Energy system

Abstract

The invention relates to, inter alia, a device (70) for evaluating the functionality of a filter device (22b) of a fuel cell system (22), having a sensor device (71) comprising at least one first sensor element (72) for measuring impurities, in particular gaseous impurities, exiting the filter device (22b) in an air flow (73). In order to provide inexpensive solutions that use structurally simple components which have a low susceptibility to malfunctioning and function in a simple manner in that as few parameters as possible must be taken into consideration when determining the adsorption state, the device (70) has the following components: an analysis device (74) for qualitatively analyzing the change in the measured impurities in the air flow (73), said analysis device being connected to the at least one first sensor element (72) via an interface (75) and having the following components: a detection device (76) which is designed to detect the impurities in the air flow (73) measured by the at least one first sensor element (72), in particular in a continuous manner, a comparator device (77) which is designed to compare the impurities in the air flow (73) detected by the detection device (76) with comparison values, and an output device (78) which is provided so as to be capable of outputting an output signal when the impurities in the air flow (73) detected by the detection device (77) reach a specified value.

Description

[0001] Description

[0002] Energy system

[0003] The present invention relates, first, to a device for assessing the functionality of a filter device according to the preamble of patent claim 1, which is used in particular in connection with a fuel cell system of an energy system. Furthermore, the invention relates to a fuel cell system according to the preamble of patent claim 8, a ventilation system according to the preamble of patent claim 11, which is in particular a component of an energy system, and an energy system according to the preamble of patent claim 13. Finally, the invention also relates to a corresponding method for assessing the functionality of a filter device.

[0004] Energy systems of this generic type are already known in the state of the art in many different ways. Such systems are usually used to generate and provide energy for a wide variety of applications.

[0005] In one known type of such energy system, energy is generated in a first energy source. The generated energy can be hydrogen, for example. The hydrogen is produced, for example, in an electrolysis device and then stored in a storage device. This is, for example, a first mode of operation of the energy system. During operation of the energy system, the hydrogen is removed from the storage device and consumed in a fuel cell system. This is, for example, a second mode of operation of the energy system. Typically, the aforementioned components of the energy system are spatially separated from one another and connected to one another via a connecting line device. Both of the aforementioned modes of operation usually require different pressure levels.While pressures of 20 to 60 bar prevail in the first operating mode with electrolysis, pressures of less than 20 bar are required for the operation of the fuel cell device in the second operating mode. In order to enable such energy systems to be used as comprehensively as possible, for example in the form of building energy systems, it is already known in the prior art to expand an energy system as described above to include a ventilation system. The ventilation system has the particular function of creating a desired room climate in a room, for example in a common room in a building, for example by ventilating and / or heating and / or cooling the room accordingly. The ventilation system can rely on processes of the energy system during operation. One such known ventilation system is disclosed, for example, in DE 102018 133 194 A1 by the applicant.In this known solution, a supply air stream provided by an outside air supply enters the ventilation system. A ventilation unit of the ventilation system, which has a heat exchanger, generates a supply air supply and delivers it to the room as supply air. Exhaust air discharged from the room is guided through the ventilation unit as an exhaust air stream via an exhaust air discharge and removed from the ventilation system as an exhaust air stream via an exhaust air discharge.

[0006] Such energy and ventilation systems are compact systems in which the individual components are used efficiently. The multiple use of individual components in different processes can also reduce the system's manufacturing costs. Furthermore, process results generated at individual points within the system, which would otherwise be treated as "waste products," can in some cases still be used as "starting products" for processes taking place elsewhere in the system. Examples include generated air flows, heat, and the like.

[0007] For example, the exhaust air generated in the ventilation system can also be used as supply air for the fuel cell system. However, the supply air to the fuel cell system, which then corresponds, for example, to the exhaust air from the ventilation system, can contain contaminants that are harmful to the fuel cell system, particularly the fuel cells. For this reason, the fuel cell system typically includes a filter device designed to filter out contaminants, particularly gaseous contaminants, from the air flow entering the fuel cell system. The filter device is arranged, particularly on the cathode side, upstream of the actual fuel cells of the fuel cell system in the direction of air flow.When applied to building energy systems, it is known that the type and quantity of harmful contaminants not only depend heavily on the specific use of the building, but can also vary considerably over time. For example, new buildings emit many times more gaseous air pollutants through evaporation in the first few months than after several years. Fixed service intervals for filter systems are therefore considered uneconomical.

[0008] An excessive concentration of contaminants in the air stream entering the fuel cell leads at least to a reduction in the fuel cell's performance, but usually also to damage in the form of irreversible aging or an irreversible loss of fuel cell performance, leading to partial or even total failure. For this reason, it is necessary to know the loading status of the filter device upstream of the fuel cells, i.e., its adsorption state, in order to replace this filter device in a timely manner.

[0009] A solution for this has already been disclosed in DE 102 30283 A1. According to this known solution, the gases for fuel cells are passed through a regenerable filter system, which is monitored for deterioration of the filtering effect. Either the pressure difference between the pressure upstream and downstream of the filter system is compared with specified limits. Or pollutants are measured with a corresponding sensor downstream of the filter system and compared with specified limits.

[0010] DE 11 2007 001 423 B4 discloses a different solution. The starting point of this known teaching is a fuel cell system that has a filter device, such as an activated carbon filter, for removing contaminants. According to the teaching of this document, various parameters are measured, including the concentration of harmful substances in an air stream. This measurement is always performed upstream of the filter device in the direction of air flow. The measured parameters are used to estimate whether the end of the filter device's service life has been reached. This is the case when the estimated value resulting from the estimation process, usually a value of the pollutant quantity accumulated over time, exceeds a defined limit. If this is the case, a warning is generated.The disadvantage of the known solution is, first of all, that the process is complex, as it requires a computer unit that must perform extensive calculations. Furthermore, the solution is prone to failure, since to generate the estimated value, several different parameters, in particular the pollutant concentration in the gas and the gas volume flow, must be recorded simultaneously with sufficient accuracy and long-term stability, with various components having to interact. If there is a problem with just one parameter, the entire measurement is invalid. Another problem is the usually poorly known and often batch-dependent capacity of the filter device.Another disturbance factor for the precise determination of filter capacity is a generally non-uniform flow through the filter device, which creates locally varying, uneven loading levels and even causes pollutant breakthroughs when the average filter load is still well below the loading limit. However, if the fuel cell system is used in an energy system or in a ventilation system of the type mentioned above, unknown, temporally variable pollutant concentrations can occur in the exhaust air of the ventilation system, which is used as supply air for the fuel cell system. The known solution is therefore particularly unsuitable for use in conjunction with an energy system or a ventilation system.In such applications, it is therefore still necessary to check the filter system in the supply air to the fuel cells at fixed service intervals, which must be sufficiently short for safety reasons due to the aforementioned possible fluctuations in impurities in the air flow.

[0011] The present invention is therefore based on the object of developing a device for assessing the functionality of a filter device or the effectiveness of a filter device, a fuel cell system, a ventilation system and an energy system of the type mentioned above in such a way that the disadvantages described in the prior art are avoided. Since it is important for the individual system components, particularly when used in ventilation systems and energy systems, to operate in a cost-optimized manner, the object is in particular to provide cost-effective solutions that use structurally simple components that are less susceptible to failure and measurement errors, and that function simply by having to take into account as few parameters as possible when assessing the functionality of the filter device. The sensor elements used should be designed as simply as possible.Furthermore, a correspondingly improved method for assessing the functionality of a filter device is to be provided.

[0012] This object is achieved according to the invention by the device for assessing the functionality of a filter device having the features of independent patent claim 1, which represents the first aspect of the invention, by the fuel cell system having the features of independent patent claim 8, which represents the second aspect of the invention, by the ventilation system having the features of independent patent claim 11, which represents the third aspect of the invention, by the energy system having the features of independent patent claim 13, which represents the fourth aspect of the invention, and by the method for assessing the functionality of a filter device having the features of independent patent claim 14, which represents the fifth aspect of the invention.

[0013] Further features and details of the invention emerge from the dependent claims, the description, and the drawings. Features and details disclosed in connection with one aspect of the invention also apply in full to all other aspects of the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made in full to the respective other aspects of the invention.

[0014] All aspects of the invention are based on the common inventive concept that the functionality of a filter device is assessed using a device. This means that the device is designed to test the functionality of the filter device. In particular, the device can be used to draw conclusions about the loading state or the effectiveness of the filter device. For example, the device qualitatively assesses or determines the adsorption state of a filter device based on its effectiveness.

[0015] The adsorption state is understood in particular to be the degree of adsorption of atoms or molecules of substances, here of contaminants, which are particularly present in gaseous form, on the surfaces of the material of the filter device. In the new state and when the filter device is sufficiently functional, there are still a sufficient number of free sites on the surfaces of the material of the filter device and the pollutant molecules can be adsorbed and thus removed from the air stream. A suitable sensor upstream of the filter device would therefore measure a higher concentration of pollutants than a sensor downstream of the filter element. If more and more pollutant molecules adsorb on the surfaces of the material of the filter device over the course of operation, the number of free adsorption sites becomes too small and the pollutants can no longer be completely removed from the air stream.A suitable sensor will no longer be able to detect any or insufficient reduction in the pollutant content in the air stream downstream of the filter device.

[0016] According to this measurement method, a qualitative determination of the adsorption state is, in particular, a determination of the changing adsorption efficiency over time. The determination of the adsorption state is, in particular, a determination of the adsorption state.

[0017] The determination of contaminants in the air stream can be performed in various ways, for example, by measurement, by calculation, or by a combination of measurement and calculation. The latter variant, in particular, involves measuring values ​​using a sensor element, and then evaluating these measured values. It should be noted that some modern and generally expensive gas sensors can already perform complex internal calculations of the raw measured value using stored substance data to account for cross-sensitivities of various contaminants. Experience has shown that this is prone to errors with unknown contaminants.

[0018] In principle, a single sensor element is sufficient for the device, which is provided to measure contaminants contained in an air stream, in particular gaseous contaminants. Such an air stream first flows through a filter device, which is provided to reduce concentration values ​​of contaminants, in particular gaseous contaminants, in the air stream. In particular, the filter device is provided to filter out harmful gases for a fuel cell. The air stream enters the filter device with an initial amount of contaminants. The filter device filters out the contaminants and retains them in the filter device. An air stream with a reduced amount of contaminants then exits the filter device.A sensor element, which is preferably located behind the filter device, or which detects the remaining contaminants in the air stream behind the filter device. According to the invention, it is no longer necessary to detect the absolute values ​​of the contaminants in order to draw conclusions about the functionality of the filter device. Rather, it is sufficient if the sensor element, which preferably performs the measurement continuously, monitors for changes in its measured value and a temporal change is detected. Absolute values ​​are therefore not relevant; but the temporal change is. For example, a long-term change over weeks can be monitored here.It is also possible to monitor a short-term change in seconds or a few minutes if, after a switching process in the air duct, the air flow is quickly redirected in such a way that the filter device is no longer flowing through and the sensor, which was previously supplied with air purified or potentially purified via the filter device, is now supplied with air that has not flowed through the filter devices. A switching process in the other direction is also suitable for measuring filter functionality. Such a switching process can be a switched bypass. Examples and embodiments of this are explained in more detail below, particularly in connection with the other aspects of the invention.As a result, the device according to the invention can be used to detect longer loading effects (predictive maintenance), but also to use thresholds of the measurement signal change in the short-term range in several gradations (predictive maintenance up to the (temporary) switching off of a fuel cell) to protect the fuel cell.

[0019] If necessary, the measuring environment of the sensor element can be actively influenced for this change measurement, for example by hermetically closing the fuel cell supply air flap and / or by switching off the hydrogen supply to the fuel cell for a certain period of time, which is preferably longer than ten minutes.

[0020] In conjunction with the device according to the invention, simple and cost-effective commercial sensor elements, for example so-called VOC sensor elements with or without their own evaluation logic, can be used. A VOC sensor element measures, in particular, the ambient concentration of a wide range of gaseous substances associated with poor air quality. The device according to the invention is therefore less concerned with the measured value itself. Rather, it is primarily concerned with using the gradient detected by the sensor element or a short-term difference to assess the functionality of the filter device.

[0021] In the following, the basic relationships and advantages of the invention are first described according to the individual aspects of the invention.

[0022] In the solution according to the invention, the measurement of the concentration of contaminants in the air stream upstream of the filter device is not required, as is the case with the solution known from the prior art, to determine how many contaminants, which in particular are harmful substances, have entered the filter device and thereby exhausted its capacity. Rather, according to the invention, it is determined whether the concentration of contaminants in the air stream decreases significantly in quality as the air flows through the filter device. In this case, it is not necessary to know or determine the actual levels of contaminants. Rather, it is sufficient to detect the change itself. If this is the case, the filter device is still active. In the best case, this can be achieved using a single sensor element, as already described above or as explained in more detail below using preferred embodiments.For the qualitative evaluation of a signal change, a simple sensor element is usually sufficient, which also does not have to be highly precise or compensated by cross-calculations.

[0023] If the adsorption state, i.e., the loading, and thus the effectiveness of the filter device can be detected, a component downstream of the filter device, for example, a fuel cell, and in particular a cathode of the fuel cell, can be reliably protected from contamination, especially pollutants. Furthermore, this can optimize a service interval as described above. Furthermore, the invention can account for an unknown, possibly highly variable concentration of contaminants, such as a pollutant concentration, in the air stream entering the filter device.

[0024] If the filter device has reached an excessively high loading level, i.e., an excessively high adsorption level, which can be referred to as the critical adsorption level, the concentration of contaminants in the air stream leaving the filter device rises sharply and may even exceed the permissible limits. Sensor elements exist, a number of preferred embodiments of which are described below, that can detect one or more contaminant materials, i.e., substances, in an air stream. When the change in contaminants downstream of the filter device is measured, the current effectiveness of the filter device with respect to this contaminant group or with respect to the contaminant group in question becomes apparent.In particular, it is assumed that a less effective filter device indicates the occupancy of a large number of the filter device's active centers and thus a deteriorating filtering effect of other contaminant materials, i.e., substances with comparable adsorption behavior. In this case, it is sufficient to measure the qualitative change. This means that lower demands can be placed on the absolute accuracy of the sensor elements. This leads to more cost-effective solutions.

[0025] According to the invention, it is therefore sufficient to detect the temporal change in the presence of one or more contaminant classes or substance classes. It is preferable to measure the concentration differences downstream of the filter device, and if necessary also upstream of the filter device. Under special conditions, which will be discussed in more detail below, it is even sufficient to measure with a sensor element or a group of sensor elements at a single location. This then leads to a saving in the number of sensor elements if only one location is to be measured.

[0026] According to the invention, the functionality of the filter device is assessed via a sensor element placed downstream of the filter device, for example by determining, for example measuring and / or calculating the load of the filter device. This can be used to indicate the replacement interval of the filter device. The filter device is loaded when there is a measurable increase in the concentration of contaminants in the air stream being examined over a time interval via the sensor element. The use of an optional additional sensor element upstream of the filter device leads to an improvement in accuracy, since the absorption capacity of the filter device can be determined by calculating the difference upstream and downstream of the filter device and / or the accuracy of the two sensors can then be mutually compared under certain operating conditions.In one embodiment, the measurement of contaminants by the sensor element is accompanied by additional measures that further simplify the measurement. For example, the measurement can be performed when the fuel cell operation of the fuel cell system is switched off. In this state, the fuel cells are flowing without load, i.e., in particular, without hydrogen and electrical current. When the fuel cells are not running, a sensor element arranged downstream of the fuel cells will not detect any elevated temperatures, vapor content, or traces of hydrogen during the measurement, which could adversely affect the measurement result. Such measures are particularly advantageous when a bypass solution as described below is implemented.

[0027] Advantages of the present invention include, in particular, that service intervals can be optimized, the costs for required service actions can be reduced, and that there is a low risk of damage to components downstream of the filter device, for example, degradation of fuel cells shaded by the filter device. This leads to a longer service life.

[0028] In the following, the individual aspects of the invention are explained in detail, also taking into account the above general explanations of the invention.

[0029] According to the first aspect of the invention, a device for assessing the functionality of a filter device is provided, which device has the features of independent patent claim 1. In particular, this device is provided for assessing the filter device of a fuel cell system. The device thus indirectly determines the loading state of the filter device. In particular, a critical adsorption degree, i.e., a critical adsorption intensity, is determined.

[0030] The device, which will occasionally also be referred to as a determination device below, has a sensor device. This sensor device comprises one or more sensor elements. In some embodiments, which are described in more detail below, the sensor device has only one sensor element. In other embodiments, the sensor device has more than one sensor element, for example two or three sensor elements. According to the invention, the sensor device has at least a first sensor element for measuring contaminants, in particular gaseous ones, in an air stream. The sensor element is provided in particular for continuous measurement. In particular, the sensor element is provided for the preferably continuous determination of concentration values ​​of contaminants in an air stream exiting the filter device.In light of the present description, the first sensor elements are functionally characterized, as will be explained in detail below with reference to preferred embodiments, in that they determine, for example measure, contaminants in an air stream, in particular concentration values, that exits the filter device or is located downstream of the filter device in the flow direction of the air stream, or that is guided past the filter device in the bypass. In some embodiments, second sensor elements are also used. These determine, for example measure, contaminants in an air stream that enters the filter device or is located upstream of the filter device in the flow direction of the air stream. The invention is not limited to specific types of sensor elements. Some preferred embodiments in this regard will be explained in more detail below.

[0031] Furthermore, the determination device comprises an evaluation device for qualitatively evaluating the change in the measured contaminants in the air stream, which also makes it possible to draw conclusions about a change in concentration. The evaluation device is connected to the at least one first sensor element via an interface. The evaluation device comprises a series of components. These components can be present, for example, as independent components, for example, as electronic components or components that interact with one another. The components can also be implemented, for example, as electronic circuits or circuit parts. In other embodiments, the components are logic modules or algorithms or components of a computer program.For example, a computer program enables a data processing system or an electronic circuit with corresponding components or logic modules to carry out the method according to the fifth aspect of the invention, which is described further below. In a preferred embodiment, the components are functional components of a controller. This means that the components are those components of a controller that perform a specific function and are defined by this function. The evaluation device can, for example, be a component of the sensor element, in particular an intelligent one, or of the sensor device. The results are generated in the sensor element itself and subsequently transmitted to a receiver via the interface. In another preferred embodiment, the evaluation device is a component of a control device.In the latter case, the determination device, preferably the evaluation device, can have an interface to a control device. The control device can be, for example, a control device specifically provided for the determination device, or, in accordance with the further aspects of the invention, a control device or a component of a control device of a ventilation system or an energy system. In another embodiment, the control device can be a component of the evaluation device.

[0032] The following describes the individual components of the evaluation device, which, as described above, can be implemented either as physical components or in the form of functional processes.

[0033] One component is a detection device, which is provided for the, in particular continuous, detection of the contaminants in the air stream measured by the at least one first sensor element. The contaminant values ​​detected by the first sensor element are transmitted to the evaluation device via a sensor tap and a corresponding interface, and are detected by the detection device.

[0034] The detection device interacts with another component, a comparator device. The comparator device is provided to compare the contaminant levels in the air stream detected by the detection device with reference values, for example, with reference values. This can be done in different ways, as explained in more detail later in the description. Likewise, different types of reference values ​​can be used.For example, the reference values ​​can be in the form of previously detected values ​​of contaminants in the air stream exiting the filter device and / or with contaminants in or in an air stream that does not flow through the filter device, and / or in the form of contaminant threshold values ​​and / or in the form of concentration values ​​of contaminants in an air stream that is bypassed past the filter device, and / or in the form of concentration values ​​of contaminants in an air stream that enters the filter device. The values ​​detected by the first sensor element indicate, in particular, the concentration of contaminants in the air stream exiting the filter device. If, for example, no concentration of contaminants is detected by the first sensor element, this means that the filter device is active and any contaminants are being effectively adsorbed in the filter device.If, however, the first sensor element measures a concentration, the comparator device determines the extent to which the concentration in the air stream is harmful. In a preferred embodiment, if the currently measured concentration values ​​in the comparator device are compared, for example, with previously measured concentration values ​​or with bypass values, a trend regarding the concentration change and thus the qualitative change in the effectiveness of the filter device can be determined. If the measured concentration values ​​are compared in another embodiment or additionally with concentration limit values, it can be determined whether the concentration values ​​are approaching these concentration limit values. For example, limit values ​​can be provided that reflect a critical load of the filter device.If such a limit is reached, or if the measured concentration values ​​approach such a limit, this is an indication that the quality of the filter device is decreasing and the filter device may need to be replaced.

[0035] Furthermore, the evaluation device has an output device configured to output an output signal when the contaminants in the air stream detected by the detection device reach a predetermined level. This can be accomplished in various ways. For example, a warning light could be activated. Or a signal, such as a message, is generated, which is transmitted to a monitoring location, particularly a central one.

[0036] The determination device according to the invention is provided in particular to detect or be able to detect the temporal change of impurities, in particular of concentration values ​​of impurities, in the air flow exiting the filter device.

[0037] In a preferred embodiment, at least one first sensor element is provided for measuring contaminants in an air stream, in particular for determining contaminant concentrations in an air stream exiting the filter device, and additionally for at least temporarily measuring contaminants, in particular for determining contaminant concentrations, in an air stream passing the filter device in a bypass. The sensor element is then positioned such that, in some operating states, it measures the contaminants in the air stream passing the filter device in a bypass, and, in some operating states, it measures the contaminants in the air stream passing through the filter device.An exemplary embodiment of this, which also explains the basic functionality of such a bypass solution, is described below in connection with the fuel cell system according to the invention. Regarding the general design and functionality of the bypass design, reference is made here to the corresponding explanations below and made in full. Shadowing then produces increasingly divergent measurement signals as the filter device load increases.In this embodiment, it is preferably realized that the evaluation device, in particular the comparator device, has a device for forming the difference between values, in particular concentration values, of impurities in an air flow exiting the filter device, which are detected by the at least one first sensor element, and values, in particular concentration values, of impurities in an air flow that is guided past the filter device in the bypass, which are detected by the at least one first sensor element. In another embodiment, instead of just one sensor element, two first sensor elements can be provided, wherein one sensor element detects values, in particular concentration values, in the air flow exiting the filter device, and another first sensor element detects values, in particular concentration values, in the air flow that is guided past the filter device in the bypass.

[0038] Since the solution according to the invention does not require knowledge of the absolute accuracy of the values, in particular the concentration values, of contaminants in the air stream, but rather only a stable, qualitatively usable signal, the present invention has an advantage if the values ​​of the same sensor element are measured and compared at the same location with different flow guidance, for example through the filter device vs. not through the filter device. This can also be achieved with two sensor elements, possibly with different designs. In such a case, the output device is preferably provided in such a way that it is capable of outputting an output signal when a change in contaminants in the air stream detected by the detection device reaches, for example falls below, a predetermined value in at least two different operating states.

[0039] In a preferred embodiment, the sensor device comprises, in addition to at least one first sensor element, a second sensor element which is provided for the, in particular continuous, determination of values, in particular concentration values, of contaminants in an air stream entering the filter device.

[0040] The values ​​detected by the first and second sensor elements are compared with each other in the evaluation device, in particular in the comparator device. If the concentration in the air stream entering the filter device is already low, this is an indication that the air contains few contaminants, meaning that the filter device is not contaminated. If the contaminant levels in the air stream upstream of the filter device are higher than the contaminant levels in the air stream downstream of the filter device, this means that the filter device is active and functioning properly. If the values ​​​​similar, in particular if the contaminant levels in the air stream downstream of the filter device increase, this means that the effectiveness of the filter device is decreasing.In this embodiment, it is preferably realized that the evaluation device, in particular the comparator device, has a device for forming the difference between values ​​of impurities in an air flow exiting the filter device, which are detected by the at least one first sensor element, and values ​​of impurities in an air flow entering the filter device, which are detected by the second sensor element.

[0041] In a preferred embodiment, the determination device comprises a storage device in which at least temporarily values, in particular concentration values, of contaminants in an air flow upstream and / or downstream of the filter device, and / or in a bypass air flow, which are detected by the at least one first sensor element and / or the second sensor element, and / or comparison values, in particular concentration reference values, are or are stored. According to the second aspect of the invention, a fuel cell system is provided which has the features of independent patent claim 8. The fuel cell system initially comprises a fuel cell module.In the light of the present description, the fuel cell module refers in particular to the actual fuel cells, which are implemented either as individual fuel cells or in the form of a fuel cell stack. The basic structure of such fuel cell systems is known and familiar to those skilled in the art. The invention is not limited to specific types of fuel cells. For example, these can be so-called PEM (proton exchange membrane) fuel cells. These are preferably air-cooled fuel cells with an open cathode.The efficient removal of pollutants from the air is particularly important for a directly air-cooled fuel cell, in which the cooling air flow simultaneously represents the oxygen supply on the cathode, i.e. in which a relatively large air volume flow, which may contain the contaminants, is in direct contact with the cathode of the fuel cell.

[0042] The fuel cell system also includes a filter device designed to reduce the concentration of impurities, particularly gaseous ones, in an air stream flowing through the fuel cell module. The filter device is arranged in the air supply path to the fuel cell module, preferably on the cathode side. In addition, the fuel cell system includes a device for assessing the functionality of the filter device, preferably for determining a critical adsorption level of the filter device. This determination device is either a direct component of the fuel cell system. Or the fuel cell system, particularly its filter device and corresponding sensor elements, has suitable interfaces to spatially distant components of the determination device, for example, to the evaluation device.The determination device is designed according to the first aspect of the invention, so that with regard to the design of the fuel cell system, in particular also with regard to its mode of operation, reference is made here in full to the statements on the first aspect of the invention and to the general description of the invention in order to avoid repetition.

[0043] In the following, some preferred embodiments of the fuel cell system are described based on the various embodiments of the determination device above, so that reference is also made to the corresponding statements above.

[0044] For example, the at least one first sensor element of the determination device can be arranged downstream of the filter device and / or downstream of the filter device and, in particular on the cathode side, upstream of the fuel cell module and / or downstream of the fuel cell module. In the first two cases, the adsorption state of the filter device alone can be assessed. As the air flows through the cathode, some of the pollutants still present can be adsorbed on the cathode catalyst itself. This can irreversibly damage the activity of the catalyst, while also reducing the pollutant concentration at the cathode outlet. In the third case, the load on the fuel cell module is therefore also determined.Two such first sensor elements can also be realized, wherein a first sensor element is arranged behind the filter device and a further first sensor element is arranged behind the fuel cell module.

[0045] In one embodiment, the first sensor element is installed in the fuel cell system, downstream of the filter device, but before or after the air-cooled fuel cells with open cathode, i.e. with air space, of the fuel cell module.

[0046] Preferably, the loading of the filter device of the fuel cell system is determined, for example measured and / or calculated, via a sensor element located downstream of the filter device. This can be used to indicate the replacement interval of the filter device. The filter device is loaded when there is a measurable concentration of contaminants in the air stream being examined via the sensor element. The use of an additional sensor element upstream of the filter device leads to improved accuracy, since the absorption capacity of the filter device can be determined by calculating the difference upstream and downstream of the filter device. Measuring the concentration downstream of the fuel cell module can also be used to determine the loading of the fuel cell(s).

[0047] In a preferred embodiment, at least a first sensor element of the determination device is additionally connected to an air stream that is guided past the filter device in a bypass. The sensor element is then positioned such that, in non-fuel cell operation, the air that would otherwise enter the fuel cell system is measured in the bypass of the filter device, and in fuel cell operation, the air flows through the filter device. Switching then produces increasingly divergent measurement signals with increasing load. For example, the sensor element can draw the fuel cell air via a hose connection between the filter device and the fuel cell module inlet. This is precisely when a driving pressure gradient exists. When the fuel cell module is not running, the sensor element draws the air from the bypass air stream automatically or via a tapping point. This can be implemented completely passively.Instead of only one first sensor element, two first sensor elements can also be used, each sensor element being assigned to a single air flow, as is also described above in the corresponding embodiment of the determination device.

[0048] In a preferred embodiment, the air flow passing the filter device in the bypass is an air flow passing through the electrolysis device. This will be illustrated using a specific example in the context of an energy system that has an electrolysis device and a fuel cell system.

[0049] The energy system has various operating states, which are also described at the beginning of the introduction to the description, so that reference is also made to the information from the introduction to the description at this point. First, in fuel cell operation, at least a portion of the air flow flows through the filter device and the fuel cell, which is thus cleaned in the filter element. The air flow flows around the sensor element and generates the reference signal for cleaned air. Then, when changing from fuel cell operation to electrolysis operation, the air path switches from the fuel cell device towards the electrolysis system. The individual, in particular counter-rotating flaps of the fuel cell system and the electrolysis device preferably serve as actuators for the flow switching by being opened and / or closed in a suitable manner.The comparison values ​​measured by the sensor element are thus provided by a process in which the operating states are switched from fuel cell operation to electrolysis operation and vice versa. It is irrelevant whether the electrolysis system is operating or not. Active operation of the electrolysis device is not required. It is sufficient to shut down the fuel cell system and adjust the corresponding flaps accordingly. Preferably, when neither the fuel cell system nor the electrolysis device is running, the air flow, which represents the bypass air flow, passes through the electrolysis device.

[0050] This "switching" is usually a continuous, counter-current process. For example, a fuel cell flap closes completely and a flap of the electrolysis unit opens. In the described system and operating concept, the air then flows completely through the electrolysis unit without passing through the filter unit. Subsequently, a portion of the exhaust air, which still contains the original contaminants, reaches the location of the sensor element through simple turbulence and backflow or through diffusion, generating the measurement signal for the condition of the unfiltered, contaminated air.

[0051] In one embodiment, when the fuel cells are in standby mode, the control room is passively air-flowed by turbulence of the passing main air stream. Leakage gases, particularly hydrogen, that may potentially distort the measurement result can be "switched off" for evaluation.

[0052] In one embodiment, the sensor device has a second sensor element which is provided for the, in particular continuous, determination of values, in particular concentration values, of contaminants in an air stream entering the filter device. The values ​​detected by the sensor elements are compared with one another in the evaluation device, in particular in the comparator device. If the values, in particular concentration values, of contaminants in the air stream upstream of the filter device are higher than the values ​​of contaminants in the air stream downstream of the filter device, this means that the filter device is active and functioning properly. If the values ​​equalize, in particular if the values ​​of contaminants in the air stream downstream of the filter device become higher, this means that the effectiveness of the filter device is diminishing.In this regard, reference is also made to the explanations regarding the corresponding embodiment according to the first aspect of the invention. If the filter device has reached an excessively high loading state, i.e., an excessively high adsorption state, which can be referred to as the critical adsorption level, the concentration of contaminants in the air stream leaving the filter device rises sharply and may even exceed the permissible limits of the fuel cell supply air. Sensor elements exist that can detect some of the pollutants for fuel cells. These sensors are already partially used in indoor air conditioning technology. If the contaminant levels, in particular their concentration, can be measured before and / or after the filter device, the current effectiveness with regard to this substance or the relevant group of substances can be determined.A less effective filter device indicates that many of the filter device's active centers are occupied and thus that the filtering effectiveness of other pollutants with comparable adsorption behavior is also deteriorating. According to the invention, it is sufficient to measure the qualitative change. This means that lower demands can be placed on the absolute accuracy of the sensors. This leads to more cost-effective solutions. It is therefore sufficient to detect the temporal change in the values, particularly the concentration, of one or more substance classes in the air stream. Ideally, the concentration differences should be measured upstream and downstream of the filter device. However, according to the invention, it is sufficient to measure with one sensor or with a group of sensors at just one point.

[0053] The invention is not limited to specific types of the sensor elements described above. The sensor elements must merely be capable of recognizing or sensing or detecting contaminant levels, i.e., the presence of contaminants, in particular contaminant concentrations, in an air stream. For example, the at least one sensor element and / or the second sensor element can be designed to detect pollutants in an air stream or to detect volatile organic compounds, also called "Volatile Organic Compounds" (VOCs), in the air stream. Pollutants or contaminants in the air stream that pose a threat to fuel cells can be harmful gases, such as, in particular, nitrogen monoxide, nitrogen dioxide, hydrogen sulfide, sulfur dioxide, carbon monoxide, ammonia, benzene, toluene, and the like.

[0054] Likewise, the invention is not limited to specific types of filter devices. Depending on the application, the filter devices must be capable of filtering out harmful substances and contaminants from an air stream for components downstream of the filter device, such as fuel cells. For example, the filter device can be or comprise a chemically or physically active filter element by adsorption, in particular an activated carbon filter element.

[0055] According to the third aspect of the invention, a ventilation system for a room is provided, wherein the ventilation system is in particular a component of an energy system, which has the features of independent patent claim 11. The ventilation system has an outside air supply which is provided in such a way that it is capable of allowing a provided supply air flow to enter the ventilation system via it, a ventilation device which is provided in such a way that it is capable of generating a supply air supply and providing it to the room as supply air, an exhaust air discharge which is provided in such a way that it is capable of discharging exhaust air from the room via it and guiding it over the ventilation device, and an exhaust air discharge which is provided in such a way that it is capable of discharging the discharged exhaust air as an exhaust air flow from the ventilation system.According to the invention, the ventilation system is characterized in that the ventilation device has an interface to a device for assessing the functionality of a filter device, preferably for determining a critical adsorption level of the filter device according to the first aspect of the invention, or to a fuel cell system according to the second aspect of the invention, or in that the ventilation device has such a determination device according to the first aspect of the invention, or a fuel cell system according to the second aspect of the invention. To avoid repetition, reference is therefore made in full at this point to the statements on the first and second aspects of the invention as well as to the general description of the invention.

[0056] In one embodiment, the ventilation system comprises a sensor element, which is provided for monitoring the room air and / or for controlling the ventilation system and which interacts at least temporarily with the device for assessing the functionality of the filter device. The values ​​detected by this sensor element are then preferably used as reference values ​​in calculating the measured value change of the primary sensor, i.e., the first sensor element of the determination device. This preferably occurs similarly to a calibration or for general function monitoring. This additional sensor element is preferably arranged upstream of the fuel cells, in particular in the main flow, such as the house exhaust air, of the ventilation system.

[0057] According to the fourth aspect of the invention, an energy system, in particular a building energy system, is provided which has the features of independent claim 13.

[0058] The energy system comprises an electrolysis device, a fuel cell system, optionally a high-pressure storage device, and a connecting line device via which the electrolysis device is connected to the fuel cell system, and the high-pressure storage device is connected to the fuel cell system. According to the invention, the energy system is characterized in that it comprises a device for assessing the functionality of the filter device, preferably for determining a critical adsorption level of the filter device of the energy system according to the first aspect of the invention, and / or that the fuel cell system is designed according to the second aspect of the invention, and / or that the energy system comprises a ventilation system according to the third aspect of the invention.In order to avoid repetition, reference is made here in full to the statements on the first, second and third aspects of the invention as well as to the general description of the invention.

[0059] The energy system is, in particular, a whole consisting of several components, wherein the components are connected to one another to form a dedicated unit. In the present case, the energy system is a system for generating or providing energy, preferably electrical energy. In principle, the invention is not limited to specific types of energy systems. Various preferred embodiments are described below.

[0060] In a preferred embodiment, the energy system is a building energy system. Building energy systems are generally known from the prior art and serve to supply buildings, for example, low-energy houses, passive houses, or zero-energy houses, with energy in the form of heat and, in particular, in the form of electricity, for example, electricity from renewable energy sources such as photovoltaic (PV) generators or small wind turbines.Such a building energy system creates the basis for the energy requirements of a building, for example a low-energy house, a passive house or a zero-energy house, to be covered entirely from renewable energy sources, both in terms of electricity and heat requirements, and thus to ensure complete CCk freedom during operation. At least, however, the electricity requirements of a building can be covered almost entirely from renewable energy sources, in particular by means of a PV generator and / or a small wind turbine, in order to achieve an increase in self-consumption.

[0061] Such an energy system is disclosed and described, for example, in the applicant's patent applications WO 2017 / 089468 A1 and WO 2017 / 089469 A1, the disclosure content of which is incorporated into the description of the present patent application.

[0062] According to a preferred embodiment, an energy system of the type mentioned has the following basic features: a DC feed-in point, preferably designed for a nominal voltage of 48 volts or for a nominal voltage between 200 and 1000 volts and / or an AC feed-in point, preferably designed for a voltage of 230 volts or 110 volts or a 3-phase feed-in with 230 volts or 110 volts per phase, wherein the DC feed-in point and / or the AC feed-in point is connected during operation at least temporarily to an electrical consumer having a consumption power, a PV generator electrically connected to the DC feed-in point at least temporarily for generating electrical PV power, a fuel cell unit electrically connected to the DC feed-in point or to the AC feed-in point at least temporarily for generating electrical fuel cell power,an electrolysis unit electrically connected to the DC feed point for generating hydrogen to be consumed by the fuel cell unit, wherein the electrolysis unit is supplied with an electrical electrolysis input power during operation, a hydrogen tank, in particular as a long-term energy storage device, which is at least temporarily fluidically connected to the fuel cell unit and the electrolysis unit and is designed to store hydrogen to be generated by the electrolysis unit and consumed by the fuel cell unit, a storage battery unit, in particular as a short-term energy storage device, which is or is to be electrically connected to the DC feed point,so that an electrical PV power and an electrical fuel cell power can be stored in the storage battery unit, and an electrical electrolysis input power and a consumption power can be drawn from the storage battery unit; and a control module for controlling the home energy system.

[0063] According to the fifth aspect of the invention, a method for assessing the functionality of a filter device, preferably for determining a critical adsorption level of the filter device, in particular using a device according to the first aspect of the invention, is provided. The method is preferably used for a fuel cell system according to the second aspect of the invention, or in a ventilation device according to the third aspect of the invention, or in an energy system according to the fourth aspect of the invention. The method comprises the features of independent claim 15.With regard to the design of the method, in particular also with regard to its mode of operation, in order to avoid repetition, reference is made here in full to the statements on the first aspect of the invention, the second aspect of the invention, the third aspect of the invention, the fourth aspect of the invention, and to the general description of the invention.

[0064] According to the invention, the method is characterized by the following steps:

[0065] First, impurities, in particular gaseous ones, in an air stream that exits the filter device or that is located downstream of the filter device are measured with at least one first sensor element.

[0066] In an evaluation device, which is connected to the at least one first sensor element via an interface, values ​​of the measured impurities are received, in particular continuously, and a qualitative evaluation of the change in the measured impurities, in particular a change in the concentration of impurities, in the air flow is carried out by detecting, in particular, the temporal change in the measured impurities in the air flow exiting the filter device.

[0067] Preferably, the qualitative evaluation of the measured impurity values, in particular a change in the concentration of impurities in the air stream is carried out by detecting the impurities measured by the at least one first sensor element, in particular the concentration values ​​of impurities in the air stream, in particular continuously; in a comparator device, the values ​​detected by the detection device, in particular concentration values, of impurities in the air stream are compared with comparison values, in particular concentration reference values; in an output device, an output signal is output when a value detected by the detection device, in particular concentration value, of impurities in the air stream reaches a predetermined value, for example exceeds or falls below it.

[0068] For the qualitative determination of the adsorption state in the filter device, the values ​​detected by the detection device, in particular concentration values, of contaminants in the air stream are preferably compared in the comparator device with previously detected values, in particular concentration values, of contaminants in the air stream, and / or with comparison values, in particular reference values, such as concentration reference values ​​in the form of previously detected values, in particular concentration values, of contaminants in the air stream, and / or with contaminants in or in an air stream that does not flow through the filter device, and / or with detected values ​​of contaminants, in particular concentration values, in a bypass air stream, and / or with contaminant limit values. In this regard, the disclosure also refers in particular to the various exemplary embodiments relating to the first and second aspects of the invention.

[0069] In a preferred embodiment of the method, first values, in particular concentration values, of contaminants in the air stream exiting the filter device are detected using the at least one first sensor element. Second values, in particular concentration values, of contaminants in an air stream passing the filter device in a bypass are additionally detected using the at least one first sensor element, or using a second first sensor element. In the evaluation device, the first and second values ​​are compared with one another, in particular by calculating the difference between the first and second values.

[0070] In a preferred embodiment, the air flow passing the filter device in the bypass is an air flow passing through the electrolysis device. In this regard, reference is also made to the corresponding statements in connection with the second aspect of the invention above, and reference is made in full.

[0071] This will be illustrated using a concrete example in the context of an energy system that features an electrolysis unit and a fuel cell system. During fuel cell operation, at least a portion of the airflow flows through the filter unit and the fuel cell, which is then cleaned in the filter element. The airflow flows around the sensor element and generates the reference signal for cleaned air. When switching from fuel cell operation to electrolysis operation, the air path switches from the fuel cell unit to the electrolysis system. To carry out this change, corresponding flaps assigned to the fuel cell system and the electrolysis unit are preferably opened and / or closed. It is irrelevant whether the electrolysis system is operating or not.When neither the fuel cell system nor the electrolysis system is running, the airflow, which represents the bypass airflow, passes through the electrolysis system without passing through the filter system. Subsequently, a portion of the exhaust air, which still contains the original contaminants, reaches the location of the sensor element through simple turbulence and backflow or through diffusion, generating the measurement signal for the condition of the unfiltered, contaminated air. This "switching" preferably occurs continuously and / or in a countercurrent process.

[0072] In another preferred embodiment, second values, in particular concentration values ​​of contaminants in an air stream entering the filter device, i.e., which is upstream of the filter device, are detected, in particular continuously, via a second sensor element of the sensor device. In the evaluation device, the first and second values ​​are compared with one another, in particular by calculating the difference between the first and second values. Preferably, values, in particular concentration values, of contaminants in an air stream, which are detected by the at least one first sensor element and / or the second sensor element, and / or comparison values, are stored at least temporarily in a memory device.

[0073] The present invention, as described in the context of the various aspects of the invention, enables in particular the indirect detection of the loading of a filter device, for example an activated carbon filter, as part of an air-cooled fuel cell system in an energy system, for example a home energy system, or in a ventilation system.

[0074] The invention will now be explained in more detail using various embodiments with reference to the accompanying drawings.

[0075] Figure 1 shows a schematic view of an energy system according to the invention which is provided for the realization of a device according to the invention for determining the adsorption state of a filter device;

[0076] Figure 2 shows a schematic view of a ventilation system according to the invention, which is in particular a component of an energy system provided for the realization of a device according to the invention for determining the adsorption state of a filter device;

[0077] Figure 3 shows a schematic view of a first embodiment of a device according to the invention for determining the adsorption state of a filter device;

[0078] Figure 4 shows a schematic view of a second embodiment of a device according to the invention for determining the adsorption state of a filter device;

[0079] Figure 5 shows a schematic view of a third embodiment of a device according to the invention for determining the adsorption state of a filter device;

[0080] Figure 6 shows a schematic view of a first embodiment of a ventilation system according to the invention, which is particularly a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented; Figure 7 shows a schematic view of a second embodiment of a ventilation system according to the invention, which is particularly a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented;

[0081] Figure 8 shows a schematic view of a third embodiment of a ventilation system according to the invention, which is in particular a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented;

[0082] Figure 9 shows a schematic view of a fourth embodiment of a ventilation system according to the invention, which is in particular a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented;

[0083] Figure 10 shows a schematic view of a fifth embodiment of a ventilation system according to the invention, which is in particular a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented; and

[0084] Figure 11 shows a schematic view of a sixth embodiment of a ventilation system according to the invention, which is in particular a component of an energy system in which a device according to the invention for determining the adsorption state of a filter device is implemented.

[0085] A device for assessing the functionality of a filter device, in particular a filter device of a fuel cell system, can be used in different ways and in a wide variety of systems.

[0086] One possible system is an energy system. Figure 1 first describes the basic structure of such an energy system 10, with the energy system 10 being used as a home energy system.

[0087] The energy system 10 initially has a first subsystem 20, which is designed as an indoor system. This means that the first subsystem 20 is located inside the house. In addition, the energy system 10 has a second subsystem 30 in the form of an outdoor system. This means that the second subsystem 30 is located outside the house. The first subsystem 20 has an electrolysis device 21 for producing hydrogen. The first subsystem 20 also has a fuel cell system 22. The fuel cell system 22 consists of the fuel cell module 22a, which comprises the actual fuel cell or a fuel cell stack. A filter device 22b, which is in the form of an activated carbon filter, for example, is connected upstream of the fuel cell module 22a.Air entering the fuel cell system 22 first flows through the filter device 22b, where it is filtered to remove contaminants that may be harmful to the fuel cell(s) before the air flow enters the fuel cell(s). Figure 1 shows a device 70 according to the invention for assessing the functionality of the filter device 22b, which will be explained in detail later with reference to Figures 3 to 11 in the context of a series of different exemplary embodiments.

[0088] The second subsystem 30 has a high-pressure storage device 31. The generated hydrogen is stored in the high-pressure storage device at up to 700 bar. Additionally, the second subsystem 30 has a medium-pressure storage device 32, in which the generated hydrogen is temporarily stored at pressures between 20 and 30 bar before being finally stored in the high-pressure storage device 31.

[0089] The individual components of the energy system 10 are connected to one another via a connecting line device 40, which consists of a number of different line sections 40a to 40k.

[0090] For flushing the electrolysis device 21 and / or the fuel cell system 22, a flushing device 23 with a flushing chamber is provided, which is connected to the two aforementioned components via a line section 40g.

[0091] The hydrogen produced by electrolysis in the electrolysis device 21 leaves the electrolysis device 21 via a line section 40f, which merges into the line section 40e. In the two line sections 40f and 40e, in the flow direction of the produced hydrogen, there is a check valve device 24, followed by a filter device 25 and a dryer device 26, in which the produced hydrogen is filtered and dried. The filter device 25 and the dryer device 26 can alternatively also be located in the second subsystem 30. From the dryer device 26, the produced hydrogen flows via the line sections 40a and 40c to another check valve device 35, which marks one end of the line section 40c.From there, the generated hydrogen flows via a line section 40h and 40i into the medium-pressure accumulator 32, which is connected to a further line section 40j via a valve device 33, which is designed in particular as a shut-off valve, for example in the form of a solenoid valve. In the line section 40j, which ends in the high-pressure accumulator 31, a compressor device 34, in particular in the form of a piston compressor, is located upstream of the high-pressure accumulator 31. The generated hydrogen is stored in the high-pressure accumulator 31 via the compressor device 34. The hydrogen temporarily stored in the medium-pressure accumulator 32 is stored in the high-pressure accumulator 31 by actuating the compressor device 34.

[0092] This hydrogen production process up to its storage in the high-pressure storage device 31 represents a first operating mode of the energy system 10. In this first operating mode of the energy system 10, a pressure of 20 to 60 bar prevails in the line sections 40a to 40e of the connecting line device 40. A similar pressure also prevails in the medium-pressure storage device 32. The compressor device 34 compresses the hydrogen extracted from the medium-pressure storage device 32, which is an intermediate storage device, to such an extent that it can be stored in the high-pressure storage device 31 at pressures of up to 700 bar.

[0093] The hydrogen stored in the high-pressure storage device 31 is used to operate the fuel cell system 22. The fuel cell system 22 is operated in the second operating mode of the energy system 10. However, the fuel cell system 22 can only operate at pressures below 20 bar. In the second operating mode of the energy system 10, the hydrogen is withdrawn from the high-pressure storage device 31 via a line section 40k, expanded to the required pressure via an expansion device 36 in the form of a pressure reducer, and transported via a line section 40d into the bidirectional line section 40a, from where it enters the fuel cell system 22 via the line section 40b and there initially into the filter device 22b. At least one pressure measuring device 41, for example in the form of a pressure sensor, is provided to measure the pressure.The energy system 10 shown in Figure 1 represents a sub-area of ​​an overall home energy system, which is an electrically self-sufficient and completely renewable energy-based multi-hybrid home energy storage system.

[0094] The multi-hybrid home energy storage system makes it possible to distribute the electrical energy generated by a photovoltaic (PV) system, a small wind turbine, or similar system as needed throughout the year. The system can operate as an off-grid system, independent of the electrical grid, or as a backup power supply in the event of a power outage. The system can also ensure the home's electrical self-sufficiency, eliminating the need to draw electrical energy from the grid throughout the year.

[0095] The primary task of a home energy system is to make the electrical energy generated from photovoltaic (PV) modules or similar devices available to the consumer in the home. Secondarily, surplus electrical energy can be temporarily stored in a short-term battery storage system during periods of low load or high irradiation. Tertiary, the electrical energy can be stored as gaseous hydrogen in a long-term hydrogen storage system for medium- to long-term periods during periods of low irradiation, such as night, winter, or similar periods, and then made available again at any time as needed using a fuel cell.

[0096] In addition to energy-related tasks, the system also functions as controlled residential ventilation through a built-in ventilation system, which is shown in Figure 2. During fuel cell operation, the waste heat from the fuel cell can be released directly as heat into the fresh air and thus into the living spaces via the controlled residential ventilation.

[0097] The hydrogen produced in the electrolysis plant flows via the hydrogen pipeline into the external pressure storage system.

[0098] If PV energy is missing or insufficient, energy is drawn from the battery to meet the consumer load. If the energy stored in the short-term storage system is insufficient, the fuel cell system can cover the additional electrical demand. In fuel cell operation, the hydrogen flows from the pressure storage system to the fuel cell system via the hydrogen line. Simultaneous operation of the fuel cell system and the electrolysis system is not possible. The entire system is operated centrally via an energy manager with predictive energy management.

[0099] The second subsystem is principally intended for outdoor operation, but under certain conditions can also be installed and operated within a specific area of ​​the house.

[0100] The home energy system 10 can be connected to other systems or subsystems for the effective use of individual components or for the further recycling of individual process products. One of these additional systems is, as schematically shown in Figure 1, a ventilation system 42, which will initially be explained in general terms below with reference to Figure 2. The ventilation system 42 interacts with the fuel cell system 22.

[0101] Figure 2 shows a highly simplified illustration of a ventilation system 42, which is a component of an energy system 10. The ventilation system 42 serves to set a desired indoor climate in at least one room, for example, a common room in a house. In addition to the illustration in Figures 1 and 2, the ventilation system 42 and the energy system 10, each of which is a complex system, may of course include additional system components, which, however, are not explicitly illustrated in Figures 1 and 2 for the sake of clarity.

[0102] The ventilation system 42 is located inside the house, of which only one wall 43 is shown schematically.

[0103] One component of the ventilation system 42 is a ventilation device 47, in which a heat exchanger 48 is located. In the exemplary embodiment shown in Figure 2, the ventilation device 47 is also located in the first subsystem 20 shown in Figure 1. However, this is not absolutely necessary. Outside air from outside the house is introduced into the ventilation device 47 via an outside air supply 44 in the form of a supply air stream 46 and guided via the heat exchanger 48. An outside air filter device 45 is arranged in the supply air stream 46 downstream of the outside air supply 44 in the flow direction. Using a pressure measuring device assigned to the outside air filter device 45, pressure values ​​of the outside air filter device 45, in particular defined pressure loss values, can be determined.

[0104] After leaving the heat exchanger 48, the supply air flow 46 is introduced into a ventilation system 51 located in a room via a device 49 for adjusting the supply air flow, which can be designed as a supply air flap or as a supply air valve device, via a supply air inlet 50. The quantity of supply air entering the ventilation system 51 can be adjusted via a device for adjusting the supply air flow (not shown). If the device for adjusting the supply air flow is completely closed, no supply air can enter the ventilation system 51 and thus into the room. If, on the other hand, the device is completely open, a maximum amount of supply air enters the ventilation system 51 via the supply air inlet 50. In order to create a suitable control option for the supply air for the user of the ventilation system 42, a bypass device 56 is also provided, which can be designed as a bypass flap or bypass valve device.Via this bypass device 56, at least a certain amount of the supply air can be diverted from the supply air supply 50 and passed past the ventilation system 51 in the form of a bypass flow 57.

[0105] Exhaust air exiting the room via the ventilation system 51 is discharged via an exhaust air outlet 52 in the form of an exhaust air stream 53. An exhaust air filter device 54 is arranged in the exhaust air stream 53 downstream of the exhaust air outlet 52. Pressure values ​​of the exhaust air filter device 54 can be determined using a pressure measuring device associated with the exhaust air filter device 54.

[0106] In order to be able to convey the exhaust air flow 53 back towards the heat exchanger 48 and to regulate the quantity of the exhaust air flow, a fan 55 is provided in the exhaust air flow 53.

[0107] The exhaust air stream 53 can then be guided, via the corresponding line sections 40b and 40f, which are also shown in Figure 1, as well as via corresponding flaps 62, 63 or valve devices, optionally through the electrolysis device 21 and / or the fuel cell system 22, comprising the filter device 22b and the fuel cell module 22a, and then via the line section 40g from Figure 1, via a flushing device 23 for the electrolysis device 21 and / or the fuel cell system 22, as can also be seen in Figure 1, as well as via a cooling device or an air / water exchanger 58, before the exhaust air stream 53 re-enters the ventilation device 47. Also indicated in Figure 2 is a device 70 according to the invention for assessing the functionality of the filter device 22b.Depending on the configuration, the device 70 can interact, at least temporarily, with a sensor element 64, which is provided for monitoring the room air and / or for controlling the ventilation system. This sensor element 64 preferably interacts with the exhaust air discharge 53 or the exhaust air stream 53, preferably downstream of an exhaust air filter device 54.

[0108] In the ventilation system 47, the exhaust air stream 53 is again directed through the heat exchanger 48, where it can transfer its stored heat to the supply air stream 46. Depending on the operating mode and initial position, the exhaust air stream 53 can also be directed past the heat exchanger 48. This is done by means of a bypass device 59, which is designed, for example, as a bypass flap or bypass valve device. Upon appropriate actuation of the bypass device 59, the exhaust air stream 53 can be directed past the heat exchanger 48 via an exhaust air bypass stream 60.

[0109] The exhaust air flow 53 leaves the ventilation device 47 via an exhaust air discharge 61, via which the exhaust air volume flow 53 leaves the house again in the form of an exhaust air flow.

[0110] In order to utilize the individual components and processes in the energy system 10 as efficiently as possible, multiple use is advantageous at various points. For example, the exhaust air 53 from the ventilation system 42 can also be used as supply air for the fuel cell system 22. However, this exhaust air 53 can contain contaminants that are harmful to the fuel cell system 22, or rather, the fuel cell module 22a. For this reason, the fuel cell system 22 has the filter device 22b, which has the function of filtering out contaminants from the air flow entering the fuel cell system 22, here the exhaust air flow 53. The filter device 22b is arranged, in particular on the cathode side, upstream of the fuel cells of the fuel cell module 22a in the direction of air flow.

[0111] An excessive concentration of contaminants in the air stream entering the fuel cell module 22a will, at best, lead to a reduction in the performance of the fuel cell(s), but will usually also result in damage to the fuel cell(s), up to and including partial or even total failure. For this reason, it is necessary to know the loading state of the filter device 22b upstream of the fuel cells, i.e., its adsorption state.

[0112] For this purpose, according to the invention, the device 70 for assessing the functionality of the filter device is provided, which is also referred to as a determination device and is described below with reference to various preferred embodiments.

[0113] Figures 3 to 5 initially describe, in a general manner, various embodiments of the determination device 70, which are used in particular in an energy system 10 according to Figure 1 and / or in a ventilation system 42 according to Figure 2. Therefore, identical components are each provided with identical reference numerals, and with regard to the structure, operation, and nature of the determination device 70, reference is also made in full to the explanations relating to Figures 1 and 2.

[0114] Figure 3 shows a schematic view of a first embodiment of a device 70 according to the invention for assessing the functionality of the filter device 22b.

[0115] If the filter device 22b has reached an excessively high loading level, i.e., an excessively high adsorption level, which can be referred to as the critical adsorption level, the concentration of contaminants increases sharply and may even exceed the permissible limits. Sensor elements exist that can detect one or more contaminant materials, i.e., substances, in an air stream. When the concentration is measured downstream of the filter device 22b, the current effectiveness of the filter device 22b with respect to this contaminant group or with respect to the contaminant group in question becomes apparent. In particular, it is assumed that a less effective filter device indicates the occupancy of a large number of the active centers of the filter device and thus a deteriorating filtering effect of other contaminant materials, i.e., substances, with comparable adsorption behavior.According to the invention, it is sufficient to detect the qualitative change, i.e., the temporal change in the adsorption of one or more contaminant classes or substance classes. In the exemplary embodiment of the determination device 70 shown in Figure 3, the supply air, which is the exhaust air 53 from the ventilation system 51, as can be seen from Figures 1 and 2, flows into the filter device 22a via the line section 40b and a flap 62, which is preferably a fuel cell system flap, as described in connection with Figures 6 to 11. The change in the load of the filter device 22b can be determined via a first sensor element 72 of a sensor device 71, which is located behind the filter device 22b. This can be used to specify the replacement interval of the filter device 22b.The filter device 22b is loaded when there is a measurable concentration of contaminants in the air stream being examined via the first sensor element 72.

[0116] The first sensor element 72 detects values, particularly concentration values, of contaminants in an air stream 73 exiting the filter device 22b and located downstream of the filter device 22b, and flowing through the line section 40g. The corresponding sensor tap is identified by reference numeral 85.

[0117] Furthermore, the determination device 70 has an evaluation device 74 for qualitatively evaluating the contamination values, in particular the change in the concentration of contaminants, in the air stream 73, which is connected to the at least one first sensor element 72 via an interface 75. The values ​​detected by the sensor element 72 are transmitted via the signal transmission path 90 to the interface 75 of the evaluation device 74.

[0118] The contamination values, in particular the concentration values, are received by a detection device 76, which is provided for the, in particular continuous, detection of the values ​​of contamination in the air stream 73 measured by the at least one first sensor element 72. In a subsequent comparator device 77, the values ​​of contamination in the air stream 73 detected by the detection device 76 are compared with comparison values. For example, the comparison values ​​can be in the form of, in particular immediately previously detected values ​​of contamination in the air stream exiting the filter device and / or in the form of contamination limit values. The values ​​detected by the first sensor element 72 provide information about the concentration of contamination in the air stream 73 exiting the filter device 22b.If the first sensor element 72 does not detect any concentration of contaminants, this means that the filter device 22b is active and any contaminants are effectively adsorbed in the filter device 22b. If, however, the first sensor element 72 measures a concentration, the comparator device 77 determines the extent to which the concentration in the air stream 73 is harmful. By comparing the measured values ​​with reference values, it can be determined whether the measured values ​​are approaching these reference values. If, for example, a limit value is reached or the measured values ​​are approaching such a limit value, this is an indication that the quality of the filter device 22b is deteriorating and the filter device 22b may need to be replaced.In principle, it is sufficient for such a determination if the sensor element 72 detects that the measured impurity values ​​are changing, in particular that these values ​​are increasing, which means an increase in the concentration of impurities in the air stream 73 and indicates a deterioration in the filter performance of the filter device 22b.

[0119] The evaluation device 74 has an output device 78, which is provided in such a way that it is capable of outputting an output signal when a value of contaminants in the air stream 73 detected by the detection device 76 reaches, for example, exceeds or falls below, a predetermined value. For this purpose, a signal, for example, a message, can be generated and transmitted to a control device 81 via an interface 80. Values ​​measured by the sensor element 72 and / or reference values ​​and / or comparison values ​​can be stored, at least temporarily, in a memory device 79.

[0120] The determination device 70 is provided in particular to detect or be able to detect the temporal change of values, in particular concentration values, of contaminants in the air stream 73 exiting the filter device 22b.

[0121] Figure 4 shows a schematic view of a second embodiment of a device 70 for assessing the functionality of a filter device 22b. In its basic structure, this device 70 corresponds to the determination device 70 shown in Figure 3, so that identical components are provided with identical reference numerals. Regarding the basic structure of the determination device 70, reference is made to the explanations for Figure 3 to avoid repetition. Therefore, only the differences in the determination device 70 will be discussed below.

[0122] In the embodiment according to Figure 4, the first sensor element 72 is additionally connected to a bypass air stream 84, which is guided past the filter device 22b in the bypass 83. Via a flap 83, which is preferably an electrolysis device flap, and via the flap 62, which is preferably a fuel cell system flap, as described in connection with Figures 6 to 11, the air stream flowing via the line section 40b can be guided either as air stream 73 through the filter device 22b, or as bypass air stream 84 in the bypass 83 past the filter device 22b. Via a sensor tap 86, the sensor element 72 can also detect values, in particular concentration values, of contaminants in the bypass air stream 64 and transmit them via the signal transmission path 90 to the interface 75 of the evaluation device 74.

[0123] In some operating states, the sensor element 72 measures the concentration of contaminants in the air stream 84, which is guided past the filter device 22b in the bypass 83. This is the case, for example, during electrolysis operation. In some operating states, the concentration of contaminants in the air stream 73 passing through the filter device 22b is measured. This is the case, for example, during fuel cell operation. Switching then produces increasingly divergent measurement signals as the load of the filter device 22b increases.In this embodiment, it is preferably realized that the evaluation device 74, in particular the comparator device 77, has a device for forming the difference between values, in particular concentration values, of impurities in the air flow 73 which exits from the filter device 22b or is located downstream of the filter device 22b, which are detected by the at least one first sensor element 72, and values, in particular concentration values, of impurities in the air flow 84 which is guided past the filter device 22b in the bypass 83, which are also detected by the at least one first sensor element 72.

[0124] Figure 5 shows a schematic view of a third embodiment of a device 70 for determining the adsorption state of a filter device 22b. In its basic structure, this device 70 corresponds to the determination device 70 shown in Figures 3 and 4, so that identical components are provided with identical reference numerals, and with regard to the basic structure, reference is made to the explanations for Figures 3 and 4 to avoid repetition. Therefore, only the differences in the determination device 70 will be discussed below.

[0125] In the embodiment shown in Figure 5, the sensor device 71 has, in addition to the first sensor element 72, a second sensor element 88, which is provided for the, in particular continuous, determination of values, in particular concentration values, of contaminants in an air stream 87 entering the filter device 22b, i.e., located upstream of the filter device 22b. The values, in particular concentration values, of contaminants in the air stream 87 entering the filter device 22b are detected by the second sensor element 88 via a sensor tap 89 and transmitted via a signal transmission path 91 to the interface 75 of the evaluation device 74. The values ​​detected by the sensor elements 72, 88 are compared with one another in the evaluation device 74, in particular in the comparator device 77.For this purpose, the evaluation device 74, in particular the comparator device 77, has a device for forming the difference between values, in particular concentration values, of impurities in the air flow 73 exiting the filter device 22b, which are detected by the at least one first sensor element 72, and values, in particular concentration values, of impurities in the air flow 87 entering the filter device 22b, which are detected by the second sensor element 88.

[0126] Figures 6 to 11 now describe various embodiments of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10, wherein the ventilation system 42 interacts with a fuel cell system 22. The basic structure of the ventilation system 42 corresponds in all of the following embodiments to the ventilation system 42 shown and described in Figure 2, so that identical components are each provided with identical reference numerals, and with regard to the basic structure, reference is made to the explanations for Figure 2 to avoid repetition.

[0127] In contrast to the ventilation system 42 shown in Figure 2, the ventilation systems 42 shown in Figures 6 to 11 each have a detailed device 70 for assessing the functionality of the filter device 22b of the fuel cell system 22. With regard to Figures 6 to 11, therefore, only the particular design of the determination device 70 will be discussed below, and otherwise reference will be made in full to the explanations for Figure 2, as well as for Figure 1.

[0128] Figure 6 shows a schematic view of a first embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10 in which a device 70 according to the invention for assessing the functionality of a filter device 22b is implemented. The structure of the determination device 70, as well as its mode of operation, corresponds approximately to the exemplary embodiment shown in Figure 3, so that at this point, to avoid repetition, reference is also made in full to the explanations relating to Figure 3. While the determination device 70 shown and described in Figure 3 is of a general nature, the determination device 70 shown in Figure 6 is specifically aimed at the interaction with the fuel cell system 22.

[0129] As can be seen in Figure 6, the sensor device 71 of the determination device 70 has a first sensor element 72, which, via the sensor tap 85, measures concentration values ​​of contaminants in an air stream leaving the filter device 22b or located downstream of the filter device 22b. The values ​​determined by the sensor element 72 are transmitted via the signal transmission path 90 to the evaluation device 74, where they are qualitatively evaluated. Based on these evaluation results, it is possible, for example, to control other components of the ventilation system 42 or the energy system 10. In the example shown, for example, the fan 55, which is located in the exhaust air stream 53 from the ventilation system 51, can be controlled. In the exemplary embodiment shown in Figure 6, the sensor element 72, or the sensor tap 85, is located between the filter device 22b and the fuel cell module 22a.In this way, qualitative statements in the form of statements about the temporal change of values, in particular concentration values, of contaminants in the air stream 73 exiting the filter device 22b can be detected and statements about the effectiveness of the filter device 22b can be made therefrom.

[0130] Figure 7 shows a schematic view of a second embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10 in which a device 70 according to the invention for assessing the functionality of a filter device 22b is implemented. The embodiment shown in Figure 7 corresponds essentially in terms of structure and operation to the embodiment shown in Figure 6, so that at this point, to avoid repetition, reference is also made in full to the explanations relating to Figure 6.

[0131] In contrast to Figure 6, in the embodiment shown in Figure 7, the first sensor element 72 is located behind the fuel cell module 22a. The sensor tap 85 of the sensor element 72 is thus located behind the fuel cell module 22a or behind the fuel cell(s) in the direction of air flow through the fuel cell system 22. In this way, the determination device 70 can also be used to determine the load on the fuel cell(s).

[0132] The exemplary embodiment shown in Figure 8, which represents a third embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10, in which an inventive device 70 for assessing the functionality of a filter device is implemented, is a combination of the two exemplary embodiments shown in Figures 6 and 7. To avoid repetition, reference is therefore made in full to the explanations relating to Figures 6 and 7.

[0133] Figure 9 shows a schematic view of a fourth embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10, in which a device 70 according to the invention for assessing the functionality of a filter device 22b is implemented. The structure of the determination device 70, as well as its mode of operation, corresponds approximately to the embodiment shown in Figure 4, so that at this point, to avoid repetition, reference is also made in full to the explanations relating to Figure 4. While the device shown and described in Figure 4

[0134] While the determination device is of a general nature, the determination device 70 shown in Figure 9 is specifically designed for interaction with the fuel cell system 22.

[0135] As can be seen in Figure 9, the sensor device 71 of the determination device 70 has a first sensor element 72, which measures concentration values ​​of contaminants in an air stream leaving the filter device 22b via the sensor tap 85. The values ​​determined by the sensor element 72 are transmitted via the signal transmission path 90 to the evaluation device 74, where they are qualitatively evaluated. In addition, the first sensor element 72 is connected via the sensor tap 86 to an air stream that is guided past the filter device 22b in a bypass. In the present embodiment, the bypass air stream is guided through the electrolysis device 21. The values ​​determined by the sensor element 72 in the bypass air stream are also transmitted via the signal transmission path 90 to the evaluation device 74, where they are qualitatively evaluated.The sensor element 72, or the sensor tap 85, is located between the filter device 22b and the fuel cell module 22a.

[0136] The sensor element 72 is positioned such that, during non-fuel cell operation, the air that would otherwise enter the fuel cell system 22 is measured in the bypass of the filter device 22b, while during fuel cell operation, the air flows through the filter device 22b. Switching then produces increasingly divergent measurement signals as the load increases. For example, the sensor element 72 can draw the fuel cell air via a hose connection between the filter device 22b and the inlet of the fuel cell module 22a. This is precisely when a driving pressure gradient exists. When the fuel cell module 22a is not running, the sensor element 72 draws the air automatically or via a tapping point from the bypass air flow.

[0137] Figure 10 shows a schematic view of a fifth embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10 in which a device 70 according to the invention for assessing the functionality of a filter device 22b is implemented. The structure of the determination device 70, as well as its mode of operation, corresponds approximately to the exemplary embodiment shown in Figure 5, so that at this point, to avoid repetition, reference is also made in full to the explanations relating to Figure 5. While the determination device shown and described in Figure 5 is of a general nature, the determination device 70 shown in Figure 10 is specifically aimed at the interaction with the fuel cell system 22.

[0138] As can be seen in Figure 10, the sensor device 71 of the determination device 70 has a first sensor element 72, which measures concentration values ​​of contaminants in an air stream leaving the filter device 22b via the sensor tap 85 between the filter device 22b and the inlet of the fuel cell module 22a. The values ​​determined by the sensor element 72 are transmitted via the signal transmission path 90 to the evaluation device 74, where they are qualitatively evaluated.

[0139] In addition, the sensor device 71 has a second sensor element 88, which, in particular continuously, detects, via the sensor tap 89, concentration values ​​of contaminants in an air stream entering the filter device 22b. The values ​​determined by the sensor element 88 are transmitted via the signal transmission path 91 to the evaluation device 74, where they are qualitatively evaluated. The evaluation provides that the values ​​detected by the sensor elements 72, 88 are compared with one another in the evaluation device 74, for example, by calculating the difference. If the contaminant values ​​in the air stream upstream of the filter device 22b are higher than the contaminant values ​​in the air stream downstream of the filter device 22b, this means that the filter device 22b is active and functioning properly.If the values ​​become similar, especially if the values, in particular concentration values, of impurities in the air flow after the filter device 22b become larger, this means that the effect of the filter device 22b decreases.

[0140] Finally, Figure 11 shows a sixth embodiment of a ventilation system 42 according to the invention, which is in particular a component of an energy system 10, in which a device 70 according to the invention for determining the adsorption state of a filter device 22b is implemented. The embodiment shown in Figure 11 corresponds essentially in terms of structure and operation to the embodiment shown in Figure 10, so that at this point, to avoid repetition, reference is also made in full to the explanations relating to Figure 10.

[0141] In contrast to Figure 10, in the embodiment shown in Figure 11, the first sensor element 72 is located behind the fuel cell module 22a, i.e., downstream of the fuel cell module 22a. The sensor tap 85 of the sensor element 72 is thus located in the direction of air flow through the fuel cell system 22 behind the fuel cell module 22a or the fuel cell(s). In this way, the determination device 70 can also be used to determine the load on the fuel cell(s). List of reference symbols

[0142] 10 Energy system (house energy system)

[0143] 20 First subsystem (internal system)

[0144] 21 Electrolysis device

[0145] 22 Fuel cell system

[0146] 22a Fuel cell module

[0147] 22b Filter device

[0148] 23 Flushing device (rinsing chamber)

[0149] 24 Check valve device

[0150] 25 Filter device

[0151] 26 Dryer device

[0152] 30 Second subsystem (external system)

[0153] 31 High-pressure storage facility

[0154] 32 medium-pressure storage device

[0155] 33 Valve device

[0156] 34 Compressor setup

[0157] 35 Check valve device

[0158] 36 Pressure relief device (pressure reducer)

[0159] 40 Connecting line device

[0160] 40a to 40k line section

[0161] 41 Pressure measuring device

[0162] 42 Ventilation system

[0163] 43 house wall

[0164] 44 Outside air supply

[0165] 45 Outside air filter device

[0166] 46 Supply air flow

[0167] 47 Ventilation system

[0168] 48 heat exchangers

[0169] 49 Device for adjusting the supply air flow (supply air damper)

[0170] 50 Supply air supply

[0171] 51 Ventilation system

[0172] 52 Exhaust air extraction

[0173] 53 Exhaust air flow 54 Exhaust air filter device

[0174] 55 blowers

[0175] 56 Bypass device

[0176] 57 Bypass current

[0177] 58 air / water exchangers

[0178] 59 Bypass device

[0179] 60 exhaust air bypass flow

[0180] 61 Exhaust air extraction

[0181] 62 Fuel cell system flap

[0182] 63 Electrolysis device flap

[0183] 64 sensor element

[0184] 70 Device for assessing the functionality of a filter device

[0185] (Determination device)

[0186] 71 Sensor device

[0187] 72 First sensor element

[0188] 73 Air flow exiting the filter device

[0189] 74 Evaluation device

[0190] 75 Interface

[0191] 76 Detection device

[0192] 77 Comparator device

[0193] 78 Output device

[0194] 79 Storage device

[0195] 80 interface

[0196] 81 Control device

[0197] 82 Bypass valve

[0198] 83 Bypass to the filter device

[0199] 84 Bypass airflow

[0200] 85 Sensor tap

[0201] 86 Sensor tap

[0202] 87 Air flow entering the filter device

[0203] 88 Second sensor element

[0204] 89 Sensor tap

[0205] 90 Signal transmission path

[0206] 91 Signal transmission path

Claims

Patent claims 1. Device (70) for assessing the functionality of a filter device (22b) provided for reducing concentration levels of, in particular gaseous, impurities in an air stream (73), preferably for determining a critical adsorption capacity of the filter device (22b), in particular a filter device (22b) of a fuel cell system (22), comprising a sensor device (71) with at least one first sensor element (72) for measuring, in particular gaseous, impurities exiting the filter device (22b) in the air stream (73), an evaluation device (74) for qualitatively evaluating the change in the measured impurities in the air stream (73), which is connected to the at least one first sensor element (72) via an interface (75), and which comprises the following components: a detection device (76) for, in particular continuous,The device (76) provides a device for detecting the impurities in the airflow (73) measured by the at least one first sensor element (72), a comparator device (77) for comparing the impurities in the airflow (73) detected by the detection device (76) with comparison values, in particular with reference values, and an output device (78) that is provided in such a way that it is able to output a signal when the impurities in the airflow (73) detected by the detection device (77) reach a predetermined value.

2. Device according to claim 1, characterized in that it is provided to detect the change over time of measured impurities in the airflow (73) exiting the filter device (22b).

3. Device according to claim 1 or 2, characterized in that the comparator device (77) is provided to compare the impurities detected by the detection device (76) in the airflow (73) with reference values ​​in the form of previously detected impurities in the airflow (73) exiting the filter device (22b), and / or with impurities in the airflow (73) not passing through the filter device (22b), and / or impurity limit values.

4. Device according to one of claims 1 to 3, characterized in that at least one first sensor element (72) is provided for measuring impurities in an airflow (84) which is bypassed past the filter device (22b).

5. Device according to one of claims 1 to 4, characterized in that the sensor device (71) has a second sensor element (88) which is provided for, in particular continuously, measuring impurities in an air stream (87) entering the filter device (22b).

6. Device according to claim 4 or 5, characterized in that the evaluation device (74), in particular the comparator device (77), has a device for forming the difference between values ​​of impurities in an air stream (73) exiting the filter device (22b), which are detected by the at least one first sensor element (72), and values ​​of impurities in an air stream (84) passing by the filter device (22b) in the bypass (83), which are detected by the at least one first sensor element (72), or values ​​of impurities in an air stream (87) entering the filter device (22b), which are detected by the second sensor element (88).

7. Device according to one of claims 1 to 6, characterized in that it has a storage device (79) which is provided for at least temporary storage of values ​​of impurities in an airflow (73, 87) and / or in a bypass airflow (84) which are detected by the at least one first sensor element (72) and / or the second sensor element (88), and / or of comparison values.

8. Fuel cell system (22), comprising a fuel cell module (22a), a filter device (22b) which is provided for reducing concentration levels of, in particular gaseous, impurities in an airflow (73) flowing through the fuel cell module and which is arranged in the air supply path to the fuel cell module (22a), and with a device (70) for assessing the functionality of the filter device (22), in particular for determining a critical adsorption rate of the Filter device (22b), characterized in that the device (70) is designed according to one of claims 1 to 7.

9. Fuel cell system according to claim 8, characterized in that the at least one first sensor element (72) of the device (70) is arranged in the direction of flow of the airflow after the filter device (22b) and / or after the filter device (22b) and, in particular on the cathode side, before the fuel cell module (22a) and / or after the fuel cell module (22a).

10. Fuel cell system according to one of claims 8 or 9, characterized in that at least one first sensor element (72) of the device (70) is additionally connected at least temporarily to an airflow (84) which is guided past the filter device (22b) in the bypass (83), and that the airflow (84) which is guided past the filter device (22b) in the bypass (83) is in particular an airflow carried through an electrolysis device (21).

11. Ventilation system (42) for a room, wherein the ventilation system (42) is in particular part of an energy system (10), comprising an outside air supply (44) which is provided such that it is able to allow a supplied (46) supply air flow to enter the ventilation system (42), a ventilation device (47) which is provided such that it is able to generate a supply air supply (50) and provide it to the room as supply air, an exhaust air outlet (52) which is provided such that it is able to allow exhaust air to be discharged from the room and passed over the ventilation device (47), an exhaust air outlet (61) which is provided such that it is able to discharge the discharged exhaust air as an exhaust air flow from the ventilation system (42), characterized in that the ventilation device (47) has an interface to a device (70) for assessing the functionality of a filter device (22b),preferably for determining a critical adsorption capacity of the filter device (22b), according to one of claims 1 to 8, or to a fuel cell system (22) according to one of claims 9 to 11, or that the ventilation device (47) is connected to a device (70) for assessing the functionality of a filter device (22b), preferably for determining a critical adsorption capacity of the filter device (22b) according to one of claims 1 to 7, or to a fuel cell system (22) according to one of claims 8 to 10.

12. Ventilation system (42) according to claim 11, comprising a sensor element (64) which is provided for monitoring the room air and / or for controlling the ventilation system and which at least temporarily cooperates with the device (70) for assessing the functionality of the filter device (22).

13. Energy system (10) comprising an electrolysis device (21), a fuel cell system (22), optionally a high-pressure storage device (31), and a connecting line device (40, 40a to 40k) via which the electrolysis device (21), the fuel cell system (22), and optionally the high-pressure storage device (31) are connected to each other, characterized in that the energy system (10) comprises a device (70) for assessing the functionality of a filter device (22b), preferably for determining a critical adsorption capacity of the filter device (22b) of the energy system (10) according to one of claims 1 to 7, and / or that the fuel cell system (22) is configured according to one of claims 98 to 10, and / or that the energy system (10) comprises a ventilation system (42) according to claim 11 or 12.

14. Method for assessing the functionality of a filter device (22b), preferably for determining a critical adsorption capacity of the filter device (22b), in particular using a device (70) according to any one of claims 1 to 7, wherein the method is preferably used for a fuel cell system (22) according to any one of claims 8 to 10 or in a ventilation system according to claim 11 or 12, or in an energy system according to claim 13, comprising the following steps: Measuring, in particular gaseous, impurities that escape from the filter device (22b) in an air stream (73) with at least one first sensor element (72); In an evaluation unit (74) which is connected via an interface (75) to the at least one first sensor element (72), the values ​​of measured impurities are received and the change in the measured impurities in the airflow (73) is qualitatively evaluated, in particular by detecting the change in the measured impurities in the airflow (73).

15. Method according to claim 14, characterized in that the at least one first sensor element (72) detects first concentration values ​​of impurities in the airflow (73) exiting the filter device (22b), and that the at least one first sensor element (72) additionally detects second concentration values ​​of impurities in an airflow (84) entering the filter device (22b) via the bypass (83). is passed by, is recorded, wherein the airflow passed by the filter device (22b) in the bypass (83) is in particular an airflow passed through an electrolysis device (21), and that in the evaluation device (74) the first and second concentration values ​​are compared with each other, in particular by forming the difference between the first and second concentration values.

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