CN110006034B - Optimized air distribution method for reducing NOx emission and slag coking of W-shaped flame furnace - Google Patents
Optimized air distribution method for reducing NOx emission and slag coking of W-shaped flame furnace Download PDFInfo
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- CN110006034B CN110006034B CN201910250674.XA CN201910250674A CN110006034B CN 110006034 B CN110006034 B CN 110006034B CN 201910250674 A CN201910250674 A CN 201910250674A CN 110006034 B CN110006034 B CN 110006034B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C7/00—Combustion apparatus characterised by arrangements for air supply
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23L—SUPPLYING AIR OR NON-COMBUSTIBLE LIQUIDS OR GASES TO COMBUSTION APPARATUS IN GENERAL ; VALVES OR DAMPERS SPECIALLY ADAPTED FOR CONTROLLING AIR SUPPLY OR DRAUGHT IN COMBUSTION APPARATUS; INDUCING DRAUGHT IN COMBUSTION APPARATUS; TOPS FOR CHIMNEYS OR VENTILATING SHAFTS; TERMINALS FOR FLUES
- F23L9/00—Passages or apertures for delivering secondary air for completing combustion of fuel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23N—REGULATING OR CONTROLLING COMBUSTION
- F23N3/00—Regulating air supply or draught
- F23N3/06—Regulating air supply or draught by conjoint operation of two or more valves or dampers
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Abstract
The invention discloses an optimized air distribution method for reducing NOx emission and slag coking of a W-shaped flame furnace. The opening degrees of the secondary air doors of the D-layer vertical wall and the E-layer vertical wall are respectively 5% and 7%; according to the unit load, the opening degrees of the F-layer vertical wall secondary air door, the arch wall secondary air door I and the arch wall secondary air door II are respectively 35%, 15% and 30-60%, and the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 30-60%; controlling the differential pressure of the secondary air box to be 0.3-0.88Kpa, controlling the operation oxygen amount to be 3.5-6.0%, wherein the higher the unit load is, the higher the differential pressure of the secondary air box is, and the higher the unit load is, the lower the operation oxygen amount is; wherein, the differential pressure of the secondary air box is the differential pressure between the secondary air box and the pressure of the hearth; the opening degree of the control center OFA secondary air door is 75-85%, and the opening degree of the perimeter OFA secondary air door is 15-20%; and controlling the outlet pressure of the grinding powder pipe to be 2.6-4.8 Kpa. The method can reduce the generation of NOX and reduce the coking of the boiler.
Description
Technical Field
The invention relates to the technical field of combustion of W-shaped flame furnaces, in particular to an optimized air distribution method for reducing NOx emission and slag coking of the W-shaped flame furnaces.
Background
The boiler technology adopted by many thermal power plants at present is a supercritical parameter variable-pressure direct-current boiler, a single hearth, single reheating, balanced ventilation, open-air arrangement, solid slag discharge, an all-steel framework, W-shaped flame combustion, a vertical internal threaded tube water-cooled wall and an n-shaped variable-pressure direct-current boiler. The boiler burns conventional coal mixture of anthracite and local coal. The boiler pulverized coal combustion equipment adopts a novel double-cyclone cylinder fuel preheating pulverized coal burner and an exhaust gas-over-fire air combustion system, and can obviously reduce the emission concentration of NOx on the basis of adapting to the combustion of low-volatile smokeless coal. The burners are symmetrically arranged on the furnace arch at the lower part of the hearth in parallel, and 18 burners are arranged at the front and the back of the furnace arch respectively. The boiler is provided with 6 sets of powder making systems which are of a primary cooling fan positive pressure direct blowing type, and each set of system comprises 1 double-inlet and double-outlet coal mill.
Referring to fig. 1, secondary air required for combustion is supplied from windboxes, and the secondary air from an air preheater is supplied to front and rear wall windboxes through air ducts at both sides of a boiler, and is supplied to a furnace from air ports on and under the arch of the boiler and over-fire air nozzles. The windboxes are separated by partitions and are independent of each other, so that each burner is a unit and can be adjusted independently. The air quantity regulation of each unit (combustor) is controlled by a D-layer vertical wall secondary air door, an E-layer vertical wall secondary air door, an F-layer vertical wall secondary air door, an arch wall secondary air door I6, an arch wall secondary air door II 8, a center OFA secondary air door 3 and a perimeter OFA secondary air door 4, the perimeter air quantity of a pulverized coal nozzle 7 of the combustor is regulated by the arch wall secondary air door II 8, and the air quantity of an ignition oil gun 5 and the oil fire detection is controlled by the arch wall secondary air door I6. The secondary air doors of the D-layer vertical wall, the E-layer vertical wall and the vertical wall F control secondary air of the arched vertical wall, the D, E-layer vertical wall secondary air doors are manual, the vertical wall secondary air door F is pneumatic, and all manual baffles are generally not adjusted after combustion adjustment is finished unless fuel or combustion working conditions are greatly changed. The perimeter OFA secondary air door 4 and the center OFA secondary air door 3 are pneumatic and respectively control the annular direction of the over-fire air and the secondary air quantity of the center air. The 36 exhaust-burnout air burners which correspond to the double-cyclone-barrel pulverized coal burners one by one are uniformly arranged on the front wall and the rear wall above the boiler arch, and each exhaust-burnout air burner comprises 1 burnout air central nozzle 1 and a burnout air annular nozzle 2. The electric butterfly valve on the exhaust pipe 11 is used for adjusting the exhaust amount led out from the cyclone coal burner, thereby adjusting the air amount of the coal nozzle 7, namely the coal concentration. Corresponding to each double-cyclone-cylinder pulverized coal burner, a concentric over-fire air nozzle is arranged on a boiler arch, the concentric nozzle is composed of a circumferential air nozzle 2 and a central air nozzle 1, a first exhaust secondary air door 12 and a second exhaust secondary air door 13 jointly control the flow of the central air nozzle 1, and the over-fire air nozzle sprays jet flow into the boiler by 30 degrees downwards along a horizontal line. This is the approximate arrangement condition of the communication between the burner and the hearth of the current W-shaped flame furnace.
Although the W flame furnace has the advantages in the aspect of stable combustion, the W flame furnace also has the characteristics of easy coking and high NOx concentration, and ventilation air adjustment and boiler oxygen adjustment which are main means for adjusting NOx have great influence on boiler coking, thereby restricting the adjustment of NOx. In the process of combustion adjustment, by opening the ventilation air, the NOx index can be reduced, but the coking of the hearth is aggravated, and even the safe operation of the boiler is influenced. Therefore, under the existing equipment condition, how to gradually reduce the concentration of the NOx at the outlet of the boiler and ensure that the coking of the boiler is not intensified or even not generated is a technical problem which needs to be solved at present.
Disclosure of Invention
Aiming at the problems, the invention obtains an optimized air distribution mode by reasonably controlling the opening of each pipeline valve of the burner, so that the generation of NOX is reduced, simultaneously the coking of the boiler is reduced, and the difficult problem that the generation of Nox and the simultaneous reduction of the coking of the boiler are difficult to realize in the prior art is solved.
To achieve these objects and other advantages in accordance with the purpose of the invention, an optimized air distribution method for reducing NOx emissions and slag coking in a W-flame furnace according to the invention comprises the following aspects:
1) the opening degree of the secondary air door of the D-layer vertical wall is 4-6%, and the opening degree of the secondary air door of the E-layer vertical wall is 6-8%;
2) according to the unit load, the opening degree of the F-layer vertical wall secondary air door is 20-35%, the opening degrees of the exhaust secondary air door I and the exhaust secondary air door II are the same and are 30-60%, the opening degree of the arch wall secondary air door I is 5-15%, and the opening degree of the arch wall secondary air door II is 30-60%;
3) controlling the differential pressure of the secondary air box to be 0.3-0.88Kpa, controlling the operation oxygen amount to be 3.5-6.0%, wherein the higher the unit load is, the higher the differential pressure of the secondary air box is, and the higher the unit load is, the lower the operation oxygen amount is; wherein, the differential pressure of the secondary air box is the differential pressure between the secondary air box and the pressure of the hearth;
4) the opening degree of the control center OFA secondary air door is 75-85%, and the opening degree of the perimeter OFA secondary air door is 15-20%;
5) and controlling the outlet pressure of the grinding powder pipe to be 2.6-4.8 Kpa.
Preferably, when the unit load is 450MW, the opening degree of the F-layer vertical wall secondary air door is 25%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30%, the opening degree of the arch wall secondary air door I is 5%, the opening degree of the arch wall secondary air door II is 30%, the differential pressure of the secondary air box is controlled to be 0.3-0.7Kpa, the running oxygen amount is 5.0-6.0%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.0Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Preferably, when the unit load is 500MW, the opening degree of the F-layer vertical wall secondary air door is 30%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 30%, the opening degree of the arch wall secondary air door I is 8%, the opening degree of the arch wall secondary air door II is 35%, the differential pressure of the secondary air box is controlled to be 0.5-0.75Kpa, the running oxygen amount is 5.0-6.0%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Preferably, when the unit load is 550MW, the opening degree of the F-layer vertical wall secondary air door is 30%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 30-35%, the opening degree of the arch wall secondary air door I is 10%, the opening degree of the arch wall secondary air door II is 40%, the differential pressure of the secondary air box is controlled to be 0.65-0.75Kpa, the running oxygen amount is 4.2-4.8%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Preferably, when the unit load is 600MW, the opening degree of the F-layer vertical wall secondary air door is 32%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 30-35%, the opening degree of the arch wall secondary air door I is 12%, the opening degree of the arch wall secondary air door II is 45%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the running oxygen amount is 3.8-4.3%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the peripheral OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.5-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Preferably, when the unit load is 630MW, the opening degree of the F-layer vertical wall secondary air door is 33%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 35-40%, the opening degree of the arch wall secondary air door I is 15%, the opening degree of the arch wall secondary air door II is 50%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the running oxygen amount is 3.7-4.7%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the peripheral OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Preferably, when the unit load is 670MW, the opening degree of the F-layer vertical wall secondary air door is 35%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 35-40%, the opening degree of the arch wall secondary air door I is 15%, the opening degree of the arch wall secondary air door II is 50%, the differential pressure of the secondary air box is controlled to be 0.78-0.88Kpa, the running oxygen amount is 3.5-4.5%, the opening degree of the central OFA secondary air door is 85%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.8Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
The invention at least comprises the following beneficial effects: the invention optimizes and controls the vertical wall secondary air door D, the vertical wall secondary air door E, the vertical wall secondary air door F, the arch wall secondary air door I and the arch wall secondary air door II of the burner, controls the same opening degree of the exhaust gas secondary air door I and the exhaust gas secondary air door II to be 30-60 percent, and controls the opening degree of the central OFA secondary air door to be 75-85 percent, so that a proper amount of secondary air carries partial coal powder to be sprayed out from a central air nozzle of the exhaust gas-burn-out air burner, oxidizing atmosphere is formed on the water-cooled wall surface of a hearth in the area above the arch part, combustion is promoted, the oxygen content and the hearth temperature in the burn-out air area are reduced, and therefore, the thermal NOx formed under the high-temperature condition of nitrogen molecules in the air is inhibited, and the NOx generated in the combustion process is reduced on. The circumferential air quantity of the overfire air is controlled by controlling the opening degree of the perimeter OFA secondary air door to be 15-20%, the overfire air jet on the arch is sprayed out from the circumferential nozzle, the hearth penetration capacity is high, the upward flowing flue gas can be sucked in a curling mode and is fully mixed with the upward flowing flue gas, and graded air distribution is provided for later-stage overfire and low NOx emission of carbon particles, so that NOx emission is reduced, slag coking is reduced, the coal slag is normal in shape, and combustion is full.
The opening degree of the central OFA secondary air door is fixed to be 75%, and the opening degree of the peripheral OFA secondary air door is fixed to be 15%, so that the rigidity of the air flow sprayed out of the central air nozzle is higher than that of the air flow sprayed out of the annular nozzle, the coal powder on the upper portion of the arch is guaranteed to have sufficient rigidity, and the coal powder is prevented from adhering to the wall.
Drawings
FIG. 1 is a schematic view of a prior art W-shaped flame furnace;
fig. 2 is an enlarged schematic view of part III of fig. 1.
The air distribution device comprises a central air nozzle 1, a circumferential nozzle 2, a central OFA secondary air door 3, a perimeter OFA secondary air door 4, an oil gun 5, an arch wall secondary air door I6, a coal powder nozzle 7, an arch wall secondary air door II 8, a cyclone cylinder separator 9, a coal powder uniform separator 10, an exhaust air pipe 11, an exhaust air secondary air door I12 and an exhaust air secondary air door II 13.
Detailed Description
The method of the invention is obtained by a plurality of test analyses, and the groping test process of the invention is illustrated by the specific operation and results of a plurality of adjustment tests.
Constantly adjust D layer vertical wall secondary air door, E layer vertical wall secondary air door, F layer vertical wall secondary air door, exhaust gas secondary air door one, exhaust gas secondary air door two, it is one to encircle wall secondary air door, it is two to encircle wall secondary air door, the aperture of center OFA secondary air door and perimeter OFA secondary air door to and the differential pressure of control secondary bellows, operation oxygen volume and crocus pipe exit pressure value, wherein, the differential pressure of secondary bellows is the differential pressure between secondary bellows and furnace pressure. Referring specifically to the first to fourteenth adjustments of tables one, two and three, the results of the adjustments from the inside and the outside show that it is also difficult to obtain how to reduce NOx emissions and slag coking in the W-flame furnace by changing the air distribution mode, and the inventors have analyzed the adjustment data of tables one, two and three as follows:
table one:
in the first table, it is shown that,under the load of a 600MW unit, in the process of adjusting from the first time to the second time, the opening degree of a secondary air door of the F-layer vertical wall is reduced to 25% from 30%, the opening degrees of a first air exhaust secondary air door and a second air exhaust secondary air door are increased to 25% from 15%, the oxygen content is reduced to 4.9% from 5.5%, and NO is reducedXThe concentration is 2226mg/Nm3Down to 1410mg/Nm3，NOXThe temperature of the hearth of the observation hole is obviously reduced and increased and is controlled within 1500 ℃, but the melting state of coke blocks in the slag is greatly improved, so that the slag and NO are obviously reducedXThe concentration can not meet the requirement, and the economical efficiency is low.
In the third adjustment and the fourth adjustment, the oxygen content is reduced from 4.9% to 4.7% and then reduced to 4.1%, and the opening degree of the secondary air door of the vertical wall of the F layer under the arch is increased in the fourth adjustment so as to ensure that the oxygen content under the arch is not influenced and the opening degree of the secondary air door of the arch wall is increased. Regulated NOXThe concentration is 1219mg/Nm3Down to 1127mg/Nm3，NOXAnd the current of the induced draft fan is further reduced obviously, the temperature of the hearth of the observation hole and the flame form are not changed greatly, but the outside of the coke block in the slag is still in a molten state, the amount of the molten state of the slag adjusted for the third time is reduced to a certain extent compared with the amount of the molten state of the slag adjusted for the third time, and the amount of the molten state of the slag adjusted for the fourth time and the third time is not changed. By the optimization combustion adjustment of the current day, NO is enabled under the condition that the coking of the hearth is not intensifiedXThe concentration is significantly reduced to correspond to NOXAnd (4) emission standard.
In the fifth and sixth adjustment processes, the opening degree of the F-layer vertical wall secondary air door is changed from 35% to 40%, the opening degree of the arch wall secondary air door is reduced from 30% to 20%, the opening degree of the arch wall secondary air door is increased from 30% to 35%, the opening degree of the perimeter OFA air door is reduced from 25% to 15%, the oxygen content is reduced from 4.8% to 3.8%, and the secondary air bellow air differential pressure is reduced from 0.87KPa to 0.62 KPa. The air distribution mode aims at further reducing the whole oxygen content of the boiler on the premise of ensuring the oxygen content of the combustor area under the arch, and simultaneously trying to equalize the oxygen content deviation of the hearth twice. Adjusted, NOXThe concentration is 1413mg/Nm3Down to 1253mg/Nm3The current of the induced draft fan is obviously reduced, the temperature of the hearth outlet is reduced, the melting state of the coke blocks in the slag adjusted for the sixth time is reduced and tends to common coke blocks,the slag amount is small and normal, but NO is not realizedXThe concentration is effectively reduced. By the optimization combustion adjustment of the current day, NO is enabled under the condition that the coking of the hearth is not intensifiedXThe concentration is significantly reduced to correspond to NOXAnd (4) emission standard.
Table two:
in the second table, the unit load is increased to 670MW, and under full load, in the process of adjusting from the seventh time to the eighth time, the pipe wall temperature of the heated surface of the hearth adjusted for the seventh time is characterized by high in the middle and low on two sides, so that the conditions that the heat load is higher along the middle part of the furnace width than on two sides, the oxygen content is also low in the middle and high on two sides, the coking of the hearth is easy to form are reflected, and the slag amount of each slag hopper is slightly more. In order to reduce coking in the middle of the hearth, the opening degree of a second secondary air door of the arch wall is reduced from 60% to 50% by eighth adjustment, the opening degree of a central OFA secondary air door is reduced from 70% to 65%, the opening degree of a peripheral OFA secondary air door is reduced from 30% to 20%, so that the oxygen content of the middle arch of the hearth is properly increased, the total oxygen content is reduced by 0.2%, the vertical air of D, E layers which is adjusted for the fifth and sixth times is 0-30% and is not uniform, and D, E layers of vertical air are uniformly fixed at 10% and 15% by seventh and eighth adjustments respectively. The slag form is improved by adjustment, most coke falls from a slag hopper to be solid loose common coke blocks, the coke particles in a molten state are less, the current of a blower is reduced, but NO is reducedXThe concentration increases.
In the ninth and tenth adjustment, the oxygen amount is reduced, the secondary air quantity on the arch and the ventilation air are adjusted, the slag form is still better, but NO is still betterXAnd (4) increasing the concentration, judging the reason to be related to the secondary air volume on the arch and the ventilation air volume on the hearth, and trying to adjust the secondary air volume on the arch and the ventilation air volume again next time.
Table three:
in the third table, the unit is adjusted for the eleventh to fourteen times under full load, wherein the opening degrees of the first arch wall secondary air door, the second arch wall secondary air door and the second F-layer vertical wall secondary air door are continuously reduced, and the air quantity and NO of the lower hearth are reducedXThe discharge is gradually reduced, but the coke blocks in a molten state in the slag are obviously increased, the water-cooled wall has an overtemperature phenomenon, the flame center moves upwards, the temperature of smoke at the screen inlet rises by about 100 ℃ and exceeds a specified value, and the control of coking is not facilitated.
Through observation and analysis of data in the first, second and third tables, in the sixth, ninth and tenth adjustments, the opening degree of the F-layer vertical wall secondary air door is about 40%, the opening degree of the arch wall secondary air door is about 17%, the opening degree of the arch wall secondary air door is about 50%, the opening degrees of the exhaust gas secondary air door and the exhaust gas secondary air door are about 25%, coking of the boiler is obviously relieved, but the opening degrees of the arch wall secondary air doors are larger, so that pulverized coal downwards falls, the opening degree of the F-layer vertical wall secondary air door is large, the pulverized coal is intensively combusted at the lower part of an arch, the highest Nox emission is 2100mg/Nm3, and the denitration pressure is larger. Therefore, in the sixth, ninth and tenth adjustments, the emphasis of the adjustment is to reduce NOXAnd (5) discharging. The opening degrees of the F-layer vertical wall secondary air door and the arch wall secondary air door I and II are adjusted to be small, meanwhile, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are adjusted to be equal to each other to be 30-60%, the opening degree of the central OFA secondary air door is adjusted to be 75-85%, and a proper amount of secondary air carries part of coal powder to be sprayed out from a central air nozzle of the exhaust gas-over-fire air burner, so that oxidizing atmosphere is formed on the water-cooled wall surface of the hearth above the arch part, combustion is promoted, the oxygen content and the hearth temperature of the over-fire air area are reduced, thermal NOx formed under the high-temperature condition of nitrogen molecules in the air is inhibited, and NOx generated in the combustion process is reduced on the whole. And the control opening degree of the perimeter OFA secondary air door is kept between 15 and 20 percentThe annular air quantity of the over-fire air is controlled, so that over-fire air jet flow on the arch is sprayed out from the annular nozzle, the hearth penetration capacity is high, upward flowing flue gas can be sucked in an entrainment mode and is fully mixed with the upward flowing flue gas, graded air distribution is provided for later-stage over-fire and low NOx emission of carbon particles, NOx emission is reduced, slag coking is reduced, the slag is normal in shape, no fused coke blocks exist, no hard coke, large coke and other coke blocks exist, combustion is sufficient, and economic benefits are improved. See examples 1-6 and the results of Table four to enable one skilled in the art to practice them in light of the specification.
Example 1
When the load of the unit is 450MW, the opening degree of the F-layer vertical wall secondary air door is 25%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30%, the opening degree of the arch wall secondary air door I is 5%, the opening degree of the arch wall secondary air door II is 30%, the differential pressure of the secondary air box is controlled to be 0.3-0.7Kpa, the operating oxygen content is 5.0-6.0%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.0Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is.
Example 2
When the load of the unit is 500MW, the opening degree of the F-layer vertical wall secondary air door is 30%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30%, the opening degree of the arch wall secondary air door I is 8%, the opening degree of the arch wall secondary air door II is 35%, the differential pressure of the secondary air box is controlled to be 0.5-0.75Kpa, the operating oxygen amount is 5.0-6.0%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is.
Example 3
When the load of the unit is 550MW, the opening degree of a F-layer vertical wall secondary air door is 30%, the opening degrees of a first exhaust gas secondary air door and a second exhaust gas secondary air door are the same and are 30-35%, the opening degree of a first arch wall secondary air door is 10%, the opening degree of a second arch wall secondary air door is 40%, the differential pressure of a secondary air box is controlled to be 0.65-0.75Kpa, the operation oxygen amount is 4.2-4.8%, the opening degree of a central OFA secondary air door is 75%, the opening degree of a peripheral OFA secondary air door is 15%, the outlet pressure of a grinding pipe is 3.0-4.5Kpa, the opening degree of a D-layer vertical wall secondary air door is 5%, and the opening degree of an E-layer vertical wall secondary air door is 7.
Example 4
When the unit load is 600MW, the opening degree of the F-layer vertical wall secondary air door is 32%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 30-35%, the opening degree of the arch wall secondary air door I is 12%, the opening degree of the arch wall secondary air door II is 45%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the operation oxygen amount is 3.8-4.3%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.5-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
Example 5
When the load of the unit is 630MW, the opening degree of the F-layer vertical wall secondary air door is 33%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 35-40%, the opening degree of the arch wall secondary air door I is 15%, the opening degree of the arch wall secondary air door II is 50%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the operation oxygen amount is 3.7-4.7%, the opening degree of the center OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7.
Example 6
When the load of the unit is 670MW, the opening degree of a F-layer vertical wall secondary air door is 35%, the opening degrees of a first exhaust gas secondary air door and a second exhaust gas secondary air door are the same and are 35-40%, the opening degree of a first arch wall secondary air door is 15%, the opening degree of a second arch wall secondary air door is 50%, the differential pressure of a secondary air box is controlled to be 0.78-0.88Kpa, the operation oxygen amount is 3.5-4.5%, the opening degree of a central OFA secondary air door is 85%, the opening degree of a peripheral OFA secondary air door is 15%, the outlet pressure of a grinding pipe is 3.0-4.8Kpa, the opening degree of a D-layer vertical wall secondary air door is 5%, and the opening degree of an E-layer vertical wall secondary air door is 7.
Table four:
the coal powder adopted by the invention is the mixed coal of conventional anthracite and local coal, the part of the coal powder with the particle size larger than 90 mu m accounts for 18-25% of the total amount of the coal powder, the raw materials are easy to obtain, and the components and the characteristics of the adopted coal are as follows:
table five:
composition and characteristics of coal
| Item | Symbol | Unit of | Checking |
|
| 1. Industrial analysis | ||||
| Total water content of the received base | Mt | ％ | 7.0 | |
| Ash content of received base | Aar | ％ | 31.1 | |
| Air-drying ash-free base volatile | Vdaf | ％ | 12 | |
| Low calorific value of received power | Qnet.v.ar | kJ/kg | 19653 | |
| Total sulfur content | St.ar | ％ | 5.10 | |
| 2. Elemental analysis | ||||
| Carbon of oxo group | Car | ％ | 51.0 | |
| Radical hydrogen generation | Har | ％ | 2.4 | |
| Oxygen radical take-up | Oar | ％ | 2.2 | |
| Radical nitrogen recovery | Nar | ％ | 1.2 | |
| 3. Ash fusion temperature | ||||
| Ash deformation temperature | DT(T1) | ℃ | 1289 | |
| Ash softening temperature | ST(T2) | ℃ | 1421 | |
| Temperature of gray hemisphere | HT | ℃ | 1450 | |
| Ash fusion temperature | FT(T3) | ℃ | 1491 |
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.
Claims (6)
1. The optimized air distribution method for reducing NOx emission and slag coking of the W-shaped flame furnace is characterized by comprising the following aspects:
1) the opening degree of the secondary air door of the D-layer vertical wall is 4-6%, and the opening degree of the secondary air door of the E-layer vertical wall is 6-8%;
2) according to the unit load, the opening degree of the F-layer vertical wall secondary air door is 20-35%, the opening degrees of the exhaust secondary air door I and the exhaust secondary air door II are the same and are 30-60%, the opening degree of the arch wall secondary air door I is 5-15%, and the opening degree of the arch wall secondary air door II is 30-60%;
3) controlling the differential pressure of the secondary air box to be 0.3-0.88Kpa, controlling the operation oxygen amount to be 3.5-6.0%, wherein the higher the unit load is, the higher the differential pressure of the secondary air box is, and the higher the unit load is, the lower the operation oxygen amount is; wherein, the differential pressure of the secondary air box is the differential pressure between the secondary air box and the pressure of the hearth;
4) the opening degree of the control center OFA secondary air door is 75%, and the opening degree of the perimeter OFA secondary air door is 15%;
5) and controlling the outlet pressure of the grinding powder pipe to be 2.6-4.8 Kpa.
2. The optimized air distribution method for reducing NOx emission and slag coking of a W-type flame furnace as claimed in claim 1, wherein when the unit load is 450MW, the opening degree of the F-layer vertical wall secondary air door is 25%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30%, the opening degree of the arch wall secondary air door I is 5%, the opening degree of the arch wall secondary air door II is 30%, the differential pressure of the secondary air box is controlled to be 0.3-0.7Kpa, the operation oxygen amount is 5.0-6.0%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.0Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
3. The optimized air distribution method for reducing NOx emission and slag coking of a W-type flame furnace as claimed in claim 1, wherein when the unit load is 500MW, the opening degree of the F-layer vertical wall secondary air door is 30%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30%, the opening degree of the arch wall secondary air door I is 8%, the opening degree of the arch wall secondary air door II is 35%, the differential pressure of the secondary air box is controlled to be 0.5-0.75Kpa, the operation oxygen amount is 5.0-6.0%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the perimeter OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
4. The optimized air distribution method for reducing NOx emission and slag coking of the W-type flame furnace as claimed in claim 1, wherein when the unit load is 550MW, the opening degree of the F-layer vertical wall secondary air door is 30%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30-35%, the opening degree of the arch wall secondary air door I is 10%, the opening degree of the arch wall secondary air door II is 40%, the differential pressure of the secondary air box is controlled to be 0.65-0.75Kpa, the operation oxygen amount is 4.2-4.8%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the peripheral OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
5. The optimized air distribution method for reducing NOx emission and slag coking of a W-type flame furnace according to claim 1, wherein when the unit load is 600MW, the opening degree of the F-layer vertical wall secondary air door is 32%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are both 30-35%, the opening degree of the arch wall secondary air door I is 12%, the opening degree of the arch wall secondary air door II is 45%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the operation oxygen amount is 3.8-4.3%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the peripheral OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.5-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
6. The optimized air distribution method for reducing NOx emission and slag coking of a W-type flame furnace as claimed in claim 1, wherein when the unit load is 630MW, the opening degree of the F-layer vertical wall secondary air door is 33%, the opening degrees of the exhaust gas secondary air door I and the exhaust gas secondary air door II are the same and are 35-40%, the opening degree of the arch wall secondary air door I is 15%, the opening degree of the arch wall secondary air door II is 50%, the differential pressure of the secondary air box is controlled to be 0.68-0.78Kpa, the operation oxygen amount is 3.7-4.7%, the opening degree of the central OFA secondary air door is 75%, the opening degree of the peripheral OFA secondary air door is 15%, the outlet pressure of the grinding pipe is 3.0-4.5Kpa, the opening degree of the D-layer vertical wall secondary air door is 5%, and the opening degree of the E-layer vertical wall secondary air door is 7%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0819885A2 (en) * | 1996-07-18 | 1998-01-21 | Toyota Jidosha Kabushiki Kaisha | Combustion apparatus |
| CN101545639A (en) * | 2009-05-08 | 2009-09-30 | 哈尔滨工业大学 | Method for adjusting combustion of W flame furnace by changing quantity of oil secondary air |
| CN107355807A (en) * | 2016-06-02 | 2017-11-17 | 中国大唐集团科学技术研究院有限公司 | W type flame boiler air distribution mode optimization methods |
-
2019
- 2019-03-29 CN CN201910250674.XA patent/CN110006034B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0819885A2 (en) * | 1996-07-18 | 1998-01-21 | Toyota Jidosha Kabushiki Kaisha | Combustion apparatus |
| CN101545639A (en) * | 2009-05-08 | 2009-09-30 | 哈尔滨工业大学 | Method for adjusting combustion of W flame furnace by changing quantity of oil secondary air |
| CN107355807A (en) * | 2016-06-02 | 2017-11-17 | 中国大唐集团科学技术研究院有限公司 | W type flame boiler air distribution mode optimization methods |
Non-Patent Citations (1)
| Title |
|---|
| W型火焰锅炉燃烧检测与优化研究;汪华剑;《中国博士学位论文全文数据库 工程科技Ⅱ辑》;20101130;第2章，第4章，第5章，表4-6 * |
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