A dual-purpose burner device for coal and ammonia

Abstract

The present invention discloses a dual-purpose burner device for coal and ammonia, comprising an inner ammonia pipe, a primary air duct, a primary air sleeve, an outer ammonia sleeve, a secondary air sleeve, and a tertiary air sleeve, which are sequentially sleeved from the inside to the outside, wherein the outlets of the inner ammonia pipe, the primary air duct, the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve face the burner, and the outlets of the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve are expanded, and the outlet end of the outer ammonia sleeve is connected to a first blocking plate, and a first fire hole is formed on the first blocking plate, and the outlet of the inner ammonia pipe is a tapered tube, and the outlet end of the tapered tube is connected to a second blocking plate, and a second fire hole is formed on the tapered tube and the second blocking plate. The present invention improves the adaptability of the burner to fuel, improves the stability of combustion, and reduces NO during combustion. x Generation of.

Description

Technical Field

[0001] The invention relates to the technical field of burners, and in particular to a dual-purpose burner device for coal and ammonia. Background Art

[0002] According to statistics, China's coal, oil and natural gas consumption account for about 51%, 14% and 7.8% of the world's total respectively. About half of China's coal is used for combustion for power generation, which is the largest single source of carbon dioxide. Reducing coal consumption in the power industry is an effective means to reduce carbon dioxide emissions, but China's current resource status of rich coal, poor oil and little gas makes it difficult for the power industry to completely break away from coal. In recent years, in the face of severe carbon emissions, research on carbon-free fuels has received more and more attention. Ammonia is regarded as a promising clean energy carrier and storage medium. Compared with hydrogen, ammonia has a lower cost per unit of stored energy, a higher volume energy density, and is safer and more reliable. Therefore, the blending of coal and zero-carbon fuel ammonia is one of the effective measures to reduce carbon emissions in the thermal power sector.

[0003] In the prior art, some burners are currently capable of burning two or more clean energy sources at the same time. However, these dual-purpose burner devices have clear requirements for fuels, especially for the blending of high calorific value methane, but not for the blending of low calorific value ammonia. The effective use of ammonia fuel is very challenging at this stage. Compared with conventional hydrocarbon fuels, the laminar combustion velocity and calorific value of pure ammonia are relatively low, and the energy required for ignition is higher, and the combustion limit range is narrow, making the combustion of pure ammonia more difficult. In addition, due to the composition characteristics of ammonia fuel, NO X The high production of nitrogen oxides further inhibits its application as a new carbon-free fuel in boilers. Therefore, a dual-purpose burner is urgently needed to achieve mixed low-nitrogen combustion of coal and ammonia, thereby significantly reducing the carbon emission intensity in the thermal power field.

[0004] Therefore, technicians in this field are committed to providing a dual-purpose burner device for coal and ammonia, so as to achieve efficient and stable combustion by replacing part of the coal powder with ammonia, and reduce NO X emissions. Summary of the invention

[0005] In view of the defects of the prior art, the technical problem to be solved by the present invention is how to provide a fuel adaptability that can improve fuel adaptability and reduce NO X Dual-purpose burner unit for discharge.

[0006] To achieve the above-mentioned purpose, the present invention provides a dual-purpose burner device for coal and ammonia, comprising an inner ammonia pipe, a primary air duct, a primary air sleeve, an outer ammonia sleeve, a secondary air sleeve, and a tertiary air sleeve which are sequentially sleeved from the inside to the outside, the outlets of the inner ammonia pipe, the primary air duct, the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve face the burner, the outlets of the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve are flared, the outlet end of the outer ammonia sleeve is connected to a first blocking plate, a first fire hole is opened on the first blocking plate, the outlet of the inner ammonia pipe is a tapered tube, the outlet end of the tapered tube is connected to a second blocking plate, and second fire holes are opened on the tapered tube and the second blocking plate.

[0007] Preferably, it also includes a bellows, which is sleeved on the outside of the tertiary air sleeve.

[0008] Preferably, the ratio of the length of the tapered pipe to the straight pipe section of the inner ammonia pipe is 0.1.

[0009] Preferably, the ratio of the diameter of the second fire hole to the straight tube diameter of the inner ammonia tube is 0.12.

[0010] Preferably, the ratio of the flow area of ​​the first fire hole to the flow area of ​​the second fire hole is 6:1.

[0011] Furthermore, a burner elbow is connected to the inlet of the primary air duct, and a flame stabilizing tooth is provided at the outlet of the primary air channel.

[0012] Furthermore, a first coal powder concentration ring and a second coal powder concentration ring are provided in the primary air duct.

[0013] Furthermore, the external ammonia sleeve is connected to an external ammonia inlet pipe.

[0014] Furthermore, a swirl blade fixing plate is provided in the secondary air sleeve, and a swirl blade is provided on the swirl blade fixing plate.

[0015] Furthermore, the secondary air sleeve is also provided with a secondary air volume adjustment rod and a secondary air swirl intensity adjustment rod.

[0016] The present invention has at least the following beneficial technical effects:

[0017] The coal and ammonia dual-purpose burner device provided by the present invention performs multi-stage feeding and zoned oxygen supply in the entire combustion area to form a fuel-poor zone and a fuel-rich zone, which can significantly inhibit fuel-type NO during the combustion process. x By controlling the ratio of primary air to secondary air, the flame center temperature can be appropriately lowered to reduce thermal NO xAt the same time, the multi-stage feeding and zoned air supply make the coal adaptability of the present invention good, and the ammonia blending ratio can be adjusted in a wide range. The present invention enhances the adaptability of the burner to the raw materials, improves the combustion stability, and reduces the NO x generate.

[0018] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of a dual-purpose burner provided by an embodiment of the present invention;

[0020] Figure 2 is a front view of a dual-purpose burner provided by an embodiment of the present invention;

[0021] Figure 3 is a schematic diagram of a reducer provided in an embodiment of the present invention;

[0022] Figure 4 It is a schematic diagram of a first blocking plate provided in an embodiment of the present invention.

[0023] In the figure,

[0024] 1-center sleeve, 2-primary air sleeve, 3-external ammonia inlet pipe, 4-external ammonia sleeve, 5-secondary air sleeve, 6-winding box inner cover, 7-inner ammonia pipe, 8-first blocking plate, 9-primary air duct, 10-burner elbow, 11-winding box baffle, 12-winding box, 13-winding box flange, 14-first coal powder concentration ring, 15-second coal powder concentration ring, 16-tertiary air sleeve, 17-swirl blade fixing plate, 18-swirl blade, 19-ignition device, 20- Secondary air volume adjusting rod, 21-flame stabilizing tooth, 22-primary air flaring, 23-external ammonia flaring, 24-secondary air flaring, 25-tertiary air flaring, 26-tertiary air volume adjusting rod, 27-secondary air adjusting mechanism connecting plate, 28-secondary air adjusting mechanism cylinder, 29-secondary air adjusting mechanism bolt joint, 30-secondary air adjusting mechanism connecting rod, 31-secondary air swirl intensity adjusting rod, 32-gradient tube, 33-second fire hole, 34-second blocking plate, 35-first fire hole. DETAILED DESCRIPTION

[0025] The following describes several preferred embodiments of the present invention with reference to the drawings in the specification, so that the technical content is clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the protection scope of the present invention is not limited to the embodiments mentioned in the text.

[0026] In the drawings, components with the same structure are indicated by the same numerical reference numerals, and components with similar structures or functions are indicated by similar numerical reference numerals. The size and thickness of each component shown in the drawings are arbitrarily shown, and the present invention does not limit the size and thickness of each component. In order to make the illustration clearer, the thickness of the components is appropriately exaggerated in some places in the drawings.

[0027] The present invention provides a dual-purpose burner device for coal and ammonia, such as Figure 1 and Figure 2 As shown, the innermost side of the dual-purpose burner device of the present invention is the inner ammonia pipe 7, and the outlet of the inner ammonia pipe 7 is arranged at the center of the burner shell. The outlet end of the inner ammonia pipe 7 is a tapered pipe 32, and a second blocking plate 34 is provided at the end of the tapered pipe 32. A second fire hole 33 is opened on the second blocking plate 34 to form an inner ammonia jet at a certain speed. A central sleeve 1 is coaxially arranged outside the inner ammonia pipe 7. The central sleeve 1 is used to fix the coal powder concentration mechanism to separate the burning coal powder into thick and thin, so that the primary air coal powder airflow injected into the furnace forms an outer thick and inner thin coal powder distribution effect. A primary air duct 9 and a primary air sleeve 2 are coaxially arranged outside the central sleeve 1, and the annular space formed by the central sleeve 1 and the primary air duct 9 constitutes a primary air channel. A flame stabilizing tooth 21 is arranged at the end of the primary air duct 9. The flame stabilizing tooth 21 is a tooth-like structure evenly distributed in the annular direction, which plays a flame stabilizing role. An external ammonia sleeve 4 is coaxially arranged outside the primary air sleeve 2, and the annular space formed by the external ammonia sleeve 4 and the primary air sleeve 2 constitutes an external ammonia channel. A first blocking plate 8 is arranged at the end of the external ammonia channel, and a first fire hole 35 is opened on the first blocking plate 8 to form an external ammonia jet at a certain speed. A secondary air sleeve 5 is coaxially arranged outside the external ammonia sleeve 4, and the annular space formed by the secondary air sleeve 5 and the external ammonia sleeve 4 constitutes a secondary air channel. A rotation direction adjustment mechanism is arranged in the secondary air channel, which can be flexibly adjusted according to different types of coal and ammonia blending ratios. The high-concentration pulverized coal airflow at the primary air outlet and the external ammonia jet in the external ammonia channel are strongly mixed with the high-temperature flue gas entrained by the high-temperature and high-turbulence secondary air, thereby strengthening the combustion process of pulverized coal and ammonia. A tertiary air sleeve 16 is coaxially arranged outside the secondary air sleeve 5. The annular space formed by the secondary air sleeve 5 and the tertiary air sleeve 16 constitutes a tertiary air channel, which generates direct current air with higher momentum, improves the combustion of coal powder and ammonia, and prevents the occurrence of flame flash.

[0028] In this embodiment, the internal ammonia pipe 7 is composed of a straight pipe section and a tapered pipe 32, and the ratio of the length of the tapered pipe 32 to the straight pipe section is about 0.1. Figure 3As shown, the reducer 32 is provided with an oblique second fire hole 33, and the second plugging plate 34 at the end of the reducer 32 is provided with an axial second fire hole 33, and the ratio of the diameter of the second fire hole 33 to the diameter of the straight pipe section is about 0.12, so as to provide a higher speed ammonia jet to prevent flashback in the center area of ​​the burner. Considering the poor combustion characteristics of ammonia, the second fire hole 33 is provided on the reducer 32 to ensure that the oblique jet of the internal ammonia is premixed with the primary air in advance, so as to improve the combustion characteristics of the internal ammonia jet.

[0029] The primary air channel structure of this embodiment is composed of a burner elbow 10, a primary air duct 9, a primary air sleeve 2, a flame stabilizing tooth 21, a first coal powder concentration ring 14 and a second coal powder concentration ring 15, and a primary air expansion port 22. Anti-wear ceramic sheets are arranged on the windward surface of the primary air channel to reduce the abrasion of the coal powder airflow on the pipeline. The flame stabilizing tooth 21 can intensify the mixing of coal powder and primary air, make the combustion more complete, and the temperature field is evenly distributed without local high temperature areas, reducing NO x generate.

[0030] The first coal powder concentration ring 14 and the second coal powder concentration ring 15 make the primary coal powder airflow injected into the furnace form a distribution effect of thick coal powder on the outside and thin coal powder on the inside. The high-concentration coal powder airflow is in direct contact with the boundary of the high-temperature flue gas sucked by the secondary air, and they are strongly mixed, thereby strengthening the combustion process of the coal powder. At the same time, the first coal powder concentration ring 14 and the second coal powder concentration ring 15 form a distribution effect of high-concentration and high-calorific value coal powder wrapped in low-concentration and low-calorific value ammonia, thereby improving the combustion characteristics of the internal ammonia jet.

[0031] The external ammonia channel is composed of a primary air sleeve 2, an external ammonia sleeve 4, an external ammonia expansion port 23, a primary air expansion port 22 and a first blocking plate 8. Figure 4 As shown, in this embodiment, the first blocking plate 8 is 3 mm thick and is fixed by fastening screws between the primary air expansion port 22 and the external ammonia expansion port 23. Six first fire holes 35 are evenly arranged in the circumferential direction on the first blocking plate 8, and the ratio of the diameter of the first fire hole 35 to the diameter of the first blocking plate 8 is about 0.08. The external ammonia expansion port 23 is conducive to the dense phase airflow in the primary air being sucked into the external ammonia jet, enhancing mixing and achieving enhanced combustion of ammonia.

[0032] The secondary air channel is composed of an outer ammonia sleeve 4, a secondary air sleeve 5, an outer ammonia expansion 23, a secondary air expansion 24, a secondary air volume adjustment rod 20, a swirl blade 18, a swirl blade fixing plate 17 and a secondary air swirl intensity adjustment rod 31. The secondary air volume is controlled by the secondary air volume adjustment rod 20 extending to the outside. The swirl parameters of the secondary air are mainly controlled by the swirl adjustment mechanism to rotate, drive the swirl blade 18 to rotate, and thus obtain a secondary air with a certain swirl intensity. The swirl adjustment mechanism includes a secondary air adjustment mechanism connecting plate 27, a secondary air adjustment mechanism cylinder 28, a secondary air adjustment mechanism bolt joint 29, and a secondary air adjustment mechanism connecting rod 30. The secondary air realizes the entrainment and mixing of coal powder and ammonia, and increases the combustion time of air, ammonia and coal powder through swirl. The swirl intensity can be flexibly adjusted according to the mixing ratio of ammonia.

[0033] The tertiary air channel is composed of a tertiary air sleeve 16, a secondary air sleeve 5, a tertiary air expansion port 25 and a secondary air expansion port 24, and is used to generate a high momentum direct current wind, thereby preventing the occurrence of flame flash and slagging on the wall near the burner, and at the same time ensuring that the swirl secondary air can be better mixed with the primary air in the later stage, thereby improving the burnout rate of the coal powder and ammonia mixed airflow. The air volume of the tertiary air channel is adjusted by the tertiary air volume adjustment lever 26.

[0034] The inlet of the dual-purpose burner of the present embodiment is provided with an inner ammonia channel, a primary air powder channel, an outer ammonia channel, a secondary air channel and a tertiary air channel in sequence. The ammonia fuel is divided into two parts, namely the main ammonia fuel and the secondary ammonia fuel. The main ammonia fuel accounts for about 90%, and the secondary ammonia fuel accounts for about 10%. The secondary ammonia fuel is arranged at the center of the burner. Under the effect of the expansion, a negative pressure zone is formed at the nozzle of the burner, which is conducive to the internal circulation of the high-temperature coal powder flame flue gas and ignites the small torch of the secondary fuel. The main ammonia fuel is arranged between the primary air and the secondary air, which is conducive to strong mixing with the high-temperature and high-turbulence secondary air to achieve efficient combustion of ammonia.

[0035] like Figure 1 and Figure 2 As shown, an external ammonia inlet pipe 3 is also connected to the external ammonia sleeve 4, and ammonia is provided to the external ammonia channel through the external ammonia inlet pipe 3. A bellows 12 is also arranged outside the tertiary air channel, and the bellows 12 contains the internal ammonia channel, the primary air powder channel, the external ammonia channel, the secondary air channel and the tertiary air channel, so as to encapsulate the pipeline system. A bellows inner cover plate 6 is arranged inside the bellows 12, a bellows baffle 11 is arranged at the end of the bellows 12, and a bellows flange 13 is arranged on the circumferential outer side of the bellows 12, and the bellows 12 can be disassembled and assembled through the bellows baffle 11 and the bellows flange 13.

[0036] like Figure 1 and Figure 2 As shown, the dual-purpose burner device of this embodiment is integrally fixed on a frame at the bottom, and the frame is further fixed on the ground of the working area.

[0037] like Figure 1 As shown, an ignition device 19 is arranged obliquely above the tertiary air duct, and the outlet end of the ignition device 19 is arranged in the burner body to ignite the fuel in the burner. The ignition device 19 can be an ignition oil gun.

[0038] The present embodiment is a coal and ammonia dual-purpose burner device with adjustable swirl intensity. The coal powder required for combustion passes through the burner elbow 10, the primary air duct 9, the first coal powder concentration ring 14, the second coal powder concentration ring 15, and the flame stabilizing teeth 21, and then enters the furnace through the primary air expansion 22, forming a coal powder distribution effect of thick outside and thin inside, and then burns. The mixed ammonia is sent into the furnace in two ways, divided into main ammonia (accounting for about 90% of the total ammonia) and secondary ammonia (accounting for about 10% of the total ammonia), wherein the secondary ammonia passes through the inner ammonia pipe 7 of the central sleeve 1. At the position of the inner ammonia pipe 7 near the end of the burner, a part of the secondary ammonia passes through the oblique second fire hole 33 of the reducer 32 and is partially premixed with the air in the primary air in advance, and the other part of the secondary ammonia passes through the second fire hole 33 on the second blocking plate 34 at the end of the reducer 32 and then sprays out. The main ammonia gas is injected into the furnace through the external ammonia gas inlet pipe 3, the external ammonia gas sleeve 4, and the first fire hole 35 of the first blocking plate 8. The total area ratio of the first fire hole 35 of the external ammonia gas pipe to the total area ratio of the second fire hole 33 of the internal ammonia gas pipe 7 is about 6:1. A large amount of main ammonia gas is injected from the first fire hole 35 to absorb the heat of the coal powder combustion flame and the heat of the high-temperature secondary air, thereby improving the combustion characteristics of ammonia. The flow rate of the ammonia gas mixed with combustion is controlled by the flow valve in front of the internal ammonia gas pipe 7 and the external ammonia gas inlet pipe 3.

[0039] The present embodiment is a coal and ammonia dual-purpose burner device with adjustable swirl intensity, and the combustion air area includes a primary air channel, a secondary air channel and a tertiary air channel. The air required for combustion is drawn out from the outlet air duct of the blower of the boiler, and enters each sleeve of the burner through the flow regulating valve and the air volume control rod. The primary cold air carries coal powder through the burner elbow 10, the first coal powder concentration ring 14, the second coal powder concentration ring 15, and the flame stabilizing tooth 21 and enters the furnace at a speed of about 20m / s. The secondary air passes through the secondary air sleeve 5 at a speed of about 40-50m / s and then enters the furnace through the rotating guide vane 18. The secondary air with high speed and high swirl intensity is easier to mix coal and ammonia, produce a reflow zone, and form a stable and high-quality flame. The tertiary air enters the furnace at a speed of about 30m / s through the tertiary air sleeve 16, which improves the burnout of coal powder and ammonia, and prevents the flame from sticking to the wall and damaging the burner. The secondary air volume is adjusted by pushing and pulling the secondary air volume adjustment rod 20, the secondary air swirl intensity is adjusted by rotating the secondary air swirl intensity adjustment rod 31, and the tertiary air volume is adjusted by pushing and pulling the tertiary air volume adjustment rod 26.

[0040] The preferred specific embodiments of the present invention are described in detail above. It should be understood that ordinary technicians in the field can make many modifications and changes based on the concept of the present invention without creative work. Therefore, all technical solutions that can be obtained by technicians in the technical field based on the concept of the present invention through logical analysis, reasoning or limited experiments on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A dual-purpose burner device for coal and ammonia, characterized in that: It includes an inner ammonia pipe, a primary air duct, a primary air sleeve, an outer ammonia sleeve, a secondary air sleeve, and a tertiary air sleeve which are sequentially sleeved from the inside to the outside, the outlets of the inner ammonia pipe, the primary air duct, the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve face the burner, the outlets of the primary air sleeve, the outer ammonia sleeve, the secondary air sleeve, and the tertiary air sleeve are expanded, a first coal powder concentration ring and a second coal powder concentration ring are arranged in the primary air duct, the outlet end of the outer ammonia sleeve is connected to a first blocking plate, a first fire hole is opened on the first blocking plate, the outlet of the inner ammonia pipe is a tapered pipe, the outlet end of the tapered pipe is connected to a second blocking plate, a second fire hole is opened on the tapered pipe and the second blocking plate, the inner ammonia pipe transports secondary ammonia, and the outer ammonia sleeve transports primary ammonia.

2. The coal and ammonia dual-purpose burner device according to claim 1, characterized in that: It also includes a bellows, which is sleeved on the outside of the tertiary air sleeve.

3. The coal and ammonia dual-purpose burner device according to claim 1, characterized in that: The ratio of the length of the tapered pipe to the length of the straight pipe section of the inner ammonia pipe is 0.

1.

4. The coal and ammonia dual-purpose burner device according to claim 3, characterized in that: The ratio of the diameter of the second fire hole to the straight tube diameter of the inner ammonia tube is 0.

12.

5. The coal and ammonia dual-purpose burner device according to claim 4, characterized in that: The ratio of the flow area of ​​the first fire hole to the flow area of ​​the second fire hole is 6:

1.

6. The coal and ammonia dual-purpose burner device according to claim 1, characterized in that: A central sleeve is coaxially arranged outside the inner ammonia pipe, and the annular space formed by the central sleeve and the primary air duct constitutes a primary air channel. The inlet of the primary air duct is connected to a burner elbow, and a flame stabilizing tooth is arranged at the outlet of the primary air channel.

7. The coal and ammonia dual-purpose burner device according to claim 1, characterized in that: The external ammonia sleeve is connected with an external ammonia inlet pipe.

8. The coal and ammonia dual-purpose burner device according to claim 1, characterized in that: A swirl blade fixing plate is arranged in the secondary air sleeve, and a swirl blade is arranged on the swirl blade fixing plate.

9. The coal and ammonia dual-purpose burner device according to claim 8, characterized in that: The secondary air sleeve is also provided with a secondary air volume adjustment rod and a secondary air swirl intensity adjustment rod.

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