A method for calibrating an oxygen sensor for a cooking appliance

Abstract

The application discloses a kind of oxygen sensor calibration methods for cooking equipment, according to the altitude of the current position of user using cooking equipment is different to cause the temperature change when water boils, so by judging whether the atmospheric pressure of the place where user is and the atmospheric pressure of initial factory place have barometric pressure difference, to judge whether oxygen sensor needs to be recalibrated, since the volume fraction of oxygen in air is basically the same, oxygen sensor can be recalibrated in normal temperature air according to this property, its method is simple and feasible, can be recalibrated whether oxygen sensor needs to be recalibrated according to the temperature change when water boils caused by different altitude pressure, to effectively improve the accuracy of oxygen sensor measurement humidity.

Description

Technical Field

[0001] This invention relates to the field of kitchen appliance technology, and in particular to a method for calibrating an oxygen sensor for cooking equipment. Background Technology

[0002] Humidity is one of the important parameters of the cooking environment. Since the humidity of steam ovens is relatively high, most related technologies use oxygen sensors to indirectly measure the humidity of the cooking environment of steam ovens. The humidity measured by the oxygen sensor is related to the density of oxygen in the air. That is, the higher the oxygen density, the higher the oxygen sensor reading. It can be seen that the oxygen sensor is relatively easily affected by the high altitude climate, which leads to low accuracy of humidity measurement. Summary of the Invention

[0003] This invention aims to at least partially solve one of the problems existing in the prior art. To this end, this invention proposes a calibration method for oxygen sensors in cooking equipment. The method is simple and feasible, and can determine whether the oxygen sensor needs to be recalibrated based on the changes in water boiling temperature caused by different altitude air pressures, thereby effectively improving the accuracy of oxygen sensor in measuring humidity.

[0004] The above objective is achieved through the following technical solution:

[0005] A method for calibrating an oxygen sensor for a cooking appliance, the method comprising the following steps:

[0006] After the cooking equipment is powered on, the oxygen sensor obtains the current oxygen concentration value inside the inner pot;

[0007] Determine whether the current oxygen concentration value meets the preset conditions. If the current oxygen concentration value does not meet the preset conditions, compare the current oxygen concentration value with the preset oxygen concentration value, and decide whether to start the evaporator based on the comparison result.

[0008] Obtain the current temperature value when the water in the evaporator boils;

[0009] The current temperature value is compared with the temperature value when the water in the evaporator boiled during the last use, and the oxygen sensor is recalibrated based on the comparison result.

[0010] In some embodiments, the step of determining whether the current oxygen concentration value meets a preset condition, and comparing the current oxygen concentration value with a preset oxygen concentration value if the current oxygen concentration value does not meet the preset condition, includes:

[0011] Determine whether the current oxygen concentration value meets the preset conditions;

[0012] If the current oxygen concentration value meets the preset conditions, then the oxygen sensor is determined to be in normal condition;

[0013] If the current oxygen concentration value does not meet the preset conditions, the current oxygen concentration value is compared with the preset oxygen concentration value.

[0014] In some embodiments, the step of comparing the current oxygen concentration value with a preset oxygen concentration value and determining whether to start the evaporator based on the comparison result includes:

[0015] Determine whether the current oxygen concentration value is less than the first preset oxygen concentration value;

[0016] If so, then determine whether the temperature of the inner liner is at room temperature;

[0017] If not, it is determined that the current oxygen concentration value is greater than the second preset oxygen concentration value, and the evaporator is started simultaneously.

[0018] In some embodiments, the step of determining whether the temperature of the inner liner is room temperature includes:

[0019] Determine if the temperature of the inner liner is at room temperature;

[0020] If so, then start the evaporator;

[0021] If not, the test will be performed again at room temperature.

[0022] In some implementations, the preset condition is that the current oxygen concentration value is greater than or equal to the first preset oxygen concentration value, and the current oxygen concentration value is less than or equal to the second preset oxygen concentration value.

[0023] In some embodiments, the step of comparing the current temperature value with the temperature value when the water in the evaporator boiled during the last use, and determining whether to recalibrate the oxygen sensor based on the comparison result, includes:

[0024] Determine whether the current temperature value is equal to the temperature value when the water in the evaporator boiled during the last use;

[0025] If so, it is determined that the oxygen sensor is faulty, and the user is reminded to replace the oxygen sensor;

[0026] If not, it is determined that the operating environment of the oxygen sensor has changed, and the oxygen sensor is recalibrated.

[0027] In some embodiments, the step of determining whether to recalibrate the oxygen sensor based on the comparison results includes:

[0028] After recalibrating the oxygen sensor, the preset atmospheric pressure value before calibration is changed to the current atmospheric pressure value after calibration, and the current atmospheric pressure value is substituted into the calculation formula for relative humidity.

[0029] According to claim 1, the method for calibrating an oxygen sensor for a cooking device is characterized in that the formula for calculating the relative humidity is: Where C is the relative humidity value, X is the oxygen concentration value, P is the current atmospheric pressure value, t is the temperature, and 21% is the percentage of oxygen concentration in the air.

[0030] In some implementations, the recalibration of the oxygen sensor is scheduled to be performed before the user starts the cooking appliance.

[0031] In some embodiments, during the recalibration of the oxygen sensor, if the user starts the cooking device to cook, the recalibration of the oxygen sensor is stopped and the cooking continues according to the parameters before the oxygen sensor was calibrated. After the cooking is completed, the oxygen sensor is recalibrated again.

[0032] Compared with the prior art, the present invention has at least the following beneficial effects:

[0033] 1. The present invention provides a method for calibrating oxygen sensors in cooking equipment. The method is simple and feasible. It can determine whether the oxygen sensor needs to be recalibrated based on the changes in water boiling temperature caused by different altitude air pressures, thereby effectively improving the accuracy of the oxygen sensor in measuring humidity. Attached Figure Description

[0034] Figure 1 This is a schematic flowchart of the oxygen sensor calibration method in an embodiment of the present invention. Detailed Implementation

[0035] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of the technical solutions claimed in the present invention.

[0036] like Figure 1As shown, this embodiment provides a calibration method for an oxygen sensor in a cooking device. Based on the altitude difference at the user's current location when using the cooking device, which causes variations in the boiling temperature of water, the method determines whether the oxygen sensor needs recalibration by comparing the atmospheric pressure at the user's current location with the initial atmospheric pressure at the factory location. Since the volume fraction of oxygen in the air is essentially the same, this property allows for recalibration of the oxygen sensor in ambient air. This method is simple and feasible, effectively improving the accuracy of humidity measurement by determining whether the oxygen sensor needs recalibration based on the temperature changes in boiling water caused by different altitudes and air pressures.

[0037] In this embodiment, the cooking equipment is a steam oven, a steam oven, a microwave steam oven, a microwave steam oven, or a steam oven combination unit, but is not limited to the above-mentioned equipment. Of course, other more suitable steam cooking equipment can also be selected. In this embodiment, a steam oven is used as an example to describe the cooking equipment, and the others will not be described in detail. The steam oven has an inner liner for cooking food. An evaporator is installed on the inner liner to heat external water to generate high-temperature steam. A temperature sensor is installed inside the evaporator to detect the temperature inside the evaporator. An oxygen sensor is installed on the inner liner to obtain the humidity inside the inner liner by the current oxygen concentration value. The evaporator, temperature sensor, and oxygen sensor are electrically connected to the controller so that the controller controls the operation of the evaporator, temperature sensor, and oxygen sensor respectively.

[0038] In this embodiment, the calibration method for the oxygen sensor includes the following steps:

[0039] Step S101: After the cooking device is powered on, the oxygen sensor obtains the current oxygen concentration value inside the inner pot.

[0040] In this embodiment, before the steam oven is packaged at the factory, the oxygen sensor is pre-calibrated in a normal open environment to serve as the reference value for the oxygen sensor. Before leaving the factory, the steam oven starts the evaporator for heating. Since the air pressure varies at different altitudes, the boiling point of the water also changes. Therefore, the local air pressure can be calculated using a conversion formula based on the boiling point. This can be obtained by referring to a table showing the relationship between the existing air pressure and the boiling point, and the boiling point and local air pressure are recorded each time the evaporator is used. Furthermore, after the steam oven leaves the factory and is used for cooking at the user's home, when the steam oven is powered on, the oxygen sensor is activated to detect the oxygen concentration inside the inner tank to obtain the current oxygen concentration value.

[0041] Step S102: Determine whether the current oxygen concentration value meets the preset conditions;

[0042] If the current oxygen concentration value meets the preset conditions, the oxygen sensor is determined to be in normal condition.

[0043] If the current oxygen concentration value does not meet the preset conditions, the current oxygen concentration value is compared with the first preset oxygen concentration value.

[0044] In this embodiment, the preset condition is that the current oxygen concentration value is greater than or equal to the first preset oxygen concentration value, and the current oxygen concentration value is less than or equal to the second preset oxygen concentration value. In this embodiment, the first preset oxygen concentration value is preferably 20%, but it is not limited to the above value. Other more suitable values ​​can be selected according to actual needs. In this embodiment, the first preset oxygen concentration value is described using 20% ​​as an example. Other values ​​will not be described. In this embodiment, the second preset oxygen concentration value is preferably 22%, but it is not limited to the above value. Other more suitable values ​​can be selected according to actual needs. In this embodiment, the second preset oxygen concentration value is described using 22% as an example. Other values ​​will not be described. In addition, if the current oxygen concentration value does not meet the preset condition, the main reasons are as follows: ① The temperature inside the inner liner has not returned to normal temperature since the last use by the user, that is, the inner liner contains moisture and has not been completely dried; ② The altitude of the factory location is different from that of the user's usage environment, or the air pressure is different due to the change of the user's usage environment, and the oxygen content also changes; ③ The oxygen sensor is faulty, has a reading deviation, or is damaged.

[0045] Step S103: Determine whether the current oxygen concentration value is less than the first preset oxygen concentration value;

[0046] If so, then determine whether the temperature of the inner liner is at room temperature;

[0047] If not, it is determined that the current oxygen concentration value is greater than the second preset oxygen concentration value, and the evaporator is started at the same time.

[0048] Step S104: Determine whether the temperature of the inner liner is at room temperature;

[0049] If so, then start the evaporator;

[0050] If not, the test will be performed again at room temperature.

[0051] In this embodiment, when the current oxygen concentration of the inner liner is less than the first preset oxygen concentration value, that is, when the current oxygen concentration of the inner liner is less than 20%, the temperature of the inner liner is first measured by the inner liner temperature sensor to see if it is at room temperature. Room temperature means that the room temperature is 25°C. If the temperature of the inner liner is not at room temperature, that is, when the temperature of the inner liner is greater than 35°C, it is determined that the humidity of the inner liner is relatively high. The test can be performed again at room temperature for further confirmation. If the temperature of the inner liner is at room temperature, the evaporator is started to heat the liner.

[0052] In this embodiment, when the current oxygen concentration of the inner liner is greater than the second preset oxygen concentration value, that is, when the current oxygen concentration of the inner liner is greater than 22%, the evaporator is started to perform heating.

[0053] Step S105: After starting the evaporator, obtain the current temperature value when the water in the evaporator boils.

[0054] In this embodiment, after the evaporator is started, the temperature of the water boiling inside the evaporator is detected by a temperature sensor to obtain the current temperature value of the water boiling inside the evaporator.

[0055] Step S106: Determine whether the current temperature value is equal to the temperature value when the water in the evaporator boiled during the last use;

[0056] If so, the oxygen sensor is determined to be faulty, and the user is reminded to replace the oxygen sensor.

[0057] If not, it is determined that the operating environment of the oxygen sensor has changed, and the oxygen sensor needs to be recalibrated.

[0058] In this embodiment, if the boiling temperature of the water is different from the boiling temperature of the water in the evaporator during the previous use, it is determined that the oxygen sensor is inaccurate due to reason ②, that is, the operating environment of the oxygen sensor has changed, and the oxygen sensor is recalibrated to ensure the accuracy of the oxygen sensor detection. If the boiling temperature of the water is the same as the boiling temperature of the water in the evaporator during the previous use, it is determined that the oxygen sensor is inaccurate due to reason ③, that is, the oxygen sensor is faulty, and the user is reminded to replace the oxygen sensor.

[0059] In this embodiment, if it is determined that the oxygen sensor's detection of the oxygen concentration in the inner liner is inaccurate due to reason ②, after recalibrating the oxygen sensor, the air pressure value in the corresponding conversion formula between the oxygen concentration value and the humidity value will also change accordingly. This changes the preset atmospheric pressure value before calibration to the current atmospheric pressure value after calibration. Substituting the current atmospheric pressure value into the relative humidity calculation formula, the conversion formula between the relative humidity value C, oxygen concentration value X, atmospheric pressure value P, and temperature value t is as follows: Where C is the relative humidity value, X is the oxygen concentration value, P is the current atmospheric pressure value, t is the temperature, and 21% is the percentage of oxygen concentration in the air. The formula for calculating relative humidity in this embodiment is derived from an empirical formula.

[0060] To prevent user error, the oxygen sensor recalibration is scheduled to occur before the user starts the cooking equipment. The recalibration process is set to begin before cooking and will automatically perform the calibration. Since the recalibration process takes approximately 3 minutes, user actions during this time can disrupt the process. Therefore, if the user starts the cooking equipment (e.g., starts the steamer during the calibration process), the recalibration will automatically stop, and cooking will continue according to the parameters set before calibration. After cooking, the oxygen sensor will be recalibrated again.

[0061] The above descriptions are merely some embodiments of the present invention. Those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A method for calibrating an oxygen sensor for a cooking device, characterized in that, The oxygen sensor calibration method includes the following steps: After the cooking equipment is powered on, the oxygen sensor obtains the current oxygen concentration value inside the inner pot; Determine whether the current oxygen concentration value meets the preset conditions. If the current oxygen concentration value does not meet the preset conditions, compare the current oxygen concentration value with the preset oxygen concentration value, and decide whether to start the evaporator based on the comparison result. Obtain the current temperature value when the water in the evaporator boils; The current temperature value is compared with the temperature value when the water in the evaporator boiled during the last use, and a decision is made on whether to recalibrate the oxygen sensor based on the comparison result. The step of determining whether the current oxygen concentration value meets the preset conditions, and comparing the current oxygen concentration value with the preset oxygen concentration value if the current oxygen concentration value does not meet the preset conditions, includes: determining whether the current oxygen concentration value meets the preset conditions; if the current oxygen concentration value meets the preset conditions, determining that the oxygen sensor is in a normal state; if the current oxygen concentration value does not meet the preset conditions, comparing the current oxygen concentration value with the preset oxygen concentration value. The step of comparing the current oxygen concentration value with a preset oxygen concentration value and deciding whether to start the evaporator based on the comparison result includes: determining whether the current oxygen concentration value is less than a first preset oxygen concentration value; if so, determining whether the temperature of the inner tank is at room temperature; if not, determining that the current oxygen concentration value is greater than a second preset oxygen concentration value, and starting the evaporator simultaneously. The step of determining whether the temperature of the inner liner is at room temperature includes: determining whether the temperature of the inner liner is at room temperature; If yes, then start the evaporator; if not, then perform the test again at room temperature. The preset condition is that the current oxygen concentration value is greater than or equal to the first preset oxygen concentration value, and the current oxygen concentration value is less than or equal to the second preset oxygen concentration value.

2. The method for calibrating an oxygen sensor for a cooking device according to claim 1, characterized in that, The step of comparing the current temperature value with the temperature value when the water in the evaporator boiled during the last use, and determining whether to recalibrate the oxygen sensor based on the comparison result, includes: Determine whether the current temperature value is equal to the temperature value when the water in the evaporator boiled during the last use; If so, it is determined that the oxygen sensor is faulty, and the user is reminded to replace the oxygen sensor; If not, it is determined that the operating environment of the oxygen sensor has changed, and the oxygen sensor is recalibrated.

3. The method for calibrating an oxygen sensor for a cooking device according to claim 1, characterized in that, The step of determining whether to recalibrate the oxygen sensor based on the comparison results includes: After recalibrating the oxygen sensor, the preset atmospheric pressure value before calibration is changed to the current atmospheric pressure value after calibration, and the current atmospheric pressure value is substituted into the calculation formula for relative humidity.

4. The method for calibrating an oxygen sensor for a cooking device according to claim 3, characterized in that, The formula for calculating the relative humidity is: Where C is the relative humidity value, X is the oxygen concentration value, P is the current atmospheric pressure value, t is the temperature, and 21% is the percentage of oxygen concentration in the air.

5. A method for calibrating an oxygen sensor for a cooking device according to any one of claims 1 to 4, characterized in that, The oxygen sensor recalibration is scheduled to be performed before the user starts the cooking device.

6. The method for calibrating an oxygen sensor for a cooking device according to claim 5, characterized in that, During the recalibration process of the oxygen sensor, if the user starts the cooking device to cook, the recalibration of the oxygen sensor is stopped and the cooking continues according to the parameters before the oxygen sensor was calibrated. After the cooking is completed, the oxygen sensor is recalibrated again.

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