Ion flame detection method for heating furnace burner

Abstract

The present invention discloses an ion flame detection method for a heating furnace burner, and the detection method includes the following steps: oscillating electric field generation, ion current charging and discharging, drive control and signal output: Step A. Oscillating electric field generation; after power-on, the input AC 220V voltage is converted into AC 300V voltage through a transformer, and an alternating oscillating electric field is formed between the ion probe and the burner casing, which is applied to the flame to generate ion current. The ion flame detection method for a heating furnace burner can not only realize rapid detection of the flame state, but also adapt to a relatively harsh working environment and ensure the reliability of flame state detection; the specially designed short circuit / leakage protection module can also discharge the current in time when the ion probe has a short circuit or leakage problem, effectively improving the safety of the detection circuit.

Description

Technical Field

[0001] The invention relates to the field of burners, in particular to an ion flame detection method for a heating furnace burner. Background Art

[0002] The heating furnace / boiler is the most widely used oilfield special equipment in the heating, transportation and heating links of the oil and gas gathering and transportation system. It is the only open flame equipment in the oilfield station and has very high requirements for its operating safety. The burner (also called the burner) is the core ignition equipment of the heating furnace / boiler. Its control system must be able to quickly, accurately and reliably detect the flame establishment, flame loss and other states, so as to ensure the safe and stable operation of the heating furnace / boiler and the burner.

[0003] One of the most widely used flame detection methods at present is ion flame detection. An ion probe is installed near the flame, and the burner casing is grounded. Through oscillation, an electric field is formed between the ion probe and the casing. When the flame is burning, due to the unidirectional conductivity of the flame, an ion reaction will occur in the combustion process. Under the action of the external electric field, the flow of positive and negative ions will form a microcurrent. The current is converted into a voltage signal and after appropriate amplification and filtering, it can be used as a control signal to judge the state of the flame. Despite this, the working environment of the heating furnace / boiler burner is often harsh, and the traditional ion flame detection circuit is prone to failure or misjudgment after being disturbed by the environment. In addition, after a certain number of years of use, the ion probe will experience probe short circuit or leakage. The traditional ion flame detection circuit has no countermeasures for these problems, which can easily lead to circuit failure.

[0004] Therefore, it is necessary to design a new ion flame detection scheme that can not only quickly and accurately detect the state changes of the flame, but also promptly deal with problems such as short circuit and leakage. Summary of the invention

[0005] In order to fill the gap in the market, the present invention provides an ion flame detection method for a heating furnace burner.

[0006] The object of the present invention is to provide an ion flame detection method for a heating furnace burner to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: an ion flame detection method for a heating furnace burner, the detection method comprising the following steps: oscillating electric field generation, ion current charging and discharging, drive control and signal output:

[0008] Step A. Oscillating electric field generation: After power is turned on, the input AC 220V voltage is converted into AC 300V voltage through a transformer, and an alternating oscillating electric field is formed between the ion probe and the burner casing, which is applied to the flame to generate ion current;

[0009] Step B. charging and discharging of ion current: after the ion current passes through the filter circuit, it charges the capacitor, and when the capacitor is fully charged, it discharges to form an effective output high-level signal;

[0010] Step C. drive control: the effective high-level signal outputted from step B drives the linkage circuit composed of three transistors to output an effective low-level signal;

[0011] Step D: Signal output; The effective low-level signal outputted in step C turns on the relay coil and closes it, thereby turning on the common pin of the output terminal and the normally open pin.

[0012] Furthermore, the oscillating electric field generation in step A is implemented by an oscillating electric field generation module, which includes a transformer, a fuse, a rectifier bridge, a first electrolytic capacitor, a current limiting resistor, a filter capacitor a, an ion probe and a varistor. The oscillating electric field generation module is connected to the short-circuit / leakage protection module and the drive control module through Net1.

[0013] Furthermore, the short circuit / leakage protection module includes a transistor b and a first working resistor, and the first working resistor is provided in two groups, and the transistor b and the first working resistor are electrically connected.

[0014] Furthermore, the drive control module includes a transistor a, a resistance structure and a third diode. The transistor a is set to three groups, the resistance structure is set to seven groups, and one end of the drive control module is connected to the ion current charging and discharging module through Net2, and the other end of the drive control module is connected to the signal output module through Net3; the transistor a is electrically connected to the resistance structure, and the three groups of transistors a are Q2, Q3 and Q4, and Q2, Q3 and Q4 are connected in series, and the seven groups of resistance structures are R10, R11, R12, R13, R14, R15 and R16.

[0015] Furthermore, the signal output module includes a relay, a second diode and a wiring terminal, and the signal output module is connected to the drive control module through Net3, and the relay, the second diode and the wiring terminal are electrically connected.

[0016] Further, the ion current charge and discharge module includes a second working resistor, a filter capacitor b, a second electrolytic capacitor, a first diode and a burner casing, and the second working resistor is set to five groups, and the second electrolytic capacitor is set to two groups, and the filter capacitor b is set to four groups, the five groups of second working resistors are R5, R6, R7, R8 and R9, and R5, R6, R7 and R8 are connected in series, the four groups of filter capacitors b are C4, C5, C6 and C7, and C4, C5, C6 and C7 are connected in parallel, and the two groups of second electrolytic capacitors are C8 and C9, and C8 and C9 are connected in parallel.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] When powered on: the input AC 220V voltage is converted into AC 300V voltage through the transformer, and an alternating oscillating electric field is formed between the ion probe and the burner shell, which is applied to the flame to generate ion current; after the ion current passes through the filter circuit, it charges the capacitor. When the capacitor is fully charged, it discharges to form an effective output high-level signal; the output effective high-level signal drives the linkage circuit composed of three transistors to output an effective low-level signal;

[0019] The effective low-level signal output makes the relay coil conduct and attract, so that the common pin of the output terminal is conducted with the normally open pin. The controller can determine the current flame state by reading the level of the normally open or normally closed pin of the output terminal. It can not only realize rapid detection of flame state, but also adapt to relatively harsh working environment and ensure the reliability of flame state detection. The specially designed short-circuit / leakage protection module can also discharge the current in time when the ion probe has a short-circuit or leakage problem, effectively improving the safety of the detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A circuit diagram of an oscillating electric field generating module of the structure of the present invention;

[0021] Figure 2 A circuit diagram of an ion current charging and discharging module of the structure of the present invention;

[0022] Figure 3 A circuit diagram of a drive control module of the structure of the present invention;

[0023] Figure 4 A circuit diagram of a signal output module of the structure of the present invention;

[0024] Figure 5 The circuit diagram of the short circuit / leakage protection module of the present invention is shown in FIG.

[0025] In the figure: 1. Oscillating electric field generating module; 11. Transformer; 12. Fuse; 13. Rectifier bridge; 14. First electrolytic capacitor; 15. Current limiting resistor; 16. Filter capacitor a; 17. Ion probe; 18. Varistor; 2. Ion current charging and discharging module; 21. Second working resistor; 22. Filter capacitor b; 23. Second electrolytic capacitor; 24. First diode; 25. Burner casing; 3. Drive control module; 31. Transistor a; 32. Resistor structure; 33. Third diode; 4. Signal output module; 41. Relay; 42. Second diode; 43. Terminal block; 5. Short circuit / leakage protection module; 51. Transistor b; 52. First working resistor. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0027] Specific implementation method 1: Please refer to Figure 1-5 The present invention provides a technical solution: an ion flame detection method for a heating furnace burner, the detection method comprising the following steps: oscillating electric field generation, ion current charging and discharging, drive control and signal output:

[0028] Step A. Oscillating electric field generation: After power is turned on, the input AC 220V voltage is converted into AC 300V voltage through the transformer 11, and an alternating oscillating electric field is formed between the ion probe 17 and the burner housing 25, which is applied to the flame to generate ion current;

[0029] Step B. charging and discharging of ion current: after the ion current passes through the filter circuit, it charges the capacitor, and when the capacitor is fully charged, it discharges to form an effective output high-level signal;

[0030] Step C. drive control: the effective high-level signal outputted from step B drives the linkage circuit composed of three transistors to output an effective low-level signal;

[0031] Step D. Signal output; The effective low-level signal outputted in step C turns on the coil of relay 41 and closes it, thereby turning on the common pin of output terminal 43 and the normally open pin.

[0032] After power is turned on, the input AC 220V voltage is converted into AC 300V voltage through transformer 11, and an alternating oscillating electric field is formed between the ion probe 17 and the burner housing 25, which is applied to the flame to generate ion current; after the ion current passes through the filter circuit, the capacitor is charged, and when the capacitor is fully charged, it is discharged to form an effective output high-level signal; the output effective high-level signal drives the linkage circuit composed of three transistors to output an effective low-level signal; the output effective low-level signal turns on and attracts the coil of the relay 41, so that the common pin of the output terminal 43 is turned on with the normally open pin, and the controller can judge the current flame state by reading the level of the normally open or normally closed pin of the output terminal; not only can the flame state be detected quickly, but also it can adapt to a relatively harsh working environment and ensure the reliability of flame state detection; the specially designed short-circuit / leakage protection module 5 can also discharge the current in time when the ion probe 17 has a short-circuit or leakage problem, effectively improving the safety of the detection circuit.

[0033] Specific implementation method two: This implementation method is a further limitation of specific implementation method one. The oscillating electric field generation in step A is implemented by an oscillating electric field generation module 1. The oscillating electric field generation module includes a transformer 11, a fuse 12, a rectifier bridge 13, a first electrolytic capacitor 14, a current limiting resistor 15, a filter capacitor a16, an ion probe 17 and a varistor 18. The oscillating electric field generation module 1 is connected to the short-circuit / leakage protection module 5 and the drive control module 3 through Net1.

[0034] like Figure 1 As shown: the oscillating electric field generating module 1 converts the input AC 220V voltage into a DC 24V voltage through a transformer 11 for powering other circuits; at the same time, it converts it into another AC 300V voltage for powering the ion probe 17, generating an oscillating electric field with a frequency of about 50Hz.

[0035] Specific implementation method three: This implementation method is a further limitation of specific implementation method two. The short circuit / leakage protection module 5 includes a transistor b51 and a first working resistor 52, and the first working resistor 52 is provided in two groups. Meanwhile, the transistor b51 and the first working resistor 52 are electrically connected.

[0036] like Figure 5 As shown: when the ion probe 17 is short-circuited or there is a serious leakage between the probe and the burner housing 25, an effective high level is generated at the Net1 end, the transistor b51Q1 is turned on, and the short-circuit current or leakage current is discharged to the COM end through the first working resistor 52R3.

[0037] Specific implementation method four: This implementation method is a further limitation of specific implementation method two. The drive control module 3 includes a transistor a31, a resistance structure 32 and a third diode 33. The transistor a31 is set to three groups, and the resistance structure 32 is set to seven groups. One end of the drive control module 3 is connected to the ion current charging and discharging module 2 through Net2, and the other end of the drive control module 3 is connected to the signal output module 4 through Net3; the transistor a31 is electrically connected to the resistance structure 32, and the three groups of transistors a31 are Q2, Q3 and Q4, and Q2, Q3 and Q4 are connected in series. At the same time, the seven groups of resistance structures 32 are R10, R11, R12, R13, R14, R15 and R16.

[0038] Specific implementation mode five: This implementation mode is a further limitation of specific implementation mode four. The signal output module 4 includes a relay 41, a second diode 42 and a terminal 43, and the signal output module 4 is connected to the drive control module 3 through Net3. The relay 41, the second diode 42 and the terminal 43 are electrically connected.

[0039] like Figure 4 As shown: when there is no flame, the drive control module outputs an invalid level signal to make relay 41 not energized, and the common pin is connected to the normally closed pin; when there is flame, the drive control module outputs a valid low level signal to make 41 energized, and the common pin is connected to the normally open pin; the normally closed or normally open pin is connected to the controller, and the controller determines the flame state through the level signal output by the normally closed or normally open pin.

[0040] Specific embodiment six: This embodiment is a further limitation of specific embodiment four. The ion current charge and discharge module 2 includes a second working resistor 21, a filter capacitor b22, a second electrolytic capacitor 23, a first diode 24 and a burner casing 25, and the second working resistor 21 is set to five groups, and the second electrolytic capacitor 23 is set to two groups, and the filter capacitor b22 is set to four groups. The five groups of second working resistors 21 are R5, R6, R7, R8 and R9, and R5, R6, R7 and R8 are connected in series, the four groups of filter capacitors b22 are C4, C5, C6 and C7, and C4, C5, C6 and C7 are connected in parallel, and the two groups of second electrolytic capacitors 23 are C8 and C9, and C8 and C9 are connected in parallel.

[0041] like Figure 2As shown: the input end of the ion current charging and discharging module 2 is connected to the burner casing 25, and the burner casing 25 is connected to the ground; the main function of this module is: through the oscillating electric field, the ion current generated by the flame is input through the burner casing 25 to charge and discharge the electrolytic capacitor, thereby generating a correspondingly transformed output voltage at both ends of the electrolytic capacitor for driving the back-end circuit; wherein, the five groups of second working resistors 21 are R5, R6, R7, R8 and R9, respectively, and the four groups of filter capacitors b22 are C4, C5, C6 and C7, R5 to R7; capacitors C5 to C7 constitute a three-stage low-pass filter circuit.

[0042] like Figure 3 As shown: three sets of transistors a31 and resistor structure 32 form a linkage control circuit, and the ion current is a voltage signal generated by the capacitor charging and discharging to drive this linkage control circuit, so that an effective low-level signal is generated when there is a flame; specifically:

[0043] like Figure 3 As shown: when there is flame, Net2 inputs a valid high level signal, Q2 is turned on, Q3 is turned off, Q4 is turned on, and Net3 outputs a valid low level signal; when there is no flame, Net2 inputs an invalid level signal, Q2 is turned off, Q3 is turned on, Q4 is turned off, and Net3 outputs an invalid level signal.

[0044] Although 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 the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ion flame detection method for a heating furnace burner, the detection method comprising the following steps: oscillating electric field generation, ion current charging and discharging, drive control and signal output, characterized in that: Step A. generating an oscillating electric field; after power is turned on, the input AC 220V voltage is converted into an AC 300V voltage through a transformer, and an alternating oscillating electric field is formed between the ion probe (17) and the burner housing (25), which is applied to the flame to generate an ion current; Step B. ion current charging and discharging; After the ion current passes through the filter circuit, it charges the capacitor. When the capacitor is fully charged, it discharges to form an effective output high-level signal. Step C. drive control: the effective high-level signal outputted from step B drives the linkage circuit composed of three transistors to output an effective low-level signal; Step D. Signal output; The effective low-level signal outputted from step C turns on the coil of the relay (41) and closes, thereby turning on the common pin of the output terminal and the normally open pin.

2. The ion flame detection method for a heating furnace burner according to claim 1, characterized in that: The oscillating electric field generation in step A is implemented by an oscillating electric field generation module (1), which comprises a transformer (11), a fuse (12), a rectifier bridge (13), a first electrolytic capacitor (14), a current limiting resistor (15), a filter capacitor a (16), an ion probe (17) and a varistor (18), and the oscillating electric field generation module (1) is connected to the short-circuit / leakage protection module (5) and the drive control module (3) via Net1.

3. The ion flame detection method for a heating furnace burner according to claim 2, characterized in that: The short circuit / leakage protection module (5) comprises a transistor b (51) and a first working resistor (52), and the first working resistor (52) is arranged in two groups, and the transistor b (51) and the first working resistor (52) are electrically connected.

4. The ion flame detection method for a heating furnace burner according to claim 2, characterized in that: The drive control module (3) comprises a transistor a (31), a resistance structure (32) and a third diode (33); the transistor a (31) is arranged in three groups, the resistance structure (32) is arranged in seven groups, and one end of the drive control module (3) is connected to the ion current charging and discharging module (2) via Net2, and the other end of the drive control module (3) is connected to the signal output module (4) via Net3; the transistor a (31) is electrically connected to the resistance structure (32), and the three groups of transistors a (31) are respectively Q2, Q3 and Q4, and Q2, Q3 and Q4 are connected in series, and the seven groups of resistance structures (32) are respectively R10, R11, R12, R13, R14, R15 and R16.

5. The ion flame detection method for a heating furnace burner according to claim 4, characterized in that: The signal output module (4) comprises a relay (41), a second diode (42) and a wiring terminal (43), and the signal output module (4) is connected to the drive control module (3) via Net3, and the relay (41), the second diode (42) and the wiring terminal (43) are electrically connected.

6. The ion flame detection method for a heating furnace burner according to claim 4, characterized in that: The ion current charge and discharge module (2) comprises a second working resistor (21), a filter capacitor b (22), a second electrolytic capacitor (23), a first diode (24) and a burner casing (25), wherein the second working resistor (21) is arranged in five groups, the second electrolytic capacitor (23) is arranged in two groups, and the filter capacitor b (22) is arranged in four groups, the five groups of second working resistors (21) are respectively R5, R6, R7, R8 and R9, and R5, R6, R7 and R8 are connected in series, the four groups of filter capacitors b (22) are respectively C4, C5, C6 and C7, and C4, C5, C6 and C7 are connected in parallel, and the two groups of second electrolytic capacitors (23) are respectively C8 and C9, and C8 and C9 are connected in parallel.

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