Ignition control method for heating furnace

Abstract

The invention belongs to the technical field of automatic ignition control, and particularly relates to a heating furnace ignition control method. The heating furnace ignition control method specifically comprises the steps that S1, the ignition condition of a heating furnace is reset to be in an initial state; s2, detecting and adjusting actual ignition conditions of the heating furnace; s3, when the target ignition condition is met, a fuel pipeline of a first incandescent light of the heating furnace is connected, and it is confirmed that a hand valve and an electromagnetic valve of the first incandescent light are closed; s4, the concentration of combustible gas in the cavity of the heating furnace is detected, and it is determined that the concentration of the combustible gas is lower than the explosion lower limit; s5, opening a hand valve of the first incandescent light, and sending an ignition instruction to control an ignition device to ignite; and S6, after the ignition instruction is sent out for a first preset time, the electromagnetic valve is controlled to be opened, the ignition device conducts ignition continuously, the ignition result is detected, if ignition succeeds, the electromagnetic valve is controlled to be opened, and if ignition fails, the electromagnetic valve is cut off, and ignition is stopped. In this way, the combustible gas is prevented from entering the hearth before ignition due to equipment failure or misoperation.

Description

Technical Field

[0001] This disclosure belongs to the field of automatic ignition control technology, and specifically relates to an ignition control method for a heating furnace. Background Technology

[0002] Heating furnaces are an important piece of equipment in hazardous chemical production enterprises. As open flame equipment, they are highly dangerous. In recent years, there have been many safety accidents caused by heating furnaces in China. In particular, during the ignition process, there is a risk of flash explosion caused by equipment failure or improper operation by personnel, which can easily lead to production safety accidents.

[0003] Existing heating furnaces lack remote automatic ignition of the automatic lamp and flameout interlock protection functions. Before ignition, the automatic lamp may cause combustible gas to enter the heating furnace cavity before ignition due to equipment failure or incorrect operation, which may lead to an accident. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a method for controlling the ignition of a heating furnace.

[0005] This disclosure provides a method for controlling the ignition of a heating furnace, the method comprising: S1. Reset the ignition conditions of the heating furnace to the initial state; S2. Detect and adjust the actual ignition conditions of the heating furnace; S3. When the target ignition conditions are met, connect the fuel line of the first lamp of the heating furnace and confirm that the manual valve and solenoid valve of the first lamp are closed. S4. Detect the concentration of combustible gas in the cavity of the heating furnace and determine that the concentration of combustible gas is lower than the lower explosive limit; S5. Open the hand valve of the first permanent light and issue an ignition command to control the ignition device to ignite; S6. After the ignition command is issued for a first preset time, the solenoid valve is controlled to open. The ignition device continuously ignites and detects the ignition result. If ignition is successful, the solenoid valve is controlled to remain open. If ignition fails, the solenoid valve is shut off and ignition stops.

[0006] In one embodiment of this disclosure, step S1 specifically includes: S11. Automatically reset the ignition conditions to the initial state according to the reset conditions. The specific reset conditions are ignition failure, ignition success, or the target ignition conditions being met for a second preset time. S12, Manually issue a reset command.

[0007] In one embodiment of this disclosure, step S2 specifically includes: S21. Determine that there is no flame detection signal inside the cavity of the heating furnace; S22. Determine that the interlock between the burner solenoid valve and the first solenoid valve of the heating furnace has not been triggered; S23. Displace the ventilation in the cavity of the heating furnace and continue for a third preset time; S24. Determine that the combustible gas inside the cavity of the heating furnace is qualified.

[0008] In one embodiment of this disclosure, the step of "displacement ventilation within the cavity of the heating furnace" specifically includes: Operating the fan; Adjust the opening degree of the flue damper of the heating furnace to ≥50%, and adjust the opening degree of the damper of the heating furnace to ≥50%.

[0009] In one embodiment of this disclosure, if any of the actual ignition conditions determined in step S2 disappears, the third preset time stops and returns to zero, and the target ignition conditions are no longer met.

[0010] In one embodiment of this disclosure, the first preset time is 2 seconds, and the continuous ignition time of the ignition device is ≤8 seconds; and / or, The second preset time is ≥30 min; and / or, The third preset time is ≥5 min.

[0011] In one embodiment of this disclosure, after ignition fails in step S6, the furnace cavity is forcibly ventilated for a third preset time, and after the fault is cleared, the process starts again from step S4.

[0012] In one embodiment of this disclosure, the furnace ignition control method further includes: S7. After the first lamp is successfully ignited, connect the fuel line corresponding to the other lamp, open the manual valve of the corresponding lamp, and issue an ignition command to ignite it, until the remaining lamps in the heating furnace are ignited one by one.

[0013] In one embodiment of this disclosure, the furnace ignition control method further includes: S8. Ignite the corresponding burners one by one with the continuous lamp in a diagonal order.

[0014] In one embodiment of this disclosure, step S8 specifically includes: S81. Connect the fuel line of the target burner to be ignited and open the hand valve of the target burner; S82. Ignite the target burner using the corresponding continuous lamp.

[0015] One of the beneficial effects of this disclosure is that the furnace ignition control method disclosed herein first completely disconnects the fuel line of the permanent lamp from the fuel line of the burner, preventing combustible gas from entering the furnace before ignition due to equipment failure or incorrect operation, thereby ensuring the inherent safety of the furnace ignition operation.

[0016] During ignition, the operator first resets the ignition conditions of the heating furnace to the initial state, clears the previous ignition record, restarts the ignition attempt count, triggers the control system to recheck all safety conditions, and restores valves and other structures to the initial ignition position to avoid the risk of explosion that may be caused by direct restart, and forces operation according to the safety procedure.

[0017] Afterwards, the actual ignition conditions of the heating furnace are checked and adjusted. When the target ignition conditions are met, the fuel pipeline of the first lamp of the heating furnace is connected, and it is confirmed that the manual valve and solenoid valve of the first lamp are closed to prevent fuel from leaking into the furnace or fuel pipeline in advance, which could cause the furnace to explode upon contact with ignition sparks or high temperatures, resulting in equipment damage and personnel casualties.

[0018] Furthermore, the concentration of combustible gas in the furnace cavity is detected. If the concentration of combustible gas is determined to be lower than the lower explosive limit, the hand valve of the first permanent light is opened, and an ignition command is issued. After the ignition command is issued for a first preset time, the solenoid valve is opened. The ignition result is detected. If the ignition is successful, the solenoid valve is kept open. If the ignition fails, the solenoid valve is shut off and the ignition is stopped.

[0019] Thus, this disclosure provides an automatic ignition control method for a heating furnace with safety protection procedures. Through automated control logic, it reduces the frequency of direct contact between operators and the high-temperature furnace, lowering the risk of personal injury. With a strict pre-ignition condition confirmation process, potential safety hazards such as fuel leaks and abnormal fan operation can be detected in advance, preventing accidents caused by faulty ignition from spreading to surrounding areas. Simultaneously, the standardized ignition operation procedure effectively avoids ignition failures due to human error, and the system has a rapid response mechanism for abnormal conditions such as ignition failure, which can immediately cut off the fuel supply to prevent continuous fuel leakage from causing a fire, ensuring the safety and stability of the heating furnace's ignition and operation. Attached Figure Description

[0020] Embodiments of this disclosure are illustrated in conjunction with the accompanying drawings, which are included and form part of this specification, and together with their description serve to explain the principles of this disclosure.

[0021] Figure 1 This is a schematic diagram of the ignition condition logic control of a heating furnace ignition control method provided in an embodiment of the present disclosure; Figure 2 This is a schematic diagram of the logic control of the solenoid valve for the continuous lamp in a heating furnace ignition control method provided in an embodiment of this disclosure; Figure 3 This is a schematic flowchart of a heating furnace ignition control method provided in an embodiment of the present disclosure; Figure 4 This is a schematic flowchart of a heating furnace ignition control method provided in another embodiment of this disclosure; Figure 5 This is a schematic flowchart of a heating furnace ignition control method provided in another embodiment of the present disclosure. Detailed Implementation

[0022] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0023] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0024] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0025] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0027] In this article, terms such as "up," "down," "front," "back," "left," and "right" are used only to indicate the relative positional relationship between related parts, rather than to define the absolute position of these related parts.

[0028] In this article, "first," "second," etc., are used only to distinguish one another, and not to indicate degree of importance, order, or prerequisite for each other.

[0029] In this document, terms such as “equal” and “same” are not strict mathematical and / or geometric limitations, but also include errors that are understandable to those skilled in the art and permissible in manufacturing or use.

[0030] Heating furnaces are an important piece of equipment in hazardous chemical production enterprises. As open flame equipment, they are highly dangerous. In recent years, there have been many safety accidents caused by heating furnaces in China. In particular, during the ignition process, there is a risk of flash explosion caused by equipment failure or improper operation by personnel, which can easily lead to production safety accidents.

[0031] Existing heating furnaces lack remote automatic ignition of the automatic lamp and flameout interlock protection functions. Before ignition, the automatic lamp may cause combustible gas to enter the heating furnace cavity before ignition due to equipment failure or incorrect operation, which may lead to an accident.

[0032] To this end, this disclosure provides a method for controlling the ignition of a heating furnace, which specifically includes: S1, resetting the ignition conditions of the heating furnace to the initial state; S2, detecting and adjusting the actual ignition conditions of the heating furnace; S3, when the target ignition conditions are met, connecting the fuel pipeline of the first permanent light of the heating furnace, and confirming that the manual valve and solenoid valve of the first permanent light are closed; S4, detecting the concentration of combustible gas in the furnace cavity and determining that the concentration of combustible gas is lower than the lower explosive limit; S5, opening the manual valve of the first permanent light and issuing an ignition command to control the ignition device to ignite; S6, after the ignition command is issued for a first preset time, controlling the solenoid valve to open, the ignition device to continuously ignite, and detecting the ignition result. If ignition is successful, the solenoid valve is kept open; if ignition fails, the solenoid valve is shut off and ignition is stopped.

[0033] The ignition control method for the heating furnace disclosed herein first completely disconnects the fuel line of the permanent lamp from the fuel line of the burner to prevent combustible gas from entering the furnace before ignition due to equipment failure or incorrect operation, thereby ensuring the inherent safety of the heating furnace ignition operation.

[0034] During ignition, the operator first resets the ignition conditions of the heating furnace to the initial state, clears the previous ignition record, restarts the ignition attempt count, triggers the control system to recheck all safety conditions, and restores valves and other structures to the initial ignition position to avoid the risk of explosion that may be caused by direct restart, and forces operation according to the safety procedure.

[0035] Afterwards, the actual ignition conditions of the heating furnace are checked and adjusted. When the target ignition conditions are met, the fuel pipeline of the first lamp of the heating furnace is connected, and it is confirmed that the manual valve and solenoid valve of the first lamp are closed to prevent fuel from leaking into the furnace or fuel pipeline in advance, which could cause the furnace to explode upon contact with ignition sparks or high temperatures, resulting in equipment damage and personnel casualties.

[0036] Furthermore, the concentration of combustible gas in the furnace cavity is detected. If the concentration of combustible gas is determined to be lower than the lower explosive limit, the hand valve of the first permanent light is opened, and an ignition command is issued. After the ignition command is issued for a first preset time, the solenoid valve is opened. The ignition result is detected. If the ignition is successful, the solenoid valve is kept open. If the ignition fails, the solenoid valve is shut off and the ignition is stopped.

[0037] Thus, this disclosure provides an automatic ignition control method for a heating furnace with safety protection procedures. Through automated control logic, it reduces the frequency of direct contact between operators and the high-temperature furnace, lowering the risk of personal injury. With a strict pre-ignition condition confirmation process, potential safety hazards such as fuel leaks and abnormal fan operation can be detected in advance, preventing accidents caused by faulty ignition from spreading to surrounding areas. Simultaneously, the standardized ignition operation procedure effectively avoids ignition failures due to human error, and the system has a rapid response mechanism for abnormal conditions such as ignition failure, which can immediately cut off the fuel supply to prevent continuous fuel leakage from causing a fire, ensuring the safety and stability of the heating furnace's ignition and operation.

[0038] For ease of understanding, please refer to the following: Figures 1 to 5 The working principle of the heating furnace ignition control method provided in this disclosure will be explained in detail with reference to the embodiments.

[0039] In one embodiment, the furnace ignition control method disclosed herein includes: S1. Reset the ignition conditions of the heating furnace to the initial state; S2. Detect and adjust the actual ignition conditions of the heating furnace; S3. When the target ignition conditions are met, connect the fuel line to the first lamp of the heating furnace and confirm that the manual valve and solenoid valve of the first lamp are closed. S4. Detect the concentration of combustible gas in the cavity of the heating furnace and determine that the concentration of combustible gas is below the lower explosive limit; S5. Open the hand valve of the first permanent light and issue an ignition command to control the ignition device to ignite; S6. After the ignition command is issued for the first preset time, the solenoid valve is opened, the ignition device continues to ignite, and the ignition result is detected. If ignition is successful, the solenoid valve is kept open; if ignition fails, the solenoid valve is shut off and ignition stops.

[0040] Combination Figure 1 and Figure 3 The heating furnace ignition control method disclosed herein first resets the ignition conditions of the heating furnace to the initial state, clears the previous ignition records, restarts the ignition attempt count, triggers the control system to recheck all safety conditions, and restores valves and other structures to the initial ignition position, avoiding the risk of explosion that may be caused by direct restart, and forcing operation according to the safety procedure.

[0041] Afterwards, the actual ignition conditions of the heating furnace are checked and adjusted. Before ignition, the fuel lines of the burner and the pilot light are completely disconnected. When the target ignition conditions are met, the fuel line of the first pilot light of the heating furnace is connected, and it is confirmed that the manual valve and solenoid valve of the first pilot light are closed to prevent fuel from leaking into the furnace or fuel line in advance. If the fuel leaks into the furnace or fuel line in time, it may cause an explosion in the furnace due to the ignition spark or high temperature, resulting in equipment damage and personnel casualties.

[0042] Furthermore, combined Figure 2 The system detects the concentration of combustible gas in the furnace chamber. If the concentration is below the lower explosive limit, the manual valve of the first pilot light is opened, issuing an ignition command. After a preset time following the issuance of this command, the solenoid valve opens, and the ignition result is detected. If ignition is successful, the solenoid valve remains open; otherwise, it closes and stops ignition. The solenoid valve promptly supplies gas to the pilot light, providing a combustible medium to the ignition electrode for rapid ignition. Once the pilot light is successfully ignited and a stable flame is formed, the solenoid valve remains open to continuously supply gas, maintaining the pilot light's constant flame and providing a reliable ignition source for the subsequent main burner. If the pilot light is accidentally extinguished due to airflow fluctuations, equipment malfunction, or when the furnace stops, the solenoid valve will respond to the control signal and quickly close, cutting off the fuel supply to the pilot light and preventing continuous gas leakage into the furnace chamber, thus avoiding the risk of forming an explosive gas mixture.

[0043] In one embodiment, the night lamp is a self-priming structure, and the night lamp is equipped with a night lamp burner, a natural air intake regulating damper and an ignition electrode. The gas ignites the air into the night lamp to form a premixed gas, and the electric spark generated by the ignition electrode ignites the premixed gas to form the night lamp flame.

[0044] Furthermore, this disclosure employs three basic logic gates—AND, OR, and NOT—as well as SR flip-flops to draw the logic circuit. Specifically, an AND gate outputs a valid state only when all input signals are valid; if any input is invalid, the output is invalid. An OR gate outputs a valid state only when any input signal is valid; if all inputs are invalid, the output is invalid. A NOT gate completely reverses the input and output states. SR flip-flops control and maintain the output state through set (S) and reset (R) signals. Specifically, set: input S is 1, R is 0, output Q is 1, output is set to 1, and stored as 1; reset: input S is 0, R is 1, output Q is 0, output is reset, and stored as 0; maintain: input S is 0, R is 0, output Q maintains its original state.

[0045] In detail, this disclosure ensures that ignition can only be performed after any actual ignition condition meets the target ignition condition through AND gates, and ensures that a reset is performed immediately whenever any reset condition is triggered through OR gates, and maintains the output state of the control logic circuit in conjunction with SR flip-flops to make the output of the logic circuit stable.

[0046] High-energy igniters convert direct current from a high-voltage power supply into a high-frequency pulsed current, which is then converted into sparks and arcs through ignition electrodes to serve functions such as ignition, combustion, heating, or as a light source. Currently, high-energy igniters are widely used, with common types including pulse discharge igniters, microwave plasma spark igniters, and plasma igniters.

[0047] A flame detector is an electronic device used to detect combustion in equipment or flames. It determines the presence of a flame by detecting its radiation wavelength and intensity. If the flame extinguishes or exhibits abnormal combustion, the flame detector promptly sends a signal to the control system, enabling the system to take appropriate measures to ensure the safety of equipment and personnel.

[0048] See Figure 1 and Figure 5 In one embodiment of this disclosure, step S1 specifically includes: S11. Automatically reset the ignition conditions to the initial state according to the reset conditions. The specific reset conditions are ignition failure, ignition success, or the target ignition conditions are met and the second preset time is reached. S12, Manually issue a reset command.

[0049] In detail, the furnace ignition control method disclosed herein is based on timing logic control and safety interlocking. Ignition failure is first determined and an automatic reset is triggered if any of the following conditions are met: after the ignition command is issued, the flame detector fails to detect a stable flame within a set time limit; the blower operation disappears during ignition; the induced draft fan operation disappears; the flue damper command is <50%; or the duct damper command is <50%. Afterward, the initial state of the ignition condition judgment logic is restored.

[0050] The criteria for successful ignition are: the lamp is burning stably, meaning that any solenoid valve command and the corresponding flame detection signal are present simultaneously, and key parameters such as fuel pressure, flow rate, and air pressure are all within the normal operating range. This avoids temporary parameters during the ignition phase affecting normal operation and reserves a clean initial state for possible subsequent shutdowns and restarts.

[0051] The system has met all the target ignition conditions, but ignition has not started. After the set time limit is reached, a reset is triggered. For example, if the operator does not issue an ignition command, the system will remain in a fuel-ready, ignition-ready state for a long time, reducing potential risks such as fuel valve leakage.

[0052] This ensures the safety and repeatability of the ignition process, avoids interlocking disruptions or secondary ignition risks caused by residual states, improves the system's automation level, forces the reset of the unignited state, prevents the system from being in a high-risk standby state for a long time, and reduces safety hazards when unattended.

[0053] See Figure 1and Figure 5 In one embodiment of this disclosure, step S2 specifically includes: S21. Determine that there is no flame detection signal inside the furnace cavity; S22. It is determined that the interlock between the burner solenoid valve and the first night lamp solenoid valve of the heating furnace has not been triggered. S23. Displace the ventilation in the furnace cavity and continue for a third preset time; S24. Confirm that the combustible gas inside the furnace cavity is qualified.

[0054] In detail, the absence of a flame detection signal in the furnace before ignition proves the absence of residual flames and continuous fuel combustion, eliminating the risk of hidden flames going undetected. If residual flames were present, the newly injected fuel during ignition would combine with the high-temperature internal environment, potentially triggering instantaneous deflagration. The absence of a flame detection signal ensures the furnace is in a safe, flameless initial state upon ignition. Simultaneously, pre-ignition purging ventilation is a crucial step in removing residual combustible gases. The presence of a flame detection signal indicates the possible continued combustion of incompletely burned fuel within the furnace; ventilation would accelerate airflow, potentially leading to flame spread or the diffusion of incomplete combustion products. Without a flame detection signal, purging can reduce the concentration of combustible gases in the furnace below the lower explosive limit through forced ventilation, eliminating the risk of explosion during ignition and ensuring the safety and effectiveness of purging ventilation.

[0055] Furthermore, the burner solenoid valve interlock is a safety interlock for the fuel supply valve of the heater burner. It can control ignition and provide emergency shut-off in case of abnormal operating conditions, ensuring that fuel is supplied only under safe conditions and is instantly shut off in case of abnormalities. The keep-on lamp solenoid valve interlock is an interlock for the fuel supply valve of the keep-on lamp. It can control the keep-on lamp ignition and provide emergency shut-off in case of flame loss, ensuring that the keep-on lamp is only turned on during the ignition preparation phase and that gas supply stops immediately after the flame is extinguished. The interlock system will not be triggered unless the furnace environment is safe, ensuring that there are no known safety hazards during ignition startup and avoiding major risks such as explosions, fires, and equipment damage from the source. Therefore, the system will only allow the ignition procedure to start if the safety conditions are met.

[0056] Afterwards, the furnace cavity is continuously ventilated for a third preset time. By starting the fan, air is forced to flow through the furnace and flue. The airflow displacement effect is used to discharge the remaining combustible gases, carbon monoxide, carbon black and other substances in the furnace, so that the concentration of combustible gases is reduced to the lower explosive limit.

[0057] See Figure 1 In one embodiment of this disclosure, the displacement ventilation within the heating furnace specifically includes: Operating the fan; Adjust the opening of the flue damper of the heating furnace to ≥50%, and adjust the opening of the damper of the heating furnace to ≥50%.

[0058] In detail, this disclosure uses an induced draft fan and a blower for displacement ventilation. The blower is a device that forcibly delivers clean air into the heating furnace, while the induced draft fan is a device that forcibly extracts the flue gas generated by combustion in the furnace and discharges it into the flue. By creating a negative pressure in the furnace, the flow of flue gas is guided, and the furnace pressure is adjusted in conjunction with the blower.

[0059] Flue dampers are adjustable baffles installed in the flue. By changing their opening degree, they control the cross-sectional area of ​​flue gas flow, adjust the flue gas emission resistance, and thus control the furnace negative pressure and flue gas flow rate. Air dampers are adjustable baffles installed at the blower outlet, burner inlet, or main air supply duct. By changing their opening degree, they control the air flow cross-sectional area, adjust the air supply volume and velocity, and provide a precisely proportioned air volume for fuel combustion. Working in conjunction with the induced draft fan, they create furnace negative pressure, preventing high-temperature flue gas and flames from escaping from furnace doors, observation holes, or sealing gaps due to furnace positive pressure. This prevents burns to operators or fires, inhibits flame from entering fuel pipelines, and protects fuel valves and burner nozzles.

[0060] See Figure 1 and Figure 5 In one embodiment of this disclosure, if any actual ignition condition determined in step S2 disappears, the third preset time stops and returns to zero, and the target ignition condition is no longer met.

[0061] In detail, during replacement ventilation, if any actual ignition condition disappears, the third preset time stops and resets to zero, indicating that ignition conditions are not met. The actual ignition conditions include the disappearance of any of the following: induced draft fan operation status, blower operation status, flue damper command ≥50%, or damper command ≥50%. Alternatively, if a reset condition is triggered, the third preset time stops and resets to zero.

[0062] See Figure 1 and Figure 4 In one embodiment of this disclosure, the first preset time is 2s, and the continuous ignition time of the ignition device is ≤8s; and / or, the second preset time is ≥30min; and / or, the third preset time is ≥5min.

[0063] In detail, in one embodiment, the first preset time is 2 seconds. This disclosure uses a high-energy igniter for ignition. The core function of the high-energy igniter is to generate a high-voltage electric spark to ignite the lamp. Therefore, the high-energy igniter ignites the lamp for the first preset time in advance to ensure that a stable spark has been formed before the fuel of the lamp enters the heating furnace. The high-temperature spark generated in advance preheats the air in the ignition area, improves the fuel atomization and combustion reaction rate, shortens the ignition delay time, and ensures that the fuel of the lamp comes into contact with the ignition source immediately after injection, reducing the residence time of the fuel in the heating furnace and avoiding ignition failure caused by uneven fuel distribution.

[0064] Furthermore, the ignition device has a continuous ignition time of ≤8s. Since the ignition of the lamp requires the process of gas injection and mixing with air to form a combustible mixture, the continuous ignition time prevents the lamp from failing due to improper timing of a single ignition, ensuring that the gas quickly contacts the continuous spark after being injected to complete the ignition and avoiding fuel accumulation.

[0065] In one embodiment, the second preset time is ≥30 minutes. If the system has met all ignition preconditions but has not received an ignition command within the second preset time and has not started ignition, the actual ignition conditions are automatically reset, restoring the logic state to its initial state. The validity of ignition conditions is time-sensitive. After the second preset time has elapsed, environmental factors may cause the original compliant ignition conditions to become invalid. After resetting, the system needs to be re-executed for testing to ensure that each ignition is based on fresh safety conditions, eliminating safety hazards caused by long wait times, and ensuring the standardization and repeatability of the ignition process.

[0066] In one embodiment, the third preset time is ≥5 minutes. Specifically, by extending the forced ventilation time, it is ensured that residual combustible gases and incompletely burned products in the furnace are completely replaced, thus eliminating the risk of deflagration from the source.

[0067] See Figure 1 , Figure 2 and Figure 4 In one embodiment of this disclosure, after ignition fails in step S6, the furnace cavity is forced to undergo displacement ventilation for a third preset time. After the fault is cleared, the process starts again from step S4.

[0068] In detail, after ignition failure, a certain amount of fuel has already been injected into the pilot light. If this fuel is not vented in time, it will mix with the air in the furnace to form an explosive mixture. Therefore, forced displacement ventilation is carried out in the heating furnace for at least the third preset time to ensure that the concentration of combustible gas in the furnace is below the lower explosive limit, that is, the combustible gas content is less than 0.2%. Even if fuel is injected again, an explosive gas mixture will not be formed. During the ventilation process, oxygen-deficient air is replaced, providing sufficient oxygen for secondary ignition and avoiding re-ignition failure due to insufficient oxygen. The heating furnace furnace flame detection and real-time flame video monitoring are implemented. The flame detection signal is interlocked with the fuel gas feed valve to prevent the formation of an explosive gas mixture after flameout, which could lead to flash explosions or explosions. See Figure 2 and Figure 5 In one embodiment of this disclosure, the furnace ignition control method further includes: S7. After the first lamp is successfully ignited, connect the fuel line corresponding to the other lamp, open the hand valve of the corresponding lamp, and issue an ignition command to ignite it, until the remaining lamps in the heating furnace are ignited one by one.

[0069] In detail, the industrial heating furnace is equipped with multiple continuous lamps to avoid the failure of a single continuous lamp and to cope with complex scenarios such as airflow disturbance, uneven temperature distribution, and fuel composition fluctuations in the furnace. Multiple ignition points can improve flame stability, and evenly distributed continuous lamps can ensure uniform mixing of air and fuel in the furnace, thereby improving combustion efficiency.

[0070] Once the first lamp is lit and burns stably, it indicates that a safe, stable, and combustible environment has been established within the furnace, providing the necessary conditions for the direct ignition of the remaining lamps. Each remaining lamp is equipped with an independent high-energy igniter, flame detector, fuel shut-off valve, and manual valve. Ignition is performed independently by activating the high-energy igniter, eliminating the need for repeated purging ventilation. The flame status is monitored independently after ignition. Furthermore, when igniting the remaining lamps one by one, the fuel line for that lamp is first connected, then the corresponding manual valve is opened, followed by ignition. Thus, based on the successful ignition of the first lamp, the remaining lamps can be ignited individually without the need for ignition condition checks.

[0071] See Figure 5 In one embodiment of this disclosure, the furnace ignition control method further includes: S8. Ignite the corresponding burners one by one using the continuous lamp in a diagonal order.

[0072] In detail, after all the lamps inside the heating furnace are lit, the corresponding burners are lit one by one in a diagonal sequence. The operation follows the order of lighting one pair of diagonal burners first, and then lighting the other pair after the initial ignition has stabilized. This avoids localized overheating and excessive temperature differences in the furnace caused by single-point or unilateral ignition, ensuring uniform heating of the material. Symmetrical ignition also allows for uniform expansion of the furnace body, reducing the risk of structural deformation due to temperature differences.

[0073] See Figure 5 In one embodiment of this disclosure, step S8 specifically includes: S81. Connect the fuel line of the target burner to be ignited and open the hand valve of the target burner; S82. Ignite the target burner using the corresponding continuous lamp.

[0074] In detail, after connecting the fuel line of the target burner to be ignited and opening the manual valve of the target burner, the operator evacuates, the central control personnel confirm ignition, and the target burner is ignited using the corresponding continuous light. Furthermore, when igniting the target burner, only the fuel line of that specific burner is connected, rather than connecting the fuel lines of multiple burners simultaneously. The airflow disturbance range created by the flame of a single burner is limited, preventing complex eddies within the furnace and avoiding fuel accumulation in dead zones, while simultaneously creating a stable airflow environment for subsequent burner ignition. After each burner is ignited, a 10-30 second stabilization period is allowed to verify the flame morphology and combustion completeness using a flame detector. Only after confirming there is no flameout or backfire should the next burner be ignited, avoiding the potential hazard of some burners failing to ignite undetected due to batch ignition.

[0075] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for controlling the ignition of a heating furnace, characterized in that, The furnace ignition control method includes: S1. Reset the ignition conditions of the heating furnace to the initial state; S2. Detect and adjust the actual ignition conditions of the heating furnace; S3. When the target ignition conditions are met, connect the fuel line of the first lamp of the heating furnace and confirm that the manual valve and solenoid valve of the first lamp are closed. S4. Detect the concentration of combustible gas in the cavity of the heating furnace and determine that the concentration of combustible gas is lower than the lower explosive limit; S5. Open the hand valve of the first permanent light and issue an ignition command to control the ignition device to ignite; S6. After the ignition command is issued for a first preset time, the solenoid valve is controlled to open. The ignition device continuously ignites and detects the ignition result. If ignition is successful, the solenoid valve is controlled to remain open. If ignition fails, the solenoid valve is shut off and ignition stops.

2. The furnace ignition control method according to claim 1, characterized in that, Step S1 specifically includes: S11. Automatically reset the ignition conditions to the initial state according to the reset conditions. The specific reset conditions are ignition failure, ignition success, or the target ignition conditions being met for a second preset time. S12, Manually issue a reset command.

3. The ignition control method for a heating furnace according to claim 2, characterized in that, Step S2 specifically includes: S21. Determine that there is no flame detection signal inside the cavity of the heating furnace; S22. Determine that the interlock between the burner solenoid valve and the first solenoid valve of the heating furnace has not been triggered; S23. Displace the ventilation in the cavity of the heating furnace and continue for a third preset time; S24. Determine that the combustible gas inside the cavity of the heating furnace is qualified.

4. The ignition control method for a heating furnace according to claim 3, characterized in that, The step "displacement ventilation within the cavity of the heating furnace" specifically includes: Operating the fan; Adjust the opening degree of the flue damper of the heating furnace to ≥50%, and adjust the opening degree of the damper of the heating furnace to ≥50%.

5. The ignition control method for a heating furnace according to claim 4, characterized in that, If any of the actual ignition conditions determined in step S2 disappears, the third preset time stops and returns to zero, and the target ignition conditions are no longer met.

6. The furnace ignition control method according to any one of claims 3 to 5, characterized in that, The first preset time is 2 seconds, and the continuous ignition time of the ignition device is ≤8 seconds; and / or, The second preset time is ≥30 min; and / or, The third preset time is ≥5 min.

7. The furnace ignition control method according to claim 6, characterized in that, If ignition fails in step S6, the furnace cavity is forced to undergo displacement ventilation for a third preset time. After troubleshooting, the process restarts from step S4.

8. The ignition control method for a heating furnace according to claim 6, characterized in that, The furnace ignition control method further includes: S7. After the first lamp is successfully ignited, the fuel pipeline corresponding to the other lamp is connected, the manual valve of the corresponding lamp is opened, and an ignition command is issued to ignite it, until the remaining lamps in the heating furnace are ignited one by one.

9. The ignition control method for a heating furnace according to claim 8, characterized in that, The furnace ignition control method further includes: S8. Ignite the corresponding burners one by one with the continuous lamp in a diagonal order.

10. The furnace ignition control method according to claim 9, characterized in that, Step S8 specifically includes: S81. Connect the fuel line of the target burner to be ignited and open the hand valve of the target burner; S82. Ignite the target burner using the corresponding continuous lamp.

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