Ventilation device for interior air in an interior space and method for operating the same

Abstract

The invention relates to a method for operating a ventilation device for interior air in an interior space and a corresponding ventilation device, the method comprising the steps of providing a fresh air proportion η of the supplied fresh air according to a predetermined or selected operating strategy. R and return air volume flow Q R ; determining the setting of the return air damper (5) for setting the fresh air ratio and the fan power of the fan (7) for setting the mixed air volume flow rate composed of the supplied return air and fresh air; increasing the fresh air ratio λ and / or the mixed air volume flow rate Q according to the pathogen interior concentration limit value as the maximum pathogen aerosol concentration, the pathogen filtration efficiency of the interior space filter (8) and the predetermined load protection volume flow rate M The fresh air proportion and / or the mixed air volume flow are increased incrementally until the threshold value of the pathogen interior concentration, which is determined by the pathogen filtration efficiency of the interior filter and the predetermined load protection volume flow, is fallen below.

Description

Technical Field

[0001] The present invention relates to a ventilation device, such as a ventilation and air-conditioning device or a ventilation and air-conditioning system for interior spaces, in particular for the interior spaces of vehicles or other devices. The invention also relates to controlling or regulating the air-handling system while maintaining a maximum pathogenic aerosol load for people in the interior space. Background Art

[0002] Ventilation systems for interior spaces, in particular vehicles, can be operated in various control strategies and operating modes. These may include, for example, temperature-controlled operation, return air or secondary air operation, defrost operation for the fastest possible defrosting of vehicle glass surfaces, such as the windshield, operation with maximum cooling capacity for the interior air, operation for optimizing the air purification effect, in particular with respect to pathogenic aerosols, and the like.

[0003] The current status of the operating parameters of the ventilation system and the status of the interior air can also be displayed to the user in a suitable manner.

[0004] The various operating modes can be activated manually by the user or according to a predefined program based on a predefined operating strategy and ambient conditions or other operating conditions. Return air or secondary air operation is particularly advantageous in air handling systems whose sole or partial purpose is to control the air temperature of the interior space, because the energy input is no less when circulating precooled or preheated interior air than when supplying a partial or maximum amount of outside air.

[0005] However, a disadvantage of using return air operation is that pathogenic aerosols, such as pollutant particles or bioaerosols, can accumulate in the interior space. These aerosols can, for example, contain copies of pathogenic viruses. Therefore, when the interior air is contaminated with such bioaerosols, the risk of infection for people in the interior space increases. For these people, the risk of infection due to pathogen input from pathogenic ambient air is negligible compared to the risk of infection due to pathogen input from interior sources (typically other people in the interior space). Therefore, if an air purification strategy is not implemented, return air operation can significantly increase the risk of infection for people in the interior space. Summary of the Invention

[0006] The object of the present invention is therefore to provide a method for operating a ventilation device in which the pathogen load on the interior due to pathogen aerosols from emission sources located in the interior, such as infected persons or smokers, is reduced.

[0007] This object is achieved by the method according to the invention for operating a ventilation device and by the ventilation device according to the invention.

[0008] According to a first aspect, a method for operating a ventilation device for interior air in an interior, in particular an interior of a motor vehicle, is provided, comprising the following steps:

[0009] - Provide the fresh air ratio and return air volume flow of the supplied fresh air according to the predetermined or selected operating strategy;

[0010] - determining the setting of a return air damper for setting the outdoor air proportion, in particular a return air flap or a return air valve, and the fan power for setting the mixed air volume flow of supplied return air and outdoor air;

[0011] - Increasing the fresh air proportion and / or the mixed air volume flow rate as a function of the pathogen interior concentration limit value, the pathogen filtration efficiency of the interior filter, and a predetermined load protection volume flow rate as a maximum permissible pathogen aerosol concentration, wherein the fresh air proportion and / or the mixed air volume flow rate is increased incrementally until the threshold value for the pathogen interior concentration is fallen below the threshold value determined by the pathogen filtration efficiency of the interior filter and the predetermined load protection volume flow rate.

[0012] In this way, in a ventilation device of an air treatment system for interior spaces, it is achieved that the ventilation device circulates the air of the interior space and mixes it with a predeterminable, variable fresh air ratio according to a predetermined operating strategy, wherein the fresh air ratio is set as a function of the volume flow through the ventilation device and as a function of the maximum permissible pathogen load of pathogen aerosols, such as pollutant particles and / or bioaerosols, which a person inhales by breathing during their stay in the interior space.

[0013] Interior filters are components of ventilation systems that remove pollutants from the air flow supplied to the interior. For this purpose, the interior filters include particle filter areas that filter out airborne particles and aerosols. In another embodiment, the interior filters can additionally include absorption areas, on the surfaces of which organic and / or inorganic gases in the air flow can accumulate.

[0014] Technically speaking, return air is defined as exhaust air that is returned to the air handling system and supplied to at least one space again as part of the unextracted supply air. A distinction should be made between return air and secondary air, which is air extracted from a space and supplied to the same space again after treatment. In colloquial language, and particularly in vehicle air handling systems, contrary to the technical definition, "secondary air operation" is not used, but rather "return air operation," in which no outside air is supplied, for example to achieve the desired temperature conditions more quickly. This "return air operation" can also temporarily prevent exhaust gases, particles, or odors from the environment from entering the interior space. To simplify the language, the term "return air" will be used below for "secondary air and / or return air."

[0015] The above method can make the operation strategy of the ventilation equipment subject to the maintenance of the pathogenic aerosol, such as pollutant particles and / or bioaerosol, pathogenic agent concentration limit value (number unit / m 3 , where the quantity unit may comprise, for example, the number of viruses determined by a PCR method or the number of viable viruses (plaque-forming units) determined, for example, by a pfu method), so that the load of pathogen aerosols to which a person is exposed during their stay in the interior space is limited to below a critical concentration value predetermined by the pathogen interior space concentration limit value.

[0016] Operating strategies can include temperature-controlled operation to maintain a constant interior air temperature, operation with maximum cooling capacity for the interior air, defrost operation with maximum heating capacity for the interior air, and air quality control for the interior air, particularly while taking into account energy-saving potential. These operating strategies specify the settings for the delivered mixed air volume flow, the fresh air fraction, and, if necessary, other setting options.

[0017] Since the input of pathogens into the interior space caused by the ambient aerosol concentration is negligible compared to the input of pathogens through interior space sources, the input of pathogens into the interior space through interior space sources can be expressed as the pathogen emission rate E (number units / h).

[0018] When observing steady state conditions (at equilibrium, where conditions do not change over time in the absence of external influences), three processes can be used as pathogen reduction measures to remove pathogens from interior space air through bioaerosol emissions:

[0019] - Expulsion of pathogens through the air flow out of the interior space (building / cabin), through the balance between the inflow and outflow flows:

[0020] Q L - Volume flow rate penetrating into the inner space shell (m 3 / h),

[0021] Q N - Unforced natural ventilation, such as through open windows (m 3 / h),

[0022] Q F - Fresh air volume flow rate by forced mechanical convection (m 3 / h),

[0023] - Filtering pathogens by filtering the circulating mixed air:

[0024] Q R - Volume flow of return air from forced mechanical recirculation (m3 / h),

[0025] η R - Pathogen filtration efficiency for pathogenic aerosols, such as pollutant particles or bioaerosols,

[0026] - Pathogen aerosols deposited on interior surfaces:

[0027] V-internal space volume (m 3 ),

[0028] The coefficient of deposition of β-pathogens on the surface of the interior space (h -1 ).

[0029] By quantitatively observing the process of adding or removing pollutant particles or bioaerosols to the air in the interior space, under the condition that the interior space is ideally mixed and the ambient concentration of pathogenic pollutant particles or bioaerosols is negligible, the cumulative fresh air volume flow rate Q* from the environment is simplified. F =Q F +Q L +Q N The stable concentration C of pathogens in the internal space of the generated pollutant particles or bioaerosols can be easily determined:

[0030]

[0031] Especially in air-conditioned vehicle cabins, such a stable interior concentration is established within a short time, which is compared with the residence time of the occupants in the interior, which is usually used as the basis for assessing the infection risk: If the interior is free of any pathogen load and pathogens are fed via the interior source starting at time t=0 with a pathogen emission rate E, the relaxation time of such a system is typically a few minutes, while the residence time usually used as the basis for assessing the infection risk can be several hours.

[0032] In closed systems, in pure return air operation and under the simplified assumptions of critical load risk assessment or infection risk assessment, i.e., no fresh air ventilation that dilutes the pathogens, no infiltration of diluted pathogens, and no pathogenic pollutant particles or bioaerosols that are discharged from the interior air by deposition or inactivation over time, the steady-state concentration C of pathogenic pollutant particles or bioaerosols in the interior for the ventilation system configuration results from the following relationship:

[0033]

[0034] In addition, the maximum allowable pathogen load (the amount of pathogenic pollutant particles or bioaerosols at the infection threshold) that a person can inhale through breathing during their stay in the interior space can be determined to assess the risk of infection for the person in the interior space. The maximum allowable pathogen load is the maximum allowable interior space concentration C P The product of the respiratory volume ingested during the stay. The maximum permissible pathogen load—for example, given as a certain order of magnitude of contaminant particles, PCR viral copies, or viable virus counts (pfu)—and the emission rates of different pathogen sources (usually infected individuals) can be determined based on infection studies and the type of pathogen aerosol. The respiratory volume can be derived from the minute volume of the breath during different activity states.

[0035] Therefore, in steady state, the pathogen-specific air cleaning performance required for pure return air operation is

[0036] pCCM=C P η R Q R ≥E

[0037] Wherein pCCM corresponds to the pathogen-specific air purification performance in pure return air operation according to the Chinese standard GB / T 18801-2015 (Air Purifiers) without taking into account the critical load risk assessment of the penetration, deposition and inactivation of pathogenic bioaerosols (number units / h) or the critical infection risk assessment (for bioaerosols) (pCCM: Pathogen Cumulative Cleaning Material) (Virus Cumulative Cleaning Material = vCCM) and C P Corresponding to the concentration limit of pathogenic body in the internal space (quantity unit / m 3 ).

[0038] The above-described method particularly relates to an operating strategy that predetermines a mixed air volume flow rate without a fresh air proportion (corresponding to a return air volume flow rate) for a ventilation system based on its pathogen-specific air purification performance. If a limit value for the interior pathogen concentration is determined for the residence time, a return air volume flow rate is generated by the pathogen-specific air purification performance to be ensured in all adjustable operating strategies of the ventilation system, which, for infection protection reasons, cannot be lowered. This return air volume flow rate, which cannot be lowered and depends on the pathogen filtration efficiency of the interior space filter for pollutant particles or bioaerosols, advantageously supplements the operating strategy of the ventilation system to prevent people in the interior from being exposed to pathogen aerosols exceeding the predetermined limit value.

[0039] In particular, the above method can be used not only to determine the mixed air volume flow rate, but also to determine the fresh air ratio. By determining the fresh air ratio, the dilution effect of the incoming fresh air is taken into account. In particular, the pathogen-specific air purification performance is correspondingly improved by supplying fresh air:

[0040] pCCM*=C P (Q * F +η R Q R )≥E

[0041] Here, pCCM* corresponds to the pathogen-specific air purification performance for mixed operation consisting of supplied return air and fresh air in steady state (quantity units / h), without taking into account the critical load risk assessment or critical infection risk assessment for the penetration, deposition and inactivation of pathogen bioaerosols.

[0042] In order to ensure effective protection against pollutant particles or effective protection against infection of persons in the interior space, the method provides for determining the load volume flow (infection protection volume flow) Q for each operating state of the air handling system according to the following formula IS , i.e. by selecting the mixed air volume flow rate according to the pathogen filtration efficiency and the pathogen interior concentration limit value depending on the interior residence time The adjustment of the fresh air ratio is based on the specific air purification performance required for the internal space to be discharged. This applies without taking into account the critical load risk assessment of pollutant particles or the critical infection risk assessment for the penetration, deposition and inactivation of pathogenic bioaerosols:

[0043]

[0044] The load volume flow (infection protection volume flow in the case of pathogen bioaerosols) represents a characteristic value of the quotient of the interior emission value and the pathogen interior concentration threshold value for the concentration of pollutant particles or other pathogen aerosols.

[0045] This results in the return air volume flow Q required for infection protection in pure return air operation. R =Q IS / η R .

[0046] In mixed operation, the fresh air ratio λ is generated

[0047]

[0048] where λ = Q * F / (Q * F +Q R ) and (λ≠1).

[0049] Therefore, the load on the interior of the pathogenic body can be controlled by varying the fresh air proportion and the return air volume flow. Depending on the selected operating strategy, either the fresh air proportion or the return air volume flow can now be adjusted.

[0050] In particular, the fresh air proportion and / or the mixed air volume flow can be increased incrementally until, depending on the pathogen filtration efficiency of the interior filter for pollutant particles or bioaerosols, a predetermined load protection volume flow or a predetermined infection protection volume flow is exceeded.

[0051] Therefore, in the temperature control operation of the ventilation equipment, if the difference between the temperature of the ambient air and the target temperature of the interior space air is small (for example, the ambient temperature ), the adjustment of the fresh air ratio should take precedence over the adjustment of the return air volume flow rate (until λ=1). On the contrary, in very cold weather (such as ) or very hot (such as ) in the ambient air, the fresh air volume flow should not be changed, but instead the return air volume flow should be increased. The above method stipulates that it should not fall below the infection protection flow Q, especially when the return air volume flow is more preferred, usually for energy reasons. IS .

[0052] It can be provided that the fresh air proportion and / or the return air volume flow is increased outside the predetermined operating strategy only if there is more than one person in the interior space or if no windows are open which ensure sufficient air exchange between the interior space and the surroundings.

[0053] Therefore, the operating strategy can be designed to consider the number of people in the interior as a potential emission source, as the emission rate of pathogenic agents from interior sources can significantly influence the interior air concentration. For example, in a vehicle, the number of people can be determined using seat occupancy sensors in the occupant restraint system, which may already be present, or by using interior cameras. For example, the strategy for maintaining the pathogenic agent interior concentration limit according to the above-described method is only implemented if there is more than one person in the interior.

[0054] Furthermore, the load or infection risk can be assessed based on the location of the interior, particularly the vehicle. If the vehicle is located in a hazardous area, the priority for adjusting the fresh air ratio can be lowered accordingly. Furthermore, the operating strategy can assess the air quality of the interior, for example using a CO2 air quality sensor as a hygienic indicator of air quality. The operating strategy can also predefine a minimum fresh air ratio.

[0055] According to one embodiment, the pathogen-specific air purification performance of the interior space filter can be determined based on the pathogen filtration efficiency of the interior space filter for pathogen aerosols, the return air volume flow, the fresh air ratio and the pathogen interior space concentration limit value that depends on the interior space residence time, the pathogen filtration efficiency depending on the age of the interior space filter and / or the cumulative air volume flow that passes through the interior space filter during its total operating time (the amount and characteristics of the mixed air volume flow to be purified, consisting of supplied return air and fresh air).

[0056] Provision can be made to increase the fresh air proportion and / or the mixed air volume flow according to a priority which is determined according to the operating strategy as a function of the state of the interior air, the state of the fresh air and / or the target quota of the operating strategy.

[0057] According to one embodiment, a visual or acoustic signal can be emitted, in particular, when a predetermined or selected operating strategy is intervened as a function of the pathogen filtration efficiency and the pathogen interior concentration limit value.

[0058] Furthermore, the bypass regulator is controlled in accordance with the selected operating strategy and in accordance with the increased fresh air proportion and / or the mixed air volume flow in order to set the cooling capacity.

[0059] According to another aspect, a ventilation device for interior air in an interior is proposed, comprising:

[0060] -Return air regulator for variably setting the fresh air ratio;

[0061] - a fan for variably generating a mixed air volume flow consisting of supplied return air and fresh air;

[0062] - A control or regulating unit, which is designed to provide a fresh air proportion and a mixed air volume flow according to a predetermined or selected operating strategy, so as to control a return air damper for setting the fresh air proportion and a fan with a fan power for setting the mixed air volume flow consisting of supplied return air and fresh air, and to increase the fresh air proportion and / or the return air volume flow according to the pathogen filtration efficiency of the interior space filter for bioaerosols and the infection protection volume flow, wherein the fresh air proportion and / or the mixed air volume flow increases incrementally until it falls below a threshold value of the pathogen interior concentration determined by the pathogen filtration efficiency of the interior space filter and the predetermined load protection volume flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The following is a detailed description of the embodiments with reference to the accompanying drawings.

[0064] Figure 1 A schematic diagram showing an air handling system having ventilation equipment for an interior space;

[0065] Figure 2 Shown for illustration purposes only. Figure 1 Flowchart of a method for a ventilation device. DETAILED DESCRIPTION

[0066] Figure 1The schematic diagram shows an air handling system 1 having a ventilation system 2 and an interior space 3. The ventilation system 2 is used to treat the air intended for the interior space 3. This treatment may include adding fresh air, preparing and filtering fresh and return air, and temperature / air conditioning. The treated air is then supplied to the interior space 3.

[0067] The operation of the ventilation device 2 is controlled or regulated by a control or regulating unit 10 , which has a microcontroller in which the functions of the operating strategy for the ventilation device 2 are implemented.

[0068] The ventilation device 2 draws interior air via an exhaust air line 4 and supplies it to a return air damper 5, in particular in the form of a return air flap. The return air damper 5 is variably adjustable and can supply the interior air drawn in as return air with fresh air from the surroundings 15, which is supplied via a fresh air line 6. The proportion of fresh air in the mixed air volume flow of supplied return air and fresh air, which is provided at the output side of the return air damper 5, is predetermined by the setting of the return air damper 5.

[0069] For this purpose, a control or regulating unit 10 is provided, which sets the return air damper 5 as a function of the fresh air proportion to be predetermined.

[0070] The return air damper 5 is connected to an electrically controllable fan 7 , the speed or the fan power of which can also be set by a control or regulating unit 10 . The fan 7 causes the return air flow to pass through the ventilation device 2 and draws in fresh air from the environment 15 .

[0071] An interior filter 8 is provided on the output side of the fan 7. This filter removes particles and, in particular, bioaerosols from the supplied air. The pathogen filtration efficiency of the interior filter 8 depends on the service life of the interior filter 8 and the cumulative filtered volume of the supplied return and fresh air. In addition to the aforementioned arrangement of the interior filter on the pressure side downstream of the fan 7, the interior filter 8 can also be provided on the suction side upstream of the fan 7.

[0072] A bypass regulator 9, in particular a bypass flap or a bypass valve, is provided downstream of the interior filter 8 and can be variably adjusted in a controlled or regulated manner by a control or regulating unit 10. By means of the bypass regulator 9, a settable proportion or the entire mixed air volume flow of the return air and fresh air supplied at the outlet of the interior filter 8 can be passed through the cooling unit 11 in order to cool the passing air according to a cooling power predetermined or adjustable by the control or regulating unit 10 or, alternatively, to bypass the cooling unit 11 via a bypass line 16.

[0073] The regulating task of the bypass regulator 9 is to cause the mixed air volume flow of supplied return air and fresh air at the outlet of the interior filter 8, consisting of supplied return air and fresh air, to bypass the cooling unit 11 in an increasing proportion or entirely via the bypass line 16 as the difference between the actual value of the interior air temperature and the target value of the interior air temperature decreases. As a result, the mixed air volume flow of supplied return air and fresh air, which is required to ensure pathogen-specific air purification performance, can circulate in the ventilation system without absorbing cooling power and thus drawing excess cooling capacity from the cooling device 11.

[0074] The cooling unit 11 is connected downstream to a heating unit 12 in order to heat the air flowing through it according to a heating power predetermined or adjustable by the control or regulating unit 10. The output of the heating device 12 is returned via a supply line 13 to the interior.

[0075] Furthermore, a volume or mass flow sensor 14 can be provided, which can directly or indirectly determine a measure of the mixed air volume consisting of the supplied return air and fresh air. Furthermore, the fresh air proportion can also be determined by the position of the return air damper 5 predetermined by the control or regulation unit 10 or by another volume or mass flow sensor. In an operating strategy of an air handling system, such as temperature-controlled operation, the control deviation is the difference between a target temperature value for the interior air as a reference variable and the actual temperature value for the interior air as a controlled variable. Furthermore, depending on the complexity of the control and regulation method for the ventilation system, the ambient temperature, ambient and interior humidity or dew point, building or vehicle surface temperature, or solar radiation can be determined as disturbance variables and taken into account by the control or regulation unit 10.

[0076] The method for operating an air treatment system is carried out in the control or regulating unit 10, as described below with reference to Figure 2 The method can be implemented as software or hardware in the control or regulating unit 10. For example, the method can be updated and modified with respect to the regulating method or parameters (particularly the load protection volume flow or the infection protection volume flow or the pathogen filtration efficiency of the interior space filter) by manually or remotely modifying the ventilation system's software, in order to, for example, take into account the latest knowledge on infection protection in air hygiene research.

[0077] In step S1, a check is performed to determine whether the interior airborne pathogen load must be taken into account. For example, if only one person is in the interior, the interior airborne pathogen load need not be taken into account. This can be determined, for example, using seat occupancy sensors in the vehicle, or by a suitable camera whose image is evaluated using a person recognition method, or the like. Furthermore, if windows or other devices are open, thereby ensuring air exchange between the interior and the surroundings, then the method for limiting the interior pathogen aerosol concentration need not be executed.

[0078] If it is determined that the pathogenic body interior load must be taken into account (option: yes), the method continues with step S2. Otherwise (option: no), the method continues with step S10, in which the ventilation system 2 is operated in a conventional manner according to the selected operating strategy. To this end, the selected operating strategy predetermines a specific fresh air flow rate and a specific mixed air volume flow rate.

[0079] In step S2, the mixed air volume flow rate consisting of the supplied return air and fresh air and its fresh air ratio are determined according to the selected operating strategy. The operating strategy can specify temperature-controlled operation, operation with maximum cooling power, defrosting operation or other operating modes. Temperature-controlled operation can, for example, specify to keep the temperature of the air in the interior space constant. For reasons of energy efficiency, this operating strategy stipulates that the fresh air volume flow rate delivered by the fan is reduced as much as possible and the circulation of the mixed air is minimized. However, this will reduce the specific air purification performance of the pathogen, so that the amount of pathogen aerosols filtered out is lower. For example, in order to maintain the microbial air quality of the interior space, it may be necessary to add a minimum proportion of fresh air to the return air. Determining the fresh air ratio and the return air volume flow rate according to the predetermined operating strategy is carried out according to conventional known methods, in particular adjustment methods.

[0080] In step S3, the position of the return air damper 5 and the fan power for electrically controlling the fan 7 are determined based on the determined ratio of the fresh air to the mixed air volume flow rate composed of the supplied return air and fresh air and the determined return air volume flow rate. In addition, the heating power and the position of the bypass damper 9 for setting the cooling power can be determined based on the operating strategy.

[0081] In step S4, the pathogen filtration efficiency of the interior filter 8 for pathogen aerosols is first determined. The pathogen filtration efficiency depends on the age of the interior filter 8 and the cumulative air volume flow through the interior filter 8 during its total operating time. The pathogen filtration efficiency can be determined, for example, using a distribution function based on the age and / or total operating time of the interior filter 8 and / or the cumulative air volume flow through the interior filter 8. The distribution function is provided as a set of characteristic curves or a lookup table.

[0082] In addition, the load protection volume flow Q IS The internal space pathogen emission rate E and the internal space concentration limit C P According to the following formula, the supply of fresh air QF can help meet the load protection volume flow standard. It is applicable when the critical load risk assessment or infection risk assessment does not consider the penetration, deposition and time inactivation of pathogenic aerosols:

[0083]

[0084] In step S5, a check is performed to determine whether the determined fresh air ratio and the determined mixed air volume flow rate, at the determined pathogen filtration efficiency, meet the load protection volume flow standard, which is based on the interior pathogen emission rate E and the pathogen interior concentration limit value, which is based on the interior residence time. The following applies when the critical load risk assessment is not considered, which includes penetration, deposition, and temporal inactivation of pathogen bioaerosols:

[0085]

[0086] where λ = Q* F / (Q* F +Q R ), and (λ≠1).

[0087] In order to determine the standard of the load protection volume flow, information for evaluating the risk of harm or infection to people staying in the interior space during the residence time can be stored or implemented in the control or regulation unit for the operation of the ventilation equipment. This can include the maximum allowable pathogen load taken in by breathing, which can be expressed as the product of the maximum allowable interior space concentration and the respiratory volume taken in during the residence time. In addition to the maximum allowable pathogen load and the interior space emission rate of different pathogen sources, other load protection related parameters can also be used to evaluate the load risk based on the type of pathogen aerosol based on load studies or infection studies. In order to determine the load protection volume flow, especially in critical cases of risk assessment without taking into account the penetration, deposition and temporal inactivation of pathogen bioaerosols, this can be the load protection related parameters of the interior space emission rate and the pathogen interior space concentration limit value.

[0088] The pathogen filtration efficiency of an interior filter is a measure of how effectively its particle filtration area filters pathogen aerosols in the air. This parameter represents the degree of filtration across the entire particle size distribution of pathogen aerosols typically generated in interior spaces by contaminated / infected individuals. If the pathogen filtration efficiency is determined in laboratory tests of interior filters using deviating particle size distributions, such as artificially generated fine viral aerosols with a small mean geometric aerosol diameter, and / or if leaks in the ventilation system are taken into account, then appropriate corrections or supplementation of the load-protection volume flow standard can help maintain a specific interior load of pathogens.

[0089] If it is determined in step S5 that the settings for the determined fresh air ratio and the determined return air volume flow generated by the operating strategy do not meet the conditions of the above-mentioned load protection volume flow standard (option: no), the method continues with step S6, otherwise (option: yes) the method continues with step S10.

[0090] For example, the pathogen emission rate and the pathogen internal space concentration limit C determined by infection studiesP The values ​​of 170 m³ / s and the pathogen filtration efficiency, which is determined by artificially generated aerosols with a small mean geometric diameter, and the typical leakage rate of the ventilation system can be used to determine the infection protection volume flow rate standard value of 170 m³ / s in the critical case of risk assessment without taking into account the penetration, deposition and temporal inactivation of pathogenic bioaerosols. 3 / h.

[0091] In the case of pure fresh air operation of the ventilation equipment (λ=1), if the fresh air volume flow rate predetermined by the operation strategy is greater than or equal to 170m 3 / h, the load protection volume flow standard will be met (option: yes, then the method continues with step S10). If the fresh air volume flow rate predetermined by the operation strategy is lower than 170m 3 / h, the load protection volume flow criterion is not met (option: No, the method continues with step S6).

[0092] In the case of pure return air operation of the ventilation system (λ=0), the fulfillment of the load protection volume flow standard depends on the value of the return air volume flow and the pathogen filtration efficiency: if the return air volume flow predetermined by the operating strategy is 200m 3 / h and the pathogen filtration efficiency is 85%, then the infection protection volume flow standard is just met (option: yes, the method continues with step S10).

[0093] On the contrary, if the return air volume flow rate predetermined by the operation strategy is lower than 170m 3 / h, even with the technically maximum possible pathogen filtration efficiency of 100%, the load protection volume flow standard can no longer be met (option: No, the method continues with step S6).

[0094] In the case of mixed operation of ventilation equipment consisting of fresh air and return air (0<λ<1), the satisfaction of the load protection volume flow standard depends on the values ​​of the return air volume flow and the fresh air ratio specified by the operation strategy and the value of the pathogen filtration efficiency: when the return air volume flow specified by the operation strategy is 60m 3 / h and the pathogen filtration efficiency is 85%, if the fresh air ratio predetermined by the operation strategy is not less than 67%, the load protection volume flow standard can be met (option: yes, the method continues with step S10).

[0095] On the contrary, the same 60m is scheduled in the running strategy 3 / h return air volume flow, if the fresh air ratio predetermined by the operating strategy is lower than 64%, the load protection volume flow standard cannot be met even with the technically maximum possible pathogen filtration efficiency of 100% (option: No, the method continues with step S6).

[0096] In step S6, the set fresh air ratio (via the corresponding position of the return air damper) and / or the mixed air volume flow rate of the supplied return air and fresh air (via the corresponding setting of the fan power) are increased according to the priority level to meet the above conditions. The priority level can be determined based on the operating strategy, the state of the interior air, the state of the fresh air, and the target quota of the operating strategy. For example, during temperature control operation, if the temperature difference between the target interior air temperature and the outside air temperature is less than a predetermined temperature difference threshold, increasing the fresh air ratio is prioritized. If the temperature difference between the target interior air temperature and the outside air temperature is greater than the temperature difference threshold, increasing the fan power is prioritized.

[0097] Therefore, in order to meet the pathogen-specific interior space load criteria, for the application cases previously described in step S5 , the fresh air proportion and / or the return air volume flow can be increased as a priority:

[0098] If the return air volume flow rate is set to 60m due to the operation strategy 3 / h and the operating strategy specifies a fresh air ratio of 64%, then even with the technically maximum possible pathogen filtration efficiency of 100%, the load protection volume flow standard cannot be met. In this case, for example, during temperature-controlled operation, when the temperature difference between the target interior air temperature and the outside air temperature is less than a predetermined temperature difference threshold, it is preferable to further increase the fresh air ratio. Conversely, when the temperature difference between the target interior air temperature and the outside air temperature is greater than the temperature difference threshold, it is preferable to further increase the fan power.

[0099] A similar priority pattern can be implemented based on the particle and pollutant load in the ambient air. In addition, the presetting of the filters protecting the interior space can cause a reduction in the proportion of fresh air according to a predetermined weighting.

[0100] Then return to step S5.

[0101] In step S10 , the ventilation system can be operated based on the determined fresh air ratio and the determined return air volume flow rate. Furthermore, interventions in the operating strategy aimed at reducing the pathogenic aerosol load in the interior can be displayed to the user in a corresponding manner. This can, in particular, inform the user why the fan power is higher than expected, particularly if the fan power would result in reduced acoustic comfort.

[0102] For this purpose, a signal can be given visually via a display, for example via known display elements in vehicles (pictograms or as text messages on digital display panels), and / or by acoustic signal tones or voice prompts in one or more of the following situations:

[0103] - when activating or deactivating the method according to step S1, and

[0104] - When the method intervenes (for the first time) in the usual operating strategy after the start of a journey or a stop by changing the fan speed (increase) or the flap position (return air / fresh air, bypass) as a result, in particular if disruptive effects are expected / possible (reduced acoustic comfort due to increased fan speed).

[0105] Information can also be sent to systems connected to the vehicle, such as smartphones.

[0106] In step S10, the bypass regulator 9 can also be set according to the temperature control specified in the selected operating strategy. Thus, the setting of the bypass regulator 9 changes with the increased mixed air volume flow caused by the above-described method.

[0107] For example, if the "temperature-controlled operation" operating strategy is used in a hot environment, and the interior has already approached a lower target temperature due to the prolonged operation of the ventilation system (to achieve low control deviations and high thermal comfort), then only a low mixed air volume flow rate is required due to the operating strategy. If a significantly higher mixed air volume flow rate is required due to the present method (due to load protection) and this mixed air volume flow rate is directed through the evaporator, this may lead to further undesirable cooling of the interior, and the remaining cooling capacity of the evaporator is no longer available for subsequent cooling requirements because this cooling capacity has already been transported away.

Claims

1. A method for operating a ventilation device for interior air in an interior, the method comprising the following steps: -The fresh air ratio η of the fresh air supplied according to the predetermined or selected operation strategy R and return air volume flow Q R ; - Determine the setting of the return air damper (5) for setting the fresh air proportion and the mixed air volume flow Q consisting of the supplied return air and fresh air M The fan power of the fan (7); - Based on the pathogen internal space concentration limit C as the maximum concentration of pathogen aerosol P The pathogen filtration efficiency of the internal space filter (8) and the predetermined load protection volume flow increase fresh air ratio λ and / or mixed air volume flow Q M ,in, The fresh air ratio λ and / or the mixed air volume flow Q M The concentration of the pathogens in the interior space is increased incrementally until it falls below a threshold value for the pathogenic agent filtration efficiency of the interior space filter (8) and a predetermined load protection volume flow.

2. The method according to claim 1, characterized in that Only when there is more than one person in the interior space or no windows are open, the increase of the fresh air ratio λ and / or the return air volume flow Q is performed outside the predetermined operation strategy. R .

3. The method according to claim 1 or 2, wherein: The operating strategy prescribes: a temperature control operation for maintaining a constant interior air temperature, an operation with a maximum cooling power for the interior air, or a defrost operation with a maximum heating power for the interior air.

4. The method according to claim 1 or 2, wherein: The interior space is the interior space of a motor vehicle.

5. The method according to claim 1 or 2, wherein: The pathogen filtering efficiency of the interior space filter (8) depends on the age of the interior space filter (8) and / or the cumulative air volume flow through the interior space filter (8) during the total operating time of the interior space filter.

6. The method according to claim 1 or 2, wherein: Increase the fresh air ratio λ or the mixed air volume flow Q according to the priority M The priority is determined according to the operating strategy based on the state of the air in the interior space, the state of the fresh air and / or the target quota of the operating strategy.

7. The method according to claim 1 or 2, wherein: When the pathogen filtration efficiency and the pathogen internal space concentration limit C P Signals intervention in the planned or selected operating strategy.

8. The method according to claim 1 or 2, wherein: When the pathogen filtration efficiency and the pathogen internal space concentration limit C P Visual or acoustic signals are given when intervention in the planned or selected operating strategy is made.

9. The method according to claim 1 or 2, wherein: Depending on the selected operating strategy and the increased fresh air proportion λ and / or mixed air volume flow Q M To control the bypass regulator (9) to set the cooling power.

10. The method according to claim 1 or 2, wherein: The return air regulator is a return air flap or a return air valve.

11. A ventilation device for interior space air in an interior space, the ventilation device comprising: - a return air regulator (5), which is designed to variably set the fresh air ratio λ; - a fan (7) for generating a mixed air volume flow consisting of supplied return air and fresh air; - a control or regulating unit (10) configured to provide a fresh air ratio λ and a mixed air volume flow Q according to a predetermined or selected operating strategy M , in order to control the return air regulator (5) for setting the fresh air ratio λ and the mixed air volume flow Q composed of the supplied return air and fresh air M A fan (7) having a fan power, and in order to adjust the concentration limit value C of the pathogenic body inner space as the maximum concentration of the pathogenic body aerosol P The pathogen filtration efficiency of the internal space filter (8) and the predetermined load protection volume flow increase fresh air ratio λ and / or mixed air volume flow Q M , wherein the fresh air ratio λ and / or the mixed air volume flow Q M The concentration of the pathogens in the interior space is increased incrementally until it falls below a threshold value for the pathogenic agent filtration efficiency of the interior space filter (8) and a predetermined load protection volume flow.

12. The ventilation device according to claim 11, wherein The return air regulator is a return air flap or a return air valve.

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