Blast furnace gas double-heat-storage type heating furnace oxygen-fuel combustion air-smoke zero-emission coupling system

Abstract

The utility model relates to the technical field of heat accumulating type heating furnaces, in particular to a blast furnace gas double heat accumulating type heating furnace oxygen-fuel combustion air and smoke zero emission coupling system which comprises a heat accumulating type heating furnace, a reversing valve, a gas burner, an air burner, a pure oxygen nozzle, a gas pipeline, a soot pipeline, an air and smoke pipeline, a smoke return pipeline and a pure oxygen pipeline. A gas burner and an air burner are arranged on the furnace walls of the two sides of the heat accumulating type heating furnace, a pure oxygen nozzle is arranged between the gas burner and the air burner, the gas burner is connected with a gas pipeline and a soot pipeline through a reversing valve, and the pure oxygen nozzle is connected with a pure oxygen pipeline through an oxygen fast switching valve. The air-smoke full-backflow oxygen-deficient combustion device has the advantages that pure oxygen combustion and air-smoke full-backflow oxygen-deficient combustion are combined, so that the production effects of energy conservation, emission reduction, pollution reduction, carbon reduction and low cost are achieved.

Description

Technical Field

[0001] This utility model relates to the field of regenerative heating furnace technology, and in particular to a coupling system for zero-emission air-gas combustion in a dual regenerative blast furnace gas heating furnace. Background Technology

[0002] Traditional dual-regenerative heating furnaces employ air-gas reversing regenerative systems, which have the following main drawbacks:

[0003] 1) Its fatal shortcomings are: high furnace pressure, frequent fluctuations, instability and non-adjustability; gas leakage during reversal, which wastes fuel and adds pollution; high power consumption of blowers and induced draft fans, resulting in high operation and maintenance costs.

[0004] 2) Traditional dual regenerators, whether they mix air and gas at the top and bottom or at the left and right nozzles, have defects such as large oxidation loss, high nitrogen oxide concentration, and excessive particulate matter. They even need to be equipped with desulfurization, denitrification and high-efficiency dust removal systems to meet ultra-low emission requirements, which greatly increases operating costs.

[0005] 3) Blast furnace gas has a low calorific value (usually <800 kcal / Nm³). 3 Although it employs dual heat storage technology, it is difficult to achieve stable combustion in the high-temperature zone required by the temperature regime above 1300℃ using conventional air as a combustion aid.

[0006] 4) The exhaust temperature of the heat storage chamber is still relatively high, generally greater than 150℃, and sometimes as high as 200℃ or above. The residual oxygen in the flue gas often exceeds 12%, resulting in energy waste and NOx pollution.

[0007] 5) According to the law of conservation of water equivalent during heat exchange, approximately 30% to 40% of the high-temperature flue gas in the production process of a regenerative heating furnace does not participate in the heat exchange process of the regenerator. This portion of high-temperature flue gas is a dead zone trapped in the furnace, and even if it is discharged through the auxiliary flue, heat waste is inevitable.

[0008] Advanced oxygen-enriched combustion technology has been widely used in conventional combustion steel rolling furnaces, making significant contributions to energy saving, emission reduction, pollution reduction, carbon reduction, and stable production with low burn-off. However, there are no pioneering cases of its direct application to existing regenerative furnaces. Industry calculations show that when directly applied to existing regenerative furnaces, oxygen consumption is high, energy-saving benefits are not obvious, and there are compatibility issues with the current reversing system, which require technological innovation to solve.

[0009] Challenges in applying oxygen-enriched and oxygen-oxygen-based combustion in regenerative heating furnaces:

[0010] 1) The regenerative combustion mechanism fully utilizes the regenerator as a heat energy carrier, transferring the waste heat from high-temperature exhaust gas to the incoming air and gas through storage and reversing heat exchange. This maximizes the enthalpy of the incoming gas medium, resulting in exhaust gas temperatures that are more than 200°C lower than those of conventional heating furnaces with dual air and gas preheating, thus saving energy. Its advantage lies in meeting the conditions for burning low-calorific-value gas in steelmaking. Low-calorific-value gas is a byproduct of long-process steelmaking and is inexpensive. However, full-oxygen and oxygen-enriched combustion consumes about five times more oxygen than its cost, making it difficult to further improve upon existing energy-saving effects.

[0011] 2) Regenerative combustion employs a reversing mechanism, making it difficult to couple oxygen burners (both full-oxygen and oxygen-enriched combustion) with existing air and gas regenerative burners. Since regenerative burners are typically connected by furnace columns, the furnace structure and beam arrangement significantly influence the placement of external oxygen burners or lances. Embedding these burners within the regenerative burner body presents several problems. One is that the high furnace temperature can affect the oxygen burner's lifespan, while the high temperature of oxygen combustion can damage the regenerator. Another issue is the risk of backflow of flue gas into the oxygen burner during reversing operations.

[0012] 3) The furnace temperature of full oxygen and oxygen-enriched combustion is 100-300℃ higher than that of conventional combustion, and the flue gas volume is significantly reduced. Its application in existing regenerative heating furnaces requires technological innovation. First, it is necessary to solve the effect of weakened convective heat transfer caused by the small flue gas volume. Second, it is necessary to avoid local high temperatures that affect the furnace temperature uniformity and avoid the impact of high temperature zones on nitrogen oxide indicators. Third, it is necessary to conduct simulation of oxygen combustion in regenerative furnaces to reasonably arrange the installation position of oxygen lances or oxygen burners. It is also necessary to solve the problem of installation space. Utility Model Content

[0013] To overcome the shortcomings of existing technologies, this utility model provides a zero-emission coupling system for blast furnace gas dual regenerative heating furnace with all-oxygen combustion. Through a process method that achieves zero emissions by returning all flue gas to the furnace, it employs a combination of full flue gas return and staged pure oxygen injection technology. This implements a gradient oxygen combustion coupling technology with flue gas recirculation and oxygen-deficient combustion, while maintaining normal flue gas emissions and retaining the gas backflushing system. Simultaneously, the automatic oxygen combustion control system is upgraded and integrated with the original system to achieve energy saving, emission reduction, pollution reduction, carbon reduction, and low-cost production effects. This provides a complete set of equipment and systems for extremely efficient, environmentally friendly, ultra-low emission, and pollution-free regenerative combustion with all-oxygen participation.

[0014] To achieve the above objectives, the present invention adopts the following technical solution:

[0015] A blast furnace gas dual regenerative heating furnace with all-oxygen combustion and zero-emission air-to-flue gas coupling system includes a regenerative heating furnace, a reversing valve, gas burners, air burners, pure oxygen nozzles, gas pipelines, flue gas pipelines, air-to-flue gas pipelines, return flue gas pipelines, and pure oxygen pipelines. Regenerative gas burners and air burners are installed on both sides of the furnace walls of the regenerative heating furnace. A pure oxygen nozzle is installed between the gas burners and air burners. The gas burners are connected to the gas pipeline and flue gas pipeline respectively via the reversing valve, and the air burners are connected to the return flue gas pipeline and air-to-flue gas pipeline respectively via the reversing valve. The pure oxygen nozzle is connected to the pure oxygen pipeline. The air-to-flue gas pipeline is connected to the intake ports of the air-to-flue gas induced draft fan and the combustion air fan respectively, and both intake pipes connected to the fans are equipped with pneumatic quick-cut valves. The outlet pipes of the air-to-flue gas induced draft fan and the combustion air fan are connected to the return flue gas pipeline via electric switching valves. A vent pipe with an electric regulating shut-off valve is installed at the high point of the air-to-flue gas induced draft fan outlet pipe.

[0016] Furthermore, the air burner is connected to the flue gas duct via a reversing valve, and a thermocouple, a flow orifice plate, a CO analyzer, a pressure transmitter, an electric flow regulating valve, a residual oxygen analyzer, and a NOx analyzer are sequentially installed on the duct.

[0017] Furthermore, the flue gas return pipe is sequentially equipped with a flow orifice plate and an electric butterfly valve.

[0018] Furthermore, the regenerative heating furnace is a dual regenerative heating furnace with upper and lower mixing. The regenerative heating furnace is divided into upper and lower heating burner regenerators. In the upper heating burner regenerator, the gas burner is in the lower part and the air burner is in the upper part. In the lower heating burner regenerator, the gas burner is in the upper part and the air burner is in the lower part. A swirling pure oxygen nozzle is added between the burner regenerators along the length of the furnace, with the center line of the interface between the gas burner and the air burner in the burner regenerator.

[0019] Furthermore, the regenerative heating furnace is a dual regenerative heating furnace with left and right mixing. The gas burner and air burner in the regenerative box of the furnace wall are arranged at an angle to each other. The oxygen nozzle is a swirling pure oxygen nozzle, which is set between the two regenerative boxes on the center line of the angle between the gas burner and the air burner in the length direction of the furnace.

[0020] Furthermore, the pure oxygen nozzle has swirling orifices distributed in a circular pattern, with the two swirling orifices on the horizontal line being larger than those in other directions.

[0021] Furthermore, the heat storage chambers on both sides of the furnace wall where the gas burner and air burner of the regenerative heating furnace are located are equipped with heat storage bodies, which absorb heat when the gas burner and air burner exhaust the flue gas in the furnace, and heat the gas and flue gas when the gas and flue gas are switched.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] 1) Low input, high output. Adding pure oxygen nozzles to regenerative furnaces is feasible. The air duct and flue gas duct are reorganized to form flue gas ducts and flue gas return ducts for flue gas recirculation. The regenerative heating furnace full oxygen flue gas return system has a small engineering workload, low investment, fast implementation and good results.

[0024] 2) Because the flame of the regenerative furnace's all-oxygen flue gas high-temperature combustion technology is not generated in the burner, but rather formed by the high-temperature heating of coal gas and flue gas in the furnace wall regenerator and the entry of pure oxygen into the furnace space, the combustion begins to diffuse. The participation of pure oxygen in diffusion, disturbance, and entrainment is more conducive to combustion. The use of all-oxygen combustion reduces the participation of nitrogen, significantly reducing the amount of flue gas, reducing NOx generation, and lowering pollutant emissions. The triatomic gases in the combustion products and the triatomic gases in the high-temperature flue gas after return to the furnace increase the flame radiation intensity and enhance radiative heat transfer. The participation of pure oxygen can significantly increase the combustion speed and promote complete combustion. It also lowers the ignition temperature of the fuel and reduces the burnout time, greatly increasing heat release.

[0025] 3) The flue gas is reheated by the regenerator and returned to the furnace from the air burner. This maintains the flue gas filling degree of the regenerator furnace and allows the system to control the oxygen supply to meet the combustion conditions of the oxygen-deficient flue gas and gas. It also makes up for the shortcoming of small flue gas volume in full oxygen combustion. The pure oxygen nozzle is inserted into the furnace wall between the regenerator boxes of the air burner and the gas burner. The high-pressure oxygen draws the surrounding furnace gas and the high-temperature returned flue gas oxygen flow together with the fuel injected at the same time to achieve combustion. The entrainment and turbulence gradient combustion of the swirling oxygen jet form a new type of flameless combustion that is completely different from the traditional flame, creating an excellent temperature field in the furnace and greatly improving the uniformity of furnace temperature.

[0026] 4) Oxygen combustion replaces combustion air, and the air reversal is replaced by air-smoke reversal. After the smoke is discharged, it is all reheated and reversed back to the furnace. The enthalpy of the smoke is fully utilized, which improves heating efficiency, reduces flue gas emissions, and reduces pollution.

[0027] 5) The regenerative heating furnace uses full oxygen combustion coupled with flue gas recirculation. It adopts a pure oxygen supply method and combines staged pure oxygen injection technology with reversing and flue gas recirculation closed-loop control to avoid the risk of excessive combustion temperature caused by flue gas recirculation. It ensures the synergy and adjustability of reversing cycle and full oxygen combustion, avoids mutual interference, and achieves precise combustion control, complete combustion, uniform heat distribution, high combustion efficiency, and good heating quality.

[0028] 6) Based on the furnace's real-time heat load requirements, the monitoring parameters of oxygen-fuel ratio, residual oxygen in flue gas and coal smoke, and CO concentration are used to shorten the flue gas reversal cycle to 120-150 seconds, while maintaining the original gas reversal cycle. Based on CO and NOx concentration analysis and sensor feedback, the oxygen-fuel ratio is dynamically adjusted, and the pure oxygen content is adjusted in real time. Automatic control and process control upgrades management to achieve ultimate energy efficiency, ensuring that ultra-low emission environmental products meet standards. At the same time, the oxidation loss rate will be greatly reduced, improving the yield and achieving significant economic and social benefits. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the blast furnace gas dual regenerative heating furnace all-oxygen combustion air-smoke zero-emission coupling system described in this utility model.

[0030] Figure 2 This is a schematic diagram of the burner structure of the upper and lower mixed regenerative heating furnace described in this utility model, combined with the arrangement of pure oxygen nozzles.

[0031] Figure 3 This is a schematic diagram of the burner structure of the left-right hybrid regenerative heater described in this utility model, combined with the arrangement of pure oxygen nozzles.

[0032] Figure 4 This is a top view of the installation arrangement of the pure oxygen nozzle in the regenerative heating furnace described in this utility model.

[0033] In the diagram: 1. Pure oxygen nozzle; 2. Air burner; 3. Gas burner; 4. Gas pipeline; 5. Pure oxygen pipeline; 6. Flue gas pipeline; 7. Return flue gas pipeline; 8. Reversing valve; 9. Pneumatic quick-cut valve; 10. NOx analyzer; 11. Residual oxygen analyzer; 12. Electric flow regulating valve; 13. Pressure transmitter; 14. CO analyzer; 15. Flow orifice plate one; 16. Thermocouple; 17. Electric butterfly valve; 18. Flow orifice plate two; 19. Electric regulating shut-off valve; 20. Flue gas induced draft fan; 21. Smoke fan; 22. Regenerative heating furnace; 23. Venting pipeline; 24. Smoke pipeline; 25. Combustion air pipeline; 26. Oxygen-specific valve assembly; 27. Steel billet; 28. Flue gas chimney; 29. ​​Smoke chimney; 30. Combustion fan; 31. Oxygen quick-cut valve. Detailed Implementation

[0034] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings:

[0035] like Figures 1-4As shown, the working principle of a zero-emission coupling system for all-oxygen combustion of blast furnace gas in a dual regenerative regenerator is as follows: By adding a pure oxygen nozzle 1 between the gas burners 3 and air burners 2 installed on both sides of the regenerative regenerator 22, the pure oxygen in the pure oxygen nozzle 1 is fully mixed with the high-temperature flue gas returned from the air burners 2 and the gas in the gas burners 3 within the regenerative regenerator 22 through entrainment and diffusion, achieving complete combustion of gas and pure oxygen. The high-temperature flue gas in the regenerative regenerator 22 is discharged from the air burners 2 on the opposite side of the combustion. After heat exchange, the low-temperature flue gas is transported to the return flue gas pipe 7 through the low-temperature flue gas path reversing valve 8 and then returned to the air burners 2 on the combustion side for further heating before returning to the regenerative regenerator 22. The high-temperature dilute oxygen flue gas returned to the furnace contributes to low burn-off and low nitrogen. The entrainment and disturbance effect of the pure oxygen nozzle 1 ensures complete combustion of residual carbon in the furnace and achieves excellent furnace temperature uniformity.

[0036] The high-temperature flue gas discharged from the regenerative heating furnace 22 via the gas burner 3 on the opposite side of the combustion chamber undergoes heat exchange. After this exchange, the low-temperature flue gas is transported to the flue gas chimney 29 via the flue gas pipeline 24 connected to the gas burner 3 and the flue gas induced draft fan 21. To prevent gas leakage during the switching moment when the gas burner 3 is supplying gas, the gas backflushing system continues to operate according to the original procedure.

[0037] like Figures 1-4As shown, a blast furnace gas dual regenerative heating furnace with all-oxygen combustion and zero-emission air-flue gas coupling system includes a regenerative heating furnace 22, a reversing valve 8, gas burners 3, air burners 2, pure oxygen nozzles 1, a gas pipeline 4, a flue gas pipeline 24, an air-flue gas pipeline 6, a return flue gas pipeline 7, and a pure oxygen pipeline 5. The regenerative gas burners 3 and air burners 2 are installed on both sides of the furnace wall of the regenerative heating furnace 22, and the pure oxygen nozzle 1 is installed between the gas burners 3 and air burners 2. The gas burners 3 are connected by a reversing valve. Valve 8 reverses the connection between the gas pipeline 4 and the smoke pipeline 24. The air burner 2 is reversed via valve 8 to connect the return smoke pipeline 7 and the air-to-smoke pipeline 6. The pure oxygen nozzle 1 is connected to the pure oxygen pipeline 5. The air-to-smoke pipeline 6 is connected to the intake ports of the air-to-smoke induced draft fan 20 and the combustion-supporting fan 30, respectively. The method for the combustion-supporting fan 30 and the air-to-smoke induced draft fan 20 to switch functions and be mutually redundant is to change the combustion-supporting air reversal to the air-to-smoke reversal. Both intake pipelines connected to the air-to-smoke induced draft fan 20 and the combustion-supporting fan 30 are equipped with... A pneumatic quick-cut valve 9 is provided; the outlet pipes of the exhaust fan 20 and the combustion air fan 30 are both connected to the return smoke pipe 7, so that the original exhaust fan 20 inlet exhaust smoke pipe 6 remains unchanged. The exhaust fan 20 outlet smoke pipe is changed from being connected to the exhaust chimney 28 to being connected to the original combustion air pipe 25 and an electric butterfly valve 17 is installed. The original combustion air pipe 25 is the return smoke pipe 7. A pneumatic quick-cut valve 9 is installed on the exhaust fan 20 inlet exhaust smoke pipe 6. A bypass is connected to the front of this pneumatic quick-cut valve 9. The flue gas duct 6 is connected to the intake port of the combustion blower 30 with a pneumatic quick-cut valve 9, and an electric butterfly valve 17 is installed on the outlet duct of the combustion blower 30. This forms a production condition in which the flue gas induced draft fan 20 and the original combustion blower 30 are in operation and on standby in the flue gas recirculation process. Only when the flue gas induced draft fan 20 is in an accident state, the combustion blower 30 is switched to start, while the flue gas recirculation continues. The outlet duct of the flue gas induced draft fan 20 is equipped with a vent pipe 23 and an electric regulating shut-off valve 19 at the high point.

[0038] Furthermore, the air burner 2 is connected to the flue gas duct 6 via the reversing valve 8, and a thermocouple 16, a flow orifice plate 15, a CO analyzer 14, a pressure transmitter 13, an electric flow regulating valve 12, a residual oxygen analyzer 11, and a NOx analyzer 10 are sequentially installed on the duct 6. The flue gas return volume of the flue gas duct 6 is determined based on the instantaneous heat load demand of the furnace, the oxygen-fuel ratio, the residual oxygen content and CO concentration of the flue gas and coal smoke, and the monitoring parameters of nitrogen oxides. When the measured residual oxygen content, CO concentration, nitrogen oxides, and other related parameters in the flue gas of the flue gas duct 6 deviate from the standard values, the flue gas return volume of the flue gas duct 6 is adjusted and determined according to the instantaneous heat load demand of the furnace. Under the condition that the oxygen-fuel ratio requirement is met, the flue gas volume is adjusted by the electric regulating shut-off valve 19 of the vent pipe 23 at the high point of the flue gas return duct 7, and the flow orifice plate 18 of the flue gas return duct 7 is used for precise verification.

[0039] Furthermore, the flue gas return pipe 7 is sequentially equipped with a flow orifice plate 18 and an electric butterfly valve 17, and the flue gas return pipe 7 is connected to an air burner 2 on one side of the furnace wall via a reversing valve 8.

[0040] Furthermore, the regenerative heating furnace 22 is a dual regenerative heating furnace with upper and lower heating elements. The regenerative heating furnace 22 is divided into upper and lower heating burner regenerative boxes. In the upper heating burner regenerative box, the gas burner 3 is in the lower part and the air burner 2 is in the upper part. In the lower heating burner regenerative box, the gas burner 3 is in the upper part and the air burner 2 is in the lower part. A swirl pure oxygen nozzle 1 is added between the burner regenerative boxes along the furnace length direction at the center line of the interface between the gas burner 3 and the air burner 2. The two swirl holes on the horizontal line of the pure oxygen nozzle 1 are larger than the swirl holes in other directions. The oxygen supply load of the pure oxygen nozzle 1 is customized according to the different output of the heating furnace.

[0041] Furthermore, the regenerative heating furnace 22 is a dual regenerative heating furnace with left and right mixing. The gas burner 3 and air burner 2 in the heat storage box of the furnace wall of the regenerative heating furnace 22 are arranged at an angle to each other. The pure oxygen nozzle 1 is a swirl pure oxygen nozzle, which is set between the two heat storage boxes on the center line of the angle between the gas burner 3 and the air burner 2 in the furnace length direction. The two swirl holes on the horizontal line of the pure oxygen nozzle 1 are larger than the swirl holes in other directions. The oxygen supply load of the pure oxygen nozzle 1 is customized according to the different output of the heating furnace.

[0042] Replacing air with pure oxygen reduces N2 participation by 78%, thus reducing flue gas volume. The air heat storage reversing channel allows for air-to-flue gas reheating and circulation replenishment. This maintains the flue gas fullness of the regenerative furnace while allowing time-controlled oxygen supply to meet the oxygen-deficient flue gas and gas combustion conditions. The swirling oxygen jet entrainment and turbulent gradient combustion form a new type of flameless combustion that is completely different from traditional flames, creating a uniform distribution of excellent temperature field within the furnace.

[0043] like Figure 1-4 As shown, a heating method for a blast furnace gas dual regenerative heating furnace with all-oxygen combustion and zero-emission air-flue gas coupling system specifically includes the following steps:

[0044] During combustion on this side, the working condition of the burner on this side is as follows: gas is introduced into the gas burner 3 on the wall of the regenerative heating furnace 22 through the gas pipeline 4 controlled by reversing, and the flue gas pipeline 7 provides the flue gas discharged from the air burner 2 on the wall of the regenerative heating furnace 22 to the air burner on this side. At the same time, oxygen is introduced into the pure oxygen nozzle 1 on this side through the pure oxygen pipeline 5. The gas, flue gas and oxygen are mixed and burned to heat the steel billet.

[0045] When combustion occurs on this side, the oxygen quick-cut valve 31 of the pure oxygen pipeline 5 is closed, and the pure oxygen nozzle 1 on the opposite side is not supplied with oxygen. A portion of the high-temperature flue gas is heat-exchanged by the heat storage body in the gas burner 3 on the opposite side of the furnace wall and then discharged through the flue gas pipeline 24 via the reversing valve 8. The flue gas is discharged into the atmosphere from the flue gas chimney 29. Another portion of the high-temperature flue gas is heat-exchanged by the heat storage body in the air burner 2 on the opposite side of the furnace wall and then discharged through the air flue gas pipeline 6 via the reversing valve 8. The air flue gas is sent to the return flue gas pipeline 7 through the air flue gas pipeline 6 and returned to the furnace through the air burner 2 on this side connected to the return flue gas pipeline 7, and this air flue gas is continuously supplied to the air burner 2 on this side.

[0046] In the next cycle, the burners and connected pipes on this side and the opposite side are switched via a reversing valve. Under the combustion condition on the opposite side, the oxygen quick-cut valve 31 of the pure oxygen pipe 5 on this side is closed, and the pure oxygen nozzle 1 on this side is not supplied with oxygen. The gas pipe 4 controlled by the reversing valve supplies gas to the gas burner 3 on the opposite side wall of the regenerative heating furnace 22. The gas burner 3 on this side is connected to the smoke pipe 24 to exhaust the smoke. The air burner 2 on this side is connected to the air smoke pipe 6 to exhaust the air smoke. The air smoke is sent back to the air burner 2 on the opposite side for reheating and returning to the furnace via the air smoke induced draft fan 20. At the same time, the pure oxygen pipe 5 supplies oxygen to the pure oxygen nozzle 1 on the opposite side. The gas, air smoke and oxygen are mixed and burned to heat the steel billet.

[0047] Furthermore, the flue gas is returned to the furnace through the flue gas return pipe 7 and driven by the flue gas induced draft fan 20, while the coal smoke is discharged externally and driven by the coal smoke fan 21.

[0048] Furthermore, the gas burner 3 and air burner 2 of the regenerative heating furnace 22 are provided with heat storage chambers on the two sides of the furnace wall, which absorb heat when the gas burner 3 and air burner 2 exhaust the flue gas in the furnace, and reheat the gas and flue gas when the gas and air are switched to be supplied.

[0049] The heating method of the blast furnace gas dual regenerative heating furnace's all-oxygen combustion zero-emission coupled system replaces combustion air with pure oxygen. In effect, oxygen and gas burn at a precise air-to-oxygen ratio, and the flue gas is completely circulated back into the furnace via a reversing mechanism through the combustion air duct. The returned flue gas is a high-temperature, oxygen-deficient triatomic gas, increasing radiant heat within the furnace and further reducing oxidation loss. The initial temperature of the flue gas before entering the regenerator is more than 150°C higher than the original combustion air, and it is also heated to 800-1000°C before returning to the furnace. Compared to existing blast furnace gas dual regenerative heating furnaces, this method requires minimal modification to the regenerative burners and reversing devices. It only requires reconnecting the existing flue gas and combustion air ducts and implementing valve and instrument adjustments and controls to achieve all-oxygen combustion and zero emissions. This method is more energy-efficient, more effective, and more environmentally friendly than the original dual regenerative heating method. By recycling all the flue gas from a regenerative furnace and coupling it with full oxygen combustion, the production goals of energy saving, emission reduction, pollution reduction, carbon reduction, and low burn-off in the furnace and kiln can be achieved.

[0050] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A full-oxygen combustion air-steam zero-emission coupling system of a regenerative heating furnace using blast furnace gas, comprising a regenerative heating furnace, a reversing valve, a gas burner, an air burner, a pure oxygen nozzle, a gas pipeline, a coal smoke pipeline, an air-steam pipeline, a back smoke pipeline and a pure oxygen pipeline, characterized in that, The heat accumulating heating furnace is provided with heat accumulating gas burners and air burners on the two side walls, pure oxygen nozzles are arranged between the gas burners and the air burners, the gas burners are connected with gas pipelines and coal smoke pipelines respectively through reversing valves, the air burners are connected with back smoke pipelines and air smoke pipelines respectively through reversing valves, the pure oxygen nozzles are connected with pure oxygen pipelines, the air smoke pipelines are connected with air smoke draft fans and combustion air fans respectively, pneumatic quick cut valves are arranged on the two air inlet pipelines connected with the fans, the outlet pipelines of the air smoke draft fans and the combustion air fans are connected with the back smoke pipelines through electric switch valves, and a diffusion pipeline is arranged on the high point of the outlet pipeline of the air smoke draft fan and an electric regulating cut valve is arranged on the diffusion pipeline.

2. The full-oxygen combustion air-steam zero-emission coupled system of a double regenerative heating furnace of blast furnace gas according to claim 1, characterized in that, The air burners are connected with the air smoke pipelines through reversing valves, and a thermocouple, a flow orifice plate one, a CO analyzer, a pressure transmitter, a flow electric regulating valve, a residual oxygen analyzer and a NOx analyzer are arranged on the air smoke pipelines in sequence.

3. The full-oxygen combustion air and flue gas zero emission coupling system of a double regenerative heating furnace of blast furnace gas according to claim 1, characterized in that, The back smoke pipelines are provided with a flow orifice plate two and an electric butterfly valve in sequence.

4. The full-oxygen combustion air zero emission coupled system of a double regenerative heating furnace of the blast furnace gas according to claim 1, characterized in that, The heat accumulating heating furnace is a double heat accumulating heating furnace mixed in an up-down mode, the heat accumulating heating furnace is divided into upper and lower heating burner heat accumulating boxes, the gas burners are arranged in the lower part of the upper heating burner heat accumulating box and the air burners are arranged in the upper part, the gas burners are arranged in the upper part of the lower heating burner heat accumulating box and the air burners are arranged in the lower part, and a rotational flow pure oxygen nozzle is arranged between the center lines of the dividing surfaces of the gas burners and the air burners along the furnace length direction.

5. The full-oxygen combustion air zero emission coupled system of a double regenerative furnace heated by blast furnace gas according to claim 1, characterized in that, The heat accumulating heating furnace is a double heat accumulating heating furnace mixed in a left-right mode, the gas burners and the air burners in the heat accumulating boxes of the furnace walls are arranged in a left-right angle mode, the oxygen nozzles are rotational flow pure oxygen nozzles, and the nozzles are arranged between the two heat accumulating boxes on the center lines of the angles between the gas burners and the air burners along the furnace length direction.

6. The full-oxygen combustion air zero emission coupled system of a double regenerative furnace of the blast furnace gas according to claim 1 or 4 or 5, characterized in that, The pure oxygen nozzles are provided with rotational flow holes in a circumferential distribution mode, and the rotational flow holes on the horizontal line are larger than the rotational flow holes in other directions.

7. The full-oxygen combustion air zero emission coupled system of a dual regenerative furnace heated by blast furnace gas according to claim 1, characterized in that, The heat accumulating chambers in the two side walls of the heat accumulating heating furnace are provided with heat accumulating bodies, the heat accumulating bodies absorb heat when the gas burners and the air burners exhaust flue gas, and the heat accumulating bodies heat the gas and the air smoke when the gas and the air smoke are reversed and supplied.

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