A burner, a boiler and a combustion system

Abstract

The combustor, boiler and combustion system disclosed by the application, the combustor comprises a biomass pipeline, a pulverized coal pipeline, an air pipeline, an ammonia gas combustion assembly and a hydrogen gas combustion assembly, the pulverized coal pipeline is arranged outside the biomass pipeline, an internal part of the biomass pipeline forms a biomass passage, and a pulverized coal passage is formed between the pulverized coal pipeline and the biomass pipeline; the air pipeline is arranged outside the pulverized coal pipeline, and an air passage is formed between the air pipeline and the pulverized coal pipeline; the ammonia gas combustion assembly comprises an ammonia gas distributor, the ammonia gas distributor comprises a plurality of ammonia gas nozzles, and each ammonia gas nozzle is arranged in the pulverized coal passage or the air passage; the hydrogen gas combustion assembly comprises a hydrogen gas distributor, the hydrogen gas distributor comprises a plurality of hydrogen gas nozzles, and each hydrogen gas nozzle is arranged in the air passage. The combustor disclosed by the application can reduce the emission of NOx and improve the combustion efficiency of the boiler.

Description

Technical Field

[0001] This application relates to the field of burner technology, and more specifically, to a burner, boiler and combustion system. Background Technology

[0002] Biomass, ammonia (NH3), and hydrogen (H2), as low-carbon fuels, have attracted widespread attention in the field of coal-fired power generation due to their potential to replace traditional fossil fuels. Blending a certain proportion of low-carbon fuels into coal-fired boilers can reduce carbon dioxide (CO2) emissions from coal-fired units. However, improper control during the blending process, or an inappropriate blending ratio, can easily lead to the generation of large amounts of nitrogen oxides (NOx) or increase the carbon content of boiler fly ash, thereby reducing boiler efficiency.

[0003] Therefore, how to reduce the generation of nitrogen oxides in order to improve boiler efficiency has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] In view of this, the purpose of this application is to disclose a burner that reduces the generation of nitrogen oxides in order to improve boiler efficiency.

[0005] Another key aspect of this application is the disclosure of a boiler that includes the aforementioned burner.

[0006] Another key aspect of this application is the disclosure of a combustion system that includes the aforementioned boiler.

[0007] To achieve the above objectives, this application provides the following technical solution:

[0008] A burner includes a biomass pipeline, a pulverized coal pipeline, a combustion air pipeline, an ammonia combustion assembly, and a hydrogen combustion assembly. The pulverized coal pipeline is disposed outside the biomass pipeline, and a biomass channel is formed inside the biomass pipeline. A pulverized coal channel is formed between the pulverized coal pipeline and the biomass pipeline. The combustion air pipeline is disposed outside the pulverized coal pipeline, and a combustion air channel is formed between the combustion air pipeline and the pulverized coal pipeline.

[0009] The biomass pipeline has a biomass inlet at one end and a biomass nozzle at the other end; the pulverized coal pipeline has a pulverized coal inlet at one end and a pulverized coal nozzle at the other end.

[0010] The ammonia combustion assembly includes an ammonia distributor, which includes a plurality of ammonia nozzles spaced apart circumferentially along the ammonia distributor. Each of the ammonia nozzles is located in the pulverized coal channel or in the combustion air channel.

[0011] The hydrogen combustion assembly includes a hydrogen distributor, which includes a plurality of hydrogen nozzles spaced apart circumferentially along the hydrogen distributor, each of the hydrogen nozzles being disposed in the combustion air channel.

[0012] Optionally, in the above-described burner, the ammonia combustion assembly includes an ammonia cyclone separator, which is movably disposed in the combustion air duct; and / or,

[0013] The hydrogen combustion assembly includes a hydrogen cyclone separator, which is movably disposed in the combustion air channel.

[0014] Optionally, in the above-mentioned burner, each of the ammonia nozzles is arranged circumferentially at intervals along the pulverized coal channel, and the axis of the ammonia nozzle of each of the ammonia nozzles is parallel to the axis of the biomass channel; and / or, the angle between the axis of the ammonia nozzle of each of the ammonia nozzles and the axis of the burner is 0° to 50°.

[0015] Optionally, in the above-mentioned burner, each of the hydrogen nozzles is arranged circumferentially at intervals along the combustion air passage; and / or, the angle between the axis of the hydrogen nozzle of each of the hydrogen nozzles and the axis of the burner is 0° to 50°.

[0016] Optionally, in the above-mentioned burner, each of the ammonia nozzles and each of the hydrogen nozzles are arranged at circumferential intervals along the combustion air passage, and the ammonia nozzles and the hydrogen nozzles are arranged alternately.

[0017] Optionally, in the above-described burner, the hydrogen nozzle of the hydrogen injector is located downstream of the pulverized coal nozzle, and the axial distance between them is 0~100mm; and / or,

[0018] The ammonia nozzle of the ammonia spray pipe is located upstream of the pulverized coal nozzle, and the axial distance between the ammonia nozzle and the hydrogen nozzle is 0mm to 200mm.

[0019] Optionally, in the above-mentioned burner, a biomass distributor is provided inside the biomass channel, and the axis of the biomass distributor is collinear with the axis of the biomass channel.

[0020] Optionally, in the above-mentioned burner, the expansion angle of the biomass distributor's feed-facing surface is 20°~180°.

[0021] Optionally, in the above-mentioned burner, the area of ​​the back powder surface of the biomass distributor is 30% to 100% of the area of ​​the biomass channel; and / or, the distance between the small-diameter end of the gradually expanding section of the biomass distributor and the biomass distributor is 0 mm to 100 mm.

[0022] Optionally, in the above-mentioned burner, the side of the biomass nozzle facing the pulverized coal flow is provided with an anti-wear structure.

[0023] A boiler includes the burner described above, wherein the number of burners is at least one.

[0024] A combustion system includes a boiler, a steam turbine, a condenser, and a liquid ammonia evaporator, wherein the boiler, the steam turbine, the condenser, and the liquid ammonia evaporator are connected in sequence, and the liquid ammonia evaporator is connected to an ammonia distributor of the burners of the condenser and the boiler, respectively.

[0025] The boiler is as described above.

[0026] As can be seen from the above scheme, the burner disclosed in this application, during use, delivers biomass powder gas flow through the biomass channel, pulverized coal gas flow through the pulverized coal channel, hydrogen through the hydrogen nozzle, and ammonia through the ammonia nozzle. This forms an airflow structure at the burner outlet end face, with biomass powder, pulverized coal gas flow at the center, and combustion air on the outside – a "wind-wrapped pulverized coal, pulverized coal-wrapped biomass powder" structure. This structure effectively encapsulates large biomass powder particles in the center, facilitating their flow towards the center of the boiler furnace and preventing them from scouring the water-cooled walls. Hydrogen is introduced through the hydrogen distributor, and combustion air is ejected through the combustion air nozzle of the combustion air duct. This entrains surrounding high-temperature flue gas, enabling rapid ignition of the hydrogen and ensuring stable combustion. Furthermore, it reduces the oxygen content of the combustion air surrounding the hydrogen, thus decreasing NOx generation during hydrogen combustion. After hydrogen combustion, the oxygen in the combustion air is consumed. Pulverized coal and ammonia are then transported through the pulverized coal channel and ammonia distributor 310. On one hand, the mixture of pulverized coal and ammonia burns in an oxygen-deficient environment, reducing NOx formation. On the other hand, the input of ammonia can reduce the NOx produced during combustion, further reducing NOx emissions. Furthermore, the high-temperature flame of hydrogen can ignite the pulverized coal gas flow, enhancing the combustion stability of the pulverized coal gas flow, which in turn is beneficial for the stable combustion of biomass pulverized coal.

[0027] The boiler disclosed in this application has the same technical effect as the burner, and will not be described in detail here.

[0028] The combustion system disclosed in this application returns the condensate from the liquid ammonia evaporator to the boiler as feedwater. This method can improve the vacuum degree of the condenser, improve the unit efficiency, and at the same time reduce the construction scale of the cooling tower and reduce the investment in the cooling tower. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A cross-sectional view of the burner disclosed in the embodiments of this application. Figure 1 ;

[0031] Figure 2 A cross-sectional view of the burner disclosed in the embodiments of this application. Figure 2 ;

[0032] Figure 3 This is a schematic diagram of the structure of the hydrogen nozzle disclosed in the embodiments of this application. Figure 1 ;

[0033] Figure 4 This is a schematic diagram of the arrangement of hydrogen nozzles disclosed in the embodiments of this application. Figure 2 ;

[0034] Figure 5 This is a schematic diagram of the arrangement of hydrogen nozzles disclosed in the embodiments of this application. Figure 3 ;

[0035] Figure 6 This is a schematic diagram of the arrangement of hydrogen nozzles disclosed in the embodiments of this application. Figure 4 ;

[0036] Figure 7 This is a schematic diagram of the arrangement of ammonia nozzles disclosed in the embodiments of this application. Figure 5 ;

[0037] Figure 8 This is a schematic diagram of the arrangement of hydrogen nozzles disclosed in the embodiments of this application. Figure 6 ;

[0038] Figure 9 This is a schematic diagram showing the arrangement of the ammonia and hydrogen nozzles disclosed in the embodiments of this application;

[0039] Figure 10 This is a schematic diagram of the structure of the biomass equalizer disclosed in the embodiments of this application. Figure 1 ;

[0040] Figure 11 This is a schematic diagram of the structure of the biomass equalizer disclosed in the embodiments of this application. Figure 2 ;

[0041] Figure 12 This is a schematic diagram of the combustion system disclosed in an embodiment of this application.

[0042] Among them, 100-biomass pipeline, 110-biomass inlet, 120-biomass nozzle, 130-biomass distributor;

[0043] 200 - Pulverized coal pipeline, 210 - Pulverized coal inlet, 220 - Pulverized coal nozzle;

[0044] 300-Ammonia combustion assembly, 310-Ammonia distributor, 3101-Ammonia inlet, 311-Ammonia nozzle, 3111-Ammonia nozzle;

[0045] 400-Hydrogen combustion assembly, 410-Hydrogen distributor, 4101-Hydrogen inlet, 411-Hydrogen nozzle, 4111-Hydrogen nozzle, 420-Hydrogen cyclone separator, 430-Pull rod;

[0046] 500-Combustion air duct,

[0047] R1 - Biomass channel, R2 - Pulverized coal channel, R3 - Combustion air channel;

[0048] 10-Boiler, 20-Steam turbine, 30-Condenser, 40-Liquid ammonia evaporator. Detailed Implementation

[0049] The core of this application is to disclose a burner that reduces the generation of nitrogen oxides in order to improve boiler efficiency.

[0050] Another key aspect of this application is the disclosure of a boiler that includes the aforementioned burner.

[0051] Another key aspect of this application is the disclosure of a combustion system that includes the aforementioned boiler.

[0052] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0053] like Figure 1As shown in the illustration, this application discloses a burner including a biomass pipe 100, a pulverized coal pipe 200, a combustion air pipe 500, an ammonia combustion assembly 300, and a hydrogen combustion assembly 400. The biomass pipe 100 forms a biomass channel R1, which is used to transport a biomass pulverized coal gas stream, which is a mixture of biomass and air. The biomass pipe 100 has a biomass inlet 110 at one end and a biomass nozzle 120 at the other end. Biomass enters the biomass channel from the biomass inlet 110 and is ejected from the biomass nozzle 120 into the furnace. It should be noted that the biomass pipe 100, the pulverized coal pipe 200, and the combustion air pipe 500 are arranged coaxially.

[0054] A pulverized coal pipeline 200 is located outside the biomass pipeline 100, forming a pulverized coal channel R2 between the pulverized coal pipeline 200 and the biomass pipeline 100. The pulverized coal channel R2 is used to transport pulverized coal gas flow. The first end of the pulverized coal pipeline 200 has a pulverized coal inlet 210, and the second end has a pulverized coal nozzle 220. The pulverized coal gas flow enters from the pulverized coal inlet 210 and exits from the pulverized coal nozzle 220 into the furnace. A combustion air pipeline 500 is located outside the pulverized coal pipeline 200, forming a combustion air channel R3 between the combustion air pipeline 500 and the pulverized coal pipeline 200. The combustion air channel R3 is used to transport the combustion air required for combustion.

[0055] The ammonia combustion assembly 300 includes an ammonia distributor 310, which has an ammonia inlet 3101. Ammonia can be supplied to the ammonia distributor 310 by an ammonia supply assembly. The ammonia distributor 310 includes a plurality of ammonia nozzles 311 arranged at circumferential intervals along the ammonia distributor 310. Each ammonia nozzle 311 is located in the pulverized coal channel R2 or in the combustion air channel R3.

[0056] The hydrogen combustion assembly 400 includes a hydrogen distributor 410, which includes a plurality of hydrogen nozzles 411 spaced circumferentially along the distributor 410. Each hydrogen nozzle 411 is located in the combustion air passage R3. The hydrogen distributor 410 has a hydrogen inlet 4101, from which hydrogen can be supplied by a hydrogen supply assembly.

[0057] It should be noted that the biomass mentioned in this application refers to bio-based organic materials suitable for solid fuel burners, including but not limited to: lignocellulosic biomass, agricultural residues, and pretreated organic waste. Lignocellulosic biomass includes wood, wood chips, sawdust, bark, forestry residues and their shaped products (such as wood pellets and wood blocks); agricultural residues include crop straw (such as rice straw, wheat straw, and corn straw), rice husks, fruit shells (such as coconut shells and almond shells), and sugarcane bagasse; pretreated organic waste includes dried animal manure and sorted and dried food processing waste. The average diameter of the biomass powder is preferably 0.001 mm to 5 mm. If the diameter of the biomass powder is too large, it will reduce combustion efficiency and increase incomplete combustion losses.

[0058] The burner disclosed in this application, during use, delivers biomass gas flow through biomass channel R1, pulverized coal gas flow through pulverized coal channel R2, hydrogen through hydrogen nozzle 411, and ammonia through ammonia nozzle 311. This creates an airflow structure at the burner outlet face, with biomass powder, pulverized coal gas flow at the center, and combustion air on the outside – a "wind-wrapped pulverized coal, pulverized coal-wrapped biomass powder" configuration. This structure effectively encapsulates large biomass powder particles at the center, facilitating their flow towards the center of the boiler furnace and preventing them from scouring the water-cooled walls. Hydrogen is introduced through hydrogen distributor 410, and combustion air is ejected through the combustion air nozzle of combustion air duct 500. This entrains surrounding high-temperature flue gas, enabling rapid ignition of the hydrogen and ensuring stable combustion. Furthermore, it reduces the oxygen content of the combustion air surrounding the hydrogen, decreasing NOx generation during combustion. After hydrogen combustion, the oxygen in the combustion air is consumed. Pulverized coal and ammonia are then transported through the pulverized coal channel R2 and the ammonia distributor 310. On one hand, the mixture of pulverized coal and ammonia burns in an oxygen-deficient environment, reducing NOx formation. On the other hand, the input of ammonia can reduce the NOx produced during combustion, further reducing NOx emissions. Furthermore, the high-temperature flame of hydrogen can ignite the pulverized coal gas flow, enhancing the combustion stability of the pulverized coal gas flow, which in turn is beneficial to the stable combustion of biomass pulverized coal.

[0059] It should be noted that in the burner disclosed in this application, the blending ratio of ammonia and hydrogen is between 0% and 100%, and the blending ratio can be adjusted according to actual conditions. Hydrogen can be fed into the furnace through multiple hydrogen nozzles 4111 to perform staged combustion of hydrogen fuel, which can disperse the flame, reduce its maximum flame temperature, and reduce the residence time of hydrogen in the high-temperature flame, thereby reducing NOx generation. When combined with ammonia, ammonia can be used to reduce the NOx generated by hydrogen combustion, thus reducing the overall NOx generation. It should be noted that in the burner disclosed in this application, hydrogen and ammonia can be fed simultaneously, or only one of them can be fed, which can be determined according to actual operating requirements.

[0060] In some specific embodiments, the ammonia combustion assembly 300 includes an ammonia cyclone separator, which is movably disposed in the combustion air channel R3. When the ammonia nozzle 311 is disposed in the pulverized coal channel R2, the ammonia cyclone separator is not disposed to avoid severe wear of the ammonia cyclone separator, which would affect normal use; and / or, the hydrogen combustion assembly 400 includes a hydrogen cyclone separator 420, which is movably disposed in the combustion air channel R3, specifically as follows: Figure 1 As shown in the diagram. It should be noted that, in addition to the ammonia cyclone, the ammonia cyclone is positioned upstream of the ammonia nozzle 3111, and the hydrogen cyclone 420 is positioned upstream of the hydrogen nozzle 4111. The placement of the ammonia and hydrogen cyclones 420 enables the combustion air to generate a strong swirling flow, forming a central recirculation zone. Then, ammonia and hydrogen are injected into the rotating airflow field, providing a high-temperature ignition source for flame stability. The hydrogen cyclone 420 helps to increase the mixing intensity of hydrogen and combustion air, and entrains high-temperature flue gas, reducing the oxygen concentration around the hydrogen flame, lowering the peak temperature of the hydrogen flame, and reducing NOx generation. The ammonia cyclone increases the mixing intensity of ammonia and combustion air, and entrains high-temperature flue gas, enhancing ammonia ignition; simultaneously, it reduces the oxygen concentration around the ammonia flame, reducing NOx generation.

[0061] Specifically, the ammonia cyclone and hydrogen cyclone 420 are respectively installed at the corresponding nozzle positions via pull rods 430. One end of the pull rod 430 is connected to the ammonia cyclone or hydrogen cyclone 420, and the other end of the pull rod 430 is located on the outside of the burner. The inner wall of the ammonia cyclone is in sliding fit with the outer wall of the ammonia nozzle 311, and the inner wall of the hydrogen cyclone 420 is in sliding fit with the outer wall of the hydrogen nozzle 411. With this configuration, the distance between the hydrogen cyclone 420 and the hydrogen nozzle 4111, and the distance between the ammonia cyclone and the ammonia nozzle 3111 can be adjusted by pulling the pull rod 430. The pull rod 430 can adjust the mixing and entrainment intensity of high-temperature flue gas.

[0062] In some specific embodiments, such as Figure 1 and Figure 2 As shown, the ammonia nozzles 311 are arranged at intervals along the circumference of the pulverized coal channel R2, and the axis of the ammonia nozzle 3111 of each ammonia nozzle 311 is parallel to the axis of the burner. Preferably, the ammonia nozzles 311 are evenly arranged along the circumference of the pulverized coal channel R2, and the specific number can be determined according to the actual situation. Figure 2 The number of six ammonia nozzles 311 shown is merely an example and should not be considered limiting. And / or, the spatial angle between the axis of the ammonia nozzle 3111 of each ammonia nozzle 311 and the axis of the burner is 0° to 50°, i.e. Figure 6 The range of a1 shown is 0° to 50°. Here, the axis of the burner refers to the axis of the biomass channel R1, that is, the centerline of the biomass channel R1. Figure 5 The diagram shows the axes of ammonia gas injection from each ammonia nozzle 3111 towards the burner; that is, the axes of all ammonia gas injection nozzles 3111 intersect at the same point in the central region of the furnace. In some specific embodiments, the axes of each ammonia gas injection nozzle 3111 are tangentially deflected by 1°-50° relative to the axis of the burner. Figure 7 The range of a3 shown is 1°-50°, ensuring the outlet gas flow forms a tangential circle. If the angle between the axis of the ammonia nozzle 3111 and the burner axis is too large, ammonia will directly penetrate the high-temperature zone of the flame. Ammonia burns faster than pulverized coal, competing for oxygen and reducing the combustion rate and stability of pulverized coal. Therefore, it is necessary to reasonably control the angle between the axis of the ammonia nozzle 3111 and the burner axis to ensure that ammonia enters a relatively oxygen-deficient environment after entering the furnace, utilizing its reducing properties to control NOx generation. It should be noted that... Figure 5 and Figure 7 The nozzle shown can represent either ammonia nozzle 3111 or hydrogen nozzle 4111; only one of them is used as a label in the figure for illustration.

[0063] The ammonia nozzle 311 is located inside the pulverized coal channel R2, which allows the pulverized coal and ammonia to mix rapidly. In the initial stage, both fuels burn in an oxygen-deficient environment, which can reduce NOx generation. At the same time, the ammonia ignites and burns early, and the heat generated promotes the combustion of pulverized coal particles. Later, oxygen is added from the combustion air, which to some extent constitutes air staging. Air staging can reduce NOx generation, help to make the heat distribution more uniform, avoid excessive heat concentration, and improve the stability of ignition.

[0064] In some specific embodiments, such as Figure 2 , Figure 4 , Figure 7 and Figure 8 As shown, the hydrogen nozzles 411 are arranged at circumferential intervals along the combustion air channel R3, preferably in a uniform arrangement. The specific number of hydrogen nozzles 411 can be determined according to the actual situation. Figure 2 The number of six hydrogen nozzles 411 shown is merely an example and should not be considered limiting. And / or, the angle between the axis of the hydrogen nozzle 4111 of each hydrogen nozzle 411 and the axis of the burner is 0° to 50°, i.e. Figure 8 The range of a2 shown is 0° to 50°. The axes of all hydrogen nozzles 4111 intersect at the same point in the central region of the furnace. (Refer to...) Figure 5 As shown; the axis of each ammonia nozzle 3111 is deflected tangentially by 1°-50° relative to the axis of the burner, that is... Figure 7The range of a3 shown is 1°-50°, which makes the outlet airflow form a tangential circle. If the angle between the axis of the hydrogen nozzle 4111 and the axis of the burner is too large, the hydrogen will come into contact with the primary air pulverized coal too early. The hydrogen will burn quickly and compete for oxygen in the primary air pulverized coal combustion, reducing the pulverized coal combustion rate and combustion stability. Therefore, it is necessary to reasonably set the angle between the axis of the hydrogen nozzle 4111 and the axis of the burner to reduce the amount of NOx generated while ensuring stable ignition and combustion of pulverized coal.

[0065] Figure 2 The diagram shows ammonia nozzles 311 installed in the pulverized coal channel R2 and hydrogen nozzles 411 installed in the combustion air channel R3. The diagram shows the same number of ammonia nozzles 311 and hydrogen nozzles 411; however, it should be noted that the number of ammonia nozzles 311 and hydrogen nozzles 411 can also be different. Figure 3 As shown, the orifice diameter D1 of the hydrogen nozzle 4111 is preferably 0.1mm~10mm. If the orifice diameter of the hydrogen nozzle 4111 is too small, the flow resistance of hydrogen will be large; if the orifice diameter of the hydrogen nozzle 4111 is too large, the hydrogen flow rate will be low, while the combustion rate of hydrogen will be high, posing a risk of backfire. Therefore, it is necessary to reasonably set the orifice diameter of the hydrogen nozzle 4111 to ensure a reasonable hydrogen flow rate and reduce NOx generation while preventing backfire. Setting multiple hydrogen nozzles 4111 allows for staged injection of hydrogen fuel into the furnace for combustion, which can reduce the peak temperature of the hydrogen flame, reduce the residence time of hydrogen in the high-temperature flame, and also reduce NOx generation.

[0066] In some specific embodiments, such as Figure 4 and Figure 9 As shown, each ammonia nozzle 311 and each hydrogen nozzle 411 are arranged at circumferential intervals along the combustion air passage R3, with the ammonia nozzles 311 and hydrogen nozzles 411 arranged alternately. Specifically, as... Figure 4As shown in the figure, the number of ammonia nozzles 311 and hydrogen nozzles 411 are the same. Along the circumference of the combustion air channel R3, they are arranged in the form of hydrogen nozzles 411, ammonia nozzles 311, hydrogen nozzles 411, and ammonia nozzles 311. It should be noted that the figure is only an example. The number of ammonia nozzles 311 and hydrogen nozzles 411 may be the same or different. It is preferred that they are arranged alternately. In this way, after hydrogen and ammonia are mixed, the high-temperature flue gas generated by hydrogen combustion can, on the one hand, enhance the ignition of ammonia, and on the other hand, reduce the oxygen concentration around ammonia and reduce the formation of NOx. Ammonia can also be used to reduce the NOx generated by hydrogen combustion, thereby reducing the overall amount of NOx generated. In this scheme, the ammonia nozzle 311 is placed in the combustion air channel R3, which can reduce the competition of ammonia for oxygen in the pulverized coal airflow to a certain extent. It does not affect the oxygen content when the pulverized coal is initially ignited. After the ammonia is ignited and burned, it consumes the oxygen in the combustion air and produces high-temperature flue gas, which helps to reduce the NOx generated during coal combustion and can also promote the combustion of pulverized coal. To a certain extent, it belongs to the fuel classification of ammonia and pulverized coal, which can reduce the generation of nitrogen oxides.

[0067] In some specific embodiments, such as Figure 5 As shown, the nozzle axes of each ammonia nozzle 3111 are configured to intersect at the same point P within the furnace. At this intersection point P, multiple fuel jets collide with each other, resulting in a violent exchange of momentum and mass, forming a stable high-turbulence combustion zone, which is beneficial for rapid fuel ignition and burnout. In other specific embodiments, such as Figure 7 As shown, the nozzle axis of each group of ammonia nozzles 3111 is tangent to an imaginary tangent circle at the center of the furnace on a horizontal plane. During operation, the ammonia gas flow of each group is ejected along the tangent direction of the imaginary circle, forming an overall airflow rotating around the vertical center line of the furnace on the cross-section of the furnace, with the rotation direction being either clockwise or counterclockwise.

[0068] In some specific embodiments of this application, the ammonia gas flow and the hydrogen gas flow can rotate clockwise simultaneously, or rotate counterclockwise simultaneously, or one of them can rotate clockwise and the other counterclockwise. The installation method of the corresponding nozzle can be selected according to actual needs.

[0069] In some specific embodiments, such as Figure 9 As shown, the ammonia nozzle 3111 and the hydrogen nozzle 4111 are arranged in pairs. The hydrogen gas flow rotates to the right (clockwise) and the ammonia gas flow rotates to the left (counterclockwise), so that the hydrogen and ammonia gas flows cross each other. This facilitates the mixing of the hydrogen and ammonia gas flows. The ammonia gas entrains the high-temperature flue gas generated by the combustion of hydrogen gas. On the one hand, this can enhance the ignition of ammonia gas, and on the other hand, it can reduce the oxygen concentration around ammonia gas and reduce the formation of NOx.

[0070] In some specific embodiments, such as Figure 1As shown, the hydrogen nozzle 4111 of the hydrogen nozzle 411 is located downstream of the pulverized coal nozzle 220, with an axial distance L2 of 0~100mm between them; and / or, the ammonia nozzle 3111 of the ammonia nozzle 311 is located upstream of the pulverized coal nozzle 220, where ammonia and pulverized coal gas flow are mixed to form a pulverized coal-ammonia mixture, which is then ejected through the pulverized coal nozzle 220. The axial distance L3 between the ammonia nozzle 3111 and the hydrogen nozzle 4111 is 0mm~200mm. This method allows the combustion air nozzle to entrain surrounding high-temperature flue gas, which on the one hand rapidly ignites the hydrogen, ensuring stable combustion; on the other hand, it reduces the amount of oxygen in the combustion air around the hydrogen, thus reducing the amount of NOx generated during hydrogen combustion. The combustion of hydrogen consumes oxygen in the combustion air and mixes with the pulverized coal-ammonia mixture, allowing the ammonia to burn in an oxygen-deficient environment, thus reducing NOx formation. Furthermore, ammonia can reduce the NOx produced by hydrogen combustion, further lowering NOx emissions. In addition, the high-temperature flame of hydrogen can ignite the pulverized coal gas stream, enhancing the stability of the combustion and thus contributing to the stable combustion of biomass pulverized coal.

[0071] The hydrogen nozzle 4111 of the hydrogen nozzle 411 is located downstream of the pulverized coal nozzle 220, with an axial distance L2 of 0-100 mm between them. This allows the hydrogen to first burn with some air, consuming oxygen and creating a high-temperature, oxygen-deficient reduction zone. Subsequently, pulverized coal is injected into this zone. Under this oxygen-deficient environment, the nitrogen in the pulverized coal will generate harmless nitrogen gas, rather than nitrogen oxides, thus reducing NOx formation. If the distance between the hydrogen nozzle 4111 and the pulverized coal nozzle 220 is too large, the flame from the pulverized coal combustion will burn the hydrogen nozzle 4111, which is detrimental to the safe operation of the burner. Therefore, the distance between the hydrogen nozzle 4111 and the pulverized coal nozzle 220 needs to be appropriately set to create a staged air distribution, reducing NOx formation.

[0072] The ammonia nozzle 3111 of the ammonia nozzle 3111 is located upstream of the pulverized coal nozzle 220, and the axial distance L3 between the ammonia nozzle 3111 and the hydrogen nozzle 4111 is 0mm~200mm. If the axial distance between the ammonia nozzle 3111 and the hydrogen nozzle 4111 is too large, the reduction effect of ammonia on NOx produced by hydrogen combustion will be poor, which is not conducive to reducing NOx emissions. Therefore, it is necessary to reasonably set the axial distance between the ammonia nozzle 3111 and the hydrogen nozzle 4111 to ensure the reduction effect of ammonia on NOx produced by hydrogen combustion and reduce NOx generation and emissions.

[0073] In some specific embodiments, such as Figure 1 , Figure 10 and Figure 11As shown, a biomass distributor 130 is installed within the biomass channel R1, and the biomass distributor 130 is located within the biomass nozzle 120. The biomass nozzle 120 has a gradually expanding section, and the axis of the biomass distributor 130 is collinear with the axis of the burner. Specifically, in some embodiments, the biomass distributor 130 is conical with a triangular cross-section, and its facing angle b1 is 20°~180°. The expanding angle b2 of the gradually expanding section of the biomass nozzle 120 ranges from 0° to 60°. The area S1 of the facing surface of the biomass distributor 130 is 30%~100% of the area S2 of the biomass channel R1; and / or, the distance L1 between the small-diameter end of the gradually expanding section of the biomass nozzle 120 and the biomass distributor 130 is 0~100mm.

[0074] If the expansion angle of the biomass distributor 130's pulverized coal-facing surface is too small, sufficient mixing of the biomass stream and air cannot be achieved, resulting in low combustion efficiency. Therefore, the expansion angle of the biomass distributor 130's pulverized coal-facing surface needs to be set appropriately. The expansion angle b1 of the pulverized coal-facing surface should be 20°~180° to ensure sufficient mixing of the biomass stream and air, improve combustion efficiency, and reduce NOx formation. If the expansion angle b2 of the gradually expanding section of the biomass nozzle 120 is too large, it will lead to uneven mixing of biomass fuel and air, reduced combustion efficiency, decreased fuel burnout rate, and unstable flame, which is not conducive to reducing NOx formation. Therefore, the expansion angle b2 of the gradually expanding section of the biomass nozzle 120 needs to be set appropriately to ensure uniform mixing of biomass fuel and air, improve combustion efficiency, and reduce NOx formation.

[0075] If the ratio of the area S1 of the back powder surface of the biomass distributor 130 to the area S2 of the biomass channel R1 is too small, it will lead to uneven mixing of biomass fuel and air, reduced combustion efficiency, decreased fuel burnout rate, unstable flame, and hinder the reduction of NOx formation. If the distance L1 between the small-diameter end of the diffuser section of the biomass nozzle 120 and the biomass distributor 130 is too large, the velocity distribution of the biomass powder airflow after deceleration and pressurization through the diffuser section will be uneven. The biomass distributor 130 will be unable to evenly distribute the biomass powder airflow, leading to unstable combustion, reduced combustion efficiency, and increased NOx emissions. Therefore, it is necessary to reasonably set the distance L1 between the small-diameter end of the diffuser section of the biomass nozzle 120 and the biomass distributor 130 to ensure the even distribution of the biomass powder airflow by the biomass distributor 130, thereby stabilizing the burner and improving combustion efficiency.

[0076] In some other specific embodiments, the feed-facing surface of the biomass distributor 130 is arc-shaped, specifically as follows: Figure 11As shown, after the pulverized coal airflow passes through the biomass nozzle 120 at the front end of the pulverized coal channel R2, the airflow stratifies due to inertia. The outer side of the annular layer near the pulverized coal channel R2 contains concentrated pulverized coal, while the inner side contains less concentrated pulverized coal, with a larger volume of concentrated pulverized coal near the outer layer. The biomass airflow is dispersed by collisions in the biomass distributor 130, which enhances mixing with the less concentrated pulverized coal airflow and entrains the high-temperature flue gas generated by pulverized coal combustion, heating the concentrated biomass and accelerating its preheating, ignition, and stable combustion. The biomass distributor 130 prevents biomass agglomeration and clogging of the nozzle, enhancing the uniformity of mixing between the biomass and pulverized coal airflow.

[0077] In some specific embodiments, to prevent the pulverized coal in the pulverized coal channel R2 from abrading the biomass nozzle 120, an anti-wear structure is provided on the side of the biomass nozzle 120 facing the pulverized coal flow (i.e., the pulverized coal facing side). Specifically, the anti-wear structure can be made of silicon carbide or wear-resistant ceramics, or a 10mm~20mm thick layer of wear-resistant castable can be applied to the pulverized coal facing side of the biomass nozzle 120, and the wear-resistant castable can be fixed to the pulverized coal facing side of the biomass nozzle 120 with pins or wire mesh.

[0078] In addition, this application also discloses a boiler, including the burner of the above embodiment, wherein the number of burners includes one or more.

[0079] Furthermore, embodiments of this application also disclose a combustion system, such as Figure 12 As shown, the system includes a boiler 10, a steam turbine 20, a condenser 30, and a liquid ammonia evaporator 40, which are connected in sequence. The liquid ammonia evaporator 40 is connected to the ammonia gas distributor 310 of both the condenser 30 and the burner of the boiler 10. The boiler 10 is the boiler described in the above embodiment. The liquid ammonia evaporator 40 uses the heat of the condensate in the condenser 30 to evaporate liquid ammonia into ammonia gas. The ammonia gas enters the ammonia gas distributor 310 and is then fed into the furnace. The condensate in the liquid ammonia evaporator 40 is returned to the boiler 10 as feedwater. This method can improve the vacuum level of the condenser 30, thereby increasing the unit efficiency, while also reducing the size of the cooling tower and lowering the investment in the cooling tower.

[0080] It should be noted that the various embodiments in this specification mainly describe the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.

[0081] The terminology used in the above embodiments is for the purpose of describing specific embodiments only and is not intended to be limiting of this application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the," "the," "the," and "this" are intended to also include expressions such as "one or more," unless the context clearly indicates otherwise. It should also be understood that in the embodiments of this application, "one or more" refers to one, two, or more; "and / or" describes the relationship between related objects, indicating that three relationships may exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0082] References to "one embodiment" or "some embodiments" as described in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0083] The "multiple" mentioned in the embodiments of this application refers to two or more. It should be noted that in the description of the embodiments of this application, terms such as "first" and "second" are used only for the purpose of distinguishing descriptions and should not be construed as indicating or implying relative importance, nor should they be construed as indicating or implying order.

[0084] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A burner, characterized in that, The system includes a biomass pipeline (100), a pulverized coal pipeline (200), a combustion air pipeline (500), an ammonia combustion assembly (300), and a hydrogen combustion assembly (400). The pulverized coal pipeline (200) is located outside the biomass pipeline (100), and a biomass channel (R1) is formed inside the biomass pipeline (100). A pulverized coal channel (R2) is formed between the pulverized coal pipeline (200) and the biomass pipeline (100). The combustion air pipeline (500) is located outside the pulverized coal pipeline (200), and a combustion air channel (R3) is formed between the combustion air pipeline (500) and the pulverized coal pipeline (200). The biomass pipeline (100) has a biomass inlet (110) at its first end and a biomass nozzle (120) at its second end; the pulverized coal pipeline (200) has a pulverized coal inlet (210) at its first end and a pulverized coal nozzle (220) at its second end. The ammonia combustion assembly (300) includes an ammonia distributor (310), which includes a plurality of ammonia nozzles (311) arranged circumferentially along the ammonia distributor (310), and each of the ammonia nozzles (311) is located in the pulverized coal channel (R2) or in the combustion air channel (R3). The hydrogen combustion assembly (400) includes a hydrogen distributor (410), which includes a plurality of hydrogen nozzles (411) arranged circumferentially along the hydrogen distributor (410), and each of the hydrogen nozzles (411) is disposed in the combustion air passage (R3).

2. The burner as claimed in claim 1, characterized in that, The ammonia combustion assembly (300) includes an ammonia cyclone separator, which is movably disposed in the combustion air duct (R3); and / or, The hydrogen combustion assembly (400) includes a hydrogen cyclone separator (420) which is movably disposed in the combustion air duct (R3).

3. The burner as described in claim 2, characterized in that, Each of the ammonia nozzles (311) is arranged circumferentially along the pulverized coal channel (R2), and the axis of the ammonia nozzle (3111) of each of the ammonia nozzles (3111) is parallel to the axis of the biomass channel (R1); and / or, the angle between the axis of the ammonia nozzle (3111) of each of the ammonia nozzles (3111) and the axis of the burner is 0°~50°.

4. The burner as described in claim 3, characterized in that, Each of the hydrogen nozzles (411) is arranged circumferentially at intervals along the combustion air passage (R3); and / or, the angle between the axis of the hydrogen nozzle (4111) of each of the hydrogen nozzles (411) and the axis of the burner is 0° to 50°.

5. The burner as described in claim 2, characterized in that, Each of the ammonia nozzles (311) and each of the hydrogen nozzles (411) are arranged at circumferential intervals along the combustion air passage (R3), and the ammonia nozzles (311) and the hydrogen nozzles (411) are arranged alternately.

6. The burner as claimed in claim 1, characterized in that, The hydrogen nozzle (4111) of the hydrogen nozzle (4111) is located downstream of the pulverized coal nozzle (220), and the axial distance between them is 0~100mm; and / or, The ammonia nozzle (3111) of the ammonia nozzle (3111) is located upstream of the pulverized coal nozzle (220), and the axial distance between the ammonia nozzle (3111) and the hydrogen nozzle (4111) is 0mm~200mm.

7. The burner as claimed in claim 1, characterized in that, The biomass channel (R1) is equipped with a biomass distributor (130), and the axis of the biomass distributor (130) is collinear with the axis of the biomass channel (R1).

8. The burner as claimed in claim 7, characterized in that, The expansion angle of the feed-facing surface of the biomass distributor (130) is 20°~180°.

9. The burner as claimed in claim 8, characterized in that, The area of ​​the back powder surface of the biomass distributor (130) is 30% to 100% of the area of ​​the biomass channel (R1); and / or, the distance between the small diameter end of the expanding section of the biomass distributor (130) and the biomass distributor (130) is 0 mm to 100 mm.

10. The burner as claimed in claim 1, characterized in that, The biomass nozzle (120) has an anti-wear structure on the side facing the pulverized coal airflow.

11. A boiler, characterized in that, Includes a burner as described in any one of claims 1-10, wherein the number of said burners is at least one.

12. A combustion system, characterized in that, The system includes a boiler (10), a steam turbine (20), a condenser (30), and a liquid ammonia evaporator (40), which are connected in sequence. The liquid ammonia evaporator (40) is connected to the ammonia distributor (310) of the burner of the condenser (30) and the boiler (10), respectively. The boiler (10) is the boiler as described in claim 11.

Images