Air supply pipeline

Abstract

The utility model discloses an air supply pipeline, belongs to the technical field of thermal power generation, and is mainly used for a blower for thermal power generation in severe cold areas. The air supply pipeline comprises a first air inlet pipe, the first air inlet pipe comprises an L-shaped first pipeline, and the two ends of the first pipeline are provided with a first air suction opening communicated with external air and a first air outlet communicated with an air feeder respectively; the bent part of the first pipeline is communicated with a second air inlet pipe with the two ends provided with a second air suction opening and a second air outlet respectively, the second air suction opening is communicated with the top of the boiler, and the second air outlet is communicated with the first pipeline. According to the air supply pipeline, the second air inlet pipe is obliquely inserted into the bending part of the first air inlet pipe, so that hot air input by the second air suction port and cold air input by the first air suction port are converged in the first pipeline, the requirement for the air inlet temperature of an air preheater at the inlet of the air feeder is met, normal operation of the boiler air feeder is guaranteed, the structure is compact, the occupied area is small, and cost is low. The installation is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal power generation, in particular to an air supply duct for an air blower in severely cold areas. Background Art

[0002] Thermal power plants use blowers to deliver air required for combustion to the furnace. Coal is burned in the boiler to heat water, turning it into steam, which drives the turbine generator to generate electricity. However, in extremely cold regions (i.e., where the average temperature in the coldest month is ≤ -10°C or the average daily temperature is ≤ 5°C for ≥ 145 days), low temperatures can cause blade icing, changes in material and structural properties, and load variations, adversely affecting the operation of the boiler blower. The blower delivers hot air required for combustion to the furnace via the air preheater. However, since the air supply for the blower is typically drawn from the outside through air ducts, the inlet air temperature is too low in these regions, resulting in low flue gas temperatures and wall temperatures often below the flue gas dew point. This causes sulfuric acid vapor to condense on the heating surfaces of the air preheater, causing corrosion. This can reduce boiler output and even force a shutdown. If a heater is added at the blower inlet, it will not only increase the equipment construction cost, but also make the entire process system complicated and add additional operational risks. Utility Model Content

[0003] The technical problem to be solved by the present invention is to provide an air supply duct, which is mainly used for the air supply fan of thermal power generation in severe cold areas, so as to ensure that the air temperature when the air supply duct in severe cold areas supplies air to the air supply fan meets the air inlet temperature requirement of the air preheater, thereby ensuring that the boiler air supply fan can operate stably.

[0004] The utility model discloses an air supply duct, including a first air inlet duct connected to the blower, the first air inlet duct including a first duct, the first duct being L-shaped and having a first air suction port and a first air outlet respectively provided at both ends, the first air suction port being connected to the external air, and the first air outlet being connected to the blower; the bending portion of the first duct is connected to a second air inlet duct extending away from the first air outlet, the second air inlet duct including a second duct, an end of the second duct away from the first air inlet duct being vertically provided with a second air suction port connected to the top of the boiler, a first elbow being provided between the second air suction port and the second duct, an end of the second duct close to the first air inlet duct being provided with a second air outlet connected to the first air inlet duct, and a second elbow being provided between the second air outlet and the second duct.

[0005] Furthermore, the first elbow is a 90° shrimp elbow, and the second elbow is a 30° shrimp elbow.

[0006] Furthermore, a first adjustment baffle is provided at the first air suction port, and a second adjustment baffle is provided at the second air suction port.

[0007] Furthermore, the first air suction port and the second air suction port are obliquely cut pipe ports that are inclined downward.

[0008] Furthermore, a filter is provided in each of the first air suction port and the second air suction port.

[0009] Furthermore, a hot air recirculation interface and a flue gas recirculation interface are provided on the first air inlet pipe, and the hot air recirculation interface and the flue gas recirculation interface are sequentially opened on the vertical section of the first pipe from top to bottom; the hot air recirculation interface is connected to the hot air duct connected to the air preheater at the rear of the boiler, and the flue gas recirculation interface is connected to the flue gas duct connected to the rear of the boiler.

[0010] Furthermore, a muffler is provided at one end of the first pipe close to the first air outlet.

[0011] Furthermore, the cross section of the first air inlet pipe is square, and the cross section of the second air inlet pipe is circular.

[0012] Furthermore, a reducing section is provided at one end of the first air outlet close to the blower inlet, and the cross-sectional diameter of the reducing section gradually decreases from the first air outlet to the blower inlet. A third elbow is provided at one end of the reducing section away from the first air outlet for connecting to the blower inlet.

[0013] The beneficial effect of the present invention is that the air supply duct is formed by obliquely inserting the second air inlet duct connected to the top of the boiler for inputting hot air into the bending part of the first air inlet duct which is L-shaped and is used to input outdoor cold air, so that the second air inlet duct can directly merge the hot air into the vertical section of the first duct, and the hot air input through the second air suction port merges with the cold air input through the first air suction port in the vertical section of the first duct, thereby adjusting the gas temperature in the vertical section of the first duct to meet the air inlet temperature of the blower inlet, and the first air inlet duct and the second air inlet duct used in the air supply duct have a compact structure, occupy a small space, are easy and quick to install, use less materials, and have low construction cost; they can also meet the combustion requirements such as air volume and temperature in the boiler furnace, ensure the normal operation of the entire unit, and can also play a role in regulating the temperature in the boiler room, thereby improving the thermal efficiency of the entire unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 : Schematic diagram of the structure of the air supply duct;

[0015] Figure 2 : Figure 1 Left view of;

[0016] Figure markings: 1-first air inlet pipe; 11-first pipe; 111-horizontal section; 112-vertical section; 12-first air suction port; 121-first adjusting baffle; 13-first air outlet; 14-hot air recirculation interface; 141-hot air duct; 15-flue gas recirculation interface; 151-flue gas duct; 16-muffler; 17-reducing section; 171-third elbow; 2-second air inlet pipe; 21-second pipe; 22-second air suction port; 23-second air outlet; 231-second adjusting baffle; 24-first elbow; 25-second elbow. DETAILED DESCRIPTION

[0017] The utility model is further described below.

[0018] The utility model provides an air supply duct, which is mainly used for air blowers of thermal power generation in severely cold areas. It comprises a first air inlet duct 1 connected to the air blower, the first air inlet duct 1 comprising a first duct 11, the first duct 11 is L-shaped and has a first air suction port 12 and a first air outlet 13 at both ends, the first air suction port 12 is connected to the external air, and the first air outlet 13 is connected to the air blower; the bent portion of the first duct 11 is connected to a second air inlet duct 2 extending away from the first air outlet 13, the second air inlet duct 2 comprises a second duct 21, an end of the second duct 21 away from the first air inlet duct 1 is vertically provided with a second air suction port 22 connected to the top of the boiler, a first elbow 24 is provided between the second air suction port 22 and the second duct 21, an end of the second duct 21 close to the first air inlet duct 1 is provided with a second air outlet connected to the first air inlet duct 1, and a second elbow 25 is provided between the second air outlet and the second duct 21.

[0019] like Figure 1 、 Figure 2As shown, the air supply duct includes a first air inlet duct 1 and a second air inlet duct 2. The first air inlet duct 1 includes a first duct 11. The first duct 11 is L-shaped and has a first air suction port 12 and a first air outlet 13 at both ends. The horizontal section 111 of the first duct 11 serves as an external gas input section and introduces external cold air into the first duct 11 through the first air suction port 12 provided at the end of the horizontal section 111. The vertical section 112 of the first duct 11 serves as a converging section, which combines the outdoor cold air input from the first air suction port 12 with the outdoor cold air input from the second air suction port 13. The hot air from the boiler inputted from the air vent 22 is merged, and then the merged gas is inputted into the blower inlet through the first air outlet 13 provided at the end of the vertical section 112; the second air inlet pipe 2 is plugged into the bend of the first pipe 11, and the second air inlet pipe 2 includes a second pipe 21, which is obliquely inserted into the bend of the first pipe 11 and extends in a direction away from the first air outlet 13. The oblique plug connection method can ensure that the air in the second pipe 21 will not be turbulent when it is inputted into the first pipe 11. To ensure smooth airflow input, the oblique insertion position can be flexibly arranged according to actual construction needs; the second duct 21 is vertically provided with a second air suction port 22 connected to the boiler top at one end away from the first air inlet duct 1, and the second duct 21 is provided with a second air outlet connected to the first air inlet duct 1 at one end close to the first air inlet duct 1. The hot air generated at the boiler top is guided into the second duct 21 through the second air suction port 22, and then input into the vertical section 112 of the first duct 11 through the second air outlet of the second duct 21, and merged with the cold air in the first air inlet duct 1, thereby adjusting the gas temperature in the vertical section 112 of the first duct 11 to meet the air inlet temperature requirement of the blower inlet; in order to ensure smooth airflow between the second air suction port 22, the second air outlet and the second duct 21, a first elbow 24 is provided between the second air suction port 22 and the second duct 21, and a second elbow 25 is provided between the second air outlet and the second duct 21; the above-mentioned first air inlet duct 1 and second air inlet duct 2 can be made as a whole or can be formed by welding. The air supply duct is configured to obliquely insert the second air inlet duct 2 connected to the top of the boiler for inputting hot air into the bending part of the first air inlet duct 1 which is L-shaped and is used to input outdoor cold air, so that the second air inlet duct 2 can directly merge the hot air into the vertical section 112 of the first duct 11, and the hot air input through the second air suction port 22 and the cold air input through the first air suction port 12 merge in the vertical section 112 of the first duct 11, thereby adjusting the gas temperature in the vertical section 112 of the first duct 11 to meet the air inlet temperature of the blower inlet. The first air inlet duct 1 and the second air inlet duct 2 used in the air supply duct are compact in structure, occupy a small space, are easy and quick to install, use less materials, and have low construction cost. They can also meet the combustion requirements such as air volume and temperature in the boiler furnace, ensure the normal operation of the entire unit, and regulate the temperature in the boiler room, thereby improving the thermal efficiency of the entire unit.

[0020] As a preferred method, in order to ensure the streamline of the incoming air and realize the connection in a limited space, the first elbow 24 is a 90° shrimp elbow, and the second elbow 25 is a 30° shrimp elbow; specifically, the above-mentioned 90° shrimp elbow and 30° shrimp elbow are welded with circular pipes of different angles. Such a design can not only change the incoming air direction, but also ensure the incoming air streamline, meet the requirements for air supply of the blower, and at the same time, the design is compact, reducing the volume of the air supply duct so that it can be connected in a limited space.

[0021] In order to adjust the air volume and control the air temperature, Figure 1 As shown, a first regulating baffle 121 is provided at one end of the first duct 11 near the first air intake 12, and a second regulating baffle 231 is provided at one end of the second duct 21 near the second air outlet. The first regulating baffle 121 and the second regulating baffle 231 can adopt existing baffle dampers. By providing the first regulating baffle 121 at the first duct 11 near the first air intake 12, the amount of cold air entering the air intake can be effectively controlled. The second regulating baffle 231 is provided at the second duct 21 near the second air outlet to adjust the amount of air entering the air intake directed to the second air outlet through the second duct 21, thereby adjusting the amount of air entering the first air inlet duct 1 and the second air inlet duct 2. By changing the amount of air entering, the temperature of the mixed air of the cold air in the first air inlet duct 1 and the hot air in the second air inlet duct 2 is controlled, so that the temperature of the air entering the blower meets the air supply requirements of the blower and does not overheat or overcool.

[0022] To avoid rainy weather when used outdoors, rainwater enters the first air inlet duct and the second air inlet pipe 2 through the first air inlet 12 and the second air inlet 22, affecting the normal operation of the blower; Figure 1 As shown, the first air suction port 12 and the second air suction port 22 are beveled pipe ports inclined downward; by designing the first air suction port 12 and the second air suction port 22 as beveled pipe ports inclined downward, the upper side of the pipe port is longer than the lower side of the pipe port, which effectively reduces the entry of raindrops into the pipe during rainfall; as a preferred embodiment, the bevel angle of the beveled pipe port is 30°.

[0023] In order to prevent indoor debris, larger particles, etc. from entering the air supply system and to ensure the purity of the air supply, a filter is provided in the first air intake port 12 and the second air intake port 22; by providing a filter, indoor debris and larger particles are isolated from the outside of the first air inlet pipe 1 and the second air inlet pipe 2 to prevent them from entering the pipe and entering the blower through the pipe, thereby affecting the normal operation of the blower; in order to facilitate regular cleaning and replacement of the filter, the filter can be removably arranged in the first air intake port 12 and the second air intake port 22, and can be specifically connected by a snap connection or a latch.

[0024] When the outdoor temperature is too low, the temperature of the air flow input from the first air inlet pipe 1 is too low, resulting in the air flow input from the second air inlet pipe 2 and the air flow input from the first air inlet pipe 1 still being unable to meet the air supply requirements at the inlet of the blower after mixing. In order to further increase the temperature at the inlet of the blower and thus meet the temperature requirements of the air preheater; the first air inlet pipe 1 is also provided with a hot air recirculation interface 14 and a flue gas recirculation interface 15, the hot air recirculation interface 14 and the flue gas recirculation interface 15 are sequentially opened on the vertical section 112 of the first pipe 11 from top to bottom, the hot air recirculation interface 14 is connected to the hot air duct 141 connected to the air preheater at the tail end of the boiler, and the flue gas recirculation interface 15 is connected to the flue gas duct 151 connected to the tail end of the boiler; by opening the hot air recirculation interface 14 on the vertical section 112 of the first pipe 11, and using the hot air recirculation interface 14 to connect to the air preheater at the tail end of the boiler The hot air duct 141 connected to the preheater inputs part of the hot air generated after heat exchange in the air preheater at the rear of the boiler into the first duct 11 through the hot air duct 141, thereby realizing hot air recycling and effectively increasing the temperature at the inlet of the blower, thereby meeting the temperature requirement of the air preheater at the inlet of the blower; by opening a flue gas recirculation interface 15 on the vertical section 112 of the first duct 11, and using the flue gas recirculation interface 15 to connect to the flue gas duct 151 connected to the rear of the boiler, the gas at the rear of the flue gas can be input into the first duct 11 through the flue gas duct 151, and then enter the boiler again through the blower, realizing flue gas circulation; when the emission of nitrogen oxides at the rear of the boiler exceeds the standard, the gas at the rear of the boiler can be recycled through the flue gas duct 151 connected to the first duct 11, thereby reducing the oxygen concentration in the furnace and adjusting the emission concentration of nitrogen oxides to meet environmental protection requirements.

[0025] To reduce the noise at the blower inlet and affect the surrounding environment, such as Figure 1 As shown, a muffler 16 is provided at one end of the first pipe 11 close to the first air outlet 13; when the first air outlet 13 is connected to the blower, the muffler 16 close to one end of the first air outlet 13 can muffle the noise at the inlet of the blower and reduce the noise. Specifically, the muffler 16 can adopt an existing impedance composite muffler.

[0026] In order to ensure the smooth connection between the air supply duct and the blower, as well as the smoothness of the air flow in the duct, the cross section of the first air inlet duct 1 is square, and the cross section of the second air inlet duct 2 is circular. Since the blower inlet is square, the first air inlet duct 1 connected to the blower inlet is designed to be square, so as to facilitate the connection between the air supply duct and the blower inlet. Since the second air suction port 22 of the second air inlet duct 2 needs to be connected to the top of the boiler, it is far away from the connection between the second air inlet duct 2 and the first air inlet duct 1. In order to ensure the smoothness of the air flow in the second air inlet duct 2, the second air inlet duct 2 is designed to be circular. As a preferred method, Figure 1 As shown, the first air outlet 13 is provided with a reducing section 17 at one end close to the blower inlet, and the cross-sectional diameter of the reducing section 17 gradually decreases along the first air outlet 13 toward the blower inlet, and the reducing section 17 is provided with a third elbow 171 for connecting to the blower inlet at one end away from the first air outlet 13, and the third elbow 171 is a rectangular elbow; by providing the reducing section 17, both the air intake volume of the first air inlet pipe 1 and the smooth connection between the first air inlet pipe 1 and the blower inlet can be guaranteed, while avoiding air flow turbulence caused by a sudden change in the pipe diameter. In order to ensure the smooth connection between the reducing section 17 and the blower inlet, a third elbow 171 for connecting to the blower inlet is provided at the end of the reducing section 17 away from the first air outlet 13. In order to facilitate communication with the blower inlet, the cross-section of the third elbow 171 is rectangular.

Claims

1. An air supply duct, characterized in that: The invention comprises a first air inlet pipe (1) connected to a blower, wherein the first air inlet pipe (1) comprises a first pipe (11), the first pipe (11) is L-shaped and has a first air suction port (12) and a first air outlet (13) at both ends, the first air suction port (12) is connected to the external air, and the first air outlet (13) is connected to the blower; the bent portion of the first pipe (11) is connected to a second air inlet pipe (2) extending in a direction away from the first air outlet (13), and the second air inlet pipe (2) is The invention comprises a second pipe (21), wherein the second pipe (21) is vertically provided with a second air suction port (22) connected to the top of the boiler at one end away from the first air inlet pipe (1), a first elbow (24) is provided between the second air suction port (22) and the second pipe (21), and the second pipe (21) is provided with a second air outlet (23) connected to the first air inlet pipe (1) at one end close to the first air inlet pipe (1), and a second elbow (25) is provided between the second air outlet (23) and the second pipe (21).

2. The air supply duct according to claim 1, characterized in that: The first elbow (24) is a 90° shrimp elbow, and the second elbow (25) is a 30° shrimp elbow.

3. The air supply duct according to claim 1, characterized in that: A first regulating baffle (121) is provided at one end of the first pipe (11) close to the first air inlet (12), and a second regulating baffle (231) is provided at one end of the second pipe (21) close to the second air outlet (23).

4. The air supply duct according to claim 1, characterized in that: The first air suction port (12) and the second air suction port (22) are obliquely cut pipe ports that are inclined downward.

5. The air supply duct according to claim 4, characterized in that: Filters are provided in the first air suction port (12) and the second air suction port (22).

6. The air supply duct according to claim 1, characterized in that: The first air inlet pipe (1) is also provided with a hot air recirculation interface (14) and a flue gas recirculation interface (15), and the hot air recirculation interface (14) and the flue gas recirculation interface (15) are sequentially opened on the vertical section of the first pipe (11) from top to bottom; the hot air recirculation interface (14) is connected to a hot air duct (141) connected to an air preheater at the rear of the boiler, and the flue gas recirculation interface (15) is connected to a flue gas duct (151) connected to the rear of the boiler.

7. The air supply duct according to claim 1, characterized in that: A silencer (16) is provided at one end of the first pipe (11) close to the first air outlet (13).

8. The air supply duct according to claim 1, characterized in that: The cross section of the first air inlet pipe (1) is square, and the cross section of the second air inlet pipe (2) is circular.

9. The air supply duct according to claim 8, characterized in that: A reducing section (17) is provided at one end of the first air outlet (13) close to the blower inlet (3), wherein the cross-sectional diameter of the reducing section (17) gradually decreases along the first air outlet (13) toward the blower inlet (3), and a third elbow (171) for connecting to the blower inlet (3) is provided at one end of the reducing section (17) away from the first air outlet (13).

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