Air preheater dust self-cleaning device for boiler of thermal power plant

Abstract

This application discloses a self-cleaning device for air volume and dust in air preheaters used in thermal power plant boilers, belonging to the field of air preheaters for thermal power plant boilers. This self-cleaning device includes an air preheater, a heat exchange tube bundle fixedly installed in the middle of the air preheater, a flue gas inlet and outlet respectively connected to the inlet and outlet of the heat exchange tube bundle, and air inlets and outlets located on both sides of the heat exchange tube bundle. The heat exchange tube bundle consists of longitudinally arranged down-flowing and up-flowing tubes. A dust collection box communicating with the bottom of the heat exchange tube bundle and a dust discharge valve fixedly installed at the outlet end of the dust collection box are provided at the bottom of the air preheater. The inlet at the top of the down-flowing tube is connected to the flue gas inlet. Belonging to the field of air preheaters for thermal power plant boilers, this device achieves inertial dust removal through a U-shaped channel design, combined with active dust removal technology using piezoelectric ceramics to drive the vibration of the inner tubes, solving the problems of easy dust accumulation and frequent shutdowns for cleaning in traditional tubular air preheaters.

Description

Technical Field

[0001] This application relates to the technical field of air preheaters for thermal power plant boilers, specifically a self-cleaning device for air volume and dust in air preheaters for thermal power plant boilers. Background Technology

[0002] Air preheaters in thermal power plant boilers are key equipment used in boiler systems to recover waste heat from flue gas and heat the air entering the furnace. Their core function is to improve boiler efficiency and reduce energy consumption through heat exchange.

[0003] Small and medium-sized boilers typically use tubular air preheaters, but the flue gas ducts of tubular air preheaters are prone to ash accumulation. Ash accumulation will reduce the air temperature at the air preheater outlet, decrease boiler efficiency, and in severe cases, require shutdown for cleaning, increasing operation and maintenance costs and affecting production efficiency.

[0004] Therefore, this application provides a self-cleaning device for air volume dust in air preheaters of thermal power plant boilers to solve the above-mentioned problems. Utility Model Content

[0005] This application provides a self-cleaning device for air volume dust in air preheaters used in thermal power plant boilers, which aims to solve the problem mentioned in the background art that the flue gas ducts of existing tubular air preheaters are prone to dust accumulation, leading to a decrease in boiler efficiency, and in severe cases, requiring shutdown for cleaning, increasing operation and maintenance costs, and affecting production efficiency.

[0006] To achieve the above objectives, this application provides the following technical solution: a self-cleaning device for air volume and dust in an air preheater of a thermal power plant boiler, comprising an air preheater, a heat exchange tube bundle fixedly installed in the middle of the air preheater, a flue gas inlet and a flue gas outlet respectively connected to the inlet and outlet of the heat exchange tube bundle, and an air inlet and an air outlet disposed on both sides of the heat exchange tube bundle. The heat exchange tube bundle consists of a longitudinally arranged down pipe and an up pipe. The bottom of the air preheater is provided with a dust collection box communicating with the bottom end of the heat exchange tube bundle and a dust discharge valve fixedly installed at the outlet end of the dust collection box. The top inlet of the down pipe is connected to the flue gas inlet, the top outlet of the up pipe is connected to the flue gas outlet, and the bottom outlet of the down pipe and the bottom inlet of the up pipe are both connected to the dust collection box. The flue gas inlet, the down pipe, the dust collection box, the up pipe and the flue gas outlet are sequentially connected to form a U-shaped channel.

[0007] The downcomer tube includes an outer tube, an inner tube fitted inside the outer tube and connected to both ends of the outer tube by metal corrugated pipes, and a piezoelectric ceramic vibrating plate attached to the outer wall of the inner tube. In this way, inertial dust removal is achieved through the U-shaped channel design, combined with active dust removal technology that uses piezoelectric ceramics to drive the vibration of the inner tube, solving the problems of easy dust accumulation and frequent shutdown for cleaning in traditional tubular air preheaters.

[0008] Preferably, the piezoelectric ceramic vibrator is connected to an external power source.

[0009] Preferably, the metal corrugated pipe is made of stainless steel and is fixed to the end of the outer pipe and the end of the inner pipe by welding.

[0010] Preferably, the piezoelectric ceramic vibrator is fitted with a buffer pad that is fixedly connected to the inner wall of the outer tube.

[0011] Preferably, the inner wall of the inner tube has an enamel coating.

[0012] Preferably, the dust collection box is bucket-shaped.

[0013] Preferably, a dust filter screen is fixedly connected inside the dust collection box at the position corresponding to the bottom inlet of the upward pipe.

[0014] This air preheater dust self-cleaning device for boilers in thermal power plants achieves inertial dust removal through a U-shaped channel design, combined with active dust removal technology that uses piezoelectric ceramics to drive the vibration of the inner tube. This solves the problem of easy dust accumulation and frequent shutdowns for cleaning in traditional tubular air preheaters.

[0015] The air preheater dust self-cleaning device for the boiler in this thermal power plant requires the flue gas to pass through a dust filter screen when it transfers from the downpipe to the uppipe. The screen screen intercepts fine ash particles that have not settled, preventing them from entering the uppipe and avoiding secondary deposition of ash particles in the uppipe. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a self-cleaning device for air volume and dust in an air preheater of a thermal power plant boiler.

[0017] Figure 2 This is a schematic diagram of the internal structure of a self-cleaning device for air volume and dust in an air preheater of a thermal power plant boiler.

[0018] Figure 3 This is a schematic diagram of the structure of a side section of the downpipe of a self-cleaning device for dust in an air preheater of a thermal power plant boiler.

[0019] In the picture:

[0020] 1. Air preheater; 11. Flue gas inlet; 12. Flue gas outlet; 13. Air inlet; 14. Air outlet; 15. Dust collection box; 16. Dust discharge valve;

[0021] 2. Heat exchanger tube bundle; 21. Downflow tube; 211. Outer tube; 212. Inner tube;

[0022] 213. Piezoelectric ceramic vibrator; 214. Buffer pad; 215. Metal bellows; 22. Upward tube;

[0023] 3. Dust filter. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] This embodiment provides a self-cleaning device for air volume and dust in air preheaters used in thermal power plant boilers, such as... Figures 1-3 As shown, the air volume and dust self-cleaning device for the air preheater of the boiler in the thermal power plant includes an air preheater 1, a heat exchange tube bundle 2 fixedly installed in the middle of the air preheater 1, a flue gas inlet 11 and a flue gas outlet 12 respectively connected to the inlet and outlet of the heat exchange tube bundle 2, and an air inlet 13 and an air outlet 14 arranged on both sides of the heat exchange tube bundle 2. The heat exchange tube bundle 2 is composed of a longitudinally arranged down pipe 21 and an up pipe 22. The bottom of the air preheater 1 is provided with a dust collection box 15 connected to the bottom end of the heat exchange tube bundle 2 and a dust discharge valve 16 fixedly installed at the outlet end of the dust collection box 15. The top inlet of the down pipe 21 is connected to the flue gas inlet 11, the top outlet of the up pipe 22 is connected to the flue gas outlet 12, and the bottom outlet of the down pipe 21 and the bottom inlet of the up pipe 22 are both connected to the dust collection box 15. The flue gas inlet 11, the down pipe 21, the dust collection box 15, the up pipe 22 and the flue gas outlet 12 are connected in sequence to form a U-shaped channel. The piezoelectric ceramic vibrator 213 is connected to an external power source.

[0026] The downcomer tube 21 includes an outer tube 211, an inner tube 212 fitted inside the outer tube 211 and connected to both ends of the outer tube 211 by metal corrugated tubes 215, and a piezoelectric ceramic vibrator 213 attached to the outer wall of the inner tube 212.

[0027] During use, flue gas enters the downcomer pipe 21 from the flue gas inlet 11, flowing in the opposite direction to the cold air outside the outer pipe. Heat is transferred to the air through the pipe wall. Ash in the flue gas partially settles into the dust collection box 15 due to inertia and gravity in the U-shaped channel. The cleaning program is triggered periodically by the external control system, which applies an AC signal to the piezoelectric ceramic vibrator 213. The inner pipe 212 vibrates at high frequency under the drive of the piezoelectric ceramic. The metal bellows 215 keeps the seal while compensating for the displacement of the inner pipe 212, shaking off the ash adhering to the pipe wall. The ash flows with the flue gas to the dust collection box 15. After the cleaning is completed, the dust discharge valve 16 automatically opens, discharging the ash in the dust collection box to the external ash hopper.

[0028] Specifically, the metal corrugated pipe 215 is made of stainless steel and is fixed to the ends of the outer pipe 211 and the inner pipe 212 by welding. Stainless steel has corrosion resistance and high temperature resistance, is suitable for flue gas environment, and the welding fixing method is a mature process that does not require complicated assembly, thus reducing manufacturing costs.

[0029] Furthermore, the piezoelectric ceramic vibrator 213 is externally fitted with a buffer pad 214 fixedly connected to the inner wall of the outer tube 211; when the inner tube 212 vibrates, the buffer pad absorbs part of the vibration energy, reduces the transmission of vibration outward, and at the same time reduces the impact of the inner tube vibration on the air preheater as a whole, reduces noise, improves the working environment, and can also prevent the inner tube and outer tube from colliding due to vibration, thus extending the life of the piezoelectric ceramic plate.

[0030] Specifically, the inner wall of the inner tube 212 has an enamel coating; the enamel coating has a smooth surface and is resistant to acid, alkali and high temperature, resisting corrosion from acidic gases such as SO2 and SO3 in the flue gas, extending the service life of the inner tube, and the smooth surface reduces the adhesion of ash, making it easier for ash to be carried away by the flue gas or shaken off by vibration, thus improving the ash removal efficiency.

[0031] Specifically, the dust collection box 15 is hopper-shaped; the hopper-shaped structure prevents ash from accumulating in dead corners inside the box, and the ash can be completely discharged when the dust discharge valve 16 is opened, reducing secondary dust.

[0032] Furthermore, a dust filter 3 is fixedly connected inside the dust collection box 15 at the position corresponding to the bottom inlet of the upward pipe 22; when the flue gas is transferred from the downward pipe 21 to the upward pipe 22, it needs to pass through the dust filter 3. The filter intercepts the fine ash that has not settled, preventing it from entering the upward pipe and avoiding secondary deposition of ash in the upward pipe.

[0033] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A self-cleaning device for air volume and dust in an air preheater of a thermal power plant boiler, comprising an air preheater (1), a heat exchange tube bundle (2) fixedly installed in the middle of the air preheater (1), a flue gas inlet (11) and a flue gas outlet (12) respectively connected to the inlet and outlet of the heat exchange tube bundle (2), and an air inlet (13) and an air outlet (14) disposed on both sides of the heat exchange tube bundle (2), characterized in that: The heat exchange tube bundle (2) is composed of a longitudinally arranged down pipe (21) and an up pipe (22). The air preheater (1) is provided with a dust collection box (15) connected to the bottom end of the heat exchange tube bundle (2) and a dust discharge valve (16) fixedly installed at the outlet end of the dust collection box (15). The top inlet of the down pipe (21) is connected to the flue gas inlet (11), the top outlet of the up pipe (22) is connected to the flue gas outlet (12), and the bottom outlet of the down pipe (21) and the bottom inlet of the up pipe (22) are both connected to the dust collection box (15). The flue gas inlet (11), the down pipe (21), the dust collection box (15), the up pipe (22) and the flue gas outlet (12) are connected in sequence to form a U-shaped channel. The down tube (21) includes an outer tube (211), an inner tube (212) fitted inside the outer tube (211) and connected to both ends of the outer tube (211) by metal corrugated tubes (215) at both ends, and a piezoelectric ceramic vibrating plate (213) attached to the outer wall of the inner tube (212).

2. The air volume and dust self-cleaning device for air preheaters in thermal power plant boilers according to claim 1, characterized in that: The piezoelectric ceramic vibrator (213) is connected to an external power source.

3. The air preheater dust self-cleaning device for a boiler of a thermal power plant according to claim 2, characterized in that: The metal corrugated pipe (215) is made of stainless steel and is fixed to the end of the outer pipe (211) and the end of the inner pipe (212) by welding.

4. The air preheater dust self-cleaning device for a boiler of a thermal power plant according to claim 3, characterized in that: The piezoelectric ceramic vibrating plate (213) is fitted with a buffer pad (214) that is fixedly connected to the inner wall of the outer tube (211).

5. The air volume and dust self-cleaning device for air preheaters in thermal power plant boilers according to claim 4, characterized in that: The inner wall of the inner tube (212) has an enamel coating.

6. The air volume and dust self-cleaning device for air preheaters in thermal power plant boilers according to claim 5, characterized in that: The dust collection box (15) is bucket-shaped.

7. The air preheater dust self-cleaning device for a thermal power plant boiler according to claim 6, characterized in that: A dust filter (3) is fixedly connected inside the dust collection box (15) at the position corresponding to the bottom inlet of the upward pipe (22).

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