Temperature measurement system and method for temperature control of a hot surface ignition device

Abstract

A temperature measurement system for temperature control of a hot surface igniter includes: a power supply module configured to supply power to the hot surface igniter; an acquisition module configured to acquire a resistance value of the hot surface igniter; and a processing module configured to acquire a temperature value corresponding to a current resistance value from the preset resistance and temperature according to the resistance value, where the resistance and temperature are preset. The acquisition module is used to acquire the resistance value of the hot surface igniter, and the current temperature of the hot surface igniter is obtained using the relationship between the resistance and temperature, thereby realizing a temperature measurement function and improving the accuracy of the measured temperature. Furthermore, a temperature measurement method for temperature control of a hot surface igniter is disclosed.

Description

[Technical Field]

[0001] The present invention relates to a temperature measurement system, and more particularly to a temperature measurement system and method for temperature control of a hot surface ignition device. [Background technology]

[0002] Currently, high-frequency ignition is the most commonly used ignition method for ignition devices. When the ignition device is powered on, a high-frequency voltage is generated and applied to a discharge electrode. This causes a spark discharge, generating an electric spark and igniting the combustible gas. However, this type of high-frequency ignition device has the disadvantage of generating electric sparks during operation, which can cause noise pollution and lead to dangerous combustion and explosions. Therefore, safer hot-surface ignition devices are gradually replacing high-frequency ignition devices. Hot-surface ignition devices, which are automatic ignition devices, use hot-surface ignition technology. The hot-surface ignition device reaches a high temperature before the combustible gas / fuel enters the combustion area, completely avoiding the potential problems caused by electric sparks.

[0003] Since the temperature that a hot surface igniter can ultimately reach is related to the magnitude of the voltage supplied to the hot surface igniter, the temperature of the hot surface igniter can be adjusted by adjusting the voltage supplied to the hot surface igniter. However, in practice, on the one hand, the voltage supplied to the hot surface igniter is usually increased to make the hot surface igniter quickly reach the required temperature. On the other hand, to minimize damage to the hot surface igniter, the supply voltage must be reduced and adjusted in a timely manner after the required temperature is reached. On the other hand, because the hot surface igniter needs to reach different temperatures under the operating conditions of different applications, the supply voltage must be adjusted according to the temperature.

[0004] Chinese Patent CN 1640195 B discloses a system and method for regulating the voltage of a resistance igniter. The system and method determine the line voltage of a system and control the voltage applied to the resistance igniter. An initially applied first voltage is maintained for a fixed period of time, after which a second voltage, which is the rated voltage of the igniter, is applied. The system and method determine the line voltage of the system and control the voltage applied to the resistance igniter. An initially applied first voltage is maintained for a fixed period of time, after which a second voltage, which is the rated voltage of the igniter, is applied. The system and method shortens the time required to heat the resistance igniter to a temperature sufficient to ignite the gas and regulates the output voltage supplied to the igniter to prevent damage to the igniter due to overvoltage. The system and method shortens the time required to heat the resistance igniter to a temperature sufficient to ignite the gas and regulates the output voltage supplied to the igniter to prevent damage to the igniter due to overvoltage.

[0005] Although the above invention measures the output voltage, the actual voltage supplied to the hot surface igniter in the entire circuit is not exactly equal to the output voltage, so using the output voltage to characterize the voltage of the hot surface igniter is inaccurate, resulting in an inaccurate voltage being supplied to the hot surface igniter, and as a result, the heating temperature of the hot surface igniter is inaccurate. Summary of the Invention [Problem to be solved by the invention]

[0006] To solve the problem of inaccurate temperature control of a hot surface igniter in the prior art, the present disclosure provides a temperature measurement system for temperature control of a hot surface igniter, which includes: a power supply module configured to supply power to the hot surface igniter; an acquisition module configured to acquire a resistance value of the hot surface igniter; and a processing module configured to acquire a temperature value corresponding to a current resistance value from the preset resistance-temperature table according to the resistance value, the temperature measurement system including a power supply module configured to supply power to the hot surface igniter; an acquisition module configured to acquire a resistance value of the hot surface igniter; and a processing module configured to acquire a temperature value corresponding to a current resistance value from the preset resistance-temperature table according to the resistance value. [Means for solving the problem]

[0007] The heat generated by the hot surface igniter comes from the heat generated by the thermal resistor of the hot surface igniter itself. Since the thermal resistor has a positive temperature coefficient that changes with the temperature of the hot surface igniter, the resistance value of the thermal resistor also changes during the heating process. Therefore, this solution chooses to characterize the temperature of the hot surface igniter using the resistance value. First, the resistance value is obtained, and then the temperature value is looked up in a preset resistance-temperature table. Compared with the prior art, the resistance value obtained by this solution is closer to the resistance value of the hot surface igniter itself, so the obtained temperature value is more accurate, and the subsequent temperature control of the hot surface igniter is also more accurate.

[0008] Preferably, the acquisition module includes a current measurement circuit for acquiring the current value of the hot surface igniter, a terminal voltage measurement circuit for acquiring the terminal voltage of the hot surface igniter, and a processing unit for calculating the resistance value from the terminal voltage. In this solution, the resistance value is indirectly characterized using the relationship between voltage and current. The resistance value of the hot surface igniter itself is calculated using the current measurement circuit and the terminal voltage measurement circuit. Operation is simple.

[0009] Preferably, the current measurement circuit includes a first sampling resistor connected to the positive voltage terminal of the power supply module and one electrode of the hot surface igniter, and a first amplifier circuit for amplifying the voltage of the first sampling resistor, with the other electrode of the hot surface igniter electrically connected to the negative voltage terminal of the power supply module. In this solution, when power is supplied to the hot surface igniter, current flows through the positive voltage terminal of the power supply, the first sampling resistor, the one electrode of the hot surface igniter, the hot surface igniter, and the other electrode of the hot surface igniter, and finally returns to the negative voltage terminal of the power supply. The current flowing through the hot surface igniter is converted to a small voltage by the first sampling resistor. After being amplified by the first amplifier circuit, a voltage Vrt is output, which is linearly related to the current flowing through the hot surface igniter. Finally, a processing module calculates the current value of the hot surface igniter based on the proportional relationship between the voltage Vrt and the current of the hot surface igniter. This solution has a simple structure.

[0010] Preferably, the terminal voltage measurement circuit includes a positive voltage terminal of the power supply, a second sampling resistor, a third sampling resistor, and a negative voltage terminal of the power supply, connected in series, and further includes a second amplifier circuit for amplifying the terminal voltage of the third sampling resistor, the second sampling resistor and the third sampling resistor being connected in series with each other and in parallel to the hot surface igniter. In this solution, the second sampling resistor and the third sampling resistor are connected in series, and the hot surface igniter is connected in parallel to the second and third sampling resistors connected in series. Therefore, after obtaining the terminal voltage of the third sampling resistor using the second amplifier circuit, the current voltage value of the hot surface igniter can be calculated based on the proportional relationship between the terminal voltage of the third sampling resistor and the terminal voltage of the hot surface igniter. This has a simple structure.

[0011] Preferably, the power supply module adopts a wide voltage input, which can meet the requirements of hot surface ignition devices with different rated operating voltages through the wide voltage input method, thereby expanding the application range of the hot surface ignition device.

[0012] Preferably, the power supply module further includes an H-bridge driver circuit for periodically changing the current direction, which can extend the service life of the hot surface ignition device, and can also significantly improve the stability of the thermal resistor of the hot surface ignition device, making the correlation between thermal resistance and temperature more stable and ensuring the accuracy of the temperature obtained.

[0013] In a second aspect, the present disclosure further provides a temperature measurement method for temperature control of a hot surface ignition device, the temperature measurement method comprising: a power supply step of supplying power to the hot surface igniter; obtaining a resistance value of the hot surface igniter; and The method includes a processing step of obtaining a temperature value corresponding to the current resistance value from a preset resistance-temperature table according to the resistance value. [Effects of the Invention]

[0014] The present disclosure has the following advantageous effects. 1. In this disclosure, a current measurement circuit and a terminal voltage measurement circuit are used to measure the current value and voltage value of the hot surface ignition device, respectively, and then calculate the current resistance value of the hot surface ignition device itself, and obtain the current temperature of the hot surface ignition device from the relationship between resistance and temperature, thereby realizing the temperature measurement function. Compared with the prior art, the temperature measured in this disclosure is more accurate.

[0015] 2. Considering that in practice, the rated voltage required for a hot surface ignition device may vary depending on the actual operating conditions, the present disclosure adopts a wide voltage input to meet the voltage requirements of the hot surface ignition device under a wider range of operating conditions.

[0016] 3. Furthermore, in order to improve the accuracy of the temperature measurement structure, the present disclosure further includes an H-bridge driving circuit, which improves the stability of the thermal resistor of the hot surface ignition device and makes it easier to stabilize the relationship between thermal resistance and temperature. [Brief explanation of the drawings]

[0017] FIG. 1 is a modular block diagram of one embodiment of a temperature measurement system and method for temperature control of a hot surface ignition device of the present disclosure.

[0018] FIG. 2 is a circuit diagram of an H-bridge drive circuit.

[0019] FIG. 3 is a diagram of the current measurement circuit.

[0020] FIG. 4 is a diagram of the terminal voltage measurement circuit. DETAILED DESCRIPTION OF THE INVENTION

[0021] The present invention will be described in further detail below in conjunction with specific embodiments.

[0022] 1. Definition Wide voltage input: In this disclosure, the wide voltage input range is 9V to 36V.

[0023] 2. This embodiment is substantially as shown in Figure 1. The temperature measurement system for temperature control of a hot surface igniter includes a power supply module configured to supply power to the hot surface igniter and using a wide voltage input. In particular, this embodiment applies a highly efficient and high-performance DC-DC conversion circuit, with the purpose of supporting applications with a wide voltage input range (9V to 36V). The power supply module further includes an H-bridge driver circuit that periodically changes the current direction, as shown in Figure 2.

[0024] An acquisition module configured to acquire a resistance value of a hot surface igniter, particularly the acquisition module includes a current measurement circuit for acquiring a current value of the hot surface igniter, a terminal voltage measurement circuit for acquiring a terminal voltage of the hot surface igniter, and a processing unit for calculating the resistance value from the current value and the terminal voltage. Specifically, the current measurement circuit includes a first sampling resistor connected to a positive voltage terminal of the power supply module and one electrode of the hot surface igniter, and a first amplifier circuit for amplifying the voltage of the first sampling resistor, as shown in Fig. 3, the other electrode of the hot surface igniter is electrically connected to a negative voltage terminal of the power supply module. The terminal voltage measurement circuit includes a positive voltage terminal of the power supply module, a second sampling resistor, a third sampling resistor, and a negative voltage terminal of the power supply module, connected in series in this order, and further includes a second amplifier circuit for amplifying the terminal voltage of the third sampling resistor, the second sampling resistor and the third sampling resistor being connected in series with each other and further connected in parallel to the hot surface igniter. After obtaining the terminal voltage and current values ​​of the hot surface igniter, the processing module calculates the resistance value of the hot surface igniter using the formula: resistance = voltage / current.

[0025] a processing module configured to obtain a temperature value corresponding to the current resistance value from the preset resistance-temperature table according to the obtained resistance value, the processing module having a preset resistance-temperature table;

[0026] This embodiment further discloses a measurement method based on the above measurement system. This measurement method includes: a power supply step of supplying power to the hot surface igniter; obtaining a resistance value of the hot surface igniter; and The method includes a processing step of obtaining a temperature value corresponding to the current resistance value from a preset resistance-temperature table according to the resistance value.

[0027] The specific implementation procedure is as follows: In use, the temperature measurement system of the present disclosure is powered by a power supply module. When power is supplied, the H-bridge driving circuit is driven to reverse the current flowing through the hot surface igniter, as shown in Figure 2. Here, CN1 and CN2 of the H-bridge driving circuit are the connection points of the two electrodes of the hot surface igniter, and the driving circuit includes four MOSFETs Q1, Q4, Q2, and Q3, which are turned on and off in a preset sequence to realize the reversal of the current flowing through the hot surface igniter.

[0028] As shown in Figure 3, when measuring the current of the hot surface igniter, IGT is the hot surface igniter, R1 is the first sampling resistor, OPA is the first amplifier circuit, and V+ and V- are the positive and negative voltage terminals of the hot surface igniter's power supply. When power is supplied to the hot surface igniter IGT, the current I flows through V+, R1, CN1, the hot surface igniter IGT, CN2, and finally back to V-. The current I through the hot surface igniter IGT is converted to a small voltage by the first sampling resistor R1. After being amplified by the first amplifier circuit OPA, a voltage Vrt, which is linearly related to the current I through the hot surface igniter, is output and sent to the processing unit. The processing module calculates the current value of the hot surface igniter IGT based on the proportional relationship between the voltage Vrt and the current through the hot surface igniter IGT.

[0029] The terminal voltage measurement circuit shown in Figure 4 obtains a voltage value Vp representing the magnitude of the terminal voltage when measuring the voltage of the hot surface igniter, and transmits the voltage value Vp to a processing unit. The processing unit calculates the current terminal voltage of the hot surface igniter based on the proportional relationship between the voltage value Vp and the terminal voltage of the hot surface igniter IGT. Finally, the processing unit calculates the current resistance value (i.e., thermal resistance) Rt of the hot surface igniter based on the measured voltage and current of the hot surface igniter. Then, based on the obtained resistance value, the processing module looks up the temperature value corresponding to the resistance value in a preset resistance-temperature table.

[0030] The above content is merely an embodiment of the present disclosure, and common general technical knowledge, such as well-known specific structures and characteristics of the solutions of the present invention, is not redundantly described in this specification. A person skilled in the art is aware of all common general technical knowledge in the technical field to which the present invention pertains prior to the filing date or priority date, has access to all prior art in the field, and is capable of applying routine experimental means prior to the said date. A person skilled in the art can improve and implement the solutions of the present invention based on the motivation set forth in this application and in combination with his or her own abilities. Some typical well-known structures or methods should not pose an obstacle to the practice of the present application by a person skilled in the art. Furthermore, a person skilled in the art may make various modifications and improvements without departing from the scope of the present application, and these modifications and improvements are also considered to fall within the scope of protection of the present invention. None of these modifications and improvements affect the practical effects and patent applicability of the present invention. The scope of protection of the present application is limited by the claims, and the disclosure of specific embodiments, etc. in the specification can be used to interpret the claims.

Claims

1. 1. A temperature measurement system for temperature control of a hot surface ignition device, comprising: a power supply module configured to supply power to the hot surface igniter; an acquisition module configured to acquire a resistance value of the hot surface igniter; a processing module configured to preset a resistance-temperature table and to obtain a temperature value corresponding to a current resistance value from the preset resistance-temperature table according to the resistance value; Temperature measurement system for temperature control of hot surface ignition devices.

2. 2. The temperature measurement system for temperature control of a hot surface ignition device as claimed in claim 1, wherein the acquisition module includes: a current measurement circuit for acquiring a current value of the hot surface ignition device; a terminal voltage measurement circuit for acquiring a terminal voltage of the hot surface ignition device; and a processing unit for calculating a resistance value from the current value and the terminal voltage.

3. 3. The temperature measurement system for temperature control of a hot surface igniter as described in claim 2, wherein the current measurement circuit includes a first sampling resistor connected to the positive voltage terminal of the power supply module and one electrode of the hot surface igniter, and a first amplifier circuit for amplifying the voltage of the first sampling resistor, and the other electrode of the hot surface igniter is electrically connected to the negative voltage terminal of the power supply module.

4. 4. The temperature measurement system for temperature control of a hot surface ignition device as claimed in claim 3, wherein the terminal voltage measurement circuit is configured by sequentially connecting a positive voltage terminal of the power supply, a second sampling resistor, a third sampling resistor, and a negative voltage terminal of the power supply in series, and further includes a second amplifier circuit for amplifying the terminal voltage of the third sampling resistor, the second sampling resistor and the third sampling resistor being connected in series with each other and further connected in parallel with the hot surface ignition device.

5. 5. The temperature measurement system for temperature control of a hot surface ignition device according to claim 1, wherein the power supply module has a wide voltage input range.

6. 6. The temperature measurement system for temperature control of a hot surface ignition device as claimed in claim 5, wherein the power supply module further includes an H-bridge driver circuit that periodically changes the direction of current.

7. 1. A temperature measurement method for temperature control of a hot surface ignition device, comprising: a power supply step of supplying power to the hot surface igniter; obtaining a resistance value of the hot surface igniter; and a processing step of acquiring a temperature value corresponding to the current resistance value from a preset resistance-temperature table according to the resistance value; Temperature measurement method for temperature control of hot surface ignition devices.

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