CN114484421A - Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion - Google Patents
Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion Download PDFInfo
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- CN114484421A CN114484421A CN202210181805.5A CN202210181805A CN114484421A CN 114484421 A CN114484421 A CN 114484421A CN 202210181805 A CN202210181805 A CN 202210181805A CN 114484421 A CN114484421 A CN 114484421A
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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
- F23C7/008—Flow control devices
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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
- F23C5/00—Disposition of burners with respect to the combustion chamber or to one another; Mounting of burners in combustion apparatus
- F23C5/08—Disposition of burners
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J1/00—Removing ash, clinker, or slag from combustion chambers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23M—CASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
- F23M5/00—Casings; Linings; Walls
- F23M5/08—Cooling thereof; Tube walls
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Abstract
The invention provides a primary air chamber of a direct-flow burner and a method for preventing the slag bonding and the high-temperature corrosion of a boiler, wherein the primary air chamber of the direct-flow burner for preventing the slag bonding and the high-temperature corrosion of the boiler comprises a pulverized coal nozzle, a first peripheral air nozzle, a second peripheral air nozzle and an isolating device; the first peripheral air nozzle and the second peripheral air nozzle are arranged on two sides of the isolating device and surround the pulverized coal nozzle; the first peripheral air nozzle is positioned on the fire facing side of the pulverized coal airflow, and the second peripheral air nozzle is positioned on the back fire side of the pulverized coal airflow; the first peripheral air nozzle is communicated with the secondary air box, and the second peripheral air nozzle, the secondary air box and the hot primary air main pipe can be connected and disconnected. The first periphery air nozzle and the second periphery air nozzle are arranged in a differentiated mode, and the air source of the second periphery air nozzle on the back fire side is switched on line, so that the problems of slagging and high-temperature corrosion of the four-corner tangential firing boiler are effectively solved on the premise that pulverized coal airflow is not influenced to catch fire and stabilize combustion.
Description
Technical Field
The invention belongs to the field of boiler combustion of coal-fired power stations, and relates to a primary air chamber of a direct-current combustor and a method for preventing boiler slagging and high-temperature corrosion.
Background
The tangential firing at four corners is the main firing mode of the boiler of the coal-fired power plant, and the direct-flow burners are arranged at the four corners of the boiler hearth, the pulverized coal airflow and the secondary air are jetted into the hearth through the jet flow of the direct-flow burners to converge in a tangential form, one side of the pulverized coal airflow facing fire is directly impacted by the high-temperature flame at the adjacent corner of the upstream to be ignited, and the jet flows at the four corners are mutually supported to form rotary combustion flame.
Slagging and high-temperature corrosion of a four-corner tangential firing boiler are related to tangential firing diameter, melting point of coal ash entering the boiler, sulfur content of the coal entering the boiler, adherence atmosphere and rigidity of pulverized coal airflow. The pulverized coal airflow is injected into the hearth at a high speed through the primary air nozzle, and in the process of rotating airflow, the pulverized coal airflow is sucked to inject surrounding airflow, so that relatively low-pressure areas are formed on two sides of the pulverized coal airflow. When the upstream corner coal dust airflow is injected into the hearth through the primary air nozzle of the straight-flow combustor, under the influence of a relatively low-pressure area formed by the downstream coal dust airflow towards the fire side, the upstream coal dust airflow is sucked to the relatively low-pressure area formed by the downstream coal dust airflow towards the fire side, so that unburned coke particles of the upstream coal dust airflow are caused to impact a downstream water-cooled wall, and therefore boiler slagging and high-temperature corrosion are caused. Because of the characteristic of the tangential firing mode of four corners, the slagging and the high-temperature corrosion area of the hearth of the tangential firing boiler of four corners are consistent and are all positioned on the half-wall of the downstream of the jet direction of the burner, when the velocity of the pulverized coal airflow is higher and the rigidity is higher, the influence of the entrainment of the downstream pulverized coal airflow to the relatively low-pressure area of the fire side is smaller, the upstream pulverized coal airflow is not easy to wash the water-cooled wall of the downstream pulverized coal airflow to the fire side, and the area of the slagging and the high-temperature corrosion area is smaller; when the airflow speed of the pulverized coal is low and the rigidity is insufficient, the areas of slagging and high-temperature corrosion areas are large, and more than half of the four walls of the hearth can be subjected to slagging or high-temperature corrosion at the maximum.
In order to solve the problems of slag bonding and high-temperature corrosion of a four-corner tangential firing boiler, besides ensuring the melting point of the ash of the coal entering the boiler and controlling the sulfur of the coal entering the boiler, the rigidity of the pulverized coal airflow, namely the momentum of the pulverized coal airflow, needs to be improved. When the combustion is optimized and adjusted, the baffle opening of the peripheral air door around the primary air nozzle is enlarged, so that the diffusion of pulverized coal gas to the periphery can be well restrained, the rigidity of the pulverized coal gas flow is enhanced, and the problems of boiler slagging and high-temperature corrosion can be relieved; more importantly, with the wide application of the low-nitrogen combustion technology, the pressure of the air boxes of the hearth of most four-corner tangential firing boilers is lower, and even if the opening degree of the peripheral air door is fully opened, because the pressure of the air boxes is lower, the peripheral air speed is also lower, the capability of restraining pulverized coal airflow from diffusing to the periphery is weakened, the rigidity of the pulverized coal airflow is reduced, and the problems of boiler slagging and high-temperature corrosion are caused.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a primary air chamber of a direct-current combustor and a method for preventing the boiler from slagging and high-temperature corrosion, so that the problems of slagging and high-temperature corrosion of a boiler with tangential firing at four corners are solved on the premise of not influencing the ignition and stable combustion of pulverized coal airflow.
The invention is realized by the following technical scheme:
a primary air chamber of a direct-current combustor for preventing boiler slagging and high-temperature corrosion comprises a pulverized coal nozzle, a first peripheral air nozzle, a second peripheral air nozzle and an isolating device;
the first peripheral air nozzle and the second peripheral air nozzle are arranged on two sides of the isolation device and surround the pulverized coal nozzle;
the first peripheral air nozzle is positioned on the fire facing side of the pulverized coal airflow, and the second peripheral air nozzle is positioned on the back fire side of the pulverized coal airflow;
the first peripheral air nozzle is communicated with the secondary air box, and the second peripheral air nozzle, the secondary air box and the hot primary air main pipe can be connected and disconnected.
Preferably, the cross-sectional areas of the first peripheral air nozzle and the second peripheral air nozzle are equal.
Preferably, the primary air chamber of the direct current burner is connected with an electric actuating mechanism, the first peripheral air nozzle and the second peripheral air nozzle are both internally provided with adjusting baffles, and the adjusting baffles are connected with the electric actuating mechanism.
Preferably, an air duct is arranged between the air inlet of the second peripheral air nozzle and the primary hot air main pipe, a plurality of through holes are formed in the air duct and located inside the secondary air box, and an isolation sleeve is arranged at the through hole.
Preferably, the isolation sleeve is slidably disposed at the through hole.
Preferably, the through holes are formed in the side wall of the air duct, and the distance from the air inlet of the second peripheral air nozzle is equal.
Preferably, an electric stop valve and an electric regulating valve are arranged on the air duct and are located outside the secondary air box.
Preferably, the cross section of the air duct is rectangular.
A once-through combustor comprises the once-through combustor primary air chamber for preventing boiler slagging and high-temperature corrosion.
When the load of a coal-fired power plant unit is not less than 70%, and the melting point of coal ash for combustion is not more than 1300 ℃ or the sulfur content is not less than 1%, the air inlet of the first peripheral air nozzle is communicated with the secondary air box, and the second peripheral air nozzle is communicated with the hot primary air main pipe; otherwise, the air inlet of the first peripheral air nozzle is communicated with the secondary air box, and the second peripheral air nozzle is communicated with the secondary air box.
Compared with the prior art, the invention has the following beneficial technical effects:
a primary air chamber of a direct-current combustor for preventing boiler slagging and high-temperature corrosion is characterized in that a first peripheral air nozzle is located on the fire facing side of pulverized coal airflow, a second peripheral air nozzle is located on the fire back side of the pulverized coal airflow, wherein a first peripheral air nozzle air source is taken from a secondary air box, and the second peripheral air nozzle, the secondary air box and a primary hot air main pipe can be switched on and off, so that switching of the second peripheral air nozzle air source between the secondary air box and the primary hot air main pipe is realized, and utilization of primary hot air with higher pressure is realized. The pressure of a second peripheral air nozzle on the back fire side is higher, so that the rigidity of pulverized coal airflow can be enhanced, and the pulverized coal airflow is prevented from deflecting or scouring a water-cooled wall of the downstream pulverized coal airflow towards the fire side, so that the slag bonding and high-temperature corrosion of the boiler are prevented; and the second periphery air nozzle on the back fire side is positioned on the back fire side of the pulverized coal airflow, so that the mixing of the pulverized coal airflow and the high-temperature flue gas of the hearth cannot be influenced, and the ignition and the combustion of the pulverized coal are not influenced. The first peripheral air nozzle air source on the fire facing side is a secondary air box, the air pressure is small, pulverized coal airflow can be sprayed into the hearth and then quickly mixed with high-temperature flue gas, and ignition and combustion of pulverized coal are accelerated; and the wind pressure of the peripheral wind nozzle at the fire side is small, the relatively low-pressure area formed by pulverized coal airflow at the fire side is small, and the capability of absorbing the upstream pulverized coal airflow is weakened, so that the phenomenon that the upstream pulverized coal airflow washes a water-cooling wall to cause slag bonding and high-temperature corrosion is avoided. Therefore, the first periphery air nozzle and the second periphery air nozzle are arranged in a distinguishing mode, and the air source of the second periphery air nozzle on the back fire side is switched on line, so that the problems of slagging and high-temperature corrosion of the four-corner tangential firing boiler are effectively solved on the premise that ignition and stable combustion of pulverized coal airflow are not influenced.
Furthermore, the sectional areas of the first peripheral air nozzle and the second peripheral air nozzle are equal, so that the air intake of the first peripheral air nozzle and the air intake of the second peripheral air nozzle are equal, and the combustion stability is ensured.
Furthermore, the adjusting baffle can enable the air intake of the first peripheral air nozzle and the air intake of the second peripheral air nozzle to be independently controlled.
Furthermore, the through hole and the isolation sleeve can realize the on-off setting between the air inlet of the second periphery air nozzle and the secondary air box.
Furthermore, the isolation sleeve is arranged at the through hole in a sliding mode, so that the space of the device is saved, and the operation of the device is facilitated.
Furthermore, the length of the plurality of through holes from the air inlet of the second peripheral air nozzle is equal, so that the pressure of the hot primary air entering the second peripheral air nozzle is equal, and the rigidity of the pulverized coal airflow is more stable.
Furthermore, the electric stop valve and the electric regulating valve effectively realize the on-off and control of the hot primary air in the hot primary air main pipe.
A direct-flow burner comprises the primary air chamber of the direct-flow burner for preventing the boiler from slagging and high-temperature corrosion, and can effectively prevent the boiler from slagging and the high-temperature corrosion.
A method for preventing boiler slagging and high-temperature corrosion is provided, wherein the direct-current burners are arranged on four corners of a boiler, when fused pulverized coal particles are bonded at a water-cooled wall, an air source of a second peripheral air nozzle on a back fire side is switched to a hot primary air main pipe, the air pressure of the peripheral air nozzle on the back fire side is improved, the rigidity of pulverized coal airflow is enhanced, and the pulverized coal airflow is prevented from brushing the water-cooled wall to cause boiler slagging and high-temperature corrosion; by the direct-current burner, the problems of slag bonding and high-temperature corrosion of the tangential firing boiler at four corners are solved on the premise of not influencing the ignition and stable combustion of pulverized coal airflow.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic front view of a primary plenum of the present invention;
FIG. 2 is a schematic side view of a second peripheral air nozzle air supply from the hot primary air manifold on the backfire side of the primary air plenum of the present invention;
FIG. 3 is a schematic side view of a second peripheral air jet supply on the backfire side of the primary plenum taken from the secondary windbox in accordance with the present invention;
FIG. 4 is a view of the placement of the primary plenum in the boiler of the present invention.
Wherein: 1. pulverized coal nozzle, 21, first periphery wind nozzle, 22, second periphery wind nozzle, 3, isolating device, 4, secondary air box, 5, hot primary air main pipe, 6, adjusting baffle, 7, air duct, 71, through hole, 72, isolating sleeve, 73, electric stop valve, 74 and electric adjusting valve.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually arranged when the product of the present invention is used, the description is merely for convenience and simplicity, and the indication or suggestion that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, cannot be understood as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.
Furthermore, the term "horizontal", if present, does not mean that the component is required to be absolutely horizontal, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the embodiments of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The invention is described in further detail below with reference to the accompanying drawings:
peripheral air is arranged around a pulverized coal nozzle of a traditional four-corner tangential firing boiler, and a peripheral air source is taken from a secondary air box. As the pressure of the secondary air box of the existing coal-fired power plant boiler is generally less than 200Pa, the air quantity of the peripheral air is reduced, so that the capability of the peripheral air for wrapping the pulverized coal airflow is weakened, and the pulverized coal airflow is easily sucked by a relatively low-pressure area to scour the downstream water-cooled wall of the pulverized coal airflow, thereby causing the slagging and high-temperature corrosion of the boiler. The reasons for the lower pressure of the secondary bellows are mainly: (1) due to the wide application of the low-nitrogen combustion technology, 30-35% of air quantity required by a burner area is sprayed into a hearth by an over-fire air burner, so that the pressure of a secondary air box is reduced; (2) in order to meet the requirement of drying output of a coal mill, the primary air rate reaches 40%, and the pressure of a secondary air box is difficult to exceed 200Pa under the condition that the total air volume entering a furnace is constant.
The hot primary air pressure of the coal-fired power plant boiler is 7 kPa-10 kPa, and if the peripheral air source is changed from a secondary air box to hot primary air, the problem of insufficient airflow rigidity of pulverized coal caused by low pressure of the secondary air box can be solved. If hot primary air is used as a peripheral air source, the air pressure of the hot primary air is higher than that of secondary air and the flue gas pressure of a hearth, so that pulverized coal airflow is isolated by the hot primary air, the pulverized coal airflow is sprayed into the hearth to be mixed with the secondary air and high-temperature flue gas for delay, ignition, combustion and burnout of the pulverized coal airflow are influenced, and the problems of unstable combustion, rising of combustible substance content of fly ash and the like can occur. In addition, the increase of the hot primary air quantity leads to the increase of the power consumption rate of the primary air fan, and is not beneficial to reducing the plant power consumption rate.
According to the characteristic of tangential firing at four corners, the invention divides the peripheral air nozzles around the pulverized coal nozzles of the primary air chamber into two parts, as shown in figure 1, the primary air chamber of the direct-current burner for preventing the slag bonding and the high-temperature corrosion of the boiler comprises the pulverized coal nozzles 1, a first peripheral air nozzle 21, a second peripheral air nozzle 22 and an isolating device 3, wherein the isolating device 3 can be a vertical partition plate, and the pulverized coal nozzles 1 are rectangular or square nozzles. The boundary air nozzle is divided into a first boundary air nozzle 21 and a second boundary air nozzle 22 through the isolation device 3, and the first boundary air nozzle 21 and the second boundary air nozzle 22 are arranged on two sides of the isolation device 3 and surround the pulverized coal nozzle 1; the first peripheral air nozzle 21 is positioned on the fire facing side of the pulverized coal airflow, namely the peripheral air nozzle on the fire facing side, and the second peripheral air nozzle 22 is positioned on the fire back side of the pulverized coal airflow, namely the peripheral air nozzle on the fire back side; the air inlet of the first peripheral air nozzle 21 is communicated with the secondary air box 4, and the sectional areas of the first peripheral air nozzle 21 and the second peripheral air nozzle 22 are equal.
As shown in fig. 2, an air duct 7 is disposed between the air inlet of the second peripheral air nozzle 22 and the primary hot air main pipe 5, a plurality of through holes 71 are disposed on the air duct 7, the through holes 71 are located inside the secondary air box 4, and an isolation sleeve 72 is disposed at the through holes 71. The isolation sleeve 72 can realize the switching of the air source of the second periphery air nozzle on the back fire side, and when the isolation sleeve is opened, the air source of the second periphery air nozzle on the back fire side is taken from the secondary air box; when the isolation sleeve is closed, the air source of the second peripheral air nozzle on the back fire side is taken from the hot primary air main pipe. The second peripheral air nozzle 22 and the secondary air box 4 can be opened and closed through a through hole 71 and an isolation sleeve 72, the isolation sleeve 72 is arranged at the through hole 71 in a sliding mode, the through holes 71 are arranged on the side wall of the air duct 7 and used as an air inlet of a secondary air box 4 air source of the second peripheral air nozzle 22, the distance between the air inlet and the second peripheral air nozzle 22 is equal, and the air inlet is square.
The wind source of the first peripheral wind nozzle at the fire side is a secondary wind box 4, the wind pressure is small, the pulverized coal airflow can be quickly mixed with high-temperature flue gas after being sprayed into the hearth, and the ignition and combustion of the pulverized coal are accelerated; and the wind pressure of the first peripheral wind nozzle at the fire side is smaller, the relatively low-pressure area formed at the coal powder airflow at the fire side is smaller, and the capacity of entraining the upstream coal powder airflow is weakened, so that the phenomenon that the upstream coal powder airflow washes a water-cooled wall to cause slag formation and high-temperature corrosion is avoided. The pressure of the second peripheral air nozzle 22 on the back fire side is higher, so that the rigidity of the pulverized coal airflow can be enhanced, the pulverized coal airflow is prevented from deflecting or scouring the downstream pulverized coal airflow to the water-cooled wall on the fire side, and therefore, the slag bonding and high-temperature corrosion of the boiler are prevented; and the peripheral air nozzle at the back fire side is positioned at the back fire side of the pulverized coal airflow, so that the mixing of the pulverized coal airflow and high-temperature flue gas of a hearth cannot be influenced, and the ignition and combustion of the pulverized coal are not influenced.
The air duct 7 is further provided with an electric stop valve 73 and an electric regulating valve 74, the electric stop valve 73 and the electric regulating valve 74 are located outside the secondary air box 4, the second peripheral air nozzle 22 and the primary hot air main pipe 5 can be opened and closed through the electric stop valve 73 and the electric regulating valve 74, and the cross section of the air duct 7 is rectangular.
The primary air chamber of the direct current burner is also connected with an electric actuating mechanism, the first peripheral air nozzle 21 and the second peripheral air nozzle 22 are internally provided with adjusting baffles 6 for independently controlling the air inlet volume, and the adjusting baffles 6 are connected with the electric actuating mechanism.
A once-through combustor comprises the once-through combustor primary air chamber for preventing boiler slagging and high-temperature corrosion.
As shown in fig. 4, the above-mentioned one type of direct-flow burners are disposed at four corners of the boiler, and when the fused pulverized coal particles are bonded at the water-cooled wall, the air inlet of the first peripheral air nozzle 21 is communicated with the secondary air box 4, and the second peripheral air nozzle 22 is communicated with the primary hot air main pipe 5, otherwise, the air inlet of the first peripheral air nozzle 21 is communicated with the secondary air box 4, and the second peripheral air nozzle 22 is communicated with the secondary air box 4.
The boiler is fired with coal with low ash melting point and high sulfur content, when the rigidity of the coal dust airflow is insufficient, the downstream coal dust airflow is easy to scour the water-cooled wall of the fire side, the fused coal dust particles are bonded on the water-cooled wall to form slag, the unburned coal dust particles consume the oxygen content of the downstream coal dust airflow to the fire side water-cooled wall accessory, and the water-cooled wall of the fire side is corroded at high temperature due to the enhancement of reducing atmosphere. As shown in fig. 2, when the load of the coal-fired power plant unit is more than 70%, the melting point of coal ash for combustion is lower than 1300 ℃ or the sulfur content is higher than 1%, the isolation sleeve 72 outside the air duct 7 is closed, the electric stop valve 73 on the air duct 7 is opened, so that the air inlets on two sides of the air duct are closed, the air source of the peripheral air nozzle on the back fire side is switched to the primary hot air main pipe 5 from the secondary air box 4, the opening of the electric control valve 74 on the air duct is adjusted as required to adjust the proper air pressure of the peripheral air nozzle on the back fire side, after the air pressure of the peripheral air nozzle on the back fire side is raised, the rigidity of pulverized coal airflow is enhanced, the pulverized coal airflow is prevented from being washed on the downstream pulverized coal airflow facing the water cooling wall on the fire side, and the slag formation and the high-temperature corrosion of the boiler are prevented.
As shown in fig. 3, when the unit load is below 70%, because the overall temperature of the furnace is low and the temperature of the wall of the water-cooled wall is low, slag bonding and high-temperature corrosion of the boiler are not easy to occur at this time, the electric stop valve 73 on the air duct 7 is closed, the insulating sleeve 72 outside the air duct 7 is opened, the through holes 71 on two sides of the air duct 7 are opened, the air source of the peripheral air nozzle on the backfire side is switched to the secondary air box 4 from the primary hot air main pipe 5, and the air pressure of the peripheral air nozzle on the backfire side is reduced. When the melting point of the coal ash for combustion is higher than 1350 ℃ or the sulfur content of the coal is lower than 1%, the conditions for forming slag formation and high-temperature corrosion of the boiler are weaker, and at the moment, the air source of the peripheral air nozzle at the back fire side of the primary air chamber is switched to the secondary air box 4.
The invention divides the peripheral air nozzle of the primary air chamber of the traditional four-corner tangential firing boiler into a fire-facing side peripheral air nozzle and a back fire side peripheral air nozzle, wherein the air source of the fire-facing side peripheral air nozzle is taken from the secondary air box, and the air source of the back fire side peripheral air nozzle can be switched between the secondary air box and the hot primary air main pipe. When the coal ash for combustion has a low melting point and a high sulfur content, the air source of the peripheral air nozzle on the back fire side is switched to the hot primary air main pipe, so that the air pressure of the peripheral air nozzle on the back fire side is improved, the rigidity of pulverized coal airflow is enhanced, and the pulverized coal airflow is prevented from scouring the water-cooled wall to cause boiler slagging and high-temperature corrosion; the air source of the peripheral air nozzle at the fire facing side is a secondary air box, the air pressure of the secondary air box is relatively low, a relatively low-pressure area formed at the fire facing side of the pulverized coal airflow is relatively weak, the mixing of the pulverized coal airflow, secondary air and high-temperature flue gas is not influenced, and the ignition and combustion of the pulverized coal airflow are not influenced. The division of the peripheral air nozzles of the primary air chamber and the on-line switching of the air sources of the peripheral air nozzles at the back fire side solve the problems of slag bonding and high-temperature corrosion of the tangential firing boiler at four corners on the premise of not influencing the ignition and stable combustion of pulverized coal airflow.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A primary air chamber of a direct-current combustor for preventing boiler slagging and high-temperature corrosion is characterized by comprising a pulverized coal nozzle (1), a first peripheral air nozzle (21), a second peripheral air nozzle (22) and an isolating device (3);
the first peripheral air nozzle (21) and the second peripheral air nozzle (22) are arranged on two sides of the isolating device (3) and surround the pulverized coal nozzle (1);
the first peripheral air nozzle (21) is positioned on the fire facing side of the pulverized coal airflow, and the second peripheral air nozzle (22) is positioned on the back fire side of the pulverized coal airflow;
the first peripheral air nozzle (21) is communicated with the secondary air box (4), and the second peripheral air nozzle (22) can be connected with the secondary air box (4) and the hot primary air main pipe (5) in an on-off mode.
2. The once-through combustor primary plenum for preventing boiler slagging and high temperature corrosion according to claim 1, wherein the first peripheral air port (21) and the second peripheral air port (22) have the same cross-sectional area.
3. The once-through combustor primary air chamber for preventing the boiler slagging and the high-temperature corrosion according to claim 1, characterized in that an electric actuator is connected to the once-through combustor primary air chamber, and an adjusting baffle (6) is arranged in each of the first peripheral air nozzle (21) and the second peripheral air nozzle (22), and the adjusting baffle (6) is connected to the electric actuator.
4. The once-through combustor primary air chamber for preventing the boiler from slagging and high-temperature corrosion as claimed in claim 1, wherein an air duct (7) is arranged between the air inlet of the second peripheral air nozzle (22) and the primary hot air main pipe (5), a plurality of through holes (71) are arranged on the air duct (7), the plurality of through holes (71) are located inside the secondary air box (4), and an isolation sleeve (72) is arranged at the through holes (71).
5. The once-through combustor primary plenum for preventing boiler slagging and high temperature corrosion according to claim 4, wherein said insulating sleeve (72) is slidably disposed at said through hole (71).
6. The primary air chamber of the once-through burner for preventing the boiler from slagging and high-temperature corrosion according to claim 4, wherein the plurality of through holes (71) are formed on the side wall of the air duct (7) and have the same length from the air inlet of the second peripheral air nozzle (22).
7. The primary air chamber of the once-through combustor for preventing the boiler slagging and the high temperature corrosion according to claim 4, characterized in that an electric stop valve (73) and an electric regulating valve (74) are arranged on the air duct (7), and the electric stop valve (73) and the electric regulating valve (74) are positioned outside the secondary air chamber (4).
8. The primary plenum of the once-through burner for preventing the slagging and the high temperature corrosion of the boiler according to claim 4, wherein the cross section of the air duct (7) is rectangular.
9. A once-through combustor comprising a once-through combustor primary plenum for preventing boiler slagging and high temperature corrosion as claimed in any one of claims 1 to 8.
10. A method for preventing the slag bonding and the high-temperature corrosion of a boiler, which is characterized in that the four corners of the boiler are provided with the direct-current burners as claimed in claim 9, when the load of a coal-fired power plant unit is not less than 70%, and the melting point of coal ash for combustion is not more than 1300 ℃ or the sulfur content is not less than 1%, the air inlet of the first peripheral air nozzle (21) is communicated with a secondary air box (4), and the second peripheral air nozzle (22) is communicated with a hot primary air main pipe (5); otherwise, the air inlet of the first peripheral air nozzle (21) is communicated with the secondary air box (4), and the second peripheral air nozzle (22) is communicated with the secondary air box (4).
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210181805.5A CN114484421A (en) | 2022-02-25 | 2022-02-25 | Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion |
| PCT/CN2022/132087 WO2023160032A1 (en) | 2022-02-25 | 2022-11-15 | Direct-current burner primary air chamber and method for preventing boiler slagging and high-temperature corrosion |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210181805.5A CN114484421A (en) | 2022-02-25 | 2022-02-25 | Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion |
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| Publication Number | Publication Date |
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| CN114484421A true CN114484421A (en) | 2022-05-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202210181805.5A Pending CN114484421A (en) | 2022-02-25 | 2022-02-25 | Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion |
Country Status (2)
| Country | Link |
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| CN (1) | CN114484421A (en) |
| WO (1) | WO2023160032A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023160032A1 (en) * | 2022-02-25 | 2023-08-31 | 西安热工研究院有限公司 | Direct-current burner primary air chamber and method for preventing boiler slagging and high-temperature corrosion |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56149517A (en) * | 1980-04-22 | 1981-11-19 | Mitsubishi Heavy Ind Ltd | Pulverized-coal burner |
| CN201306708Y (en) * | 2008-11-25 | 2009-09-09 | 上海锅炉厂有限公司 | Quick ignition coal dust nozzle capable of automatically adjusting ignition point |
| CN103672885A (en) * | 2013-12-31 | 2014-03-26 | 北京国电龙高科环境工程技术有限公司 | Vertical thick and thin direct flow coal powder combustion device realizing primary air spray nozzle inside deflection |
| CN103697463B (en) * | 2013-12-31 | 2016-02-03 | 北京国电龙高科环境工程技术有限公司 | The burner of upper and lower deep or light First air centralized arrangement |
| CN203628631U (en) * | 2013-12-31 | 2014-06-04 | 北京国电龙高科环境工程技术有限公司 | Low-nitrogen combustion device without main secondary air |
| CN214370153U (en) * | 2021-01-04 | 2021-10-08 | 西安热工研究院有限公司 | Side wall water-cooled wall adherence protection device based on thick and thin pulverized coal separation combustor |
| CN112879899A (en) * | 2021-02-20 | 2021-06-01 | 西安热工研究院有限公司 | Primary air opposite flushing device for preventing slag bonding and corrosion of water-cooled wall of rear wall of boiler |
| CN112902154A (en) * | 2021-03-30 | 2021-06-04 | 西安热工研究院有限公司 | Over-fire air system with controllable steam temperature deviation and CO concentration at two sides of opposed firing boiler |
| CN114484421A (en) * | 2022-02-25 | 2022-05-13 | 西安热工研究院有限公司 | Primary air chamber of direct-current combustor and method for preventing boiler slagging and high-temperature corrosion |
-
2022
- 2022-02-25 CN CN202210181805.5A patent/CN114484421A/en active Pending
- 2022-11-15 WO PCT/CN2022/132087 patent/WO2023160032A1/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023160032A1 (en) * | 2022-02-25 | 2023-08-31 | 西安热工研究院有限公司 | Direct-current burner primary air chamber and method for preventing boiler slagging and high-temperature corrosion |
Also Published As
| Publication number | Publication date |
|---|---|
| WO2023160032A1 (en) | 2023-08-31 |
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