A Combustion Adjustment Test Method for a W-Flame Boiler Equipped with a Double-Inlet and Double-Outlet Ball Mill

Abstract

The invention discloses a combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill, which includes the following steps: setting target indicators; recording the water levels on the left and right sides of the boiler steam drum; during the combustion adjustment process, ensuring that the highest wall temperature of each heating surface does not exceed the alarm value; observing the horizontal oxygen content and CO distribution and comparing them with the dial parameters to verify the reliability of the dial data; respectively testing the primary air velocities in the primary air pipelines at the outlets of each coal mill to check whether the primary air velocity deviation is within the design range; respectively sampling the pulverized coal in the primary air pipelines at the outlets of each coal mill, analyzing the fineness of the pulverized coal in a single tube of the test report, and checking whether it is within the design range; determining the opening degrees of the C baffle, F baffle, exhaust gas baffle, OFA air rate baffle and the optimal controlled oxygen content at high, medium and low loads respectively; adjusting the target indicators to eliminate the deviation. The invention can guide the further operation adjustment and design modification of the W-flame boiler and ensure the safe operation of the boiler.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal-fired thermal power units, and particularly relates to a combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill. Background Art

[0002] As of the end of 2021, the coal-fired power generation units with ultra-low emissions in China exceeded 1 billion kilowatts. Among them, pulverized coal-fired boilers in power plants accounted for about 1 billion kilowatts, and circulating fluidized bed boilers in power plants accounted for about 100 million kilowatts. Classified by the combustion organization form, pulverized coal-fired boilers mainly include tangential combustion, front-back wall opposed firing, and W-shaped combustion. The W-flame boiler is mainly used to burn anthracite or lean coal. The W-flame boiler mainly burns low-volatile coal types, and factors such as the furnace structure, burner arrangement, air supply method, and powder-air ratio are designed in accordance with the combustion characteristics of low-volatile coal. After ignition, the pulverized coal air flow becomes lighter in weight when it reaches the lower part of the furnace. At this time, the flame is lifted by the staged air at the lower part of the combustion chamber and turns upward, forming a W-shaped flame in the lower combustion chamber. The combustion schematic diagram is as Figure 1 shown.

[0003] In W-flame boilers, there are generally problems such as flame skewing in the furnace and large steam temperature deviations on the left and right sides of the boiler. The main reasons are that the W-flame boiler has a large width-depth ratio of the furnace (close to 4:1), uneven distribution of air and powder along the width direction of the furnace, uneven combustion of air and powder in the furnace, which is likely to have a greater impact on the left and right sides of the steam drum water level, and relatively large deviations in the CO concentration on the left and right sides at the outlet of the economizer. The consequences are as follows: a large deviation in the steam drum water level is likely to cause steam to carry water or burn out the boiler drum. Both high and low water levels are likely to cause alarms, and in severe cases, it will cause the unit to shut down. The relatively large deviation in the CO concentration on the left and right sides at the outlet of the economizer directly affects the economy of the boiler; the uneven combustion in the furnace seriously affects the economic and safe operation of the unit.

[0004] Since the W-flame boilers in China have been put into operation for a short time, there is little experience accumulation, and there is a lack of an effective adjustment test method.

[0005] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present disclosure. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0006] In order to solve the technical problems such as uneven combustion in the left and right side furnaces of W-flame boilers existing in the prior art, the purpose of the present invention is to provide a combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill.

[0007] To achieve the above object and reach the above technical effect, the technical solution adopted by the present invention is as follows:

[0008] A combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill, comprising the following steps:

[0009] Set target indicators, where the target indicators include one or a combination of the water level deviation between the left and right sides of the steam drum, the temperature deviation at the outlet of the left and right separators, the oxygen content deviation on the left and right sides at the outlet of the economizer, and the CO concentration deviation on the left and right sides at the outlet of the economizer;

[0010] Under the habitual operating conditions, record the water levels on the left and right sides of the boiler steam drum;

[0011] During the combustion adjustment process, the highest point of the wall temperature of each heating surface is a restrictive indicator, ensuring that it does not exceed its alarm value;

[0012] Test at each measuring hole in the cross-section at the outlet of the economizer, observe the transverse oxygen content and CO distribution, and compare with the dial parameters to verify the reliability of the dial data;

[0013] Test the primary air velocity in the primary air pipeline at the outlet of each coal mill respectively, and check whether the primary air velocity deviation at the outlet of the same coal mill is within the design range;

[0014] Take samples of the pulverized coal in the primary air pipeline at the outlet of each coal mill respectively, analyze the fineness of the pulverized coal in a single tube of the test report, and check whether it is within the design range;

[0015] Determine the opening degrees of the C baffle, F baffle, exhaust gas baffle, OFA air rate baffle and the optimal controlled oxygen content at high, medium and low loads respectively;

[0016] Adjust the target indicators to eliminate the deviation.

[0017] If the primary air velocity deviation exceeds the design range, adjust and reduce the deviation value through the adjustable choke at the outlet of the coal mill. The adjustment principle is: first open the adjustable choke of the primary air pipeline with the lowest air velocity, and then close the adjustable choke of the primary air pipeline with the highest air velocity, and try to keep the primary air velocity deviation in each primary air pipeline within 10%.

[0018] If the fineness of the pulverized coal is not within the design range, adjust the fineness of the pulverized coal by adjusting the single-side deflector baffle door of the coal mill. For a steel ball mill, when the fineness of the pulverized coal meets the requirements, if the output of the coal mill fails to meet the requirements, appropriately add steel balls.

[0019] Further, the steps for determining the opening degrees of the C baffle at high, medium and low loads respectively include:

[0020] At high, medium or low load, adjust the C auxiliary air, and under the condition that other operating parameters remain unchanged, adjust the opening degree of the C baffle, record the boiler operating parameters at different opening degrees of the C baffle, analyze the changes in the water level of the steam drum, the oxygen content at the outlet of the economizer, and the left and right side deviations of carbon monoxide at the outlet of the economizer, and determine the appropriate opening degree of the C baffle.

[0021] The steps for determining the opening degrees of the F baffle at high, medium, and low loads respectively include:

[0022] At high, medium, or low loads, under the condition that other operating parameters remain unchanged, adjust the opening degree of the F baffle, record the boiler operating parameters at different opening degrees of the F baffle, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left - right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening degree of the F baffle.

[0023] Furthermore, the steps for determining the opening degrees of the lean gas baffle at high, medium, and low loads respectively include:

[0024] At high, medium, or low loads, under the condition that other operating parameters remain unchanged, adjust the opening degree of the lean gas baffle, record the boiler operating parameters at different opening degrees of the lean gas baffle, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left - right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening degree of the lean gas baffle.

[0025] Furthermore, the steps for determining the opening degrees of the OFA air ratio at high, medium, and low loads respectively include:

[0026] At high, medium, or low loads, under the condition that other operating parameters remain unchanged, adjust the OFA air ratio, record the boiler operating parameters at different OFA air ratios, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left - right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening degree of the OFA air ratio.

[0027] Furthermore, the steps for determining the optimal controlled oxygen content at high, medium, and low loads respectively include:

[0028] At high, medium, or low loads, under the condition that other operating parameters remain unchanged, only change the output of the forced draft fan to change the total boiler air volume, thereby changing the excess air coefficient at the furnace outlet, which is reflected on the dial as the change in the oxygen content of the flue gas at the economizer outlet, and determine the optimal controlled oxygen content of the boiler according to the carbon monoxide concentration at the economizer outlet.

[0029] Furthermore, the steps for adjusting the target index to eliminate the deviation include:

[0030] When the left - right side deviation of the drum water level exceeds the set absolute value, adjust the combustion intensity in the furnace by stopping one of the burners on the side with the lower water level, thereby adjusting the balance of the left - right side water levels of the drum. At the same time, close the corresponding C air and F air doors of the stopped burner to 10%;

[0031] When stopping the burner, balance the oxygen content on the left - right sides at the economizer outlet and the balance of CO on the left - right sides at the economizer outlet, and control that at most one burner at the single - side outlet of a single coal mill is stopped;

[0032] After adopting the asymmetric shutdown burner, if the water levels on the left and right sides of the steam drum are basically balanced and the deviation value is less than the set absolute value, it indicates that the combustion intensities on the left and right sides in the furnace are basically balanced;

[0033] Through appropriate differential adjustment of the C damper and F damper, keep the oxygen content at the economizer outlet basically balanced on the left and right sides, with the oxygen content deviation on the left and right sides not exceeding 25%, and the CO deviation on the left and right sides at the economizer outlet not exceeding 200 mg / m 3 ;

[0034] When differentially adjusting the C damper, first close both dampers by 10% appropriately, and the corresponding F damper should also be closed by 5% appropriately; keep the oxygen content on the left and right sides at the economizer outlet basically balanced;

[0035] Control the appropriate air coefficient at the furnace outlet through the adjustment of the total air volume entering the furnace, and keep the average value of the CO concentration on the left and right sides at the economizer outlet not exceeding 200 mg / m 3 ;

[0036] Control the NOx at the SCR device inlet by adjusting the OFA damper.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] The present invention discloses a combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill. First, set the target indicators including one or several combinations of the water level deviation between the left and right sides of the steam drum, the temperature deviation at the outlet of the separators on the left and right sides, the oxygen content deviation on the left and right sides at the economizer outlet, and the CO concentration deviation on the left and right sides at the economizer outlet. Then, adjust the target indicators to eliminate the deviation, and can also determine the opening degrees of the C baffle, F baffle, exhaust gas baffle, OFA air rate baffle and the optimal control oxygen content at high, medium and low loads. It has strong operability, can guide the further operation adjustment and design modification of the W-flame boiler, ensure the safe operation of the boiler, and is more economical and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of a W-flame boiler. DETAILED DESCRIPTION OF THE INVENTION

[0040] The present invention will be elaborated in detail below so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0041] A brief overview of one or more aspects is given below to provide a basic understanding of these aspects. This overview is not an exhaustive survey of all contemplated aspects and is neither intended to identify key or decisive elements of all aspects nor to define the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description to follow.

[0042] A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill. First, set the following target indicators: water level deviation between the left and right sides of the steam drum (for subcritical boilers), temperature deviation between the left and right sides of the separator outlet (for supercritical boilers), oxygen content deviation between the left and right sides at the economizer outlet, and CO concentration deviation between the left and right sides at the economizer outlet. Taking a subcritical boiler as an example, the method includes the following steps:

[0043] (1) Record the water levels on the left and right sides of the boiler steam drum under the habitual operating conditions.

[0044] (2) During the combustion adjustment process, the highest wall temperature of each heating surface is a restrictive indicator to ensure that it does not exceed its alarm value; the target indicators should be as close as possible to the allowable variation range of their design values.

[0045] (3) Test at the midpoint of each measuring hole in the cross-section of the economizer outlet to observe the lateral oxygen content and CO distribution, and compare with the dial parameters to verify the reliability of the dial data.

[0046] (4) Measure the primary air velocities in the primary air pipelines at the outlets of each coal mill respectively to check whether the primary air velocity deviation at the outlet of the same coal mill is within the design range.

[0047] (5) Take samples of the pulverized coal in the primary air pipelines at the outlets of each coal mill respectively, analyze the fineness of the pulverized coal in a single tube of the test report, and check whether it is within the design range.

[0048] (6) If the primary air velocity deviation exceeds the allowable range, adjust it through the adjustable throttling orifice at the outlet of the coal mill to reduce the deviation value. The principle of adjustment is to first open the adjustable throttling orifice of the pipeline with the lowest wind speed preferentially, and then close the adjustable throttling orifice of the pipeline with the highest wind speed. Try to keep the primary air velocity deviation in each primary air pipeline within 10%, preferably within 5%.

[0049] (7) Adjust the fineness of the pulverized coal to keep it within the design range. For example, the fineness of the pulverized coal can be adjusted by adjusting the single-side deflector baffle door of the coal mill.

[0050] (8) When the fineness of the pulverized coal meets the requirements, if the output of the coal mill fails to meet the requirements, for a steel ball mill, steel balls can be appropriately added according to the on-site situation.

[0051] (9) When above 90% of the rated load, adjust the C auxiliary air, and under the condition that other operating parameters remain unchanged, adjust the opening of the C baffle. Record the boiler operating parameters at different openings of the C baffle, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left-right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening of the C baffle.

[0052] (10) When above 90% of the rated load, under the condition that other operating parameters remain unchanged, adjust the opening of the F baffle. Record the boiler operating parameters at different openings of the F baffle, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left-right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening of the F baffle.

[0053] (11) When above 90% of the rated load, under the condition that other operating parameters remain unchanged, adjust the opening of the exhaust gas baffle. Record the boiler operating parameters at different openings of the exhaust gas baffle, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left-right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening of the exhaust gas baffle.

[0054] (12) When above 90% of the rated load, under the condition that other operating parameters remain unchanged, adjust the OFA air ratio. Record the boiler operating parameters at different OFA air ratios, analyze the changes in the drum water level, oxygen content at the economizer outlet, and left-right side deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening of the OFA air ratio.

[0055] (13) When above 90% of the rated load, under the condition that other operating parameters remain unchanged, only change the output of the forced draft fan to change the total boiler air volume, thereby changing the excess air coefficient at the furnace outlet, which is reflected on the dial as the change in the oxygen content of the flue gas at the economizer outlet. Determine the optimal controlled oxygen content of the boiler according to the carbon monoxide concentration at the economizer outlet.

[0056] (14) When the left-right side deviation of the drum water level exceeds 50 mm (absolute value), it is necessary to adjust the combustion intensity in the furnace by shutting down one of the burners on the side with the lower water level, so as to adjust the balance of the left-right side water levels of the drum. At the same time, close the corresponding C air and F air of the shutdown burner to about 10%.

[0057] (15) The shutdown burner takes into account the balance of the oxygen content on the left and right sides at the economizer outlet, as well as the balance of CO on the left and right sides at the economizer outlet. Generally, at most one burner on the single-side outlet of a single coal mill is shut down.

[0058] (16) After adopting the asymmetric shutdown of the burner, if the left-right side water levels of the drum are basically balanced and the deviation value is less than 50 mm, it indicates that the combustion intensities on the left and right sides in the furnace are basically balanced.

[0059] (17) By appropriately differentiating and adjusting the C air damper and F air damper, the oxygen content at the economizer outlet is kept basically balanced on the left and right sides, and the deviation of the oxygen content on the left and right sides does not exceed 25% (relative value). The deviation of CO on the left and right sides at the economizer outlet does not exceed 200 mg / m 3 (absolute value).

[0060] (18) When differentiating and adjusting the C air damper, first appropriately close the two air dampers by 10%, and the corresponding F air damper should also be appropriately closed by 5%; keep the oxygen content on the left and right sides at the economizer outlet basically balanced.

[0061] (19) By adjusting the total air volume entering the furnace, control the appropriate air coefficient at the furnace outlet to keep the average value of CO on the left and right sides at the economizer outlet not exceeding 200 mg / m 3 is appropriate.

[0062] (20) By adjusting the OFA air damper, control the NOx at the SCR device inlet.

[0063] At 75% medium load and 50% low load, use the same adjustment method as above to keep the deviation of the drum water level on the left and right sides, the deviation of the oxygen content on the left and right sides at the economizer outlet, the deviation of CO on the left and right sides at the economizer outlet and the average value, and control the NOx at the SCR device inlet.

[0064] The above high, medium and low load burner operation modes and air distribution modes can be used as the optimal operation modes.

[0065] Example 1

[0066] A certain factory's 600MW subcritical unit with W flame adopts the adjustment test method of the present invention and achieves good expected results, providing an effective reference for power plant technicians.

[0067] The test results of the C baffle opening characteristics are shown in Table 1.

[0068] Table 1

[0069]

[0070] The test results of the F baffle opening characteristics are shown in Table 2.

[0071] Table 2

[0072]

[0073] The test results of the lean gas baffle opening characteristics are shown in Table 3.

[0074] Table 3

[0075]

[0076] The test results of the lean gas baffle opening characteristics are shown in Table 4.

[0077] Table 4

[0078]

[0079] The test results of the oxygen content characteristics are shown in Table 5 as follows.

[0080] Table 5

[0081]

[0082] The test results of the left - right balance of the drum water level are shown in Table 6 as follows.

[0083] Table 6

[0084]

[0085] Among them, the bold C3, D2, and B5 in Table 6 indicate that the burners are out of service, and the water level deviation between the left and right sides of the drum decreases after adjustment.

[0086] The test results of the left - right balance of the oxygen content / CO at the economizer outlet are shown in Table 7 as follows.

[0087] Table 7

[0088]

[0089]

[0090] For the parts or structures not specifically described in the present invention, existing technologies or existing products can be adopted, and no further elaboration will be made here.

[0091] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be included in the patent protection scope of the present invention by the same token.

Claims

1. A combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill, characterized in that, It includes the following steps: Set target indicators, where the target indicators include one or a combination of several of the water level deviation between the left and right sides of the steam drum, the temperature deviation at the outlet of the separators on the left and right sides, the oxygen content deviation on the left and right sides at the outlet of the economizer, and the CO concentration deviation on the left and right sides at the outlet of the economizer; Under the habitual operating conditions, record the water levels on the left and right sides of the boiler steam drum; During the combustion adjustment process, the highest point of the wall temperature of each heating surface is the restrictive indicator to ensure that it does not exceed its alarm value; Test at each measuring hole in the cross-section of the economizer outlet, observe the transverse oxygen content and CO distribution, and compare with the dial parameters to verify the reliability of the dial data; Test the primary air velocity in the primary air pipelines at the outlets of each coal mill respectively to check whether the primary air velocity deviation at the outlet of the same coal mill is within the design range; Take samples of the pulverized coal in the primary air pipelines at the outlets of each coal mill respectively, analyze the fineness of the pulverized coal in a single tube of the test report, and check whether it is within the design range; Determine the opening degrees of the C baffle, F baffle, exhaust gas baffle, OFA air rate opening, and the optimal controlled oxygen content at high, medium, and low loads respectively; Adjust the target indicators to eliminate the deviation.

2. The combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that, If the primary air velocity deviation exceeds the design range, adjust and reduce the deviation value through the adjustable throttling orifice at the outlet of the coal mill. The adjustment principle is: first open the adjustable throttling orifice of the primary air pipeline with the lowest air velocity, and then close the adjustable throttling orifice of the primary air pipeline with the highest air velocity, and try to keep the primary air velocity deviation in each primary air pipeline within 10%; 3. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that, If the fineness of the pulverized coal is not within the design range, adjust the fineness of the pulverized coal by adjusting the single-side deflector baffle door of the coal mill.

4. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 3, characterized in that For the steel ball mill, when the fineness of the pulverized coal meets the requirements, if the output of the coal mill fails to meet the requirements, appropriately add steel balls.

5. A combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that, The steps for determining the opening degrees of the C baffle at high, medium, and low loads respectively include: At high, medium, or low load, adjust the C auxiliary air, and under the condition that other operating parameters remain unchanged, adjust the opening degree of the C baffle, record the boiler operating parameters at different opening degrees of the C baffle, analyze the changes in the water level of the steam drum, the oxygen content at the outlet of the economizer, and the left and right side deviations of carbon monoxide at the outlet of the economizer, and determine the appropriate opening degree of the C baffle.

6. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that The steps for determining the opening degrees of the F baffle at high, medium, and low loads respectively include: At high, medium, or low load, under the condition that other operating parameters remain unchanged, adjust the opening degree of the F baffle, record the boiler operating parameters at different opening degrees of the F baffle, analyze the changes in the water level of the steam drum, the oxygen content at the outlet of the economizer, and the left and right side deviations of carbon monoxide at the outlet of the economizer, and determine the appropriate opening degree of the F baffle.

7. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that The steps for determining the opening degrees of the exhaust gas baffle at high, medium, and low loads respectively include: At high, medium, or low load, under the condition that other operating parameters remain unchanged, adjust the opening degree of the exhaust gas baffle, record the boiler operating parameters at different opening degrees of the exhaust gas baffle, analyze the changes in the water level of the steam drum, the oxygen content at the outlet of the economizer, and the left and right side deviations of carbon monoxide at the outlet of the economizer, and determine the appropriate opening degree of the exhaust gas baffle.

8. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that The steps for determining the opening degrees of the OFA air rate at high, medium, and low loads respectively include: Under high, medium or low loads, with other operating parameters remaining unchanged, adjust the OFA air ratio, record the boiler operating parameters at different OFA air ratios, analyze the changes in the drum water level, oxygen content at the economizer outlet, and the left-right deviation of carbon monoxide at the economizer outlet, and determine the appropriate opening of the OFA air ratio.

9. A combustion adjustment test method for a W-flame boiler equipped with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that, The steps to determine the optimal controlled oxygen content at high, medium and low loads respectively include: Under high, medium or low loads, with other operating parameters remaining unchanged, only change the output of the forced draft fan to change the total boiler air volume, thereby changing the excess air coefficient at the furnace outlet, which is reflected on the dial as the change in the oxygen content of the flue gas at the economizer outlet, and determine the optimal controlled oxygen content of the boiler according to the carbon monoxide concentration at the economizer outlet.

10. A combustion adjustment test method for a W-flame boiler configured with a double-inlet and double-outlet steel ball mill according to claim 1, characterized in that, The steps to adjust the target index to eliminate the deviation include: When the left-right deviation of the drum water level exceeds the set absolute value, adjust the combustion intensity in the furnace by stopping one of the burners on the side with the lower water level, so as to adjust the balance of the left-right water levels of the drum, and at the same time close the corresponding C air damper and F air damper of the stopped burner to 10%; When stopping the burner, take into account the balance of the oxygen content on the left and right sides at the economizer outlet and the balance of CO on the left and right sides at the economizer outlet, and control that at most one burner at the single-sided outlet of a single coal mill is stopped; After using asymmetric burner shutdown, if the left-right water levels of the drum are basically balanced and the deviation value is less than the set absolute value, it indicates that the combustion intensities on the left and right sides in the furnace are basically balanced; By appropriately and differentially adjusting the C air damper and F air damper, the oxygen content at the economizer outlet is kept basically balanced on the left and right sides, with the oxygen content deviation on the left and right sides not exceeding 25%, and the CO deviation on the left and right sides at the economizer outlet not exceeding 200 mg / m 3 ; When making differential adjustments to the C air damper, first close both sides of the damper by 10% appropriately, and the corresponding F air damper should also be closed by 5% appropriately; Keep the oxygen content on the left and right sides at the economizer outlet basically balanced; By adjusting the total air volume entering the furnace, control the appropriate air coefficient at the furnace outlet to keep the average value of the CO concentration on both sides at the economizer outlet not exceeding 200 mg / m 3 ; Control the NOx at the inlet of the SCR device by adjusting the OFA air damper.

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