CN101526226B - Double-helix pneumatic nebulized micro-oil igniting and flame stabilizing device - Google Patents

Abstract

The invention relates to a double-helix pneumatic nebulized micro-oil igniting and flame stabilizing device, which comprises a bumping coal dust concentrated and fractional combustion pulverized coal burner and a double-helix pneumatic nebulization micro-oil gun. Concentration of micro-oil employs a form combining bumping concentrating block and concentrating loop; a combustion chamber of the device comprises a combination of an inner combustion chamber and an outer combustion chamber; the bumping concentrating block is an annular lug boss with a triangular section; the bumping concentrating loop is an tapered circle structure; the inner combustion chamber and the outer combustion chamber are concentric and symmetric structures of different inner diameters .The double-helix pneumatic nebulized micro-oil gun and the pulverized coal burner employ a concentric assembly structure. 4 inner atomizing gas channels of the fuel nozzle of the micro-oil gun are spirally formed; 4 outer atomizing gas channels of the middle nozzle are also spirally formed; rotation directions of the inner atomizing channels are the same as rotation directions of the outer atomizing channels. The device of the invention is mainly applicable to start-up igniting and under-load flame stabilizing stages of pulverized coal fired boiler, thereby replacing presently used large-oil-gun igniting and flame stabilizing method. The method use coal to replace oil, so as to reach the goal of cost saving.

Description

Double helix pneumatic atomization micro-oil ignition and stable combustion device

technical field

The invention relates to a double-helix pneumatic atomized micro-oil ignition and stable combustion device, which is mainly used in the cold or hot start-up ignition and low-load stable combustion stages of pulverized coal boilers, and can also be used in cement, ceramics, metallurgy, etc. Industries that use pulverized coal as the main energy source. The new device has strong adaptability to coal powder, and can ignite coal powder of various coal types such as lignite, bituminous coal, lean coal, anthracite, mixed coal, etc., and belongs to the technical field of thermal power.

Background technique

With the continuous increase of international and domestic fuel prices and the continuous expansion of electric power and heating units, the oil consumption of various pulverized coal boilers in the electric power, petrochemical and other industries has increased significantly for cold or hot start-up ignition and low-load stable combustion. At the same time, with the increase of oil consumption in various industries such as transportation and chemical industry, the price of fuel oil continues to rise. In order to solve this problem, all countries are researching oil-free or micro-oil ignition and stable combustion technology, trying to replace fuel oil with coal with lower price in the stage of boiler ignition and stable combustion in electric power, petrochemical and other industries, so as to achieve the goal of replacing fuel oil with coal. Oil, for the purpose of saving energy costs.

As early as the 1970s, American G-E Company, B-W Company, Westinghouse Company, the former Soviet Union, Australia and other companies, as well as China's Tsinghua University, Harbin Boiler Factory, Wuhan Boiler Factory and other units conducted research on plasma oil-free ignition technology, especially from At the beginning of this century, Yantai Longyuan Electric Power Technology Co., Ltd. and Luoyang Bonnet Engineering Technology Co., Ltd. made use of the high fuel prices in recent years to promote plasma oil-free ignition. The decline in the coal quality of the unit has caused some problems in the application of plasma oil-free ignition, mainly for coal types with relatively low volatile content such as lean coal and anthracite, in the process of ignition and stable combustion, ignition failure occurs Based on the problem of unstable combustion, in recent years, China has begun to conduct research on micro-oil ignition technology, replacing the thermal power of the plasma spray gun with the thermal power generated by the combustion of micro-oil guns, and greatly improving the ignition efficiency. The thermal power of the heat source is improved, so that the ignition range of pulverized coal can cover pulverized coal of various coal types including lignite, bituminous coal, lean coal, anthracite, mixed coal, etc. The incomplete combustion of the gun has not fundamentally solved the problems of unsuccessful ignition and unstable combustion. The present invention will adopt multi-stage concentration and staged combustion of pulverized coal burners and double-helix pneumatic atomization, complete combustion, high efficiency and long service life. The combination of the long micro oil gun fundamentally solves the problems of unsuccessful ignition and unstable combustion.

Contents of the invention

The technical problem of the present invention is to overcome the deficiencies of the prior art, and provide a double-helix pneumatic atomized fine oil ignition and stable combustion device with high ignition success rate and stable combustion.

Technical solution of the present invention: double-helix pneumatic atomization micro-oil ignition and stable combustion device, including collision-type pulverized coal concentration and graded combustion pulverized coal burner and double-helix pneumatic atomization micro-oil gun, double-helix pneumatic atomization micro-oil gun The front support body and the rear support body are fixedly installed on the collision-type pulverized coal concentration and graded combustion pulverized coal burner, and the double-helix pneumatic atomization micro-oil gun and the collision-type coal concentration and graded combustion pulverized coal burner are installed coaxially;

Among them, the 4 inner atomizing gas channels of the fuel nozzle of the double-helix pneumatic atomizing micro-oil gun are in the form of a spiral, and the 4 outer atomizing gas channels of the nozzle in the micro-oil gun are in the form of a spiral, and the inner atomizing gas channel and the outer The direction of rotation of the atomizing gas channels is the same.

The colliding pulverized coal concentration staged combustion pulverized coal burner includes a primary air powder inlet, a straight pipe section, a conical pipe section, an outer nozzle, a collision concentration block, a collision concentration ring, an inner combustion chamber, an outer combustion chamber, and an inner combustion chamber. Chamber disturbance block, rear disturbance block of the outer combustion chamber, front disturbance block of the outer combustion chamber, collision concentration ring support plate, inner combustion chamber support plate and outer combustion chamber support plate;

The primary air powder inlet, straight pipe section, tapered pipe section and outer nozzle together constitute the external structure of the collision type pulverized coal concentration staged combustion pulverized coal burner. The collision concentration block is fixedly installed on the inner wall of the straight pipe section, and the collision concentration ring passes through the collision concentration ring support plate. Fixedly installed on the inner wall of the straight pipe section, the inner combustion chamber is fixedly installed on the inner wall of the tapered pipe section through the inner combustion chamber support plate, the outer combustion chamber is fixed and installed on the inner wall of the outer nozzle through the outer combustion chamber support plate, and the inner combustion chamber is disturbed The block is fixedly installed on the inner wall of the inner layer combustion chamber, and the rear disturbance block of the outer layer combustion chamber and the front disturbance block of the outer layer combustion chamber are fixedly installed on the inner wall of the outer layer combustion chamber.

The collision concentration block is an annular boss with a triangular cross-section, the collision concentration ring is a conical ring structure, and the channel area formed by the collision concentration ring is consistent with the channel area formed by the collision concentration block. The collision concentration block and the collision concentration ring are based on Different angles are used for different coal powder components.

Compared with the prior art, the present invention has beneficial effects as follows:

(1) The present invention adopts a double-helix pneumatic atomization micro-oil gun, and the atomization method adopts a double-helix pneumatic secondary atomization. , fully mixed with the combustion-supporting air, the equivalent ratio of oil and gas is about 1 kg of oil/13 kg of air, to achieve complete combustion;

(2) The pulverized coal burner of the present invention adopts the combination of multi-stage concentration mode and staged combustion technology, and is composed of a burner collision concentration block and a burner collision concentration ring, and the primary air powder mixture is concentrated efficiently, and the concentrator and concentration The rings all adopt a conical structure, and the burner nozzle adopts a concentric two-cylinder structure to ensure the heating and expansion capacity of the pulverized coal after ignition;

(3) the micro-oil gun of the present invention is coaxial with the pulverized coal burner, thereby ensuring that the combustion flame of the micro-oil gun has the same axial direction as the motion of the pulverized coal, and can also entrain the pulverized coal simultaneously, and the combustion flame of the micro-oil gun is in contact with the coal. Coal powder can be in good contact, so as to ensure successful ignition of coal powder and stable combustion;

(4) The present invention adopts the heat that the micro-oil gun directly ignites pulverized coal and emits to replace the heat emitted by the combustion of a large oil gun, and replaces oil with coal, and the fuel-saving rate can reach more than 90%;

(5) There is a certain gap between the outer layer combustion chamber of the burner of the present invention and the outer spout of the pulverized coal burner, so that a part of the light air powder flow flows out from the gap, and cools the outer spout of the pulverized coal burner;

(6) The present invention can be applied to various power station pulverized coal boilers, as well as cement rotary kilns, ceramic kilns and other industries that use coal powder as an energy source. It can be installed at the position of the ignition oil gun to replace the ignition function of the oil gun; It can also be installed directly at the position of the main burner of the boiler to replace the main pulverized coal burner, so as to realize the cold start ignition and low load stable combustion of the boiler.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the present invention;

Fig. 2 is the schematic diagram of the collision type pulverized coal concentration staged combustion pulverized coal burner of the present invention;

Fig. 3 is a schematic diagram of a double-helix pneumatic atomizing micro-oil gun of the present invention;

Fig. 4 is a schematic diagram of the front end of the double-helix pneumatic atomization micro oil gun of the present invention;

Figure 5 is a schematic diagram of the rear end of the double-helix pneumatic atomization micro-oil gun of the present invention;

Figure 6 is a partial enlarged view at Figure 4A;

Fig. 7 is a partially enlarged view at Fig. 5B;

Fig. 8 is a partially enlarged view at Fig. 5C;

Fig. 9 is a distribution diagram of disturbance blocks before and after the outer combustion chamber of the present invention;

Fig. 10 is a distribution diagram of disturbing blocks in the inner combustion chamber of the present invention;

Fig. 11 is a schematic diagram of the combustion-supporting air nozzle of the present invention;

Figure 12 is a schematic diagram of the fuel nozzle of the present invention;

Fig. 13 is a schematic diagram of the nozzle in the present invention;

Figure 14 is a schematic diagram of the collision enrichment ring of the present invention;

Fig. 15 is a schematic diagram of the collision enrichment block of the present invention.

Detailed ways

As shown in Figure 1, the present invention includes a collision type pulverized coal concentrated and graded combustion pulverized coal burner and a double-helix pneumatic atomization micro-oil gun, and the double-helix pneumatic atomization micro-oil gun is fixedly installed through the front support body 23 and the rear support body 28 On the collision type pulverized coal concentration staged combustion pulverized coal burner, the double helix pneumatic atomization micro-oil gun and the collision type coal concentration staged combustion pulverized coal burner must be installed coaxially.

The collision-type pulverized coal concentration staged combustion pulverized coal burner is shown in Figure 2, including primary air powder inlet 1, straight pipe section 2, tapered pipe section 3, outer nozzle 4, collision concentration block 5, collision concentration ring 6, and inner combustion chamber 7. Outer combustion chamber 8, inner combustion chamber disturbance block 9, outer combustion chamber rear disturbance block 10, outer combustion chamber front disturbance block 11, collision concentration ring support plate 12, inner combustion chamber support plate 13 and outer Layer combustion chamber support plate 14. The primary air powder inlet 1, the straight pipe section 2, the tapered pipe section 3 and the outer nozzle 4 together form the external structure of the collision type pulverized coal concentration and staged combustion pulverized coal burner, and the external structure is circular.

The collision concentration block 5 is fixedly installed on the inner wall of the straight pipe section 2, the collision concentration ring 6 is fixedly installed on the inner wall of the straight pipe section 2 through the collision concentration ring support plate 12, and the inner layer combustion chamber 7 is fixedly installed on the cone through the inner layer combustion chamber support plate 13. On the inner wall of the pipe section 3, the outer combustion chamber 8 is fixedly installed on the inner wall of the outer nozzle 4 through the outer combustion chamber support plate 14, and each component is in an axisymmetric structure with the center line.

As shown in Fig. 15, the collision enrichment block 5 is a triangular boss in section, which can ensure the effect of collision enrichment without affecting the smooth passage of coal powder.

As shown in FIG. 14 , the collision concentration ring 6 is a conical ring structure, and the channel area formed by the collision concentration ring 6 is consistent with the channel area formed by the collision concentration block 5 .

The cone angles of the collision thickening block 5 and the collision thickening ring 6 can adopt different angles according to the different coal powder components, and the distance between them can also be adjusted as required.

The inner diameter of the inner combustion chamber 7 is consistent with the front cone inner diameter of the collision enrichment ring 6 .

The inner combustion chamber 7 and the outer combustion chamber 8 are concentric axisymmetric structures with different inner diameters. The rear end face of the outer combustion chamber 8 is flush with the front end face of the inner combustion chamber 7. The diameter and length of the chamber 7 are selected in different sizes according to the different components of the pulverized coal.

There is a certain gap between the outer layer combustion chamber 8 and the outer nozzle 4, so that a part of the light wind powder air flow flows out from the gap to cool the outer nozzle 4. The outer combustion chamber 8 and the outer nozzle 4 are made of heat-resistant and wear-resistant steel, which can obtain a longer service life.

The disturbing blocks 9 of the inner combustion chamber are evenly distributed on the inner circumference of the inner combustion chamber 7 at intervals as shown in FIG. The number is 4-8 (only the distribution of 4 disturbance blocks is shown in Figure 10, and the distribution of other numbers of disturbance blocks can be known in the same way).

As shown in Figure 9, the disturbance block 11 before the outer combustion chamber and the rear disturbance block 10 of the outer combustion chamber are evenly distributed on the inner circumference of the outer combustion chamber 8 at intervals respectively, and the disturbance block 11 and the outer combustion chamber before the outer combustion chamber The length of the circumference occupied by the rear disturbance blocks 10 of the combustion chamber is half of the circumference of the outer combustion chamber 8, and there are 4 pieces respectively.

The double-helix pneumatic atomizing micro-oil gun is shown in Figures 3, 4, 5, 6, 7, and 8, including a high-energy igniter 15, a flame detector 16, a combustion-supporting air inlet 17, a tee 18, a combustion-supporting air nozzle 19, a micro Oil gun outer nozzle 20, micro oil gun middle nozzle 21, micro oil gun fuel nozzle 22, front support body 23, micro oil gun outer tube 24, micro oil gun middle tube 25, micro oil gun oil tube 26, micro oil gun gun body 27. The rear support body 28 and the connecting flange 29.

Fuel nozzle 22 is shown in Figure 12, and 4 inner atomizing gas passages 221 are in spiral form, and middle nozzle 21 is shown in Figure 13, and 4 outer atomizing gas passages 211 are in spiral form, and inner atomizing gas passage 221 and outer The rotation directions of the atomizing gas channels 211 are the same. The nozzle 20 of the micro-oil gun, the middle nozzle 21 of the micro-oil gun, and the fuel nozzle 22 are all made of heat-resistant stainless steel, which can obtain a longer service life.

The combustion-supporting air nozzle 19, as shown in Figure 11, is a double-layer interlayer structure, so that a part of the combustion-supporting air is ejected from the interlayer space, reducing the temperature of the outer wall of the combustion-supporting air nozzle 19, thereby preventing the pulverized coal from coking at the nozzle; its front end is distributed 4-8 Disturbance strips 191 (the distribution of 4 disturbance strips is only shown in Fig. 11, and the distribution of other disturbance strips can be known in the same way), the width of each disturbance strip 191 is 10-25 mm, which can make the combustion air generate certain disturbance , so as to better provide the amount of oxygen required for stable combustion.

The high-energy igniter 15 and the flame detector 16 of the double-helix pneumatic atomization micro-oil gun are parallel to the center line of the micro-oil gun body 27 .

The working principle of the present invention: the primary air powder inlet 1 of the pulverized coal burner is connected with the primary air powder pipeline on the boiler site, the front end of the outer nozzle 4 of the burner is connected with the water wall of the boiler, and the interface of water, electricity, gas and signal lines is checked, and the system After the installation is complete, first debug the micro-oil gun, connect the switch signal of the high-energy igniter 15, and after 2 seconds, first open the atomizing gas solenoid valve, then open the fuel solenoid valve, and detect the ignition state of the micro-oil gun through the flame detector 16 Good, forming a high-temperature flame at a temperature of 1500°C-2000°C, these high-temperature airflows can cause coal powder particles with a particle size of 20-200μm to explode after being heated, and regenerate volatiles, so this high-temperature airflow flame has a good effect on igniting coal powder After the micro oil gun ignites and stabilizes, the air powder mixture valve is opened once, and the air powder mixture is concentrated multiple times by the pulverized coal burner to form a thick coal powder flow in the inner layer and a light coal powder flow in the outer layer, so that the inner layer The thick pulverized coal flow and the combustion flame of the micro-oil gun have a state of parallel motion, and have a certain contact time. Function, the volatile matter in the pulverized coal is first ignited, and in the process of advancing the pulverized coal, a volatile matter is first ignited, and the wind powder air flow is ignited and expanded while moving, and the dense coal powder flow is ignited through the inner combustion chamber 7 Finally, contact and mix with the light coal powder flow of the outer layer combustion chamber 8 again, so that the heat released by the combustion of the thick coal powder flow ignites the coal powder of the outer layer light coal powder flow, and then the thick coal powder flow and the light coal powder flow edge Combustion while advancing to form a stable combustion flame, and then enter the furnace to continue burning.

At present, in industries that use coal as the combustion medium, due to the combustion characteristics of coal itself, pulverized coal cannot be ignited directly at low temperature. The furnace must be heated to a certain temperature before putting in pulverized coal. In China, only the cold-state ignition and low-load stable combustion of power plant boilers burn about 10 million tons of fuel oil every year in China. At present, in the case of rising prices of liquid fuel and gas fuel, the price of fuel oil per ton is 5500.00 yuan Calculated, it is equivalent to RMB 55.000 billion, plus other industries such as cement, ceramics, and metallurgy, so the cost of liquid fuel consumed for the annual cold start ignition and low-load stable combustion is a huge figure, and using this This technology uses the heat released by direct ignition of pulverized coal with a micro oil gun to replace the heat released by the combustion of a large oil gun, and replaces oil with coal, and the fuel saving rate can reach more than 90%. Therefore, the application of this technology in the current energy supply shortage Under such circumstances, it will provide strong support for the safe supply of fuel oil and gas in the country.

The contents not described in detail in the present invention are common knowledge of those skilled in the art.

Claims (10)

1. The double-helix pneumatic atomization micro-oil ignition and stable combustion device is characterized in that it includes a collision type pulverized coal concentration and graded combustion pulverized coal burner and a double-helix pneumatic atomization micro-oil gun, and the double-helix pneumatic atomization micro-oil gun passes through The front support body (23) and the rear support body (28) are fixedly installed on the collision type pulverized coal concentration and graded combustion pulverized coal burner. Guaranteed to be coaxial; Wherein the 4 inner atomizing gas passages (221) of the fuel nozzle (22) of the double-helix pneumatic atomization micro-oil gun are in a spiral form, and the 4 outer atomization channels (21) of the middle nozzle (21) of the double-helix pneumatic atomization micro-oil gun The channel (211) is also in the form of a spiral, and the rotation direction of the inner atomization channel (221) and the outer atomization channel (211) are the same. 2. The double-helix pneumatic atomization micro-oil ignition and stable combustion device according to claim 1, characterized in that: the collision-type pulverized coal concentration staged combustion pulverized coal burner includes a primary air powder inlet (1), a direct Pipe section (2), tapered pipe section (3), outer nozzle (4), collision enrichment block (5), collision enrichment ring (6), inner combustion chamber (7), outer combustion chamber (8), inner combustion chamber Chamber disturbance block (9), rear disturbance block of the outer combustion chamber (10), front disturbance block of the outer combustion chamber (11), collision concentration ring support plate (12), inner combustion chamber support plate (13), outer Combustion chamber support plate (14); The primary air powder inlet (1), the straight pipe section (2), the tapered pipe section (3) and the outer nozzle (4) together form the external structure of the collision type pulverized coal concentration staged combustion pulverized coal burner, and the collision concentration block (5) is fixed and installed On the inner wall of the straight pipe section (2), the collision enrichment ring (6) is fixedly installed on the inner wall of the straight pipe section (2) through the collision enrichment ring support plate (12), and the inner combustion chamber (7) passes through the inner combustion chamber support plate ( 13) Fixedly installed on the inner wall of the tapered pipe section (3), the outer combustion chamber (8) is fixedly installed on the inner wall of the outer nozzle (4) through the outer combustion chamber support plate (14), and the inner combustion chamber disturbance block (9) is fixed Installed on the inwall of the inner layer combustion chamber (7), the disturbance block (10) and the front disturbance block (11) of the outer layer combustion chamber are fixedly installed on the inner wall of the outer layer combustion chamber (8) after the outer layer combustion chamber. 3. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: the collision concentration block (5) is an annular boss with a triangular cross section, and the collision concentration ring (6) It is a conical ring structure, and the channel area formed by the collision enrichment ring (6) is consistent with the channel area formed by the collision enrichment block (5). different angles. 4. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: the disturbance blocks (9) in the inner combustion chamber are evenly distributed in the inner combustion chamber (7) at intervals On the inner circumference of the inner combustion chamber, the inner combustion chamber disturbing block (9) occupies half of the inner circumference of the inner combustion chamber (7), and the number is 4-8. 5. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: the front disturbance block (11) of the outer combustion chamber and the rear disturbance block (10) of the outer combustion chamber They are evenly distributed at intervals on the inner circumference of the outer combustion chamber (8), and the length of the circumference occupied by the front disturbance block (11) of the outer combustion chamber and the rear disturbance block (10) of the outer combustion chamber is respectively the outer combustion chamber ( 8) There are 4 halves of the circumference, and the disturbance blocks (11) in front of the outer combustion chamber and the rear disturbance blocks (10) in the outer combustion chamber are misplaced and aligned. 6. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: the inner diameter of the inner combustion chamber (7) is consistent with the inner diameter of the front cone of the collision concentration ring (6) . 7. double-helix pneumatic atomization micro-oil ignition and stable combustion device according to claim 1, is characterized in that: described double-helix pneumatic atomization micro-oil gun also includes combustion-supporting air spout (19), combustion-supporting air spout ( 19) is a double-layer sandwich structure, with 4-8 disturbing bars (191) at its front end, and the width of each disturbing bar (191) is 10-25 mm. 8. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: the rear end surface of the outer combustion chamber (8) and the front end surface of the inner combustion chamber (7) Flush, the diameter and length of the outer layer combustion chamber (8) and the inner layer combustion chamber (7) are selected in different sizes according to the different coal powder components. 9. The double-helix pneumatic atomized fine oil ignition and stable combustion device according to claim 2, characterized in that: there is a part of light air between the outer combustion chamber (8) and the outer nozzle (4). The powder airflow flows out, cools the gap of the outer nozzle (4). 10. double helix pneumatic atomization micro oil ignition and stable combustion device according to claim 1, is characterized in that: described double helix pneumatic atomization micro oil gun also comprises high-energy igniter (15), flame detector ( 16) with micro-oil gun gun body (27), high-energy igniter (15), flame detector (16) and micro-oil gun gun body (27) centerline parallel.

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