Fine ash overload automatic clearing device for interior of dry slag conveyor body of coal-fired power plant

Abstract

The invention relates to a fine ash overload automatic cleaning device for the interior of a dry slag conveyor body of a coal-fired power plant, which comprises a transition section and a horizontal section of the dry slag conveyor body, the transition section and the horizontal section of the dry slag conveyor body are both connected with instrument compressed air, and the transition section of the dry slag conveyor is provided with at least one dust raising unit. A plurality of dust raising units are arranged on a horizontal section of the dry slag conveyor, the dust raising units are the same in structure, the dust raising units are connected with compressed air after being connected in parallel, accumulated dust on a bottom plate of a box body of the dry slag conveyor is blown and raised through the compressed air, and fine dust of the raised dust enters a boiler hearth under the action of a negative pressure working condition in a shell of the dry slag conveyor. According to the dry slag conveyor, by means of compressed air in the dry slag conveyor shell, the leakproofness of the inner space of the dry slag conveyor shell and the operation environment of the negative pressure working condition, fine ash flying dust enters a hearth through negative pressure as power, the conveying load of the dry slag conveyor is reduced, and ash blowing flying dust cannot cause pollution to the peripheral environment of the dry slag conveyor.

Description

Technical Field

[0001] The present invention relates to an automatic fine ash overload removal device inside a dry slag machine, and particularly to an automatic fine ash overload removal device for the inside of the main body of a dry slag conveyor in a coal-fired power plant. Background Art

[0002] As the main production cost of a coal-fired power plant, coal has a relatively large cost proportion. During periods of tight coal resources or affected by the market conditions of coal types, most coal-fired power plants, when considering factors such as the economy of coal combustion, often do not actually use the designed coal type for the boiler but instead blend it, resulting in a large amount of fine ash actually brought by the bottom ash conveying. Particularly, a large amount of ash accumulation is bound to occur at the bottom of the dry slag conveyor box body and the transition section, which will bring a great load to the operation of the main body of the dry slag conveyor until it overloads and trips. The long-term full-load or overload operation of the dry slag conveyor has a certain impact on the service life of the equipment;

[0003] Currently, the existing technology can only manually remove the fine ash at the bottom of the box body through the maintenance doors on both sides of the dry slag conveyor. After most of the fine ash is manually removed and the operation load of the dry slag conveyor is met, the dry slag conveyor can be started to normally convey materials. The operation and maintenance of the dry ash removal system require a huge investment in manpower and material resources, and the degree of automation is low. At the same time, there are dead corners and blind spots for the fine ash on both sides of the conveying scraper at the bottom of the dry slag conveyor box body, and the cleaning is not thorough; when the dry slag conveyor trips for maintenance, the manual ash removal takes a long time, which has a certain impact on the stable operation of the coal-fired power plant. Summary of the Invention

[0004] Object of the Invention: The object of the present invention is to propose an automatic fine ash overload removal device for the inside of the main body of a dry slag conveyor in a coal-fired power plant, which utilizes the negative pressure operation condition of the dry slag conveyor itself to reduce the fine ash conveying load of the dry slag conveyor and ensure the continuous and stable operation of the dry slag conveyor.

[0005] Technical Solution: The present invention includes a transition section of the dry slag conveyor and a horizontal section of the dry slag conveyor. Both the transition section of the dry slag conveyor and the horizontal section of the dry slag conveyor are connected to instrument air. The transition section of the dry slag conveyor is provided with at least one dust-raising unit, and the horizontal section of the dry slag conveyor is provided with a plurality of dust-raising units. Each dust-raising unit has the same structure. After the plurality of dust-raising units are connected in parallel, they are connected to the compressed air. The accumulated ash on the bottom plate of the dry slag conveyor box body is blown and raised by the compressed air, and the raised fine ash enters the boiler furnace under the action of the negative pressure condition inside the dry slag conveyor shell.

[0006] The negative pressure condition is the negative pressure environment formed by the boiler induced draft fan for the boiler.

[0007] The dust-raising unit includes a plurality of compressed air nozzles arranged at the lower part of the transition section of the dry slag conveyor or the horizontal section of the dry slag conveyor. The plurality of compressed air nozzles located in the transition section of the dry slag conveyor are connected in parallel and then connected to the instrument air.

[0008] Between the compressed air nozzles in the transition section of the dry slag conveyor and the instrument air, a solenoid valve, an oil-water separator, and a stop valve are sequentially arranged in units; the solenoid valve is connected to the compressed air nozzles; the stop valve is connected to the instrument air through a pipeline.

[0009] Multiple compressed air nozzles in the horizontal section of the dry slag conveyor are connected in parallel and then connected to the instrument air.

[0010] Between the compressed air nozzles in the horizontal section of the dry slag conveyor and the instrument air, a solenoid valve, an oil-water separator, and a stop valve are sequentially arranged, wherein the solenoid valve is connected to the compressed air nozzles, and the stop valve is connected to the instrument air through a pipeline.

[0011] The solenoid valve is connected to the DCS centralized control.

[0012] The DCS centralized control is used to monitor the change of the motor current of the dry slag conveyor. According to the rise and fall of the motor current of the dry slag conveyor, the DCS remotely and automatically opens or closes the solenoid valves on the compressed air pipelines of each unit.

[0013] The instrument air is connected in parallel through a pipeline to the transition section and the horizontal section of the dry slag conveyor.

[0014] A gate valve is arranged at the outlet of the instrument air.

[0015] Beneficial effects: The present invention has the following advantages:

[0016] (1) By using compressed air to blow ash and raise dust inside the shell of the dry slag conveyor, and at the same time using the closed space of the shell of the dry slag conveyor and the negative pressure operating environment, the fine ash and dust are drawn into the furnace through negative pressure, reducing the conveying load of the dry slag conveyor, and at the same time, the blowing ash and raising dust will not cause pollution to the surrounding environment of the dry slag conveyor;

[0017] (2) The present invention adopts an innovative combination method of electric control, mechanical equipment, and compressed air to automatically remove the overload of fine ash in the dry slag conveyor in the dry slag removal system;

[0018] (3) Using the motor current of the dry slag conveyor as the judgment basis for whether the fine ash is overloaded; the whole process is automatically controlled. Compared with manual ash removal, the degree of automation is high, the input of manpower and material resources is low, and the cost is greatly reduced. Brief description of the drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 It is a side view of the present invention. Detailed implementation manners

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] As Figure 1 and Figure 2 shown, the fine ash overload automatic removal device for the inside of the dry slag conveyor body of a coal-fired power plant in this embodiment includes instrument air 1, DCS centralized control 2, gate valve 3, solenoid valve 4, oil-water separator 5, stop valve 6, compressed air nozzles 7 and pipeline 8; both the transition section and the horizontal section of the dry slag conveyor are connected to the instrument air 1, and the instrument air 1 is connected in parallel with the transition section and the horizontal section of the dry slag conveyor through the pipeline 8, and a gate valve 3 is arranged at the outlet of the instrument air 1. Among them, at least one dust generation unit is provided in the transition section of the dry slag conveyor, and a plurality of dust generation units are provided in the horizontal section of the dry slag conveyor. Each dust generation unit has the same structure, and after being connected in parallel, the plurality of dust generation units are connected to the compressed air.

[0023] Each dust generation unit includes a plurality of compressed air nozzles 7 arranged at the lower part of the transition section or the horizontal section of the dry slag conveyor. The plurality of compressed air nozzles 7 located in the transition section of the dry slag conveyor are connected in parallel and then connected to the instrument air 1. An electromagnetic valve 4, an oil-water separator 5 and a stop valve 6 are sequentially arranged between the compressed air nozzle 7 and the instrument air 1. The electromagnetic valve 4 is connected to the compressed air nozzle 7, and the stop valve 6 is connected to the instrument air 1 through the pipeline 8; the plurality of compressed air nozzles 7 located in the horizontal section of the dry slag conveyor are also connected in parallel and then connected to the instrument air 1. An electromagnetic valve 4, an oil-water separator 5 and a stop valve 6 are sequentially arranged between the compressed air nozzle 7 and the instrument air 1. Among them, the electromagnetic valve 4 is connected to the compressed air nozzle 7, and the stop valve 6 is connected to the instrument air 1 through the pipeline 8. Each electromagnetic valve 4 is connected to the DCS centralized control 2.

[0024] By monitoring the change of the motor current of the dry slag conveyor through the existing DCS centralized control 2 in the coal-fired power plant, according to the need of the rise and fall of the motor current of the dry slag conveyor, the solenoid valve 4 on the compressed air pipeline of each unit is remotely automatically opened or closed by the program set by the DCS, and then the compressed air in the coal-fired power plant is used to blow and raise the ash accumulated on the bottom plate of the dry slag conveyor box body. The fine ash raised by the dust enters the boiler furnace under the action of the negative pressure working condition inside the dry slag conveyor housing. This negative pressure is the negative pressure environment formed by the boiler induced draft fan for the boiler. The automatic removal of the fine ash reduces the conveying load of the dry slag conveyor, thereby effectively ensuring the continuous and stable operation of the dry slag conveyor.

[0025] The DCS centralized control of a coal-fired power plant monitors the real-time change of the motor current of the dry slag conveyor. Under normal operating conditions of the motor current of the dry slag conveyor, the solenoid valve of the automatic fine ash overload removal device of the dry slag conveyor is not powered on and is in a closed state; when the motor current is 1.2 times higher than the normal operating condition, the DCS program is set to start automatically powering on the solenoid valve of the dust generation unit in the transition section of the dry slag conveyor to open, and then gradually open or close the solenoid valves of each dust generation unit according to the rise and fall of the motor current. A dust generation unit is set every 4 meters in the horizontal section of the dry slag conveyor. The gate valves and globe valves on the gas pipeline are always open. After the solenoid valve on the gas pipeline is opened, compressed air with a pressure of 0.6 to 0.7 Mpa in the coal-fired power plant is used to blow and raise the ash accumulated on the bottom plate of the dry slag conveyor box body of the dry ash removal system. The raised fine ash is sucked into the boiler furnace under the action of the negative pressure condition caused by the connection between the inside of the dry slag conveyor and the boiler furnace, and then is transported to the ash silo together with the boiler flue gas through the electric dust removal and pneumatic ash removal methods for special ash removal in the coal-fired power plant.

[0026] Through the automatic blowing and raising of fine ash by the automatic fine ash overload removal device and combined with the negative pressure condition, automatic control is achieved, a large amount of manpower and material resources for maintenance are reduced, and the degree of automation is high; at the same time, the conveying load of the dry slag conveyor in the dry ash removal system is effectively reduced, overload tripping is avoided, and the continuous and stable operation of the dry slag conveyor is ensured.

Claims

1. An automatic device for removing fine ash overload inside the dry slag conveyor body of a coal-fired power plant, characterized in that: It includes a transition section and a horizontal section of a dry slag conveyor, both of which are connected to compressed air for instruments. The transition section of the dry slag conveyor is provided with at least one dust removal unit, and the horizontal section of the dry slag conveyor is provided with multiple dust removal units, each of which has the same structure. Multiple dust removal units are connected to compressed air after being connected in parallel, and the compressed air is used to blow away the accumulated dust on the bottom plate of the dry slag conveyor box. The fine dust is subjected to the negative pressure condition inside the dry slag conveyor casing and enters the boiler furnace.

2. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 1 is characterized in that: The negative pressure working condition refers to the negative pressure environment formed by the boiler induced draft fan on the boiler.

3. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 1 is characterized in that: The dust raising unit comprises a plurality of compressed air nozzles arranged at the lower part of the transition section of the dry slag conveyor. The plurality of compressed air nozzles located at the transition section of the dry slag conveyor or the horizontal section of the dry slag conveyor are connected to the instrument compressed air after being arranged in parallel.

4. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 3 is characterized in that: A solenoid valve, an oil-water separator and a stop valve are sequentially arranged between the compressed air nozzle of the transition section of the dry slag conveyor and the instrument compressed air; the solenoid valve is connected to the compressed air nozzle; and the stop valve is connected to the instrument compressed air through a pipeline.

5. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 4 is characterized in that: A plurality of compressed air nozzles at the lower part of the horizontal section of the dry slag conveyor are arranged in parallel and connected to the instrument compressed air.

6. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 5 is characterized in that: A solenoid valve, an oil-water separator and a stop valve are sequentially arranged between the compressed air nozzles of the horizontal section and the transition section of the dry slag conveyor and the instrument compressed air, wherein the solenoid valve is connected to the compressed air nozzle, and the stop valve is connected to the instrument compressed air through a pipeline.

7. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 6 is characterized in that: The solenoid valves of the various units are connected to the DCS centralized control.

8. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 7, characterized in that: The DCS centralized control is used to monitor the change of the motor current of the dry slag conveyor. According to the rise and fall of the motor current of the dry slag conveyor, the DCS remotely and automatically opens or closes the solenoid valve on the compressed air pipeline of each unit.

9. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 1, characterized in that: The instrument compressed air is connected in parallel with the transition section of the dry slag conveyor and the horizontal section of the dry slag conveyor through pipelines.

10. The automatic fine ash overload removal device for the interior of the dry slag conveyor body of a coal-fired power plant according to claim 9, characterized in that: The compressed air outlet of the instrument is provided with a gate valve.

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