Temperature control system, temperature control method and refrigeration equipment

Abstract

The invention relates to a temperature control system, a temperature control method and refrigeration equipment, the temperature control system is applied to temperature control of an odor sensor, and the temperature control system comprises the temperature sensor used for detecting the temperature of the odor sensor; the switch unit is used for controlling the smell sensor to heat / stop heating; the control unit is electrically connected with the temperature sensor and the switch unit and can control the switch unit to be closed in response to the situation that the temperature of the smell sensor is lower than a preset range, so that heating of the smell sensor is achieved; the problem of low measurement accuracy caused by inaccurate temperature control of the odor sensor can be solved, and the reliability and the service life of the sensor can be improved and prolonged through accurate temperature control; the working temperatures of a plurality of smell sensors can be kept consistent, and the reliability and consistency of measurement are ensured; and through precise temperature control, the odor sensor can be ensured to work under different environmental conditions with relatively large temperature difference, and the adaptability and the stability of the odor sensor are improved.

Description

Technical Field

[0001] The present application relates to the field of refrigeration technology, and in particular to a temperature control system, a temperature control method and a refrigeration device. Background Art

[0002] In order to provide users with a better user experience, existing refrigeration equipment uses odor sensors / odor sensors in the refrigeration chamber to detect the storage status of food. Once the food is detected to have an odor, the user can be notified and sterilization can be performed simultaneously. Since the odor sensor / odor sensor is a temperature-sensitive semiconductor device, its detection accuracy is closely related to the change in the temperature of the refrigeration chamber, which is specifically manifested in:

[0003] Accuracy: The working principle of semiconductor sensors is based on the effect of temperature on resistance or voltage. Precise temperature control can ensure that the sensor's measurement results are accurate. Small changes in temperature may cause significant fluctuations in the sensor's output value.

[0004] Reliability: The performance and life of semiconductor sensors are affected by temperature. Too high or too low temperature may cause the performance of the sensor to degrade or damage, and in severe cases even cause the sensor to fail. Consistency: In some applications, multiple semiconductor sensors need to be used for measurement at the same time, such as monitoring temperature distribution. If the operating temperatures of the sensors are inconsistent, their performance will be different, thus affecting the accuracy of the overall measurement results.

[0005] Environmental adaptability: In some special environments, such as extremely high or low temperatures or large temperature changes, the performance and stability of the sensor may be affected.

[0006] The temperature control method of the odor sensor / odor sensor in the prior art is mainly to heat it so that its temperature in the refrigeration chamber will not be too low. However, since its temperature control is not timely and accurate enough, its measurement results are prone to deviations, which not only causes unnecessary power consumption, but also easily misleads users and brings a poor user experience. Summary of the invention

[0007] Based on this, it is necessary to provide a temperature control system or temperature control method that can control the temperature of the odor sensor in real time and accurately to address the above technical problems.

[0008] The present application provides a temperature control system, which is used to control the temperature of an odor sensor, including:

[0009] a temperature sensor configured to detect a temperature of the odor sensor;

[0010] a switch unit configured to control heating / stop heating of the smell sensor; and

[0011] The control unit is electrically connected to the temperature sensor and the switch unit respectively, and can control the switch unit to close in response to the temperature of the odor sensor being lower than a preset range, so as to achieve heating of the odor sensor.

[0012] Optionally, the temperature sensor includes a voltage divider circuit and a filter circuit, the voltage divider circuit includes a thermistor and a voltage divider resistor connected in series, the first end of the thermistor is configured to be connected to a power supply, the second end of the voltage divider resistor is configured to be connected to a common ground, the second end of the thermistor is configured to be connected to an input end / sampling end of the control unit, the filter circuit is connected between the voltage divider circuit and the input end / sampling end of the control unit, and the control unit is configured to sample an electrical signal representing the temperature of the odor sensor.

[0013] Optionally, the filtering circuit includes a second resistor and a capacitor, the second end of the capacitor is connected to a common ground, the first end of the capacitor is connected to the first end of the second resistor, the first end of the second resistor is connected to the first end of the resistor, and the second end of the second resistor is connected to the input end (sampling end) of the control unit.

[0014] Optionally, the odor sensor includes a heating electrode, and the switching unit includes: a switching tube and a first resistor, the gate of the switching tube is configured to be connected to the control end of the control unit, the source of the switching tube is grounded, the drain of the switching tube is connected to the second end of the first resistor, the first end of the first resistor is connected to the second end of the heating electrode of the odor sensor, the first end of the heating electrode is configured to be connected to a power supply, and the control unit is configured to send a corresponding level signal to the gate of the switching tube in response to the relationship between the temperature of the odor sensor and a preset range.

[0015] In order to achieve the above-mentioned object of the invention, the present application provides a temperature control method, which uses the temperature control system described above to control the temperature of the odor sensor.

[0016] In order to achieve the above-mentioned object of the invention, the present application provides a temperature control method, which is applied to control the temperature of the odor sensor, comprising the steps of:

[0017] detecting an actual temperature of the odor sensor;

[0018] Determining whether the actual temperature is within a preset range;

[0019] If not, the odor sensor is heated so that the actual temperature is raised to a preset range.

[0020] Optionally, the “detecting the actual temperature of the odor sensor” includes:

[0021] regularly sampling the temperature of the odor sensor;

[0022] The average value of the multiple sampling values ​​is calculated as the actual temperature of the odor sensor.

[0023] Optionally, the temperature control method described above further comprises the steps of:

[0024] In response to the actual temperature returning to within a preset range, heating of the odor sensor is stopped.

[0025] In order to achieve the above-mentioned object of the invention, the present application also provides a temperature control method, which is applied to control the temperature of the odor sensor, comprising the steps of:

[0026] Detecting a comparison relationship between an actual temperature T of the odor sensor and a first preset value T1;

[0027] If T≤T1, controlling PWM to heat the odor sensor with a duty cycle of 100%;

[0028] If T>T1, then further determine the comparison relationship between the actual temperature T and the second preset value T2;

[0029] If T<T2, the odor sensor is heated by controlling the duty cycle of PWM by PID;

[0030] If T≥T2, the heating of the odor sensor is stopped.

[0031] Among them, T1 and T2 are set based on the target temperature and the dead zone temperature, and T1<T2.

[0032] In order to achieve the above-mentioned purpose of the invention, the present application provides a refrigeration device, which is equipped with an odor sensor, and uses the temperature control system or temperature control method described above to control the temperature of the odor sensor.

[0033] The temperature control system, temperature control method and refrigeration equipment provided by the present application can solve the problem of low measurement accuracy of odor sensors due to inaccurate temperature control in the prior art. Through precise temperature control, it can ensure that the odor sensor is within a suitable operating temperature range, thereby improving the reliability and life of the sensor; when odor sensors are installed in multiple positions in the refrigeration equipment, the system or method provided by the present application can make the operating temperature of each odor sensor remain consistent, ensuring the reliability and consistency of the measurement; through precise temperature control, it can also ensure that the odor sensor can work normally under different environmental conditions with large temperature differences, thereby improving its adaptability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the circuit structure of a temperature control system provided in an embodiment of the present application;

[0035] Figure 2 A flow chart of a temperature control method is provided for an embodiment of the present application;

[0036] Figure 3 A flow chart of another temperature control method provided in an embodiment of the present application;

[0037] Figure 4 A flow chart of another temperature control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0040] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first resistor may be referred to as a second resistor, and similarly, a second resistor may be referred to as a first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0041] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0042] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0043] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0044] In one embodiment, Figure 1 As shown, the present embodiment provides a temperature control system of an odor sensor 10, wherein the odor sensor 10 includes a gas-sensitive electrode end and a heating electrode end, and the temperature control system includes: a temperature sensor 110, configured to detect the temperature of the odor sensor 10; specifically, referring to Figure 1The temperature sensor 110 includes a voltage divider circuit and a filter circuit. The voltage divider circuit includes a thermistor NTC1 and a voltage divider resistor R connected in series. The first end of the thermistor NTC1 is configured to be connected to the power supply VCC, and the second end of the voltage divider resistor R is configured to be connected to the common ground. The second end of the thermistor NTC1 (i.e., the first end of the voltage divider resistor R) is configured to be connected to the input end of the control unit 120. The analog-to-digital converter integrated in the control unit 120 can convert the electrical signal sampled from the input end into a digital signal. Taking the number of bits of the analog-to-digital converter as 12 bits as an example, assuming that the resistance value of the thermistor NTC1 is rt, the resistance value of the voltage divider resistor R is r, and the electrical signal collected by the analog-to-digital converter is ADC, then: rt = ADC*r / (4095-AD C), based on the formula, it can be known that the resistance value of the thermistor NTC1 can be detected in real time or periodically through the control unit 120. Further, the control unit 120 can convert the resistance value of the thermistor NTC1 into the temperature of the odor sensor 10 detected by the thermistor NTC1 by looking up the table; the filtering circuit includes a second resistor R2 and a capacitor C, and its main function is to filter out the electromagnetic interference that may be caused when the analog-to-digital converter samples the electrical signal, so as to improve the accuracy of the sampled electrical signal. Specifically, the second end of the capacitor C is connected to the common ground, the first end of the capacitor C is connected to the first end of the second resistor R2, the first end of the second resistor R2 is connected to the first end of the resistor R, and the second end of the second resistor R2 is connected to the input end (sampling end) of the control unit 120.

[0045] Optionally, the control unit 120 may be a single chip microcomputer, in which the bit number of the analog-to-digital converter is usually 10 bits or 12 bits. 10 bits, that is, 2 to the power of 10, is 1024, which can convert the analog signal into a digital value of 0-1023. Similarly, if it is a 12-bit ADC, that is, 2 to the power of 12, is 4096, which can convert the analog signal into a digital value of 0-4095.

[0046] The temperature control system also includes: a control unit 120 and a switch unit 130, whose functions are mainly to cooperate with the temperature sensor 110 to detect the temperature of the odor sensor 10 as described above, and to control the heating electrode to heat the odor sensor 10 when the temperature of the odor sensor 10 exceeds the preset range, so that the temperature of the odor sensor 10 rises to the preset range again. Figure 1The control unit 120 is connected to the control end of the switch unit 130, and can send a corresponding control signal to the switch unit 130 in response to the temperature detected by the temperature sensor 110 exceeding a preset range. The output end of the switch unit 130 is connected to the heating electrode end of the odor sensor 10, and can be closed in response to the control signal to power on the heating electrode, thereby heating the odor sensor 10 to adjust the temperature of the odor sensor 10 to within the preset range.

[0047] Specifically, the switching unit 130 includes: a switching tube Q and a first resistor R1, the gate of the switching tube Q is configured to be connected to the control end of the control unit 120, the source of the switching tube Q is grounded, the drain of the switching tube Q is connected to the second end of the first resistor R1, the first end of the first resistor R1 is connected to the second end of the heating electrode of the odor sensor 10, and the first end of the heating electrode is configured to be connected to the power supply VCC.

[0048] Reference below Figure 1 , the working principle of the temperature control system is described in detail. After the temperature sensor 110 samples the electrical signal data representing the temperature through the control unit 120, the actual temperature of the detected odor sensor 10 is obtained. The control unit 120 compares the temperature with the preset temperature range. If the actual temperature is lower than the preset range, it is determined that the temperature of the odor sensor 10 is too low. In response to the signal representing that the temperature of the odor sensor 10 is too low, the control unit 120 sends a high-level signal to the switch unit 130, and the switch tube Q is turned on, so that the heating electrode of the odor sensor 10 is powered on to heat the odor sensor 10.

[0049] It should be noted that the temperature detection of the temperature sensor 10 and the electrical signal sampling of the control unit 120 are performed in real time. In response to detecting that the temperature of the odor sensor 10 has recovered to within the preset range, the control unit 120 will output a low-level signal to the switch unit 130, the switch tube Q is cut off, and the heating electrode stops heating, thereby achieving accurate and real-time temperature control of the odor sensor 10.

[0050] Since the odor sensor 10 is a temperature-sensitive semiconductor device, the accuracy of its measurement results will be directly affected by temperature changes. The temperature control system provided in this embodiment can accurately detect and control the temperature of the odor sensor 10, and its control circuit has a relatively simple structure and low power consumption. In addition, the accuracy and response speed of temperature detection and control are relatively fast, which not only reduces the cost of temperature control of the odor sensor 10, but also improves the accuracy of temperature detection of the odor sensor 10.

[0051] Optionally, refer to Figure 2 This embodiment provides a temperature detection method of an odor sensor 10, comprising the steps of:

[0052] Detecting the actual temperature of the odor sensor 10;

[0053] Determine whether the actual temperature is within the preset range;

[0054] If not, the odor sensor 10 is heated so that the actual temperature is raised to a preset range.

[0055] Specifically, detecting whether the temperature of the odor sensor 10 is within a preset range includes: determining whether the timer count meets a preset time, and if so, comparing the temperature of the odor sensor 10 with the preset range.

[0056] Furthermore, if the actual temperature is within the preset range, there is no need to control the temperature of the odor sensor 10 / stop heating the odor sensor 10. If not, the temperature control system described above can be used to adjust the temperature of the odor sensor 10.

[0057] Furthermore, the preset range is defined by a first preset value T1 and a second preset value T2, and the first preset value T1 and the second preset value T2 are set based on the target temperature and the dead zone temperature. Specifically, the first preset value T1 = target temperature - dead zone temperature, and the second preset value T2 = target temperature + dead zone temperature, that is, T1 < T2, wherein the target temperature is based on the factory setting or experience configuration of the odor sensor 10, and is a temperature at which the odor sensor 10 is suitable for working, and the dead zone temperature is set by the technician based on the user manual or experience, and is an allowable error temperature based on the target temperature.

[0058] Based on this, reference Figure 3 This embodiment provides a temperature detection method of an odor sensor 10, comprising the steps of:

[0059] Detecting the actual temperature T of the odor sensor 10;

[0060] If the actual temperature T ≥ the second preset value T2, the heating of the odor sensor 10 is stopped;

[0061] If the actual temperature T is less than the second preset value T2, then further determining whether the actual temperature T is less than or equal to the first preset value T1;

[0062] If so, the odor sensor 10 is heated.

[0063] The temperature is more accurate when this method is used for temperature control, and the temperature control is more reasonable because the error of the dead zone temperature is allowed.

[0064] It should be noted that the acquisition process of ADC (analog-to-digital sensor) is a timed scan, for example, a scan every 10ms. The timing function can use the timer of the microcontroller to determine whether 10ms has been reached. When the 10ms timing is reached, the ADC collects a digital signal. After collecting 10 times, the sum of the 10 times is divided by 10 to get the ADC sampling value. The formula rt=ADC*r / (4095-ADC) is called to get the value of the resistance rt. After obtaining rt, the temperature comparison table corresponding to the thermistor can be used to find out the current temperature. The above process is completed inside the microcontroller.

[0065] Therefore, in the temperature control method described above, “detecting the actual temperature of the odor sensor 10” includes:

[0066] Regularly sampling the temperature of the odor sensor 10;

[0067] The average value of the plurality of sampling values ​​is calculated as the actual temperature of the odor sensor 10 .

[0068] In addition, when the odor sensor 10 is used in a refrigeration system, it is usually the case that the temperature of the odor sensor 10 is too low, which affects its performance. Therefore, the example in this embodiment is to heat it up by heating. In some embodiments not shown, based on this application, those skilled in the art can easily think of that when the temperature of the odor sensor is too high, the odor sensor can be cooled based on the corresponding design of the circuit of this application. The above implementation modes are all within the protection scope of this application.

[0069] Optionally, in order to further accurately control the temperature of the odor sensor 10 in real time, the temperature control is performed based on the duty cycle of the PID control PWM, such as Figure 4 As shown, this embodiment also provides another temperature control method of the odor sensor 10, comprising the steps of:

[0070] Detecting a comparison between the actual temperature T of the odor sensor 10 and the first preset value T1;

[0071] If T≤T1, PWM is controlled to heat the odor sensor 10 at a duty cycle of 100%;

[0072] If T>T1, then further determine the comparison relationship between T and the second preset value T2;

[0073] If T<T2, the odor sensor 10 is heated by controlling the duty cycle of PWM through PID;

[0074] If T≥T2, the heating of the odor sensor 10 is stopped.

[0075] Among them, T1 is the first preset value mentioned above, and T2 is the second preset value mentioned above. The two are set based on the target temperature and the dead zone temperature. Since a certain dead zone is allowed in the temperature control in the PID program, that is, the temperature control hysteresis, for example, the target temperature is 200°C. When the actual temperature / detected temperature is within the range of 200±dead zone temperature, it is still considered that the temperature meets the requirements and the temperature is not frequently controlled. T2 is the dead zone temperature value. When T2≤T<T1, it indicates that the temperature of the odor sensor 10 exceeds the preset range, but the exceeded temperature is relatively low. Therefore, the heating control can be accurately performed by controlling the PWM duty cycle by PID. In this way, the temperature of the odor sensor 10 can be controlled within a relatively small temperature range, neither too low nor too high, so that the detection accuracy is always maintained at a high level.

[0076] Specifically, this embodiment shows the parameters and codes of PID control to facilitate understanding of the specific implementation of the control method.

[0077]

[0078]

[0079]

[0080] It can be seen from the above code that in this embodiment, the dead zone temperature is set to ±1°C, which can be set by the technician based on the application scenario. In addition, when PID control is performed, the specific value of the PWM duty cycle can also be calculated and configured.

[0081] The present embodiment further provides a refrigeration device, which is equipped with the odor sensor 10 described above, and uses the temperature control system or temperature control method provided in the present embodiment to control the temperature of the odor sensor 10, thereby making the detection accuracy and stability of the odor sensor 10 better.

[0082] Specifically, the refrigeration equipment can be common refrigeration products such as refrigerators and freezers, and the odor sensor 10 can be installed in the refrigerator, freezer, or fresh-keeping cabinet of the refrigeration equipment, and the number of odor sensors 10 configured in the same chamber can be multiple.

[0083] The temperature control system, temperature control method and refrigeration equipment provided in this embodiment can solve the problem of low measurement accuracy of the odor sensor due to inaccurate temperature control in the prior art. Through precise temperature control, it can ensure that the odor sensor is within a suitable operating temperature range, thereby improving the reliability and life of the sensor; when odor sensors are installed in multiple positions in the refrigeration equipment, the system or method provided by this application can make the operating temperature of each odor sensor remain consistent, ensuring the reliability and consistency of the measurement; through precise temperature control, it can also ensure that the odor sensor can work normally under different environmental conditions with large temperature differences, thereby improving its adaptability and stability.

[0084] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A temperature control system, used for temperature control of an odor sensor, characterized in that: include: a temperature sensor configured to detect a temperature of the odor sensor; A switch unit configured to control heating / stop heating of the smell sensor; as well as The control unit is electrically connected to the temperature sensor and the switch unit respectively, and can control the switch unit to close in response to the temperature of the odor sensor being lower than a preset range, so as to achieve heating of the odor sensor.

2. The temperature control system according to claim 1, characterized in that: The temperature sensor includes a voltage divider circuit and a filter circuit. The voltage divider circuit includes a thermistor and a voltage divider resistor connected in series. The first end of the thermistor is configured to be connected to a power supply, the second end of the voltage divider resistor is configured to be connected to a common ground, the second end of the thermistor is configured to be connected to an input end / sampling end of the control unit, the filter circuit is connected between the voltage divider circuit and the input end / sampling end of the control unit, and the control unit is configured to sample an electrical signal representing the temperature of the odor sensor.

3. The temperature control system according to claim 2, characterized in that: The filtering circuit includes a second resistor and a capacitor, the second end of the capacitor is connected to a common ground, the first end of the capacitor is connected to the first end of the second resistor, the first end of the second resistor is connected to the first end of the resistor, and the second end of the second resistor is connected to the input end (sampling end) of the control unit.

4. The temperature control system according to any one of claims 1 to 3, characterized in that: The odor sensor includes a heating electrode, and the switching unit includes: a switching tube and a first resistor, the gate of the switching tube is configured to be connected to the control end of the control unit, the source of the switching tube is grounded, the drain of the switching tube is connected to the second end of the first resistor, the first end of the first resistor is connected to the second end of the heating electrode of the odor sensor, the first end of the heating electrode is configured to be connected to a power supply, and the control unit is configured to send a corresponding level signal to the gate of the switching tube in response to the relationship between the temperature of the odor sensor and a preset range.

5. A temperature control method, characterized in that: The temperature of the odor sensor is controlled by using the temperature control system described in any one of claims 1 to 4.

6. A temperature control method, applied to control the temperature of an odor sensor, characterized in that: Includes steps: detecting an actual temperature of the odor sensor; Determining whether the actual temperature is within a preset range; If not, the odor sensor is heated so that the actual temperature is raised to a preset range.

7. The temperature control method according to claim 6, characterized in that: The “detecting the actual temperature of the odor sensor” includes: regularly sampling the temperature of the odor sensor; The average value of the multiple sampling values ​​is calculated as the actual temperature of the odor sensor.

8. The temperature control method according to claim 6 or 7, characterized in that: Also includes the steps: In response to the actual temperature returning to within a preset range, heating of the odor sensor is stopped.

9. A temperature control method, applied to control the temperature of an odor sensor, characterized in that: Includes steps: Detecting a comparison relationship between an actual temperature T of the odor sensor and a first preset value T1; If T≤T1, controlling PWM to heat the odor sensor with a duty cycle of 100%; If T>T1, then further determine the comparison relationship between the actual temperature T and the second preset value T2; If T<T2, the odor sensor is heated by controlling the duty cycle of PWM by PID; If T≥T2, stop heating the odor sensor; Among them, T1 and T2 are set based on the target temperature and the dead zone temperature, and T1<T2.

10. A refrigeration device equipped with an odor sensor, characterized in that: The temperature of the odor sensor is controlled by using the temperature control system described in any one of claims 1 to 4, or the temperature control method described in any one of claims 5 to 9.

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