A backfire prevention control system

Abstract

The present invention discloses a backfire prevention control system. The system includes a gas pipeline, on which a gas regulating valve, a first temperature sensing element, a first flame detection element, and a combustion device are sequentially provided; a first nitrogen pipeline, on which a first nitrogen control valve is provided; a programmable logic controller (PLC) control cabinet, wherein a first output terminal of the PLC control cabinet is connected to the gas regulating valve, and a second output terminal is connected to the first nitrogen control valve; and a host computer, which is connected to an input terminal of the PLC control cabinet and transmits a received first temperature signal and a first flame signal to the host computer. The host computer is configured to determine whether a fire exists in the gas pipeline based on the first temperature signal and / or the first flame signal, and, when a fire exists, transmits a first control signal to the PLC control cabinet to control the opening of the first nitrogen control valve and the reduction of the opening of the gas regulating valve to a set opening. The present invention can remotely extinguish fires in gas pipelines and combustion devices, eliminating the need for manual operation and eliminating safety hazards.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of backfire prevention, and in particular to a backfire prevention control system. Background Art

[0002] Currently, when a flashback occurs, the only solution is to shut down the gas system (by shutting down the gas boiler). During this time, the flashback escalates, endangering equipment and personnel, and even the safety of the gas pipeline network. Because a flashback requires on-site personnel to open the appropriate valves and extinguish the fire in the gas pipeline and combustion device, the flashback escalates while personnel are on site, posing a serious safety hazard. Summary of the Invention

[0003] The present invention provides an anti-backfire control system to realize remote and automatic execution of corresponding actions to extinguish fires in gas pipelines and combustion devices, without the need for staff to go to the site for manual operation, thus eliminating the safety hazards caused by manual operation.

[0004] An embodiment of the present invention provides an anti-backfire control system, which includes:

[0005] A gas pipeline, on which a gas regulating valve, a first temperature sensing element, a first flame detection element and a combustion device are sequentially arranged;

[0006] a first nitrogen pipeline, wherein a first nitrogen control valve is provided on the first nitrogen pipeline, one end of the first nitrogen pipeline is connected to the gas pipeline between the gas regulating valve and the first temperature sensing element, and the other end of the first nitrogen pipeline is used for inputting nitrogen;

[0007] A PLC control cabinet, wherein a first output end of the PLC control cabinet is connected to the gas regulating valve, and a second output end of the PLC control cabinet is connected to the first nitrogen control valve;

[0008] The first temperature sensing element is used to detect the temperature of the gas pipeline between the gas regulating valve and the combustion device and send a first temperature signal to the PLC control cabinet; the first flame detection element is used to detect the flame condition of the gas pipeline between the gas regulating valve and the combustion device and send a first flame signal to the PLC control cabinet;

[0009] A host computer is connected to the input end of the PLC control cabinet, and the PLC control cabinet is used to send the received first temperature signal and the first flame signal to the host computer; the host computer is used to determine whether there is a fire in the gas pipeline based on the first temperature signal and / or the first flame signal, and when there is a fire, send a first control signal to the PLC control cabinet, so that the PLC control cabinet controls the first nitrogen control valve to open and controls the opening of the gas regulating valve to be reduced to a set opening.

[0010] Optionally, a gas quick-cut valve is further provided on the gas pipeline, and the gas quick-cut valve is located between the gas regulating valve and the first temperature sensing element;

[0011] One end of the first nitrogen pipeline is connected to the gas pipeline between the gas quick-cut valve and the first temperature sensing element, and the other end is used for inputting nitrogen;

[0012] The third output terminal of the PLC control cabinet is connected to the gas quick-cut valve;

[0013] The host computer is further configured to send a second control signal to the PLC control cabinet when a fire occurs, so that the PLC control cabinet controls the gas quick-cut valve to close.

[0014] Optionally, when the host computer determines that the fire is over based on the first temperature signal and the first flame signal, it sends a third control signal to the PLC control cabinet, so that the PLC control cabinet controls the gas quick-cut valve to open, the gas regulating valve to increase its opening, and the first nitrogen control valve to close.

[0015] Optionally, the anti-backfire control system further comprises a second temperature sensing element and a second flame detection element sequentially installed between the gas regulating valve and the gas quick cut-off valve;

[0016] a second nitrogen pipeline, wherein a second nitrogen control valve is provided on the second nitrogen pipeline, one end of the second nitrogen pipeline is connected to the gas pipeline between the gas quick-cut valve and the second temperature sensing element, and the other end is used for inputting nitrogen;

[0017] The fourth output end of the PLC control cabinet is connected to the second nitrogen control valve, the second temperature sensing element is used to detect the temperature of the gas pipeline between the gas regulating valve and the gas quick-cut valve and send a second temperature signal to the PLC control cabinet, the second flame detection element is used to detect the flame condition of the gas pipeline between the gas regulating valve and the gas quick-cut valve and send a second flame signal to the PLC control cabinet, and the PLC control cabinet is used to send the collected second temperature signal and second flame signal to the host computer;

[0018] The host computer is used to determine whether there is a fire in the gas pipeline based on the second temperature signal and / or the second flame signal, and when a fire exists, sends a fourth control signal to the PLC control cabinet, so that the PLC control cabinet controls the second nitrogen control valve to open, the opening of the gas regulating valve to be reduced to a set opening, and the gas quick-cut valve to be closed.

[0019] Optionally, the host computer is used to determine that the fire is over based on the second temperature signal and the second flame signal, and send a fifth control signal to the PLC control cabinet, so that the PLC control cabinet controls the gas quick-cut valve to open, the gas regulating valve to increase the opening, and the second nitrogen control valve to close.

[0020] Optionally, the host computer is configured to determine that there is a fire in the gas pipeline between the gas regulating valve and the combustion device when the first temperature signal is greater than a set threshold and / or when the presence of an open flame is determined according to the first flame signal;

[0021] The host computer is used to determine whether there is a fire in the gas pipeline between the gas regulating valve and the gas quick-cut valve when the second temperature signal is greater than a set threshold and / or when the presence of an open flame is determined based on the second flame signal.

[0022] Optionally, the host computer is configured to send a fourth control signal to the PLC control cabinet when determining that the fire is over based on the first temperature signal and the first flame signal, so that the PLC control cabinet controls the gas quick-cut valve to open.

[0023] Optionally, the anti-backfire control system further includes:

[0024] An on-site remote switching control cabinet, the on-site remote switching control cabinet being connected to the host computer, and the on-site remote switching control cabinet being used to send a remote control signal to the host computer, so that the host computer can send a control signal to the PLC control cabinet;

[0025] The local remote switching control cabinet is also used to send a local control signal to the host computer, so that the host computer cannot send a control signal to the PLC control cabinet.

[0026] Optionally, the host computer is further used to obtain a control instruction input by a user, and send a sixth control signal to the PLC control cabinet according to the control instruction, so that the PLC control cabinet controls the first nitrogen control valve, the second nitrogen control valve, the gas regulating valve and the gas quick-cut valve.

[0027] Optionally, the set threshold is greater than or equal to 150 degrees.

[0028] Optionally, the set opening is less than or equal to 5%.

[0029] The technical solution of this embodiment uses a first temperature sensing element to detect the temperature of the gas pipeline between the gas regulating valve and the combustion device and sends a first temperature signal to the PLC control cabinet. The first flame detection element detects the flame condition of the gas pipeline between the gas regulating valve and the combustion device and sends a first flame signal to the PLC control cabinet. A host computer is connected to the input end of the PLC control cabinet, and the PLC control cabinet sends the received first temperature signal and first flame signal to the host computer. The host computer determines whether there is a fire in the gas pipeline based on the first temperature signal and / or the first flame signal. When a fire is present, the host computer sends a first control signal to the PLC control cabinet, causing the PLC control cabinet to control the opening of the first nitrogen control valve and the reduction of the opening of the gas regulating valve, thereby achieving backfire prevention or fire extinguishing in the gas pipeline. The technical solution of this embodiment solves the problem that when a backfire accident occurs, workers need to go to the site to open the corresponding valves and extinguish the gas pipeline, which poses a serious safety hazard to workers operating on site. The technical solution of this embodiment can realize remote and automatic execution of corresponding actions to extinguish the gas pipeline fire, eliminating the need for workers to go to the site for manual operation, thereby eliminating the safety hazards caused by manual operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic structural diagram of an anti-backfire control system provided by an embodiment of the present invention;

[0031] Figure 2 This is a structural diagram of another anti-backfire control system provided by an embodiment of the present invention;

[0032] Figure 3 This is a structural diagram of another anti-backfire control system provided by an embodiment of the present invention;

[0033] Figure 4 This is a structural diagram of another anti-backfire control system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0035] Figure 1 A schematic diagram of the structure of an anti-backfire control system provided by an embodiment of the present invention, referring to Figure 1The anti-backfire control system includes: a gas pipeline 1, on which a gas regulating valve 2, a first temperature sensing element 3, a first flame detection element 4 and a combustion device 5 are sequentially arranged; a first nitrogen pipeline 6, on which a first nitrogen control valve 7 is arranged, one end of the first nitrogen pipeline 6 is connected to the gas pipeline 1 between the gas regulating valve 2 and the first temperature sensing element 3, and the other end is used to input nitrogen; a PLC control cabinet 8, a first output end of the PLC control cabinet 8 is connected to the gas regulating valve 2, and a second output end of the PLC control cabinet 8 is connected to the first nitrogen control valve 7; the first temperature sensing element 3 is used to detect the temperature of the gas pipeline 1 between the gas regulating valve 2 and the combustion device 5 and ... The signal is sent to the PLC control cabinet 8, the first flame detection element 4 is used to detect the flame condition of the gas pipeline 1 between the gas regulating valve 2 and the combustion device 5 and send the first flame signal to the PLC control cabinet 8; the host computer 9 is connected to the input end of the PLC control cabinet 8, and the PLC control cabinet 8 is used to send the received first temperature signal and the first flame signal to the host computer 9; the host computer 9 is used to determine whether there is a fire in the gas pipeline 1 according to the first temperature signal and / or the first flame signal, and when there is a fire, send a first control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the first nitrogen control valve 7 to open and controls the opening of the gas regulating valve 2 to be reduced to the set opening.

[0036] Specifically, the combustion device 5 includes a burner 51, a swirl plate 52, and an air distribution duct 53. The host computer 9 is used to determine whether there is a fire in the gas pipeline 1 based on the first temperature signal and / or the first flame signal. The host computer 9 can determine whether there is a fire based on the first temperature signal, or the host computer 9 determines whether there is a fire based on the first flame signal, or the host computer 9 determines whether there is a fire based on the first temperature signal and the first flame signal. If a backfire fault occurs in the gas pipeline 1 or there are signs of backfire, the host computer 9 sends a first control signal to the PLC control cabinet 8, causing the PLC control cabinet 8 to control the first nitrogen control valve 7 to open, and nitrogen enters the gas pipeline 1 through the first nitrogen pipeline 6 to extinguish the fire; the PLC control cabinet 8 controls the opening of the gas regulating valve 2 to be reduced to the set opening, thereby preventing the gas pipeline 1 from backfire.

[0037] Optionally, the opening degree is set to be less than or equal to 5%.

[0038] Among them, the opening of the gas regulating valve 2 can be adjusted to 5% of the maximum opening, which can not only reduce the flow rate and concentration of the gas entering the gas pipeline 1, but also avoid excessive pressure difference between the inside and outside of the gas pipeline 1 after the gas regulating valve 2 is completely closed, thereby avoiding accidents.

[0039] The technical solution of this embodiment uses a first temperature sensing element to detect the temperature of the gas pipeline between the gas regulating valve and the combustion device and sends a first temperature signal to the PLC control cabinet. A first flame detection element detects the flame condition of the gas pipeline between the gas regulating valve and the combustion device and sends a first flame signal to the PLC control cabinet. A host computer is connected to an input end of the PLC control cabinet, and the PLC control cabinet sends the received first temperature signal and first flame signal to the host computer. The host computer determines whether there is a fire in the gas pipeline based on the first temperature signal and / or the first flame signal. When a fire is present, the host computer sends a first control signal to the PLC control cabinet, causing the PLC control cabinet to control the opening of the first nitrogen control valve and the opening of the gas regulating valve to be reduced to a set opening, thereby achieving backfire prevention or fire extinguishing in the gas pipeline. The technical solution of this embodiment solves the problem that when a backfire accident occurs, workers need to go to the site to open the corresponding valves and extinguish the gas pipeline, which poses a serious safety hazard to workers operating on site. The technical solution of this embodiment can realize remote and automatic execution of corresponding actions to extinguish the gas pipeline fire, eliminating the need for workers to go to the site for manual operation, thereby eliminating the safety hazards caused by manual operation.

[0040] Figure 2 This is another structural diagram of an anti-backfire control system provided by an embodiment of the present invention, refer to Figure 2 Optionally, a gas quick-cut valve 10 is further provided on the gas pipeline 1, and the gas quick-cut valve 10 is located between the gas regulating valve 2 and the first temperature sensing element 3;

[0041] One end of the first nitrogen pipeline 6 is connected to the gas pipeline 1 between the gas quick cut-off valve 10 and the first temperature sensing element 3, and the other end is used to input nitrogen;

[0042] The third output terminal of the PLC control cabinet 8 is connected to the gas quick-cut valve 2;

[0043] The host computer 9 is further configured to send a second control signal to the PLC control cabinet 8 when a fire occurs, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to close.

[0044] Specifically, the host computer 9 determines whether there is a fire in the gas pipeline 1 between the gas quick-cut valve 10 and the burner 51 based on the first temperature signal detected by the first temperature sensing element 3 and / or the first flame signal detected by the first flame detection element 4. If there is a fire, it indicates that the burner 51 has a backfire fault or a backfire sign. The host computer 9 sends a second control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to close, cutting off the flow of gas in the gas pipeline 1. The PLC control cabinet 8 controls the first nitrogen control valve 7 to open, and nitrogen enters the gas pipeline 1 through the first nitrogen pipeline 6 to extinguish the fire, thereby preventing the backfire of the burner 51.

[0045] Continue to refer Figure 2 Optionally, the host computer 9 is used to determine that the fire is over according to the first temperature signal and the first flame signal, and send a third control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to open, the gas regulating valve 2 to increase its opening, and the first nitrogen control valve 7 to close.

[0046] Specifically, when the upper computer determines that the fire of the burner 51 has ended based on the first temperature signal and the first flame signal, it sends a third control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to open, so that the gas can flow normally in the gas pipeline 1 between the gas quick-cut valve 10 and the burner 51; the gas regulating valve 2 is opened to a larger degree, so that the gas can flow normally in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10; and the first nitrogen control valve 7 is controlled to be closed, so that nitrogen no longer enters the gas pipeline 1 through the first nitrogen pipeline 6.

[0047] Figure 3 This is another structural diagram of an anti-backfire control system provided by an embodiment of the present invention, refer to Figure 3 Optionally, the anti-backfire control system further includes: a second temperature sensing element 11 and a second flame detection element 12 sequentially installed between the gas regulating valve 2 and the gas quick cut-off valve 10;

[0048] A second nitrogen pipeline 13 is provided with a second nitrogen control valve 14. One end of the second nitrogen pipeline 13 is connected to the gas pipeline 1 between the gas quick-cut valve 10 and the second temperature sensing element 11, and the other end is used for inputting nitrogen;

[0049] The fourth output terminal of the PLC control cabinet 8 is connected to the second nitrogen control valve 14. The second temperature sensing element 11 is used to detect the temperature of the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10 and send a second temperature signal to the PLC control cabinet 8. The second flame detection element 12 is used to detect the flame condition of the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10 and send a second flame signal to the PLC control cabinet 8. The PLC control cabinet 8 is used to send the collected second temperature signal and second flame signal to the host computer 9.

[0050] The host computer 9 is used to determine whether there is a fire in the gas pipeline 1 based on the second temperature signal and / or the second flame signal. When a fire exists, it sends a fourth control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the second nitrogen control valve 14 to open, the opening of the gas regulating valve 2 to be reduced to the set opening, and the gas quick-cut valve 10 to be closed.

[0051] Specifically, the host computer 9 determines whether there is a fire in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10 based on the second temperature signal and / or the second flame signal. This can be: the host computer 9 determines whether there is a fire based on the second temperature signal, or the host computer 9 determines whether there is a fire based on the second flame signal, or the host computer 9 determines whether there is a fire based on the second temperature signal and the second flame signal. When there is a fire, the host computer 9 sends a fourth control signal to the PLC control cabinet 8, causing the PLC control cabinet 8 to control the second nitrogen control valve 14 to open, allowing nitrogen to enter the gas pipeline 1 through the second nitrogen pipeline 13 and extinguish the fire; control the opening of the gas regulating valve 2 to be reduced to a set opening, reducing the flow rate and concentration of the gas entering the gas pipeline 1; and control the gas quick-cut valve 10 to be closed, thereby cutting off the flow of gas in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10, thereby preventing backfire in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10.

[0052] On the basis of the above embodiment, when there is a fire in the gas pipeline 1 between the gas quick-cut valve 10 and the burner 51, the host computer 9 sends a control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to close, cuts off the flow of gas in the gas pipeline 1, controls the opening of the gas regulating valve 2 to be reduced to the set opening, reduces the flow rate and concentration of the gas entering the gas pipeline 1, controls the first nitrogen control valve 7 to open, and nitrogen enters the gas pipeline 1 through the first nitrogen pipeline 6 to extinguish the fire. The PLC control cabinet 8 controls the second nitrogen control valve 14 to open, and nitrogen enters the gas pipeline 1 through the second nitrogen pipeline 13 to extinguish the fire, thereby preventing the burner 51 from backfire.

[0053] The PLC control cabinet 8 collects the first temperature signal, the first flame signal, the second temperature signal, and the second flame signal, and sends the collected signals to the host computer. The host computer 9 determines the specific location of the fire based on the received signals, and then remotely sends corresponding signals to the PLC control cabinet 8. The PLC control cabinet 8 controls the first nitrogen control valve 7 to open, the second nitrogen control valve 14 to open, the opening of the gas regulating valve 2 to be reduced to the set opening, and the gas quick-cut valve 10 to be closed, so as to prevent the gas pipeline 1 and the burner 51 from backfire.

[0054] Continue to refer Figure 3 Optionally, the host computer 9 is used to determine that the fire is over according to the second temperature signal and the second flame signal, and send a fifth control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to open, the gas regulating valve 2 to increase its opening, and the second nitrogen control valve 14 to close.

[0055] Specifically, when the upper computer determines that the fire in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10 is over based on the second temperature signal and the second flame signal, it sends a fifth control signal to the PLC control cabinet 8, so that the PLC control cabinet 8 controls the gas quick-cut valve 10 to open, so that the gas flows normally in the gas pipeline 1 between the gas quick-cut valve 10 and the burner 51; the opening of the gas regulating valve 2 is increased, so that the gas flows normally in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10; the second nitrogen control valve 14 is controlled to be closed, and nitrogen no longer enters the gas pipeline 1 through the second nitrogen pipeline 13.

[0056] Optionally, the host computer is configured to determine that there is a fire in the gas pipeline between the gas regulating valve and the combustion device when the first temperature signal is greater than a set threshold and / or when the presence of an open flame is determined according to the first flame signal;

[0057] The host computer is used to determine that there is a fire in the gas pipeline between the gas regulating valve and the gas quick-cut valve when the second temperature signal is greater than a set threshold and / or when the presence of an open flame is determined according to the second flame signal.

[0058] Optionally, the set threshold is greater than or equal to 150 degrees.

[0059] When the first temperature signal is greater than or equal to 150°C and / or the first flame signal indicates the presence of an open flame, the host computer determines that a fire exists in the gas pipeline between the gas regulating valve and the combustion device. When the second temperature signal is greater than or equal to 150°C and / or the second flame signal indicates the presence of an open flame, the host computer determines that a fire exists in the gas pipeline between the gas regulating valve and the gas quick-cut valve.

[0060] Figure 4 This is another structural diagram of an anti-backfire control system provided by an embodiment of the present invention, refer to Figure 4 Optionally, the anti-backfire control system further includes:

[0061] The local remote switching control cabinet 15 is connected to the host computer 9. The local remote switching control cabinet 15 is used to send remote control signals to the host computer 9, so that the host computer can send control signals to the PLC control cabinet. The local remote switching control cabinet 15 is also used to send local control signals to the host computer 9, so that the host computer cannot send control signals to the PLC control cabinet 8.

[0062] Specifically, when the local remote switching control cabinet 15 sends a remote control signal, the system is in the remote control working mode. At this time, the interlocking software switch in the host computer is in the on state. The host computer 9 can remotely control the PLC control cabinet 8 to open the first nitrogen control valve 7, open the second nitrogen control valve 14, reduce the opening of the gas regulating valve 2 to the set opening, and control the gas quick-cut valve 10 to close, so as to realize the backfire of the gas pipeline 1 and prevent the burner 51.

[0063] When the local remote switching control cabinet 15 sends a local control signal, the system is in the local control working mode. At this time, the interlocking software switch in the upper computer is in the exit state. The upper computer 9 cannot control the PLC control cabinet 8 to open the first nitrogen control valve 7 and the second nitrogen control valve 14, cannot reduce the opening of the gas regulating valve 2 to the set opening, and cannot control the gas quick-cut valve 10 to close. The staff can only manually open the first nitrogen control valve 7 and the second nitrogen control valve 14 on site, reduce the opening of the gas regulating valve 2 to the set opening, and control the gas quick-cut valve 10 to close, so as to realize the backfire of the gas pipeline 1 and prevent the burner 51.

[0064] It should be noted that the interlocking software switch set in the host computer is designed to avoid confusion caused by simultaneous remote and local control. When the interlocking software switch is on, only remote control can be executed, and personnel on site cannot manually open the first nitrogen control valve 7 and the second nitrogen control valve 14. When the interlocking software switch is off, only local control can be executed, and the host computer 9 cannot remotely control the PLC control cabinet 8 to open the first nitrogen control valve 7 and the second nitrogen control valve 14.

[0065] Continue to refer Figure 4 Optionally, the host computer 9 is also used to obtain the control instructions input by the user, and send a sixth control signal to the PLC control cabinet 8 according to the control instructions, so that the PLC control cabinet 8 controls the first nitrogen control valve 7, the second nitrogen control valve 14, the gas regulating valve 2 and the gas quick-cut valve.

[0066] Specifically, when the first temperature sensing element 3, the first flame detection element 4, the second temperature sensing element 11 and the second flame detection element 12 all fail, and the staff finds that the gas pipeline 1 and the burner 51 have backfired or there are signs of backfire, the staff inputs the corresponding control instructions in the system interface of the upper computer 9. The upper computer 9 sends a sixth control signal to the PLC control cabinet 8 according to the instructions input by the user, so that the PLC control cabinet 8 controls the first nitrogen control valve 7 to open, and nitrogen enters the gas pipeline 1 through the first nitrogen pipeline 6 to extinguish the fire; the second nitrogen control valve 14 is opened, and nitrogen enters the gas pipeline 1 through the second nitrogen pipeline 13 to extinguish the fire; the opening of the gas regulating valve 2 is controlled to be reduced to the set opening, reducing the flow rate and concentration of the gas entering the gas pipeline 1; the gas quick-cut valve 10 is controlled to be closed, thereby cutting off the flow of gas in the gas pipeline 1 between the gas regulating valve 2 and the gas quick-cut valve 10; and finally preventing the backfire of the gas pipeline 1 and the burner 51.

[0067] Note that the above are only preferred embodiments of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments and may include many other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A backfire prevention control system, characterized in that: include: A gas pipeline, on which a gas regulating valve, a first temperature sensing element, a first flame detection element and a combustion device are sequentially arranged; a first nitrogen pipeline, wherein a first nitrogen control valve is provided on the first nitrogen pipeline, one end of the first nitrogen pipeline is connected to the gas pipeline between the gas regulating valve and the first temperature sensing element, and the other end of the first nitrogen pipeline is used for inputting nitrogen; A PLC control cabinet, wherein a first output end of the PLC control cabinet is connected to the gas regulating valve, and a second output end of the PLC control cabinet is connected to the first nitrogen control valve; The first temperature sensing element is used to detect the temperature of the gas pipeline between the gas regulating valve and the combustion device and send a first temperature signal to the PLC control cabinet; the first flame detection element is used to detect the flame condition of the gas pipeline between the gas regulating valve and the combustion device and send a first flame signal to the PLC control cabinet; a host computer connected to an input end of the PLC control cabinet, the PLC control cabinet being configured to send the received first temperature signal and the first flame signal to the host computer; the host computer being configured to determine whether a fire exists in the gas pipeline based on the first temperature signal and / or the first flame signal, and when a fire exists, sending a first control signal to the PLC control cabinet so that the PLC control cabinet controls the first nitrogen control valve to open and controls the opening of the gas regulating valve to be reduced to 5% of the maximum opening; The gas pipeline is further provided with a gas quick-cut valve, which is located between the gas regulating valve and the first temperature sensing element; One end of the first nitrogen pipeline is connected to the gas pipeline between the gas quick-cut valve and the first temperature sensing element, and the other end is used for inputting nitrogen; The third output terminal of the PLC control cabinet is connected to the gas quick-cut valve; The host computer is further configured to send a second control signal to the PLC control cabinet when a fire occurs, so that the PLC control cabinet controls the gas quick-cut valve to close.

2. The anti-backfire control system according to claim 1, characterized in that: The host computer is used to determine that the fire is over according to the first temperature signal and the first flame signal, and send a third control signal to the PLC control cabinet, so that the PLC control cabinet controls the gas quick-cut valve to open, the gas regulating valve to increase the opening, and the first nitrogen control valve to close.

3. The anti-backfire control system according to claim 1, characterized in that: Also includes: A second temperature sensing element and a second flame detection element are sequentially installed between the gas regulating valve and the gas quick cut-off valve; a second nitrogen pipeline, wherein a second nitrogen control valve is provided on the second nitrogen pipeline, one end of the second nitrogen pipeline is connected to the gas pipeline between the gas quick-cut valve and the second temperature sensing element, and the other end is used for inputting nitrogen; The fourth output end of the PLC control cabinet is connected to the second nitrogen control valve, the second temperature sensing element is used to detect the temperature of the gas pipeline between the gas regulating valve and the gas quick-cut valve and send a second temperature signal to the PLC control cabinet, the second flame detection element is used to detect the flame condition of the gas pipeline between the gas regulating valve and the gas quick-cut valve and send a second flame signal to the PLC control cabinet, and the PLC control cabinet is used to send the collected second temperature signal and second flame signal to the host computer; The host computer is used to determine whether there is a fire in the gas pipeline based on the second temperature signal and / or the second flame signal, and when a fire exists, sends a fourth control signal to the PLC control cabinet, so that the PLC control cabinet controls the second nitrogen control valve to open, the opening of the gas regulating valve to be reduced to a set opening, and the gas quick-cut valve to be closed.

4. The anti-backfire control system according to claim 3, characterized in that: The host computer is used to determine that the fire is over according to the second temperature signal and the second flame signal, and send a fifth control signal to the PLC control cabinet, so that the PLC control cabinet controls the gas quick-cut valve to open, the gas regulating valve to increase the opening, and the second nitrogen control valve to close.

5. The anti-backfire control system according to claim 3, characterized in that: The host computer is used to determine whether there is a fire in the gas pipeline between the gas regulating valve and the combustion device when the first temperature signal is greater than a set threshold and / or when the presence of an open flame is determined according to the first flame signal; The host computer is used to determine whether there is a fire in the gas pipeline between the gas regulating valve and the gas quick-cut valve when the second temperature signal is greater than a set threshold and / or when the presence of an open flame is determined based on the second flame signal.

6. The anti-backfire control system according to claim 1, characterized in that: Also includes: An on-site remote switching control cabinet, the on-site remote switching control cabinet being connected to the host computer, and the on-site remote switching control cabinet being used to send a remote control signal to the host computer, so that the host computer can send a control signal to the PLC control cabinet; The local remote switching control cabinet is also used to send a local control signal to the host computer, so that the host computer cannot send a control signal to the PLC control cabinet.

7. The anti-backfire control system according to claim 3, characterized in that: The host computer is further configured to obtain a control instruction input by a user, and send a sixth control signal to the PLC control cabinet according to the control instruction, so that the PLC control cabinet controls the first nitrogen control valve, the second nitrogen control valve, the gas regulating valve, and the gas quick-cut valve.

8. The anti-backfire control system according to claim 5, characterized in that: The set threshold is greater than or equal to 150 degrees.

Images