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

Abstract

The present application belongs to the technical field of flexible transformation of coal-fired power plant boilers, and discloses a micro-hydro oxygen-enriched combustion-supporting combustion device and a working method thereof, which comprises a pulverized coal burner, a hydrogen burner and a pulverized coal precombustion chamber, the combustion end of the hydrogen burner extends to the combustion end of the pulverized coal burner, the shape of the pulverized coal precombustion chamber is cylindrical, the pulverized coal precombustion chamber is coaxially arranged at the combustion end of the hydrogen burner, and an annular gap is left between the inner wall of the pulverized coal precombustion chamber and the outer wall of the combustion end of the hydrogen burner; in the pulverized coal burner, an adjustable baffle is arranged upstream of the pulverized coal precombustion chamber, and the adjustable baffle can guide the flow of pulverized coal in the pulverized coal burner into the annular gap. The device can realize 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.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of flexible transformation of coal-fired power plant boilers, and particularly relates to a micro-hydro oxygen-enriched combustion supporting device and a working method thereof. BACKGROUND

[0002] At present, the installed capacity of renewable energy is increasing year by year, while the annual utilization hours of coal-fired units continue to decline. At the same time, due to the instability of renewable energy, coal-fired units gradually change from power-type power sources to regulating power sources, and unit peak regulation has become the new normal. It is necessary for coal-fired power plants to survive in the future to tap the potential of deep peak regulation of coal-fired units, improve the operational flexibility of coal-fired units, and comprehensively improve the system regulation capability. On the other hand, as a major carbon emitter, coal-fired power plants are also subject to carbon reduction. If green hydrogen and green ammonia are directly delivered to the pulverized coal boiler for blending and burning, it can not only enhance the minimum peak regulation capacity of the unit, but also provide a new way for the low-carbon development of coal power.

[0003] At present, there are increasing studies on the coupling of coal-fired boilers with green ammonia, but few attention is paid to the ignition and combustion support of hydrogen in pulverized coal boilers. The 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 the disadvantages of single coal adaptability and high carbon emissions. SUMMARY

[0004] The present application aims to overcome the shortcomings of the above-mentioned existing pulverized coal ignition technology, and provides a micro-hydro oxygen-enriched combustion supporting device and a working method thereof. The device can realize the safe and stable operation of the coal-fired boiler during startup and low-load stable combustion, improve the deep peak regulation capacity of the coal-fired unit, and reduce carbon emissions.

[0005] To achieve the above-mentioned purpose, the technical solutions adopted by the present application are as follows:

[0006] A micro-hydro oxygen-enriched combustion supporting device, comprising a pulverized coal burner, a hydrogen burner and a pulverized coal precombustion chamber, the combustion end of the hydrogen burner extends to the combustion end of the pulverized coal burner, the shape of the pulverized coal precombustion chamber is cylindrical, the pulverized coal precombustion chamber is coaxially arranged at the combustion end of the hydrogen burner, and an annular gap is left between the inner wall of the pulverized coal precombustion chamber and the outer wall of the combustion end of the hydrogen burner; an adjustable baffle is arranged upstream of the pulverized coal precombustion chamber in the pulverized coal burner, and the adjustable baffle can guide the pulverized coal gas flow in the pulverized coal burner into the annular gap.

[0007] Preferably, a bluff body block is arranged downstream of the hydrogen burner at the outlet end of the pulverized coal precombustion chamber, and the bluff body block is arranged opposite to the combustion end of the hydrogen burner.

[0008] Preferably, the shape of the bluff body block is oval or triangular, and the bluff body block is arranged at the outlet plane of the pulverized coal precombustion chamber.

[0009] Preferably, the coal powder precombustion chamber is externally sleeved with a precombustion chamber cooling ring, one end of the precombustion chamber cooling ring is closed towards the hydrogen gas burner, and the other end is an air outlet of the precombustion chamber cooling ring.

[0010] Preferably, the coal powder burner combustion end is externally sleeved with a burner cooling ring, one end of the burner cooling ring is closed away from the furnace, and the other end is an air outlet of the burner cooling ring.

[0011] Preferably, the hydrogen gas burner combustion end is arranged at the center of the coal powder burner combustion end, and the hydrogen gas burner combustion end extends into the coal powder precombustion chamber by a length of 0.1m-0.3m.

[0012] Preferably, a plurality of groups of adjustable baffles are uniformly distributed in the circumferential direction of the coal powder precombustion chamber, each group of adjustable baffles comprises a plurality of adjustable blocks, the plurality of adjustable blocks are spaced apart in the axial and radial directions of the coal powder precombustion chamber, and each adjustable baffle is adjustable in angle in the incoming flow direction of the coal powder gas flow of the coal powder burner.

[0013] Preferably, the angle between the adjustable block and the incoming flow direction of the coal powder gas flow is 10°-60°.

[0014] Preferably, the hydrogen gas burner is provided with a hydrogen gas flame detection device and an oxygen content monitoring device, the coal powder precombustion chamber is provided with a precombustion chamber wall temperature monitoring device, and the coal powder burner is provided with a burner wall temperature monitoring device.

[0015] The application also provides a working method of the micro-hydro oxygen-enriched combustion-supporting combustion device as described above, comprising the following processes:

[0016] When the micro-hydro oxygen-enriched combustion-supporting combustion device works, the hydrogen gas burner works to generate a high-temperature flame, the coal powder gas flow enters the coal powder burner and is separated into a dense-phase coal powder gas flow and a dilute-phase coal powder gas flow after being guided by the adjustable baffles, the dense-phase coal powder gas flow is heated and combusted by the high-temperature flame generated by the hydrogen gas burner after entering the coal powder precombustion chamber, when a flame signal is detected in the coal-fired boiler, it indicates that the micro-hydro oxygen-enriched ignition combustion-supporting combustion is realized, and then the angle of the adjustable baffles is adjusted to make the coal powder burner enter a normal working state.

[0017] The application has the following beneficial effects:

[0018] The micro-hydro oxygen-rich combustion supporting combustion device in the application, in specific work, hydrogen gas sprayed by the hydrogen gas burner mixes with oxygen-rich air to produce an extremely high-temperature flame core, the coal powder gas flow is separated into two gas flows with different densities after passing through the adjustable baffle, the dense-phase coal powder gas flow is heated and combusted by the high-temperature flame core after entering the coal powder precombustion chamber, the temperature of the coal powder particles rises sharply, a large amount of volatile components are separated out and rapidly combusted. The high-temperature gas flow combusted in the precombustion chamber expands and accelerates through the coal powder precombustion chamber into the coal powder burner, when the high-temperature gas flow exits the coal powder precombustion chamber, the high-temperature gas diffuses to the four directions and absorbs and heats the dilute-phase coal powder gas flow, realizing rapid ignition. The adjustable baffle helps to adjust the separation ratio of the dense and dilute phases, and the air with different oxygen-rich concentrations, so that the burner can adapt to different types and calorific values of coal powder, realizing micro-hydro oxygen-rich ignition and combustion supporting combustion. When the furnace is normally combusted, the hydrogen gas burner stops working, the angle of the adjustable baffle is adjusted, the coal powder burner enters the normal working state, the safety and reliability of the burner are improved, and a plurality of operating conditions can be adapted. In summary, a small amount of hydrogen gas can be used as an ignition and stable combustion fuel to ignite and heat the first-stage coal powder gas flow, the heat generated by the combustion of the first-stage coal powder gas flow is used to ignite the subsequent coal powder gas flow, achieving the purpose of ignition and combustion supporting. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0020] Figure 1 The structure of the present application is shown in the figure;

[0021] Among them, 1 is the coal powder burner, 1-1 is the primary air powder pipe, 2 is the hydrogen gas burner, 2-1 is the hydrogen gas pipe, 2-2 is the central oxygen-rich air pipe, 2-3 is the outer oxygen-rich air pipe, 3 is the coal powder precombustion chamber, 4 is the adjustable baffle, 4-1 is the adjustable baffle block, 5-1 is the hydrogen gas flame detection device, 5-2 is the coal powder flame detection device, 6 is the burner cooling ring, 6-1 is the burner cooling ring air inlet, 7 is the precombustion chamber cooling ring, 7-1 is the precombustion chamber cooling ring air inlet, 8 is the blunt block, 9-1 is the precombustion chamber wall temperature monitoring device, 9-2 is the burner wall temperature monitoring device, 9-3 is the oxygen content monitoring device, and 10 is the annular gap. DETAILED DESCRIPTION

[0022] According to the technical solutions of the present application, those skilled in the art can propose a plurality of structures and implementation manners which can be replaced with each other without changing the essential spirit of the present application. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solutions of the present application, and should not be regarded as the whole or limitation of the technical solutions of the present application.

[0023] Referring to Figure 1 , the micro-hydro oxygen-enriched combustion supporting combustion device comprises a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal precombustion chamber 3. The combustion end (i.e. the right end shown in the figure) of the hydrogen burner 2 extends to the combustion end (i.e. the right end shown in the figure) of the pulverized coal burner 1. The pulverized coal precombustion chamber 3 is in the shape of a cylinder. 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. left side) of the pulverized coal precombustion chamber 3 or extend into the pulverized coal precombustion chamber 3 by a certain distance. 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, an adjustable baffle 4 is arranged upstream (i.e. left side shown in the figure) of the pulverized coal precombustion chamber 3. The adjustable baffle 4 can guide the pulverized coal gas flow in the pulverized coal burner 1 into the annular gap 10. Figure 1 Figure 1 Figure 1

[0024] The working method of the micro-hydro oxygen-enriched combustion supporting combustion device according to the above embodiment of the present application comprises the following processes:

[0025] When the micro-hydro oxygen-enriched combustion supporting combustion device is working, the hydrogen burner 2 generates high-temperature flame. The pulverized coal gas flow enters the pulverized coal burner 1 and is separated into dense-phase pulverized coal gas flow and dilute-phase pulverized coal gas flow after being guided by the adjustable baffle 4. The dense-phase pulverized coal gas flow is heated and combusted by the high-temperature flame generated by the hydrogen burner 2 after entering the pulverized coal precombustion chamber 3. When the flame signal is detected in the coal-fired boiler, it indicates that the micro-hydro oxygen-enriched ignition combustion supporting combustion is realized. At this time, the boiler has been normally ignited. Then, the angle of the adjustable baffle 4 is adjusted so that the pulverized coal burner 1 enters the normal working state. The shape of the pulverized coal precombustion chamber 3 can be specifically a cylinder without a bottom.

[0026] As a preferred embodiment of the present application, in the present embodiment, a blunt block 8 is arranged at the outlet end of the pulverized coal precombustion chamber 3 downstream of the hydrogen burner 2. The blunt 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 high-temperature gas can form a relatively strong entrainment effect at the outlet (i.e. right end) of the pulverized coal precombustion chamber 3 by the arranged blunt block 8, which can better heat the dilute-phase pulverized coal gas flow, which is conducive to the full combustion of the pulverized coal and further conducive to rapid ignition.

[0027] As a preferred embodiment of the present application, referring to Figure 1 , in the present embodiment, the shape of the blunt block 8 is oval or triangular. The blunt block 8 is arranged at the outlet plane of the pulverized coal precombustion chamber 3.

[0028] As a preferred embodiment of the present application, referring to Figure 1 ​​​In the embodiment, the coal powder pre-combustion chamber 3 is externally sleeved with a pre-combustion chamber cooling ring 7, one end of the pre-combustion chamber cooling ring 7 is closed and the other end is an air outlet of the pre-combustion chamber cooling ring 7. The pre-combustion chamber cooling ring 7 can cool the coal powder pre-combustion chamber 3 and protect the coal powder pre-combustion chamber 3. The pre-combustion chamber cooling ring air inlet 7-1 of the pre-combustion chamber cooling ring 7 is in communication with the left end of the pre-combustion chamber cooling ring 7 and penetrates in the radial direction of the coal powder combustor 1 to reduce the influence on the flow rate of the coal powder in the coal powder combustor 1.

[0029] As a preferred embodiment of the present application, refer to Figure 1 In the embodiment, the coal powder combustor 1 is externally sleeved with a combustor cooling ring 6, one end of the combustor cooling ring 6 is closed and the other end is an air outlet of the combustor cooling ring 6. The combustor cooling ring 6 can cool the ignition end of the coal powder combustor 1, prolong the service life of the coal powder combustor 1, and the combustor cooling ring air inlet 6-1 of the combustor cooling ring 6 is arranged at the left end of the combustor cooling ring 6.

[0030] As a preferred embodiment of the present application, refer to Figure 1 In the embodiment, the combustion end of the hydrogen combustor 2 is arranged at the center of the combustion end of the coal powder combustor 1 and the length of the combustion end of the hydrogen combustor 2 extending into the coal powder pre-combustion chamber 3 is 0.1m-0.3m. The appropriate length of the extending end can form a certain negative pressure at the inlet end (i.e. the left end) of the annular gap 10, and when the dense phase coal powder gas flow enters the annular gap 10, a small range of entrainment effect can be formed inside the combustion end of the hydrogen combustor 2, so that the dense phase coal powder gas flow and the high-temperature flame generated by the hydrogen combustor 2 can be fully mixed, thereby facilitating the temperature rise and combustion of the dense phase coal powder gas flow.

[0031] As a preferred embodiment of the present application, refer to Figure 1 In the embodiment, a plurality of groups of adjustable baffles 4 are uniformly distributed in the circumferential direction of the coal powder pre-combustion chamber 3, each group of adjustable baffles 4 includes a plurality of adjustable baffle blocks 4-1, and the plurality of adjustable baffle blocks 4-1 are spaced apart in the axial and radial directions of the coal powder pre-combustion chamber 3. The angle of each adjustable baffle block 4-1 in the direction of the coal powder gas flow of the coal powder combustor 1 is adjustable. Preferably, the angle between the adjustable baffle block 4-1 and the direction of the coal powder gas flow is 10°-60°, which can achieve a better separation (i.e. separation into two gas flows) effect on the coal powder gas flow.

[0032] Preferably, the hydrogen combustor 2 is provided with a hydrogen flame detection device 5-1 and an oxygen monitoring device 9-3, the coal powder pre-combustion chamber 3 is provided with a pre-combustion chamber wall temperature monitoring device 9-1, and the coal powder combustor 1 is provided with a combustor wall temperature monitoring device 9-2.

[0033] Embodiment 1

[0034] Reference Figure 1 The micro-hydro oxygen-enriched combustion supporting device comprises a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal pre-combustion chamber 3. The pulverized coal burner 1 comprises a primary air pulverized coal pipe 1-1 and a burner cooling ring 6. The pulverized coal burner 1 is further 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 comprises a hydrogen pipe 2-1, a central oxygen-enriched air pipe 2-2 and an outer oxygen-enriched air pipe 2-3. The hydrogen burner 2 is further 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 in a cylindrical shape, and the two ends of the pulverized coal pre-combustion chamber 3 are open. The pulverized coal pre-combustion chamber 3 is externally provided with a pre-combustion chamber cooling ring 7, and the outlet end of the pulverized coal pre-combustion chamber 3 is provided with a blunt body block 8. The pulverized coal pre-combustion chamber 3 is further provided with a pre-combustion chamber wall temperature monitoring device 9-1. The hydrogen burner 2 is inserted into the inlet of the pulverized coal pre-combustion chamber 3 of the pulverized coal burner 1 by a certain distance. According to tests, the length of the combustion end of the hydrogen burner 2 extending into the pulverized coal pre-combustion chamber 3 is 0.1 m. 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 type. The hydrogen fire detection device 5-1 is horizontally arranged in the central oxygen-enriched air pipe 2-2 and used for detecting whether the hydrogen is ignited. The angle between the adjustable baffle 4 and the direction of the incoming pulverized coal gas flow is adjusted according to the coal type and working conditions. Three groups of adjustable baffles 4 are arranged in each single pulverized coal burner 1, and each group comprises three baffles. The three groups of adjustable baffles 4 are arranged in front of the inlet of the pulverized coal pre-combustion chamber 3, and are evenly distributed in the circumferential direction in front of the inlet of the pulverized coal pre-combustion chamber 3. The inclination angle of the adjustable baffles can be adjusted, and the angle between the adjustable baffles and the direction of the incoming pulverized coal gas flow is 10°-60°. The blunt body block 8 is in an elliptical shape and is arranged at the center of the outlet plane of the pulverized coal pre-combustion chamber 3. The pulverized coal fire detection device 5-2 is obliquely arranged at the combustion end of the pulverized coal burner 1 and used for detecting whether the main fire is ignited. The pulverized coal fire detection device 5-2 is provided with a fire detection cooling air to prevent burning. The wall surfaces of the pulverized coal pre-combustion chamber 3 and the pulverized coal burner 2 are provided with wall temperature monitoring devices for monitoring 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 provided with oxygen content monitoring devices 9-3 for controlling the oxygen content of the air to be within the range of 22%-33%. The burner cooling ring 6 is annularly arranged on the outer wall surface of the pulverized coal burner 1. The cooling air enters from the side and then enters the pulverized coal pre-combustion chamber 3 from the outlet end surface. The pre-combustion chamber cooling ring 7 is annularly arranged on the outer wall surface of the pulverized coal pre-combustion chamber 3. The cooling air enters from the side and then enters the pulverized coal burner 1 from the outlet end surface.

[0035] In the specific operation of the embodiment, first, according to the calorific value characteristics of the pulverized coal, oxygen-enriched air with an oxygen concentration of 22%-33% is introduced into the central oxygen-enriched air pipe 2-2 and the outer layer oxygen-enriched air pipe 2-3, and then the hydrogen gas flow introduced by the hydrogen gas pipe 2-1 is ignited, and the hydrogen gas and the oxygen-enriched air are rapidly ignited and burned to generate a local high-temperature flame core. After the hydrogen fire detection device 5-1 detects the flame signal, the pulverized coal gas flow enters from the primary air pulverized coal pipe 1-1, is separated into two gas flows with different concentrations after the adjustable baffle 4, and the dense phase pulverized coal gas flow enters the pulverized coal pre-combustion chamber 3 and is heated and burned by the high-temperature flame core. The mixture is rolled up and absorbs the dilute phase pulverized coal gas flow around the blunt body block 8, until the pulverized coal fire detection device 5-2 detects the flame signal, and the micro-hydrogen oxygen-enriched ignition combustion is realized. When the wall temperature rises, the cooling air is introduced, and when the wall temperature exceeds the warning temperature, the oxygen content of the air in the hydrogen gas burner 2 is reduced, and if the wall temperature continues to rise, the hydrogen gas burner 2 is stopped, and the angle of the adjustable baffle 4 is adjusted to make the pulverized coal burner 1 enter the normal working state, so that the safety and reliability of the burner are improved, and various operating conditions can be adapted.

[0036] Example 2

[0037] Reference Figure 1The micro-hydro oxygen-enriched combustion supporting device comprises a pulverized coal burner 1, a hydrogen burner 2 and a pulverized coal pre-combustion chamber 3. The pulverized coal burner 1 comprises a primary air pulverized coal pipe 1-1 and a burner cooling ring 6. The pulverized coal burner 1 is further provided with adjustable baffles 4, a pulverized coal fire detection device 5-2 and a burner wall temperature monitoring device 9-2. The hydrogen burner 2 comprises a hydrogen pipe 2-1, a central oxygen-enriched air pipe 2-2 and an outer oxygen-enriched air pipe 2-3. The hydrogen burner 2 is further 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 in a cylindrical shape, and the two ends of the pulverized coal pre-combustion chamber 3 are open. The pulverized coal pre-combustion chamber 3 is externally provided with a pre-combustion chamber cooling ring 7, and the outlet end of the pulverized coal pre-combustion chamber 3 is provided with a blunt body block 8. The pulverized coal pre-combustion chamber 3 is further provided with a pre-combustion chamber wall temperature monitoring device 9-1. The hydrogen burner 2 is inserted into the inlet of the pulverized coal pre-combustion chamber 3 of the pulverized coal burner 1 by a certain distance. According to tests, the length of the hydrogen burner 2 combustion end extending into the pulverized coal pre-combustion chamber 3 is 0.3 m. 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 type. The hydrogen fire detection device 5-1 is horizontally arranged in the outer oxygen-enriched air pipe 2-3 and used for detecting whether the hydrogen is ignited. The angle between the adjustable baffles 4 and the coal powder air flow direction is adjusted according to the coal type and working conditions. Four groups of adjustable baffles 4 are arranged in the single pulverized coal burner 1, and each group comprises four baffles. The four groups of adjustable baffles 4 are arranged in front of the inlet of the pulverized coal pre-combustion chamber 3, and are evenly distributed in the circumferential direction in front of the inlet of the pulverized coal pre-combustion chamber 3. The adjustable baffles have adjustable inclination angles, and the angle between the adjustable baffles and the coal powder air flow direction is 10°-60°. The blunt body block 8 is in a triangular shape and is arranged at the center of the outlet plane of the pulverized coal pre-combustion chamber 3. The pulverized coal fire detection device 5-2 is obliquely arranged at the combustion end of the pulverized coal burner 1 and used for detecting whether the main fire is ignited. The pulverized coal fire detection device 5-2 is provided with a fire detection cooling air to prevent burning. The wall temperature monitoring devices are arranged on the wall surfaces of the pulverized coal pre-combustion chamber 3 and the pulverized coal burner 2 and used for monitoring 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 provided with oxygen content monitoring devices 9-3, and the oxygen content of the air is controlled to be within the range of 22%-33%. The burner cooling ring 6 is annularly arranged on the outer wall surface of the pulverized coal burner 1. The cooling air enters from the side and then enters the pulverized coal pre-combustion chamber 3 from the outlet end surface. The pre-combustion chamber cooling ring 7 is annularly arranged on the outer wall surface of the pulverized coal pre-combustion chamber 3. The cooling air enters from the side and then enters the pulverized coal burner 1 from the outlet end surface.

[0038] In the specific operation of the embodiment, the process is the same as that of embodiment 1.

[0039] The present application couples hydrogen combustion with the coal powder burner, on the one hand, the high-temperature flame core generated by hydrogen and oxygen-enriched air combustion is used to ignite the coal powder gas flow, the ignition energy is amplified step by step, the purpose of ignition and combustion supporting under different coal types and different working conditions is achieved, on the other hand, part of fossil fuels is replaced, and the unit is clean and low-carbon. In the specific operation, aiming at the problem of unstable combustion of coal-fired boiler ignition and deep peak load under low load, a micro-hydrogen oxygen-enriched direct ignition stable combustion technical route is given, which has the functions of stable combustion and self-adaption during the ignition and low load stable combustion of the coal-fired boiler, and has the function of load self-adaption during the normal operation of the boiler. The device has 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 the actual situation, and the device system is safe and reliable.

[0040] Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0041] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by the same, without departing from the spirit and scope of the present application. Any modification or equivalent replacement, which does not depart from the spirit and scope of the present application, should be covered in the protection scope of the claims of the present application.

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 hydrogen burner (2) comprises a central oxygen-enriched air pipe (2-2), a hydrogen pipe (2-1) and an outer oxygen-enriched air pipe (2-3) arranged in sequence from the inside to the outside, the hydrogen burner (2) is inserted into the pulverized coal burner (1), and the combustion end of the hydrogen burner (2) extends to the combustion end of the pulverized coal burner (1), and the pulverized coal pre-combustion chamber (3) is arranged on the pulverized coal burner (1). In the embodiment, the pulverized coal precombustion chamber (3) is cylindrical in shape, the pulverized coal precombustion 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 precombustion 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 precombustion chamber (3), and the adjustable baffle (4) can guide the pulverized coal airflow in the pulverized coal burner (1) into the annular gap (10); The pulverized coal airflow is separated into two streams, dense and thin, after passing through the adjustable baffle (4). The dense phase pulverized coal airflow enters the pulverized coal pre-combustion chamber (3) and is heated and burned by a high-temperature flame generated by the combustion of a mixture of hydrogen and oxygen-enriched air.

2. A micro-hydrogen-enriched oxygen-supported 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-supported 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-supported combustion device according to claim 1, characterized in that: A precombustion chamber cooling ring (7) is provided 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-supported combustion device according to claim 1, characterized in that: A burner cooling ring (6) is provided 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 0.1m-0.3m.

7. A micro-hydrogen-enriched oxygen-supported combustion device according to claim 1, characterized in that: Several groups of adjustable baffles (4) are evenly distributed in the circumferential direction of the pulverized coal precombustion chamber (3), each group of adjustable baffles (4) includes several adjustable blocks (4-1), the several adjustable blocks (4-1) are spaced apart in the axial and radial directions of the pulverized coal precombustion chamber (3), and the angle of each adjustable block (4-1) is adjustable in the incoming direction of the pulverized coal airflow of the pulverized coal burner (1).

8. A micro-hydrogen-enriched oxygen-supported 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. The 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 quantity 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 operating method of the micro-hydrogen-enriched oxygen-supported 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 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 a flame signal is detected in the coal-fired boiler, it indicates that micro-hydrogen-enriched oxygen-assisted ignition combustion has been achieved, and 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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