A temperature control method for an electric oven with self-temperature inspection

Abstract

The present invention discloses a temperature control method for an electric oven with self-checking of temperature, which includes: obtaining a set temperature T0 to be reached; obtaining temperature values within a sampling period, determining the time difference between two adjacent sampling periods and the temperature difference between two detected temperature values, determining the measured temperature rise rate value of the temperature group as the ratio of the temperature difference to the time difference, and determining whether to make temperature compensation by comparing the difference between the standard temperature rise rate value V0 and the measured temperature rise rate value; adjusting the heating power of the heating device by referring to the temperature value. The present invention belongs to the technical field of electric ovens, and specifically provides a temperature control method for an electric oven with self-checking of temperature, which can avoid temperature detection failure or abnormality by adding a self-checking function of temperature detection, has low cost, high practicability and good effect, and adjusts the heating power by using temperature detection to basically keep the temperature field in the electric oven unchanged, which is more conducive to the uniform heating of food.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric ovens, and specifically refers to a temperature control method for an electric oven with self-checking temperature. Background Art

[0002] All temperature detections adopted by current oven products are based on the characteristics of a series of components such as NTC and PTC to design temperature detection circuits, enabling the MCU to recognize the temperature inside the oven and make corresponding judgments. If key components malfunction, parameter changes occur, or other components in the circuit application are defective, resulting in the failure or abnormality of the temperature detection circuit, the heating function of the entire oven will be affected: the oven may be in a continuous heating state, causing the food to burn; or the oven may always be in a low-temperature state, resulting in the inability to cook the food thoroughly. And if there are fluctuations in the power grid, the voltage rises or falls, which will cause the heating power of the oven to rise or fall correspondingly. Summary of the Invention

[0003] In view of the above situation, to overcome the defects of the prior art, the present invention provides a temperature control method for an electric oven with self-checking temperature, which can avoid temperature detection failure or abnormality, has low cost, high practicability and good effect, adjusts the heating power by using temperature detection, keeps the temperature field in the electric oven basically unchanged, and is more conducive to the uniform heating of food.

[0004] The technical solution adopted by the present invention is as follows: A temperature control method for an electric oven with self-checking temperature, the electric oven is provided with an MCU, a temperature detection device and a plurality of heating devices, the MCU includes a temperature detection circuit, the temperature detection circuit is used to detect the temperature inside the electric oven, and the temperature control method includes the following steps:

[0005] S1: Obtain the set temperature T0 to be reached;

[0006] S2: When the electric oven is in use for heating, obtain the temperature value inside the electric oven in each acquisition period of n1 sampling periods, and obtain n1 detected temperature values, where n1 is a positive integer greater than or equal to 4;

[0007] S3: Divide the n1 detected temperature values into n2 temperature groups, and calculate the measured temperature rise rate value of each temperature group to obtain n2 measured temperature rise rate values; where n2 is a positive integer and n2 is less than or equal to n1 / 2, and each temperature group contains at least 2 adjacent detected temperature values, and the detected temperature values included in different temperature groups are different;

[0008] S4: Calculate the difference between each of the n2 measured temperature rise rate values and the standard temperature rise rate value V0 within the MCU to obtain n2 rate differences. If the difference between the maximum and minimum values among the n2 rate differences is greater than a certain value, the MCU determines that the existing temperature detection circuit is in a failure state or the power grid is abnormal. Furthermore, the MCU compensates the real-time detected data to bring the temperature rise rate back to the standard;

[0009] S5: Compare the reference temperature value among the n1 detected temperature values with the set maximum temperature T0. If the reference temperature value is greater than or equal to the set temperature T0, control the heating device to stop heating; if the reference temperature value is less than the set temperature T0, adjust the heating power of the heating device. The reference temperature value is one of the n1 detected temperature values.

[0010] As a further elaborated solution, calculating the measured temperature rise rate value of each temperature group includes performing the following operations for each temperature group:

[0011] Determine two adjacent sampling periods in the sampling period corresponding to the detected temperature value in the temperature, determine the time difference between the two adjacent sampling periods, and determine the temperature difference between the two detected temperature values obtained in the two adjacent sampling periods. Determine the ratio of the temperature difference to the time difference as the measured temperature rise rate value of the temperature group.

[0012] As a preferred solution, in step S2, let n1 be 4, divide the 4 detected temperature values into 2 temperature groups, and calculate the measured temperature rise rate value of each temperature group to obtain 2 measured temperature rise rate values, including the following specific steps:

[0013] Let the time difference between the first detected temperature and the second detected temperature be ΔS1, the temperature difference between the first detected temperature T1 and the second detected temperature T2 be ΔT1 = T2 - T1, and the climbing rate of the first detected temperature and the second detected temperature be V1 = ΔT1 / ΔS1;

[0014] Let the time difference between the third detected temperature and the fourth detected temperature be ΔS2, the temperature difference between the third detected temperature T3 and the fourth detected temperature T4 be ΔT2 = T4 - T3, and the climbing rate of the third detected temperature and the fourth detected temperature be V2 = ΔT2 / ΔS2.

[0015] Furthermore, the reference temperature value is the most recently obtained detected temperature value Tn1 among the n1 detected temperature values.

[0016] Further, if the reference temperature value is less than the set temperature T0, the heating power of the heating device is adjusted. The specific steps include: when T0 - Tn > 100 °C, the electric oven heats with 75% power; when T0 - 100 < T1 < T0 - 50, the electric oven heats with 50% power. By controlling the heating power, the effect of energy saving is achieved.

[0017] Further, in step S3, the temperature rise rate V0 of different power combinations needs to be written into the MCU in advance.

[0018] Further, the MCU contains a memory, and the memory is used to store the standard temperature rise rate value V0.

[0019] Further, the heating power of the electric oven can be specifically controlled by controlling the conduction or disconnection time of each heating element. When the countdown of the timer reaches zero (i.e., the countdown ends), the MCU controls all heating elements to stop working and reminds the user to take out the bread.

[0020] As a further elaborated solution, the heating device includes multiple groups, and adjusting the heating power of the heating device further includes: controlling the heating device to be turned on alternately.

[0021] The beneficial effects achieved by the present invention using the above solution are as follows: The design of an electric oven with temperature self-checking in this solution only needs to add a self-checking function for temperature detection to avoid a series of abnormal oven functions caused by temperature detection failure or abnormality. The cost is low and the effect is very good, with good practical value. At the same time, the oven uses different powers for heating in different modes, but the combination of different powers is limited. By using temperature detection to adjust the heating power and controlling the heating power by controlling the conduction or disconnection time of each heating element, the temperature field in the electric oven is basically kept unchanged, which is more conducive to the uniform heating of food. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the composition of the temperature control method for the electric oven with temperature self-checking in this solution.

[0023] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] The following will describe the technical solutions in the embodiments of the present invention clearly and completely in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0025] This solution provides a temperature control method for an electric oven with temperature self-check. Among them, the electric oven is provided with an MCU, a temperature detection device, and a plurality of heating devices. The MCU contains a temperature detection circuit. The temperature detection circuit is used to detect the internal temperature of the electric oven, and a standard temperature rise rate value is stored in the MCU. The temperature control method includes the following steps:

[0026] S1: Obtain the set temperature T0 to be reached;

[0027] S2: When the electric oven is in use for heating, obtain the temperature value inside the electric oven in each acquisition cycle of n1 sampling cycles, and obtain n1 detected temperature values. Among them, n1 is a positive integer greater than or equal to 4;

[0028] S3: Divide the n1 detected temperature values into n2 temperature groups, and calculate the measured temperature rise rate value of each temperature group to obtain n2 measured temperature rise rate values; where n2 is a positive integer and n2 is less than or equal to n1 / 2. Each temperature group contains at least 2 adjacent detected temperature values, and the detected temperature values included in different temperature groups are different;

[0029] In step S3, calculating the measured temperature rise rate value of each temperature group includes performing the following operations for each temperature group:

[0030] Determine two adjacent sampling cycles in the sampling cycles corresponding to the detected temperature values in the temperature, determine the time difference between the two adjacent sampling cycles, and determine the temperature difference between the two detected temperature values obtained in the two adjacent sampling cycles. Determine the ratio of the temperature difference to the time difference as the measured temperature rise rate value of the temperature group.

[0031] S4: Calculate the difference between each measured temperature rise rate value among the n2 measured temperature rise rate values and the standard temperature rise rate value V0 in the MCU to obtain n2 rate differences. If the difference between the maximum value and the minimum value among the n2 rate differences is greater than a certain value, it is determined by the MCU that the existing temperature detection circuit is in a failure state or the power grid is abnormal. Then, the MCU compensates the real-time detected data so that the temperature rise rate returns to the standard;

[0032] S5: Compare the reference temperature value among the n1 detected temperature values with the set maximum temperature T0. If the reference temperature value is greater than or equal to the set temperature T0, control the heating device to stop heating; if the reference temperature value is less than the set temperature T0, adjust the heating power of the heating device. The reference temperature value is one of the n1 detected temperature values.

[0033] Embodiment 1. The temperature control method for an electric oven with temperature self-checking in this solution includes the following steps:

[0034] S1: Obtain the set temperature T0 to be reached.

[0035] S2: During the heating process of the electric oven, obtain the temperature value inside the electric oven in each acquisition period of n1 sampling periods to obtain n1 detected temperature values. Here, n1 is a positive integer greater than or equal to 4; divide the n1 detected temperature values into n2 temperature groups, and calculate the measured temperature rise rate value of each temperature group to obtain n2 measured temperature rise rate values. Here, n2 is a positive integer and n2 is less than or equal to n1 / 2. Each temperature group contains at least 2 adjacent detected temperature values, and the detected temperature values included in different temperature groups are different.

[0036] S3: In the above steps, set the value of n1 to 4, that is, obtain the temperature value inside the electric oven in each acquisition period of 4 sampling periods to obtain 4 detected temperature values, divide the 4 detected temperature values into 2 temperature groups, and calculate the measured temperature rise rate value of each temperature group to obtain 2 measured temperature rise rate values; calculate the difference between each measured temperature rise rate value among the 2 measured temperature rise rate values and the standard temperature rise rate value V0 in the MCU to obtain 2 rate differences; determine the two adjacent sampling periods in the sampling period corresponding to the detected temperature value in the temperature, determine the time difference between the two adjacent sampling periods, and determine the temperature difference between the two detected temperature values obtained in the two adjacent sampling periods. Determine the ratio of the temperature difference and the time difference as the measured temperature rise rate value of the temperature group.

[0037] Let the time difference between the first detected temperature and the second detected temperature be ΔS1, the temperature difference between the first detected temperature T1 and the second detected temperature T2 be ΔT1 (ΔT1 = T2 - T1), and the climbing rate of the first detected temperature and the second detected temperature be V1 = ΔT1 / ΔS1;

[0038] Let the time difference between the third detected temperature and the fourth detected temperature be ΔS2, the temperature difference between the third detected temperature T3 and the fourth detected temperature T4 be ΔT2 (ΔT2 = T4 - T3), and the climbing rate of the third detected temperature and the fourth detected temperature be V2 = ΔT2 / ΔS2;

[0039] S3: Write the standard temperature rise rate value V0 of different power combinations into the MCU in advance, compare the difference between V0 and V1, and between V0 and V2. If the difference between the maximum and minimum values ​​of the two rate differences is greater than a certain value, the MCU determines that the existing temperature detection circuit is in a failed state or the power grid is abnormal, and then compensates the real-time detection data through the MCU to make the temperature rise rate return to the standard;

[0040] S4: Compare the reference temperature value among the four detected temperature values ​​with the set maximum temperature T0. If the reference temperature value is greater than or equal to the set temperature T0, control the heating device to stop heating; if the reference temperature value is less than the set temperature T0, adjust the heating power of the heating device, and the reference temperature value is one of the n1 detected temperature values.

[0041] In a preferred embodiment, the heating power of the electric oven can be controlled by controlling the on or off time of each heating element.

[0042] As a further elaboration of the scheme, the heating device includes a plurality of groups, and adjusting the heating power of the heating device further includes: controlling the heating device to be turned on alternately.

[0043] When used specifically, the electric oven is heated at full power in preheating mode. In countdown mode, the oven reference temperature value T1 monitored in real time by the MCU is compared with the temperature value T0 set by the user. If the reference temperature value is less than the set temperature T0, the heating power of the heating device is adjusted and heating is performed in different gears. For example, T1 <T0-100时,电烤箱使用75%的功率加热;T0-100<T1<T0-50时电烤箱使用50%的功率加热。

[0044] Specifically, the heating power can be controlled by controlling the on or off time of each heating element. When the countdown of the timer reaches zero (i.e., the countdown ends), the MCU controls all heating elements to stop working and reminds the user to take out the bread.

[0045] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0046] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

[0047] The above description of the present invention and its embodiments is not restrictive. What is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. In general, if those of ordinary skill in the art are inspired by it and, without departing from the purpose of the present invention, design similar structural forms and embodiments to this technical solution without creative efforts, they shall fall within the protection scope of the present invention.

Claims

1. A temperature control method for an electric oven with self-temperature inspection, characterized in that, The electric oven is provided with an MCU, a temperature detection device and a heating device. The MCU includes a temperature detection circuit for detecting the internal temperature of the electric oven, and a standard temperature rise rate value is stored in the MCU. The temperature control method includes the following steps: S1: Obtain the set temperature T0 to be reached; S2: When the electric oven is in use for heating, obtain the temperature values inside the electric oven in each acquisition cycle of n1 sampling cycles, and obtain n1 detected temperature values. Herein, n1 is a positive integer greater than or equal to 4; S3: Divide the n1 detected temperature values into n2 temperature groups, and calculate the measured temperature rise rate values of each temperature group to obtain n2 measured temperature rise rate values. Herein, n2 is a positive integer and n2 is less than or equal to n1 / 2. Each temperature group contains at least 2 adjacent detected temperature values, and the detected temperature values included in different temperature groups are different; S4: Calculate the difference between each measured temperature rise rate value among the n2 measured temperature rise rate values and the standard temperature rise rate value V0 in the MCU to obtain n2 rate differences. If the difference between the maximum value and the minimum value among the n2 rate differences is greater than a certain value, it is determined by the MCU that the existing temperature detection circuit is in a failure state or the power grid is abnormal. Furthermore, the MCU makes compensation for the real-time detected data to make the temperature rise rate return to the standard; S5: Compare the size of the reference temperature value among the n1 detected temperature values with the set temperature T0. If the reference temperature value is greater than or equal to the set temperature T0, control the heating device to stop heating; if the reference temperature value is less than the set temperature T0, adjust the heating power of the heating device. The reference temperature value is one of the n1 detected temperature values.

2. A temperature control method for an electric oven with self-temperature inspection according to claim 1, characterized in that: Calculating the measured temperature rise rate value of each of the temperature groups includes: Perform the following operations for each temperature group: Determine two adjacent sampling cycles in the sampling cycles corresponding to the detected temperature values in the temperature, determine the time difference between the two adjacent sampling cycles, and determine the temperature difference between the two detected temperature values obtained in the two adjacent sampling cycles. Determine the ratio of the temperature difference to the time difference as the measured temperature rise rate value of the temperature group.

3. A temperature control method for an electric oven with self-temperature inspection according to claim 2, characterized in that: In step S2, n1 is 4. Divide the 4 detected temperature values into 2 temperature groups, and calculate the measured temperature rise rate values of each temperature group to obtain 2 measured temperature rise rate values, including the following specific steps: Let the time difference between the first detected temperature and the second detected temperature be ΔS1, the temperature difference between the first detected temperature T1 and the second detected temperature T2 be ΔT1 = T2 - T1, and the rising rate of the first detected temperature and the second detected temperature be V1 = ΔT1 / ΔS1; Let the time difference between the third detected temperature and the fourth detected temperature be ΔS2, the temperature difference between the third detected temperature T3 and the fourth detected temperature T4 be ΔT2 = T4 - T3, and the rising rate of the third detected temperature and the fourth detected temperature be V2 = ΔT2 / ΔS2.

4. A temperature control method for an electric oven with self-temperature inspection according to claim 3, characterized in that: The reference temperature value is the most recently obtained detected temperature value Tn1 among the n1 detected temperature values.

5. A temperature control method for an electric oven with self-temperature inspection according to claim 4, characterized in that: If the reference temperature value is less than the set temperature T0, adjusting the heating power of the heating device includes: When T0 - Tn > 100, the electric oven heats at 75% power; when T0 - 100 < T1 < T0 - 50, the electric oven heats at 50% power.

6. A temperature control method for an electric oven with self-temperature inspection according to claim 1, characterized in that: In step S3, the temperature rise rate V0 of different power combinations needs to be written into the MCU in advance.

7. A temperature control method for an electric oven with self-temperature inspection according to claim 6, characterized in that: The MCU contains a memory, and the memory is used to store the standard temperature rise rate value V0.

8. A temperature control method for an electric oven with self-temperature inspection according to claim 1, characterized in that: The heating power of the electric oven is specifically controlled by controlling the conduction or disconnection time of each heating element.

9. A temperature control method for an electric oven with self-temperature inspection according to claim 8, characterized in that: The heating device includes multiple groups, and adjusting the heating power of the heating device further includes: controlling the heating device to be turned on alternately.

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