A separator efficiency adjustable circulating fluidized bed boiler system and a control method thereof

Abstract

The present application relates to the technical field of boiler control, and discloses a circulating fluidized bed boiler system with adjustable separator efficiency and a control method thereof, the system comprising: a furnace, multiple separators, multiple inlet depth adjustable baffles, multiple baffle driving mechanisms, an ash amount buffer bin, a return feeder, a denitration injection device, a recirculation regulating valve and an intelligent master control system, wherein the intelligent master control system is used to change the separator efficiency by adjusting the insertion depth of the inlet depth adjustable baffles based on the measurement signals of the boiler system, and to realize the coordinated control between the separator efficiency and the boiler combustion state by controlling the recirculation regulating valve, the ash amount regulating valve, the return air system and the denitration injection device in linkage. The present application realizes the coordinated control of the separator efficiency, the combustion state and the denitration process by taking the separator efficiency as the core regulating variable, and improves the operation stability and environmental protection performance of the boiler in a wide load range.

Description

Technical Field

[0001] This invention relates to the field of boiler control technology, specifically to a circulating fluidized bed boiler system with adjustable separator efficiency and its control method. Background Technology

[0002] Circulating fluidized bed (CFB) boilers are widely used in the power and heating sectors due to their advantages such as wide fuel adaptability, good load regulation performance, and low pollutant emissions. Their core feature lies in the material circulation loop formed by the furnace and cyclone separator; the separator efficiency directly affects the circulating ash concentration, furnace heat transfer, combustion efficiency, and pollutant control. Large CFB boilers face three major technical challenges when operating under deep peak-shaving conditions (25%-70% rated load): Firstly, the uneven flow field in parallel multiple separators, deviations in the flow field distribution at the furnace outlet, and differences in resistance in each flue lead to uneven flue gas velocity and solid concentration at the inlet of each separator. This results in inconsistent separator efficiency, imbalanced circulating ash distribution, and the risk of localized wear, decreased circulation stability, and even "ash collapse." Existing adjustment methods are mostly static, making it difficult to achieve precise, differentiated, and balanced control.

[0003] Secondly, the furnace temperature drops during deep peak shaving, causing the Selective Non-Catalytic Reduction (SNCR) denitrification system to be unable to maintain the ideal reaction temperature window of 850-1050℃, resulting in a sharp decrease in denitrification efficiency and an increase in ammonia slip. Currently, SNCR control and combustion control are mostly independent loops, lacking deep coupling with key parameters of material circulation.

[0004] Third, existing online adjustment methods for separator efficiency are limited, and the adjustment behavior only focuses on optimizing the performance of the separator itself, failing to take separation efficiency as the core lever for linkage combustion, material balance and environmental protection systems, and thus failing to systematically solve the complex operation problems under low load. Summary of the Invention

[0005] In view of this, the present invention provides a circulating fluidized bed boiler system with adjustable separator efficiency and its control method, so as to solve the problem of poor coordination between multiple separator efficiency adjustment methods and boiler systems in the prior art.

[0006] In a first aspect, the present invention provides a circulating fluidized bed boiler system with adjustable separator efficiency, comprising: a furnace, multiple separators, multiple inlet depth adjustable baffles, multiple baffle drive mechanisms, an ash buffer silo, a return feeder, a denitrification injection device, a recirculation regulating valve, and an intelligent central control system. The inlet of each separator is connected to the furnace outlet via a furnace outlet flue, and the gas outlets of each separator are connected to a common separator outlet flue. The lower ash discharge port of each separator is sequentially connected to an ash buffer silo and a return feeder, and the outlet of the return feeder is connected back to the furnace. The separator outlet flue is connected to the furnace via a flue gas recirculation pipeline, and a recirculation regulating valve is installed on the flue gas recirculation pipeline. The denitrification injection device is located in the separator outlet flue. The upper part; adjustable inlet depth baffles are installed in the inlet flue of each separator. Each adjustable inlet depth baffle is connected to a baffle drive mechanism, which drives the adjustable inlet depth baffle to make linear extension and retraction movements along the radial direction of the flue. The intelligent central control system is connected to the baffle drive mechanism, the recirculation regulating valve, the ash regulating valve at the bottom outlet of the ash buffer bin, the return air system at the inlet of the return air chamber, and the denitrification injection device. The intelligent central control system is used to change the separator efficiency by adjusting the insertion depth of the adjustable inlet depth baffle based on the measurement signals of the boiler system, and to control the recirculation regulating valve, the ash regulating valve, the return air system, and the denitrification injection device in a coordinated manner to achieve coordinated control between the separator efficiency and the boiler combustion state.

[0007] The circulating fluidized bed boiler system with adjustable separator efficiency provided by this invention achieves stepless adjustment of separator efficiency through the setting of an adjustable inlet depth baffle and a baffle drive mechanism. It features a simple structure, reliable operation, and the ability to adjust separation efficiency online to adapt to different operating conditions. Through the connection between the intelligent central control system and each actuator, the baffle insertion depth is adjusted in real time based on the boiler system's measurement signals, and the recirculation regulating valve, ash quantity regulating valve, return air system, and denitrification injection device are controlled in conjunction, achieving coordinated control of separator efficiency and boiler combustion state. Therefore, on the one hand, by differentially adjusting the depth of each baffle, the solid flow rate among multiple separators can be effectively balanced, solving the problem of uneven flow field; on the other hand, by synchronously adjusting the baffle depth, the circulating ash concentration can be actively controlled to stabilize the furnace combustion state; furthermore, through the coordinated control of the ash quantity buffer bin, return air system, and recirculation valve, fluctuations in circulating ash quantity can be smoothed, bed temperature stability maintained, and the risk of ash collapse prevented, thereby significantly improving the boiler's operational stability and coordination over a wide load range.

[0008] In one alternative embodiment, the windward side of the adjustable inlet depth baffle is provided with a wear-resistant ceramic layer; a sealing structure is provided between the adjustable inlet depth baffle and the wall of the inlet flue.

[0009] In one optional embodiment, the system further includes: a furnace outlet flow field probe, a separator inlet flow field probe, an ash flow monitor, a first bed temperature sensor, a second bed temperature sensor, an oxygen concentration sensor, an online coal quality analyzer, a NOx raw emission sensor, a temperature sensor, a NOx emission sensor, and an ammonia slip sensor. The furnace outlet flow field probe is located within the furnace outlet flue; the separator inlet flow field probe is located within each inlet flue; the ash flow monitor is located on the riser of each separator; the first bed temperature sensor, the second bed temperature sensor, and the oxygen concentration sensor are located within the furnace; the online coal quality analyzer is located on the coal feeding system connected to the furnace; the NOx raw emission sensor is located on the furnace outlet flue or the separator inlet flue; the temperature sensor, the NOx emission sensor, and the ammonia slip sensor are located on the separator outlet flue, with the temperature sensor located upstream of the spray gun of the denitrification injection device, and the NOx emission sensor and the ammonia slip sensor located downstream of the spray gun.

[0010] In an alternative embodiment, the device further includes a displacement sensor, which is integrated into the baffle drive mechanism for providing feedback on the insertion depth of the inlet depth adjustable baffle.

[0011] Secondly, the present invention provides a control method for a circulating fluidized bed boiler system with adjustable separator efficiency, used to control the system described in the first aspect or any corresponding embodiment above. The method includes: adjusting each inlet depth adjustable baffle to a preset initial insertion depth and closing all recirculation regulating valves; when the boiler is under rated load, adjusting the insertion depth of each inlet depth adjustable baffle and the ammonia injection quantity of the denitrification injection device based on the boiler system's measurement signals to match the separator efficiency with the boiler combustion state; when a load reduction command is received, adjusting the insertion depth of each inlet depth adjustable baffle, controlling the air volume of the ash buffer silo storing circulating ash and the return air system, and opening the recirculation regulating valves; when a load increase command is received, adjusting the insertion depth of each inlet depth adjustable baffle, reducing the opening of all recirculation regulating valves to a preset opening, and then controlling the ash regulating valves to return the circulating ash stored in the ash buffer silo to the furnace.

[0012] The control method for a circulating fluidized bed boiler system with adjustable separator efficiency provided by this invention achieves coordinated adjustment of separator efficiency and boiler combustion state through a phased control strategy. During the startup phase, the baffle depth is preset and the recirculation valve is closed to establish initial conditions for stable system operation. Under rated load conditions, the baffle insertion depth and ammonia injection rate are dynamically adjusted based on measurement signals to match separator efficiency with combustion state in real time, optimizing material circulation and combustion efficiency. After a load reduction command is triggered, the separation efficiency is reduced by decreasing the baffle depth, the ash buffer silo is controlled to store circulating ash, and the return air volume is adjusted to match ash volume changes. Simultaneously, the recirculation valve is opened to introduce flue gas to maintain bed temperature, effectively mitigating fluctuations in circulating ash volume and bed temperature drops caused by sudden load changes. After a load increase command is triggered, the separation efficiency is restored by increasing the baffle depth, the recirculation valve is closed to gradually exit the recirculation mode, and the circulating ash stored in the buffer silo is returned to the furnace to quickly replenish materials and support load recovery. Therefore, this invention achieves coordinated control of separator efficiency and combustion state under all operating conditions, improving the boiler's operational stability and responsiveness during load changes.

[0013] In one optional implementation, the process of adjusting the insertion depth of each inlet depth adjustable baffle and the ammonia injection quantity of the denitrification injection device based on the measurement signals of the boiler system to match the separator efficiency with the boiler combustion state includes: acquiring flow field monitoring data, combustion state monitoring data, and NOx emission monitoring data of the boiler system; calculating the first depth adjustment amount of each inlet depth adjustable baffle based on the flow field monitoring data, and then controlling the extension and retraction of the corresponding baffle drive mechanism to make the solid flow rate deviation of each separator less than a preset threshold; wherein, each first depth adjustment amount is calculated by multiplying the deviation of the solid flow rate of each separator from the average flow rate by a preset adjustment coefficient; The second depth adjustment amount of each inlet depth adjustable baffle is calculated based on the flow field monitoring data, and the corresponding baffle drive mechanism is controlled to extend and retract, so that the furnace bed temperature is maintained within the preset temperature window; wherein, each second depth adjustment amount is calculated by multiplying the difference between the average furnace bed temperature and the target bed temperature by a preset adjustment coefficient; the ammonia injection amount adjustment of the denitrification injection device is calculated based on the NOx emission monitoring data, and the ammonia injection amount of the denitrification injection device is adjusted so that the denitrification efficiency is greater than the preset efficiency and the ammonia slip concentration is less than the preset concentration; wherein, the ammonia injection amount adjustment is calculated by the difference between the current denitrification efficiency and the preset target denitrification efficiency and the difference between the current ammonia slip concentration and the preset upper limit.

[0014] In one optional implementation, when a load reduction command is received, the process of adjusting the insertion depth of each inlet depth adjustable baffle includes: calculating the third depth adjustment amount of each inlet depth adjustable baffle according to the load reduction magnitude, and then controlling the corresponding baffle drive mechanism to extend or retract; wherein, each third depth adjustment amount is calculated from the load reduction magnitude and a preset baffle depth adjustment curve.

[0015] In one optional implementation, when a load reduction command is received, the process of controlling the air volume of the ash buffer silo storing circulating ash and the return air system, and opening the recirculation regulating valve, includes: controlling the ash regulating valve to open, allowing circulating ash to enter the ash buffer silo for storage; calculating the reduction in the air volume of the return air system based on each third depth adjustment amount, and then controlling the return air system to reduce the air volume so that the return air volume matches the circulating ash volume; wherein, the reduction in air volume is calculated by the sum of the reductions in the depths of each baffle and a preset air volume adjustment coefficient; when the furnace bed temperature is lower than a preset value, calculating the increase in the opening of the recirculation regulating valve, and controlling the recirculation regulating valve to open based on the increase in opening, allowing flue gas to return to the furnace through the flue gas recirculation pipe; wherein, the increase in opening is calculated by the difference between the current bed temperature and the preset target bed temperature.

[0016] In one optional implementation, when a load increase command is received, the process of adjusting the insertion depth of each inlet depth adjustable baffle includes: calculating the fourth depth adjustment amount of each inlet depth adjustable baffle according to the load increase amplitude, and then controlling the corresponding baffle drive mechanism to extend or retract; wherein, each fourth depth adjustment amount is calculated from the load increase amplitude and a preset baffle depth adjustment curve.

[0017] In one optional implementation, when a load increase command is received, the process of reducing the opening of all recirculation regulating valves to a preset opening and then controlling the ash quantity regulating valve to return the circulating ash stored in the ash quantity buffer bin to the furnace includes: calculating the amount of reduction in the opening of the recirculation regulating valve and then controlling the recirculation regulating valve to gradually decrease; wherein, the amount of reduction in opening is calculated from the difference between the current load and the target load; when the recirculation regulating valve is fully closed, calculating the amount of increase in the opening of the ash quantity regulating valve and controlling the ash quantity regulating valve to open based on the amount of increase in opening, so that the circulating ash stored in the ash quantity buffer bin is returned to the furnace via the return feeder; wherein, the amount of increase in opening is calculated from the amount of circulating ash stored in the ash quantity buffer bin and a preset return rate. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a composition diagram of a circulating fluidized bed boiler system with adjustable separator efficiency according to an embodiment of the present invention; Figure 2 This is a schematic flowchart of a control method for a circulating fluidized bed boiler system with adjustable separator efficiency according to an embodiment of the present invention. Figure 3 This is a diagram showing the composition of the control device for a circulating fluidized bed boiler system with adjustable separator efficiency according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0021] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0022] This embodiment provides a circulating fluidized bed boiler system with adjustable separator efficiency, such as... Figure 1 As shown, it includes: furnace 1, multiple separators 5, multiple inlet depth adjustable baffles 14, multiple baffle drive mechanisms 15, ash buffer silo 10, return feeder 12, denitrification injection device 18, recirculation regulating valve 17 and intelligent central control system.

[0023] Figure 1 In this system, the inlet of each separator 5 is connected to the outlet of the furnace 1 through the furnace outlet flue 4. The gas outlets of each separator 5 are connected to the separator outlet flue 7. The lower ash discharge port of each separator 5 is connected to the ash buffer bin 10 and the return feeder 12 in sequence. The outlet of the return feeder 12 is connected back to the furnace 1. The separator outlet flue 7 and the furnace 1 are connected through the flue gas recirculation pipe 16. The flue gas recirculation pipe 16 is equipped with a recirculation regulating valve 17. The denitrification injection device 18 is installed on the separator outlet flue 7. The inlet depth adjustable baffle 14 is installed in the inlet flue 6 of each separator 5. Each inlet depth adjustable baffle 14 is connected to a baffle drive mechanism 15. The baffle drive mechanism 15 is used to drive the inlet depth adjustable baffle 14 to make linear extension and retraction movements along the radial direction of the flue.

[0024] Specifically, Figure 1During boiler operation, the dust-laden flue gas generated in the furnace 1 is diverted through the furnace outlet flue 4 into the inlet flue 6 of each separator 5. The adjustable inlet depth baffles 14, installed within each inlet flue 6, can linearly extend and retract radially along the flue under the drive of the baffle drive mechanism 15. By changing the depth of the baffles extending into the flue, the flow cross-sectional area of ​​the inlet flue 6 is adjusted, thereby changing the flue gas velocity and flow pattern entering the separator 5, achieving stepless adjustment of the separator efficiency.

[0025] Specifically, Figure 1 In the process, the flue gas purified by separator 5 is collected from its gas outlet into separator outlet flue 7. A denitrification injection device 18 installed on it injects a reducing agent into the flue, reacting with nitrogen oxides in the flue gas to achieve denitrification. The circulating ash separated by separator 5 enters the ash buffer bin 10 and return feeder 12 sequentially through the lower ash discharge port. The return feeder 12 then sends it back to the furnace 1 for recirculation, forming a material circulation loop. Part of the flue gas is drawn out from separator outlet flue 7 and returned to the furnace 1 via flue gas recirculation pipe 16 and recirculation regulating valve 17. By adjusting the opening of the recirculation regulating valve 17, the recirculated flue gas flow rate can be controlled, utilizing the sensible heat of the high-temperature flue gas to stabilize the furnace bed temperature.

[0026] Figure 1 In the middle, the intelligent central control system is connected to the baffle drive mechanism 15, the recirculation regulating valve 17, the ash regulating valve 11 at the bottom outlet of the ash buffer silo 10, the return air system 13 at the air chamber inlet of the return feeder 12, and the denitrification injection device 18. The intelligent central control system is used to change the separator efficiency by adjusting the insertion depth of the inlet depth adjustable baffle 14 based on the measurement signal of the boiler system, and to control the recirculation regulating valve 17, the ash regulating valve 11, the return air system 13, and the denitrification injection device 18 in a coordinated manner to achieve coordinated control between the separator efficiency and the boiler combustion state.

[0027] Specifically, Figure 1 In this system, the intelligent central control system, as the core control unit, performs comprehensive calculations and decisions based on the real-time operating status of the boiler system, including multi-dimensional information such as flow field distribution, combustion parameters, load commands, and equipment feedback. On one hand, the intelligent central control system adjusts the insertion depth of each inlet adjustable baffle 14 through the baffle drive mechanism 15, thereby changing the separation efficiency of the separator 5 and controlling the circulating ash concentration, furnace heat transfer intensity, and material circulation rate. On the other hand, based on the changes in separation efficiency, the intelligent central control system coordinates the recirculation regulating valve 17, ash quantity regulating valve 11, return air system 13, and denitrification injection device 18. By adjusting the recirculated flue gas flow rate, circulating ash storage and release rate, return air volume, and ammonia injection volume, the various actuators cooperate to achieve dynamic matching and coordinated control of separator efficiency and boiler combustion state under all operating conditions.

[0028] Optionally, separator 5 is a cyclone separator, and denitrification injection device 18 is an SNCR type.

[0029] The circulating fluidized bed boiler system with adjustable separator efficiency provided in this embodiment features an adjustable inlet depth baffle and its drive mechanism, which achieves stepless adjustment of separation efficiency through a single linear telescopic motion. This design completely eliminates complex rotating or angle adjustment components, resulting in a simple mechanical structure and fewer moving parts. Under the inherent high temperature, high dust, and high wear conditions of CFB boilers, the failure rate is significantly reduced, sealing reliability is high, and daily maintenance and online inspection are more convenient, effectively improving equipment availability and lifespan.

[0030] Optionally, the windward side of the adjustable inlet depth baffle 14 is provided with a wear-resistant ceramic layer. This layer utilizes the high hardness and wear resistance of the ceramic material to resist the high-speed erosion of dust-laden flue gas, extending the baffle's service life. A high-temperature sealing structure is provided between the adjustable inlet depth baffle 14 and the wall of the inlet flue 6 to prevent unseparated flue gas from leaking directly through the gap between the baffle and the wall, ensuring adjustment accuracy and separation effect. Together, these features enable the adjustable inlet depth baffle 14 to operate stably for extended periods under harsh conditions of high temperature and high dust, achieving reliable adjustment of the separator efficiency.

[0031] In some alternative implementations, such as Figure 1 As shown, it also includes: a furnace outlet flow field probe 101, a separator inlet flow field probe 102, an ash flow monitor 103, a first bed temperature sensor 104, a second bed temperature sensor 105, an oxygen concentration sensor 106, an online coal quality analyzer 107, a NOx raw emission sensor 108, a temperature sensor 109, a NOx emission sensor 110, and an ammonia slip sensor 111. The furnace outlet flow field probe 101 is installed inside the furnace outlet flue 4; the separator inlet flow field probe 102 is installed inside each inlet flue 6; and the ash flow monitor 103 is installed on the vertical shaft of each separator 5. On pipe 9; the first bed temperature sensor 104, the second bed temperature sensor 105 and the oxygen concentration sensor 106 are installed inside the furnace 1; the online coal quality analyzer 107 is installed on the coal feeding system 2 connected to the furnace 1; the NOx raw emission sensor 108 is installed on the furnace outlet flue 4 or the separator inlet flue 6; the temperature sensor 109, the NOx emission sensor 110 and the ammonia escape sensor 111 are installed on the separator outlet flue 7, with the temperature sensor 109 located upstream of the spray gun of the denitrification injection device 18, and the NOx emission sensor 110 and the ammonia escape sensor 111 located downstream of the spray gun.

[0032] Specifically, Figure 1In this system, sensors work together to acquire comprehensive operational data of the boiler system. The furnace outlet flow field probe 101 and the separator inlet flow field probe 102 collect velocity distribution data at the furnace outlet and each separator inlet, respectively. The ash flow monitor 103 monitors the solid flow rate within each separator riser 9 in real time, collectively forming a flow field monitoring system. The first bed temperature sensor 104, the second bed temperature sensor 105, and the oxygen concentration sensor 106 collect temperature distribution and oxygen content data within the furnace 1. The online coal quality analyzer 107 collects coal quality parameters from the coal feeding system 2, collectively forming a combustion state monitoring system. The NOx raw emission sensor 108 collects the NOx concentration before denitrification, the temperature sensor 109 collects the flue gas temperature upstream of the spray gun to determine if it is within the denitrification reaction window, and the NOx emission sensor 110 and ammonia slip sensor 111 collect the NOx concentration and ammonia slip downstream of the spray gun after denitrification, collectively forming an environmental emission monitoring system. All the above measurement signals are transmitted in real time to the intelligent central control system, providing data support for separator efficiency adjustment and the coordinated control of various actuators.

[0033] This embodiment addresses the industry challenge of uneven flow fields in parallel multi-separator systems of large CFB boilers. Through a flow field simulation and optimization unit integrated into the intelligent central control system, combined with real-time data from furnace outlet flow field probes, separator inlet flow field probes, and ash flow monitors, it can accurately analyze and predict the operational deviations of each separator. The system can issue different depth commands to the adjustable baffle at the inlet depth of each separator, achieving precise differentiated adjustment for each separator. This fundamentally solves the problems of efficiency deviation, localized wear, and circulation stability caused by uneven flow fields, resulting in highly uniform solid flow rates in each separator and improving the overall economic efficiency and safety of the boiler operation. Using separator efficiency as the core adjustment variable, a closed-loop control logic of "baffle depth—separation efficiency—circulating ash concentration—furnace bed temperature—NOx reduction" is established. Based on data from the online coal quality analyzer, bed temperature sensor, and NOx emission sensor, the system can intelligently decide and synchronously adjust the depth of all baffles, thereby optimizing combustion efficiency while actively reducing the initial NOx formation concentration, effectively resolving the traditional contradiction of balancing low-NOx combustion and boiler thermal efficiency. In some alternative implementations, such as Figure 1 As shown, it also includes: a displacement sensor 112, wherein the displacement sensor 112 is integrated on the baffle drive mechanism 15 and is used to provide feedback on the insertion depth of the inlet depth adjustable baffle 14.

[0034] Specifically, Figure 1In this system, the displacement sensor 112 detects the displacement of the adjustable inlet depth baffle 14 in real time as the baffle drive mechanism 15 extends and retracts, and feeds back the detected insertion depth signal to the intelligent control system. The intelligent control system compares the feedback signal with the target depth command. If a deviation exists, it further adjusts the baffle drive mechanism 15 to form a closed-loop control, thereby achieving precise control of the insertion depth of the adjustable inlet depth baffle 14 and ensuring the accuracy and repeatability of the separator efficiency adjustment.

[0035] Optionally, the boiler system also includes an air distribution system 3 and a tail flue 8. The air distribution system 3 is used to provide primary air and secondary air to the furnace 1 to fluidize the bed material and achieve staged combustion. Its primary air outlet is connected to the air distribution plate at the bottom of the furnace 1, and its secondary air outlet is connected to the secondary air inlet at the bottom of the furnace 1. The tail flue 8 is located downstream of the separator outlet flue 7 and is used to receive the flue gas after purification by the separator 5 and treatment by the denitrification injection device 18. It is also equipped with a heating surface to recover the waste heat of the flue gas.

[0036] Optionally, the boiler system also includes a recirculated flue gas temperature sensor 113 and a buffer silo level gauge 114. The recirculated flue gas temperature sensor 113 is installed on the flue gas recirculation pipe 16 to monitor the temperature of the recirculated flue gas in real time and transmit the temperature signal to the intelligent control system. The intelligent control system determines the thermal state of the recirculated flue gas based on the signal and then adjusts the opening of the recirculation regulating valve 17 to control the amount of recirculated flue gas entering the furnace 1, thereby achieving active regulation of the furnace bed temperature. The buffer silo level gauge 114 is installed on the side wall of the ash buffer silo 10 to monitor the accumulation height of the circulating ash in the silo in real time and transmit the level signal to the intelligent control system. The intelligent control system controls the opening of the ash regulating valve 11 based on the signal to regulate the storage and release rate of the circulating ash, preventing the ash buffer silo 10 from overflowing or emptying, and ensuring the continuity and stability of material circulation.

[0037] This embodiment provides a control method for a circulating fluidized bed boiler system with adjustable separator efficiency, used to control the system described in the above embodiment or any corresponding implementation, wherein, as Figure 2 As shown, the method includes: Step S1: Adjust each inlet depth adjustable baffle 14 to the preset initial insertion depth and close all recirculation regulating valves 17.

[0038] Specifically, after boiler ignition, the intelligent central control system is initialized. The system sends commands to each baffle drive mechanism 15 to adjust each inlet depth adjustable baffle 14 to a preset initial insertion depth. This initial depth corresponds to the typical separation efficiency setting under 50% of the boiler's rated load. Simultaneously, it controls the ash amount regulating valve 11 of each ash amount buffer bin 10 to be closed and the recirculation regulating valve 17 on the flue gas recirculation pipeline 16 to be fully closed, cutting off the flue gas recirculation loop. This step establishes a stable initial operating state for the boiler, ensuring that material circulation and flue gas flow remain within a controllable range during ignition and load increase.

[0039] Step S2: When the boiler is under rated load, adjust the insertion depth of each inlet depth adjustable baffle 14 and the ammonia injection amount of the denitrification injection device 18 based on the measurement signal of the boiler system, so as to match the separator efficiency with the boiler combustion state.

[0040] Specifically, when the boiler is operating at its rated load (i.e., between 70% and 100% of the rated load), the intelligent central control system automatically enters the normal load optimization mode: The intelligent central control system, based on signals from measuring devices such as the furnace outlet flow field probe 101, separator inlet flow field probe 102, ash flow monitor 103, bed temperature sensors 104 and 105, oxygen concentration sensor 106, online coal quality analyzer 107, and NOx raw emission sensor 108, calculates and adjusts the insertion depth of each inlet adjustable baffle 14 in real time. On the one hand, it controls the solid flow rate deviation of each separator 5 within a preset threshold through differentiated adjustment; on the other hand, it changes the overall separation efficiency through synchronous adjustment to optimize the furnace combustion state. At the same time, based on the feedback signals from the NOx emission sensor 110 and the ammonia escape sensor 111, it adjusts the ammonia injection amount of the denitrification injection device 18 in linkage, so that the separator efficiency and the boiler combustion state maintain dynamic matching under all operating conditions.

[0041] For example, under the conventional load optimization mode, the intelligent central control system first performs flow field homogenization adjustment. The flow field simulation and optimization unit within the intelligent central control system starts working, periodically reading data from the furnace outlet flow field probe 101, the inlet flow field probes 102 of each separator, and the ash flow monitor 103, and analyzing the flow field deviation of each cyclone separator 5. For instance, when a low solids flow rate is detected in a certain separator, the unit generates a command to drive the corresponding inlet depth adjustable baffle 14 through the baffle drive mechanism 15 to increase the insertion depth, thereby improving the efficiency of that separator. Through continuous differential adjustment, the solids flow rate deviation of all separators is ultimately controlled within 5%.

[0042] Simultaneously, combustion and denitrification are controlled in a coordinated manner. The combustion and denitrification coordinated control unit within the intelligent central control system continuously receives data from bed temperature sensors 104 and 105, oxygen concentration sensor 106, NOx raw emission sensor 108, and online coal quality analyzer 107. This unit makes decisions based on a built-in model. For example, when it detects a deterioration in coal quality leading to a downward trend in bed temperature, it instructs all baffle drive mechanisms 15 to synchronously and slightly increase the insertion depth of each baffle 14 to improve overall separation efficiency and circulating ash concentration, thereby stabilizing the bed temperature and utilizing unburned carbon in the ash to reduce raw NOx emissions. Subsequently, based on the raw NOx emissions and the reading of the SNCR outlet NOx sensor 110, the system adjusts the ammonia injection rate of the SNCR denitrification injection device 18 to ensure a denitrification efficiency ≥85% and ammonia slip ≤3ppm, while maintaining the furnace bed temperature within the optimal window of 850-1050℃.

[0043] Step S3: When a load reduction command is received, adjust the insertion depth of each inlet depth adjustable baffle 14, control the air volume of the ash buffer bin 10 storing circulating ash and the return air system 13, and open the recirculation regulating valve 17.

[0044] Specifically, when the intelligent control system receives a load reduction command, it calculates the depth reduction of each inlet depth adjustable baffle 14 according to the load reduction magnitude, controls the baffle drive mechanism 15 to drive each baffle to retract radially along the flue, actively reducing the separator efficiency to reduce the amount of circulating ash; simultaneously, it controls the ash amount regulating valve 11 to open, so that the excess circulating ash separated by the separator enters the ash amount buffer bin 10 for temporary storage, and at the same time reduces the air volume of the return air system 13 to match the reduced circulating ash amount, preventing the return feeder 12 from being blocked or fluidized unstable; when the bed temperature sensor detects that the furnace temperature has dropped to a preset value, it controls the recirculation regulating valve 17 to open, so that the high-temperature flue gas in the separator outlet flue 7 is led back to the furnace 1 through the flue gas recirculation pipe 16, using the sensible heat of the flue gas to stabilize the bed temperature, preventing the bed temperature from being too low due to the reduction of circulating ash amount.

[0045] For example, when the intelligent central control system receives a load reduction and peak shaving command from the power grid, it automatically switches to the deep peak shaving operation management unit for dominant control. During the load reduction process, this unit directs all baffle drive mechanisms 15 according to a preset curve, gradually reducing the insertion depth of each baffle 14 from the high load value to the low load set value, thereby actively and smoothly reducing the overall separation efficiency. Simultaneously, to buffer changes in the circulating ash content, the system controls each ash buffer bin 10 to start feeding, storing excess ash, and monitoring it through the buffer bin level gauge 114. At the same time, it coordinates the return air system 13 to operate at a reduced frequency and controls the ash regulating valve 11 to maintain a small opening for return material to ensure basic fluidization stability.

[0046] When the bed temperature sensor 105 detects that the bed temperature has dropped to around 850℃, the system immediately opens the recirculation regulating valve 17 on the flue gas recirculation pipeline 16 to a certain degree. Based on the monitoring data of the recirculated flue gas temperature sensor 113 and the real-time feedback of the bed temperature, the opening of the recirculation regulating valve 17 is dynamically adjusted to guide the high-temperature flue gas back to the furnace 1, thereby stabilizing the bed temperature within the effective denitrification window above 870℃. Under this operating condition, the system automatically reduces the ammonia injection rate of the SNCR denitrification injection device 18 according to the reduction of the original NOx concentration, and makes fine adjustments based on the readings of the SNCR outlet NOx sensor 110 and the ammonia slip sensor 111, achieving environmental compliance operation under low load.

[0047] Step S4: When the load increase command is received, adjust the insertion depth of each inlet depth adjustable baffle 14, and reduce the opening of all recirculation regulating valves 17 to the preset opening. Then, control the ash quantity regulating valve 11 to return the circulating ash stored in the ash quantity buffer bin 10 to the furnace 1.

[0048] Specifically, when the intelligent central control system receives a load increase command, it calculates the depth increase of each inlet depth adjustable baffle 14 according to the load increase magnitude, and controls the baffle drive mechanism 15 to drive each baffle to extend radially along the flue, increasing the separator efficiency to restore the circulating ash concentration; simultaneously, it calculates the reduction in the opening of the recirculation regulating valve 17, gradually closing the recirculation regulating valve 17 until it is fully closed, smoothly exiting the flue gas recirculation mode; after the recirculation regulating valve 17 is fully closed, it controls the ash quantity regulating valve 11 to open, so that the circulating ash temporarily stored in the ash quantity buffer bin 10 is returned to the furnace 1 at a uniform speed through the return feeder 12, quickly replenishing the material in the furnace, so that the bed temperature steadily follows the load increase, avoiding temperature rise lag.

[0049] For example, when a load increase command is received, the system initiates a load recovery procedure. The intelligent central control system increases coal feeding and air supply at a set rate, while simultaneously directing all damper drive mechanisms 15 to increase the insertion depth of each damper 14 in a stepwise manner to restore separation efficiency. During the load increase process, the system proportionally reduces the opening of the recirculation regulating valve 17 until it is completely closed, smoothly exiting the flue gas recirculation mode.

[0050] Synchronously, the system controls the ash quantity regulating valves 11 of each ash quantity buffer bin 10 to open at a predetermined rate, uniformly sending the temporarily stored circulating ash back to the return feeder 12 and finally back to the furnace 1 within 10-20 minutes. This quickly replenishes the material in the furnace, allowing the bed temperature to rise steadily and rapidly with the load, avoiding sluggish heating. Once the load stabilizes at the target value, the system automatically switches back to the conventional load optimization mode.

[0051] The control method for a circulating fluidized bed boiler system with adjustable separator efficiency provided in this embodiment offers a systematic solution for low-load operation through the collaborative design of a deep peak-shaving management unit, flue gas recirculation pipeline, and ash buffer bin. During load reduction, the system automatically executes a combined strategy of "step-wise efficiency reduction + flue gas recirculation for temperature stabilization + ash buffer to prevent collapse": reducing baffle depth to decrease ash and prevent collapse; activating recirculation to utilize the sensible heat of high-temperature flue gas to stabilize the bed temperature and ensure the SNCR temperature window; and using the buffer bin to smooth out sudden changes in ash content. This successfully solves three major problems during deep peak shaving: sudden drop in bed temperature, denitrification failure, and high risk of ash collapse. It achieves a balance between environmental compliance and safe operation under low load, expanding the unit's peak-shaving range and profitability. Through embedded multiple models and algorithms, data from dozens of measuring points across the entire system are fused, processed, and simulated proactively, upgrading from traditional "passive feedback regulation" to "model-predictive feedforward active regulation." All actuators receive unified command and coordinate actions, resulting in precise adjustment commands and a fast system response. This not only significantly improves control quality, but also fully meets the stringent requirements of the power grid for the unit to respond quickly and accurately to the peak-shaving commands of Automatic Generation Control (AGC).

[0052] In some alternative embodiments, the process of adjusting each inlet depth adjustable baffle 14 to a preset initial insertion depth and closing all recirculation regulating valves 17 includes: When the boiler is cold-started, the initialization of the intelligent central control system and the communication self-test of all related devices are completed first to ensure smooth signal transmission to the baffle drive mechanism 15, measuring equipment, and actuators. Based on the design separation efficiency corresponding to 50% of the boiler's rated load, the initial insertion depth of the adjustable inlet baffle 14 is determined using the following formula: (1) in, h 0 represents the preset initial insertion depth of the adjustable baffle 14. k init The initial adjustment coefficient (valued at 0.45-0.55, calibrated by CFD simulation of the boiler structure; 0.5 is used in this embodiment). Q 50% This is 50% of the boiler's rated load (e.g., 330MW for a 660MW boiler). Q 100% The boiler is operating at 100% rated load. D flue The width of the separator inlet flue 6 (unit: mm, such as the design value of 800 mm).

[0053] Based on the calculation results, the intelligent control system adjusts all baffles 14 to their positions via the baffle drive mechanism 15. hPosition 0 ensures that the initial separation efficiency matches the material circulation requirements during the start-up phase. Afterwards, the initial state is locked. Once the system confirms that the ash buffer silo 10 is empty via the buffer silo level gauge 114, it controls the ash regulating valve 11 to close. A feedback signal from the recirculated flue gas temperature sensor 113 locks the recirculation regulating valve 17 in the fully closed position (0% opening). After completing the above settings, the boiler executes the ignition, heating, and pressurization process according to regulations.

[0054] In some alternative embodiments, the process of adjusting the insertion depth of each inlet depth adjustable baffle 14 and the ammonia injection rate of the denitrification injection device 18 based on measurement signals from the boiler system to match the separator efficiency with the boiler combustion state includes: Step S21: Obtain flow field monitoring data, combustion status monitoring data and NOx emission monitoring data of the boiler system.

[0055] Specifically, the flow field monitoring data comes from the furnace outlet flow field probe 101, the flow field probes 102 at the inlets of each separator, and the ash flow monitors 103 on each separator riser 9, and is used to reflect the uniformity of the distribution of flue gas and solid particles at the inlets of each separator; the combustion state monitoring data comes from the first bed temperature sensor 104, the second bed temperature sensor 105, the oxygen concentration sensor 106 in the furnace, and the online coal quality analyzer 107 on the coal feeding system 2, and is used to reflect the temperature level, oxygen content, and fuel characteristics in the furnace; the NOx emission monitoring data comes from the NOx raw emission sensor 108 on the furnace outlet flue 4 or the separator inlet flue 6, and the NOx emission sensor 110 and ammonia slip sensor 111 on the separator outlet flue 7, and is used to reflect the NOx concentration and ammonia slip level before and after denitrification.

[0056] Step S22: After calculating the first depth adjustment amount of each inlet depth adjustable baffle 14 based on the flow field monitoring data, control the corresponding baffle drive mechanism 15 to extend and retract, so that the solid flow rate deviation of each separator 5 is less than the preset threshold; wherein, each first depth adjustment amount is calculated by multiplying the deviation of the solid flow rate of each separator 5 from the average flow rate by the preset adjustment coefficient.

[0057] Specifically, based on the acquired flow field monitoring data, the intelligent central control system first calculates the deviation between the solid flow rate of each separator 5 and the average flow rate of all separators. When the solid flow rate deviation of a certain separator exceeds a preset threshold, the system multiplies the deviation by a preset adjustment coefficient to calculate the first depth adjustment amount of the inlet depth adjustable baffle 14 corresponding to that separator. If the deviation is positive, it indicates that the solid flow rate of that separator is too high, and the baffle insertion depth needs to be increased to improve the separation efficiency; if the deviation is negative, it indicates that the solid flow rate is too low, and the baffle insertion depth needs to be decreased to reduce the separation efficiency. The intelligent central control system sends the calculated first depth adjustment amounts to the corresponding baffle drive mechanisms 15, driving each inlet depth adjustable baffle 14 to extend and retract radially along the flue until the solid flow rate deviation of all separators is controlled within the preset threshold, thereby achieving flow field homogenization among multiple separators.

[0058] Specifically, when the boiler load is stable within the 70%-100% rated load range, the intelligent central control system automatically switches to the conventional load optimization mode, achieving optimal system operation through dual quantitative adjustment.

[0059] The flow field simulation and optimization unit of the intelligent central control system collects the total flow field data of the furnace outlet flow field probe 101 and the local flow velocity data of each separator inlet flow field probe 102 every 30 seconds. v i and solid flow rate data from ash flow monitor 103. G i ( i (The separators are numbered 1-n).

[0060] First, calculate the average solids flow rate of each separator. : (2) Then calculate the flow rate deviation of a single separator. : (3) When a certain separator's | δG i When |> 5%, the depth adjustment of the separator baffle 14 is calculated using the following formula: (4) in, The adjustment amount for the baffle of the i-th separator (positive value increases depth, negative value decreases depth); The flow rate-depth adjustment coefficient is set to 0.9-1.1 (1.0 in this embodiment, calibrated by cold-state testing). After the system performs adjustment via the baffle drive mechanism 15, it continuously monitors until the solid flow rate deviation of all separators is less than or equal to 5%, thus achieving flow field homogenization.

[0061] The combustion and denitrification co-control unit of the intelligent central control system receives bed temperature data from the first bed temperature sensor 104 and the second bed temperature sensor 105 in real time. T bed1 、T bed2 Oxygen content data from oxygen concentration sensor 106 O 2. The received basis lower heating value of the online coal quality analyzer 107 Q net,ar and the concentration data from the NOx raw emission sensor 108. C NOx,in .

[0062] Step S23: Calculate the second depth adjustment amount of each inlet depth adjustable baffle 14 based on the flow field monitoring data, and control the extension and retraction of the corresponding baffle drive mechanism 15 to maintain the furnace bed temperature within the preset temperature window; wherein, each second depth adjustment amount is calculated by multiplying the difference between the furnace average bed temperature and the target bed temperature by a preset adjustment coefficient.

[0063] Specifically, the intelligent central control system calculates the difference between the average bed temperature in the furnace and the preset target bed temperature based on the acquired combustion status monitoring data. When this difference exceeds the preset allowable range, the system multiplies the bed temperature difference by a preset adjustment coefficient to calculate the second depth adjustment amount of each inlet depth adjustable baffle 14, and the second depth adjustment amount of all baffles is the same. If the average bed temperature is lower than the target bed temperature, the second depth adjustment amount calculated by the system is a positive value, and the insertion depth of each baffle needs to be increased to improve the separator efficiency, thereby increasing the circulating ash concentration and the heat transfer intensity in the furnace, so that the bed temperature rises; if the average bed temperature is higher than the target bed temperature, the insertion depth of the baffle needs to be reduced to reduce the separator efficiency, reduce the circulating ash concentration and the heat transfer intensity, so that the bed temperature drops. The intelligent central control system synchronously controls all baffle drive mechanisms 15 to drive each inlet depth adjustable baffle 14 to extend and retract synchronously along the flue radially until the furnace bed temperature is maintained within the preset temperature window.

[0064] Specifically, bed temperature is regulated in a coordinated manner, and the average bed temperature is calculated. T avg : (5) when T avg When the temperature deviates from the optimal range of 850-1050℃ by more than 30℃, the overall baffle depth adjustment Δ is calculated using the following formula. h all : (6) in, T opt The target bed temperature is 950℃. The bed temperature-depth adjustment coefficient (values ​​range from 1.2 to 1.4, and 1.3 is used in this embodiment). This represents the current average depth of the baffle. After adjustment, the bed temperature is stabilized by changes in the circulating ash concentration, while unburned carbon in the ash is used to reduce raw NOx emissions.

[0065] Step S24: Calculate the ammonia injection adjustment amount of the denitrification injection device 18 based on the NOx emission monitoring data, and adjust the ammonia injection amount of the denitrification injection device 18 so that the denitrification efficiency is greater than the preset efficiency and the ammonia slip concentration is less than the preset concentration; wherein, the ammonia injection adjustment amount is calculated by the difference between the current denitrification efficiency and the preset target denitrification efficiency and the difference between the current ammonia slip concentration and the preset upper limit.

[0066] Specifically, the intelligent central control system calculates the current denitrification efficiency and ammonia slip concentration based on the acquired NOx emission monitoring data. The current denitrification efficiency is calculated by dividing the concentration difference between the original NOx emission sensor 108 and the original NOx emission sensor 110 by the original concentration. When the denitrification efficiency is lower than the preset target denitrification efficiency and the ammonia slip concentration does not exceed the preset upper limit, it indicates that the ammonia injection amount is insufficient. The system calculates the increase in ammonia injection amount based on the difference in denitrification efficiency, increasing the ammonia injection amount of the denitrification injection device 18 to improve the denitrification effect. When the ammonia slip concentration exceeds the preset upper limit, it indicates that the ammonia injection amount is excessive. The system calculates the decrease in ammonia injection amount based on the difference between the ammonia slip concentration and the preset upper limit, reducing the ammonia injection amount to reduce ammonia slip. The intelligent central control system sends the calculated ammonia injection adjustment amount to the denitrification injection device 18 for adjustment until the denitrification efficiency is greater than the preset efficiency and the ammonia slip concentration is less than the preset concentration, thus achieving optimized control of the denitrification process.

[0067] Specifically, ammonia injection rate correction is performed based on the outlet concentration of the NOx sensor 110 at the SNCR outlet. C NOx,out The monitored value of ammonia escape sensor 111 C NH3 Calculate the current denitrification efficiency η DeNOx : (7) when and At that time, increase the ammonia injection amount according to the following formula; when C NH3 >3 ppm At that time, reduce the amount of ammonia injected according to the formula: (8) in, Q NH3,corr The corrected ammonia injection amount; Q NH3,base This represents the current ammonia injection rate; η target The target denitrification efficiency is 85%; 1.05 is the ammonia slip safety correction factor.

[0068] In some optional embodiments, when a load reduction command is received, the process of adjusting the insertion depth of each inlet depth adjustable baffle 14, controlling the air volume of the ash buffer silo 10 storing circulating ash and the return air system 13, and opening the recirculation regulating valve 17 includes: Step S31: After calculating the third depth adjustment amount of each inlet depth adjustable baffle according to the load reduction magnitude, control the extension and retraction of the corresponding baffle drive mechanism; wherein, each third depth adjustment amount is calculated from the load reduction magnitude and the preset baffle depth adjustment curve.

[0069] Specifically, after receiving a load reduction command, the intelligent central control system consults the preset baffle depth adjustment curve based on the load reduction magnitude and calculates the third depth adjustment amount for each inlet depth adjustable baffle 14. A negative adjustment amount indicates that the baffle insertion depth needs to be reduced to decrease separator efficiency. The intelligent central control system sends each third depth adjustment amount to the corresponding baffle drive mechanism 15, controlling it to drive the inlet depth adjustable baffle 14 to retract radially along the flue, allowing the separator efficiency to decrease gradually and avoiding sudden changes in circulating ash content.

[0070] Specifically, after receiving a load reduction and peak shaving command from the power grid, the intelligent central control system automatically activates the deep peak shaving operation management unit and executes coordinated control according to the following quantitative logic: based on the load reduction magnitude... ΔQ=Q current Q target The baffle depth adjustment value is calculated in 3-5 stages, using the following formula: (9) in, h stage,j Let the depth of the baffle be the j-th stage. h high This is the baffle stabilization depth under high load. h low The baffle depth corresponding to the target low load (value is...) h 0 (40%-50%) m To adjust the total number of stages (4 in this embodiment); j The current stage (value 1-4) lasts 8-10 minutes each, ensuring a gradual decrease in separation efficiency and avoiding sudden changes in the amount of cyclic ash.

[0071] Step S32: Control the ash quantity regulating valve 11 to open, so that the circulating ash enters the ash quantity buffer silo 10 for storage.

[0072] Specifically, while reducing the separator efficiency, the intelligent central control system controls the ash quantity regulating valve 11 at the bottom outlet of the ash quantity buffer bin 10 to open. As the separator efficiency decreases, the amount of circulating ash separated decreases, while the amount of ash returned to the furnace has not been adjusted synchronously. The excess circulating ash enters the ash quantity buffer bin 10 for temporary storage under the action of gravity, thereby smoothing out the instantaneous fluctuations in the circulating ash quantity and preventing the risk of "ash collapse" caused by ash quantity imbalance.

[0073] Step S33: After calculating the reduction in air supply volume of the return air system 13 based on the adjustment amount of each third depth, control the return air system 13 to reduce the air supply volume so that the return air volume matches the circulating ash volume; wherein, the reduction in air supply volume is calculated by the sum of the reduction in depth of each baffle and the preset air supply volume adjustment coefficient.

[0074] Specifically, the intelligent control system calculates the sum of the depth reductions of each adjustable baffle 14 based on the third depth adjustment amount of each inlet depth baffle 14, and multiplies this sum by a preset airflow adjustment coefficient to obtain the reduction in airflow of the return air system 13. The intelligent control system controls the return air system 13 to reduce the airflow, so that the return airflow matches the reduced circulating ash volume, maintaining the normal fluidization state of the return feeder 12 and preventing unstable return due to excessive airflow or blockage due to insufficient airflow.

[0075] Step S34: When the furnace bed temperature is lower than the preset value, calculate the increase in the opening of the recirculation regulating valve 17, and control the recirculation regulating valve 17 to open based on the increase in the opening, so that the flue gas returns to the furnace 1 through the flue gas recirculation pipe 16; wherein, the increase in the opening is calculated by the difference between the current bed temperature and the preset target bed temperature.

[0076] Specifically, when the furnace bed temperature sensor detects that the bed temperature has dropped below a preset value, the intelligent control system calculates the difference between the current bed temperature and the preset target bed temperature. This difference is then multiplied by a preset opening adjustment coefficient to obtain the increase in the opening of the recirculation regulating valve 17. The intelligent control system controls the recirculation regulating valve 17 to open to the corresponding degree, allowing the high-temperature flue gas in the separator outlet flue 7 to return to the furnace 1 via the flue gas recirculation pipe 16. The sensible heat of the high-temperature flue gas is used to raise the furnace bed temperature, maintaining it within the optimal temperature window required for the denitrification reaction.

[0077] Specifically, flue gas recirculation flow rate control: when the second bed temperature sensor 105 detects... At ℃, the required recirculated flue gas flow rate is calculated using the following formula to maintain the denitrification temperature window: (10) in, V rec This refers to the recirculated flue gas flow rate; c p,gThe specific heat capacity of flue gas at constant pressure is taken as 1.08; ρ g The density of the flue gas is taken as 0.65 (based on the operating conditions of 380-420℃). V flue This refers to the total amount of flue gas emitted by the boiler. T rec The temperature of the recirculated flue gas (detected in real time by the recirculated flue gas temperature sensor 113). c p,s The specific heat capacity of the bed material under constant pressure is taken as 0.86. ρ s The density of the bed material is taken as 2600. G cir The current circulating ash amount (calculated cumulatively by the ash flow monitor 103); T target The target bed temperature is 870℃.

[0078] The opening degree of the recirculation regulating valve 17 is linearly related to the flow rate, according to... V rec Adjust the opening to the corresponding degree (0%-30%) according to demand, and make real-time corrections based on bed temperature feedback.

[0079] Ash quantity buffering and coordinated control: based on the total circulating ash amount accumulated by the ash flow monitor 103. G total The amount of circulating ash required for the target low load G req Calculate the storage capacity of the ash buffer bin 10. G store : (11) in, t low The estimated duration of low load; k reserve The reserve coefficient is set at 1.15 to avoid insufficient ash content. The system monitors the material level through the buffer silo level gauge 114, adjusts the opening of the ash content regulating valve 11, controls the ash content storage rate, ensures that the ash content buffer silo 10 does not overflow or become empty, and maintains the ash content required for the basic fluidization of the return feeder 12 (achieved by reducing the frequency of the return air system 13 to 40%-60% of the rated frequency).

[0080] In some optional embodiments, when a load increase command is received, the process of adjusting the insertion depth of each inlet depth adjustable baffle 14 and reducing the opening of all recirculation regulating valves 17 to a preset opening, and then controlling the ash quantity regulating valve 11 to return the circulating ash stored in the ash quantity buffer bin 10 to the furnace 1 includes: Step S41: After calculating the fourth depth adjustment amount of each inlet depth adjustable baffle 14 according to the load increase amplitude, control the corresponding baffle drive mechanism 15 to extend and retract; wherein, each fourth depth adjustment amount is calculated from the load increase amplitude and the preset baffle depth adjustment curve.

[0081] Specifically, after receiving the load increase command, the intelligent control system consults the preset baffle depth adjustment curve based on the load increase magnitude and calculates the fourth depth adjustment amount for each inlet depth adjustable baffle 14. A positive adjustment amount indicates that the baffle insertion depth needs to be increased to improve separator efficiency. The intelligent control system sends each fourth depth adjustment amount to the corresponding baffle drive mechanism 15, controlling it to drive the inlet depth adjustable baffle 14 to extend radially along the flue, gradually restoring separator efficiency, increasing circulating ash concentration, providing more heat transfer medium to the furnace, and supporting a smooth load recovery.

[0082] Step S42: After calculating the amount of reduction in the opening of the recirculation regulating valve 17, control the recirculation regulating valve 17 to gradually decrease; wherein, the amount of reduction in the opening is calculated from the difference between the current load and the target load.

[0083] Specifically, while increasing the baffle depth, the intelligent control system calculates the reduction in the opening of the recirculation regulating valve 17 based on the difference between the current load and the target load. As the load gradually recovers, the heat generated by combustion in the furnace increases, and the demand for external recirculated flue gas heat sources gradually decreases. The intelligent control system gradually closes the recirculation regulating valve 17 according to the calculated reduction in opening, ensuring a smooth decrease in recirculated flue gas flow. This avoids bed temperature fluctuations caused by sudden interruptions in recirculated flue gas flow, ensuring the stability of the load recovery process.

[0084] Step S43: When the recirculation regulating valve 17 is fully closed, calculate the increase in the opening of the ash quantity regulating valve 11, and control the ash quantity regulating valve 11 to open based on the increase in the opening, so that the circulating ash stored in the ash quantity buffer bin 10 returns to the furnace 1 via the return feeder 12; wherein, the increase in the opening is calculated by the amount of circulating ash stored in the ash quantity buffer bin 10 and the preset return rate.

[0085] Specifically, when the recirculation regulating valve 17 is completely closed, the flue gas recirculation mode smoothly exits. At this time, the intelligent central control system calculates the increase in the opening of the ash regulating valve 11 based on the amount of circulating ash stored in the ash buffer bin 10 and the preset return rate, and controls the ash regulating valve 11 to gradually open according to this opening. The circulating ash temporarily stored in the ash buffer bin 10 falls into the return feeder 12 under the action of gravity, and returns to the furnace 1 through the return feeder 12, quickly replenishing the material concentration in the furnace, so that the bed temperature can rise steadily with the load, avoiding the heating delay or bed temperature fluctuation caused by insufficient material.

[0086] Specifically, after receiving a load increase command, the intelligent central control system initiates a load recovery program, achieving rapid system adaptation according to the following quantitative logic: Baffle depth recovery calculation: Calculate the baffle depth recovery amount simultaneously based on a load increase rate of 5% rated load / minute. (12) in, h rec,j To increase the baffle depth in stage j; h target The baffle depth corresponding to the target load; p To increase the total number of stages, each stage lasts 4-5 minutes to ensure that separation efficiency and load are improved simultaneously.

[0087] Ash release rate control: based on the stored ash amount detected by buffer silo level gauge 114. G store and the time required for recovery t rec (Typically 15 minutes) Calculate the ash release rate. v release : (13) The system controls the release rate through ash quantity regulating valve 11 to ensure that the stored ash quantity returns to the furnace 1 at a uniform speed, replenishes the circulating ash concentration, and avoids bed temperature fluctuations exceeding 50℃ / min.

[0088] Recirculation regulating valve closing logic: When the second bed temperature sensor 105 detects... At ℃, calculate the closing rate of the recirculation control valve 17 using the following formula: (14) Where, Δ β The percentage of opening closed per minute; β current Current valve opening (%); T close The total closing time is 6 minutes, until the valve is fully closed, smoothly exiting the flue gas recirculation mode.

[0089] When the load stabilizes at 70% or above the rated load, the intelligent central control system automatically switches back to the normal load optimization mode and ends the recovery process.

[0090] This embodiment also provides a control device for a circulating fluidized bed boiler system with adjustable separator efficiency. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0091] This embodiment provides a control device for a circulating fluidized bed boiler system with adjustable separator efficiency, such as... Figure 3 As shown, it includes: The initialization module 301 is started to adjust each inlet depth adjustable baffle 14 to the preset initial insertion depth and close all recirculation regulating valves 17.

[0092] The constant load coordination module 302 is used to adjust the insertion depth of each inlet depth adjustable baffle 14 and the amount of ammonia injected by the denitrification injection device 18 based on the measurement signal of the boiler system when the boiler is under rated load conditions, so as to match the separator efficiency with the boiler combustion state.

[0093] The load reduction buffer module 303 is used to adjust the insertion depth of each inlet depth adjustable baffle 14 when a load reduction command is received, control the air volume of the ash buffer bin 10 storing circulating ash and the return air system 13, and open the recirculation regulating valve 17.

[0094] The load increase and replenishment module 304 is used to adjust the insertion depth of each inlet depth adjustable baffle 14 when a load increase command is received, and after reducing the opening of all recirculation regulating valves 17 to the preset opening, control the ash quantity regulating valve 11 to return the circulating ash stored in the ash quantity buffer bin 10 to the furnace 1.

[0095] The control device for the circulating fluidized bed boiler system with adjustable separator efficiency provided in this embodiment of the invention can execute the method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0096] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0097] The following is a detailed reference. Figure 4The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 001, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 002 or a program loaded from memory 008 into random access memory (RAM) 003. The RAM 003 also stores various programs and data required for the operation of the electronic device. The processor 001, ROM 002, and RAM 003 are interconnected via bus 004. An input / output (I / O) interface 005 is also connected to bus 004.

[0098] Typically, the following devices can be connected to I / O interface 005: input devices 006 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 007 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 008 including, for example, magnetic tapes, hard disks, etc.; and communication devices 009. Communication device 009 allows electronic devices to exchange data via wireless or wired communication with other devices. Although Figure 4 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0099] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication device 009, or installed from memory 008, or installed from ROM 002. When the computer program is executed by processor 001, it performs the functions defined in the methods of the embodiments of the present invention.

[0100] Figure 4 The electronic device shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0101] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0102] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0103] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A circulating fluidized bed boiler system with adjustable separator efficiency, characterized in that, include: The furnace (1), multiple separators (5), multiple inlet depth adjustable baffles (14), multiple baffle drive mechanisms (15), ash buffer silo (10), return feeder (12), denitrification injection device (18), recirculation regulating valve (17), and intelligent central control system, among which, The inlet of each separator (5) is connected to the outlet of the furnace (1) through the furnace outlet flue (4). The gas outlets of each separator (5) are connected to the separator outlet flue (7). The lower ash discharge port of each separator (5) is connected to the ash buffer bin (10) and the return feeder (12) in sequence. The outlet of the return feeder (12) is connected back to the furnace (1). The separator outlet flue (7) is connected to the furnace (1) through a flue gas recirculation pipe (16), and a recirculation regulating valve (17) is provided on the flue gas recirculation pipe (16). The denitrification injection device (18) is installed on the separator outlet flue (7); The adjustable inlet depth baffle (14) is disposed in the inlet flue (6) of each separator (5), and each adjustable inlet depth baffle (14) is connected to a baffle driving mechanism (15). The baffle driving mechanism (15) is used to drive the adjustable inlet depth baffle (14) to make linear extension and retraction movements along the radial direction of the flue. The intelligent control system is connected to the baffle drive mechanism (15), the recirculation regulating valve (17), the ash regulating valve (11) at the bottom outlet of the ash buffer silo (10), the return air system (13) at the air chamber inlet of the return feeder (12), and the denitrification injection device (18). The intelligent control system is used to adjust the insertion depth of the inlet depth adjustable baffle (14) to change the separator efficiency based on the measurement signal of the boiler system, and to control the recirculation regulating valve (17), the ash regulating valve (11), the return air system (13) and the denitrification injection device (18) in a coordinated manner to achieve coordinated control between separator efficiency and boiler combustion state.

2. The system according to claim 1, characterized in that, The windward side of the adjustable inlet depth baffle (14) is provided with a wear-resistant ceramic layer; a sealing structure is provided between the adjustable inlet depth baffle (14) and the wall of the inlet flue (6).

3. The system according to claim 1, characterized in that, Also includes: The furnace outlet flow field probe (101), separator inlet flow field probe (102), ash flow monitor (103), first bed temperature sensor (104), second bed temperature sensor (105), oxygen concentration sensor (106), online coal quality analyzer (107), NOx raw emission sensor (108), temperature sensor (109), NOx emission sensor (110), and ammonia slip sensor (111) are included. The furnace outlet flow field probe (101) is installed inside the furnace outlet flue (4); The separator inlet flow field probe (102) is installed in each of the inlet flues (6); The ash flow monitoring instrument (103) is installed on the riser (9) of each of the separators (5); The first bed temperature sensor (104), the second bed temperature sensor (105), and the oxygen concentration sensor (106) are disposed inside the furnace (1); The online coal quality analyzer (107) is installed on the coal feeding system (2) connected to the furnace (1); The NOx raw emission sensor (108) is installed on the furnace outlet flue (4) or the separator inlet flue (6); The temperature sensor (109), NOx emission sensor (110) and ammonia escape sensor (111) are installed on the separator outlet flue (7), with the temperature sensor (109) located upstream of the spray gun of the denitrification injection device (18), and the NOx emission sensor (110) and ammonia escape sensor (111) located downstream of the spray gun.

4. The system according to claim 1, characterized in that, Also includes: Displacement sensor (112), wherein, The displacement sensor (112) is integrated on the baffle drive mechanism (15) and is used to provide feedback on the insertion depth of the inlet depth adjustable baffle (14).

5. A control method for a circulating fluidized bed boiler system with adjustable separator efficiency, characterized in that, For controlling the system according to any one of claims 1 to 4, wherein the method comprises: Adjust each inlet depth adjustable baffle (14) to the preset initial insertion depth and close all recirculation regulating valves (17). When the boiler is under rated load, the insertion depth of each inlet depth adjustable baffle (14) and the amount of ammonia injected by the denitrification injection device (18) are adjusted based on the measurement signal of the boiler system so that the separator efficiency matches the boiler combustion state. When a load reduction command is received, the insertion depth of each inlet depth adjustable baffle (14) is adjusted to control the air volume of the ash buffer bin (10) storing circulating ash and the return air system (13), and the recirculation regulating valve (17) is opened. When a load increase command is received, the insertion depth of each inlet depth adjustable baffle (14) is adjusted, and the opening of all the recirculation regulating valves (17) is reduced to the preset opening. Then, the ash quantity regulating valve (11) is controlled to return the circulating ash stored in the ash quantity buffer bin (10) to the furnace (1).

6. The method according to claim 5, characterized in that, The process of adjusting the insertion depth of each inlet depth adjustable baffle (14) and the ammonia injection amount of the denitrification injection device (18) based on the measurement signals of the boiler system to match the separator efficiency with the boiler combustion state includes: Acquire flow field monitoring data, combustion status monitoring data, and NOx emission monitoring data of the boiler system; After calculating the first depth adjustment amount of each of the inlet depth adjustable baffles (14) based on the flow field monitoring data, the corresponding baffle drive mechanism (15) is controlled to extend and retract, so that the solid flow rate deviation of each of the separators (5) is less than a preset threshold; wherein, each first depth adjustment amount is calculated by multiplying the deviation of the solid flow rate of each separator (5) from the average flow rate by a preset adjustment coefficient. The second depth adjustment amount of each of the inlet depth adjustable baffles (14) is calculated based on the flow field monitoring data, and the corresponding baffle drive mechanism (15) is controlled to extend and retract, so that the furnace bed temperature is maintained within the preset temperature window; wherein, each of the second depth adjustment amounts is calculated by multiplying the difference between the furnace average bed temperature and the target bed temperature by a preset adjustment coefficient; The ammonia injection rate adjustment of the denitrification injection device (18) is calculated based on the NOx emission monitoring data. The ammonia injection rate of the denitrification injection device (18) is adjusted so that the denitrification efficiency is greater than the preset efficiency and the ammonia escape concentration is less than the preset concentration. The ammonia injection rate adjustment is calculated from the difference between the current denitrification efficiency and the preset target denitrification efficiency and the difference between the current ammonia escape concentration and the preset upper limit.

7. The method according to claim 5, characterized in that, The process of adjusting the insertion depth of each inlet depth adjustable baffle (14) when a load reduction command is received includes: After calculating the third depth adjustment amount of each of the inlet depth adjustable baffles (14) according to the load reduction magnitude, the corresponding baffle drive mechanism (15) is controlled to extend and retract; wherein, each of the third depth adjustment amounts is calculated from the load reduction magnitude and the preset baffle depth adjustment curve.

8. The method according to claim 7, characterized in that, When a load reduction command is received, the process of controlling the ash quantity buffer silo (10) to store the air volume of the circulating ash and return air system (13) and opening the recirculation regulating valve (17) includes: The ash quantity regulating valve (11) is opened to allow circulating ash to enter the ash quantity buffer silo (10) for storage; After calculating the reduction in air supply volume of the return air system (13) based on the third depth adjustment amount, the return air system (13) is controlled to reduce the air supply volume so that the return air volume matches the circulating ash volume; wherein, the reduction in air supply volume is calculated by the sum of the reduction in depth of each baffle and the preset air supply volume adjustment coefficient. When the furnace bed temperature is lower than the preset value, the opening increase of the recirculation regulating valve (17) is calculated, and the recirculation regulating valve (17) is controlled to open based on the opening increase, so that the flue gas returns to the furnace (1) through the flue gas recirculation pipe (16); wherein, the opening increase is calculated by the difference between the current bed temperature and the preset target bed temperature.

9. The method according to claim 5, characterized in that, The process of adjusting the insertion depth of each inlet depth adjustable baffle (14) when receiving a load increase command includes: After calculating the fourth depth adjustment amount of each of the inlet depth adjustable baffles (14) according to the load increase amplitude, the corresponding baffle drive mechanism (15) is controlled to extend and retract; wherein, each of the fourth depth adjustment amounts is calculated from the load increase amplitude and the preset baffle depth adjustment curve.

10. The method according to claim 9, characterized in that, When a load increase command is received, the process of reducing the opening of all the recirculation regulating valves (17) to a preset opening and then controlling the ash quantity regulating valve (11) to return the circulating ash stored in the ash quantity buffer bin (10) to the furnace (1) includes: After calculating the amount of reduction in the opening of the recirculation regulating valve (17), the recirculation regulating valve (17) is controlled to gradually decrease; wherein, the amount of reduction in the opening is calculated from the difference between the current load and the target load; When the recirculation regulating valve (17) is fully closed, the increase in the opening of the ash quantity regulating valve (11) is calculated, and the ash quantity regulating valve (11) is controlled to open based on the increase in the opening, so that the circulating ash stored in the ash quantity buffer bin (10) is returned to the furnace (1) via the return feeder (12); wherein, the increase in the opening is calculated by the amount of circulating ash stored in the ash quantity buffer bin (10) and the preset return rate.

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