A control system and control method for a waste liquid incinerator
By integrating BMS and SIS systems into the BMS program architecture, intelligent control of the waste liquid incinerator is achieved, solving the problem of frequent crossover between DCS and ESD systems, improving operational convenience and safety, and meeting SIL safety level requirements.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SUPCON TECH CO LTD
- Filing Date
- 2023-06-30
- Publication Date
- 2026-08-04
AI Technical Summary
The existing three-stage waste liquid incinerators have frequent overlap between the DCS and ESD systems, making process parameter adjustments complex, resulting in low safety and difficulty in achieving the ideal SIL safety level requirements. Furthermore, they are complex to operate and have high time costs.
The BMS and SIS systems are integrated into the BMS program architecture to achieve intelligent guidance on start-up sequence and condition display, judgment, and early warning. The process safety control system monitors the environmental parameters of the incinerator, automatically executes safety interlock actions, optimizes alarm information, and simplifies the operation process.
It improves ease of operation and safety, simplifies operating procedures, enhances system availability and security, reduces time and fuel costs, and meets SIL safety level requirements.
Smart Images
Figure CN116878001B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of industrial control technology, and in particular relates to a control system and control method for a waste liquid incinerator. Background Technology
[0002] A three-stage waste liquid incinerator is a device used to treat waste liquid, mainly composed of a main burner, secondary combustion chambers A / B, four burners (SCR - Selective Catalytic Reduction), and a waste heat recovery device. This equipment decomposes waste liquid into harmless substances through high-temperature combustion, while simultaneously recovering energy using the waste heat recovery device, achieving energy conservation and environmental protection. Burner management in the waste liquid incinerator includes fuel supply, air conditioning, ignition, and combustion control, requiring regular inspection and maintenance to ensure its normal operation. An emergency shutdown system based on safety instrumented control immediately cuts off the fuel supply and shuts down the burner in case of malfunction or dangerous situations to protect equipment and personnel safety. This system typically consists of sensors, controllers, and actuators.
[0003] Conventional DCS (Distributed Control System) control of waste liquid incinerators involves steps such as main combustion system purging, main combustion system startup, main burner purging, main burner startup, and main burner shutdown; secondary burner purging, secondary burner startup, and secondary burner shutdown. This process is cumbersome, with interconnected and restrictive processes, resulting in high risk. Conventional manual control is also complex, with monitoring, operational, alarm, and process status information intertwined and requiring a high level of operator expertise, proficiency, focus, and time commitment.
[0004] To ensure the safe operation of the combustion furnace, the ESD (Emergency Shutdown Device) system is built using an independent SIS (Safety Instrumented System). This approach, independent of the DCS control system, increases hardware costs. Frequent overlap of shared I / O tags between the DCS and ESD systems leads to frequent adjustments of process parameters and redundant alarm information. Furthermore, the three-stage waste liquid combustion furnace requires flexible start-up and shutdown adjustments based on waste liquid composition, operating condition changes, and temperature rise requirements. Consequently, parameters such as natural gas flow and valve openings will vary and cannot be precisely controlled. Before each start-up, real-time parameters and status updates must be communicated to the ESD system according to the DCS control system's startup requirements. This communication process suffers from low security, hindering stable system operation and subsequent maintenance. Moreover, the combustion control is complex, with nested sequential controls that require careful consideration of safety-related constraints. This makes operational debugging and parameter setting difficult, thus making it challenging to achieve the ideal SIL (Safety Integrity Level) safety requirements. Summary of the Invention
[0005] To address the aforementioned problems, the present invention aims to provide a waste liquid incinerator control system and control method. This waste liquid incinerator control system intelligently integrates the BMS and SIS systems within the BMS program architecture. It can intelligently guide the start-up sequence and current steps, and intelligently display, judge, and warn about the conditions during the execution of each step, thereby improving the convenience and safety of operation. Under the premise of ensuring the safety of the system, production, and personnel, it rationally optimizes process alarms and simplifies the operator's operation process.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a waste liquid incinerator control system, wherein the waste liquid incinerator includes a main burner and a secondary combustion chamber, characterized in that it includes: a process safety control system, which is signal-connected to multiple shut-off valves and multiple regulating valves of the waste liquid incinerator, for controlling the process operation of the waste liquid incinerator and monitoring the safe operation of the waste liquid incinerator; and a DCS control system, which is signal-connected to the process safety control system, for adjusting the opening degree of multiple unsafe operating regulating valves during the safe operation of the waste liquid incinerator.
[0007] Preferably, the process safety control system includes a BMS control system and an SIS control system. The BMS control system automatically performs purging, start-up, and shutdown sequence control according to a preset program. The SIS control system monitors and controls multiple shut-off valves of the waste liquid incinerator based on preset parameters and / or interlocking conditions according to the process stage of the incinerator to achieve full-process safety monitoring of the system.
[0008] Preferably, the process safety control system monitors the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors, compares the collected sensor parameters with the corresponding thresholds, and immediately executes the relevant safety interlock actions and pops up interlock alarm information when an interlock is triggered.
[0009] Preferably, when the interlock is triggered, the sequential control logic of the current process stage is automatically cut off, the safe shutdown logic is executed, and the system is initialized to achieve safe monitoring of the combustion process.
[0010] Preferably, the process safety control system further includes an HMI interface, which displays the process stage of the incinerator in real time and displays corresponding abnormal prompts when an abnormality occurs.
[0011] Preferably, the DCS control system is capable of receiving changes made by the user to the preset regulating valve parameters and sending the changed parameters to the target regulating valve through the process safety control system.
[0012] Preferably, the AI signals of the opening degree of the multiple regulating valves are input to the AI terminal board of the SIS control system via hard wiring to improve the safety level of the SIL circuit and allow the SIS control system to monitor the valve opening parameters throughout the process.
[0013] Based on the same concept, the present invention also provides a control method for a waste liquid incinerator, comprising the following steps: initializing the BMS control system in the process safety control system, and performing self-checks on all sensors and valve actuators within the BMS control system; acquiring purging parameters input from a preset interface, and performing a purging operation on the incinerator based on the purging parameters; detecting whether the BMS control system meets the start-up conditions, and performing a start-up operation based on a preset ignition valve setpoint if the start-up conditions are met; after successful start-up, releasing the control authority of the preset regulating valve to the DCS control system; and the SIS control system in the process safety control system monitoring and controlling multiple shut-off valves of the waste liquid incinerator according to preset parameters and / or interlocking conditions based on the process stage of the system to achieve full-process safety monitoring of the system.
[0014] Preferably, the process safety control system also includes: monitoring the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors; comparing the collected sensor parameters with the corresponding thresholds; and immediately executing the relevant safety interlock actions and displaying interlock alarm information when an interlock is triggered. At the same time, it automatically cuts off the sequential control logic of the current process stage, executes the safety shutdown logic, and initializes the system to achieve safe monitoring of the combustion process.
[0015] Preferably, the system further includes performing system initialization based on the preset safety shutdown logic within the BMS control system when the parameters of the preset shut-off valve detected by the SIS control system exceed a preset threshold.
[0016] Because the present invention adopts the above technical solution, it has the following advantages and positive effects compared with the prior art:
[0017] 1. The technical solution of the present invention intelligently integrates the BMS and SIS systems in the BMS program architecture, which can intelligently guide the start-up sequence and current steps, and intelligently display, judge and warn the conditions in the execution process of each step, thereby improving the convenience and safety of operation. Under the premise of ensuring the safety of the system, production and personnel, the process alarm is reasonably optimized and the operator operation process is simplified.
[0018] 2. The technical solution of this invention is based on preset interlocking logic. When an interlock is triggered, the relevant interlocking action is executed and a corresponding interlocking alarm message is displayed, providing timely reminders to operators while ensuring the combustion process remains safe. The safety interlock priority is set to the highest level to ensure the safe operation of the system.
[0019] 3. The technical solution of this invention provides unified and integrated management of instrument I / O data, operating parameters, and monitoring data, enabling intelligent process flow control. It automatically completes sequential control of purging, start-up, and shutdown, and monitors parameters at each stage of the process. Key alarm information is displayed step-by-step, avoiding irrelevant alarm messages and improving the effectiveness and usability of the overall system information. Attached Figure Description
[0020] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:
[0021] Figure 1 This is a system architecture diagram of the present invention;
[0022] Figure 2 This is a schematic diagram of the signal transmission principle of the control system of the present invention;
[0023] Figure 3 This is a flowchart of an ignition control method for a waste liquid incinerator according to an embodiment of the present invention. Detailed Implementation
[0024] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become clearer from the following description and claims. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.
[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.
[0026] like Figure 1 The diagram shown illustrates the system architecture of the present invention. Figure 2 A schematic diagram of the signal transmission principle of the control system of the present invention is shown.
[0027] The technical solution of this embodiment is: a waste liquid incinerator control system, wherein the waste liquid incinerator includes a main burner and a secondary combustion chamber, characterized in that it includes: a process safety control system, which is signal-connected to multiple shut-off valves and multiple regulating valves of the waste liquid incinerator, for controlling the process operation of the waste liquid incinerator and monitoring the safe operation of the waste liquid incinerator; and a DCS control system, which is signal-connected to the process safety control system, for adjusting the opening degree of multiple unsafe operation regulating valves during the safe operation of the waste liquid incinerator.
[0028] In the technical solution of this invention, the process safety control system is signal-connected to multiple shut-off valves and regulating valves of the incinerator and can control the state and / or opening degree of each shut-off valve and regulating valve through actuators, thereby enabling purging, start-up, and shutdown operations. Simultaneously, it performs real-time safety operation monitoring based on the process stage of the incinerator, and executes a safety shutdown logic whenever an abnormality occurs, thus ensuring the safe operation of the system. Compared with existing technologies, the technical solution of this application has a higher degree of automation, intelligence, and safety. It significantly improves the system's availability and intelligence while ensuring safe production.
[0029] The non-safety-related control valves include those that operators adjust according to operating conditions, such as temperature, pressure, and flow rate, during production operations. These control valves do not involve the operation of the SIS control system. During operation, the DCS control system also records system logs and alarms.
[0030] Preferably, the process safety control system includes a BMS control system and an SIS control system. The BMS control system automatically performs purging, start-up, and shutdown sequence control according to a preset program. The SIS control system monitors and controls multiple shut-off valves of the waste liquid incinerator based on preset parameters and / or interlocking conditions according to the process stage of the incinerator to achieve full-process safety monitoring of the system.
[0031] In the BMS program architecture, the BMS control system and SIS control system are intelligently integrated, which can intelligently guide the start-up sequence and current steps, and intelligently display, judge and warn the conditions in the execution process of each step, thereby improving the convenience and safety of operation. Under the premise of ensuring the safety of the system, production and personnel, the process alarms are reasonably optimized and the operator operation process is simplified.
[0032] Preferably, the process safety control system monitors the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors, compares the collected sensor parameters with the corresponding thresholds, and immediately executes the relevant safety interlock actions and pops up interlock alarm information when an interlock is triggered.
[0033] Based on preset interlocking logic, when an interlock is triggered, the corresponding interlocking action is executed and a corresponding interlocking alarm message is displayed, providing timely reminders to operators while ensuring the combustion process remains safe. The safety interlock priority is set to the highest level to guarantee the safe operation of the system.
[0034] Preferably, when the interlock is triggered, the sequential control logic of the current process stage is automatically cut off, the safe shutdown logic is executed, and the system is initialized to achieve safe monitoring of the combustion process.
[0035] This embodiment provides unified and integrated management of instrument I / O data, operating parameters, and monitoring data, enabling intelligent process control. It automatically completes sequential control of purging, start-up, and shutdown, and monitors parameters at each stage of the process. Key alarm information is displayed step-by-step, avoiding irrelevant alarm messages and improving the effectiveness and usability of overall system information. The system is highly flexible, allowing modification of process flows and execution times in complex wastewater incineration systems, reducing time and fuel costs and improving economic efficiency.
[0036] Preferably, the process safety control system further includes an HMI interface, which displays the process stage of the incinerator in real time and displays corresponding abnormal prompts when an abnormality occurs.
[0037] Preferably, the DCS control system is capable of receiving changes made by the user to the preset regulating valve parameters and sending the changed parameters to the target regulating valve through the process safety control system.
[0038] The HMI interface tracks process progress in real time, offering a high degree of visualization. Upon system startup, it automatically detects sensors and actuators, as well as various conditions and parameters. Operators only need to adjust a few parameters such as purging time and purging air volume on the HMI interface based on the current burner operating conditions. The system then completes the burner startup and ignition, displaying the current process stage. The control path is clear and easy to understand, facilitating operation and control. A safety parameter input interface is provided to process operators, eliminating the need to modify the controller's underlying logic through an engineering workstation, allowing operators to independently adjust parameters. This improves work efficiency, reduces upfront project costs, enhances system reliability, and optimizes operation and maintenance. While improving safety, it also facilitates debugging, parameter calibration, experimentation, and adjustment.
[0039] Preferably, the AI signals of the opening degree of the multiple regulating valves are input to the AI terminal board of the SIS control system via hard wiring to improve the safety level of the SIL circuit and allow the SIS control system to monitor the valve opening parameters throughout the process.
[0040] See Figure 1 and Figure 2 To meet SIL3 level certification requirements, controllers acquire field instrument data point-to-point. Within the BMS program architecture, the SIS system is placed above sequential control, prioritizing the safety of the system, production, and personnel. Process alarms are optimized, and operator procedures are simplified; the BMS and SIS systems are intelligently integrated.
[0041] See Figure 2 The diagram illustrates the signal transmission principle. Key parameters are pre-configured in the DCS control system. When the start-up process reaches the step requiring the valve to open, the valve opening command is transmitted to the DCS control system via the DO signal. The DCS control system then controls the valve opening degree and compares it with the signal transmitted from the SIS control system. When the feedback opening degree is within the normal accuracy range, a "correct opening degree" signal is sent back to the BMS control system, completing the closed-loop information transmission. Parameter adjustments can be made instantly in the DCS control system's operating screen.
[0042] After receiving the "correct valve opening signal", the BMS will continue to complete the predetermined process steps. To avoid the risks that may arise from communication failure, and to set up failure detection for the MODBUS-RTU communication signal, if the "correct valve opening signal" is not received within a certain period of time, the burner control will be reset to the initial state, the predetermined shutdown procedure will be executed, and the natural gas feed valve will be closed in sequence to ensure the production safety of the waste liquid incinerator.
[0043] Based on the same concept, this embodiment also provides a control method for a waste liquid incinerator, including the following steps:
[0044] Initialize the BMS control system in the process safety control system, and perform self-tests on all sensors and valve actuators within the BMS control system;
[0045] Obtain the purging parameters input from the preset interface, and perform a purging operation on the incinerator based on the purging parameters;
[0046] The system checks whether the BMS control system meets the start-up conditions. If the start-up conditions are met, the start-up operation is performed based on the preset ignition valve setpoint.
[0047] After successful startup, the control authority of the preset regulating valve is released to the DCS control system.
[0048] The SIS control system in the process safety control system monitors and controls multiple shut-off valves of the waste liquid incinerator according to preset parameters and / or interlocking conditions based on the process stage of the system, so as to realize the whole process safety monitoring of the system.
[0049] In this embodiment, the SIS control system and BMS system are integrated, enabling the system to automatically start, stop, and perform safety checks based on preset control logic at any stage of the process. This results in a high degree of system integration, intelligence, and safety.
[0050] For details, see Figure 3 This is a flowchart of an ignition control method for a waste liquid incinerator.
[0051] Preferably, in one embodiment, the critical path sequence control chart can clearly show the complete start-up, shutdown, and purging steps:
[0052] The system performs a self-test upon startup to ensure all sensors and actuators are functioning properly, enabling intelligent process tracking, step sequence timing display, and prompting key information status.
[0053] After the main BMS is initialized, the operator sets the purge time.
[0054] Execute the system's general purge procedure;
[0055] Check the main BMS running license;
[0056] The main BMS runs and constantly monitors the running permit conditions. If the conditions are not met, it automatically shuts down.
[0057] When the main BMS is running, it can execute the ignition program of the main burner and the A / B ignition program of the two-chamber burner with one click;
[0058] Once the main burner and the two-chamber burners A / B are initialized, the purging procedures for each combustion chamber can be executed independently.
[0059] After the independent combustion chamber is purged, the operator presets the ignition valve setpoint in the HMI, and the BMS automatically executes the ignition procedure.
[0060] After successful ignition, this system autonomously monitors the operational clearance (necessary operating conditions) of each combustion chamber throughout its entire lifecycle.
[0061] When the requirements for combustion chambers are not met, an automatic shutdown procedure is executed.
[0062] Preferably, in one embodiment, the permission conditions or jump conditions for each of the above steps are displayed in real time during the execution of the subroutine. Furthermore, the timing of purging, feeding, and depressurization can be flexibly adjusted to avoid situations where the burner stops due to abnormal operating conditions, eliminating the need for re-purging or requiring full-process purging. In such cases, adjustments can be made in real time through the HMI write window, significantly saving both financial and time costs.
[0063] Preferably, the method further includes: the process safety control system monitors the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors, compares the collected sensor parameters with the corresponding thresholds, and immediately executes the relevant safety interlock actions and pops up interlock alarm information when an interlock is triggered; at the same time, it automatically cuts off the sequential control logic of the current process stage, executes the safe shutdown logic, and performs system initialization to achieve safe monitoring of the combustion process.
[0064] Safety detection is achieved through pre-set interlocking logic, resulting in higher system safety. The protective layer of the waste liquid incinerator is determined based on LOPA analysis. HAZOP analysis is used to analyze the system's design, operation, and maintenance, identifying potential hazards and operational problems, and determining the SIL loop level and priority. Based on the above qualitative and quantitative analysis, interlocking logic is written, and an ESD interlocking matrix diagram is drawn. In this invention, the BMS system does not adhere to rigid interlocking conditions but dynamically judges the combustion process and the current operation, utilizing reliable interlocking conditions to establish intelligent SIL loops. For example, the "main burner feed valve shut-off interlock" only takes effect autonomously when the main burner is running, and the "flame detection" interlocking condition is activated.
[0065] 1) Because if the interlock is not disconnected before starting the engine, the "flame detection" will always be OFF, the shut-off valve will be closed, and the start-up sequence control will not be able to be executed;
[0066] 2) To solve this problem, the traditional solution is to set up an operation bypass, manually disconnect it before starting the engine, and then manually reactivate it after the engine is started and controlled.
[0067] This invention automatically determines the activation / deactivation status of interlocking conditions by matching process status; it eliminates the need for manual operation of bypass switching, avoiding both human error and forgetting to operate after successful ignition. This significantly improves the system's availability and intelligence while ensuring safe production.
[0068] Preferably, the system further includes performing system initialization based on the preset safety shutdown logic within the BMS control system when the parameters of the preset shut-off valve detected by the SIS control system exceed a preset threshold.
[0069] The SIS control system has the highest control priority, ensuring system safety above all else. It features rapid response, intelligent operation, high automation, and high reliability, effectively improving the safety and efficiency of the incinerator.
[0070] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as mobile storage devices, read-only memory (ROM), magnetic disks, or optical disks.
[0071] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they shall still fall within the protection scope of the present invention.
Claims
1. A control system for a waste liquid incinerator, the waste liquid incinerator comprising a main burner and a secondary combustion chamber, characterized in that, include: The process safety control system is connected to multiple shut-off valves and multiple regulating valves of the waste liquid incinerator for controlling the process operation of the waste liquid incinerator and monitoring the safe operation of the waste liquid incinerator. The DCS control system is connected to the process safety control system and is used to adjust the opening of multiple unsafe operating regulating valves during the safe operation of the waste liquid incinerator. The process safety control system includes a BMS control system and an SIS control system. The BMS control system automatically performs purging, start-up, and shutdown sequence control according to a preset program. The SIS control system monitors and controls multiple shut-off valves of the waste liquid incinerator based on preset parameters and / or interlocking conditions according to the process stage of the incinerator to achieve full-process safety monitoring of the system. The AI signal for the valve opening is hardwired to the AI terminal block of the SIS control system to improve the safety level of the SIL circuit and allow the SIS control system to monitor the valve opening parameters throughout the process.
2. The waste liquid incinerator control system according to claim 1, characterized in that, The process safety control system monitors the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors. It compares the collected sensor parameters with the corresponding thresholds. When an interlock is triggered, it immediately executes the relevant safety interlock action and displays an interlock alarm message.
3. The waste liquid incinerator control system according to claim 2, characterized in that, When the interlock is triggered, the sequential control logic of the current process stage is automatically cut off, the safe shutdown logic is executed, and the system is initialized to achieve safe monitoring of the combustion process.
4. The waste liquid incinerator control system according to claim 1, characterized in that, The process safety control system also includes an HMI interface, which displays the process stage of the incinerator in real time and displays corresponding abnormal prompts when an abnormality occurs.
5. The waste liquid incinerator control system according to claim 1, characterized in that, The DCS control system can receive changes to the preset regulating valve parameters from the user and send the changed parameters to the target regulating valve through the process safety control system.
6. A control method for a waste liquid incinerator, characterized in that, The control system applied to any one of claims 1-5 includes the following steps: Initialize the BMS control system in the process safety control system, and perform self-tests on all sensors and valve actuators within the BMS control system; Obtain the purging parameters input from the preset interface, and perform a purging operation on the incinerator based on the purging parameters; The system checks whether the BMS control system meets the start-up conditions. If the start-up conditions are met, the start-up operation is performed based on the preset ignition valve setpoint. After successful startup, the control authority of the preset regulating valve is released to the DCS control system. The SIS control system in the process safety control system monitors and controls multiple shut-off valves of the waste liquid incinerator according to preset parameters and / or interlocking conditions based on the process stage of the system, so as to realize the whole process safety monitoring of the system.
7. The control method for a waste liquid incinerator according to claim 6, characterized in that, Also includes: The process safety control system monitors the environmental parameters inside the incinerator through temperature, pressure, flow, and liquid level sensors. It compares the collected sensor parameters with the corresponding thresholds. When an interlock is triggered, it immediately executes the relevant safety interlock actions and pops up an interlock alarm message. At the same time, it automatically cuts off the sequential control logic of the current process stage, executes the safety shutdown logic, and initializes the system to achieve safe monitoring of the combustion process.
8. The control method for a waste liquid incinerator according to claim 6, characterized in that, It also includes the function of initializing the system based on the preset safety shutdown logic within the BMS control system when the parameters of the preset shut-off valve detected by the SIS control system exceed a preset threshold.