A comprehensive treatment method for high-temperature corrosion of the water-cooled wall of a coal-fired boiler

Abstract

The present invention provides a comprehensive treatment method for high-temperature corrosion of the side wall water-cooled wall of a coal-fired boiler, comprising the following steps: S1, analyzing the root cause of the high-temperature corrosion of the side wall water-cooled wall of the coal-fired boiler by combining on-site testing with numerical simulation; S2, adopting numerical simulation technology, combining the structure and flow field distribution characteristics of the large wind box and the layered secondary wind box, carrying out the influence characteristics of the wind box flow field distribution on the high-temperature corrosion of the side wall, and completing the design and installation of the wind box guide device and the side wall burner wind gathering device; S3, adopting numerical simulation technology, completing the design of the side wall wall wind, arranging the side wall wall wind in the height direction of the side wall in the burner area and the burnout wind area, and determining the position and quantity according to the numerical simulation results; S4, implementing the comprehensive wind box flow field and wall wind optimization technology on the unit, and verifying the effect of the comprehensive treatment of the high-temperature corrosion of the side wall water-cooled wall of the coal-fired boiler through cold and hot state debugging after the transformation and combining the test data before and after the transformation.

Description

Technical Field

[0001] The invention relates to the technical field of high-temperature corrosion of a side wall water-cooled wall of a coal-fired boiler, and in particular to a comprehensive treatment method for high-temperature corrosion of a side wall water-cooled wall of a coal-fired boiler. Background Art

[0002] With the gradual improvement of the unit's operating parameters and the implementation of ultra-clean emissions, the problem of high-temperature corrosion of the water-cooled wall in the furnace has become increasingly prominent, and water-cooled wall tube bursts have occurred frequently. Especially for coal-fired boilers with front and rear wall hedges, the secondary air duct has a special structure and layout. Due to the left-right symmetrical layout, a single side is selected, as shown in the attached figure. Figure 1 As shown, in this arrangement, the airflow first flows through the burners 2 (burnout air 7) on both sides at a high flow rate, and then converges at the middle burner 2 (burnout air 7) with a low flow rate. This will cause the static pressure of the middle burner 2 (burnout air 7) inside the burner 2 (burnout air 7) wind box to be high, and the static pressure of the burners 2 (burnout air 7) on both sides to be low. In addition, the secondary air flow enters the secondary main air duct 1 after passing through several elbows, and then enters the layer air duct 3 through the elbow. The flow field of the airflow is also very turbulent. In addition, there is a significant slope 4 when entering the burner 2 wind box from the layer air duct, resulting in vortices and backflows near the burners 2 on both sides. The above two factors are superimposed, resulting in the side wall burner 2 being in an oxygen-deficient state. Under hot operation, it is easy to cause the side wall to be in a strong reducing atmosphere with a high H2S concentration, which can easily cause high-temperature corrosion of the side wall.

[0003] In view of the high-temperature corrosion that easily occurs on the side walls of the coal-fired boilers with opposite walls, a wall-attached wind system for front and rear wall opposite combustion boilers (Announcement No.: CN103438437B) has been announced. The system is arranged at the edge of the front and rear walls, with the wind source drawn from the primary fan, and the baffle angle at the wall-attached wind nozzle is flexibly adjustable. The wall-attached wind system can ensure the penetration depth of the wall-attached wind, prevent the erosion and wear of the water-cooled wall, and thus effectively prevent the problems of coking and high-temperature corrosion of the water-cooled wall. However, the practical application of this system has great limitations, especially for the modification of existing furnace types. For the wall-attached wind whose wind source is drawn from the secondary air, since the wind source is changed to the primary air, it is necessary to draw a stream of air from the primary hot air duct at the air preheater outlet to the wall-attached wind outlet, and at the same time consider whether there is a margin in the primary fan, and the modification cost is relatively high. If there is no wall-attached wind, the front and rear wall wall-attached wind outlets need to be modified, and the modification cost is high.

[0004] In order to counteract the high-temperature corrosion of the side walls of coal-fired boilers and prevent high-temperature corrosion of the water-cooled walls, a boiler device and method (Announcement No.: CN103225805B) proposes installing high-nitrogen swirl burners in the area of ​​the front and rear walls close to the left and right walls, and installing low-nitrogen swirl burners in the middle area of ​​the front and rear walls away from the left and right walls. By reasonably arranging the two swirl burners, the problem of high-temperature corrosion of the side water-cooled walls is solved. However, this method requires large modifications and is expensive, and the matching problem of high-nitrogen swirl burners and low-nitrogen swirl burners needs to be considered. A system and method for preventing and controlling high-temperature corrosion of the water-cooled wall of a power station boiler (publication number: CN113339784A) proposes the modification of a new type of burner. The new type of burner is arranged near the two side walls and can swing flexibly up and down and left and right. At the same time, a louver-type baffle installed on the primary wind box is used to achieve a large primary air volume for the new type of burner close to the side wall and a small primary air volume for the traditional burner away from the side wall, thereby alleviating high-temperature corrosion of the side wall water-cooled wall. This technology uses a device that can be flexibly adjusted up and down and left and right. It is difficult to adjust in a hot state and may get stuck, and the operability is not strong. The other secondary air only accounts for about 20% of the total air volume. Compared with the secondary air volume, it is not the root cause of the high-temperature corrosion of the side wall. Simply increasing the primary air volume of the new type of burner is not enough, and it is necessary to consider increasing the secondary air volume of the new type of burner. Summary of the Invention

[0005] The present invention aims to provide a comprehensive treatment method for high-temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler, so as to overcome the deficiencies in the prior art.

[0006] To solve the above technical problems, the technical solution of the present invention is: a comprehensive treatment method for high-temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler, comprising the following steps:

[0007] S1. Analyze the root cause of high-temperature corrosion of the water-cooled sidewalls of opposed coal-fired boilers by combining field testing with numerical simulation.

[0008] S2. Using numerical simulation technology, combined with the structure and flow field distribution characteristics of the large wind box and the layered secondary wind box, the influence of the wind box flow field distribution on the high-temperature corrosion of the side wall was studied, and the design and installation of the wind box guide device and the side wall burner wind gathering device were completed;

[0009] S3. Use numerical simulation technology to complete the design of side wall wind. Arrange side wall wind in the height direction of the burner area and the burnout wind area. The position and number of side wall wind are determined according to the numerical simulation results.

[0010] S4. Comprehensive wind box flow field and wall wind optimization technology was implemented on the unit. Through cold and hot state commissioning after the transformation, combined with the comparison of test data before and after the transformation, the effectiveness of the comprehensive treatment of high-temperature corrosion of the water-cooled wall of the coal-fired boiler side wall was verified.

[0011] As an improvement of the comprehensive treatment method for high-temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler according to the present invention, in step S1, the flow velocity state of the airflow passing through the burners on both sides and then merging at the middle burner is arranged in combination with field tests and numerical simulation analysis. According to the Bernoulli equation, the static pressure of the middle burner and the burners on both sides inside the burner bellows is analyzed; and the flow field of the secondary air flow entering the secondary main air duct after passing through several elbows and then entering the layer air duct through the elbow is analyzed. The flow field of the air flow entering the burner bellows from the layer air duct through the slope is analyzed to cause the air flow to be close to the burners on both sides.

[0012] As an improvement of the comprehensive treatment method for high-temperature corrosion of the side wall water-cooled wall of a counter-hedge coal-fired boiler according to the present invention, in step S1, a cold fireworks tracer test is carried out in the wall-attached wind system installed on the front and rear walls, and the area of ​​the side wall water-cooled wall protected by the wall-attached wind system and the blind area protected by the wall-attached wind system are analyzed under the maximum wall-attached wind volume. The situation in which the wall-attached wind outlet is blocked by coke blocks is checked, and the root cause of the high-temperature corrosion of the side wall water-cooled wall of the counter-hedge coal-fired boiler is summarized.

[0013] As an improvement of the comprehensive treatment method for high-temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler according to the present invention, in step S2, a guide device and a flow equalizing grid are installed at the elbow, wherein the guide device is distributed in several blocks in the height direction of the elbow, and the position and angle of the guide device need to be determined after numerical simulation; the flow equalizing grid divides the air duct into several sections in the height direction and divides the air duct into several sections in the width direction.

[0014] As an improvement of the comprehensive treatment method for high-temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler according to the present invention, in step S2, a tapered wind gathering device is provided at the air inlet of the outer secondary air duct of the burner on the wall side, and its structure is a tapered structure, wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, to ensure that the incoming flow is gathered into the secondary air duct outside the burner through the device, thereby increasing the amount of secondary air outside the burner; a wind direction steering device is provided at the air inlet of the inner secondary air duct of the burner on the wall side, to align the air inlet with the incoming flow direction, to facilitate the smooth flow of the incoming flow into the secondary air duct inside the burner, thereby increasing the amount of secondary air inside the burner; the first and second burnt-out air outer secondary air ducts at the elbow inlet on the wall side are A second annular air gathering device is provided at the entrance, and its structure is an annular structure. It is arranged on the circumference of the secondary air duct outside the burnt air, wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the secondary air duct outside the burnt air through the device, thereby increasing the amount of secondary air outside the burnt air; a third tapered air gathering device is provided at the entrance of the first and second secondary air ducts inside the burnt air at the elbow inlet on the wall side, and its structure is a tapered structure. wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the secondary air duct inside the burnt air through the device, thereby increasing the amount of secondary air outside the burnt air. The detailed inlet and outlet areas need to be determined through numerical simulation.

[0015] As an improvement of the comprehensive treatment method for high-temperature corrosion of the side wall water-cooled wall of a coal-fired boiler according to the present invention, in step S3, for a system with an existing wall-attached wind design, combined with step S1, the area of ​​the side wall water-cooled wall protected by the wall-attached wind system and the blind area protected by the wall-attached wind system are found through numerical simulation and test results, side wall wall-attached winds are designed in this area, and the number of wall-attached winds is numerically simulated and designed to form a new wall-attached wind system to achieve full side wall coverage of the wall-attached winds; for a system without a wall-attached wind design, the height, orientation and number of the side wall wall-attached winds are numerically simulated and designed and determined to ensure full side wall coverage of the wall-attached wind system.

[0016] As an improvement of the comprehensive treatment method for high-temperature corrosion of the side water-cooled wall of a coal-fired boiler according to the present invention, in step S4, the effects of the individual or combined implementation of the wind box flow field and the wall-adhering wind optimization technology are evaluated, and the CO concentration and H2S concentration of the side water-cooled wall after the application of the wind box flow field optimization alone are evaluated; the CO concentration and H2S concentration of the side water-cooled wall after the application of the wall-adhering wind optimization alone are evaluated; and the CO concentration and H2S concentration of the side water-cooled wall after the combined application of the wind box flow field and the wall-adhering wind optimization technology are evaluated.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Compared with the use of wind box flow field optimization technology alone or the use of wall-adhering wind optimization technology alone, the comprehensive application of wind box flow field and wall-adhering wind optimization technology is expected to reduce the reducing atmosphere of the side wall water-cooled wall by 10% to 40%, and the high-temperature corrosion of the water-cooled wall will be significantly alleviated. It is an important supplement to the existing high-temperature corrosion control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a structural diagram of the prior art in the background technology;

[0021] Figure 2 This is the layout diagram of the secondary air duct of the coal-fired boiler with front and rear walls facing each other;

[0022] Figure 3 It is a tapered air collecting device outside the side wall burner;

[0023] Figure 4 It is a wind direction turning device inside the burner close to the side wall;

[0024] Figure 5 The second annular wind gathering device is located outside the side wall burner;

[0025] Figure 6 It is a tapered air gathering device three in the burner against the side wall;

[0026] Figure 7 This is a schematic diagram of the wall-mounted wind modification layout for the water-cooled wall.

[0027] in, Figure 1 、 Figures 3 to 6 In the figure, the arrows indicate the direction of hot air flow.

[0028] Among them, 1. Secondary main air duct; 2. Burner; 3. Layer air duct; 4. Slope; 5. Guide device; 6. Flow equalizing grille; 7. Burnout air. DETAILED DESCRIPTION

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] A comprehensive treatment method for high temperature corrosion of the water-cooled wall of the side wall of a coal-fired boiler comprises the following steps:

[0031] S1. A combination of field testing and numerical simulation was used to analyze the root cause of high-temperature corrosion of the side water-cooled walls of opposed coal-fired boilers.

[0032] Among them, in step S1, Figure 1 As shown, this arrangement causes the airflow to first flow through the burners 2 (burnout air 7) on both sides at a high velocity, then converge at the middle burner 2 (burnout air 7) at a low velocity. According to the Bernoulli equation, this will result in high static pressure in the middle burner 2 (burnout air 7) and low static pressure in the burners 2 (burnout air 7) on both sides of the wind box. Furthermore, the secondary airflow passes through several elbows before entering the secondary main air duct 1 and then the layer air duct 3. The flow field is also very turbulent. Furthermore, there is a significant slope 4 from the layer air duct into the burner 2 wind box, causing vortices and backflows near the burners 2 on both sides. The combination of these two factors results in an oxygen-deficient state in the side wall burners 2.

[0033] For example, numerical simulations and field measurements at a power plant indicate a significant air shortage in the side walls, resulting in low operating oxygen levels and a significant risk of high-temperature corrosion. Under rated load, numerical simulations show that the secondary air flow rate across the furnace width near the side walls is significantly lower than that in the center, by an average of 5.5%; the secondary air flow rate near the side walls is also significantly lower than that in the center, by an average of 4.6%. Due to the significant air shortage near burner 2 near the side wall, the measured operating oxygen level near the side wall at the economizer outlet is significantly lower, resulting in high CO emissions.

[0034] Table 1 Simulation results of air volume between floors

[0035]

[0036] Note: 1 is close to the side wall, 3 is far from the side wall.

[0037] Table 2 Distribution data of measured oxygen content (volume percentage) at the economizer outlet section

[0038]

[0039] Note: A1 is close to the side wall, A6 is far from the side wall; B1 is far from the side wall, B6 is close to the side wall, the same below.

[0040] Table 3 Measured CO concentration distribution data of economizer outlet section

[0041]

[0042] In the cold fireworks tracer test of the wall-attached wind system installed on the front and rear walls, it was found that under the maximum wall-attached wind volume, due to insufficient rigidity, the wall-attached wind could only protect 3 / 4 of the side wall water-cooled wall area, and the middle position of the side wall was still in the protection blind spot; at the same time, inspection of the wall-attached wind outlet found that the wall-attached wind outlet was hung with coke blocks blocking the nozzle, affecting the effect of the wall-attached wind.

[0043] In summary, the inherent structural characteristics of the windboxes in opposed coal-fired boilers, the lack of rigidity in existing wall-mounted air systems, and the resulting buildup of coke on the wall-mounted air nozzles are the root causes of high-temperature corrosion in the side water-cooled walls of opposed coal-fired boilers. To address these issues, the following technical improvements have been implemented to mitigate high-temperature corrosion in the side water-cooled walls.

[0044] S2: Based on the evaluation results, numerical simulation technology is used to combine the structure and flow field distribution characteristics of the large wind box and the layered secondary wind box to study the influence of the wind box flow field distribution on the high-temperature corrosion of the side wall, and complete the design of the wind box guide device 5 and the side wall burner 2 wind gathering device.

[0045] a) In order to make the secondary air flow smooth, 3-4 guide plates are added at the three elbows (the position and angle need to be designed and calculated in detail by numerical simulation software). After implementation, the relative standard deviation of the velocity of the secondary air test section is reduced to 6.0%, and the uniformity and smoothness of the flow field are greatly improved. The velocity field distribution is balanced by adding guide devices 5 and equalizing grids 6 at the elbows. Among them, the guide devices 5 are distributed in 3-4 pieces in the height direction, and the position and angle need to be determined after numerical simulation. The equalizing grid 6 divides the air duct into 3 sections in the height direction and 4 sections in the width direction. After implementation, the maximum relative standard deviation of the secondary test section is reduced to 38.8%, and the uniformity of the flow field is significantly improved, as shown in the attached figure. Figure 2 shown.

[0046] b) To increase the air volume of the side wall burner 2 and the burnout air 7, as shown in the attached Figure 3 As shown in the figure, a tapered air gathering device is set at the air inlet of the secondary air duct outside the burner on the wall side. Its structure is a tapered structure, in which the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the secondary air duct outside the burner through the device, thereby increasing the amount of secondary air outside the burner. Figure 4 As shown in the figure, a wind direction steering device is installed at the air inlet of the secondary air duct of the burner on the wall side, and the air inlet is aligned with the incoming air flow direction, so that the incoming air can flow smoothly into the secondary air duct of the burner, thereby increasing the secondary air volume in the burner; as shown in the figure, Figure 5As shown, an annular air gathering device 2 is provided at the entrance of the first and second overburned air burner external secondary air ducts at the elbow inlet on the wall side. The structure is an annular structure and is arranged on the circumference of the overburned air external secondary air duct. The side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the overburned air external secondary air duct through the device, thereby increasing the amount of the overburned air external secondary air. As shown in the attached figure Figure 6 As shown, a tapered air gathering device 3 is provided at the entrance of the first and second burnt air secondary air ducts of the elbow inlet on the wall side. The structure is a tapered structure, wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, to ensure that the incoming flow is gathered into the burnt air secondary air duct through the device, thereby increasing the secondary air volume outside the burnt air. The detailed inlet and outlet areas need to be determined through numerical simulation.

[0047] S3: Based on the evaluation results, numerical simulation technology is used to complete the design of the side wall wind, study the impact of different positions and different numbers of nozzles on the high-temperature corrosion of the side wall, and determine the appropriate position and number of nozzles.

[0048] a) For systems with existing wall-mounted windshield designs, numerical simulation and test results are used to find the blind spots protected by the wall-mounted windshield system. Side-wall wall-mounted windshields are designed in this area. The position of the wall-mounted windshields is relatively fixed, and the number of wall-mounted windshields needs to be numerically simulated and designed to form a new wall-mounted windshield system to achieve full side wall coverage of the wall-mounted windshields.

[0049] b) For systems that have not previously been designed for wall-mounted wind, it is necessary to conduct numerical simulation design and determine the height, direction and number of side wall-mounted winds to ensure full side wall coverage of the wall-mounted wind system.

[0050] Schematic diagram of side wall wind Figure 7 As shown, the wall-attached air is directly drawn out from the secondary large air box at the outlet of the air preheater. The construction workload is significantly lower than that of the primary air duct, and there is no need to consider the problem of low secondary air pressure under medium and low loads.

[0051] S4: The integrated wind box flow field and wall wind optimization technology was implemented on the unit. Through hot and cold state commissioning after the transformation, combined with the test data before and after the transformation, the comprehensive treatment effect of high-temperature corrosion of the water-cooled wall of the coal-fired boiler side wall was verified.

[0052] According to the evaluation of the effects of implementing the windbox flow field and wall-adjacent wind optimization technologies separately or in combination, the CO concentration and H2S concentration in the side wall water-cooled wall were reduced by about 35%-40% after the windbox flow field optimization was applied alone; the CO concentration and H2S concentration in the side wall water-cooled wall were reduced by about 50%-60% after the wall-adjacent wind optimization was applied alone; and the CO concentration and H2S concentration in the side wall water-cooled wall were expected to be reduced by about 60%-80% after the combined application of the windbox flow field and wall-adjacent wind optimization technologies.

[0053] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0054] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A comprehensive treatment method for high-temperature corrosion of the water-cooled wall of a coal-fired boiler, characterized in that: The following steps are involved: S1. Analyze the root cause of high-temperature corrosion of the water-cooled sidewalls of opposed coal-fired boilers by combining field testing with numerical simulation. S2. Using numerical simulation technology, combined with the structure and flow field distribution characteristics of the large wind box and the layered secondary wind box, the influence of the wind box flow field distribution on the high-temperature corrosion of the side wall was studied, and the design and installation of the wind box guide device and the side wall burner wind gathering device were completed; S3. Use numerical simulation technology to complete the design of side wall airflow. Arrange side wall airflow in the height direction of the side wall in the burner area and the burnout air area. The position and number of side wall airflow are determined based on the numerical simulation results. S4. Comprehensive windbox flow field and wall-wind optimization technology was implemented on the unit. Through hot and cold commissioning after the transformation, combined with test data before and after the transformation, the effectiveness of the comprehensive treatment of high-temperature corrosion of the coal-fired boiler side wall water-cooled wall was verified; In step S1, the flow velocity state of the airflow passing through the burners on both sides and then merging at the middle burner is arranged in combination with the field test and numerical simulation analysis. According to the Bernoulli equation, the static pressure of the middle burner and the burners on both sides inside the burner bellows is analyzed; and the flow field of the secondary air flow entering the secondary main air duct after passing through several elbows and then entering the laminar air duct through the elbows is analyzed. The flow field of the air flow entering the burner bellows from the laminar air duct through the slope is analyzed.

2. The method for comprehensive treatment of high-temperature corrosion of the side water-cooled wall of a coal-fired boiler according to claim 1 is characterized in that: In step S1, a cold fireworks tracer test is performed in the wall-attached wind system installed on the front and rear walls to analyze the area of ​​the side wall water-cooled wall protected by the wall-attached wind system under the maximum wall-attached wind volume and the blind area protected by the wall-attached wind system. The situation of coke blocks hanging on the wall air outlet blocking the nozzle is checked, and the root cause of the high-temperature corrosion of the side wall water-cooled wall of the hedge coal-fired boiler is summarized.

3. The comprehensive treatment method for high-temperature corrosion of the side water-cooled wall of a coal-fired boiler according to claim 1 is characterized in that: In step S2, a flow guide device and a flow equalizing grid are installed at the elbow, wherein the flow guide device is distributed in several blocks in the height direction of the elbow, and the position and angle of the flow guide device need to be determined after numerical simulation; the flow equalizing grid divides the air duct into several sections in the height direction and the air duct into several sections in the width direction.

4. The method for comprehensive treatment of high-temperature corrosion of the side water-cooled wall of a coal-fired boiler according to claim 1 is characterized in that: In step S2, a first tapered air gathering device is provided at the air inlet of the outer secondary air duct of the burner on the wall side. The structure of the device is a tapered structure, wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, to ensure that the incoming flow is gathered into the secondary air duct outside the burner through the device, thereby increasing the amount of secondary air outside the burner; a wind direction steering device is provided at the air inlet of the inner secondary air duct of the burner on the wall side, to align the air inlet with the incoming flow direction, to facilitate the smooth flow of the incoming flow into the inner secondary air duct of the burner, thereby increasing the amount of secondary air inside the burner; a second annular air gathering device is provided at the entrance of the first and second burnt-out air outer secondary air ducts of the elbow inlet on the wall side, the structure of the device is It is a ring structure and is arranged on the circumference of the secondary air duct outside the burnt air. The side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the secondary air duct outside the burnt air through the device, thereby increasing the amount of secondary air outside the burnt air; a tapered wind gathering device three is arranged at the entrance of the first and second secondary air ducts inside the burnt air at the elbow inlet on the wall side, and its structure is a tapered structure, wherein the side with a larger area facing the incoming flow direction is the air inlet, and the side with a smaller area is the air outlet, ensuring that the incoming flow is gathered into the secondary air duct inside the burnt air through the device, thereby increasing the amount of secondary air outside the burnt air. The detailed inlet and outlet areas need to be determined through numerical simulation.

5. The comprehensive treatment method for high-temperature corrosion of the side water-cooled wall of a coal-fired boiler according to claim 1 is characterized in that: In step S3, for systems with existing wall-attached wind designs, combined with step S1, the area of ​​the side wall water-cooled wall protected by the wall-attached wind system and the blind area protected by the wall-attached wind system are found through numerical simulation and experimental results, side wall wall-attached winds are designed in this area, and the number of wall-attached winds is numerically simulated and designed to form a new wall-attached wind system to achieve full side wall coverage of the wall-attached winds; for systems without wall-attached wind designs, the height, orientation and number of side wall wall-attached winds are numerically simulated and designed and determined to ensure full side wall coverage of the wall-attached wind system.

6. The comprehensive treatment method for high-temperature corrosion of the water-cooled wall of a coal-fired boiler according to claim 1 is characterized in that: In step S4, the effects of the individual or combined implementation of the wind box flow field and wall wind optimization technologies are evaluated, including the CO concentration and H2S concentration of the side wall water-cooled wall after the wind box flow field optimization is applied alone; the CO concentration and H2S concentration of the side wall water-cooled wall after the wall wind optimization is applied alone; and the CO concentration and H2S concentration of the side wall water-cooled wall after the combined application of the wind box flow field and wall wind optimization technologies.

Images