Energy-saving and emission-reducing system for producing cement clinker through oxygen-enriched combustion

Abstract

The invention discloses an energy-saving and emission-reducing system for producing cement clinker by oxygen-enriched combustion, which belongs to the technical field of cement production, and comprises an electricity-to-gas device for electrolyzing water to generate H2 and O2, and a clinker sintering system is arranged beside the electricity-to-gas device. The clinker firing system comprises a kiln head burner used for burning pulverized coal, a kiln tail burner used for burning the pulverized coal, a rotary kiln connected with the kiln head burner, a smoke chamber connected with the rotary kiln and a decomposing furnace connected with the smoke chamber, and the kiln tail burner is connected with the decomposing furnace. The power-to-gas device is connected with the kiln head burner and the kiln tail burner, the power-to-gas device is connected with the CH4 storage tank, the CH4 storage tank is connected with the decomposing furnace, the CH4 storage tank is connected with the kiln tail burner, and the CH4 storage tank is connected with the smoke chamber. The device has the effects that the oxygen production cost and the denitration cost are reduced, and carbon emission is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cement production, and in particular to an energy-saving and emission-reducing system for producing cement clinker by oxygen-enriched combustion. Background Art

[0002] Environmental pollution and energy shortages have accelerated the global trend toward low-carbonization and clean energy. The cement industry accounts for 7%-8% of global carbon emissions and is one of the main sources of anthropogenic CO2 emissions. In the process of cement production, carbon capture, utilization and storage for end-of-pipe disposal are considered to be an important technical approach to achieving global emission reduction actions and an important means for my country to respond to climate change.

[0003] Carbon capture during combustion refers to the use of a high-concentration mixed gas of O2 and CO2 to replace air in a kiln to carry out a combustion reaction with coal powder and other fuels. Among them, O2 is obtained using an industrial-grade air separation device, and the cost of oxygen production is high. In addition, the denitrification problem is another difficult problem currently faced by the cement industry in reducing atmospheric pollutant emissions. During the denitrification process, a large amount of ammonia water needs to be purchased from outside, which makes the denitrification cost high.

[0004] In view of the above-mentioned related technologies, it is urgent to design and develop an energy-saving and emission-reduction system for producing cement clinker through oxygen-enriched combustion. A power-to-gas device is used to electrolyze water to produce H2 and O2. O2 is used for the combustion of fuels such as coal powder. CO2 and H2 are then reacted under high temperature and high pressure to produce CH4. CH4 is used as a reducing agent for denitrification, which reduces the cost of oxygen production and denitrification and reduces carbon emissions. Summary of the invention

[0005] In order to reduce the cost of oxygen production and denitrification and reduce carbon emissions, the present application provides an energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion.

[0006] In the first aspect, the present application provides an energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion, which mainly adopts the following technical solutions: An energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion, comprising an electric-to-gas device for electrolyzing water to produce H2 and O2, a clinker burning system being arranged next to the electric-to-gas device, the clinker burning system comprising a kiln head burner for burning pulverized coal, a kiln tail burner for burning pulverized coal, a rotary kiln connected to the kiln head burner, a smoke chamber connected to the rotary kiln, and a decomposition furnace connected to the smoke chamber, the kiln tail burner being connected to the decomposition furnace, the electric-to-gas device being connected to the kiln head burner and the kiln tail burner, the electric-to-gas device being connected to a CH4 storage tank, the CH4 storage tank being connected to the decomposition furnace, the CH4 storage tank being connected to the kiln tail burner, and the CH4 storage tank being connected to the smoke chamber.

[0007] By adopting the above technical scheme, the electric gas conversion device is connected with the kiln head burner and the kiln tail burner, the electric gas conversion device generates O2 for the kiln head burner and the kiln tail burner for burning pulverized coal, the rotary kiln is connected with the kiln head burner, the smoke chamber is connected with the rotary kiln, the decomposition furnace is connected with the smoke chamber, the decomposition furnace is connected with the kiln tail burner, the electric gas conversion device is connected with the CH4 storage tank, the CH4 storage tank is connected with the decomposition furnace, the CH4 storage tank is connected with the kiln tail burner, the CH4 storage tank is connected with the smoke chamber, the electric gas conversion device generates H2 and high-concentration CO2 to generate CH4 under high temperature and high pressure conditions, and CH4 is used as a reducing agent for denitrification in the kiln tail burner and the decomposition furnace, thereby reducing the cost of oxygen production and denitrification, and reducing carbon emissions.

[0008] Preferably, an ammonia water preparation system is arranged next to the power-to-gas device, and the ammonia water preparation system includes an ammonia synthesis device connected to the power-to-gas device, an ammonia water storage tank connected to the ammonia synthesis device, and an air separation nitrogen production device for producing nitrogen, the air separation nitrogen production device is connected to the ammonia synthesis device, and the ammonia water storage tank is connected to the decomposition furnace.

[0009] By adopting the above technical scheme, the air separation nitrogen production device is connected to the ammonia synthesis device, the ammonia synthesis device is connected to the power-to-gas device, and the ammonia water storage tank is connected to the ammonia synthesis device. The power-to-gas device produces H2 and high-concentration nitrogen to produce ammonia under high temperature, high pressure and catalyst conditions. The ammonia gas reacts with water to produce ammonia water, which is used as a reducing agent for denitrification in the decomposition furnace, thereby saving resources.

[0010] Preferably, an oxygen and gas production system is arranged next to the electric-to-gas device, and the oxygen and gas production system includes an air-separation oxygen production device and an oxygen storage tank connected to the air-separation oxygen production device, the air-separation oxygen production device is connected to the kiln tail burner, the air-separation oxygen production device is connected to the kiln head burner, the oxygen storage tank is connected to the electric-to-gas device, the oxygen storage tank is connected to the kiln tail burner, and the oxygen storage tank is connected to the kiln head burner.

[0011] By adopting the above technical scheme, the air separation oxygen making device is connected to the kiln tail burner, the air separation oxygen making device is connected to the kiln head burner, the oxygen storage tank is connected to the air separation oxygen making device, the oxygen storage tank is connected to the electric gas conversion device, the oxygen storage tank is connected to the kiln tail burner, and the oxygen storage tank is connected to the kiln head burner. The high concentration O2 produced by the air separation oxygen making device can be stored in the oxygen storage tank, and the high concentration O2 produced by the electric gas conversion device can be stored in the oxygen storage tank, which is beneficial to maintaining the normal combustion reaction.

[0012] Preferably, the oxygen and gas production system includes an external power grid connected to the air separation oxygen production device and a wind photovoltaic power generation system connected to the power-to-gas device, the external power grid is connected to the power-to-gas device, the external power grid is connected to the ammonia synthesis device, the external power grid is connected to the air separation nitrogen production device, the wind photovoltaic power generation system is connected to the air separation oxygen production device, the wind photovoltaic power generation system is connected to the air separation nitrogen production device, and the wind photovoltaic power generation system is connected to the ammonia synthesis device.

[0013] By adopting the above technical scheme, the external power grid is connected to the air separation oxygen production device, the external power grid is connected to the power-to-gas device, the external power grid is connected to the ammonia synthesis device, the external power grid is connected to the air separation nitrogen production device, the wind photovoltaic power generation system is connected to the power-to-gas device, the wind photovoltaic power generation system is connected to the air separation oxygen production device, the wind photovoltaic power generation system is connected to the air separation nitrogen production device, and the wind photovoltaic power generation system is connected to the ammonia synthesis device. When the output of the wind photovoltaic power generation system is large, its electric energy is supplied to the air separation oxygen production device and the power-to-gas device to produce O2, and part of the produced O2 is transmitted to the kiln head burner and the kiln tail burner, and the surplus O2 enters the oxygen storage tank for storage; when the output of the wind photovoltaic power generation system is small, and the O2 produced by its electric energy supplied to the air separation oxygen production device and the power-to-gas device cannot meet the oxygen-rich operation demand of the system, the difference in O2 is supplied by the oxygen storage tank, and when there is still a difference, the external power grid is enabled to supplement the power supply for oxygen production, thereby ensuring the normal progress of the entire reaction.

[0014] Preferably, the clinker burning system includes a grate cooler, a kiln head hood connected to the first cooling zone in the grate cooler, a preheater assembly, a high-temperature dust collector and a pressure reamer connected to the second-stage preheater in the preheater assembly, the pressure reamer is connected to the connecting pipes of the second-stage preheater and the high-temperature dust collector, the kiln head hood is connected to the decomposition furnace, the rotary kiln is connected to the kiln head hood, the rotary kiln is connected to the first cooling zone in the grate cooler, and the kiln head burner is connected to the kiln head hood.

[0015] By adopting the above technical scheme, the kiln head hood is connected to the first cooling zone in the grate cooler, the high-temperature dust collector is connected to the second-stage preheater in the preheater assembly, the pressure reamer is connected to the connecting pipes of the second-stage preheater and the high-temperature dust collector, the kiln head hood is connected to the decomposition furnace, the rotary kiln is connected to the kiln head hood, the kiln head burner is connected to the kiln head hood, and the rotary kiln is connected to the first cooling zone in the grate cooler, which is beneficial to the stable production of clinker.

[0016] Preferably, the grate cooler also includes a second cooling zone and a third cooling zone, the first cooling zone, the second cooling zone, and the third cooling zone are connected in sequence, the first cooling zone is connected to the air separation oxygen production device, the first cooling zone is connected to the oxygen storage tank, the first cooling zone is connected to the power-to-gas device, the third cooling zone is provided with a raw material drying system, the third cooling zone is provided with a coal mill drying system, and the third cooling zone is provided with a clinker storage.

[0017] By adopting the above technical scheme, the first cooling zone, the second cooling zone, and the third cooling zone are connected in sequence, the first cooling zone is connected to the air separation oxygen production device, the first cooling zone is connected to the oxygen storage tank, the first cooling zone is connected to the power-to-gas device, the third cooling zone is provided with a raw material drying system, the third cooling zone is provided with a coal mill drying system, and the third cooling zone is provided with a clinker warehouse to facilitate the collection and processing of clinker.

[0018] Preferably, the preheater assembly also includes a third-stage preheater, a fourth-stage preheater and a fifth-stage preheater, the second-stage preheater, the third-stage preheater, the fourth-stage preheater and the fifth-stage preheater are connected in sequence, the fifth-stage preheater is connected to the decomposition furnace, and the fifth-stage preheater is connected to the ammonia water storage tank.

[0019] By adopting the above technical scheme, the second-stage preheater, the third-stage preheater, the fourth-stage preheater and the fifth-stage preheater are connected in sequence, the fifth-stage preheater is connected to the decomposition furnace, and the fifth-stage preheater is connected to the ammonia water storage tank to improve the heat exchange performance and reduce energy consumption.

[0020] Preferably, the high-temperature dust collector is connected to the SCR device, the SCR device is connected to the high-temperature fan, the SCR device is connected to the ammonia water storage tank, the high-temperature fan is connected to heat exchanger 1, the heat exchanger 1 is connected to the circulating fan, the circulating fan is connected to the dehydration device, the circulating fan is connected to the chimney, the circulating fan is connected to the CO2 capture system, the dehydration device is connected to heat exchanger 2, the dehydration device is connected to the air sealing system, the dehydration device is connected to the first cooling zone, the dehydration device is connected to the second cooling zone, and the CO2 capture system is connected to the electric-to-gas device.

[0021] By adopting the above technical scheme, the high-temperature dust collector is connected to the SCR device, the SCR device is connected to the high-temperature fan, the SCR device is connected to the ammonia storage tank, the high-temperature fan is connected to heat exchanger one, heat exchanger one is connected to the circulating fan, the circulating fan is connected to the dehydration device, the circulating fan is connected to the chimney, the circulating fan is connected to the CO2 capture system, the dehydration device is connected to heat exchanger two, the dehydration device is connected to the air sealing system, the dehydration device is connected to the first cooling zone, the dehydration device is connected to the second cooling zone, and the CO2 capture system is connected to the power-to-gas device, thereby effectively reducing the emission of nitrogen oxides. Part of the high-concentration CO2 captured by the CO2 capture system is used as a reaction raw material for the power-to-gas device, which not only reduces the carbon storage cost.

[0022] Preferably, the second heat exchanger is connected to an air compressor device, the second heat exchanger is connected to a Roots blower, the second heat exchanger is connected to a pulverized coal conveying system, the air compressor device is connected to a ash cleaning system, the Roots blower is connected to a kiln head burner, the Roots blower is connected to a kiln tail burner, the pulverized coal conveying system is connected to the kiln head burner, the pulverized coal conveying system is connected to the kiln tail burner, and the second cooling zone is connected to the connecting pipe between the decomposition furnace and the fifth-stage preheating device.

[0023] By adopting the above technical scheme, heat exchanger 2 is connected to the air compressor device, heat exchanger 2 is connected to the Roots blower, heat exchanger 2 is connected to the coal powder conveying system, the air compressor device is connected to the ash cleaning system, the Roots blower is connected to the kiln head burner, the Roots blower is connected to the kiln tail burner, the coal powder conveying system is connected to the kiln head burner, the coal powder conveying system is connected to the kiln tail burner, and the second cooling zone is connected to the connecting pipe between the decomposition furnace and the fifth-stage preheating device to facilitate the transmission of coal powder.

[0024] In a second aspect, the present application provides an energy-saving and emission-reducing method for producing cement clinker by oxygen-enriched combustion, which adopts the following technical solution: An energy-saving and emission-reducing method for producing cement clinker by oxygen-enriched combustion comprises the following steps: S1. The raw material is fed into the connecting pipe from the second stage preheater to the high temperature dust collector through a pressure reamer, undergoes heat exchange with the circulating gas rich in high concentration of CO2 in the pipe, and enters the high temperature dust collector along with the circulating gas; S2. The raw meal is filtered through the high-temperature dust collector and then enters the connecting pipe between the third-stage preheater and the second-stage preheater. After heat exchange with the circulating gas therein, it enters the second-stage preheater. The raw meal is heat exchanged with the circulating gas in the second and fourth-stage preheaters in turn and then enters the decomposition furnace. After the circulating gas leaves the high-temperature dust collector, it is mixed and homogenized with ammonia water from the ammonia water storage tank and enters the SCR device to remove part of the nitrogen oxides, so that the NOx content in the circulating gas leaving the SCR device is less than 50mg / m³. The circulating gas is transported to the heat exchanger 1 through the high-temperature fan, and passes through the circulating fan after heat exchange and cooling; S3, the raw material enters the fifth-stage preheater after being pre-decomposed in the decomposition furnace, and then enters the smoke chamber after being collected by the fifth-stage preheater, and then enters the rotary kiln. After being burned into clinker in the rotary kiln, it enters the first cooling zone of the grate cooler. The clinker is cooled to the required temperature in the first cooling zone, the second cooling zone, and the third cooling zone of the grate cooler in sequence, and then enters the clinker storage; After the circulating gas passes through the circulating fan, the CO2 dry basis concentration is greater than 80%, and its flow is divided into three routes: the first route of circulating gas is purified by the CO2 capture system, and part of the high-concentration CO2 is sealed and stored, and part is sent to the power-to-gas device for reuse; the second route of circulating gas is further recycled after part of the water is removed by the dehydration device; the third route of circulating gas is discharged into the chimney when needed and is closed at other times; After entering the first cooling zone of the grate cooler, the circulating gas exchanges heat with the clinker from the rotary kiln and then enters the kiln head hood. The gas temperature in the kiln head hood is 950-1250℃. Part of the gas in the kiln head hood enters the rotary kiln as secondary air, and part of it enters the decomposition furnace as tertiary air; the circulating gas entering the second cooling zone of the grate cooler exchanges heat with the clinker from the first cooling zone and has a temperature of 400-500℃, and then enters the decomposition furnace outlet for cooling and air replenishment; in the third cooling zone of the grate cooler, the air and the clinker from the second cooling zone are heat exchanged to become 200-250℃ hot air for use by other systems; After the circulating gas passes through the dehydration device (7), the CO2 dry basis concentration is greater than 80% and the temperature is 75-80°C. The circulating gas is divided into four routes. The first route is cooled to room temperature through the second heat exchanger and then goes to the air compressor device, the Roots blower and the coal powder conveying system respectively; the second route goes to the gas sealing system; the third route is mixed with the high-concentration O2 from the oxygen and gas production system and then goes to the first cooling zone of the grate cooler; the fourth route goes to the second cooling zone of the grate cooler; The wind-powered photovoltaic power generation system has a large output, and its electric energy is used to supply the air-separation oxygen-generating device and the power-to-gas device (1) to produce O2. A part of the produced O2 is transmitted to the kiln head burner and the kiln tail burner, and the surplus O2 is stored in the oxygen storage tank. When the wind-powered photovoltaic power generation system has a small output, and the O2 produced by the electric energy supplied to the air-separation oxygen-generating device and the power-to-gas device cannot meet the oxygen-rich operation demand of the system, the difference in O2 is supplied by the oxygen storage tank. If there is still a difference, the external power grid is used to supplement the power supply for oxygen production, thereby ensuring the normal operation of the entire reaction. The wind-photovoltaic power generation system and the external power grid provide the electricity required for the air-separation oxygen production unit, the power-to-gas unit, the air-separation nitrogen production unit and the ammonia synthesis unit. The oxygen and gas production system and the ammonia preparation system flexibly schedule the output plans and energy distribution relationships of each equipment, and comprehensively coordinate the peak and valley time periods and wind and solar intensity to schedule the electricity utilization of the external power grid and the wind-photovoltaic power generation system. The wind-photovoltaic power generation system is used first.

[0025] By adopting the above technical scheme, the raw material is input into the system through a pressure reamer at the connecting pipe from the second-stage preheater to the high-temperature dust collector, and after heat exchange with the circulating gas rich in high-concentration CO2 in the pipe, it enters the high-temperature dust collector with the circulating gas. The pressure reamer isolates the air from entering the system in the form of a material seal. The raw material in the circulating gas is filtered and collected by the filter bag of the high-temperature dust collector and enters the connecting pipe between the third-stage preheater and the second-stage preheater, avoiding the leakage of air into the air lock valve of the dust collector under high negative pressure. After heat exchange with the circulating gas therein, it enters the second-stage preheater; the raw material successively exchanges heat with the circulating gas in the second to fourth-stage preheaters and then enters the decomposition furnace. After pre-decomposition in the decomposition furnace, the raw material enters the fifth-stage preheater, and after being collected by the fifth-stage preheater, it enters the smoke chamber, and then enters the rotary kiln. After being burned into clinker in the rotary kiln, it enters the first cooling zone of the grate cooler. The clinker is successively cooled to the required temperature in the first cooling zone, the second cooling zone, and the third cooling zone of the grate cooler and then enters the clinker warehouse for storage.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. The electric-to-gas device is connected to the kiln head burner and the kiln tail burner. The electric-to-gas device generates O2 for the kiln head burner and the kiln tail burner for burning pulverized coal. The rotary kiln is connected to the kiln head burner, the smoke chamber is connected to the rotary kiln, the decomposition furnace is connected to the smoke chamber, the decomposition furnace is connected to the kiln tail burner, the electric-to-gas device is connected to the CH4 storage tank, the CH4 storage tank is connected to the decomposition furnace, and the CH4 storage tank is connected to the kiln tail burner. The electric-to-gas device generates H2 and high-concentration CO2 to generate CH4 under high temperature and high pressure conditions. CH4 is used as a reducing agent for denitration in the kiln tail burner and the decomposition furnace, thereby reducing the cost of oxygen production and denitration, and reducing carbon emissions; 2. The air separation nitrogen production device is connected to the ammonia synthesis device, the ammonia synthesis device is connected to the power-to-gas device, and the ammonia water storage tank is connected to the ammonia synthesis device. The power-to-gas device generates H2 and high-concentration nitrogen to generate ammonia under high temperature, high pressure and catalyst conditions. The ammonia reacts with water to generate ammonia water, which is used as a reducing agent for denitrification in the decomposition furnace to save resources; 3. The external power grid is connected to the air separation oxygen production device, the external power grid is connected to the power-to-gas device, the external power grid is connected to the ammonia synthesis device, the external power grid is connected to the air separation nitrogen production device, the wind photovoltaic power generation system is connected to the power-to-gas device, the wind photovoltaic power generation system is connected to the air separation oxygen production device, the wind photovoltaic power generation system is connected to the air separation nitrogen production device, and the wind photovoltaic power generation system is connected to the ammonia synthesis device. When the wind photovoltaic power generation system has a large output, its electricity is supplied to the air separation oxygen production device and the power-to-gas device to produce oxygen. 2. Part of the produced O2 is transported to the kiln head burner and the kiln tail burner, and the surplus O2 is stored in the oxygen storage tank; when the output of the wind photovoltaic power generation system is small, and the O2 produced by its electricity supply to the air separation oxygen production device and the power-to-gas device cannot meet the oxygen-rich operation demand of the system, the difference in O2 is supplied by the oxygen storage tank. When there is still a difference, the external power grid is used to supplement the power supply for oxygen production, thereby ensuring the normal progress of the entire reaction. The wind photovoltaic power generation system reduces the operating costs of the air separation oxygen production device, air separation nitrogen production device, power-to-gas device and ammonia synthesis device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall system flow of an energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion in an embodiment of the present application.

[0028] Figure 2 It is a schematic diagram of the process of the clinker burning system in the embodiment of the present application.

[0029] Figure 3 It is a schematic diagram of the structure of the kiln head sealing device in the embodiment of the present application.

[0030] Figure 4 It is a schematic diagram of the structure of the kiln tail sealing device in the embodiment of the present application.

[0031] Figure 5 It is a schematic diagram of the structure of a high-temperature dust collector in an embodiment of the present application.

[0032] Figure 6 It is a schematic diagram of the process of the ammonia preparation system in the embodiment of the present application.

[0033] Figure 7 It is a schematic diagram of the flow chart of the oxygen and gas production system in the embodiment of the present application.

[0034] Description of reference numerals: 1. Electricity-to-gas device; 2. Clinker burning system; 21. Kiln head burner; 22. Kiln tail burner; 23. Rotary kiln; 24. Smoke chamber; 25. Decomposition furnace; 26. Grate cooler; 261. First cooling zone; 262. Second cooling zone; 263. Third cooling zone; 27. Kiln head cover; 28. Preheater assembly; 281. Second stage preheater; 282. Third stage preheater; 283. Fourth stage preheater; 284. Five-stage preheater; 29, high-temperature dust collector; 291, dust collector shell; 292, shed; 293, pulse cleaning device; 294, air lock valve; 210, pressure reamer; 3, SCR device; 4, high-temperature fan; 5, heat exchanger 1; 6, circulating fan; 7, water removal device; 8, air compressor device; 9, cleaning system; 91, air cannon; 10, heat exchanger 2; 11, air sealing system; 111, kiln head sealing device; 1 111. Friction ring; 1112. Sealing cover; 1113. Sealing sheet; 1114. Circulating gas inlet 1; 1115. Circulating gas inlet 2; 1116. Circulating gas outlet; 112. Kiln tail sealing device; 1121. Compression seal fixed end; 1122. Compression seal rotating end; 1123. Isolation cover; 1124. Fish scale sheet; 1125. Contact ring; 1126. Circulating gas inlet 3; 12. Coal powder conveying system ; 13. Ammonia preparation system; 131. Ammonia synthesis unit; 132. Ammonia storage tank; 133. Air separation nitrogen production unit; 14. Oxygen and gas production system; 141. Air separation oxygen production unit; 142. Oxygen storage tank; 15. Wind photovoltaic power generation system; 16. External power grid; 17. CO2 capture system; 18. Raw material drying system; 19. Coal mill drying system; 20. Clinker warehouse; 211. CH4 storage tank; 212. Roots blower. DETAILED DESCRIPTION

[0035] The following is combined with Figure 1-7 This application is described in further detail.

[0036] The present application embodiment discloses an energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion. Figure 1 As shown, the energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion includes a power-to-gas device 1, a clinker burning system 2, an SCR device 3, a high-temperature fan 4, a heat exchanger 1 5, a circulating fan 6, a water removal device 7, an air compressor device 8, a dust cleaning system 9, a heat exchanger 2 10, a gas sealing system 11, a pulverized coal conveying system 12, an ammonia water preparation system 13, an oxygen and gas production system 14, a wind power photovoltaic power generation system 15, an external power grid 16, a CO2 capture system 17, a raw material drying system 18, a coal mill drying system 19, and a clinker storage 20.

[0037] Reference Figure 1 and Figure 2As shown, the clinker burning system 2 includes a kiln head burner 21, a kiln tail burner 22, a rotary kiln 23, a smoke chamber 24, a decomposition furnace 25, a grate cooler 26, a kiln head hood 27, a preheater assembly 28, a high-temperature dust collector 29, a pressure reamer 210 and an air cannon 91, the rotary kiln 23 is connected to the kiln head burner 21, the smoke chamber 24 is connected to the rotary kiln 23, the decomposition furnace 25 is connected to the smoke chamber 24, the kiln tail burner 22 is connected to the decomposition furnace 25, the electric-to-gas device 1 is connected to the kiln head burner 21 and the kiln tail burner 22, the electric-to-gas device 1 is connected to the CH4 storage tank 211, the CH4 storage tank 211 is connected to the decomposition furnace 25, the CH4 storage tank 211 is connected to the kiln tail burner 22, and the CH4 storage tank 211 is connected to the smoke chamber 24.

[0038] Reference Figure 1 and Figure 2 As shown, the air-tight sealing system 11 includes a kiln head sealing device 111, a kiln tail sealing device 112, and improved inspection doors, valves, holes, covers and a pipeline system connecting various sealing points in various parts of the system.

[0039] Reference Figure 2 and Figure 3 As shown, the kiln head sealing device 111 adopts a double-layer fish scale sealing structure, and the kiln head sealing device 111 includes a friction ring 1111, a sealing cover 1112 and a sealing sheet 1113. The friction ring 1111 is fixed on the outer wall of the rotary kiln 23, and the sealing cover 1112 is fixed on the kiln head cover 27; there are a plurality of sealing sheets 1113, and the plurality of sealing sheets 1113 are stacked to form a double-layer fish scale annular cover body, one end of the annular cover body is pressed on the friction ring 1111, and the other end of the annular cover is fixed on the sealing cover 1112; the plurality of sealing sheets 1113, the friction ring 1111 and the sealing cover 1112 are enclosed to form an isolation chamber, and the sealing cover 1112 is provided with a circulating gas inlet 1 1114, a circulating gas inlet 2 1115 and a circulating gas outlet 1116.

[0040] Reference Figure 2 and Figure 3 As shown, the circulating gas enters the isolation chamber from the circulating gas inlet 1114 and maintains a slight positive pressure in the isolation chamber. Part of the circulating gas passes through the gap between the sealing sheets 1113 and enters the external air, so that the external air cannot enter the isolation chamber. The circulating gas entering from the circulating gas inlet 1115 enters the cold air jacket to cool the kiln head, and most of it is discharged through the circulating gas outlet, and a small part enters the system through the kiln head cover 27, that is, the kiln head sealing device 111 isolates the outside air from entering the system.

[0041] Reference Figure 2 and Figure 4As shown, the kiln tail sealing device 112 adopts a double-layer sealing structure of compression sealing and fish scale sealing. The kiln tail sealing device 112 includes a compression sealing fixed end 1121, a compression sealing rotating end 1122, an isolation cover 1123, fish scales 1124 and a contact ring 1125. The contact part of the compression sealing fixed end 1121 and the compression sealing rotating end 1122 forms a friction pair to constitute a compression sealing structure; the isolation cover 1123 is fixed on the side wall of the smoke chamber 24, and the fish scales 1124 are fixed to the side wall of the smoke chamber 24. 24 has several, several fish scales 1124 are stacked into a fish scale-shaped annular cover body, one end of several fish scales 1124 is fixed on the isolation cover 1123, and the other end of several fish scales 1124 is pressed on the contact ring 1125, and the contact ring 1125 is fixed on the compression seal rotating end 1122. The isolation cover 1123, the fish scales 1124, the contact ring 1125, the compression seal fixed end 1121 and the compression seal rotating end 1122 together form a sealing cavity.

[0042] Reference Figure 2 and Figure 3 As shown, the compression seal rotating end 1122 rotates with the rotary kiln 23 to form a double sealing structure of fish scales 1124 and friction pairs. The circulating gas enters the sealing cavity from the circulating gas inlet 1126 and maintains a slight positive pressure in the sealing cavity. Part of the circulating gas passes through the gaps between the sealing plates 1113 and enters the external air, and part of the circulating gas passes through the gaps between the friction pairs of the compression seal structure and enters the smoke chamber 24. The function is to prevent external air from entering the sealing cavity, that is, the kiln tail sealing device 112 isolates the external air from entering the system.

[0043] Reference Figure 2 As shown, the cleaning system 9 includes a dust collector pulse cleaning device and a pipeline system connecting various cleaning points, and the air cannon 91 is connected to the smoke chamber 24.

[0044] Reference Figure 2 and Figure 5 As shown, the high-temperature dust collector 29 adopts a high-box shed structure, including a dust collector shell 291, a shed 292, a pulse cleaning device 293, a double-layer inspection door and an air lock valve 294. The shed 292 is a closed structure, which is fixed to the upper part of the shell. A number of double-layer inspection doors are arranged on the shed 292, and a closed partition cavity is formed in the middle of the double doors. The air lock valve 294 is arranged at the lower part of the shell.

[0045] Reference Figure 2 and Figure 5As shown, the circulating air is passed into the partition chamber between the double-layer inspection doors to maintain a slight positive pressure in the partition chamber. Under the action of the slight positive pressure, outside air cannot enter the partition chamber, that is, it cannot enter the high-temperature dust collector 29. The lower part of the dust collector is connected to a double-layer air lock valve 294, and the double-layer air lock valve 294 is connected to the connecting pipe between the third-stage preheater 282 and the second-stage preheater 281 to prevent the air lock valve 294 from leaking air. The cleaning air of the pulse cleaning device 293 is the circulating air from the air compressor device 8 to prevent air from entering the system.

[0046] Reference Figure 3 and Figure 4 As shown, the ammonia preparation system 13 includes an ammonia synthesis device 131, an ammonia storage tank 132 and an air separation nitrogen production device 133. The ammonia synthesis device 131 is connected to the power-to-gas device 1, the ammonia storage tank 132 is connected to the ammonia synthesis device 131, the air separation nitrogen production device 133 is connected to the ammonia synthesis device 131, and the ammonia storage tank 132 is connected to the decomposition furnace 25.

[0047] Reference Figure 1 , Figure 2 and Figure 6 As shown, after the circulating gas leaves the high-temperature dust collector 29, it is mixed and homogenized with the ammonia water from the ammonia water storage tank 132, and enters the SCR device 3 to remove part of the nitrogen oxides, so that the NOx content in the circulating gas leaving the SCR device 3 is less than 50 mg / m³. The circulating gas is transported to the heat exchanger 5 through the high-temperature fan 4, and passes through the circulating fan 6 after heat exchange and cooling.

[0048] Reference Figure 1 , Figure 2 and Figure 6 As shown, the CO2 dry basis concentration of the circulating gas after passing through the circulating fan 6 is greater than 80%, and its flow is divided into three routes: the first circulating gas is purified by the CO2 capture system 17, and a part of the high-concentration CO2 obtained is sealed and stored, and a part is transmitted to the power-to-gas device 1 for reuse; the second circulating gas is further recycled after part of the moisture is removed by the dehydration device 7; the third circulating gas enters the chimney for discharge when needed and is closed at other times.

[0049] Reference Figure 1 , Figure 2 and Figure 6As shown, the grate cooler 26 includes a first cooling zone 261, a second cooling zone 262 and a third cooling zone 263, which are connected in sequence, the kiln head hood 27 is connected to the first cooling zone 261, the rotary kiln 23 is connected to the first cooling zone 261 in the grate cooler 26, the kiln head burner 21 is connected to the kiln head hood 27, the first cooling zone 261 is connected to the air separation oxygen production device 141, the first cooling zone 261 is connected to the oxygen storage tank 142, the first cooling zone 261 is connected to the electric-to-gas device 1, the third cooling zone 263 is connected with a raw material drying system, the coal mill drying system 19 is arranged at the third cooling zone 263, the coal mill drying system 19 is connected to the third cooling zone 263, the clinker warehouse 20 is arranged at the third cooling zone 263, and the clinker warehouse 20 is connected to the third cooling zone 263.

[0050] Reference Figure 1 , Figure 2 and Figure 6 As shown, the circulating air entering the first cooling zone 261 of the grate cooler 26 exchanges heat with the clinker from the rotary kiln 23 and then enters the kiln head hood 27. The gas temperature in the kiln head hood 27 is 950-1250°C. Part of the gas in the kiln head hood 27 enters the rotary kiln 23 as secondary air, and part of it enters the decomposition furnace 25 as tertiary air; the circulating air entering the second cooling zone 262 of the grate cooler 26 exchanges heat with the clinker from the first cooling zone 261 and has a temperature of 400-500°C, and then enters the outlet of the decomposition furnace 25 for cooling and air replenishment; in the third cooling zone 263 of the grate cooler 26, the air and the clinker from the second cooling zone 262 are heat exchanged to become hot air at 200-250°C, and the hot air goes to the raw material drying system 18 and the coal mill drying system 19 respectively.

[0051] Reference Figure 1 and Figure 2 As shown, the preheater assembly 28 includes a second-stage preheater 281, a third-stage preheater 282, a fourth-stage preheater 283 and a fifth-stage preheater 284. The second-stage preheater 281, the third-stage preheater 282, the fourth-stage preheater 283 and the fifth-stage preheater 284 are connected in sequence, the fifth-stage preheater 284 is connected to the decomposition furnace 25, the fifth-stage preheater 284 is connected to the ammonia water storage tank 132, and the high-temperature dust collector 29 is connected to the second-stage preheater 281.

[0052] Reference Figure 1 and Figure 2As shown, the high-temperature dust collector 29 is connected to the SCR device 3, the SCR device 3 is connected to the high-temperature fan 4, the SCR device 3 is connected to the ammonia storage tank 132, the high-temperature fan 4 is connected to the heat exchanger 1 5, the heat exchanger 1 5 is connected to the circulating fan 6, the circulating fan 6 is connected to the dehydration device 7, the circulating fan 6 is connected to the chimney, the circulating fan 6 is connected to the CO2 capture system, the dehydration device 7 is connected to the heat exchanger 2 10, the dehydration device 7 is connected to the air sealing system 11, the dehydration device 7 is connected to the first cooling zone 261, the dehydration device 7 is connected to the second cooling zone 262, and the CO2 capture system is connected to the electric-to-gas device 1.

[0053] Reference Figure 1 and Figure 2 As shown, the heat exchanger 10 is connected to the air compressor device 8, the heat exchanger 10 is connected to the Roots blower 212, the heat exchanger 10 is connected to the coal powder conveying system 12, the air compressor device 8 is connected to the ash cleaning system 9, the Roots blower 212 is connected to the kiln head burner 21, the Roots blower 212 is connected to the kiln tail burner 22, the coal powder conveying system 12 is connected to the kiln head burner 21, the coal powder conveying system 12 is connected to the kiln tail burner 22, and the second cooling zone 262 is connected to the connecting pipe between the decomposition furnace 25 and the fifth stage preheater 284.

[0054] Reference Figure 1 and Figure 2 As shown, after the circulating gas passes through the dehydration device 7, the CO2 dry basis concentration is greater than 80%, and the temperature is 75-80°C. Its direction is divided into four routes. The first route is cooled to room temperature through the heat exchanger 10 and then goes to the air compressor device 8, the Roots blower 212 and the coal powder conveying system 12 respectively; the second route goes to the gas sealing system 11; the third route is mixed with the high-concentration O2 from the oxygen and gas production system 14 and then goes to the first cooling zone 261 of the grate cooler 26; the fourth route goes to the second cooling zone 262 of the grate cooler 26.

[0055] Reference Figure 1 and Figure 2 As shown, the compressed circulating gas after passing through the air compressor device 8 is used as the air source of the ash cleaning system 9, and the circulating gas after passing through the Roots blower 212 is divided into two paths: the first path is mixed with the high-concentration O2 from the oxygen-making gas system 14 and transported to the kiln tail burner 22; the second path is mixed with the high-concentration O2 from the oxygen-making gas system 14 as primary air and transported to the kiln head burner 21. By adjusting the ratio of the circulating gas and the high-concentration O2, different combustion flame forms are obtained, and the coal powder conveying system 12 uses the circulating gas to pneumatically convey the coal powder to the kiln tail burner 22 and the kiln head burner 21 respectively.

[0056] Reference Figure 1 , Figure 2 and Figure 7As shown, the oxygen and gas production system 14 includes an air separation oxygen production device 141 and an oxygen storage tank 142, the oxygen storage tank 142 is connected to the air separation oxygen production device 141, the air separation oxygen production device 141 is connected to the kiln tail burner 22, the air separation oxygen production device 141 is connected to the kiln head burner 21, the oxygen storage tank 142 is connected to the electric-to-gas device 1, the oxygen storage tank 142 is connected to the kiln tail burner 22, and the oxygen storage tank 142 is connected to the kiln head burner 21.

[0057] Reference Figure 1 , Figure 2 and Figure 7 As shown, the external power grid 16 is connected to the power-to-gas device 1, the external power grid 16 is connected to the air separation oxygen production device 141, the external power grid 16 is connected to the ammonia synthesis device 131, the external power grid 16 is connected to the air separation nitrogen production device 133, the wind photovoltaic power generation system 15 is connected to the air separation oxygen production device 141, the wind photovoltaic power generation system 15 is connected to the power-to-gas device 1, the wind photovoltaic power generation system 15 is connected to the air separation nitrogen production device 133, and the wind photovoltaic power generation system 15 is connected to the ammonia synthesis device 131.

[0058] Reference Figure 1 , Figure 2 and Figure 7 As shown, when the output of the wind photovoltaic power generation system 15 is large, its electric energy is supplied to the air separation oxygen production device 141 and the power-to-gas device 1 to produce O2, and a part of the produced O2 is transmitted to the kiln head burner 21 and the kiln tail burner 22, and the surplus O2 enters the oxygen storage tank 142 for storage; when the output of the wind photovoltaic power generation system 15 is small, and the O2 produced by its electric energy supplied to the air separation oxygen production device 141 and the power-to-gas device 1 cannot meet the oxygen-enriched operation demand of the system, the O2 difference is supplied by the oxygen storage tank 142, and when there is still a difference, the external power grid 16 is enabled to supplement the power supply for oxygen production, thereby ensuring the normal progress of the entire reaction.

[0059] Reference Figure 1 , Figure 2 and Figure 7 As shown, the wind photovoltaic power generation system 15 and the external power grid 16 provide the electric energy required by the air separation oxygen production device 141, the power-to-gas device 1, the air separation nitrogen production device 133 and the ammonia synthesis device 131. The oxygen and gas production system 14 and the ammonia preparation system 13 flexibly schedule the output plan and energy distribution relationship of each device, and comprehensively schedule the electric energy utilization of the external power grid 16 and the wind photovoltaic power generation system 15 during peak and valley time periods and wind and solar intensity, and the wind photovoltaic power generation system 15 is used first.

[0060] Reference Figure 1 , Figure 2 and Figure 7As shown, the O2 produced by the air separation oxygen production device 141 enters the oxygen storage tank 142 for storage or is directly transported to the kiln head burner 21, the kiln tail burner 22, and the first cooling zone 261 of the grate cooler 26 for use, and the power-to-gas device 1 electrolyzes water to generate O2 and H2, of which the O2 enters the oxygen storage tank 142 for storage or is directly transported to the kiln head burner 21, the kiln tail burner 22, and the first cooling zone 261 of the grate cooler 26 for use.

[0061] Reference Figure 1 , Figure 2 and Figure 7 As shown, the flow of H2 is divided into two paths: one part of H2 and the high-concentration CO2 purified from the CO2 capture system 17 undergo a CH4 conversion reaction under the action of a catalyst to generate CH4, which is then stored in a CH4 storage tank; the other part of H2 enters the ammonia synthesis device 131, where it undergoes an ammonia synthesis reaction with the high-concentration N2 produced by the air separation nitrogen production device 133 under the action of a catalyst to generate ammonia gas, and then the synthesized ammonia gas is mixed with water to form ammonia water, which is stored in an ammonia water storage tank 132; the ammonia water in the ammonia water storage tank 132 is respectively transported to the SCR device 3, the fifth-stage preheater 284 and the decomposition furnace 25 to reduce and eliminate part of the nitrogen oxides in the circulating gas.

[0062] Reference Figure 1 , Figure 2 and Figure 7 As shown, the oxygen storage tank 142 realizes the cross-time use of O2. When the output of the wind-photovoltaic power generation system is large, its electric energy is supplied to the air separation oxygen production device 141 and the power-to-gas device 1 to produce O2. A part of the produced O2 is transmitted to the kiln head burner 21, the kiln tail burner 22, and the first cooling zone 261 of the grate cooler 26 for utilization, and the surplus O2 enters the oxygen storage tank 142 for storage; when the output of the wind-photovoltaic power generation system is small, and the O2 produced by its electric energy supplied to the air separation oxygen production device 141 and the power-to-gas device 1 cannot meet the oxygen-rich operation demand of the system, the difference in O2 is supplied by the oxygen storage tank 142. When there is still a difference, the external power grid 16 is enabled to supplement the power supply for oxygen production.

[0063] Reference Figure 1 , Figure 2 and Figure 7 As shown, the CH4 storage tank realizes the cross-time use of CH4. A part of the CH4 stored in the CH4 storage tank is used as auxiliary fuel to stably supply the kiln tail burner 22 to reduce coal powder consumption, and a part of it is used as a denitrification reducing agent at the outlet of the smoke chamber 24.

[0064] Reference Figure 1 , Figure 2 and Figure 7As shown, the ammonia storage tank 132 realizes the use of ammonia across time periods, and preferentially uses the electric energy of the wind-photovoltaic power generation system to supply the power-to-gas device 1, the air separation nitrogen production device 133 and the ammonia synthesis device 131 to produce ammonia water which enters the ammonia storage tank 132 for storage. When the ammonia reserves in the ammonia storage tank 132 cannot meet the nitrogen reduction demand of the system, the external power grid 16 is activated to supplement the power supply to produce ammonia water.

[0065] The implementation principle of the energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion in the embodiment of the present application is as follows: The electric-to-gas device 1 is connected to the kiln head burner 21 and the kiln tail burner 22. The electric-to-gas device 1 generates O2 for the kiln head burner 21 and the kiln tail burner 22 for burning pulverized coal. The rotary kiln 23 is connected to the kiln head burner 21, the smoke chamber 24 is connected to the rotary kiln 23, the decomposition furnace 25 is connected to the smoke chamber 24, the decomposition furnace 25 is connected to the kiln tail burner 22, the electric-to-gas device 1 is connected to the CH4 storage tank 211, the CH4 storage tank 211 is connected to the decomposition furnace 25, and the CH4 storage tank 211 is connected to the kiln tail burner 22. The electric-to-gas device 1 generates H2 and high-concentration CO2 to generate CH4 under high temperature and high pressure conditions. CH4 is used as a reducing agent for denitrification in the kiln tail burner 22 and the decomposition furnace 25, thereby reducing the cost of oxygen production and denitrification and reducing carbon emissions.

[0066] The present application also discloses a method for energy saving and emission reduction in producing cement clinker by oxygen-enriched combustion, comprising the following steps: S1, the raw material is input into the connecting pipe from the second stage preheater 281 to the high temperature dust collector 29 through the pressure reamer 210, and heat is exchanged with the circulating gas rich in high concentration of CO2 in the pipe, and enters the high temperature dust collector 29 with the circulating gas; S2, the raw material is filtered by the high-temperature dust collector 29 and enters the connecting pipe between the third-stage preheater 282 and the second-stage preheater 281, and enters the second-stage preheater 281 after heat exchange with the circulating gas therein. The raw material is heat exchanged with the circulating gas in the second and fourth-stage preheaters in turn and then enters the decomposition furnace 25. After the circulating gas leaves the high-temperature dust collector 29, it is mixed and homogenized with the ammonia water from the ammonia water storage tank 132, and enters the SCR device 3 to remove part of the nitrogen oxides, so that the NOx content in the circulating gas leaving the SCR device 3 is less than 5mg / m³. The circulating gas is transported to the heat exchanger 5 through the high-temperature fan 4, and passes through the circulating fan 6 after heat exchange and cooling; S3, the raw material enters the fifth-stage preheater 284 after being pre-decomposed in the decomposition furnace 25, and enters the smoke chamber 24 after being collected by the fifth-stage preheater 284, and then enters the rotary kiln 23. After being burned into clinker in the rotary kiln 23, the raw material enters the first cooling zone 261 of the grate cooler 26. The clinker is cooled to the required temperature in the first cooling zone 261, the second cooling zone 262, and the third cooling zone 263 of the grate cooler 26 in sequence, and then enters the clinker storage 20 for storage; After the circulating gas passes through the circulating fan 6, the CO2 dry basis concentration is greater than 80%, and its flow is divided into three routes: the first circulating gas is purified by the CO2 capture system 17, and a part of the high-concentration CO2 is sealed and stored, and a part is transmitted to the power-to-gas device 1 for reuse; the second circulating gas is further recycled after part of the water is removed by the dehydration device 7; the third circulating gas enters the chimney for evacuation when needed and is closed at other times; After the circulating gas enters the first cooling zone 261 of the grate cooler 26, it exchanges heat with the clinker from the rotary kiln 23 and then enters 27. The gas temperature in the kiln head cover 27 is 950-1250°C. Part of the gas in the kiln head cover 27 enters the rotary kiln 23 as secondary air, and part of it enters the decomposition furnace 25 as tertiary air; the circulating gas entering the second cooling zone 262 of the grate cooler 26 exchanges heat with the clinker from the first cooling zone 261 and has a temperature of 400-500°C, and then enters the outlet of the decomposition furnace 25 for cooling and air replenishment; in the third cooling zone 263 of the grate cooler 26, the air and the clinker from the second cooling zone 262 are heat exchanged to become hot air of 200-250°C for use by other systems; After the circulating gas passes through the dehydration device 7, the CO2 dry basis concentration is greater than 80%, and the temperature is 75-80℃. The circulating gas is divided into four routes. The first route is cooled to room temperature through the heat exchanger 10 and then goes to the air compressor device 8, Roots blower 212 and coal powder conveying system 12 respectively; the second route goes to the gas sealing system 11; the third route is mixed with the high-concentration O2 from the oxygen and gas production system 14 and then goes to the first cooling zone 261 of the grate cooler 26; the fourth route goes to the second cooling zone 262 of the grate cooler 26.

[0067] The wind photovoltaic power generation system 15 has a large output, and its electric energy is supplied to the air separation oxygen production device 141 and the power-to-gas device 1 to produce O2. A part of the produced O2 is transmitted to the kiln head burner 21 and the kiln tail burner 22, and the surplus O2 enters the oxygen storage tank 142 for storage; when the wind photovoltaic power generation system 15 has a small output, and the O2 produced by its electric energy supplied to the air separation oxygen production device 141 and the power-to-gas device 1 cannot meet the oxygen-enriched operation demand of the system, the difference in O2 is supplied by the oxygen storage tank 142. When there is still a difference, the external power grid 16 is activated to supplement the power supply for oxygen production, thereby ensuring the normal progress of the entire reaction; The wind photovoltaic power generation system 15 and the external power grid 16 provide the electric energy required by the air separation oxygen production device 141, the power-to-gas device 1, the air separation nitrogen production device 133 and the ammonia synthesis device 131. The oxygen and gas production system 14 and the ammonia preparation system 13 flexibly schedule the output plan and energy distribution relationship of each device, and comprehensively schedule the electric energy utilization of the external power grid 16 and the wind photovoltaic power generation system 16 according to the peak and valley time periods and wind and light intensity, with wind-photovoltaic power generation being given priority.

[0068] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. An energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion, comprising a power-to-gas device (1) for electrolyzing water to produce H2 and O2, characterized in that: A clinker burning system (2) is arranged next to the electric-to-gas device (1), and the clinker burning system (2) comprises a kiln head burner (21) for burning coal powder, a kiln tail burner (22) for burning coal powder, a rotary kiln (23) connected to the kiln head burner (21), a smoke chamber (24) connected to the rotary kiln (23), and a decomposition furnace (25) connected to the smoke chamber (24), wherein the kiln tail burner (22) The electric gas conversion device (1) is connected to the decomposition furnace (25), the electric gas conversion device (1) is connected to the kiln head burner (21) and the kiln tail burner (22), the electric gas conversion device (1) is connected to a CH4 storage tank (211), the CH4 storage tank (211) is connected to the decomposition furnace (25), the CH4 storage tank (211) is connected to the kiln tail burner (22), and the CH4 storage tank (211) is connected to the smoke chamber (24).

2. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 1, characterized in that: An ammonia water preparation system (13) is arranged next to the power-to-gas device (1), and the ammonia water preparation system (13) comprises an ammonia synthesis device (131) connected to the power-to-gas device (1), an ammonia water storage tank (132) connected to the ammonia synthesis device (131), and an air separation nitrogen production device (133) for producing nitrogen, wherein the air separation nitrogen production device (133) is connected to the ammonia synthesis device (131), and the ammonia water storage tank (132) is connected to the decomposition furnace (25).

3. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 2, characterized in that: An oxygen and gas production system (14) is arranged next to the power-to-gas device (1), and the oxygen and gas production system (14) comprises an air separation oxygen production device (141) and an oxygen storage tank (142) connected to the air separation oxygen production device (141), the air separation oxygen production device (141) is connected to the kiln tail burner (22), the air separation oxygen production device (141) is connected to the kiln head burner (21), the oxygen storage tank (142) is connected to the power-to-gas device (1), the oxygen storage tank (142) is connected to the kiln tail burner (22), and the oxygen storage tank (142) is connected to the kiln head burner (21).

4. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 3 is characterized in that: The oxygen and gas production system (14) comprises an external power grid (16) connected to the air separation oxygen production device (141) and a wind photovoltaic power generation system (15) connected to the power-to-gas device (1); the external power grid (16) is connected to the power-to-gas device (1); the external power grid (16) is connected to the ammonia synthesis device (131); the external power grid (16) is connected to the air separation nitrogen production device (133); the wind photovoltaic power generation system (15) is connected to the air separation oxygen production device (141); the wind photovoltaic power generation system (15) is connected to the air separation nitrogen production device (133); and the wind photovoltaic power generation system (15) is connected to the ammonia synthesis device (131).

5. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 4, characterized in that: The clinker burning system (2) comprises a grate cooler (26), a kiln head hood (27) connected to a first cooling zone (261) in the grate cooler (26), a preheater assembly (28), a high-temperature dust collector (29) connected to a second-stage preheater (281) in the preheater assembly (28), and a pressure reamer (210), wherein the pressure reamer (210) is connected to connecting pipes of the second-stage preheater (281) and the high-temperature dust collector (29), the kiln head hood (27) is connected to the decomposition furnace (25), the rotary kiln (23) is connected to the kiln head hood (27), the rotary kiln (23) is connected to the first cooling zone (261) in the grate cooler (26), and the kiln head burner (21) is connected to the kiln head hood (27).

6. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 5, characterized in that: The grate cooler (26) further comprises a second cooling zone (262) and a third cooling zone (263); the first cooling zone (261), the second cooling zone (262) and the third cooling zone (263) are connected in sequence; the first cooling zone (261) is connected to the air separation oxygen production device (141); the first cooling zone (261) is connected to the oxygen storage tank (142); the first cooling zone (261) is connected to the power-to-gas device (1); the third cooling zone (263) is provided with a raw material drying system; the third cooling zone (263) is provided with a coal mill drying system (19); and the third cooling zone (263) is provided with a clinker storage (20).

7. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 5, characterized in that: The preheater assembly (28) further comprises a third-stage preheater (282), a fourth-stage preheater (283) and a fifth-stage preheater (284); the second-stage preheater (281), the third-stage preheater (282), the fourth-stage preheater (283) and the fifth-stage preheater (284) are connected in sequence; the fifth-stage preheater (284) is connected to the decomposition furnace (25); and the fifth-stage preheater (284) is connected to the ammonia water storage tank (132).

8. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 5, characterized in that: The high-temperature dust collector (29) is connected to the SCR device (3), the SCR device (3) is connected to the high-temperature fan (4), the SCR device (3) is connected to the ammonia storage tank (132), the high-temperature fan (4) is connected to the heat exchanger 1 (5), the heat exchanger 1 (5) is connected to the circulation fan (6), the circulation fan (6) is connected to the dehydration device (7), the circulation fan (6) is connected to the chimney, the circulation fan (6) is connected to the CO2 capture system (17), the dehydration device (7) is connected to the heat exchanger 2 (10), the dehydration device (7) is connected to the air sealing system (11), the dehydration device (7) is connected to the first cooling zone (261), the dehydration device (7) is connected to the second cooling zone (262), and the CO2 capture system (17) is connected to the power-to-gas device (1).

9. The energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to claim 8, characterized in that: The heat exchanger 2 (10) is connected to the air compressor device (8), the heat exchanger 2 (10) is connected to a Roots blower (212), the heat exchanger 2 (10) is connected to a pulverized coal conveying system (12), the air compressor device (8) is connected to a dust cleaning system (9), the Roots blower (212) is connected to a kiln head burner (21), the Roots blower (212) is connected to a kiln tail burner (22), the pulverized coal conveying system (12) is connected to the kiln head burner (21), the pulverized coal conveying system (12) is connected to the kiln head burner (21), the pulverized coal conveying system (12) is connected to the kiln tail burner (22), and the second cooling zone (262) is connected to the connecting pipe between the decomposition furnace (25) and the fifth stage preheater (284).

10. An energy-saving and emission-reduction method for producing cement clinker by oxygen-enriched combustion, according to an energy-saving and emission-reduction system for producing cement clinker by oxygen-enriched combustion according to any one of claims 1 to 9, characterized in that: The steps include: S1, the raw material is input into the second stage preheater (281) through the pressure reamer (210) to the connecting pipe of the high temperature dust collector (29), performs heat exchange with the circulating gas rich in high concentration of CO2 in the pipe, and enters the high temperature dust collector (29) along with the circulating gas; S2, the raw material is filtered through the high-temperature dust collector (29) and then enters the connecting pipe between the third-stage preheater (282) and the second-stage preheater (281), and then enters the second-stage preheater (281) after heat exchange with the circulating gas therein. The raw material successively exchanges heat with the circulating gas in the second-stage preheater and then enters the decomposition furnace (25). After the circulating gas leaves the high-temperature dust collector (29), it is mixed and homogenized with ammonia water from the ammonia water storage tank (132), and then enters the SCR device (3) to remove part of the nitrogen oxides, so that the NOx content in the circulating gas leaving the SCR device (3) is less than 50 mg / m³. The circulating gas is transported to the heat exchanger 1 (5) through the high-temperature fan (4), and then passes through the circulating fan (6) after heat exchange and cooling. S3, the raw material enters the fifth-stage preheater (284) after being pre-decomposed in the decomposition furnace (25), enters the smoke chamber (24) after being collected by the fifth-stage preheater (284), and then enters the rotary kiln (23). After being burned into clinker in the rotary kiln (23), the raw material enters the first cooling zone (261) of the grate cooler (26). The clinker is sequentially cooled to a required temperature in the first cooling zone (261), the second cooling zone (262), and the third cooling zone (263) of the grate cooler (26) and then enters the clinker storage (20) for storage; After the circulating gas passes through the circulating fan (6), the CO2 dry basis concentration is greater than 80%, and its flow is divided into three paths: the first path of circulating gas is purified by the CO2 capture system (17), and a part of the high-concentration CO2 obtained is sealed and stored, and a part is transmitted to the power-to-gas device (1) for reuse; The second circulating gas is further recycled after some of the water is removed by the dehydration device (7); the third circulating gas is discharged into the chimney when needed and is closed at other times; After the circulating gas enters the first cooling zone (261) of the grate cooler (26), it exchanges heat with the clinker from the rotary kiln (23) and then enters the kiln head hood (27). The gas temperature in the kiln head hood (27) is 950-1250°C. A part of the gas in the kiln head hood (27) enters the rotary kiln (23) as secondary air, and a part of the gas enters the decomposition furnace (25) as tertiary air. After entering the second cooling zone (262) of the grate cooler (26), the circulating gas exchanges heat with the clinker from the first cooling zone (261) and has a temperature of 400-500°C. Then, it enters the outlet of the decomposition furnace (25) for cooling and air replenishment. In the third cooling zone (263) of the grate cooler (26), the air exchanges heat with the clinker from the second cooling zone (262) to become hot air at 200-250°C for use by other systems. After the circulating gas passes through the dehydration device (7), the CO2 dry basis concentration is greater than 80% and the temperature is 75-80°C. The circulating gas is divided into four routes. The first route is cooled to room temperature through the heat exchanger 2 (10) and then goes to the air compressor device (8), the Roots blower (212) and the coal powder conveying system (12); the second route goes to the gas sealing system (11); the third route is mixed with the high-concentration O2 from the oxygen and gas production system (14) and then goes to the first cooling zone (261) of the grate cooler (26); the fourth route goes to the second cooling zone (262) of the grate cooler (26); The wind power photovoltaic power generation system (15) has a large output, and its electric energy is supplied to the air separation oxygen production device (141) and the power-to-gas device (1) to produce O2. A part of the produced O2 is transmitted to the kiln head burner (21) and the kiln tail burner (22), and the surplus O2 enters the oxygen storage tank (142) for storage; when the wind power photovoltaic power generation system (15) has a small output, and its electric energy is supplied to the air separation oxygen production device (141) and the power-to-gas device (1) and the produced O2 cannot meet the oxygen-enriched operation demand of the system, the difference in O2 is supplied by the oxygen storage tank (142), and when there is still a difference, the external power grid (16) is activated to supplement the power supply for oxygen production, thereby ensuring the normal progress of the entire reaction; The wind photovoltaic power generation system (15) and the external power grid (16) provide the electric energy required by the air separation oxygen production device (141), the power-to-gas device (1), the air separation nitrogen production device (133) and the ammonia synthesis device (131). The oxygen and gas production system (14) and the ammonia water preparation system (13) flexibly dispatch the output plan and energy distribution relationship of each device, and comprehensively dispatch the electric energy utilization of the external power grid (16) and the wind photovoltaic power generation system (15) according to the peak and valley time periods and the intensity of wind and light, and the wind photovoltaic power generation system (15) is used first.

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