Hydrogen burner and hydrogen-doped combustion system of coal-fired unit

Abstract

According to the hydrogen burner, the three pipe bodies are sequentially arranged from inside to outside in a sleeving mode to form the rotational flow combustion-supporting air channel, the second gas channel and the direct flow combustion-supporting air channel, the three diffusion barrels are connected to the ends of the three pipe bodies correspondingly, and the axial lengths of outlets of the three diffusion barrels are sequentially increased from inside to outside. And a hydrogen spray pipe and an ignition gun are arranged in the innermost pipe body. In the working process, hydrogen of the hydrogen spray pipe is mixed with rotational flow combustion-supporting gas of the rotational flow combustion-supporting air channel, and the mixture is ignited by the ignition gun. And the ignited high-temperature gas in the diffusion cylinder is in a high-speed rotating state and entrains the hydrogen and ammonia gas in the second gas channel for mixing. And then the gas is mixed with direct-current combustion-supporting gas of the direct-current combustion-supporting air According to the hydrogen burner, rotational flow and direct flow combustion-supporting gas is mixed in a staged mode and burnt in a staged and staged mode, ammonia gas is used as gas for adjusting hydrogen combustion activity, the hydrogen combustion speed is slowed down, the flame length is increased, and safe and stable combustion is facilitated. The invention further provides a hydrogen-doped combustion system of the coal-fired unit.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen energy utilization, and particularly relates to a hydrogen burner and a hydrogen-doped combustion system for a coal-fired unit. Background Art

[0002] With the country's high attention to the hydrogen energy industry, the "Medium- and Long-Term Development Plan for the Hydrogen Energy Industry (2021-2035)" issued in 2022 clarified the strategic position of the hydrogen energy industry and listed it as a key development direction for strategic emerging industries and future industries. On this basis, documents such as the "Energy Conservation and Carbon Reduction Action Plan (2024-2025)" were successively issued in 2024 to vigorously promote the full-chain development of "hydrogen production, storage, transportation, and utilization" of hydrogen energy.

[0003] In China's energy structure, coal-fired power generation units are one of the main sources of carbon emissions, and their CO2 emissions account for about 34% of China's total CO2 emissions. Therefore, how to organically combine hydrogen energy with coal-fired units to achieve stable, clean, and efficient co-combustion of hydrogen energy in coal-fired units is of crucial significance for reducing the carbon emissions of coal-fired units and promoting the green and low-carbon transformation of China's energy application, and its impact will profoundly change the future of China's energy application.

[0004] Hydrogen itself has unique combustion characteristics. Its flammable limit range is relatively wide, from 4.0% to 74.2%. The flame propagation speed is extremely fast, reaching hundreds of meters or even more than a thousand meters per second, and the flame temperature is extremely high, above 2000°C. When hydrogen is co-combusted with coal, on the one hand, it helps to reduce the carbon emissions generated by coal combustion, and on the other hand, it can achieve stable combustion of the coal-fired boiler at low loads. However, there are also some problems with hydrogen combustion, such as early ignition, short flame length, and high local flame peak temperature. These problems may lead to burner burnout and a large amount of thermal NOx generated in the local high-temperature area, thus affecting the stability and environmental protection of the combustion process.

[0005] Currently, in response to these problems, the prior art has proposed a solution of mixing non-combustible gases (such as nitrogen or CO2) into hydrogen to slow down the combustion speed, increase the flame length, and reduce the flame peak temperature. However, nitrogen and CO2 themselves do not have combustion activity, and mixing them may have an adverse impact on combustion stability. Moreover, nitrogen is also one of the main sources of thermal NOx, which to a certain extent limits the application effect of this solution. Summary of the Invention

[0006] The purpose of the present invention is to provide a hydrogen burner and a hydrogen-doped combustion system for a coal-fired unit, using ammonia as a gas to adjust the combustion activity of hydrogen, slowing down the hydrogen combustion speed, increasing the flame length, and being conducive to safe and stable combustion.

[0007] To solve the above technical problems, the present invention provides a hydrogen burner, comprising: a first pipe body, a second pipe body, and a third pipe body, a hydrogen nozzle, a ignition gun, a first diffuser, a second diffuser, and a third diffuser, which are arranged from outside to inside in sequence. The first pipe body, the second pipe body, and the third pipe body are all straight pipes, and the first diffuser, the second diffuser, and the third diffuser are all divergent pipes;

[0008] The first ends of the first diffuser, the second diffuser, and the third diffuser are respectively connected to the second ends of the third pipe body, the second pipe body, and the first pipe body. The hydrogen nozzle and the ignition gun are both located in the inner cavity of the third pipe body;

[0009] A DC combustion-supporting air channel for introducing DC combustion-supporting gas is formed between the first pipe body and the second pipe body. A second gas channel for introducing a mixed gas of hydrogen and ammonia is formed between the second pipe body and the third pipe body. A swirling combustion-supporting air channel for introducing swirling combustion-supporting gas is formed between the third pipe body and the hydrogen nozzle. The hydrogen nozzle has a first gas channel for introducing hydrogen;

[0010] The second ends of the first diffuser, the second diffuser, and the third diffuser increase in axial length in sequence.

[0011] Optionally, in the above hydrogen burner, the number of the hydrogen nozzles is multiple, and at least two of the multiple hydrogen nozzles have different lengths.

[0012] Optionally, in the above hydrogen burner, the first pipe body, the second pipe body, the third pipe body, the ignition gun, the first diffuser, the second diffuser, and the third diffuser are coaxially arranged.

[0013] Optionally, in the above hydrogen burner, the swirling combustion-supporting gas in the swirling combustion-supporting air channel accounts for 20% - 30% of the total air volume in the hydrogen burner;

[0014] And / or, the mixed gas in the second gas channel is high-speed DC wind;

[0015] And / or, the DC combustion-supporting gas in the DC combustion-supporting air channel accounts for 70% - 80% of the total air volume in the hydrogen burner;

[0016] And / or, the volume flow rate of ammonia gas in the second gas channel accounts for 10% - 50% of the volume flow rate of hydrogen gas;

[0017] And / or, the hydrogen in the hydrogen nozzle accounts for 15% - 25% of the total calorific value of the fuel;

[0018] And / or, the diffusion angles of the first diffusion cylinder, the second diffusion cylinder, and the third diffusion cylinder are 15° to 30°.

[0019] Optionally, in the above hydrogen burner, a swirl vane is further disposed in the swirl combustion-supporting air passage.

[0020] The present invention further provides a coal-fired unit hydrogen-blended combustion system, including a boiler, a pulverized coal burner, and a hydrogen burner, wherein the pulverized coal burner and the hydrogen burner are respectively disposed in the boiler;

[0021] The hydrogen burner is the hydrogen burner as described above.

[0022] Optionally, in the above coal-fired unit hydrogen-blended combustion system, the hydrogen burner is arranged at the middle and lower positions or the reduction zone of the main combustion zone of the boiler.

[0023] Optionally, in the above coal-fired unit hydrogen-blended combustion system, the number of the hydrogen burners is multiple, and the multiple hydrogen burners are arranged along the height direction of the boiler.

[0024] Optionally, in the above coal-fired unit hydrogen-blended combustion system, a hydrogen production unit, a hydrogen storage unit, a synthetic ammonia unit, and an ammonia storage unit are further included. The outlet of the hydrogen production unit is respectively communicated with the inlets of the hydrogen storage unit and the synthetic ammonia unit. The outlet of the hydrogen storage unit is communicated with the inlet of the second gas passage of the hydrogen burner through a first regulating valve. The outlet of the synthetic ammonia unit is communicated with the inlet of the second gas passage of the hydrogen burner through a second regulating valve.

[0025] Optionally, in the above coal-fired unit hydrogen-blended combustion system, the outlet of the hydrogen storage unit is communicated with the inlet of the first gas passage through a third regulating valve.

[0026] The present invention provides a hydrogen burner, and its beneficial effects are as follows:

[0027] By sleeving three pipe bodies successively from the inside out to form a swirling combustion-supporting air channel, a second gas channel, and a direct-current combustion-supporting air channel, and connecting three diffusion cylinders to the ends of the three pipe bodies respectively, the axial lengths of the outlets of the three diffusion cylinders from the inside out increase successively. A hydrogen nozzle and the ignition gun are respectively arranged inside the innermost pipe body. During operation, the hydrogen in the hydrogen nozzle is gradually mixed with the swirling combustion-supporting gas in the swirling combustion-supporting air channel. The swirling combustion-supporting gas has a combustion-supporting effect and is ignited by the ignition gun. The high-temperature gas ignited inside the diffusion cylinder is in a high-speed rotating state and continues to entrain the hydrogen-ammonia gas in the second gas channel, providing heat for the mixed combustion of the hydrogen-ammonia gas in the second gas channel. Then it is mixed with the direct-current combustion-supporting gas from the direct-current combustion-supporting air channel, thereby realizing radial staged combustion. By using two kinds of combustion-supporting gases, namely the swirling combustion-supporting gas and the direct-current combustion-supporting gas, to achieve staged distribution of the combustion-supporting gas, the hydrogen burner realizes staged and sectional combustion, effectively achieving stable ignition and suppressing NOx generation. Adopting the combustion mode of hydrogen mixed with ammonia, using ammonia as the gas to adjust the combustion activity of hydrogen, slowing down the hydrogen combustion speed and increasing the flame length, which is beneficial to safe and stable combustion. Brief Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0029] Figure 1 It is a perspective view of the structure of a hydrogen burner provided by an embodiment of the present invention;

[0030] Figure 2 It is a partial perspective view of the structure of a hydrogen burner provided by an embodiment of the present invention;

[0031] Figure 3 It is a front view of a hydrogen burner provided by an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of a hydrogen-doped combustion system for a coal-fired unit provided by an embodiment of the present invention;

[0033] Figure 5 It is a schematic diagram of the structure of the burner arranged on the boiler in the second form provided by an embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the structure of the burner arranged on the boiler in the third form provided by an embodiment of the present invention.

[0035] In the above figures:

[0036] 100 - Hydrogen burner:

[0037] 110 - First pipe body; 111 - DC combustion-supporting air channel; 120 - Second pipe body; 121 - Second gas channel; 130 - Third pipe body; 131 - Swirl combustion-supporting air channel; 140 - Hydrogen nozzle; 141 - First gas channel; 142 - First hydrogen nozzle; 143 - Second hydrogen nozzle; 144 - Third hydrogen nozzle; 150 - Ignition gun; 160 - Rotating blade; 171 - First diffusion cylinder; 172 - Second diffusion cylinder; 173 - Third diffusion cylinder;

[0038] 200 - Hydrogen production unit; 300 - Hydrogen storage unit; 400 - Ammonia synthesis unit; 500 - Ammonia storage unit; 600 - Pulverized coal burner; 700 - Boiler; 710 - Main combustion zone; 720 - Reduction zone; 730 - Burnout zone; 810 - Three-way valve; 820 - First regulating valve; 830 - Second regulating valve;

[0039] A - Hydrogen-ammonia mixed gas pipeline; B - Pulverized coal pipeline. Detailed implementation manner

[0040] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0041] The core of the present invention is to provide a hydrogen burner and a hydrogen-doped combustion system for a coal-fired unit, using ammonia as a gas to regulate the combustion activity of hydrogen, slowing down the hydrogen combustion speed, increasing the flame length, and being beneficial to safe and stable combustion.

[0042] According to the prior art, hydrogen / ammonia is a new zero-carbon fuel, and no pollutants such as CO2, SO2, and soot are directly generated during the combustion utilization process. However, NOx is easily generated if not properly controlled. Developing clean and efficient hydrogen / ammonia combustion equipment can strongly promote the realization of the "dual carbon" goal. Hydrogen can be directly generated by electrolyzing water and has a high energy density, making it more suitable as a clean zero-carbon fuel.

[0043] In contrast, ammonia has the characteristics of a high ignition temperature and a low flame propagation speed, and can also play a role in reducing the generated NOx. Therefore, feeding hydrogen mixed with ammonia into a coal-fired boiler is expected to meet the combustion requirements of hydrogen-coal co-combustion in terms of safety, flexibility, cleanliness, and efficiency, providing a potentially effective way to solve many problems faced by existing hydrogen co-firing.

[0044] To enable those skilled in the art to better understand the technical solution provided by the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0045] Specifically, please refer to Figures 1 - 3 , a hydrogen burner 100 provided by the present invention includes: a first pipe body 110, a second pipe body 120, a third pipe body 130, a hydrogen nozzle 140, a igniter 150, a first diffuser 171, a second diffuser 172, and a third diffuser 173.

[0046] Among them, the first pipe body 110, the second pipe body 120, and the third pipe body 130 are arranged in sequence from outside to inside. The first pipe body 110, the second pipe body 120, and the third pipe body 130 are all straight pipes, and the first diffuser 171, the second diffuser 172, and the third diffuser 173 are all divergent pipes.

[0047] The first ends of the first diffuser 171, the second diffuser 172, and the third diffuser 173 are respectively connected to the second ends of the third pipe body 130, the second pipe body 120, and the first pipe body 110, and the hydrogen nozzle 140 and the igniter 150 are both located in the inner cavity of the third pipe body 130.

[0048] A DC combustion-supporting air channel 111 for introducing DC combustion-supporting gas is formed between the first pipe body 110 and the second pipe body 120. A second gas channel 121 for introducing a mixed gas of hydrogen and ammonia is formed between the second pipe body 120 and the third pipe body 130. A swirling combustion-supporting air channel 131 for introducing swirling combustion-supporting gas is formed between the third pipe body 130 and the hydrogen nozzle 140. The swirling combustion-supporting gas has a combustion-supporting effect and can ensure the stability of the root combustion of hydrogen. The DC combustion-supporting gas and the swirling combustion-supporting gas can specifically be air, or a mixed gas of hydrogen and air. The hydrogen nozzle 140 has a first gas channel 141 for introducing hydrogen, and the hydrogen in the first gas channel 141 is pure hydrogen, which can be mixed with the swirling combustion-supporting gas and ignited by the igniter 150.

[0049] The DC combustion-supporting air channel 111, the second gas channel 121, and the swirling combustion-supporting air channel 131 are all annular channels.

[0050] The second ends of the first diffuser 171, the second diffuser 172, and the third diffuser 173 increase in axial length in sequence. Due to the different axial lengths of the three diffusers, the gases meet in the three diffusers in a certain order. Specifically, the hydrogen from the hydrogen nozzle 140 and the swirling combustion-supporting gas from the swirling combustion-supporting air channel 131 are initially mixed in the first diffuser 171, then mixed again with the mixed gas of hydrogen and ammonia from the second gas channel 121, and then mixed with the DC combustion-supporting gas from the DC combustion-supporting air channel 111, thereby realizing radial staged combustion.

[0051] A hydrogen burner 100 provided by the present invention successively sleeved with three pipe bodies from inside to outside, forming a swirling combustion-supporting air channel 131, a second gas channel 121, and a direct-current combustion-supporting air channel 111. Three diffusion cylinders are respectively connected to the ends of the three pipe bodies, and the axial lengths of the outlets of the three diffusion cylinders from inside to outside increase successively. A hydrogen nozzle 140 and a igniter 150 are respectively arranged in the innermost pipe body. During operation, the hydrogen in the hydrogen nozzle 140 is gradually mixed with the swirling combustion-supporting gas in the swirling combustion-supporting air channel 131. The swirling combustion-supporting gas has a combustion-supporting effect and is ignited by the igniter 150. The high-temperature gas ignited in the diffusion cylinder is in a high-speed rotating state, and continues to entrain the hydrogen-ammonia gas in the second gas channel 121, providing heat for the mixed combustion of the hydrogen-ammonia gas in the second gas channel 121. Then it is mixed with the direct-current combustion-supporting gas from the direct-current combustion-supporting air channel 111, thereby realizing radial staged combustion. By using two kinds of combustion-supporting gases, namely the swirling combustion-supporting gas and the direct-current combustion-supporting gas, to realize the staged distribution of the combustion-supporting gas, the hydrogen burner 100 realizes staged and segmented combustion, effectively realizes stable ignition, and inhibits the generation of NOx. Adopting the combustion mode of hydrogen mixed with ammonia, using ammonia as the gas to adjust the combustion activity of hydrogen, slowing down the hydrogen combustion speed, increasing the flame length, and reducing the peak flame temperature, further solves the problems of burner burnout and high NOx emissions caused by concentrated heat load in the hydrogen burner, and provides an effective technical solution for the safe, stable, flexible, and clean combustion of hydrogen.

[0052] In a specific embodiment, the number of the hydrogen nozzles 140 is multiple, and at least two of the multiple hydrogen nozzles 140 have different lengths to form axial staged combustion. Combining the above structure, thus realizing multiple staging of hydrogen (including radial staging and axial staging) and combustion of hydrogen mixed with ammonia, to realize the adjustment of the hydrogen combustion flame state, achieve the functions of stable combustion, inhibiting the generation of NOx, and avoiding the burnout of the burner nozzle, and achieve the purpose of safe and clean combustion of hydrogen. Of course, some of the multiple hydrogen nozzles 140 may have the same length and some may have different lengths. For example, at least one of the multiple hydrogen nozzles 140 has a length greater than the length of the igniter 150, at least one of the multiple hydrogen nozzles 140 has a length equal to the length of the igniter 150, and at least one of the multiple hydrogen nozzles 140 has a length less than the length of the igniter 150.

[0053] Further, the number of the hydrogen nozzles 140 is 4 - 10. As Figure 3 shown, specifically, the igniter 150 is located on the central axis of the hydrogen burner, and the multiple hydrogen nozzles 140 are evenly arranged circumferentially around the central axis. The length of the first hydrogen nozzle 142 is greater than the length of the igniter 150; the length of the second hydrogen nozzle 143 is equal to the length of the igniter 150; the length of the third hydrogen nozzle 144 is less than the length of the igniter 150. The hydrogen nozzles 140 with different lengths can realize the axial and radial staged distribution of hydrogen.

[0054] With the above settings, axial staging of hydrogen is achieved, and it is mixed step by step with the swirling combustion-supporting gas. After being ignited by the igniter 150, it is ignited step by step. Utilizing the flammable characteristics of hydrogen to achieve stable ignition, and using axial staging to disperse the heat load to inhibit the generation of NOx at the initial stage of ignition.

[0055] To achieve stable combustion, the first pipe body 110, the second pipe body 120, the third pipe body 130, the igniter 150, the first diffuser 171, the second diffuser 172, and the third diffuser 173 are coaxially arranged to make the gas distribution in each channel relatively uniform.

[0056] In a preferred embodiment, the swirling combustion-supporting gas in the swirling combustion-supporting air channel 131 accounts for 20% - 30% of the total air volume in the hydrogen burner. The direct-current combustion-supporting gas in the direct-current combustion-supporting air channel 111 accounts for 70% - 80% of the total air volume in the hydrogen burner, which can provide the combustion-supporting gas required for the later combustion of the hydrogen-ammonia mixed gas to ensure the burnout rate.

[0057] The volume flow rate of ammonia gas in the second gas channel 121 accounts for 10% - 50% of the volume flow rate of hydrogen gas. That is, the hydrogen blending ratio is 10% - 50%. By adjusting the ratio of hydrogen blended with ammonia, the position of the hydrogen flame and the peak flame temperature can be flexibly adjusted to avoid burning damage to the nozzle of the hydrogen burner and inhibit the generation of thermal NOx.

[0058] The hydrogen in the hydrogen nozzle 140 accounts for 15% - 25% of the total calorific value of the fuel. The diffusion angles of the first diffuser 171, the second diffuser 172, and the third diffuser 173 are 15° - 30°.

[0059] The mixed gas in the second gas channel 121 is high-speed direct-current air. By adjusting the ratio of hydrogen blended with ammonia, the flame position and the peak flame temperature are adjusted to avoid nozzle burning damage and local high heat load, and effectively inhibit the generation of NOx.

[0060] This solution further includes swirl vanes 160 arranged in the swirling combustion-supporting air channel 131. The number of swirl vanes 160 is 6 - 12, and the swirl angle is 40° - 60°, which promotes the full mixing of the combustion-supporting gas in the swirling combustion-supporting air channel 131. The ends of the swirl vanes 160 can be arranged on the inner wall of the swirling combustion-supporting air channel 131.

[0061] In addition, the present invention also provides a hydrogen-blended combustion system for a coal-fired unit, as Figure 4 shown, including a boiler 700, a pulverized coal burner 600, and a hydrogen burner 100. The pulverized coal burner 600 and the hydrogen burner 100 are respectively arranged in the boiler 700.

[0062] The hydrogen burner 100 is the hydrogen burner in the above specific embodiment.

[0063] Obviously, the coal-fired unit hydrogen blending combustion system including the above hydrogen burner has the same beneficial effects and will not be elaborated here.

[0064] Furthermore, as Figure 5 shown, the hydrogen burner 100 is a hydrogen-ammonia gas burner, and the hydrogen burner 100 is arranged in the reduction zone 720 of the boiler 700. The pulverized coal burner 600 is arranged below the hydrogen burner 100 and is located in the middle and lower layers of the main combustion zone 710. Utilize the NOx reduction characteristic of hydrogen to achieve low-carbon and clean operation of the unit. By means of blending hydrogen with ammonia, flexibly adjust the position and temperature of the hydrogen flame to avoid burning damage to the nozzles of the hydrogen / ammonia gas burner.

[0065] As Figure 6 shown, the hydrogen burner 100 is a hydrogen-ammonia gas burner, and the hydrogen burner 100 is arranged in the middle and lower layers of the main combustion zone 710 of the boiler 700. Utilize the stable combustion characteristic of hydrogen to achieve low-carbon and flexible operation of the unit. By means of blending hydrogen with ammonia, flexibly adjust the position and temperature of the hydrogen flame to avoid burning damage to the nozzles of the hydrogen / ammonia gas burner and inhibit the generation of thermal NOx.

[0066] To improve the combustion efficiency, the number of hydrogen burners 100 can also be multiple, and multiple hydrogen burners 100 are arranged along the height direction of the boiler 700.

[0067] In a specific embodiment, the solution further includes a hydrogen production unit 200, a hydrogen storage unit 300, a synthetic ammonia unit 400, and an ammonia storage unit 500. The outlet of the hydrogen production unit 200 is respectively communicated with the inlets of the hydrogen storage unit 300 and the synthetic ammonia unit 400. The outlet of the hydrogen storage unit 300 is communicated with the inlet of the second gas passage 121 of the hydrogen burner 100 through a first regulating valve 820, and the outlet of the synthetic ammonia unit 400 is communicated with the inlet of the second gas passage 121 of the hydrogen burner 100 through a second regulating valve 830.

[0068] The hydrogen produced by the hydrogen production unit 200 enters the hydrogen storage unit 300 in one way and enters the synthetic ammonia unit 400 to produce ammonia and enter the ammonia storage unit 500 in the other way. After the hydrogen in the hydrogen storage unit 300 is mixed with the ammonia in the ammonia storage unit 500, it is introduced into the hydrogen burner 100 through the hydrogen-ammonia mixed gas pipeline A as shown in Figure 5 and Figure 6 shown, and then enters the boiler 700 for combustion. Pulverized coal enters the pulverized coal burner 600 through the pulverized coal pipeline B for combustion. This part belongs to the prior art and will not be elaborated here.

[0069] By adjusting the first regulating valve 820 and the second regulating valve 830, the ratio of hydrogen blending with ammonia (the volume flow rate of ammonia gas accounts for the volume flow rate of hydrogen gas) can be realized to be 5% - 40%, and ammonia accounts for 5% - 30% of the total calorific value of the gas.

[0070] In addition, the hydrogen production unit 200, the hydrogen storage unit 300, and the ammonia synthesis unit 400 are connected through a three-way valve 810. The combination of the three-way valve 810, the first regulating valve 820, and the second regulating valve 830 can achieve only hydrogen storage, only ammonia production, or simultaneous hydrogen storage and ammonia production. And the number of hydrogen production units 200 is reduced.

[0071] The outlet of the hydrogen storage unit 300 can also be connected to the inlet of the first gas passage 141 through a third regulating valve. By controlling the opening and closing of the first regulating valve 820, the second regulating valve 830, and the third regulating valve, the flow rates of hydrogen and hydrogen-ammonia mixed gas in each passage can be controlled.

[0072] Through the above settings, within the wide load range (40% - 100% BMCR) of the coal-fired unit hydrogen-doped combustion system, the proportion of ammonia doped in hydrogen is 20% - 40%. The higher the unit load, the higher the overall temperature level of the boiler. To control the generation of NOx, the higher the proportion of ammonia doped in hydrogen.

[0073] As the load of the coal-fired unit further decreases (20% - 40% BMCR), the proportion of ammonia doped in hydrogen is 5% - 20%. At low loads, the overall temperature level of the boiler is low. By reducing the proportion of ammonia doped in hydrogen, the combustion advantage of hydrogen can be fully utilized to achieve stable combustion at low loads.

[0074] In the description of this application, the meaning of "a plurality" is more than two. If the first and the second are described, it is only for the purpose of distinguishing technical features and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or the sequence relationship of the indicated technical features.

[0075] As shown in this application and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one", and / or "the" are not specifically singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements. An element defined by the statement "comprising one..." does not exclude the existence of another identical element in the process, method, commodity, or device including the element.

[0076] Among them, in the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "a plurality" means two or more than two.

[0077] In the description of this application, unless otherwise clearly defined, terms such as "arrangement", "installation", "connection", etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in this application in combination with the specific content of the technical solution.

[0078] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts among the various embodiments can be referred to each other.

[0079] Specific examples are used in this article to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A hydrogen burner, characterized in that, Including: A first pipe body (110), a second pipe body (120), a third pipe body (130), a hydrogen nozzle (140), a igniter (150), a first diffuser (171), a second diffuser (172), and a third diffuser (173) which are arranged from outside to inside in sequence. The first pipe body (110), the second pipe body (120), and the third pipe body (130) are all straight pipes, and the first diffuser (171), the second diffuser (172), and the third diffuser (173) are all divergent pipes; The first ends of the first diffuser (171), the second diffuser (172), and the third diffuser (173) are respectively connected to the second ends of the third pipe body (130), the second pipe body (120), and the first pipe body (110). The hydrogen nozzle (140) and the igniter (150) are both located in the inner cavity of the third pipe body (130); A DC combustion-supporting air channel (111) for introducing DC combustion-supporting gas is formed between the first pipe body (110) and the second pipe body (120). A second gas channel (121) for introducing a mixed gas of hydrogen and ammonia is formed between the second pipe body (120) and the third pipe body (130). A swirling combustion-supporting air channel (131) for introducing swirling combustion-supporting gas is formed between the third pipe body (130) and the hydrogen nozzle (140). The hydrogen nozzle (140) has a first gas channel (141) for introducing hydrogen; The second ends of the first diffuser (171), the second diffuser (172), and the third diffuser (173) increase in axial length in sequence.

2. The hydrogen burner according to claim 1, characterized in that, The number of the hydrogen nozzles (140) is multiple, and at least two of the multiple hydrogen nozzles (140) have different lengths.

3. The hydrogen burner according to claim 1, characterized in that, The first pipe body (110), the second pipe body (120), the third pipe body (130), the igniter (150), the first diffuser (171), the second diffuser (172), and the third diffuser (173) are coaxially arranged.

4. The hydrogen burner according to claim 1, characterized in that, The swirling combustion-supporting gas in the swirling combustion-supporting air channel (131) accounts for 20% - 30% of the total air volume in the hydrogen burner; And / or, the mixed gas in the second gas channel (121) is high-speed DC air; And / or, the DC combustion-supporting gas in the DC combustion-supporting air channel (111) accounts for 70% - 80% of the total air volume in the hydrogen burner; And / or, the volume flow rate of ammonia gas in the second gas channel (121) accounts for 10% - 50% of the volume flow rate of hydrogen gas; And / or, the hydrogen in the hydrogen nozzle (140) accounts for 15% - 25% of the total calorific value of the fuel; And / or, the diffusion angles of the first diffuser (171), the second diffuser (172), and the third diffuser (173) are 15° - 30°; 5. The hydrogen burner according to claim 1, characterized in that, It further includes a swirling vane (160) arranged in the swirling combustion-supporting air channel (131).

6. A hydrogen-doped combustion system for a coal-fired unit, characterized in that, It includes a boiler (700), a pulverized coal burner (600), and a hydrogen burner (100). The pulverized coal burner (600) and the hydrogen burner (100) are respectively arranged inside the boiler (700). The hydrogen burner (100) is the hydrogen burner according to any one of claims 1-5.

7. The hydrogen-blended combustion system for a coal-fired unit according to claim 6, characterized in that The hydrogen burner (100) is arranged at the middle and lower position of the main combustion zone (710) or the reduction zone (720) of the boiler (700).

8. The hydrogen-doped combustion system for a coal-fired unit according to claim 6, characterized in that, The number of the hydrogen burners (100) is multiple, and the multiple hydrogen burners (100) are arranged along the height direction of the boiler (700).

9. The hydrogen-blended combustion system for a coal-fired unit according to claim 6, wherein It further includes a hydrogen production unit (200), a hydrogen storage unit (300), a synthetic ammonia unit (400), and an ammonia storage unit (500). The outlet of the hydrogen production unit (200) is respectively communicated with the inlets of the hydrogen storage unit (300) and the synthetic ammonia unit (400). The outlet of the hydrogen storage unit (300) is communicated with the inlet of the second gas passage (121) of the hydrogen burner (100) through a first regulating valve (820). The outlet of the synthetic ammonia unit (400) is communicated with the inlet of the second gas passage (121) of the hydrogen burner (100) through a second regulating valve (830).

10. The hydrogen-doped combustion system for a coal-fired unit according to claim 9, wherein, The outlet of the hydrogen storage unit (300) is communicated with the inlet of the first gas passage (141) through a third regulating valve.

Images