Pulse type oxygen-enriched combustion control method for heat accumulating type heating furnace

Abstract

According to the pulse type oxygen-enriched combustion control method for the heat accumulating type heating furnace, preconditions for oxygen-enriched starting of the heat accumulating type heating furnace are added, a series of linkage conditions and logic judgment conditions are set for starting and stopping of an oxygen lance, and before the oxygen lance is started, a burner quick switching valve and the residual oxygen concentration are judged. The technical problem that an existing conventional combustion heating furnace oxygen-enriched combustion control technology is difficult to meet the oxygen-enriched combustion safety control requirement of a heat storage type heating furnace can be solved.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, and in particular to a pulse-type oxygen-enriched combustion control method for a regenerative heating furnace. Background Technology

[0002] Currently, there are three main methods of oxygen-enriched combustion in heating furnaces: oxygen enrichment through the main combustion air pipe, oxygen enrichment via independent oxygen lance injection next to the burner, and full oxygen combustion via dedicated burners. Main pipe oxygen enrichment involves introducing a certain proportion of fuel gas into the combustion air pipe, making the oxygen concentration in the combustion air higher than the air concentration, achieving an oxygen enrichment concentration of approximately 26%, with a production increase and energy saving of 3-5%. The second method uses oxygen lance injection, achieving a concentration as high as 40% or more, with a production increase and energy saving of 10%-15%. The third method, full oxygen combustion, can achieve a production increase of over 30%. These oxygen enrichment methods are generally used in conventional heating furnaces. However, regenerative combustion technology requires burners to alternate and switch combustion directions, and existing oxygen enrichment control technologies for conventional combustion heating furnaces are insufficient to meet the safety control requirements of oxygen enrichment combustion in regenerative heating furnaces. Summary of the Invention

[0003] This invention provides a pulsed oxygen-enriched combustion control method for a regenerative heater, which solves the technical problem that existing conventional combustion heater oxygen-enriched combustion control technologies cannot meet the safety control requirements for oxygen-enriched combustion in regenerative heaters.

[0004] This invention provides a pulse-type oxygen-enriched combustion control method for a regenerative heater, comprising: Before starting oxygen-enriched combustion in the heating section, determine whether the quick-cut valve of the main gas pipe is open; Before starting oxygen-enriched combustion in the heating section, it is determined whether the gas flow rate in the upper and lower parts of the heating section is greater than 0. After starting the oxygen-enriched combustion in the heating section, check whether the burner gas quick-cut valve is open before starting the oxygen lance.

[0005] In one embodiment of the present invention, the step of determining whether the burner gas quick-cut valve is open before starting the oxygen lance after starting oxygen-enriched combustion in the heating section includes: Scan the switch status signal of the burner gas quick-cut valve in the heating section to determine whether the burner gas quick-cut valve is open; The determination of whether the burner gas quick-cut valve is open includes: If the judgment result is yes, then determine whether the residual oxygen value of the heating section is <8%; If the result is negative, scan the switch status signal of the gas quick-cut valve of the next burner in the heating section to determine whether the gas quick-cut valve of the next burner is open.

[0006] In one embodiment of the present invention, the determination of whether the residual oxygen value of the heating section is <8% includes: If the judgment result is yes, then the oxygen lance of the burner is turned on. After the oxygen lance of the burner is turned on for 3 seconds, the step of judging whether the gas quick-cut valve of the burner is turned on is executed. If the result is negative, the oxygen lance activation scanning procedure will be stopped.

[0007] In one embodiment of the present invention, after executing the stop-scanning procedure for the oxygen lance for 3 seconds, it is determined whether the residual oxygen detection value in the heating section is <8%. If the judgment result is yes, then the step of scanning the switch status signal of the burner gas quick-cut valve in the heating section is executed to determine whether the burner gas quick-cut valve is open is performed. If the judgment result is negative, then return to the step of stopping the oxygen lance start-up scanning procedure.

[0008] In one embodiment of the present invention, after starting oxygen-enriched combustion in the heating section, a procedure for shutting down the oxygen lance is executed, including: Real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determination of whether the burner gas quick-cut valves are closed: If the judgment result is yes, then shut down all oxygen lances corresponding to the burner; If the judgment result is negative, return to the step of real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determine whether the burner gas quick-cut valves are closed.

[0009] In one embodiment of the present invention, after starting oxygen-enriched combustion in the heating section, executing the oxygen lance shutdown procedure further includes: Delay for 3 seconds to determine if the residual oxygen level in the heating section is <8%. If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the result is negative, scan the oxygen lance quick-cut valve switch status signal in the heating section according to the oxygen lance closing scan sequence, and determine whether the oxygen lance quick-cut valve is open.

[0010] In one embodiment of the present invention, the step of scanning the oxygen lance quick-cut valve switch status signal in the oxygen lance closing scan sequence and determining whether the oxygen lance quick-cut valve is open includes: If the judgment result is yes, then turn off the scanned oxygen lance. After turning off the oxygen lance for 3 seconds, check whether the residual oxygen detection value in the heating section is <8%. If the judgment result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

[0011] In one embodiment of the present invention, determining whether the residual oxygen detection value in the heating section is <8% after the oxygen lance is turned off for 3 seconds includes: If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the determination result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

[0012] In one embodiment of the present invention, the determination of whether the quick-cut valve of the main gas pipe is open before starting oxygen-enriched combustion in the heating section includes: If the result is yes, proceed to the next step; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off; The step of determining whether the gas flow rate at the upper and lower parts of the heating section is greater than 0 before starting oxygen-enriched combustion in the heating section includes: If the result is yes, proceed to the next step; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off.

[0013] In one embodiment of the present invention, the shut-off of the oxygen-enriched combustion in the heating section includes: Three conditions must be met: real-time judgment of whether the gas flow rate at the upper part of the heating section is 0, real-time judgment of whether the gas flow rate at the lower part of the heating section is 0, and real-time judgment of whether the quick-cut valve of the main gas pipe is closed. If any one of the conditions is not met, the three conditions will continue to be executed; If all conditions are met, then the oxygen-enriched combustion of the closed heating section is completed; If a malfunction occurs during execution and an alarm is triggered, the oxygen-enriched combustion step of shutting off the heating section can only be executed again after a 5-minute countdown.

[0014] The beneficial effects of this invention: The pulse-type oxygen-enriched combustion control method for a regenerative heating furnace proposed in this invention sets up multi-dimensional pre-judgment conditions and oxygen lance start-stop interlock logic for oxygen-enriched combustion in the regenerative heating furnace. By judging the opening status of the gas main quick-cut valve before starting oxygen-enriched combustion in the heating section, detecting whether the gas flow rate in the upper and lower parts of the heating section is greater than 0, and judging the opening status of the burner gas quick-cut valve before starting the oxygen lance, the safety risks such as gas leakage and air-fuel ratio imbalance that are prone to occur in the reversing combustion of the regenerative heating furnace are avoided from the source, and the occurrence of problems such as reversing equipment alarm and abnormal furnace pressure is effectively prevented.

[0015] Meanwhile, this technical solution significantly reduces gas consumption and greatly improves the heating capacity of the furnace while ensuring safety. It is particularly effective for furnaces with insufficient heating capacity and makes up for the shortcoming of the limited energy saving and production increase of conventional oxygen-enriched combustion methods on regenerative equipment.

[0016] It requires no large-scale modification to the main structure of the regenerative thermal radiator, has strong adaptability, and not only continues the energy-saving advantages of oxygen-enriched combustion but also provides a reliable guarantee for the safe and stable operation of the regenerative thermal radiator, possessing significant safety, economic, and practical benefits. It breaks through the application bottleneck of conventional oxygen-enriched combustion control technology in regenerative thermal radiators, precisely solving the safety control problem of oxygen-enriched combustion caused by the alternating combustion direction of burners in regenerative thermal radiators. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] In the attached diagram: Figure 1 The flowchart illustrates a pulse-type oxygen-enriched combustion control method for a regenerative heater according to an embodiment of the present invention. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0020] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0021] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0022] Please see Figure 1 , Figure 1 A pulse-type oxygen-enriched combustion control method for a regenerative heater provided in one embodiment of the present invention includes: Before starting oxygen-enriched combustion in the heating section, determine whether the quick-cut valve of the main gas pipe is open; Before starting oxygen-enriched combustion in the heating section, it is determined whether the gas flow rate in the upper and lower parts of the heating section is greater than 0. After starting the oxygen-enriched combustion in the heating section, check whether the burner gas quick-cut valve is open before starting the oxygen lance.

[0023] By checking the opening status of the quick-cut valve in the main gas pipe before starting oxygen-enriched combustion in the heating section, detecting whether the gas flow rate in the upper and lower parts of the heating section is greater than 0, and checking the opening status of the burner gas quick-cut valve before starting the oxygen lance, this technology avoids safety risks such as gas leakage and air-fuel ratio imbalance that are prone to occur in regenerative thermal radiators during reversing combustion. It effectively prevents problems such as reversing equipment alarms and abnormal furnace pressure. At the same time, this technical solution significantly reduces gas consumption and significantly improves the heating capacity of the radiator while ensuring safety. It is particularly effective for radiators with insufficient heating capacity, making up for the limited energy-saving and production-increasing effects of conventional oxygen-enriched combustion methods on regenerative equipment.

[0024] For example, in this embodiment, determining whether the quick-cut valve of the main gas pipe is open before starting oxygen-enriched combustion in the heating section includes: If the judgment result is yes, then the judgment is performed on whether the gas flow rate in the upper and lower parts of the heating section is greater than 0; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off.

[0025] The determination of whether the gas flow rate at the upper and lower parts of the heating section is greater than 0 includes: If the judgment result is yes, then execute the oxygen lance start procedure or the oxygen lance stop procedure; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off.

[0026] By using a two-stage pre-interlock judgment system based on the opening status of the main gas pipe quick-cut valve and the gas flow rate in the upper and lower parts of the heating section > 0, the oxygen-enriched combustion in the heating section is shut off if the standard is not met. This solves the safety control problem of reversing combustion in regenerative heating furnaces, effectively avoids risks such as gas leakage, reduces gas consumption, improves heating capacity, has strong adaptability, and ensures stable operation.

[0027] For example, in this embodiment, the step of shutting down the oxygen-enriched combustion in the heating section includes: The following three conditions must be met: real-time determination of whether the gas flow rate at the upper part of the heating section is 0, real-time determination of whether the gas flow rate at the lower part of the heating section is 0, and real-time determination of whether the quick-cut valve of the main gas pipe is closed.

[0028] If any one of the conditions is not met, then all three conditions will continue to be executed; If all conditions are met, the oxygen-enriched combustion step of shutting off the heating section is complete; If a malfunction occurs during execution and an alarm is triggered, the oxygen-enriched combustion step of shutting off the heating section can only be executed again after a 5-minute countdown.

[0029] This embodiment uses a triple real-time judgment based on the upper and lower gas flow rates being 0 and the gas main quick-cut valve being closed. If the standard is not met, the detection continues. After a fault alarm, a 5-minute countdown restart mechanism is set up to enhance the safety and stability of the oxygen-enriched combustion shutdown process of the regenerative heating furnace, avoid the risk of residual gas, and at the same time help reduce gas consumption and improve heating capacity.

[0030] For example, in this embodiment, the determination of whether the burner gas quick-cut valve is open after starting oxygen-enriched combustion in the heating section and before starting the oxygen lance includes: Scan the switch status signal of the burner gas quick-cut valve in the heating section to determine whether the burner gas quick-cut valve is open; The steps for determining whether the burner gas quick-cut valve is open include: If the judgment result is yes, then determine whether the residual oxygen value of the heating section is <8%; If the result is negative, scan the switch status signal of the gas quick-cut valve of the next burner in the heating section to determine whether the gas quick-cut valve of the next burner is open.

[0031] For example, in this embodiment, the determination of whether the residual oxygen value in the heating section is <8% includes: If the judgment result is yes, then the oxygen lance of the burner is turned on. After the oxygen lance of the burner is turned on for 3 seconds, the step of judging whether the gas quick-cut valve of the burner is turned on is executed. If the result is negative, the oxygen lance activation scanning procedure will be stopped.

[0032] For example, in this embodiment, after executing the stop oxygen lance start scanning procedure for 3 seconds, it is determined whether the residual oxygen detection value in the heating section is <8%. If the judgment result is yes, then the step of scanning the switch status signal of the burner gas quick-cut valve in the heating section is executed to determine whether the burner gas quick-cut valve is open is performed. If the judgment result is negative, then return to the step of stopping the oxygen lance start-up scanning procedure.

[0033] A dual control mechanism is employed, consisting of individual scanning and judgment of the burner gas quick-cut valve and a residual oxygen value of <8%, coupled with a 3-second delay cycle and re-inspection logic. If the quick-cut valve is not activated, the system switches to the next scan; if the residual oxygen value is not up to standard, the scan stops and a delayed re-inspection is performed. This precisely solves the problem of fine-grained control of oxygen lance startup under reversing combustion in regenerative thermal radiators, effectively avoiding risks such as air-fuel ratio imbalance and incomplete gas combustion, ensuring combustion uniformity, reducing gas consumption, increasing heating capacity, and significantly enhancing the safety and stability of oxygen-enriched combustion.

[0034] For example, in this embodiment, after starting oxygen-enriched combustion in the heating section, the oxygen lance shut-off procedure is executed, including: Real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determination of whether the burner gas quick-cut valves are closed: If the judgment result is yes, then shut down all oxygen lances corresponding to the burner; If the judgment result is negative, return to the step of real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determine whether the burner gas quick-cut valves are closed.

[0035] For example, in this embodiment, after starting oxygen-enriched combustion in the heating section, executing the oxygen lance shutdown procedure further includes: Delay for 3 seconds to determine if the residual oxygen level in the heating section is <8%. If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the result is negative, scan the oxygen lance quick-cut valve switch status signal in the heating section according to the oxygen lance closing scan sequence, and determine whether the oxygen lance quick-cut valve is open.

[0036] The step of scanning the oxygen lance quick-cut valve switch status signal in the heating section according to the oxygen lance closing scan sequence, and determining whether the oxygen lance quick-cut valve is open, includes: If the judgment result is yes, then turn off the scanned oxygen lance. After turning off the oxygen lance for 3 seconds, check whether the residual oxygen detection value in the heating section is <8%. If the judgment result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

[0037] The step of determining whether the residual oxygen level in the heating section is less than 8% 3 seconds after the oxygen lance is turned off includes: If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the determination result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

[0038] This embodiment employs a dual control system for shutting down the oxygen lance: a gas quick-cut valve linkage and a closed-loop control of residual oxygen levels. By monitoring the burner's gas quick-cut valve status in real time, it ensures that the oxygen lance is shut down only after the gas supply is cut off, thus mitigating the safety hazard of gas and oxygen mixing at the source. Simultaneously, a 3-second delay for residual oxygen detection and sequential scanning shutdown logic are added. If the residual oxygen level is below standard, the oxygen lance quick-cut valve is checked sequentially, and the residual oxygen level is rechecked after shutdown, forming a cyclical control system. This embodiment can accurately adapt to the special operating conditions of regenerative furnace reversing combustion, completely solving problems such as incomplete oxygen lance shutdown and excessive residual oxygen in conventional control. It ensures the safety and stability of the oxygen-enriched combustion system shutdown process, reduces gas waste through precise oxygen control, and further improves the furnace's operating efficiency, resulting in significant safety and economic benefits.

[0039] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for controlling pulsed oxygen-enriched combustion in a regenerative heating furnace, characterized in that, include: Before starting oxygen-enriched combustion in the heating section, determine whether the quick-cut valve of the main gas pipe is open; Before starting oxygen-enriched combustion in the heating section, it is determined whether the gas flow rate in the upper and lower parts of the heating section is greater than 0. After starting the oxygen-enriched combustion in the heating section, check whether the burner gas quick-cut valve is open before starting the oxygen lance.

2. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 1, characterized in that, The determination of whether the burner gas quick-cut valve is open after starting oxygen-enriched combustion in the heating section and before starting the oxygen lance includes: Scan the switch status signal of the burner gas quick-cut valve in the heating section to determine whether the burner gas quick-cut valve is open; The determination of whether the burner gas quick-cut valve is open includes: If the judgment result is yes, then determine whether the residual oxygen value of the heating section is <8%; If the result is negative, scan the switch status signal of the gas quick-cut valve of the next burner in the heating section to determine whether the gas quick-cut valve of the next burner is open.

3. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 2, characterized in that, The determination of whether the residual oxygen value in the heating section is <8% includes: If the judgment result is yes, then the oxygen lance of the burner is turned on. After the oxygen lance of the burner is turned on for 3 seconds, the step of judging whether the gas quick-cut valve of the burner is turned on is executed. If the result is negative, the oxygen lance activation scanning procedure will be stopped.

4. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 3, characterized in that, After executing the stop-start scanning procedure for oxygen lance for 3 seconds, determine whether the residual oxygen detection value in the heating section is <8%. If the judgment result is yes, then the step of scanning the switch status signal of the burner gas quick-cut valve in the heating section is executed to determine whether the burner gas quick-cut valve is open is performed. If the judgment result is negative, then return to the step of stopping the oxygen lance start-up scanning procedure.

5. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 4, characterized in that, After starting oxygen-enriched combustion in the heating section, execute the oxygen lance shutdown procedure, including: Real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determination of whether the burner gas quick-cut valves are closed: If the judgment result is yes, then shut down all oxygen lances corresponding to the burner; If the judgment result is negative, return to the step of real-time monitoring of the on / off status of all burner gas quick-cut valves in the heating section, and determine whether the burner gas quick-cut valves are closed.

6. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 5, characterized in that, After starting oxygen-enriched combustion in the heating section, the procedure for shutting down the oxygen lance also includes: Delay for 3 seconds to determine if the residual oxygen level in the heating section is <8%. If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the result is negative, scan the oxygen lance quick-cut valve switch status signal in the heating section according to the oxygen lance closing scan sequence, and determine whether the oxygen lance quick-cut valve is open.

7. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 6, characterized in that, The step of scanning the oxygen lance quick-cut valve switch status signal in the heating section according to the oxygen lance closing scan sequence, and determining whether the oxygen lance quick-cut valve is open, includes: If the judgment result is yes, then turn off the scanned oxygen lance. After turning off the oxygen lance for 3 seconds, check whether the residual oxygen detection value in the heating section is <8%. If the judgment result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

8. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 7, characterized in that, The step of determining whether the residual oxygen value in the heating section is less than 8% after the oxygen lance is turned off for 3 seconds includes: If the judgment result is yes, then stop executing the oxygen lance shutdown scanning procedure; If the determination result is negative, then the step of scanning the oxygen lance quick-cut valve switch status signal of the heating section according to the oxygen lance closing scan sequence is performed for the next oxygen lance, and determining whether the oxygen lance quick-cut valve is open is performed.

9. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 1, characterized in that, The determination of whether the quick-cut valve of the main gas pipe is open before starting oxygen-enriched combustion in the heating section includes: If the result is yes, proceed to the next step; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off; The step of determining whether the gas flow rate at the upper and lower parts of the heating section is greater than 0 before starting oxygen-enriched combustion in the heating section includes: If the result is yes, proceed to the next step; If the result is negative, then the oxygen-enriched combustion in the heating section is shut off.

10. The pulse-type oxygen-enriched combustion control method for a regenerative heater according to claim 9, characterized in that, The closed heating section oxygen-enriched combustion includes: Three conditions must be met: real-time judgment of whether the gas flow rate at the upper part of the heating section is 0, real-time judgment of whether the gas flow rate at the lower part of the heating section is 0, and real-time judgment of whether the quick-cut valve of the main gas pipe is closed. If any one of the conditions is not met, the three conditions will continue to be executed; If all conditions are met, then the oxygen-enriched combustion of the closed heating section is completed; If a malfunction occurs during execution and an alarm is triggered, the oxygen-enriched combustion step of shutting off the heating section can only be executed again after a 5-minute countdown.

Images