Inlet airflow distribution device for SCR (Selective Catalytic Reduction) denitration

Abstract

The utility model discloses an inlet airflow distribution device for SCR (Selective Catalytic Reduction) denitration, which comprises a flue gas pipeline and an inlet of an SCR denitration reactor, the inlet of the SCR denitration reactor is provided with a rectification grid, a first upper sealing plate and a second upper sealing plate are arranged above the rectification grid, the first upper sealing plate and the second upper sealing plate are arranged obliquely downwards, and the first upper sealing plate and the second upper sealing plate are arranged obliquely downwards. A first layer of catalyst is arranged below the rectification grid, the first upper sealing plate is connected with a flue gas pipeline, one end of the second upper sealing plate is connected with the tail end of the first upper sealing plate, the other end of the second upper sealing plate is connected with the tail end of the rectification grid, and an included angle alpha is formed between the first upper sealing plate and the vertical side wall of the SCR denitration reactor. Air flow distribution devices such as a flow guide plate do not need to be additionally arranged in the denitration device, long-term scouring and abrasion in the high-dust and high-flow-speed state do not exist, and long-term, stable and reliable operation of the denitration device can be guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of SCR denitration reactors, in particular to the technical field of inlet airflow distribution devices. Background Art

[0002] NOx is one of the main pollutants in the atmosphere. Among the several technologies for NOx treatment, the selective catalytic reduction technology (SCR) has occupied the mainstream of the denitrification market with its advantages such as high NOx removal rate, mature and reliable technology, and easy operation. Figure 1 ), adopts an integrated upper sealing plate, side sealing plates, adds angle steel and guide plates and other air flow distribution devices, and applies a rectifier grid to achieve good air flow distribution in the test section before the first layer of catalyst, which can ensure efficient denitrification and meet the requirements of ultra-low NOx emissions.

[0003] The prior art has the following defects:

[0004] 1. It is necessary to add a certain number of air flow distribution devices such as guide plates and angle steels, which will result in a certain amount of consumables;

[0005] 2. The additional airflow distribution devices such as guide plates and angle steels are operated under high dust and high flow rate for a long time, which are constantly washed and easily worn, and have a certain impact on the long-term, stable and reliable operation of the later denitrification device; 3. The corresponding positions of angle steels and side sealing plates are prone to cause local large airflow (see Figure 2 , Figure 3 ). Utility Model Content

[0006] The purpose of the utility model is to solve the problems in the prior art and to provide an inlet airflow distribution device for SCR denitration, which can solve the above problems.

[0007] To achieve the above-mentioned purpose, the utility model proposes an inlet airflow distribution device for SCR denitration, comprising a flue gas duct and an inlet of an SCR denitration reactor, a rectifying grid is provided at the inlet of the SCR denitration reactor, a first upper sealing plate and a second upper sealing plate are provided above the rectifying grid, the first upper sealing plate and the second upper sealing plate are both arranged obliquely downward, a first layer of catalyst is provided below the rectifying grid, the first upper sealing plate is connected to the flue gas duct, one end of the second upper sealing plate is connected to the end of the first upper sealing plate, and the other end is connected to the end of the rectifying grid, an angle formed by the first upper sealing plate and the vertical side wall of the SCR denitration reactor is α, a vertical distance between a high end and a low end of the first upper sealing plate is X, and a horizontal distance is Y.

[0008] Preferably, Y is 1000 mm.

[0009] Preferably, the length of the first upper sealing plate is smaller than the length of the second upper sealing plate.

[0010] Preferably, the angle formed by the second upper sealing plate and the vertical side wall of the SCR denitration reactor is β, and α is smaller than β.

[0011] Beneficial effects of the utility model:

[0012] 1. The utility model does not need to add air flow distribution devices such as guide plates inside, and there is no long-term erosion and wear under high dust and high flow rate conditions, which can ensure the long-term, stable and reliable operation of the denitrification device;

[0013] 2. The air intake for SCR denitrification adopts a reasonable external structure, which saves air flow distribution devices such as guide plates, achieves a more optimized flow field distribution, and truly reflects cost reduction and efficiency improvement.

[0014] The features and advantages of the present invention will be described in detail through embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the prior art;

[0016] Figure 2 It is the mid-section velocity vector diagram of the prior art;

[0017] Figure 3 This is the velocity distribution cloud diagram of the first layer catalyst inlet in the prior art;

[0018] Figure 4 It is a structural schematic diagram of the utility model;

[0019] Figure 5 It is the mid-section velocity vector diagram of the utility model;

[0020] Figure 6 This is the velocity distribution cloud diagram of the first layer catalyst inlet of the utility model;

[0021] Figure 7 It is a top view of the utility model.

[0022] In the figure: 1-first upper sealing plate, 2-second upper sealing plate, 3-rectifier grid, 4-front test section, 5-first layer of catalyst. DETAILED DESCRIPTION

[0023] See also Figure 4-7, an inlet air flow distribution device for SCR denitration, comprising a flue gas duct and an SCR denitration reactor inlet, a rectifying grid 3 is provided at the inlet of the SCR denitration reactor, a first upper sealing plate 1 and a second upper sealing plate 2 are provided above the rectifying grid 3, the first upper sealing plate 1 and the second upper sealing plate 2 are both arranged obliquely downward, a first layer of catalyst 5 is provided below the rectifying grid 3, the first upper sealing plate 1 is connected to the flue gas duct, one end of the second upper sealing plate 2 is connected to the end of the first upper sealing plate 1, and the other end is connected to the end of the rectifying grid 3, an angle formed by the first upper sealing plate 1 and the vertical side wall of the SCR denitration reactor is α, a vertical distance between the high end and the low end of the first upper sealing plate 1 is X, and a horizontal distance is Y, wherein Y is 1000 mm, a length of the first upper sealing plate 1 is less than a length of the second upper sealing plate 2, an angle formed by the second upper sealing plate 2 and the vertical side wall of the SCR denitration reactor is β, and α is less than β.

[0024] The utility model divides the upper sealing plate into two sections, adjusts the X value and the angle α value related to the first upper sealing plate, cancels the side sealing plate in the prior art solution (i.e., h=0), and does not need to add air flow distribution devices such as guide plates and angle steels in the denitration air intake structure. The grid rectification 3 is applied to achieve a better air flow distribution in the test section 4 in front of the first layer of catalyst 5, further ensuring efficient denitration and meeting the requirements of ultra-low NOx emissions.

[0025] The utility model uses computational fluid dynamics software (CFD) to perform flow field simulation tests, conduct personalized and precise design, and ensure the rationality of the X value and the angle α value.

[0026] The above embodiments are intended to illustrate the present invention, not to limit the present invention. Any solution that is a simple transformation of the present invention falls within the protection scope of the present invention.

Claims

1. An inlet air flow distribution device for SCR denitration, characterized in that: The invention comprises a flue gas duct and an inlet of an SCR denitration reactor, wherein a rectifying grid (3) is provided at the inlet of the SCR denitration reactor, a first upper sealing plate (1) and a second upper sealing plate (2) are provided above the rectifying grid (3), the first upper sealing plate (1) and the second upper sealing plate (2) are both arranged to be inclined downward, a first layer of catalyst (5) is provided below the rectifying grid (3), the first upper sealing plate (1) is connected to the flue gas duct, one end of the second upper sealing plate (2) is connected to the end of the first upper sealing plate (1), and the other end is connected to the end of the rectifying grid (3), an angle formed between the first upper sealing plate (1) and the vertical side wall of the SCR denitration reactor is α, the vertical distance between the high end and the low end of the first upper sealing plate (1) is X, and the horizontal distance is Y.

2. The inlet airflow distribution device for SCR denitration according to claim 1, characterized in that: The Y is 1000 mm.

3. The inlet airflow distribution device for SCR denitration according to claim 1, characterized in that: The length of the first upper sealing plate (1) is smaller than the length of the second upper sealing plate (2).

4. The inlet airflow distribution device for SCR denitration according to claim 1, characterized in that: The included angle formed by the second upper sealing plate (2) and the vertical side wall of the SCR denitration reactor is β, and α is smaller than β.

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