A tangential coal powder boiler system for burning ammonia and ammonia-mixed combustion method

Abstract

The present invention relates to the technical field of coal powder combustion, in particular to a four-corner cut-circle coal powder boiler system for mixing combustion with ammonia and an ammonia mixing combustion method, comprising a boiler, a combustion device, a gas conveying device and a coal powder conveying device, wherein the combustion device comprises a branch pipe, a cover plate, a cylinder, a plasma ignition device, a first coal powder pipe, a box body, a fourth electronic valve, a fifth electronic valve and a first air supply pipe, wherein the gas conveying device comprises a high-pressure ammonia tank, a first electronic valve, a second electronic valve, a gas conveying pipe, a first connecting pipe, a second connecting pipe, a third electronic valve, a first blower and a high-pressure oxygen tank, wherein the coal powder conveying device comprises a second blower, a coal powder tank, a first feeding pipe and a second feeding pipe, so that oxygen and ammonia are mixed, so that ammonia is in an oxygen-rich environment, so that oxygen is fully ignited, and the conveying amount of ammonia and coal powder of different burners can be controlled by controlling the fourth electronic valve and the fifth electronic valve in different second coal powder pipes and the second air supply pipe.

Description

Technical Field

[0001] The invention relates to the technical field of pulverized coal combustion, in particular to a tangential pulverized coal boiler system mixed with ammonia combustion and an ammonia-mixed combustion method. Background Art

[0002] Pulverized coal combustion technology is widely used. The research on combustion characteristics and NOx emission characteristics has been tested by long-term engineering practice at home and abroad. The relevant technology is mature, but facing the trend of "low carbonization", it is necessary to consider reducing the carbon emissions of pulverized coal combustion technology. Ammonia (NH3) is a good carrier of hydrogen energy. Compared with hydrogen (H2), the main advantages of ammonia are high hydrogen content and high volume energy density. The unit volume hydrogen content and volume energy density of liquid ammonia are even higher than liquid hydrogen. At the same time, due to its mature production process, easy liquefaction for storage and transportation, and high safety, it is considered to be a more promising clean fuel that can effectively serve as a carrier of hydrogen and energy. However, ammonia has poor combustion characteristics and is currently rarely used in four-corner cut-circle pulverized coal boiler systems. Summary of the invention

[0003] The object of the present invention is to provide a tangential coal-fired pulverized coal boiler system and an ammonia-blended combustion method for solving the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A tangential coal powder boiler system mixed with ammonia gas comprises a boiler, a combustion device, a gas conveying device and a coal powder conveying device;

[0006] The combustion device comprises a branch pipe, a cover plate, a cylinder, a plasma ignition device, a first pulverized coal pipe, a box body and a first air supply pipe;

[0007] The gas delivery device comprises a high-pressure ammonia tank, a gas delivery pipe, a first connecting pipe, a second connecting pipe, a first blower and a high-pressure oxygen tank;

[0008] The pulverized coal conveying device comprises a second blower, a pulverized coal tank, a first feeding pipe and a second feeding pipe;

[0009] The combustion device is arranged at the four corners of the boiler, a plurality of first pulverized coal pipes and a plurality of first air supply pipes are arranged in the cover plate, a plurality of box bodies are fixedly connected to one side of the cover plate, a cylinder body is fixedly connected to one side of the box body, one end of the first pulverized coal pipe and the first air supply pipe are arranged in the cylinder body, a plasma ignition device is sleeved on the side wall of the cylinder body, the plasma ignition device is fixedly connected to the cylinder body, the branch pipe includes a second pulverized coal pipe and a second air supply pipe, the second pulverized coal pipe is connected to the first pulverized coal pipe, and the second air supply pipe is connected to the first air supply pipe;

[0010] One end of the gas delivery pipe is fixedly connected to a first blower, one side of the gas delivery pipe is fixedly connected to a first connecting pipe, the other side of the gas delivery pipe is fixedly connected to a second connecting pipe, one end of the first connecting pipe is fixedly connected to a high-pressure ammonia tank, and one end of the second connecting pipe is fixedly connected to a high-pressure oxygen tank;

[0011] The pulverized coal tank is connected to the second blower through a pipeline, a first feeding pipe is fixedly connected to one side of the pulverized coal tank, a second feeding pipe is fixedly connected to one end of the first feeding pipe, the second feeding pipe has the same structure as the branch pipe, the second pulverized coal pipe of the second feeding pipe is connected to the first feeding pipe and the second pulverized coal pipe of the branch pipe, and the second air delivery pipe of the second feeding pipe is connected to the gas delivery pipe and the second air delivery pipe of the branch pipe.

[0012] A further improvement of the present invention is that a denitration device is provided on one side of the boiler.

[0013] A further improvement of the present invention is that the denitration device comprises a denitration material conveying pipe, a denitration spray gun and a nozzle, one end of the denitration spray gun is fixedly connected to the denitration material conveying pipe, and the other end of the denitration spray gun is fixedly connected to a plurality of nozzles.

[0014] A further improvement of the present invention is that a plurality of guide plates are fixedly connected inside the gas delivery pipe, and the guide plates are arranged in a staggered manner inside the gas delivery pipe.

[0015] A further improvement of the present invention is that a first electronic valve is arranged in the first connecting tube.

[0016] A further improvement of the present invention is that a second electronic valve is arranged in the second connecting tube.

[0017] A further improvement of the present invention is that a third electronic valve is provided in the gas delivery pipe, and the third electronic valve is used to control the amount of wind from the first blower entering the gas delivery pipe.

[0018] A further improvement of the present invention is that a fourth electronic valve is provided in the first pulverized coal pipe.

[0019] A further improvement of the present invention is that a fifth electronic valve is provided in the first air supply pipe.

[0020] An ammonia-blended combustion method for a tangentially pulverized coal boiler system that burns ammonia, based on the tangentially pulverized coal boiler system that burns ammonia, comprising:

[0021] S1. The second blower conveys the pulverized coal in the pulverized coal tank into the first feed pipe, and then the pulverized coal enters the second pulverized coal pipe of the branch pipe through the second pulverized coal pipe of the second feed pipe, and the plasma ignition device ignites the pulverized coal mixed with air, so that the pulverized coal burns in the boiler;

[0022] S2. The first blower supplies air into the gas delivery pipe, and then the airflow of the gas delivery pipe is mixed with the ammonia delivered into the body delivery pipe by the high-pressure ammonia tank and the oxygen delivered into the body delivery pipe by the high-pressure oxygen tank. Since the gas delivery pipe is fixedly connected with a plurality of mutually staggered guide plates, the air ammonia and oxygen in the gas delivery pipe will be fully mixed, and then the oxygen-enriched ammonia is delivered into the boiler through the second air delivery pipe of the branch pipe. Since ammonia can be ignited in an oxygen-rich environment, the ammonia in the branch pipe can be ignited by the plasma ignition device;

[0023] S3. When no ammonia is added for combustion, the first electronic valve and the second electronic valve are used to prevent ammonia and oxygen from being transported into the boiler, respectively. The wind transported into the boiler by the first blower can become secondary air supply, so that the pulverized coal and air are fully mixed, thereby fully burning the pulverized coal;

[0024] S4. By controlling the fourth and fifth electronic valves in the second pulverized coal pipe and the second air supply pipe, the delivery amount of ammonia and pulverized coal of different burners can be controlled, so that the pulverized coal can be burned in three different ways in the boiler: positive pagoda, inverted pagoda and equal air supply;

[0025] S5. Reduce NOx produced by coal powder combustion through denitrification equipment.

[0026] Compared with the prior art, the present invention has at least the following beneficial technical effects:

[0027] 1. In the present invention, oxygen and ammonia are mixed, so that the ammonia is in an oxygen-rich environment, so that the oxygen is fully ignited. By controlling the fourth electronic valve and the fifth electronic valve in different second pulverized coal pipes and the second air supply pipe, the delivery amount of ammonia and pulverized coal of different burners can be controlled, so that the pulverized coal can be burned in three different ways in the boiler: upright pagoda, inverted pagoda and equal air supply.

[0028] 2. In the present invention, when ammonia is not needed for combustion, the first electronic valve and the second electronic valve can be used to prevent ammonia and oxygen from being transported into the boiler respectively. The wind transported into the boiler by the first blower can become secondary air supply, so that the coal powder is fully mixed with the air, thereby making the coal powder fully burnt. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the overall structure of a tangential coal powder boiler system mixed with ammonia combustion according to the present invention;

[0030] Figure 2It is a structural schematic diagram of a combustion device of a tangential coal powder boiler system mixed with ammonia combustion according to the present invention;

[0031] Figure 3 It is a schematic structural diagram of a gas delivery pipe of a square-tangent pulverized coal boiler system for mixing combustion of ammonia gas according to the present invention;

[0032] Figure 4 It is a structural schematic diagram of a denitration device of a tangential coal-fired pulverized coal boiler system mixed with ammonia combustion according to the present invention;

[0033] Figure 5 The present invention is a schematic structural diagram of the branch pipes of a four-corner tangential pulverized coal boiler system that burns ammonia.

[0034] Figure 6 The present invention is a schematic diagram of air supply for a tangentially pulverized coal boiler system that burns ammonia.

[0035] In the figure: 1, boiler; 2, cover plate; 3, combustion device 4, branch pipe; 5, high-pressure ammonia tank; 6, first electronic valve; 7, second electronic valve; 8, gas delivery pipe; 9, first connecting pipe; 10, second connecting pipe; 11, third electronic valve; 12, gas delivery device; 13, first blower; 14, high-pressure oxygen tank; 15, second blower; 16, pulverized coal delivery device; 17, pulverized coal tank; 18, first feeding pipe; 19, second feeding pipe; 20, denitration device; 21, guide plate; 22, denitration material delivery pipe; 23, denitration spray gun; 24, nozzle; 25, cylinder; 26, plasma ignition device; 27, first pulverized coal pipe; 28, box body; 29, fourth electronic valve; 30, fifth electronic valve; 31, first air supply pipe; 32, second pulverized coal pipe; 33, second air supply pipe. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0040] See also Figure 1-6 , the present invention provides a technical solution:

[0041] A four-corner tangential pulverized coal boiler system for burning ammonia gas comprises a boiler 1, a combustion device 3, a gas conveying device 12 and a pulverized coal conveying device 16, wherein the combustion device 3 comprises a branch pipe 4, a cover plate 2, a cylinder 25, a plasma ignition device 26, a first pulverized coal pipe 27, a box body 28, a fourth electronic valve 29, a fifth electronic valve 30 and a first gas supply pipe 31; the gas conveying device 12 comprises a high-pressure ammonia tank 5, a first electronic valve 6, a second electronic valve 7, a gas conveying pipe 8, a first connecting pipe 9, a second connecting pipe 10, a third electronic valve 11, a first blower 13 and a high-pressure oxygen tank 14; the pulverized coal conveying device 16 comprises a second blower 15, a pulverized coal tank 17, a first feeding pipe 18 and a second feeding pipe 19.

[0042] In this embodiment, please refer to Figure 1 and Figure 2 The combustion device 3 is arranged at the four corners of the boiler 1, a plurality of first pulverized coal pipes 27 and a plurality of first air supply pipes 31 are arranged in the cover plate 2, a fourth electronic valve 29 is arranged in the first pulverized coal pipe 27, and a fifth electronic valve 30 is arranged in the first air supply pipe 31, a plurality of box bodies 28 are fixedly connected to one side of the cover plate 2, a cylinder body 25 is fixedly connected to one side of the box body 28, one end of the first pulverized coal pipe 27 and the first air supply pipe 31 are arranged in the cylinder body 25, a plasma ignition device 26 is sleeved on the side wall of the cylinder body 25, and the plasma ignition device 26 is fixedly connected to the cylinder body 25, and the branch pipe 4 includes a second pulverized coal pipe 32 and a second air supply pipe 33, the second pulverized coal pipe 32 is connected to the first pulverized coal pipe 27, and the second air supply pipe 33 is connected to the first air supply pipe 31.

[0043] In this embodiment, please refer to Figure 1 and Figure 3One end of the gas delivery pipe 8 is fixedly connected to a first blower 13, one side of the gas delivery pipe 8 is fixedly connected to a first connecting pipe 9, the other side of the gas delivery pipe 8 is fixedly connected to a second connecting pipe 10, a first electronic valve 6 is arranged in the first connecting pipe 9, a second electronic valve 7 is arranged in the second connecting pipe 10, one end of the first connecting pipe 9 is fixedly connected to a high-pressure ammonia tank 5, one end of the second connecting pipe 10 is fixedly connected to a high-pressure oxygen tank 14, a plurality of guide plates 21 are fixedly connected in the gas delivery pipe 8, the guide plates 21 are staggeredly arranged in the gas delivery pipe 8, a third electronic valve 11 is arranged in the gas delivery pipe 8, and the third electronic valve 11 is used to control the amount of wind from the first blower 13 entering the gas delivery pipe 8.

[0044] In this embodiment, please refer to Figure 1 and Figure 5 The pulverized coal tank 17 is connected to the second blower 15 through a pipeline, a first feeding pipe 18 is fixedly connected to one side of the pulverized coal tank 17, a second feeding pipe 19 is fixedly connected to one end of the first feeding pipe 18, the second feeding pipe 19 has the same structure as the branch pipe 4, the second pulverized coal pipe of the second feeding pipe 19 is connected to the first feeding pipe 18 and the second pulverized coal pipe 32 of the branch pipe 4, and the second air delivery pipe of the second feeding pipe 19 is connected to the gas delivery pipe 8 and the second air delivery pipe 33 of the branch pipe 4.

[0045] In this embodiment, please refer to Figure 1 and Figure 4 A denitration device 20 is provided on one side of the boiler 1, and the denitration device 20 includes a denitration material conveying pipe 22, a denitration spray gun 23 and a nozzle 24. One end of the denitration spray gun 23 is fixedly connected to the denitration material conveying pipe 22, and the other end of the denitration spray gun 23 is fixedly connected to a plurality of nozzles 24.

[0046] Working principle of the present invention: An ammonia-blended combustion method for a tangential coal-fired pulverized boiler system that burns ammonia, comprising the following steps:

[0047] S1. The second blower 15 conveys the pulverized coal in the pulverized coal tank 17 into the first feed pipe 18, and then the pulverized coal enters the second pulverized coal pipe 32 of the branch pipe 4 through the second pulverized coal pipe of the second feed pipe 19, and the plasma ignition device 26 ignites the pulverized coal mixed with air, so that the pulverized coal burns in the boiler 1;

[0048] S2. The first blower 13 blows air into the gas delivery pipe 8, and then the airflow of the gas delivery pipe 8 is mixed with the ammonia delivered into the body delivery pipe 8 by the high-pressure ammonia tank 5 and the oxygen delivered into the body delivery pipe 8 by the high-pressure oxygen tank 14. Since a plurality of mutually staggered guide plates 21 are fixedly connected in the gas delivery pipe 8, the air ammonia and oxygen in the gas delivery pipe 8 will be fully mixed, and then the oxygen-enriched ammonia is delivered into the boiler 1 through the second air delivery pipe 33 of the branch pipe 4. Since ammonia can be ignited in an oxygen-enriched environment, the ammonia in the branch pipe 4 can be ignited by the plasma ignition device 26;

[0049] S3. When ammonia is not used for combustion, the first electronic valve 6 and the second electronic valve 7 can be used to prevent ammonia and oxygen from being transported into the boiler 1, respectively. The wind transported into the boiler 1 by the first blower 13 can become secondary air supply, so that the pulverized coal and air are fully mixed, thereby fully burning the pulverized coal;

[0050] S4. By controlling the fourth electronic valve 29 and the fifth electronic valve 30 in different second pulverized coal pipes 32 and second air supply pipes 33, the delivery amount of ammonia and pulverized coal of different burners can be controlled, so that the pulverized coal can be burned in three different ways in the boiler 1: positive tower, inverted tower and equal air supply;

[0051] S5. Reduce NOx generated by coal powder combustion through the denitrification device 20.

[0052] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tangential coal-fired pulverized coal boiler system with ammonia combustion, characterized in that: It comprises a boiler (1), a combustion device (3), a gas conveying device (12) and a pulverized coal conveying device (16); The combustion device (3) comprises a branch pipe (4), a cover plate (2), a cylinder (25), a plasma ignition device (26), a first pulverized coal pipe (27), a box body (28) and a first air supply pipe (31); The gas delivery device (12) comprises a high-pressure ammonia tank (5), a gas delivery pipe (8), a first connecting pipe (9), a second connecting pipe (10), a first blower (13) and a high-pressure oxygen tank (14); The pulverized coal conveying device (16) comprises a second blower (15), a pulverized coal tank (17), a first feeding pipe (18) and a second feeding pipe (19); The combustion device (3) is arranged at four corners of the boiler (1); a plurality of first pulverized coal pipes (27) and a plurality of first air supply pipes (31) are arranged in the cover plate (2); a plurality of box bodies (28) are fixedly connected to one side of the cover plate (2); a cylinder (25) is fixedly connected to one side of the box body (28); one end of the first pulverized coal pipe (27) and the first air supply pipe (31) are arranged in the cylinder (25); a plasma ignition device (26) is sleeved on the side wall of the cylinder (25); the plasma ignition device (26) is fixedly connected to the cylinder (25); the branch pipe (4) comprises a second pulverized coal pipe (32) and a second air supply pipe (33); the second pulverized coal pipe (32) is connected to the first pulverized coal pipe (27); and the second air supply pipe (33) is connected to the first air supply pipe (31); One end of the gas delivery pipe (8) is fixedly connected to a first blower (13), one side of the gas delivery pipe (8) is fixedly connected to a first connecting pipe (9), the other side of the gas delivery pipe (8) is fixedly connected to a second connecting pipe (10), one end of the first connecting pipe (9) is fixedly connected to a high-pressure ammonia tank (5), and one end of the second connecting pipe (10) is fixedly connected to a high-pressure oxygen tank (14); The pulverized coal tank (17) is connected to the second blower (15) through a pipeline; a first feed pipe (18) is fixedly connected to one side of the pulverized coal tank (17); a second feed pipe (19) is fixedly connected to one end of the first feed pipe (18); the second feed pipe (19) has the same structure as the branch pipe (4); the second pulverized coal pipe of the second feed pipe (19) is connected to the first feed pipe (18) and the second pulverized coal pipe (32) of the branch pipe (4); and the second air delivery pipe of the second feed pipe (19) is connected to the gas delivery pipe (8) and the second air delivery pipe (33) of the branch pipe (4).

2. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 1, characterized in that: A denitration device (20) is provided on one side of the boiler (1).

3. The tangential coal-fired pulverized coal boiler system with ammonia combustion as claimed in claim 2, characterized in that: The denitration device (20) comprises a denitration material conveying pipe (22), a denitration spray gun (23) and a nozzle (24); one end of the denitration spray gun (23) is fixedly connected to the denitration material conveying pipe (22), and the other end of the denitration spray gun (23) is fixedly connected to a plurality of nozzles (24).

4. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 2, characterized in that: A plurality of guide plates (21) are fixedly connected inside the gas delivery pipe (8), and the guide plates (21) are arranged in a staggered manner inside the gas delivery pipe (8).

5. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 4, characterized in that: A first electronic valve (6) is arranged in the first connecting pipe (9).

6. The tangential coal-fired pulverized coal boiler system mixed with ammonia according to claim 5, characterized in that: A second electronic valve (7) is arranged in the second connecting pipe (10).

7. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 6, characterized in that: A third electronic valve (11) is arranged in the gas delivery pipe (8), and the third electronic valve (11) is used to control the amount of wind from the first blower (13) entering the gas delivery pipe (8).

8. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 7, characterized in that: A fourth electronic valve (29) is arranged in the first pulverized coal pipe (27).

9. The tangential coal-fired pulverized coal boiler system with ammonia combustion according to claim 8, characterized in that: A fifth electronic valve (30) is arranged in the first air supply pipe (31).

10. An ammonia-blended combustion method for a tangential coal-fired pulverized boiler system that burns ammonia, characterized in that: The method is based on a tangential coal-fired pulverized coal boiler system mixed with ammonia as described in claim 9, comprising: S1. The second blower (15) conveys the pulverized coal in the pulverized coal tank (17) into the first feed pipe (18), and then the pulverized coal enters the second pulverized coal pipe (32) of the branch pipe (4) through the second pulverized coal pipe of the second feed pipe (19), and the plasma ignition device (26) ignites the pulverized coal mixed with air, so that the pulverized coal burns in the boiler (1); S2. The first blower (13) supplies air into the gas delivery pipe (8), and then the airflow of the gas delivery pipe (8) is mixed with the ammonia delivered into the gas delivery pipe (8) by the high-pressure ammonia tank (5) and the oxygen delivered into the gas delivery pipe (8) by the high-pressure oxygen tank (14). Since a plurality of mutually staggered guide plates (21) are fixedly connected in the gas delivery pipe (8), the ammonia and oxygen in the air in the gas delivery pipe (8) are fully mixed. Then the oxygen-enriched ammonia is delivered into the boiler (1) through the second air delivery pipe (33) of the branch pipe (4). Since ammonia can be ignited in an oxygen-enriched environment, the ammonia in the branch pipe (4) can be ignited by the plasma ignition device (26); S3. When ammonia is not needed for combustion, the first electronic valve (6) and the second electronic valve (7) are used to prevent ammonia and oxygen from being transported into the boiler (1), respectively. The air transported into the boiler (1) by the first blower (13) can become secondary air supply, so that the pulverized coal and air are fully mixed, thereby fully burning the pulverized coal; S4. By controlling the fourth electronic valve (29) and the fifth electronic valve (30) in different second pulverized coal pipes (32) and second air supply pipes (33), the delivery amount of ammonia and pulverized coal to different burners can be controlled, so that the pulverized coal can be burned in three different ways in the boiler (1): positive tower, inverted tower and equal air supply; S5. Reduce NOx generated by coal powder combustion through a denitrification device (20).

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