Coal dust and ammonia gas mixed combustion system and boiler

Abstract

The present disclosure provides a coal powder and ammonia mixed combustion system and a boiler. The coal powder and ammonia mixed combustion system comprises: a combustion device, a downstream end of the combustion device being configured to communicate with a furnace of the boiler; an ignition device, having an ignition end arranged in the combustion device, and being configured to ignite a fuel delivered to the ignition end; a coal powder gas flow providing device, having a fuel nozzle arranged upstream of the ignition end and being configured to provide a coal powder gas flow to the combustion device; an ammonia gas providing device, having an ammonia gas nozzle arranged to communicate with the combustion device, and being configured to provide ammonia gas to the combustion device; and a combustion-supporting medium providing device, having a combustion-supporting medium nozzle arranged to communicate with the combustion device, and being configured to provide a combustion-supporting medium to the combustion device; wherein at least one of the ammonia gas nozzle and the combustion-supporting medium nozzle is arranged downstream of the fuel nozzle.

Description

Technical Field

[0001] This disclosure relates to the field of boiler combustion equipment, and in particular to a pulverized coal and ammonia co-combustion system and boiler. Background Technology

[0002] The escalating global emissions of pollutants such as carbon dioxide pose a serious threat to the human living environment, and carbon reduction, or even zero emissions, is a new challenge facing humanity. One of the key methods to achieve carbon dioxide emission targets is to increase the use of renewable, low-carbon, or zero-carbon fuels in electricity and energy systems to reduce or even replace the use of traditional non-renewable hydrocarbon fuels.

[0003] Ammonia is a promising clean energy carrier and storage medium that can be obtained from fossil fuels, biomass, or other renewable resources. When completely burned, it is a potentially clean fuel. However, mature ammonia-coal co-combustion technology is currently lacking. When co-combusting zero-carbon fuel ammonia with pulverized coal, it is difficult to ensure stable combustion and complete burnout of ammonia, especially for units burning low-quality coal. Summary of the Invention

[0004] The purpose of this disclosure is to provide a coal-ammonia co-combustion system and boiler that enables stable combustion and complete combustion of ammonia when co-combusted with coal.

[0005] The first aspect of this disclosure provides a coal-ammonia co-combustion system, comprising:

[0006] A combustion device, the downstream end of which is connected to the furnace of a boiler;

[0007] An ignition device having an ignition end disposed within the combustion device and configured to ignite fuel supplied to the ignition end;

[0008] A pulverized coal gas flow supply device has a fuel nozzle located upstream of the ignition end and communicating with the combustion device, and is configured to supply pulverized coal gas flow to the combustion device;

[0009] An ammonia supply device, having an ammonia nozzle in communication with the combustion device, is configured to supply ammonia to the combustion device; and

[0010] A combustion-supporting medium supply device having a combustion-supporting medium nozzle in communication with the combustion device, configured to supply a combustion-supporting medium to the combustion device;

[0011] Wherein, at least one of the ammonia gas nozzle and the combustion medium nozzle is disposed downstream of the fuel nozzle.

[0012] According to some embodiments of this disclosure, the combustion medium nozzle includes a first combustion medium nozzle disposed at the ignition end, the ammonia nozzle is disposed downstream of the first combustion medium nozzle, the fuel nozzle is configured to inject the pulverized coal gas flow into the combustion device, the ignition end is configured to ignite the pulverized coal gas flow, the first combustion medium nozzle is configured to inject the combustion medium into the flame of the pulverized coal gas flow, and the ammonia nozzle is configured to inject the ammonia into the flame of the pulverized coal gas flow.

[0013] According to some embodiments of this disclosure, the combustion device includes a first combustion cylinder and a second combustion cylinder. The first combustion cylinder is sleeved outside the ignition end, and the second combustion cylinder is sleeved outside the first combustion cylinder. The outlet end of the second combustion cylinder is located downstream of the outlet end of the first combustion cylinder. The first combustion medium nozzle is connected to the first combustion cylinder, and the ammonia nozzle is connected to the second combustion cylinder.

[0014] According to some embodiments of this disclosure, the combustion medium nozzle includes a second combustion medium nozzle, the ammonia nozzle is disposed at the ignition end, the second combustion medium nozzle is connected to the pulverized coal gas flow supply device and is located upstream of the fuel nozzle, the second combustion medium nozzle is configured to inject the combustion medium into the pulverized coal gas flow provided by the pulverized coal gas flow supply device to form a first mixed gas flow, the fuel nozzle is configured to inject the first mixed gas flow into the combustion device, the ammonia nozzle is configured to inject the ammonia into the first mixed gas flow, and the ignition end is configured to ignite the first mixed gas flow and the ammonia.

[0015] According to some embodiments of this disclosure, the combustion medium nozzle includes a first combustion medium nozzle and a second combustion medium nozzle. The first combustion medium nozzle is disposed at the ignition end, the second combustion medium nozzle is connected to the pulverized coal gas flow supply device and located upstream of the fuel nozzle, and the ammonia nozzle is disposed downstream of the first combustion medium nozzle. The second combustion medium nozzle is configured to inject the combustion medium into the pulverized coal gas flow provided by the pulverized coal gas flow supply device to form a second mixed gas flow. The fuel nozzle is configured to inject the second mixed gas flow into the combustion device. The ignition end is configured to ignite the second mixed gas flow. The first combustion medium nozzle is configured to inject the combustion medium into the flame of the second mixed gas flow, and the ammonia nozzle is configured to inject the ammonia into the flame of the second mixed gas flow.

[0016] According to some embodiments of this disclosure, the combustion medium nozzle includes a first combustion medium nozzle disposed at the ignition end, the ammonia nozzle is connected to the pulverized coal gas flow supply device and located upstream of the fuel nozzle, the ammonia nozzle is configured to inject the ammonia into the pulverized coal gas flow provided by the pulverized coal gas flow supply device to form a third mixed gas flow, the fuel nozzle is configured to inject the third mixed gas flow into the combustion device, the ignition end is configured to ignite the third mixed gas flow, and the first combustion medium nozzle is configured to inject the combustion medium into the flame of the third mixed gas flow.

[0017] According to some embodiments of this disclosure, the combustion medium nozzle includes a first combustion medium nozzle, the ammonia nozzle is disposed at the ignition end, the first combustion medium nozzle is disposed downstream of the ammonia nozzle, the fuel nozzle is configured to inject the pulverized coal gas stream into the combustion device, the ammonia nozzle is configured to inject the ammonia into the pulverized coal gas stream, the ignition end is configured to ignite the pulverized coal gas stream and the ammonia, and the first combustion medium nozzle is configured to inject the combustion medium into the flame of the pulverized coal gas stream and the ammonia.

[0018] According to some embodiments of this disclosure, the combustion device includes a first combustion cylinder and a second combustion cylinder. The first combustion cylinder is sleeved outside the ignition end, and the second combustion cylinder is sleeved outside the first combustion cylinder. The outlet end of the second combustion cylinder is located downstream of the outlet end of the first combustion cylinder. The ammonia gas nozzle is connected to the first combustion cylinder, and the first combustion-supporting medium nozzle is connected to the second combustion cylinder.

[0019] According to some embodiments of this disclosure, the combustion-supporting medium is pure oxygen.

[0020] According to some embodiments of this disclosure, a plurality of the combustion-supporting medium nozzles are distributed circumferentially along the combustion device.

[0021] According to some embodiments of this disclosure, it also includes:

[0022] A first flow regulating unit is configured to regulate the flow rate of the ammonia gas; and / or

[0023] The second flow regulating unit is configured to regulate the flow rate of the combustion-supporting medium.

[0024] A second aspect of this disclosure provides a boiler including the pulverized coal and ammonia co-combustion system described in the first aspect of this disclosure.

[0025] In the pulverized coal and ammonia co-combustion system provided in this disclosure, at least one of the ammonia nozzle S2 and the combustion-supporting medium nozzle is located downstream of the fuel nozzle S1, allowing the pulverized coal gas flow, ammonia, and combustion-supporting medium to be fully mixed and combusted within the combustion device 3. Depending on the coal quality, ammonia can be ignited by the flame of the pulverized coal gas flow and aided by the combustion-supporting medium, reducing ignition difficulty and ensuring stable and complete combustion of ammonia; alternatively, it can be mixed with the pulverized coal gas flow and ignited together, then aided by the combustion-supporting medium, maintaining stable and complete combustion of ammonia. Therefore, the pulverized coal and ammonia co-combustion system provided in this disclosure can reduce carbon emissions from coal-fired power units, achieving the carbon emission reduction target of coal-fired boilers. The boiler provided in this disclosure possesses the advantages of the pulverized coal and ammonia co-combustion system provided in this disclosure.

[0026] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some embodiments of this disclosure.

[0029] Figure 2 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0030] Figure 3 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0031] Figure 4 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0032] Figure 5 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0033] Figure 6 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0034] Figure 7 This is a schematic diagram of the structure of a coal powder and ammonia co-combustion system according to some other embodiments of this disclosure.

[0035] Figures 1 to 7 In the figures, the labels represent:

[0036] 1. Pulverized coal gas supply device; 2. Ignition device; 3. Combustion device; 31. First combustion chamber; 32. Second combustion chamber; 4. Furnace; 5. Combustion medium supply device; 6. Ammonia supply device; 7. Second flow regulating unit; 8. First flow regulating unit; S1. Fuel nozzle; S2. Ammonia nozzle; S31. First combustion medium nozzle; S32. Second combustion medium nozzle; f1. Flame of pulverized coal gas flow; f2. Flame of first mixed gas flow; f3. Flame of second mixed gas flow; f4. Flame of third mixed gas flow; f5. Flame of pulverized coal gas flow and ammonia; K. Ignition end. Detailed Implementation

[0037] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0039] In the description of this disclosure, it should be understood that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this disclosure.

[0040] In the description of this disclosure, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this disclosure and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this disclosure; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0041] In the process of developing this disclosure, the inventors discovered that pure ammonia has a lower laminar combustion rate and calorific value compared to conventional hydrocarbon fuels, and requires higher energy for ignition, resulting in a narrower combustion limit range, making the combustion of pure ammonia more difficult. Because ammonia is not easily combustible and has a low flame propagation speed, it is difficult to ensure stable combustion and complete burnout, which will be even more challenging for units burning low-quality coal.

[0042] To improve the above problems, such as Figures 1 to 7 As shown, some embodiments of this disclosure provide a coal powder and ammonia co-combustion system, including a combustion device 3, an ignition device 2, a coal powder gas supply device 1, an ammonia supply device 6, and a combustion-supporting medium supply device 5.

[0043] The downstream end of the combustion device 3 is connected to the furnace 4 of the boiler. The ignition device 2 has an ignition terminal K located within the combustion device 3 and is configured to ignite the fuel supplied to the ignition terminal K. The pulverized coal gas flow supply device 1 has a fuel nozzle S1 located upstream of the ignition terminal K and connected to the combustion device 3, and is configured to supply pulverized coal gas flow to the combustion device 3. The ammonia supply device 6 has an ammonia nozzle S2 connected to the combustion device 3 and is configured to supply ammonia to the combustion device 3. The combustion medium supply device 5 has a combustion medium nozzle connected to the combustion device 3 and is configured to supply combustion medium to the combustion device 3. At least one of the ammonia nozzle S2 and the combustion medium nozzle is located downstream of the fuel nozzle S1.

[0044] The pulverized coal gas stream, ammonia, and combustion-supporting medium are mixed within the combustion device 3. The ignition device 2 can be a plasma generator, a micro-oil ignition device, a micro-gas ignition device, etc. The gas stream used to transport the pulverized coal can be primary air, and correspondingly, the pulverized coal gas stream supply device 1 can include a pulverized coal gas stream delivery pipeline, such as a primary air duct. The ammonia supply device 6 can include an ammonia storage tank and an ammonia delivery pipeline connecting the ammonia nozzle S2 and the ammonia storage tank. The combustion-supporting medium supply device 5 can include a combustion-supporting medium storage tank and a combustion-supporting medium delivery pipeline connecting the combustion-supporting medium nozzle and the combustion-supporting medium storage tank.

[0045] In the pulverized coal and ammonia co-combustion system provided in the embodiments of this disclosure, at least one of the ammonia nozzle S2 and the combustion-supporting medium nozzle is located downstream of the fuel nozzle S1, allowing the pulverized coal gas flow, ammonia, and combustion-supporting medium to be fully mixed and combusted within the combustion device 3. Depending on the coal quality, ammonia can be ignited by the flame of the pulverized coal gas flow and aided by the combustion-supporting medium, reducing ignition difficulty and maintaining stable combustion and complete burnout of ammonia; alternatively, it can be mixed with the pulverized coal gas flow and ignited together, then aided by the combustion-supporting medium, maintaining stable combustion and complete burnout of ammonia. Therefore, the pulverized coal and ammonia co-combustion system provided in the embodiments of this disclosure can reduce carbon emissions from coal-fired power units, achieving the carbon emission reduction target of coal-fired boilers.

[0046] In some embodiments, the combustion-supporting medium is pure oxygen.

[0047] Using pure oxygen as the combustion medium can lower the fuel ignition temperature, making both pulverized coal and ammonia easier to ignite. It also increases the combustion rate, achieving better co-combustion results, effectively improving the burnout rate of pulverized coal and ammonia, reducing pollutant emissions, and meeting the mixed ammonia combustion requirements of low-quality coal units.

[0048] In other embodiments, the combustion medium may also be oxygen-containing air, and the proportion of oxygen in the oxygen-containing air may be determined according to the coal quality and the ratio of pulverized coal gas flow to ammonia.

[0049] In some embodiments, the positions of the ammonia nozzle S2 and the combustion medium nozzle along the airflow direction of the combustion device 3 are adjustable. By adjusting the addition positions of the combustion medium and ammonia, good combustion of pulverized coal mixed with ammonia of different coal qualities can be achieved.

[0050] In some embodiments, such as Figure 1 As shown, the combustion medium nozzle includes a first combustion medium nozzle S31, which is located at the ignition end K. An ammonia nozzle S2 is located downstream of the first combustion medium nozzle S31. The fuel nozzle S1 is configured to inject pulverized coal gas flow into the combustion device 3. The ignition end K is configured to ignite the pulverized coal gas flow. The first combustion medium nozzle S31 is configured to inject the combustion medium into the flame f1 of the pulverized coal gas flow. The ammonia nozzle S2 is configured to inject ammonia into the flame f1 of the pulverized coal gas flow.

[0051] In the above embodiments, the pulverized coal gas supply device 1 injects pulverized coal gas into the combustion device 3 through the fuel nozzle S1, and the ignition device 2 ignites the pulverized coal gas. The combustion medium supply device 5 injects combustion medium such as pure oxygen into the ignition area of ​​the combustion device 3 through the first combustion medium nozzle S31. This allows the combustion medium to directly enter the flame f1 of the pulverized coal gas, avoiding dilution of the combustion medium, which helps to enhance pulverized coal combustion and cultivate a stable and intense flame. The ammonia supply device 6 injects ammonia into the downstream position of the ignition area through the ammonia nozzle S2 and into the flame f1 of the pulverized coal gas. The flame f1 of the generated pulverized coal gas is used to ignite the ammonia, while the combustion medium such as pure oxygen continues to support the combustion of the ammonia, so that the ammonia is ignited and maintains stable combustion. This not only solves the problem of low laminar flame velocity of ammonia and difficulty in stable combustion alone, but also enhances the combustion effect of the mixture of ammonia and pulverized coal, which helps to improve the combustion efficiency of pulverized coal and ammonia and reduce ammonia escape.

[0052] For the above-described pulverized coal and ammonia co-combustion system, the combustion device 3 can be composed of one or more combustion chambers.

[0053] In some embodiments, such as Figure 2 As shown, the combustion device 3 includes a first combustion cylinder 31 and a second combustion cylinder 32. The first combustion cylinder 31 is sleeved outside the ignition end K, and the second combustion cylinder 32 is sleeved outside the first combustion cylinder 31. The outlet end of the second combustion cylinder 32 is located downstream of the outlet end of the first combustion cylinder 31. The first combustion medium nozzle S31 is connected to the first combustion cylinder 31, and the ammonia nozzle S2 is connected to the second combustion cylinder 32.

[0054] In the above embodiments, the pulverized coal gas supply device 1 injects pulverized coal gas into the combustion device 3 through the fuel nozzle S1, and the ignition device 2 ignites the pulverized coal gas. The combustion medium supply device 5 injects combustion medium such as pure oxygen into the first combustion chamber 31 of the combustion device 3 through the first combustion medium nozzle S31, and the ammonia supply device 6 injects ammonia into the second combustion chamber 32 of the combustion device 3 through the ammonia nozzle S2. The combustion medium such as pure oxygen introduced first intensifies the combustion of pulverized coal, and then the flame f1 of the generated pulverized coal gas is used to ignite the ammonia. At the same time, the input combustion medium such as pure oxygen continues to assist the combustion of ammonia, igniting the ammonia and maintaining stable combustion of ammonia.

[0055] In some embodiments, such as Figure 3As shown, the combustion medium nozzle includes a second combustion medium nozzle S32, and an ammonia nozzle S2 is disposed at the ignition end K. The second combustion medium nozzle S32 is connected to the pulverized coal gas supply device 1 and is located upstream of the fuel nozzle S1. The second combustion medium nozzle S32 is configured to inject the combustion medium into the pulverized coal gas supply device 1 to form a first mixed gas flow. The fuel nozzle S1 is configured to inject the first mixed gas flow into the combustion device 3. The ammonia nozzle S2 is configured to inject ammonia into the first mixed gas flow. The ignition end K is configured to ignite the first mixed gas flow and ammonia.

[0056] In the above embodiments, the combustion medium supply device 5 injects combustion medium such as pure oxygen into the pulverized coal gas stream through the second combustion medium nozzle S32, where it mixes thoroughly with the pulverized coal gas stream to form a first mixed gas stream with a higher oxygen concentration. By setting the oxygen content of the combustion medium to an appropriate ratio, an oxygen-rich environment with an oxygen content greater than 21% can be gradually formed as the combustion medium is continuously injected. The ammonia supply device 6 injects ammonia gas into the ignition zone of the combustion device 3 through the ammonia gas nozzle S2, where it directly contacts and mixes with the oxygen-rich first mixed gas stream, and is then ignited by the ignition device 2. Ammonia gas is more easily ignited in an oxygen-rich environment. This arrangement of the second combustion medium nozzle S32 and the ammonia gas nozzle S2 helps to improve the ignition performance and burnout characteristics of the ammonia-coal mixture, ensuring stable and complete combustion of the ammonia-coal mixture, and improving the combustion efficiency of the boiler.

[0057] In some embodiments, such as Figure 4 As shown, the combustion medium nozzle includes a first combustion medium nozzle S31 and a second combustion medium nozzle S32. The first combustion medium nozzle S31 is located at the ignition end K. The second combustion medium nozzle S32 is connected to the pulverized coal gas supply device 1 and is located upstream of the fuel nozzle S1. The ammonia nozzle S2 is located downstream of the first combustion medium nozzle S31. The second combustion medium nozzle S32 is configured to inject the combustion medium into the pulverized coal gas supply device 1 to form a second mixed gas flow. The fuel nozzle S1 is configured to inject the second mixed gas flow into the combustion device 3. The ignition end K is configured to ignite the second mixed gas flow. The first combustion medium nozzle S31 is configured to inject the combustion medium into the flame f3 of the second mixed gas flow. The ammonia nozzle S2 is configured to inject ammonia into the flame f3 of the second mixed gas flow.

[0058] In the above embodiments, the combustion medium supply device 5 injects combustion medium such as pure oxygen into the ignition zone of the pulverized coal gas flow provided by the pulverized coal gas flow supply device 1 and the combustion device 3 simultaneously through the first combustion medium nozzle S31 and the second combustion medium nozzle S32. The pulverized coal gas flow supply device 1 injects a second mixed gas flow into the combustion device 3 through the fuel nozzle S1, and the ignition device 2 ignites the second mixed gas flow. On the one hand, the second mixed gas flow forms an oxygen-rich environment with an oxygen content greater than 21%. On the other hand, a portion of the combustion medium can also directly enter the flame f3 of the second mixed gas flow through the first combustion medium nozzle S31, which can enhance the combustion of pulverized coal and help cultivate a stable and intense flame. The ammonia supply device 6 injects ammonia gas into the downstream position of the ignition zone through the ammonia gas nozzle S2 and into the flame f3 of the second mixed gas flow. The flame f3 of the generated second mixed gas flow is used to ignite the ammonia gas, while pure oxygen is used to continue to support the combustion of the ammonia gas, so that the ammonia gas is ignited and maintained in stable combustion. By setting the first combustion medium nozzle S31 and the second combustion medium nozzle S32, the combustion medium can be simultaneously added to the ignition zone of the pulverized coal gas flow pipeline and the combustion device, thereby doubly enhancing the combustion effect of the ammonia and pulverized coal mixture and improving the combustion efficiency of pulverized coal and ammonia.

[0059] In some embodiments, such as Figure 5 As shown, the combustion medium nozzle includes a first combustion medium nozzle S31, which is located at the ignition end K. An ammonia nozzle S2 is connected to the pulverized coal gas supply device 1 and is located upstream of the fuel nozzle S1. The ammonia nozzle S2 is configured to inject ammonia into the pulverized coal gas supply device 1 to form a third mixed gas flow. The fuel nozzle S1 is configured to inject the third mixed gas flow into the combustion device 3. The ignition end K is configured to ignite the third mixed gas flow. The first combustion medium nozzle S31 is configured to inject the combustion medium into the flame f4 of the third mixed gas flow.

[0060] In the above embodiments, the ammonia supply device 6 injects ammonia gas into the pulverized coal gas flow provided by the pulverized coal gas flow supply device 1 through the ammonia gas nozzle S2. Under the high-speed impact of the pulverized coal gas flow, such as the primary air-pulverized coal gas flow, the ammonia gas and pulverized coal can achieve full contact and mixing. Subsequently, the third mixed gas flow formed by the pulverized coal gas flow and ammonia gas is injected into the combustion device 3 through the fuel nozzle S1 and ignited by the ignition device 2. The combustion medium supply device 5 injects pure oxygen and other combustion mediums into the ignition zone of the combustion device 3 through the first combustion medium nozzle S31. By adding pure oxygen and other combustion mediums to the ignition zone, the combustion mediums are rapidly integrated into the flame f4 of the third mixed gas flow, increasing the oxygen concentration in the ignition zone, promoting stable and complete combustion of the ammonia-coal mixture in the furnace. With the help of the combustion medium, the combustion reaction is enhanced, the flame propagation ability is improved, the ignition performance and burnout characteristics of the ammonia-coal mixture are improved, and the ammonia escape is reduced, thereby solving the problems of incomplete combustion and low combustion efficiency of the ammonia-coal mixture.

[0061] In some embodiments, such as Figure 6 As shown, the combustion medium nozzle includes a first combustion medium nozzle S31, an ammonia nozzle S2 is disposed at the ignition end K, the first combustion medium nozzle S31 is disposed downstream of the ammonia nozzle S2, the fuel nozzle S1 is configured to inject pulverized coal gas flow into the combustion device 3, the ammonia nozzle S2 is configured to inject ammonia into the pulverized coal gas flow, the ignition end K is configured to ignite the pulverized coal gas flow and ammonia, and the first combustion medium nozzle S31 is configured to inject the combustion medium into the flame f5 of the pulverized coal gas flow and ammonia.

[0062] In the above embodiments, the pulverized coal gas supply device 1 injects pulverized coal gas into the ignition zone of the combustion device 3 through the fuel nozzle S1, and the ammonia gas supply device 6 injects ammonia gas into the ignition zone of the combustion device 3 through the ammonia gas nozzle S2. The pulverized coal gas and ammonia gas are ignited after mixing in the ignition zone. The combustion medium supply device 5 injects combustion medium such as pure oxygen into the downstream position of the ignition zone through the first combustion medium nozzle S31, and injects it into the flame f5 of the pulverized coal gas and ammonia gas. Since ammonia gas is not easily ignited, after some pulverized coal is ignited, a small amount of ammonia gas can be ignited by the combustion flame. After adding the combustion medium, the ignition effect of the upstream ammonia gas and pulverized coal gas can be further enhanced, the flame propagation ability can be strengthened, and thus the combustion of the ammonia-coal mixture can be more complete, significantly improving the ignition performance and burnout effect.

[0063] For the above-described pulverized coal and ammonia co-combustion system, the combustion device 3 can be composed of one or more combustion chambers.

[0064] In some embodiments, such as Figure 7 As shown, the combustion device 3 includes a first combustion cylinder 31 and a second combustion cylinder 32. The first combustion cylinder 31 is sleeved outside the ignition end K, and the second combustion cylinder 32 is sleeved outside the first combustion cylinder 31. The outlet end of the second combustion cylinder 32 is located downstream of the outlet end of the first combustion cylinder 31. The ammonia gas nozzle S2 is connected to the first combustion cylinder 31, and the first combustion medium nozzle S31 is connected to the second combustion cylinder 32.

[0065] In the above embodiments, the pulverized coal gas supply device 1 injects pulverized coal gas into the combustion device 3 through the fuel nozzle S1, and the ignition device 2 ignites the pulverized coal gas. The ammonia gas supply device 6 injects ammonia gas into the first combustion chamber 31 of the combustion device 3 through the ammonia gas nozzle S2, and the combustion medium supply device 5 injects a combustion medium such as pure oxygen into the second combustion chamber 32 of the combustion device 3 through the first combustion medium nozzle S31. The flame f5 of the pulverized coal gas gas first ignites part of the ammonia gas, realizing the initial mixing and combustion of ammonia gas and pulverized coal. Then, the combustion medium such as pure oxygen is used to intensify the mixing and combustion reaction, enhance the flame propagation, and further improve the combustion efficiency of pulverized coal and ammonia gas.

[0066] In some embodiments, a plurality of combustion medium nozzles are distributed circumferentially along the combustion device 3.

[0067] By setting multiple circumferentially distributed combustion medium nozzles, the flexible supply of combustion medium can be achieved, enabling the ammonia-coal mixture to burn evenly and completely. For example, multiple first combustion medium nozzles S31 can be evenly or unevenly distributed along the circumference of the combustion device 3; or multiple second combustion medium nozzles S32 can be evenly or unevenly distributed along the circumference of the combustion device 3 on the pulverized coal gas flow pipeline upstream of the fuel nozzle S1.

[0068] In some embodiments, the pulverized coal and ammonia co-combustion system further includes a first flow regulating unit 8 and / or a second flow regulating unit 7. The first flow regulating unit 8 is configured to regulate the flow rate of ammonia. The second flow regulating unit 7 is configured to regulate the flow rate of the combustion-supporting medium.

[0069] By providing at least one of the first flow regulating unit 8 and the second flow regulating unit 7, the ratio of ammonia to combustion-supporting medium can be flexibly adjusted according to the coal quality and the combustion conditions within the combustion device. The first flow regulating unit 8 and the second flow regulating unit 7 can be air valves. The first flow regulating unit 8 can be installed independently on the combustion-supporting medium storage tank, independently on the combustion-supporting medium delivery pipeline, or simultaneously on both the combustion-supporting medium storage tank and the combustion-supporting medium delivery pipeline. The second flow regulating unit 7 can be installed independently on the ammonia storage tank, independently on the ammonia delivery pipeline, or simultaneously on both the ammonia storage tank and the ammonia delivery pipeline.

[0070] Some embodiments of this disclosure also provide a boiler including the aforementioned pulverized coal and ammonia co-fired system. The boiler provided by the embodiments of this disclosure has the advantages of the pulverized coal and ammonia co-fired system provided by the embodiments of this disclosure.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure and not to limit them; although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this disclosure or equivalent substitutions can be made to some technical features, all of which should be covered within the scope of the technical solutions claimed in this disclosure.

Claims

1. A coal pulverized gas and ammonia co-combustion system, characterized in that, include: Combustion device (3), the downstream end of which is used to communicate with the furnace (4) of the boiler; The ignition device (2) has an ignition end (K) disposed in the combustion device (3) and is configured to ignite the fuel supplied to the ignition end (K); The pulverized coal flow supply device (1) has a fuel nozzle (S1) located upstream of the ignition end (K) and connected to the combustion device (3), and is configured to supply pulverized coal flow to the combustion device (3). An ammonia supply device (6) having an ammonia nozzle (S2) connected to the combustion device (3) is configured to supply ammonia to the combustion device (3); and The combustion medium supply device (5) has a combustion medium nozzle connected to the combustion device (3) and is configured to supply combustion medium to the combustion device (3); Wherein, at least one of the ammonia gas nozzle (S2) and the combustion medium nozzle is disposed downstream of the fuel nozzle (S1); The combustion medium nozzle includes a first combustion medium nozzle (S31), which is located at the ignition end (K). The ammonia nozzle (S2) is located downstream of the first combustion medium nozzle (S31). The fuel nozzle (S1) is configured to inject the pulverized coal gas flow into the combustion device (3). The ignition end (K) is configured to ignite the pulverized coal gas flow. The first combustion medium nozzle (S31) is configured to inject the combustion medium into the flame (f1) of the pulverized coal gas flow. The ammonia nozzle (S2) is configured to inject the ammonia into the flame (f1) of the pulverized coal gas flow. The combustion device (3) includes a first combustion cylinder (31) and a second combustion cylinder (32). The first combustion cylinder (31) is sleeved outside the ignition end (K), and the second combustion cylinder (32) is sleeved outside the first combustion cylinder (31). The outlet end of the second combustion cylinder (32) is located downstream of the outlet end of the first combustion cylinder (31). The first combustion medium nozzle (S31) is connected to the first combustion cylinder (31) to inject the combustion medium into the first combustion cylinder (31) from downstream of the ignition end (K) through the first combustion medium nozzle (S31). The ammonia nozzle (S2) is connected to the second combustion cylinder (32) to inject the ammonia into the second combustion cylinder (32) from downstream of the outlet end of the first combustion cylinder (31) through the ammonia nozzle (S2).

2. The pulverized coal and ammonia co-combustion system according to claim 1, characterized in that, The combustion medium nozzle further includes a second combustion medium nozzle (S32), which is connected to the pulverized coal gas supply device (1) and located upstream of the fuel nozzle (S1). The second combustion medium nozzle (S32) is configured to inject the combustion medium into the pulverized coal gas supply provided by the pulverized coal gas supply device (1) to form a second mixed gas flow. The fuel nozzle (S1) is configured to inject the second mixed gas flow into the combustion device (3). The ignition end (K) is configured to ignite the second mixed gas flow. The first combustion medium nozzle (S31) is configured to inject the combustion medium into the flame (f3) of the second mixed gas flow. The ammonia nozzle (S2) is configured to inject the ammonia into the flame (f3) of the second mixed gas flow.

3. A coal pulverized gas and ammonia co-combustion system, characterized in that, include: Combustion device (3), the downstream end of which is used to communicate with the furnace (4) of the boiler; The ignition device (2) has an ignition end (K) disposed in the combustion device (3) and is configured to ignite the fuel supplied to the ignition end (K); The pulverized coal airflow supply device (1) has a fuel nozzle (S1) located upstream of the ignition end (K) and connected to the combustion device (3), and is configured to supply pulverized coal airflow to the combustion device (3). An ammonia supply device (6) having an ammonia nozzle (S2) connected to the combustion device (3) is configured to supply ammonia to the combustion device (3); and The combustion medium supply device (5) has a combustion medium nozzle connected to the combustion device (3) and is configured to supply combustion medium to the combustion device (3); Wherein, at least one of the ammonia gas nozzle (S2) and the combustion medium nozzle is disposed downstream of the fuel nozzle (S1); The combustion medium nozzle includes a first combustion medium nozzle (S31), the ammonia nozzle (S2) is disposed at the ignition end (K), the first combustion medium nozzle (S31) is disposed downstream of the ammonia nozzle (S2), the fuel nozzle (S1) is configured to inject the pulverized coal gas flow into the combustion device (3), the ammonia nozzle (S2) is configured to inject the ammonia into the pulverized coal gas flow, the ignition end (K) is configured to ignite the pulverized coal gas flow and the ammonia, and the first combustion medium nozzle (S31) is configured to inject the combustion medium into the flame (f5) of the pulverized coal gas flow and the ammonia; The combustion device (3) includes a first combustion cylinder (31) and a second combustion cylinder (32). The first combustion cylinder (31) is sleeved outside the ignition end (K), and the second combustion cylinder (32) is sleeved outside the first combustion cylinder (31). The outlet end of the second combustion cylinder (32) is located downstream of the outlet end of the first combustion cylinder (31). The ammonia nozzle (S2) is connected to the first combustion cylinder (31) to inject the ammonia gas into the first combustion cylinder (31) from downstream of the ignition end (K) through the ammonia nozzle (S2). The first combustion medium nozzle (S31) is connected to the second combustion cylinder (32) to inject the combustion medium into the second combustion cylinder (32) from downstream of the outlet end of the first combustion cylinder (31) through the first combustion medium nozzle (S31).

4. The pulverized coal and ammonia co-combustion system according to any one of claims 1 to 3, characterized in that, The combustion-supporting medium is pure oxygen.

5. The pulverized coal and ammonia co-combustion system according to any one of claims 1 to 3, characterized in that, Multiple combustion-supporting medium nozzles are distributed circumferentially along the combustion device (3).

6. The pulverized coal and ammonia co-combustion system according to any one of claims 1 to 3, characterized in that, Also includes: The first flow regulating unit (8) is configured to regulate the flow rate of the ammonia gas; and / or The second flow regulating unit (7) is configured to regulate the flow rate of the combustion-supporting medium.

7. A boiler, characterized in that, Including the coal pulverized gas and ammonia co-combustion system according to any one of claims 1 to 6.

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