CN101101115A - A small amount of oil gasification combustion side-ignition center-feeding powder swirl burner - Google Patents

Abstract

The utility model relates to a small-volume oil gasification combustion side-ignition center powder feeding swirl burner, which relates to a swirl burner. The purpose of the present invention is to solve the problem of fuel saving in the case of starting, stopping and low-load stable combustion of a large pulverized coal boiler using a swirl burner while reducing NOx emissions. In the present invention, the first truncated conical separating ring, the second truncated conical separating ring and the third truncated conical separating ring are sequentially arranged in the middle of the primary air duct of the burner, and the inverted "V"-shaped partition is fixed on the right side of the third truncated conical separating ring in the primary air duct of the burner. The invention greatly reduces the ignition energy required for pulverized coal combustion, and satisfies the requirements of boiler startup and shutdown and low-load stable combustion. Pulverized coal is burned in a low-oxygen reducing atmosphere, prolonging the residence time of pulverized coal and controlling the generation of combustion-type NOx. Since the secondary air is divided into inner and outer parts, staged combustion is formed, and combined with central powder feeding, low NOx emissions are achieved.

Description

A small amount of oil gasification combustion side-ignition center-feeding powder swirl burner

technical field

The invention relates to a swirl burner.

Background technique

In the large-capacity power plant boilers operating in my country, the amount of oil used for boiler ignition and low-load stable combustion is huge. In order to save fuel, power generation companies shift the focus of fuel saving from the low-load stable combustion process to the boiler ignition and shutdown process (when the power plant boiler starts and stops Fuel consumption accounts for 60%, low-load stable fuel consumption accounts for 40%). According to the traditional method, the ignition oil gun is arranged in the secondary air port of the burner. The distance between the oil gun and the pulverized coal nozzle is relatively far, and the two airflows are parallel to each other. Therefore, the heat generated by the fuel oil is directly used for heating during ignition. The part of pulverized coal is relatively small, and the heat utilization rate is low, so that when the boiler is ignited, the fuel consumption is very large. Micro-oil ignition technology is a new method applied to power plant boiler start-up, stop and low-load stable combustion. The utility model patent whose Chinese patent number is ZL200520145352.2, authorized announcement number is CN2854368, and authorized announcement date is January 3, 2007 discloses a kind of "wide coal type micro-oil ignition burner". The device is simple in structure, stable and reliable, does not deflagrate, does not coke, has large ignition output, fast speed, and the fuel saving rate can reach more than 90%, and is suitable for various types of pulverized coal. The Chinese patent application number is 200610053092.5, the publication number is CN1912462, and the invention patent published on February 14, 2007 discloses a swirling flow burner with "micro-oil cold furnace ignition, ultra-low load stable combustion and low NOx emissions" ", through this device, the fuel saving rate can reach more than 95%, and it has low-load and ultra-low-load stable combustion capabilities. But the oil guns of these two devices all extend into the primary air duct of the burner. When the burner is running, the casing of the oil gun is scoured by pulverized coal particles for a long time, which will easily cause the wear of the casing of the main oil gun. Once the wear occurs, the ignition of the small oil will not start, and it is difficult to meet the required service life. The service life requirements of the equipment are relatively high. On the other hand, the multi-stage combustion chamber of the two devices is located behind the diversion cone or the pulverized coal concentrator and is connected to the outlet of the oil gun. The whole set of oil gun combustion device occupies a certain area in the center of the primary air duct of the burner. At this time, the pulverized coal concentrated by the pulverized coal concentrator is concentrated outside the central recirculation zone, so that the NOx is not reduced to the maximum extent.

Swirl burners occupy a certain proportion in my country's power plant boilers and other pulverized coal applications. The large pulverized coal boiler with swirl burner has its unique advantages: firstly, it can avoid the thermal deviation in the superheater area; secondly, there is no strict requirement on the shape of the furnace. The swirl burner relies on the high-temperature recirculation zone as a stable heat source, so that the pulverized coal airflow can be ignited in time and burn stably. Ordinary swirl burners have strong mixing of primary and secondary air, high temperature peaks, and large amounts of nitrogen oxides (NOx) . There are two main ways to control NOx in thermal power plants. One is to use low-NOx combustion technology to reduce the generation of NOx, and the other is to remove NOx from flue gas. Under the current economic level of our country, the former is more effective and economically feasible; the latter is the method. The main problem of the investors is that the investment is too high, which is not suitable for our country's national conditions. With the development of large-capacity units in my country, there is an urgent requirement for the development of swirling pulverized coal combustion technology. Therefore, the research on micro-oil ignition swirling combustion technology is of great significance to the development of my country's electric power industry and the entire national economy.

Contents of the invention

The purpose of the present invention is to solve the problem of fuel saving when the large pulverized coal boiler using the swirl burner reduces NOx emissions while the power plant boiler is started, stopped, and low-load stable combustion, and the problem of wear and tear caused by long-term use , a small amount of oil gasification combustion side ignition center to the powder swirl burner is now proposed. The present invention consists of a burner primary air duct 1, a first truncated conical separating ring 2-1, a second truncated conical separating ring 2-2, a third truncated conical separating ring 2-3, an inner swirler 3, and two internal burner Secondary air passage 4, external swirler 5, secondary air passage outside the burner 6, burner 7, inverted "V"-shaped partition 8, secondary combustion chamber 9, primary combustion chamber 10, auxiliary oil gun 11, The main oil gun casing 12, the ignition gun 13, the main oil gun 14 and the fire detection tube 15 are composed. The outlet end of the primary air channel 1 of the burner is the burner 7, and the secondary air channel 4 in the burner is fixed on the primary air channel of the burner. On the outer surface of the outlet end of channel 1, the inner swirler 3 is fixed between the primary air channel 1 of the burner and the secondary air channel 4 in the burner, and the outer swirler 5 is fixed outside the secondary air channel 4 in the burner. On the side, the secondary air channel 6 outside the burner is fixed on the outer surface of the secondary air channel 4 in the burner on the right side of the outer swirler 5, the first truncated conical separating ring 2-1, the second truncated conical separating ring 2 -2 and the third truncated conical separation ring 2-3 are sequentially arranged in the middle of the primary air duct 1 of the burner, and the inverted "V" shaped partition 8 is fixed on the primary burner on the right side of the third truncated conical separation ring 2-3 In the air duct 1, the auxiliary oil gun 11 is fixed on the primary air duct 1 of the burner on the left side of the secondary air duct 4 in the burner, and the main oil gun casing 12 is fixed on the primary air duct of the burner on the left side of the auxiliary oil gun 11 1, the ignition gun 13 and the main oil gun 14 are fixed in the main oil gun sleeve 12, and the flame detector tube 15 is fixed on the primary air duct 1 of the burner on the left side of the main oil gun sleeve 12, in an inverted "V" shape The secondary combustion chamber 9 is formed in the primary air channel 1 of the burner on the right side of the partition 8, and the primary combustion chamber 10 is formed under the inverted "V" shaped partition 8, the auxiliary oil gun 11, the main oil gun casing 12 and the fire The connecting end of the inspection pipe 15 and the primary air duct 1 of the burner is in communication with the primary combustion chamber 10 below the inverted "V" shaped partition 8 . The present invention has the advantages that: the primary air passage 1 of the burner is located at the center of the burner, and the oil gun tip is directed to the center of the pulverized coal to form a high-temperature flame. After the pulverized coal and air sent from the primary air pulverized pipeline flow into the three frustum-shaped separation rings in the primary air passage 1 of the burner, the pulverized coal is concentrated in the center of the burner to form high-concentration pulverized coal. Part of the high-concentration pulverized coal enters the primary combustion chamber 10, and the ignition gun 13 first ignites the main oil gun 14, and then the high-temperature flame formed by the main oil gun 14 directly contacts with the dense coal powder particles in the primary combustion chamber 10 to make the coal powder particles The characteristics change, the extremely high heating rate greatly accelerates the precipitation of volatile matter, the temperature of the pulverized coal particles rises sharply, bursts, pulverizes and burns violently, and then enters the secondary combustion chamber 9 to contact with the remaining pulverized coal particles and ignite the remaining pulverized coal particles Pulverized coal realizes the staged combustion of pulverized coal, and the combustion energy is amplified step by step. Finally, it is sprayed into the furnace through the burner 7 to achieve the purpose of igniting and accelerating the combustion of pulverized coal, greatly reducing the ignition energy required for pulverized coal combustion, and meeting the needs of boilers. Start, stop and low-load stable combustion requirements. Auxiliary oil gun 11, main oil gun casing 12, ignition gun 13 and main oil gun 14 are all outside the primary air duct 1 of the burner, which solves the wear problem of main oil gun casing 12. The flame detection tube 15 can detect the flame stability in the primary combustion chamber 10 at any time. When the flame is unstable, the auxiliary oil gun 11 can be activated in time to help the pulverized coal to burn. The primary air is always flowing outside the inverted V-shaped partition of the primary combustion chamber 10, and the secondary air is always flowing outside the primary air duct of the burner. The primary and secondary air play the role of wind film cooling and can cool the primary combustion chamber. 10 and the secondary combustion chamber 9, prevent the inverted V-shaped dividing plate and the primary air duct wall of the burner from burning. Since there are few parts in the primary air duct 1 of the burner, the area occupied by the primary air duct 1 of the burner is small, and the effect on the frustum-shaped separation ring is not greatly affected. NOx burners are used. The secondary air enters the burner through the secondary air box and is divided into two parts. They respectively pass through the secondary air duct 6 outside the burner and the secondary air duct 4 inside the burner and enter the furnace 8 to adjust the opening of the inner and outer swirlers. The ratio of the internal and external swirling secondary air can be changed, and the secondary air is rotated by the internal swirler 3 and the external swirling device 5 to form a central recirculation zone in the central area of the burner. The pulverized coal is injected into the central part of the central recirculation zone of the burner, the amount of pulverized coal passing through the central recirculation zone increases, and the pulverized coal burns in a low-oxygen reducing atmosphere, prolonging the residence time of pulverized coal and controlling combustion NOx generation. Since the secondary air is divided into inner and outer parts, staged combustion is formed, and combined with central powder feeding, low NOx emissions are achieved. Therefore, the present invention is a swirl pulverized coal combustion device that saves fuel and emits low NOx.

Description of drawings

Fig. 1 is a main sectional view of the overall structure of the present invention, and Fig. 2 is a sectional view along A-A of Fig. 1 .

Detailed ways

Specific embodiment one: (see Fig. 1, Fig. 2) this embodiment consists of a burner primary air duct 1, a first truncated conical separating ring 2-1, a second truncated conical separating ring 2-2, and a third truncated conical separating ring 2-3. Internal swirler 3. Secondary air passage inside the burner 4. External swirler 5. Secondary air passage outside the burner 6. Burner 7. Inverted "V"-shaped partition 8. Secondary combustion Chamber 9, primary combustion chamber 10, auxiliary oil gun 11, main oil gun casing 12, ignition gun 13, main oil gun 14 and flame detector tube 15, the outlet end of the primary air duct 1 of the burner is the burner 7, The secondary air duct 4 inside the burner is fixed on the outer surface of the outlet end of the primary air duct 1 of the burner, the inner swirl 3 is fixed between the primary air duct 1 of the burner and the secondary air duct 4 inside the burner, and the outer swirl flow The device 5 is fixed on the outer surface of the secondary air duct 4 in the burner, the secondary air duct 6 outside the burner is fixed on the outer surface of the secondary air duct 4 in the burner on the right side of the outer swirler 5, and the first cone The frustum-shaped separation ring 2-1, the second truncated-cone-shaped separation ring 2-2 and the third truncated-cone-shaped separation ring 2-3 are sequentially arranged in the middle of the primary air duct 1 of the burner, and the inverted "V"-shaped partition 8 is fixed on the second In the primary air duct 1 of the burner on the right side of the three-cone-shaped separation ring 2-3, the auxiliary oil gun 11 is fixed on the primary air duct 1 of the burner on the left side of the secondary air duct 4 in the burner, and the main oil gun casing 12 It is fixed on the primary air duct 1 of the burner on the left side of the auxiliary oil gun 11, the ignition gun 13 and the main oil gun 14 are fixed in the main oil gun sleeve 12, and the flame detector tube 15 is fixed on the left side of the main oil gun sleeve 12 On the primary air channel 1 of the burner, the secondary combustion chamber 9 is formed in the primary air channel 1 of the burner on the right side of the inverted "V"-shaped partition 8, and the primary combustion chamber 10 is formed under the inverted "V"-shaped partition 8 , the auxiliary oil gun 11, the main oil gun casing 12 and the fire detection tube 15 are connected with the primary air duct 1 of the burner and communicate with the primary combustion chamber 10 below the inverted "V" shaped partition 8.

Specific embodiment two: (see Fig. 1) the head of the main oil gun 14, auxiliary oil gun 11, ignition gun 13 and main oil gun casing 12 of the present embodiment faces the direction of the nozzle 7 of the primary air duct 1 of the burner Set on one side of the primary air duct 1 of the burner, the tails of the main oil gun 14, auxiliary oil gun 11, ignition gun 13 and main oil gun casing 12 are warped outwards, the main oil gun 14, auxiliary oil gun 11, ignition gun 13 and the angle between the main oil gun casing 12 and the centerline of the burner are 55° to 65°. Others are the same as in the first embodiment.

Specific embodiment three: (referring to Fig. 1) the included angle of main oil gun 14, auxiliary oil gun 11, ignition gun 13 and main oil gun casing 12 and burner center line of this embodiment is 60 °. Others are the same as in the second embodiment.

Specific embodiment four: (referring to Fig. 1) main oil gun 14 of the present embodiment, auxiliary oil gun 11, fire detection pipe 15 are all telescopic structures, promptly withdraw from working position when oil gun device is out of service, thereby protected oil gun The gun mechanism is not burned out. Others are the same as in the third embodiment.

Specific embodiment five: (see Fig. 1, Fig. 2) the two lower ends of the inverted "V" shaped partition plate 8 of the present embodiment are connected with the primary air duct 1 of the burner, and the top of the inverted "V" shaped partition plate 8 center is connected with the The axes of the primary air duct 1 of the burner are coincident, and the cross-sectional area of the primary combustion chamber 10 accounts for 1/4 to 1/3 of the cross-sectional area of the primary air duct 1 of the burner. Others are the same as in Embodiment 4.

Specific embodiment six: (referring to Fig. 1) the diameter of the 3rd truncated conical separating ring 2-3 large end of the present embodiment is less than the diameter of the second truncated conical separating ring 2-2 small end, the diameter of the second truncated conical separating ring 2-2 large end The diameter is smaller than the diameter of the small end of the first truncated conical separation ring 2-1. Others are the same as in the fifth embodiment.

Specific embodiment seven: (see Fig. 1) the small end side of the first truncated conical separating ring 2-1, the second truncated conical separating ring 2-2 and the third truncated conical separating ring 2-3 of this embodiment are all facing the combustion Fire nozzle 7 of primary air duct 1. Others are the same as in the sixth embodiment.

Claims (7)

1, a kind of small oil mass gasification combustion side direction is lighted the center powder-feeding swirling burner, it is by an air channel of burner (1), the first truncated cone eseparation ring (2-1), the second truncated cone eseparation ring (2-2), the 3rd truncated cone eseparation ring (2-3), interior cyclone (3), secondary air duct (4) in the burner, outer cyclone (5), the outer secondary air duct (6) of burner, nozzles (7), fall " V " shape dividing plate (8), secondary combustion chamber (9), one-level combustion chamber (10), auxiliary oil gun (11), main oil gun sleeve pipe (12), burning torch (13), main oil gun (14) and fire inspection pipe (1 5) are formed, the port of export in an air channel of burner (1) is nozzles (7), secondary air duct (4) is fixed on the lateral surface of an air channel of burner (1) port of export in the burner, interior cyclone (3) is fixed between an air channel of burner (1) and the interior secondary air duct (4) of burner, outer cyclone (5) is fixed on the lateral surface of secondary air duct (4) in the burner, the outer secondary air duct (6) of burner is fixed on the lateral surface of the interior secondary air duct (4) of burner on outer cyclone (5) right side, it is characterized in that the first truncated cone eseparation ring (2-1), the second truncated cone eseparation ring (2-2) and the 3rd truncated cone eseparation ring (2-3) are successively set on the middle part in the air channel of burner (1), " V " shape dividing plate (8) that falls is fixed in the air channel of burner (1) on the 3rd truncated cone eseparation ring (2-3) right side, auxiliary oil gun (11) is fixed on the air channel of burner (1) in secondary air duct (4) left side in the burner, main oil gun sleeve pipe (12) is fixed on the air channel of burner (1) in auxiliary oil gun (11) left side, burning torch (13) and main oil gun (14) all are fixed in the main oil gun sleeve pipe (12), fire inspection pipe (15) is fixed on the air channel of burner (1) in main oil gun sleeve pipe (12) left side, form secondary combustion chamber (9) in the air channel of burner (1) on " V " shape dividing plate (8) right side, oil gun (11) is assisted in the following formation one-level combustion chamber (10) of " V " shape dividing plate (8), main oil gun sleeve pipe (12) and fire inspection pipe (15) and an air channel of burner (1) link all are connected with the following one-level combustion chamber (10) of " V " shape dividing plate (8).

2, a kind of small oil mass gasification combustion side direction according to claim 1 is lighted the center powder-feeding swirling burner, it is characterized in that main oil gun (14), auxiliary oil gun (11), the head of burning torch (13) and main oil gun sleeve pipe (12) is arranged on the side in an air channel of burner (1) towards the direction of the nozzles (7) in an air channel of burner (1), main oil gun (14), auxiliary oil gun (11), the afterbody of burning torch (13) and main oil gun sleeve pipe (12) sticks up outward, main oil gun (14), auxiliary oil gun (11), burning torch (13) and main oil gun sleeve pipe (12) are 55 °～65 ° with the angle of burner center line.

3, a kind of small oil mass gasification combustion side direction according to claim 2 is lighted the center powder-feeding swirling burner, it is characterized in that main oil gun (14), auxiliary oil gun (11), burning torch (13) and main oil gun sleeve pipe (12) and the angle of burner center line are 60 °.

4, a kind of small oil mass gasification combustion side direction according to claim 3 is lighted the center powder-feeding swirling burner, it is characterized in that main oil gun (14), auxiliary oil gun (11), fire inspection pipe (15) are telescopic structure.

5, a kind of small oil mass gasification combustion side direction according to claim 4 is lighted the center powder-feeding swirling burner, two lower ends that it is characterized in that down " V " shape dividing plate (8) are connected with an air channel of burner (1), the top at " V " shape dividing plate (8) center and the dead in line in an air channel of burner (1), the sectional area of one-level combustion chamber (10) accounts for 1/4th to 1/3rd of an air channel of burner (1) sectional area.

6, a kind of small oil mass gasification combustion side direction according to claim 5 is lighted the center powder-feeding swirling burner, it is characterized in that the diameter of the diameter of the big end of the 3rd truncated cone eseparation ring (2-3) less than second truncated cone eseparation ring (2-2) small end, the diameter of the big end of the second truncated cone eseparation ring (2-2) is less than the diameter of first truncated cone eseparation ring (2-1) small end.

7, a kind of small oil mass gasification combustion side direction according to claim 6 is lighted the center powder-feeding swirling burner, and small end one side that it is characterized in that the first truncated cone eseparation ring (2-1), the second truncated cone eseparation ring (2-2) and the 3rd truncated cone eseparation ring (2-3) is all towards the nozzles (7) in an air channel of burner (1).

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