Novel flame detection scheme for ion bar of burner
阅读说明：本技术 一种新型燃烧机离子棒火焰检测方案 (Novel flame detection scheme for ion bar of burner ) 是由 刘兴元 于 2020-06-28 设计创作，主要内容包括：本发明提供了以下技术方案：离子棒与燃烧机外壳的高压电采用PWM方波信号,利用PWM方波信号产生的火焰离子电流给电容充放电,利用电容对电荷积分效应,得到对应火焰离子电流信号变化的电压。采用单片机对电压信号进行ADC数字化处理,提高信号处理抗干扰能力。本发明的火焰离子棒信号是通过电容充放电原理,利用电流积分效应实现对火焰微电流信号的检测,从而省去使用功放电路处理微电流信号,降低信号处理电路的复杂度和提高了电路抗干扰能力,采用单片机对后续电压信号数字化处理,进一步增强方案的抗干扰能,提高方案的稳定可靠性,因此,采用本发明可大大提高燃烧机控制器的安全可靠性和降低生产制造成本。(The invention provides the following technical scheme: the high voltage of the ion bar and the combustor shell adopts PWM square wave signals, the flame ion current generated by the PWM square wave signals is used for charging and discharging the capacitor, and the voltage corresponding to the change of the flame ion current signal is obtained by utilizing the charge integration effect of the capacitor. And the singlechip is used for carrying out ADC digital processing on the voltage signal, so that the signal processing anti-interference capability is improved. The flame ion rod signal of the invention realizes the detection of the flame micro-current signal by utilizing the current integral effect through the principle of capacitance charging and discharging, thereby saving the power amplifier circuit to process the micro-current signal, reducing the complexity of the signal processing circuit and improving the anti-interference capability of the circuit.)
1. The utility model provides a novel combustor ion stick flame detection scheme, includes novel combustor ion stick flame detection principle, its characterized in that, novel combustor ion stick flame detection principle is:
the current charges and discharges the capacitor within a period of time, and the voltage at two ends of the capacitor changes correspondingly with the magnitude of the charging current under the condition that the capacitor is not saturated.
2. The novel ion rod flame detection scheme for the combustion engine as claimed in claim 1, wherein the specific steps of the novel ion rod flame detection scheme for the combustion engine are as follows:
s1: an electric field is applied between the ion bar and the combustor shell, when the combustor works, weak ion current can be formed between the ion bar and the combustor shell, and different flame intensities are linearly changed corresponding to the ion current.
S2: the collected ion current is charged and discharged to the capacitor through the flame ion current collecting circuit, and voltage values corresponding to linear changes can be generated at two ends of the capacitor.
S3: the voltage at two ends of the capacitor is read through the single chip microcomputer ADC, and detection of the corresponding flame signal intensity can be achieved.
3. The novel burner ion rod flame detection scheme as claimed in claim 2, wherein the electric field is applied by:
and applying an electric field to the ion bar and the combustor shell by adopting a high-voltage PWM square wave, wherein the weak ion current formed between the ion bar and the combustor shell is synchronous with the PWM square wave.
4. The novel flame detection scheme for the ion rod of the combustion engine as claimed in claim 2, wherein during the charge and discharge of the capacitor, the voltage value corresponding to the change of the current is obtained through the integral effect of the capacitor on the current.
5. The novel flame detection scheme for the ion rod of the combustion engine as claimed in claim 2, wherein the detection of the corresponding flame signal intensity can be realized by reading the voltage at two ends of the capacitor through the single chip microcomputer ADC, and the specific method comprises the following steps:
the ADC reads the flame signal and judges whether flame exists according to a set threshold value;
and if the flame signal is not detected, executing a flame signal undetected subroutine.
If the flame signal is detected, the flame intensity subprogram is judged, and the flame signal detection subprogram is executed.
Technical Field
The invention mainly relates to the technical field of burners, in particular to a novel flame detection scheme for an ion bar of a burner.
Background
The burner for boiler or industrial heating belongs to an industrial product with high safety requirements, safety accidents such as hearth deflagration and the like easily occur due to control or operation errors, and a burner controller must detect the flame combustion state safely and reliably in real time to ensure safe and reliable operation of the burner. Therefore, the improvement of the reliability of the flame detection scheme plays a very important role in ensuring the safe operation of the burner.
The flame detection of the ion bar of the burner is generally that a stable high-voltage power supply is connected to the ion bar, meanwhile, the burner shell is grounded, a stable electric field is formed between the ion bar and the burner shell, when flame burns, flame ions can form an ionic current under the action of the electric field, the ionic current is collected and converted into a voltage signal, and then the voltage signal is amplified by a power amplifier so as to judge the state of the burning flame.
The combustor usually works under the more abominable operating mode, and flame detection circuit easily receives environment interference everywhere, adopts above-mentioned mode, and flame detection circuit is more complicated, and manufacturing cost is high. Moreover, in the process of converting the flame ion current into the voltage signal and amplifying the voltage signal, the interference and the flame signal are easily amplified together to obtain an incorrect judgment result, and potential safety hazards are generated when the combustion machine works reliably.
Disclosure of Invention
The invention mainly provides a novel flame detection scheme for an ion bar of a burner, which is used for solving the technical problems in the background technology.
The technical scheme adopted by the invention for solving the technical problems is as follows:
the utility model provides a novel combustor ion stick flame detection scheme, includes novel combustor ion stick flame detection principle, novel combustor ion stick flame detection principle is:
the current charges and discharges the capacitor within a period of time, and the voltage at two ends of the capacitor changes correspondingly with the magnitude of the charging current under the condition that the capacitor is not saturated.
Preferably, the novel flame detection scheme for the ion rod of the burner comprises the following specific steps:
s1: an electric field is applied between the ion bar and the combustor shell, when the combustor works, weak ion current can be formed between the ion bar and the combustor shell, and different flame intensities are linearly changed corresponding to the ion current.
S2: the collected ion current is charged and discharged to the capacitor through the flame ion current collecting circuit, and voltage values corresponding to linear changes can be generated at two ends of the capacitor.
S3: the voltage at two ends of the capacitor is read through the single chip microcomputer ADC, and detection of the corresponding flame signal intensity can be achieved.
Preferably, the method for applying the electric field comprises:
and applying an electric field to the ion bar and the combustor shell by adopting a high-voltage PWM square wave, wherein the weak ion current formed between the ion bar and the combustor shell is synchronous with the PWM square wave.
Preferably, in the charging and discharging processes of the capacitor, the voltage value corresponding to the current change is obtained through the integral effect of the capacitor on the current.
Preferably, the voltage at two ends of the capacitor is read through the single chip microcomputer ADC, so that the detection of the corresponding flame signal intensity can be realized, and the specific method comprises the following steps:
the ADC reads the flame signal and judges whether flame exists according to a set threshold value;
and if the flame signal is not detected, executing a flame signal undetected subroutine.
If the flame signal is detected, the flame intensity subprogram is judged, and the flame signal detection subprogram is executed.
Compared with the prior art, the invention has the beneficial effects that: the flame ion rod signal of the invention realizes the detection of flame micro-current signals by utilizing the current integral effect through the principle of capacitance charge and discharge, thereby saving the power amplifier circuit to process the micro-current signals, reducing the complexity of the signal processing circuit and improving the anti-interference capability of the circuit. Therefore, the invention can greatly improve the safety and reliability of the burner controller and reduce the production and manufacturing cost.
The present invention will be explained in detail below with reference to the drawings and specific embodiments.
Drawings
FIG. 1 is a schematic diagram of the hardware schematic of the present invention;
FIG. 2 is a simplified diagram of the charge/discharge of a capacitor according to the present invention;
FIG. 3 is a schematic diagram of a capacitor charging curve structure according to the present invention;
FIG. 4 is a theoretical calculation formula for charge and discharge of the capacitor according to the present invention;
FIG. 5 is a flow chart of the capacitive software test of the present invention.
Detailed Description
In order to facilitate an understanding of the invention, the invention will now be described more fully hereinafter with reference to the accompanying drawings, in which several embodiments of the invention are shown, but which may be embodied in different forms and not limited to the embodiments described herein, but which are provided so as to provide a more thorough and complete disclosure of the invention.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may be present, and when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present, as the terms "vertical", "horizontal", "left", "right" and the like are used herein for descriptive purposes only.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and the knowledge of the terms used herein in the specification of the present invention is for the purpose of describing particular embodiments and is not intended to limit the present invention, and the term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Please refer to fig. 1-5, a novel flame detection scheme for an ion bar of a burner, which comprises a novel flame detection principle for an ion bar of a burner, wherein the novel flame detection principle for an ion bar of a burner is as follows:
the current charges and discharges the capacitor within a period of time, and the voltage at two ends of the capacitor changes correspondingly with the magnitude of the charging current under the condition that the capacitor is not saturated.
Specifically, referring to fig. 2, fig. 3 and fig. 4, fig. 2 is a simplified diagram of capacitor charging and discharging, fig. 3 is a curve of capacitor charging for briefly explaining the theoretical principle of detecting flame ion current by the integral effect of the capacitor on current, in the diagram, E is a flame ion current source, Vi is the equivalent voltage of the ion current passing through R, V is the voltage at two ends of the capacitor charging, switch K is an equivalent circuit of an ion current switch, ton time K for charging the capacitor by the ion current is equivalent to be closed, and toff time K for discharging is equivalent to be open.
When the flame ion current charges the capacitor, the voltage at two ends of the capacitor can be increased or reduced along with the transformation of the charged amount of the capacitor, a
The novel flame detection scheme for the ion bar of the burner comprises the following specific steps:
s1: an electric field is applied between the ion bar and the combustor shell, when the combustor works, weak ion current can be formed between the ion bar and the combustor shell, and different flame intensities are linearly changed corresponding to the ion current.
S2: the collected ion current is charged and discharged to the capacitor through the flame ion current collecting circuit, and voltage values corresponding to linear changes can be generated at two ends of the capacitor.
S3: the voltage at two ends of the capacitor is read through the single chip microcomputer ADC, and detection of the corresponding flame signal intensity can be achieved.
The method for applying the electric field comprises the following steps:
and applying an electric field to the ion bar and the combustor shell by adopting a high-voltage PWM square wave, wherein the weak ion current formed between the ion bar and the combustor shell is synchronous with the PWM square wave.
And in the process of charging and discharging the capacitor, the voltage value corresponding to the current change is obtained through the integral effect of the capacitor on the current.
Specifically, referring to fig. 1, fig. 1 is a hardware schematic diagram of the present invention, a high-voltage PWM square wave is isolated by a C36 capacitor, and then passes through resistors R39 and R95 and is applied to a flame detection ion rod, an electric field consistent with the on-off time of the PWM square wave is formed between the high-voltage PWM square wave and a grounded burner housing, when there is a flame signal, the PWM square wave high level time ton charges a capacitor C33 with a flame ion current, the PWM square wave low level time toff discharges the capacitor C33, R1, R28 resistors and C35 form a flame ion current pickup circuit, R96 and R106 resistors form a voltage configuration circuit, the C33 capacitor voltage is adjusted to a range of ADC
Furthermore, hardware parameters are adjusted to enable the charge-discharge voltage curve of the C33 and the flame ion current to form a linear relation similar to that of the charge-discharge curve shown in FIG. 3, when the combustion flame becomes large, the corresponding flame ion current is correspondingly increased, the voltage values at the two ends of the C33 are correspondingly changed, and the single chip microcomputer judges whether the combustion state of the corresponding flame is good or not through the ADC according to the voltage value conditions at the two ends of the C33.
The voltage at two ends of the capacitor is read through the single chip ADC, so that the detection of the corresponding flame signal intensity can be realized, and the specific method comprises the following steps:
the ADC reads the flame signal and judges whether flame exists according to a set threshold value;
and if the flame signal is not detected, executing a flame signal undetected subroutine.
If the flame signal is detected, the flame intensity subprogram is judged, and the flame signal detection subprogram is executed.
Specifically, referring to fig. 5, fig. 5 is a flowchart of the detection of the capacitor software according to the present invention.
The specific operation mode of the invention is as follows: after the high-voltage PWM square wave is isolated by a C36 capacitor, the high-voltage PWM square wave passes through a resistor R39 and a resistor R95 and is applied to a flame detection ion rod, an electric field consistent with the on-off time of the PWM square wave is formed between the high-voltage PWM square wave and a grounded burner shell, when a flame signal exists, the high-level time ton of the PWM square wave charges a capacitor C33 through flame ion current, the low-level time toff of the PWM square wave discharges the capacitor C33, the resistor R1, the resistor R28 and the capacitor C35 form a flame ion current pickup circuit, the resistors R96 and R106 form a voltage allocation circuit, the voltage of the capacitor C33 is adjusted to the amplitude range of the ADC measurable voltage of a single chip microcomputer from 0 to VCC, the single chip microcomputer can conveniently process the converted corresponding flame voltage signal, and the resistor R92 is used for.
Furthermore, hardware parameters are adjusted to enable the charge-discharge voltage curve of the C33 and the flame ion current to form a linear relation similar to that of the charge-discharge curve shown in FIG. 3, when the combustion flame becomes large, the corresponding flame ion current is correspondingly increased, the voltage values at the two ends of the C33 are correspondingly changed, and the single chip microcomputer judges whether the combustion state of the corresponding flame is good or not through the ADC according to the voltage value conditions at the two ends of the C33.
The invention is described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the above-described embodiments, and it is within the scope of the invention to adopt such insubstantial modifications of the inventive method concept and solution, or to apply the inventive concept and solution directly to other applications without modification.
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