Coal-fired unit coal pulverizing system and method based on multi-bin cooperation

Abstract

The invention discloses a coal-fired unit coal pulverizing system and method based on multi-bin cooperation, and aims to solve the problems that in the prior art, due to inflexible coal quality allocation and system response lag, the quality of pulverized coal is difficult to guarantee under the low-load working condition, and the peak regulation response speed of a unit is insufficient. The system comprises a peak-shaving raw coal bunker and a common raw coal bunker which are respectively connected with a peak-shaving coal mill and a basic coal mill through corresponding coal feeders, and the peak-shaving raw coal bunker is connected with a common bunker coal feeder through an external coal bunker and a mixed coal feeder; a separator is arranged at an outlet of the peak-shaving coal mill, the separator is connected with a peak-shaving powder bin and the coal mill in a branching mode, and the peak-shaving powder bin is connected with a combustor. According to the method, coal is supplied through double bins, pulverized coal is pulverized through a coal mill, pulverized coal is stored to a peak shaving powder bin through a separator during peak shaving and is preferentially used, accurate coal quality allocation and rapid pulverized coal supply are achieved, and the low-load pulverized coal quality and the unit peak shaving response capacity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal-fired power plant pulverizing system, in particular to a coal-fired unit pulverizing system and method based on multi-bin coordination. BACKGROUND

[0002] Under the background of accelerating energy structure transformation, the grid-connected scale of renewable energy such as wind power and photovoltaic continues to expand, and the intermittency and volatility of its output pose a serious challenge to the stable operation of the power grid. As an important regulating power source of the current power system, coal-fired power units need to undertake a deeper peak shaving task to smooth power fluctuations and support new energy consumption.

[0003] The medium-speed coal mill direct-fired pulverizing system currently widely used in coal-fired units has significant technical bottlenecks under deep peak shaving low load conditions. The output and fineness of the system are highly dependent on the air volume and load of the coal mill. When the load decreases, the reduced air volume will cause the coal powder pipeline flow rate to decrease, which may easily cause coal powder deposition and blockage. At the same time, the reduced outlet temperature of the coal mill and the decreased grinding efficiency will cause the coal powder fineness to become coarse, which will directly affect the ignition stability of the boiler, the combustion efficiency, and the pollution emission control performance. In addition, due to the large material inventory of the system, the regulation inertia is significant, and it is difficult to achieve rapid response to the load command, which cannot meet the requirements of the power grid for power regulation rate.

[0004] To improve the peak shaving capacity of the unit, existing technologies focus on boiler burner modification or end-of-pipe treatment methods such as wide-load denitrification. Although these methods can alleviate the low-load operation problem to some extent, they do not address the root cause of the lack of flexibility and rapid response capability of the pulverizing system, and often involve high modification costs and limited applicable load range. Therefore, it is urgent to break through the technical limitations of the existing pulverizing system and develop a new coordinated pulverizing scheme that can effectively widen the stable load range, ensure the quality of low-load coal powder, and significantly improve the load response rate. SUMMARY

[0005] The purpose of the present application is to provide a coal-fired unit pulverizing system and method based on multi-bin coordination to overcome the problems of poor coal quality under low load conditions and insufficient peak shaving response speed of the unit caused by the inflexible coal quality allocation and system response lag of the existing technology.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions: In a first aspect, the present application provides a coal-fired unit pulverizing system based on multi-bin coordination, comprising: a peak shaving raw coal bin and a normal raw coal bin, the peak shaving raw coal bin being connected with a peak shaving coal mill through a peak shaving bin coal feeder; the normal raw coal bin being connected with a basic coal mill through a normal bin coal feeder; The peak-shaving raw coal bunker is also connected with an external coal bunker, the external coal bunker is connected with the ordinary bunker coal feeder through the mixed coal feeder, and is used for conveying part of the raw coal in the peak-shaving raw coal bunker to the ordinary bunker coal feeder; The outlet pipes of the peak-shaving coal mill and the base coal mill are respectively connected to the burner; a separator is further connected to the outlet pipe of the peak-shaving coal mill, and the outlet of the separator is divided into two paths, one of which is connected to the peak-shaving powder bunker, and the other of which returns to the peak-shaving coal mill and the base coal mill. The outlet of the peak-shaving powder bunker is connected to the inlet pipe of the burner.

[0007] A control valve is arranged on the pipe between the separator and the peak-shaving powder bunker, and is used for controlling the on-off of the coal powder flow to the peak-shaving powder bunker.

[0008] The burner is connected with a boiler, and the boiler preferentially uses the coal powder in the peak-shaving powder bunker when the peak load is operated.

[0009] The quality of the raw coal stored in the peak-shaving raw coal bunker is better than that of the raw coal stored in the ordinary raw coal bunker.

[0010] In a second aspect, the present application provides a coal-fired unit pulverizing method based on multi-bunker cooperation, which adopts the above-mentioned system, and comprises the following steps: S1, conveying the raw coal in the peak-shaving raw coal bunker and the ordinary raw coal bunker to the peak-shaving coal mill and the base coal mill; S2, the peak-shaving coal mill and the base coal mill grind the raw coal into coal powder, and convey the ground coal powder to the burner; S3, under the peak-shaving working condition, part of the coal powder output by the peak-shaving coal mill is stored in the peak-shaving powder bunker through the separator, and at this time, the coal powder stored in the peak-shaving powder bunker is preferentially used.

[0011] When the boiler has no peak-shaving demand, S1 comprises: The raw coal in the peak-shaving raw coal bunker is conveyed to the peak-shaving coal mill through the peak-shaving bunker coal feeder, the raw coal in the ordinary raw coal bunker is conveyed to the base coal mill through the ordinary bunker coal feeder, and the coal powder is directly conveyed to the burner.

[0012] When the boiler needs to be mixedly burned, S1 comprises: Part of the raw coal in the peak-shaving raw coal bunker is conveyed to the ordinary bunker coal feeder through the external coal bunker and the mixed coal feeder, and is mixed with the poor raw coal in the ordinary raw coal bunker, and is then conveyed to the base coal mill.

[0013] Under the peak-shaving working condition, S1 comprises: The raw coal in the peak-shaving raw coal bunker is conveyed to the peak-shaving coal mill through the peak-shaving bunker coal feeder, part of the raw coal in the peak-shaving raw coal bunker is conveyed to the ordinary bunker coal feeder through the external coal bunker and the mixed coal feeder, and the output of the raw coal in the ordinary raw coal bunker is reduced.

[0014] Further comprising: When the load needs to be quickly increased, the amount of coal powder supplied from the peak shaving pulverized coal bin is increased; When the load needs to be quickly reduced, the amount of coal powder supplied from the peak shaving pulverized coal bin is reduced, and the raw coal output of the ordinary raw coal bin is gradually increased, and mixed coal powder is supplied to the burner through the base coal mill and the peak shaving coal mill.

[0015] S3 comprises: A control valve is arranged on the pipeline between the separator and the peak shaving pulverized coal bin, and the on-off of the coal powder flowing to the peak shaving pulverized coal bin is controlled through the control valve to adjust the storage amount of the coal powder.

[0016] Compared with the prior art, the present application has the following beneficial technical effects: In the first aspect, the present application provides a coal-fired unit pulverizing system based on multi-bin cooperation, which realizes the classified storage and independent delivery of different quality raw coals through the double-bin configuration of the peak shaving raw coal bin and the ordinary raw coal bin, and the passage of the external coal bin to the ordinary bin coal feeder to deliver the peak shaving raw coal, so that the mixing ratio of high-quality raw coal and ordinary raw coal can be flexibly adjusted. This multi-bin cooperation structure solves the problem of inflexible coal quality allocation in the prior art, optimizes the coal quality entering the mill according to the low load working condition requirement, avoids the coal powder quality fluctuation caused by single coal quality grinding, and ensures that the coal powder fineness and uniformity meet the standard under low load. The separator arranged at the outlet of the peak shaving coal mill and the peak shaving pulverized coal bin form a coal powder storage loop, and the peak shaving pulverized coal bin is directly connected to the burner inlet pipeline, so that qualified coal powder can be reserved in advance. This design breaks the limitation of the traditional pulverizing system which relies on real-time grinding of the coal mill, and when the unit receives the peak shaving instruction, it does not need to wait for the raw coal grinding process, and can quickly supply coal powder to the burner, greatly reducing the system adjustment inertia, effectively improving the problem of unit peak shaving response lag in the prior art, and improving the response speed and stable combustion ability when the load changes.

[0017] In a second aspect, the present application provides a coal pulverizing method based on multi-bin cooperation for a coal-fired unit, which adopts the above-mentioned coal pulverizing system, and through the operation of conveying the raw coal in the peak-shaving raw coal bin and the ordinary raw coal bin to the peak-shaving coal mill and the basic coal mill in S1, a directional conveying process of double-bin raw coal is constructed. This step can flexibly allocate the conveying proportion of the two types of raw coal according to the working condition requirements, realize the accurate deployment and adaptation grinding of raw coal of different qualities, solve the passive and rigid problem of coal quality deployment in the prior art, can optimize the coal quality into the mill for low load conditions, avoid the problems of coarse coal fineness and unstable quality caused by single coal source grinding, and guarantee the coal combustion adaptability under low load. In S3, the strategy of storing the coal powder in the separator to the peak-shaving powder bin and preferentially using it under the peak-shaving condition, a preset and preferential supply mechanism of peak-shaving coal powder is established. When peak-shaving, there is no need to rely on the long process of real-time grinding of the coal mill, and the qualified coal powder pre-stored in the powder bin can be directly called, which greatly shortens the time difference of load response, effectively solves the problems of large system adjustment inertia and response lag in the prior art. This "pre-storage and post-use" method design can quickly match the load change of peak-shaving, and further guarantee the stability of combustion under low load conditions through the stable supply of pre-stored coal powder. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a coal pulverizing system based on multi-bin cooperation for a coal-fired unit in an embodiment of the present application.

[0019] Figure 2 It is a coal pulverizing system based on multi-bin cooperation for a coal-fired unit in another embodiment of the present application.

[0020] Figure 3 It is a coal pulverizing method based on multi-bin cooperation for a coal-fired unit in an embodiment of the present application.

[0021] In the figure, 1 is a boiler; 2 is a peak-shaving raw coal bin; 3 is an ordinary raw coal bin; 4 is an external coal bin; 5 is a mixed coal feeder; 6 is a peak-shaving bin coal feeder; 7 is an ordinary bin coal feeder; 8 is a basic coal mill; 9 is a peak-shaving coal mill; 10 is a separator; 11 is a peak-shaving powder bin; 12 is a burner; and 13 is a control valve. DETAILED DESCRIPTION

[0022] Under the background of accelerating energy structure transformation, the grid-connected scale of renewable energy such as wind power and photovoltaic continues to expand, and the intermittency and volatility of its output pose a serious challenge to the stability of the power grid. As a core regulating power source, the coal-fired power unit needs to undertake a deeper peak-shaving task to support new energy consumption.

[0023] The current mainstream medium-speed coal mill direct-fired pulverizing system has bottlenecks under deep peak shaving and low load conditions: reduced ventilation volume can easily cause coal dust deposition and blockage, and decreased coal mill grinding efficiency leads to coarser coal dust, affecting boiler ignition stability and pollutant control; moreover, the system has a large adjustment inertia and is difficult to respond quickly to load commands.

[0024] Existing technologies mostly focus on end-stage solutions such as boiler burner retrofitting. While these can alleviate localized problems, they fail to address the core issue of insufficient flexibility in pulverizing systems. Furthermore, retrofitting is costly and has limited applicability. Therefore, there is an urgent need to develop a new collaborative pulverizing solution that can broaden the load range, ensure pulverized coal quality, and improve response speed.

[0025] Based on the above background, this invention proposes a coal-fired power unit pulverizing system and method based on multi-compartment collaboration. By using a dual-compartment setup of peak-shaving raw coal compartment 2 and ordinary raw coal compartment 3, coupled with an external coal compartment 4 providing a pathway for feeding peak-shaving raw coal to the ordinary compartment feeder 7, the supply ratio of raw coal of different qualities can be flexibly adjusted. This avoids the limitations of grinding a single coal quality under low load, ensuring stable pulverized coal quality. The separator 10 at the outlet of the peak-shaving mill 9 and the peak-shaving pulverized coal compartment 11 form a pulverized coal storage loop. Under peak-shaving conditions, the coal stored in the pulverized coal compartment is used preferentially, eliminating the need to wait for the mill to grind in real time, significantly reducing system adjustment inertia and improving the unit's response speed to load commands.

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0028] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a number" means two or more, unless otherwise explicitly specified.

[0030] Reference Figure 1 The image shows a specific embodiment of the coal-fired power unit pulverizing system based on multi-compartment collaboration provided by the present invention, comprising: Peak-shaving raw coal bunker 2 and ordinary raw coal bunker 3 are connected to peak-shaving coal mill 9 via peak-shaving bunker feeder 6; ordinary raw coal bunker 3 is connected to basic coal mill 8 via ordinary bunker feeder 7. The peak-shaving raw coal bunker 2 is also connected to an external coal bunker 4. The external coal bunker 4 is connected to the ordinary coal bunker feeder 7 via a mixed coal feeder 5, which is used to transport part of the raw coal in the peak-shaving raw coal bunker 2 to the ordinary coal bunker feeder 7. The outlets of the peak shaving coal mill 9 and the basic coal mill 8 are respectively connected to the burner 12; the outlet pipe of the peak shaving coal mill 9 is also connected to the separator 10, and the outlet of the separator 10 is divided into two paths, one of which is connected to the peak shaving powder bin 11, and the other path returns to the peak shaving coal mill 9 and the basic coal mill 8. The outlet of the peak-shaving powder silo 11 is connected to the inlet pipe of the burner 12.

[0031] In this specific embodiment, the dual-compartment configuration of peak-shaving raw coal bunker 2 and ordinary raw coal bunker 3 provides a basis for the classified storage of raw coal of different qualities. In conjunction with the independent pathways of peak-shaving bunker feeder 6 and ordinary bunker feeder 7 connected to peak-shaving coal mill 9 and basic coal mill 8 respectively, the two types of raw coal can be transported and ground separately to meet the coal supply needs under different operating conditions.

[0032] The external coal bunker 4 and the matching mixing feeder 5 connected to the peak-shaving raw coal bunker 2 form a conveying channel from the peak-shaving raw coal to the ordinary coal feeder 7. The supply flow of peak-shaving raw coal can be flexibly allocated according to the working conditions. By mixing and grinding with ordinary raw coal, the coal quality ratio is optimized, and the adaptability and quality stability of coal powder grinding under low load are improved.

[0033] The outlet of the peak-shaving coal mill 9 is directly connected to the burner 12, ensuring that the ground coal powder can be quickly transported to the combustion stage, guaranteeing a continuous coal powder supply for the combustion system. A separator 10 installed at the outlet pipe of the peak-shaving coal mill 9 can classify the coal powder. A portion of the separated qualified coal powder is sent to the peak-shaving powder silo 11 for storage, reserving high-quality coal powder for peak-shaving operations. The other portion is returned to the coal mill for secondary grinding, further ensuring that the coal powder fineness meets the standards and preventing insufficient grinding from affecting combustion efficiency.

[0034] In another specific embodiment of the present invention, the provided coal-fired unit pulverizing system based on multi-compartment collaboration refers to... Figure 2 As shown, the control valve 13 installed on the pipeline between the separator 10 and the peak-shaving pulverized coal silo 11 can precisely regulate the flow of pulverized coal into the peak-shaving pulverized coal silo 11. During non-peak-shaving operations, closing the control valve 13 avoids unnecessary pulverized coal storage and ensures that the ground pulverized coal is directly delivered to the burner 12. When peak-shaving demand occurs, opening the control valve 13 enables directional storage of pulverized coal, providing a controllable pathway for peak-shaving reserves and improving the system's operational flexibility and energy efficiency.

[0035] When the boiler 1 connected to the burner 12 is running at peak load, it will prioritize the use of pulverized coal in the peak shaving pulverized coal bin 11. With the help of the pre-stored pulverized coal in the bin, it can quickly respond to high load demand without relying on the lag process of real-time grinding by the coal mill. This can significantly shorten the response time of load increase, ensure the stable pulverized coal supply and combustion state of the boiler 1 under peak load conditions, and enhance the peak shaving support capability of the unit.

[0036] The raw coal stored in peak-shaving coal bunker 2 is of higher quality than that stored in ordinary raw coal bunker 3, laying the foundation for coal quality allocation under different operating conditions. High-quality raw coal can be transported and ground through independent or mixed channels to provide high-combustion-efficiency pulverized coal during peak shaving, while ordinary raw coal is suitable for conventional operating conditions. Through quality-graded storage, precise matching and efficient utilization of coal quality are achieved, further optimizing pulverized coal quality and combustion performance.

[0037] A specific embodiment of the present invention also provides a coal-fired power unit pulverizing method based on multi-compartment collaboration, employing the above-described system, comprising: S1, transport the raw coal in the peak-shaving raw coal bunker 2 and the ordinary raw coal bunker 3 to the peak-shaving coal mill 9 and the basic coal mill 8; S2, the peak-shaving coal mill 9 and the basic coal mill 8 grind the raw coal into pulverized coal, and then transport the ground pulverized coal to the burner 12; S3, under peak shaving conditions, part of the coal powder output from the peak shaving coal mill 9 is stored in the peak shaving powder bin 11 through the separator 10. At this time, the coal powder stored in the peak shaving powder bin 11 is used first.

[0038] In this specific embodiment, S1, which transports raw coal from peak-shaving coal bunker 2 and ordinary coal bunker 3 to peak-shaving coal mill 9 and basic coal mill 8, establishes a basic process of classified coal supply and independent grinding based on the corresponding connection between the two coal bunkers and the two coal mills. This step allows for flexible allocation of the two types of raw coal according to actual operational needs, enabling raw coal of different qualities to be processed by the corresponding coal mills. This provides conditions for pulverized coal quality control from the source and avoids the problem of mismatched grinding parameters caused by a single coal source.

[0039] The process of grinding raw coal into pulverized coal by the S2 peak-shaving coal mill 9 and the basic coal mill 8, and then conveying the pulverized coal to the burner 12, improves the pulverized coal production efficiency through the synchronous operation of the two coal mills. Moreover, the pulverized coal is directly conveyed to the burner 12, which reduces the retention and loss of pulverized coal in the transmission process, and ensures that the combustion system can continuously obtain a pulverized coal supply that meets the requirements, providing core support for the stable combustion of boiler 1.

[0040] Under S3 peak-shaving conditions, a portion of the pulverized coal output from the peak-shaving mill 9 is stored in the peak-shaving pulverized coal bin 11 via separator 10. The design prioritizes the use of pulverized coal stored in bin 11, utilizing the screening function of separator 10 to achieve targeted storage of qualified pulverized coal, reserving a high-quality pulverized coal reserve for peak-shaving operations. Prioritizing the use of pulverized coal in bin 11 eliminates reliance on real-time grinding by the peak-shaving mill 9, effectively reducing system adjustment inertia, enabling rapid response to changes in peak-shaving load, ensuring the continuity and stability of pulverized coal supply during peak-shaving, and thus improving the unit's peak-shaving response rate and combustion operation reliability.

[0041] In another specific embodiment of the coal-fired power unit pulverizing method based on multi-compartment collaboration provided by this invention, when boiler 1 has no peak-shaving demand, the raw coal in peak-shaving raw coal compartment 2 in S1 is transported to peak-shaving coal mill 9 through peak-shaving compartment feeder 6, and the raw coal in ordinary raw coal compartment 3 is transported to basic coal mill 8 through ordinary compartment feeder 7. The pulverized coal is directly transported to burner 12. This configuration, relying on independent coal supply and grinding channels, achieves separate processing and direct pulverization of the two types of raw coal. This operation is suitable for conventional operating conditions, eliminating the need for additional coal quality blending and pulverized coal storage, simplifying the system operation process while ensuring a stable pulverized coal supply to burner 12, supporting the efficient operation of boiler 1.

[0042] When boiler 1 requires co-firing, a portion of the raw coal in peak-shaving raw coal bunker 2 in S1 is transported to the ordinary raw coal bunker feeder 7 via the external coal bunker 4 and the mixing feeder 5. This coal is then mixed with the lower-quality raw coal in the ordinary raw coal bunker 3 and jointly transported to the basic coal mill 8. This design establishes a coal quality blending pathway through the external coal bunker 4 and the mixing feeder 5. Precise mixing of high-quality and lower-quality raw coal optimizes the quality of the coal entering the mill, avoiding insufficient pulverized coal quality caused by grinding only lower-quality raw coal, thus improving fuel economy while ensuring combustion efficiency.

[0043] Under peak-shaving conditions, the raw coal in peak-shaving raw coal bunker 2 in S1 is transported to peak-shaving coal mill 9 via peak-shaving bunker feeder 6. Simultaneously, some raw coal is sent to ordinary bunker feeder 7 via external coal bunker 4 and mixed feeder 5, reducing the output of raw coal from ordinary raw coal bunker 3 and increasing the proportion of high-quality raw coal entering the mill. The high adaptability and easy grinding characteristics of high-quality raw coal ensure the fineness and output efficiency of pulverized coal during peak-shaving, providing a stable pulverized coal base for load regulation.

[0044] Under peak-shaving conditions, when a rapid load increase is needed, the amount of pulverized coal supplied by the peak-shaving pulverized coal silo 11 can be increased. The qualified pulverized coal pre-loaded in the silo can quickly replenish the combustion demand without waiting for the real-time grinding response of the coal mill, thus significantly increasing the load ramp-up rate. When a rapid load decrease is needed, the amount of pulverized coal supplied by the peak-shaving pulverized coal silo 11 can be reduced, and the output of the ordinary raw coal silo 3 can be gradually increased. The setting of supplying mixed pulverized coal through the coal mill can achieve a smooth load decrease through the pulverized coal supply transition. At the same time, the coal quality ratio can be gradually switched to avoid combustion fluctuations caused by a sudden load drop and ensure the stability of the load reduction process.

[0045] A control valve 13 is installed on the pipeline between the separator 10 and the peak-shaving pulverized coal silo 11 in S3. The control valve 13 controls the flow of pulverized coal to and from the peak-shaving pulverized coal silo 11 and adjusts the storage amount, achieving precise and controllable pulverized coal storage. Closing the control valve 13 during non-peak-shaving periods avoids ineffective storage. Opening the control valve 13 before peak-shaving allows for pulverized coal storage, and the storage amount can be adjusted according to load demand, ensuring that the peak-shaving pulverized coal silo 11 accurately matches the pulverized coal supply demand during load fluctuations, further enhancing the system's peak-shaving flexibility.

[0046] To make the objectives, advantages, and technical effects of the technical solution provided by this invention clearer and more intuitive, the specific implementation methods of this invention will be described in detail below, taking into account the actual operation scenario of deep peak shaving in a large coal-fired power plant. It should be noted that the specific embodiments described herein are only for explaining this invention and are not intended to limit it. Any modifications and improvements made by those skilled in the art based on the spirit and substance of this invention should be included within the scope of protection of this invention.

[0047] When boiler 1 has no peak-shaving demand, the pulverizing system is in normal operating mode. At this time, control valve 13 is closed, and the peak-shaving raw coal bunker 2 and the ordinary raw coal bunker 3 respectively feed the raw coal in their respective bunkers into the corresponding peak-shaving coal mill 9 and the basic coal mill 8 through the matching peak-shaving bunker feeder 6 and ordinary bunker feeder 7. After the two types of coal mills grind the raw coal into qualified pulverized coal, it is sent to the corresponding burner 12 on boiler 1 through the primary air outlet pipe. After mixing with the supplied air, it enters the furnace for combustion. This mode is suitable for the power plant's normal load operation and ensures a stable and efficient supply of pulverized coal to the pulverizing system.

[0048] When boiler 1 requires blended coal combustion for economic reasons, the pulverizing system switches to blending mode. High-quality raw coal is stored in peak-shaving raw coal bin 2, while lower-quality raw coal is stored in ordinary raw coal bin 3. A portion of the high-quality raw coal from peak-shaving raw coal bin 2 is transported from bin 2 to ordinary raw coal bin feeder 7 via external coal bin 4, where it is mixed with the lower-quality raw coal from ordinary raw coal bin 3. Both types of raw coal are then fed together to the basic coal mill 8 via ordinary raw coal bin feeder 7. After being ground into qualified pulverized coal, it is fed into the corresponding burner 12 on boiler 1 via primary air outlet pipe, mixed with the supplied air, and then enters the furnace for combustion. Through a reasonable ratio of high-quality to lower-quality raw coal, fuel costs are reduced while ensuring combustion efficiency.

[0049] When the power plant receives a peak-shaving order and needs to adjust the load, the pulverizing system activates the first-level peak-shaving mode. High-quality raw coal is stored in peak-shaving raw coal bin 2, while lower-quality raw coal is stored in ordinary raw coal bin 3. A portion of the high-quality raw coal in peak-shaving raw coal bin 2 is transferred from bin 2 to ordinary raw coal bin feeder 7 via external bin 4 using a mixing feeder 5. Simultaneously, ordinary raw coal bin 3 reduces the output of lower-quality raw coal. Peak-shaving bin feeder 6 and ordinary bin feeder 7 respectively deliver high-quality raw coal to peak-shaving mill 9 and basic mill 8. After grinding the high-quality raw coal into qualified pulverized coal, it is fed into the corresponding burner 12 on boiler 1 via primary air outlet pipes. After mixing with the supplied air, it enters the furnace for combustion. By improving the quality of the raw coal entering the mill, the quality of the pulverized coal and the stability of combustion are ensured during the initial stage of peak shaving.

[0050] When boiler 1 has higher requirements for peak-shaving capacity and needs to rapidly increase or decrease load, the pulverizing system enters the secondary peak-shaving mode. When it is necessary to quickly increase to the target load, high-quality raw coal is stored in peak-shaving raw coal silo 2, and lower-quality raw coal is stored in ordinary raw coal silo 3. A portion of the high-quality raw coal in peak-shaving raw coal silo 2 is transported to ordinary raw coal feeder 7 by mixing feeder 5 through external coal silo 4. Peak-shaving raw coal feeder 6 and ordinary raw coal feeder 7 respectively transport high-quality raw coal to peak-shaving pulverizer 9 and basic pulverizer 8. A portion of the high-quality pulverized coal ground by the two types of pulverizers is directly fed into the corresponding burner 12 on boiler 1 for combustion, and another portion is sent to separator 10 after control valve 13 is opened. A portion of the pulverized coal separated by separator 10 is stored in peak-shaving pulverized coal silo 11, and the remainder is returned to the pulverizer for further grinding and combustion. When operating at peak load for a long time, boiler 1 prioritizes using the high-quality pulverized coal stored in peak-shaving pulverized coal silo 11. When a rapid load reduction is required, the pulverized coal required for boiler 1 combustion is still supplied by the peak shaving pulverized coal silo 11, and the supply amount decreases as the load decreases. At the same time, the supply of high-quality raw coal from the external coal silo 4 to the mixing feeder 5 and the peak shaving silo feeder 6 is reduced. The ordinary raw coal silo 3 gradually outputs raw coal to the ordinary silo feeder 7. The two types of raw coal are ground into mixed pulverized coal in the peak shaving pulverizer 9 and the basic pulverizer 8 for later combustion, thereby enhancing the boiler's rapid response to load and stable combustion capability.

[0051] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A coal-fired power unit pulverizing system based on multi-compartment collaboration, characterized in that, include: Peak-shaving raw coal bunker (2) and ordinary raw coal bunker (3). Peak-shaving raw coal bunker (2) is connected to peak-shaving coal mill (9) through peak-shaving bunker feeder (6); ordinary raw coal bunker (3) is connected to basic coal mill (8) through ordinary bunker feeder (7). The peak-shaving raw coal bunker (2) is also connected to an external coal bunker (4). The external coal bunker (4) is connected to the ordinary bunker feeder (7) through a mixing feeder (5) and is used to transport part of the raw coal in the peak-shaving raw coal bunker (2) to the ordinary bunker feeder (7). The outlets of the peak shaving coal mill (9) and the basic coal mill (8) are respectively connected to the burner (12); a separator (10) is also connected to the outlet pipe of the peak shaving coal mill (9). The outlet of the separator (10) is divided into two paths, one of which is connected to the peak shaving powder bin (11), and the other path returns to the peak shaving coal mill (9) and the basic coal mill (8). The outlet of the peak-shaving powder hopper (11) is connected to the inlet pipe of the burner (12).

2. The coal-fired power unit pulverizing system based on multi-compartment collaboration according to claim 1, characterized in that, A control valve (13) is installed on the pipeline between the separator (10) and the peak shaving powder bin (11) to control the flow of pulverized coal to the peak shaving powder bin (11).

3. The coal-fired power unit pulverizing system based on multi-compartment collaboration according to claim 1, characterized in that, The burner (12) is connected to a boiler (1), which preferentially uses the pulverized coal in the peak shaving pulverized coal bin (11) when the boiler (1) is operating at peak load.

4. A coal-fired power unit pulverizing system based on multi-compartment collaboration according to claim 1, characterized in that, The quality of raw coal stored in the peak-shaving raw coal silo (2) is better than that of raw coal stored in the ordinary raw coal silo (3).

5. A pulverizing method for a coal-fired power unit based on multi-compartment collaboration, employing the system described in any one of claims 1 to 4, characterized in that, include: S1, transport the raw coal in the peak-shaving raw coal bunker (2) and the ordinary raw coal bunker (3) to the peak-shaving coal mill (9) and the basic coal mill (8); S2, the peak shaving coal mill (9) and the basic coal mill (8) grind the raw coal into coal powder and transport the ground coal powder to the burner (12); S3, Under peak shaving conditions, part of the coal powder output from the peak shaving coal mill (9) is stored in the peak shaving powder bin (11) through the separator (10). At this time, the coal powder stored in the peak shaving powder bin (11) is used first.

6. The pulverizing method for a coal-fired power unit based on multi-compartment collaboration according to claim 5, characterized in that, When the boiler has no peak-shaving requirement, S1 includes: The raw coal in the peak-shaving raw coal bunker (2) is transported to the peak-shaving coal mill (9) through the peak-shaving bunker feeder (6), and the raw coal in the ordinary raw coal bunker (3) is transported to the basic coal mill (8) through the ordinary bunker feeder (7). The pulverized coal is directly transported to the burner (12).

7. A coal-fired power unit pulverizing method based on multi-compartment collaboration according to claim 5, characterized in that, When the boiler requires co-firing, S1 includes: Part of the raw coal in the peak-shaving raw coal bunker (2) is transported to the ordinary bunker feeder (7) through the external coal bunker (4) and the mixing feeder (5). After being mixed with the inferior raw coal in the ordinary raw coal bunker (3), the coal is transported together to the basic coal mill (8).

8. A coal-fired power unit pulverizing method based on multi-compartment collaboration according to claim 5, characterized in that, Under peak-shaving conditions, S1 includes: The raw coal in the peak-shaving raw coal bunker (2) is transported to the peak-shaving coal mill (9) through the peak-shaving bunker feeder (6). At the same time, part of the raw coal in the peak-shaving raw coal bunker (2) is transported to the ordinary bunker feeder (7) through the external coal bunker (4) and the mixed feeder (5), thereby reducing the output of raw coal from the ordinary raw coal bunker (3).

9. A coal-fired power unit pulverizing method based on multi-compartment collaboration according to claim 8, characterized in that, Also includes: When a rapid increase in load is required, increase the amount of pulverized coal supplied from the peak shaving pulverized coal silo (11); When a rapid load reduction is required, the amount of pulverized coal supplied from the peak shaving pulverized coal silo (11) is reduced, and the output of raw coal from the ordinary raw coal silo (3) is gradually increased. The mixed pulverized coal is then ground by the basic coal mill (8) and the peak shaving coal mill (9) and supplied to the burner (12).

10. A coal-fired power unit pulverizing method based on multi-compartment collaboration according to claim 5, characterized in that, S3 includes: A control valve (13) is installed on the pipeline between the separator (10) and the peak shaving powder silo (11). The flow of coal powder to the peak shaving powder silo (11) is controlled by the control valve (13) to regulate the amount of coal powder stored.

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