filter to regenerate the filter, characterized in that, for less than a predetermined time from the start of use of the vehicle, the filter is heated at a first temperature that evaporates the gas components originating from the interior of the cabin that are adsorbed on the filter, and for the predetermined time or longer, the filter is heated at a second temperature higher than the first temperature that evaporates the gas components originating from the occupants in the cabin and items (food and pets) brought into the vehicle that are adsorbed on the filter.

[0012] In the initial period after a vehicle is put into use, the concentration of gases originating from the interior materials is higher than the concentration of gases originating from people in the vehicle's interior. Therefore, the filter will adsorb more of the gases originating from the interior. The boiling point of these gases originating from the interior is lower than the boiling point of the gases originating from people, such as those emitted from the bodies of occupants and items they bring into the vehicle (food, pets, etc.).

[0013] Given this technological background, the inventors have devised the following filter regeneration control method, which effectively removes substances adsorbed on the filter while suppressing the energy required for filter heating, by changing the filter heating temperature before and after a predetermined period of time has elapsed.

[0014] In other words, if less than a predetermined time has passed since the start of vehicle use, the filter can be heated to a first temperature during filter regeneration, thereby evaporating and selectively removing gas components originating from the interior. If more than a predetermined time has passed, the filter can be heated to a second temperature higher than the first temperature, thereby removing gas components originating from humans that have higher boiling points.

[0015] Furthermore, until a predetermined time has elapsed, during filter regeneration, the filter is heated at a first temperature lower than the second temperature to selectively remove only the components of the gas originating from the interior, thus reducing the energy required for filter heating. As a result, energy consumption during filter regeneration can be suppressed, as can filter deterioration due to heating.

[0016] As a result, substances adsorbed on the filter can be effectively removed during filter regeneration, and the energy required for filter heating can be reduced.

[0017] In the filter control method described above, it is preferable that the predetermined time is a time determined using the change over time in the decrease in the concentration of volatile organic compounds originating from the interior of the vehicle as a variable.

[0018] With these features, it becomes possible to determine a predetermined time until the rate of decrease of volatile organic compounds (VOCs) originating from the interior slows down to a certain level. Therefore, at the optimal time when the concentration of gases originating from the interior has sufficiently decreased, it is possible to switch to removing human-derived gas components by filter heating at a second temperature, which is higher than the first temperature.

[0019] In the filter control method described above, the predetermined time may be a time determined from the vehicle's mileage.

[0020] With these features, by determining a predetermined time from the vehicle's mileage, it is possible to switch to removing human-derived gas components by filter heating at a second temperature, which is higher than the first temperature, at an optimal time according to the actual usage conditions of the vehicle.

[0021] In the filter control method described above, the first temperature is preferably 110°C or higher and less than 190°C.

[0022] Since the boiling point of toluene, which accounts for a large portion of the components of the gas derived from the interior, is 110°C or higher, by heating the filter at a first temperature of 110°C or higher and lower than 190°C, it is possible to effectively evaporate the toluene adsorbed on the filter and remove it from the filter.

[0023] In the above filter control method, the second temperature is preferably 190°C or higher.

[0024] Since the boiling point of 3-mercapto-3-methyl-1-butanol, which has the highest boiling point among the components of the gas derived from one source, is 190°C, by heating the filter at 190°C or higher, it is possible to effectively evaporate the components of the gas derived from one source adsorbed on the filter and remove them from the filter.

[0025] The present invention relates to an air conditioning system for adjusting the air inside a vehicle cabin, comprising: a blower for introducing air into the cabin; a heater for heating the air sent from the blower; a filter for purifying the air inside the cabin; a flow path switching damper for switching between a first flow path that circulates air in the order of the blower, the filter, the heater, the cabin, and the blower, and a second flow path that circulates air in the order of the blower, the heater, the filter, and the outside of the vehicle; a temperature sensor for detecting the temperature of the filter; a control unit for controlling the heater and the flow path switching damper; and a timer for measuring the time elapsed since the start of use of the vehicle. During filter regeneration, the air sent from the blower through the second flow path is purified. An air conditioning system capable of regenerating a filter by heating it with a heater and then sending the heat to the filter to heat the filter, thereby evaporating and removing substances adsorbed on the filter, wherein the control unit controls the heater to heat the filter at a first temperature during filter regeneration, which is high enough to evaporate gas components originating from the interior of the vehicle cabin that are adsorbed on the filter, when the time is less than a predetermined time from the start of use of the vehicle, and further controls the heater to heat the filter at a second temperature higher than the first temperature during filter regeneration, which is high enough to evaporate gas components originating from people in the vehicle cabin that are adsorbed on the filter, when the time is greater than or equal to the predetermined time.

[0026] In the above air conditioning system, during filter regeneration, a flow path switching damper switches to a second flow path in which air flows in the order of blower, heater, filter, and outside the vehicle. Then, through the second flow path, the air sent from the blower and heated by the heater is sent to the filter, where substances adsorbed on the filter are evaporated and removed.

[0027] Within less than a predetermined time from the start of vehicle use, during filter regeneration, the control unit controls the heater to heat the filter at a first temperature that evaporates the components of the gas derived from the vehicle interior adsorbed on the filter. Thereby, the filter can be heated at the first temperature, and it is possible to evaporate the components of the gas derived from the interior and selectively remove them from the filter.

[0028] On the other hand, when it is more than the predetermined time, during filter regeneration, the control unit controls the heater to heat the filter at a temperature higher than the first temperature, that is, at a second temperature that evaporates the components of the gas derived from a person in the vehicle interior adsorbed on the filter. Thereby, it is possible to remove the components of the gas derived from a person with a higher boiling point.

[0029] Also, until the predetermined time elapses, during filter regeneration, since the filter is heated at a first temperature lower than the second temperature to selectively remove only the component substances of the gas derived from the interior, it is possible to suppress the energy for filter heating. Therefore, it is possible to suppress the energy consumption during filter regeneration and also suppress the deterioration of the filter due to heating.

[0030] As a result, it is possible to effectively remove the substances adsorbed on the filter during filter regeneration and suppress the energy for filter heating.

[0031] In the above air conditioning system, it further includes a passenger number sensor that detects the number of passengers in the vehicle. When, within less than the predetermined time, the total of the product of the number of passengers and the riding time reaches a predetermined number or more from the start of vehicle use, it is preferable that the control unit controls the heater to heat the filter at the second temperature during filter regeneration.

[0032] If the time spent with a large number of passengers accumulates from the start of vehicle use, the concentration of human-derived gases in the vehicle may exceed the concentration of interior-derived gases, even if it is less than a predetermined time. Therefore, as described above, even if it is less than a predetermined time, when the sum of the product of the number of passengers and the time spent in the vehicle reaches a predetermined number or more, the control unit controls the heater to heat the filter to a second temperature during filter regeneration, thereby effectively removing human-derived gas components from the filter in accordance with the vehicle usage conditions. [Effects of the Invention]

[0033] As described above, the filter regeneration control method and air conditioning system of the present invention can effectively remove substances adsorbed on the filter during filter regeneration and reduce the energy required for filter heating. [Brief explanation of the drawing]

[0034] [Figure 1] This block diagram shows the configuration of the control system of an air conditioning system according to an embodiment of the present invention. [Figure 2] Figure 1 is a schematic plan view showing the overall configuration of the air conditioning system, specifically the internal air circulation mode. [Figure 3] Figure 2 shows the ventilation mode in which outside air is introduced into the air conditioning system. [Figure 4] Figure 2 shows the regeneration control mode in the air conditioning system. [Figure 5] This graph shows the relationship between the number of days Td since the vehicle was manufactured and P1, which is the ratio of the initial concentration of toluene, a representative component of gases derived from the interior of the vehicle, to the initial value. [Figure 6] This graph shows the relationship between the vehicle's mileage D and the proportion of human-derived gases P2. [Figure 7] This graph shows the relationship between the number of years since the vehicle was manufactured (Ty) and the total volatile organic compound (TVOC) concentration (C) inside the vehicle. [Figure 8] This flowchart shows an example of a file playback control method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0035] Hereinafter, a filter regeneration control method and air conditioning system according to embodiments of the present invention will be described in detail with reference to the drawings.

[0036] An air conditioning system 1 according to an embodiment of the present invention will be described with reference to Figures 1 and 2.

[0037] Here, Figure 1 is a block diagram showing the configuration of the control system of the air conditioning system 1 according to an embodiment of the present invention. Figure 2 is a schematic plan view showing the overall configuration of the air conditioning system 1 of Figure 1, and is a diagram showing the internal air circulation mode.

[0038] As shown in Figures 1 and 2, the air conditioning system 1 is a system for improving the air quality (heating, cooling, dehumidification, and ventilation) to make the air inside the passenger compartment 22 of a vehicle such as an automobile comfortable. Figure 2 shows the internal air circulation mode of the air conditioning system, which circulates air between the blower 2 and the passenger compartment 22.

[0039] As shown in Figure 1, the air conditioning system 1 includes, as its main control system, a blower 2 for introducing air into the passenger compartment 22, a heater 3 (heating device) for heating the air sent from the blower 2, an evaporator (not shown), a filter 21 for purifying the air in the passenger compartment 22 in internal circulation mode, a pair of regeneration control switching dampers 4 and 5, an outside air intake damper 6, a passenger compartment exhaust damper 7, a control device 8, a pair of gas sensors 9 and 10 for detecting the gas concentration on both sides of the filter 21, a passenger count detection sensor 11 for detecting the number of passengers in the passenger compartment 22, a measurement start unit 12, a timer 13, and a filter temperature sensor 14.

[0040] Blower 2 is a conventional blower (for example, a blower equipped with a sirocco fan, propeller fan, turbo fan, etc.) that draws in air from one side (right side in Figure 2) and blows it out from the other side (left side in Figure 2).

[0041] The filter 21 is a gas filter that removes gas components originating from the interior of the passenger compartment 22 and gas components originating from people such as occupants, and is a filter containing, for example, activated carbon or zeolite.

[0042] Here, interior-derived gases are gases emitted from the interior materials of the passenger compartment 22 from the start of vehicle use, and include, for example, volatile organic compounds (VOCs) such as formaldehyde, acetaldehyde, acrolein, benzene, toluene, xylene, ethylbenzene, and styrene. Toluene accounts for a large proportion of the components of the interior-derived gases mentioned above. The boiling point of toluene is 110°C, and the boiling points of the other components of the interior-derived gases are also below 190°C.

[0043] Furthermore, human-derived gases are gases emitted from the bodies of occupants in the passenger compartment 22 or from items (food or pets) brought into the vehicle by the occupants. These mainly consist of VOCs, such as gases emitted from humans like acetic acid, isobutyric acid, isovaleric acid, pelargonic acid, diacetyl, 2-nonenal, ammonia, and CO2; gases emitted from pet cats or their excrement, such as ammonia and 3-mercapto-3-methyl-1-butanol; and gases emitted from pet dogs or their excrement, such as ammonia and methyl mercaptan. Of the components of the human-derived gases mentioned above, 3-mercapto-3-methyl-1-butanol has the highest boiling point at 190°C.

[0044] The control device 8 shown in Figure 1 controls the adjustment of the heating intensity of the heater 3 and the switching of a pair of regeneration control switching dampers 4 and 5 (flow path switching dampers), an outside air intake damper 6, and a cabin exhaust damper 7. The control device 8 also has an adsorption amount calculation unit 15, which will be described later.

[0045] Furthermore, the filter temperature sensor 14 shown in Figures 1-2 detects the temperature of the filter 21 and sends the detected temperature data to the control device 8, at least when executing the regeneration control mode described later for regenerating the filter 21.

[0046] The pair of gas sensors 9 and 10 shown in Figures 1 and 2 detect the gas concentration on both the front and back sides of the filter 21 and send the data to the control device 8. As a result, in the internal air circulation mode shown in Figure 2 and the regeneration control mode shown in Figure 4, the adsorption amount calculation unit 15 of the control device 8 calculates the amount of gas components adsorbed by the filter 21 from the difference in gas concentrations detected by the pair of gas sensors 9 and 10.

[0047] The passenger count detection sensor 11 is a sensor that detects the number of occupants in the vehicle compartment 22. The passenger count detection sensor 11 may be, for example, a pressure sensor or photo sensor attached to each seat in the vehicle compartment, or a module having an image receiving unit that acquires images of the vehicle compartment and a recognition unit that recognizes occupants from the images. The passenger count detection sensor 11 is capable of detecting the number of occupants in the vehicle compartment 22 from 0 to the maximum number of occupants.

[0048] The measurement start unit 12 shown in Figure 1 sends a trigger signal to the control device 8 to start measuring for a predetermined time from the time of vehicle purchase. Upon receiving the trigger signal, the control device 8 activates the timer 13 and controls it to measure for the predetermined time. For example, the measurement start unit 12 sends a measurement start signal to the control device 8 when the vehicle's mileage reaches 20 km, assuming that this is the time of vehicle purchase.

[0049] Timer 13 measures the time elapsed since the vehicle began to be used, after receiving a measurement start signal from control device 8.

[0050] As shown in Figure 2, the air conditioning system 1 of this embodiment includes a main flow path 31 that connects the blower 2, filter 21, heater 3, and passenger compartment 22 in that order, as a flow path for achieving air conditioning of the passenger compartment 22 and regeneration of the filter 21; a return flow path 32 that returns the air exhausted from the passenger compartment 22 to the upstream side of the blower 2; an outside air intake flow path 33 that guides outside air to the upstream side of the blower 2; a passenger compartment side discharge flow path 34 that discharges the air in the passenger compartment 33 to the outside of the vehicle; a filter regeneration flow path 35 (i.e., a bypass flow path 35) that guides the air from the blower 2 to the filter 21 from the side closer to the passenger compartment 22 for filter regeneration; and a filter side discharge flow path 36 that discharges substances detached from the filter 21 during filter regeneration to the outside of the vehicle.

[0051] The main flow path 31 is a passage that connects the outlet side of the blower 2 (the left side of the blower 2 in Figure 2) and the inlet side of the passenger compartment 22 (the left side of the passenger compartment 22 in Figure 2). Along the main flow path 31, the filter 21 and the heater 3 are arranged in order from the side closest to the blower 2. Although not shown in Figures 2-4, an evaporator that performs cooling, heating, and dehumidification is also located in the main flow path 31.

[0052] The return passage 32 is a passage that connects the exhaust side of the passenger compartment 22 (the left side of the passenger compartment 22 in Figure 2) and the intake side of the blower 2 (the right side of the blower 2 in Figure 2).

[0053] The outside air intake passage 33 is a passage that connects the outside of the vehicle to the intake side of the blower 2 (the right side of the blower 2 in Figure 2), separate from the return passage 32.

[0054] The passenger compartment-side discharge passage 34 is a passage branched from the return passage 32, and is a passage that connects the exhaust side of the passenger compartment 22 (the left side of the passenger compartment 22 in Figure 2) to the outside of the vehicle.

[0055] The filter regeneration channel 35 is a bypass channel that deviates from the main channel 31 and has an upstream end 35a and a downstream end 35b. The upstream end 35a is connected to the outlet side of the blower 2 (the left side of the blower 2 in Figure 2), and the downstream end 35b is connected to the section of the main channel 31 between the heater 3 and the vehicle compartment 22.

[0056] The filter-side discharge passage 36 is connected to the section of the main passage 31 between the blower 2 and the filter 22.

[0057] The outside air intake damper 6 is located near or upstream of the intake side of the blower 2 (the right side of the blower 2 in Figure 2) (i.e., upstream of the airflow generated by the blower 2). The outside air intake damper 6 alternately switches between an internal air circulation position, in which the return passage 32 is open and the outside air introduction passage 33 is closed, and an outside air introduction position, in which the return passage 32 is closed and the outside air introduction passage 33 is open.

[0058] The cabin exhaust damper 7 is positioned where the cabin-side exhaust passage 34 branches off from the return passage 32. The cabin exhaust damper 7 alternately switches between an internal air circulation posture, which closes the cabin-side exhaust passage 34 and opens the section of the return passage 3 extending from the aforementioned branching point to the blower 2, and a ventilation posture, which opens the cabin-side exhaust passage 34 and closes the section of the return passage 32 extending from the aforementioned branching point to the blower 2.

[0059] The pair of regeneration control switching dampers 4 and 5 are specifically composed of a first damper 4 located in the main flow path 31 near the blower 2, and a second damper 5 located in the main flow path 31 near the passenger compartment 22.

[0060] The first damper 4 is positioned in the main flow path 31 where the filter-side discharge flow path 36 is connected. The first damper 4 alternately changes between a normal position in which the filter-side discharge flow path 36 is closed and the main flow path 31 is open, and a regeneration position in which the filter-side discharge flow path 36 is open and the portion of the main flow path 31 closest to the blower 2 is closed.

[0061] The second damper 5 is positioned in the main flow path 31 where the filter regeneration flow path 35 is connected. The second damper 5 alternately changes between a normal position in which the filter regeneration flow path 35 is closed and the main flow path 31 is open, and a regeneration position in which the filter regeneration flow path 35 is open and the portion of the main flow path 31 closest to the passenger compartment 22 is closed.

[0062] Therefore, by selectively changing between the normal position and the regeneration position, the pair of regeneration control switching dampers 4 and 5 can switch between a first flow path I of the internal air circulation mode, which circulates air in the order of blower 2, filter 21, heater 3, passenger compartment 22, and blower 2 as shown in Figure 2, and a second flow path II of the regeneration control mode, which circulates air in the order of blower 2, heater 3, filter 21, and outside the vehicle as shown in Figure 4.

[0063] Next, the internal circulation mode of the air conditioning system in Figure 2 will be described in more detail. In the internal circulation mode, in order to form the first flow path I of the internal circulation mode described above, in which air circulates between the blower 2 and the passenger compartment 22 by the airflow generated by the blower 2, a pair of regeneration control switching dampers 4 and 5 return to their normal positions, so that the first damper 4 closes the filter-side discharge flow path 36 and the second damper 5 closes the filter regeneration flow path 5. At the same time, the outside air intake damper 6 and the passenger compartment exhaust damper 7 return to the internal circulation position, so that the outside air intake damper 6 closes the outside air introduction flow path 33 and the passenger compartment exhaust damper 7 closes the passenger compartment-side exhaust flow path 34. As a result, in the internal circulation mode of Figure 2, the air sent from the blower 2 is adjusted to a predetermined temperature and humidity by the heater 3 and an evaporator (not shown) before being introduced into the passenger compartment 22, and the air discharged from the passenger compartment 22 passes through the return flow path 32 and then passes through the blower 2 again before being purified by the filter 21.

[0064] Furthermore, in the ventilation mode of the air conditioning system shown in Figure 3, the airflow generated by the blower 2 introduces outside air through the outside air intake channel 33, purifies it with the filter 21, and then sends it to the passenger compartment 22, while simultaneously discharging the air from the passenger compartment 22 to the outside of the vehicle. At this time, when the pair of regeneration control switching dampers 4 and 5 return to their normal positions, the first damper 4 closes the filter-side discharge channel 36, and the second damper 5 closes the filter regeneration channel 5. Simultaneously, the outside air intake damper 6 returns to the outside air intake position, closing the return channel 32 and opening the outside air intake channel 33. In addition, when the passenger compartment exhaust damper 7 returns to the ventilation position, it opens the passenger compartment-side discharge channel 34 and closes the section of the return channel 3 extending from the aforementioned branching point to the blower 2.

[0065] Furthermore, in the regeneration control mode of the air conditioning system shown in Figure 4, air sent from the blower 2 is heated by the heater 3 through the second flow path II, which includes the filter regeneration flow path 35, and then sent to the filter 21. The filter 21 is heated by the passage of this heated air. This causes substances adsorbed on the filter 21 to evaporate and be removed from the filter 21, thereby regenerating the filter 21. The air containing the removed substances is discharged outside the vehicle through the filter-side discharge flow path 36. In this regeneration control mode, when the pair of regeneration control switching dampers 4 and 5 are in the regeneration position, the first damper 4 opens the filter-side discharge flow path 36 and closes the portion of the main flow path 31 closest to the blower 2, and the second damper 5 opens the filter regeneration flow path 35 and closes the portion of the main flow path 31 closest to the passenger compartment 22. At the same time, the outside air intake damper 6 is in the outside air intake position, closing the return flow path 32 and opening the outside air intake flow path 33. Note that the cabin exhaust damper 7 in Figure 4 is in an internal air circulation position, closing the cabin-side exhaust passage 34, but it may also be in the ventilation position shown in Figure 3.

[0066] In the above-described air conditioning system 1, as shown in Figure 4, during filter regeneration, the air sent from the blower 2 through the second flow path II is heated by the heater 3 and then sent to the filter 21. By heating the filter 21, the substances adsorbed on the filter 21 are evaporated and removed from the filter 21, thereby performing filter regeneration.

[0067] Here, the substances adsorbed by the filter 21 tend to have a higher proportion of gas components derived from interior materials within the vehicle interior than from human-derived gas components within a certain period of time after the vehicle is put into use. Beyond that period, the proportion of gas components derived from occupants and items brought in by occupants tends to increase compared to the proportion of gas components derived from interior materials.

[0068] For example, as shown in the graph in Figure 5, the ratio P1 of toluene, which accounts for a large portion of the gas components derived from the interior, to the initial value of the in-vehicle concentration decreases exponentially as the number of days Td after manufacturing elapses.

[0069] On the other hand, as shown in the graph in Figure 6, the proportion of human-derived gases P2(%) to the total air in the vehicle cabin tends to increase in proportion to the number of days that have passed since the vehicle was manufactured and the vehicle's mileage D has increased.

[0070] Therefore, combining the results from the graphs in Figures 5 and 6 above, as shown in the graph in Figure 7, the total concentration C of volatile organic compounds (TVOCs), which is the sum of both interior-derived gases and human-derived gases, decreases with the decrease in interior-derived gases until the vehicle's age Ty is one year, but tends to increase with the increase in human-derived gases after the predetermined age Ty is one year. This trend can be said to be generally common to all vehicles.

[0071] As mentioned above, the boiling points of components in interior-derived gases are generally between 110°C and less than 190°C, with toluene having a boiling point of 110°C. On the other hand, the highest boiling point among components in human-derived gases is 190°C, which is the boiling point of 3-mercapto-3-methyl-1-butanol. Therefore, the boiling points of components in interior-derived gases tend to be lower than those of components in human-derived gases.

[0072] Therefore, in the filter regeneration control method of this embodiment, in order to effectively heat and remove these interior-derived gas components and human-derived gas components from the filter while suppressing energy consumption, the filter 21 is heated at a first temperature to evaporate the interior-derived gas components of the passenger compartment 22 that are adsorbed on the filter 21 when the vehicle is in use for less than a predetermined time (for example, less than one year). On the other hand, when the vehicle is in use for a predetermined time or longer (for example, more than one year), the filter 21 is heated at a second temperature higher than the first temperature to evaporate the human-derived gas components emitted from the occupants in the passenger compartment 22 that are adsorbed on the filter 21.

[0073] Here, the predetermined time is preferably the time obtained by using the change over time in the decrease in the concentration of volatile organic compounds originating from the interior in the air inside the vehicle compartment 22 as a variable (parameter in the example only). For example, as shown in the graph of Figure 5, the predetermined time can be the number of days (for example, about 360 days in Figure 5) at which the degree of change over time in the decrease in the percentage of toluene concentration P1 originating from the interior inside the vehicle compartment (the slope of the graph in Figure 5) reaches a certain value.

[0074] Furthermore, since the predetermined time is correlated with the vehicle's mileage D shown in Figure 6, it is also possible to calculate the predetermined time from the vehicle's mileage D.

[0075] Here, the first temperature mentioned above should be set to between 110°C and 190°C, taking into consideration that toluene, which makes up a large portion of the components of the interior-derived gas, has a boiling point of 110°C or higher.

[0076] Furthermore, the second temperature should be 190°C or higher, taking into consideration the boiling point of 3-mercapto-3-methyl-1-butanol, which has the highest boiling point among the components of the human-derived gas, which is 190°C. The upper limit of the second temperature should be the durability temperature of the filter 21, for example, in the case of a filter 21 containing activated carbon, it should be a temperature below the ignition temperature of activated carbon, which is 350-400°C, for example, 300°C or lower.

[0077] Therefore, in the above-described air conditioning system 1 shown in Figures 1 to 4, when controlling the regeneration of the filter 21, the control device 8 controls the heater 3 to heat the filter 21 to a first temperature that evaporates the gas components originating from the interior of the passenger compartment 22 adsorbed on the filter 21 during regeneration, if less than a predetermined time has passed since the start of vehicle use. Furthermore, if more than a predetermined time has passed, the control device 8 should control the heater 3 to heat the filter 21 to a second temperature that is higher than the first temperature and evaporates the gas components originating from people in the passenger compartment 22 adsorbed on the filter 21 during regeneration.

[0078] Furthermore, even if the usage time is less than the predetermined time, if there are frequent periods of use with a large number of passengers, specifically, when the sum of the product of the number of passengers and the usage time from the start of vehicle use reaches a predetermined number or more, the control device 8 may control the heater 3 to heat the filter 21 to a second temperature during the regeneration of the filter 21. This makes it possible to evaporate human-derived gas components from the filter 21 at an early stage.

[0079] The specific operation of the air conditioning system 1 of this embodiment (internal air circulation mode and regeneration control mode) is performed according to the steps in the flowchart shown in Figure 8.

[0080] In the recirculation mode shown in Figure 2, which is the normal operation of the air conditioning system 1, the reading of various sensors of the air conditioning system 1 (gas sensors 9 and 10 and passenger sensor 11) is first initiated, as shown in step S1 of Figure 8. In recirculation mode, gas sensors 9 and 10 detect the total volatile organic compound (TVOC) gas concentration, which is the sum of interior-derived gases and human-derived gases, at the upstream and downstream positions of the filter 21, respectively.

[0081] Next, in step S2, the adsorption amount calculation unit 15 of the control device 8 calculates the amount of gas components adsorbed by the filter 21 from the difference in gas concentrations detected by the pair of gas sensors 9 and 10 in the internal air circulation mode shown in Figure 2.

[0082] Next, in step S3, the control device 8 determines whether the calculated gas adsorption amount has reached a predetermined saturation adsorption amount, which is the adsorption limit of the filter 21.

[0083] If it is determined in step S3 that the saturation adsorption amount has been reached (if step S3 is YES), the process proceeds to step S4. In step S4, the control device 8 determines whether there are passengers in the vehicle based on the passenger count data obtained by the passenger count sensor 11.

[0084] If it is determined in step S4 that the passenger is present (step S4 is YES), the process proceeds to step S6, where the control device 8 switches the various dampers 4 to 7 to switch to the ventilation mode shown in Figure 3 in order to take in outside air into the passenger compartment 22.

[0085] On the other hand, if it is determined in step S4 that the vehicle is not in use (if step S4 is NO), the process proceeds to step S5, and the control device 8 executes the regeneration control mode. In this case, the various dampers 4 to 7 are switched to transition to the regeneration control mode shown in Figure 4.

[0086] In the regeneration control mode of step S5, first, in step 51, the control device 8 determines whether it has been less than one year since the vehicle was purchased. This elapsed time determination is performed based on the measurement time of the timer 13, which started measuring after the control device 8 received the purchase start trigger signal from the measurement start unit 12.

[0087] If step 51 determines that it has been less than one year since purchase (if the answer in step 51 is YES), the process proceeds to step 52, where the control device 8 controls the output of the heater 3 to regenerate the filter 21 by heating it to a first temperature of 110°C or higher but less than 190°C (i.e., the temperature at which the components of the interior-derived gas evaporate).

[0088] On the other hand, if step 51 determines that it has not been less than one year since purchase (i.e., it has been more than one year) (the answer in step 51 is NO), the process proceeds to step 53, where the control device 8 controls the output of the heater 3 to regenerate the filter 21 by heating it to a second temperature of 190°C or higher (i.e., the temperature at which human-derived gas components evaporate).

[0089] Furthermore, the heating and regeneration operation of the filter 21 in steps 52 and 53 is performed until all total volatile organic compounds (TVOCs) adsorbed on the filter 21 are gone, that is, until the difference in gas concentrations measured by the gas sensors 9 and 10 becomes zero.

[0090] After completing the heating and regeneration operation in step 52 or step 53 above, return to step S1.

[0091] (Features of this embodiment) (1) In this embodiment, the filter regeneration control method is a filter regeneration control method in which substances adsorbed on the filter 21 of an air conditioning system 1 equipped with a filter 21 that purifies the air in the passenger compartment 22 of a vehicle are desorbed by heating the filter 21, and within a predetermined time from the start of vehicle use, the filter 21 is heated to a first temperature that evaporates the gas components originating from the interior of the passenger compartment 22 that are adsorbed on the filter 21. This makes it possible to selectively remove the gas components originating from the interior from the filter 21 by evaporating them.

[0092] On the other hand, for a predetermined period of time or longer, the filter 21 is heated to a second temperature higher than the first temperature, which evaporates the human-derived gas components emitted from the occupants in the passenger compartment 22 and items (food and pets) brought into the vehicle by the occupants that have been adsorbed onto the filter 21. This makes it possible to remove human-derived gas components with high boiling points.

[0093] Furthermore, until a predetermined time has elapsed, during filter 21 regeneration, the filter 21 is heated at a first temperature lower than the second temperature to selectively remove only the components of the gas originating from the interior, thus reducing the energy required to heat the filter 21. As a result, energy consumption during filter 21 regeneration can be suppressed, and deterioration of the filter 21 due to heating can also be reduced.

[0094] As a result, substances adsorbed on the filter 21 can be effectively removed during filter 21 regeneration, and the energy required to heat the filter 21 can be reduced.

[0095] (2) In the filter regeneration control method of this embodiment, the predetermined time is preferably the time obtained by using the change over time in the decrease in the concentration of volatile organic compounds originating from the interior of the vehicle interior in the air inside the vehicle compartment 22 as a variable.

[0096] With these features, it becomes possible to determine a predetermined time until the rate of decrease of volatile organic compounds (VOCs) originating from the interior slows down to a certain rate. Therefore, at the optimal time when the concentration of gases originating from the interior has sufficiently decreased, it is possible to switch to removing human-derived gas components by heating the filter 21 at a second temperature, which is higher than the first temperature.

[0097] (3) In the filter regeneration control method of this embodiment, the predetermined time may be a time determined from the vehicle's mileage.

[0098] With this feature, by determining a predetermined time from the vehicle's mileage, it is possible to switch to removing human-derived gas components by heating the filter 21 at a second temperature, which is higher than the first temperature, at an optimal time according to the actual usage conditions of the vehicle.

[0099] (4) In the filter regeneration control method of this embodiment, the first temperature is 110°C or higher and less than 190°C.

[0100] Since toluene, which accounts for a large portion of the components of interior-derived gases, has a boiling point of 110°C or higher, heating the filter 21 to a first temperature of 110°C or higher but less than 190°C makes it possible to effectively evaporate and remove the toluene adsorbed on the filter 21.

[0101] (5) In the filter 21 regeneration control method of this embodiment, the second temperature is 190°C or higher.

[0102] Since 3-mercapto-3-methyl-1-butanol, which has the highest boiling point among the human-derived gas components, has a boiling point of 190°C, heating the filter 21 to 190°C or higher makes it possible to effectively evaporate and remove the human-derived gas components adsorbed on the filter 21.

[0103] (6) The air conditioning system 1 of this embodiment is an air conditioning system 1 that adjusts the air inside the passenger compartment 22 of a vehicle, and comprises a blower 2 for introducing air into the passenger compartment 22, a heater 3 for heating the air sent from the blower 2, a filter 21 for purifying the air inside the passenger compartment 22, a regeneration control switching damper 4, 5 (flow path switching damper) that switches between a first flow path I that circulates air in the order of blower 2, filter 21, heater 3, passenger compartment 22, and blower 2, and a second flow path II that circulates air in the order of blower 2, heater 3, filter 21, and outside the vehicle, a filter temperature sensor 14 for detecting the temperature of the filter 21, a control device 8 that controls the heater 3 and the regeneration control switching dampers 4, 5, and a timer 13 for measuring the time since the start of vehicle use.

[0104] In this air conditioning system 1, when regenerating the filter 21, it is possible to regenerate the filter 21 by heating the air sent from the blower 2 through the second flow path II with the heater 3 and then sending it to the filter 21, thereby heating the filter 21 and evaporating the substances adsorbed on the filter 21, allowing them to be removed from the filter 21.

[0105] The control device 8 controls the heater 3 to heat the filter 21 to a first temperature during filter 21 regeneration, within a predetermined time from the start of vehicle use, so as to evaporate the gas components originating from the interior of the passenger compartment 22 that have been adsorbed onto the filter 21. This allows the filter 21 to be heated to the first temperature, making it possible to evaporate the gas components originating from the interior and selectively remove them from the filter 21.

[0106] Furthermore, for a predetermined period of time or longer, the control device 8 controls the heater 3 to heat the filter 21 to a second temperature higher than the first temperature during filter 21 regeneration, which is the second temperature at which the human-derived gas components adsorbed on the filter 21 in the vehicle compartment 22 evaporate. This makes it possible to remove human-derived gas components with higher boiling points.

[0107] Furthermore, until a predetermined time has elapsed, during filter 21 regeneration, the filter 21 is heated at a first temperature lower than the second temperature to selectively remove only the components of the gas originating from the interior, thus reducing the energy required to heat the filter 21. As a result, energy consumption during filter 21 regeneration can be suppressed, and deterioration of the filter 21 due to heating can also be reduced.

[0108] As a result, substances adsorbed on the filter 21 can be effectively removed during filter 21 regeneration, and the energy required to heat the filter 21 can be reduced.

[0109] (7) The air conditioning system 1 of this embodiment includes a passenger sensor 11 that detects the number of people in the vehicle. If, within a predetermined time, the sum of the product of the number of passengers and the time spent in the vehicle reaches a predetermined number or more, the control device 8 may control the heater 3 to heat the filter 21 at a second temperature during filter 21 regeneration.

[0110] If the time spent with a large number of passengers accumulates from the start of vehicle use, the concentration of human-derived gases in the vehicle compartment 22 may exceed the concentration of interior-derived gases, even if it is less than a predetermined time. Therefore, as described above, even if it is less than a predetermined time, when the sum of the product of the number of passengers and the time spent in the vehicle reaches a predetermined number or more, the control device 8 controls the heater 3 to heat the filter 21 to a second temperature during filter 21 regeneration, thereby effectively removing human-derived gas components from the filter 21 in accordance with the vehicle usage conditions.

[0111] (modified version) In the filter 21 regeneration control mode shown in Figure 4 above, the filter 21 is heated by heating the air supplied from the blower 2 with the heater 3 and then blowing it onto the filter 21. The filter regeneration control method of the present invention is not particularly limited to the method of heating the filter 21. Therefore, the filter 21 may be directly heated using a heating device such as a heater coil or an infrared heater 3. [Explanation of Symbols]

[0112] 1. Air conditioning system 2 Blower 3 Heaters 4, 5 Regeneration control switching damper (flow path switching damper) 8 Control device 9, 10 Gas sensors 11. Passenger count sensor 12 Measurement start section 13 Timer 14. Filter temperature sensor

Claims

1. In a filter regeneration control method for an air conditioning system equipped with a filter that purifies the air inside a vehicle's cabin, the filter is regenerated by desorbing substances adsorbed on the filter by heating the filter, For a predetermined period of time or less from the start of use of the vehicle, the filter is heated to a first temperature that evaporates the gas components originating from the interior of the vehicle's cabin that have been adsorbed onto the filter. For a predetermined time or longer, the filter is heated to a second temperature higher than the first temperature, which is a second temperature that evaporates the components of human-derived gases emitted from the occupants in the vehicle cabin and items (food and pets) brought into the vehicle by the occupants that have been adsorbed onto the filter. A filter regeneration control method characterized by the following.

2. In the filter regeneration control method according to claim 1, The predetermined time is the time obtained by using the change over time in the decrease in the concentration of volatile organic compounds originating from the interior of the vehicle as a variable. A filter regeneration control method characterized by the following.

3. In the filter regeneration control method according to claim 1, The predetermined time is the time determined from the distance traveled by the vehicle. A filter regeneration control method characterized by the following.

4. In the filter regeneration control method according to claim 1, The first temperature is 110°C or higher and less than 190°C. A filter regeneration control method characterized by the following.

5. In the filter regeneration control method according to any one of claims 1 to 4, The second temperature is 190°C or higher. A filter regeneration control method characterized by the following.

6. An air conditioning system that adjusts the air inside the cabin of a vehicle, A blower for introducing air into the vehicle interior, A heater that heats the air sent from the blower, A filter for purifying the air inside the vehicle cabin, A flow path switching damper that switches between a first flow path that circulates air in the order of blower, filter, heater, vehicle interior, and blower, and a second flow path that circulates air in the order of blower, heater, filter, and outside the vehicle, A temperature sensor for detecting the temperature of the filter, A control unit that controls the heater and the flow path switching damper, A timer for measuring the time elapsed since the start of use of the aforementioned vehicle, Prepare, In an air conditioning system capable of regenerating a filter, during filter regeneration, the air sent from the blower through the second channel is heated by the heater and then sent to the filter to heat the filter, thereby evaporating substances adsorbed on the filter and removing them from the filter, The control unit controls the heater to heat the filter to a first temperature during filter regeneration, which is higher than the first temperature, and which is higher than the first temperature An air conditioning system characterized by the following features.

7. In the air conditioning system according to claim 6, The vehicle is further equipped with a passenger sensor that detects the number of people riding in it. If, within the predetermined time, the sum of the product of the number of passengers and the riding time from the start of use of the vehicle reaches a predetermined number or more, the control unit controls the heater to heat the filter at the second temperature during filter regeneration. An air conditioning system characterized by the following features.

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