System and method for preventing high-temperature corrosion of opposed firing boiler

Abstract

The invention provides a system and method for preventing high-temperature corrosion of an opposed firing boiler. The system for preventing high-temperature corrosion of the opposed firing boiler comprises a plurality of combustors, a coal mill and a pulverized coal concentration adjusting assembly, the combustors are arranged on the front wall or the rear wall of the water cooling wall of the boiler and are sequentially arranged in the width direction of the front wall and the rear wall. The combustors comprise the first combustors close to the side wall of the water cooling wall of the boiler and the second combustors located between the first combustors. A plurality of pulverized coal pipes are arranged at a discharge port of the coal mill, and the pulverized coal pipes comprise a first pulverized coal pipe for supplying pulverized coal to the first combustor and a second pulverized coal pipe for supplying pulverized coal to the second combustor; the pulverized coal concentration adjusting assembly is arranged on the first pulverized coal pipe, and the pulverized coal concentration adjusting assembly is arranged to be capable of adjusting the concentration of pulverized coal in the first pulverized coal pipe. According to the system, the wall-adhering atmosphere of the side wall water cooling wall is improved by reducing the pulverized coal concentration of the wall-adhering side combustor, and the problem of high-temperature corrosion of the water cooling wall can be effectively relieved.

Description

Technical Field

[0001] This application relates to the technical field of boilers, and in particular, to a system and method for preventing high-temperature corrosion of opposed firing boilers. Background Art

[0002] With the continuous promotion of the national energy conservation and emission reduction policies, coal-fired power plants generally adopt the technical means of combining air staging combustion with low-NOx burners to control the generation of nitrogen oxides (NOx) and meet the ultra-low emission requirements. Under this background, the front and rear wall opposed swirling combustion system has been widely used in domestic supercritical and ultra-supercritical boilers due to its advantages such as flexible arrangement of combustion equipment, uniform furnace temperature distribution, and high combustion efficiency.

[0003] However, relatively serious high-temperature corrosion problems of the water wall have emerged during the actual operation of this type of combustion system. To reduce NOx emissions, usually, the method of reducing the excess air coefficient in the main burner area is adopted, and oxygen is supplemented in the overfire air area, thus forming a strongly reducing atmosphere in the main combustion area. This strongly reducing environment leads to an increase in the concentration of sulfides such as H2S in the flue gas, which destroys the iron oxide protective film on the outer surface of the water wall tube, and then causes sulfide-type high-temperature corrosion. Moreover, due to the presence of alkali metals and sulfur elements in the pulverized coal ash, the enhancement of the reducing atmosphere in the furnace will also significantly reduce the ash melting point of the coal, resulting in serious slagging on the water wall in the main combustion area, further exacerbating the development of high-temperature corrosion.

[0004] In addition, for the front and rear wall opposed combustion system, the burner arrangement method determines the flow characteristics of the pulverized coal airflow in the furnace. While the pulverized coal particles move vertically upward, they are also affected by the mutual opposition of the jets from the front and rear wall burners, generating a large lateral diffusion flow, which significantly increases the pulverized coal concentration in the side wall area. At the same time, due to insufficient oxygen supplementation, a local reducing atmosphere is easily formed in this area, resulting in high-temperature corrosion of the water wall mainly concentrated on the left and right side walls of the main burner area.

[0005] Currently, the main measures to alleviate high-temperature corrosion of the water wall include: water wall anti-corrosion spraying and wall-attached air technology. The former realizes passive protection by spraying anti-oxidation and anti-corrosion materials on the surface of the water wall. However, this method can only be implemented during maintenance, with high construction costs, and the coating is prone to peeling off, and the protection effect is limited. By sending a small amount of secondary air near the water wall to improve the atmosphere environment in the wall-attached area. However, due to the small air supply momentum and low air pressure, it is difficult to effectively improve the reducing atmosphere in practical applications, and the introduction of wall-attached air may affect the overall combustion efficiency of the boiler. Summary of the Invention

[0006] The embodiments of the present application at least provide a system and method for preventing high-temperature corrosion of a opposed firing boiler. The system can improve the wall-attached atmosphere of the side wall water-cooled wall by reducing the pulverized coal concentration of the burners on the wall-attached side, and can effectively alleviate the problem of high-temperature corrosion of the water-cooled wall.

[0007] In a first aspect, the embodiments of the present application provide a system for preventing high-temperature corrosion of an opposed firing boiler. The system includes: a plurality of burners, a coal mill, and a pulverized coal concentration adjustment component;

[0008] The burners are arranged on the front wall or the rear wall of the boiler water-cooled wall in sequence along the width direction of the front wall and the rear wall. The burners include a first burner close to the side wall of the boiler water-cooled wall and a second burner located between the first burners;

[0009] A plurality of powder pipes are provided at the discharge port of the coal mill. The powder pipes include a first powder pipe for supplying pulverized coal to the first burner and a second powder pipe for supplying pulverized coal to the second burner;

[0010] The pulverized coal concentration adjustment component is arranged on the first powder pipe, and is configured to be able to adjust the concentration of the pulverized coal in the first powder pipe.

[0011] In an optional implementation manner, the pulverized coal concentration adjustment component includes a pneumatic powder separator, a powder bin, a coal feeder, a pneumatic powder mixer, and a fan. The pneumatic powder separator, the powder bin, the coal feeder, and the pneumatic powder mixer are connected in series on the first powder pipe in sequence from the coal mill to the first burner. The coal powder separator is used to separate the pulverized coal and the primary air. The powder bin is used to store the separated pulverized coal. The coal feeder is used to control the coal powder output of the powder bin. The pneumatic powder mixer is used to mix the pulverized coal with the primary air for transporting the pulverized coal. The air outlet of the fan is communicated with the air inlet of the pneumatic powder mixer, and the fan is used to send the primary air into the pneumatic powder mixer.

[0012] In an optional implementation manner, the pneumatic powder separator is a cyclone separator, and the air inlet of the fan is communicated with the air outlet of the pneumatic powder separator.

[0013] In an optional implementation manner, the system further includes: a plurality of water-cooled wall wall-attached atmosphere measuring devices, which are respectively arranged on the side wall of the boiler water-cooled wall, and are configured to be able to detect the contents of H2S and CO in the wall-attached atmosphere.

[0014] In an optional implementation manner, when H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjustment component reduces the concentration of the pulverized coal in the first powder pipe.

[0015] In an alternative embodiment, the system further includes: a plurality of pulverized coal concentration measuring devices, which are respectively arranged in a plurality of the powder pipes, and each of the pulverized coal concentration measuring devices is configured to be able to detect the concentration of pulverized coal in the corresponding powder pipe.

[0016] In an alternative embodiment, the pulverized coal concentration measuring device includes a first measuring device arranged in the first powder pipe and a second measuring device arranged in the second powder pipe, and the first measuring device is located downstream of the pulverized coal concentration adjusting assembly.

[0017] In a second aspect, the embodiments of the present application further provide a method for preventing high-temperature corrosion of an opposed firing boiler, which is applicable to the system for preventing high-temperature corrosion of an opposed firing boiler described above. The method includes: during the process of supplying pulverized coal to the first burner through the first powder pipe and supplying pulverized coal to the second burner through the second powder pipe, reducing the concentration of pulverized coal in the first powder pipe through the pulverized coal concentration adjusting assembly, so as to reduce the concentration of pulverized coal in the side wall area of the boiler water wall.

[0018] In an alternative embodiment, the method further includes: monitoring the contents of H2S and CO in the atmosphere adhering to the water wall. When H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjusting assembly reduces the concentration of pulverized coal in the first powder pipe until H2S is not greater than 100 ppm or CO is not greater than 2000 ppm.

[0019] The above technical solutions of the present application have the following beneficial technical effects:

[0020] The system for preventing high-temperature corrosion of an opposed firing boiler according to the embodiments of the present application includes a first burner arranged close to the side wall, a second burner located between the first burners, a first powder pipe for supplying pulverized coal to the first burner, a second powder pipe for supplying pulverized coal to the second burner, and a pulverized coal concentration adjusting assembly arranged in the first powder pipe. While the first powder pipe supplies pulverized coal to the first burner, the pulverized coal concentration adjusting assembly can be used to adjust the concentration of pulverized coal in the first powder pipe, so as to achieve differential control of the pulverized coal concentration between different powder pipes of the same layer of burners, and achieve the distribution effect of "thick in the middle and thin on both sides", thereby optimizing the combustion atmosphere in the side wall area and alleviating the problem of high-temperature corrosion of the water wall.

[0021] To make the above objects, features, and advantages of the present application more obvious and understandable, the following specific preferred embodiments are given below in conjunction with the accompanying drawings and are described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. The accompanying drawings herein are incorporated into the specification and form a part of this specification. These accompanying drawings show the embodiments consistent with the present application and are used together with the specification to illustrate the technical solutions of the present application. It should be understood that the following accompanying drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related accompanying drawings can be obtained based on these accompanying drawings without creative efforts.

[0023] Figure 1 It shows a schematic diagram of a system for preventing high-temperature corrosion in a opposed firing boiler provided by an embodiment of the present application;

[0024] In the figure: 1. Boiler; 2. Burner; 3. Coal mill; 4. Powder-air separator; 5. Powder bin; 6. Coal feeder; 7. Air-coal mixer; 8. Fan; 9. Measuring device for the atmosphere near the water wall; 10. Measuring device for pulverized coal concentration. Detailed implementation manners

[0025] Now, various exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and values set forth in these embodiments do not limit the scope of the present application.

[0026] The embodiments of the present application will be described in detail below. Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as limiting the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0027] The terms "first" and "second" in the description and claims of the present application may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0028] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0029] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0030] The embodiment of the present application provides a system for preventing high-temperature corrosion in a opposed firing boiler. This system improves the wall-attached atmosphere of the side wall water wall by reducing the pulverized coal concentration of the wall-attached burners, and can effectively alleviate the problem of high-temperature corrosion of the water wall.

[0031] Reference Figure 1 , the system for preventing high-temperature corrosion in the opposed firing boiler 1 includes: a plurality of burners 2, a coal mill 3, and a pulverized coal concentration adjustment component. The burners 2 are arranged on the front wall or the rear wall of the water wall of the boiler 1 and are arranged in sequence along the width direction of the front wall and the rear wall. The burner 2 includes a first burner close to the side wall of the boiler water wall and a second burner located between the first burners. A plurality of powder pipes are provided at the discharge port of the coal mill 3. The powder pipes include a first powder pipe for supplying pulverized coal to the first burner and a second powder pipe for supplying pulverized coal to the second burner. The pulverized coal concentration adjustment component is arranged on the first powder pipe and is set to be able to adjust the concentration of the pulverized coal in the first powder pipe. It should be noted that the side wall includes a left side wall and a right side wall. The left side wall and the right side wall are respectively located on both sides of the width direction of the front wall and the rear wall, and the left side wall and the right side wall enclose the boiler water wall with the front wall and the rear wall.

[0032] In this embodiment, the number of the first burners is two, and the two first burners are respectively defined as A1 and A4. Among them, A1 is close to the left wall, and A4 is close to the right wall. The number of the second burners is two, and the two second burners are respectively defined as A2 and A3. Among them, A2 is located on the side of A1 close to A4, and A3 is located between A2 and A4. The number of the first coal pipes is two. Among them, one first coal pipe is used to supply pulverized coal to A1, and the other first coal pipe is used to supply pulverized coal to A4. The number of the second coal pipes is two. Among them, one second coal pipe is used to supply pulverized coal to A2, and the other second coal pipe is used to supply pulverized coal to A3. During the use process, the coal mill 3 grinds raw coal into pulverized coal. After the ground pulverized coal is mixed with primary air, it is divided into four paths. Among them, the first path is transported to A1 through one first coal pipe, the second path is transported to A4 through the other first coal pipe, the third path is transported to A2 through one second coal pipe, and the fourth path is transported to A3 through the other second coal pipe. Since the first coal pipe is provided with a pulverized coal concentration adjustment component, the concentration of the pulverized coal in the first coal pipe can be reduced through the pulverized coal concentration adjustment component, so as to reduce the pulverized coal concentration in the side wall area and relieve the high-temperature corrosion problem of the water wall. It should be noted that the number of the first burners is consistent with the number of the first coal pipes, and the number of the second burners is consistent with the number of the second coal pipes. In a specific implementation, the number of the burners 2 and the coal pipes can be selected according to actual conditions, and is not limited to the above-discussed manner.

[0033] The system for preventing high-temperature corrosion of the opposed firing boiler 1 according to the embodiment of the present application includes a first burner arranged close to the side wall, a second burner located between the first burners, a first coal pipe for supplying pulverized coal to the first burner, a second coal pipe for supplying pulverized coal to the second burner, and a pulverized coal concentration adjustment component arranged on the first coal pipe. While the first coal pipe supplies pulverized coal to the first burner, the pulverized coal concentration adjustment component can be used to adjust the concentration of the pulverized coal in the first coal pipe, so as to realize the differential control of the pulverized coal concentration between different coal pipes of the same-layer burners 2, achieve the distribution effect of "thick in the middle and thin on both sides", thereby optimizing the combustion atmosphere in the side wall area and relieving the high-temperature corrosion problem of the water wall.

[0034] In some embodiments, the burner 2 can be a swirl burner 2. For example, the burner 2 can be a volute pulverized coal burner 2, an axial vane pulverized coal burner 2, a tangential vane pulverized coal burner 2, etc. This embodiment does not make specific limitations on this.

[0035] In some embodiments, the coal mill 3 can be a medium-speed coal mill 3. For example, the coal mill 3 can be an HP type medium-speed coal mill 3, an MPS type medium-speed coal mill 3, a ZGM type medium-speed coal mill 3, etc. This embodiment does not make specific limitations on this.

[0036] In some embodiments, the pulverized coal concentration adjustment assembly includes a pulverized coal-air separator 4, a coal bin 5, a coal feeder 6, a pulverized coal-air mixer 7, and a blower 8. The pulverized coal-air separator 4, the coal bin 5, the coal feeder 6, and the pulverized coal-air mixer 7 are connected in series to the first pulverized coal pipe in sequence from the coal mill 3 to the direction of the first burner. The air outlet of the blower 8 is communicated with the air inlet of the pulverized coal-air mixer 7. During specific use, the pulverized coal separator is used to separate pulverized coal and primary air. The coal bin 5 is used to store the separated pulverized coal. The coal feeder 6 is used to control the coal output amount of the coal bin 5. The pulverized coal-air mixer 7 is used to mix the pulverized coal with the primary air for transporting the pulverized coal. The blower 8 is used to send the primary air into the pulverized coal-air mixer 7.

[0037] In some embodiments, the coal feeder 6 can be a screw feeder. The coal feeder 6 can be arranged at the coal outlet of the coal bin 5. The coal feeder 6 controls the coal output amount by controlling the screw rotation speed. Specifically, when the screw rotation speed increases, the coal output amount increases. When the screw rotation speed decreases, the coal output amount decreases. Of course, the setting method and structure of the coal feeder 6 can be selected according to actual situations, and are not limited to the above-discussed method.

[0038] In some embodiments, the pulverized coal-air separator 4 is a cyclone separator. The air inlet of the blower 8 is communicated with the air outlet of the pulverized coal-air separator 4. During specific use, the blower 8 can transport the separated primary air to the pulverized coal-air mixer 7 to carry the pulverized coal into the burner 2. In this way, it can avoid the pulverized coal being discharged with the primary air, causing waste of resources. Regarding this, no specific limitation is made in this embodiment.

[0039] In some embodiments, the system further includes: a plurality of water-cooled wall attached atmosphere measuring devices 9. The water-cooled wall attached atmosphere measuring devices 9 are respectively arranged on the side walls of the water-cooled wall of the boiler 1. The water-cooled wall attached atmosphere measuring devices 9 are configured to be able to detect the contents of H2S and CO in the attached atmosphere. Specifically, the water-cooled wall attached atmosphere measuring devices 9 are used to detect the atmosphere components attached to the surface of the water-cooled wall during the combustion process of the boiler 1, especially the concentrations of harmful gases such as H2S and CO. In this way, it can facilitate the control system to control the pulverized coal concentration adjustment assembly according to the concentrations of harmful gases such as H2S and CO to improve the combustion atmosphere in the side wall area.

[0040] In some embodiments, the water-cooled wall attached atmosphere measuring device 9 can be a gas concentration sensor. For example, the water-cooled wall attached atmosphere measuring device 9 can be an electrochemical sensor or an infrared sensor, etc. Regarding this, no specific limitation is made in this embodiment.

[0041] In some embodiments, when H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjustment assembly reduces the concentration of pulverized coal in the first pulverized coal pipe. Specifically, when the water-cooled wall wall-attached atmosphere measuring device 9 detects that H2S in the wall-attached atmosphere is greater than 200 ppm or CO is greater than 5000 ppm, the control system can control the pulverized coal concentration adjustment assembly to reduce the concentration of pulverized coal in the first pulverized coal pipe, so as to reduce the pulverized coal concentration in the side wall area, reduce the production of H2S and CO, and improve the combustion atmosphere in the side wall area. It should be understood that reducing the pulverized coal concentration in the side wall area is to make H2S in the wall-attached atmosphere not greater than 100 ppm or CO not greater than 2000 ppm, so as to avoid excessive content of H2S and CO and exacerbate the corrosion of the water-cooled wall.

[0042] In some embodiments, the system further includes: a plurality of pulverized coal concentration measuring devices 10, which are respectively arranged in a plurality of pulverized coal pipes, and each pulverized coal concentration measuring device 10 is arranged to be able to detect the concentration of pulverized coal in the corresponding pulverized coal pipe. In specific use, each pulverized coal concentration measuring device 10 is used to monitor the concentration of pulverized coal in each pulverized coal pipe and feedback to the operator or the control system, so that the operator or the control system can timely control the pulverized coal concentration adjustment assembly to reduce the concentration of pulverized coal in the first pulverized coal pipe and improve the combustion atmosphere in the side wall area. In this embodiment, the pulverized coal concentration measuring device 10 includes a first measuring device arranged in the first pulverized coal pipe and a second measuring device arranged in the second pulverized coal pipe, and the first measuring device is located downstream of the pulverized coal concentration adjustment assembly.

[0043] In some embodiments, the pulverized coal concentration measuring device 10 can be a dust concentration sensor. For example, the pulverized coal concentration measuring device 10 can be a microwave sensor, a capacitive sensor, a differential pressure flowmeter, an optical density sensor or an ultrasonic sensor, etc. No specific limitation is made in this regard in this embodiment.

[0044] In some embodiments, the system for preventing high-temperature corrosion of the opposed firing boiler 1 can be controlled by an intelligent program. For example, based on a big data model, the historical operation data is cleaned and feature extraction is performed to achieve adaptive optimization of operation parameters. The characteristic parameters include the sulfur content of the coal entering the furnace, the unit load, the water-cooled wall wall-attached atmosphere, the output of the coal mill 3, the rotation speed of the coal feeder 6, the opening degree of the secondary air damper of the burner 2, etc. The reinforcement learning algorithm is used to optimize the parameters such as the output of the coal mill 3, the rotation speed of the coal feeder 6, and the opening degree of the secondary air damper of the burner 2 under different sulfur contents of the coal entering the furnace and unit loads with the optimal water-cooled wall wall-attached atmosphere as the goal.

[0045] The embodiment of the present application also provides a method for preventing high-temperature corrosion of the opposed firing boiler 1, which is applicable to the system for preventing high-temperature corrosion of the opposed firing boiler 1 described above.

[0046] The method includes: during the process of supplying pulverized coal to the first burner through the first pulverized coal pipe and supplying pulverized coal to the second burner through the second pulverized coal pipe, reducing the concentration of pulverized coal in the first pulverized coal pipe through a pulverized coal concentration adjustment component, so as to reduce the pulverized coal concentration in the side wall area of the water wall of boiler 1.

[0047] In this method, while the first pulverized coal pipe supplies pulverized coal to the first burner, the pulverized coal concentration adjustment component can be used to adjust the concentration of pulverized coal in the first pulverized coal pipe, so as to achieve differential control of the pulverized coal concentration between different pulverized coal pipes of the same-layer burners 2, and achieve the distribution effect of "thick in the middle and thin on both sides", thereby optimizing the combustion atmosphere in the side wall area and alleviating the problem of high-temperature corrosion of the water wall.

[0048] In some embodiments, the method further includes: monitoring the contents of H2S and CO in the wall-attached atmosphere of the water wall, and when H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjustment component reduces the concentration of pulverized coal in the first pulverized coal pipe until H2S is not greater than 100 ppm or CO is not greater than 2000 ppm.

[0049] Specifically, when the wall-attached atmosphere measuring device 9 of the water wall detects that H2S in the wall-attached atmosphere is greater than 200 ppm or CO is greater than 5000 ppm, the control system can control the pulverized coal concentration adjustment component to reduce the concentration of pulverized coal in the first pulverized coal pipe, so as to be able to reduce the pulverized coal concentration in the side wall area, reduce the production of H2S and CO, and improve the combustion atmosphere in the side wall area.

[0050] One or more embodiments of this specification are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification shall be included in the protection scope of this application.

[0051] The above is only the specific implementation manner of this application, but the protection scope of this application is not limited thereto. Any person skilled in the art within the technical scope disclosed by this application can easily think of changes or substitutions, which should all be covered by the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

1. A system for preventing high-temperature corrosion in a opposed firing boiler, characterized in that, The system includes: a plurality of burners, a coal mill, and a pulverized coal concentration adjustment assembly; The burners are arranged on the front wall or the rear wall of the boiler water wall and are arranged in sequence along the width direction of the front wall and the rear wall. The burners include a first burner close to the side wall of the boiler water wall and a second burner located between the first burners; A plurality of powder pipes are provided at the discharge port of the coal mill. The powder pipes include a first powder pipe for supplying pulverized coal to the first burner and a second powder pipe for supplying pulverized coal to the second burner; The pulverized coal concentration adjustment assembly is arranged in the first powder pipe and is configured to be able to adjust the concentration of the pulverized coal in the first powder pipe.

2. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 1, wherein The pulverized coal concentration adjustment assembly includes a gas-powder separator, a powder bin, a feeder, a gas-powder mixer, and a fan. The gas-powder separator, the powder bin, the feeder, and the gas-powder mixer are connected in series in the first powder pipe in sequence from the coal mill to the first burner. The coal powder separator is used to separate the pulverized coal and the primary air. The powder bin is used to store the separated pulverized coal. The feeder is used to control the powder output amount of the pulverized coal in the powder bin. The gas-powder mixer is used to mix the pulverized coal with the primary air for transporting the pulverized coal. The air outlet of the fan is communicated with the air inlet of the gas-powder mixer, and the fan is used to send the primary air into the gas-powder mixer.

3. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 2, characterized in that, The gas-powder separator is a cyclone separator, and the air inlet of the fan is communicated with the air outlet of the gas-powder separator.

4. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 1, wherein The system further includes: a plurality of water wall wall-attached atmosphere measuring devices, which are respectively arranged on the side walls of the boiler water wall, and the water wall wall-attached atmosphere measuring devices are configured to be able to detect the contents of H2S and CO in the wall-attached atmosphere.

5. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 4, wherein, When H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjustment assembly reduces the concentration of the pulverized coal in the first powder pipe.

6. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 1, characterized in that, The system further includes: a plurality of pulverized coal concentration measuring devices, which are respectively arranged on the plurality of powder pipes, and each pulverized coal concentration measuring device is configured to be able to detect the concentration of the pulverized coal in the corresponding powder pipe.

7. The system for preventing high-temperature corrosion of a opposed firing boiler according to claim 6, characterized in that, The pulverized coal concentration measuring device includes a first measuring device arranged in the first powder pipe and a second measuring device arranged in the second powder pipe, and the first measuring device is located downstream of the pulverized coal concentration adjustment assembly.

8. A method for preventing high-temperature corrosion of a opposed firing boiler, applicable to the system for preventing high-temperature corrosion of an opposed firing boiler according to any one of claims 1-7, characterized in that, The method includes: during the process of supplying pulverized coal to the first burner through the first powder pipe and supplying pulverized coal to the second burner through the second powder pipe, reducing the concentration of the pulverized coal in the first powder pipe through the pulverized coal concentration adjustment assembly to reduce the pulverized coal concentration in the area of the side wall of the boiler water wall.

9. The method according to claim 8, wherein The method further includes: monitoring the contents of H2S and CO in the water wall wall-attached atmosphere. When H2S is greater than 200 ppm or CO is greater than 5000 ppm, the pulverized coal concentration adjustment assembly reduces the concentration of the pulverized coal in the first powder pipe until H2S is not greater than 100 ppm or CO is not greater than 2000 ppm.

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