Coal pulverizing system for flexible blending combustion of boiler fire coal in thermal power plant

Abstract

The utility model discloses a coal pulverizing system for flexible blending combustion of fire coal of a boiler in a thermal power plant, and relates to the technical field of thermal power generation. Comprising a multi-stage layered raw coal bunker assembly, a distributed coal feeder array and a control system. The multi-stage layered raw coal bunker assembly is composed of raw coal bunker layers which are vertically arranged in a layered mode, all the raw coal bunkers are connected with different coal conveying belts through coal falling openings to store coal in a classified mode, and the layers are communicated through conveying pipelines. And the coal feeders in the distributed coal feeder array correspond to the outlet of the lowermost raw coal bunker and are connected with the coal mills. Raw coal is blended according to coal quality analysis and the blending combustion proportion, and through cooperative operation of all the devices, flexible blending combustion of fire coal and efficient and stable operation of the coal pulverizing system are achieved. Compared with the prior art, the system has the advantages that accurate blending combustion and stable coal supply can be realized, the coal grinding efficiency is improved, the automation level is improved, the space utilization is optimized, the coal utilization rate is improved, the cost is reduced, and the service life of equipment is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of thermal power generation technology, specifically a pulverizing system for flexible co-firing of coal in boilers of thermal power plants. Background Technology

[0002] In the global energy structure, thermal power generation plays a crucial role in meeting societal electricity demand as a vital means of electricity supply. Coal, as the primary fuel for thermal power generation, requires efficient utilization and flexible blending for improving its economic, environmental, and energy security benefits. Traditional thermal power plant pulverizing systems typically use a single coal silo, resulting in relatively simple coal storage and transportation methods. This system lacks flexibility when dealing with raw coal of varying qualities. When coal quality changes, and its calorific value, volatile matter, and ash content fluctuate, it is difficult to quickly and effectively adjust the blending ratio, thus affecting boiler combustion efficiency and stability. When burning low-quality coal, the inability to precisely control the blending ratio of different coal types leads to incomplete combustion, increased pollutant emissions, reduced power generation efficiency, and increased power generation costs. With the increasing scarcity of coal resources and the diversification of the coal market, thermal power plants need to be able to blend various types of raw coal to reduce fuel procurement costs and improve the comprehensive utilization rate of coal resources. Meanwhile, in order to meet increasingly stringent environmental protection requirements, thermal power plants need to optimize the combustion process by flexibly blending different types of coal to reduce emissions of pollutants such as sulfur dioxide, nitrogen oxides, and particulate matter.

[0003] While some existing pulverizing systems have been improved to some extent by increasing the number of raw coal silos or adopting simple blending devices, they still have shortcomings in terms of raw coal classification and storage, precise conveying, and intelligent control. The allocation of raw coal between different silos is not flexible enough; the conveying precision of the coal feeder is low, making it difficult to accurately control the amount of raw coal conveyed and the blending ratio; and the control system lacks real-time monitoring and rapid response capabilities for changes in coal quality, thus failing to achieve refined control of the entire pulverizing process.

[0004] Furthermore, problems such as coal blockage and poor conveying exist during the raw coal transportation process. Traditional raw coal bunkers are prone to coal accumulation and bridging, which affects the normal transportation of raw coal, leading to a decrease in the operational stability of the pulverizing system and even requiring frequent shutdowns for cleaning and maintenance, increasing equipment maintenance costs and downtime.

[0005] To overcome the shortcomings of existing technologies and meet the demand for flexible coal blending in thermal power plants, developing a pulverizing system capable of classified storage, precise blending, intelligent control, and stable transportation of raw coal is of significant practical importance. The pulverizing system for flexible coal blending in thermal power plant boilers provided by this invention, through multi-level layered raw coal storage components, a distributed coal feeder array, and an intelligent control system, aims to improve the flexibility, stability, and intelligence of the pulverizing system, thereby achieving efficient utilization of coal resources and sustainable development of thermal power generation. Utility Model Content

[0006] The purpose of this invention is to provide a pulverizing system for flexible co-firing of coal in a thermal power plant boiler. Different types of raw coal are categorized and stored in multi-level, layered raw coal silos via a conveyor belt. The outlet of the lowest raw coal silo is controlled by a gate valve at the inlet of the coal feeder. The coal feeder delivers coal to the coal mill. Simultaneously, the amount of coal in each layer of the raw coal silo is adjusted according to coal quality analysis and blending ratio using conveying pipelines and conveying motors. Blockages and abnormal feedback are prevented by side wall vibrators and flow monitoring devices in the raw coal silos. The coal level is monitored by a level gauge in the coal mill, and the coal feeder is adjusted accordingly. The coal drop angle is adjusted based on coal quality using a coal drop guide device at the outlet of the coal feeder, thereby achieving flexible co-firing of coal and efficient and stable operation of the pulverizing system.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A pulverizing system for flexible co-firing of coal in a thermal power plant boiler is characterized by comprising a multi-level layered raw coal bunker assembly, a distributed coal feeder array, and a control system.

[0009] The multi-level layered raw coal storage assembly consists of multiple layers of raw coal storage arranged vertically. This layered design makes full use of space and facilitates the classification, storage, and management of different types of raw coal.

[0010] Each layer of raw coal storage contains multiple raw coal bins, which are the basic units for storing raw coal. Each raw coal bin has a coal drop outlet at the top, which is connected to different conveyor belts to receive different types of raw coal. The bottom of each raw coal bin has an outlet with a feeder inlet gate valve. The feeder inlet gate valve controls the flow of raw coal from the raw coal bin to the feeder. When raw coal needs to be fed to the feeder, the gate valve is opened; when no feeding is needed, the gate valve is closed. Each layer of raw coal storage in this multi-level, layered raw coal storage assembly is connected by conveying pipelines to achieve the transfer and distribution of raw coal.

[0011] The distributed coal feeder array consists of multiple feeders, each corresponding to the outlet at the bottom of the lowest raw coal bunker. Each feeder is connected to the feed inlet of the coal mill. This one-to-one correspondence allows for precise delivery of raw coal from the lowest coal bunker to the coal mill feed inlet. The feeders play a crucial role in the system, transporting raw coal from storage to grinding, supplying it to the coal mill at a specific speed and flow rate to ensure its normal operation.

[0012] Each raw coal bunker is equipped with a vibrator on its side wall. During the storage and transportation of raw coal, due to the characteristics of raw coal, it may accumulate or become blocked within the bunker. The function of the vibrator is to keep the raw coal in a loose state through periodic vibration, preventing accumulation and blockage, and ensuring that the raw coal can flow smoothly out of the bottom outlet of the bunker.

[0013] A level gauge is installed on the grinding chamber of the coal mill to monitor the coal level in real time. The level gauge is connected to the control system signal. By monitoring the coal level in real time, the amount of raw coal in the coal mill can be understood in a timely manner, avoiding the impact of too much or too little coal on the normal operation of the coal mill.

[0014] A conveying motor is installed in the conveying pipeline. The conveying motor is connected to the control system. The speed of the conveying motor is adjusted according to the results of the actual coal quality analysis module and the ratio set by the blending ratio setting module to realize the allocation of raw coal between different raw coal bins.

[0015] The raw coal bunker is equipped with a flow monitoring device, which is connected to the control system to detect blockages. The flow monitoring device can monitor the flow rate of raw coal from the bottom outlet of the bunker in real time. When a blockage occurs, the flow rate of raw coal will change significantly, and the flow monitoring device will promptly feed this information back to the control system. Upon receiving the signal, the control system will issue an alarm to alert personnel to take action and ensure the normal operation of the raw coal bunker.

[0016] The distributed coal feeder array is equipped with a coal guide device at the feeder outlet. This device guides raw coal into the coal mill at different angles by adjusting the coal dropping angle. The device is connected to the control system, and its angle is adjusted according to the coal quality to optimize the distribution of raw coal entering the grinding unit. Based on coal quality analysis results, adjusting the angle of the coal guide device allows the raw coal to enter the coal mill more evenly, improving the grinding efficiency and effectiveness of the mill.

[0017] Each connecting pipe in the system is equipped with an electric valve, which controls the mixing of different types of raw coal by closing and opening each pipe.

[0018] Different types of raw coal are transported via their respective conveyor belts and enter the various layers of the multi-level, layered raw coal storage assembly through the coal drop inlet for classified storage. When raw coal needs to be transported to the coal mill, the inlet gate valve of the feeder at the bottom outlet of the lowest raw coal silo opens, and the corresponding feeder transports the raw coal to the coal mill inlet. If the coal quantity in the lowest raw coal silo is insufficient, the control system issues commands to adjust the speed of the conveyor motors in the conveying pipes connecting each layer of raw coal silos, based on the results of the actual coal quality analysis module and the proportion set by the blending ratio setting module. This controls the mixing of different types of raw coal through the opening and closing of each pipe, achieving the allocation of raw coal between different layers of raw coal silos and transporting coal from the upper layers to the lower layers. The vibrators on the side walls of the raw coal silos vibrate periodically to prevent raw coal accumulation and blockage. At the same time, the flow monitoring device inside the raw coal silos monitors the raw coal flow in real time, and promptly feeds back to the control system if a blockage is detected. The level gauge on the grinding chamber of the coal mill monitors the coal level in real time and feeds the information back to the control system to adjust the operation of the coal feeder. Furthermore, the coal guide device at the feeder outlet adjusts the coal dropping angle under the command of the control system based on coal quality analysis results, guiding the raw coal into the coal mill at a suitable angle. This optimizes the distribution of raw coal entering the grinding unit, thereby enabling flexible co-firing of coal in the boiler of the thermal power plant and improving the efficiency and stability of the pulverizing system.

[0019] Compared with the prior art, the beneficial effects of this utility model are:

[0020] The multi-level, layered raw coal storage system allows for the categorized storage of different types of raw coal. Each storage bin is connected to a different conveyor belt, enabling precise reception of various coal types. By adjusting the speed of the conveyor motors in the pipelines through the control system, the system can flexibly allocate raw coal from different storage bin layers based on the actual coal quality and set blending ratios. This achieves precise coal blending, improves the comprehensive utilization rate of coal resources, optimizes combustion effects, and reduces power generation costs.

[0021] The vibrators installed on the side walls of the raw coal bunker effectively prevent raw coal from accumulating and clogging, ensuring smooth flow of raw coal. The internal flow monitoring device can detect blockages in real time and provide feedback to the control system so that timely measures can be taken. The combination of these two features ensures a stable supply of raw coal to the bunker, reduces system downtime caused by poor coal supply, and improves the stability and reliability of the pulverizing system.

[0022] The level gauge on the grinding chamber of the coal mill monitors the coal level in real time, providing accurate data for the control system to adjust the coal feeder, ensuring a suitable coal level within the mill and preventing empty grinding or excessive coal from affecting grinding efficiency. Simultaneously, the coal guide device at the feeder outlet adjusts the coal drop angle according to the coal quality, optimizing the distribution of raw coal entering the grinding unit, further improving the grinding efficiency and effect of the coal mill, and extending its service life.

[0023] All key components of the system, such as conveyor motors, vibrators, level gauges, flow monitoring devices, and coal guide devices, are connected to the control system signals, enabling real-time monitoring and intelligent control of the entire pulverizing system's operating status. This reduces manual intervention, lowers the labor intensity of operators, and improves the automation level and management efficiency of the production process.

[0024] The vertically layered arrangement of the multi-level raw coal silo components makes full use of space. Compared with the traditional raw coal silo layout, it can store more types and quantities of raw coal in a limited space. Moreover, the structure is compact and the connections between the parts are reasonable, which facilitates the installation, maintenance and repair of the equipment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a coal pulverizing system for flexible co-firing in a thermal power plant boiler, according to the present invention.

[0026] In the diagram: 11. Raw coal bunker layer; 12. Raw coal bunker; 121. Coal feeder inlet gate valve; 122. Vibrator; 123. Flow monitoring device; 13. Coal conveyor belt; 14. Conveying pipeline; 141. Conveying motor; 21. Coal feeder; 22. Coal drop guide device; 3. Coal mill; 31. Level gauge. Detailed Implementation

[0027] The technical solutions of the present invention will now be described in detail with reference to the accompanying drawings of the embodiments.

[0028] like Figure 1 As shown, a pulverizing system for flexible co-firing of coal in a thermal power plant boiler is characterized by comprising a multi-level layered raw coal bunker assembly, a distributed coal feeder array, and a control system.

[0029] The multi-level layered raw coal bunker assembly consists of multiple raw coal bunker layers 11 arranged vertically. Each raw coal bunker layer contains multiple raw coal bunkers 12. Each raw coal bunker 12 has a coal drop outlet at the top, which is connected to different coal conveyor belts 13 to receive different types of raw coal. The raw coal bunker 12 has an outlet at the bottom, and a coal feeder inlet gate valve 121 is provided at the outlet. Each raw coal bunker layer in the multi-level layered raw coal bunker assembly is connected to each other through a conveying pipe 14.

[0030] The distributed coal feeder array consists of multiple coal feeders 21, each coal feeder 21 corresponding to the outlet at the bottom of the lowest raw coal bunker 12, and the coal feeder 21 is connected to the feed inlet of the coal mill 3.

[0031] Each raw coal bunker 12 has a vibrator 122 installed on its side wall.

[0032] A level gauge 31 is installed on the grinding chamber of the coal mill 3 to monitor the coal level in real time. The level gauge 31 is connected to the control system signal.

[0033] A conveying motor 141 is installed in the conveying pipeline 14. The conveying motor 141 is connected to the control system signal. According to the results of the actual coal quality analysis module and the ratio set by the blending ratio setting module, the speed of the conveying motor 141 is adjusted to realize the allocation of raw coal between different raw coal bunker layers 11.

[0034] The raw coal bunker 12 is equipped with a flow monitoring device 123, which is connected to the control system signal to detect blockage.

[0035] The coal feeder 21 in the distributed coal feeder array is equipped with a coal drop guide device 22 at its outlet end. The coal drop guide device 22 guides the raw coal into the coal mill 3 at different angles by adjusting the coal drop angle. The coal drop guide device 22 is connected to the control system signal and adjusts the angle of the coal drop guide device according to the coal quality to optimize the distribution of raw coal entering the coal milling unit.

[0036] Each connecting pipe in the system is equipped with an electric valve, which controls the mixing of different types of raw coal by closing and opening each pipe.

[0037] Its specific implementation method is as follows:

[0038] Different types of raw coal are transported via their respective conveyor belts 13 and enter the coal hoppers 12 at the top of the multi-level coal hopper assembly for classified storage. When the coal mill 3 needs raw coal, the feeder inlet gate valve 121 at the bottom outlet of the lowest coal hopper 12 opens, and the corresponding feeder 21 transports the raw coal from the lowest coal hopper 12 to the feed inlet of the coal mill 3. If the amount of coal in the lowest coal hopper 12 is insufficient, the control system, based on the results of the actual coal quality analysis module and the ratio set by the blending ratio setting module, opens the feeder inlet gate valve 121 and sends a command to the conveyor motor 141 in the conveying pipeline 14 to adjust its speed, thereby realizing the allocation of raw coal between different coal hopper layers 11 and transporting the coal from the upper coal hopper 12 to the lower layer via the conveying pipeline 14. During the storage and transportation of raw coal, the vibrators 122 on the side walls of the raw coal bunker 12 vibrate periodically to prevent raw coal from accumulating and clogging. Simultaneously, the flow monitoring device 123 inside the raw coal bunker 12 monitors the raw coal flow rate in real time, and sends a signal to the control system if a blockage is detected. The level gauge 31 on the grinding chamber of the coal mill 3 continuously monitors the coal level height in real time and sends the data back to the control system to adjust the operating status of the feeder 21, ensuring a suitable amount of coal in the coal mill 3. Furthermore, the coal guide device 22 at the outlet of the feeder 21 adjusts the coal dropping angle under the command of the control system based on the coal quality analysis results, guiding the raw coal into the coal mill 3 at different angles and optimizing the distribution of raw coal entering the grinding unit.

Claims

1. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler, characterized in that, This includes multi-level, layered raw coal bunker components, distributed coal feeder arrays, and control systems. The multi-level layered raw coal bunker assembly consists of multiple raw coal bunker layers (11) arranged vertically. Each raw coal bunker layer contains multiple raw coal bunkers (12). Each raw coal bunker (12) has a coal drop port at the top, which is connected to different coal conveying belts (13) to receive different types of raw coal. The raw coal bunker (12) has an outlet at the bottom, and a coal feeder inlet gate valve (121) is provided at the outlet. Each raw coal bunker layer in the multi-level layered raw coal bunker assembly is connected to each other through a conveying pipe (14). The distributed coal feeder array consists of multiple coal feeders (21), each coal feeder (21) corresponding to the outlet at the bottom of the lowest raw coal bunker (12), and the coal feeder (21) is connected to the feed inlet of the coal mill (3).

2. The pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, Each raw coal bunker (12) has a vibrator (122) installed on its side wall.

3. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, A level gauge (31) is installed on the grinding chamber of the coal mill (3) to monitor the coal level in real time. The level gauge (31) is connected to the control system signal.

4. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, A conveying motor (141) is installed in the conveying pipeline (14). The conveying motor (141) is connected to the control system signal. The speed of the conveying motor (141) is adjusted according to the results of the actual coal quality analysis module and the ratio set by the blending ratio setting module, so as to realize the allocation of raw coal between different raw coal bunker layers (11).

5. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, The raw coal bunker (12) is equipped with a flow monitoring device (123), which is connected to the control system signal to detect blockage.

6. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, The coal feeder (21) in the distributed coal feeder array is equipped with a coal drop guide device (22) at the outlet end. The coal drop guide device (22) guides the raw coal into the coal mill (3) at different angles by adjusting the coal drop angle. The coal drop guide device (22) is connected to the control system signal and adjusts the angle of the coal drop guide device according to the coal quality to optimize the distribution of raw coal entering the coal mill unit.

7. A pulverizing system for flexible co-firing of coal in a thermal power plant boiler according to claim 1, characterized in that, Each connecting pipe in the system is equipped with an electric valve, which controls the mixing of different types of raw coal by closing and opening each pipe.

Images