Calibration method for a device having a fan, operating method for a device having a fan, and device having a fan

Abstract

The invention relates to a calibration method for a device (2) with a fan (8) for purging a treatment chamber (4) of the device (2) with a gas mixture, wherein the calibration method comprises the following process steps in the specified order: Sensorless determination of the density of the gas mixture at a known or assumed relative humidity of the gas mixture as a function of an installation altitude of the device (2) during initial commissioning of the device (2) at an installation location of the device (2); Sensorless correction of the density of the gas mixture thus determined at a known or assumed relative humidity of the gas mixture as a function of a weather condition at this installation location of the device (2) when a previously defined operating condition stored in a control unit (6) of the device (2) is present;Adaptation of a relationship stored in the control unit (6) of the device (2) between the electrical power consumption of the fan (8) and the density of the gas mixture as a function of the sensorless determined and corrected density of the gas mixture. Furthermore, the invention relates to an operating method for a device (2) and a device (2).

Description

[0001] The invention relates to a calibration method for a device with a fan, an operating method for a device with a fan and a device with a fan according to the preamble of patent claim 9.

[0002] Such devices with a fan and methods for their operation are already known from the prior art. For example, EP 1 342 414 A1 discloses a method for detecting the humidity in a device for treating and preparing food, as well as a device for treating and preparing food. In this method, current temperature values ​​and speed values ​​of the asynchronous motor driving a gas conveying and circulating device are compared with at least one characteristic curve stored in a computer, and the current humidity in the gas mixture is determined from the deviation of the measured speed from the speed of the stored characteristic curve. The disadvantage of this is that the accuracy of the method of EP 1 342 414 A1 depends on the quality of the characteristic curve stored in the computer and on the quality of the detected speed values ​​of the asynchronous motor.If one of these values, and especially if both of these values ​​themselves are inaccurate, this leads to a correspondingly inaccurate conclusion about the humidity in the closed cooking chamber during the cooking process.

[0003] The invention therefore addresses the problem of improving a device with a fan and a method for the device with a fan.

[0004] According to the invention, this problem is solved by a calibration method for a device having the features of patent claim 1, according to which the calibration method comprises the following method steps in the specified order: Sensorless determination of the density of the gas mixture at a previously known or assumed relative humidity of the gas mixture as a function of an installation altitude of the device during initial commissioning of the device at an installation location of the device; Sensorless correction of the density of the gas mixture thus determined at a previously known or assumed relative humidity of the gas mixture as a function of a weather condition at this installation location of the device when a previously defined execution condition stored in a control system of the device is present;Adjusting a relationship stored in the device's control system between the fan's electrical power consumption and the density of the gas mixture as a function of the sensorlessly determined and corrected density of the gas mixture. Furthermore, this problem is solved by an operating method having the features of patent claim 7 and a device having the features of patent claim 10. Advantageous embodiments and refinements of the invention emerge from the following subclaims. For example, the previously known or assumed relative humidity of the gas mixture can be 0% relative humidity of the gas mixture.

[0005] The advantage achievable with the invention lies in the particular improvement of a device with a fan and a method for the device with a fan. Due to the inventive design of the calibration method, the operating method, and the device, it is possible to determine the humidity of the gas mixture, for example an air-water mixture, in the treatment chamber, for example a cooking chamber of a device designed as a cooking appliance, more accurately, reliably, simply, and cost-effectively than before. This is because, for example, no explicit humidity sensor is required to determine the humidity of the gas mixture. At the very least, an alternative to known methods and devices is to be provided.

[0006] Thus, the power consumption of the fan's electric motor, i.e., the electrical power consumption of the fan, can be used to determine the humidity of the gas mixture in the treatment room without an explicit humidity sensor. This gas mixture can be, for example, ambient air or a gas mixture of ambient air and water vapor, or steam for short. This is based on the knowledge that the power consumption of the electric motor is proportional to the density of the gas mixture in the treatment room. From the density of this gas mixture, at a known temperature of this gas mixture, the humidity of this gas mixture and thus the humidity in the treatment room of the device can be determined.

[0007] The power consumption of the fan's electric motor depends not only on the humidity but also on the air pressure at the device's installation location. Accordingly, the accuracy and reliability of determining the humidity of the gas mixture can be increased by prior calibration of the relationship between the fan's power consumption and the density of the gas mixture stored in the device's control system. This can be achieved simply and cost-effectively using the method according to the invention.

[0008] In principle, the calibration method according to the invention and the operating method according to the invention can be freely selected within wide suitable limits.

[0009] An advantageous development of the calibration method according to the invention provides that the aforementioned sensorless determination of the density of the gas mixture comprises at least one of the following methods: Manual input of the device's installation altitude using a user interface of the device that is connected to the controller for signal transmission; Automatic adoption of the device's installation altitude from another device installed at the same installation location using a device interface of the device that is connected to the controller for signal transmission; Measurement of the electrical power consumption of the fan at at least one predetermined, constant speed of a fan impeller of the fan at at least one predetermined temperature of the gas mixture. This allows the aforementioned sensorless determination of the density to be carried out advantageously depending on the device's installation altitude at the installation location, depending on the circumstances and requirements of the individual case.Since the air pressure that influences the density of the gas mixture depends, among other things, on the device's installation altitude, it is advisable to take this dependency into account when adjusting the aforementioned relationship between the fan's electrical power consumption and the density of the gas mixture. According to the latter variant of this further development, it is possible, for example, to perform multiple measurements at multiple different speeds and / or at multiple different temperatures of the gas mixture.

[0010] A further advantageous development of the calibration method according to the invention provides that the aforementioned sensorless correction of the density of the gas mixture comprises measuring the electrical power consumption of the fan at at least one predetermined, constant speed of a fan impeller of the fan at at least one predetermined temperature of the gas mixture. In this way, the dependence of the air pressure influencing the density of the gas mixture on the weather conditions can also be determined by at least one measurement and used to adjust the aforementioned relationship between the electrical power consumption of the fan and the density of the gas mixture.Analogous to the aforementioned measurement for the purpose of sensorless determination of the density of the gas mixture as a function of the installation altitude, it is also conceivable here that a plurality of measurements are carried out at a plurality of different rotational speeds and / or at a plurality of different temperatures of the gas mixture.

[0011] Another advantageous development of the calibration method according to the invention provides that the aforementioned relationship between the electrical power consumption of the fan and the density of the gas mixture is stored in the controller as an algorithm, as a characteristic curve, or as a table. This provides several useful options for storing, i.e., saving, the aforementioned relationship in the controller over a predetermined value range that is suitable and useful for operation of the device for the electrical power consumption of the fan on the one hand and the density of the gas mixture on the other. For example, if a characteristic curve for the aforementioned relationship is stored in the controller, this characteristic curve can be adjusted based on the calibration method according to the invention by means of a parallel shift of this characteristic curve.

[0012] A further advantageous development of the calibration method according to the invention provides that the at least one predetermined temperature of the gas mixture is measured by means of a temperature sensor of the device that is connected to the controller in a signal-transmitting manner. In this way, a temperature of the gas mixture that corresponds very precisely to the actual temperature of the gas mixture can be used for the respective measurement when carrying out the calibration method according to the invention.

[0013] Another advantageous development of the calibration method according to the invention provides that the aforementioned sensorless determination and / or the aforementioned sensorless correction are / is carried out when the temperature of the gas mixture is substantially equal to a room temperature at the installation location, preferably additionally when at least one temperature of the gas mixture is substantially greater than the room temperature at the installation location. The room temperature, i.e., approximately 25°C, indicates a standard temperature of the gas mixture that is well-suited for the calibration method according to the invention and can be determined, for example, solely based on the presence of a standby state of the device and thus, in principle, even without explicitly measuring the temperature of the gas mixture.The preferred embodiment of this further development has the additional advantage that, due to the majority of measurements at different temperatures of the gas mixture, a broader database is available for adapting the aforementioned relationship, so that the quality of this adaptation is increased.

[0014] In principle, the relationship between the fan's electrical power consumption and the density of the gas mixture can be used within wide, suitable limits for the operation of the device according to the invention. As already explained above, the device is expediently operated depending on the humidity of the gas mixture determined using the aforementioned relationship between the fan's electrical power consumption and the density of the gas mixture.

[0015] The device according to the invention can be freely selected within wide, suitable limits in terms of type, mode of operation, material and dimensions.

[0016] An advantageous development of the device according to the invention provides that the device has a user interface connected to the controller for signal transmission and / or a device interface connected to the controller for signal transmission. This makes it possible, among other things, to manually enter the installation altitude of the device using the aforementioned user interface, so that a very precise sensorless determination of the density of the gas mixture at a previously known or assumed relative humidity of the gas mixture, for example at a relative humidity of the gas mixture of 0%, is possible depending on the installation altitude of the device during initial commissioning of the device at the respective installation location of the device. The aforementioned device interface makes it possible to use an installation altitude already known and stored in another device installed at the installation location for the inventive calibration method in the device according to the invention.

[0017] Furthermore, a further advantageous development of the device according to the invention provides that the device is designed as a cooking appliance, preferably as an oven, a steamer, a microwave oven, or a combination device with radiant heating and a steam generator. In this way, devices are specified in which the invention can be used particularly meaningfully and beneficially. This is because the humidity in a treatment chamber designed as a cooking chamber is of particular importance for a cooking process taking place in the cooking chamber. However, other designs of the device according to the invention are also conceivable. Purely by way of example, reference is made here to dishwashers and tumble dryers. The device according to the invention, for example the device according to the invention designed as a cooking appliance, can be designed as a household appliance or as a commercial appliance, i.e., a device for professional use.

[0018] An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows Figure 1 shows an embodiment of the device according to the invention for carrying out the calibration method according to the invention and for carrying out the operating method according to the invention, Figure 2 shows a first diagram with the density of the gas mixture on the abscissa and with the electrical power consumption of the fan on the ordinate, to explain the first step of the calibration method, Figure 3 shows a second diagram with the density of the gas mixture on the abscissa and with the electrical power consumption of the fan on the ordinate, to explain the second step of the calibration method and Figure 4 shows a third diagram with the density of the gas mixture on the abscissa and with the electrical power consumption of the fan on the ordinate, to explain the third step of the calibration method.

[0019] In the Fig. 1 bis 4 An embodiment of the invention is shown purely by way of example.

[0020] The appliance 2, designed as a household steam cooker, has a treatment chamber 4 designed as a cooking chamber for a product to be treated, namely a product not shown. Furthermore, the appliance 2 has a controller 6, a fan 8 connected to the controller 6 for signal transmission for flushing the treatment chamber 4 with a gas mixture not shown, namely an air-water mixture, and a temperature sensor 10 connected to the controller 6 for signal transmission for measuring the temperature of the gas mixture. The fan 8 here has an electric drive motor (not shown) designed as a BLDC motor and connected to the controller 6 for signal transmission and power transmission. The term "BLDC motor" stands for a brushless DC motor. However, another motor type can also be used, e.g., a PMDC motor or a single-phase motor.In addition, the device 2 has a user interface 12 connected to the controller 6 for signal transmission and a device interface 14 connected to the controller 6 for signal transmission. See the . Fig. 1 .

[0021] The functioning of the device according to the invention, the calibration method according to the invention and the operating method according to the invention according to the present embodiment are described below with reference to Fig. 1 bis 4 explained in more detail.

[0022] Device 2 was delivered to the end customer and installed at a location not shown for device 2 for later operation of device 2.

[0023] During initial commissioning of the device 2 at the installation location of the device 2, the first step is to determine the density of the gas mixture using a sensorless method at a previously known or assumed relative humidity of the gas mixture, depending on the installation altitude of the device 2. Since the device 2 has not yet been operated and therefore no cooking process has taken place in the treatment chamber 4 designed as a cooking chamber, it can be assumed that the gas mixture in the device 2 has a relative humidity of 0%. Due to the aforementioned features of the device 2, the aforementioned sensorless determination can be carried out using three different methods, namely: Manual input of the installation altitude of the device 2 by means of the user interface 12 of the device 2, which is connected to the controller 6 for signal transmission; Automatic adoption of the installation altitude of the device 2 from another device installed at the same installation location by means of the device interface 14 of the device 2, which is connected to the controller 6 for signal transmission; Automatic adoption of the installation altitude of the device 2 from a remote server via a device interface 14 of the device 2; Measurement of the electrical power consumption of the fan 8 at at least one predetermined, constant speed of a fan impeller (not shown) of the fan 8 at at least one predetermined temperature of the gas mixture.

[0024] If a user of the device 2 (not shown) actually knows the installation altitude of the device 2, the user can manually enter the installation altitude, i.e. the height of the device 2 above sea level, using the user interface 12.

[0025] If the user does not know the installation altitude and another device is already present at the installation location of device 2, it is also possible for the installation altitude already stored in the additional device to be automatically transferred to device 2 via the device interface 14 and stored in the controller 6. However, this requires that the installation altitude is actually stored in the additional device and that the additional device can communicate with device 2, namely with the device interface 14 of device 2, in a manner known to those skilled in the art.

[0026] Alternatively, the installation height can also be taken over via the device interface 14 of the device 2 from a remote server, for example via a manufacturer cloud to which the device 2 is connected.

[0027] If the aforementioned methods are not applicable, the device 2 has the option of measuring the electrical power consumption of the fan 8 at at least one predetermined, constant speed of the fan wheel of the fan 8 at at least one predetermined temperature of the gas mixture. See the Fig. 2 . From this diagram it can be seen that the electrical power consumption of the fan 8 is determined at a total of three different speeds a, b, c, where: speed a is greater than speed b and speed b is greater than speed c. The above measurements are carried out at room temperature; the gas mixture therefore has a temperature of approximately 25°. Furthermore, Fig. 2 Two vertical, dashed lines A and B are shown, where lines A and B represent two different installation altitudes by way of example, and the installation altitude along line A is higher than the installation altitude along line B. At a higher installation altitude, under otherwise identical conditions, i.e., with the same humidity and temperature of the gas mixture and the same speed of the fan 8, a lower electrical input power is required than at a lower installation altitude. However, it is also conceivable that the aforementioned measurements are carried out not just at a single temperature of the gas mixture, but at a plurality of different temperatures of the gas mixture.

[0028] The initial commissioning of device 2 is complete and the user now wants to carry out a cooking process.

[0029] For this purpose, the user switches on the device 2 in a manner known per se to those skilled in the art. In the present exemplary embodiment, the aforementioned switching on of the device 2 for the purpose of carrying out a cooking process is stored in the controller 6 as an execution condition for the second step of the calibration method. In principle, other execution conditions for the second step of the calibration method according to the invention are conceivable as an alternative or in addition. Purely by way of example, it should be noted here that this second step, alternatively or in addition to the aforementioned switching on of the device 2 for the purpose of carrying out a cooking process, can also be carried out automatically at predetermined times, for example after the expiration of predetermined and stored time intervals.

[0030] Due to the existence of the previously defined execution condition stored in the controller 6, the method step of sensorless correction of the density of the gas mixture determined in the first method step is now carried out automatically at a previously known or assumed relative humidity of the gas mixture depending on the weather conditions at the location of the device 2. In the present embodiment, this sensorless correction of the density of the gas mixture comprises measuring the electrical power consumption of the fan 8 at a previously defined, constant speed of the fan wheel of the fan 8 at a previously defined temperature of the gas mixture, for example, the room temperature when the device 2 is switched on for the purpose of carrying out the cooking process. The relative humidity of the gas mixture is assumed to be 0%, analogous to the first method step of the calibration method. See the Fig. 3 As can be seen from this diagram, the measurement is carried out only at a single speed of the fan wheel of fan 8, namely speed b. Furthermore, analogous to the Fig. 2 , in the Fig. 3 two vertical, dashed lines C, D are shown, with lines C and D representing examples of two different weather conditions at the installation location of the device 2, namely a low-pressure weather condition C and a high-pressure weather condition D. In a low-pressure weather condition, with otherwise identical conditions, i.e., with the same humidity and temperature of the gas mixture and the same speed of the fan 8, a lower electrical input power is required than in a high-pressure weather condition. However, it is also conceivable that the aforementioned measurements are carried out not only at a single speed and a single temperature of the gas mixture, but at a plurality of different speeds and / or temperatures of the gas mixture.

[0031] In the third and final step of the calibration process, a relationship stored in the controller 6 of the device 2 between the electrical power consumption of the fan 8 and the density of the gas mixture is automatically adjusted depending on the sensorlessly determined and corrected density of the gas mixture. For example, it can be provided that the aforementioned relationship between the electrical power consumption of the fan 8 and the density of the gas mixture is stored in the controller 6 as a characteristic curve d.The aforementioned adjustment ideally leads to a parallel shift of the characteristic curve d stored in the control unit 6, so that for the subsequent operation of the appliance 2, i.e., for the cooking process, the characteristic curve e shifted parallel to the characteristic curve d is used to convert the measured electrical power consumption of the fan 8 into the density of the gas mixture and thus into the humidity prevailing in the treatment chamber 4 designed as a cooking chamber. See the . Fig. 4 .

[0032] Due to the inventive design of the present calibration method, the present operating method, and the device 2, it is thus possible to determine the humidity of the gas mixture, namely the air-water mixture in the treatment chamber 4 designed as a cooking chamber, more accurately, reliably, simply, and cost-effectively than before during a cooking process in the device 2. This is because, for example, no explicit humidity sensor is required to determine the humidity of the gas mixture.

[0033] Thus, the input power of the electric motor of fan 8, i.e., the electrical input power of fan 8, can be used to determine the humidity of the gas mixture in treatment chamber 4 without an explicit humidity sensor. This gas mixture can be, for example, ambient air or a gas mixture of ambient air and water vapor, or steam for short.

[0034] The aforementioned calibration method takes into account the fact that the power consumption of the electric motor of the fan 8 depends not only on the humidity but also on the air pressure at the installation location of the appliance 2. Accordingly, the accuracy and reliability of determining the humidity of the gas mixture during a cooking process in the appliance 2 can be increased by using the aforementioned calibration method, namely a prior calibration of the relationship stored in the controller 6 of the appliance 2 between the electrical power consumption of the fan 8 and the density of the gas mixture. This can be achieved simply and cost-effectively in the manner according to the present embodiment.

[0035] However, the invention is not limited to the present embodiment. See, for example, the relevant statements in the introduction to the description as well as the corresponding information on optional features in the explanation of the specific embodiment.

Claims

1. Calibration method for a device (2) with a fan (8) for flushing a treatment chamber (4) of the device (2) with a gas mixture, according to which the calibration method comprises the following method steps in the specified order: - Sensorless determination of the density of the gas mixture at a previously known or assumed relative humidity of the gas mixture as a function of an installation altitude of the device (2) during initial commissioning of the device (2) at an installation location of the device (2); - Sensorless correction of the density of the gas mixture thus determined at a previously known or assumed relative humidity of the gas mixture as a function of a weather situation at this installation location of the device (2) in the presence of a previously defined execution condition stored in a controller (6) of the device (2);- adaptation of a relationship stored in the control (6) of the device (2) between an electrical power consumption of the fan (8) and the density of the gas mixture as a function of the sensorlessly determined and corrected density of the gas mixture; 2. Calibration method according to claim 1, characterized in thatthe aforementioned sensorless determination of the density of the gas mixture comprises at least one of the following methods: - manual input of the installation altitude of the device (2) by means of a user interface (12) of the device (2) which is connected to the controller (6) in a signal-transmitting manner; - automatic adoption of the installation altitude of the device (2) from another device installed at the same installation location by means of a device interface (14) of the device (2) which is connected to the controller (6) in a signal-transmitting manner; - automatic adoption of the installation altitude of the device (2) from a remote server via a device interface (14) of the device (2); - measurement of the electrical power consumption of the fan (8) at at least one predetermined, constant speed of a fan impeller of the fan (8) at at least one predetermined temperature of the gas mixture.

3. Calibration method according to claim 1 or 2, characterized in thatthe aforementioned sensorless correction of the density of the gas mixture comprises measuring the electrical power consumption of the fan (8) at at least one predetermined, constant speed of a fan wheel of the fan (8) at at least one predetermined temperature of the gas mixture.

4. Calibration method according to one of claims 1 to 3, characterized in that the aforementioned relationship between the electrical power consumption of the fan (8) and the density of the gas mixture is stored in the control (6) as an algorithm, as a characteristic curve (d) or as a table.

5. Calibration method according to one of claims 1 to 4, characterized in that the at least one predetermined temperature of the gas mixture is measured by means of a temperature sensor (10) of the device (2) which is connected to the controller (6) in a signal-transmitting manner.

6. Calibration method according to one of claims 1 to 5, characterized in thatthe aforementioned sensorless determination and / or the aforementioned sensorless correction are / is carried out when the temperature of the gas mixture is substantially equal to a room temperature at the installation location, preferably additionally when at least one temperature of the gas mixture is substantially greater than the room temperature at the installation location.

7. Operating method for a device (2) with a fan (8) for flushing a treatment chamber (4) of the device (2) with a gas mixture, according to which the device (2) is operated as a function of the relationship between the electrical power consumption of the fan (8) and the density of the gas mixture, which relationship is adjusted by means of the calibration method according to one of claims 1 to 6.

8. Operating method according to claim 7, characterized in thatthe device (2) is operated as a function of the humidity of the gas mixture determined by means of the aforementioned relationship between the electrical power consumption of the fan (8) and the density of the gas mixture.

9. Device (2) with a treatment chamber (4) for a material to be treated, a control system (6), a fan (8) connected to the control system (6) for transmitting signals for flushing the treatment chamber (4) with a gas mixture and a temperature sensor (10) connected to the control system (6) for measuring a temperature of the gas mixture, characterized in that the device (2) is designed and configured to carry out the method according to one of claims 1 to 8.

10. Device (2) according to claim 9, characterized in that the device (2) has a user interface (12) connected to the controller (6) for signal transmission and / or a device interface (14) connected to the controller (6) for signal transmission.

11. Device (2) according to claim 9 or 10, characterized in that the device (2) is designed as a cooking device, preferably as an oven, a steamer, a microwave cooking device or a combination device with radiant heating and a steam generator.

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