Micro-hydrogen oxygen-enriched combustion-supporting combustion device and working method thereof

Abstract

The invention belongs to the technical field of flexibility transformation of coal-fired power plant boilers, and discloses a micro-hydrogen oxygen-enriched combustion-supporting combustion device and a working method thereof.The micro-hydrogen oxygen-enriched combustion-supporting combustion device comprises a pulverized coal burner, a hydrogen burner and a pulverized coal pre-combustion chamber, the combustion end of the hydrogen burner extends to the combustion end of the pulverized coal burner, and the pulverized coal pre-combustion chamber is cylindrical; the pulverized coal pre-combustion chamber is coaxially arranged at the combustion end of the hydrogen combustor, and an annular gap is reserved between the inner wall of the pulverized coal pre-combustion chamber and the outer wall of the combustion end of the hydrogen combustor. In the pulverized coal burner, an adjustable baffle is arranged on the upstream portion of the pulverized coal pre-combustion chamber, and the adjustable baffle can guide pulverized coal airflow in the pulverized coal burner into the annular space. By means of the device, safe and stable operation of the coal-fired boiler in the starting and low-load stable combustion process can be achieved, the deep peak regulation capacity of a coal-fired unit is improved, and carbon emission is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of flexibility transformation of coal-fired power station boilers, and specifically relates to a micro-hydrogen-enriched oxygen-assisted combustion device and a working method thereof. Background Art

[0002] Under the "dual carbon" goal, the installed capacity of renewable energy has increased year by year, while the annual utilization hours of coal-fired units have continued to decline. At the same time, due to the instability of renewable energy, coal-fired power units have gradually transformed from electric power sources to regulating power sources, and unit peak regulation has become the new normal. Exploring the deep peak regulation potential of coal-fired units, improving the operating flexibility of coal-fired units, and comprehensively improving the system regulation capabilities are necessary conditions for the future survival of coal-fired power plants. On the other hand, as a major carbon emitter, coal-fired power plants are also subject to carbon reduction transformation. If green hydrogen and green ammonia are directly transported to pulverized coal boilers for blending and utilization, it can not only enhance the minimum peak regulation capacity of the unit, but also provide new ideas for the low-carbon development of coal-fired power.

[0003] At present, there are more and more studies on the coupling of coal-fired boilers with green ammonia, but few have paid attention to the ignition of hydrogen blending and low-load combustion support in pulverized coal boilers. Common ignition and combustion support methods for coal-fired boilers can be divided into plasma ignition, micro-oil ignition, air and pulverized coal preheating ignition, etc., but they all have disadvantages such as single coal adaptability and high carbon emissions. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned existing coal powder ignition technology and provide a micro-hydrogen-rich oxygen-assisted combustion device and its working method. The device of the present invention can realize the safe and stable operation of the coal-fired boiler during startup and low-load stable combustion, improve the deep peak-shaving capacity of the coal-fired unit, and reduce carbon emissions.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A micro-hydrogen-enriched oxygen-assisted combustion device comprises a pulverized coal burner, a hydrogen burner and a pulverized coal pre-combustion chamber, wherein the combustion end of the hydrogen burner extends to the combustion end of the pulverized coal burner, the pulverized coal pre-combustion chamber is cylindrical in shape, and is coaxially arranged at the combustion end of the hydrogen burner, with an annular gap being left between the inner wall of the pulverized coal pre-combustion chamber and the outer wall of the combustion end of the hydrogen burner; in the pulverized coal burner, an adjustable baffle is provided upstream of the pulverized coal pre-combustion chamber, and the adjustable baffle can guide the pulverized coal airflow in the pulverized coal burner into the annular gap.

[0006] Preferably, a bluff block is provided at the outlet end of the pulverized coal precombustion chamber downstream of the hydrogen burner, and the bluff block is arranged opposite to the combustion end of the hydrogen burner.

[0007] Preferably, the shape of the bluff block is elliptical or triangular, and the bluff block is arranged at the outlet plane of the pulverized coal precombustion chamber.

[0008] Preferably, the outer sleeve of the pulverized coal precombustion chamber is provided with a precombustion chamber cooling ring, the end of the precombustion chamber cooling ring facing the hydrogen burner is closed, and the end facing the outlet of the pulverized coal precombustion chamber is the air outlet of the precombustion chamber cooling ring.

[0009] Preferably, a burner cooling ring is sleeved on the outside of the combustion end of the pulverized coal burner, the end of the burner cooling ring away from the furnace is closed, and the end facing the furnace is an air outlet of the burner cooling ring.

[0010] Preferably, the combustion end of the hydrogen burner is arranged at the center of the combustion end of the coal powder burner, and the combustion end of the hydrogen burner extends into the coal powder pre-combustion chamber by a length of 0.1m-0.3m.

[0011] Preferably, several groups of adjustable baffles are evenly distributed around the circumference of the pulverized coal precombustion chamber, each group of adjustable baffles includes several adjustable blocks, and the several adjustable blocks are spaced apart in the axial and radial directions of the pulverized coal precombustion chamber, and each adjustable baffle is adjustable in angle in the direction of pulverized coal airflow of the pulverized coal burner.

[0012] Preferably, the angle between the adjustable stopper and the incoming direction of the coal powder airflow is 10°-60°.

[0013] Preferably, the hydrogen burner is provided with a hydrogen fire detection device and an oxygen content monitoring device, the pulverized coal precombustion chamber is provided with a precombustion chamber wall temperature monitoring device, and the pulverized coal burner is provided with a burner wall temperature monitoring device.

[0014] The present invention also provides a working method of the micro-hydrogen-enriched oxygen-assisted combustion device as described above, comprising the following process: When the micro-hydrogen-enriched oxygen-assisted combustion device is working, the hydrogen burner produces a high-temperature flame, the pulverized coal airflow enters the pulverized coal burner, and is separated into a dense phase pulverized coal airflow and a light phase pulverized coal airflow after being guided by an adjustable baffle. The dense phase pulverized coal airflow enters the pulverized coal pre-combustion chamber and is heated and burned by the high-temperature flame generated by the hydrogen burner. When the flame signal is detected in the coal-fired boiler, it indicates that the micro-hydrogen-enriched oxygen-assisted ignition and combustion is achieved. Then the adjustable baffle angle is adjusted to make the pulverized coal burner enter a normal working state.

[0015] The present invention has the following beneficial effects: When the micro-hydrogen-enriched oxygen combustion-supporting combustion device of the present invention is in operation, the hydrogen sprayed from the hydrogen burner is mixed with oxygen-enriched air to burn and produce an extremely high temperature flame core. The coal powder airflow is separated into two streams of dense and thin airflows after passing through the adjustable baffle. The dense phase coal powder airflow enters the coal powder pre-combustion chamber and is heated and burned by the high temperature flame core. The temperature of the coal powder particles rises sharply, a large amount of volatiles are precipitated and quickly ignites and burns. The high temperature airflow burning in the pre-combustion chamber expands and accelerates to enter the coal powder burner through the coal powder pre-combustion chamber. When the high temperature air flows out of the coal powder pre-combustion chamber, the high temperature gas will diffuse to the surroundings and entrain and heat the light phase coal powder airflow to achieve rapid ignition. The use of an adjustable baffle helps to adjust the dense and thin separation ratio, as well as air with different oxygen-enriched concentrations, so that the burner can adapt to coal powders of different types and calorific values, and realize micro-hydrogen-enriched oxygen ignition and combustion. When the furnace is burning normally, the hydrogen burner is stopped, and the adjustable baffle angle is adjusted to make the coal powder burner enter a normal working state, so that the safety and reliability of the burner are improved, and it can adapt to a variety of operating conditions. In summary, the present invention can use a small amount of hydrogen as an ignition and stabilizing fuel to ignite and heat the first-stage pulverized coal airflow, and then use the heat from the combustion of the first-stage pulverized coal airflow to ignite subsequent pulverized coal airflows, thereby achieving the purpose of ignition and combustion assistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a structural schematic diagram of the present invention; Among them, 1 is a pulverized coal burner, 1-1 is a primary air pulverized pipe, 2 is a hydrogen burner, 2-1 is a hydrogen pipe, 2-2 is a central oxygen-enriched air pipe, 2-3 is an outer oxygen-enriched air pipe, 3 is a pulverized coal precombustion chamber, 4 is an adjustable baffle, 4-1 is an adjustable block, 5-1 is a hydrogen fire detection device, 5-2 is a pulverized coal fire detection device, 6 is a burner cooling ring, 6-1 is a burner cooling ring air inlet, 7 is a precombustion chamber cooling ring, 7-1 is a precombustion chamber cooling ring air inlet, 8 is a blunt body block, 9-1 is a precombustion chamber wall temperature monitoring device, 9-2 is a burner wall temperature monitoring device, 9-3 is an oxygen content monitoring device, and 10 is an annular gap. DETAILED DESCRIPTION

[0018] According to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structures and implementations. Therefore, the following specific implementation methods and drawings are only examples of the technical solution of the present invention and should not be regarded as the entirety of the present invention or the limitation of its technical solution.

[0019] See also Figure 1 The micro-hydrogen-enriched oxygen combustion device of this embodiment includes a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal pre-combustion chamber 3. The combustion end of the hydrogen burner 2 (i.e. Figure 1 The right end shown in FIG. 1 extends to the combustion end of the pulverized coal burner 1 (i.e. Figure 1 As shown in the right end, the pulverized coal precombustion chamber 3 is cylindrical in shape, and the pulverized coal precombustion chamber 3 is coaxially arranged at the combustion end of the hydrogen burner 2. Specifically, the combustion end of the hydrogen burner 2 can be located upstream (i.e., on the left side) of the pulverized coal precombustion chamber 3 or extend into the left end of the pulverized coal precombustion chamber 3 by a certain distance, and an annular gap 10 is left between the inner wall of the pulverized coal precombustion chamber 3 and the outer wall of the combustion end of the hydrogen burner 2; in the pulverized coal burner 1, upstream (i.e., Figure 1 An adjustable baffle 4 is provided (as shown on the left side) which can guide the pulverized coal airflow in the pulverized coal burner 1 into the annular gap 10.

[0020] The working method of the micro-hydrogen-enriched oxygen combustion-supporting combustion device of the above embodiment of the present invention includes the following process: When the micro-hydrogen-enriched oxygen-assisted combustion device is working, the hydrogen burner 2 works to generate a high-temperature flame, the pulverized coal airflow enters the pulverized coal burner 1, and is separated into a dense phase pulverized coal airflow and a light phase pulverized coal airflow after being diverted by the adjustable baffle 4. The dense phase pulverized coal airflow enters the pulverized coal pre-combustion chamber 3 and is heated and burned by the high-temperature flame generated by the hydrogen burner 2. When the flame signal is detected in the coal-fired boiler, it indicates that the micro-hydrogen-enriched oxygen-assisted ignition combustion has been achieved. At this time, the boiler has been ignited normally. Then, the angle of the adjustable baffle 4 is adjusted to make the pulverized coal burner 1 enter a normal working state. The shape of the pulverized coal pre-combustion chamber 3 can be a bottomless cylindrical shape.

[0021] As a preferred embodiment of the present invention, in this embodiment, a bluff block 8 is provided at the outlet end of the pulverized coal precombustion chamber 3 downstream of the hydrogen burner 2, and the bluff block 8 is arranged opposite to the combustion end of the hydrogen burner 2. When the high-temperature gas in the pulverized coal precombustion chamber 3 flows out, the bluff block 8 can enhance the strong entrainment effect of the high-temperature gas at the outlet (i.e., the right end) of the pulverized coal precombustion chamber 3, and can achieve a better heating effect on the light-phase pulverized coal airflow, which is conducive to the full combustion of the pulverized coal and is also conducive to rapid ignition.

[0022] As a preferred embodiment of the present invention, see Figure 1 In this embodiment, the shape of the bluff block 8 is elliptical or triangular, and the bluff block 8 is arranged at the outlet plane of the pulverized coal precombustion chamber 3 .

[0023] As a preferred embodiment of the present invention, see Figure 1In this embodiment, the outer sleeve of the pulverized coal precombustion chamber 3 is provided with a precombustion chamber cooling ring 7, the end of the precombustion chamber cooling ring 7 facing the hydrogen burner 2 is closed, and the end facing the outlet of the pulverized coal precombustion chamber 3 is the air outlet of the precombustion chamber cooling ring 7. The precombustion chamber cooling ring 7 can be used to cool the pulverized coal precombustion chamber 3 and protect the pulverized coal precombustion chamber 3. Among them, the precombustion chamber cooling ring air inlet 7-1 of the precombustion chamber cooling ring 7 is connected to the left end of the precombustion chamber cooling ring 7, and the precombustion chamber cooling ring air inlet 7-1 penetrates the pulverized coal burner 1 in the radial direction to reduce the influence on the flow rate of the pulverized coal in the pulverized coal burner 1.

[0024] As a preferred embodiment of the present invention, see Figure 1 In this embodiment, a burner cooling ring 6 is provided on the outside of the combustion end of the pulverized coal burner 1. The end of the burner cooling ring 6 away from the furnace is closed, and the end facing the furnace is the air outlet of the burner cooling ring 6. The burner cooling ring 6 can be used to cool the ignition end of the pulverized coal burner 1 and extend the service life of the pulverized coal burner 1. The burner cooling ring air inlet 6-1 of the burner cooling ring 6 is arranged at the left end of the burner cooling ring 6.

[0025] As a preferred embodiment of the present invention, see Figure 1 In this embodiment, the combustion end of the hydrogen burner 2 is arranged at the center of the combustion end of the pulverized coal burner 1, and the combustion end of the hydrogen burner 2 extends into the pulverized coal precombustion chamber 3 by a length of 0.1m-0.3m. The extending distance is appropriate and can form a certain negative pressure at the inlet end (i.e., the left end) of the annular gap 10. When the dense pulverized coal airflow enters the annular gap 10, a small-scale entrainment effect can be formed inside the combustion end of the hydrogen burner 2, so that the dense pulverized coal airflow and the high-temperature flame generated by the hydrogen burner 2 are fully mixed, which is beneficial to the temperature increase and combustion of the dense pulverized coal airflow.

[0026] As a preferred embodiment of the present invention, see Figure 1 In this embodiment, several groups of adjustable baffles 4 are evenly distributed in the circumferential direction of the pulverized coal pre-combustion chamber 3, and each group of adjustable baffles 4 includes several adjustable blocks 4-1, which are spaced apart in the axial and radial directions of the pulverized coal pre-combustion chamber 3, and each adjustable block 4-1 is adjustable in angle in the incoming direction of the pulverized coal airflow of the pulverized coal burner 1. Preferably, the angle between the adjustable block 4-1 and the incoming direction of the pulverized coal airflow is 10°-60°, which can achieve a better separation effect of the pulverized coal airflow (i.e., separation into two streams of thick and thin airflows).

[0027] Preferably, the hydrogen burner 2 is provided with a hydrogen fire detection device 5-1 and an oxygen content monitoring device 9-3, the pulverized coal precombustion chamber 3 is provided with a precombustion chamber wall temperature monitoring device 9-1, and the pulverized coal burner 1 is provided with a burner wall temperature monitoring device 9-2.

[0028] Example 1 refer to Figure 1 The micro-hydrogen-enriched oxygen-assisted combustion device of this embodiment includes a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal pre-combustion chamber 3. Among them, the pulverized coal burner 1 includes a primary air pulverized pipe 1-1 and a burner cooling ring 6; the pulverized coal burner 1 is also provided with an adjustable baffle 4, a pulverized coal fire detection device 5-2 and a burner wall temperature monitoring device 9-2; the hydrogen burner 2 includes a hydrogen pipe 2-1, a central oxygen-enriched air pipe 2-2 and an outer oxygen-enriched air pipe 2-3, and the hydrogen burner 2 is also provided with a hydrogen fire detection device 5-1 and an oxygen content monitoring device 9-3; the pulverized coal pre-combustion chamber 3 is cylindrical in shape, with both ends of the pulverized coal pre-combustion chamber 3 open, a pre-combustion chamber cooling ring 7 is provided outside the pulverized coal pre-combustion chamber 3, a blunt body block 8 is provided at the outlet end of the pulverized coal pre-combustion chamber 3, and a pre-combustion chamber wall temperature monitoring device 9-1 is also provided on the pulverized coal pre-combustion chamber 3. Among them, the hydrogen burner 2 is inserted into the entrance of the coal powder pre-combustion chamber 3 in the coal powder burner 1 for a certain distance. After testing, the combustion end of the hydrogen burner 2 extends into the coal powder pre-combustion chamber 3 for a length of 0.1m. The hydrogen pipe 2-1, the central oxygen-enriched air pipe 2-2 and the outer oxygen-enriched air pipe 2-3 are arranged in a concentric annular sleeve. The hydrogen fire detection device 5-1 is arranged horizontally in the central oxygen-enriched air pipe 2-2 to detect whether the hydrogen is ignited. The angle between the adjustable baffle 4 and the flow direction of the coal powder airflow is adjusted according to the type of coal and working conditions. Three groups are set in a single coal powder burner 1, and the number of each group is 3. The three groups of adjustable baffles 4 are arranged in front of the entrance of the coal powder pre-combustion chamber 3, and the three groups of adjustable baffles 4 are evenly distributed in the circumferential direction in front of the entrance of the coal powder pre-combustion chamber 3. The inclination angle of the adjustable baffle is adjustable, and the angle with the flow direction of the coal powder airflow is 10°-60°. The shape of the blunt body block 8 is elliptical and arranged at the center of the outlet plane of the coal powder pre-combustion chamber 3. The coal powder fire detection device 5-2 is arranged obliquely at the combustion end of the coal powder burner 1, which is used to detect whether the main fire is ignited, and is equipped with fire detection cooling wind to prevent burning. The wall surfaces of the coal powder pre-combustion chamber 3 and the coal powder burner 2 are both provided with wall temperature monitoring devices to monitor whether the wall temperature is over-temperature; the central oxygen-enriched air pipe 2-2 and the outer oxygen-enriched air pipe 2-3 are both provided with oxygen content monitoring devices 9-3 to control the oxygen content of the air within the range of 22%-33%. The burner cooling ring 6 is arranged in an annular shape on the outer wall surface of the coal powder burner 1, and the cooling wind enters from the side and then enters the coal powder pre-combustion chamber 3 from the outlet end face; the pre-combustion chamber cooling ring 7 is arranged in an annular shape on the outer wall surface of the coal powder pre-combustion chamber 3, and the cooling wind enters from the side and then enters the coal powder burner 1 from the outlet end face.

[0029] In the specific operation of this embodiment, firstly, oxygen-enriched air with an oxygen concentration of 22%-33% is introduced into the central oxygen-enriched air pipe 2-2 and the outer oxygen-enriched air pipe 2-3 according to the calorific value characteristics of the coal powder, and then the hydrogen gas flow entering from the hydrogen pipe 2-1 is ignited, and the hydrogen and oxygen-enriched air quickly ignite and burn to produce a local high-temperature flame core. After the hydrogen fire detection device 5-1 detects the flame signal, the coal powder airflow enters from the primary air powder pipe 1-1, and is separated into two streams of dense and thin airflows after passing through the adjustable baffle 4. The dense phase coal powder airflow enters the coal powder pre-combustion chamber 3 and is heated and burned by the high-temperature flame core. The mixture is sucked around and heats the thin phase coal powder airflow after passing through the blunt body block 8, until the coal powder fire detection device 5-2 detects the flame signal, and the micro-hydrogen-enriched oxygen ignition and combustion is realized. When the wall temperature rises, cooling air is started to flow. After the wall temperature over-temperature warning is given, the oxygen content of the air in the hydrogen burner 2 is lowered. If the wall temperature continues to rise, the hydrogen burner 2 is stopped, and the angle of the adjustable baffle 4 is adjusted to make the pulverized coal burner 1 enter a normal working state, so that the safety and reliability of the burner is improved and it can adapt to various operating conditions.

[0030] Example 2 refer to Figure 1The micro-hydrogen-enriched oxygen-assisted combustion device of this embodiment includes a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal pre-combustion chamber 3. Among them, the pulverized coal burner 1 includes a primary air pulverized pipe 1-1 and a burner cooling ring 6; the pulverized coal burner 1 is also provided with an adjustable baffle 4, a pulverized coal fire detection device 5-2 and a burner wall temperature monitoring device 9-2; the hydrogen burner 2 includes a hydrogen pipe 2-1, a central oxygen-enriched air pipe 2-2 and an outer oxygen-enriched air pipe 2-3, and the hydrogen burner 2 is also provided with a hydrogen fire detection device 5-1 and an oxygen content monitoring device 9-3; the pulverized coal pre-combustion chamber 3 is cylindrical in shape, with both ends of the pulverized coal pre-combustion chamber 3 open, a pre-combustion chamber cooling ring 7 is provided outside the pulverized coal pre-combustion chamber 3, a blunt body block 8 is provided at the outlet end of the pulverized coal pre-combustion chamber 3, and a pre-combustion chamber wall temperature monitoring device 9-1 is also provided on the pulverized coal pre-combustion chamber 3. Among them, the hydrogen burner 2 is inserted into the entrance of the coal powder precombustion chamber 3 in the coal powder burner 1 for a certain distance. After testing, the combustion end of the hydrogen burner 2 extends into the coal powder precombustion chamber 3 for a length of 0.3m. The hydrogen pipe 2-1, the central oxygen-enriched air pipe 2-2 and the outer oxygen-enriched air pipe 2-3 are arranged in a concentric annular sleeve. The hydrogen fire detection device 5-1 is horizontally arranged in the outer oxygen-enriched air pipe 2-3 to detect whether the hydrogen is ignited. The angle between the adjustable baffle 4 and the flow direction of the coal powder airflow is adjusted according to the type of coal and working conditions. Four groups are set in a single coal powder burner 1, and the number of each group is 4. The four groups of adjustable baffles 4 are arranged in front of the entrance of the coal powder precombustion chamber 3, and the four groups of adjustable baffles 4 are evenly distributed in the circumferential direction in front of the entrance of the coal powder precombustion chamber 3. The inclination angle of the adjustable baffle is adjustable, and the angle with the flow direction of the coal powder airflow is 10°-60°. The bluff block 8 is in the shape of a triangle and is arranged at the center of the outlet plane of the pulverized coal precombustion chamber 3. The pulverized coal fire detection device 5-2 is arranged obliquely at the combustion end of the pulverized coal burner 1 to detect whether the main fire is ignited, and is equipped with fire detection cooling wind to prevent burning. The walls of the pulverized coal precombustion chamber 3 and the pulverized coal burner 2 are both provided with wall temperature monitoring devices to monitor whether the wall temperature is over-temperature; the central oxygen-enriched air pipe 2-2 and the outer oxygen-enriched air pipe 2-3 are both provided with oxygen content monitoring devices 9-3 to control the oxygen content of the air within the range of 22%-33%. The burner cooling ring 6 is arranged in an annular shape on the outer wall of the pulverized coal burner 1, and the cooling wind enters from the side and then enters the pulverized coal precombustion chamber 3 from the outlet end face; the precombustion chamber cooling ring 7 is arranged in an annular shape on the outer wall of the pulverized coal precombustion chamber 3, and the cooling wind enters from the side and then enters the pulverized coal burner 1 from the outlet end face.

[0031] The specific operation of this embodiment is the same as that of embodiment 1.

[0032] The present invention couples hydrogen combustion through a pulverized coal burner. On the one hand, the high-temperature flame core generated by the combustion of hydrogen and oxygen-enriched air is used to ignite the pulverized coal airflow, thereby achieving a step-by-step amplification of the ignition energy, and realizing the purpose of ignition and combustion support under different types of coal and different working conditions. On the other hand, it replaces part of the fossil fuels, and realizes the clean and low-carbon unit. In specific operation, the present invention aims at the problem of unstable combustion under low load during ignition and deep peak regulation of coal-fired boilers, and provides a technical route for direct ignition and stable combustion of micro-hydrogen-enriched oxygen. During the ignition of coal-fired boilers and low-load stable combustion, the device has stable combustion and adaptive functions; during the normal operation of the boiler, it has a load adaptive function. The device has a wide adaptability to coal types and furnace types, and has no special requirements for the primary air powder concentration. The oxygen content of the oxygen-enriched air and the power of the hydrogen burner can be adjusted according to actual conditions, and the device system has high safety and reliability.

[0033] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A micro-hydrogen-enriched oxygen-assisted combustion device, characterized in that: The invention comprises a pulverized coal burner (1), a hydrogen burner (2) and a pulverized coal pre-combustion chamber (3), wherein the combustion end of the hydrogen burner (2) extends to the combustion end of the pulverized coal burner (1), the pulverized coal pre-combustion chamber (3) is cylindrical in shape, the pulverized coal pre-combustion chamber (3) is coaxially arranged at the combustion end of the hydrogen burner (2), and an annular gap (10) is left between the inner wall of the pulverized coal pre-combustion chamber (3) and the outer wall of the combustion end of the hydrogen burner (2); in the pulverized coal burner (1), an adjustable baffle (4) is provided upstream of the pulverized coal pre-combustion chamber (3), and the adjustable baffle (4) can guide the pulverized coal airflow in the pulverized coal burner (1) into the annular gap (10).

2. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: A bluff block (8) is provided at the outlet end of the pulverized coal pre-combustion chamber (3) downstream of the hydrogen burner (2), and the bluff block (8) is arranged opposite to the combustion end of the hydrogen burner (2).

3. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 2, characterized in that: The shape of the bluff block (8) is elliptical or triangular, and the bluff block (8) is arranged at the outlet plane of the pulverized coal pre-combustion chamber (3).

4. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: A precombustion chamber cooling ring (7) is sleeved on the outside of the pulverized coal precombustion chamber (3); one end of the precombustion chamber cooling ring (7) facing the hydrogen burner (2) is closed, and the end facing the outlet of the pulverized coal precombustion chamber (3) is an air outlet of the precombustion chamber cooling ring (7).

5. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: A burner cooling ring (6) is sleeved on the outside of the combustion end of the pulverized coal burner (1); one end of the burner cooling ring (6) away from the furnace is closed, and the end facing the furnace is an air outlet of the burner cooling ring (6).

6. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: The combustion end of the hydrogen burner (2) is arranged at the center of the combustion end of the pulverized coal burner (1), and the combustion end of the hydrogen burner (2) extends into the pulverized coal pre-combustion chamber (3) by a length of 0.1 m to 0.3 m.

7. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: A plurality of groups of adjustable baffles (4) are evenly distributed in the circumferential direction of the pulverized coal pre-combustion chamber (3), each group of adjustable baffles (4) comprising a plurality of adjustable baffle blocks (4-1), the plurality of adjustable baffle blocks (4-1) being distributed at intervals in the axial and radial directions of the pulverized coal pre-combustion chamber (3), and each adjustable baffle block (4-1) is adjustable in angle in the incoming direction of the pulverized coal airflow of the pulverized coal burner (1).

8. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 7, characterized in that: The angle between the adjustable stopper (4-1) and the incoming direction of the coal powder airflow is 10°-60°.

9. A micro-hydrogen-enriched oxygen-assisted combustion device according to claim 1, characterized in that: The hydrogen burner (2) is provided with a hydrogen fire detection device (5-1) and an oxygen content monitoring device (9-3), the pulverized coal precombustion chamber (3) is provided with a precombustion chamber wall temperature monitoring device (9-1), and the pulverized coal burner (1) is provided with a burner wall temperature monitoring device (9-2).

10. The working method of the micro-hydrogen-enriched oxygen-assisted combustion device according to any one of claims 1 to 9, characterized in that: The process includes the following: When the micro-hydrogen-enriched oxygen-assisted combustion device is in operation, the hydrogen burner (2) operates to generate a high-temperature flame, the pulverized coal airflow enters the pulverized coal burner (1), and is separated into a dense phase pulverized coal airflow and a light phase pulverized coal airflow after being guided by the adjustable baffle (4). The dense phase pulverized coal airflow enters the pulverized coal pre-combustion chamber (3) and is heated and burned by the high-temperature flame generated by the hydrogen burner (2). When a flame signal is detected in the coal-fired boiler, it indicates that micro-hydrogen-enriched oxygen-assisted ignition combustion has been achieved. Then, the angle of the adjustable baffle (4) is adjusted to allow the pulverized coal burner (1) to enter a normal working state.

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