Adjusting method and device for reducing W flame boiler fly ash carbon content

Abstract

The invention discloses an adjusting method and device for reducing the carbon content of fly ash of a W flame boiler, and the method comprises the steps: testing volatile components of coal as fired, and controlling the volatile components of the coal as fired; adjusting the opening degree of a baffle plate of a separator of the coal mill and shrinkage cavities of an air door and a powder pipe, and adjusting the primary air temperature, the pulverized coal fineness and the primary air uniformity of each layer of running combustors to be within a required range; the operation oxygen amount of the boiler, the opening degree of a secondary air door of a single combustor and the opening degree of a secondary air box are adjusted, and the level and distribution of the oxygen amount entering the boiler are controlled; the opening degree of exhaust air of a main combustor of the boiler is adjusted, the proportion of main primary air and the exhaust air is reasonably distributed, ignition can be stably achieved, and excessive air shortage is avoided; the proportion of the on-arch air door to the under-arch air door is reasonably set, that is, the on-arch air door is partially opened, and the under-arch air door is expanded or even fully opened, so that air is reasonably supplied for burnout in the later period of combustion, proper undershoot depth is provided for primary air, and a large amount of under-arch air is supplemented in time so as to facilitate burnout of pulverized coal.

Description

Technical Field

[0001] This invention belongs to the field of economic operation and energy conservation of power plant boilers, and specifically relates to an adjustment method and device for reducing the carbon content of fly ash in W-flame boilers. Background Technology

[0002] Anthracite reserves are estimated at 474.243 billion tons, accounting for approximately 10% of my country's total coal resources. It is mainly distributed in Shanxi, Henan, Guizhou, Shaanxi, and Ningxia provinces, with a stable production of about 400 million tons per year. Along with bituminous coal and lignite, it is one of my country's important coal sources for thermal power generation. Anthracite is characterized by high fixed carbon content and high calorific value, but low volatile matter content, with a dry ash-free volatile matter content (V0.05). daf The ignition point is generally between 6.5% and 12.0%, resulting in a high ignition point, a long combustion path, and a low burnout rate. When used in pulverized coal boilers in power plants, except for a small number that use the four-corner tangential method, the vast majority use the W-flame combustion method.

[0003] W-flame boilers, whose technology was initially introduced by companies such as FW in the United States and Babcock in the United Kingdom, are currently mainly designed and manufactured by Dongfang and Harbin Boiler Plants in my country. This type of boiler has a furnace consisting of a lower arched ignition furnace and an upper radiant furnace. The tops of the protruding sections at the front and rear of the ignition furnace form an arch. Pulverized coal nozzles and secondary air nozzles spray downwards from the arch. The high-temperature flue gas from the W-shaped flame formed in the ignition furnace below the arch flows back to the root of the pulverized coal airflow, which is highly beneficial to the ignition process. As the ignited pulverized coal airflow flows downwards and expands, it meets the tertiary air in the lower part of the ignition furnace and then turns 180° upwards, forming a W-shaped flame. The high-temperature flue gas generated by combustion enters the upper radiant furnace. Numerous protective combustion strips are laid around the burners in the arch and on the water-cooled walls on both sides below the arch, creating a high-temperature ignition zone that is conducive to ignition. Domestic and international practical experience shows that W-flame boilers equipped with double-inlet, double-outlet steel ball mills produce finer pulverized coal with a longer residence time in the furnace, making them effective for burning low-volatile coals.

[0004] However, in recent years, with the rapid development of new energy installed capacity in my country, smokeless coal-fired power plants are facing a situation of declining power generation and electricity prices. Power plants are experiencing operational difficulties and have to use large quantities of coal with lower prices and calorific values, which leads to a decline in coal combustion characteristics. In order to ensure output, coal mills need to maintain a large primary air volume, resulting in coarser coal powder, which makes it difficult to ignite and burn completely. The carbon content of fly ash has increased significantly from about 3% to more than 5%. With high ash content, boiler efficiency decreases by 1% and coal consumption for power generation increases by more than 3g / kWh, which seriously affects the economic indicators of the unit and the economic efficiency of power plant operation.

[0005] To improve the combustion economy of W-type boilers and enhance power plant operating performance, power plants typically employ methods such as increasing the amount of steel balls loaded, optimizing the steel ball diameter ratio, and replacing coal mill liners, aiming to reduce the carbon content of fly ash by decreasing the fineness of the pulverized coal. However, these methods often prove ineffective. To improve boiler combustion and enhance adaptability to high-ash, low-calorific-value, and low-volatile coals, a new method for reducing the carbon content of boiler fly ash is urgently needed. Summary of the Invention

[0006] This invention addresses the aforementioned problems by providing a method and apparatus for reducing the carbon content of fly ash in W-flame boilers. This invention helps solve problems such as increased carbon content in fly ash from power plant boilers due to deteriorating coal quality, unreasonable coal blending methods, and improper operational adjustments.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A method for reducing the carbon content of fly ash from a W-flame boiler includes the following steps: 1) Test the quality of coal fed into the furnace and control the volatile matter content (V) of the coal. daf ≥10-12%; 2) Adjust the baffle or rotation speed of the coal mill separator to adjust the fineness R of the pulverized coal. 90 Keep it between 3-8%; 3) Adjust the uniformity of the primary air velocity of the coal mill, and control the primary air velocity deviation within ±5%; 4) Adjust the outlet air temperature of the coal mill to 70-120℃; 5) When the boiler load is above 80% ECR, adjust the boiler operating oxygen content to 4.2-4.5% and adjust the oxygen distribution in the furnace width direction; 6) Adjust the exhaust gas damper of the main burner. The exhaust gas damper should be set to 30-70% according to the different volatile matter requirements of the coal. 7) Adjust the opening of the secondary air damper around the primary air nozzle on the arch to 30-50% to supplement the oxygen required for the initial ignition of the pulverized coal airflow and ensure the rigidity and downward injection depth of the primary air; 8) Adjust the opening of the tertiary air damper under the arch to 70-100% to replenish the oxygen required for later combustion.

[0008] A further improvement of the present invention is that, in step 1), the volatile matter in coal is determined in accordance with GB / T 212-2008 "Industrial Analysis Methods for Coal".

[0009] A further improvement of the present invention is that, in step 1), if the volatile matter content of the coal fed into the furnace is low, it is pre-mixed and co-fired with coal of high volatile matter content before being fed into the mill and furnace.

[0010] A further improvement of the present invention is that, in step 2), for boilers burning lean coal, the fineness R of the pulverized coal is increased. 90For boilers burning anthracite, the pulverized coal fineness R should be controlled at 6-8%. 90 Keep it between 3-5%.

[0011] A further improvement of the present invention is that, in step 3), the primary wind speed measurement and adjustment are carried out in accordance with the "Performance Test of Power Plant Coal Mill and Pulverizing System" (DL / T 467-2019).

[0012] A further improvement of the present invention is that, in step 4), when the boiler burns lean coal or anthracite, the primary air temperature is controlled at 110-120℃, and when it burns bituminous coal, the primary air temperature is controlled at 70℃.

[0013] A further improvement of the present invention is that, in step 5), the oxygen uniformity is adjusted by measuring the oxygen distribution from the denitrification inlet and adjusting the air volume distribution of a single burner or the three air boxes (left, middle, and right).

[0014] A further improvement of the present invention is that, in step 6), when the boiler burns lean coal or anthracite, the exhaust gas damper is controlled at 50-70%, and for boilers burning bituminous coal, the exhaust gas damper is controlled at 30-50%.

[0015] A further improvement of the present invention is that, in step 8), the opening of the tertiary air damper under the arch is adjusted so that when the boiler load is above 80% ECR, the opening of the secondary air box is not less than 70%; after adjustment, the carbon content of the boiler fly ash is reduced to ≤3.0%.

[0016] An adjustment device for reducing the carbon content of fly ash from a W-flame boiler includes: The coal quality testing unit tests the quality of the coal entering the furnace and controls the volatile matter content (V) of the coal. daf ≥10-12%; The separator adjustment unit adjusts the baffles or rotation speed of the coal mill separator to control the fineness of the coal powder at 3-8%. The primary air temperature regulation unit adjusts the outlet air temperature of the coal mill and controls the primary air temperature of each burner layer to 70-120℃. The total air volume regulating unit adjusts the boiler operating oxygen level to 4.2-4.5% when the boiler load is above 80% ECR. The primary air velocity adjustment unit adjusts the primary air exhaust damper of the main burner to 30-70%. Secondary air regulating unit, adjust the opening of the secondary air damper on the arch by 30-50%; The tertiary air conditioning unit has a tertiary air damper opening of 70-100% under the arch.

[0017] Compared with the prior art, the present invention has at least the following beneficial technical effects: This invention provides a method and apparatus for adjusting the carbon content of fly ash in a W-flame boiler. First, it optimizes and controls the volatile matter content of the coal fed into the boiler and the blending method of coals with different volatile matter content, reducing the input of ultra-low volatile matter coals at the source and preventing the boiler from deteriorating due to severely deteriorated coal quality or uneven mixing, which could lead to worsened burnout. Then, by controlling the fineness of the pulverized coal, the uniformity of the primary air, and the air temperature, it ensures rapid and stable ignition of the pulverized coal primary air flow in the main burner. Finally, by supplying a high total air volume, ensuring uniform distribution along the width of the furnace, and rationally setting the opening of the air dampers above and below the burner arch, it ensures sufficient contact between the pulverized coal and air and the downward thrust of the primary air in the initial ignition stage, while also ensuring a large and timely mixing of tertiary air below the burner during the burnout period, effectively improving the degree of pulverized coal burnout.

[0018] Therefore, this invention does not require equipment modification. It only requires optimization and adjustment of the volatile matter content of the coal fed into the furnace and the uniformity of the primary air velocity, primary air temperature, coal powder fineness, operating oxygen content, exhaust air damper, upper secondary air damper and lower tertiary air damper to improve boiler ignition and combustion and reduce the carbon content of fly ash. The operation is simple. After adjustment, the carbon content of fly ash can be reduced to below 3%, and the boiler efficiency can be increased by 0.5-1.0%, meeting the requirements for economical boiler operation.

[0019] In summary, after adjustments made according to this invention, the pulverized coal airflow achieves stable ignition and combustion, a reasonable downward flow depth, and appropriate mixing of secondary and tertiary air, balancing ignition and combustion with complete pulverized coal combustion. The fly ash carbon content is ≤3.0%, thus improving boiler efficiency. Furthermore, it is estimated that using the adjustment scheme provided by this invention can save 2.5-5 million yuan in fuel costs annually for a single 300MW or 600MW boiler unit. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for adjusting the carbon content of fly ash from a W-flame boiler according to the present invention.

[0022] Figure 2 This is a structural block diagram of an adjustment device for reducing the carbon content of fly ash from a W-flame boiler according to the present invention. Detailed Implementation

[0023] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0029] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0030] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0031] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0032] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] Example 1 This invention provides a method for reducing the carbon content of fly ash from a W-flame boiler, comprising the following steps: 1) Test the quality of coal fed into the furnace and control the volatile matter content (V) of the coal. daf ≥10-12%; 2) Adjust the baffle or rotation speed of the coal mill separator to adjust the fineness R of the pulverized coal. 90 Keep it between 3-8%; 3) Adjust the uniformity of the primary air velocity of the coal mill, and control the primary air velocity deviation within ±5%; 4) Adjust the outlet air temperature of the coal mill to 70-120℃; 5) When the boiler load is above 80% ECR, adjust the boiler operating oxygen content to 4.2-4.5% and adjust the oxygen distribution in the furnace width direction; 6) Adjust the exhaust gas damper of the main burner. The exhaust gas damper should be set to 30-70% according to the different volatile matter requirements of the coal. 7) Adjust the opening of the secondary air damper around the primary air nozzle on the arch to 30-50% to supplement the oxygen required for the initial ignition of the pulverized coal airflow and ensure the rigidity and downward injection depth of the primary air; 8) Adjust the opening of the tertiary air damper under the arch to 70-100% to replenish the oxygen required for later combustion.

[0034] In this embodiment, in step 1), the volatile matter in the coal is determined according to GB / T 212-2008 "Industrial Analysis Methods for Coal". If the volatile matter content of the coal entering the furnace is low, it is pre-mixed and co-fired with coal with high volatile matter content before entering the mill and furnace.

[0035] In this embodiment, in step 2), for boilers burning lean coal, the fineness of the pulverized coal is controlled at 6-8%, and for boilers burning anthracite, the fineness of the pulverized coal is controlled at 3-5%.

[0036] In this embodiment, in step 3), the primary wind speed measurement and adjustment are carried out in accordance with the "Performance Test of Power Plant Coal Mill and Pulverizing System" (DL / T 467-2019).

[0037] In this embodiment, in step 4), when the boiler burns lean coal or anthracite, the primary air temperature is controlled at 110-120℃, and when it burns bituminous coal, the primary air temperature is controlled at 70℃.

[0038] In this embodiment, in step 5), the oxygen uniformity is adjusted by measuring the oxygen distribution from the denitrification inlet and adjusting the air volume distribution of a single burner or the three air boxes (left, middle, and right).

[0039] In this embodiment, in step 6), when the boiler burns lean coal or anthracite, the exhaust gas damper is controlled at 50-70%, and for boilers burning bituminous coal, the exhaust gas damper is controlled at 30-50%.

[0040] In this embodiment, in step 8), the opening of the tertiary air damper under the arch is adjusted so that when the boiler load is above 80% ECR, the opening of the secondary air box is not less than 70%; after adjustment, the carbon content of the boiler fly ash is reduced to ≤3.0%.

[0041] Example 2 A power plant's 300MW-class flame-fired boiler burns lean coal with a sulfur content of approximately 15%. During operation, when the boiler is at over 90% load, the carbon content of the fly ash reaches as high as 4-5%, which cannot meet the requirements for economical operation. To improve this situation, the power plant mainly adopted the following technical steps: 1) Increase the primary air temperature from the current 95℃ to 120℃; 2) Adjust the uniformity of the primary air velocity in the eight powder pipes at the outlet of each of the three coal mills, and control the primary air velocity deviation within ±5%. 3) Adjust the opening of the separator baffle at the coal mill outlet to adjust the fineness R of the pulverized coal. 90 The percentage has been adjusted from 15% to below 8%. 4) Increase the operating oxygen content from 3.5% to 4.2%, and at the same time, open the local secondary air damper of the burner corresponding to the point where the denitrification inlet flue gas temperature is too low; 5) Reduce the exhaust air damper from 50% to 30% to increase the air supply to the primary air during the initial combustion stage; 6) Adjust the opening of the secondary air damper on the arch to 50%; 7) Adjust the opening of the tertiary air damper under the arch from 50% to 70%, and at the same time raise the swing angle of the tertiary air nozzle under the arch by 5° to accelerate the mixing with the pulverized coal airflow.

[0042] After the adjustment, the carbon content of boiler fly ash decreased from 5.0% to 2.8%, boiler efficiency increased by 1%, and coal consumption for power generation decreased by 3.4 g / kWh.

[0043] Example 3 A power plant's 330MW-class flame-fired boiler burns local low-calorific-value lean coal with a volatile matter content of approximately 14%. During operation, the carbon content of fly ash at medium and high loads is 7-8%. To improve this situation, the power plant mainly adopted the following technical steps: 1) Adjust the uniformity of the primary air velocity in the four powder pipes at the outlet of each of the four coal mills, and control the primary air velocity deviation within ±5%. 2) Adjust the opening of the separator baffle at the coal mill outlet to adjust the fineness R of the pulverized coal. 90 Controlled at 3-6%; 3) Increase the operating oxygen content from 4.0% to 4.5%, and at the same time increase the opening of the local secondary air damper and intermediate secondary air box of the burner corresponding to the low point of the denitrification inlet flue gas temperature; 4) Reduce the exhaust air damper from 50% to 30% to increase the air supply to the primary air during the initial combustion stage; 5) Adjust the opening of the secondary air damper on the arch from 30% to 50%; 6) Increase the opening of the tertiary air damper under the arch from 50% to 90%, and decrease the burnout air damper to 30%.

[0044] After the adjustment, the carbon content of boiler fly ash decreased from 5.0% to 2.8%, boiler efficiency increased by 1%, and coal consumption for power generation decreased by 3.4 g / kWh.

[0045] Example 4 like Figure 2 As shown, the present invention provides an adjustment device for reducing the carbon content of fly ash from a W-flame boiler, comprising: The coal quality testing unit tests the quality of the coal entering the furnace and controls the volatile matter content (V) of the coal. daf ≥10-12%; The separator adjustment unit adjusts the coal mill separator baffles or rotation speed to reduce the coal powder fineness R. 90 Keep it between 3-8%; The primary air temperature regulation unit adjusts the outlet air temperature of the coal mill and controls the primary air temperature of each burner layer to 70-120℃. The total air volume regulating unit adjusts the boiler operating oxygen level to 4.2-4.5% when the boiler load is above 80% ECR. The primary air velocity adjustment unit adjusts the primary air exhaust damper of the main burner to 30-70%. The secondary air conditioning unit adjusts the opening of the secondary air damper on the arch to 30-50%, and the opening of the tertiary air damper under the arch to 70-100%.

[0046] The tertiary air conditioning unit has a tertiary air damper opening of 70-100% under the arch.

[0047] In summary, this invention controls the volatile matter content of the coal fed into the furnace by testing it; adjusts the opening of the separator baffles and dampers and the reduction orifice of the pulverized coal pipe to adjust the primary air temperature, pulverized coal fineness, and primary air uniformity of each burner layer to the required range; adjusts the oxygen content of the boiler, the opening of the secondary air damper of each burner, and the opening of the secondary air box to control the oxygen content level and its distribution; adjusts the exhaust air opening of the main burner of the boiler to reasonably allocate the ratio of primary air to exhaust air, which can stabilize ignition without excessive air shortage; and reasonably sets the ratio of the upper and lower arch dampers, that is, partially opening the upper arch damper and opening it fully or even completely, to reasonably supply air for the burnout in the later stage of combustion, providing a suitable downward thrust depth for the primary air and timely and large-scale replenishment of the lower arch air to facilitate the burnout of pulverized coal. After adjustment, the pulverized coal airflow ignites and burns stably, the downward jet depth is reasonable, and the mixing of secondary and tertiary air is appropriate, taking into account both ignition and combustion and complete combustion of pulverized coal. This effectively reduces the carbon content of fly ash, improves boiler efficiency, and reduces unit coal consumption.

[0048] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0049] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for adjusting the carbon content of fly ash from a W-flame boiler, characterized in that, Includes the following steps: 1) Test the quality of coal fed into the furnace and control the volatile matter content (V) of the coal. daf ≥10-12%; 2) Adjust the baffle or rotation speed of the coal mill separator to adjust the fineness R of the pulverized coal. 90 Controlled at 3-8%; 3) Adjust the uniformity of the primary air velocity of the coal mill, and control the primary air velocity deviation within ±5%; 4) Adjust the outlet air temperature of the coal mill to 70-120℃; 5) When the boiler load is above 80% ECR, adjust the boiler operating oxygen content to 4.2-4.5% and adjust the oxygen distribution in the furnace width direction; 6) Adjust the exhaust gas damper of the main burner. The exhaust gas damper should be set to 30-70% according to the different volatile matter requirements of the coal. 7) Adjust the opening of the secondary air damper around the primary air nozzle on the arch to 30-50% to supplement the oxygen required for the initial ignition of the pulverized coal airflow and ensure the rigidity and downward injection depth of the primary air; 8) Adjust the opening of the tertiary air damper under the arch to 70-100% to replenish the oxygen required for later combustion.

2. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 1), the volatile matter in coal is determined according to GB / T 212-2008 "Industrial Analysis Methods for Coal".

3. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 1), if the volatile matter content of the coal fed into the furnace is too low, it should be pre-mixed and co-fired with coal of high volatile matter content before being fed into the mill and furnace.

4. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 2), for boilers burning lean coal, the fineness R of the pulverized coal is adjusted. 90 For boilers burning anthracite, the pulverized coal fineness R should be controlled at 6-8%. 90 Keep it between 3-5%.

5. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 3), the initial wind speed measurement and adjustment are carried out in accordance with the "Performance Test of Power Plant Coal Mill and Pulverizing System" (DL / T 467-2019).

6. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 4), when the boiler is burning lean coal or anthracite, the primary air temperature is controlled at 110-120℃, and when burning bituminous coal, the primary air temperature is controlled at 70℃.

7. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 5), the oxygen uniformity is adjusted by measuring the oxygen distribution from the denitrification inlet and adjusting the air volume distribution of a single burner or the three air boxes (left, middle, and right).

8. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 6), when the boiler is burning lean coal or anthracite, the exhaust gas damper should be controlled at 50-70%, and for boilers burning bituminous coal, the exhaust gas damper should be controlled at 30-50%.

9. The method for adjusting the carbon content of fly ash from a W-flame boiler according to claim 1, characterized in that, In step 8), the opening of the tertiary air damper under the arch is adjusted. When the boiler load is above 80% ECR, the opening of the secondary air box is not less than 70%. After the adjustment, the carbon content of the boiler fly ash is reduced to ≤3.0%.

10. An adjustment device for reducing the carbon content of fly ash from a W-flame boiler, characterized in that, include: The coal quality testing unit tests the quality of the coal entering the furnace and controls the volatile matter content (V) of the coal. daf ≥10-12%; The separator adjustment unit adjusts the baffles or rotation speed of the coal mill separator to control the fineness of the coal powder at 3-8%. The primary air temperature regulation unit adjusts the outlet air temperature of the coal mill and controls the primary air temperature of each burner layer to 70-120℃. The total air volume regulating unit adjusts the boiler operating oxygen level to 4.2-4.5% when the boiler load is above 80% ECR. The primary air velocity adjustment unit adjusts the primary air exhaust damper of the main burner to 30-70%. Secondary air regulating unit, adjust the opening of the secondary air damper on the arch by 30-50%; The tertiary air conditioning unit has a tertiary air damper opening of 70-100% under the arch.

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