Cold rolling continuous annealing furnace oxygen-enriched combustion system and combustion monitoring method

Abstract

The invention discloses an oxygen-enriched combustion system of a cold rolling continuous annealing furnace, which comprises a radiant tube combustion heating system arranged in a hearth of the continuous annealing furnace, an online combustion monitoring system, a data acquisition and processing system, and a combustion-supporting air oxygen-enriched allocation system and a coal gas supply system which are connected with the radiant tube combustion heating system, the data collecting and processing system is arranged to control the oxygen content of combustion-supporting air in the radiant tube combustion heating system according to data collected by the online combustion monitoring system. According to the oxygen-enriched combustion system of the cold rolling continuous annealing furnace, the oxygen content of combustion-supporting air is controlled and increased in a combustion-supporting air main pipe filling mode, the combustion optimization effect is achieved by monitoring the surface temperature of the radiant tube on line, controlling the proportion of the oxygen-enriched amount in the combustion-supporting air, monitoring the residual oxygen of the flue gas of the radiant tube on line and controlling the combustion-supporting air amount on line, and the combustion efficiency is improved. The invention further discloses a combustion monitoring method of the cold rolling continuous annealing furnace oxygen-enriched combustion system.

Description

Technical Field

[0001] The invention belongs to the technical field of cold rolling continuous annealing furnaces, and in particular relates to an oxygen-enriched combustion system and a combustion monitoring method for a cold rolling continuous annealing furnace. Background Art

[0002] Cold rolling continuous annealing furnace is an important heat treatment equipment in the steel industry, which is used for continuous annealing of strip steel. It mainly adopts the indirect heating mechanism of radiation tubes. The existing combustion system uses air-assisted combustion, which has problems such as low combustion efficiency, high energy consumption, and large exhaust gas emissions.

[0003] A Chinese patent application with application number 201610041452.3 discloses an oxygen-enriched combustion system, wherein the oxygen-enriched combustion system comprises a boiler (1) and a coal mill (2), wherein the furnace inlet (11) of the boiler is connected to the coal mill outlet (22) of the coal mill, and the furnace outlet (12) of the boiler is connected to the coal mill inlet (21) of the coal mill, and an oxygen injection device group for supplying oxygen to the boiler and a flue gas cooling device for condensing at least a portion of water in the flue gas are arranged on a pipeline between the furnace outlet and the coal mill inlet.

[0004] It is desirable to provide an improved oxygen-enriched combustion system for a cold rolling continuous annealing furnace, particularly with respect to improving combustion efficiency. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides an oxygen-enriched combustion system for a cold rolling continuous annealing furnace, the purpose of which is to improve the combustion efficiency.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an oxygen-enriched combustion system for a cold rolling continuous annealing furnace, including a radiant tube combustion and heating system arranged in the furnace of the continuous annealing furnace, an online combustion monitoring system, a data acquisition and processing system, and a combustion air oxygen-enriched adjustment system and a gas supply system connected to the radiant tube combustion and heating system, and the data acquisition and processing system is configured to control the oxygen content of the combustion air in the radiant tube combustion and heating system according to the data collected by the online combustion monitoring system.

[0007] The radiant tube combustion heating system includes a radiant tube combustion heater arranged in the furnace of the continuous annealing furnace, the radiant tube combustion heater includes a combustion tube body and a burner, and the air inlet of the combustion tube body is connected to the combustion air oxygen enrichment system and the gas supply system.

[0008] A waste heat recovery device is arranged at the gas outlet of the combustion tube body, the waste heat recovery device is connected to the flue gas branch pipe, and the flue gas branch pipe is connected to the flue gas main pipe.

[0009] The combustion-supporting air oxygen-enriched mixing system comprises an oxygen pipeline, an air main pipe, a gas mixing chamber connected to the oxygen pipeline and the air main pipe, a blower connected to the gas mixing chamber, and an air branch pipe connected to the air main pipe and the radiant tube combustion heating system.

[0010] A first pressure sensor, a first flow meter, a first quick-cut-off solenoid valve and a first regulating valve are arranged in the oxygen pipeline.

[0011] An oxygen content detector and a second pressure sensor are arranged between the blower and the air branch pipe.

[0012] A second flow meter, a second quick-cut solenoid valve and a second regulating valve are arranged in the air branch pipe.

[0013] The gas supply system comprises a gas main pipe and a gas branch pipe connected to the gas main pipe, and the gas branch pipe is connected to the radiant tube combustion heating system.

[0014] A third flow meter, a third quick-cut-off solenoid valve and a third regulating valve are arranged in the gas branch pipe.

[0015] The present invention also provides a combustion monitoring method for an oxygen-enriched combustion system of a cold rolling continuous annealing furnace, wherein the surface temperature of the radiant tube combustion heating system is monitored by the online combustion monitoring system, and the online combustion monitoring system transmits the collected data to the data acquisition and processing system, and the data acquisition and processing system controls the oxygen content of the combustion-supporting air in the radiant tube combustion heating system.

[0016] The oxygen-enriched combustion system of the cold rolling continuous annealing furnace of the present invention controls and increases the oxygen content of the combustion-supporting air by filling the combustion-supporting air main pipe, controls the oxygen-enriched ratio in the combustion-supporting air by online monitoring of the surface temperature of the radiant tube, controls the combustion-supporting air volume by online monitoring of the residual oxygen in the flue gas of the radiant tube, achieves a combustion optimization effect, and improves combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] This specification includes the following drawings, which show the following contents:

[0018] Figure 1 It is a structural schematic diagram of the oxygen-enriched combustion system of the cold rolling continuous annealing furnace of the present invention;

[0019] The following are marked in the figure: 1. continuous annealing furnace; 2. radiant tube combustion heater; 3. waste heat recovery device; 4. flue gas branch pipe; 5. first temperature sensor; 6. first pressure sensor; 7. first quick-cut solenoid valve; 8. first flow meter; 9. first regulating valve; 10. air branch pipe; 11. gas branch pipe; 12. blower; 13. gas pressure stabilizing device; 14. variable frequency induced draft fan; 15. manual detection port; 16. first oxygen content detector; 17. gas mixing chamber; 18. data acquisition and processing system; 19. second pressure sensor; 20. second quick-cut solenoid valve; 22. second flow meter; 23. second regulating valve; 24. second oxygen content detector; 25. third quick-cut solenoid valve; 26. third flow meter; 27. third regulating valve; 28. second temperature sensor; 29. ​​third pressure sensor; 30. fourth pressure sensor; 31. fifth pressure sensor. DETAILED DESCRIPTION

[0020] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0021] It should be noted that, in the following embodiments, the “first”, “second” and “third” mentioned do not represent an absolute distinction in structure and / or function, nor do they represent a sequence of execution, but are merely for the convenience of description.

[0022] like Figure 1 As shown, the present invention provides an oxygen-enriched combustion system for a cold rolling continuous annealing furnace, comprising a radiant tube combustion and heating system arranged in the furnace of the continuous annealing furnace, an online combustion monitoring system, a data acquisition and processing system 18, and a combustion air oxygen-enriched blending system and a gas supply system connected to the radiant tube combustion and heating system. The data acquisition and processing system 18 is configured to control the oxygen content of the combustion air in the radiant tube combustion and heating system according to data collected by the online combustion monitoring system.

[0023] Specifically, the oxygen-enriched combustion system for a cold rolling continuous annealing furnace provided by the present invention is aimed at the problem of online combustion optimization control under the oxygen-enriched combustion mode of a radiant tube burner in a pulse combustion control mode:

[0024] 1. Control and increase the oxygen content of the combustion air by filling the combustion air main pipe, reduce the amount of combustion air, reduce smoke exhaust, and improve the heating temperature effect;

[0025] 2. The combustion-supporting air volume and oxygen enrichment rate are controlled by online monitoring of the radiation tube surface temperature and online monitoring of flue gas, so as to achieve online optimization and adjustment of the radiation tube air-fuel ratio.

[0026] In terms of practical significance, the use of oxygen-enriched combustion technology can effectively increase the theoretical combustion temperature of low calorific value gas and expand its scope of application. At the same time, it can effectively reduce fuel consumption, combustion-supporting air and flue gas volume, and achieve an improvement in the heating capacity of the continuous annealing furnace without increasing the original blast and induced draft loads.

[0027] The present invention aims to establish a simple and effective oxygen-enriched combustion system and combustion monitoring method for a cold rolling continuous annealing furnace, so as to improve the combustion efficiency and heating capacity, and promote the popularization and application of energy-saving and carbon-reduction technologies such as oxygen-enriched combustion.

[0028] The main idea of ​​the present invention is that: relevant theories show that when the absolute value of the oxygen content of the combustion-supporting air increases by 1%, the theoretical combustion temperature increases by 15-30°C.

[0029] ① Control and increase the oxygen content of combustion air by filling the combustion air main pipe;

[0030] ② By online monitoring of the surface temperature of the radiation tube, the oxygen-enriched ratio in the combustion-supporting air is controlled. By online monitoring of the residual oxygen in the flue gas of the radiation tube, the combustion-supporting air volume is controlled to achieve combustion optimization effect.

[0031] like Figure 1 As shown, the continuous annealing furnace mainly includes a furnace body, and the radiant tube combustion heating system includes a radiant tube combustion heater 2 arranged in the furnace of the continuous annealing furnace. A plurality of radiant tube combustion heaters 2 are arranged, and the coal gas is fully burned in the radiant tube burner. The strip steel continuously moving in the furnace of the continuous annealing furnace is heated by the radiant tube combustion heater 2 to achieve the annealing heat treatment effect.

[0032] The radiant tube combustion heater 2 heats the material in the furnace. The temperature of the continuous annealing furnace should be controlled within 900°C. The furnace of the continuous annealing furnace is filled with protective gas, and the pressure in the furnace is controlled at a slightly positive pressure. The pressure in the furnace is set within the range of 130-200 Pa. The protective gas includes nitrogen and hydrogen, with a nitrogen ratio of 95% and a hydrogen ratio of 5%.

[0033] like Figure 1 As shown, the radiant tube combustion heater 2 includes a combustion tube body, a burner and a combustion control unit. The burner is arranged on the combustion tube body. The air inlet of the combustion tube body is connected to the combustion air oxygen enrichment system and the gas supply system. The coal gas provided by the gas supply system and the combustion air provided by the combustion air oxygen enrichment system enter the combustion tube body. The fuel gas is completely burned in the radiant tube combustion heater 2 made of heat-resistant steel or heat-resistant ceramic material, and the radiant heat emitted by the heated radiant tube combustion heater 2 is used to heat the workpiece or material to be processed in the furnace.

[0034] Preferably, the combustion tube body has a temperature resistance requirement greater than 1200°C and is made of an iron-nickel-based heat-resistant alloy such as 5Cr28Ni48W5, ensuring that it can maintain high strength in a high temperature environment and is not prone to deformation and cracking at high temperatures, thereby ensuring the stability and reliability of the combustion tube body.

[0035] like Figure 1 As shown, as a preferred embodiment, a waste heat recovery device 3 is provided at the gas outlet of the combustion tube body. The waste heat recovery device 3 is a heat exchanger. The waste heat recovery device 3 is connected to the flue gas branch pipe 4, and the flue gas branch pipe 4 is connected to the flue gas main pipe. The high-temperature flue gas generated by the combustion in the combustion tube body enters from the first air inlet of the waste heat recovery device 3, and the high-temperature flue gas enters the flue gas branch pipe 4 after being discharged from the first air outlet of the waste heat recovery device 3. The oxygen-enriched blending system of the combustion-supporting air is connected to the second air inlet of the waste heat recovery device 3, and the second air outlet of the waste heat recovery device 3 is connected to the air inlet of the fuel gas tube body, and the second air inlet is connected to the second air outlet. The temperature of the high-temperature flue gas is greater than the temperature of the combustion-supporting air. The high-temperature flue gas entering the waste heat recovery device 3 exchanges heat with the combustion-supporting air entering the waste heat recovery device 3, so that the combustion-supporting air can be heated, and the waste heat utilization effect can be achieved while increasing the number of activated molecules in the combustion reaction, thereby promoting the combustion reaction. Heating the combustion-supporting air can significantly improve the combustion efficiency, make the fuel more fully utilized, and reduce pollutant emissions.

[0036] like Figure 1 As shown, each radiant tube combustion heater 2 is connected to the flue gas main pipe through a flue gas branch pipe 4. The flue gas generated by the combustion of gas in each radiant tube combustion heater 2 is collected through the flue gas branch pipe 4 and enters the flue gas main pipe. The flue gas main pipe is connected to a variable frequency induced draft fan 14. The variable frequency induced draft fan 14 extracts the flue gas in the flue gas main pipe and discharges it to the outside. The variable frequency control technology is used to ensure that the flue gas negative pressure in the flue gas main pipe remains stable. A fourth pressure sensor 30 is arranged in the flue gas main pipe.

[0037] like Figure 1 As shown, the combustion air oxygen enrichment system includes an oxygen pipeline, an air main, a gas mixing chamber 17 connected to the oxygen pipeline and the air main, a blower 12 connected to the gas mixing chamber 17, and an air branch pipe 10 connected to the air main and the radiant tube combustion heating system. The pure oxygen transported by the oxygen pipeline and the air transported by the air main are fully mixed in the gas mixing chamber 17 to form combustion air. The pressure of the pure oxygen transported by the oxygen pipeline is about 5000 Pa, and the oxygen is sent to the gas mixing chamber 17 to achieve the preparation of the combustion air.

[0038] like Figure 1As shown, the first pressure sensor 6, the first flow meter 8, the first quick-cut solenoid valve 7 and the first regulating valve 9 are arranged in the oxygen pipeline to ensure that the oxygen flow is distributed according to demand. The first flow meter 8 is arranged on the oxygen pipeline, and reflects the medium flow by measuring the difference between the total pressure and the static pressure. The first regulating valve 9 adjusts the oxygen flow according to the indication of the first flow meter 8. The first quick-cut solenoid valve 7 is arranged on the oxygen pipeline to realize the rapid use and cut-off of oxygen. The first pressure sensor 6 is used to measure the pressure parameters of the medium in the oxygen pipeline.

[0039] like Figure 1 As shown, the combustion air is distributed to each radiant tube combustion heater 2 through the air branch pipe 10 for combustion. On the air main pipe, a first oxygen content detector 16 and a second pressure sensor 19 are arranged between the blower 12 and the air branch pipe 10. The blower 12 is a variable frequency blower, which supplies pressurized combustion air to the air main pipe, and the air pressure in the air main pipe is kept stable through the variable frequency control technology. The first oxygen content detector 16 uses the in-situ zirconium oxide method to monitor the oxygen concentration in the combustion air flowing to the air branch pipe 10, that is, the oxygen enrichment rate of the combustion air is detected by the first oxygen content detector 16 to guide the oxygen content control of oxygen-enriched combustion. The accuracy of zirconium oxide is ≤1% points, and the resolution is 0.01% vol.

[0040] like Figure 1 As shown, one end of the air branch pipe 10 is connected to the second air inlet of the waste heat recovery device 3, and the other end of the air branch pipe 10 is connected to the air main pipe. A second flow meter 22, a second quick cut-off solenoid valve 20 and a second regulating valve 23 are arranged in the air branch pipe 10. The second flow meter 22 is arranged on the air branch pipe 10, and reflects the medium flow rate by measuring the difference between the total pressure and the static pressure. The second regulating valve 23 adjusts the flow rate of the combustion air according to the indication of the second flow meter 22. The second quick cut-off solenoid valve 20 is arranged on the air branch pipe 10 to realize the rapid use and cut-off of the combustion air.

[0041] In the present invention, an oxygen-enriched blending system for combustion-supporting air is provided, so that after pure oxygen and air are blended in a mixer, the oxygen content of the combustion-supporting air main pipe is increased by adding oxygen-enriched gas at the inlet of the combustion-supporting fan, and the oxygen-enriched supply is controlled by a related valve group to achieve accurate and safe blending.

[0042] like Figure 1As shown, the gas supply system includes a gas main and a gas branch pipe 11 connected to the gas main, and the gas branch pipe 11 is connected to the radiant tube combustion heating system. One end of the gas branch pipe 11 is connected to the air inlet of the radiant tube combustion heater 2, and the other end of the gas branch pipe 11 is connected to the gas main. A third flow meter 26, a third fast cut-off solenoid valve 25 and a third regulating valve 27 are arranged in the gas branch pipe 11 to ensure that the gas flow is distributed according to demand. The third flow meter 26 is arranged on the gas pipeline, and reflects the medium flow by measuring the difference between the total pressure and the static pressure. The third regulating valve 27 adjusts the gas flow according to the indication of the third flow meter 26. The third fast cut-off solenoid valve 25 is arranged on the gas pipeline to realize the rapid use and cut-off of the gas.

[0043] like Figure 1 As shown, a plurality of first temperature sensors 5 are arranged on the radiation surface of the radiant tube combustion heater 2, and the first temperature sensors 5 are used to collect the radiation surface temperature of the radiant tube combustion heater 2. A second temperature sensor 28 is arranged in the flue gas branch pipe 4, and the second temperature sensor 28 is used to collect the flue gas temperature in the flue gas branch pipe 4.

[0044] like Figure 1 As shown, high-pressure gas (pressure is about 10000pa) is distributed to each gas branch pipe 11 through the gas main pipe, and provides gas to each gas radiation pipe gas branch pipe 11. A fifth pressure sensor 31 is provided in the gas main pipe, and the fifth pressure sensor 31 is used to measure the pressure parameters of the medium in the gas main pipe. A gas pressure stabilizing device 13 is provided in the gas main pipe, and the gas pressure stabilizing device 13 is used to ensure the pressure stability of the gas branch pipe 11.

[0045] like Figure 1 As shown, an artificial detection port 15 is provided on the flue gas branch pipe 4, and the artificial detection port 15 is an opening for carrying out flue gas component detection on a single radiation tube.

[0046] The main purpose of the online combustion monitoring system is to use the in-situ zirconium oxide method to monitor the surface temperature of each radiation tube and the oxygen concentration in the combustion flue gas online. The online combustion monitoring system includes a first oxygen content detector 16, a second oxygen content detector 24, a first pressure sensor 6, a second pressure sensor 19, a third pressure sensor 29, a fourth pressure sensor 30, a first flow meter 8, a second flow meter 22, a third flow meter 26, a first temperature sensor 5 and a second temperature sensor 28. The first oxygen content detector 16, the second oxygen content detector 24, the variable frequency induced draft fan 14, the blower 12, the first pressure sensor 6, the second pressure sensor 19, the third pressure sensor 29, the fourth pressure sensor 30, the first flow meter 8, the second flow meter 22, the third flow meter 26, the first temperature sensor 5 and the second temperature sensor 28 are electrically connected to the data acquisition and processing system 18 through a data line and are controlled by the data acquisition and processing system 18.

[0047] The first regulating valve 9 and the second regulating valve 23 are electric valves, which are electrically connected to the data acquisition and processing system 18 and are controlled by the data acquisition and processing system 18. The data acquisition and processing system 18 receives data from the online combustion monitoring system in real time to guide combustion optimization adjustment.

[0048] The present invention also provides a combustion monitoring method for an oxygen-enriched combustion system of a cold rolling continuous annealing furnace, wherein the surface temperature of the radiant tube combustion heating system is monitored by an online combustion monitoring system, and the online combustion monitoring system transmits the collected data to a data acquisition and processing system 18, and the data acquisition and processing system 18 controls the oxygen content of the combustion-supporting air in the radiant tube combustion heating system.

[0049] The data collected by the online combustion monitoring system include the radiation surface temperature of the radiation tube combustion heater 2, the flue gas temperature in the flue gas branch 4, the oxygen pressure in the oxygen pipe, the combustion air pressure in the air main, the gas pressure in the gas main, the gas flow in the gas branch 11, the combustion air flow in the air branch 10 and the flue gas pressure in the flue gas branch 4.

[0050] About 5000pa oxygen is sent to the gas mixing chamber 17 through the oxygen pipeline. The oxygen pipeline is equipped with a first pressure sensor 6, a first flow meter 8, a first quick-cut solenoid valve 7 and a first regulating valve 9 to ensure that the oxygen flow is distributed according to demand. After the oxygen and air are mixed in the gas mixing chamber 17, they are pressurized by the blower 12 and sent to the air main pipe, and distributed to each radiation tube through each air branch pipe 10; the air branch pipe 10 is equipped with a second flow meter 22, a second quick-cut solenoid valve 20 and a second regulating valve 23 to adjust the flow. The combustion-supporting air from the air branch pipe 10 is heated by the waste heat recovery device 3 and enters the radiation tube combustion heater 2 for combustion. The air main pipe is equipped with a pressure sensor and an oxygen content detector to guide the blower 12 to achieve stable pressure regulation of the air main pipe and guide the precise allocation of the oxygen content in the combustion-supporting air.

[0051] After the pressurized gas is sent to each gas branch pipe 11 through the gas main pipe, it is distributed to each radiant tube combustion heater 2. The gas branch pipe 11 is equipped with an electronic flow orifice plate and a manual electric regulating valve to adjust the flow. The gas main pipe is equipped with a gas pressure stabilizing device 13 to achieve constant pressure in each gas branch pipe 11.

[0052] The air branch pipe 10 and the gas branch pipe 11 corresponding to each radiant tube combustion heater 2 are provided with a quick cut-off solenoid valve to realize the quick commissioning (combustion) and cut-off of each radiant tube combustion heater 2.

[0053] The flue gas generated by the combustion of each radiant tube combustion heater 2 is cooled by heat exchange in the waste heat recovery device 3 and then collected to the flue gas main pipe through the flue gas branch pipe 4, and then extracted by the variable frequency induced draft fan 14 and discharged. In front of the variable frequency induced draft fan 14, a third pressure sensor 29 is provided on the flue gas main pipe, and the third pressure sensor 29 guides the variable frequency induced draft fan 14 to adjust and realize constant negative pressure control of the flue gas main pipe pressure.

[0054] A plurality of first temperature sensors 5 are arranged on the radiation surface (high temperature zone) of each radiation tube combustion heater 2; to guide the adjustment and control of the oxygen content in the combustion-supporting air, a second oxygen content detector 24 is provided on the flue gas branch pipe 4 behind each radiation tube combustion heater 2. The second oxygen content detector 24 adopts an in-situ zirconium oxide method. The second oxygen content detector 24 monitors the oxygen concentration flowing into the flue gas branch pipe 4, guides the adjustment of the combustion-supporting air flow rate, and realizes the online optimization and adjustment effect of the radiation tube combustion.

[0055] The control method and control logic of the cold rolling continuous annealing furnace oxygen-enriched combustion monitoring system of the present invention are as follows:

[0056] 1. Control methods

[0057] Relevant theories show that for every 1% increase in the absolute value of the oxygen content in the combustion-supporting air, the theoretical combustion temperature will increase by 15-30°C.

[0058] The oxygen content of the combustion air is adjusted by the radiant tube surface temperature feedback;

[0059] The residual oxygen content in the flue gas of each radiant tube is guided and adjusted to achieve the online optimization and adjustment effect of the air-fuel ratio of the radiant tube.

[0060] 2. Control Logic

[0061] 2.1 Gas calorific value, adjusted gas main, air main, flue gas main, oxygen main pressure determination

[0062] a) The gas calorific value is set to: 2500Kcal / m 3 ±10%;

[0063] b) The gas main pressure is set to: 10Kpa±5%, the air main pressure: 10Kpa±5%;

[0064] c) The main flue gas pressure is set to: -20Kpa±5%;

[0065] d) The oxygen main pipe pressure is set to: 5Kpa±5%, oxygen concentration ≧92%.

[0066] 2.2 Adjustment and curing of the combustion state of each radiant tube combustion heater 2

[0067] Cold adjustment, each individual adjustment, manually ignite the radiant tube burner, by adjusting the oxygen ratio, adjusting the radiant tube combustion heater 2 air, gas manual electric regulating valve, to ensure:

[0068] a) The oxygen concentration in the air main is between 24-26%;

[0069] b) The gas flow of each radiant tube combustion heater 2 is at the rated value: the flow orifice pressure difference is 2400pa-2600pa, and the oxygen concentration in the flue gas branch pipe 4 is between 2.5% and 3.5%;

[0070] c) The surface temperature of each radiant tube combustion heater 2 is ≤1200°C.

[0071] 2.3 Online monitoring under normal production conditions

[0072] a) When the surface temperature of each radiant tube combustion heater 2 is ≦1200°C, the oxygen enrichment rate of the combustion air is increased, and the rising rate of the oxygen enrichment rate of the combustion air is set to 1% / min, until the surface temperature of each radiant tube combustion heater 2 is ≦1200°C and the oxygen enrichment rate of the combustion air is <30%, so as to achieve the regulation of the oxygen content of the combustion air; conversely, when the surface temperature of each radiant tube combustion heater 2 is >1200°C, the oxygen enrichment rate of the combustion air is reduced, and the reduction rate of the oxygen enrichment rate of the combustion air is set to 1% / min, until the surface temperature of each radiant tube combustion heater 2 is ≦1200°C, so as to achieve the regulation of the oxygen content of the combustion air;

[0073] b) When the oxygen concentration in the flue gas branch pipe 4 is greater than 3.5%, adjust the opening of the second regulating valve 23 in the corresponding air branch pipe 10, reduce the opening of the second regulating valve 23 to reduce the amount of combustion air entering the radiant tube combustion heater 2, and adjust the amount of combustion air until the oxygen concentration in the flue gas branch pipe 4 reaches 2.5-3.5%; conversely, when the oxygen concentration in the flue gas branch pipe 4 is less than or equal to 2.5%, adjust the opening of the second regulating valve 23 in the corresponding air branch pipe 10, increase the opening of the second regulating valve 23 to increase the amount of combustion air entering the radiant tube combustion heater 2, and adjust the amount of combustion air until the oxygen concentration in the flue gas branch pipe 4 reaches 2.5-3.5%.

[0074] c) The above steps are repeated to achieve online monitoring and ensure the safety and high efficiency of the system.

[0075] The above-mentioned cold rolling continuous annealing furnace radiant tube oxygen-enriched combustion system and combustion monitoring method can improve the production efficiency of the cold rolling continuous annealing furnace by optimizing the combustion process, improving the combustion efficiency, reducing energy consumption, and reducing exhaust gas emissions. By adopting oxygen-enriched combustion technology and combining the design of radiant tubes, efficient, environmentally friendly, and energy-saving operation of the cold rolling continuous annealing furnace is achieved.

[0076] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. Oxygen-enriched combustion system for cold rolling continuous annealing furnace, characterized in that: It includes a radiant tube combustion and heating system arranged in the furnace of a continuous annealing furnace, an online combustion monitoring system, a data acquisition and processing system, and a combustion air oxygen enrichment adjustment system and a gas supply system connected to the radiant tube combustion and heating system. The data acquisition and processing system is configured to control the oxygen content of the combustion air in the radiant tube combustion and heating system based on data collected by the online combustion monitoring system.

2. The oxygen-enriched combustion system of the cold rolling continuous annealing furnace according to claim 1 is characterized in that: The radiant tube combustion heating system includes a radiant tube combustion heater arranged in the furnace of the continuous annealing furnace, the radiant tube combustion heater includes a combustion tube body and a burner, and the air inlet of the combustion tube body is connected to the combustion air oxygen enrichment system and the gas supply system.

3. The oxygen-enriched combustion system for a cold rolling continuous annealing furnace according to claim 2, characterized in that: A waste heat recovery device is arranged at the gas outlet of the combustion tube body, the waste heat recovery device is connected to the flue gas branch pipe, and the flue gas branch pipe is connected to the flue gas main pipe.

4. The oxygen-enriched combustion system of the cold rolling continuous annealing furnace according to any one of claims 1 to 3, characterized in that: The combustion-supporting air oxygen-enriched mixing system comprises an oxygen pipeline, an air main pipe, a gas mixing chamber connected to the oxygen pipeline and the air main pipe, a blower connected to the gas mixing chamber, and an air branch pipe connected to the air main pipe and the radiant tube combustion heating system.

5. The oxygen-enriched combustion system of the cold rolling continuous annealing furnace according to claim 4, characterized in that: A first pressure sensor, a first flow meter, a first quick-cut-off solenoid valve and a first regulating valve are arranged in the oxygen pipeline.

6. The oxygen-enriched combustion system for a cold rolling continuous annealing furnace according to claim 4, characterized in that: An oxygen content detector and a second pressure sensor are arranged between the blower and the air branch pipe.

7. The oxygen-enriched combustion system for a cold rolling continuous annealing furnace according to claim 4, characterized in that: A second flow meter, a second quick-cut solenoid valve and a second regulating valve are arranged in the air branch pipe.

8. The oxygen-enriched combustion system for a cold rolling continuous annealing furnace according to any one of claims 1 to 7, characterized in that: The gas supply system comprises a gas main pipe and a gas branch pipe connected to the gas main pipe, and the gas branch pipe is connected to the radiant tube combustion heating system.

9. The oxygen-enriched combustion system for a cold rolling continuous annealing furnace according to claim 8, characterized in that: A third flow meter, a third quick-cut-off solenoid valve and a third regulating valve are arranged in the gas branch pipe.

10. The combustion monitoring method of the oxygen-enriched combustion system of a cold rolling continuous annealing furnace according to any one of claims 1 to 9, characterized in that: The surface temperature of the radiant tube combustion heating system is monitored by the online combustion monitoring system, and the online combustion monitoring system transmits the collected data to the data acquisition and processing system, and the data acquisition and processing system controls the oxygen content of the combustion-supporting air in the radiant tube combustion heating system.

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