Wall-attached air nozzle device of boiler

Abstract

The invention relates to the technical field of power station boilers, in particular to a near-wall air nozzle device of a boiler. The boiler near-wall air nozzle device is used for controlling the flowing track of near-wall air so that the near-wall air can form an air film on the surface of a boiler water cooling wall, the nozzle device comprises a flow guide part, a flow channel is formed in the flow guide part, one end of the flow channel is connected with a near-wall air channel, and the other end of the flow channel bends and extends in the center direction of a hearth. The flow channel is used for enabling the wall-attached air to have a speed component in the height direction and a speed component in the hearth depth direction when flowing out. According to the scheme, the impact influence of opposed combustion flue gas can be counteracted after adherence air enters the hearth, so that an air film is formed on the surface of the water-cooled wall, and the water-cooled wall is protected. Moreover, the adherence air has a velocity component in the height direction when flowing out of the flow channel, so that the adherence air can flow upwards along the water-cooled wall, the coverage area of the adherence air on the water-cooled wall can be increased, and the utilization efficiency of the adherence air can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of power station boilers, and in particular to a boiler wall-mounted air nozzle device. Background Art

[0002] In recent years, coal-fired power plants have made remarkable achievements in the control of ultra-low pollutant emissions, and pollutant control technology has been greatly improved. Most power plants have controlled the generation of NOx in the furnace through concentration-lean deviation combustion and air staged combustion, achieving ultra-low pollutant emissions. However, the contradiction between efficient combustion and low nitrogen emissions has become more prominent. The furnace is severely lacking in oxygen locally, and the use of high-sulfur coal makes the concentration of CO and H2S in the local atmosphere of the furnace water-cooled wall very high, resulting in large-scale high-temperature corrosion of the water-cooled wall and frequent unit pipe explosion accidents.

[0003] In order to alleviate the problem of high-temperature corrosion, some opposed-firing boilers have adopted the side wall wind technology. In theory, the side wall wind nozzles are arranged on the side wall, and the wind comes from the secondary air ducts on each layer. The wind nozzles are arranged on the side wall water-cooled wall, which can directly increase the O2 concentration in the high-temperature corrosion zone near the wall and reduce the CO and H2S content; and the side wall wind only needs to flow upward along the water-cooled wall, and does not require high wind speed and rigid airflow, which perfectly solves the problem that traditional wind cannot effectively protect the water-cooled wall due to insufficient rigidity. However, in actual applications, the wind nozzles use a simple rectangular or circular cross-section structure, and the flow field is like Figure 1 As shown, the wall-attached wind nozzle structure allows the wall-attached wind to enter the furnace perpendicular to the side wall, that is, the wall-attached wind flows in the depth direction of the furnace, with a limited protection range in the height direction, and is affected by the impact of the opposing combustion flue gas in the width direction. The wall-attached wind quickly flows toward the front and rear walls, and the wall-attached wind airflow is difficult to form a wind film in the near-wall area of ​​the side wall, which greatly weakens the protection effect of the side wall water-cooled wall. Summary of the invention

[0004] The embodiments of the present application at least provide a boiler wall-attached wind nozzle device to improve the problem of weak wall-attached wind protection effect on the boiler side wall, thereby effectively alleviating the problem of high-temperature corrosion of the boiler water-cooled wall.

[0005] An embodiment of the present application provides a boiler wall-adhering wind nozzle device for controlling the flow trajectory of the wall-adhering wind so that the wall-adhering wind forms an air film on the surface of the boiler water-cooled wall. The nozzle device includes a guide member, and the guide member has a flow channel. One end of the flow channel is connected to the wall-adhering wind duct, and the other end is bent and extended toward the center of the furnace. The flow channel is used to make the wall-adhering wind have a velocity component in the height direction and a velocity component in the furnace depth direction when flowing out.

[0006] In an optional embodiment, the guide member is a tubular structure, and the guide member is partially twisted and / or bent so that the flow channel bends and extends toward the center of the furnace.

[0007] In an optional embodiment, the guide member includes a first guide segment, a second guide segment and a third guide segment connected in sequence along the guide direction, wherein the second guide segment is twisted and rotated along the guide direction, and an angle is formed between the second guide segment and the third guide segment.

[0008] In an optional embodiment, the air inlet end of the air guide member is a flared structure, and both sides of the air inlet end of the air guide member along the width direction are arc-shaped.

[0009] In an optional embodiment, a plurality of first guide plates are provided at the air inlet end of the guide member, and the plurality of first guide plates are distributed at intervals along the width direction of the air inlet end of the guide member.

[0010] In an optional implementation, the first guide plate is a curved plate.

[0011] In an optional embodiment, the first guide plate extends outside the first guide section into the wall-attached air duct.

[0012] In an optional embodiment, a plurality of second guide plates are provided at the air outlet end of the guide member, and the plurality of second guide plates are distributed at intervals along the width direction of the air outlet end of the guide member.

[0013] In an optional embodiment, the angle between the air outlet direction of the air outlet end of the guide member and the height direction is 45°~60°.

[0014] In an optional embodiment, the angle between the air outlet direction of the air outlet end of the guide member and the furnace depth direction is 45°~60°.

[0015] The above technical solution of the present application has the following beneficial technical effects: The boiler wall-attached wind nozzle device of the embodiment of the present application enables the wall-attached wind to offset the impact of the combustion flue gas after entering the furnace, thereby forming an air film on the surface of the water-cooled wall to protect the water-cooled wall. In addition, since the wall-attached wind has a velocity component in the height direction when flowing out of the flow channel, the wall-attached wind can flow upward along the water-cooled wall, which can increase the coverage area of ​​the water-cooled wall by the wall-attached wind, thereby facilitating the improvement of the utilization efficiency of the wall-attached wind.

[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. The drawings herein are incorporated into the specification and constitute a part of the specification. These drawings illustrate embodiments consistent with the present application and are used together with the specification to illustrate the technical solutions of the present application. It should be understood that the following drawings only illustrate certain embodiments of the present application and should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can also be obtained based on these drawings without creative work.

[0018] Figure 1 The following illustrates a use scenario of a boiler wall-mounted air nozzle device provided in an embodiment of the present application; Figure 2 A schematic structural diagram of a boiler wall-mounted air nozzle device provided in an embodiment of the present application is shown; Figure numerals: 1, wall-attached air duct; 2, guide member; 21, first guide section; 22, second guide section; 23, third guide section; 24, first guide plate; 25, second guide plate. DETAILED DESCRIPTION

[0019] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present application.

[0020] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0021] The term "first" or "second" in the specification and claims of this application may include one or more of the features explicitly or implicitly. In the description of this application, unless otherwise specified, "plurality" means two or more. In addition, "and / or" in the specification and claims means at least one of the connected objects, and the character " / " generally means that the objects connected before and after are in an "or" relationship.

[0022] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] refer to Figure 1 An embodiment of the present application provides a boiler wall-attached wind nozzle device, which is used to be arranged in a wall-attached wind duct 1, and can control the flow trajectory of the wall-attached wind so that the wall-attached wind forms an air film on the surface of the boiler water-cooled wall.

[0025] refer to Figure 1 and Figure 2 In some embodiments, the nozzle device includes a guide member 2, and the guide member 2 has a flow channel, one end of the flow channel is connected to the wall-adhering air duct 1, and the other end is bent and extended toward the center of the furnace, and the flow channel is used to make the wall-adhering wind have a velocity component in the height direction and a velocity component in the depth direction of the furnace when it flows out. Specifically, the flow channel of the guide member 2 is connected to the wall-adhering air duct 1, and the wall-adhering wind can flow into the furnace through the flow channel, and because the flow channel is bent and extended toward the center of the furnace, the wall-adhering wind has a velocity component in the height direction and a velocity component in the depth direction of the furnace when it flows out of the flow channel. Among them, the velocity component in the height direction refers to the wall-adhering wind that can flow upward along the water-cooled wall when it flows out of the flow channel, and the velocity component in the depth direction of the furnace refers to the wall-adhering wind that can flow toward the center of the furnace when it flows out of the flow channel. This arrangement allows the wall-adhering wind to offset the impact of the combustion flue gas after entering the furnace, thereby forming an air film on the surface of the water-cooled wall to protect the water-cooled wall. Furthermore, since the wall-adhering wind can flow upward along the water-cooled wall when flowing out of the flow channel, this can increase the coverage area of ​​the water-cooled wall by the wall-adhering wind, thereby facilitating improving the utilization efficiency of the wall-adhering wind.

[0026] In some embodiments, the angle between the outlet direction of the outlet end of the guide member 2 and the height direction is 45° to 60°, and the angle between the outlet direction of the outlet end of the guide member 2 and the furnace depth direction is 45° to 60°. However, the present application does not impose any limitation on this.

[0027] In some embodiments, the flow guide 2 is a tubular structure. For example, the flow guide 2 can be a rectangular tubular structure, a circular tubular structure, etc. In this embodiment, the flow guide 2 is preferably a Q355 or 310S rectangular tubular structure. However, this embodiment of the application does not make any limitation to this.

[0028] In some embodiments, the guide member 2 is partially twisted and / or bent so that the flow channel bends and extends toward the center of the furnace. In this embodiment, the guide member 2 can be twisted and bent at the same time so that the flow channel can bend and extend toward the center of the furnace. For example, the guide member 2 includes a first guide section 21, a second guide section 22, and a third guide section 23 connected in sequence along the guide direction, wherein the second guide section 22 is twisted and rotated along the guide direction, and an angle is formed between the second guide section 22 and the third guide section 23. In other words, the guide member 2 is twisted in the second guide section 22, and is bent between the second guide section 22 and the third guide section 23, so that the flow channel bends and extends toward the center of the furnace. However, the embodiments of the present application do not impose any limitation on this.

[0029] In some embodiments, the first guide section 21 and the third guide section 23 are straight pipe sections. This arrangement makes the velocity distribution of the wall-adhering wind relatively uniform in the first guide section 21 and the third guide section 23, thereby avoiding the existence of a local low-speed area in the nozzle, causing dust accumulation, burning and other problems. However, the embodiments of the present application do not make any limitation to this.

[0030] In some embodiments, the air inlet end of the air guide 2 (i.e., the first air guide section 21) is a flared structure, and the air inlet end of the air guide 2 is arc-shaped on both sides along the width direction. This arrangement can guide the airflow to transition smoothly, reduce the turbulence and vortex of the airflow, and the arc-shaped wall surface can change the airflow path so that the airflow is evenly distributed before entering the nozzle. At the same time, the arc-shaped wall surface can reduce the resistance of the airflow and increase the airflow speed and flow rate. However, the embodiments of the present application do not make any limitation to this.

[0031] In some embodiments, the air inlet end of the air guide 2 is provided with a plurality of first air guide plates 24, and the plurality of first air guide plates 24 are spaced apart along the width direction of the air inlet end of the air guide 2. Specifically, the first air guide plates 24 are arranged close to the windward side, and the first air guide plates 24 are arc-shaped plates. Such an arrangement can change the airflow path, so that the airflow is evenly distributed before entering the nozzle, and at the same time, eddies and vortices in the airflow can be reduced, thereby improving the stability of the airflow. However, the embodiments of the present application do not make any limitation to this.

[0032] In some embodiments, the first guide plate 24 extends outside the first guide section 21 into the wall-attached air duct 1. According to the actual high-temperature corrosion situation, by adjusting the length of the first guide plate 24 extending into the wall-attached air duct 1, the air volume entering the nozzle can be changed and the wall-attached air volume distribution can be optimized. In specific settings, the lengths of each first guide plate 24 extending into the wall-attached air duct 1 can be the same or different. However, the embodiments of the present application do not make any limitation on this.

[0033] In some embodiments, the air outlet end of the guide member 2 is provided with a plurality of second guide plates 25, and the plurality of second guide plates 25 are spaced apart along the width direction of the air outlet end of the guide member 2. Specifically, the second guide plates 25 are located in the third guide section 23, and the second guide plates 25 are flat plates. This arrangement enables the airflow to be evenly distributed in the air outlet end area, so that the airflow is evenly distributed when entering the furnace, and the second guide plates 25 reduce eddies and vortices in the airflow, thereby improving the stability of the airflow. However, the embodiments of the present application do not make any limitation to this.

[0034] The boiler wall-attached wind nozzle device of the embodiment of the present application enables the wall-attached wind to offset the impact of the combustion flue gas after entering the furnace, thereby forming an air film on the surface of the water-cooled wall to protect the water-cooled wall. In addition, since the wall-attached wind has a velocity component in the height direction when flowing out of the flow channel, the wall-attached wind can flow upward along the water-cooled wall, which can increase the coverage area of ​​the water-cooled wall by the wall-attached wind, thereby facilitating the improvement of the utilization efficiency of the wall-attached wind.

[0035] One or more embodiments of this specification are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification should be included in the scope of protection of this application.

[0036] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A boiler wall-adhering wind nozzle device, used to control the flow trajectory of the wall-adhering wind so that the wall-adhering wind forms an air film on the surface of the boiler water-cooled wall, characterized in that: The nozzle device includes a guide member, which has a flow channel. One end of the flow channel is connected to the wall-adhering air duct, and the other end is bent and extended toward the center of the furnace. The flow channel is used to make the wall-adhering wind have a velocity component in the height direction and a velocity component in the furnace depth direction when flowing out.

2. The boiler wall-mounted air nozzle device according to claim 1, characterized in that: The guide member is a tubular structure, and the guide member is partially twisted and / or bent so that the flow channel bends and extends toward the center of the furnace.

3. The boiler wall-mounted air nozzle device according to claim 2, characterized in that: The flow guide member includes a first flow guide segment, a second flow guide segment and a third flow guide segment connected in sequence along the flow guide direction, wherein the second flow guide segment twists and rotates along the flow guide direction, and an angle is formed between the second flow guide segment and the third flow guide segment.

4. The boiler wall air nozzle device according to claim 1, characterized in that: The air inlet end of the air guide member is a flared structure, and both sides of the air inlet end of the air guide member along the width direction are arc-shaped.

5. The boiler wall-mounted air nozzle device according to claim 1, characterized in that: The air inlet end of the air guide member is provided with a plurality of first air guide plates, and the plurality of first air guide plates are distributed at intervals along the width direction of the air inlet end of the air guide member.

6. The boiler wall-mounted air nozzle device according to claim 5, characterized in that: The first guide plate is an arc-shaped plate.

7. The boiler wall-mounted air nozzle device according to claim 5, characterized in that: The first guide plate extends out of the first guide section into the wall-attached air duct.

8. The boiler wall-mounted air nozzle device according to claim 1, characterized in that: The air outlet end of the air guide member is provided with a plurality of second air guide plates, and the plurality of second air guide plates are distributed at intervals along the width direction of the air outlet end of the air guide member.

9. The boiler wall-mounted air nozzle device according to claim 1, characterized in that: The angle between the air outlet direction of the air outlet end of the guide member and the height direction is 45°~60°.

10. The boiler wall air nozzle device according to claim 1, characterized in that: The angle between the air outlet direction of the air outlet end of the guide member and the furnace depth direction is 45°~60°.

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