Coal-fired boiler small powder bin island pulverized coal storage and supply system and operation method

Abstract

The invention discloses a coal-fired boiler small powder bin island pulverized coal storage and supply system and an operation method thereof, and relates to the technical field of coal-fired power generation. The system comprises a closed small powder bin island independently arranged outside a boiler plant, a coal grinding unit, a raw coal powder channel communicated with the coal grinding unit and a burner, and a powder storage channel and a powder supply channel which are connected with the small powder bin island. A small powder bin, a pulverized coal conveying device, an exhaust gas treatment system and a ventilation device used for maintaining 40-100 Pa micro-positive pressure in the island are arranged in the small powder bin island. The method comprises a basic load direct blowing mode, a load-reducing powder storage mode and a load-increasing powder supply mode, and flexible switching of pulverized coal between the direct blowing mode and the storage mode is achieved by controlling a valve and starting and stopping a conveying device. Through the modular independent island design, the problems of space, load and construction period of old factory transformation are solved; through cooperation of micro-positive pressure and exhaust gas negative pressure, the fire blast risk is remarkably reduced; and through flexible operation of'control-storage-use ', the peak regulation rate and the response flexibility of the unit are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of coal-fired power generation technology, specifically to a coal-fired boiler pulverized coal storage and supply system and its operation method for improving the peak-shaving flexibility of coal-fired power generating units. Background Technology

[0002] While new energy sources such as wind and solar power are being integrated into the power grid on a large scale, their power generation is characterized by fluctuations and intermittency, posing challenges to the stability of the power grid load. Coal-fired power generating units are currently the key flexible resource for achieving large-scale, economical, deep, and rapid peak shaving. Therefore, improving the flexibility of existing coal-fired power units, especially their load response rate, has become an urgent requirement for the safe and stable operation of the power grid.

[0003] The core challenge in improving the flexibility of coal-fired boilers lies in the lag in the response of their coal pulverizing systems. By adding small pulverized coal silos between the mill and the burner, excess pulverized coal can be stored when the unit reduces load, and the stored pulverized coal can be quickly released when the load increases, thus significantly improving the unit's load increase and decrease rates. However, carrying out such retrofits in older, already operational power plants presents significant challenges: 1. Space constraints: The old factory has a compact design and lacks sufficient space to install the new small powder silos and their auxiliary equipment.

[0004] 2. Structural load: Adding heavy equipment to the existing factory structure may exceed its load-bearing capacity, requiring complex structural testing and reinforcement.

[0005] 3. Construction Interference and Safety: During the renovation, some units need to be kept running. Construction and production areas overlap, posing high safety risks. Furthermore, noise and dust can easily interfere with the operating equipment.

[0006] 4. Tight schedule: The power grid usually only provides a very short downtime maintenance window (such as about 30 days), which puts enormous pressure on the construction schedule.

[0007] 5. Safety risks: When storing high-volatile coal powder, there is a risk that combustible gases may be released from the small powder silo system, potentially causing a combustion or explosion.

[0008] To solve the above problems, there is an urgent need for a technical solution that can effectively improve the flexibility of the unit, adapt to the harsh conditions of old plant renovation, and has high safety. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to provide a pulverized coal storage and supply system and operation method that can effectively improve the peak-shaving flexibility of coal-fired units, adapt to the harsh conditions of space, load and construction period of old plant renovation, and have high safety.

[0010] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A pulverized coal storage and supply system for a coal-fired boiler includes a pulverized coal storage island that is set up independently of the boiler plant. A coal grinding unit, the coal grinding unit including at least one coal mill, the coal mill being connected to a burner through a raw coal powder channel; The small powder silo island is equipped with at least one small powder silo. The powder inlet of the small powder silo is connected to the coal mill through a powder storage channel, and the powder outlet of the small powder silo is connected to the burner through a powder supply channel. The small pink warehouse island is also equipped with an island ventilation device to maintain a positive pressure environment of 40Pa to 100Pa inside the small pink warehouse island.

[0011] The beneficial effects of this invention are as follows: by setting up an independent small powder storage island, the powder storage, powder supply and related auxiliary systems are placed externally, which not only fundamentally solves the problems of insufficient plant space, limited original structural load and mutual interference between construction and operation faced in the renovation of old units, but also eliminates the need for large-scale structural reinforcement of the original plant, greatly shortening the construction period; during the renovation, only some systems need to be isolated for a short time, and the remaining systems can operate normally, and the construction and production areas are completely separated, significantly reducing safety risks; Meanwhile, the ventilation system inside the island ensures that the interior of the small powder silo is always kept at a slightly positive pressure of 40Pa-100Pa, which effectively prevents external air from seeping in. Combustible gases that may be released from the equipment inside the island (such as the small powder silo) are extracted by the negative pressure of the exhaust gas pipeline, ensuring that the combustible volatiles that may be released from the small powder silo are directionally drawn into the boiler for combustion, rather than accumulating inside the island. This significantly reduces the risk of combustion and explosion in the system. Through this synergistic effect of "positive pressure isolation and negative pressure extraction", the possibility of combustible gases accumulating inside the island is fundamentally eliminated, and the safety level of the system is significantly improved.

[0012] Furthermore, the small pink island is a sealed compartment, and the ventilation device inside the island includes a ventilation fan connected to the small pink island and a grille ventilation opening set on the side wall of the small pink island.

[0013] The beneficial effects of adopting the above-mentioned further solutions are: the sealed chamber is the foundation for establishing and maintaining a stable micro-positive pressure environment, ensuring the effective implementation of positive pressure explosion-proof measures. At the same time, it can confine the dust and noise generated by equipment operation within the island, improving the plant environment and reducing the impact of external climate and dust on internal equipment, thereby improving the system's reliability and service life.

[0014] Furthermore, a first control valve is installed on the powder storage channel, and a second control valve is installed on the raw coal powder channel.

[0015] The beneficial effects of adopting the above-mentioned further solution are: by controlling the opening of the first control valve and the second control valve, the flow direction of pulverized coal at the outlet of the coal mill can be flexibly and accurately allocated, thereby effectively adjusting the ratio of pulverized coal entering the small pulverized coal bin and directly entering the burner. This enables rapid and precise adjustment of the pulverized coal "supply" and "storage" ratio under different operating conditions of the unit, providing a key execution means for flexible peak shaving of the unit.

[0016] Furthermore, a first-stage separator and a second-stage separator are sequentially installed on the powder storage channel, and the second-stage separator is provided with a waste gas outlet.

[0017] The beneficial effects of adopting the above-mentioned further scheme are as follows: the first-stage separator performs coarse separation, separating qualified coal powder; the first-stage and second-stage separators are used to perform fine separation of the coal powder entering the small powder silo, ensuring that the stored coal powder has the required fineness and optimizing combustion efficiency. Simultaneously, the second-stage separator effectively separates and removes the exhaust gas carrying combustible gases and ultrafine powder, creating conditions for subsequent safe handling and further improving the safety of the coal powder storage process. The coal powder fine classification and combustible separation structure formed by the first-stage and second-stage separators connected in series not only achieves precise control of coal powder particle size but also simultaneously removes volatile matter and fine dust during the separation process. This ensures that the coal powder entering the small powder silo possesses both high combustion activity and low explosive tendency, fundamentally solving the industry pain point of the difficulty in simultaneously addressing the risks of spontaneous combustion and explosion of coal powder in traditional siloed pulverizing systems.

[0018] Furthermore, it also includes a waste gas treatment system, which includes a waste gas fan and a waste gas burner. The inlet of the waste gas fan is connected to the waste gas outlet of the second-stage separator, and the outlet of the waste gas fan is connected to the waste gas burner.

[0019] The beneficial effect of adopting the above-mentioned further solution is that the exhaust gas treatment system provides a safe final disposal path for the separated exhaust gas. After the exhaust gas fan starts, it maintains a high negative pressure in the pipeline, thereby stably and continuously transporting the exhaust gas (containing combustible gases) discharged from the second separator to the exhaust gas burner for complete combustion, fundamentally eliminating the hidden danger of combustible gases accumulating in the system and causing deflagration.

[0020] Furthermore, the coal supply channel is equipped with a coal powder conveying device for conveying the coal powder stored in the small coal powder bin to the burner.

[0021] The beneficial effects of adopting the above-mentioned further solution are: the pulverized coal conveying device enables the pulverized coal stored in the small pulverized coal bin to be actively and controllably conveyed, so that when the unit needs to quickly increase the load, it can bypass the inherent pulverization delay of the coal mill and directly convert the "energy reserve" into the boiler's immediate fuel input. It is a key functional module to break through the response rate bottleneck of the traditional direct-fired pulverizing system and realize rapid load ramp-up.

[0022] Furthermore, the pulverized coal conveying device includes a power mechanism and a coal feeder connected to the small pulverized coal silo. The outlet of the power mechanism and the outlet of the coal feeder are merged through an air-coal mixer and connected to the burner.

[0023] The beneficial effects of adopting the above-mentioned further scheme are as follows: the power mechanism provides a stable and sufficient airflow as a carrier; the coal feeder, as a precise metering and feeding device, adjusts the coal powder output according to load demand. The two converge in the air-coal mixer, achieving uniform mixing of coal powder and airflow to form a suitable concentration of gas-coal two-phase flow. This ensures stable flow rate and controllable concentration during the coal supply process, meeting both the rapid response flow requirements and the stability of the coal powder concentration at the burner inlet. Thus, while increasing the load rate, it also ensures stable and efficient boiler combustion.

[0024] Furthermore, the power mechanism is a Roots blower, or a branch pipeline from the primary air blower of the coal mill unit.

[0025] The advantages of adopting the above-mentioned further solutions are: Roots blowers can provide stable flow rates of conveyed air, almost unaffected by back pressure, ensuring the independence and reliability of the powder supply system. Furthermore, the method of drawing air from a branch pipeline of the primary blower can effectively utilize existing air sources. By adding regulating dampers to control the conveyed air pressure and volume, it can significantly save on equipment investment and island space, making it particularly suitable for renovation projects in older plants that are sensitive to modification costs. It also increases design flexibility. Both solutions have their own advantages.

[0026] An operation method for a pulverized coal storage and supply system in a small pulverized coal storage island of a coal-fired boiler includes the following operation modes: Basic load operation mode: Close the first control valve on the pulverized coal storage channel and open the second control valve on the raw pulverized coal channel, so that all the pulverized coal produced by the coal mill is directly transported to the burner through the raw pulverized coal channel; Reduced load pulverized coal storage mode: While keeping the second control valve open, the first control valve is opened, so that part of the pulverized coal produced by the coal mill is diverted through the pulverized coal storage channel, and after being separated by the first-stage separator and the second-stage separator, it is stored in the corresponding small pulverized coal bin; Increased load coal supply mode: While keeping the second control valve open, start the coal powder conveying device to transport the coal powder stored in the small coal silo to the burner through the coal supply channel.

[0027] The beneficial effects of this invention are: by using a small pulverized coal silo as an energy buffer unit, it enables the orderly switching between three modes: "basic load direct blowing - load reduction pulverized coal storage - load increase pulverized coal supply". This transforms the traditional single "on-demand" operation mode of coal-fired boilers into a flexible operation mode that combines "production, storage and use". It can store excess pulverized coal in real time when the load is reduced and release it quickly when the load is increased, thereby realizing the dynamic decoupling of fuel supply and boiler load demand. This allows the unit output to respond quickly and accurately to the grid dispatch instructions, significantly improving the peak shaving rate and operational flexibility of coal-fired units.

[0028] Furthermore, in the reduced-load coal storage operation mode, the coal powder diverted from the coal storage channel passes through the first-stage separator and the second-stage separator for graded separation before entering the small coal silo; the exhaust gas separated by the second-stage separator is drawn in by the exhaust gas fan and sent to the exhaust gas burner. In the pulverized coal supply operation mode with increased load, the specific process of starting the pulverized coal conveying device is as follows: start the power mechanism and turn on the coal feeder corresponding to the target small pulverized coal bin, so that the stored pulverized coal is mixed with the conveying air and then output through the pulverized coal supply channel.

[0029] The beneficial effects of adopting the above-mentioned further scheme are as follows: During load reduction and pulverized coal storage, the first-stage and second-stage separators refine the pulverized coal, ensuring not only the combustion quality of the stored pulverized coal but, more importantly, effectively separating the exhaust gas rich in combustible gases and guiding it to a safe disposal path, thus achieving simultaneous energy storage and the diversion of hazardous substances. During load increase and pulverized coal supply, the coordinated start-stop and precise control of the power mechanism and the coal feeder enable rapid, stable, and on-demand delivery of stored pulverized coal, ensuring a smooth and reliable load increase process. These two refined operation procedures together constitute a core technological closed loop for achieving rapid and safe peak shaving. Attached Figure Description

[0030] Figure 1 This invention provides a schematic diagram of the structure of a Roots blower as the power mechanism in a small pulverized coal storage and supply system for a coal-fired boiler. Figure 2 This is a schematic diagram of the structure of a coal pulverized coal storage and supply system for a small coal pulverized coal storage island in a coal-fired boiler, where the power mechanism is a branch pipe drawn from the primary air fan of the coal mill unit.

[0031] The attached diagram lists the components represented by each number as follows: 1. Coal mill one; 2. Coal mill two; 3. Original primary separator one; 4. Original primary separator two; 5. Primary air fan; 6. Burner; 7. Secondary control valve one; 8. Secondary control valve two; 300. Small powder silo island; 301. Power mechanism; 302. Primary separator one; 303. Primary separator two; 304. Primary control valve one; 305. Primary control valve two; 307. Air-powder mixer one; 308. Air-powder mixer two; 311. Coal feeder one; 312. Coal feeder two; 313. Small powder silo one; 314. Small powder silo two; 315. Secondary separator one; 316. Secondary separator two; 317. Exhaust gas fan; 318. Exhaust gas burner; 319. Ventilation fan; 320. Grille vent. Detailed Implementation

[0032] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: Example 1 like Figure 1 As shown, this embodiment provides a pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler, including a small pulverized coal storage island 300 set up independently of the boiler plant; The coal grinding unit includes two coal mills, namely coal mill 1 and coal mill 2. Coal mill 1 and coal mill 2 are respectively connected to the burner 6 through independent raw coal powder channels. The small powder storage island 300 is equipped with two small powder storage chambers, namely small powder storage chamber one 313 and small powder storage chamber two 314. The powder inlets of small powder storage chamber one 313 and small powder storage chamber two 314 are respectively connected to coal mill one 1 and coal mill two 2 through independent powder storage channels. The powder outlets of small powder storage chamber one 313 and small powder storage chamber two 314 are connected to burner 6 through powder supply channels. The small pink warehouse island 300 is also equipped with an island ventilation device for maintaining a positive pressure environment of 40Pa to 100Pa inside the small pink warehouse island 300.

[0034] This embodiment sets up an independent small powder storage island 300, externalizing the powder storage, powder supply, and related auxiliary systems. This not only fundamentally solves the problems of insufficient plant space, limited original structural load, and mutual interference between construction and operation faced in the renovation of old units, but also eliminates the need for large-scale structural reinforcement of the original plant, significantly shortening the construction period. During the renovation, only some systems need to be isolated for a short period of time, while the remaining systems can operate normally. The construction and production areas are completely separated, significantly reducing safety risks. Meanwhile, the ventilation device 319 inside the island ensures that the interior of the small powder storage island 300 is always maintained at a slightly positive pressure environment of 40Pa-100Pa, which can effectively prevent the infiltration of external air. The combustible gases that may be released from the small powder storage tanks 313 and 314 inside the island are extracted by the negative pressure of the exhaust gas pipeline, ensuring that the combustible volatiles that may be released from the small powder storage tanks 313 and 314 are directionally drawn into the boiler for combustion, rather than accumulating inside the island. This significantly reduces the risk of combustion and explosion of the system. Through this synergistic effect of "positive pressure isolation and negative pressure extraction", the possibility of combustible gas accumulating inside the island is fundamentally eliminated, and the safety level of the system is significantly improved.

[0035] Example 2 Based on Example 1, the small pink storage island 300 in this example is a sealed storage island, and the ventilation device inside the island includes a ventilation fan 319 connected to the small pink storage island 300 and a grille ventilation opening 320 provided on the side wall of the small pink storage island 300.

[0036] In this embodiment, the sealed chamber is the foundation for establishing and maintaining a stable micro-positive pressure environment, ensuring the effective implementation of positive pressure explosion-proof measures. Simultaneously, it confines dust and noise generated during equipment operation within the island, improving the plant environment and reducing the impact of external climate and dust on internal equipment, thereby enhancing system reliability and lifespan.

[0037] Example 3 Based on Example 2, this example provides a first control valve 304 and a first control valve 305 on the coal storage channels connecting coal mill 1 and small coal storage bin 313 and coal mill 2 and small coal storage bin 2 314, respectively. On the raw coal powder channels connecting coal mill 1 and coal mill 2 and burner 6, a second control valve 7 and a second control valve 8 are installed respectively.

[0038] This embodiment, by controlling the opening degrees of the first control valve 304, the first control valve 305, the second control valve 7, and the second control valve 8, can flexibly and accurately allocate the flow direction of pulverized coal at the outlets of pulverizer 1 and pulverizer 2, thereby effectively adjusting the ratio of pulverized coal entering the small pulverized coal bins 313 and 314 to that directly entering the burner 6. This enables rapid and precise adjustment of the pulverized coal "supply" and "storage" ratio under different operating conditions of the unit, providing a key execution means for flexible peak shaving of the unit.

[0039] Example 4 Based on Example 3, in this example, a first-stage separator 302 and a second-stage separator 315 are sequentially installed on the powder storage channel connecting the coal mill 1 and the small powder silo 313, and a first-stage separator 303 and a second-stage separator 316 are sequentially installed on the powder storage channel connecting the coal mill 2 and the small powder silo 314. Both the second-stage separator 315 and the second-stage separator 316 are provided with exhaust gas outlets.

[0040] In this embodiment, the gas-powder mixture from coal mill 1 and coal mill 2 first enters the first-stage separator 302 and the first-stage separator 303 respectively for preliminary coarse and fine separation. Qualified coal powder is initially collected under gravity, while finer particles and gas enter the second-stage separator 315 and the second-stage separator 316 for secondary fine separation. This ensures that the majority of qualified coal powder is stored in the small powder bins 313 and 314, guaranteeing the fineness of the stored coal powder and optimizing combustion efficiency. The exhaust from the second-stage separators 315 and 316 contains ultrafine powder and volatile organic compounds released from the coal. The exhaust gas from the combustible gas VOCs is discharged, creating conditions for subsequent safe handling and further improving the safety of the coal powder storage process. The coal powder fine classification and combustible separation structure, which is formed by connecting the first-stage separator 302 and the second-stage separator 315 and the first-stage separator 303 and the second-stage separator 316 in series, not only achieves precise control of coal powder particle size, but also removes volatile matter and fine dust simultaneously during the separation process. This makes the coal powder entering the small powder bins 313 and 314 have both high combustion activity and low combustion and explosion tendency, fundamentally solving the industry pain point that it is difficult to balance the risk of spontaneous combustion and explosion of coal powder in traditional storage-type pulverizing systems.

[0041] Example 5 Based on Example 4, this example also includes a waste gas treatment system, which includes a waste gas fan 317 and a waste gas burner 318. The inlet of the waste gas fan 317 is connected to the waste gas outlet of the second-stage separator 315 and the second-stage separator 316, respectively, and the outlet of the waste gas fan 317 is connected to the waste gas burner 318.

[0042] In this embodiment, the exhaust gas treatment system provides a safe final disposal path for the separated exhaust gas. After the exhaust gas fan 317 is started, it maintains a high negative pressure in the pipeline, thereby stably and continuously transporting the exhaust gas containing combustible gases discharged from the second-stage separator 315 and the second-stage separator 316 to the exhaust gas burner 318 for complete combustion, fundamentally eliminating the hidden danger of combustible gases accumulating in the system and causing deflagration.

[0043] Example 6 Based on Example 5, in this example, the coal supply channel is provided with a coal powder conveying device for conveying the coal powder stored in the small coal powder bin 1 313 and the small coal powder bin 2 314 to the burner 6.

[0044] In this embodiment, the pulverized coal conveying device enables the pulverized coal stored in small pulverized coal bins 313 and 314 to be actively and controllably conveyed. Thus, when the unit needs to rapidly increase the load, it can bypass the inherent pulverizing delay of pulverizers 1 and 2 respectively, and directly convert the "energy reserve" into the boiler's immediate fuel input. This is a key functional module that breaks through the response rate bottleneck of traditional direct-fired pulverizing systems and achieves rapid load ramp-up.

[0045] Example 7 Based on Example 6, the pulverized coal conveying device in this example includes a power mechanism and a coal feeder 311 and a coal feeder 312 that are respectively connected to the small pulverized coal bin 313 and the small pulverized coal bin 314. The outlet of the power mechanism and the outlet of the coal feeder 311 and the coal feeder 312 are respectively connected to the burner 6 through the air-pulverized coal mixer 307 and the air-pulverized coal mixer 308.

[0046] In this embodiment, a stable and sufficient airflow is provided by a power mechanism as the carrier. Coal feeder 311 and coal feeder 312 serve as precise metering and feeding devices, adjusting the coal powder output in small coal powder bins 313 and 314 respectively according to load requirements. The output coal powder and airflow are uniformly mixed in air-coal mixer 307 and air-coal mixer 308 respectively, forming a gas-coal two-phase flow of suitable concentration. This ensures stable flow and controllable concentration during the coal supply process, meeting both the rapid response flow requirements and the stability of the coal powder concentration entering the burner 6. Thus, while increasing the load rate, it also ensures stable and efficient boiler combustion.

[0047] Example 8 Based on Example 7, the power mechanism described in this example is a Roots blower 301 (see Example 7). Figure 1 ), or a branch pipe leading from the primary air fan 5 of the coal mill unit (see Figure 2 ).

[0048] In this embodiment, the Roots blower 301 can provide a stable flow rate of conveying air, almost unaffected by back pressure, ensuring the independence and reliability of the powder supply system. The method of drawing air from the five branch pipes of the primary blower effectively utilizes existing air sources. By adding regulating dampers to control the conveying air pressure and volume, it can significantly save on equipment investment and island space, making it particularly suitable for renovation projects in older plants that are sensitive to modification costs. This increases design flexibility; both solutions have their advantages.

[0049] Example 9 Based on Examples 1-8, this example provides an operation method for a pulverized coal storage and supply system in a small pulverized coal storage island of a coal-fired boiler, including the following operation modes: Basic load operation mode: Close the first control valve 304 and the first control valve 305 on the pulverized coal storage channel, and then open the second control valve 7 and the second control valve 8 on the raw pulverized coal channel respectively, so that all the pulverized coal produced by the coal mill 1 and the coal mill 2 is directly transported to the burner 6 through the raw pulverized coal channel. Reduced load pulverized coal storage mode: While keeping the second control valve 7 and the second control valve 8 open, the first control valve 304 and the first control valve 305 are opened, so that the pulverized coal produced by the coal mill 1 and the coal mill 2 is diverted through each pulverized coal storage channel, and after being separated by the first-stage separator 302 and the second-stage separator 315, and the first-stage separator 303 and the second-stage separator 316, it is stored in the small pulverized coal bins 313 and 314 respectively. Increased load coal supply mode: While keeping the second control valve 7 and the second control valve 8 open, start the coal powder conveying device to transport the coal powder stored in the small coal powder bins 313 and 314 to the burner 6 through the coal supply channel.

[0050] This embodiment utilizes small pulverized coal bin 1 (313) and small pulverized coal bin 2 (314) as energy buffer units to achieve orderly switching between three modes: "basic load direct blowing - load reduction pulverized coal storage - load increase pulverized coal supply". This transforms the traditional single "on-demand" operation mode of coal-fired boilers into a flexible operation mode that combines "production, storage, and use". It can store excess pulverized coal in real time when the load is reduced and release it quickly when the load is increased, thereby realizing the dynamic decoupling of fuel supply and boiler load demand. This enables the unit output to respond quickly and accurately to the grid dispatch instructions, significantly improving the peak shaving rate and operational flexibility of coal-fired units.

[0051] Example 10 Based on Example 9, in this example, in the reduced-load coal storage operation mode, the coal powder diverted from the coal storage channel passes through the first-stage separator 302 and the second-stage separator 315, and the first-stage separator 303 and the second-stage separator 316 respectively for graded separation before entering the small coal storage bins 313 and 314; the exhaust gas separated by the second-stage separator 315 and the second-stage separator 316 is drawn by the exhaust gas fan 317 and sent to the exhaust gas burner 318. In the above-mentioned load-increasing coal supply operation mode, the specific process of starting the coal powder conveying device is as follows: start the power mechanism and turn on the coal feeder 311 and coal feeder 312 corresponding to the small coal silo 313 and the small coal silo 314 respectively, so that the stored coal powder is mixed with the conveying air and output through the coal supply channel.

[0052] In this embodiment, during load reduction and pulverized coal storage, the pulverized coal is finely processed through the first-stage separator 302 and the second-stage separator 315, as well as the first-stage separator 303 and the second-stage separator 316. This not only ensures the combustion quality of the pulverized coal stored in the small pulverized coal bins 313 and 314, but more importantly, it effectively separates the exhaust gas rich in combustible gases and guides it to a safe processing path, achieving simultaneous energy storage and diversion of hazardous substances. During load increase and pulverized coal supply, the coordinated start-stop and precise control of the power mechanism, coal feeder 311, and coal feeder 312 enable rapid, stable, and on-demand delivery of stored pulverized coal, ensuring a smooth and reliable load increase process. These two refined operation procedures together constitute the core technological closed loop for achieving rapid and safe peak shaving.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler, characterized in that, Including a small powder storage island (300) set up independently of the boiler plant; A coal grinding unit, the coal grinding unit including at least one coal mill, the coal mill being connected to the burner (6) through a raw coal powder channel; The small powder storage island (300) is provided with at least one small powder storage chamber. The powder inlet of the small powder storage chamber is connected to the coal mill through the powder storage channel, and the powder outlet of the small powder storage chamber is connected to the burner (6) through the powder supply channel. The small pink warehouse island (300) is also equipped with an island ventilation device for maintaining a positive pressure environment of 40Pa to 100Pa inside the small pink warehouse island (300).

2. The pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 1, characterized in that, The small pink warehouse island (300) is a sealed warehouse, and the ventilation device inside the island includes a ventilation fan (319) connected to the small pink warehouse island (300) and a grid ventilation opening (320) set on the side wall of the small pink warehouse island (300).

3. The pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 2, characterized in that, A first control valve is installed on the powder storage channel, and a second control valve is installed on the raw coal powder channel.

4. The pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 1, characterized in that, The powder storage channel is equipped with a first-stage separator and a second-stage separator in sequence, and the second-stage separator is provided with a waste gas outlet.

5. A pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 4, characterized in that, It also includes a waste gas treatment system, which includes a waste gas fan (317) and a waste gas burner (318). The inlet of the waste gas fan (317) is connected to the waste gas outlet of the second-stage separator, and the outlet of the waste gas fan (317) is connected to the waste gas burner (318).

6. A pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 1, characterized in that, The coal supply channel is equipped with a coal powder conveying device for conveying the coal powder stored in the small coal powder bin to the burner (6).

7. A pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 6, characterized in that, The pulverized coal conveying device includes a power mechanism and a coal feeder connected to a small pulverized coal silo. The outlet of the power mechanism and the outlet of the coal feeder are merged through an air-powder mixer and connected to the burner (6).

8. A pulverized coal storage and supply system for a small pulverized coal storage island in a coal-fired boiler according to claim 7, characterized in that, The power mechanism is a Roots blower (301) or a branch pipeline from the primary air blower (5) of the coal mill unit.

9. A method for operating the pulverized coal storage and supply system according to any one of claims 1-8, characterized in that, Including the following operating modes: Basic load operation mode: Close the first control valve on the pulverized coal storage channel and open the second control valve on the raw pulverized coal channel so that all the pulverized coal produced by the coal mill is directly transported to the burner (6) through the raw pulverized coal channel. Reduced load pulverized coal storage mode: While keeping the second control valve open, the first control valve is opened, so that part of the pulverized coal produced by the coal mill is diverted through the pulverized coal storage channel, and after being separated by the first-stage separator and the second-stage separator, it is stored in the corresponding small pulverized coal bin; Increased load coal supply mode: While keeping the second control valve open, start the coal powder conveying device to transport the coal powder stored in the small coal silo to the burner (6) through the coal supply channel.

10. The operating method according to claim 9, characterized in that, In the reduced load pulverized coal storage operation mode, the pulverized coal diverted from the pulverized coal storage channel passes through the first-stage separator and the second-stage separator for graded separation before entering the small pulverized coal bin; the exhaust gas separated by the second-stage separator is drawn by the exhaust gas blower (317) and sent to the exhaust gas burner (318). In the pulverized coal supply operation mode with increased load, the specific process of starting the pulverized coal conveying device is as follows: start the power mechanism and turn on the coal feeder corresponding to the target small pulverized coal bin, so that the stored pulverized coal is mixed with the conveying air and then output through the pulverized coal supply channel.

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