Denitration and ammonia spraying mixing device of gas turbine

Abstract

The utility model discloses a gas turbine denitration ammonia injection mixing device which is installed at the front end in a waste heat boiler, an ammonia injection grid, a flow equalizing mixer and an SCR catalyst layer are sequentially arranged in the flue gas flowing direction, the ammonia injection grid comprises a plurality of ammonia supply main pipes, each ammonia supply main pipe is vertically connected with a plurality of ammonia supply branch pipes, and the ammonia supply branch pipes are connected with the flow equalizing mixer. The ammonia supply branch pipes located in the same vertical line direction are jointly connected with the same ammonia spraying main pipe, ammonia spraying branch pipes are evenly and vertically arranged on the two sides of each ammonia spraying main pipe, and a nozzle is arranged at the end of each ammonia spraying branch pipe. According to the utility model, the mounting space of the denitration device is saved, and meanwhile, the uniformity of ammonia in flue gas is improved.

Description

Technical Field

[0001] This utility model belongs to the field of gas turbine flue gas denitrification technology, specifically relating to a gas turbine denitrification ammonia injection mixing device. Background Technology

[0002] Against the backdrop of low-carbon energy transition, gas turbine generator sets have become rapidly popular due to their lower pollutant emission characteristics compared to traditional coal-fired units. Although the NOx generation concentration per unit of power generation of gas turbines is about 50-70% lower than that of coal-fired boilers, the total NOx emissions still show a significant environmental burden because their flue gas flow rate can be 2-3 times that of coal-fired units of the same level.

[0003] To address this environmental challenge, various regions have issued stricter NOx emission standards for gas turbines. In order to meet these standards, SCR denitrification systems have been promoted to become standard equipment in gas-fired power plants. However, the compact layout of the gas turbine tail flue places higher demands on the design and installation of the ammonia injection system for SCR denitrification. How to achieve dynamic and precise ammonia injection control within a limited space has become a key technological breakthrough direction for improving the performance of gas turbine SCR systems. Utility Model Content

[0004] To address the aforementioned problems, the purpose of this utility model is to provide a gas turbine denitrification ammonia injection mixing device.

[0005] The specific technical solution is as follows:

[0006] A gas turbine denitrification ammonia injection mixing device is installed at the front end inside a waste heat boiler. In the direction of flue gas flow, it consists of an ammonia injection grid, a flow equalization mixer, and an SCR catalyst layer. The ammonia injection grid includes multiple main ammonia supply pipes, each of which is vertically connected to multiple branch ammonia supply pipes. The multiple branch ammonia supply pipes located on the same vertical line are connected to the same main ammonia injection pipe. Ammonia injection branch pipes are evenly and vertically arranged on both sides of each main ammonia injection pipe, and each branch ammonia injection pipe has a nozzle at its end.

[0007] Furthermore, the flow equalization mixer is provided with rectangular flow equalization holes evenly distributed around each flow equalization hole, and a baffle plate is evenly arranged around each flow equalization hole in the direction of flue gas flow.

[0008] Furthermore, the spoiler is rectangular, and one side of the spoiler is connected to the edge of the flow equalization hole.

[0009] Furthermore, the ammonia injection branch pipes are evenly distributed within the cross-section of the flue, each ammonia injection branch pipe corresponds to 4 flow equalization holes, and each ammonia injection branch pipe has 4 nozzles at its end, with each nozzle facing one flow equalization hole.

[0010] Furthermore, the inner diameter of the ammonia injection branch pipe is 4-8 times the inner diameter of the nozzle, the inner diameter of the ammonia injection main pipe is 2-4 times the inner diameter of the ammonia injection branch pipe, and both ends of the ammonia injection main pipe are sealed.

[0011] Furthermore, the side length of the spoiler is half the side length of the flow equalization hole.

[0012] An operating method for a gas turbine denitrification ammonia injection mixing device includes the following steps: the denitrification reducing agent is introduced into the ammonia supply main pipe, distributed through the ammonia supply branch pipe and then enters the ammonia injection main pipe, then enters the ammonia injection branch pipe, and finally enters the flue through the nozzle. After the denitrification reducing agent is mixed with the flue gas, it flows through the flow equalization hole and is affected by the baffle to form a swirling flow so that it is mixed evenly. Then it passes through the SCR catalyst layer for reaction.

[0013] The beneficial effects of this utility model are as follows:

[0014] This invention uses an ammonia injection grid to uniformly distribute ammonia and employs a flow equalization mixer to create a swirling flow of flue gas passing through the flow equalization holes, thereby improving the uniformity of ammonia in the flue gas. Attached Figure Description

[0015] Figure 1 This is a layout diagram of the device of this utility model;

[0016] Figure 2 This is a schematic diagram of the ammonia injection grid structure after installation according to this utility model;

[0017] Figure 3 This is a partial structural diagram of an ammonia injection grid;

[0018] Figure 4 This is a schematic diagram of a flow equalization mixer.

[0019] In the diagram: 1. Waste heat boiler; 2. Ammonia injection grid; 21. Ammonia supply main pipe; 22. Ammonia supply branch pipe; 23. Ammonia injection main pipe; 24. Ammonia injection branch pipe; 25. Nozzle; 3. Flow equalization mixer; 31. Flow equalization orifice; 32. Baffle plate; 4. SCR catalyst layer. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited thereto.

[0021] like Figure 1 As shown, a gas turbine denitrification ammonia injection mixing device is installed at the front end inside the waste heat boiler 1. Along the flue gas flow direction, it consists of an ammonia injection grid 2, a flow equalization mixer 3, and an SCR catalyst layer 4. Figure 2 and Figure 3 As shown, Figure 3(a) is a front view of a portion of the structure of the ammonia injection grid 2, and (b) is a side view of a portion of the structure. The ammonia injection grid 2 includes multiple horizontally parallel ammonia supply main pipes 21. Each ammonia supply main pipe 21 is uniformly and vertically connected to multiple ammonia supply branch pipes 22. The ammonia supply branch pipes 22 are parallel to each other. Multiple ammonia supply branch pipes 22 located in the same vertical direction are connected to the same ammonia injection main pipe 23. The ammonia injection main pipes 23 are vertically parallel to each other. Each ammonia injection main pipe 23 has ammonia injection branch pipe 24 uniformly and vertically arranged on both sides. Each ammonia injection branch pipe 24 has 4 nozzles 25 at its end. The inner diameter of the ammonia injection branch pipe 24 is 4-8 times the inner diameter of the nozzle 25. The inner diameter of the ammonia injection main pipe 23 is 2-4 times the inner diameter of the ammonia injection branch pipe 24. The two ends of the ammonia injection main pipe 23 are sealed.

[0022] like Figure 4 As shown, Figure 4 (a) is the front view of the flow equalization mixer 3 and (b) is the side view. Rectangular flow equalization holes 31 are evenly opened on the flow equalization mixer 3. Each flow equalization hole 31 is evenly arranged with a baffle plate 32 opened in the direction of flue gas flow around it. The baffle plate 32 is rectangular and one side of the baffle plate 32 is connected to the edge of the flow equalization hole 31. The side length of the baffle plate 32 is half the side length of the flow equalization hole 31.

[0023] The ammonia injection branch pipes 24 are evenly distributed within the cross-section of the flue, and each ammonia injection branch pipe 24 corresponds to 4 flow equalization holes 31, with each nozzle 25 facing one flow equalization hole 31.

[0024] An operating method for a gas turbine denitrification ammonia injection mixing device includes the following steps: the denitrification reducing agent is introduced into the ammonia supply main pipe 21, distributed through the ammonia supply branch pipe 22 and then enters the ammonia injection main pipe 23, then enters the ammonia injection branch pipe 24, and finally enters the flue through the nozzle 25. After the denitrification reducing agent is mixed with the flue gas, it flows through the flow equalization hole 31 and is affected by the baffle plate 32 to form a swirling flow to make it evenly mixed. Then it passes through the SCR catalyst layer 4 for reaction.

Claims

1. A denitration ammonia injection mixing device for a combustion engine, installed at the front end inside a waste heat boiler (1), characterized in that, The ammonia injection grid (2), the flow equalizing mixer (3) and the SCR catalyst layer (4) are sequentially arranged in the flue gas flow direction, the ammonia injection grid (2) comprises a plurality of ammonia supply main pipes (21), each of the ammonia supply main pipes (21) is vertically connected with a plurality of ammonia supply branch pipes (22), the ammonia supply branch pipes (22) located in the same vertical direction are connected with the same ammonia injection main pipe (23), the ammonia injection main pipe (23) is uniformly and vertically provided with the ammonia injection branch pipes (24) on both sides, and the end of each of the ammonia injection branch pipes (24) is provided with a nozzle (25).

2. The ammonia injection mixing device for denitration of a combustion engine according to claim 1, characterized in that, The flow equalizing mixer (3) is uniformly provided with rectangular flow equalizing holes (31), and each of the flow equalizing holes (31) is uniformly provided with flow disturbing plates (32) which are arranged in the flue gas flow direction.

3. The ammonia injection mixing device for denitration of a combustion engine according to claim 2, characterized in that, The flow disturbing plate (32) is rectangular, and one side of the flow disturbing plate (32) is connected with the edge of the flow equalizing hole (31).

4. The ammonia injection mixing device for denitration of a combustion engine according to claim 2, characterized in that, The ammonia injection branch pipes (24) are uniformly distributed in the flue gas passage section, each of the ammonia injection branch pipes (24) corresponds to four flow equalizing holes (31), the end of each of the ammonia injection branch pipes (24) is provided with four nozzles (25), and each of the nozzles (25) faces one of the flow equalizing holes (31).

5. The ammonia injection mixing device for denitration of a combustion engine according to claim 1, characterized in that, The inner diameter of the ammonia injection branch pipe (24) is 4-8 times of the inner diameter of the nozzle (25), the inner diameter of the ammonia injection main pipe (23) is 2-4 times of the inner diameter of the ammonia injection branch pipe (24), and the two ends of the ammonia injection main pipe (23) are sealed.

6. The ammonia injection mixing device for denitration of a combustion engine according to claim 1, wherein The length of the flow disturbing plate (32) is half of the length of the flow equalizing hole (31).

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