WO2023160032A1

WO2023160032A1 - Direct-current burner primary air chamber and method for preventing boiler slagging and high-temperature corrosion

Info

Publication number: WO2023160032A1
Application number: PCT/CN2022/132087
Authority: WO
Inventors: 杨辉; 党小建; 张海龙; 沈植; 张良平; 张宇博; 刘超
Original assignee: 西安热工研究院有限公司
Priority date: 2022-02-25
Filing date: 2022-11-15
Publication date: 2023-08-31
Also published as: CN114484421A

Abstract

A direct-current burner primary air chamber and method for preventing boiler slagging and high-temperature corrosion. The direct-current burner primary air chamber for preventing boiler slagging and high-temperature corrosion comprises: a pulverized coal nozzle (1), a first surrounding air nozzle (21), a second surrounding air nozzle (22) and an isolation device (3); the first surrounding air nozzle (21) and the second surrounding air nozzle (22) are arranged on two sides of the isolation device (3) and define the pulverized coal nozzle (1); the first surrounding air nozzle (21) is located on an exposed side of a pulverized coal airflow, and the second surrounding air nozzle (22) is located on an unexposed side of the pulverized coal airflow; the first surrounding air nozzle (21) is communicated with a secondary air box (4), and the second surrounding air nozzle (22) can be communicated with or disconnected from the secondary air box (4) and a hot primary air mother pipe (5). By means of distinguishing configuration of the first surrounding air nozzle (21) and the second surrounding air nozzle (22), and on-line switching of an air source of the second surrounding air nozzle (22) on the unexposed side, the problems of slagging and high-temperature corrosion of a tangentially fired boiler are effectively solved on the premise of not affecting ignition and stable combustion of the pulverized coal airflow.

Description

Once-through burner primary air chamber and method for preventing boiler slagging and high temperature corrosion

Cross References to Related Applications

This application is based on a Chinese patent application with application number 202210181805.5 and a filing date of February 25, 2022, and claims the priority of this Chinese patent application. The entire content of this Chinese patent application is hereby incorporated by reference into this application.

technical field

The disclosure belongs to the field of boiler combustion in a coal-fired power station, and in particular relates to a primary air chamber of a once-through burner and a method for preventing boiler slagging and high-temperature corrosion.

Background technique

Four-corner tangential combustion is the main combustion method of coal-fired power plant boilers. Direct-flow burners are arranged on the four corners of the boiler furnace. The side of the powder flow towards the fire is ignited by the direct impact of the high-temperature flame at the upstream adjacent corners, and the four-corner jets support each other to form a rotating combustion flame.

The slagging and high-temperature corrosion of four-corner tangential combustion boilers are related to the diameter of tangential combustion, the melting point of incoming coal ash, the sulfur content of incoming coal, the atmosphere attached to the wall, and the rigidity of pulverized coal airflow. The pulverized coal airflow is injected into the rotating airflow process in the furnace through the primary air nozzle at high speed, and its suction ejects the surrounding airflow, forming a relatively low pressure area on both sides of the pulverized coal airflow. When the upstream pulverized coal flow is injected into the furnace through the primary air nozzle of the once-through burner, the upstream pulverized coal flow will be entrained to the downstream pulverized coal flow to the fire side due to the influence of the relatively low pressure area formed by the downstream pulverized coal flow to the fire side. The relatively low-pressure area on the side of the boiler causes the unburned coke particles in the upstream pulverized coal flow to rush to the downstream water-cooled wall, resulting in boiler slagging and high-temperature corrosion. Due to the characteristics of the four-corner tangential combustion mode, the slagging and high-temperature corrosion areas of the four-corner tangential combustion boiler are consistent, and they are all located on the half wall downstream of the burner jet flow direction. The downstream pulverized coal flow to the fire side has less entrainment effect than the low-pressure area, and the upstream pulverized coal flow is not easy to wash the downstream pulverized coal flow to the water wall on the fire side, and the area of slagging and high-temperature corrosion is small; when the pulverized coal flow velocity is low, When the rigidity is insufficient, the area of slagging and high-temperature corrosion is relatively large, and at the maximum, more than half of the four walls of the furnace will have slagging or high-temperature corrosion.

In order to solve the problems of slagging and high-temperature corrosion in tangential combustion boilers, in addition to ensuring the ash melting point of the incoming coal and controlling the sulfur content of the incoming coal, it is necessary to try to improve the rigidity of the pulverized coal flow, that is, the flow rate of the pulverized coal gas. When the combustion is optimized and adjusted, the baffle opening of the perimeter air door around the primary air nozzle is increased, which can better restrict the diffusion of pulverized coal airflow to the surroundings, enhance the rigidity of pulverized coal airflow, and alleviate the problems of boiler slagging and high temperature corrosion , however, when the opening of the perimeter damper baffle increases, it will cause the pulverized coal flow to the fire side and the unfired side to form a relatively low pressure area. Although the rigidity of the pulverized coal flow increases, the relative low pressure around the pulverized coal flow downstream More importantly, with the wide application of low-nitrogen combustion technology, the air box pressure of most tangentially fired boilers is relatively low. Low, the ability to restrict the diffusion of pulverized coal gas flow to the surrounding is weakened, resulting in a decrease in the rigidity of pulverized coal gas flow, leading to boiler slagging and high temperature corrosion problems.

Contents of the invention

Aiming at the problems existing in related technologies, the embodiments of the present disclosure provide a primary air chamber and method for preventing boiler slagging and high-temperature corrosion, so as to solve the problem of four-corner cutting without affecting the ignition and stable combustion of pulverized coal airflow. Problems of slagging and high temperature corrosion in circular combustion boilers.

The embodiment of the first aspect of the present disclosure proposes a once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion, including a pulverized coal nozzle, a first peripheral air nozzle, a second peripheral air nozzle and an isolation device;

The first peripheral wind nozzle and the second peripheral wind nozzle are arranged on both sides of the isolation device, and are arranged to surround the pulverized coal nozzle;

The first peripheral wind nozzle is located on the fire side of the pulverized coal flow, and the second peripheral wind nozzle is located on the backfire side of the pulverized coal flow;

The first peripheral air nozzle is connected to the secondary air box, and the second peripheral air nozzle is connected to the secondary air box and the hot primary air main pipe.

In some embodiments, the cross-sectional areas of the first peripheral wind nozzle and the second peripheral wind nozzle are equal.

In some embodiments, the primary air chamber of the DC burner is connected with an electric actuator, the first peripheral air nozzle and the second peripheral air nozzle are both provided with an adjustment baffle, and the adjustment baffle and the electric actuator connect.

In some embodiments, an air duct is provided between the air inlet of the second peripheral air nozzle and the hot primary air main duct, and several through holes are arranged on the air duct, and the several through holes are located inside the secondary air box, An insulating sleeve is arranged at the through hole.

In some embodiments, the insulating sleeve is slidably disposed at the through hole.

In some embodiments, the plurality of through holes are arranged on the side wall of the air duct, and have the same length from the air inlet of the second peripheral air nozzle.

In some embodiments, an electric shut-off valve and an electric regulating valve are arranged on the air duct, and the electric shut-off valve and the electric regulating valve are located outside the secondary air box.

In some embodiments, the cross-section of the air duct is rectangular.

The embodiment of the second aspect of the present application proposes a once-through burner, including the above-mentioned primary air chamber of the once-through burner for preventing boiler slagging and high-temperature corrosion.

The embodiment of the third aspect of the present application proposes a method for preventing boiler slagging and high-temperature corrosion, including: installing the above-mentioned once-through burner on the four corners of the boiler, when the load of the coal-fired power plant unit is not less than 70% , and the ash melting point of the burning coal is not greater than 1300°C or the sulfur content is not less than 1%, the air inlet of the first peripheral air nozzle is connected to the secondary air box, and the second peripheral air nozzle is connected to the hot primary air parent Otherwise, the air inlet of the first peripheral air nozzle is connected to the secondary air box, and the second peripheral air nozzle is connected to the secondary air box.

Compared with related technologies, the technical solution disclosed in the present disclosure has the following beneficial technical effects:

A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion. The first peripheral air nozzle is located on the fire side of the pulverized coal flow, and the second peripheral air nozzle is located on the backfire side of the pulverized coal flow. The first peripheral The air source of the air nozzle is taken from the secondary air box, and the second peripheral air nozzle, the secondary air box and the hot primary air main pipe can be set on and off, so that the air source of the second peripheral air nozzle is between the secondary air box and the hot primary air main pipe The switch to realize the utilization of hot primary air with higher pressure. The pressure of the second peripheral air nozzle on the backfire side is higher, which can enhance the rigidity of the pulverized coal flow, prevent the pulverized coal flow from deflecting or scouring the downstream pulverized coal flow to the water wall on the fire side, thereby preventing boiler slagging and high temperature corrosion; and The second peripheral air nozzle on the backfire side is located on the backfire side of the pulverized coal flow, which will not affect the mixing of the pulverized coal flow and the high-temperature flue gas of the furnace, and has no effect on the ignition and combustion of the pulverized coal. The air source of the first perimeter air nozzle on the fire side is the secondary air box, and the wind pressure is relatively small, which can make the pulverized coal flow mixed with the high-temperature flue gas quickly after being sprayed into the furnace, and accelerate the ignition and combustion of the pulverized coal; and The air pressure of the peripheral wind nozzle on the fire side is small, and the relatively low pressure area formed by the pulverized coal flow to the fire side is small, and the ability to entrain the upstream pulverized coal flow is weakened, thereby avoiding slagging and high-temperature corrosion caused by the upstream pulverized coal flow scouring the water wall . Therefore, the differentiated setting of the first peripheral air nozzle and the second peripheral air nozzle, and the online switching of the air source of the second peripheral air nozzle on the unfired side effectively solve the four-corner cut problem without affecting the ignition and stability of the pulverized coal flow. Problems of slagging and high temperature corrosion in circular fired boilers.

In some embodiments, the cross-sectional areas of the first peripheral air nozzle and the second peripheral air nozzle are equal, so that the air intake volumes of the first peripheral air nozzle and the second peripheral air nozzle can be equal to ensure combustion stability.

In some embodiments, adjusting the baffle can independently control the air intake volumes of the first peripheral air nozzle and the second peripheral air nozzle.

In some embodiments, the through hole and the insulating sleeve can realize the on-off arrangement between the air inlet of the second peripheral air nozzle and the secondary air box.

In some embodiments, the insulating sleeve is slidably disposed at the through hole, which saves the space of the device and facilitates the operation of the device.

In some embodiments, the lengths of the through holes from the air inlet of the second peripheral air nozzle are equal, so that the pressure of the hot primary air entering the second peripheral air nozzle is equal, so that the rigidity of the pulverized coal airflow is more stable.

In some embodiments, the electric cut-off 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.

The once-through burner proposed in the embodiment of the present application includes the above-mentioned primary air chamber of the once-through burner for preventing boiler slagging and high-temperature corrosion, which can effectively prevent boiler slagging and high-temperature corrosion.

The method for preventing boiler slagging and high-temperature corrosion proposed in the embodiment of the present application includes: the above-mentioned one-way burner is arranged on the four corners of the boiler, and when the molten pulverized coal particles are bonded at the water wall, The air source of the second peripheral air nozzle on the back fire side is switched to the hot primary air main pipe, which increases the air pressure of the peripheral air nozzle on the back fire side, enhances the rigidity of the pulverized coal flow, and prevents the boiler slagging and high temperature corrosion caused by the pulverized coal flow scouring the water wall ; Through the above-mentioned direct-flow burner, the problems of slagging and high-temperature corrosion of the four-corner tangential combustion boiler are solved without affecting the ignition and stable combustion of the pulverized coal flow.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore are not It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is a schematic front view of a primary air chamber according to an embodiment of the present disclosure;

Fig. 2 is a schematic side view of the air source of the second peripheral air nozzle on the back fire side of the primary air chamber taken from the hot primary air main pipe according to an embodiment of the present disclosure;

Fig. 3 is a schematic side view of the air source of the second peripheral air nozzle on the back fire side of the primary air chamber taken from the secondary air box according to an embodiment of the present disclosure;

Fig. 4 is a layout diagram of a primary air chamber in a boiler according to an embodiment of the present disclosure.

Reference signs: 1. Pulverized coal nozzle, 21. First peripheral air nozzle, 22. Second peripheral air nozzle, 3. Isolation device, 4. Secondary air box, 5. Hot primary air main pipe, 6. Regulating baffle , 7, air duct, 71, through hole, 72, isolation sleeve, 73, electric stop valve, 74, electric regulating valve.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments It is a part of the embodiments of the present disclosure, but not all of them. The components of the disclosed embodiments generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely represents selected embodiments of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present disclosure.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the embodiments of the present disclosure, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "horizontal", "inside" etc. is based on the orientation or positional relationship shown in the drawings , or the orientation or positional relationship that the product of the invention is usually placed in use is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation or be constructed in a specific orientation and operation, and therefore should not be construed as limiting the present disclosure. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions, and should not be construed as indicating or implying relative importance.

In addition, when the term "horizontal" appears, it does not mean that the part is required to be absolutely horizontal, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal than "vertical", and it does not mean that the structure must be completely horizontal, but can be slightly inclined.

In the description of the embodiments of the present disclosure, it should also be noted that, unless otherwise specified and limited, the terms "setting", "installation", "connection" and "connection" should be interpreted in a broad sense, for example, It can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present disclosure according to specific situations.

The technical solutions of the present disclosure will be further described in detail below in conjunction with the accompanying drawings.

The pulverized coal nozzle of the traditional four-corner tangentially fired boiler is provided with perimeter wind around the pulverized coal nozzle, and the source of the perimeter wind is taken from the secondary air box. Since the pressure of the secondary air box of the coal-fired power plant boiler is generally less than 200Pa, the volume of the peripheral air decreases, which weakens the ability of the peripheral wind to wrap the pulverized coal airflow. Slagging and high temperature corrosion. The main reasons for the low pressure of the secondary air box are: (1) Due to the wide application of low-nitrogen combustion technology, 30% to 35% of the air volume required by the burner area is injected into the furnace by the overfired air burner, resulting in secondary The pressure of the secondary air box is reduced; (2) Some combustion power plant boilers burn high-moisture bituminous coal or lignite. In order to meet the drying output requirements of the coal mill, the primary air rate reaches 40%. The pressure of the bellows is difficult to exceed 200Pa.

The hot primary air pressure of coal-fired power plant boilers is 7kPa to 10kPa. If the source of the peripheral air is changed from the secondary air box to the hot primary air, the problem of insufficient rigidity of the pulverized coal airflow caused by the low pressure of the secondary air box can be solved. If the hot primary air is used as the source of the peripheral air, since the pressure of the hot primary air is higher than the pressure of the secondary air and the pressure of the furnace flue gas, the pulverized coal airflow is isolated by the hot primary air, and the pulverized coal airflow is sprayed into the furnace to communicate with the secondary air. Secondary air and high-temperature flue gas mixing are delayed, affecting the ignition, combustion, and burnout of the pulverized coal airflow, and problems such as unstable combustion and increased content of fly ash combustibles may occur. In addition, the increase in the primary air volume leads to an increase in the power consumption rate of the primary fan, which is not conducive to reducing the power consumption rate of the plant.

According to the characteristics of four-corner tangential combustion, the embodiment of the present disclosure divides the peripheral air nozzle around the pulverized coal nozzle of the primary air chamber into two parts, as shown in Figure 1, the direct-current combustion to prevent boiler slagging and high-temperature corrosion proposed by the embodiment of the present application The primary air chamber of the device includes a pulverized coal nozzle 1, a first peripheral wind nozzle 21, a second peripheral wind nozzle 22 and an isolating device 3. The isolating device 3 can be a vertical partition, and the pulverized coal nozzle 1 is a rectangular or square nozzle. The boundary wind nozzle is divided into the first peripheral wind nozzle 21 and the second peripheral wind nozzle 22 by the isolation device 3, and the first peripheral wind nozzle 21 and the second peripheral wind nozzle 22 are arranged on both sides of the isolation device 3, and surround the coal The powder nozzle 1 is set; the first peripheral wind nozzle 21 is located on the fire side of the pulverized coal flow, which is the peripheral wind nozzle on the fire side, and the second peripheral wind nozzle 22 is located on the backfire side of the pulverized coal flow, which is the peripheral wind nozzle on the backfire side The air inlet of the first peripheral wind nozzle 21 is connected to the secondary air box 4, and the cross-sectional areas of the first peripheral wind nozzle 21 and the second peripheral wind nozzle 22 are equal.

As shown in Figure 2, an air duct 7 is provided between the air inlet of the second peripheral air nozzle 22 and the hot primary air main pipe 5, and the air duct 7 is provided with a plurality of through holes 71, and the plurality of through holes 71 are located on the two sides. Inside the secondary air box 4 , an insulating sleeve 72 is provided at the through hole 71 . The isolation sleeve 72 can realize the switching of the air source of the second peripheral air nozzle on the back fire side. When the isolation sleeve is opened, the air source of the second peripheral air nozzle on the back fire side is taken from the secondary bellows; when the isolation sleeve is closed, the air source of the back fire side The air source of the second perimeter air nozzle is taken from the hot primary air main pipe. The connection between the second peripheral air nozzle 22 and the secondary air box 4 can be set through the through hole 71 and the insulating sleeve 72. The insulating sleeve 72 is slidably arranged at the through hole 71, and several through holes 71 are arranged in the air duct 7. On the side wall, as the air inlet of the secondary air box 4 air source of the second peripheral air nozzle 22, the length of the air inlet from the second peripheral air nozzle 22 is equal, and the air inlet is square.

The air source of the first peripheral air nozzle on the fire side is the secondary air box 4, and the wind pressure is relatively small, which can make the pulverized coal air flow sprayed into the furnace and mix with the high-temperature flue gas quickly, so as to accelerate the ignition and combustion of the pulverized coal; and The wind pressure of the first peripheral air nozzle on the fire side is relatively small, and the relatively low pressure area formed by the pulverized coal flow to the fire side is small, and the ability to entrain the upstream pulverized coal flow is weakened, thereby avoiding the impact caused by the upstream pulverized coal flow scouring the water wall. Slagging, high temperature corrosion. The pressure of the second peripheral air nozzle 22 on the unfired side is higher, which can enhance the rigidity of the pulverized coal flow, prevent the pulverized coal flow from deflecting or scour the downstream pulverized coal flow to the water wall on the fire side, thereby preventing boiler slagging and high temperature corrosion ; and the peripheral air nozzle on the backfire side is located on the backfire side of the pulverized coal flow, which will not affect the mixing of the pulverized coal flow and the high-temperature flue gas in the furnace, and has no effect on the ignition and combustion of the pulverized coal.

The air duct 7 is also 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, and the second peripheral air nozzle 22 and the hot primary air main pipe 5 pass through the electric The stop valve 73 and the electric regulating valve 74 can be set on and off, and the cross section of the air duct 7 is rectangular.

The primary air chamber of the DC burner is also connected with an electric actuator. The first peripheral air nozzle 21 and the second peripheral air nozzle 22 are equipped with an adjusting baffle 6 for independently controlling the air intake. The adjusting baffle 6 and the electric actuator connect.

The once-through burner proposed in the embodiment of the present application includes the above-mentioned primary air chamber of the once-through burner for preventing boiler slagging and high-temperature corrosion.

As shown in Figure 4, the four corners of the boiler are provided with the above-mentioned a kind of once-through burner. The bellows 4 are communicated, and the second peripheral air nozzle 22 is communicated with the hot primary air main pipe 5; otherwise, the air inlet of the first peripheral air nozzle 21 is connected with the secondary air box 4, and the second peripheral air nozzle 22 is connected with the secondary The bellows 4 are connected to each other.

Boilers use coal with low ash melting point and high sulfur content. When the pulverized coal flow is not rigid enough, it is easy to wash the downstream pulverized coal flow to the water wall on the fire side. The molten coal particles stick to the water wall and slagging occurs. The exhausted pulverized coal particles consume the oxygen content of the downstream pulverized coal flow to the water wall near the fire side, and the reducing atmosphere increases, causing high temperature corrosion of the water wall at this place. As shown in Figure 2, when the unit load of the coal-fired power station is above 70%, the coal ash melting point is lower than 1300°C or the sulfur content is higher than 1%, the outer insulating sleeve 72 of the air duct 7 is closed, and the air duct 7. Open the electric cut-off valve 73 on both sides of the air duct, so that the air inlets on both sides of the air duct are closed. At this time, the air source of the peripheral air nozzle on the back fire side is switched from the secondary air box 4 to the hot primary air main pipe 5. Adjust the opening of the electric regulating valve 74 on the air duct as required. In order to adjust the appropriate air pressure of the peripheral air nozzle on the back fire side, after the wind pressure of the peripheral air nozzle on the back fire side is increased, the rigidity of the pulverized coal air flow is enhanced, preventing the pulverized coal air flow from being washed by the downstream pulverized coal air flow to the water cooling wall on the fire side, preventing Boiler slagging and high temperature corrosion.

As shown in Figure 3, when the load of the unit is below 70%, due to the low overall temperature of the furnace and the low temperature of the water-cooled wall, boiler slagging and high-temperature corrosion are not easy to occur at this time, and the electric stop valve on the air duct 7 73 is closed, and the outer insulating sleeve 72 of the air duct 7 is opened. At this time, the through holes 71 on both sides of the air duct 7 are opened. The air pressure at the nozzle drops. When the coal-fired ash melting point is higher than 1350°C or the sulfur content of coal-fired coal is lower than 1%, the conditions for boiler slagging and high-temperature corrosion are weak. Secondary air box 4.

In the embodiment of the present disclosure, the peripheral air nozzle of the primary air chamber of the traditional four-corner tangential combustion boiler is divided into the peripheral air nozzle on the fire side and the peripheral air nozzle on the back fire side. The source can be switched between the secondary air box and the hot primary air header. When the ash melting point of coal is low and the sulfur content is high, switch the air source of the peripheral air nozzle on the back fire side to the hot primary air main pipe to increase the air pressure of the peripheral air nozzle on the back fire side, enhance the rigidity of the pulverized coal airflow, and prevent The pulverized coal flow scours the water wall to cause boiler slagging and high-temperature corrosion; the air source of the peripheral air outlet on the fire side is the secondary air box, and its wind pressure is relatively low, and the relatively low pressure area formed by the pulverized coal flow to the fire side is relatively weak and does not affect The mixing of pulverized coal airflow with secondary air and high-temperature flue gas does not affect the ignition and combustion of pulverized coal airflow. The division of the peripheral air nozzles in the primary air chamber and the online switching of the air source of the peripheral air nozzles on the backfire side solve the problems of slagging and high-temperature corrosion of the four-corner tangential combustion boiler without affecting the ignition and stability of the pulverized coal flow.

The above are only preferred embodiments of the present disclosure, and are not intended to limit the present disclosure. For those skilled in the art, the present disclosure may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion, comprising a pulverized coal nozzle (1), a first peripheral air nozzle (21), a second peripheral air nozzle (22) and an isolation device (3);

The first peripheral wind nozzle (21) and the second peripheral wind nozzle (22) are arranged on both sides of the isolation device (3), and are arranged to surround the pulverized coal nozzle (1);

The first peripheral air nozzle (21) is located on the fire side of the pulverized coal airflow, and the second peripheral air nozzle (22) is located on the backfire side of the pulverized coal airflow;

The first peripheral air nozzle (21) is connected to the secondary air box (4), and the second peripheral air nozzle (22) is connected to the secondary air box (4) and the hot primary air main pipe (5). set up.
A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion according to claim 1, wherein the cross-sectional area of the first peripheral air nozzle (21) and the second peripheral air nozzle (22) equal.
The primary air chamber of a once-through burner for preventing boiler slagging and high-temperature corrosion according to claim 1 or 2, wherein the primary air chamber of the once-through burner is connected with an electric actuator, and the first peripheral air nozzle Both (21) and the second peripheral wind nozzle (22) are provided with an adjusting baffle (6), and the adjusting baffle (6) is connected with the electric actuator.
A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion according to any one of claims 1 to 3, wherein the air inlet of the second peripheral air nozzle (22) is connected to the hot primary air An air duct (7) is provided between the main pipes (5), and a plurality of through holes (71) are arranged on the air duct (7), and the plurality of through holes (71) are located at the side of the secondary air box (4). Inside, an insulating sleeve (72) is provided at the through hole (71).
The primary air chamber of a once-through burner for preventing boiler slagging and high-temperature corrosion according to claim 4, wherein the insulating sleeve (72) is slidably arranged at the through hole (71).
A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion according to claim 4 or 5, wherein the plurality of through holes (71) are arranged on the side wall of the air duct (7), And the lengths of the air inlets from the second peripheral wind nozzles (22) are equal.
A once-through burner primary air chamber for preventing boiler slagging and high-temperature corrosion according to any one of claims 4 to 6, wherein the air duct (7) is provided with an electric shut-off valve (73) and an electric The regulating valve (74), the electric shut-off valve (73) and the electric regulating valve (74) are located outside the secondary air box (4).
The primary air chamber of a once-through burner for preventing boiler slagging and high-temperature corrosion according to any one of claims 4 to 7, wherein the cross section of the air duct (7) is rectangular.
A once-through burner, comprising the primary air chamber of a once-through burner for preventing boiler slagging and high-temperature corrosion as described in any one of claims 1 to 8.
A method for preventing boiler slagging and high-temperature corrosion, comprising: installing a once-through burner as claimed in claim 9 on the four corners of the boiler, when the load of the coal-fired power plant unit is not less than 70%, and the coal-fired When the ash melting point is not greater than 1300°C or the sulfur content is not less than 1%, the air inlet of the first peripheral air nozzle (21) is connected to the secondary air box (4), and the second peripheral air nozzle (22) is connected to the hot primary air mother The pipe (5) is connected and arranged; otherwise, the air inlet of the first peripheral air nozzle (21) is connected and arranged with the secondary air box (4), and the second peripheral air nozzle (22) is connected and arranged with the secondary air box (4).