Directly blowing pulverizing, middle storage pulverizing and coal conveying multi-state coupling system

Abstract

The utility model provides a kind of direct blowing pulverizing, middle storage pulverizing and coal conveying multi-state coupling system, it is related to the technical field of boiler pulverizing system of thermal power generating unit, it includes: direct blowing pulverizing unit includes direct blowing coal pulverizer and hearth, direct blowing coal pulverizer is accessed hearth;Middle storage pulverizing unit includes middle storage coal pulverizer, intermediate powder bin and powder discharger, middle storage coal pulverizer is connected with intermediate powder bin entrance, and intermediate powder bin export is burned by powder discharger and is sent to hearth;Conventional coal conveying unit includes coal conveying belt, and coal conveying belt supplies coal to direct blowing coal pulverizer;Emergency coal conveying unit includes emergency coal trench and emergency coal trench coal belt, and emergency coal trench coal belt supplies spare coal in emergency coal trench to middle storage coal pulverizer and direct blowing coal pulverizer.The above-mentioned system realizes the flexible regulation and stable supply of pulverized coal production, flexibly switches operating mode, improves the depth peak shaving capability, combustion stability and operating reliability of thermal power generating unit, while reducing equipment wear and maintenance cost.

Description

Technical Field

[0001] This utility model relates to the technical field of boiler pulverizing systems for thermal power units, and in particular to a multi-mode coupling system for direct-fired pulverizing, intermediate storage pulverizing, and coal conveying. Background Technology

[0002] As the proportion of new energy power generation in the power system continues to increase, grid load fluctuations are becoming increasingly severe. Thermal power units have gradually transformed from traditional base load power sources to peak-shaving power sources, frequently participating in deep peak shaving, rapid start-up and shutdown, and variable load operation. Against this backdrop, traditional pure direct-fired pulverizing systems have technical shortcomings, which seriously restrict the peak-shaving capacity, operational safety, and economy of the units.

[0003] In existing technologies, the pulverized coal production and combustion process of direct-fired pulverizing systems is a "real-time pulverization and real-time combustion" mode, lacking an intermediate buffer. When the power grid load fluctuates significantly, the output of pulverized coal must be adjusted by frequently starting and stopping the coal mill, leading to increased mechanical wear and failure rate of the equipment. At the same time, the supply of pulverized coal is delayed and unstable, affecting the continuity of boiler combustion and thermal efficiency, and easily causing combustion fluctuations or even the risk of fire extinguishing. In addition, considering that direct-fired pulverizing systems cannot store pulverized coal in advance, it is difficult to achieve a smooth transition and precise control of coal quality, resulting in large fluctuations in main steam pressure and slow combustion response, making it difficult to meet the requirements of rapid frequency regulation and peak shaving of the power grid.

[0004] Therefore, a pulverizing system that can improve regulation margin, disturbance rejection capability and operational resilience, and enable thermal power units to operate safely, cleanly, efficiently and flexibly under complex operating conditions is urgently needed for research. Utility Model Content

[0005] To address the shortcomings of the existing technologies, this utility model provides a multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying. This system solves the technical problems of poor combustion safety, inability to control coal quality, and difficulty in meeting the requirements of rapid frequency regulation and peak shaving of the power grid in the existing single direct-fired pulverization system.

[0006] This utility model provides a multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying, including:

[0007] A direct-fired pulverizing unit includes a direct-fired coal mill and a furnace. The direct-fired coal mill is connected to the furnace through a first outlet pipe and is used to grind coal into pulverized coal and then transport it to the furnace for combustion.

[0008] The intermediate storage pulverizing unit includes an intermediate storage coal mill, an intermediate pulverizing silo, and a pulverizer. The intermediate storage coal mill is connected to the inlet of the intermediate pulverizing silo through a pulverizer conveying pipe, and the outlet of the intermediate pulverizing silo is connected to the pulverizer. The pulverizer is connected to the first outlet pipe through a second outlet pipe. The intermediate pulverizing silo is used to store the pulverized coal prepared by the intermediate storage coal mill, and the pulverizer is used to transport the pulverized coal in the intermediate pulverizing silo to the furnace for combustion.

[0009] A conventional coal conveying unit includes a coal conveyor belt, which is connected to the direct-fired pulverizing unit and is used to supply coal to the direct-fired coal mill.

[0010] An emergency coal conveying unit includes an emergency coal ditch and an emergency coal ditch conveyor belt. The first end of the emergency coal ditch conveyor belt is connected to the emergency coal ditch, and the second end of the emergency coal ditch conveyor belt is connected to the intermediate storage pulverizing unit and the direct-fired coal pulverizing unit, respectively. The emergency coal ditch conveyor belt is used to supply the spare coal in the emergency coal ditch to the intermediate storage pulverizer and the direct-fired pulverizer.

[0011] Optionally, the intermediate storage pulverizing unit further includes an emergency coal bunker; the inlet of the emergency coal bunker is connected to the second end of the coal conveyor belt of the emergency coal ditch, and the outlet of the emergency coal bunker is connected to the intermediate storage pulverizer; the emergency coal bunker is used to store the spare coal supplied by the emergency coal ditch.

[0012] Optionally, the direct-fired pulverizing unit includes a coal storage bin and a coal feeder; the inlet of the coal storage bin is connected to the coal conveyor belt, and the coal storage bin is connected to the direct-fired pulverizer via the coal feeder, which is used to transport the coal received by the coal storage bin to the direct-fired pulverizer.

[0013] Optionally, the coal storage silo may be equipped with multiple independent coal distribution silos.

[0014] Optionally, the emergency coal conveying unit further includes an emergency coal conveying belt, the first end of which is connected to the second end of the emergency coal ditch conveyor belt, and the second end of which is connected to the inlet of the coal storage bin.

[0015] Optionally, a coal flow interconnection device is provided at the intersection of the emergency coal conveyor belt and the coal conveyor belt, and the coal flow interconnection device is used to control the coal flow direction of the emergency coal conveyor belt and the coal conveyor belt.

[0016] Optionally, a first gate valve is provided on the first outlet pipe, and a second gate valve is provided on the second outlet pipe, wherein the first gate valve and the second gate valve are interlocked.

[0017] Optionally, the furnace is provided with multiple burners; when the multiple burners are located at the four corners of the furnace, the furnace is configured as a tangential combustion mode; when the multiple burners are located on two opposite side walls of the furnace, the furnace is configured as a counter-current combustion mode.

[0018] Optionally, the system further includes a PLC control unit, which includes a material level control module, a flow control module, and a safety protection module. The material level control module is connected to both the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, and is used to monitor the real-time material level of the coal bunker and / or powder silo in the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, and adjust the working status of the direct-fired pulverizing unit and the intermediate-storage pulverizing unit based on the real-time material level. The flow control module is connected to a flow sensor on the second outlet pipe, and is used to monitor the real-time flow rate of the coal powder output by the pulverizer, and adjust the rotation speed of the pulverizer based on the real-time flow rate. The safety protection module is connected to both the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, and is used to monitor the operating parameters of the direct-fired pulverizing unit and the intermediate-storage pulverizing unit in real time, and to issue an alarm when the operating parameters are abnormal.

[0019] Optionally, the system further includes a remote control unit; the remote control unit is connected to the PLC control unit, and the PLC control unit is connected to the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit respectively. The remote control unit controls the working status of the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit through the PLC control unit.

[0020] This utility model provides a multi-mode coupling system for direct-fired pulverization, intermediate-storage pulverization, and coal conveying. By introducing an intermediate-storage pulverization unit, it achieves pre-preparation and phased storage of pulverized coal. In the event of unit start-up and shutdown, deep peak shaving, failure of the original pulverization system, or abnormality of environmental protection equipment, the system can ensure combustion safety and normal environmental parameters through targeted coal blending. Specifically, it continuously and stably supplies pulverized coal from the intermediate pulverized coal silo through a pulverizer, avoiding combustion interruption, achieving a smooth transition and precise control of pulverized coal supply, effectively suppressing combustion disturbances, improving boiler combustion stability and thermal efficiency, and significantly improving system adjustment margin and response speed. The system can flexibly switch between direct-fired pulverization, intermediate-storage pulverization, and mixed pulverization to meet the rapid load change requirements of power grid frequency regulation and peak shaving, with faster response and more precise adjustment. An emergency coal conveying unit is set up to simultaneously transport spare coal to the intermediate-storage pulverizer and the direct-fired pulverizer, realizing dual-path coal supply and switching between multiple coal supply modes, improving the system's operational resilience and anti-interference capability under abnormal conditions such as coal quality deterioration and belt failure. The aforementioned system enables flexible adjustment and stable supply of pulverized coal production, and can flexibly switch operating modes under different load conditions, significantly improving the deep peak-shaving capability, combustion stability and operational reliability of thermal power units, while reducing equipment wear and maintenance costs.

[0021] Other features and advantages of this invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of this invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0022] The technical solution of this utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0024] Figure 1 A schematic diagram of the overall structure of a multi-mode coupled system for direct-fired pulverization, intermediate storage pulverization, and coal conveying in one embodiment provided in this application;

[0025] Figure 2 A schematic diagram of the specific structure of a multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying in one embodiment provided in this application.

[0026] In the picture:

[0027] 1. Direct-fired coal mill; 2. Furnace; 3. First outlet pipe; 4. Intermediate storage coal mill; 5. Intermediate pulverized coal silo; 6. Pulverizer; 7. Intermediate pulverized coal silo conveying pipe; 8. Second outlet pipe; 9. Coal conveyor belt; 10. Emergency coal ditch; 11. Emergency coal ditch coal conveyor belt; 12. Emergency coal bunker; 13. Coal storage bunker; 14. Coal feeder; 15. Emergency coal conveyor belt; 16. First slide gate valve; 17. Second slide gate valve. Detailed Implementation

[0028] The present application will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present application can be combined with each other.

[0029] In one embodiment, such as Figure 1 and Figure 2 As shown, a multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying is provided. It includes a direct-fired pulverization unit comprising a direct-fired coal mill 1 and a furnace 2. The direct-fired coal mill 1 is connected to the furnace 2 via a first outlet pipe 3 to pulverize coal and then convey it to the furnace 2 for combustion. The intermediate storage pulverization unit includes an intermediate storage coal mill 4, an intermediate pulverizer 5, and a pulverizer 6. The intermediate storage coal mill 4 is connected to the inlet of the intermediate pulverizer 5 via an intermediate pulverizer conveying pipe 7. The outlet of the intermediate pulverizer 5 is connected to the pulverizer 6. The pulverizer 6 is connected to the first outlet pipe 3 via a second outlet pipe 8. The intermediate pulverizer 5 is used to store the pulverized coal produced by the intermediate storage coal mill 4. The coal powder is prepared and discharged by the pulverizer 6, which is used to transport the coal powder in the intermediate coal silo 5 to the furnace 2 for combustion. The conventional coal conveying unit includes a coal conveying belt 9, which is connected to the direct-fired pulverizing unit and is used to supply coal to the direct-fired pulverizer 1. The emergency coal conveying unit includes an emergency coal trough 10 and an emergency coal trough feeding belt 11. The first end of the emergency coal trough feeding belt 11 is connected to the emergency coal trough 10, and the second end of the emergency coal trough feeding belt 11 is connected to the intermediate storage pulverizing unit and the direct-fired pulverizing unit, respectively. The emergency coal trough feeding belt 11 is used to supply the reserve coal in the emergency coal trough 10 to the intermediate storage pulverizer 4 and the direct-fired pulverizer 1.

[0030] The multi-mode coupling system of direct-fired pulverization, intermediate storage pulverization, and coal conveying provided in this embodiment achieves pre-preparation and phased storage of pulverized coal by introducing an intermediate storage pulverization unit. In the event of start-up, shutdown, deep peak shaving, failure of the original pulverization system, or abnormality of environmental protection equipment, the system can ensure combustion safety and normal environmental parameters through targeted coal blending. Specifically, the pulverizer 6 continuously and stably supplies pulverized coal from the intermediate pulverizer 5, avoiding combustion interruption, achieving a smooth transition and precise control of pulverized coal supply, effectively suppressing combustion disturbances, improving boiler combustion stability and thermal efficiency, and significantly improving system adjustment margin and response speed. The system can flexibly switch between direct-fired pulverization, intermediate storage pulverization, and mixed pulverization to meet the rapid load change requirements of power grid frequency regulation and peak shaving, with faster response and more precise adjustment. An emergency coal conveying unit is set up to simultaneously transport spare coal to the intermediate storage pulverizer 4 and the direct-fired pulverizer 1, realizing dual-path coal supply and switching between multiple coal supply modes, improving the system's operational resilience and anti-interference ability under abnormal conditions such as coal quality deterioration and belt failure. The aforementioned system enables flexible adjustment and stable supply of pulverized coal production, and can flexibly switch operating modes under different load conditions, significantly improving the deep peak-shaving capability, combustion stability and operational reliability of thermal power units, while reducing equipment wear and maintenance costs.

[0031] Specifically, this application combines direct-fired pulverization and intermediate-storage pulverization methods, and adds an emergency coal supply function, making the thermal power unit more flexible and safer to operate under conditions of large grid load fluctuations. Coal is directly fed to the direct-fired pulverizer 1 for grinding and then blown into the furnace 2 for combustion through the first outlet pipe 3. This serves as the main operating mode of the unit under normal load, offering high efficiency and a short process. Simultaneously, the intermediate-storage pulverizer 4 grinds reserve coal and pre-stores it in the intermediate pulverizer 5. This reserve coal is then used for peak shaving, load reduction, or when the main system is unstable. When the coal powder in the intermediate coal silo 5 is blown into the furnace 2 by the pulverizer 6, the boiler combustion is more stable and the peak-shaving capacity is stronger when the direct-fired coal mill 1 stops working. Conventional coal conveying: The conventional coal conveying unit delivers coal to the direct-fired coal mill 1 through the coal conveying belt 9 to ensure the coal supply for daily operation. The emergency coal conveying unit is equipped with an emergency coal ditch 10. Through an emergency coal feeding belt, spare coal can be delivered to the intermediate storage coal mill 4 or the direct-fired coal mill 1. When the coal conveying belt 9 fails, emergency coal can be used to continue operation to prevent shutdown.

[0032] In one embodiment, such as Figure 2 As shown, the medium-storage pulverizing unit also includes an emergency coal bunker 12; the inlet of the emergency coal bunker 12 is connected to the second end of the coal conveyor belt 11 of the emergency coal ditch, and the outlet of the emergency coal bunker 12 is connected to the medium-storage coal mill 4. The emergency coal bunker 12 is used to store the spare coal supplied by the emergency coal ditch 10.

[0033] Specifically, the emergency coal ditch 10 is an emergency backup coal source area for storing emergency coal; the emergency coal ditch conveyor belt 11 is a special conveyor device for transporting coal out of the emergency coal ditch 10; the emergency coal bunker 12 is connected to the end of the emergency coal ditch conveyor belt 11 and is used to temporarily store the backup coal transported from the emergency coal ditch 10. The outlet of the emergency coal bunker 12 is connected to the central storage coal mill 4 to grind the coal into powder, and finally the powder is sent into the furnace 2 for combustion through the pulverizer 6.

[0034] In this embodiment, the addition of the emergency coal bunker 12 allows for the storage of emergency coal before it is fed into the medium-storage coal mill 4 as needed. This avoids combustion interruptions caused by temporary transportation fluctuations, allows for the rapid activation of the backup pulverizing process, shortens response time, and improves system response speed and operational continuity. Furthermore, considering that emergency coal often comes from different coal sources and its quality may differ from that of the main coal, the emergency coal bunker 12 allows for the early delivery of emergency coal into the system for gradual blending, preventing combustion instability, coking, or excessive emissions caused by sudden changes in coal quality.

[0035] In one embodiment, such as Figure 2 As shown, the direct-fired pulverizing unit includes a coal storage bin 13 and a coal feeder 14; the inlet of the coal storage bin 13 is connected to the coal conveyor belt 9, and the coal storage bin 13 is connected to the direct-fired pulverizer 1 through the coal feeder 14. The coal feeder 14 is used to transport the coal received by the coal storage bin 13 to the direct-fired pulverizer 1.

[0036] Specifically, the coal storage silo 13, as a temporary container for storing raw coal, is located in front of the coal mill and is used for coal storage and buffering. The coal conveyor belt 9 transports the raw coal from the main coal conveying system of the power plant to the coal storage silo 13. The coal feeder 14 is installed below the coal storage silo 13 to control the flow of coal out of the silo and to quantitatively and evenly transport it to the direct-fired coal mill 1.

[0037] In this embodiment, the coal storage bin 13 serves as a buffer pool, which can prevent instantaneous coal shortages caused by coal breakage, blockage, or start-up / stop of the upstream coal conveyor belt 9, and continuously supply coal to the coal mill to prevent boiler combustion fluctuations or flameout. The coal feeder 14 can precisely control the amount of coal and automatically adjust according to the boiler load to achieve on-demand coal supply. The coal feeder 14 can achieve smooth start-up and flow control to prevent large pieces of coal or large amounts of coal from suddenly entering the coal mill, causing blockage, overload, or vibration. The existence of the coal storage bin 13 provides an access point for subsequent connection to the emergency coal conveying unit, which facilitates a flexible operation mode of multi-source coal supply.

[0038] Furthermore, the coal storage silo 13 is equipped with multiple independent coal distribution silos.

[0039] Specifically, multiple independent coal storage compartments can realize various functions such as separate storage of different coal types, separate backup and operation areas, and isolation for maintenance and unblocking.

[0040] In this embodiment, different coal bins can store coal with different calorific values, volatile matter, or ash content. The coal feeders 14 of each coal bin can be started and stopped proportionally to achieve precise blending and optimize combustion efficiency. When the channel of a certain coal bin is blocked, the coal supply is interrupted, or the coal feeder 14 malfunctions, the coal supply can be immediately switched to other coal bins to avoid the shutdown of the entire pulverizing system due to local failure and improve the availability of the unit. Through bin control, dynamic matching of coal quality and load can be achieved to improve economy. In addition, spare coal can be pre-stored in a certain coal bin. Once the main coal supply is interrupted, the coal supply will automatically switch to the emergency coal bin, with a fast response speed.

[0041] Furthermore, such as Figure 2 As shown, the emergency coal conveying unit also includes an emergency coal conveying belt 15. The first end of the emergency coal conveying belt 15 is connected to the second end of the emergency coal ditch coal conveying belt 11, and the second end of the emergency coal conveying belt 15 is connected to the inlet of the coal storage bin 13.

[0042] In this embodiment, the emergency coal conveyor belt 15 directly connects the spare coal in the emergency coal ditch 10 and the coal storage bin 13 to form a backup coal supply line. When the conventional coal conveyor belt 9 fails, the emergency coal conveyor belt 15 can bypass the faulty section and directly send the emergency coal into the coal storage bin 13, avoiding the unit from reducing load or shutting down due to coal shortage, ensuring combustion continuity, and improving the power plant's operational resilience and safety.

[0043] In one embodiment, an inter-convenience device is provided at the intersection of the emergency coal conveyor belt 15 and the coal conveyor belt 9. The inter-convenience device is used to control the coal flow direction of the emergency coal conveyor belt 15 and the coal conveyor belt 9.

[0044] Specifically, a coal flow interconnection device is installed at the intersection of the emergency coal conveyor belt 15 and the regular coal conveyor belt 9, which can flexibly switch the direction of coal flow and realize multiple working modes. The first is the normal mode, that is, the coal conveyor belt 9 operates normally, coal is transported from the coal conveyor belt 9, and the emergency coal trough coal conveyor belt 11 is on standby. The second is the emergency mode, in which when the coal conveyor belt 9 fails, the emergency coal trough coal conveyor belt 11 is started to send the standby coal into the direct-fired coal mill 1. In addition, it can also be a reverse support mode to supply coal in reverse.

[0045] It should be noted that the coal flow interconnection device can be implemented by using a three-way coal drop pipe in conjunction with an electric flapper. Specifically, the flapper is used to switch the direction of the coal flow, or a movable coal plow is used to push the coal flow laterally and guide it to different conveyor belts. Alternatively, a double-headed guide chute can be used in conjunction with a pneumatic or electric actuator to automatically control the distribution of the coal flow.

[0046] In this embodiment, when the conventional coal conveyor belt 9 fails, the coal flow of the emergency coal conveyor belt 15 can be introduced into the main system through the coal flow interconnection device to maintain unit operation. Conversely, if the emergency system needs to replenish coal, it can also temporarily supply coal in reverse to improve system flexibility. After adding the coal flow interconnection device, a two-way interconnection structure is formed, which enhances the overall system's coordination and resilience. When the main coal conveyor belt 9 needs to be shut down for maintenance, it can be switched to emergency coal supply mode through the coal flow interconnection device to achieve coal source switching without shutting down the machine and ensure continuous unit operation. In addition, if the emergency coal trough 10 contains different types of coal, the emergency coal can be mixed into the main coal flow in proportion using the coal flow interconnection device to achieve controllable co-firing and optimize combustion economy.

[0047] In one embodiment, such as Figure 2 As shown, a first gate valve 16 is installed on the first outlet pipe 3, and a second gate valve 17 is installed on the second outlet pipe 8. The first gate valve 16 and the second gate valve 17 are interlocked with each other.

[0048] In this embodiment, when the direct-fired pulverizing unit stops operating, the first gate valve 16 automatically closes, cutting off the connection with the furnace 2 and preventing high-pressure air or pulverized coal from the pulverizer 6 from flowing back into the coal mill, thus avoiding equipment damage and safety hazards. The interlocking mechanism ensures that only one pulverized coal supply is available at any given time, either from the direct-fired pulverizing unit or the intermediate storage pulverizing unit, avoiding the superposition or uneven distribution of pulverized coal flow and maintaining stable boiler combustion conditions. When the unit switches from normal operation to peak shaving or emergency mode, the control system can automatically close the first gate valve 16 and open the second gate valve 17, thereby closing the direct-fired pulverizing unit and opening the intermediate storage pulverizing unit, achieving seamless switching and improving operational reliability.

[0049] In one embodiment, a plurality of burners are provided inside the furnace 2; when the plurality of burners are located at the four corners of the furnace 2, the furnace 2 is configured as a tangential combustion mode; when the plurality of burners are located on two opposite sidewalls inside the furnace 2, the furnace 2 is configured as a counter-current combustion mode.

[0050] Specifically, there are two main combustion organization forms corresponding to different arrangements of boiler burners in thermal power plants. When the burners are arranged at the four corners of the furnace 2, pulverized coal and air are injected into the furnace 2 at a certain angle. The airflow from each corner forms a rotating flame cylinder in the central area of ​​the furnace 2. The rotating airflow enhances the mixing of pulverized coal and air and promotes combustion. When the burners are arranged on two opposite side walls of the furnace 2, such as the front and rear walls or the left and right walls, the pulverized coal airflow is injected from both sides and burns in a counter-current manner in the central area of ​​the furnace 2. The flame path is longer and it is suitable for burning difficult-to-burn coal types.

[0051] In this embodiment, the four-corner tangent combustion is suitable for burning high-volatile bituminous coal, with stable combustion and mature technology; the offset combustion is suitable for burning low-volatile and difficult-to-burn coal, with good burnout. The system provided by this application is compatible with the two mainstream combustion methods, applicable to the transformation and application of different types of units, optimizes combustion organization, improves combustion efficiency, supports flexible operation and deep peak shaving, and provides a matching basis for multi-mode coupled pulverizing systems.

[0052] In one embodiment, the system further includes a PLC control unit, which includes a level control module, a flow control module, and a safety protection module. The level control module is connected to the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, respectively, and is used to monitor the real-time level of the coal bunker and / or powder silo in the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, and adjust the working status of the direct-fired pulverizing unit and the intermediate-storage pulverizing unit based on the real-time level. The flow control module is connected to a flow sensor on the second outlet pipe 8, and is used to monitor the real-time flow rate of the coal powder output by the pulverizer 6, and adjust the rotation speed of the pulverizer 6 based on the real-time flow rate. The safety protection module is connected to the direct-fired pulverizing unit and the intermediate-storage pulverizing unit, respectively, and is used to monitor the operating parameters of the direct-fired pulverizing unit and the intermediate-storage pulverizing unit in real time, and to alarm when the operating parameters are abnormal.

[0053] In this embodiment, the PLC control unit is equipped with multiple functional modules, specifically including a material level control module, a flow control module, and a safety protection module. The material level control module utilizes material level sensors installed in each coal bunker and / or powder silo in the direct-fired pulverizing unit and the intermediate storage pulverizing unit to monitor the coal powder level in the coal and powder silos in real time. Based on the material level changes, the PLC control unit automatically adjusts the operating status of the direct-fired pulverizer 1 and the pulverizer 6 to ensure that the coal powder level in the powder silos remains within a reasonable range, avoiding overfilling or emptying of the coal and powder silos, and ensuring continuous and stable coal powder supply. A flow sensor is installed on the second outlet pipe 8 connected to the pulverizer 6 to monitor the coal powder flow rate in real time, and then adjusts the flow rate according to the unit load. The PLC control unit automatically adjusts the speed of the pulverizer 6 to control the flow rate of pulverized coal, ensuring that the pulverized coal supply matches the unit load, maintaining stable combustion of the burner, and improving unit efficiency. Specifically, the safety protection module can be used for pulverized coal silo temperature monitoring to prevent accidents caused by high temperatures. It can also monitor pulverized coal concentration to prevent excessive concentration from causing explosion risks. Explosion-proof doors can be installed to automatically open in emergencies to release pressure and prevent explosions. Furthermore, it can handle abnormal situations; when the system malfunctions, it can promptly issue alarm signals and take corresponding protective measures, such as emergency shutdown and power cut-off, to ensure the safe operation of the system.

[0054] In one embodiment, the system further includes a remote control unit; the remote control unit is connected to a PLC control unit, which is connected to the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit respectively; the remote control unit controls the working status of the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit through the PLC control unit.

[0055] In this embodiment, the remote control unit can achieve programmed start-up and shutdown of the intermediate pulverizing unit and the coal conveyor belt 9, while completing related protection interlocks, including belt tear protection to detect belt tears and prevent material leakage; coal blockage protection to detect coal blockage and prevent equipment damage; and pull rope protection, which allows operators to stop equipment operation by pulling a rope in emergencies to ensure the safety, reliability, and efficiency of the coal conveying process. A PLC control unit is used, which, through integration with the unit's DCS (Distributed Control System), achieves coordinated control of the intermediate pulverizing silo 5 and the overall unit operation. Real-time data interaction between the PLC control unit and the DCS system allows for the sharing of key parameters such as material level, flow rate, and temperature, ensuring collaborative work between subsystems. Operators can also monitor the operating status of each device in real time through the DCS system interface, enabling remote operation and fault diagnosis.

[0056] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0057] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying, characterized in that, include: The direct-fired pulverizing unit includes a direct-fired coal mill (1) and a furnace (2). The direct-fired coal mill (1) is connected to the furnace (2) through a first outlet pipe (3) and is used to grind coal into pulverized coal and then transport it to the furnace (2) for combustion. The intermediate storage pulverizing unit includes an intermediate storage coal mill (4), an intermediate pulverizing silo (5), and a pulverizer (6). The intermediate storage coal mill (4) is connected to the inlet of the intermediate pulverizing silo (5) through an intermediate pulverizing silo conveying pipe (7). The outlet of the intermediate pulverizing silo (5) is connected to the pulverizer (6). The pulverizer (6) is connected to the first outlet pipe (3) through a second outlet pipe (8). The intermediate pulverizing silo (5) is used to store the coal powder prepared by the intermediate storage coal mill (4). The pulverizer (6) is used to transport the coal powder in the intermediate pulverizing silo (5) to the furnace (2) for combustion. A conventional coal conveying unit includes a coal conveying belt (9), which is connected to the direct-fired pulverizing unit and is used to supply coal to the direct-fired coal mill (1). An emergency coal conveying unit includes an emergency coal ditch (10) and an emergency coal ditch conveyor belt (11). The first end of the emergency coal ditch conveyor belt (11) is connected to the emergency coal ditch (10), and the second end of the emergency coal ditch conveyor belt (11) is connected to the intermediate storage pulverizing unit and the direct-fired pulverizing unit, respectively. The emergency coal ditch conveyor belt (11) is used to supply the spare coal in the emergency coal ditch (10) to the intermediate storage pulverizer (4) and the direct-fired pulverizer (1).

2. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 1, characterized in that, The medium-sized coal pulverizing unit also includes an emergency coal bunker (12); The inlet of the emergency coal bunker (12) is connected to the second end of the coal conveyor belt (11) of the emergency coal ditch, and the outlet of the emergency coal bunker (12) is connected to the medium storage coal mill (4). The emergency coal bunker (12) is used to store the spare coal supplied by the emergency coal ditch (10).

3. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 1, characterized in that, The direct-fired pulverizing unit includes a coal storage bin (13) and a coal feeder (14); The inlet of the coal storage bin (13) is connected to the coal conveyor belt (9), and the coal storage bin (13) is connected to the direct-fired coal mill (1) through the coal feeder (14). The coal feeder (14) is used to transport the coal received by the coal storage bin (13) to the direct-fired coal mill (1).

4. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 3, characterized in that, The coal storage silo (13) is equipped with multiple independent coal distribution silos.

5. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 3, characterized in that, The emergency coal conveying unit also includes an emergency coal conveying belt (15), the first end of which is connected to the second end of the emergency coal ditch coal conveying belt (11), and the second end of which is connected to the inlet of the coal storage bin (13).

6. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 5, characterized in that, A coal flow interconnection device is provided at the intersection of the emergency coal conveyor belt (15) and the coal conveyor belt (9). The coal flow interconnection device is used to control the coal flow direction of the emergency coal conveyor belt (15) and the coal conveyor belt (9).

7. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 1, characterized in that, A first gate valve (16) is provided on the first outlet pipe (3), and a second gate valve (17) is provided on the second outlet pipe (8). The first gate valve (16) and the second gate valve (17) are mutually interlocked.

8. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 1, characterized in that, The furnace (2) is equipped with multiple burners; When multiple burners are arranged at the four corners of the furnace (2), the furnace (2) is configured as a combustion mode with tangential circles at the four corners; When multiple burners are disposed on two opposite sidewalls within the furnace (2), the furnace (2) is configured for a counter-current combustion mode.

9. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 1, characterized in that, The system also includes a PLC control unit, which includes a material level control module, a flow control module, and a safety protection module; The material level control module is connected to the direct-fired pulverizing unit and the intermediate storage pulverizing unit respectively, and is used to monitor the real-time material level of the coal bunker and / or powder silo in the direct-fired pulverizing unit and the intermediate storage pulverizing unit, and adjust the working status of the direct-fired pulverizing unit and the intermediate storage pulverizing unit based on the real-time material level. The flow control module is connected to the flow sensor on the second outlet pipe (8) to monitor the real-time flow of coal powder output by the pulverizer (6) and adjust the rotation speed of the pulverizer (6) based on the real-time flow. The safety protection module is connected to the direct-blown pulverizing unit and the intermediate-storage pulverizing unit respectively, and is used to monitor the operating parameters of the direct-blown pulverizing unit and the intermediate-storage pulverizing unit in real time, and to alarm when the operating parameters are abnormal.

10. The multi-mode coupling system for direct-fired pulverization, intermediate storage pulverization, and coal conveying according to claim 9, characterized in that, The system also includes a remote control unit; The remote control unit is connected to the PLC control unit, and the PLC control unit is connected to the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit respectively. The remote control unit controls the working status of the direct-fired pulverizing unit, the intermediate-storage pulverizing unit, the conventional coal conveying unit, and the emergency coal conveying unit through the PLC control unit.

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