Air conditioning system and related method of operation

Abstract

The invention relates to a method for operating an air conditioning system of a motor vehicle having a vehicle interior for air conditioning an air flow introduced into the vehicle interior, comprising a damper device, a fan device driving the air flow, a main filter device and an additional filter device filtering the air flow, a bypass device bypassing the additional filter device and an air quality sensor device detecting a current pollutant concentration in the air flow, the method comprising an air quality check cycle: step A: checking whether the current pollutant concentration is below a predetermined first pollutant limit value, step B: checking whether the bypass device is fully open or a current flow rate of the fan device corresponds to a current air quantity demand of the air conditioning system in case of positive checking in step A, step D: checking whether the current pollutant concentration is below a predetermined second pollutant limit value in case of negative checking in step B, step E: ending the current air quality check cycle in case of negative checking in step D.

Description

TECHNICAL FIELD

[0001] The invention relates to a method for operating an air conditioning system of a motor vehicle having a vehicle interior. The invention also relates to an air conditioning system which is suitable for carrying out the operating method and is equipped with a control device for carrying out the operating method. BACKGROUND

[0002] An air conditioning system of a motor vehicle having a vehicle interior serves to air-condition an air flow of circulating air and / or fresh air which is provided for introduction into the vehicle interior. The air conditioning system can comprise a damper device which is multistage adjustable with respect to the circulating air content in the air flow and a fan device which is multistage adjustable with respect to its flow rate for driving the air flow in the flow direction. Furthermore, the air conditioning system can comprise a main filter device for filtering the air flow and an additional filter device for filtering the air flow. Furthermore, the air conditioning system can comprise a bypass device for bypassing the additional filter device, which is multistage adjustable for opening and closing, and an air quality sensor device for detecting a current pollutant concentration in the air flow, which can comprise at least one air quality sensor, which can be arranged, for example, downstream of the main filter device, downstream of the additional filter device and downstream of the bypass device with respect to the flow direction.

[0003] From DE 10 2014 225 272 A1 an air conditioning system is known which has a main filter device and an additional filter device and a bypass device for bypassing the additional filter device. In the known air conditioning system, the bypass device is configured such that the entire air flow can be guided through the main filter device and the additional filter device in an arbitrary distribution. In the case of a complete closure of the bypass device, then the entire air flow flows only through the additional filter device. In the case of a complete opening of the bypass device, then the entire air flow flows only through the main filter device. For this purpose, the two filter devices are arranged such that a parallel flow through the two filter devices is possible.

[0004] An air conditioning system having two filter devices can solve different filtering tasks. For example, the main filter device can primarily serve as a particle filter in order to filter out particulate contamination. The additional filter device can be designed in particular for gaseous contamination, for example in order to filter odours from the air flow. According to the concept it can be provided that the air flow is guided only through the main filter device or only through the additional filter device or proportionally through the main filter device and through the additional filter device depending on the contamination. Likewise, it is conceivable that the filter devices are arranged in series such that the air flow first flows through the main filter device and subsequently through the additional filter device. By means of the bypass device, then the air flow can be distributed downstream of the main filter device onto the additional filter device and onto a bypass path which bypasses the additional filter device.

[0005] The main filter device and the additional filter device can have different service lives. In order to reduce maintenance costs, it is desirable to achieve a preferably identical and preferably longer service life for the main filter device and the additional filter device so that both filter devices can be replaced simultaneously in maintenance situations. Summary of the Invention

[0006] The present invention achieves the object of providing a cost-effective maintenance approach for such an air-conditioning system or a corresponding operating method, wherein the aim is in particular to optimize the service life of the main filter device and the additional filter device.

[0007] The invention is based on the following general idea: during the operation of the air conditioning system, an air quality check cycle is performed regularly. By checking the current air quality, the flow through the additional filter device can be adjusted as needed, thereby improving its service life.

[0008] The operating method according to the invention comprises an air quality check cycle, wherein the air quality check cycle comprises the following steps. These steps are denoted by letters and are preferably executed or carried out in alphabetical order.

[0009] In step A, it is checked whether the current pollutant concentration in the air flow is below a predetermined first pollutant limit value. Obviously, the air quality sensor device for this purpose comprises at least one air quality sensor in the air flow downstream of the main filter device and downstream of the additional filter device in order to measure the pollutant concentration in the air flow.

[0010] In step B, if it is determined in step A that the current pollutant concentration is below the first pollutant limit value, it is checked whether the bypass device is fully open or whether the current flow rate of the fan device corresponds to the current air volume demand of the air conditioning system.

[0011] In step D, if it is determined in step B that the bypass device is not fully open or the current flow rate does not correspond to the current air volume demand, it is checked whether the current pollutant concentration is lower than a predetermined second pollutant limit value, which is lower than the first pollutant limit value.

[0012] In step E, if it is determined in step D that the current pollutant concentration is not lower than the second pollutant limit value, the current air quality check cycle is continued according to step O.

[0013] The current air quality check cycle is ended in step O. Ending the air quality check cycle can in particular include storing data of the current air quality check cycle.

[0014] Therefore, the pollutant concentration is checked twice or in two stages via two different pollutant limit values ​​in order to optimize the flow through the auxiliary filter device as required.

[0015] In an advantageous refinement, the air quality check cycle can further comprise a step C, in which, in the case of a determination in step B that the bypass device is fully open or that the current flow rate corresponds to the current air quantity requirement, the current air quality check cycle is continued in accordance with step O, such that the current air quality check cycle is ended.

[0016] The air quality check cycle can be optionally performed in a comfort mode or in a service life mode. In the comfort mode, the air quality check cycle is essentially unnoticed by the vehicle occupants. In contrast, in the service life mode, the load on the auxiliary filter device is optimized. Thus, the comfort mode slightly sacrifices the service life of the auxiliary filter device, while the service life mode slightly sacrifices the comfort of the vehicle occupants.

[0017] For the comfort mode, steps B and D of the air quality check cycle are changed to steps B1 and D1, in which, in step B1, it is checked whether the bypass device is fully open in the case of a determination in step A that the current pollutant concentration is below the first pollutant limit value. In step D1, it is checked whether the current pollutant concentration is below the second pollutant limit value in the case of a determination in step B1 that the bypass device is not fully open.

[0018] According to an advantageous refinement, in the comfort mode, step C can further be changed to step C1: such that, in step C1, in the case of a determination in step B1 that the bypass device is fully open, the current air quality check cycle is continued in accordance with step O and is thus ended.

[0019] In the comfort mode, the air quality check cycle can optionally comprise the following additional steps.

[0020] In step F1, the bypass device is actuated to open one stage in the case of a determination in step D1 that the current pollutant concentration is below the second pollutant limit value. This step is based on the consideration that, when the second pollutant limit value is not exceeded, the air quality is too good, and the additional filter device is unnecessarily loaded. By expanding the bypass content, the load and the load on the additional filter device are reduced, and the service life thereof is increased.

[0021] In step G1, the current air quality check cycle is reset to step A after the bypass device is opened by one stage, such that it is subsequently checked again whether the current pollutant concentration is below the first pollutant limit value. In this way, the bypass content can be increased step by step until the air quality is no longer too good, such that the pollutant concentration is no longer below the second pollutant limit value, but is still good enough such that the pollutant concentration is still below the first pollutant limit value.

[0022] In the comfort mode, the air quality check cycle can further comprise the following steps.

[0023] In step H1, in case the current pollutant concentration is determined in step A not to be below the first pollutant limit value, it is checked whether the bypass device is completely closed.

[0024] In step 11, in case the bypass device is determined in step H1 to be completely closed, it is checked whether the maximum flow rate is adjusted on the fan device.

[0025] In step J1, in case the maximum flow rate is determined in step 11 to be adjusted on the fan device, the current air quality check cycle is continued according to step O. The current air quality check cycle is ended here, since the performance limit of the air conditioning system with respect to air cleaning is reached in case of bypass closure and in case of maximum flow rate.

[0026] In one refinement of the comfort mode, the following steps can also be provided.

[0027] In step K1, in case the maximum flow rate is determined in step 11 not to be adjusted on the fan device, the shutter device is actuated to increase the recirculation air content in the air flow by one level. By increasing the recirculation air content, more air is repeatedly directed through the filter device, whereby the air quality is improved. For this purpose, it is assumed that there are external dirt sources located outside the vehicle interior, i.e. in the vehicle surroundings. If, on the other hand, there are internal dirt sources located inside the vehicle interior, the recirculation air share has to be reduced.

[0028] In step L1, after the recirculation air content has been modified, i.e. increased or reduced by one level, the current air quality check cycle is reset to step A, so that it is again checked whether the current pollutant concentration is below the first pollutant limit value. Thus, the recirculation air content can be increased step by step until the air quality corresponds to the requirements, i.e. until the pollutant concentration falls below the first pollutant limit value.

[0029] Thus, for the comfort mode, further steps can be provided.

[0030] In step M1, in case the bypass device is determined in step H1 not to be completely closed, the bypass device is actuated to close by one level. As a result, the bypass content is reduced, so that a proportionally greater amount of air is directed through the additional filter device, which improves the air quality.

[0031] In step N1, after the bypass device has been closed by one level, the current air quality check cycle is reset to step A, so that it is again checked whether the current pollutant concentration is below the first pollutant limit value. Thus, the bypass device is closed step by step here until the air quality corresponds to the requirements, i.e. until the pollutant concentration falls below the first pollutant limit value.

[0032] In contrast, for the service life mode, the air quality check cycle is modified: steps B and D are changed to steps B2 and D2 as follows.

[0033] In step B2, in the case that it is determined in step A that the current pollutant concentration is below the first pollutant limit value, it is checked whether the current flow rate of the fan device corresponds to the current air quantity requirement of the air conditioning system.

[0034] In step D2, in the case that it is determined in step B2 that the current flow rate does not correspond to the current air quantity requirement, it is checked whether the current pollutant concentration is below the second pollutant limit value.

[0035] According to an advantageous refinement, in the service life mode, step C can also be changed to step C2, such that in step C2, in the case that it is determined in step B2 that the current flow rate corresponds to the air quantity requirement, the current air quality check cycle is continued in accordance with step O and is ended.

[0036] In the service life mode, the air quality check cycle can also comprise the following steps.

[0037] In step F2, in the case that it is determined in step D2 that the current pollutant concentration is below the second pollutant limit value, the shutter device is actuated to reduce the recirculation air content in the air flow by one level. This step is based on the consideration that, when the second pollutant limit value is not exceeded, the air quality is too good and the additional filter device is unnecessarily loaded. By reducing the recirculation air content, the load and the stress of the additional filter device are reduced and its service life is increased.

[0038] In step G2, after the recirculation air content in the air flow has been reduced by one level, the current air quality check cycle is reset to step A, such that it is again checked whether the current pollutant concentration is below the first pollutant limit value. In this way, the recirculation air content can be reduced step by step until the air quality is no longer too good, such that the pollutant concentration is no longer below the second pollutant limit value, but is still good enough such that the pollutant concentration is only below the first pollutant limit value.

[0039] According to a refinement of the service life mode, the air quality check cycle can also comprise the following steps.

[0040] In step H2, in the case that it is determined in step A that the current pollutant concentration is not below the first pollutant limit value, it is checked whether the maximum flow rate is adjusted on the fan device.

[0041] In step I2, in the case that it is determined in step H2 that the maximum flow rate is adjusted on the fan device, it is checked whether the bypass device is completely closed.

[0042] In step J2, in case the bypass device is determined to be fully closed in step I2, the current air quality check cycle is continued according to step O, i.e. it is ended.

[0043] Optionally, the service life mode can also be supplemented by the following additional steps.

[0044] In step K2, in case the bypass device is determined not to be fully closed in step I2, the bypass device is actuated to close one level. By reducing the bypass content, the air flow content guided through the additional filter device is increased, which improves the filtration and increases the air quality.

[0045] Subsequently, in step L2, i.e. after closing the bypass device by one level, the current air quality check cycle is reset to step A, so that it is checked again whether the current pollutant concentration is below the first pollutant limit value. In this way, the bypass content can be reduced step by step until the air quality is good enough, i.e. until the pollutant concentration falls below the first pollutant limit value.

[0046] One refinement of the service life mode can comprise the following additional steps.

[0047] In step M2, in case the maximum flow rate is not adjusted on the fan device in step H2, the flap device is actuated to increase the recirculation air content in the air flow by one level. By increasing the recirculation air content, more air is repeatedly guided through the additional filter device, thereby improving its filtration. For this purpose, it is assumed that there is an external dirt source located outside the vehicle interior, i.e. in the vehicle's surroundings. If, on the other hand, there is an internal dirt source located inside the vehicle interior, the recirculation air content must be reduced.

[0048] In the subsequent step N2, after the recirculation air content in the air flow has been modified or increased or reduced by one level, the current air quality check cycle is reset to step A, so that it is checked again whether the current pollutant concentration is below the first pollutant limit value. In this way, the recirculation air content can be reduced step by step until the air quality is good enough, i.e. until the pollutant concentration falls below the first pollutant limit value.

[0049] For starting the air quality check cycle, optionally an initialization operation is carried out, in which a number of parameters are preset, for example. For example, a minimum value for the fresh air content in the air flow is determined in preparation for the air quality check cycle. This corresponds to a maximum value for the recirculation air content in the air flow. Different parameters can be taken into account here, namely, for example, the number of vehicle occupants, the current CO2 value in the vehicle interior, the humidity value and the current status regarding the open status of the vehicle interior windows. In addition or alternatively, the air quantity requirement of the air conditioning system can be determined. Different parameters can also be taken into account here, namely, for example, the operating input of the user or the vehicle occupants, the defogging requirement, the deicing requirement and the cooling requirement. Optionally, the system data can be updated by the current service life data of the main filter device and the additional filter device.

[0050] The above-mentioned air quality check cycle is particularly useful especially when the contamination of the air flow is caused mainly by contamination sources located outside the vehicle, i.e. in the surroundings. Such external contamination sources are, for example, environmental contaminants, such as fine dust and pollen, and unpleasant odors in industrial or agricultural environments. In contrast, internal contamination sources are located in the vehicle interior and can be formed, for example, by the vehicle occupants or the load. For example, the interior space air is consumed by the respiration of the vehicle occupants. Likewise, dogs, cats and other animals carried in the vehicle can also form such internal contamination sources.

[0051] The above-mentioned measures for reducing the contamination, i.e. for increasing the recirculation air content, for example, are useful especially when the contamination originates from external contamination sources. In contrast, in the case of unexpected, additional internal contamination sources, these measures can be counterproductive. There is therefore a need to be able to detect the presence of additional internal contamination sources.

[0052] The operating method described in detail above preferably carries out the respective air quality check cycle under the assumption of a predetermined standard situation in the vehicle interior with at least one vehicle occupant. By means of seat occupancy detection it can be determined, for example, how many vehicle occupants are actually present in the vehicle interior. The air conditioning system can then be self-adjusted accordingly. In contrast, additional internal contamination sources cannot be detected or can be difficult to detect.

[0053] According to an advantageous embodiment, the operating method can also carry out a contamination source detection cycle with the aid of which such additional internal contamination sources can be determined. In the case of detection of an additional internal contamination source, according to an advantageous embodiment it can be provided to deactivate or even reverse steps K1 in the comfort mode and steps M2 in the service life mode, so that the recirculation air content is not increased, but rather reduced, in order to improve the air quality.

[0054] According to a first embodiment, the contamination source detection cycle can comprise the following steps.

[0055] In step P1, it is checked whether the current dirt concentration in the vehicle interior is below a predetermined dirt limit value. For example, the dirt concentration in the vehicle interior can be determined in the circulating air which is discharged from the vehicle interior and which is fed to the air conditioning system. Likewise, the air quality in the vehicle interior can be determined. Obviously, the air quality sensor arrangement then comprises at least one air quality sensor in the circulating air flow or in the vehicle interior. The dirt concentration determined in the course of the dirt source detection can correspond to or be identical to the pollutant concentration determined in the course of the air quality check, in particular.

[0056] In step Q1, in the case where it is determined in step P1 that the dirt concentration in the vehicle interior is below the dirt limit value, the dirt source detection cycle is continued in accordance with step V1.

[0057] In step R1, in the case where it is determined in step P1 that the dirt concentration in the vehicle interior is not below the dirt limit value, the shutter arrangement is actuated to adjust to the circulating air mode, such that the air flow comprises a maximum circulating air content. In the ideal case, the maximum adjustable circulating air content can be 100%. However, it is generally the case that even in the case of an adjustment of the circulating air content to a maximum, the air conditioning system still adds a certain fresh air content to the air flow.

[0058] In step S1, after the adjustment of the circulating air mode, it is checked whether the actual decrease in the dirt concentration in the vehicle interior is greater than an expected decrease in the dirt concentration in the vehicle interior calculated by means of the service life data of the primary filter arrangement and the additional filter arrangement.

[0059] In step T1, in the case where it is determined in step S1 that the actual decrease is greater than the expected decrease, it is determined that there is no additional internal dirt source. The dirt source detection cycle is then continued in accordance with step V1.

[0060] In step U1, in the case where it is determined in step S1 that the actual decrease is not greater than the expected decrease, it is determined that there is an internal dirt source. Subsequently, the dirt source detection cycle is continued in accordance with step V1.

[0061] In accordance with step V1, the current dirt source detection cycle is finally ended. In order to end the dirt source detection cycle, it can be provided, in particular, that data of the dirt source detection cycle are stored.

[0062] In a second embodiment of the dirt source detection cycle, the following steps are carried out.

[0063] In step P2, the expected dirt concentration in the vehicle interior is calculated from the current dirt concentration of the vehicle surroundings and the current service life data of the main filter device and the additional filter device. Here, the current vehicle occupancy, i.e. the number of vehicle occupants, can also be taken into account. For example, the current dirt concentration of the vehicle surroundings can be determined in fresh air by means of an air quality sensor.

[0064] In step Q2, the current dirt concentration in the vehicle interior or in the circulating air flow is measured. Furthermore, it is checked whether the currently measured dirt concentration is within a predetermined tolerance range. Here, the tolerance range is predetermined independently of the vehicle surroundings and the current service life data of the filter devices and is generally not adjustable or variable.

[0065] In step R2, in the case of a current measured dirt concentration within the tolerance range, it is determined that there is no internal dirt source. The dirt source detection cycle is then continued in accordance with step V2.

[0066] In step S2, in the case of a current measured dirt concentration not within the tolerance range, it is checked whether the currently measured dirt concentration is greater than the expected dirt concentration.

[0067] In step T2, in the case of a determination in step S2 that the currently measured dirt concentration is greater than the expected dirt concentration, it is determined that there is an internal dirt source. The dirt source detection cycle is then continued in accordance with step V2.

[0068] In step U2, in the case of a determination in step S2 that the currently measured dirt concentration is not greater than the expected dirt concentration, it is determined that there is an additional internal dirt sink. In this case, the dirt source detection cycle is then also continued in accordance with step V2. The additional internal dirt sink can be formed, for example, by a dirt-absorbing load in the vehicle interior.

[0069] Finally, in step V2, the current dirt source detection cycle is ended. In order to end the dirt source detection cycle, it is possible, inter alia, to provide for the data of the dirt source detection cycle to be stored.

[0070] According to the invention, a motor vehicle comprising a vehicle interior is provided with an air conditioning system for air conditioning an air flow composed of recirculated air and / or fresh air and arranged for introduction into the vehicle interior. The air conditioning system comprises a damper device which is multistage adjustable with respect to the recirculated air content in the air flow, a fan device for driving the air flow in flow direction, which fan device is multistage adjustable with respect to its flow rate, a main filter device for filtering the air flow, an additional filter device for filtering the air flow, a bypass device for bypassing the additional filter device, which bypass device is multistage adjustable for opening and closing, an air quality sensor device for detecting a current pollutant concentration in the air flow, and a control device, which, for operating the air conditioning system, is coupled to the damper device, the fan device, the bypass device and the air quality sensor device. Furthermore, the control device is configured and / or programmed for carrying out an operating method of the above-mentioned type

[0071] Further important features and advantages of the invention are obtained from the attached drawings and by the related description of the drawings.

[0072] It is to be understood that the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or in isolation without departing from the scope of the present invention. BRIEF DESCRIPTION OF DRAWINGS

[0073] Preferred exemplary embodiments of the invention are shown in the attached drawings and explained in more detail in the following description, in which the same reference signs refer to identical or similar or functionally identical parts.

[0074] Schematically shown are:

[0075] Figure 1 a highly simplified circuit diagram-like illustration of the air conditioning system,

[0076] Figure 2 a block diagram of a first embodiment of an air quality check cycle of the operating method,

[0077] Figure 3 a block diagram of a second embodiment of an air quality check cycle of the operating method,

[0078] Figure 4 a block diagram of a first embodiment of a pollutant source detection cycle of the operating method,

[0079] Figure 5 a block diagram of a second embodiment of a pollutant source detection cycle of the operating method. DETAILED DESCRIPTION

[0080] According to Figure 1The air conditioning system 1 is used to air-condition a vehicle interior 2 of a not further shown motor vehicle. For this purpose, the air conditioning system 1 air-conditions an air flow 3 indicated by an arrow, which is ultimately delivered to the vehicle interior 2. Here, the air flow 3 consists of recirculated air 4 indicated by an arrow, which is discharged from the vehicle interior 2, and / or fresh air 5 indicated by an arrow, which is input or drawn in from the surroundings 6 of the vehicle.

[0081] The air conditioning system 1 comprises a damper device 7, which is multistage adjustable with regard to the recirculated air content in the air flow 3. Furthermore, the air conditioning system 1 comprises a fan device 8 for driving the air flow in the flow direction, which is adjustable with regard to its flow rate. Furthermore, the air conditioning system 1 is equipped with a main filter device 9 and an additional filter device 10, which are each used to filter the air flow 3. Each of these filter devices 9, 10 comprises at least one filter element. Furthermore, the air conditioning system 1 is equipped with a bypass device 11 for bypassing the additional filter device 10, which is multistage adjustable for opening and closing. In the example shown, the additional filter device 10 is arranged downstream of the main filter device 9. Furthermore, the bypass device 11 is here configured and positioned in such a way that it can distribute the entire air flow 3, which is guided through the main filter device 9, as required onto the additional filter device 10 and onto a bypass path 12 of the bypass device 11, which bypasses the additional filter device 10. In this embodiment, the air flow 3 is thus always guided through the main filter device 9 and, as required, with a variable content through the additional filter unit 10. Figure 1

[0082] In general, different configurations can also be conceivable, for example as known from DE 10 2014 225 272 Al and which are hereby incorporated by explicit reference. In such a different configuration, the bypass device 11 is arranged and configured in such a way that the air flow 3 can thereby be distributed as required onto the main filter device 9 and onto the additional filter device 10.

[0083] Furthermore, the air conditioning system 1 is equipped with an air quality sensor device 13 for detecting the current pollutant concentration in the air flow 3, which comprises at least one air quality sensor 14 or pollutant sensor 14. In the example shown, a plurality of different air quality sensors 14 are shown purely schematically in different positions within the air conditioning system 1. It is apparent that essentially a single air quality sensor 14 would be sufficient. In practice, at least two air quality sensors 14 are provided in different positions. Figure 1

[0084] ​​The air conditioning system 1 is further equipped with a control device 15, which is coupled to the controllable components of the air conditioning system 1 mentioned here via corresponding control lines 16. Thus, the control device 15 is coupled to the flap device 7, the fan device 8, and the bypass device 11 via the control lines 16. The control device 15 is connected to the air quality sensor 14 of the air quality sensor device 13 via a signal line 17.

[0085] The control device 15 is configured or programmed to perform the following operations by Figures 2 to 5 The operating method, with which the air-conditioning system 1 can be operated, is described in more detail.

[0086] The operating method comprises an air quality check cycle 18, which is Figure 2 and Figure 3 The air quality check cycle 18 is automatically executed within the operating method, in particular periodically during the operation of the air conditioning system 1 .

[0087] according to Figure 2 and Figure 3 The start of each air quality test cycle 18 occurs in box 19. After start 19, an initialization operation can optionally be performed in box 20, in which, for example, multiple parameters are preset. For example, to prepare for the air quality test cycle 18, the minimum fresh air content in air flow 2 can be determined in box 20. This corresponds to the maximum recirculated air content in air flow 3. Various parameters can be taken into account here, such as the number of vehicle occupants, the current CO2 value in the vehicle interior, the humidity value, and the current status regarding the opening status of the vehicle interior windows. Additionally or alternatively, the air volume requirement of the air conditioning system 1 can be determined in box 20. Various parameters can also be taken into account here, such as user or vehicle occupant inputs, anti-fog requirements, de-icing requirements, and cooling requirements. Optionally, the system data can be updated using the current service life data of the main filter device 9 and the additional filter device 10.

[0088] First refer to Figure 2The air quality check cycle 18 for the comfort mode 21 is described. In step A, it is checked whether the current pollutant concentration in the air flow 3 is below a predetermined first pollutant limit value. If this is the case (+), it is checked in step B or Bl whether the bypass device 11 is fully open. If this is not the case (-), it is checked in step D or Dl whether the current pollutant concentration is below a predetermined second pollutant limit value, which is lower than the first pollutant limit value. If this is not the case (-), according to step E, the current air quality check cycle 18 is continued according to step O. Here, step O represents the end of the current air quality check cycle 18 with all measures required for this purpose, i.e. for example the storage of the required data of the air quality check cycle 18.

[0089] In contrast, if it is determined in step B or Bl that the bypass device is fully open (+), according to step C or Cl, the current air quality check cycle 18 is continued, i.e. ended, according to step O.

[0090] If, according to step D, it is determined that the current pollutant concentration is below the second pollutant limit value (+), the bypass device 11 is actuated in step F to open one stage. Subsequently, according to step G, the current air quality check cycle 18 is reset to step A. Figure 2 In step Dl, it is determined that the current pollutant concentration is below the second pollutant limit value (+), the bypass device 11 is actuated in step Fl to open one stage. Subsequently, according to step Gl, the current air quality check cycle 18 is reset to step A.

[0091] If it is determined at this point in step A that the current pollutant concentration is not below the first pollutant limit value (-), it is checked in step HI whether the bypass device 11 is fully closed. If the bypass device 11 is fully closed (+), it is checked in step II whether the maximum flow rate is adjusted on the fan device 8. If the maximum flow rate is adjusted on the fan device 8 (+), the current air quality check cycle 18 is continued, i.e. ended, according to step O in step Jl.

[0092] In contrast, if it is determined in step II that the maximum flow rate is not adjusted on the fan device 8 (-), the flap device 7 is actuated in step Kl to increase the recirculation air content in the air flow 3 by one stage. Subsequently, according to step LI, the current air quality check cycle 18 is reset to step A.

[0093] In contrast, if it is determined in step HI that the bypass device 11 is not fully closed (-), the bypass device 11 is actuated in step Ml to close one stage. Subsequently, in step Nl, the current air quality check cycle 18 is reset to step A.

[0094] In the following, the air quality check cycle 18 for the comfort mode 21 is described in more detail by means of the flowchart in Fig. 2. In step A, it is checked whether the current pollutant concentration in the air flow 3 is below a predetermined first pollutant limit value. If this is the case (+), it is checked in step B or Bl whether the bypass device 11 is fully open. If this is not the case (-), it is checked in step D or Dl whether the current pollutant concentration is below a predetermined second pollutant limit value, which is lower than the first pollutant limit value. If this is not the case (-), according to step E, the current air quality check cycle 18 is continued according to step O. Here, step O represents the end of the current air quality check cycle 18 with all measures required for this purpose, i.e. for example the storage of the required data of the air quality check cycle 18. Figure 3The service life mode 22 for the air quality check cycle 18 is explained in more detail. Here, steps A and O are identical in the service life mode 22 and the comfort mode 21. If the check in step A in the service life mode 22 shows that the current pollutant concentration is not below the first pollutant limit value (-), step H2 is carried out. In contrast, if the current pollutant concentration is below the first pollutant limit value (+), step B or B2 is carried out.

[0095] In step B2, it is checked whether the current flow rate of the fan device 8 corresponds to the current air quantity requirement of the air conditioning system 1. If this is the case (+), step C or C2 is carried out. In contrast, if this is not the case (-), step D or D2 is carried out.

[0096] In step C2, the current air quality check cycle 18 is further carried out in accordance with step O, i.e. it is ended.

[0097] In step D2, it is checked whether the current pollutant concentration is below the second pollutant limit value. If the check is positive (+), step F2 is carried out. In contrast, if the check is negative (-), step E is carried out. In accordance with step E, the current air quality check cycle 18 is then continued in accordance with step O, i.e. it is ended. In contrast, if the current pollutant concentration is not below the second pollutant limit value, the shutter device 7 is actuated in step F2 to reduce the recirculation air content in the air flow by one level. Subsequently, the current air quality check cycle 18 can be reset to step A in step G2.

[0098] If the current pollutant concentration is determined in step A at this time to be not below the first pollutant limit value, it is checked in step H2 whether the maximum flow rate is adjusted on the fan device 8. If this is the case (+), step I2 is carried out. In contrast, if this is not the case (-), step M2 is carried out.

[0099] In step I2, i.e. in the case where it is determined in step H2 that the maximum flow rate is adjusted on the fan device 8, it is checked at this time whether the bypass device 11 is completely closed. If this is the case (+), step I2 is carried out, in which the current air quality check cycle 18 is continued in accordance with step O, i.e. it is ended.

[0100] In contrast, if it is determined in step I2 that the bypass device 11 is not completely closed (-), the bypass device 11 is actuated in step K2 to close by one level. Subsequently, the current air quality check cycle 18 is reset to step A in step L2.

[0101] If it is determined in step H2 that the maximum flow rate is not adjusted on the fan device 8 (-), the damper device 7 is actuated in step M2 to increase the recirculation air content in the air flow 3 by one level. Subsequently, the current air quality check cycle 18 is reset to step A in step N2.

[0102] In Figure 4 and Figure 5 two embodiments of an air quality check cycle 23 are reproduced, which can be executed by the control device 15 during operation of the air conditioning system 1. Here, such a dirt source detection cycle 23 can be executed before or after the air quality check cycle 18.

[0103] According to Figure 4 , the block 24 represents the respective start of the dirt source detection cycle 23. In step PI, it is first checked whether the current dirt concentration in the vehicle interior 2 is below a predetermined dirt limit value. For the current dirt concentration in the vehicle interior 2, for example, the air quality sensor 14 arranged in the recirculation air flow 4 can be used. In fact, the dirt concentration of the dirt source detection cycle 23 can be identical to the pollutant concentration introduced above in connection with the air quality check cycle 18. In particular, the dirt limit value of the dirt source detection cycle 23 can be equal to the first pollutant limit value of the air quality check cycle 18.

[0104] If the result of this check is positive (+) in step PI, the dirt source detection cycle 23 is continued in step Ql according to step VI, wherein step VI represents the end of the dirt source detection cycle 23, wherein the result of the dirt source detection cycle 23 can be stored in a memory. In this case, it is assumed in step Ql that no additional internal dirt source is present. By contrast, if the check is negative (-) in step PI, the damper device 7 is actuated in step Rl to adjust to the recirculation air mode, so that the air flow 3 contains the maximum recirculation air content. In particular, the air flow 3 then contains 100% recirculation air 4.

[0105] Below, it is checked in step SI whether the actual drop in the dirt concentration in the vehicle interior 2 is greater than the expected drop in the dirt concentration in the vehicle interior 2, which is calculated from the service life of the main filter device 9 and the additional filter device 10. If this is the case (+), step Tl is performed. By contrast, if this is not the case (-), step Ul is performed. In step Tl, it is determined that no internal dirt source is present. The dirt source detection cycle 23 is then continued according to step VI, i.e. it is ended. By contrast, in step Ul, it is determined that an internal dirt source is present. Here, too, the dirt source detection cycle 23 is continued according to step VI, i.e. it is ended.

[0106] Figure 5One different embodiment of the dirt source detection cycle 23 is shown. The dirt source detection cycle 23 is also started here with a start block 24. Subsequently, in step P2, the expected dirt concentration in the vehicle interior 2 is calculated, i.e. by means of the current dirt concentration in the vehicle surroundings 6 and by means of the current service life of the main filter device 9 and the additional filter device 10. Subsequently, it is checked in step Q2 whether the currently measured dirt concentration is within a predetermined tolerance range. This predetermined tolerance range is in particular independent of the calculated, expected dirt concentration. If the check in step Q2 is positive (+), step R2 is performed. In contrast, if the check in step Q2 is negative (-), step S2 is performed. In step R2, it is determined that there is no additional internal dirt source, so that the dirt source detection cycle 23 can be continued according to step V2. Here, step V2 represents the end of the dirt source detection cycle 23, wherein the result of the dirt source detection cycle 23 can be stored in a memory.

[0107] In step S2, it is checked whether the currently measured dirt concentration is greater than the expected dirt concentration. If this is the case (+), step T2 is performed. If this is not the case (-), step U2 is performed. In step T2, it is determined that there is an additional internal dirt source. Subsequently, the dirt source detection cycle 23 can be continued or ended according to step V2. In contrast, in step U2, it is determined that there is an additional internal dirt sink. Subsequently, the dirt source detection cycle 23 is continued according to step V2, i.e. in fact ended.

[0108] If an additional internal dirt source is identified by means of the dirt source detection cycle 23, it can be provided according to one preferred embodiment that the air quality check cycle 18 is modified. For example, step K1 can be changed in the comfort mode 21 so that the circulating air content is not increased, but rather reduced by one stage. Similarly, step M2 can be changed in the service life mode 22 so that the circulating air content is not increased, but rather reduced by one stage.

Claims

1. A method for operating an air conditioning system (1) of a motor vehicle having a vehicle interior (2), - wherein the air conditioning system (1) is for air conditioning an air flow (3) consisting of recirculated air (4) and / or fresh air (5), which is provided for introduction into the vehicle interior (2), and comprises: a flap device (7) which is adjustable in multiple stages with respect to the circulating air content in the air flow (3); a fan device (8) for driving the air flow (3) in a flow direction, the fan device being adjustable in multiple stages with respect to its flow rate; a main filter device (9) for filtering the air flow (3); an additional filter device (10) for filtering the air flow (3); a bypass device (11) for bypassing the additional filter device (10), the bypass device being adjustable in multiple stages for opening and closing; and an air quality sensor device (13) for detecting a current pollutant concentration in said air flow (3), - In the method, an air quality check cycle (18) is performed, the air quality check cycle comprising the following steps: - Step A: Check whether the current pollutant concentration is lower than a predetermined first pollutant limit value, - Step B: if it is determined in step A that the current pollutant concentration is below the first pollutant limit value, checking whether the bypass device (11) is fully open or whether the current flow rate of the fan device (8) corresponds to the current air volume demand of the air conditioning system (1), - Step D: if it is determined in step B that the bypass device (11) is not fully open or the current flow rate does not correspond to the current air volume demand, checking whether the current pollutant concentration is lower than a predetermined second pollutant limit value, the second pollutant limit value being lower than the first pollutant limit value, - Step E: if it is determined in step D that the current pollutant concentration is not lower than the second pollutant limit value, continuing the current air quality check cycle (18) according to step O, -Step O: End the current air quality check cycle (18).

2. The method according to claim 1, It is characterized by: The air quality check cycle (18) further comprises the following steps: - Step C: If it is determined in step B that the bypass device (11) is fully open or the current flow rate corresponds to the current air quantity demand, the current air quality check cycle (18) is continued according to step O.

3. The method according to claim 2, It is characterized by: The air quality check cycle (18) can be performed in comfort mode (21) by changing step B and step D to the following steps B1 and D1: - Step B1: if it is determined in step A that the current pollutant concentration is lower than the first pollutant limit value, checking whether the bypass device (11) is fully open, - Step D1: If it is determined in step B1 that the bypass device (11) is not fully opened, check whether the current pollutant concentration is lower than the second pollutant limit value.

4. The method according to claim 3, It is characterized by: In the comfort mode (21), step C is also changed to the following step C1: - Step C1: If it is determined in step B1 that the bypass device (11) is fully open, the current air quality check cycle (18) is continued according to step O.

5. The method according to claim 3 or 4, It is characterized by: The air quality check cycle (18) further comprises the following steps in the comfort mode (21): - Step F1: in case it is determined in step D1 that the current pollutant concentration is lower than the second pollutant limit value, actuating the bypass device (11) to open the first stage, - Step G1: After opening the bypass device (11) by one level, the current air quality check cycle (18) is reset to step A.

6. The method according to claim 3 or 4, It is characterized by: The air quality check cycle (18) further comprises the following steps in the comfort mode (21): - Step H1: if it is determined in step A that the current pollutant concentration is not lower than the first pollutant limit value, checking whether the bypass device (11) is completely closed, - Step I1: In case it is determined in step H1 that the bypass device (11) is completely closed, checking whether the maximum flow rate is adjusted on the fan device (8), - Step J1: In case it is determined in step I1 that the maximum flow rate is adjusted on the fan device (8), the current air quality check cycle (18) is continued according to step O.

7. The method according to claim 6, It is characterized by: The air quality check cycle (18) further comprises the following steps in the comfort mode (21): - Step K1: in case it is determined in step I1 that the maximum flow rate is not set on the fan device (8), actuating the flap device (7) to increase the circulating air content by one level, - Step L1: After modifying the flow rate by one level, the current air quality check cycle (18) is reset to step A.

8. The method according to claim 6, It is characterized by: The air quality check cycle (18) further comprises the following steps in the comfort mode (21): - Step M1: in case it is determined in step H1 that the bypass device (11) is not completely closed, actuating the bypass device (11) to close one stage, - Step N1: After closing the bypass device (11) by one level, the current air quality check cycle (18) is reset to step A.

9. The method according to claim 2, It is characterized by: The air quality check cycle (18) can be performed in a service life mode (22) where steps B and D are changed to steps B2 and D2 as follows: - Step B2: in case it is determined in step A that the current pollutant concentration is below the first pollutant limit value, checking whether the current flow rate of the fan device (8) corresponds to the current air volume demand of the air conditioning system (1), Step D2 : if it is determined in step B2 that the current flow rate does not correspond to the current air quantity demand, it is checked whether the current pollutant concentration is below the second pollutant limit value.

10. The method according to claim 9, It is characterized by: In the service life mode (22), step C is also changed to the following step C2: - Step C2: If it is determined in step B1 that the bypass device (11) is fully open, the current air quality check cycle (18) is continued according to step O.

11. The method according to claim 9 or 10, It is characterized by: The air quality check cycle (18) further comprises the following steps in the service life mode (22): - step F2: if it is determined in step D2 that the current pollutant concentration is below the second pollutant limit value, actuating the flap device (7) to reduce the recirculated air content in the air flow (3) by one level, - Step G2: After reducing the circulating air content in the air flow (3) by one level, the current air quality check cycle (18) is reset to step A.

12. The method according to claim 9 or 10, It is characterized by: The air quality check cycle (18) further comprises the following steps in the service life mode (22): - Step H2: in case it is determined in step A that the current pollutant concentration is not lower than the first pollutant limit value, checking whether the maximum flow rate is adjusted on the fan device (8), - Step I2: in case it is determined in step H2 that the maximum flow rate is adjusted on the fan device (8), checking whether the bypass device (11) is completely closed, - Step J2: If it is determined in step I2 that the bypass device (11) is completely closed, the current air quality check cycle (18) is continued according to step O.

13. The method according to claim 12, It is characterized by: The air quality check cycle (18) further comprises the following steps in the service life mode (22): - Step K2: in case it is determined in step I2 that the bypass device (11) is not completely closed, actuating the bypass device (11) to close one stage, - Step L2: After closing the bypass device (11) by one level, the current air quality check cycle (18) is reset to step A.

14. The method according to claim 12, It is characterized by: The air quality check cycle (18) further comprises the following steps in the service life mode (22): - step M2: in case it is determined in step H2 that the maximum flow rate is not adjusted on the fan device (8), actuating the flap device (7) to increase the circulating air content in the air flow (3) by one level, - Step N2: After modifying the circulating air content in the air flow (3) by one level, the current air quality check cycle (18) is reset to step A.

15. The method according to any one of claims 1 to 4, It is characterized by: In the air quality check cycle (18), before step A, a minimum content of fresh air (5) in the air flow is determined and the flap arrangement (7) is actuated to adjust the circulating air content associated therewith.

16. The method according to any one of claims 1 to 4, It is characterized by: In the air quality check cycle (18), before step A, the air volume demand of the air conditioning system (1) is determined and the fan device (8) is actuated to adjust the flow rate associated therewith.

17. The method according to claim 7, It is characterized by: A contamination source detection cycle (23) is executed, the contamination source detection cycle comprising the following steps: - Step P1: Checking whether the current dirt concentration in the vehicle interior (2) is below a predetermined dirt limit value, - step Q1: in case it is determined in step P1 that the dirt concentration in the vehicle interior (2) is below the dirt limit value, determining that no additional internal dirt sources are present and continuing the dirt source detection cycle (23) according to step V1, - Step R1: If it is determined in step P1 that the dirt concentration in the vehicle interior (2) is not below the dirt limit value, actuating the flap arrangement (7) to adjust to the recirculated air mode so that the air flow (3) contains a maximum recirculated air content, - Step S1: After adjusting the recirculated air mode, checking whether the actual drop in the dirt concentration in the vehicle interior (2) is greater than the expected drop in the dirt concentration in the vehicle interior (2) calculated from the service life data of the main filter device (9) and the additional filter device (10), - step T1 : in case it is determined in step S1 that the actual drop is greater than the expected drop, it is determined that no additional internal pollution sources are present and the pollution source detection cycle ( 23 ) is continued according to step V1 , - step U1 : in case it is determined in step S1 that the actual drop is not greater than the expected drop, determining the presence of an additional internal dirt source and continuing the dirt source detection cycle ( 23 ) according to step V1 , - Step V1: End the current pollution source detection cycle (23).

18. The method according to claim 14, It is characterized by: A contamination source detection cycle (23) is executed, the contamination source detection cycle comprising the following steps: - Step P2: Calculating the expected dirt concentration in the vehicle interior (2) by means of the current dirt concentration in the vehicle surroundings (6) and the current service life data of the main filter device (9) and the additional filter device (10), - step Q2: measuring the current dirt concentration in the vehicle interior (2) and checking whether the currently measured dirt concentration is within a predetermined tolerance range, - step R2: in case the currently measured dirt concentration is within the tolerance range, determining that no additional internal dirt sources are present and continuing the dirt source detection cycle (23) according to step V2, - Step S2: in case the currently measured dirt concentration is not within the tolerance range, checking whether the currently measured dirt concentration is greater than the expected dirt concentration, - step T2: in case it is determined in step S2 that the currently measured dirt concentration is greater than the expected dirt concentration, determining the presence of an additional internal dirt source and continuing the dirt source detection cycle (23) according to step V2, - step U2: in case it is determined in step S2 that the currently measured dirt concentration is not greater than the expected dirt concentration, determining the presence of an additional internal dirt sink and continuing the dirt source detection cycle (23) according to step V2, - Step V2: End the current pollution source detection cycle (23).

19. The method according to claim 17, It is characterized by: If the result of the pollution source detection loop (23) is that an additional internal pollution source is determined to be present, the air quality check loop (18) is modified so that step K1 is changed in the comfort mode (21) so that the circulating air content is reduced by one level.

20. The method according to claim 18, It is characterized by: If the result of the pollution source detection cycle (23) is that an additional internal pollution source is determined to be present, the air quality check cycle (18) is modified so that step M2 is changed in the service life mode (22) so that the circulating air content is reduced by one level.

21. An air conditioning system (1) for a motor vehicle having a vehicle interior (2), - wherein the air conditioning system (1) is used for air conditioning an air flow (3) consisting of recirculated air (4) and / or fresh air (5), which air flow is provided for introduction into the vehicle interior (2), - wherein the air conditioning system (1) comprises: a flap device (7) which is adjustable in multiple stages with respect to the circulating air content in the air flow (3), - a fan device (8) for driving the air flow (3) in a flow direction, said fan device being adjustable in multiple stages with respect to its flow rate, - a main filter device (9) for filtering said air flow (3), - additional filter means (10) for filtering said air flow (3), - a bypass device (11) for bypassing the additional filtering device (10), the bypass device being adjustable in multiple stages for opening and closing, - air quality sensor means (13) for detecting the current concentration of pollutants in said air flow (3), and - A control device (15) which is coupled to the valve device (7), the fan device (8), the bypass device (11) and the air quality sensor device (13) for operating the air-conditioning system (1) and is configured and / or programmed to carry out the method for operating an air-conditioning system (1) of a motor vehicle having a vehicle interior (2) according to any of the preceding claims.

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