A flue structure and method for reducing dust accumulation

Abstract

The present invention discloses a flue structure and method for reducing dust accumulation, comprising a flue body and a plurality of guide components located in the flue body, wherein the flue body is a vertically ascending and horizontally curved elbow flue, wherein each guide component is located at an elbow position on the flue body, and each guide component comprises a guide section guide plate, an arc section guide plate, a downward pressure guide plate and a rectifying section guide plate sequentially distributed along the direction of smoke flow, wherein the arc section guide plate is connected to the guide section guide plate and the downward pressure guide plate, a gap is provided between the rectifying section guide plate and the downward pressure guide plate, and the downward pressure guide plate is at a certain downward pressure angle with the horizontal direction, so as to increase the smoke flow velocity on the guide plate and the flue wall. The structure can reduce the problem of dust accumulation in the flue.

Description

Technical Field

[0001] The invention relates to a flue structure and method, and in particular to a flue structure and method for reducing dust accumulation. Background Art

[0002] The problem of ash accumulation is inevitable in the flue and guide plates of coal-fired units, especially in Southwest my country and Xinjiang, where the situation is more common and serious when burning highly contaminated coal. The reason for this is that the conventional flue and guide plate setting scheme is not very reasonable.

[0003] Figure 1 It is a conventional vertical rising and turning horizontal elbow flue and guide plate layout scheme. Figure 1 It can be seen that the flue shape is a structure with an inner arc and a large outer angle, and the guide plate does not divide the inlet and outlet flues equally. Therefore, the flow rate of flue gas entering each channel cut by the guide plate is inconsistent, the overall flow velocity is unevenly distributed, and the thickness of ash accumulation in each channel is uneven. Specifically for each channel, due to the inertia of the flue gas when turning, the airflow often still flows obliquely upward after entering the horizontal flue, resulting in a large area of ​​low-speed area on the upper surface of the guide plate (areas ① and ② in the figure) and the bottom surface of the flue (area ③ in the figure). Ash accumulation is particularly serious at this location. The flue and guide plate structure after ash accumulation will seriously deviate from the original design of the flue gas flow field performance, causing abnormal operation of subsequent equipment. For example, when the flue is ash-accumulated before denitrification, it will cause uneven flue gas velocity in the catalyst inlet section, which will increase ammonia escape and other problems. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a flue structure and method for reducing dust accumulation. The structure and method can reduce the problem of dust accumulation in the flue.

[0005] To achieve the above-mentioned purpose, the flue structure for reducing dust accumulation described in the present invention includes a flue body and a number of guide components located in the flue body, wherein the flue body is a vertically ascending and horizontally turning elbow flue, and each guide component is located at the elbow position on the flue body, and each guide component includes a guide section guide plate, an arc section guide plate, a downward pressure guide plate and a straightening section guide plate distributed in sequence along the direction of smoke flow, wherein the arc section guide plate is connected to the guide section guide plate and the downward pressure guide plate, there is a gap between the straightening section guide plate and the downward pressure guide plate, and the downward pressure guide plate is perpendicular to the direction of smoke flow.

[0006] The flue body is a vertically ascending and horizontally curved flue.

[0007] The radius corresponding to the arc segment guide plate is the same as the radius corresponding to the bending position on the flue body.

[0008] The flow guide components are distributed at equal intervals on the same cross section at the bending position.

[0009] The guide plate of the rectifying section is parallel to the inner wall of one side of the flue body, and the guide plate of the drainage section is parallel to the inner wall of the other side of the flue body.

[0010] The arc section guide plate is connected to the downward pressure guide plate to increase the surface velocity of the guide plate in the straightening section and facilitate the ash to slide off the downward pressure guide plate and the discontinuity. The specific downward pressure angle and discontinuity size can be optimized by CFD simulation method.

[0011] The elbow area in the flue body is divided into several flue channels of the same shape by various guide components. The flue gas enters each flue channel from top to bottom, wherein the flow resistance of the flue gas in each flue channel is the same, the flow rate of the flue gas in each flue channel is equal, the amount of ash accumulated in each flue channel is uniform, and the downward pressure on the guide plate increases the flow velocity of the subsequent guide plate and the upper surface of the flue, reducing the amount of ash accumulation. After passing through each flue channel, the flue gas flows in a horizontal direction and is finally discharged from the flue body.

[0012] The present invention has the following beneficial effects:

[0013] During specific operation, the flue structure for reducing ash accumulation described in the present invention divides the bending area in the flue body into a number of smoke channels of the same shape through the guide components, and the smoke enters each smoke channel from top to bottom, wherein the flow resistance of the smoke in each smoke channel is the same, the flow rate of the smoke in each smoke channel is equal, and the amount of ash accumulation in each smoke channel is uniform. At the same time, the downward pressure guide plate is perpendicular to the direction of smoke flow, and the particles in the smoke fall after being blocked by the downward pressure guide plate, making it difficult for the surface ash to be stable, so the amount of ash accumulation is less, thereby reducing the problem of ash accumulation in the flue. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the prior art;

[0015] Figure 2 It is a structural schematic diagram of the present invention.

[0016] Among them, 1 is the guide plate of the diversion section, 2 is the guide plate of the arc section, 3 is the downward pressure guide plate, 4 is the guide plate of the rectification section, and 5 is the flue body. DETAILED DESCRIPTION

[0017] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0018] refer to Figure 2The flue structure for reducing dust accumulation described in the present invention includes a flue body 5 and a plurality of guide components located in the flue body 5, wherein the middle elbow of the flue body 5, each guide component is located at a bending position on the flue body 5, and each guide component includes a guide plate 1 for a guide section, a circular arc guide plate 2, a downward pressure guide plate 3 and a rectifying section guide plate 4 distributed in sequence along the flue gas flow direction, wherein the circular arc guide plate 2 is connected to the guide plate 1 for the guide section and the downward pressure guide plate 3, there is a discontinuity between the rectifying section guide plate 4 and the downward pressure guide plate 3, and the downward pressure guide plate 3 is at a certain downward pressure angle with the horizontal direction, and the angle is related to the specific coal quality characteristics and can be optimized by the CFD simulation method.

[0019] The flue body 5 is a right-angle elbow that rises vertically and turns into a horizontal one.

[0020] The radius corresponding to the arc segment guide plate 2 is the same as the radius corresponding to the bending position on the flue body 5 .

[0021] The flow guide components are distributed at equal intervals on the same cross section at the bending position.

[0022] The guide plate 4 of the rectifying section is parallel to the inner wall of one side of the flue body 5 , and the guide plate 1 of the drainage section is parallel to the inner wall of the other side of the flue body 5 .

[0023] During operation, the bending area in the flue body 5 is divided into a number of flue gas channels of the same shape by the guide components, and the flue gas enters each flue gas channel from top to bottom, wherein the flow resistance of the flue gas in each flue gas channel is the same, the flow rate of the flue gas in each flue gas channel is equal, the ash accumulation in each flue gas channel is uniform, and the flue gas flows in a horizontal direction after passing through each flue gas channel and is finally discharged from the flue body 5.

[0024] For each smoke channel, after the smoke passes through the arc segment guide plate 2, it is then guided by the downward pressure guide plate 3 and changes to a horizontal angle slightly downward to enter the subsequent smoke channel. Therefore, the upper surface of the guide plate ( Figure 2 ①, ②, ③ areas) and the bottom of the flue ( Figure 2 The middle (4) area is a local high-speed area with weak dust accumulation conditions, which can significantly reduce the amount of dust accumulation. At the position of the downward pressure guide plate 3, due to its large downward pressure angle, the dust accumulation on its upper surface is difficult to be stable, so the amount of dust accumulation is small.

[0025] In summary, the present invention can make the dust accumulation more uniform and the amount of dust accumulation is small, thus providing favorable conditions for the normal operation of subsequent equipment.

Claims

1. A flue structure for reducing dust accumulation, characterized in that: The invention comprises a flue body (5) and a plurality of flow guide components located in the flue body (5), wherein the flue body (5) is a 90° elbow that rotates from vertical to horizontal, and each flow guide component is located at the elbow position on the flue body (5), and each flow guide component comprises a flow guide plate (1) for a flow guide section, a circular arc flow guide plate (2), a downward pressure flow guide plate (3) and a flow guide plate (4) for a flow guide section that are sequentially distributed along the direction of flue gas flow, wherein the circular arc flow guide plate (2) is connected to the flow guide plate (1) for a flow guide section and the downward pressure flow guide plate (3), and there is a ash drop discontinuity between the flow guide plate (4) for a flow guide section and the downward pressure flow guide plate (3), and the downward pressure flow guide plate (3) is downwardly pressed at a certain angle to the horizontal direction; The radius corresponding to the arc segment guide plate (2) is the same as the radius corresponding to the inner and outer arcs of the flue body (5); The guide components are distributed at equal intervals on the same cross section at the elbow position, the guide plate (4) of the rectifying section is parallel to the inner wall of one side of the flue body (5), and the guide plate (1) of the drainage section is parallel to the inner wall of the other side of the flue body (5); The arc segment guide plate (2) is connected to the downward pressure guide plate (3) to increase the surface flow velocity of the straightening segment guide plate (4) and facilitate the ash to slide off the downward pressure guide plate (3) and the gap.

2. The flue structure for reducing dust accumulation according to claim 1, characterized in that: The bending area in the flue body (5) is divided into a plurality of flue gas channels of the same shape by means of the guide components. The flue gas enters each flue gas channel from top to bottom. The flow resistance of the flue gas in each flue gas channel is the same, the flow rate of the flue gas in each flue gas channel is equal, and the amount of ash accumulated in each flue gas channel is uniform. The downward pressure guide plate increases the flow velocity of the subsequent guide plate and the upper surface of the flue gas, reduces the amount of ash accumulated, and the flue gas flows in a horizontal direction after passing through each flue gas channel and is finally discharged from the flue body (5).

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