Multi-fuel annealing furnace combustion control system

Abstract

The utility model provides a fuel annealing furnace combustion control system which comprises a multi-fuel annealing furnace body, a multi-fuel combustor, a combustion control system taking blast furnace gas as fuel, a combustion control system taking natural gas as fuel, a combustion control system taking fuel oil as fuel, a smoke exhaust system, an air supply pipeline, a central air pipeline, a compressed air pipeline, a smoke exhaust system and a waste heat system, the multi-fuel combustor is arranged in the multi-fuel annealing furnace body; the combustion control system taking blast furnace gas as fuel, the combustion control system taking natural gas as fuel, the combustion control system taking fuel oil as fuel, the central air pipeline and the compressed air pipeline are respectively communicated with the multi-fuel combustor; and the air supply pipeline and the smoke exhaust system are respectively communicated with a hearth of the multi-fuel annealing furnace body. According to the utility model, heat supply fuel can be flexibly selected according to on-site actual conditions. The number of holes formed in the furnace wall of the annealing furnace is greatly reduced, the overall service life of the furnace is prolonged, the sealing performance and the energy-saving efficiency of the annealing furnace are improved, and meanwhile the economical efficiency of production is guaranteed.

Description

Technical Field

[0001] The utility model relates to an annealing furnace combustion control technology, in particular to a multi-fuel annealing furnace combustion control system. Background Art

[0002] Continuous cast pipe annealing furnace is used for spheroidizing annealing of cast iron pipes. Spheroidizing annealing of ductile iron pipes is to anneal the pipes through heating, heat preservation, rapid cooling and slow cooling to eliminate cementite and pearlite generated in the casting process and transform the matrix into ferrite matrix structure of ductile iron pipes. The combustion control system is the core system of the annealing furnace. The fuel selection of the combustion control system directly affects the production efficiency, production cost and production quality. Utility Model Content

[0003] The purpose of the utility model is to propose a multi-fuel annealing furnace combustion control system in response to the increasing demand for combustion control. The combustion control system can reuse waste heat, save energy and reduce consumption, and is green and environmentally friendly; the heat storage combustion and heat exchanger technology saves fuel and reduces costs; the multi-fuel system can meet the shortage of one fuel and start another system at any time, which is flexible to use and free from external factors; and the system adopts PLC and human-machine interface control, which can realize continuous closed-loop regulation, effectively increase equipment stability, and improve product quality.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a multi-fuel annealing furnace combustion control system, including a multi-fuel annealing furnace body, a multi-fuel burner, a combustion control system using blast furnace gas as fuel, a combustion control system using natural gas as fuel, a combustion control system using fuel oil as fuel, a smoke exhaust system, an air supply pipeline, a central air pipeline, a compressed air pipeline, a smoke exhaust system and a waste heat system; the multi-fuel burner is arranged in the multi-fuel annealing furnace body, the combustion control system using blast furnace gas as fuel, the combustion control system using natural gas as fuel, the combustion control system using fuel oil as fuel, the central air pipeline, and the compressed air pipeline are respectively connected to the multi-fuel burner; the air supply pipeline and the smoke exhaust system are respectively connected to the furnace of the multi-fuel annealing furnace body; the waste heat system is connected to the smoke exhaust system.

[0005] Furthermore, the multi-fuel annealing furnace body includes a heating zone, a heat preservation zone, a rapid cooling section and a slow cooling section in sequence. The heating zone can be divided according to production needs. The more zones there are, the finer the control, for example, it can be divided into heating zone 1 and heating zone 2.

[0006] Furthermore, the multi-fuel burner is arranged in the heating zone and the heat preservation zone.

[0007] Furthermore, based on the characteristics of long and rigid flames of regenerative combustion, the multi-fuel burners on both sides of the furnace are arranged at intervals, which effectively avoids mutual interference between flames and improves the uniformity of furnace temperature.

[0008] Furthermore, the multi-fuel burner is also called a multi-fuel burner, and the multi-fuel burner comprises: a regenerative cavity, a regenerative burner shell, a burner outer chamber, a natural gas burner and a fuel oil burner, the regenerative burner shell has a built-in regenerative cavity, the regenerative burner shell is half-embedded with a natural gas burner, and the natural gas burner is half-embedded with a fuel oil burner;

[0009] The regenerative cavity comprises a refractory casting cavity and a refractory fiber blanket. The refractory casting cavity is formed by casting the casting in the regenerative burner shell; a blast furnace gas left chamber and a blast furnace gas right chamber are arranged side by side on the left and right sides of the refractory casting cavity; a natural gas burner mounting hole is arranged in the middle of the blast furnace gas left chamber and the blast furnace gas right chamber; a refractory fiber blanket is arranged between the refractory casting cavity and the inner wall of the regenerative burner shell;

[0010] The regenerative burner shell comprises a wall connection plate, a first air pipeline, a second air pipeline, an outer shell plate and a natural gas burner mounting plate, and the regenerative burner shell is fixed to the furnace through the wall connection plate; the inlets of the first air pipeline and the second air pipeline are respectively arranged above and below the outer shell plate, and the first air pipeline and the second air pipeline are respectively located at the upper and lower sides of the natural gas burner mounting hole, and the first air pipeline and the second air pipeline are combustion-supporting air pipelines for proportioning various gases; the natural gas burner mounting plate is arranged on a side of the outer shell plate away from the furnace, and cooperates with the natural gas burner mounting hole to connect and fix the natural gas burner;

[0011] The burner outer chamber includes a fixed grid, a round tube and a shell. The two burner outer chambers are respectively buckled on the side of the outer shell plate away from the furnace, and correspond to the left chamber of blast furnace gas and the right chamber of blast furnace gas. A fixed grid is arranged on the side of the shell close to the outer shell plate to prevent the honeycomb in the cavity from falling off. A round tube for external connection to the blast furnace gas pipeline is arranged on the top of the shell.

[0012] The natural gas burner includes a toothed disc, a central air duct, a natural gas pipe, a first mounting flange, a second mounting flange, a third mounting flange and a fourth mounting flange. The first mounting flange is fixed in the middle of the central air duct. The natural gas burner is inserted into the natural gas burner mounting hole and fixed to the natural gas burner mounting plate through the first mounting flange to achieve fixation of the natural gas burner to the heat storage burner shell; a second mounting flange is arranged on the side wall at one end of the central air duct, and the second mounting flange is used for external air pipeline; the natural gas pipe is inserted into the central air duct, and the gap between the central air duct and the natural gas pipe is the central air channel of the natural gas pipe. A toothed disc is arranged at one end of the natural gas pipe located in the central air duct, and a fourth mounting flange is arranged at one end of the natural gas pipe located outside the central air duct; the third mounting flange is fixed on the side wall of the natural gas pipe close to the fourth mounting flange, and the natural gas pipe and the third mounting flange constitute a natural gas channel. The third mounting flange is used for external natural gas pipeline, and the fourth mounting flange is used for fixing to the oil burner.

[0013] The fuel oil burner comprises: a nozzle, a swirler, a nozzle, a first oil pipe, a flange mounting plate, a second oil pipe, an oil nozzle, a plug, a first compressed air pipe, an inner core, and a second compressed air pipe;

[0014] The first oil pipe is threadedly connected with the second oil pipe, and the nozzle is fixed at one end of the first oil pipe away from the second oil pipe. The nozzle is a nozzle for light diesel oil and compressed air. The light diesel oil is atomized by high-pressure air at the nozzle, and the atomized oil gas is mixed with the combustion-supporting air and then fully burned.

[0015] The second compressed air pipe is located in the first oil pipe, one end of the first compressed air pipe is embedded in the inner side of the second oil pipe, the first compressed air pipe is threadedly connected to the second compressed air pipe, and the gap between the oil pipes (the first oil pipe and the second oil pipe) and the compressed air pipes (the first compressed air pipe and the second compressed air pipe) is a fuel oil channel; the outer side of the nozzle is connected to the swirler, and the inner side is threadedly connected to the second compressed air pipe, and the inner core is fixed to the inner side of the nozzle; the flange mounting plate is fixed on the side wall in the middle of the second oil pipe, and the fuel oil burner is embedded in the natural gas burner, and is fixed to the fourth mounting flange of the natural gas burner through the flange mounting plate, so as to realize the fixation of the fuel oil burner and the natural gas burner.

[0016] The oil nozzle is arranged on the side wall of the second oil pipe and is the inlet for the fuel oil to enter the fuel oil burner. The oil nozzle is communicated with the fuel oil channel.

[0017] Further, the combustion control system using blast furnace gas as fuel is an energy-saving system using heat storage, and the combustion control system using blast furnace gas as fuel includes a blast furnace gas pipeline;

[0018] In the blast furnace gas pipeline, the blast furnace gas main is arranged on one side of the annealing furnace, and a plurality of blast furnace gas branches are divided from the blast furnace gas main, leading to the heating zone and the insulation zone respectively; the heating zone and the insulation zone are respectively provided with four-way reversing valves, and the blast furnace gas branches are connected to the multi-fuel burners through the four-way reversing valves, and the multiple multi-fuel burners are divided into two groups, and each group of multi-fuel burners is in different states as the four-way reversing valve is switched. Taking six multi-fuel burners as an example, three multi-fuel burners on each side form a group, and each group of multi-fuel burners is in different states as the four-way reversing valve is switched.

[0019] Furthermore, there are multiple blast furnace gas branch pipes on the blast furnace gas main pipe, and blast furnace gas pneumatic shut-off valves and blast furnace gas regulating valves are respectively provided on the blast furnace gas branch pipes. The function of the pneumatic shut-off valve is to quickly and automatically cut off the blast furnace gas and stop working to ensure safe production when the system detects abnormal conditions that affect production or pose safety risks. The function of the electric regulating valve is that when the PLC and the human-machine interface receive the furnace temperature signal collected by the main control thermocouple, it is compared with the set process temperature and then outputs a signal after PID calculation. By controlling the opening of the electric regulating valve, the actual demand for blast furnace gas can be effectively regulated to achieve precise temperature control.

[0020] Furthermore, a manual sealing butterfly valve is provided at the connection between the next-level blast furnace gas branch line of each blast furnace gas branch pipe and the blast furnace gas interface of the burner, which is used for refined independent control of each burner during production debugging and the cut-off function under special circumstances.

[0021] Furthermore, the air supply branch pipe is provided with an electric regulating valve, and the valve opening is adjusted according to the pid calculation to control the air flow. A manual regulating butterfly valve is provided in front of each burner air interface to facilitate the cut-off or fine adjustment of the air flow in front of each burner.

[0022] Furthermore, a plurality of air supply branches are branched from the main air supply line of the air supply line, which are respectively connected to the furnaces in the heating zone and the heat preservation zone. Specifically, the air supply branches are connected to the furnaces through the multi-fuel burners;

[0023] A fan and a heat exchanger are provided in the air supply pipeline. The fan is used to supply air to the furnace. Specifically, the fan sends air into the heat exchanger to exchange heat with the flue gas in the smoke exhaust system. After preheating, the air enters the air supply branch pipelines of each zone through the air supply main pipeline, and finally enters the furnace through the burner air interface 1 and the burner air interface 2, and is mixed with the blast furnace gas and then burned to provide heat.

[0024] Furthermore, the air supply branch pipe is provided with an electric regulating valve, and the valve opening is adjusted according to the pid calculation to control the air flow. A manual regulating butterfly valve is provided in front of each burner air interface to facilitate the cut-off or fine adjustment of the air flow in front of each burner.

[0025] Furthermore, the central air duct can protect the core components of the burner from being damaged by high temperature, and at the same time provide air for the air supply duct. The central air duct includes a small fan arranged at the top of the furnace, a central air branch duct is arranged on both sides of the furnace body, and a central air branch duct is connected to the central air branch duct in front of each burner, and a manual regulating butterfly valve is arranged on the central air branch duct. The central air branch duct is connected to the multi-fuel burner, specifically, to the central air interface of the central air duct.

[0026] Furthermore, the combustion control system using natural gas as fuel includes a natural gas pipeline; the combustion control system using natural gas as fuel has a simple structure and precise control. In the natural gas pipeline, a natural gas main pipe is arranged on one side of the annealing furnace, and a plurality of natural gas branches are branched from the natural gas main pipe, leading to the heating zone and the insulation zone respectively. Specifically, the natural gas branch pipe is connected to the natural gas interface of the multi-fuel burner;

[0027] Furthermore, the natural gas main is provided with a manual ball valve, a filter, an electric shut-off valve, a pressure gauge and a pressure switch at the incoming gas interface. 1. The manual ball valve is used for shutting off or manually adjusting the flow; 2. The pressure gauge and the pressure buffer tube are used for displaying and observing the pressure; 3. The filter is used to filter welding slag, iron filings, dust and other impurities brought by the gas medium to protect downstream equipment, improve the safety performance of downstream equipment, and effectively extend the service life of downstream equipment; 4. The pressure switch (low pressure) is used to detect the incoming gas pressure, and an alarm will be triggered when the pressure is lower than the set value; 5. The relief valve automatically releases the pressure when the pressure exceeds the overpressure. It is used to release the instantaneous pressure rise caused by the opening of the upstream valve to protect the downstream valve. 6. The electric shut-off valve is used for safe shut-off of the main gas; 7. The pressure gauge and the high-pressure switch are used to detect the incoming gas pressure, and an alarm will be triggered when the pressure is higher than the set value;

[0028] Furthermore, an electric regulating butterfly valve is respectively provided on the natural gas branch pipe, which receives the furnace temperature signal collected by the main control thermocouple through the PLC and the human-machine interface, compares it with the set process temperature, and outputs the signal after PID calculation. The electric regulating valve controls the natural gas flow rate in proportion to achieve precise temperature control. A manual ball valve is added to the natural gas branch pipe on the natural gas branch pipe, where it is connected to the natural gas interface of the burner, for refined control to compensate for the error of theoretical calculation.

[0029] Furthermore, the combustion control system using natural gas as fuel and the combustion control system using blast furnace gas as fuel use the same air supply pipeline and central air pipeline, but when using different fuels, the combustion air consumption is different and the valve opening is different.

[0030] Furthermore, the combustion control system using fuel oil as fuel includes a fuel oil pipeline;

[0031] In the fuel oil pipeline, the fuel oil main pipe is arranged on one side of the annealing furnace, and a plurality of fuel oil branch pipes are divided from the fuel oil main pipe, leading to the heating zone and the insulation zone respectively; specifically, the fuel oil branch pipes are connected to the fuel oil interface of the multi-fuel burner;

[0032] Two rows of valve groups are set in parallel on the oil inlet main pipe in the fuel oil pipeline, which is convenient for maintenance and replacement, and the other set can be used as a spare; each row of valve groups is equipped with a first manual ball valve, a first flexible joint, a filter, a second flexible joint, and a second manual ball valve. 1. The first manual ball valve is used to adjust or cut off the oil volume; 2. The first flexible joint is easy to disassemble; 3. The filter is used to filter impurities in the fuel oil on the main pipe to protect the downstream equipment and extend the service life of the downstream equipment; 4. The second flexible joint is easy to maintain; 5. The second manual ball valve is used for cutting. After the valve group, a pressure gauge is set on the main pipe for pressure detection and observation;

[0033] The return oil main pipe in the fuel oil pipeline is equipped with a pressure transmitter, a manual shut-off valve and a pressure regulating valve. 1. The pressure transmitter is used to extract and record the pressure; 2. The manual shut-off valve is used to cut off; 3. The pressure regulating valve is used to stabilize and regulate the circulating oil circuit pressure of the fuel oil.

[0034] Furthermore, the fuel oil main pipe is provided with a plurality of fuel oil branch pipes, which are divided into two groups, and each group of fuel oil branch pipes is provided with a first flexible joint, an electric regulating valve, a second flexible joint, and a manual regulating valve. 1. The first flexible joint is easy to disassemble; 2. The function of the electric regulating valve is that when the PLC and the human-machine interface receive the furnace temperature signal collected by the main control thermocouple, it outputs a signal after comparing it with the set process temperature and calculating it through PID, and the fuel oil flow is proportionally controlled through the electric regulating valve to achieve precise temperature control; 3. The second flexible joint is easy to disassemble; 4. The manual regulating valve is used for auxiliary adjustment and cutting.

[0035] Furthermore, each fuel oil branch pipe has multiple fuel oil branches leading to each multi-fuel burner; the fuel oil branch pipe in front of the multi-fuel burner is equipped with a manual shut-off valve, a manual adjustment needle valve and a flexible joint. 1. The manual shut-off valve is used to cut off the fuel oil; 2. The manual adjustment needle valve is used for fine adjustment of the fuel oil in front of the nozzle; 3. The flexible joint is easy to disassemble.

[0036] Furthermore, the air supply pipeline and central air pipeline used by the combustion control system using fuel oil as fuel and the combustion control system using blast furnace gas as fuel are the same pipeline, but when using different fuels, the combustion air consumption is different and the valve opening is different.

[0037] Furthermore, the smoke exhaust system includes: a furnace mouth smoke exhaust area, a heating and heat preservation section smoke exhaust area and a slow cooling section smoke exhaust area;

[0038] The furnace mouth smoke exhaust area is shared by three fuel systems (a combustion control system using blast furnace gas as fuel, a combustion control system using natural gas as fuel, and a combustion control system using fuel oil as fuel). The furnace mouth smoke exhaust area includes a smoke exhaust port, a heat exchanger, a smoke exhaust fan, and a chimney that are arranged in sequence. 1. The three smoke exhaust ports are passages in the furnace and the furnace mouth smoke exhaust pipeline 7; 2. The heat exchanger is used for heat exchange between the smoke in the furnace and the air in the air pipeline, which can achieve low-temperature emission of high-temperature smoke. The principle is that during the combustion process in the furnace, high-temperature smoke will be generated, which will be discharged from the smoke exhaust port. After heat exchange in the heat exchanger, the high-temperature smoke will be discharged from the furnace through the smoke exhaust fan and safely discharged from the chimney. The advantage of this system is that it can achieve low-temperature emission of smoke and preheat the air involved in combustion, saving energy.

[0039] The exhaust area of ​​the heating and heat preservation section is only used for the blast furnace gas system, that is, for exhausting smoke during reversing. The regenerative burner reversing exhausts smoke, and each burner is equipped with a thermal resistor to monitor the exhaust temperature of each regenerative burner. An electric valve is configured between each section of the exhaust pipe and the exhaust main pipe to facilitate the adjustment of the pressure of each section. The advantages of this system are accurate and automatic control of exhaust, low exhaust gas temperature, and less heat loss.

[0040] The slow cooling section smoke exhaust area includes auxiliary smoke exhaust ports and smoke exhaust pipes, main pipelines, electric regulating valves and smoke exhaust fans. 1. Two auxiliary smoke exhaust ports and smoke exhaust pipes are lined with refractory fiber folding blocks for heat preservation; 2. An inspection port is set on the main pipeline, which is detachable for easy maintenance; 3. The electric regulating valve is used to adjust the smoke volume on the waste heat utilization pipeline; 4. Smoke exhaust fan. The advantage of this system is that the high-temperature smoke discharged is reasonably recycled and reused for heat supply to other equipment.

[0041] Furthermore, the waste heat system is a device that can utilize waste heat, including a hot flue gas conveying pipeline, pipeline insulation, a pipeline expansion joint and waste heat utilization equipment, such as a drying furnace.

[0042] Furthermore, the compressed air pipeline includes two groups of compressed air main pipes, on which pressure gauges, pressure buffer pipes and pressure switches are arranged to detect and feedback the air pressure on the compressed air main pipes, and alarm feedback is given when the pressure is abnormal; each group of compressed air main pipes is provided with compressed air branch pipes between each multi-fuel burner and the four-way reversing valve and the main pipe. A flexible joint and a manual ball valve are arranged on the compressed air branch pipe in front of the multi-fuel burner. 1. The flexible joint is convenient for loading and unloading; 2. The manual ball valve is convenient for the refined control of the compressed air of each burner. A manual ball valve, a flexible joint and a filter pressure reducing valve are arranged in front of each four-way reversing valve. 1. The manual ball valve is convenient for individual control; 2. The interface leading to the pneumatic execution of the four-way valve; 3. The flexible joint and the manual ball valve are convenient for loading and unloading; 4. The filter pressure reducing valve is used to filter impurities in the compressed air pipeline to protect the back-line equipment.

[0043] The compressed air pipeline is mainly used for atomizing liquid fuel when using fuel oil; providing high-pressure purge air to the burner, which is beneficial for purging other residual fuel gas in the pipeline when switching fuel; and providing power for the pneumatic control system.

[0044] Furthermore, the multi-fuel annealing furnace combustion control system further includes a rapid cooling section cooling air pipeline and a slow cooling section cooling air pipeline;

[0045] The cooling air duct of the rapid cooling section and the cooling air duct of the slow cooling section are arranged on the top of the multi-fuel annealing furnace. The cooling air duct of the rapid cooling section and the cooling air duct of the slow cooling section are both provided with a fan and an electric regulating valve. 1. The fan is used to send air into the furnace under normal conditions; 2. The electric regulating valve is used to adjust the air flow. The fan is provided with a buffer base, a fan connecting pipe and other accessories.

[0046] The function of the rapid cooling section cooling air duct and the slow cooling section cooling air duct is to use the fan to send air into the furnace through the duct. According to the temperature detected by the thermocouple in the furnace, the system automatically controls the opening of the electric adjustment, and the temperature in the furnace is reduced to a predetermined temperature by the cold air entering the furnace.

[0047] Compared with the prior art, the multi-fuel annealing furnace combustion control system of the utility model has the following advantages:

[0048] 1) The utility model improves the combustion system, reutilizes waste heat, saves energy and reduces consumption, and is green and environmentally friendly;

[0049] 2) The utility model's heat storage combustion and heat exchanger technology saves fuel and reduces costs;

[0050] 3) The multi-fuel system of the utility model can meet the shortage of one fuel and start another system at any time, which is flexible to use and free from external factors;

[0051] 4) The utility model adopts PLC and human-machine interface control to achieve continuous closed-loop regulation, effectively increase equipment stability and improve product quality.

[0052] In summary, the multi-fuel annealing furnace combustion control system of the utility model is a multi-fuel combustion control system. It can meet the combustion heating of blast furnace gas, natural gas and light diesel fuel respectively. This system can flexibly select heating fuel according to the actual situation on site. It greatly reduces the number of openings in the furnace wall of the annealing furnace, prolongs the overall life of the furnace, and ensures the economic efficiency of production while improving the sealing and energy-saving efficiency of the annealing furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a schematic diagram of the combustion control system of a multi-fuel annealing furnace;

[0054] Figure 2This is the front view of the multi-fuel burner;

[0055] Figure 3 It is a top view of a multi-fuel burner;

[0056] Figure 4 It is the working state one of the four-way reversing valve;

[0057] Figure 5 It is the working state 2 of the four-way reversing valve;

[0058] Figure 6 It is the working status of the combustion control system using blast furnace gas as fuel;

[0059] Figure 7 This is the right view of the combustion control system using blast furnace gas as fuel;

[0060] Figure 8 The main view of the combustion control system using natural gas as fuel;

[0061] Fig. 9 Right view of the combustion control system using natural gas as fuel;

[0062] Fig.10 This is the front view of the combustion control system using fuel oil as fuel;

[0063] Fig.11 Top view of the central air duct;

[0064] Fig.12 This is a top view of the air supply pipeline;

[0065] Fig.13 This is the main view of the air supply pipeline;

[0066] Fig.14 Top view of the smoke exhaust system;

[0067] Fig.15 Front view of the smoke exhaust system;

[0068] Fig.16 It is a top view of the compressed air pipeline;

[0069] Fig.17 Schematic diagram of waste heat pipeline;

[0070] Fig.18 This is the main view of the cooling air pipeline in the quenching section;

[0071] Fig.19 This is a top view of the cooling air pipeline in the rapid cooling section;

[0072] Fig. 20 This is the main view of the cooling air duct in the slow cooling section.

[0073] Fig.21 This is a schematic diagram of the cooling air duct in the slow cooling section. DETAILED DESCRIPTION

[0074] The present invention is further described below with reference to the embodiments:

[0075] Example 1

[0076] This embodiment discloses a multi-fuel annealing furnace combustion control system. Figure 1-21 As shown, it includes a multi-fuel annealing furnace body, a multi-fuel burner 4, a combustion control system using blast furnace gas as fuel, a combustion control system using natural gas as fuel, a combustion control system using fuel oil as fuel, a smoke exhaust system, an air supply pipeline, a central air pipeline, a compressed air pipeline, a smoke exhaust system and a waste heat system; the multi-fuel burner is arranged in the multi-fuel annealing furnace body, and the combustion control system using blast furnace gas as fuel, the combustion control system using natural gas as fuel, the combustion control system using fuel oil as fuel, the central air pipeline, and the compressed air pipeline are respectively connected to the multi-fuel burner; the air supply pipeline and the smoke exhaust system are respectively connected to the furnace of the multi-fuel annealing furnace body; the waste heat system is connected to the smoke exhaust system.

[0077] The waste heat system is at the end of the annealing furnace exhaust system. The high-temperature flue gas in the exhaust system is diverted to the low-temperature furnace at the end of the cast pipe production line, such as the drying furnace, through the electric regulating butterfly valve and the induced draft fan. The hot air is introduced into the heating pipeline of the drying furnace through the electric regulating butterfly valve and the induced draft fan to provide heat for the drying furnace and realize the secondary utilization of the waste heat.

[0078] The multi-fuel annealing furnace body includes a heating zone, a heat preservation zone, a rapid cooling section and a slow cooling section arranged in sequence. The heating zone can be divided according to production needs. The more zones, the finer the control, for example, it can be divided into heating zone 1 and heating zone 2.

[0079] The multi-fuel burners are arranged in the heating zone and the heat preservation zone.

[0080] Based on the characteristics of long and rigid flames of regenerative combustion, the multi-fuel burners on both sides of the furnace are arranged at intervals, which effectively avoids mutual interference between flames and improves the uniformity of furnace temperature.

[0081] like Figure 2 and Figure 3 As shown, the multi-fuel burner 4 is also called a multi-fuel burner, and the multi-fuel burner comprises: a regenerative cavity, a regenerative burner shell, a burner outer chamber, a natural gas burner and a fuel oil burner, the regenerative burner shell has a built-in regenerative cavity, the regenerative burner shell is half-embedded with a natural gas burner, and the natural gas burner is half-embedded with a fuel oil burner;

[0082] The regenerative cavity comprises a refractory casting cavity and a refractory fiber blanket. The refractory casting cavity is formed by casting the casting in the regenerative burner shell; a blast furnace gas left chamber and a blast furnace gas right chamber are arranged side by side on the left and right sides of the refractory casting cavity; a natural gas burner mounting hole is arranged in the middle of the blast furnace gas left chamber and the blast furnace gas right chamber; a refractory fiber blanket is arranged between the refractory casting cavity and the inner wall of the regenerative burner shell;

[0083] The regenerative burner shell comprises a wall connection plate, a first air pipeline, a second air pipeline, an outer shell plate and a natural gas burner mounting plate, and the regenerative burner shell is fixed to the furnace through the wall connection plate; the inlets of the first air pipeline and the second air pipeline are respectively arranged above and below the outer shell plate, and the first air pipeline and the second air pipeline are respectively located at the upper and lower sides of the natural gas burner mounting hole, and the first air pipeline and the second air pipeline are combustion-supporting air pipelines for proportioning various gases; the natural gas burner mounting plate is arranged on a side of the outer shell plate away from the furnace, and cooperates with the natural gas burner mounting hole to connect and fix the natural gas burner;

[0084] The burner outer chamber includes a fixed grid, a round tube and a shell. The two burner outer chambers are respectively buckled on the side of the outer shell plate away from the furnace, and correspond to the left chamber of blast furnace gas and the right chamber of blast furnace gas. A fixed grid is arranged on the side of the shell close to the outer shell plate to prevent the honeycomb in the cavity from falling off. A round tube for external connection to the blast furnace gas pipeline is arranged on the top of the shell.

[0085] The natural gas burner includes a toothed disc, a central air duct, a natural gas pipe, a first mounting flange, a second mounting flange, a third mounting flange and a fourth mounting flange. The first mounting flange is fixed in the middle of the central air duct. The natural gas burner is inserted into the natural gas burner mounting hole and fixed to the natural gas burner mounting plate through the first mounting flange to achieve fixation of the natural gas burner to the heat storage burner shell; a second mounting flange is arranged on the side wall at one end of the central air duct, and the second mounting flange is used for external air pipeline; the natural gas pipe is inserted into the central air duct, and the gap between the central air duct and the natural gas pipe is the central air channel of the natural gas pipe. A toothed disc is arranged at one end of the natural gas pipe located in the central air duct, and a fourth mounting flange is arranged at one end of the natural gas pipe located outside the central air duct; the third mounting flange is fixed on the side wall of the natural gas pipe close to the fourth mounting flange, and the natural gas pipe and the third mounting flange constitute a natural gas channel. The third mounting flange is used for external natural gas pipeline, and the fourth mounting flange is used for fixing to the oil burner.

[0086] The fuel oil burner comprises: a nozzle, a swirler, a nozzle, a first oil pipe, a flange mounting plate, a second oil pipe, an oil nozzle, a plug, a first compressed air pipe, an inner core, and a second compressed air pipe;

[0087] The first oil pipe is threadedly connected with the second oil pipe, and the nozzle is fixed at one end of the first oil pipe away from the second oil pipe. The nozzle is a nozzle for light diesel oil and compressed air. The light diesel oil is atomized by high-pressure air at the nozzle, and the atomized oil gas is mixed with the combustion-supporting air and then fully burned.

[0088] The second compressed air pipe is located in the first oil pipe, one end of the first compressed air pipe is embedded in the inner side of the second oil pipe, the first compressed air pipe is threadedly connected to the second compressed air pipe, and the gap between the oil pipes (the first oil pipe and the second oil pipe) and the compressed air pipes (the first compressed air pipe and the second compressed air pipe) is a fuel oil channel; the outer side of the nozzle is connected to the swirler, and the inner side is threadedly connected to the second compressed air pipe, and the inner core is fixed to the inner side of the nozzle; the flange mounting plate is fixed on the side wall in the middle of the second oil pipe, and the fuel oil burner is embedded in the natural gas burner, and is fixed to the fourth mounting flange of the natural gas burner through the flange mounting plate, so as to realize the fixation of the fuel oil burner and the natural gas burner.

[0089] The oil nozzle is arranged on the side wall of the second oil pipe and is the inlet for the fuel oil to enter the fuel oil burner. The oil nozzle is communicated with the fuel oil channel.

[0090] like Figure 6 , 7 As shown, the combustion control system using blast furnace gas as fuel is an energy-saving system using heat storage, and the combustion control system using blast furnace gas as fuel includes a blast furnace gas pipeline 1;

[0091] In the blast furnace gas pipeline 1, the blast furnace gas main pipe 14 is arranged on one side of the annealing furnace, and a plurality of blast furnace gas branches are branched from the blast furnace gas main pipe, leading to the heating zone and the insulation zone respectively; the heating zone and the insulation zone are respectively provided with four-way reversing valves 17, and the blast furnace gas branches are connected to the multi-fuel burners through the four-way reversing valves 17, and the plurality of multi-fuel burners are divided into two groups, and each group of multi-fuel burners is in a different state with the switching of the four-way reversing valves 17. Taking six multi-fuel burners as an example, three multi-fuel burners on each side form a group, and each group of multi-fuel burners is in a different state with the switching of the four-way reversing valves.

[0092] There are multiple blast furnace gas branch pipes on the blast furnace gas main pipe, and the blast furnace gas pneumatic shut-off valve 16 and blast furnace gas regulating valve 15 are respectively provided on the blast furnace gas branch pipes. The function of the pneumatic shut-off valve is to quickly and automatically cut off the blast furnace gas and stop working to ensure safe production when the system detects abnormal conditions that affect production or pose safety risks. The function of the electric regulating valve is that when the PLC and the human-machine interface receive the furnace temperature signal collected by the main control thermocouple, it is compared with the set process temperature and outputs a signal after PID calculation. By controlling the opening of the electric regulating valve, the actual demand for blast furnace gas can be effectively regulated to achieve precise temperature control.

[0093] A manual sealing butterfly valve is provided on the next-level blast furnace gas branch line of each blast furnace gas branch pipe and the blast furnace gas interface connection of the burner, which is used for refined independent control of each burner in the production commissioning process and the cut-off function under special circumstances.

[0094] The air supply branch pipe is equipped with an electric regulating valve, which adjusts the valve opening according to the pid calculation to control the air flow. A manual regulating butterfly valve is provided in front of each burner air interface to facilitate the cut-off or fine adjustment of the air flow in front of each burner.

[0095] like Fig.12 and 13 As shown, a plurality of air supply branches are divided from the main air supply line 53 of the air supply line, which are respectively connected to the furnaces in the heating zone and the heat preservation zone. Specifically, the air supply branches are connected to the furnaces through the multi-fuel burners;

[0096] A combustion-supporting fan 51 and a heat exchanger 52 are provided in the air supply pipeline. The combustion-supporting fan is used to supply air to the furnace. Specifically, the combustion-supporting fan sends air into the heat exchanger to exchange heat with the flue gas in the smoke exhaust system. After preheating, the air enters the air supply branch pipelines of each zone through the main air supply pipeline, and finally enters the furnace through the burner air interface 1 and the burner air interface 2, and is mixed with the blast furnace gas and then burned to provide heat.

[0097] The function of the explosion-proof device 54 is that when there is gas in the system and it reaches the explosion limit, an explosion accident will occur during ignition. At this time, the pressure in the system is instantly released through the pressure relief device to avoid the occurrence of accidents. The manual adjustment butterfly valve 55, where the next-level branch pipe of each branch pipe is connected to the blast furnace gas interface of the burner, is equipped with a manual sealing butterfly valve for the refined independent control of each burner during the production commissioning process and the cut-off function under special circumstances. The function of the electric control valve 56 is that when the PLC and the human-machine interface receive the furnace temperature signal collected by the main control thermocouple, it is compared with the set process temperature and outputs a signal after PID calculation. By controlling the opening of the electric control valve, the actual demand for blast furnace gas can be effectively regulated to achieve precise temperature control.

[0098] The air supply branch pipe is equipped with an electric regulating valve, which adjusts the valve opening according to the pid calculation to control the air flow. A manual regulating butterfly valve is provided in front of each burner air interface to facilitate the cut-off or fine adjustment of the air flow in front of each burner.

[0099] like Fig.11As shown, the central air duct 5 can protect the core components of the burner from high temperature damage, and at the same time provide air supply for the air supply duct. The central air duct 5 includes a central air fan 43 and a welding tee 44 arranged at the top of the furnace. A central air branch duct 42 is arranged on both sides of the furnace body. A central air branch duct is connected to the central air branch duct in front of each burner. A manual regulating butterfly valve 41 is arranged on the central air branch duct. The central air branch duct is connected to the multi-fuel burner, specifically, to the central air interface of the central air duct.

[0100] like Figure 4 As shown, when the four-way reversing valve is in working state 1, the valve plate forms an angle of 45 degrees with the center line of valve port 1. The valve plate divides the cavity into two independent cavities, cavity 1 and cavity 2. At this time, the blast furnace gas enters from valve port 1 and exits from valve port 2, and enters the blast furnace gas cavity A of the burner. After the blast furnace gas on the A side is ejected, it is mixed with the air ejected from the burner air interface 1 and the burner air interface 2 and then burned. The high-temperature flue gas in the furnace is discharged from the burner cavity B, preheating the heat storage body in the cavity, so that the heat is retained in the heat storage body, and the flue gas temperature is reduced. It enters the valve port 4 of the four-way reversing valve through the pipeline, is discharged from the valve port 3, and enters the exhaust pipe 7.

[0101] like Figure 5 As shown, when the four-way reversing valve is in working state 2, the valve plate forms an angle of 135 degrees with the center line of valve port 1. The valve plate divides the cavity into two independent cavities, cavity 3 and cavity 4. At this time, the blast furnace gas enters from valve port 1, exits from valve port 4, and enters the burner blast furnace gas cavity B. When the heat storage body of cavity B is in state 1, the heat stored is used to preheat the blast furnace gas entering cavity B. After being ejected from the B side, it is mixed with the air ejected from the burner air interface 1 and 2 and then burned. The high-temperature flue gas in the furnace is discharged from the burner cavity A, preheating the heat storage body in the cavity, so that the heat is retained in the heat storage body, and the flue gas temperature is reduced to enter the valve port 4 of the four-way reversing valve, and then discharged from the valve port 3 and enter the exhaust pipe 7.

[0102] Working state 1 and working state 2 switch each other, repeatedly realizing that flue gas stores heat in the heat storage body, and the heat storage body then preheats the blast furnace gas, effectively increasing the blast furnace gas temperature, improving combustion efficiency, saving energy, and effectively reducing the exhaust gas temperature, which is safe and environmentally friendly.

[0103] like Figure 8 and Fig. 9 As shown, the combustion control system using natural gas as fuel includes a natural gas pipeline 2; the combustion control system using natural gas as fuel has a simple structure and precise control. In the natural gas pipeline 2, a natural gas main pipe is arranged on one side of the annealing furnace, and a plurality of natural gas branches are branched from the natural gas main pipe, leading to the heating zone and the insulation zone respectively. Specifically, the natural gas branch pipe is connected to the natural gas interface of the multi-fuel burner;

[0104] The natural gas main is provided with a first manual ball valve 21, a filter 22, a pneumatic shut-off valve 23, a pressure gauge 24 and a pressure switch 25 at the gas inlet interface. 1. The first manual ball valve 21 is used for shutting off or manually adjusting the flow rate; 2. The pressure gauge 24 and the pressure buffer tube are used for displaying and observing the pressure; 3. The filter 22 is used to filter welding slag, iron filings, dust and other impurities brought by the gas medium, protect the downstream equipment, improve the safety performance of the downstream equipment, and effectively extend the service life of the downstream equipment; 4. The pressure switch 25 (low pressure) is used to detect the incoming gas pressure, and alarm when the pressure is lower than the set value; 5. The relief valve automatically releases the pressure when the pressure exceeds the pressure. It is used to release the instantaneous pressure rise caused by the opening of the upstream valve and protect the downstream valve. 6. The electric shut-off valve is used for the safe shut-off of the main gas; 7. The pressure gauge 24 and the high-pressure switch are used to detect the incoming gas pressure, and alarm when the pressure is higher than the set value; the electric regulating valve 26 is used for the individual adjustment of each group of burners, as shown in the figure, each group of three burners.

[0105] An electric regulating butterfly valve is respectively arranged on the natural gas branch pipe, which receives the furnace temperature signal collected by the main control thermocouple through the PLC and the human-machine interface, compares it with the set process temperature and outputs the signal after PID calculation, and controls the natural gas flow rate in proportion through the electric regulating valve to achieve precise temperature control. The natural gas branch pipe on the natural gas branch pipe is connected to the natural gas interface of the burner, and a second natural gas manual ball valve 27 is added for refined control to compensate for the error of theoretical calculation.

[0106] The air supply pipeline and central air pipeline used by the combustion control system using natural gas as fuel and the combustion control system using blast furnace gas as fuel are the same pipeline, but when using different fuels, the combustion air consumption is different and the valve opening is different.

[0107] like Fig.10 As shown, the combustion control system using fuel oil as fuel includes a fuel oil pipeline 3;

[0108] In the fuel oil pipeline 3, the fuel oil main pipe is arranged on one side of the annealing furnace, and a plurality of fuel oil branch pipes are divided from the fuel oil main pipe, leading to the heating zone and the insulation zone respectively; specifically, the fuel oil branch pipes are connected to the fuel oil interface of the multi-fuel burner;

[0109] Two rows of valve groups are arranged in parallel on the oil inlet main pipe in the fuel oil pipeline 3, so that the other set can be used as a spare during maintenance and replacement; each row of valve groups is provided with a first fuel oil manual ball valve 37, a first fuel oil flexible joint, a fuel oil filter 36, a second fuel oil flexible joint, and a second fuel oil manual ball valve. 1. The first fuel oil manual ball valve 37 is used to adjust or cut off the oil volume; 2. The first flexible joint is easy to disassemble; 3. The filter is used to filter impurities in the fuel oil on the main pipe to protect the downstream equipment and extend the service life of the downstream equipment; 4. The second flexible joint is easy to maintain; 5. The second fuel oil manual ball valve is used for cutting. After the valve group, a pressure gauge is set on the main pipe for pressure detection and observation;

[0110] A fuel oil pressure transmitter 33, a fuel oil manual shut-off valve 34 and a fuel oil pressure regulating valve 35 are arranged on the equipment on the return oil main pipe in the fuel oil pipeline 3. 1. The fuel oil pressure transmitter 33 is used for extracting and recording the pressure; 2. The fuel oil manual shut-off valve 34 is used for cutting off; 3. The fuel oil pressure regulating valve 35 is used for stabilizing and regulating the circulating oil circuit pressure of the fuel oil.

[0111] The fuel oil main pipe is provided with a plurality of fuel oil branch pipes, and the fuel oil branch pipes are divided into two groups. Each group of fuel oil branch pipes is provided with a first flexible joint, a fuel oil electric regulating valve 31, a second flexible joint, and a manual regulating valve 32. 1. The first flexible joint is easy to disassemble; 2. The function of the fuel oil electric regulating valve 31 is that when the PLC and the human-machine interface receive the furnace temperature signal collected by the main control thermocouple, it compares with the set process temperature and outputs a signal after PID calculation. The fuel oil flow is proportionally controlled through the electric regulating valve to achieve precise temperature control; 3. The second flexible joint is easy to disassemble; 4. The manual regulating valve 32 is used for auxiliary regulation and cutting.

[0112] Each fuel oil branch pipe also has multiple fuel oil branches leading to each multi-fuel burner; the fuel oil branch pipes in front of the multi-fuel burner are equipped with manual shut-off valves, manual adjustment needle valves and unions. 1. The manual shut-off valve is used to cut off the fuel oil; 2. The manual adjustment needle valve is used for fine adjustment of the fuel oil in front of the nozzle; 3. The union is easy to disassemble.

[0113] The air supply pipeline and central air pipeline used by the combustion control system using fuel oil as fuel and the combustion control system using blast furnace gas as fuel are the same pipeline. It is just that when using different fuels, the combustion air consumption is different and the valve opening is different.

[0114] like Fig.14 and Fig.15 As shown, the smoke exhaust system includes: a furnace mouth smoke exhaust area, a heating and heat preservation section smoke exhaust area and a slow cooling section smoke exhaust area;

[0115] The furnace mouth smoke exhaust area is shared by three fuel systems (a combustion control system using blast furnace gas as fuel, a combustion control system using natural gas as fuel, and a combustion control system using fuel oil as fuel). The furnace mouth smoke exhaust area includes a smoke exhaust port, a heat exchanger 52, a smoke exhaust fan 65, and a chimney 64. The heat exchanger accelerates the air flow rate under the action of the smoke exhaust fan 65, thereby increasing the smoke flow rate. 1. The three smoke exhaust ports are passages in the furnace and the furnace mouth smoke exhaust pipeline; 2. The heat exchanger 52 is used for air heat exchange between the smoke in the furnace and the air pipeline, which can achieve low-temperature emission of high-temperature smoke. Its principle is that during the combustion process in the furnace, high-temperature smoke will be generated, and the high-temperature smoke will be discharged from the smoke exhaust port. After heat exchange in the heat exchanger 52, the high-temperature smoke will be discharged from the furnace through the smoke exhaust fan 65 and discharged safely from the chimney 64. The advantage of this system is that it not only achieves low-temperature emission of smoke, but also preheats the air involved in combustion, saving energy.

[0116] The exhaust area of ​​the heating and heat preservation section is only used for the blast furnace gas system, that is, for exhausting smoke during reversing. The regenerative burner reversing exhausts smoke, and each burner is equipped with a thermal resistor to monitor the exhaust temperature of each regenerative burner. An electric valve is configured between each section of the exhaust pipe and the exhaust main pipe to facilitate the adjustment of the pressure of each section. The advantage of this system is that the exhaust is accurately and automatically controlled.

[0117] The slow cooling section smoke exhaust area includes auxiliary smoke exhaust ports and smoke exhaust pipes 81, main pipelines 82, electric regulating valves and smoke exhaust fans 85. 1. Two auxiliary smoke exhaust ports and smoke exhaust pipes are lined with refractory fiber folding blocks for heat preservation; 2. An inspection port 83 is set on the slow cooling section smoke exhaust main pipeline 82, which is detachable and convenient for maintenance; 3. The electric regulating valve is used to adjust the smoke volume on the waste heat utilization pipeline; 4. Smoke exhaust fan 85. The advantage of this system is that the high-temperature smoke discharged is reasonably recycled and reused for heat supply to other equipment.

[0118] like Fig.17 As shown, the flue gas enters the main pipeline 82 through two auxiliary exhaust ports and the exhaust pipe 81, and is sent into the waste heat pipeline through the exhaust fan 85 (not explicitly shown in the figure). The waste heat system is at the end of the exhaust system of the annealing furnace. The high-temperature flue gas in the exhaust system is drained to the low-temperature furnace at the end of the casting pipe production line, such as the drying furnace, through the electric regulating butterfly valve and the induced draft fan. The hot air is introduced into the heating pipeline of the drying furnace through the electric regulating butterfly valve and the induced draft fan to supply heat to the drying furnace, thereby realizing the secondary utilization of the waste heat.

[0119] 1. Waste heat pipeline, there is an insulation blanket on the outside of the waste heat pipeline, and the outside of the insulation blanket is wrapped with galvanized wall plate to reduce the heat dissipation loss of the pipeline under the long path. 2. Several expansion joints are used to alleviate the deformation caused by pipeline expansion, etc. 3. induced draft fan increases the flow rate and pressure of hot air entering the low-temperature furnace. 4. Branch pipelines are distributed to unused low-temperature furnaces. 5. Electric regulating valves are convenient for independent control of the hot air demand of each furnace.

[0120] like Fig.16 As shown, the compressed air pipeline 8 includes two groups of compressed air mains (a first compressed air main 71 and a second compressed air main 75), on which a pressure gauge 74, a pressure buffer tube, and a pressure switch are provided for detecting and feeding back the air pressure on the compressed air main, and for alarming and feeding back when the pressure is abnormal; each group of compressed air mains is provided with a compressed air branch pipe between each multi-fuel burner and the four-way reversing valve and the main pipe. A flexible joint and a manual ball valve 72 are provided in front of the compressed air branch pipe of the multi-fuel burner, and a pressure transmitter 73 converts the pressure signal into a current signal to realize automatic control. 1. The flexible joint is convenient for loading and unloading; 2. The manual ball valve is convenient for switching and fine control of the compressed air of each burner. A manual ball valve 72, a flexible joint and a filter pressure reducing valve 76 are arranged in front of each four-way reversing valve. 1. The manual ball valve 72 is convenient for individual control; 2. It is an interface leading to the pneumatic execution of the four-way valve; 3. The flexible joint and the manual ball valve are convenient for loading and unloading; 4. The filter pressure reducing valve 76 is used to filter impurities in the compressed air pipeline, adjust the compressed air pressure, and protect the downstream equipment.

[0121] The compressed air pipeline is mainly used for atomizing liquid fuel when using fuel oil; providing high-pressure purge air to the burner, which is beneficial for purging other residual fuel gas in the pipeline when switching fuel; and providing power for the pneumatic control system.

[0122] like Fig.18 , Fig.19 , Fig. 20 , Fig.21 As shown, the combustion control system of the multi-fuel annealing furnace also includes a rapid cooling section cooling air duct and a slow cooling section cooling air duct. The rapid cooling section cooling air duct 10 and the slow cooling section cooling air duct 11 are arranged on the top of the multi-fuel annealing furnace. The rapid cooling section cooling air duct is provided with a rapid cooling section cooling fan 91 and a rapid cooling section electric regulating valve 93, and the slow cooling section cooling air duct is provided with a slow cooling section cooling fan 106 and a slow cooling section electric regulating valve 103. 1. The fan is used to deliver air into the furnace under normal conditions; 2. The cooling air duct electric regulating valve 93 is used to adjust the air flow. The fan is provided with a buffer base, a cooling air duct fan connecting pipe and other accessories.

[0123] The function of the rapid cooling section cooling air duct and the slow cooling section cooling air duct is to use the fan to send air into the furnace through the duct. According to the temperature detected by the thermocouple in the furnace, the system automatically controls the opening of the electric regulating valve, and the temperature in the furnace is reduced to a predetermined temperature by the cold air entering the furnace.

[0124] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A multi-fuel annealing furnace combustion control system, characterized in that: It includes a multi-fuel annealing furnace body, a multi-fuel burner, a combustion control system using blast furnace gas as fuel, a combustion control system using natural gas as fuel, a combustion control system using fuel oil as fuel, a smoke exhaust system, an air supply pipeline, a central air pipeline, a compressed air pipeline, a smoke exhaust system and a waste heat system; the multi-fuel burner is arranged in the multi-fuel annealing furnace body, the combustion control system using blast furnace gas as fuel, the combustion control system using natural gas as fuel, the combustion control system using fuel oil as fuel, the central air pipeline, and the compressed air pipeline are respectively connected to the multi-fuel burner; the air supply pipeline and the smoke exhaust system are respectively connected to the furnace of the multi-fuel annealing furnace body; the waste heat system is connected to the smoke exhaust system.

2. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The multi-fuel burner comprises: a regenerative cavity, a regenerative burner shell, a burner outer chamber, a natural gas burner and a fuel oil burner, wherein the regenerative burner shell has a built-in regenerative cavity, the regenerative burner shell is half-embedded with a natural gas burner, and the natural gas burner is half-embedded with a fuel oil burner; The regenerative cavity comprises a refractory casting cavity and a refractory fiber blanket. The refractory casting cavity is formed by casting the casting in the regenerative burner shell; a blast furnace gas left chamber and a blast furnace gas right chamber are arranged side by side on the left and right sides of the refractory casting cavity; a natural gas burner mounting hole is arranged in the middle of the blast furnace gas left chamber and the blast furnace gas right chamber; a refractory fiber blanket is arranged between the refractory casting cavity and the inner wall of the regenerative burner shell; The regenerative burner shell comprises a wall connection plate, a first air pipeline, a second air pipeline, an outer shell plate and a natural gas burner mounting plate, and the regenerative burner shell is fixed to the furnace through the wall connection plate; the inlets of the first air pipeline and the second air pipeline are respectively arranged above and below the outer shell plate, and the first air pipeline and the second air pipeline are respectively located at the upper and lower sides of the natural gas burner mounting hole; the natural gas burner mounting plate is arranged on a side of the outer shell plate away from the furnace, and cooperates with the natural gas burner mounting hole to connect and fix the natural gas burner; The burner outer chamber comprises a fixed grid, a round tube and a shell. The two burner outer chambers are respectively buckled on the side of the outer shell plate away from the furnace and correspond to the left chamber of blast furnace gas and the right chamber of blast furnace gas. A fixed grid is arranged on the side of the shell close to the outer shell plate, and a round tube for externally connecting to the blast furnace gas pipeline is arranged on the top of the shell. The natural gas burner comprises a toothed disc, a central air duct, a natural gas pipe, a first mounting flange, a second mounting flange, a third mounting flange and a fourth mounting flange. The first mounting flange is fixed in the middle of the central air duct. The natural gas burner is inserted into the natural gas burner mounting hole and fixed to the natural gas burner mounting plate through the first mounting flange to achieve the fixation of the natural gas burner and the heat storage burner shell; a second mounting flange is arranged on the side wall at one end of the central air duct, and the second mounting flange is used for an external air pipeline; the natural gas pipe is inserted into the central air duct, and the gap between the central air duct and the natural gas pipe is the central air channel of the natural gas pipe. A toothed disc is arranged at one end of the natural gas pipe located in the central air duct, and a fourth mounting flange is arranged at one end of the natural gas pipe located outside the central air duct; a third mounting flange is fixed on the side wall of the natural gas pipe close to the fourth mounting flange, and the natural gas pipe and the third mounting flange constitute a natural gas channel; The fuel oil burner comprises: a nozzle, a swirler, a nozzle, a first oil pipe, a flange mounting plate, a second oil pipe, an oil nozzle, a plug, a first compressed air pipe, an inner core, and a second compressed air pipe; The first oil pipe is threadedly connected to the second oil pipe, and the nozzle is fixed on an end of the first oil pipe away from the second oil pipe; The second compressed air pipe is located in the first oil pipe, one end of the first compressed air pipe is embedded in the inner side of the second oil pipe, the first compressed air pipe is threadedly connected to the second compressed air pipe, and the gap between the oil pipe and the compressed air pipe is a fuel oil channel; the outer side of the nozzle is connected to the swirler, and the inner side is threadedly connected to the second compressed air pipe, and the inner core is fixed to the inner side of the nozzle; the flange mounting plate is fixed to the side wall in the middle of the second oil pipe, and the fuel oil burner is embedded in the natural gas burner, and is fixed to the fourth mounting flange of the natural gas burner through the flange mounting plate, so as to realize the fixation of the fuel oil burner and the natural gas burner; The oil nozzle is arranged on the side wall of the second oil pipe, and the oil nozzle is communicated with the fuel oil channel.

3. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The combustion control system using blast furnace gas as fuel includes a blast furnace gas pipeline; in the blast furnace gas pipeline, a blast furnace gas main pipe is arranged on one side of the annealing furnace, and a plurality of blast furnace gas branch pipes are branched from the blast furnace gas main pipe, leading to a heating zone and a heat preservation zone respectively; four-way reversing valves are respectively arranged in the heating zone and the heat preservation zone, and the blast furnace gas branch pipes are connected to the multi-fuel burner through the four-way reversing valve, and the plurality of multi-fuel burners are divided into two groups.

4. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: A plurality of air supply branches are branched from the main air supply pipe of the air supply pipe, which are respectively connected with the furnaces in the heating zone and the heat preservation zone; a fan and a heat exchanger are arranged in the air supply pipe.

5. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The central air duct includes a small fan arranged at the top of the furnace, a central air branch duct is arranged on both sides of the furnace body, a central air branch duct is connected to the central air branch duct in front of each burner, and a manual regulating butterfly valve is arranged on the central air branch duct.

6. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The combustion control system using natural gas as fuel includes a natural gas pipeline; in the natural gas pipeline, a natural gas main pipe is arranged on one side of the annealing furnace, and a plurality of natural gas branches are branched from the natural gas main pipe, which lead to the heating zone and the insulation zone respectively and are connected to the natural gas interface of the multi-fuel burner.

7. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The combustion control system using fuel oil as fuel includes a fuel oil pipeline; in the fuel oil pipeline, a fuel oil main pipe is arranged on one side of the annealing furnace, and a plurality of fuel oil branch pipes are branched from the fuel oil main pipe, leading to the heating zone and the insulation zone respectively; Two rows of valve groups are arranged in parallel on the oil inlet main pipe in the fuel oil pipeline; each row of valve groups is provided with a first manual ball valve, a first flexible joint, a filter, a second flexible joint, and a second manual ball valve; a pressure transmitter, a manual stop valve, and a pressure regulating valve are arranged on the equipment on the oil return main pipe in the fuel oil pipeline.

8. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The smoke exhaust system includes: a furnace mouth smoke exhaust area, a heating and heat preservation section smoke exhaust area and a slow cooling section smoke exhaust area; The furnace exhaust area includes an exhaust port, a heat exchanger, an exhaust fan and a chimney arranged in sequence; The heating and heat preservation section exhaust area is only used for the blast furnace gas system; the regenerative burner is used for reversing exhaust, each burner is equipped with a thermal resistor, and an electric valve is arranged between each section of the exhaust pipe and the exhaust main pipe; The slow cooling section smoke exhaust area includes an auxiliary smoke exhaust port and a smoke exhaust pipe, a main pipeline, an electric regulating valve and a smoke exhaust fan.

9. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: The compressed air pipeline includes two groups of compressed air main pipes, on which pressure gauges, pressure buffer pipes and pressure switches are arranged; each group of compressed air main pipes is provided with compressed air branch pipes between each multi-fuel burner and the four-way reversing valve and the main pipe; a flexible joint and a manual ball valve are arranged in front of the multi-fuel burner; a manual ball valve, a flexible joint and a filter pressure reducing valve are arranged in front of each four-way reversing valve.

10. The multi-fuel annealing furnace combustion control system according to claim 1, characterized in that: It also includes a rapid cooling section cooling air duct and a slow cooling section cooling air duct; the rapid cooling section cooling air duct and the slow cooling section cooling air duct are arranged on the top of the multi-fuel annealing furnace; the rapid cooling section cooling air duct and the slow cooling section cooling air duct are both provided with fans and electric regulating valves.

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