Isa residual heat boiler drum liquid level three-impulse setting method

Abstract

The application is suitable for the technical field of ISA waste heat boiler, and provides an ISA waste heat boiler drum liquid level three-impulse setting method.The ISA waste heat boiler drum liquid level three-impulse setting method comprises an ISA waste heat boiler control system, the ISA waste heat boiler control system comprises a control station, an operation station node and a system network; the control station is used for receiving and processing sensor data of the waste heat boiler, generating a control signal according to a preset control logic, and sending the control signal to an actuator of the waste heat boiler; the operation station node is in communication connection with the control station, is used for receiving and processing the control signal sent by the control station, and displaying the control signal on an operation interface, and simultaneously receiving and processing operation instructions of a user.The ISA waste heat boiler drum liquid level three-impulse setting method sets PID parameters and a feedforward coefficient of inner and outer rings of drum water level control, meets three-impulse automatic adjustment of the drum water level, reduces the operation intensity of a person, and ensures that the boiler can be safely and stably operated.

Description

Technical Field

[0001] This invention belongs to the field of Isa waste heat boiler technology, and particularly relates to a three-impulse method for adjusting the liquid level of the steam drum in an Isa waste heat boiler. Background Technology

[0002] The water level in the steam drum of the waste heat boiler fluctuates greatly due to the large changes in heat source caused by factors such as feeding, slag removal, copper removal, and boiler throughput. In particular, the boiler system uses a mixed circulation method of forced circulation and natural circulation. Natural circulation has problems with circulation, and the fluctuation of the steam drum water level is particularly obvious. Therefore, the control of the steam drum liquid level in the Isa waste heat boiler is relatively complicated. Summary of the Invention

[0003] This invention provides a three-impulse method for adjusting the water level in the steam drum of an Isa waste heat boiler, aiming to solve the problems of large changes in the heat source and large fluctuations in the water level of the steam drum in current waste heat boilers.

[0004] This invention is implemented as follows: a three-impulse method for adjusting the liquid level in the steam drum of an Isa waste heat boiler, comprising: an Isa waste heat boiler control system, the Isa waste heat boiler control system including a control station, operator station nodes, and a system network; the control station is used to receive and process sensor data from the waste heat boiler, generate control signals according to preset control logic, and send the control signals to the actuators of the waste heat boiler; the operator station nodes are communicatively connected to the control station, used to receive and process the control signals sent by the control station, display the control signals on the operation interface, and simultaneously receive and process user operation commands, sending the operation commands to the control station; the system network is used to connect the control station and the operator station nodes so that they can exchange data and transmit commands.

[0005] Preferably, the Isa waste heat boiler control system further includes an engineering station for configuring and maintaining control station and operator station nodes via a system network; an operator station for providing an environment for operators to complete process monitoring and management tasks, equipped with flowcharts and application software configured, programmed, and compiled by the engineering station and transmitted correctly, with multi-window display functionality to achieve centralized display, operation, and management of production process information; a field control station, an I / O processing unit for the system to directly exchange information with field equipment, completing the tasks of information acquisition, control output, and 24VDC power supply for field instruments during real-time operation of the entire system, receiving and processing field sensor data from the waste heat boiler, and sending the data to the control station and / or operator station nodes; and a process control network for connecting the engineering station, operator station nodes, control station, and field control station together so that they can exchange data and transmit commands.

[0006] Preferably, the engineer station includes a configuration module for configuring control station and operator station nodes; and a monitoring module for monitoring the overall system operation status.

[0007] Preferably, the field control station includes a receiving module for receiving field sensor data and a sending module for sending data to the control station and / or operator station nodes.

[0008] Preferably, the Isa waste heat boiler control system also includes a two-layer SBUS bus. The first layer is SBUS-S2, which is responsible for information exchange between the main control card and the data forwarding card in the I / O cage; while the second layer, SBUS-S1, is responsible for information exchange between the data forwarding card and the I / O card.

[0009] Preferably, the field control station is equipped with two SC2 chassis. Two redundant main control cards FW243X are placed in the first two slots of the first chassis, followed by a data forwarding card FW233 and other I / O cards. The main control card communicates with the data forwarding card through the SBUS-S2 network, and the data forwarding card communicates with other I / O cards through the SBUS-S1 network. This completes the information exchange between the main control card and the I / O cards, realizing the input acquisition and output control of field signals. Therefore, the second chassis is configured with a data forwarding card plus other I / O cards.

[0010] Preferably, in addition to the main control card having 1:1 hot standby redundancy, the I / O card of the Isa waste heat boiler control system also adopts 1:1 redundancy for important I / O points.

[0011] Preferably, the Isa waste heat boiler control system uses a feedwater regulating valve to control the water flow rate, adjusting the opening of the feedwater regulating valve to achieve stable liquid level control in the steam drum.

[0012] Preferably, the water supply regulating valve includes a valve body, a valve cover is fixedly installed on the top of the valve body, a connecting cover is fixedly installed on the outside of the valve cover, and a support plate, a connecting ring, a protective cover and a top cover are fixedly installed in sequence extending upward from the top of the connecting cover. An electrically driven valve assembly is provided inside the valve body, valve cover, support plate, connecting ring, protective cover and top cover.

[0013] Preferably, the valve assembly is provided with a sensing gear, which is located inside the protective cover. A speed sensor is threadedly installed on one side of the protective cover, and the sensing end of the speed sensor is located inside the protective cover and is correspondingly arranged with the sensing gear.

[0014] Compared with related technologies, the three-impulse setting method for the steam drum liquid level of the Isa waste heat boiler provided by the present invention has the following beneficial effects: Compared with existing technologies, this solution, by adjusting the inner and outer loop PID parameters and feedforward coefficients of the steam drum water level control, satisfies the automatic adjustment of the steam drum water level using three-impulse feedwater control, reducing the intensity of manual operation and ensuring the safe and stable operation of the boiler. At the same time, this solution can achieve both manual and automatic control of the feedwater regulating valve. The feedwater regulating valve uses a combination of speed sensor and camera monitoring to provide data, which can avoid the problem of failure to detect damage to a single data point in time, making the overall use safer. Attached Figure Description

[0015] Figure 1 The system network structure framework diagram provided by this invention; Figure 2 This is a specific communication structure framework diagram of the SBUS network provided by the present invention; Figure 3 This is a framework diagram of the steam drum feedwater control program provided by the present invention; Figure 4 This is a block diagram of the three-impulse control provided by the present invention; Figure 5 The fluctuation diagram of feedwater regulating valve opening, steam drum water level and boiler feedwater flow rate provided by the present invention (A represents feedwater regulating valve opening, B represents steam drum water level and C represents boiler feedwater flow rate); Figure 6 The water level fluctuation diagram provided by this invention; Figure 7 This is a schematic diagram of the main sectional view of the water supply regulating valve provided by the present invention; Figure 8 for Figure 7 An enlarged structural diagram of part A shown in the figure; Figure 9 for Figure 7 An enlarged structural diagram of part B shown in the figure; Figure 10 for Figure 9 An enlarged structural diagram of section C shown in the figure; Figure 11 This is a top view schematic diagram of the meshing structure of the spline sleeve and spline shaft in the water supply regulating valve of the present invention; Figure 12 This is a schematic diagram of the main structure of the water supply regulating valve provided by the present invention; Figure 13 for Figure 12 An enlarged structural diagram of part D shown in the figure; Figure 14 This is a top view of the connecting bracket in the water supply regulating valve of the present invention. Figure 15 This is a three-dimensional structural diagram of the locking block in the water supply regulating valve of the present invention; Figure 16This is a three-dimensional structural diagram of the valve assembly in the water supply regulating valve of the present invention.

[0016] Reference numerals: 1. Valve body; 2. Valve cover; 3. Connecting cover; 4. Support plate; 5. Connecting ring; 6. Protective cover; 7. Top cover; 8. Valve stem; 9. Threaded rod; 10. Threaded sleeve; 11. Smooth rod; 12. Splined sleeve; 13. Motor housing; 14. Drive motor; 15. Splined shaft; 16. Guide rod; 17. Plate sleeve; 18. Sensing gear; 19. Speed ​​sensor; 20. Scale; 21. Pointing arrow; 22. Camera; 23. Card holder; 24. Connecting bracket; 25. Card block; 26. Hanger; 27. Assembly seat; 28. Sinking groove; 29. ​​Locking groove; 30. Locking block; 31. Spring; 32. Pull cable; 33. Connecting handle; 34. Inlet flange; 35. Drain flange; 36. Flow port; 37. Valve body sealing gasket; 38. Valve plate; 39. Valve core. Detailed Implementation

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0018] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0019] This invention provides a three-impulse method for setting the liquid level in the steam drum of an Isa waste heat boiler, such as... Figure 1-16As shown, the Isa waste heat boiler drum liquid level three-impulse setting method includes: an Isa waste heat boiler control system, which includes a control station, operator station nodes, and a system network; the control station is used to receive and process sensor data from the waste heat boiler, generate control signals according to preset control logic, and send the control signals to the actuators of the waste heat boiler; the operator station nodes are communicatively connected to the control station, used to receive and process the control signals sent by the control station, display the control signals on the operation interface, and simultaneously receive and process user operation commands, sending the operation commands to the control station; the system network is used to connect the control station and operator station nodes so that they can exchange data and transmit commands.

[0020] In this embodiment, the entire waste heat boiler control system consists of one engineering station, two operator stations, a field control station, and a corresponding process control network. The system structure network framework is shown below. Figure 1 This tuning method involves tuning the PID controller in two parts: outer loop and inner loop. The outer loop is tuned first, followed by the inner loop. After finding the optimal PI value for the outer loop, the inner loop is tuned.

[0021] In a further preferred embodiment of the present invention, the Isa waste heat boiler control system further includes an engineering station for configuring and maintaining control station and operator station nodes via a system network; an operator station for providing an environment for operators to complete process monitoring and management tasks, equipped with flowcharts and application software configured, programmed, and compiled by the engineering station and transmitted correctly, and featuring multi-window display functionality to achieve centralized display, operation, and management of production process information; a field control station, an I / O processing unit for the system to directly exchange information with field equipment, completing the tasks of information acquisition, control output, and 24VDC power supply for field instruments during real-time operation of the entire system, receiving and processing field sensor data from the waste heat boiler, and sending the data to the control station and / or operator station nodes; and a process control network for connecting the engineering station, operator station nodes, control station, and field control station together so that they can exchange data and transmit commands.

[0022] In this embodiment, the control system adopts the SUPCON ECS-100X DCS control system.

[0023] In a further preferred embodiment of the present invention, the engineer station includes a configuration module for configuring control station and operator station nodes; and a monitoring module for monitoring the overall system operating status.

[0024] In a further preferred embodiment of the present invention, the field control station includes a receiving module for receiving field sensor data and a sending module for sending data to the control station and / or operator station nodes.

[0025] In a further preferred embodiment of the present invention, the Isa waste heat boiler control system further includes a two-layer SBUS bus. The first layer is SBUS-S2, which is responsible for information exchange between the main control card and the data forwarding card in the I / O cage; while the second layer is SBUS-S1, which is responsible for information exchange between the data forwarding card and the I / O card.

[0026] In this embodiment, the communication network of the SUPCON ECS-100X system is divided into four layers. This system uses the second layer, the operator network; the third layer, the process control network ScnetⅡ; and the fourth layer, the I / O control bus SBUS within the control station. The operator network has peer-to-peer client / server characteristics, enabling real-time data, real-time alarms, historical trends and alarms, real-time data communication and historical data query between operator nodes, as well as time synchronization between operator nodes. ScnetⅡ is a dual-redundant high-speed industrial Ethernet network that directly connects the system control station, one engineer station, and two operator stations. It serves as the channel for transmitting real-time process information. Due to its dual redundancy structure, the ScnetⅡ network maintains normal data transmission even when any communication line fails, greatly enhancing the reliability of system communication. The SBUS network bus is the internal I / O control bus of the control station. The main control card, data forwarding card, and I / O cards all exchange information through the SBUS bus.

[0027] In a further preferred embodiment of the present invention, the field control station is equipped with two SC2 chassis. Two redundant main control cards FW243X are placed in the first two slots of the first chassis, followed by a data forwarding card FW233 and other I / O cards. The main control card communicates with the data forwarding card through the SBUS-S2 network, and the data forwarding card communicates with other I / O cards through the SBUS-S1 network. This completes the information exchange between the main control card and the I / O cards, realizing the input acquisition and output control of field signals. Therefore, the second chassis is configured with a data forwarding card plus other I / O cards.

[0028] In a further preferred embodiment of the present invention, in addition to the main control card having 1:1 hot standby redundancy, the I / O card of the Isa waste heat boiler control system also adopts 1:1 redundancy for important I / O points.

[0029] In the above embodiments, the above part is the system hardware structure.

[0030] The following describes the system control software design and human-machine interface communication, specifically including: Install the AdvanTrol-Pro software package on the Windows operating system platform, and then use the license management software (SCReg) to configure user levels and grant corresponding operating permissions.

[0031] By entering the AdvanTrol-Pro system configuration software (SCKey), the system can be configured, programmed (including graphical programming and SCLang language programming), flowcharts can be created, reports can be generated, and secondary calculations can be performed. After saving and compiling, the configuration is downloaded to the control station for execution.

[0032] Human-machine interface operation and communication: The system can be monitored in real time through the engineer station and two operator stations. Operators can choose to manually or automatically control the steam drum liquid level as required, based on factors such as the small system load and the large influence of the ISA furnace temperature, as well as their actual operating habits.

[0033] 1) Three-impulse control of boiler drum water level: After the boiler is running normally, the operator can switch the liquid level control to the three-impulse control mode through the upper-level monitoring software operation screen (the feedwater regulating valve is set to automatic on the operation screen, and the ESV (external) / SV (internal) selection switch is used to select ESV (external) and the control system will control the operation according to the three-impulse control mode according to the liquid level setting, that is, automatically control the liquid level of the boiler drum.

[0034] 2) Automatic control of boiler feedwater flow (the feedwater regulating valve is set to automatic on the operation screen, and SV is selected via the internal / external setpoint selection switch ESV / SV, not single-impulse control). When the heat load is relatively stable and the steam flow is constant, the steam flow is used as a reference. Based on operating experience, the setpoint of the boiler feedwater flow is modified. The control system compares the magnitude of the flow detection value with the setpoint and automatically adjusts the output of the boiler feedwater regulating valve to stabilize the feedwater flow and achieve constant flow control of the feedwater flow.

[0035] 3) Manual control of steam drum water level: When the water level in the steam drum fluctuates greatly and it is difficult to switch to automatic control, the operator can switch the boiler feedwater regulating valve to manual control and directly adjust the opening of the feedwater valve to control the water level in the steam drum according to the liquid level and the target control value.

[0036] System control software design and human-machine interface communication: Software design of the steam drum water level control program in the control system: The three-impulse control system essentially consists of a feedforward and cascade feedback. The controlled object is the boiler drum water level. The boiler drum water level has two level detection selection modules, allowing for a two-choice selection mode. The boiler drum water level is used as the primary impulse of the three-impulse control system; that is, the water level measurement value serves as the feedback value for the outer loop of the cascade control system. Steam flow (pressure) is selected as the feedforward, and feedwater flow is used as the measurement feedback value for the inner loop of the cascade control system. The boiler drum water level control program is shown below. Figure 3The two water level transmitters in the steam drum send the measured water level values ​​to the DCS control system in real time. The operator selects either water level gauge A or water level gauge B through the steam drum water level selection module P1_21. The selected water level gauge is the first input LE0101 and the second input LE0102 of the module P1_21 in the program.

[0037] The water level measurement value (0~1, half-floating point) is sent to the first input pin PV of the outer loop controller, i.e., the main controller, as the outer loop feedback value of the cascade control system. PV is the negative feedback of the main controller and is compared with the liquid level setpoint (the 7th input value of module P1_3, which is entered by the operator in the operation screen and is called the internal setpoint). The resulting deviation value (setpoint - PV value, which can be positive, negative, or zero) is then added to the 'steam flow rate' (0~1, half-floating point). The 'steam flow rate' (0~1, half-floating point) is the steam flow rate measurement value FE0101 multiplied by the feedforward coefficient (set and input in the engineer-level monitoring screen, generally directly taken as 1) through the half-floating point multiplication module of P1_15 as the compensation input and sent to the main controller P1_3 module. It is not a direct addition.

[0038] The main controller P1_3 module adds the final calculated deviation value (positive, negative, or zero) to the original control output MV and outputs it to the 8th input value of the auxiliary controller P1_1 module as the setpoint for the auxiliary controller's feedwater controller (provided that the operator selects the external setpoint via the internal / external setpoint switch SV / ESV, i.e., the auxiliary controller's setpoint is the main controller's output value, and the feedwater regulating valve is set to automatic). The auxiliary controller compares its first input value, the feedwater flow feedback value FE0103.PV, with the value on the 8th input ESV of the external setpoint, calculates the deviation value (positive, negative, or zero), adds it to the original control output MV, and outputs it to the feedwater regulating valve to adjust the valve opening, thereby achieving stable steam drum level control. See the control block diagram below. Figure 4 .

[0039] Automatic control program for steam drum feedwater flow: When the operator selects the internal setpoint via the internal / external setpoint switch SV / ESV (single-loop controllers only have internal setpoints, which can be directly set and input by the operator on the monitoring screen), and the water supply regulating valve is set to automatic, the program... Figure 3 The secondary controller of the cascade control system, namely the water flow controller P1_1 module, selects whether to execute internal or external setpoints through the 6th input value SwSV. When the operator selects external setpoints, the value of SV_ESV1 is 0, which is inverted and sent to the 6th input value SwSV of the P1_1 module. The value of SwSV is 1, and the external setpoint program is executed.

[0040] Conversely, when the internal setpoint is selected, SV_ESV1 is 1 and SwSV is 0. The internal setpoint control program is executed, and the secondary controller, the water flow controller, transforms into the main controller. It compares and calculates the first input value, the water flow feedback value FE0103.PV, with the value on the 7th input SV of the internal setpoint (set by the operator in the pop-up flowchart SV of the water flow regulation control on the monitoring screen). The resulting deviation value (positive, negative, or zero) is added to the original control output MV and output to the water flow regulating valve to adjust the valve opening and stabilize the water flow to the set value.

[0041] Manual control program: In the pop-up flowchart of the monitoring screen for water flow regulation control, select manual control and directly input the valve opening degree in MV. Figure 3 In the program, the third input value SwAM of the water flow controller P1_1 is 0. The water flow controller P1_1 directly outputs the MV value as the control output to the water supply regulating valve to adjust the valve opening and change the water flow.

[0042] Smooth switching between control state modes: A switches from manual control or single-loop control of the water supply to automatic three-impulse control. (In the program, the second-to-last input pin SwTV of the level control loop module P1_3 is the output tracking switch. When SwTV is 1, tracking occurs, meaning the output value MV of module P1_3 is equal to the input value of the last pin TV. When SwTV is 0, tracking does not occur. The output value MV of P1_3 is the sum of the deviation values ​​from the comparison operation.) When the control mode is manual control, the third input value SwAM of the water flow controller P1_1 is 0 (manual / automatic selection switch value). In the switch quantity and module P1_23, the second input value g_bsc{1}.SwAM is 0. Regardless of whether the first input value is 0 or 1, the output value g_bsc{0}.SwAM is always 0. Then, g_bsc{0}.SwAM is 0, inverted to 1, and sent to the second-to-last input pin of the cascade control system main controller P1_3, the output tracking switch SwTV, to control the output quantity MV of the water flow controller P1_1, making the output quantity MV value of the main controller P1_1 equal to the TV value.

[0043] Similarly, if it is a single-loop control of water supply, g_bsc{1}.SwAM is 1. Since the internal setpoint SV_ESV1 has been selected as 1, its inversion is 0. After multiplying by P1_23 with module SV_ESV1 and g_bsc{1}.SwAM, g_bsc{0}.SwAM is 0. The inversion of g_bsc{0}.SwAM equals 0 and is sent to the second-to-last input pin of the cascade control system main controller P1_3 to output the tracking switch SwTV to control the output MV of the water supply flow controller P1_1, making it equal to the TV value.

[0044] In other words, regardless of whether it is in manual or single-loop control mode, the output tracking switch SwTV of the second-to-last input pin of the cascade control system main controller P1_3 is always 1, so that the output MV of the feedwater flow controller P1_1 is always equal to the internal setpoint SV of the secondary controller, i.e., the feedwater flow controller. In manual mode, the internal setpoint SV of the secondary controller is equal to the output MV value. That is to say, in manual or single-loop feedwater flow control, the output value MV of the main controller is equal to the output value or setpoint of the secondary controller, which ensures the smooth and disturbance-free switching of the drum water level control mode from manual or single-loop control to three-impulse control.

[0045] The simplest approach is to switch from three-impulse to manual control, where the output value MV of the water flow controller remains unchanged.

[0046] The influence of PID controllers in inner and outer loops on steam drum level control: Because the ISA waste heat boiler uses a natural circulation method, during normal production, the feedwater flow rate in the rising and falling flues of the waste heat boiler flues flues varies between 700 t / h and 1048 t / h, while the feedwater flow rate in the horizontal flue flues fluctuates between 252 t / h and 968 t / h. The minimum flow rate is maintained for a long time, lasting up to about 8 minutes. After the three-stroke control is activated, the steam drum water level fluctuates between -110 mm and +118 mm, and the feedwater regulating valve opening fluctuates between 0% and 100%. It is difficult to put the three-stroke automatic control of the steam drum water level into operation.

[0047] Study and tuning of PID parameters for the outer loop (main) controller: To achieve fully automatic operation of the steam drum water level control system, the parameters of the main controller for the three-impulse automatic control of the steam drum water level (including the feedforward coefficient of steam flow, the PID parameters of the feedwater regulation control loop and the liquid level regulation control loop) were tuned and debugged. When debugging the PID parameters of the outer loop (main) controller, the PID parameters of the inner loop (secondary) controller were not adjusted. Through the revision experiment of the PID parameters of the outer loop (main) controller, the optimal parameter settings were found. During the parameter tuning and debugging process, the optimal P value was tuned to 70, the I value to 0.38, and the feedforward coefficient to 0.8. After this, the water level fluctuation could be controlled within ±100mm of the set value. However, through the analysis and study of the operating curve of the steam drum water level, it was found that the water level fluctuation exhibited a large cycle and a small cycle, with a small cycle waveform appearing within the large cycle.

[0048] Study and tuning of PID parameters for inner loop (secondary) controller: To reduce fluctuations in large-cycle waveforms and eliminate small-cycle waveforms, thus truly achieving automatic three-impulse control of the waste heat boiler drum water level, the PID parameters of the inner loop (secondary) controller of the automatic three-impulse control system for the drum water level were retuned. While adjusting the PID parameters of the inner loop (secondary) controller, the PID parameters of the outer loop (primary) controller remained unchanged. Ultimately, the optimal P value of the inner loop (secondary) controller was tuned to 78, and the I value was tuned to 1.6. This effectively controlled the water level fluctuations within ±80mm of the set value, eliminating small-cycle waveforms and achieving fully automatic three-impulse control of the drum water level.

[0049] The DCS control system for steam drum water level control allows operators to select the appropriate control mode on the monitoring screen based on production conditions and operational experience. It can manually change the opening of the regulating valve, perform automatic single-loop regulation control, and perform automatic three-impulse control. The three-impulse control not only introduces steam flow (pressure) fluctuations as feedforward variables into the control system, but also allows the feedforward coefficients to be modified in real time as required.

[0050] In the automatic control of the steam drum water level using the "three-impulse" method, the tuning of the PID parameters of the inner and outer loop controllers in the "three-impulse" automatic control loop is a crucial step. This is especially true for the steam drum water level control in the waste heat boiler water circulation mode, where the PID of both the outer loop (main) controller and the inner loop (secondary) controller needs to be studied and tuned. If only the PID parameters of one controller are adjusted, the "three-impulse" automatic control cannot be achieved.

[0051] Tuning the PID parameters requires collaboration between instrumentation and control professionals and thermal engineering professionals. Finding the optimal parameter settings is key to achieving automatic control of the steam drum water level.

[0052] In a further preferred embodiment of the present invention, the Isa waste heat boiler control system controls the water flow rate by using a feedwater regulating valve, adjusting the opening of the feedwater regulating valve to achieve stable liquid level control in the steam drum.

[0053] In a further preferred embodiment of the present invention, the water supply regulating valve includes a valve body 1, a valve cover 2 is fixedly installed on the top of the valve body 1, a connecting cover 3 is fixedly installed on the outside of the valve cover 2, and a support plate 4, a connecting ring 5, a protective cover 6 and an upper cover 7 are fixedly installed on the top of the connecting cover 3 in sequence. An electrically driven valve assembly is provided inside the valve body 1, the valve cover 2, the support plate 4, the connecting ring 5, the protective cover 6 and the upper cover 7.

[0054] In this embodiment, the valve assembly includes a valve stem 8 movably installed within the valve body 1, valve cover 2, support plate 4, connecting ring 5, and protective cover 6. The top end of the valve stem 8 is a threaded rod 9, and a threaded sleeve 10 is threaded onto the external thread of the threaded rod 9. The threaded sleeve 10 is rotatably mounted on the connecting ring 5 using a bearing. A smooth rod 11 is fixedly installed at the top end of the threaded sleeve 10. A spline sleeve 12 is rotatably installed inside the upper cover 7, and the spline sleeve 12 is fixedly connected to the top end of the smooth rod 11. A motor housing 13 is fixedly installed on the top of the upper cover 7, and a drive motor 14 is fixedly installed inside the motor housing 13. A spline shaft 15 is fixedly installed on the output shaft of the drive motor 14, and the spline shaft 15 meshes with the spline sleeve 12.

[0055] In the above-mentioned operation, when the Isa waste heat boiler control system automatically / manually controls the feedwater regulating valve, the signal is input to the drive motor 14. The output shaft of the drive motor 14 drives the spline shaft 15 to rotate. The spline shaft 15 drives the smooth rod 11 and the threaded sleeve 10 to rotate through meshing with the spline sleeve 12. The threaded sleeve 10 meshes with the threaded rod 9 to drive the valve stem 8 to rise and fall, thereby realizing the opening and closing control of the feedwater regulating valve.

[0056] In a further preferred embodiment of the present invention, the valve assembly is provided with a sensing gear 18, the sensing gear 18 is located inside the protective cover 6, and a speed sensor 19 is threadedly installed on one side of the protective cover 6. The sensing end of the speed sensor 19 is located inside the protective cover 6 and is correspondingly arranged with the sensing gear 18.

[0057] In this embodiment, the sensing gear 18 is fixedly sleeved on the light rod 11. When the light rod 11 rotates, it drives the sensing gear 18 to rotate. At this time, the speed sensor 19 on one side can monitor the speed of the sensing gear 18, thereby providing the opening and closing status of the water supply regulating valve.

[0058] In the above embodiment, in order to ensure the smooth lifting and lowering of the valve stem 8, a plate sleeve 17 that slides in contact with the support plate 4 is fixedly sleeved on the valve stem 8, and a guide rod 16 that slides through the plate sleeve 17 is fixedly installed between the connecting cover 3 and the connecting ring 5. When the valve stem 8 is lifted or lowered, the plate sleeve 17 and the guide rod 16 limit its movement to ensure smooth sliding.

[0059] To prevent damage to the speed sensor 19 from going undetected and uncontrolled, and to facilitate manual control, a scale 20 is engraved on one side of the support plate 4. A directional arrow 21 corresponding to the scale 20 is fixedly installed on the plate sleeve 17. A camera 22 is provided on one side of the support plate 4 to monitor the scale 20 and the directional arrow 21. During use, the camera 22 monitors the direction of the scale 20 and the directional arrow 21 and transmits the data to the monitoring screen for easy viewing.

[0060] To achieve synchronized movement of the camera 22, the pointing arrow 21, the valve stem 8, and the plate sleeve 17, and to reduce visual deviation, a slidable bracket 23 is provided on one side of the support plate 4. The bracket 23 is fixed to the plate sleeve 17 by a connecting bracket 24. A locking block 25 is detachably installed inside the bracket 23. A hanger 26 is fixedly installed on the locking block 25. An assembly seat 27 is fixedly installed on the hanger 26. The assembly seat 27 is fixedly connected to the camera 22. A collection groove 28 is opened on at least one inner wall of the bracket 23. A locking groove 29 corresponding to the collection groove 28 is opened on one side of the locking block 25. A locking block 30 that can engage with the locking groove 29 is slidably installed in the collection groove 28. A spring 31 that is fixedly connected to the locking block 30 is fixedly installed in the collection groove 28. A pull line 32 extending out of the bracket 23 is fixedly installed on the locking block 30. A connecting handle 33 is fixedly installed at the end of the pull line 32.

[0061] During use, the plate sleeve 17 uses the connecting frame 24 to drive the card seat 23, card block 25, hanger 26, mounting base 27 and camera 22 to move synchronously. When maintenance is required, pull the connecting handle 33, the connecting handle 33 pulls the pull cable 32, the pull cable 32 drives the locking block 30 to move, so that the locking block 30 is disengaged from the locking groove 29, thereby compressing the spring 31. At this time, the card seat 23 and the card block 25 can be separated to complete the unlocking. During installation, simply push the card block 25 into the card seat 23. Under the guidance of the inclined surface of the locking block 30, the locking block 30 can be locked into the locking groove 29 to complete the fixation.

[0062] In this invention, the valve body 1 has an inlet flange 34 and a drain flange 35 on both sides. The valve body 1 has a flow port 36 that connects to the valve cavity. A sealable valve body sealing gasket 37 is fixedly installed at the flow port 36. A sealable valve plate 38 is fastened to the valve body sealing gasket 37. The valve plate 38 is fixedly connected to the valve stem 8. A sealed valve core 39 is provided inside the valve cover 2. The valve core 39 is slidably connected to the valve stem 8.

[0063] In summary, compared with related technologies, this invention, by adjusting the inner and outer loop PID parameters and feedforward coefficients of the steam drum water level control, satisfies the automatic adjustment of the steam drum water level using three-impulse feedwater control, reducing the intensity of manual operation and ensuring the safe and stable operation of the boiler. Furthermore, this solution enables both manual and automatic control of the feedwater regulating valve. The feedwater regulating valve is monitored by a speed sensor 19 and a camera 22, which jointly provides data, avoiding the problem of undetected damage to a single data point, thus enhancing overall safety.

[0064] It should be understood that the disclosed apparatus can be implemented in other ways, as illustrated in the embodiments provided in this application. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or communication connections shown or discussed may be through some interfaces; indirect coupling or communication connections between devices or units may be in telecommunications or other forms. The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still combine, add, delete, or otherwise adjust the features in the various embodiments of the present invention according to the circumstances without conflict or creative effort, thereby obtaining different technical solutions that do not fundamentally depart from the concept of the present invention. These technical solutions are also within the scope of protection of the present invention.

Claims

1. A three-impulse method for setting the liquid level in the steam drum of an Isa waste heat boiler, characterized in that, include: The Isa waste heat boiler control system includes a control station, operator station nodes, and a system network. The control station is used to receive and process sensor data from the waste heat boiler, generate control signals according to preset control logic, and send the control signals to the actuators of the waste heat boiler. The operator station node is communicatively connected to the control station and is used to receive and process control signals sent by the control station, display the control signals on the operation interface, and receive and process user operation instructions and send the operation instructions to the control station. The system network is used to connect control stations and operator station nodes so that they can exchange data and transmit commands. The Isa waste heat boiler control system also includes an engineering station, used for configuring and maintaining control station and operator station nodes through the system network; an operator station, providing an environment for operators to complete process monitoring and management tasks, equipped with flowcharts and application software configured, programmed, and compiled by the engineering station and transmitted correctly, with multi-window screen display function, realizing centralized display, centralized operation and centralized management of production process information; and a field control station, an I / O processing unit for the system to directly exchange information with field equipment, completing the tasks of information acquisition, control output, and 24VDC power supply for field instruments during the real-time operation of the entire system. It receives and processes field sensor data from the waste heat boiler and sends the data to the control station and / or operator station nodes. And process control networks, which connect engineering workstations, operator workstations, control stations and field control stations to enable data exchange and command transmission between them; The engineer station includes a configuration module for configuring control station and operator station nodes; And a monitoring module for monitoring the overall system operating status; The field control station includes a receiving module for receiving field sensor data; And a transmission module for sending data to control station and / or operator station nodes; The Isa waste heat boiler control system also includes a two-layer SBUS bus. The first layer is SBUS-S2, which is responsible for information exchange between the main control card and the data forwarding card in the I / O cage. The second layer is SBUS-S1, which is responsible for information exchange between the data forwarding card and the I / O card. The field control station is equipped with two SC2 chassis. Two redundant main control cards, FW243X, are placed in the first two slots of the first chassis, followed by a data forwarding card, FW233, and other I / O cards. The main control cards communicate with the data forwarding cards via the SBUS-S2 network, and the data forwarding cards communicate with the other I / O cards via the SBUS-S1 network. This information exchange between the main control cards and the I / O cards enables the input acquisition and output control of field signals. Therefore, the second chassis is configured with a data forwarding card plus other I / O cards. In addition to the main control card having 1:1 hot standby redundancy, the I / O card of the aforementioned Isa waste heat boiler control system also adopts 1:1 redundancy for important I / O points. The Isa waste heat boiler control system uses a feedwater regulating valve to control the water flow rate, adjusting the opening of the feedwater regulating valve to achieve stable liquid level control in the steam drum.

2. The three-impulse adjustment method for the steam drum liquid level of the Isa waste heat boiler as described in claim 1, characterized in that, The water supply regulating valve includes a valve body, a valve cover is fixedly installed on the top of the valve body, a connecting cover is fixedly installed on the outside of the valve cover, and a support plate, a connecting ring, a protective cover and a top cover are fixedly installed in sequence on the top of the connecting cover. An electrically driven valve assembly is provided inside the valve body, valve cover, support plate, connecting ring, protective cover and top cover.

3. The three-impulse method for setting the liquid level in the steam drum of the Isa waste heat boiler as described in claim 2, characterized in that, The valve assembly is equipped with a sensing gear located inside the protective cover. A speed sensor is threaded onto one side of the protective cover, and the sensing end of the speed sensor is located inside the protective cover and is correspondingly arranged with the sensing gear.

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