阅读说明：本技术 一种燃机火焰检测电路 (Flame detection circuit of gas turbine ) 是由 梁超宇 王维建 蒋杰 于 2021-10-18 设计创作，主要内容包括：本发明公开了一种燃机火焰检测电路,涉及燃气轮机检测领域,包括激励电路、信号检测与处理电路、紫外线传感器；激励电路用于向紫外线传感器提供激励电源,包括电阻单元、电容单元,电阻单元的一端与电源连接,电阻单元的另一端与所述电容单元的一端连接,电容单元的另一端接地；信号检测与处理电路用于检测紫外线传感器的输出信号,并提供第一路脉冲信号和第二路脉冲信号至控制器,从而进行火焰的判断,第一路脉冲信号根据检测电流产生,第二路脉冲信号根据检测电压产生；紫外线传感器用于对火焰产出的紫外线进行检测。本发明全部采用分立被动原件,故障率低,结构紧凑,快速高效,灵敏度高,性能稳定。(The invention discloses a flame detection circuit of a gas turbine, which relates to the field of gas turbine detection and comprises an excitation circuit, a signal detection and processing circuit and an ultraviolet sensor; the excitation circuit is used for providing an excitation power supply for the ultraviolet sensor and comprises a resistance unit and a capacitor unit, wherein one end of the resistance unit is connected with the power supply, the other end of the resistance unit is connected with one end of the capacitor unit, and the other end of the capacitor unit is grounded; the signal detection and processing circuit is used for detecting an output signal of the ultraviolet sensor and providing a first path of pulse signal and a second path of pulse signal to the controller so as to judge flame, wherein the first path of pulse signal is generated according to detection current, and the second path of pulse signal is generated according to detection voltage; the ultraviolet sensor is used for detecting ultraviolet rays generated by the flame. The invention adopts discrete passive components, and has low failure rate, compact structure, high speed and efficiency, high sensitivity and stable performance.)

1. A flame detection circuit of a gas turbine is characterized by comprising an excitation circuit, a signal detection and processing circuit and an ultraviolet sensor;

the excitation circuit is used for providing an excitation power supply for the ultraviolet sensor and comprises a resistance unit and a capacitor unit, wherein one end of the resistance unit is connected with a first power supply, the other end of the resistance unit is connected with one end of the capacitor unit, and the other end of the capacitor unit is grounded;

the signal detection and processing circuit is used for detecting an output signal of the ultraviolet sensor and providing a first path of pulse signal and a second path of pulse signal to the controller, the controller judges flame according to the first path of pulse signal and the second path of pulse signal, the first path of pulse signal is generated according to detection current, and the second path of pulse signal is generated according to detection voltage;

the ultraviolet sensor is used for detecting ultraviolet rays generated by the flame.

2. The flame detection circuit of a combustion engine as claimed in claim 1, wherein the resistance unit is formed by connecting a first resistance, a second resistance, a third resistance, a fourth resistance, a fifth resistance, a sixth resistance, a seventh resistance, an eighth resistance, a ninth resistance and a tenth resistance in series; the capacitor unit is formed by connecting a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor in parallel.

3. The combustion engine flame detection circuit of claim 2, wherein the resistance unit further comprises a first jumper, a first end of the first jumper being connected to a first end of the sixth resistance, a second end of the first jumper being connected to a second end of the tenth resistance; the capacitor unit further comprises a second jumper wire, a third jumper wire, a fourth jumper wire and a fifth jumper wire; the second jumper is connected with the second capacitor in series, the third jumper is connected with the third capacitor in series, the fourth jumper is connected with the fourth capacitor in series, and the fifth jumper is connected with the fifth capacitor in series.

4. A combustion engine flame detection circuit as claimed in claim 1, wherein said signal detection and processing circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a sixth capacitor, a seventh capacitor, an optocoupler, a diode, an inverter, a stabilivolt and a comparator.

5. The combustion engine flame detection circuit of claim 4, wherein a first end of the eleventh resistor is connected to the ultraviolet sensor and a second end of the eleventh resistor is connected to the excitation circuit; a first end of the twelfth resistor is connected with the ultraviolet sensor, and a second end of the twelfth resistor is connected with a first end of the diode, a first end of the thirteenth resistor and a first input end of the optocoupler; the eleventh resistor and the twelfth resistor are used for limiting current.

6. A combustion engine flame detection circuit as claimed in claim 5, wherein said diode and said thirteenth resistor are used to protect said optocoupler; a second input end of the optocoupler is connected with a second end of the diode, a second end of the thirteenth resistor, a first end of the sixth capacitor, a first end of the fourteenth resistor and a first end of the voltage regulator tube; a first output end of the optocoupler is connected with a second end of the fifteenth resistor and a first end of the sixteenth resistor; and the second output end of the optical coupler is grounded.

7. A combustion engine flame detection circuit as claimed in claim 6, wherein a first end of said fifteenth resistor is connected to a second power source; a second end of the sixteenth resistor is connected with a first end of the seventh capacitor and an input end of the inverter, and a second end of the seventh capacitor is grounded; the output end of the phase inverter outputs the first path of pulse signal; the sixteenth resistor and the sixth capacitor are used for high-frequency filtering.

8. A combustion engine flame detection circuit as claimed in claim 7, wherein a first terminal of said sixth capacitor is connected to a second terminal of said diode and a second terminal of said thirteenth resistor, and a second terminal of said sixth capacitor is connected to ground; a first end of the fourteenth resistor is connected with a second end of the diode and a second end of the thirteenth resistor, and a second end of the fourteenth resistor is grounded; and the first end of the voltage-regulator tube is connected with the second end of the diode and the second end of the thirteenth resistor, and the second end of the voltage-regulator tube is grounded.

9. The combustion engine flame detection circuit of claim 8, wherein a first end of the seventeenth resistor is connected to a third power source, and a second end of the seventeenth resistor is connected to a first end of the eighteenth resistor and a first end of the nineteenth resistor; a second end of the eighteenth resistor is grounded; the eighteenth resistor is an adjustable resistor.

10. A combustion engine flame detection circuit as claimed in claim 9, wherein a positive input terminal of said inverter is connected to a second terminal of said nineteenth resistor and a first terminal of said twentieth resistor; a negative input end of the phase inverter is connected with a first end of the sixth capacitor, a first end of the fourteenth resistor and a first end of the voltage regulator tube; the output end of the inverter is connected with the second end of the twentieth resistor; and the output end of the phase inverter outputs the second path of pulse signal.

Technical Field

The invention relates to the field of gas turbine detection, in particular to a flame detection circuit of a gas turbine.

Background

At present, the gas turbine is used in the chemical production field or the power generation field, the fuel of the gas turbine is mainly natural gas, and the safety problem of the fuel and equipment is very important, which puts strict requirements on the control process and parameters. At present, many power stations and chemical enterprises use a safety monitoring and fuel safety combustion system of a combustion furnace chamber to ensure the normal start, stop and work of a gas turbine body. Wherein, whether the flame is successfully ignited or not is a key part of safety monitoring, and if the ignition is found to be failed, the fuel supply should be immediately stopped to prevent accidents caused by the combustion engine hearth explosion.

However, in the prior art, the flame detection circuit adopts a special pulse width modulation circuit to control the power supply of the detection circuit, and the modulation circuit needs to use a microprocessor such as a single chip microcomputer to generate a modulation signal. The detection circuit needs to use an analog quantity sampling circuit for detecting voltage, and has complex circuit and higher cost. And the failure is easy to occur and the reliability is reduced. In addition, the influence of field conditions is great, and when the detection distance between the probe and the flame is changed, the detection equipment is easy to misjudge, and the parameter setting is required to be carried out again manually.

Therefore, those skilled in the art are dedicated to develop a circuit for detecting whether a flame in a combustion engine hearth is ignited or not, and a stable and reliable detection function can be realized by using a small number of electronic components, so that the circuit cost is reduced.

Disclosure of Invention

In view of the above defects in the prior art, the technical problem to be solved by the present invention is how to implement flame detection without using a microprocessor such as a single chip microcomputer and an analog sampling circuit.

In order to achieve the purpose, the invention provides a flame detection circuit of a gas turbine, which comprises an excitation circuit, a signal detection and processing circuit and an ultraviolet sensor, wherein the excitation circuit is connected with the signal detection and processing circuit;

the excitation circuit is used for providing an excitation power supply for the ultraviolet sensor and comprises a resistance unit and a capacitor unit, wherein one end of the resistance unit is connected with a first power supply, the other end of the resistance unit is connected with one end of the capacitor unit, and the other end of the capacitor unit is grounded;

the signal detection and processing circuit is used for detecting an output signal of the ultraviolet sensor and providing a first path of pulse signal and a second path of pulse signal to the controller, the controller judges flame according to the first path of pulse signal and the second path of pulse signal, the first path of pulse signal is generated according to detection current, and the second path of pulse signal is generated according to detection voltage;

the ultraviolet sensor is used for detecting ultraviolet rays generated by the flame.

Furthermore, the resistance unit is formed by connecting a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor in series; the capacitor unit is formed by connecting a first capacitor, a second capacitor, a third capacitor, a fourth capacitor and a fifth capacitor in parallel.

Furthermore, the resistance unit further comprises a first jumper wire, a first end of the first jumper wire is connected with a first end of the sixth resistor, and a second end of the first jumper wire is connected with a second end of the tenth resistor; the capacitor unit further comprises a second jumper wire, a third jumper wire, a fourth jumper wire and a fifth jumper wire; the second jumper is connected with the second capacitor in series, the third jumper is connected with the third capacitor in series, the fourth jumper is connected with the fourth capacitor in series, and the fifth jumper is connected with the fifth capacitor in series.

Further, the signal detection and processing circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a nineteenth resistor, a twentieth resistor, a sixth capacitor, a seventh capacitor, an optocoupler, a diode, a phase inverter, a voltage regulator tube and a comparator.

Further, a first end of the eleventh resistor is connected with the ultraviolet sensor, and a second end of the eleventh resistor is connected with the excitation circuit; a first end of the twelfth resistor is connected with the ultraviolet sensor, and a second end of the twelfth resistor is connected with a first end of the diode, a first end of the thirteenth resistor and a first input end of the optocoupler; the eleventh resistor and the twelfth resistor are used for limiting current.

Further, the diode and the thirteenth resistor are used for protecting the optocoupler; a second input end of the optocoupler is connected with a second end of the diode, a second end of the thirteenth resistor, a first end of the sixth capacitor, a first end of the fourteenth resistor and a first end of the voltage regulator tube; a first output end of the optocoupler is connected with a second end of the fifteenth resistor and a first end of the sixteenth resistor; and the second output end of the optical coupler is grounded.

Further, a first end of the fifteenth resistor is connected with a second power supply; a second end of the sixteenth resistor is connected with a first end of the seventh capacitor and an input end of the inverter, and a second end of the seventh capacitor is grounded; the output end of the phase inverter outputs the first path of pulse signal; the sixteenth resistor and the sixth capacitor are used for high-frequency filtering.

Further, a first end of the sixth capacitor is connected to the second end of the diode and the second end of the thirteenth resistor, and a second end of the sixth capacitor is grounded; a first end of the fourteenth resistor is connected with a second end of the diode and a second end of the thirteenth resistor, and a second end of the fourteenth resistor is grounded; and the first end of the voltage-regulator tube is connected with the second end of the diode and the second end of the thirteenth resistor, and the second end of the voltage-regulator tube is grounded.

Further, a first end of the seventeenth resistor is connected to a third power supply, and a second end of the seventeenth resistor is connected to a first end of the eighteenth resistor and a first end of the nineteenth resistor; a second end of the eighteenth resistor is grounded; the eighteenth resistor is an adjustable resistor.

Further, a positive input end of the inverter is connected with a second end of the nineteenth resistor and a first end of the twentieth resistor; a negative input end of the phase inverter is connected with a first end of the sixth capacitor, a first end of the fourteenth resistor and a first end of the voltage regulator tube; the output end of the inverter is connected with the second end of the twentieth resistor; and the output end of the phase inverter outputs the second path of pulse signal.

Compared with the prior art, the invention at least has the following beneficial technical effects:

the invention adopts discrete passive components, and has low failure rate, compact structure, high speed and efficiency, high sensitivity and stable performance.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a schematic diagram of a pump circuit in accordance with a preferred embodiment of the present invention;

FIG. 2 is a diagram of a signal detection and processing circuit according to a preferred embodiment of the present invention.

Detailed Description

The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Because the flame generated when the fuel burns generates strong ultraviolet rays, the ultraviolet ray flame probe can accurately detect the ultraviolet rays so as to judge whether the flame exists or not and the strength degree of the flame, and if the flame in the hearth is extinguished, the ultraviolet rays disappear immediately, so that the method is safe and reliable.

The signal input of the flame detection circuit of the embodiment uses the output signal of the ultraviolet sensor, and the detection circuit detects the signal, so that the designed function is achieved, and the flame detection circuit comprises an excitation circuit and a signal detection and processing circuit; and simultaneously, 2 paths of flame signal output are provided, the first path outputs a flame signal through the current of the detection circuit, the front end of the detection circuit uses a diode and a resistor for protection, the second path detects the flame signal through the voltage of the detection circuit, the voltage detection uses a comparator, and the comparison reference voltage is set to be 1V by default and is adjustable.

As shown in fig. 1, the excitation circuit provided in this embodiment is used for providing an excitation power supply for an ultraviolet sensor, and includes ten resistors of 1M ohm and five high-voltage capacitors, where the package type of the resistor is 1206, and the names of the resistors are R200 to R209; the capacitor packaging model is RAD0.2, and the capacitor names are respectively C200-C204.

Ten resistors are connected in series end to end with one end of resistor R200 connected to the positive terminal (330V +) of power supply 330V. The end of the resistor R209 is connected to the upper end of the capacitor C200, and the lower end of the capacitor C200 is connected to the negative terminal (330V-) of the power supply 330V. The left end of the resistor R205 and the right end of the resistor R209 are connected in parallel by a jumper JP 200. Five capacitors are connected in parallel, and the capacitor C201 is connected in parallel with the capacitor C200 after being connected in series with a jumper JP201, and similarly, the capacitor C202, the capacitor C203 and the capacitor C204 are connected in parallel. The resistors and the capacitors form a charging circuit, when no ultraviolet radiation exists, the power supply 330V charges the capacitor C200 through the resistors, the charging is stopped until the power supply voltage at the two ends of the capacitor C200 is equal to 330V, and when the ultraviolet sensor is irradiated by the external ultraviolet, the excitation circuit completes the periodic charging and discharging process.

When the jumper JP200 jumps up, the resistance of the charging circuit is reduced, the charging time of the capacitor is shortened, and the frequency values of the pulse signals F _ OUT1 and F _ OUT2 output by the circuit are increased when the external part is irradiated by continuous ultraviolet rays, so that the sensitivity of the measuring circuit can be adjusted through the jumper JP 200. When the jumper JP201 jumps, the capacitance of the discharge circuit increases, the discharge time of the capacitor is prolonged, and when the external part is irradiated by continuous ultraviolet rays, the widths of the pulse signals F _ OUT1 and F _ OUT2 output by the circuit increase, the frequency is reduced, so that the sensitivity of the measuring circuit can be adjusted through the jumper JP 201. The action principle of jumper wires JP202, JP203 and JP204 is the same as that of JP 201.

As shown in fig. 2, the signal detecting and processing circuit provided in this embodiment is used for detecting flame, wherein FM100 is an accessed ultraviolet sensor probe, which is only sensitive to ultraviolet rays with a spectrum ranging from 190nm to 280nm, so that it is stable and reliable to detect ultraviolet rays generated by flame.

When FM100 is turned on, capacitor C200 begins to discharge, current flows through device U100, the processing circuitry at the back end operates, and F _ OUT1 outputs a high signal. When the voltage Vc (relative to 330V-) at the upper end of the capacitor C200 drops to the threshold Vs of the FM100 cut-off voltage after the capacitor C200 is discharged, the FM100 is turned off, the capacitor C200 stops discharging, no current flows in the device U100 in the circuit, and at this time, the F _ OUT1 outputs a low level signal. After the capacitor C200 stops discharging, the 330V power supply starts charging the capacitor C200 through R200 to R209. Therefore, the circuit completes a complete signal detection process to realize the output of the 1 st path of signals.

When FM100 is on, the current flows through resistor R103 and a certain voltage drop Vr occurs across it. The voltage Vr (relative to 330V-) across resistor R103 is compared to the reference voltage Vref at device U101A and F _ OUT2 outputs a low if the reference voltage Vref is exceeded. Conversely, when no current passes through the detection circuit after the FM100 is turned off, F _ OUT2 outputs a low level. Thus, the output of the 2 nd path signal is realized.

Resistors R100 and R101 in the circuit play a role in limiting current, the resistance value of the resistor R100 is 5.1K, the packaging model is 1206, the resistance value of the resistor R100 is 10K, and the packaging model is 1206. The diode D100 and the resistor R102 are connected in parallel with the optocoupler U100 in series in a loop, wherein the diode D100 (model 1N4007) and the resistor R102 play a role in protecting the optocoupler U100, and the resistor R102 is matched with the optocoupler U100 to prevent 'false detection' of signals in a detection circuit. The resistor R103 plays a role of current limiting and voltage dividing, and the voltage Vr at two ends of the resistor R is sent to the input end of the comparator U101 for comparison. The capacitor C100 is connected with the voltage regulator tube D101 and the resistor R103 in parallel, and the filtering and amplitude limiting effects on Vr are achieved.

The resistor R104 is used in cooperation with the optocoupler U100 to play a role of pulling up the level to +3.3V, the resistor R105 and the capacitor C101 play a role of high-frequency filtering, and the filtered signal passes through an inverter U102A to output a signal F _ OUT 1. F _ OUT1 is low when there is no flame, F _ OUT1 is high when there is flame, F _ OUT1 is a continuous pulse signal when there is continuous flame, the pulse frequency is higher when the light intensity is high, otherwise, it is low. The resistor R106, the resistance value 10K and the adjustable resistor R107 form a voltage division network, namely reference voltage Vref, the left end of the resistor R108 is connected with the connection point of the R106 and the R107, and the voltage at the left end of the R108 is the reference voltage Vref. When the voltage Vr (relative to 330V-) at the upper end of the resistor R103 is compared with the reference voltage Vref at the device U101A, if the reference voltage Vref is exceeded, the F _ OUT2 outputs a low level, and otherwise, the F _ OUT2 outputs a high level. The resistance value of the resistor R107 can be adjusted to compare the threshold voltage value, so that the possibility of false detection and missed detection in severe environment is avoided. Resistor R109 is used in conjunction with comparator U101A and functions to form a feedback to make the output signal F _ OUT2 more stable. The frequency value of the output signal F _ OUT2 is the same as the frequency value of F _ OUT1, and the two values are sent to a controller for judgment and jointly reflect the intensity of the flame.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.