A fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure

Abstract

The present invention relates to the technical field of combustion control, specifically to a fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure, comprising a fan pipe and an air supply pipe, a reinforced waterproof component and an air pressure monitoring component, wherein a flexible connection component is fixedly installed between the fan pipe and the air supply pipe via a flange, and the fan pipe and the air supply pipe are assembled and installed at the connection position via a flexible connection component with two annular sealing cloths. During the process of the fan pipe supplying air to the air supply pipe, the two annular sealing cloths can greatly prevent water from the external environment from entering the interior of the pipe body, and then cooperate with the reinforced waterproof component to further improve the air supply waterproof effect of the boiler control. In addition, the air pressure monitoring component can realize automatic secondary air supply status detection when the boiler is automatically controlled, and the measurement data is accurate, thereby improving the quality of boiler control.

Description

Technical Field

[0001] The invention relates to the technical field of combustion control, in particular to a full-automatic control device for a circulating fluidized bed steam boiler with a waterproof structure. Background Art

[0002] A circulating fluidized bed steam boiler is a device that heats water by burning circulating fluidized bed combustion equipment. When the circulating fluidized bed is performing combustion operations, it needs to be used with air supply for auxiliary combustion.

[0003] The existing invention with publication number CN115111599 A discloses a method for controlling ultra-low NOx emissions during the ignition and starting process of a circulating fluidized bed boiler, which is specifically as follows: first, primary air is passed, negative pressure is applied to the furnace outlet, an oil gun is ignited, the boiler bed is heated, coal is fed into the furnace, and the heating rate is controlled. When the combustion color in the furnace is normal red and the bed temperature is 760°C~780°C, the ignition oil pressure and the coal feeding amount are adjusted. When the bed temperature stabilizes and combustion is stable, NOx≤45mg / Nm3, the ignition is successful; during the heating process, the first denitrification spray gun is put into use; after successful ignition, the oil gun is withdrawn and secondary air is passed. When the furnace outlet temperature reaches above 670°C, the second denitrification spray gun is put into use, the NOx content in the flue gas decreases, the first spray gun is withdrawn, and the amount of NOx emissions from the flue gas is ≤46mg / Nm3. By adopting this method, the ignition furnace process can be effectively controlled to achieve ultra-low NOx emissions in the flue gas, effectively reducing the problem of environmental pollution. When the boiler is in use, in order to ensure the supply of oxygen and fluidization effect, secondary air will be sent to the combustion chamber. When the secondary air contains water vapor, it will greatly affect the combustion effect. However, since the fan is in vibration operation and the air supply duct is installed statically, in order to avoid water leakage at the connection between the two, the secondary air fan is mostly connected to the air supply duct with a flexible connection, resulting in a relatively poor sealing effect, and water vapor may be present in the secondary air supply. Summary of the Invention

[0004] The object of the present invention is to provide a fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solution: a fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure, comprising:

[0006] The fan pipe and the air supply pipe are fixedly installed with a flexible connection component between the fan pipe and the air supply pipe through a flange. The flexible connection component includes two assembly rings and two annular sealing cloths. The two annular sealing cloths are concentrically arranged and the two annular sealing cloths are located between the two assembly rings;

[0007] A reinforced waterproof component is provided in the assembly ring and includes four sealing airbags;

[0008] The wind pressure monitoring assembly is connected to the side of the air supply pipe close to the assembly ring. The pressure monitoring assembly includes a monitoring control seat, and a plurality of L-shaped collection tubes are movably provided on the inner peripheral side of the monitoring control seat.

[0009] Preferably, an annular assembly groove is provided on the opposite side of the two assembly rings, and conical extrusion surfaces are provided on both sides of the annular assembly groove. The two sides of the two annular sealing cloths are respectively inserted into the annular assembly grooves of the two assembly rings, and the two sides of the annular sealing cloths are respectively in contact with the conical extrusion surfaces on one side of the two annular assembly grooves.

[0010] Preferably, a fixed operating ring is movably inserted in the annular assembly groove, a conical pressure ring is oppositely provided on one side of the fixed operating ring close to the two conical extrusion surfaces, and the annular sealing cloth is tightly arranged between the conical pressure ring and the conical extrusion surface.

[0011] Preferably, the side of the assembly ring away from the annular assembly groove is provided with a pulling screw which is rotated and plugged into the sunken groove, and one side of the pulling screw is inserted into the annular assembly groove. Several fixed screw grooves are symmetrically opened on the fixed operating ring, and one side of the several pulling screws placed in the annular assembly groove is threadedly plugged into the fixed screw groove of the fixed operating ring.

[0012] Preferably, an annular groove is provided on one side of the conical extrusion surface in the annular assembly groove, a sealing airbag is inserted in the annular groove, an annular common groove is provided on one side of the assembly ring close to the annular groove, a number of sealing air guide tubes are provided between the sealing airbag and the annular common groove, a connecting hole is provided between the two annular common grooves of the assembly ring, and the connecting hole is staggered with the pulling screw.

[0013] Preferably, one side of the two assembly rings is connected to the annular common groove and is provided with a combination joint, one side of the two combination joints is horizontally connected to a transfer hose, and the upper end of one of the combination joints is provided with an air inlet.

[0014] Preferably, an air supply pipe extends from one side of the monitoring and control seat and abuts against one side of the assembly ring. A number of storage grooves are symmetrically provided on the inner circumference of the monitoring and control seat. A rotation groove is provided on one side of each of the storage grooves. A rotation seat is rotatably inserted in the rotation groove. The L-shaped collection tube is provided on one side of the rotation seat, and when not in use for detection, the L-shaped collection tube is horizontally stored in the storage groove.

[0015] Preferably, a matching groove is provided in the rotating seat and is connected to the L-shaped collection tube, a second docking groove is provided on one side of the rotating slot, a transfer groove is provided on one side of the second docking groove, a first docking groove is provided on one side of the matching groove and passes through the rotating seat, when the L-shaped collection tube is horizontally located in the storage slot, the first docking groove and the second docking groove are offset, and an inspection air groove is provided on one side of the transfer slot and passes through the monitoring and control seat located between the air supply pipe and the assembly ring, one side of the inspection air groove is connected and plugged with a detection leather hose, and one side of the detection leather hose is movable through the flange of the air supply pipe.

[0016] Preferably, an annular diverter groove is provided on one side of the monitoring and control seat close to the rotating seat, and a docking air groove is provided on one side of the annular diverter groove that passes through the monitoring and control seat close to the assembly ring. A connecting tube is provided on one side of the assembly ring close to the docking air groove, and the connecting tube is sealed and plugged into one side of the docking air groove. A transfer air groove is provided in the connecting tube and connected to one of the annular common grooves, and a switching valve ball is provided on one side of the transfer air groove, and a ventilation valve groove is provided on the switching valve ball, and both sides of the ventilation valve groove are connected to the connecting tube.

[0017] Preferably, an arc-shaped piston groove is provided on one side of the monitoring and control seat close to the rotation seat, one side of the arc-shaped piston groove is connected to the annular diversion groove, the virtual axis of the arc-shaped piston groove is coaxially arranged with the virtual axis of the rotation groove and the rotation seat, and an arc-shaped push rod is provided on one side of the L-shaped collection tube, the arc-shaped push rod is movably inserted into the arc-shaped piston groove and is provided with a pushing piston, and an arc-shaped spring is sleeved on one side of the pushing piston of the arc-shaped push rod located in the arc-shaped piston groove, and the pushing piston is arranged close to the annular diversion groove.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The fan pipe and the air supply pipe are connected at the connection position through a flexible connection component with two annular sealing cloths for assembly and installation. When the fan pipe supplies air to the air supply pipe, the two annular sealing cloths can greatly prevent water from the external environment from entering the pipe body. Then, combined with the enhanced waterproof component, the air supply waterproof effect of the boiler control can be further improved. In addition, the wind pressure monitoring component can realize automatic secondary air supply status detection when the boiler is automatically controlled, and the measurement data is accurate, thereby improving the quality of boiler control. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the partial episiotomy structure of the present invention;

[0022] Figure 3 For the present invention Figure 2 Schematic diagram of part A;

[0023] Figure 4For the present invention Figure 3 Schematic diagram of part B;

[0024] Figure 5 For the present invention Figure 3 Schematic diagram of the C part;

[0025] Figure 6 For the present invention Figure 2 Schematic diagram of the D part;

[0026] Figure 7 This is a schematic diagram of the structure of the gas slot for inspection according to the present invention;

[0027] Figure 8 For the present invention Figure 7 Schematic diagram of part E;

[0028] Figure 9 This is a schematic structural diagram of the flexible connection assembly of the present invention;

[0029] Figure 10 This is a schematic diagram of the connection structure between the monitoring control base and the air supply pipe of the present invention;

[0030] Figure 11 This is a schematic diagram of the structure of the assembly ring and two annular sealing cloths of the present invention;

[0031] Figure 12 This is a schematic diagram of the structure of the rotation tank of the present invention;

[0032] Figure 13 For the present invention Figure 12 Schematic diagram of the F part;

[0033] Figure 14 This is a schematic diagram of the L-shaped collection tube structure of the present invention.

[0034] In the figure: fan pipe 1, air supply pipe 2, assembly ring 3, conical extrusion surface 4, fixed operating ring 5, conical pressure ring 6, annular sealing cloth 7, pulling screw 8, fixed screw groove 9, sealing airbag 10, annular common groove 11, sealing air guide tube 12, combination joint 13, transfer hose 14, monitoring and control seat 15, storage groove 16, rotation groove 17, rotation seat 18, L-shaped collection tube 19, matching groove 21, first docking groove 22, second docking groove 23, transfer groove 24, inspection air groove 26, inspection leather tube 27, annular diversion groove 28, arc piston groove 29, arc push rod 30, push piston 31, arc spring 32, docking air groove 33, connecting tube 34, switching valve ball 35, ventilation valve groove 36. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Please see the attached Figure 1-14 , this application provides the following technical solutions.

[0037] The cam is secured to the vents by means of a flange, and the cam is secured to the vents by means of a flange.

[0038] A fixed operating ring 5 is movably inserted in the annular assembly groove, and a conical pressure ring 6 is relatively provided on the side of the fixed operating ring 5 close to the two conical extrusion surfaces 4, and the annular sealing cloth 7 is tightly arranged between the conical pressure ring 6 and the conical extrusion surface 4. The side of the assembly ring 3 away from the annular assembly groove is rotatably inserted with a pulling screw 8 through the sinking groove, and one side of the pulling screw 8 is inserted into the annular assembly groove. A number of fixed screw grooves 9 are symmetrically opened on the fixed operating ring 5, and the side of the number of pulling screws 8 placed in the annular assembly groove is threadedly inserted into the fixed screw groove 9 of the fixed operating ring 5. When the two annular sealing cloths 7 are combined and connected with the two assembly rings 3, they can be tightened. The adhesive structure is first combined and bonded with the conical pressure rings 6 of the two assembly rings 3, and then the several fixed screw grooves 9 of the fixed operating ring 5 are connected with the several pulling screws 8. By diagonally screwing the several pulling screws 8, the fixed operating ring 5 is moved to the side of the pulling screws 8, so that the conical pressure ring 6 clamps the end of the annular sealing cloth 7 on the two conical extrusion surfaces 4 of the assembly ring 3. By adjusting the tightening effect, the sealing quality can be adjusted. In addition, with the design of the double-layer annular sealing cloth 7, when the outer layer of the annular sealing cloth 7 has aging and water leakage problems, it still has a good sealing and waterproof effect. The air supply pipe 2 can also be a double-layer structure to avoid air leakage and water ingress problems caused by external damage.

[0039] A reinforced waterproof component is set to strengthen the waterproof state of the annular sealing cloth 7 between the conical pressure ring 6 and the conical extrusion surface 4. The reinforced waterproof component is set in the assembly ring 3. The reinforced waterproof component includes four sealing airbags 10. An annular groove is opened on one side of the conical extrusion surface 4 in the annular assembly groove. The sealing airbags 10 are inserted in the annular grooves. An annular common groove 11 is opened on one side of the assembly ring 3 close to the annular groove. A number of sealing air guide tubes 12 are connected between the sealing airbags 10 and the annular common grooves 11. The two annular common grooves of the assembly ring 3 are connected to each other. There are connecting holes between 11, and the connecting holes are staggered with the pulling screw 8. One side of the two assembly rings 3 is connected to the annular common groove 11 and a combination joint 13 is provided. One side of the two combination joints 13 is horizontally connected with a transfer hose 14, and an air inlet is provided at the upper end of one of the combination joints 13. When high-pressure air is sent into the air inlet of the combination joint 13, the high-pressure air enters the four annular common grooves 11 respectively through the transfer hose 14, and then the four sealing airbags 10 are inflated to achieve enhanced sealing and waterproofing of the four annular sealing cloths 7.

[0040] Example 2: On the basis of Example 1, a wind pressure monitoring component is set to detect the air volume and wind pressure at multiple measuring points of the same cross section, so as to facilitate the subsequent adjustment and control of the secondary air supply effect of the boiler. The wind pressure monitoring device is plugged into the air supply pipe 2 close to the side of the assembly ring 3. The partial pressure monitoring component includes a monitoring control seat 15. The inner circumference of the monitoring control seat 15 is movably provided with a plurality of L-shaped collection tubes 19. One side of the monitoring control seat 15 extends out of the air supply pipe 2 and abuts against one side of the assembly ring 3. The inner circumference of the monitoring control seat 15 is symmetrically provided with a plurality of receiving grooves 16. If A rotation groove 17 is provided on one side of the dry storage groove 16, and a rotation seat 18 is rotatably inserted in the rotation groove 17. An L-shaped collection tube 19 is provided on one side of the rotation seat 18, and when not in use for detection, the L-shaped collection tube 19 is horizontally stored in the storage groove 16. The monitoring and control seat 15 can abut against several pulling screws 8 to prevent the pulling screws 8 from rotating, and at the same time strengthen the sealing effect of the joint between the assembly ring 3 and the air supply pipe 2. A sealing pad can also be provided between the fan pipe 1 and the assembly ring 3 to achieve the purpose of limiting the rotation of the pulling screw 8 and the sealing effect of the joint.

[0041] The L-shaped collection tube 19 is connected to the rotation seat 18 and a matching groove 21 is provided in the rotation slot 17. A second docking groove 23 is provided on one side of the rotation slot 17. A transfer groove 24 is provided on one side of the second docking groove 23. A first docking groove 22 is provided on one side of the matching groove 21 through the rotation seat 18. When the L-shaped collection tube 19 is horizontally located in the storage slot 16, the first docking groove 22 and the second docking groove 23 are offset. A gas inspection groove 26 is provided on one side of the transfer groove 24 through the monitoring and control seat 15 located between the air supply pipe 2 and the assembly ring 3. One side of the air supply pipe 2 is connected and plugged with a detection leather tube 27, and one side of the detection leather tube 27 is movable through the flange of the air supply pipe 2. When the L-shaped collection tube 19 flips out of the storage slot 16 as the rotating seat 18 is turned over and is in a vertical posture, the first docking slot 22 is docked with the second docking slot 23, and the wind intercepted by the L-shaped collection tube 19 enters the matching slot 21, and then enters the transfer slot 24 from the first docking slot 22 and the second docking slot 23, and then enters the detection leather tube 27 through the inspection air slot 26. Finally, the detection leather tube 27 is connected to the detection instrument to detect the air volume partial pressure.

[0042] An annular diverter groove 28 is provided on one side of the monitoring and control seat 15 near the rotating seat 18. A docking air groove 33 is provided on one side of the annular diverter groove 28 through the monitoring and control seat 15 near the assembly ring 3. A connecting cannula 34 is provided on one side of the assembly ring 3 near the docking air groove 33. The connecting cannula 34 is sealed and plugged into one side of the docking air groove 33. A switching air groove is provided in the connecting cannula 34 and is connected to one of the annular common grooves 11. A switching valve ball 35 is provided on one side of the switching valve ball 35. A vent valve groove 36 is provided on the upper portion, and both sides of the vent valve groove 36 are connected to the adapter gas groove. An arcuate piston groove 29 is provided on one side of the monitoring and control seat 15 near the rotation seat 18. One side of the arcuate piston groove 29 is connected to the annular diverter groove 28. The virtual axis of the arcuate piston groove 29 is coaxial with the virtual axis of the rotation groove 17 and the rotation seat 18. An arcuate push rod 30 is provided on one side of the L-shaped collection tube 19. The arcuate push rod 30 is movably inserted into the arcuate piston groove 29 and is provided with a push piston 31. The arc-shaped push rod 30 is located in the arc-shaped piston groove 29. One side of the push piston 31 is sleeved with an arc spring 32, and the push piston 31 is arranged close to the annular diverter groove 28. When the L-shaped collection tube 19 needs to be rotated vertically out of the storage groove 16, the switching valve ball 35 is driven by a small electric motor to rotate the switching valve ball 35, so that the vent valve groove 36 is connected to the transfer gas groove. The high-pressure gas in the annular common groove 11 enters the docking gas groove 33 and the annular diverter groove 28 from the transfer gas groove and the connecting cannula 34. At this time, if The pushing piston 31 in the dry arc piston groove 29 is pushed by the high-pressure gas, causing the pushing piston 31 and the arc push rod 30 to move in opposite directions, pushing the L-shaped collection tube 19 to rotate out of the storage groove 16. On the contrary, when no detection is needed, the L-shaped collection tube 19 is rotated and recovered in the storage groove 16 under the rebound action of the arc spring 32, without affecting the air supply and unnecessary aging loss. The number and length of the L-shaped collection tube 19 can be customized according to needs to achieve accurate ventilation parameter detection data of the same cross-section.

[0043] The fully automatic control system also includes a boiler microcomputer control system, which consists of primary instruments, a DCS, a host computer, manual-automatic switching operations, actuators, valves, and motors. The primary instruments convert the boiler's temperature, pressure, flow rate, and oxygen content into voltage and current, which are then fed into the DCS and then into the microcomputer. The control system includes both manual and automatic control sections. Manual control allows the operator to manually control the draft and grate. Automatic control allows the microcomputer to send control signals to the actuator section, enabling automatic operation, including equipment start / stop and frequency conversion. The microcomputer monitors, generates alarms, and controls the entire boiler to ensure normal and reliable operation. Furthermore, to ensure safe operation, the microcomputer system design incorporates alarm values ​​for key parameters such as the boiler's supply and outlet water temperatures and furnace temperature. The system also incorporates a boiler interlocking control function, ensuring dual or even triple alarms to prevent serious accidents. The system can automatically control the outlet water temperature, air volume, furnace negative pressure, etc., maintaining them at the specified values ​​to ensure safe and stable operation of the boiler, thereby reducing energy consumption and improving heating quality. It also provides dynamic process diagrams for operating parameters such as pressure and temperature, along with real-time value displays for measuring points. It can also issue over-limit alarms for outlet water temperature and furnace temperature, emitting audible and visual signals. It also displays real-time and historical trends, real-time and historical alarm values, and can periodically print out data for more than a dozen operating parameters to form production logs and shift statistics reports. Printing options include scheduled, random, and custom time period printing.

[0044] The boiler microcomputer control system has networking capabilities. It can connect to other nodes throughout the plant through Ethernet to form an industrial Ethernet network, and data can also be viewed from a remote station. As a boiler control device, its main task is to ensure the safe, stable, and economical operation of the boiler and reduce the workload of operators. The computer-controlled boiler control system has a very thoughtful safety mechanism, which can be set up with multiple sound and light alarms and automatic chain shutdown to prevent major accidents caused by human negligence. The control circuits are as follows:

[0045] Combustion control and maintaining a constant outlet water temperature for circulating fluidized bed hot water boilers are fundamental regulatory requirements. Fluctuations in external heat supply cause fluctuations in outlet water temperature. To maintain this constant outlet water temperature, the amount of fuel and combustion air entering the boiler must be varied. Whether using a unit-type or a main-pipeline-controlled unit, the boiler's main control system must be designed from an energy-balanced perspective, ensuring that the outlet water temperature is maintained constant by the amount of fuel added.

[0046] Fuel quantity regulation: The fuel quantity instruction issued by the outlet water temperature regulation system is the total fuel quantity instruction. The total fuel quantity instruction and the total air volume are cross-restricted and used as the given value of the regulation system. It is calculated with the fuel quantity measurement value in the PID. The calculation results are processed by the function and used as the given quantity instructions of the coal feed quantity regulation system, the coal spreading air regulation system and the limestone regulation system respectively.

[0047] Coal feed quantity adjustment: The coal feed quantity instruction obtained by the fuel quantity adjustment system is sent to the coal feed quantity adjustment system, and PID calculation is performed with the coal feeder speed. The calculation result adjusts the feeder so that the coal supply quantity meets the unit operation requirements.

[0048] Total air volume regulation, the air volume instruction issued by the outlet water temperature regulation system is the total air volume instruction. The primary and secondary air account for the largest proportion of the total air volume, and the primary and secondary air directly affect the operation and combustion conditions of the boiler. Therefore, the total air volume regulation system ensures the required air distribution of the boiler by changing the regulation instructions of the primary and secondary air volumes. The total air volume instruction obtained by the boiler main control system is cross-limited with the fuel quantity measurement value and used as the given value of the total air volume regulation system to ensure that when the load increases, the air is added first and then the fuel is added, and when the load decreases, the fuel is reduced first and then the air is reduced, thereby ensuring a certain excess air coefficient. The given value of the total air volume regulation system is calculated with the total air volume measurement value in the PID, and the calculation result is sent to the duct burner ignition air regulation system, the primary air regulation system and the secondary air regulation system after function processing.

[0049] Primary air volume control. The primary air volume command issued by the total air volume control system serves as the setpoint for the primary air volume control system. This command, along with the measured primary air volume, is fed into the PID controller for calculation. The result is used to adjust the primary air damper opening to regulate the primary air volume entering the furnace. The measured primary air volume is fed into the PID controller for calculation after temperature and pressure corrections are taken into account. When processing the primary air volume command, coal quality characteristics and load variations must be considered. Different coal types require different amounts of combustion air. Furthermore, the proportion of primary air volume to total air volume changes with load variations. Because primary air regulates the boiler bed temperature, bed temperature correction is also considered in the design of the primary air volume control system. If the bed temperature is too high, the primary air volume can be reduced within a certain range. If the bed temperature is too low, the primary air volume can be increased within a certain range. Since bed temperature is primarily regulated by fuel supply and return, primary air volume is not the primary means of regulating bed temperature. Therefore, the bed temperature signal in the primary air volume control system serves only as a correction signal.

[0050] Secondary air volume regulation: The secondary air volume regulation system adopts a cascade regulation system. The measured value of the flue gas oxygen content is sent to the main regulator together with the given value for PID calculation. The calculation result is processed together with the secondary air volume instruction issued by the total air volume regulation system as the given value of the sub-regulator, and the PID calculation is performed with the secondary air volume measurement value. The calculation result is divided into two paths as the regulation instructions for the upper secondary air flow and the lower secondary air flow. Since it takes some time for the change in fuel quantity to change the flue gas oxygen content, the fuel quantity is directly processed in the secondary air volume regulation system, and the result is added to the regulation output as a feedforward signal to improve the rapid responsiveness of the regulation system. In the g(x) function that processes the coal feed, factors such as load instruction and primary air volume are taken into account, and the calculation result is directly superimposed on the output of the PID calculation.

[0051] Secondary air pressure regulation: the outlet water temperature representing the boiler load is used as the set value of the secondary air pressure regulation system after function calculation, and PID calculation is performed with the secondary air pressure measurement value. The calculation result adjusts the secondary fan so that the secondary air pressure meets the operating requirements.

[0052] Coal spreading air volume adjustment, the coal spreading air set amount instruction obtained by the fuel amount adjustment system is sent to the coal spreading air volume adjustment system, and PID operation is performed with the coal spreading air measurement value. The operation result adjusts the coal spreading air actuator so that the coal spreading air supply meets the operation requirements.

[0053] J-valve air flow control: The optimal operating bed temperature for a circulating fluidized bed boiler is 850°C-900°C. Within this temperature range, most coals are less prone to coking, limestone desulfurizers achieve optimal desulfurization, and NOx generation is minimal. Many factors influence the bed temperature of a circulating fluidized bed, including coal feed, limestone feed, slag discharge, primary air volume, secondary air volume, and return air volume. Coal feed primarily regulates main steam pressure. The influence of bed temperature on coal feed regulation is only reflected through the inner loop of the cascade system, making coal feed only one of the means of regulating bed temperature. Limestone feed has a relatively small impact on bed temperature, and its influence can also be indirectly reflected in coal feed. Therefore, the influence of limestone is not considered when designing the bed temperature control system. Slag discharge primarily regulates bed thickness. If the bed thickness is essentially constant, the effect of slag discharge on bed temperature can be ignored. For circulating fluidized bed boilers without external heat exchangers and using high-temperature separators, the bed temperature can be maintained stable by adjusting the ratio of primary to secondary air. For circulating fluidized bed boilers with external heat exchangers or intermediate-temperature separators, bed temperature is regulated by adjusting the return material flow. When the bed temperature rises, increasing the return material flow can lower the bed temperature. Conversely, when the bed temperature decreases, reducing the return material flow can raise it. The return material flow is regulated by the J-valve air volume control system. The J-valve air volume control system determines the setpoint for the bed temperature by comprehensively considering physical quantities such as load command, coal feed rate, primary air volume, and secondary air volume. This value, combined with the measured bed temperature, undergoes an adjustment operation, and the result is used to adjust the J-valve actuator to bring the bed temperature closer to the desired value.

[0054] The limestone feed rate control system is a cascade control system. The measured SO2 content value and the setpoint are fed into the main controller, where a PID calculation is performed. The result is then combined with the limestone setpoint command from the fuel control system and processed as a function. This result is fed into the secondary controller, where it undergoes a PID calculation with the measured limestone feed rate value. After limiting, the result is used to adjust the limestone feeder actuator to regulate the amount of limestone entering the circulating fluidized bed boiler, thereby controlling SO2 emissions.

[0055] Ignition boost fan air volume adjustment, the ignition air volume command issued by the total air volume adjustment system is used as the given value of the ignition boost fan air volume adjustment system, and is sent to the PID for calculation together with the ignition air volume measurement value. The calculation result is used to adjust the ignition air actuator to make the ignition air volume meet the operating requirements.

[0056] Bed thickness adjustment can be achieved by adjusting the bed pressure. In the bed pressure adjustment system, the measured bed pressure is combined with the set bed pressure value for PID calculation. The result of the calculation adjusts the slag discharge mechanism to ensure that the bed pressure meets the operating requirements. The set bed pressure value is determined by comprehensively considering factors such as boiler load and coal type.

[0057] In the furnace pressure regulation system, the measured furnace negative pressure value undergoes inertial hysteresis processing and is then fed into the PID control along with the setpoint for calculation. The calculated result activates the induced draft fan actuator, thereby adjusting the furnace negative pressure to meet the unit's operating requirements. In the case of multiple furnace negative pressure measurement points, a median value can be taken. Since changes in the primary and secondary air volumes require some time for the furnace negative pressure to change, the aforementioned regulation scheme directly incorporates the micro-air volume of the total air volume as a feedforward signal into the PID control output to improve the control system's responsiveness to changes in the primary and secondary air volumes.

[0058] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure, characterized in that: include: A fan pipe (1) and an air supply pipe (2), wherein a flexible connection assembly is fixedly installed between the fan pipe (1) and the air supply pipe (2) via a flange, and the flexible connection assembly comprises two assembly rings (3) and two annular sealing cloths (7), wherein the two annular sealing cloths (7) are concentrically arranged, and the two annular sealing cloths (7) are located between the two assembly rings (3); A reinforced waterproof component, the reinforced waterproof component is arranged in the assembly ring (3), and the reinforced waterproof component includes four sealing airbags (10); A wind pressure monitoring component is provided, wherein the air supply pipe (2) is provided with a wind pressure monitoring component on one side close to the assembly ring (3), and the wind pressure monitoring component includes a monitoring control seat (15), and a plurality of L-shaped collection tubes (19) are movably provided on the inner circumference of the monitoring control seat (15); An annular assembly groove is provided on opposite sides of the two assembly rings (3), and conical extrusion surfaces (4) are provided on both sides of the annular assembly groove. The two sides of the two annular sealing cloths (7) are respectively inserted into the annular assembly grooves of the two assembly rings (3), and the two sides of the annular sealing cloths (7) are respectively in contact with the conical extrusion surfaces (4) on one side of the two annular assembly grooves. A fixed operating ring (5) is movably inserted in each of the annular assembly grooves, and a conical pressure ring (6) is oppositely provided on one side of the fixed operating ring (5) close to the two conical extrusion surfaces (4), and an annular sealing cloth (7) is tightly arranged between the conical pressure ring (6) and the conical extrusion surfaces (4); The side of the assembly ring (3) away from the annular assembly groove is provided with a pulling screw (8) which is rotated and plugged into the sinking groove, and one side of the pulling screw (8) is inserted into the annular assembly groove. A plurality of fixed screw grooves (9) are symmetrically opened on the fixed operation ring (5), and the sides of the plurality of pulling screws (8) placed in the annular assembly groove are all screwed into the fixed screw grooves (9) of the fixed operation ring (5) through threads. An annular groove is provided on one side of the conical extrusion surface (4) in the annular assembly groove, and a sealing airbag (10) is inserted in the annular groove. An annular common groove (11) is provided on one side of the assembly ring (3) close to the annular groove. A plurality of sealing air guide tubes (12) are provided between the sealing airbag (10) and the annular common groove (11). A connecting hole is provided between the two annular common grooves (11) of the assembly ring (3), and the connecting hole is offset from the pulling screw (8). One side of the monitoring and control seat (15) extends out of the air supply pipe (2) and abuts against one side of the assembly ring (3). A plurality of receiving grooves (16) are symmetrically opened on the inner circumference of the monitoring and control seat (15). A rotation groove (17) is opened on one side of each of the plurality of receiving grooves (16). A rotation seat (18) is rotatably inserted in the rotation groove (17). An L-shaped collection tube (19) is arranged on one side of the rotation seat (18). When not in use for detection, the L-shaped collection tube (19) is horizontally stored in the storage groove (16).

2. The fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure according to claim 1, characterized in that: One side of each of the two assembly rings (3) is provided with a combination joint (13), the two combination joints (13) are respectively connected to the two annular common grooves (11), one side of the two combination joints (13) is horizontally connected with a transfer hose (14), and the upper end of one of the combination joints (13) is provided with an air inlet.

3. The fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure according to claim 2, characterized in that: A matching groove (21) is provided in the rotation seat (18), and the matching groove (21) is connected to the L-shaped collection tube (19). A second docking groove (23) is provided on one side of the rotation slot (17), and a transfer slot (24) is provided on one side of the second docking groove (23). A first docking groove (22) is provided on one side of the matching groove (21) through the rotation seat (18). When the L-shaped collection tube (19) is horizontally located in the storage slot (16), the first docking groove (22) and the second docking groove (23) are offset. One side of the transfer slot (24) penetrates the monitoring and control seat (15) and is located between the air supply pipe (2) and the assembly ring (3). A gas inspection groove (26) is provided on one side of the gas inspection groove (26). A detection hose (27) is provided on one side of the detection hose (27), and one side of the detection hose (27) is movable through the flange of the air supply pipe (2).

4. The fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure according to claim 3, characterized in that: An annular diverter groove (28) is provided on one side of the monitoring and control seat (15) near the self-rotating seat (18), and a docking air groove (33) is provided on one side of the annular diverter groove (28) penetrating through the monitoring and control seat (15) near the assembly ring (3). A connecting pipe (34) is provided on one side of the assembly ring (3) near the docking air groove (33). The connecting pipe (34) is sealed and plugged into one side of the docking air groove (33). A transfer air groove is provided in the connecting pipe (34) and is connected to one of the annular common grooves (11). A switching valve ball (35) is provided on one side of the switching valve ball (35), and a vent valve groove (36) is provided on the switching valve ball (35), and both sides of the vent valve groove (36) are connected to the connecting pipe.

5. The fully automatic control device for a circulating fluidized bed steam boiler with a waterproof structure according to claim 4, characterized in that: An arc-shaped piston groove (29) is provided on one side of the monitoring and control seat (15) near the rotation seat (18), one side of the arc-shaped piston groove (29) is connected to the annular diversion groove (28), and the virtual axis of the arc-shaped piston groove (29) is coaxially arranged with the virtual axis of the rotation groove (17) and the rotation seat (18). An arc-shaped push rod (30) is provided on one side of the L-shaped collection tube (19), and the arc-shaped push rod (30) is movably inserted into the arc-shaped piston groove (29) and is provided with a pushing piston (31). The arc-shaped push rod (30) is located in the arc-shaped piston groove (29) and is sleeved with an arc spring (32) on one side of the pushing piston (31), and the pushing piston (31) is arranged near the annular diversion groove (28).

Images