Flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for pulverized coal boiler

Abstract

The application discloses a kind of coal powder boiler flue gas recirculation and oxygen-enriched combustion collaborative denitrification equipment, belong to collaborative denitrification technical field;Coal powder boiler includes heat exchange tank, and combustion tank and back smoke pipe are equipped in heat exchange tank;Back smoke machine shell side is communicated with combustor shell, and combustor shell is communicated with combustion tank;Igniter and staged oxygen-enriched burner are equipped in combustor shell, and the staged oxygen-enriched burner includes center oxygen channel structure, coal powder air duct structure and compensation oxygen channel structure;The core flame for igniting coal powder wind is used by center oxygen channel structure, then the coal powder wind of low oxygen content ejected from coal powder air duct structure is ignited by core flame, and low-oxygen combustion section close to flame tongue root is formed;Oxygen is ejected by compensation oxygen channel structure, so that coal powder wind occurs oxidation reaction and fully burns;The application can form the effect of staged combustion, greatly reduce the nitrate material generated by coal powder oxidation reaction, improve the ability of combustion flue gas denitrification.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of synergistic denitration technology, and specifically relates to a flue gas recirculation and oxygen-enriched combustion synergistic denitration equipment for a pulverized coal boiler. BACKGROUND

[0002] A pulverized coal boiler is a large industrial boiler taking pulverized coal (micro-finely crushed coal particles) as main fuel and is widely applied to fields such as thermal power plants and large-scale heating systems; its core principle is to spray coal finely ground into powder into a furnace for combustion to realize high-efficiency energy conversion; a device for combustion is called a burner, and common burners directly introduce air for oxidation combustion; since other gases in air also react with coal powder to form various nitrates, the difficulty of subsequent flue gas purification is greatly increased.

[0003] The existing oxygen-enriched burner greatly reduces the generation of nitrates by replacing air with high-purity oxygen, thereby reducing the cost of subsequent flue gas purification; however, the existing oxygen-enriched burner usually causes local flame temperature to be excessively high due to excessively high oxygen content, thereby causing serious safety accidents, and thus usually works in cooperation with a flue gas recirculation system to dilute oxygen with flue gas, thereby reducing flame temperature and uniformly distributing the temperature of each part; however, the existing flue gas recirculation system usually only has a high-wear-resistance blower that can adapt to high-ash-content turbid flue gas and adjusts flue gas supply by adjusting the rotating speed; this adjustment mode has low adjustment precision, and low rotating speed affects the combustion posture, thereby causing flame disturbance and affecting heating quality.

[0004] Although the existing oxygen-enriched burner reduces the amount of nitrates generated by air by replacing air, impurities in coal powder also generate nitrates through reactions, and thus the combustion of poor-quality coal still generates a large amount of nitrates; the existing oxygen-enriched burner is usually provided with a cyclone at an air outlet for generating cyclone of flue gas to fully mix substances sprayed from each flow channel; however, there are differences in airflow distribution for combustion of different coal types, and some coal types cannot adapt to the flow posture of the existing cyclone, thereby causing insufficient combustion, flue gas ash content and increased subsequent purification cost.

[0005] The existing burner coal powder air pipe outlet is often affected by airflow dynamics due to high-speed particle wind erosion; the existing staged combustion equipment has fixed burnout and reduction zones, and different coal types have different impurity contents, and the fixed staged region easily causes problems of insufficient reduction or insufficient combustion of coal powder; therefore, the present application improves the existing equipment in view of the above problems. SUMMARY

[0006] The present application overcomes the deficiencies of the prior art, and provides a flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler.

[0007] The present application overcomes the deficiencies of the prior art, and provides a flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler.

[0008] Further, the center oxygen channel structure includes an oxygen nozzle, a center oxygen pipe and an oxygen branch pipe; the front end of the oxygen nozzle is connected to an oxygen supply system, the rear end of the oxygen nozzle is connected to the front end of the center oxygen pipe, and the rear end of the center oxygen pipe is connected to the front ends of multiple oxygen branch pipes; the rear end of the oxygen branch pipe is provided with external threads, and a screw pipe is connected to the rear end of the oxygen branch pipe through the external threads; a pilot valve is installed between the center oxygen pipe and the oxygen branch pipe.

[0009] Further, the center oxygen channel structure includes an oxygen nozzle, a center oxygen pipe and an oxygen branch pipe; the front end of the oxygen nozzle is connected to an oxygen supply system, the rear end of the oxygen nozzle is connected to the front end of the center oxygen pipe, and the rear end of the center oxygen pipe is connected to the front ends of multiple oxygen branch pipes; the rear end of the oxygen branch pipe is provided with external threads, and a screw pipe is connected to the rear end of the oxygen branch pipe through the external threads; a pilot valve is installed between the center oxygen pipe and the oxygen branch pipe.

[0010] Further, the center oxygen channel structure includes an oxygen nozzle, a center oxygen pipe and an oxygen branch pipe; the front end of the oxygen nozzle is connected to an oxygen supply system, the rear end of the oxygen nozzle is connected to the front end of the center oxygen pipe, and the rear end of the center oxygen pipe is connected to the front ends of multiple oxygen branch pipes; the rear end of the oxygen branch pipe is provided with external threads, and a screw pipe is connected to the rear end of the oxygen branch pipe through the external threads; a pilot valve is installed between the center oxygen pipe and the oxygen branch pipe.

[0011] Further, the hierarchical oxygen-enriched burner further comprises an adjustable swirler structure; the adjustable swirler structure comprises a swirler shell, an adjusting middle shaft, fixed blades, adjustable blades and rotating columns; a compensation air pipe frame is fixedly installed on the outer side of the swirler shell, and the compensation air pipe frame is fixedly connected to the inner sides of multiple compensation air branch pipes; the adjusting middle shaft is coaxially and rotationally connected to the inner side of the swirler shell, the front end of the adjusting middle shaft is connected to an electric motor, and the rear end of the adjusting middle shaft is connected to a conical head; the electric motor is fixedly installed on the front end face of the swirler shell, and the inner side of the rear end face of the swirler shell is uniformly and fixedly connected to the outer end faces of multiple fixed blades; the inner end faces of the multiple fixed blades are all fixedly connected to a same adjusting ring, and the adjusting ring is located on the outer side of the conical head; an adjustable blade is arranged between any two adjacent fixed blades, the outer end face of the adjustable blade is fixedly connected to a rotating column, the rotating column is rotationally connected to the rear end of the swirler shell, and the inner end face of the adjustable blade passes through the adjusting ring and is fixedly connected to an oblong sliding ring; the adjustable blade is rotationally connected to the adjusting ring; the conical head is uniformly and fixedly connected to sliding rods on the side wall, and the sliding rods are slidingly sleeved with the inner wall of the sliding ring.

[0012] Further, the fixed blades are provided with through holes, a screw pipe corresponds to each fixed blade, and the screw pipe passes out of the corresponding through hole to the outer side of the fixed blade; the multiple screw pipes are circularly arranged; the multiple pulverized coal air branch pipes and the air outlet head housings are located on the outer side of the screw pipes, and the multiple pulverized coal air branch pipes and the multiple air outlet head housings are on the same circumferential surface, and the multiple screw pipes, the multiple pulverized coal air branch pipes and the multiple air outlet head housings are circularly arranged around the same axis.

[0013] Further, a high-temperature-resistant lining is fixedly installed on the outer side of the compensation air pipe frame; the high-temperature-resistant lining is located on the outer sides of the oxygen air branch pipes, the pulverized coal air branch pipes and the compensation air branch pipes.

[0014] Further, a gas connection port is fixedly installed at the front end inside the air outlet head housing, one end of the gas connection port is communicated with the compensation air branch pipe, the other end of the gas connection port is communicated with one end of a connecting hose, the other end of the connecting hose is communicated with a gas outlet, the gas outlet is rotationally connected to the rear end inside the air outlet head housing, a driven gear is fixedly connected to one side of the gas outlet, a relay gear is meshingly and fixedly connected to one side of the driven gear, the relay gear is rotationally connected to the inside of the air outlet head housing, a driving gear is meshingly and fixedly connected to one side of the relay gear, the driving gear is connected to a small-sized motor and is rotationally connected to the inside of the air outlet head housing, and the small-sized motor is fixedly installed on one side of the air outlet head housing.

[0015] Further, the flue gas fan structure comprises a fan shell, a filter plate is fixedly installed on the front end surface of the fan shell, an adjustable louver structure and a supply air assembly are arranged in the fan shell; the adjustable louver structure comprises a louver frame, the louver frame is fixedly connected to the front end inside the fan shell, louver plates are equidistantly arranged on the louver frame, the louver plates are rotatably connected to the louver frame through louver shafts, the louver plates are rotatably connected to each other through a synchronous rod on one side, the louver frame is provided with an arc-shaped slot in the movement path of the synchronous rod, a belt is sleeved on the lowermost one of the louver shafts, one end of the belt away from the louver shaft is sleeved on a speed reducer motor, and the speed reducer motor is fixedly installed on the louver frame.

[0016] Further, the front end surface of the burner shell is provided with a burner controller, and the pulverized coal air pipe is provided with a proportioning control valve.

[0017] The present application has the following beneficial effects compared with the prior art:

[0018] The present application has the following beneficial effects compared with the prior art:

[0019] The present application has the following beneficial effects compared with the prior art:

[0020] The present application has the following beneficial effects compared with the prior art: BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1Overall appearance of the denitration equipment;

[0022] Figure 2 External structure of the burner shell;

[0023] Figure 3 Internal structure of the pulverized coal boiler;

[0024] Figure 4 External appearance of the staged oxygen-enriched burner;

[0025] Figure 5 Central oxygen channel structure;

[0026] Figure 6 Pulverized coal air duct structure;

[0027] Figure 7 Compensation oxygen channel structure;

[0028] Figure 8 Adjustable cyclone structure;

[0029] Figure 9 Adjustable air blade structure;

[0030] Figure 10 Flue gas fan structure;

[0031] Figure 11 Adjustable louver structure;

[0032] Figure 12 Louver structure;

[0033] Figure 13 Air supply assembly;

[0034] Figure 14 Air outlet head shell and screw pipe position of the bottom of the staged oxygen-enriched burner;

[0035] Figure 15 External structure of the air outlet head shell;

[0036] Figure 16 Internal structure of the air outlet head shell.

[0037] Figure number:

[0038] 1, support seat; 2, heat exchange tank; 3, combustion tank; 4, return smoke pipe; 5, smoke box; 6, return smoke machine shell; 7, burner shell; 8, burner controller; 9, pulverized coal air pipe; 10, proportioning control valve; 11, high temperature resistant lining; 12, oxygen air nozzle; 13, central oxygen pipe; 14, oxygen air branch pipe; 15, pulverized coal air connection pipe; 16, central pulverized coal air pipe; 17, pulverized coal air branch pipe; 18, compensation air pipe; 19, compensation air ring pipe; 20, compensation air branch pipe; 21, compensation air pipe valve; 22, compensation air pipe support; 23, air outlet head shell; 24, cyclone shell; 25, adjusting shaft; 26, motor; 27, fixed air blade; 28, adjustable air blade; 29, rotating column; 30, sliding ring; 31, sliding rod; 32, air supply machine shell; 33, ash filter plate; 34, louver support; 35, speed reduction motor; 36, belt; 37, louver shaft; 38, louver plate; 39, synchronous rod; 40, power motor; 41, air supply rotating shaft; 42, air supply blade; 43, screw pipe; 44, air inlet; 45, connecting hose; 46, air outlet; 47, driven gear; 48, relay gear; 49, driving gear; 50, small motor; 51, ignition valve. DETAILED DESCRIPTION

[0039] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects more clear and obvious, the present application will be further described in detail in conjunction with examples and drawings. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application. The technical solutions of the present application are described in detail below in conjunction with examples and drawings, but the protection scope is not limited thereto.

[0040] Referring to Figures 1 to 16 , the embodiment provides a flue gas recirculation and oxygen-enriched combustion synergistic denitration equipment for a pulverized coal boiler, which comprises a support seat 1, the support seat 1 is composed of a bottom plate and a support plate fixed on the top surface of the bottom plate, and a pulverized coal boiler is installed and fixed above the support seat 1, the pulverized coal boiler comprises a heat exchange tank 2, and a smoke box 5 and a return smoke machine shell 6 are installed on the outer side of the front end of the heat exchange tank 2; a water inlet and a steam outlet are formed in the top surface of the heat exchange tank 2, the water inlet is used to connect a water supply system, and the steam outlet is used to connect a steam power generation system; the heat exchange tank 2 is internally provided with a combustion tank 3 and a return smoke pipe 4. The return smoke pipe 4 is located above the combustion tank 3, the rear end of the return smoke pipe 4 is communicated with the combustion tank 3, the front end of the return smoke pipe 4 penetrates through the front end surface of the heat exchange tank 2 and is communicated with the smoke box 5, the smoke box 5 is communicated with the return smoke machine shell 6 through a smoke pipe, the return smoke machine shell 6 is internally provided with a flue gas fan structure, one side of the return smoke machine shell 6 is communicated with a burner shell 7, and the burner shell 7 is communicated with the combustion tank 3; an igniter and a staged oxygen-enriched burner are arranged in the burner shell 7, a burner controller 8 is arranged on the front end surface of the burner shell 7, and a pulverized coal air pipe 9 is connected to the lower end of the burner shell 7, and a proportioning control valve 10 is arranged on the pulverized coal air pipe 9.

[0041] In the application, in order to solve the problem that a large amount of nitrate is generated in the combustion of inferior coal, the hierarchical oxygen-enriched burner is adopted; the hierarchical oxygen-enriched burner comprises a center oxygen channel structure, a pulverized coal air channel structure, a compensation oxygen channel structure and an adjustable cyclone structure; the center oxygen channel structure comprises an oxygen air nozzle 12, a center oxygen pipe 13 and an oxygen air branch pipe 14; the front end of the oxygen air nozzle 12 is communicated with an oxygen supply system, the rear end of the oxygen air nozzle 12 is communicated with the front end of the center oxygen pipe 13, and the rear end of the center oxygen pipe 13 is communicated with the front ends of a plurality of oxygen air branch pipes 14; the rear end of the oxygen air branch pipe 14 is provided with an external thread, and the rear end of the oxygen air branch pipe 14 is connected with a screwed pipe 43 through the external thread. A point ignition valve 51 is installed and communicated between the center oxygen pipe 13 and the oxygen air branch pipe 14.

[0042] The pulverized coal air channel structure comprises a pulverized coal air connecting pipe 15, a center pulverized coal air pipe 16 and a pulverized coal air branch pipe 17; the lower part of the pulverized coal air connecting pipe 15 is communicated with the pulverized coal air pipe 9, the front end of the pulverized coal air connecting pipe 15 is communicated with the center pulverized coal air pipe 16, and the outer side surface of the center pulverized coal air pipe 16 is communicated with a plurality of pulverized coal air branch pipes 17; the pulverized coal air pipe 9 is used for connecting a coal supply system.

[0043] The compensation oxygen channel structure comprises a compensation air pipe 18, a compensation air ring pipe 19 and a compensation air branch pipe 20; the front end of the compensation air pipe 18 is communicated with the oxygen air nozzle 12, the rear end of the compensation air pipe 18 is communicated with the compensation air ring pipe 19, the compensation air ring pipe 19 is installed and fixed on the outer wall of the center pulverized coal air pipe 16, the rear end surface of the compensation air ring pipe 19 is communicated with a plurality of compensation air branch pipes 20, the compensation air branch pipe 20 is provided with a compensation air pipe valve 21, and the rear end of the compensation air branch pipe 20 is provided with an air outlet head shell 23. The compensation air ring pipe 19 is located outside the pulverized coal air connecting pipe 15.

[0044] The adjustable cyclone structure comprises a cyclone shell 24, an adjusting middle shaft 25, fixed blades 27, adjustable blades 28 and a rotating column 29; a compensation air pipe frame 22 is fixedly installed on the outer side of the cyclone shell 24 and is fixedly connected to the inner sides of a plurality of compensation air branch pipes 20; the cyclone shell 24 is coaxially and rotatably connected with the adjusting middle shaft 25, the front end of the adjusting middle shaft 25 is connected with an electric motor 26, and the rear end of the adjusting middle shaft 25 is connected with a conical head; the electric motor 26 is fixedly installed on the front end face of the cyclone shell 24, and the inner side of the rear end face of the cyclone shell 24 is uniformly and fixedly connected with the outer end faces of a plurality of fixed blades 27; the inner end faces of the plurality of fixed blades 27 are all fixedly connected with a same adjusting ring, and the adjusting ring is located on the outer side of the conical head; an adjustable blade 28 is arranged between any two adjacent fixed blades 27, the outer end face of the adjustable blade 28 is fixedly connected with a rotating column 29, the rotating column 29 is rotatably connected with the rear end of the cyclone shell 24, and the inner end face of the adjustable blade 28 penetrates through the adjusting ring and is fixedly connected with an oblong sliding ring 30; the adjustable blade 28 is rotatably connected with the adjusting ring; the sliding rods 31 are uniformly and fixedly connected with the side walls of the conical head, and the sliding rods 31 are slidably sleeved with the inner walls of the sliding ring 30. When the electric motor 26 drives the adjusting middle shaft 25 to rotate, the conical head is driven to rotate, the sliding rods 31 are driven to rotate around the center, and the sliding ring 30 is sleeved with the sliding rods 31, and one end of the sliding ring 30 is fixedly connected with the lower end of the adjustable blade 28, so that the sliding rods 31 drive the sliding ring 30 to rotate and the sliding rods 31 slide in the sliding ring 30, the rotation of the sliding ring 30 drives the adjustable blade 28 to rotate, so that the relative angle between the adjustable blade 28 and the fixed blade 27 changes, the angle of the smoke gas spouted can be adjusted, and the airflow distribution is optimized.

[0045] The fixed blade 27 is provided with a through hole, the screw pipe 43 corresponds to the fixed blade 27 in one-to-one correspondence, and the screw pipe 43 penetrates out of the fixed blade 27 from the corresponding through hole to the outer side of the fixed blade 27; the plurality of screw pipes 43 are circularly arranged in an array.

[0046] The plurality of pulverized coal air branch pipes 17 and the air outlet head shell 23 are located on the outer side of the screw pipe 43, and the plurality of pulverized coal air branch pipes 17 and the plurality of air outlet head shells 23 are on the same circumferential surface, and the plurality of screw pipes 43, the plurality of pulverized coal air branch pipes 17 and the plurality of air outlet head shells 23 are circularly arranged around the same axis.

[0047] The high-temperature-resistant lining 11 is fixedly installed on the outer side of the compensation air pipe frame 22; the high-temperature-resistant lining 11 is located on the outer sides of the oxygen air branch pipe 14, the pulverized coal air branch pipe 17 and the compensation air branch pipe 20.

[0048] Through the cooperation of the central oxygen channel structure, the pulverized coal air duct structure and the compensation oxygen channel structure, the oxidized reaction substances in the pulverized coal are reduced preferentially by low-purity oxygen air and pulverized coal air, and then the compensation of high-purity oxygen air is ensured to ensure the full combustion of the pulverized coal, forming the effect of staged combustion, greatly reducing the nitrate substances generated by the oxidation reaction of the pulverized coal. Through the cooperation of the adjustable cyclone structure, the smoke cyclone posture can be freely adjusted, so as to cooperate with the data model to optimize the airflow distribution and improve the combustion efficiency of the pulverized coal.

[0049] The flue gas fan structure comprises a fan shell 32, a filter plate 33 is fixedly installed on the front end face of the fan shell 32, and an adjustable louver structure and a fan assembly are arranged in the fan shell 32.

[0050] In the application, in order to solve the problem that the airflow distribution of different coal kinds is different and some coal kinds cannot adapt to the existing cyclone flow posture to cause insufficient combustion, the technical scheme of the adjustable louver structure is adopted; the adjustable louver structure comprises a louver frame 34, the louver frame 34 is fixedly connected to the front end inside the fan shell 32, louver plates 38 are equidistantly arranged on the louver frame 34, the louver plates 38 are rotatably connected to the louver frame 34 through louver shafts 37, the louver plates 38 are rotatably connected to each other through synchronous rods 39 on one side, the louver frame 34 is provided with an arc-shaped slot opening corresponding to the movement path of the synchronous rod 39, a belt 36 is sleeved on the lowermost one of the louver shafts 37 of the louver plates 38, one end of the belt 36 away from the louver shaft 37 is sleeved on a speed reducer 35, and the speed reducer 35 is fixedly installed on the louver frame 34; the fan assembly comprises a power motor 40, the power motor 40 is fixedly installed in the middle part of the fan shell 32, a fan shaft 41 is connected to the rear end of the power motor 40, and a fan blade 42 is fixedly connected to the rear end face of the fan shaft 41; through the cooperation of the fan assembly and the adjustable louver structure, the flue gas can be recovered and the flue gas supply amount can be adjusted, and the dynamic proportioning of the flue gas and oxygen is formed with the compensation air pipe valve 21, and the combustion stability of the device is improved.

[0051] In the present application, in order to solve the problem of insufficient reduction or insufficient combustion caused by the fixed classification area, the following technical scheme is adopted: the air outlet head shell 23 is internally provided with a gas connection port 44 at the front end, the gas connection port 44 is communicated with a compensation air branch pipe 20 at one end, the other end of the gas connection port 44 is communicated with one end of a connecting hose 45, the other end of the connecting hose 45 is communicated with an air outlet 46, the air outlet 46 is rotatably connected to the rear end inside the air outlet head shell 23, the air outlet 46 is fixedly connected with a driven gear 47 on one side, the driven gear 47 is meshingly connected with a relay gear 48 on one side, the relay gear 48 is rotatably connected inside the air outlet head shell 23, the relay gear 48 is meshingly connected with a driving gear 49 on one side, the driving gear 49 is connected with a small motor 50 and is rotatably connected inside the air outlet head shell 23, the small motor 50 is fixedly installed on one side of the air outlet head shell 23, through the cooperation of the small motor 50 and the air outlet 46, the cutting angle of the compensation oxygen air is conveniently adjusted, so that the proportion of the burnout zone and the reduction zone of the combustion is dynamically adjusted, and the adaptability of the device to the coal type is improved.

[0052] In the present embodiment, a use method of the flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for the pulverized coal boiler is also proposed, which comprises the following steps:

[0053] Step one, first power all electrical equipment, then connect the water passing pipe and the steam power generation system through the water passing hole and the steam outlet on the top of the heat exchange tank 2, then install and fix the burner shell 7 on the front end face of the heat exchange tank 2 and communicate with the combustion tank 3; then install and fix the smoke returning machine shell 6 on one side of the burner shell 7 and communicate the burner shell 7 and the smoke returning machine shell 6, then communicate the smoke returning machine shell 6 and the smoke box 5. One end of the pulverized coal air pipe 9 is communicated with the coal supply system, the other end is communicated with the pulverized coal air connecting pipe 15, then the oxygen air nozzle 12 is communicated with the oxygen supply system, finally, the appropriate material screw pipe 43 is selected according to the needs, so as to complete all the installation work, and after the burner controller 8 is debugged, the heating work can be started.

[0054] Step two, after starting heating work, first through the water supply system to the heat exchanger tank 2 into pure water, filled with water through the oxygen supply system and coal supply system to the center oxygen pipe 13 and the center coal powder wind pipe 16 into high purity oxygen and low oxygen content of coal powder wind, first high purity oxygen through the center oxygen pipe 13 into oxygen wind branch pipe 14, at this time the ignition valve 51 keep unobstructed, oxygen again through the oxygen wind branch pipe 14 from the screw pipe 43 spout, then through the igniter ignition screw pipe 43 spout oxygen, form the high temperature core flame for ignition of coal powder wind, then through the high temperature core flame ignition from the coal powder wind branch pipe 17 spout low oxygen content of coal powder wind, thus forming a low oxygen combustion section near the root of the flame, then through the ignition valve 51 cut off the center oxygen pipe 13 oxygen, at this time due to the low oxygen content of coal powder wind, the impurities in the coal powder during combustion do not have enough oxygen to produce nitroxide this pollutant, so as to reduce the reaction to generate other substances, but due to the poor heat release capacity of the reducing reaction, the final purpose of the device is to heat, so it is necessary to improve the oxygen content of the flame in the second half of the flame, at this time through the compensation wind pipe valve 21 control compensation wind branch pipe 20 spout high purity oxygen, so that the second half of the flame can have enough oxygen to occur oxidation reaction, get higher flame temperature and fully burn the coal powder, so as to form a low oxygen reduction zone near the root of the flame and an oxygen rich combustion zone in the second half of the flame, so as to ensure the full combustion of coal powder and prevent the production of nitroxide pollutants during coal powder combustion.

[0055] Step three, a large number of low oxygen flue gas will be produced during the combustion in the device, at this time the power motor 40 is started to drive the air supply shaft 41 to rotate, forming a negative pressure environment, so that part of the flue gas in the smoke return pipe 4 and the smoke box 5 enters the air supply casing 32, and then enters the smoke return casing 6 through the filter ash plate 33, and then enters the burner casing 7. During the air extraction, the speed reducer 35 can be used to control the rotation of the belt 36, so as to control the rotation of the lowermost louver plate 38 of the louver frame 34, and the synchronous rod 39 is used to control the synchronous rotation of the remaining louver plates 38, so as to adjust the flue gas quantity, and the flue gas can inhibit the oxidation reaction of the flame to a certain extent, so as to realize the dynamic proportioning of flue gas and oxygen and dynamically control the flame temperature, thereby avoiding local overheating of the flame.

[0056] Step four, after the flue gas enters the burner shell 7, it enters the cyclone shell 24, and then the flue gas is sprayed out of the cooperation gap of the fixed blade 27 and the adjustable blade 28, driving the flue gas to a certain angle, thereby driving the oxygen and coal powder wind to rotate and mix, improving the combustion efficiency. During this period, according to the different types of coal, the adjusting shaft 25 can be driven to rotate by the motor 26, thereby driving the conical head at the end of the adjusting shaft 25 to rotate. The conical head drives the sliding rod 31 to rotate around the center. At the same time, since the sliding ring 30 is sleeved on the sliding rod 31, and one end of the sliding ring 30 is fixedly connected to the lower end of the adjustable blade 28, the sliding rod 31 drives the sliding ring 30 to rotate. The rotation of the sliding ring 30 drives the adjustable blade 28 to rotate, thereby changing the relative angle between the adjustable blade 28 and the fixed blade 27, thereby adjusting the flue gas ejection angle and optimizing the airflow distribution.

[0057] Step five, during the operation of the staged oxygen-enriched burner, the small motor 50 can be started to drive the driving gear 49 to rotate, and then the driven gear 47 is driven to rotate through the relay gear 48, thereby driving the gas outlet 46 to rotate and changing the compensation wind cutting angle, thereby extending or reducing the length of the reduction zone in the staged combustion, so as to achieve the best coal combustion state. After the high-temperature flame is sprayed out of the staged oxygen-enriched burner, it heats the combustion tank 3, so that the pure water in the heat exchange tank 2 boils to generate steam, which is then supplied to the power generation system to complete power generation. At the same time, part of the flue gas behind the flame is drawn back into the burner shell 7 by the flue gas fan structure, and the other part of the flue gas enters the external purification system, so as to complete the entire power generation work of the power station and discharge clean air.

[0058] The above is a further detailed description of the present application in combination with a specific preferred embodiment, which cannot be considered as limiting the specific embodiments of the present application to this. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the present application, a number of simple deductions or substitutions can be made, which should be considered as belonging to the present application. The scope of patent protection is determined by the claims submitted.

Claims

1. A flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler, the pulverized coal boiler comprising a heat exchange tank (2), an outer side of the heat exchange tank (2) being provided with a smoke box (5) and a smoke return machine shell (6); the heat exchange tank (2) being internally provided with a combustion tank (3) and a smoke return pipe (4); one end of the smoke return pipe (4) being in communication with the combustion tank (3), the other end of the smoke return pipe (4) being in communication with the smoke box (5), the smoke box (5) being in communication with the smoke return machine shell (6) through a smoke pipe; one side of the smoke return machine shell (6) being in communication with a burner shell (7), the burner shell (7) being in communication with the combustion tank (3); characterized in that, The flue gas fan structure is arranged in the flue gas shell (6), the igniter and the staged oxygen-enriched burner are arranged in the burner shell (7), the coal powder air pipe (9) is connected to the lower end of the burner shell (7), and the coal powder air pipe (9) is used for connecting a coal supply system; the staged oxygen-enriched burner comprises a central oxygen channel structure, a coal powder air channel structure and a compensation oxygen channel structure; the central oxygen channel structure is used for igniting the core flame of the coal powder air, then the low-oxygen-content coal powder air sprayed from the coal powder air channel structure is ignited by the core flame, and a low-oxygen combustion section close to the root of the flame is formed; the compensation oxygen channel structure sprays oxygen, so that the coal powder air is oxidized and fully combusted. The central oxygen channel structure comprises the oxygen air branch pipe (14), the rear end of the oxygen air branch pipe (14) is connected with the screw pipe (43) through external threads; the coal powder air channel structure comprises the coal powder air branch pipe (17); the compensation oxygen channel structure comprises the compensation air branch pipe (20), and the rear end of the compensation air branch pipe (20) is provided with the air outlet head shell (23); the staged oxygen-enriched burner further comprises an adjustable cyclone structure; the adjustable cyclone structure comprises the cyclone shell (24) and the fixed air blade (27); the rear end surface of the cyclone shell (24) is fixedly connected with the outer end surfaces of the plurality of fixed air blades (27) on the inner side. The fixed air blade (27) is provided with a through hole, the screw pipe (43) corresponds to the fixed air blade (27), and the screw pipe (43) passes out to the outside of the fixed air blade (27) from the corresponding through hole; the plurality of screw pipes (43) are circularly arranged; the plurality of coal powder air branch pipes (17) and the air outlet head shells (23) are located outside the screw pipe (43), and the plurality of coal powder air branch pipes (17) and the plurality of air outlet head shells (23) are on the same circumferential surface, and the plurality of screw pipes (43), the plurality of coal powder air branch pipes (17) and the plurality of air outlet head shells (23) are circularly arranged around the same axis.

2. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 1, characterized in that, The central oxygen channel structure further comprises the oxygen air nozzle (12) and the central oxygen pipe (13); the front end of the oxygen air nozzle (12) is communicated with an oxygen supply system, the rear end of the oxygen air nozzle (12) is communicated with the front end of the central oxygen pipe (13), and the rear end of the central oxygen pipe (13) is communicated with the front ends of the plurality of oxygen air branch pipes (14); the rear end of the oxygen air branch pipe (14) is provided with external threads; the central oxygen pipe (13) and the oxygen air branch pipe (14) are installed and communicated with the igniter valve (51).

3. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 2, characterized in that, The coal powder air channel structure further comprises the coal powder air connecting pipe (15) and the central coal powder air pipe (16); the lower part of the coal powder air connecting pipe (15) is communicated with the coal powder air pipe (9), the front end of the coal powder air connecting pipe (15) is communicated with the central coal powder air pipe (16), and the outer side surface of the central coal powder air pipe (16) is communicated with the plurality of coal powder air branch pipes (17).

4. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 3, characterized in that, The compensation oxygen channel structure further comprises a compensation air pipe (18) and a compensation air ring pipe (19); the front end of the compensation air pipe (18) is communicated with the oxygen lance (12), the rear end of the compensation air pipe (18) is communicated with the compensation air ring pipe (19), the compensation air ring pipe (19) is fixedly installed on the outer wall of the central pulverized coal air pipe (16), a plurality of compensation air branch pipes (20) are communicated around the rear end surface of the compensation air ring pipe (19), and the compensation air branch pipes (20) are provided with compensation air pipe valves (21); the compensation air ring pipe (19) is located outside the pulverized coal air connecting pipe (15).

5. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 4, characterized in that, The adjustable cyclone structure further comprises an adjusting middle shaft (25), adjustable air blades (28) and rotating columns (29); the compensation air pipe frame (22) is fixedly installed on the outer side surface of the cyclone shell (24) and is fixedly connected to the inner side of the plurality of compensation air branch pipes (20); the adjusting middle shaft (25) is coaxially and rotationally connected in the cyclone shell (24), the front end of the adjusting middle shaft (25) is connected with the motor (26), and the rear end of the adjusting middle shaft (25) is connected with a conical head; the motor (26) is fixedly installed on the front end surface of the cyclone shell (24); the inner end surfaces of the plurality of fixed air blades (27) are fixedly connected to the same adjusting ring, and the adjusting ring is located outside the conical head; the adjustable air blades (28) are arranged between the adjacent two fixed air blades (27), the outer end surface of the adjustable air blade (28) is fixedly connected with the middle part of the rotating column (29), the rotating column (29) is rotationally connected to the rear end of the cyclone shell (24), the inner end surface of the adjustable air blade (28) penetrates through the adjusting ring and is fixedly connected with an oblong sliding ring (30); the adjustable air blade (28) is rotationally connected with the adjusting ring; the conical head is uniformly fixedly connected with sliding rods (31) on the side wall, and the sliding rods (31) are slidingly sleeved with the inner wall of the sliding ring (30).

6. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 1, characterized in that, The compensation air pipe frame (22) is fixedly installed with a high-temperature-resistant lining (11) on the outer side surface; the high-temperature-resistant lining (11) is located outside the oxygen air branch pipe (14), the pulverized coal air branch pipe (17) and the compensation air branch pipe (20).

7. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 1, characterized in that, The air outlet head shell (23) is internally fixedly installed with an air inlet (44) at the front end, the air inlet (44) is communicated with one end of the compensation air branch pipe (20), the other end of the air inlet (44) is communicated with one end of a connecting hose (45), the other end of the connecting hose (45) is communicated with an air outlet (46), the air outlet (46) is rotationally connected to the rear end inside the air outlet head shell (23), one side of the air outlet (46) is fixedly connected with a driven gear (47), one side of the driven gear (47) is meshingly connected with a relay gear (48), the relay gear (48) is rotationally connected inside the air outlet head shell (23), one side of the relay gear (48) is meshingly connected with a driving gear (49), the driving gear (49) is connected with a small-sized motor (50) and is rotationally connected inside the air outlet head shell (23), and the small-sized motor (50) is fixedly installed on one side of the air outlet head shell (23).

8. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 1, characterized in that, The flue gas fan structure includes a fan shell (32), the front end surface of the fan shell (32) is fixedly provided with an ash filter plate (33), and the fan shell (32) is internally provided with an adjustable louver structure and a supply air assembly; the adjustable louver structure includes a louver frame (34), the louver frame (34) is fixedly connected to the inner front end of the fan shell (32), equidistant louver plates (38) are arranged on the louver frame (34), the louver plates (38) are rotatably connected to the louver frame (34) through louver shafts (37), the louver plates (38) are rotatably connected to each other through synchronous rods (39) on one side, the louver frame (34) is provided with arc-shaped slot openings corresponding to the movement path of the synchronous rods (39), a louver shaft (37) at the lowermost position of the louver plates (38) is sleeved with a belt (36), one end of the belt (36) away from the louver shaft (37) is sleeved on a speed reducer motor (35), and the speed reducer motor (35) is fixedly installed on the louver frame (34); the supply air assembly includes a power motor (40), the power motor (40) is fixedly installed in the middle part of the fan shell (32), a supply air shaft (41) is connected to the rear end of the power motor (40), and a supply air blade (42) is fixedly connected to the rear end surface of the supply air shaft (41).

9. The flue gas recirculation and oxygen-enriched combustion collaborative denitration equipment for a pulverized coal boiler according to claim 1, characterized in that, The burner shell (7) is provided with a burner controller (8) on the front end surface, and the pulverized coal air pipe (9) is provided with a proportioning control valve (10).

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