A method for detecting ultraviolet flame of heating furnace burner

Abstract

The present invention discloses a method for detecting ultraviolet flames for a heating furnace burner, comprising the following steps: Step 1: Inputting a 220V AC voltage into a voltage conversion module; Step 2: Connecting a 350V DC power supply to a drive output module to power an ultraviolet light tube; Step 3: Connecting a 12V DC power supply to a signal conversion module to power a chip U1; Step 4: When a flame is established, a current is generated on the ultraviolet light tube, and the current passes through a resistor R4 to generate a pulse voltage; Step 5: Inputting the pulse signal into the signal conversion module to convert the pulse signal into an analog voltage signal and output it to a controller. This method for detecting ultraviolet flames for a heating furnace burner utilizes resistor and capacitor elements to form a filter circuit, effectively suppressing electromagnetic interference in the circuit and improving the accuracy of the detection results. A transistor is used to output a pulse signal in an open-drain form, and the signal conversion module is used to convert the pulse frequency signal into an analog voltage signal, thereby enhancing the signal's anti-interference capability and improving the sensitivity of the detection results.

Description

Technical Field

[0001] The present invention relates to the technical field related to burner flame detection, and in particular to an ultraviolet flame detection method for a heating furnace burner. Background Art

[0002] The heating furnace is a type of oilfield-specific equipment that is most widely used in heating, transportation, and heating in oil and gas gathering and transportation systems. It is the only open flame equipment in oilfield stations and has very high requirements for operational safety. The burner (also called a burner) is the core ignition equipment of the heating furnace. Its control system must be able to quickly, accurately, and reliably detect states such as flame establishment and flame loss, thereby ensuring the safe and stable operation of the heating furnace and burner.

[0003] In the existing technology, one of the most widely used flame detection methods is ultraviolet flame detection. A UV light tube is installed near the burner flame. When the flame is established, the ultraviolet light radiated in the wavelength range of 185-260nm can be captured by the UV light tube, and the flame status can be detected through the photoelectric effect.

[0004] However, in actual applications, it is found that the working environment of the heating furnace burner is often relatively harsh. The currently commonly used ultraviolet flame detection scheme cannot guarantee the detection sensitivity and accuracy well after being interfered by factors such as visible light and electromagnetic radiation. Summary of the Invention

[0005] In order to solve the problems raised in the above background technology, the present invention provides a method for detecting ultraviolet flame of a heating furnace burner.

[0006] The object of the present invention is to provide an ultraviolet flame detection method for a heating furnace burner, which can not only quickly and accurately detect the state change of the flame, but also has good anti-interference performance.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for detecting ultraviolet flame of a heating furnace burner, comprising the following steps:

[0008] Step 1: Input 220V AC voltage into the voltage conversion module. The 220V AC power is converted into 350V DC power by the AC conversion module. The 350V DC power is converted into 12V DC power by the DC conversion module.

[0009] Step 2: Connect 350V DC power to the driver output module to power the UV tube;

[0010] Step 3: Connect 12V DC power to the signal conversion module to power chip U1;

[0011] Step 4: When the flame is established, current is generated on the UV tube, and the current generates a pulse voltage through the resistor R4. The pulse voltage outputs a pulse signal in an open-drain form through the transistors Q1 and Q2;

[0012] Step 5: The pulse signal input signal conversion module converts it into an analog voltage signal and outputs it to the controller. The controller determines the flame condition based on the received analog voltage signal.

[0013] An ultraviolet flame detection device for a heating furnace burner, comprising:

[0014] A voltage conversion module, the voltage conversion module comprising an AC conversion module and a DC conversion module, wherein the output end of the AC conversion module is connected to the input end of the DC conversion module, and the input end of the AC conversion module is connected to an AC power supply;

[0015] A drive output module, the drive output module is connected to the AC conversion module, the drive output module is used to power the UV tube to drive it to work, and the output signal of the drive output module is connected to the signal conversion module;

[0016] A signal conversion module is connected to the DC conversion module and the drive output module, and the output signal of the signal conversion module is connected to the controller.

[0017] Furthermore, the AC conversion module includes a transformer T1, a fuse F1, a varistor R1, a rectifier bridge B1 and an electrolytic capacitor C1. The two ends of the primary winding of the transformer T1 are respectively connected to the live wire L and the neutral wire N of the AC power supply, and the two ends of the secondary winding of the transformer T1 are connected to the input end of the rectifier bridge B1. The electrolytic capacitor C1 is connected in parallel to the output end of the rectifier bridge B1, and the negative pole of the electrolytic capacitor C1 is grounded.

[0018] Furthermore, the fuse F1 is connected in series to the connection end between the primary winding of the transformer T1 and the live wire L. A varistor R1 is connected in parallel to the primary winding of the transformer T1, and the varistor R1 is close to the AC power supply.

[0019] Furthermore, the DC conversion module includes a DC-DC converter T2 and filter capacitors C2 and C3. The input and output ends of the DC-DC converter T2 are connected in parallel with the filter capacitors C2 and C3, respectively.

[0020] Furthermore, the drive output module includes transistors Q1 and Q2, the bases B of the transistors Q1 and Q2 are connected to resistors R5 and R6 respectively, the emitters E of the transistors Q1 and Q2 are both grounded, and the collectors C of the transistors Q1 and Q2 output pulse signals I and pulse signals II respectively.

[0021] Furthermore, the drive output module also includes resistors R2, R3 and R4, one end of the resistor R4 is connected to the cathode of the ultraviolet light tube, the other end of the resistor R4 is grounded, the resistor R4 is connected in parallel with the capacitor C5, and the two ends of the capacitor C5 are respectively connected to the resistor R5 and the resistor R6.

[0022] Furthermore, one end of the resistor R3 is connected to the anode of the ultraviolet light tube, and the other end of the resistor R3 is connected to the connection point of the resistor R2 and the capacitor C4. The resistor R2 and the capacitor C4 form a low-pass filter circuit.

[0023] Furthermore, the signal conversion module includes a chip U1 and an operational amplifier A1. The model of the chip U1 is LM331. Pin 8 of the chip U1 is connected to the positive pole of the 12V power supply. Pins 7 and 5 of the chip U1 are connected to resistor R9 and capacitor C7 respectively. Pins 6 and 1 of the chip U1 are connected to the frequency signal input terminal Fin and the voltage signal output terminal Vout respectively. The wire between pin 6 of the chip U1 and the frequency signal input terminal Fin is connected with resistor R10, resistor R7 and capacitor C6 in sequence. The other end of the resistor R7 is connected to the connection point of resistor R8 and pin 8. Resistor R8 is connected between pins 8 and 7 of the chip U1. Resistor R11 is connected between pins 8 and 5 of the chip U1.

[0024] Furthermore, a capacitor C9 is connected between the input and output ends of the operational amplifier A1. The capacitor C9 is connected in series with the resistor R13 and then connected in parallel at both ends of the resistor R12. The two ends of the resistor R12 are respectively connected to the capacitor C8 and the voltage signal output end Vout. The other ends of the capacitors C7 and C8 are grounded, and the other ends of the resistors R9 and R10 are grounded.

[0025] Compared with the prior art, the present invention has the following beneficial effects: the method for detecting ultraviolet flames of heating furnace burners utilizes resistors and capacitors to form a filter circuit, effectively suppressing electromagnetic interference in the circuit and improving the accuracy of the detection results; the method utilizes a transistor to output a pulse signal in an open-drain form, and cooperates with a signal conversion module to convert the pulse frequency signal into an analog voltage signal, thereby enhancing the signal's anti-interference ability and improving the sensitivity of the detection results;

[0026] 1. Use the two submodules of the voltage conversion module to convert 220V AC into 350V DC and 12V DC, respectively, to provide appropriate working voltages for the UV tube and chip U1 to ensure normal and stable operation of the circuit;

[0027] 2. Use the drive output module to output the current signal generated by the UV tube as two voltage pulse signals. The outputs of the two pulse signals are opposite, which facilitates correction and improves inspection accuracy.

[0028] 3. Use the signal conversion module to convert the frequency signal into an analog signal to enhance the anti-interference ability of the transmission signal and facilitate the controller to make judgments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a system block diagram of the present invention;

[0030] Figure 2 This is a circuit diagram of the AC conversion module of the present invention;

[0031] Figure 3 This is a circuit diagram of the DC conversion module of the present invention;

[0032] Figure 4 This is a circuit diagram of the drive output module of the present invention;

[0033] Figure 5 This is a circuit diagram of the signal conversion module of the present invention;

[0034] Figure 6 This is the pin diagram of the chip U1 of the present invention.

[0035] In the figure: 10, voltage conversion module; 20, drive output module; 30, signal conversion module; 40, controller; 50, AC power supply; 101, AC conversion module; 102, DC conversion module. DETAILED DESCRIPTION

[0036] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] Specific implementation method 1: Please refer to Figure 1-6 The present invention provides a technical solution: a method for detecting ultraviolet flame of a heating furnace burner, comprising the following steps:

[0038] Step 1: Input 220V AC voltage into the voltage conversion module 10. The 220V AC is converted into 350V DC by the AC conversion module 101. The 350V DC is converted into 12V DC by the DC conversion module 102.

[0039] Step 2: Connect 350V DC power to the drive output module 20 to power the UV tube;

[0040] Step 3: Connect 12V DC power to the signal conversion module 30 to power the chip U1;

[0041] Step 4: When the flame is established, current is generated on the UV tube, and the current generates a pulse voltage through the resistor R4. The pulse voltage outputs a pulse signal in an open-drain form through the transistors Q1 and Q2;

[0042] Step 5: The pulse signal input into the signal conversion module 30 is converted into an analog voltage signal and output to the controller 40. The controller 40 determines the flame condition according to the received analog voltage signal.

[0043] Specific embodiment 2: A UV flame detection device for a heating furnace burner, comprising:

[0044] The voltage conversion module 10 includes an AC conversion module 101 and a DC conversion module 102. The output of the AC conversion module 101 is connected to the input of the DC conversion module 102. The input of the AC conversion module 101 is connected to the AC power supply 50.

[0045] The drive output module 20 is connected to the AC conversion module 101 and is used to power the UV tube to drive it to work. The output signal of the drive output module 20 is connected to the signal conversion module 30;

[0046] The signal conversion module 30 is connected to the DC conversion module 102 and the drive output module 20 , and the output signal of the signal conversion module 30 is connected to the controller 40 .

[0047] During use, the AC power supply 50 is connected to the input end of the AC conversion module 101 to convert the AC power supply 50 into a first DC power supply. The first DC power supply is connected to the DC conversion module 102 to obtain a second DC power supply. The first DC power supply and the second DC power supply are respectively connected to the drive output module 20 and the signal conversion module 30 to power the UV tube and the chip U1. When the flame is established, the UV tube generates current under the action of the photoelectric effect. The current generates a voltage pulse signal through the resistor R4. The voltage pulse signal is output in an open-drain form through the transistors Q1 and Q2. The output signal is connected to the signal conversion module 30, and the voltage signal output terminal Vout of the signal conversion module 30 outputs:

[0048]

[0049] The output signal is transmitted to the controller 40, and the controller 40 determines the flame condition according to the output signal.

[0050] Specific implementation method three: This implementation method is a further limitation of specific implementation method two. Figure 2As shown, the AC conversion module 101 includes a transformer T1, a fuse F1, a varistor R1, a rectifier bridge B1 and an electrolytic capacitor C1. The two ends of the primary winding of the transformer T1 are respectively connected to the live wire L and the neutral wire N of the AC power source 50, and the two ends of the secondary winding of the transformer T1 are connected to the input end of the rectifier bridge B1. The electrolytic capacitor C1 is connected in parallel to the output end of the rectifier bridge B1, and the negative pole of the electrolytic capacitor C1 is grounded. The transformer T1 is used to increase the voltage value, and the rectifier bridge B1 is used to convert AC into DC.

[0051] Specific embodiment four: This embodiment is a further limitation of specific embodiment three. The fuse F1 is connected in series with the connection end between the primary winding of the transformer T1 and the live wire L. The primary winding of the transformer T1 is connected in parallel with a varistor R1. The varistor R1 is close to the side of the AC power supply 50. The varistor R1 plays a high-voltage protection role, and the fuse F1 plays an overcurrent protection role, thereby improving the safety of the circuit.

[0052] Specific implementation method 5: This implementation method is a further limitation of specific implementation method 2. Figure 3 As shown, the DC conversion module 102 includes a DC-DC converter T2, filter capacitors C2 and C3. The input and output ends of the DC-DC converter T2 are respectively connected in parallel with the filter capacitors C2 and C3. The filter capacitors C2 and C3 are arranged at both ends to ensure efficient and smooth DC output. The DC-DC converter T2 converts a higher DC voltage into a voltage value suitable for the signal conversion module 30.

[0053] Specific embodiment six: This embodiment is a further limitation of specific embodiment five. The drive output module 20 includes transistors Q1 and Q2. The bases B of the transistors Q1 and Q2 are connected to resistors R5 and R6 respectively. The emitters E of the transistors Q1 and Q2 are both grounded. The collectors C of the transistors Q1 and Q2 output pulse signals I and pulse signals II respectively. The output level can be easily adjusted by using the open-drain output of the transistors Q1 and Q2. The output level is completely determined by the power supply level connected to the pull-up resistor.

[0054] Specific embodiment seven: This embodiment is a further limitation of specific embodiment six. The drive output module 20 also includes resistors R2, R3 and R4. One end of the resistor R4 is connected to the cathode of the ultraviolet light tube, and the other end of the resistor R4 is grounded. The resistor R4 is connected in parallel with the capacitor C5. The two ends of the capacitor C5 are respectively connected to the resistor R5 and the resistor R6. The capacitor C5 is a filter capacitor, the resistor R3 is a matching current limiting resistor, the resistor R5 and the resistor R6 are current limiting resistors, and the resistor R4 is a balancing resistor.

[0055] Specific implementation method eight: This implementation method is a further limitation of specific implementation method seven. Figure 4As shown, one end of the resistor R3 is connected to the anode of the ultraviolet tube, and the other end of the resistor R3 is connected to the connection point of the resistor R2 and the capacitor C4. The resistor R2 and the capacitor C4 form a low-pass filter circuit. The low-pass filter circuit filters the input voltage, effectively reducing the impact of the pre-circuit on the ultraviolet tube circuit.

[0056] Specific implementation method 9: This implementation method is a further limitation of specific implementation method 1. Figure 5 and Figure 6 As shown, the signal conversion module 30 includes a chip U1 and an operational amplifier A1. The model of the chip U1 is LM331. Pin 8 of the chip U1 is connected to the positive electrode of the 12V power supply. Pins 7 and 5 of the chip U1 are connected to a resistor R9 and a capacitor C7, respectively. Pins 6 and 1 of the chip U1 are connected to the frequency signal input terminal Fin and the voltage signal output terminal Vout, respectively. The wire between pin 6 of the chip U1 and the frequency signal input terminal Fin is connected in sequence with a resistor R10, a resistor R7 and a capacitor C6. The other end of the resistor R7 is connected to the connection point between the resistor R8 and pin 8. A resistor R8 is connected between pins 8 and 7 of the chip U1. A resistor R11 is connected between pins 8 and 5 of the chip U1. The resistance value of the resistor R9 is:

[0057]

[0058] Among them, Vs is the voltage value connected to pin 8 of chip U1.

[0059] When the input signal enters the frequency signal input terminal Fin and passes through the differential circuit, a negative spike pulse will be generated at pin 6. When the negative spike pulse is greater than When the internal trigger of chip U1 is set, its internal current source charges capacitor C9, and the power supply V S Capacitor C7 is charged through R11. When the voltage on C9 is greater than When , the trigger inside the chip U1 is reset, C9 discharges through R13, and the timing capacitor C7 discharges quickly, completing a charge and discharge process. After each charge and discharge process, the circuit repeats the above working process, thus realizing the frequency / voltage conversion.

[0060]

[0061] Specific embodiment ten: This embodiment is a further limitation of specific embodiment nine. Capacitor C9 is connected between the input and output ends of operational amplifier A1. Capacitor C9 is connected in series with resistor R13 and then in parallel with both ends of resistor R12. Both ends of resistor R12 are respectively connected to capacitor C8 and voltage signal output end Vout. The other ends of capacitor C7 and capacitor C8 are grounded, and the other ends of resistor R9 and resistor R10 are grounded. The output voltage signal is amplified by operational amplifier A1 to facilitate reception and judgment by controller 40.

[0062] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for detecting ultraviolet flame of a heating furnace burner, characterized in that: The following steps are involved: Step 1: Inputting a 220V AC voltage into the voltage conversion module (10), the 220V AC is converted into a 350V DC via the AC conversion module (101), and the 350V DC is converted into a 12V DC via the DC conversion module (102); Step 2: Connect 350V DC power to the drive output module (20) to power the UV tube; Step 3: Connect 12V DC power to the signal conversion module (30) to power the chip U1; Step 4: When the flame is established, current is generated on the UV tube, and the current generates a pulse voltage through the resistor R4. The pulse voltage outputs a pulse signal in an open-drain form through the transistors Q1 and Q2; Step 5: The pulse signal input signal conversion module (30) is converted into an analog voltage signal and output to the controller (40), and the controller (40) determines the flame condition according to the received analog voltage signal; The voltage conversion module (10) comprises an AC conversion module (101) and a DC conversion module (102); The AC conversion module (101) comprises a transformer T1, a fuse F1, a varistor R1, a rectifier bridge B1 and an electrolytic capacitor C1; The DC conversion module (102) includes a DC-DC converter T2, and filter capacitors C2 and C3.

2. The method for detecting ultraviolet flame of a heating furnace burner according to claim 1, characterized in that: The output end of the AC conversion module (101) is connected to the input end of the DC conversion module (102), and the input end of the AC conversion module (101) is connected to an AC power source (50); a driving output module (20), the driving output module (20) being connected to the AC conversion module (101), the driving output module (20) being used to supply power to the ultraviolet light tube to drive it to operate, and an output signal of the driving output module (20) being connected to a signal conversion module (30); A signal conversion module (30) is connected to the DC conversion module (102) and the drive output module (20), and an output signal of the signal conversion module (30) is connected to a controller (40).

3. The method for detecting ultraviolet flame of a heating furnace burner according to claim 2, wherein: The two ends of the primary winding of the transformer T1 are respectively connected to the live wire L and the neutral wire N of the AC power supply (50), the two ends of the secondary winding of the transformer T1 are connected to the input end of the rectifier bridge B1, and the output end of the rectifier bridge B1 is connected in parallel with the electrolytic capacitor C1, and the negative electrode of the electrolytic capacitor C1 is grounded.

4. The method for detecting ultraviolet flame of a heating furnace burner according to claim 3, wherein: The fuse F1 is connected in series to the connection end between the primary winding of the transformer T1 and the live wire L. A varistor R1 is connected in parallel to the primary winding of the transformer T1, and the varistor R1 is close to one side of the AC power supply (50).

5. The method for detecting ultraviolet flame of a heating furnace burner according to claim 2, wherein: The input end and the output end of the DC-DC converter T2 are connected in parallel with filter capacitors C2 and C3 respectively.

6. The method for detecting ultraviolet flame of a heating furnace burner according to claim 1, wherein: The driving output module (20) comprises transistors Q1 and Q2, the bases B of the transistors Q1 and Q2 are connected to resistors R5 and R6 respectively, the emitters E of the transistors Q1 and Q2 are both grounded, the collectors C of the transistors Q1 and Q2 output pulse signals I and II respectively, and the two complementary pulse signals output by the driving output module (20) are connected to the bases of the transistors Q1 and Q2 respectively through resistors R5 and R6, forming an open-drain output structure.

7. The method for detecting ultraviolet flame of a heating furnace burner according to claim 6, characterized in that: The drive output module (20) further includes resistors R2, R3 and R4, one end of the resistor R4 is connected to the cathode of the ultraviolet tube, the other end of the resistor R4 is grounded, the resistor R4 is connected in parallel with the capacitor C5, and the two ends of the capacitor C5 are respectively connected to the resistor R5 and the resistor R6.

8. The method for detecting ultraviolet flame of a heating furnace burner according to claim 7, characterized in that: One end of the resistor R3 is connected to the anode of the ultraviolet light tube, and the other end of the resistor R3 is connected to the connection point of the resistor R2 and the capacitor C4. The resistor R2 and the capacitor C4 form a low-pass filter circuit.

9. The method for detecting ultraviolet flame of a heating furnace burner according to claim 2, wherein: The signal conversion module (30) comprises a chip U1 and an operational amplifier A1. The model of the chip U1 is LM331. Pin 8 of the chip U1 is connected to the positive electrode of a 12V power supply. Pins 7 and 5 of the chip U1 are connected to a resistor R9 and a capacitor C7, respectively. Pins 6 and 1 of the chip U1 are connected to a frequency signal input terminal Fin and a voltage signal output terminal Vout, respectively. A resistor R10, a resistor R7 and a capacitor C6 are sequentially connected to the wire between pin 6 of the chip U1 and the frequency signal input terminal Fin. The other end of the resistor R7 is connected to the connection point between resistor R8 and pin 8. A resistor R8 is connected between pins 8 and 7 of the chip U1. A resistor R11 is connected between pins 8 and 5 of the chip U1.

10. The method for detecting ultraviolet flame of a heating furnace burner according to claim 9, characterized in that: A capacitor C9 is connected between the input and output ends of the operational amplifier A1. The capacitor C9 is connected in series with the resistor R13 and then connected in parallel to the two ends of the resistor R12. The two ends of the resistor R12 are respectively connected to the capacitor C8 and the voltage signal output end Vout. The other ends of the capacitors C7 and C8 are grounded, and the other ends of the resistors R9 and R10 are grounded.

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