Power station boiler coal mill pulverizing system suitable for rapid and large-amplitude peak regulation

Abstract

The utility model relates to the technical field of thermal power generation, in particular to a power station boiler coal mill pulverizing system suitable for rapid and large-amplitude peak regulation, which comprises a coal mill and a pulverized coal feeding mechanism, a third pipeline connected with the output end of the coal mill is connected with a first pipeline, one end of the first pipeline is connected with the input end of a boiler, and the other end of the first pipeline is connected with an air-powder separator. A first gate unit and a second gate unit are arranged on the first pipeline in series, the lower output end of the air-powder separator is connected with the powder feeding mechanism through a pipeline, the upper output end of the air-powder separator is connected with a second pipeline through a pipeline, one end of the second pipeline is connected with the first pipeline, and the other end of the second pipeline is connected with a third pipeline. The powder feeding mechanism is connected with the second pipeline. According to the utility model, the coal mill in the low-load period of the boiler at night is used for pulverizing, the prepared pulverized coal is stored in the pulverized coal bunker, and the pulverized coal in the pulverized coal bunker is reasonably used, so that the full-load operation of the boiler at the peak is realized, and the deep peak regulation of a unit can be carried out.

Description

Technical Field

[0001] The utility model relates to the technical field of thermal power generation, in particular to a coal pulverizing system for a power station boiler suitable for rapid and large-scale peak regulation. Background Art

[0002] Currently, my country's electricity supply primarily consists of traditional thermal power generation and renewable energy sources such as nuclear, solar, and wind power. While the proportion of renewable energy generation has been increasing annually in recent years, the power supply still primarily relies on thermal power. As the energy mix shifts, the proportion of various energy sources in the power grid is constantly fluctuating. On the one hand, the difference between daytime and nighttime peaks and valleys in electricity consumption is increasing. On the other hand, connected solar and wind power generation equipment can be temporarily unavailable due to weather conditions, causing significant fluctuations in grid load. This puts a severe test on the peak-shaving capabilities of the thermal power generators used for load regulation.

[0003] Thermal power generation uses raw coal as a one-time energy source. Its working process is roughly as follows: first, the raw coal is ground into coal powder in a pulverizer, and the coal powder is sent into the boiler together with hot air. It is ignited and burned in the boiler. In the boiler, water is used as a medium to absorb the heat released by the combustion of the coal powder and turn it into high-temperature and high-pressure water vapor. The water vapor is sent to the steam turbine. Inside the steam turbine, the water vapor expands and does work, driving the turbine rotor to rotate. The thermal energy of the water vapor is converted into mechanical energy. The rotor of the steam turbine and the rotor of the generator are connected together. When the steam turbine rotor rotates, it drives the rotor of the generator to rotate, thereby cutting the power line to generate electricity, and the mechanical energy is converted into electrical energy in the generator. This is the energy conversion process of a thermal power plant.

[0004] At present, the main power generating units in China are mainly 600MW and 1000MW single units, and the capacity is getting larger and larger. Usually each unit is equipped with 6 coal mills, and each coal mill outlet has 4 air-powder mixture conveying pipelines, which respectively deliver the air-powder mixture to the 4 corners of the boiler and spray it into the boiler for combustion. At present, the main power generating units in China all use direct-blowing pulverizing systems. The so-called "direct-blowing pulverizing system" means that the pulverized coal will be directly sprayed into the boiler for combustion. The pulverizing amount can be matched with the power generation load at any time, and the amount of pulverized coal required will be determined by the power generation load.

[0005] The load on the power grid fluctuates dramatically throughout the 24-hour day. During the morning rush hour, as various units begin work, electricity consumption rises dramatically, requiring a rapid increase in thermal power generation. At night, when loads decrease, generators must also reduce their loads for deep peak-shaving. Typically, the power grid requires generators to have peak-shaving capabilities of 20% or even less of the rated load, requiring generators to possess deep peak-shaving capabilities. When renewable energy sources like solar and wind power are shut down due to weather or equipment issues, thermal power generators must be able to rapidly increase their loads.

[0006] To this end, the power grid has put forward strict requirements on the rapid increase and decrease of load of the generator sets of each power plant, especially the load-transferring capacity, and rewards power plants that can quickly increase load and operate at full load, and punishes power plants that cannot meet the requirements of rapid load increase and full load operation. Similarly, rewards are given to manufacturers whose units can perform deep peak regulation, and punishes manufacturers that cannot perform deep peak regulation.

[0007] In view of the operating characteristics of thermal power plant units, whether the units can quickly increase or decrease load, whether they can operate at full load, and whether they can deeply regulate peak loads all depend on the pulverizing capacity and operating characteristics of the boiler mill. Existing boilers are difficult to meet the above three requirements. Utility Model Content

[0008] The utility model aims to solve the above-mentioned defects and provide a coal pulverizing system for power station boilers suitable for rapid and large-scale peak regulation.

[0009] In order to overcome the defects existing in the background technology, the technical solution adopted by the utility model to solve its technical problems is: a power plant boiler pulverizing system suitable for rapid and large-scale peak regulation, including a coal feeding mechanism, a coal grinding mill and a powder feeding mechanism, the coal feeding mechanism is connected to the coal grinding mill, and the pipe three connected to the output end of the coal grinding mill is connected to the pipe one, one end of the pipe one is connected to the boiler input end, and the other end is connected to the air-powder separator, and a gate unit one and a gate unit two are arranged in series on the pipe one for respectively restricting coal powder from entering the boiler and the air-powder separator, the lower output end of the air-powder separator is connected to the powder feeding mechanism through a pipeline, and the upper output end is connected to the pipe two through a pipeline, and one end of the pipe two is connected to the pipe one for inputting coal powder into the boiler, and the other end is connected to the pipe three, a gate unit three for conduction and closing is arranged in series on the pipe two, and the powder feeding mechanism is connected to the pipe two.

[0010] A further improvement includes the powder feeding mechanism comprising a pulverized coal bin and a powder feeder connected to the bottom of the pulverized coal bin.

[0011] A further improvement includes the coal delivery mechanism comprising a coal bunker and a coal feeder connected to the bottom of the coal bunker.

[0012] A further improvement includes providing an explosion-proof door on the pulverized coal bin.

[0013] The beneficial effects of the utility model are as follows: this design completely solves the problems existing in the original pulverizing system. It can pulverize coal through the coal mill during the low-load period of the boiler at night, and store the prepared coal powder in the coal powder bin through the added pipeline system. Through the rational use of the coal powder in the coal powder bin, it can achieve full load operation at the peak of the boiler, improve the load opening rate, and perform deep peak regulation of the unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 It is the main view of the utility model;

[0016] In the figure, 1-coal feeder, 2-coal silo, 3-boiler, 4-pipeline 1, 5-gate unit 1, 6-gate unit 2, 7-air-powder separator, 8-explosion-proof door, 9-pipeline 3, 10-pulverized coal silo, 11-pulverized coal feeder, 12-gate unit 3, 13-pipeline 2, 14-pulverizer. DETAILED DESCRIPTION

[0017] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of them. The embodiments of the basic utility model and all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present utility model.

[0018] according to Figure 1 As shown, a power plant boiler coal pulverizing system suitable for rapid and large-scale peak regulation includes a coal feeding mechanism, a coal pulverizer 14, and a pulverizing mechanism. The coal feeding mechanism is connected to the coal pulverizer 14 for conveying coal into the coal pulverizer 14. A pipe 3 9 connected to the output end of the coal pulverizer 14 is connected to the pipe 1 4 so as to convey pulverized coal to the coal pulverizer 14 through the hot gas input into the coal pulverizer 14. One end of the pipe 1 4 is connected to the input end of the boiler 3 and the other end is connected to the air-powder separator 7. A gate unit is provided in series on the pipe 1 4 to respectively restrict the pulverized coal from entering the boiler 3 and the air-powder separator 7. Element 1 5 and gate unit 2 6, the lower output end of the air-powder separator 7 is connected to the powder feeding mechanism through a pipeline for feeding part of the coal powder collected during the transportation process into the powder feeding mechanism, and the upper output end is connected to pipeline 2 13 through a pipeline, and one end of the pipeline 2 13 is connected to the pipeline 1 4 for inputting the coal powder into the boiler 3, and the other end is connected to the pipeline 3 9 for receiving the coal powder generated by the pulverizer 14. A gate unit 3 12 for conduction and closing is arranged in series on the pipeline 2 13, and the powder feeding mechanism is connected to the pipeline 2 13 for supplying coal powder into the pipeline 2 13.

[0019] The powder feeding mechanism includes a pulverized coal bin 10 and a powder feeder 11 connected to the bottom of the pulverized coal bin 10. The powder feeder 11 transports the pulverized coal falling into the pulverized coal bin 10 and then transports it into the pipeline 2 13. The pulverized coal bin 10 receives the pulverized coal collected by the air-powder separator 7.

[0020] The coal feeding mechanism includes a coal silo 2 and a coal feeder 1 connected to the bottom of the coal silo 2. After coal is added to the coal silo 2, the coal feeder 1 inputs the coal into the pulverizer 14 for crushing. The crushed coal powder is pneumatically conveyed by the hot air conveyed into the pulverizer 14, and the air containing the coal powder is conveyed through the pipeline 3 9.

[0021] The pulverized coal bin 10 is provided with an explosion-proof door 8, which serves to relieve pressure, thereby ensuring personnel safety, protecting production equipment, and ensuring subsequent continuous production.

[0022] Working principle:

[0023] 1. Operation mode of nighttime flour production and storage

[0024] The coal mill 14 is operating normally to pulverize coal. Gate unit 1 5 and gate unit 3 12 are closed, and gate unit 2 6 is opened. The air-powder mixture output from the coal mill 14 enters the air-powder separator 7. In the air-powder separator 7, most of the pulverized coal adheres to the separator's inner wall due to centrifugal separation and falls into the lower pulverized coal bin 10. The hot air, carrying some of the pulverized coal, flows out of the outlet pipe above the air-powder separator 7 through pipeline 2 13 and into the boiler 3 for combustion. For safety reasons, an explosion-proof door 8 is installed on the pulverized coal bin 10.

[0025] 2. Operation mode under normal load

[0026] The coal mill 14 is working normally to produce pulverized coal. The gate unit 2 6 and the gate unit 3 12 are closed, and the gate unit 1 5 is opened. The produced pulverized coal is directly input into the boiler 3 through the pipeline 3 9 and the pipeline 1 4.

[0027] 3. Daytime peak and full load operation mode

[0028] During peak hours and full-load operation during the day, a large amount of pulverized coal is required. Normal pulverizing output alone cannot meet the requirement, and the pulverized coal in the pulverized coal bin 10 must be used simultaneously. The operating mode is as follows: the pulverizer 14 operates normally, gate unit 1 5 and gate unit 2 6 are closed, gate unit 3 12 is opened, and the pulverizer feeder 11 is turned on at the same time. The pulverized coal fed into the pipe 2 13 by the pulverizer feeder 11 is mixed with the air pulverized coal at the outlet of the pulverizer 14, thereby increasing the concentration of the pulverized coal entering the boiler 3, which is conducive to quickly increasing the load and ensuring that the unit is fully loaded.

[0029] 4. Operation mode of the unit during deep peak regulation at night

[0030] To ensure the reliability and stability of deep peak shaving, during deep peak shaving, coal mill 14 only ventilates without pulverizing coal. All pulverized coal from the pulverized coal bin 10 is fed into boiler 3 for combustion. The operating mode is as follows: Coal mill 14 ventilates normally, coal feeder 1 stops, gate units 1 5 and 2 6 are closed, gate unit 3 12 is opened, and pulverized coal feeder 11 is turned on. Feeder 11 feeds pulverized coal from the pulverized coal bin 10 into pipeline 2 13, where it is directly transported by the hot air entering coal mill 14.

[0031] It can be seen that the new boiler pulverizing system completely solves the shortcomings of the original pulverizing system. At the same time, it also cleverly utilizes the peak and valley electricity at night to produce pulverized coal, which can save a lot of electricity during the day. The coal mill and fan are both energy-intensive equipment. The electricity generated during the day can be connected to the grid as much as possible, which has a good energy-saving effect.

[0032] There are 4 air-powder mixing pipes at the outlet of each coal mill. Obviously, the 4 air-powder mixing pipes can be set up as a common system separately, or the 4 pipes can share the air-powder separator 7 and the coal powder bin 10. The setting can be carried out according to the on-site layout conditions. There are 6 coal mills in the boiler, so not every coal mill needs to be equipped with this system. It can be selected according to the actual situation of each factory.

[0033] The above is only a preferred specific implementation method of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the present invention can make equivalent replacements or changes based on the technical solution and utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A coal pulverizing system for power station boilers suitable for rapid and large-scale peak regulation, characterized by: The invention comprises a coal feeding mechanism, a coal mill (14) and a powder feeding mechanism, wherein the coal feeding mechanism is connected to the coal mill (14), a pipe three (9) connected to the output end of the coal mill (14) is connected to the pipe one (4), one end of the pipe one (4) is connected to the input end of the boiler (3), and the other end is connected to the air-powder separator (7), a gate unit one (5) and a gate unit two (6) are arranged in series on the pipe one (4) for respectively restricting the coal powder from entering the boiler (3) and the air-powder separator (7), the lower output end of the air-powder separator (7) is connected to the powder feeding mechanism through a pipeline, and the upper output end is connected to the pipe two (13) through a pipeline, and the pipe two (13) has one end connected to the pipe one (4) for inputting the coal powder into the boiler (3) and the other end connected to the pipe three (9), a gate unit three (12) for conducting and closing is arranged in series on the pipe two (13), and the powder feeding mechanism is connected to the pipe two (13).

2. A power plant boiler coal pulverizing system suitable for rapid and large-scale peak regulation according to claim 1, characterized in that: The pulverized coal feeding mechanism comprises a pulverized coal bin (10) and a pulverized coal feeder (11) connected to the lower side of the pulverized coal bin (10).

3. The power plant boiler coal pulverizing system suitable for rapid and large-scale peak regulation according to claim 1, characterized in that: The coal delivery mechanism comprises a coal bunker (2) and a coal feeder (1) connected to the lower side of the coal bunker (2).

4. The power plant boiler coal pulverizing system suitable for rapid and large-scale peak regulation according to claim 2, characterized in that: The pulverized coal bin (10) is provided with an explosion-proof door (8).

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