A control method for safe combustion of industrial furnace

Abstract

The present disclosure relates to a control method for the safe combustion of an industrial furnace. The method of the present disclosure performs the operation of the next link on the premise of ensuring the safety of the previous link during the ignition and operation of the industrial furnace, and reduces the safety risks of the ignition and operation of the industrial furnace to the maximum extent through real-time monitoring and adjustment of each link in the process, avoids the occurrence of explosions and other safety accidents caused by operating errors or equipment failures, and keeps the industrial furnace in a safe, efficient and stable operating state.

Description

Technical Field

[0001] The present disclosure relates to the field of industrial furnace safety control, and in particular, to a method for controlling safe combustion of an industrial furnace. Background Art

[0002] Industrial furnaces are key equipment for providing heat energy in the refining process. In recent years, as the country has placed increasingly higher requirements on safety, efficiency, environmental protection and many other aspects of refining and chemical enterprises, comprehensively improving the level of industrial furnace combustion monitoring and control, ensuring the safe production of refining and chemical enterprises, and achieving energy conservation and consumption reduction have become the development goals of the petrochemical industry.

[0003] Once unburned materials within the explosion limit come into contact with open flames, combustion and explosion will occur. As open flame equipment in the petrochemical industry, industrial furnaces often have a large heat load, and the potential explosion hazards cannot be ignored. During the ignition, operation, and re-ignition of industrial furnaces, improper operation often causes residual combustible gas in the furnace. Once the residual gas mixes with air and reaches the explosion limit, the industrial furnace will explode the moment it is ignited.

[0004] Therefore, the existing industrial furnace combustion control method is difficult to further meet the requirements of energy saving and consumption reduction and safe operation at the same time. Summary of the invention

[0005] In order to improve the safety of the combustion process of an industrial furnace, the present disclosure provides a method that can monitor and adjust the combustion process of an industrial furnace in real time to achieve safe ignition, operation and flameout of the industrial furnace.

[0006] In order to achieve the above-mentioned object, the present disclosure provides a control method for safe combustion of an industrial furnace, wherein the industrial furnace comprises an industrial furnace body, a fuel pipeline, a combustion air duct, a pilot lamp and a main burner; the control method comprises:

[0007] S1: pressurizing and depressurizing the fuel pipeline in sequence, and determining a leakage risk value of the fuel pipeline by monitoring the pressure value in the fuel pipeline;

[0008] S2: When the leakage risk value is less than the leakage safety threshold, the furnace of the industrial furnace body is purged through the combustion air duct, and the total ventilation volume of the purging is monitored;

[0009] S3: When the total ventilation volume is greater than the purge safety threshold, ignite the ever-burning lamp within a specified time, and determine the number of ever-burning lamps that are successfully ignited;

[0010] S4: When the number of successfully ignited pilot lamps is greater than the ignition safety threshold, ignite the main burner and determine the number of successfully ignited main burners;

[0011] S5: When the number of successfully ignited main burners is greater than the combustion safety threshold, monitor the furnace oxygen content and adjust the gas flow of the fuel pipeline and / or the combustion air duct according to the furnace oxygen content so that the furnace oxygen content is 1-5% by volume.

[0012] Optionally, in step S1: the fuel pipeline includes a main burner fuel pipeline and a pilot light fuel pipeline; the leakage risk value of the fuel pipeline includes a main burner fuel pipeline leakage risk value and a pilot light fuel pipeline leakage risk value;

[0013] The leakage risk value in step S2 being less than the leakage safety threshold means that the leakage risk value of the main burner fuel pipeline is less than the main burner fuel pipeline safety threshold and the leakage risk value of the pilot lamp pipeline is less than the pilot lamp fuel pipeline safety threshold.

[0014] Optionally, the pressure charging and pressure releasing method is: charging the pressure in the fuel line from atmospheric pressure to operating pressure, providing a pressure stabilization time after the pressure charging, and releasing the pressure in the fuel line to atmospheric pressure after the pressure stabilization time ends;

[0015] The pressure charging and pressure releasing are repeated at least once to complete the monitoring of the pressure value in the fuel pipeline.

[0016] Optionally, the difference between the starting pressure value and the ending pressure value of the stabilization time is recorded as the theoretical pressure change value; the starting pressure value and the ending pressure value of the stabilization time are monitored to obtain the actual pressure change value before and after the charging; the absolute value of the difference between the theoretical pressure change value and the actual pressure change value is recorded as the pressure fluctuation value; the leakage risk value is the ratio of the pressure fluctuation value to the operating pressure.

[0017] Optionally, in step S2: the leakage safety threshold refers to any value within the range of 0-3% of the leakage risk value.

[0018] Optionally, in step S2: the total ventilation volume is determined by the ventilation flow rate and / or ventilation time of the purge.

[0019] Optionally, in step S3: the purge safety threshold refers to the total ventilation volume being any value within the range of 1.0-1.2 times the furnace volume; and the prescribed time is 5-8 minutes.

[0020] Optionally, in step S4: the ignition safety threshold refers to an arbitrary value within the range of 40-60% of the total number of the ever-burning lamps that are ignited.

[0021] Optionally, in step S5: the combustion safety threshold refers to the number of the ignited main burners being any value within the range of 10-100% of the total number of burners.

[0022] Optionally, in step S5: the oxygen content in the furnace is preferably 2-3% by volume.

[0023] The method disclosed in the present invention is to carry out the operation of the next link on the premise of ensuring the safety of the previous link during the ignition and operation of the industrial furnace, and to minimize the safety risks of the ignition and operation of the industrial furnace through real-time monitoring and adjustment of each link in the process, thereby avoiding the occurrence of explosions and other safety accidents caused by operating errors or equipment failures, and keeping the industrial furnace in a safe, efficient and stable operating state.

[0024] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0026] Figure 1 It is a schematic diagram of the structure of an industrial furnace in one embodiment of the control method disclosed in the present invention.

[0027] Description of Reference Numerals

[0028] 1. Industrial furnace body 2. On-site ignition panel 3. Ever-burning lamp flame monitoring equipment

[0029] 4. Main burner flame monitoring equipment 5. Main burner 6. Steady light

[0030] 7. Combustion monitoring and control system 8. Combustion air duct 9. Air preheater 10. Air blower

[0031] 11. Cold air intake 12. Smoke induced draft fan 13. Smoke flue 14. Main flame fuel gas regulating valve

[0032] 15. Main flame fuel gas vent valve 16. Main flame fuel gas cut-off valve

[0033] 17. Everlasting lamp fuel gas regulating valve 18. Everlasting lamp fuel gas vent valve 19. Everlasting lamp fuel gas cut-off valve

[0034] 20. Main flame fuel gas pressure measuring instrument 21. Pilot light fuel gas pressure measuring instrument

[0035] 22. Main burner fuel pipeline 23. Main fuel gas vent pipeline 24. Pilot light fuel pipeline

[0036] 25. Eternal lamp fuel gas venting pipeline 26. Chimney adjustment damper 27. Blower inlet damper

[0037] 28. Furnace air flow measurement instrument 29. Furnace oxygen content monitoring instrument 30. Main air duct adjustment damper DETAILED DESCRIPTION

[0038] The specific implementation of the present disclosure is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the present disclosure, and is not used to limit the present disclosure.

[0039] In the present disclosure, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of a component in normal use. Figure 1 “Inside” and “outside” refer to the outline of the device itself.

[0040] The present disclosure provides a control method for safe combustion of an industrial furnace, the industrial furnace comprising an industrial furnace body 1, a fuel pipeline, a combustion-supporting air duct 8, a permanent lamp 6 and a main burner 5; the control method comprises: S1: pressurizing and depressurizing the fuel pipeline in sequence, and determining the leakage risk value of the fuel pipeline by monitoring the pressure value in the fuel pipeline; S2: when the leakage risk value is less than the leakage safety threshold, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S3: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S4: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S5: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S6: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S7: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S8: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging; S9: when the total ventilation volume is less than the leakage risk value, purging the furnace of the industrial furnace body 1 through the combustion-supporting air duct 8, and monitoring the total ventilation volume of the purging When the oxygen content of the furnace is greater than the purging safety threshold, the ever-burning lamp 6 is ignited within the specified time and the number of ever-burning lamps 6 that are successfully ignited is determined; S4: When the number of ever-burning lamps 6 that are successfully ignited is greater than the ignition safety threshold, the main burner 5 is ignited and the number of main burners 5 that are successfully ignited is determined; S5: When the number of main burners 5 that are successfully ignited is greater than the combustion safety threshold, the oxygen content in the furnace is monitored, and the gas flow of the fuel pipeline and / or the combustion air duct 8 is adjusted according to the oxygen content in the furnace so that the oxygen content in the furnace is 1-5% by volume.

[0041] The method disclosed in the present invention is to carry out the operation of the next link on the premise of ensuring the safety of the previous link during the ignition and operation of the industrial furnace, and to minimize the safety risks of the ignition and operation of the industrial furnace through real-time monitoring and adjustment of each link in the process, thereby avoiding the occurrence of explosions and other safety accidents caused by operating errors or equipment failures, and keeping the industrial furnace in a safe, efficient and stable operating state.

[0042] In one embodiment, the industrial furnace of the present disclosure has Figure 1 The structure shown includes an industrial furnace body 1, a fuel pipeline, a combustion air duct 8, a pilot lamp 6 and a main burner 5.

[0043] In order to ensure the safety of the fuel gas pipeline during the ignition, operation and flameout of the industrial furnace, and to prevent explosion accidents caused by gas leakage in the fuel gas pipeline, step S1 can be used to pressurize and depressurize the main burner fuel pipeline 22 and the ever-burning lamp fuel pipeline 24 in sequence, and the leakage risk value of the fuel pipeline is determined by monitoring the pressure value in the fuel pipeline. In one embodiment, the method for pressurizing and depressurizing the main burner fuel pipeline 22 and the ever-burning lamp fuel pipeline 24 can be: pressurizing the pressure in the fuel pipeline from atmospheric pressure to operating pressure, stopping the pressurization and maintaining the pressure in the pipeline stable for a period of time, recorded as the pressure stabilization time; then, after the pressure stabilization time ends, the pressure in the fuel pipeline is depressurized to atmospheric pressure, that is, a pressurization and depressurization process is completed. In one embodiment, in order to complete the monitoring of the pressure value in the fuel pipeline, it is necessary to repeat the above-mentioned pressurization and depressurization process at least once. The present disclosure has no limitation on the duration of the stabilization time, which can be a conventional choice in the art, for example, 10 to 20 minutes. In a further embodiment, the main burner fuel gas regulating valve 14, the main burner fuel gas vent valve 15, the main burner fuel gas cut-off valve 16, the ever-burning lamp fuel gas regulating valve 17, the ever-burning lamp fuel gas vent valve 18 and the ever-burning lamp fuel gas cut-off valve 19 can be opened and closed during the charging and depressurization process. By comparing the pressure difference between the main fuel gas pressure measuring instrument 20 and the ever-burning lamp fuel gas pressure measuring instrument 21 before and after the corresponding valve is switched, it is determined whether there is a leakage problem in the valve, and the completion signal of step S1 will eventually be transmitted to the combustion monitoring and control system 7.

[0044] According to the present disclosure, the leakage risk value of the fuel pipeline may include the leakage risk value of the main burner fuel pipeline 22 and the leakage risk value of the ever-burning lamp fuel pipeline 24. The leakage risk value less than the leakage safety threshold in step S2 means that the leakage risk value of the main burner fuel pipeline 22 is less than the safety threshold of the main burner fuel pipeline 22 and the leakage risk value of the ever-burning lamp pipeline 24 is less than the safety threshold of the ever-burning lamp fuel pipeline 24. In a specific implementation, the difference between the starting pressure value and the ending pressure value of the stabilization time can be recorded as the theoretical pressure change value, and the starting pressure value and the ending pressure value of the stabilization time are monitored by a pressure gauge on the fuel pipeline to obtain the actual pressure change value before and after pressurization; the absolute value of the difference between the theoretical pressure change value and the actual pressure change value is recorded as the pressure fluctuation value, then, the leakage risk value can be expressed as the ratio of the pressure fluctuation value to the operating pressure. Among them, the above theoretical pressure change value is 0 when there is no leakage in the fuel pipeline, but in actual operation, it is usually difficult to get a value of 0 due to the fluctuation of the measured value of the instrument itself. In actual engineering, the theoretical pressure change value is usually taken as 2% of the starting pressure value, or an appropriate range of variation is selected according to the actual application scenario, which will not be repeated here; the leakage safety threshold is the maximum value that the leakage risk value may take. When the leakage risk value exceeds the leakage safety threshold, it means that the leakage of the fuel pipeline is more serious and will cause an explosion accident. In one embodiment, the leakage safety threshold in step S2 can be any value in the range of 0-3%, preferably any value in the range of 0-2%.

[0045] In order to prevent the residual fuel gas in the furnace from causing explosion or fire at the initial stage of ignition, according to the present disclosure, when the leakage risk value is less than the leakage safety threshold, the furnace of the industrial furnace body 1 can be purged through the combustion air duct 8, and the total ventilation volume of the purge can be monitored to remove the residual fuel gas in the furnace; wherein the total ventilation volume can be determined by the ventilation flow rate and / or ventilation time of the purge. In one embodiment, after receiving the completion signal of step S1, the combustion monitoring and control system 7 allows the cold air to enter the blower 10 through the cold air intake port 11, and then enter the industrial furnace body 1 through the combustion air duct 8. During the purging process, the air flow rate measuring instrument 28 is used to monitor the air flow into the furnace. When the total ventilation volume is greater than the purging safety threshold, the purging process is completed, and the completion signal of step S2 is transmitted to the combustion monitoring and control system 7.

[0046] The ever-burning lamp plays an important role in the ignition, operation and flameout of the industrial furnace. It can prevent the burner flame from being extinguished, quickly re-ignite the burner when it is extinguished, and burn out uncontrollable combustible gas to prevent the combustible gas in the furnace due to special reasons and explosion during ignition. According to the present disclosure, the ever-burning lamp 6 can be ignited within a specified time when the total ventilation volume is greater than the purge safety threshold, and the number of ever-burning lamps 6 that are successfully ignited is determined; wherein the purge safety threshold refers to the minimum value that the actual total ventilation volume may reach, preferably, the value can be any value within the range of 1.0-1.2 times the furnace volume, preferably, it can be any value within the range of 1.1-1.2 times the furnace volume; the specified time can be 5-8 minutes, preferably, it can be 6-8 minutes. In one embodiment, after receiving the completion signal of step S2, the combustion monitoring and control system 7 adjusts the opening of the ever-burning lamp fuel gas regulating valve 17 and the ever-burning lamp fuel gas shut-off valve 19, closes the ever-burning lamp fuel gas vent valve 18, and the on-site operator ignites the ever-burning lamp 6 through the on-site ignition disk 2. The ever-burning lamp flame detection equipment 3 monitors the ignition status of the ever-burning lamp 6 in real time, and transmits the number of ever-burning lamps 6 ignited to the combustion monitoring and control system 7.

[0047] According to the present disclosure, after completing the pre-ignition preparation work of steps S1-S3 and confirming that the number of successfully ignited ever-burning lamps 6 is greater than the ignition safety threshold, the main burner 5 can be ignited and the number of successfully ignited main burners 5 can be determined; wherein the ignition safety threshold refers to the minimum value that the actual number of ever-burning lamps 6 that are ignited may reach, and the value can be any value within the range of 40-60% of the total number of ever-burning lamps, preferably any value within the range of 45-55% of the total number of ever-burning lamps. In one embodiment, the combustion monitoring and control system 7 adjusts the opening of the main flame fuel gas regulating valve 14 and the ever-burning lamp fuel gas shut-off valve 16, closes the main flame fuel gas vent valve 15, and the on-site operator ignites the main flame through the on-site ignition disk 2, and the main burner flame detection device 4 monitors the main flame ignition situation in real time, and transmits the number of main flame ignitions to the combustion monitoring and control system 7.

[0048] In order to monitor the combustion process of the main burner 5 in real time, ensure the stable flame combustion during the ignition and operation of the industrial furnace, and keep the industrial furnace in a safe, efficient and stable operation state, according to the present disclosure, when the number of successfully ignited main burners 5 is greater than the combustion safety threshold, the furnace oxygen content is monitored, and the gas flow of the fuel pipeline and / or the combustion air duct 8 is adjusted according to the furnace oxygen content, so that the furnace oxygen content can be 1-5% by volume, preferably the furnace oxygen content can be 2-3% by volume; wherein the combustion safety threshold refers to the minimum value that the actual ignition number of the main burners 5 may reach, and the value can be any value in the range of 10-100% of the total number of burners, preferably, it can be any value in the range of 30-90% of the total number of burners. In one embodiment, when the combustion monitoring and control system 7 receives a signal that the number of successfully ignited main burners 5 is greater than the combustion safety threshold, the operator starts to feed fuel into the furnace and completes the setting of the furnace oxygen content. The combustion monitoring and control system 7 will automatically monitor the measurement data of the furnace air flow measurement instrument 28, the furnace oxygen content monitoring instrument 29 and the main flame fuel gas pressure measurement instrument 20, and automatically adjust the opening of the main air duct regulating baffle 30 and / or the chimney regulating baffle 26 in the combustion air duct 8, as well as the gas flow of the main burner fuel pipeline 22 and the ever-burning lamp fuel pipeline 24 according to the measured data and the given combustion equation, so as to meet the furnace flame combustion needs.

[0049] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0050] Example

[0051] Figure 1 The industrial furnace shown includes an industrial furnace body 1, a main burner fuel pipeline 22, a pilot light fuel pipeline 24, a combustion air duct 8, a pilot light 6 and a main burner 5; the furnace volume is 2050m 3 , the following steps are used to safely ignite and control the operation of the industrial furnace:

[0052] S1: Leak detection of fuel lines

[0053] By sequentially pressurizing and depressurizing the main burner fuel pipeline 22 and the pilot lamp fuel pipeline 24, and coordinating the opening and closing of the main flame fuel gas regulating valve 14, the main flame fuel gas venting valve 15, the main flame fuel gas shut-off valve 16, the pilot lamp fuel gas regulating valve 17, the pilot lamp fuel gas venting valve 18, and the pilot lamp fuel gas shut-off valve 19. By comparing the pressure difference of the main flame fuel gas pressure measuring instrument 20 and the pilot lamp fuel gas pressure measuring instrument 21 before and after the corresponding valves are opened and closed, and monitoring the actual pressure value in the fuel pipeline during the pressurization and depressurization process, the leakage risk value of the fuel pipeline is determined, and the various valves on the fuel pipeline are corrected according to the size relationship between the leakage risk value and the leakage safety threshold until the leakage risk value is less than the leakage safety threshold, and the completion signal of the leakage detection is transmitted to the combustion monitoring and control system 7.

[0054] The pressure charging method is as follows: the pressure in the main burner fuel pipeline 22 and the pilot light fuel pipeline 24 is respectively charged from atmospheric pressure to the operating pressure, and the pressure is stabilized for 15 minutes after the pressure charging. After the pressure stabilization time is over, the pressure in the main fuel pipeline 22 and the pilot light fuel pipeline 24 is respectively released to atmospheric pressure; the above-mentioned charging and pressure release process is repeated once to complete the monitoring of the pressure value in the fuel pipeline;

[0055] The leakage risk value of the main burner fuel pipeline 22 is 0.1%, and the leakage safety threshold is 2%; the leakage risk value of the pilot lamp fuel pipeline 24 is 0.15%, and the leakage safety threshold is 2%.

[0056] S2: Furnace purge before ignition

[0057] The combustion monitoring and control system 7 can only perform this step after receiving the confirmation instruction that there is no leakage in the fuel pipeline. Start the blower 10, and adjust the opening of the blower inlet damper 27 and the main air duct adjustment damper 30 at the same time to control the amount of air entering the industrial furnace body 1. The flow direction of cold air is: cold air enters the blower 10 from the cold air intake port 11, and then enters the industrial furnace body 1 through the combustion air duct 8. The total ventilation volume entering the furnace is monitored by the furnace air flow measurement instrument 28. When the total ventilation volume entering the furnace is greater than the purge safety threshold, the purge step is completed, and the completion signal of the furnace purge is transmitted to the combustion monitoring and control system 7.

[0058] Among them, the total ventilation volume into the furnace is 4000m 3 , the purge safety threshold is 2400m 3 .

[0059] S3: Ignition of the eternal lamp

[0060] The combustion monitoring and control system 7 can only perform this step after receiving the instruction that the furnace purge is completed. Adjust the opening of the pilot lamp fuel gas regulating valve 17 and the pilot lamp fuel gas cut-off valve 19, and close the pilot lamp fuel gas vent valve 18. The on-site operator ignites the pilot lamp 6 through the on-site ignition panel 2, and the pilot lamp flame detection equipment 3 monitors the ignition status of the pilot lamp 6 in real time, and feeds back the number of ignitions to the combustion monitoring and control system 7. When the number of ignitions of the pilot lamp 6 within the specified time is greater than the ignition safety threshold, the ignition of the pilot lamp 6 is completed, and the furnace is ready to ignite the main flame.

[0061] Among them, the total number of ever-burning lamps of the industrial furnace is 24, the number of ever-burning lamps that are lit is 21, the ignition safety threshold is 12, and the specified time is 6 minutes.

[0062] S4: Main flame ignition

[0063] The combustion monitoring and control system 7 can only perform this step after receiving the instruction that the pilot lamp 6 has been ignited. Adjust the opening of the main flame fuel gas regulating valve 14 and the pilot lamp fuel gas cut-off valve 16, and close the main flame fuel gas vent valve 15. The on-site operator ignites the main flame through the on-site ignition panel 2, and the main burner flame detection device 4 monitors the main flame ignition situation in real time, and at the same time feeds back the ignition number to the combustion monitoring and control system 7. When the number of successfully ignited main burners 5 is greater than the combustion safety threshold, the main flame ignition is completed.

[0064] Among them, the total number of main burners of the industrial furnace is 24, the number of ignition of the main burners is 24, and the combustion safety threshold is 4.

[0065] S5: Furnace oxygen content control

[0066] When the combustion monitoring and control system 7 receives the completion of the main flame ignition, the operator starts to use the fuel and completes the setting of the furnace oxygen content. The combustion monitoring and control system 7 will automatically monitor the measurement data of the furnace air flow measurement instrument 28, the furnace oxygen content monitoring instrument 29 and the main flame fuel gas pressure measurement instrument 20, and automatically adjust the opening of the main air duct adjustment damper 30 and / or the chimney adjustment damper 26 according to the relevant measurement data and the given combustion equation to meet the furnace flame combustion needs.

[0067] The range of oxygen content in the furnace is 1-5% by volume.

[0068] The safety test method of the method of this embodiment is: whether the industrial furnace completes the process of steps S1-S4 within the specified time (40 minutes), and whether the industrial furnace runs smoothly during this process, and whether there is abnormal flame extinguishing or furnace flash explosion phenomenon. The result is: the process of steps S1-S4 is completed within the specified time, and the industrial furnace runs smoothly, and there is no abnormal flame extinguishing or furnace flash explosion phenomenon;

[0069] The thermal efficiency test method is: record the oxygen content in the furnace, the natural environment temperature, humidity, wind speed and the combustion flue gas temperature and other parameters, calculate the combustion thermal efficiency according to the thermal efficiency calculation formula, and the result is: the combustion thermal efficiency (92.3%) is better than the design point (91%);

[0070] The stability test method is: step S5 is to check whether the industrial furnace has an interlocking shutdown phenomenon due to abnormal conditions such as furnace oxygen content, furnace negative pressure or abnormal combustion state during the combustion process of the industrial furnace. The result is: no interlocking shutdown phenomenon occurs, and the industrial furnace runs smoothly.

[0071] Comparative Example

[0072] The industrial furnace of a domestic refinery was not equipped with the relevant safety monitoring process disclosed in this disclosure. After the furnace was abnormally extinguished, the operator directly carried out the furnace ignition process without carrying out the S1-S2 process described in this disclosure. Because gas still entered the furnace through the main line valve and was not ignited in time, unburned gas remained in the furnace, which was ignited during the re-ignition process of the industrial furnace. The furnace flashed and exploded instantly, causing serious casualties and property losses.

[0073] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings; however, the present disclosure is not limited to the specific details in the above embodiments. Within the technical concept of the present disclosure, a variety of simple modifications can be made to the technical solution of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0075] In addition, various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for controlling safe combustion of an industrial furnace, wherein the industrial furnace comprises an industrial furnace body, a fuel pipeline, a combustion air duct, a pilot lamp and a main burner; characterized in that: The control method comprises: S1: pressurizing and depressurizing the fuel pipeline in sequence, and determining the leakage risk value of the fuel pipeline by monitoring the pressure value in the fuel pipeline; the fuel pipeline includes a main burner fuel pipeline and a pilot light fuel pipeline; the leakage risk value of the fuel pipeline includes a main burner fuel pipeline leakage risk value and a pilot light fuel pipeline leakage risk value; The method of charging and releasing pressure is as follows: charging the pressure in the fuel pipeline from atmospheric pressure to operating pressure, providing a pressure stabilization time after charging, and releasing the pressure in the fuel pipeline to atmospheric pressure after the pressure stabilization time ends; repeating the charging and releasing pressure at least once to complete monitoring of the pressure value in the fuel pipeline; The difference between the starting pressure value and the ending pressure value of the stabilization time is recorded as the theoretical pressure change value; the starting pressure value and the ending pressure value of the stabilization time are monitored to obtain the actual pressure change value before and after the pressurization; the absolute value of the difference between the theoretical pressure change value and the actual pressure change value is recorded as the pressure fluctuation value; the leakage risk value is the ratio of the pressure fluctuation value to the operating pressure; S2: When the leakage risk value is less than the leakage safety threshold, the furnace of the industrial furnace body is purged through the combustion air duct, and the total ventilation volume of the purge is monitored; the leakage risk value is less than the leakage safety threshold, which means that the leakage risk value of the main burner fuel pipeline is less than the main burner fuel pipeline safety threshold and the leakage risk value of the ever-burning lamp pipeline is less than the ever-burning lamp fuel pipeline safety threshold; the leakage safety threshold refers to any value within the range of 0-3% of the leakage risk value; S3: When the total ventilation volume is greater than the purge safety threshold, the ever-burning lamps are ignited within a specified time, and the number of ever-burning lamps that are successfully ignited is determined; the purge safety threshold refers to the total ventilation volume being any value within the range of 1.0-1.2 times the furnace volume; the specified time is 5-8 minutes; S4: When the number of successfully ignited ever-burning lamps is greater than the ignition safety threshold, ignite the main burner and determine the number of successfully ignited main burners; the ignition safety threshold refers to the number of ignited ever-burning lamps being any value within the range of 40-60% of the total number of ever-burning lamps; S5: When the number of successfully ignited main burners is greater than the combustion safety threshold, monitor the oxygen content in the furnace, and adjust the gas flow of the fuel pipeline and / or the combustion air duct according to the furnace oxygen content so that the furnace oxygen content is 1-5% by volume; the combustion safety threshold refers to the number of ignited main burners being any value in the range of 10-100% of the total number of burners.

2. The control method according to claim 1, wherein: In step S2: the total ventilation volume is determined by the ventilation flow rate and / or ventilation time of the purge.

3. The control method according to claim 1, wherein: In step S5: the oxygen content in the furnace is 2-3% by volume.

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