Intelligent online bed material adding equipment

Abstract

The invention relates to the field of circulating fluidized bed boilers, and discloses intelligent online bed material adding equipment which comprises a drum screening machine, a bucket elevator, a second-stage bed material conveyor and a third-stage bed material conveyor. The drum screening machine is arranged on a platform of a bottom ash silo, located between the bottom ash silo and the bucket elevator and used for screening bed materials at an outlet of the bottom ash silo; unqualified bed materials are discharged into a transfer device on the lower portion of the bottom ash silo through a material distributing pipe, and qualified bed materials are conveyed into a bucket elevator through a second connecting pipe; the two feeding channels are connected with the second-stage bed material conveyor and the bottom ash silo respectively, and the discharging pipes are used for distributing bed materials to the scraper coal feeder and the third-stage bed material conveyor. Screening in the bed material circulating and adding process is achieved, the bed material quality is improved, and the personnel maintenance cost is reduced; the starting preparation time of the unit is shortened to be within 24 hours, and the starting flexibility of the unit is improved; and the function of adding multi-source materials such as bed materials or limestone powder on line is realized.

Description

Technical Field

[0001] This invention relates to the field of circulating fluidized bed boilers, specifically to an intelligent online bed material adding device. Background Technology

[0002] Circulating fluidized bed (CFB) boilers are widely used in solid waste treatment, power generation, and other fields due to their advantages such as wide fuel adaptability, high combustion efficiency, and high desulfurization efficiency. The bed material, as the core medium in the operation of a CFB boiler, directly affects the boiler's combustion efficiency, heat exchange effect, and operational safety through its quantity, particle size distribution, and stability. Furthermore, the bed material needs to be continuously replenished during boiler operation to maintain the bed height, and under certain operating conditions, desulfurizing agents such as limestone powder are required to achieve flue gas desulfurization. Therefore, the reliability, efficiency, and adaptability of the bed material addition system are crucial to the overall operation of the boiler.

[0003] In existing technologies, such as the slag removal and bed material system for a circulating fluidized bed boiler for solid waste disclosed in CN117781269A, the dust pollution problem caused by open conveying is solved by setting up equipment such as silo pumps, bed material silos, bed material bucket elevators, and rotary feeders, and slag recycling and comprehensive utilization of magnetic materials are realized. However, as industrial boilers develop towards larger scale, intelligence, and higher efficiency, existing bed material addition systems have gradually exposed many technical defects. Some bed material systems adopt a single material conveying link, which can only realize unidirectional replenishment of bed material, without considering the coordinated needs of bed material replenishment and desulfurizing agent limestone powder addition during boiler operation. In actual working conditions, the boiler needs to add desulfurizing agent conveying equipment separately, which not only increases equipment procurement costs and floor space, but also leads to asynchronous control of bed material addition and desulfurization operation, affecting desulfurization efficiency and bed stability. Summary of the Invention

[0004] This invention provides an intelligent online bed material adding device, which aims to improve the problem that boilers need to be equipped with separate desulfurizing agent conveying equipment, which not only increases the equipment purchase cost and floor space, but also causes the control of bed material adding and desulfurization operation to be out of sync, affecting desulfurization efficiency and bed stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an intelligent online bedding material adding device, comprising: The screening and circulation unit includes a drum screener, which is set on the platform of the bottom ash silo and located between the bottom ash silo and the bucket elevator. It is used to screen the bed material at the outlet of the bottom ash silo. The unqualified bed material is discharged to the transfer equipment at the bottom of the bottom ash silo through the distribution pipe, and the qualified bed material is transported to the bucket elevator through the second connecting pipe. The main conveying unit includes a bucket elevator, a secondary bed material conveyor, and a tertiary bed material conveyor. The bucket elevator is installed at the zero-meter position of the boiler and is used to lift qualified bed material. The secondary bed material conveyor is arranged laterally in the left and right directions of the boiler coal feeding operation layer and is used to receive and transfer the bed material lifted by the bucket elevator. The tertiary bed material conveyor is used to convey bed material to the external bed inlet. The multi-path distribution unit includes a three-way valve, a feeding channel, and a discharge pipe. The three-way valve is located at the top discharge port of the bucket elevator and is used to adjust the material flow direction. The feeding channel has two paths and is respectively connected to the secondary bed material conveyor and the bottom ash silo. The discharge pipe has four pipes and is installed at the lower outlet of the secondary bed material conveyor, which is used to distribute the bed material to the scraper feeder and the tertiary bed material conveyor. The multi-source material supply unit includes a weighing coal feeder, a primary bed material conveyor, and a limestone powder silo in front of the furnace. The weighing coal feeder and the primary bed material conveyor are located below the limestone powder silo in front of the furnace at an elevation of 30 meters above the boiler, and are used to convey bed material or limestone powder to the secondary bed material conveyor.

[0006] The above technical solutions enable screening during bed material circulation and addition, improving bed material quality and reducing personnel maintenance costs; the increased capacity and speed significantly shorten bed material addition time, aiming to reduce the unit start-up preparation time to within 24 hours, thus improving the unit's start-up flexibility; and the ability to add bed material or limestone powder and other multi-source materials online during operation is achieved, addressing the problem that boilers need to have separate desulfurizing agent conveying equipment, which not only increases equipment procurement costs and floor space but also leads to asynchronous control of bed material addition and desulfurization operations, affecting desulfurization efficiency and bed stability.

[0007] As a further improvement to the above technical solution: In the screening circulation unit, the lower part of the bottom ash silo is connected to the drum screener via a first connecting pipe, and a manual slide valve and an electric slide valve are installed on the first connecting pipe to adjust the bed material conveying volume; the drum screener is connected to the bucket elevator via a second connecting pipe, and an electric slide valve can be selectively installed on the second connecting pipe. Both the first connecting pipe and the second connecting pipe are seamless steel pipes with a diameter of φ219×6.

[0008] Preferably, the bucket elevator of the main conveying unit is a die-forged scale bucket elevator with an output of 50t / h and a lifting height of 43 meters. The bucket elevator, in conjunction with the main conveying unit, shortens the start-up preparation time to within 24 hours. The secondary bed material conveyor is a double-chain scale conveyor with forward and reverse operation functions. When operating in the forward direction, the bed material lifted by the bucket elevator is conveyed to the tertiary bed material conveyor. When operating in the reverse direction, the material in the limestone powder silo in front of the furnace is conveyed to the secondary bed material conveyor.

[0009] Preferably, the multi-path distribution unit has four feed pipes, all of which are seamless steel pipes with a diameter of DN200. Two of the feed pipes correspond to the interfaces of the first scraper feeder and the second scraper feeder, and each interface is equipped with an electric slide gate valve and a manual slide gate valve. The other two feed pipes are connected to the three-stage bed conveyor, and an electric slide gate valve and a manual slide gate valve are also installed at the outlet. Corrugated compensators are added at the connection between the feed pipes and the three-stage bed conveyor.

[0010] Preferably, the primary bed conveyor of the multi-source material supply unit is a double-chain apron conveyor, and is connected to the secondary bed conveyor in a driving connection. When conveying limestone powder, after the weighing coal feeder measures the material, the primary bed conveyor starts to convey the material to the secondary bed conveyor, and the secondary bed conveyor runs in reverse to convey the material from the left to the right.

[0011] Preferably, the three-way valve of the multi-path distribution unit is an electric three-way valve, which is electrically connected to the electrical control system of the matching control unit. The material flow direction is adjusted by the control signal to realize the switching of material being transported to the secondary bed conveyor or returned to the bottom ash silo for circulation.

[0012] Preferably, the discharge end of the three-stage bed material conveyor of the main conveying unit is connected to the external bed inlet through a discharge pipe. A corrugated compensator is installed at the connection between the discharge pipe and the external bed inlet. The left and right three-stage bed material conveyors are respectively set to correspond to the external beds on both sides, so as to realize the precise addition of bed material to the external beds.

[0013] Preferred options also include: The protection unit includes an overcurrent protection module, a chain break protection module, and an interlocking protection trip module, which are used to realize the safe operation protection of the equipment; The supporting control unit, including the electrical control system and the thermal control system, is electrically connected to each actuator to realize the full-process control of equipment operation; The overcurrent protection module of the protection unit is electrically connected to the drive motors of the primary bed conveyor, secondary bed conveyor, tertiary bed conveyor, and bucket elevator. When the motor current exceeds the preset threshold, an alarm signal is issued. The chain breakage protection module is installed at the chain drive mechanism of each double-chain slat conveyor to monitor the chain running status in real time. When a chain breakage occurs, a shutdown protection is triggered. The interlocking protection trip module is linked with the key execution components of the system to realize emergency tripping and shutdown of the system in the event of a major fault.

[0014] The thermal control system of the supporting control unit includes temperature sensors, pressure sensors and material level sensors, which are installed at the bottom ash silo, the limestone powder silo in front of the furnace, the first connecting pipe, the second connecting pipe, the feeding channel and the discharge pipe, respectively. The system collects operating parameters in real time and feeds them back to the control terminal to realize closed-loop control of the bed material addition process.

[0015] Preferably, the primary, secondary, and tertiary bed conveyors of the main conveying unit are all double-chain scale conveyors, and the scale material is stainless steel, in order to adapt to the high-temperature operating conditions of the boiler.

[0016] This invention provides an intelligent online bedding material adding device. It has the following beneficial effects: 1. This invention utilizes an intelligent online bed material adding device to achieve bed material circulation and screening during the adding process, thereby improving bed material quality and reducing personnel maintenance costs; it also significantly shortens bed material adding time by increasing capacity and speed, aiming to reduce the unit start-up preparation time to within 24 hours, thus improving the unit's start-up flexibility; and it enables the online addition of bed material or limestone powder and other multi-source materials, ultimately achieving the goals of flexible use, fully sealed system, and convenient maintenance.

[0017] 2. The equipment of this invention has protection functions such as overcurrent protection, chain break protection and interlock protection tripping, which reduces the probability of fault expansion and losses, and simultaneously completes the replacement and treatment work from the bottom screening and adding system of the bottom ash silo, the limestone silo bed material adding system to the main bed material and the external bed material inlet. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an intelligent online bedding material adding device according to the present invention; Figure 2 This is a schematic diagram of the structure of the bucket elevator of the present invention; Figure 3 This is a schematic diagram of the structure of the drum screen of the present invention; Figure 4 This is a top view of the secondary bed conveyor of the present invention.

[0019] The components include: 1. Bottom ash silo; 101. First connecting pipe; 102. Manual slide gate valve; 103. Electric slide gate valve; 2. Drum screen; 201. Distribution pipe; 202. Second connecting pipe; 3. Bucket elevator; 4. Three-way valve; 401. Feeding channel; 5. Secondary bed material conveyor; 501. First scraper feeder; 502. Second scraper feeder; 503. Discharge pipe; 6. Primary bed material conveyor; 7. Tertiary bed material conveyor; 8. Corrugated compensator; 9. External bed inlet; 10. Weighing feeder; 11. Furnace front limestone powder silo; 12. Boiler centerline; 13. Scraper feeder centerline. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Please see the appendix Figure 1 To be continued Figure 4 This embodiment of an intelligent online bedding material adding device includes: The screening and circulation unit includes a drum screen 2, which is installed on the platform of the bottom ash silo 1 and located between the bottom ash silo 1 and the bucket elevator 3. It is used to screen the bed material at the outlet of the bottom ash silo 1. Unqualified bed material is discharged to the transfer equipment at the bottom of the bottom ash silo 1 through the distribution pipe 201, and qualified bed material is transported to the bucket elevator 3 through the second connecting pipe 202. This realizes the screening of the bed material circulation and addition process, improves the quality of the bed material, and reduces personnel maintenance costs. The main conveying unit includes a bucket elevator 3, a secondary bed material conveyor 5, and a tertiary bed material conveyor 7. The bucket elevator 3 is installed at the zero-meter position of the boiler to lift qualified bed material. The secondary bed material conveyor 5 is arranged laterally on the left and right sides of the boiler coal feeding operating layer, distributed along both sides of the boiler centerline 12, to receive and transfer the bed material lifted by the bucket elevator 3. The tertiary bed material conveyor 7 consists of two double-chain apron conveyors, symmetrically installed on the left and right sides of the 19.4-meter operating layer of the boiler, to convey bed material to the external bed inlet 9. By increasing the capacity and speed of the bucket elevator 3, the secondary bed material conveyor 5, and the tertiary bed material conveyor 7, the bed material addition time is significantly shortened, aiming to reduce the unit start-up preparation time to within 24 hours and improve the unit's start-up flexibility. The multi-path distribution unit includes a three-way valve 4, a feeding channel 401, and a discharge pipe 503. The three-way valve 4 is located at the top discharge port of the bucket elevator 3 and is used to adjust the material flow direction. The feeding channel 401 has two paths and is connected to the secondary bed material conveyor 5 and the bottom ash silo 1 respectively. The discharge pipe 503 has four pipes and is installed at the lower outlet of the secondary bed material conveyor 5, which is used to distribute the bed material to the scraper feeder and the tertiary bed material conveyor 7. The multi-source material supply unit includes a weighing coal feeder 10, a primary bed material conveyor 6, and a limestone powder silo in front of the boiler 11. The weighing coal feeder 10 and the primary bed material conveyor 6 are located below the limestone powder silo 11 at a boiler elevation of 30 meters, and are used to convey bed material or limestone powder to the secondary bed material conveyor 5. This enables the online addition of bed material or limestone powder and other multi-source materials, ultimately achieving the goals of flexible use, a fully sealed system, and convenient maintenance.

[0022] Specifically, a drum screen 2 is installed between the boiler's bottom ash silo 1 and the bucket elevator 3 used for adding bed material. Located on the platform of the bottom ash silo 1, it screens the bed material at the outlet of the silo 1. Unqualified bed material is discharged into the bottom ash transport vehicle at the bottom of the silo 1, while qualified bed material flows directly into the bucket elevator 3. The bucket elevator 3 lifts the qualified bed material, and a three-way valve 4 adjusts the material flow direction, guiding the qualified bed material to the secondary bed material conveyor 5 for subsequent addition operations. Alternatively, it can be returned to the bottom ash silo 1 for recycling when subsequent equipment malfunctions or when bed material addition is not needed. This system can pre-remove unqualified bed material such as lumps and large-diameter impurities, preventing such materials from entering the conveying chain and causing blockages or jams. The switching function of the three-way valve enables flexible scheduling of material conveying, ensuring normal addition needs while avoiding material waste. This improves bed material quality, reduces subsequent equipment maintenance workload and downtime losses, and simultaneously increases material utilization, enhancing the system's operational flexibility and fault tolerance.

[0023] In the screening circulation unit, the lower part of the bottom ash silo 1 is connected to the drum screen 2 via a first connecting pipe 101, and a manual slide valve 102 and an electric slide valve 103 are installed on the first connecting pipe 101 to adjust the bed material conveying volume; the drum screen 2 is connected to the bucket elevator 3 via a second connecting pipe 202, and an electric slide valve 103 can be selectively installed on the second connecting pipe 202. Both the first connecting pipe 101 and the second connecting pipe 202 are seamless steel pipes with a diameter of φ219×6.

[0024] Specifically, the first connecting pipe 101 at the bottom of the ash silo 1 is made of φ219×6 seamless steel pipe, which can withstand the impact and wear of the bed material and high temperature environment; the manual slide valve 102 and the electric slide valve 103 on the pipeline adopt the principle of one main and one backup, emergency isolation. During normal operation, the electric slide valve 103 adjusts the opening according to the load feedback of the drum screen 2 to control the falling speed of the bed material and ensure uniform screening; when the equipment is under maintenance or the electric valve fails, the manual slide valve 102 can completely isolate the bed material to prevent the bed material from falling and accumulating. The second connecting pipe 202 also uses φ219×6 seamless steel pipe to ensure smooth conveying of qualified bed material. The optional electric slide valve 103 is interlocked with the operating status of the bucket elevator 3. When the bucket elevator 3 has an overload warning, the opening can be quickly reduced to decrease the feed rate. The dual-valve control system improves the accuracy and safety of bed material conveying regulation, avoiding conveying loss of control due to single valve failure; the seamless steel pipe reduces dust leakage and lowers the cost of spare parts procurement.

[0025] The main conveying unit's bucket elevator 3 is a die-forged scale bucket elevator with an output of 50t / h and a lifting height of 43 meters. In conjunction with the bucket elevator 3, the unit's start-up preparation time is shortened to within 24 hours. The secondary bed material conveyor 5 is a double-chain scale conveyor with forward and reverse operation functions. When operating in the forward direction, the bed material lifted by the bucket elevator 3 is conveyed to the tertiary bed material conveyor 7. When operating in the reverse direction, the material in the limestone powder silo 11 in front of the furnace is conveyed to the secondary bed material conveyor 5.

[0026] Specifically, the bucket elevator 3 installed at the zero-meter position of the boiler is a 50t / h high-output die-forged scale bucket elevator, which achieves efficient vertical transfer of qualified bed material. Compared with conventional bucket elevators of ≤30t / h, it increases the bed material addition speed, meeting the need for rapid filling of large amounts of bed material during boiler cold start-up. The secondary bed material conveyor 5 adopts a double-chain scale conveyor, which achieves bidirectional operation through the forward and reverse rotation principle of the motor. When running forward, the power drives the scales through chain transmission, transferring the bed material conveyed by the bucket elevator 3 to the tertiary bed material conveyor 7, adapting to the external bed addition requirements. When running in reverse, the motor rotates in the opposite direction, cooperating with the primary bed material conveyor 6 to transfer the material in the limestone powder silo 11 in front of the furnace to the main bed scraper feeder. Through the conveying link in conjunction with the bucket elevator 3, the unit start-up preparation time is shortened from more than 48 hours in the traditional way to within 24 hours, improving the flexibility of unit start-up. The bidirectional operation function of the secondary bed material conveyor 5 enables multi-condition adaptation of the same conveying link, eliminating the need for additional conveying equipment and reducing equipment costs and floor space.

[0027] The multi-path distribution unit has four feed pipes 503, all of which are seamless steel pipes with a diameter of DN200. Two of the feed pipes 503 correspond to the interfaces of the first scraper feeder 501 and the second scraper feeder 502, and each interface is equipped with an electric slide gate valve and a manual slide gate valve. The other two feed pipes 503 are connected to the three-stage bed conveyor 7, and an electric slide gate valve and a manual slide gate valve are also installed at the outlet. A corrugated compensator 8 is installed at the connection between the feed pipe 503 and the three-stage bed conveyor 7.

[0028] Specifically, the bellows compensator 8 absorbs vibrations during equipment operation and thermal expansion and contraction deformation of pipelines caused by high temperatures, preventing loosening and leakage at interfaces caused by rigid connections, improving the stability of pipeline connections, reducing the probability of leakage and pipeline damage, and extending the service life of equipment. Electric and manual slide gate valves enhance the reliability of branch control.

[0029] The primary bed conveyor 6 of the multi-source material supply unit is a double-chain apron conveyor and is connected to the secondary bed conveyor 5. When conveying limestone powder, after the weighing feeder 10 measures the material, the primary bed conveyor 6 starts to convey the material to the secondary bed conveyor 5. The secondary bed conveyor 5 runs in reverse to convey the material from the left to the right.

[0030] Specifically, the addition amount is ensured to meet the process requirements after being metered by the weighing coal feeder 10, thus avoiding material waste; the forward and reverse operation function enables flexible switching of multiple material sources, eliminating the need for additional conveying pipelines and reducing equipment costs and floor space.

[0031] The three-way valve 4 of the multi-path distribution unit is an electric three-way valve, which is electrically connected to the electrical control system of the matching control unit. It adjusts the material flow direction through control signals to realize the switching of material being conveyed to the secondary bed material conveyor 5 or returned to the bottom ash silo 1 for circulation.

[0032] In this embodiment, an electric three-way valve is used to realize the automatic switching of material flow direction. The electric three-way valve is electrically connected to the matching electrical control system, so as to facilitate the change of material conveying path. When the quality of the bed material is qualified and the subsequent equipment is running normally, the material flows to the secondary bed material conveyor 5 for addition. When the subsequent equipment fails or the bed material does not need to be added temporarily, the material is switched to the bottom ash silo 1 for cyclic storage, avoiding material waste and equipment overload.

[0033] The discharge end of the three-stage bed material conveyor 7 of the main conveying unit is connected to the external bed inlet 9 through the discharge pipe 503. A corrugated compensator 8 is installed at the connection between the discharge pipe 503 and the external bed inlet 9. The left and right three-stage bed material conveyors 7 are respectively set to correspond to the external beds on both sides to realize precise bed material addition to the external beds.

[0034] Specifically, the symmetrically arranged three-stage bed conveyor 7 enables independent addition of external beds on both sides, avoiding uneven addition that leads to unstable operation of the external beds and improving the overall operating efficiency of the boiler; the corrugated compensator 8 effectively absorbs vibration and thermal deformation, reduces stress damage at the connection interface, and lowers the probability of leakage.

[0035] In one embodiment, the device further includes: The protection unit includes an overcurrent protection module, a chain break protection module, and an interlocking protection trip module, which are used to realize the safe operation protection of the equipment; The supporting control unit, including the electrical control system and the thermal control system, is electrically connected to each actuator to realize the full-process control of equipment operation; The overcurrent protection module of the protection unit is electrically connected to the drive motors of the primary bed conveyor 6, the secondary bed conveyor 5, the tertiary bed conveyor 7, and the bucket elevator 3. When the motor current exceeds the preset threshold, an alarm signal is issued. The chain breakage protection module is installed at the chain drive mechanism of each double-chain slat conveyor to monitor the chain running status in real time. When a chain breakage occurs, the shutdown protection is triggered. The interlocking protection trip module is linked with the key execution components of the system. When a major fault occurs, the system can be tripped and shut down urgently.

[0036] The thermal control system of the supporting control unit includes temperature sensors, pressure sensors and material level sensors, which are installed at the bottom ash silo 1, the limestone powder silo in front of the furnace 11, the first connecting pipe 101, the second connecting pipe 202, the feeding channel 401 and the discharge pipe 503, respectively. The system collects operating parameters in real time and feeds them back to the control terminal to realize closed-loop control of the bed material addition process.

[0037] Specifically, this embodiment achieves safe operation of the equipment through protection units. The overcurrent protection module monitors the operating current of the drive motor to prevent the motor from burning out due to overload. The chain breakage protection module monitors the chain status of the double-chain slatter machine to prevent material accumulation and equipment damage caused by chain breakage. The interlocking protection trip module realizes emergency shutdown in case of major faults through the status linkage of multiple components to prevent the fault from escalating. The thermal control system collects operating parameters, and the two work together to realize the automated and intelligent operation of the equipment.

[0038] The primary bed conveyor 6, secondary bed conveyor 5, and tertiary bed conveyor 7 of the main conveying unit all adopt double-chain apron conveyors, and the apron material is stainless steel to adapt to the high-temperature operating conditions of the boiler.

[0039] The workflow of an intelligent online bedding material adding device is as follows: (1) A drum screen 2 is installed between the bottom ash silo 1 of the boiler and the bucket elevator 3 used for adding bed material. The screen is set on the platform of the bottom ash silo 1 to screen the bed material at the outlet of the bottom ash silo 1. The unqualified bed material is discharged into the bottom ash transport vehicle at the bottom of the bottom ash silo 1, and the qualified bed material is discharged directly into the bucket elevator 3.

[0040] (2) A bucket elevator 3 with an output of about 50t / h is installed at the zero-meter position of the boiler, with a lifting height of 43 meters. It is connected to the bottom of the bottom ash silo 1 by a connecting pipe. The connecting pipe is a seamless steel pipe of φ219×6. A manual slide valve 102 is installed on the connecting pipe at the bottom of the bottom ash silo 1 to adjust the bed material conveying volume. At the same time, a three-way valve 4 is set at the top discharge port of the bucket elevator 3. The three-way valve 4 can adjust the material flow direction. Two feeding channels 401 are set at the bottom of the three-way valve 4. One feeding channel 401 is connected to the secondary bed material conveyor 5, so that the material goes to the secondary bed material conveyor 5. The other feeding channel 401 is connected to the bottom ash silo 1, so that the material returns to the bottom ash silo 1.

[0041] (3) A double-chain scale conveyor is arranged laterally in the left and right directions of the boiler coal feeding operation layer as a secondary bed material conveyor 5. Assuming that the direction from the bucket elevator 3 to the secondary bed material conveyor 5 to the tertiary bed material conveyor 7 is positive, then the direction from the limestone powder silo 11 in front of the furnace to the primary bed material conveyor 6 to the secondary bed material conveyor 5 is negative. The bed material lifted by the bucket elevator 3 falls to the secondary bed material conveyor 5 through the discharge pipe, and is then conveyed to the tertiary bed material conveyor 7 in the positive direction through the secondary bed material conveyor 5. Four discharge pipes 503 are installed at the lower outlet of the secondary bed material conveyor 5. The discharge pipes 503 are seamless steel pipes with a diameter of DN200. Two of them are connected to two of the four coal feeding lines for adding the main bed material. The coal feeding lines adopt scraper feeders. A DN300 electric gate and a manual gate are installed at the interface of the scraper feeder to control the amount of main bed material added, or as a system isolation. At the 19.4-meter operating level of the boiler, a double-chain scale conveyor is installed on each of the left and right sides as a third-stage bed material conveyor 7 for adding bed material to the external bed. The bed material enters the third-stage bed material conveyor 7 of the external bed through two additional discharge pipes at the bottom of the second-stage bed material conveyor 5, and is connected to the top of the empty chamber of the external bed through the discharge pipes. Bed material is added to the external bed respectively. Two seamless steel pipes with a diameter of DN200 are installed at the bottom of the second-stage bed material conveyors 5 on the left and right sides respectively. One electric gate with a diameter of DN300 and one manual gate are installed at the outlet of each conveyor to control the feeding speed of the external bed or to serve as a system partition.

[0042] (4) A weighing coal feeder 10 and a primary bed material conveyor 6 are installed at the lower part of the limestone powder silo 11 in front of the boiler (elevation 30 meters). The primary bed material conveyor adopts a double-chain scale machine to realize the material from the limestone powder silo 11 in front of the boiler to the secondary bed material conveyor 5, which conveys bed material or limestone powder and other multi-source materials. At this time, the secondary bed material conveyor 5 runs in reverse to realize the purpose of conveying bed material from the left side to the right side. The rest of the process flow is the same as above.

[0043] An intelligent online bed material adding device enables screening during bed material circulation and adding, improving bed material quality and reducing personnel maintenance costs. Increased capacity and speed significantly shorten bed material adding time, aiming to reduce unit start-up preparation time to within 24 hours, improving the unit's start-up flexibility. It enables online adding of bed materials or limestone powder and other multi-source materials, ultimately achieving flexible operation, a fully sealed system, and convenient maintenance. The system also features overcurrent, chain break, and interlocking protection trip functions, reducing the probability of escalating faults and losses. Simultaneously, all replacement and remediation work was completed from the bottom screening and adding system of the bottom ash silo, the limestone silo bed material adding system to the main bed material and external bed material inlets.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An intelligent online bedding material adding device, characterized in that, include: The screening and circulation unit includes a drum screen (2), which is set on the platform of the bottom ash silo (1) and located between the bottom ash silo (1) and the bucket elevator (3). It is used to screen the bed material at the outlet of the bottom ash silo (1). The unqualified bed material is discharged to the transfer equipment at the bottom of the bottom ash silo (1) through the distribution pipe (201), and the qualified bed material is transported to the bucket elevator (3) through the second connecting pipe (202). The main conveying unit includes a bucket elevator (3), a secondary bed material conveyor (5) and a tertiary bed material conveyor (7). The bucket elevator (3) is installed at the zero-meter position of the boiler and is used to lift qualified bed material. The secondary bed material conveyor (5) is distributed on both sides of the boiler centerline (12) and is used to receive and transfer the bed material lifted by the bucket elevator (3). The tertiary bed material conveyor (7) is used to convey bed material to the external bed inlet (9). The multi-path distribution unit includes a three-way valve (4), a feeding channel (401), and a discharge pipe (503). The three-way valve (4) is located at the top outlet of the bucket elevator (3) and is used to adjust the material flow direction. The feeding channel (401) is two-way and is connected to the secondary bed material conveyor (5) and the bottom ash silo (1) respectively. The discharge pipe (503) is installed at the lower outlet of the secondary bed material conveyor (5) and is used to distribute the bed material to the scraper feeder and the tertiary bed material conveyor (7). The multi-source material supply unit includes a weighing coal feeder (10), a primary bed material conveyor (6), and a limestone powder silo in front of the furnace (11). The weighing coal feeder (10) and the primary bed material conveyor (6) are used to convey bed material or limestone powder to the secondary bed material conveyor (5).

2. The intelligent online bedding material adding device according to claim 1, characterized in that, In the screening circulation unit, the lower part of the bottom ash silo (1) is connected to the drum screen (2) through a first connecting pipe (101), and a manual slide valve (102) and an electric slide valve (103) are installed on the first connecting pipe (101) to adjust the bed material conveying amount; the drum screen (2) is connected to the bucket elevator (3) through a second connecting pipe (202).

3. The intelligent online bedding material adding device according to claim 1, characterized in that, The main conveying unit's bucket elevator (3) is a die-forged scale bucket elevator with an output of 50t / h and a lifting height of 43 meters. The bucket elevator (3) can shorten the unit's start-up preparation time to within 24 hours. The secondary bed material conveyor (5) is a double-chain scale conveyor with forward and reverse operation functions. The tertiary bed material conveyor (7) consists of two double-chain scale conveyors, symmetrically installed on the left and right sides of the boiler's 19.4-meter operating layer. The weighing coal feeder (10) and the primary bed material conveyor (6) are located below the limestone powder silo (11) in front of the boiler at an elevation of 30 meters.

4. The intelligent online bedding material adding device according to claim 1, characterized in that, The multi-path distribution unit has four feed pipes (503), all of which are seamless steel pipes with a diameter of DN200. Two of the feed pipes (503) correspond to the interfaces of the first scraper feeder (501) and the second scraper feeder (502), and each interface is equipped with an electric slide gate valve and a manual slide gate valve. The other two feed pipes (503) are connected to the three-stage bed conveyor (7), and an electric slide gate valve and a manual slide gate valve are also installed at the outlet. A corrugated compensator (8) is installed at the connection between the feed pipe (503) and the three-stage bed conveyor (7).

5. The intelligent online bedding material adding device according to claim 1, characterized in that, The primary bed conveyor (6) of the multi-source material supply unit is a double-chain scale conveyor and is connected to the secondary bed conveyor (5) for transmission. When conveying limestone powder, after the weighing feeder (10) measures the material, the primary bed conveyor (6) starts to convey the material to the secondary bed conveyor (5), and the secondary bed conveyor (5) runs in reverse to convey the material from the left to the right.

6. The intelligent online bedding material adding device according to claim 1, characterized in that, The three-way valve (4) of the multi-path distribution unit is an electric three-way valve, which is electrically connected to the electrical control system of the matching control unit. The material flow direction is adjusted by the control signal, and the material is switched to be transported to the secondary bed material conveyor (5) or returned to the bottom ash silo (1) in a cycle.

7. The intelligent online bedding material adding device according to claim 1, characterized in that, The discharge end of the three-stage bed material conveyor (7) of the main conveying unit is connected to the external bed inlet (9) through the discharge pipe (503). A corrugated compensator (8) is installed at the connection between the discharge pipe (503) and the external bed inlet (9). The left and right three-stage bed material conveyors (7) are respectively set up for the external beds on both sides to add bed material to the external beds.

8. The intelligent online bedding material adding device according to claim 1, characterized in that, Also includes: The protection unit includes an overcurrent protection module, a chain break protection module, and an interlocking protection trip module, which are used for the safe operation protection of the equipment. The supporting control unit, including the electrical control system and the thermal control system, is electrically connected to each actuator and is used for the whole process control of equipment operation; The overcurrent protection module of the protection unit is electrically connected to the drive motors of the primary bed conveyor (6), the secondary bed conveyor (5), the tertiary bed conveyor (7), and the bucket elevator (3). When the motor current exceeds the preset threshold, an alarm signal is issued. The chain breakage protection module is installed at the chain drive mechanism of each double-chain slatted machine to monitor the chain running status in real time. When a chain breakage occurs, the shutdown protection is triggered. The interlocking protection trip module is linked with the key execution components of the system. When a major fault occurs, the system trips and stops in an emergency.

9. The intelligent online bedding material adding device according to claim 8, characterized in that, The thermal control system of the supporting control unit includes a temperature sensor, a pressure sensor and a material level sensor, which are installed at the bottom ash silo (1), the limestone powder silo in front of the furnace (11), the first connecting pipe (101), the second connecting pipe (202), the feeding channel (401) and the discharge pipe (503), respectively, to collect operating parameters in real time and feed them back to the control terminal for closed-loop control of the bed material addition process.

10. The intelligent online bedding material adding device according to claim 8, characterized in that, The primary bed conveyor (6), secondary bed conveyor (5) and tertiary bed conveyor (7) of the main conveying unit all adopt double-chain scale machine, and the scale material is stainless steel to adapt to the high temperature conditions of the boiler operating environment.

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