Method for identifying a function state of an ion generator of an

Abstract

The invention relates to a method for identifying a functional state of an ionizer of an air purification device, in particular for a motor vehicle, in which a measuring device measures a current intensity at an injection electrode of the ionizer at a time t0 and transmits the current intensity to a computing device, the measuring device measures at least one further parameter at a point in time t0 and transmits it to the computing device, the measuring device measures the current intensity at the injection electrode and the at least one further parameter at a subsequent point in time t1 and transmits them to the computing device, the calculating device determines at least one comparison value from the measured values detected by the measuring device at the time t0 and the time t1 and compares the comparison value with a reference value, and the calculating device generates a signal and / or takes measures as long as the comparison value deviates from the reference value by a predefined value. As a result, during operation, a long-term high separation effect can be achieved even in the case of aging of the filter device.

Description

Technical Field

[0001] The present invention relates to a method for identifying the functional state of an ionizer of an air purification device. The present invention also relates to an air purification device, in particular an air purification device for a motor vehicle. The present invention also relates to an air conditioning facility of a motor vehicle having such an air purification device and a motor vehicle having such an air conditioning facility. Background Art

[0002] For a comfortable and healthy air quality, the air in the passenger compartment and / or supplied to the passenger compartment should be cleaned to remove pollutants (such as fine dust), harmful gases (such as hydrocarbons, nitrogen oxides) and unpleasant odors (such as ammonia, trimethylamine, hydrogen sulfide, etc.). A big problem, especially in urban areas, is the high fine dust load in the outside air. In some large cities, the fine dust load is usually higher than the current daily average of 15 micrograms per cubic meter of PM2.5 values ​​specified by the World Health Organization in the daily average. Nowadays, the dust that enters the vehicle interior through the air conditioning system is cleaned by fiber filters.

[0003] In today's air conditioning facilities, the installation space for such filters is usually very limited. Therefore, the filter must have a low flow resistance / pressure loss, so that the preset air flow can still be transported into the vehicle interior, and thus, for example, safety requirements, such as avoiding glass fogging, can be met. This has the following disadvantages, namely that the filter fiber layer that separates the particles is usually implemented with many openings, and therefore the mechanical dust separation rate of the filter is usually only very low. Therefore, many filter manufacturers ensure that the filter is electrostatically charged during the production process of the filter. As a result, the particles that are usually also electrostatically charged are separated by means of electrostatic separation. Through this separation mechanism, very small particles <0.3μm can also be separated without increasing the flow resistance / pressure loss of the filter. However, the electrostatic charge applied during the production process quickly becomes ineffective with the aging of the filter and the dust load of the filter during driving operation. Therefore, the electrostatic charge of the filter mainly only works at the beginning of its life cycle. Depending on the degree of external air pollution, the static electricity may drop significantly after a few weeks or months.

[0004] So-called ionizers also utilize the electrostatic charging mechanism of particles. Upstream of the filter, the ionizer charges the particles contained in the air flow. In addition, the filter is also partially charged by the ions introduced into the air. This combination ensures that, in addition to increasing the purely mechanical separation power of the particle filter, the separation power of the particle filter is also increased by the electrostatic separation that is maintained over a longer period of time. To charge the particles, the ionizers used usually have a negative spray electrode or a corona discharge.

[0005] In the case of negative corona discharge, electrons appear on the ejection electrode, which has the shape of a very sharp mandrel, and the electrons are strongly accelerated, especially in the near electric field of the mandrel. Therefore, the electrons collide with the gas molecules, whereby the gas molecules lose other electrons by collision and are positively ionized. Therefore, positive gas molecules and two electrons are produced. This effect mainly occurs under very high field strengths at a short distance from the ejection electrode. At a distance farther from the ejection electrode, fast-moving electrons mainly accumulate on the gas molecules and thus form negative gas ions. Compared with in positive corona discharge, more gas ions are formed in negative corona discharge because electrons move faster due to their small size. This is conducive to the charging of particles, and therefore also conducive to separation in subsequent filters or filter elements.

[0006] As mentioned, the static electricity of the filter decreases with increasing load or operating time, since the static electricity of the filter is also lost due to the dust layer on the filter. In this case, charging the particles contained in the air flow also no longer has a major influence on the separation power of the filter. Therefore, the separation power of the ionizers common today also decreases sharply with increasing aging of the filter. In addition to the decrease in the static electricity of the filter during its service life, this can also be attributed primarily to wear and contamination of the injection electrodes.

[0007] The ejection electrode of an ion generator is constructed from a very sharp stainless steel mandrel / needle. Due to the ion generation, extremely high temperatures are generated at the tip, as a result of which the mandrel becomes rounded during its service life. This occurs due to mechanical wear and / or chemical reactions, especially at the location with very high temperatures, namely at the tip. In addition, the mandrel may also become dirty, for example due to the ingress of particles. As a result, the field strength at the tip decreases and fewer ions are generated. Therefore, as the operation of the ion generator increases, its power decreases. At present, there is no possibility of identifying how well the ion generation is still running, so that the exact time point for replacing the ion generator or the ejection electrode or other countermeasures cannot be determined. Summary of the invention

[0008] The present invention therefore relates to the problem of providing for the first time a method for identifying the functional state of an ionizer of an air cleaning device.

[0009] This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject matter of the dependent claims.

[0010] The present invention is based on the following general concept, that is, the wear degree of the injection electrode of the ion generator of the air purification device is monitored for the first time, and thus the perfect function and high air purification capacity are maintained for a long time. In the method for identifying the functional state of the ion generator of the air purification device (for example, in the air conditioning facility of the motor vehicle) according to the present invention, firstly, the current intensity is measured on the injection electrode of the ion generator, especially on the mandrel of the injection electrode, at the time point t0 by means of a measuring device, and it is transmitted to the computing device. The measuring device additionally measures at least one other parameter at the time point t0, and also transmits it to the computing device. Here, the time point t0 is the initial time point, that is, for example, the time point when the air purification device or ion generator is first put into operation. Subsequently, the measuring device measures the current and at least one other parameter at the injection electrode, especially at its mandrel, at the subsequent time point t1, and also transmits these values ​​to the computing device. Here, the subsequent time point t1 can be any time point after the time point t0. The computing device now learns at least one comparison value from the measured values ​​at the time point t0 and at the time point t1, and compares the comparison value with a reference value, especially with a reference value stored in a table. This is necessary, because the measured current intensity is not only affected by the rounding of the spindle of the injection electrode during operation, but also by other parameters, such as particle concentration. Therefore, in order to be able to observe and evaluate the wear degree of the spindle of the injection electrode in isolation, other parameters that affect the current must be calculated. Subsequently, if the comparison value deviates from the reference value by at least a predefined value, the computing device generates a signal and / or takes measures. Here, the computing device can, for example, generate a replacement signal, which is used to show the user of the air purification device that the injection electrode or ion generator must be replaced. Additionally or alternatively, as long as the comparison value deviates from the reference value by at least a predefined value, the computing device can take corresponding measures, such as increasing the voltage present on the injection electrode of the ion generator. Here, the predefined value clearly indicates the no longer tolerable wear degree of the spindle of the injection electrode, wherein the reliable and sufficient generation of ions can no longer be ensured, and therefore reliable and sufficient air purification can no longer be ensured. Using the method according to the present invention, the functional state of the ion generator of the air purification device can be monitored for the first time in a relatively simple manner and method, and corresponding measures can be taken when the intolerable wear degree of the injection electrode is identified. With the method according to the invention, it is no longer necessary to periodically replace at least one ejection electrode, but rather it is possible to use the at least one ejection electrode until a predefined degree of wear is detected by the method according to the invention. With the method according to the invention, it is also possible to prevent the ion generator and thus the air purification device from no longer functioning properly, because the degree of wear during the periodic replacement is already disproportionately high, so that the ejection electrode is already severely worn and thus no longer able to generate enough ions, even though the cycle for the next replacement has not yet ended.Therefore, by using the method according to the invention, the maximum possible and constant ion generation can be achieved over the entire service life of the ion generator. In addition, resource saving and cost reduction can be achieved by replacing the ion generator or at least one ejection electrode only when necessary. In addition, by an ion generator that always operates perfectly (which can be monitored by the method according to the invention), a significantly reduced migration of particles, for example into the passenger compartment of a motor vehicle, can be achieved, thereby significantly improving air purification. By using the method according to the invention, the user of the air purification device can also be constantly informed of the degree of wear of the ion generator or at least one of its ejection electrodes, for example similar to the filling degree of a vacuum cleaner bag, so that the user can be instructed as early as possible, that is, for example, to prepare to replace at least one ejection electrode. Alternatively, the computing device can of course also increase the voltage of at least one ejection electrode as a measure, and thereby increase ion generation.

[0011] In a further advantageous embodiment of the method according to the invention, the measuring device detects the amount of air flowing around the injection electrode or its spindle as a further parameter and transmits this further parameter to a computing device, which takes this further parameter into account in the calculation of the comparison value. Thus, by means of a corresponding air quantity sensor, for example, a volume flow can be detected by the measuring device, which volume flow can also have an influence on the current intensity at the injection electrode, but is independent of the actual degree of wear of the injection electrode. For example, the air quantity measurement can be estimated by the set fan level of the vehicle air conditioning unit. In addition, the air quantity measurement can be estimated by the current consumption of the vehicle air conditioning unit.

[0012] In a further advantageous embodiment of the method according to the invention, the measuring device detects the particle concentration of the flow-around spray electrode or its spindle as a further parameter and transmits it to the computing device. For this purpose, a particle sensor, in particular a PM2.5 sensor, can be used, for example. For example, such a particle sensor can use laser scattering to measure the dust concentration in real time. The particle concentration can be used to determine the amount of ions required for the desired air quality and, therefore, the voltage to be applied to the spray electrode. The higher the particle concentration in the air flow around the spray electrode or its spindle, the higher the ion concentration required for the adequate binding of these particles. In addition, the particle concentration also affects the current intensity of the spray electrode detected by the measuring device, although it has nothing to do with the actual degree of wear of the spray electrode and must therefore be isolated in order not to distort the result.

[0013] In a further advantageous embodiment of the method according to the invention, the measuring device measures at least one of the following parameters as further parameters and transmits it to the computing device: temperature around the injection electrode or its spindle, air humidity and / or gaseous contamination. These possible further parameters also influence the current intensity measured by the measuring device at the injection electrode, although they are independent of the degree of wear of the spindle of the injection electrode. Here, the higher the temperature, the greater the mobility of the gas ions and the higher the current in the typical temperature range of HVAC (heating, ventilation and air conditioning). An increase in the moisture content reduces the current in the typical temperature range of HVAC. Gaseous contamination can affect the performance of the ionizer.

[0014] In a particularly preferred embodiment of the method according to the invention, the computing device generates a signal for replacing at least one ejection electrode or at least one of its spindles as long as the comparison value deviates from the reference value by a predefined value. If the computing device learns, for example, by the current / voltage drop measured at the shunt resistor, that at least one spindle is rounded and therefore has a relatively low performance, and the comparison value deviates from the reference value by a predefined value, the computing device notifies the user to replace the ejection electrode or its spindle or the entire ion generator. It is thus possible to replace the spindle, the ejection electrode and / or the ionizer only when the spindle, the ejection electrode and / or the ionizer are actually worn to the point that they no longer provide the ion generation required for high air quality. Premature replacement, for example due to periodic replacement, can thereby be avoided, resulting in resource savings and cost reduction.

[0015] In a particularly preferred embodiment of the method according to the invention, the computing device adaptively adjusts the input voltage at the ejection electrode of the ionizer, in particular increases it, as long as the comparison value deviates from the reference value by a predefined value. Thus, for example, if the current intensity and thus the voltage at the shunt resistor on the ejection electrode drops to such an extent that it can be inferred from this that the ejection electrode and thus the ionizer are no longer functioning perfectly, an increase in the input voltage can be taken as a measure, whereby the ejection electrode produces more ions again and the air purification function can thus be maintained for a long time.

[0016] In a further advantageous embodiment of the method according to the invention, the measuring device measures the current intensity at a shunt resistor of the ejection electrode. Such a shunt resistor enables an indirect measurement of the voltage drop via a change in the current intensity, since the resistance value is constant compared to the ejection electrode (in which the resistance changes due to the geometry from a point to a round shape). With such a shunt resistor, it is thus possible to achieve a simple but still high-quality and inexpensive measurement of the change in current intensity and thus the change in voltage at the ejection electrode.

[0017] The present invention is further based on providing the following general concept, that is, an air purification device with an ionizer is described, the ionizer having at least one ejection electrode, wherein the air purification device additionally has a measuring device, which is used to detect the current and other parameters at the ejection electrode of the ionizer, and wherein the measuring device is simultaneously configured to transmit the current intensity and at least one other parameter to the computing device. The computing device (which is also or can be a part of the air purification device) is configured so that the computing device converts the measured values ​​learned at time point t0 and time point t1 into a comparison value and compares it with a reference value. Subsequently, as long as the comparison value deviates from the reference value by at least a predefined value, the computing device generates a signal and / or takes measures. In addition, at time point t0 or t1, at least one other parameter is taken into account in the acquisition of the comparison value. It is possible for the first time to use the air purification device according to the present invention to achieve the maximum possible and constant ion generation over the entire life of the ionizer or air purification device. For example, if the countermeasure can no longer be achieved by increasing the voltage applied to the injection electrode, the computing device can generate a signal for replacing the injection electrode or the ionizer, so that the injection electrode or the ionizer is only replaced when this is actually also required for maintaining the function. As a result, compared with the periodic replacement of the ionizer (wherein, for example, the injection electrode or the ionizer is replaced even when this is not purely technically required), a considerable cost saving can be achieved. With the air purification device according to the invention, a significantly improved air purification and thus a significantly higher air quality can also be achieved, which has a positive effect on the perception of the vehicle occupants, for example.

[0018] The invention is further based on the general idea of ​​equipping an air conditioning system of a motor vehicle with an air cleaning device described in the preceding paragraphs and thereby transferring the described advantages to the air conditioning system or a motor vehicle equipped with such an air conditioning system.

Claims

1. A method for detecting a functional state of an ionizer of an air cleaning device, in particular an air cleaning device for a motor vehicle, wherein: - a measuring device measures the current intensity at the ejection electrode of the ionizer at time t0 and transmits said current intensity to a computing device, - the measuring device measures at least one further parameter at a time t0 and transmits the at least one further parameter to the computing device, - the measuring device measures the current intensity and at least one further parameter at the ejection electrode at a subsequent point in time t1 and transmits them to the computing device, - the calculation device determines at least one comparison value from the measured values ​​detected by the measuring device at the time t0 and the time t1 and compares the at least one comparison value with a reference value, As soon as the comparison value deviates from the reference value by a predefined value, the calculation device generates a signal and / or initiates a measure.

2. The method according to claim 1, characterized in that: The measuring device detects the air quantity flowing around the spray electrode or its spindle as a further parameter and transmits this air quantity to the computing device.

3. The method according to claim 1 or 2, characterized in that: The measuring device detects the particle concentration flowing around the spray electrode or its spindle as a further parameter and transmits this particle concentration to the computing device.

4. The method according to any one of the preceding claims, characterized in that The measuring device detects at least one of the following parameters as a further parameter and transmits it to the computing device: temperature in the vicinity of the spray electrode or its spindle, air humidity and / or gaseous contamination.

5. The method according to any one of the preceding claims, characterized in that As soon as the comparison value deviates from the reference value by the predefined value, the computing device generates a signal for replacing the spray electrode or its spindle.

6. The method according to any one of the preceding claims, characterized in that As long as the comparison value deviates from the reference value by the predefined value, the calculation device adaptively adjusts the input voltage at the ejection electrode of the ionizer, in particular increases the input voltage.

7. The method according to any one of the preceding claims, characterized in that The measuring device measures the current intensity at the shunt resistor of the ejection electrode of the ionizer.

8. An air purification device, comprising: - an ionizer with a spray electrode, - a measuring device for detecting the current intensity and at least one further parameter at the ejection electrode of the ionizer and for transmitting the current intensity and the at least one further parameter to a computing device, - A computing device, which is designed so that it carries out the method according to any of the preceding claims, i.e. at least one comparison value is determined from the measured values ​​of the measuring device at time t0 and time t1, and the at least one comparison value is compared with a reference value, and a signal is generated and / or measures are taken as long as the comparison value deviates from the reference value by at least a predefined value.

9. The air purification device according to claim 8, characterized in that: The measuring device has at least one of the following sensors: an air mass sensor, a particle sensor, a temperature sensor, an air humidity sensor and / or a sensor for detecting gaseous pollution.

10. An air conditioning system for a motor vehicle, comprising the air cleaning device according to claim 8 or 9.

11. A motor vehicle having an air conditioning system according to claim 10.