Temperature control system for hot surface ignition devices.

Abstract

A temperature control system for a hot surface igniter is disclosed, the temperature control system including: a power supply module for supplying power to the temperature control system; a drive module for outputting a voltage to the hot surface igniter; an acquisition module for sampling a thermoelectric signal of the hot surface igniter; a feedback module for receiving the thermoelectric signal, receiving a voltage control amount calculated based on the thermoelectric signal, and performing feedback; and a control module for receiving the fed-back voltage control amount and controlling the output of the power supply module based on the voltage control amount. In this way, by supplying a suitable voltage to the hot surface igniter, the hot surface igniter can be ensured to operate at a set target temperature, thereby precisely controlling the operating temperature of the hot surface igniter and extending the service life of the hot surface igniter.

Description

[Technical Field]

[0001] The present invention relates to control systems, and more particularly to temperature control systems for hot surface ignition devices. [Background technology]

[0002] Hot surface ignition devices as automatic ignition devices use hot surface ignition technology. With this technology, flammable gas or flammable fuel oil is introduced into the combustion zone after the hot surface ignition device reaches a high temperature, completely avoiding problems that can occur due to electric sparks. When a hot surface ignition device is in operation, a voltage is applied to the hot surface ignition device from a power source, causing the heating element of the hot surface ignition device to ignite. However, because conventional hot surface ignition devices use a constant voltage power supply method, the temperature of the hot surface ignition device cannot be adjusted after voltage is applied due to the influence of the material and physical structure of the heating element itself. Meanwhile, in most applications where hot surface ignition devices are used, conventional hot surface ignition devices only have an ignition function. This means that even if conventional hot surface ignition devices have been in use for a long time, their actual operating time is short. Therefore, the service life of hot surface ignition devices is usually long. However, in some specific application fields, such as the automotive industry, the hot surface ignition device needs to be constantly operating, which significantly shortens the service life of the hot surface ignition device used in these specific fields. In addition, the voltage fluctuates during use, and the operating conditions are complex, for example, the voltage fluctuates between high and low voltages, and the temperature of the operating environment also fluctuates between low and high voltages, which has a significant impact on the heating element of the hot surface ignition device, thereby further shortening the service life of the hot surface ignition device.

[0003] Chinese Patent Application No. 110594783B discloses a method for controlling a hot surface ignition device. Based on the hardware circuit and software algorithm of the hot surface ignition device, the method divides the operating time of the hot surface ignition device into time periods t1, t2, ..., tn. During each time period, the software algorithm adjusts the output voltage or output power of the hardware circuit to make the hot surface ignition device reach a desired temperature. The control method of the present invention easily controls the ignition time of the hot surface ignition device, thereby meeting the needs of customers who require ignition within a short period of time. The drawback of the aforementioned prior art document is that the output voltage is sampled to control the output voltage and thus the temperature, but the temperature is not measured. Therefore, the temperature control during the control process is not precise enough. If the temperature of the hot surface ignition device becomes too high, the service life of the device will be shortened. Summary of the Invention [Means for solving the problem]

[0004] To solve the problem of short service life of a hot surface ignition device in the prior art, the present invention provides a temperature control system for a hot surface ignition device, comprising: a power supply module for supplying power to the temperature control system; a driver module for outputting a voltage to the hot surface ignition device; a collection module for sampling a thermoelectric signal of the hot surface igniter; a feedback module for receiving the thermoelectric signal, receiving a voltage control amount calculated based on the thermoelectric signal, and performing feedback; a control module for receiving the feedback voltage control amount and controlling the output of the power supply module based on the voltage control amount; A temperature control system including:

[0005] The present invention has the following beneficial effects: In the solution according to the present invention, the collection module samples the electrical signal of the hot surface igniter, then the feedback module receives the electrical signal and performs feedback, and then the control module controls the output of the power supply module to ensure that the hot surface igniter receives a suitable voltage and operates at a set target temperature, thereby precisely controlling the operating temperature of the hot surface igniter and extending the service life of the hot surface igniter.

[0006] Preferably, the driving module is used to output a driving voltage to the hot surface ignition device, and the control module controls the duration of the driving voltage output by the driving module based on the voltage control amount. In this solution, the temperature of the hot surface ignition device is controlled by controlling the duration of the driving voltage output, and when the temperature needs to be increased, it is only necessary to extend the duration of the output, which is simple to operate.

[0007] Preferably, the driving module is used to output a forward driving voltage that generates a forward current and a reverse driving voltage that generates a reverse current to the hot surface igniter, and the control module controls the magnitude of the effective values ​​of the forward driving voltage and the reverse driving voltage output by the driving module based on the voltage control amount. In this solution, the output driving voltages are forward voltages that can generate a forward current and reverse voltages that can generate a reverse current. Therefore, when it is necessary to adjust the temperature of the hot surface igniter, it is only necessary to adjust the magnitude of the effective values ​​of the output forward driving voltage and the reverse driving voltage, which is simple to operate.

[0008] Preferably, the collection module includes an analog switch unit for collecting thermoelectric signals from the power supply electrodes of the hot surface igniter. Considering that the thermoelectric signals of the power supply electrodes of the hot surface igniter are at the millivolt level, the signal fluctuations with temperature are only at the microvolt level, and such weak signals are mixed into the operating voltage of the hot surface igniter. This means that the thermoelectric signals fluctuating at the microvolt level at the power supply electrodes of the hot surface igniter are accompanied by complex differential interference and common-mode interference. Therefore, in this solution, by providing an analog switch unit, the thermoelectric signals can be clearly and accurately collected from the power supply electrodes of the hot surface igniter, ensuring precise adjustment of the downstream control module.

[0009] Preferably, the collecting module further includes an amplifying unit to ensure that the thermoelectric signal can be transmitted without distortion. In this solution, when the collecting module is provided with the amplifying unit, the common-mode interference of the signal channel can be effectively suppressed, thereby smoothly collecting the thermoelectric signal.

[0010] Preferably, the collection module is further used to collect the electrical signals, the feedback module is further used to receive the electrical signals and receive feedback on whether the electrical environment is abnormal based on the electrical signals, and the control module controls the power supply module to turn off the output when receiving a feedback signal indicating that the electrical environment is abnormal. In this solution, the electrical environment of the hot surface ignition device can be determined after collecting the electrical signals, and if the electrical environment is abnormal, the output can be turned off to quickly avoid using the abnormal hot surface ignition device.

[0011] Preferably, the driver module includes an H-bridge driver circuit, which can output periodic forward and reverse pulse voltages, thereby further improving the service life of the hot surface ignition device.

[0012] Preferably, the power supply module has a built-in DC-DC conversion circuit, which allows power to be input at a wide range of voltages, making it easier to use with the next stage modules of the temperature control system. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a block diagram of modules in an embodiment of a temperature control system for a hot surface ignition device of the present invention. [Figure 2] 1 is a flow chart of an embodiment of a temperature control system for a hot surface ignition device of the present invention. [Figure 3] FIG. 2 is a schematic diagram of an H-bridge driving circuit of the driving module of the embodiment. [Figure 4] FIG. 1 is a schematic diagram of a thermoelectric signal input channel in an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] The present invention will now be described in more detail with reference to specific embodiments.

[0015] 1.Definition "Pulse voltage" refers to an instantaneous and sudden change in voltage or current. Common pulse waveforms include rectangular pulse, square wave pulse, spike pulse (positive spike pulse and negative spike pulse), sawtooth pulse, step pulse, and intermittent sine wave pulse. Pulse voltage has sudden changes and discontinuities. The pulse width is represented by Ton, and the pulse rest time is represented by Toff. The period of the pulse voltage is represented by the ratio of the Ton period to the entire pulse period, where the entire pulse period is represented by the sum of the Ton period and the Toff period.

[0016] 2. The embodiment is basically as shown in Figure 1. Figure 1 shows a temperature control system for a hot surface ignition device, and the temperature control system for a hot surface ignition device includes: a power supply module with a built-in DC-DC conversion circuit for supplying power to the temperature control system; a driver module with an H-bridge driver circuit as shown in FIG. 3 for outputting voltage to a hot surface ignition device; an acquisition module for sampling thermoelectric and electrical signals of the hot surface igniter; a feedback module for receiving the thermoelectric signal, receiving a voltage control amount calculated based on the thermoelectric signal, and performing feedback; and receiving the electrical signal, and receiving feedback on whether the electrical environment is abnormal based on the electrical signal; a control module for receiving the feedback voltage control amount, controlling the duty ratio output by the drive module based on the voltage control amount, and controlling the power supply module to turn off its output when receiving a feedback signal indicating that the electrical environment is abnormal; Includes:

[0017] The acquisition module includes an analog switch unit and an amplifier unit. By operating the analog switch unit and the amplifier unit simultaneously, the useful thermoelectric signal can be clearly and accurately extracted during the acquisition process. Specifically, at the input of the thermoelectric signal, an analog switch with very low on-resistance is used to block the input of a high differential voltage to the thermoelectric signal input channel when a high operating voltage occurs after heating. Meanwhile, once the operating voltage disappears, the analog switch immediately turns on, allowing the thermoelectric signal to enter the thermoelectric signal input channel without interference, thereby avoiding most of the differential voltage interference. Furthermore, by using the PWM square wave pulse voltage of the power supply module in combination, the voltage can be easily adjusted to obtain the thermoelectric signal when the PWM square wave is at a low level. Furthermore, by providing an amplifier unit with a high common-mode rejection ratio and very low drift, common-mode interference with the signal channel can be effectively suppressed, allowing the thermoelectric signal to be smoothly input to the acquisition channel without attenuation or interference, and the thermoelectric signal can be transmitted without distortion. In this embodiment, the analog switch unit is an analog switch chip, and the amplifier unit is an instrumentation amplifier. The thermoelectric signal input channel is shown in Figure 4.

[0018] Note: When using the temperature control system for a hot surface ignition device of this embodiment, the temperature control system operates simultaneously with a processing module incorporating a voltage control amount algorithm and a thermoelectric signal data table. To calculate the voltage control amount, the voltage control amount algorithm first obtains the difference between the current temperature and the target temperature, multiplies this difference by a proportional coefficient, an integral coefficient, and a differential coefficient, respectively, and then adds the resulting products to obtain the voltage control amount. The thermoelectric signal data table is a data table for temperature conversion. The voltage value Vt of the thermoelectric signal is obtained by an ADC (Analog-to-Digital Converter), where the voltage value is inherently correlated with the temperature of the hot surface ignition device. That is, a certain voltage value Vt corresponds to a specific temperature value T. For example, when T=800°C, the corresponding voltage value is Vt=0.373V. The thermoelectric signal data table is created in array format, with the temperature as the array index and Vt as the array element value.

[0019] In this embodiment, the power supply module may use a power supply mode using a PWM square wave, a power supply mode using a DC, and an AC power supply mode using a sine wave, and preferably uses a voltage power supply mode using a PWM pulsed square wave.

[0020] As shown in Figure 2, supplying voltage power using a PWM pulse square wave is explained as an example. The specific implementation method is described below. When used, the temperature control system is initialized, and the power supply module supplies power to the entire temperature control system. The drive module outputs periodic forward and reverse pulse voltages, i.e., PWM pulse square wave voltages, to the hot surface ignition device.

[0021] When the falling edge of the voltage signal of the hot surface ignition device occurs, i.e., during the Toff period of the PWM, the thermoelectric signal channel is opened to collect the thermoelectric signal. After receiving the collected thermoelectric signal, the processing module refers to the thermoelectric signal data table to obtain the current temperature value. If the current temperature value matches the preset target temperature, the driving module maintains the current PWM control variable to control the power supply module to continue output. If the current temperature value does not match the preset target temperature, the current temperature value is used to perform calculations using a voltage control variable algorithm to obtain a voltage control variable. Once the voltage control variable is received by the feedback module, the feedback module feeds the voltage control variable back to the control module. The control module controls the duty ratio of the forward pulse voltage and reverse pulse voltage output by the driving module based on the fed-back voltage control variable. If the current temperature is below the target temperature, the duty ratio is increased to raise the temperature, and if the current temperature is above the target temperature, the duty ratio is decreased to lower the temperature, thereby ensuring that the hot surface igniter receives a suitable voltage and thereby ensuring that the hot surface igniter operates at the set temperature.

[0022] When the rising edge of the voltage signal of the hot surface igniter occurs, i.e., during the Ton period of the PWM, the thermoelectric signal channel is closed, an electrical signal indicating an electrical parameter is collected, and based on the electrical signal, it is determined whether the current electrical environment is abnormal. Specifically, after collecting the electrical signal, the processing module obtains the electrical parameter based on the electrical signal and compares the electrical parameter with the rated parameter corresponding to the hot surface igniter to determine whether the electrical parameter is abnormal. After receiving the determination result, the feedback module feeds the determination result back to the control module. If the determination result indicates that the electrical parameter is abnormal, the control module controls the power supply module to turn off the output. If the determination result indicates that the electrical parameter is normal, it continues to output from the power supply module.

[0023] Taking DC voltage at a constant temperature as an example, when in use, the temperature control system is initialized and the power supply module supplies power to the entire temperature control system. The drive module outputs DC voltage at a constant temperature to the hot surface ignition device. The control module controls the duration of the voltage output by the power supply module based on the voltage control amount. When the power supply module stops supplying power, the collection module collects the thermoelectric signal, and when the power supply module supplies power, the collection module collects the electrical signal.

[0024] In this embodiment, the voltage supplied to the hot surface igniter is turned off for a short time, for example, 0.1 milliseconds, and the 0.1 milliseconds is used to perform temperature measurement and calculation, and then the power supply module immediately resumes supplying power. In addition, since the hot surface igniter has a certain thermal inertia, turning off the voltage for such a short time does not affect the temperature continuity of the hot surface igniter, so the normal temperature rise of the hot surface igniter can be guaranteed.

[0025] In another embodiment, the output voltage may be output in a power supply mode using a sine wave AC.

[0026] The above description relates only to the embodiments of the present invention, and does not intentionally describe general knowledge, such as specific known structures or known features, in the solutions of the present invention. It is believed that a person skilled in the art would be familiar with all common technical knowledge in the technical field to which the present invention pertains, be able to use all prior art in the technical field, and be able to carry out ordinary experimental procedures before the filing date or priority date of this application. It is also believed that a person skilled in the art would be able to improve the solutions of the present invention and implement the solutions of the present invention using the motivation provided by this application as a starting point. Generally known structures or generally known methods do not hinder a person skilled in the art from implementing this application. It is also important to note that a person skilled in the art may make various modifications and improvements without departing from the structure of the present invention, and such modifications and improvements are also within the scope of protection of the present invention, and do not affect the effects of implementing the present invention or the applicability of the patent of this application. The scope of protection of this application is governed by the claims, and the disclosure of specific embodiments, etc. in this specification can be used to interpret the claims.

Claims

1. 1. A temperature control system for a hot surface ignition device, comprising: a power supply module for supplying power to the temperature control system; a driver module for outputting a voltage to the hot surface ignition device; a collection module for sampling a thermoelectric signal of the hot surface igniter; a feedback module for receiving the thermoelectric signal, receiving a voltage control amount calculated based on the thermoelectric signal, and performing feedback; a control module for receiving the feedback voltage control amount and controlling the output of the driving module based on the voltage control amount; A temperature control system for a hot surface ignition device, including:

2. 2. The temperature control system for a hot surface igniter as described in claim 1, wherein the drive module is used to output a drive voltage to the hot surface igniter, and the control module controls the duration of the drive voltage output by the drive module based on the voltage control amount.

3. 2. The temperature control system for a hot surface igniter as described in claim 1, wherein the drive module is used to output a forward drive voltage that generates a forward current and a reverse drive voltage that generates a reverse current to the hot surface igniter, and the control module controls the magnitude of the effective values ​​of the forward drive voltage and the reverse drive voltage output by the drive module based on the voltage control amount.

4. 4. The temperature control system for a hot surface igniter of claim 3, wherein the acquisition module includes an analog switch unit for acquiring thermoelectric signals from powered electrodes of the hot surface igniter.

5. The temperature control system for a hot surface ignition device of claim 4 , wherein the acquisition module further comprises an amplification unit for enabling the thermoelectric signal to be transmitted without distortion.

6. the acquisition module is further adapted to acquire an electrical signal; the feedback module is further used to receive the electrical signal and receive feedback on whether the electrical environment is abnormal based on the electrical signal; the control module controls the power supply module to turn off its output when it receives a feedback signal indicating that the electrical environment is abnormal; A temperature control system for a hot surface ignition device according to any one of claims 1 and 3 to 5.

7. 7. The temperature control system for a hot surface ignition device of claim 6, wherein the drive module includes an H-bridge drive circuit.

8. The temperature control system for a hot surface ignition device according to any one of claims 1 to 5, wherein the power supply module has a built-in DC-DC conversion circuit.

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