Safety protection device and system for temperature control system of power plant

Abstract

The invention relates to a power plant temperature control system safety protection device and system. The power plant temperature control system safety protection device comprises a redundant temperature acquisition module, a temperature control safety processing module, an actuator control protection module, an intelligent strategy recovery module and a communication and alarm module. Through multi-point temperature data acquisition, abnormal trend intelligent identification and local linkage control, the device realizes quick response and protection control of temperature control abnormity of a key area of a boiler thermodynamic system. The system supports data interconnection with a DCS platform and an alarm analysis platform, has local independent operation and remote centralized management capabilities, and is suitable for temperature control safety protection of high heat load areas such as boilers of coal-fired power plants.

Description

Technical Field

[0001] The present invention relates to the field of thermal control safety technology for power systems, and in particular to a safety protection device and system for a temperature control system in a power plant. Background Art

[0002] In large coal-fired power plants, the boiler and its associated thermal systems operate as high-temperature, high-pressure units, and their operational safety is directly related to the stability and economy of the entire power generation system. Areas such as the boiler's water-cooled wall, drum outlet, superheater, and economizer are often subject to high thermal loads. These areas are susceptible to equipment damage due to factors such as local overheating, accumulated thermal deviations, or uneven flow rates, which can affect unit operating efficiency and even lead to emergency shutdowns. To ensure the operational safety of thermal systems under typical operating scenarios such as variable loads and frequent disturbances, establishing accurate perception and rapid response capabilities for temperature control parameters has become a key goal in thermal control system design.

[0003] Existing power plant thermal control systems often rely on a DCS platform to centrally complete all temperature acquisition, identification, and control responses. While these systems offer a high degree of overall integration, they have long response paths and limited anomaly identification capabilities, making it difficult to promptly capture sudden temperature rise events. Some power plants install independent temperature measurement circuits in key piping systems and integrate them into protection logic, but most lack primary and backup channel redundancy. Temperature data is typically only used for out-of-limit alarms and lacks trend prediction, anomaly identification, and self-recovery control capabilities. In particular, in special scenarios such as sudden changes in local boiler temperature differences, drift in temperature sensing elements, and sudden changes in load, conventional thermal control systems may experience response lags, misjudgments, or miscontrol, thereby reducing system stability and safety margins.

[0004] Therefore, there is an urgent need for a temperature control protection device and system with multi-point monitoring, data redundancy, trend prediction, local response and remote linkage capabilities to solve the technical problems of untimely identification of temperature control anomalies, serious response path dependence and insufficient control recovery mechanism in the existing centralized control structure, and to enhance the independent perception and autonomous handling capabilities of the thermal system of the power plant under abnormal operating conditions. Summary of the Invention

[0005] In order to solve the problems of the prior art, the present invention provides a safety protection device and system for a power plant temperature control system. The technical solution is as follows:

[0006] In one aspect, a safety protection device for a temperature control system of a power plant is provided, comprising:

[0007] Redundant temperature acquisition module, used to collect data from the main channel and backup channel temperature sensors in multiple key parts of the power plant thermal system, and output stable and effective temperature data through the main and backup switching logic;

[0008] A temperature control safety processing module is used to receive the temperature data uploaded by the redundant temperature acquisition module and execute an abnormality recognition logic. When it is determined that the temperature control is in an abnormal state, it generates a control instruction and an alarm signal;

[0009] An actuator control and protection module is used to receive control instructions from the temperature control safety processing module, drive the on-site actuator to perform safety response actions such as spraying, damper adjustment or cooling pump start-up, and return to the execution state;

[0010] An intelligent strategy recovery module, configured to determine whether recovery conditions are met after the abnormal state is resolved, generate a recovery control strategy and control parameters, and feed the recovery control strategy and control parameters back to the temperature control safety processing module;

[0011] The communication and alarm module is used to establish a communication connection with the host computer system to achieve the upload of status data, the output of alarm events and the remote reception of control instructions.

[0012] Furthermore, the redundant temperature acquisition module includes:

[0013] Each temperature monitoring point is equipped with a pair of main channel and backup channel sensors, the sensors are K-type thermocouples or PT100 platinum resistance;

[0014] The acquisition module is equipped with sliding filtering and differential judgment logic, and automatically switches to the backup channel when an abnormality is detected in the main channel, and outputs the channel status flag.

[0015] Furthermore, the temperature control safety processing module includes:

[0016] Embedded processor platform for performing data reception, cache management, state determination and prediction operations;

[0017] The anomaly recognition logic includes fixed threshold judgment, slope analysis, and temperature trend prediction algorithm based on LSTM or SVM model to identify abnormal temperature trends or mutations.

[0018] Furthermore, after determining that the temperature control is in an abnormal state, the temperature control safety processing module simultaneously outputs control instructions to the actuator control protection module and outputs an alarm data frame to the communication and alarm module. The data frame includes the alarm level, occurrence location, predicted trend and abnormality type.

[0019] Furthermore, the actuator control protection module includes:

[0020] Multiple isolated control output channels are connected to on-site solenoid valves, damper actuators or cooling water pumps;

[0021] Each output channel is equipped with a status feedback interface, and is provided with a control command response timeout judgment mechanism, an action failure flag and a control priority override logic.

[0022] Furthermore, the intelligent policy recovery module includes:

[0023] Strategy library and strategy matching logic, used to match recovery control strategies based on load status, trend curves, and historical operating conditions;

[0024] The control parameter adjustment unit is used to adjust the PID parameters, control period and output upper and lower limits online. The parameter adjustment is limited to the set variation range to prevent over-adjustment.

[0025] Furthermore, the intelligent strategy recovery module is provided with a soft switching logic, which uses an interpolation method to adjust the control setting value and performs a slow-start limiting process on the control output during the strategy switching process.

[0026] Furthermore, the communication and alarm module supports Modbus TCP / IP, OPC UA and Modbus RTU communication protocols, has dual communication channel redundant switching capability, as well as local sound and light alarm and remote alarm information push functions.

[0027] On the other hand, a power plant temperature control system safety protection system is provided, including multiple temperature control system safety protection devices as described above. The multiple devices are respectively deployed at the water-cooled wall, steam drum outlet, economizer outlet and superheater front area of ​​the boiler, and are connected to the power plant DCS main control system and alarm analysis platform through an industrial communication network.

[0028] Furthermore, the system has the ability to identify distributed local temperature control anomalies and centralized remote linkage control. The DCS main control system is used for graphical interface monitoring, strategy intervention and interlocking control. The alarm analysis platform is used for alarm data archiving, trend graph generation and alarm record visualization.

[0029] The technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0030] This invention provides a safety protection device and system for power plant temperature control systems. By constructing a multifunctional integrated structure comprising a redundant temperature acquisition module, a temperature control safety processing module, an actuator control and protection module, an intelligent strategy recovery module, and a communication and alarm module, this device enables rapid on-site identification, precise response, and closed-loop protection control of abnormal temperature conditions in thermal systems such as power plant boilers. The hierarchical coordination mechanism employed among these modules not only improves the reliability of temperature signal acquisition and the timeliness of response, but also enables the system to operate independently without DCS intervention, enhancing the safety and redundancy characteristics of the thermal control system.

[0031] Specifically, the present invention solves the problem of data loss caused by single-point sensor failure through dual-channel temperature acquisition and automatic switching mechanism; improves the ability to predict and identify temperature control anomalies through AI trend recognition algorithm and multi-dimensional fusion judgment mechanism; ensures the stability and verifiability of response actions through actuator priority control and feedback closed-loop mechanism; and the introduction of the strategy recovery module enables the device to adaptively recover to normal operating state after the fault is resolved, avoiding system oscillation or false recovery. At the same time, the communication and alarm module supports multi-protocol parallel communication and remote strategy control, so that the device can be flexibly embedded in the existing DCS system and expanded to the digital monitoring platform to achieve multi-system collaborative operation.

[0032] The proposed system architecture, featuring distributed deployment, local decision-making, and platform-linked capabilities, is particularly suitable for high-thermal-stress environments such as the water-wall, economizer, and drum areas of thermal power plant boilers. Through independent early warning and rapid protection of these devices, the system effectively reduces the risk of tube bursts, tripping, or unplanned shutdowns caused by overheating, improving unit safety margins and peak-shaving stability, demonstrating its potential for widespread application. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 This is a module schematic diagram of a safety protection device for a temperature control system in a power plant according to embodiment 1 of the present invention;

[0035] Figure 2 This is a module schematic diagram of a power plant temperature control system safety protection system according to embodiment 2 of the present invention. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] like Figure 1As shown, this embodiment provides a power plant temperature control system safety protection device comprising six functional modules, forming an integrated device structure. The device, with the temperature control safety processing module at its core, is connected to a redundant temperature acquisition module, a communication and alarm module, an actuator control and protection module, and an intelligent strategy recovery module, forming a closed-loop control chain of perception-identification-control-feedback. Data exchange and logical linkage between these modules are achieved through a bus structure, as detailed below:

[0039] The redundant temperature acquisition module sends the acquisition signals of the main and standby temperature sensors to the temperature control safety processing module through the multi-channel analog interface.

[0040] The temperature control safety processing module receives and analyzes the collected data, identifies abnormal trends, sends action instructions to the actuator control and protection module, and sends alarm information to the communication and alarm module.

[0041] The actuator control and protection module takes over the key actuator control tasks and feeds back its action status to the temperature control safety processing module.

[0042] After the fault is resolved, the intelligent policy recovery module determines the recovery conditions and returns the recovery instructions and policies to the temperature control safety processing module.

[0043] The communication and alarm module realizes status upload, remote control reception and local / remote alarm output, forming a complete upper and lower information flow closed loop.

[0044] Specifically, the redundant temperature acquisition module is used to perform real-time temperature monitoring of key temperature control points in the thermal system of the power plant, and provide primary and backup redundant channels to ensure that the system can continue to stably obtain temperature data under abnormal operating conditions such as sensor failure, data drift or electromagnetic interference, providing a highly reliable input basis for the temperature control safety processing module.

[0045] The module mainly includes the following structural and functional units:

[0046] 1. Temperature sensor array

[0047] A pair of temperature sensors is installed at each monitoring point, such as the boiler's left and right water walls, the drum riser, the economizer outlet, and the cooler inlet. These sensors form the primary and backup channels, respectively. K-type thermocouples or PT100 platinum resistance thermometers are preferred, offering measurement accuracy within ±0.2°C, adaptability to high-temperature environments, and long-term stability. The sensors are connected to the internal data acquisition board via highly shielded, industrial-grade, high-temperature-resistant signal cables, ensuring robust signal transmission and interference resistance.

[0048] 2. Multi-channel signal acquisition board

[0049] The primary and backup channel signals are each connected to an analog acquisition board, which features a built-in high-precision analog-to-digital converter (12-bit to 16-bit ADC), anti-interference filtering circuitry, and power surge protection. The sampling period can be configured from 0.5 to 2 seconds and supports dynamic refresh. All input channels are signal-isolated to prevent crosstalk between channels.

[0050] 3. Signal comparison and channel switching logic

[0051] This module features dual-channel data consistency detection, using a differential algorithm to perform real-time comparisons between the primary and backup channel data. If the difference between the two continuously exceeds a set threshold (e.g., ±3.0°C) or if the primary channel exhibits abnormalities such as spikes, zero drift, or disconnections, the system immediately issues a channel switch command, automatically enabling the backup channel and simultaneously outputting a "primary channel failure" status code to the temperature control safety processing module. This switching mechanism is based on a software state machine and interrupt logic, with a typical switching delay of less than 300ms.

[0052] 4. Data filtering and primary preprocessing mechanism

[0053] All collected signals are processed through sliding average filtering, median filtering, and a limiting algorithm before upload to eliminate transient spikes and high-frequency noise. The processing results, along with the current sensor operating status (active / standby), are encapsulated into a structured data frame containing fields such as the sample value, differential value, channel identifier, and timestamp. This frame is then uploaded to the temperature control safety processing module to ensure data integrity and timeliness.

[0054] 5. Condition monitoring and abnormal auxiliary diagnosis unit

[0055] This module also has the following auxiliary judgment and alarm capabilities:

[0056] Open circuit / short circuit detection: used to determine sensor circuit abnormalities;

[0057] Acquisition board temperature monitoring: When the acquisition circuit board temperature rises abnormally (e.g. >70°C), an internal alarm is issued;

[0058] Power supply voltage fluctuation detection: monitors the stability of 5V / 12V power supply to ensure normal power supply of analog circuits;

[0059] Communication status feedback: A periodic handshake mechanism is established between the controller and the main controller. Once the communication is interrupted for more than the set time, a "communication abnormality" flag will be generated.

[0060] Through the above-mentioned multi-dimensional data perception, diagnosis and fault-tolerant mechanism, the redundant temperature acquisition module effectively ensures the accuracy and continuity of the temperature measurement link, and is the front-end basic guarantee module for the device of the present invention to realize intelligent judgment and response linkage.

[0061] Specifically, the temperature control safety processing module is the central decision-making core of this device. It is responsible for receiving and processing the structured temperature data uploaded by the redundant temperature acquisition module. Based on real-time analysis, predictive modeling and multi-condition judgment, it identifies abnormal temperature control events, and coordinates the linkage actuator control protection module and the communication and alarm module to achieve rapid response and closed-loop disposal of temperature anomalies.

[0062] The module has the following core structures and functional units:

[0063] 1. Embedded processor platform

[0064] This module utilizes an integrated embedded control platform. The main control chip can be an ARM Cortex-A series or X86 architecture industrial control motherboard, supporting multi-threaded processing and floating-point calculations. The system is embedded with a Linux or RTOS operating system and features hardware and software watchdogs, hot standby automatic restart, and storage redundancy protection mechanisms to ensure computing stability and anti-interference capabilities in a continuous operation environment.

[0065] 2. Data receiving and cache analysis unit

[0066] The temperature control safety processing module establishes a periodic data exchange mechanism with the redundant temperature acquisition module via an internal communication bus, receiving complete data frames including primary and backup temperature values, differential flags, channel switching status, and preprocessing results. The module also features cache queue management capabilities, processing parallel data from multiple monitoring points and aligning timestamps to ensure timing consistency and data integrity for subsequent analysis.

[0067] 3. Temperature control anomaly identification and trend prediction unit

[0068] Logical rule layer judgment: Set a fixed threshold (such as 620°C) and a temperature rise slope limit (such as 3°C / min) for each monitoring point. If the current temperature value or derivative exceeds the threshold continuously, the system will enter the "abnormal warning state";

[0069] AI model prediction mechanism: The module embeds an offline-trained LSTM (long short-term memory) model or support vector machine (SVM) model, which uses the temperature time series of the past 30 to 60 seconds to predict the trend in the next 10 to 20 seconds, identifying potential warming trends, abnormal slopes, or abnormal fluctuations.

[0070] Fusion judgment mechanism: The logical judgment results, AI prediction results, channel status and actuator feedback are jointly involved in the comprehensive judgment of the abnormality level, and a weighted scoring model or discriminant matrix is ​​used to output the final status code (normal, warning, serious abnormality, etc.), and the corresponding monitoring point number and trigger time are recorded.

[0071] 4. Command issuance and control coordination unit

[0072] After confirming the abnormal state, the module will send a control instruction package to the actuator control and protection module, which includes the target actuator number, action type (open / close / adjust) and execution level. At the same time, it will synchronously output the current abnormal level, abnormal type code and trend prediction map index to the communication and alarm module, and support the linkage presentation of the graphical interface.

[0073] 5. Operation record and data closed-loop interface

[0074] All recognition processes, prediction results, command outputs, and feedback information are recorded in local industrial-grade eMMC storage, forming structured historical data files. The module supports data query via Modbus / OPC interfaces for higher-level DCS systems, and also features a RESTful API interface to facilitate subsequent AI model retraining dataset construction and performance evaluation.

[0075] 6. Module status self-monitoring mechanism

[0076] The module has its own diagnostic subsystem that regularly monitors CPU temperature, load rate, data processing rate, and cache occupancy. If any fault signs such as overflow, delay, or processing blockage occur, the system will output a "processor abnormality" alarm message to the communication module in advance to ensure that the data processing link is not interrupted.

[0077] Through efficient data processing capabilities and predictive intelligence, this module achieves active early warning and accurate identification of the temperature control status of the thermal system. It is the key functional core of this device to achieve "upgrade from response control to predictive intervention."

[0078] Specifically, the actuator control and protection module is a key component of the device's execution layer. Once the temperature control safety processing module confirms an abnormal temperature condition, it drives key on-site actuators to implement rapid and reliable response actions to suppress equipment temperature increases, isolate risk sources, or activate cooling systems. This module features multiple outputs, control priority determination logic, closed-loop action confirmation and feedback, and supports collaborative management with DCS system control logic.

[0079] The specific structure and functions of the module are as follows:

[0080] 1. Multi-channel actuator control unit

[0081] The module is equipped with 4 to 8 isolated control output channels, with output modes including relay dry contacts, transistor switches or analog (PWM / 4-20mA, depending on the requirements of the on-site equipment). Each output channel corresponds to a specific actuator, such as:

[0082] Water wall area spray solenoid valve;

[0083] Electric ventilation dampers;

[0084] Forced cooling fan;

[0085] Cooling water pump / spray pump;

[0086] High temperature area cuts off the gate.

[0087] The control output has optoelectronic isolation, strong anti-electrical interference capability, supports configuration as normally open / normally closed state, and has overcurrent protection and soft start control functions.

[0088] 2. Control instruction priority scheduling mechanism

[0089] This module has built-in instruction priority parsing logic, which can determine the priority and schedule instructions from multiple control sources at the same time. The priority is divided as follows:

[0090] P1: Emergency protection instruction from the temperature control safety processing module of this device (highest priority);

[0091] P2: dispatching instructions from the DCS system;

[0092] P3: recovery action from the policy recovery module;

[0093] P4: On-site manual debugging command.

[0094] While the P1 command is valid, the P2 to P4 control signals are suspended or ignored to ensure that the execution of actions under abnormal conditions is not disturbed, thus realizing the "independent control channel takeover" function.

[0095] 3.Action feedback and closed-loop confirmation unit

[0096] Each output control signal is equipped with a status feedback channel (such as contactor auxiliary contacts, valve position feedback signals), and the feedback information is transmitted back to the temperature control safety processing module through the isolation input module. The module execution logic includes:

[0097] Set a response time window (e.g. 3 seconds) after the command is output;

[0098] If the feedback does not arrive or the status is inconsistent, an "abnormal action" status code is generated;

[0099] Output "action failure alarm" to the communication module and record the event log.

[0100] 4. Control logic anti-chatter and interlock function

[0101] To prevent frequent switching or false triggering of commands, the module output logic is set with the following mechanisms:

[0102] Logic hold: maintain the shortest action cycle (e.g. 10 seconds) after the instruction is executed;

[0103] Start interlock: For example, the spray pump and damper cannot be started at the same time (to avoid spray drift);

[0104] Anti-shake motion: hysteresis control and digital filtering are used to avoid jumps.

[0105] 5.Module maintenance and testing interface

[0106] To facilitate on-site operation and maintenance and routine inspections, the module is equipped with the following auxiliary functions:

[0107] Each channel is equipped with LED status indicator (operating / feedback / fault);

[0108] Equipped with manual jog test button and USB debugging port;

[0109] Supports regular self-test procedures, and diagnostic test commands can be initiated by DCS to verify the integrity of the execution link.

[0110] Through the above structure and strategy, the actuator control protection module can respond to temperature control abnormal events in milliseconds and ensure that each control action has a complete closed-loop path of "executed - confirmed - recorded". It is an important execution hub for realizing local rapid protection control of equipment.

[0111] Specifically, the intelligent strategy recovery module is the control strategy management and system recovery control unit in this device. After the temperature control anomaly is identified and handled, it is used to intelligently select the most appropriate control recovery strategy based on the current operating status, equipment thermal inertia characteristics and historical trends, and adjust the controller parameters online to make the entire system smoothly transition from the protection state to the normal control state, avoiding new disturbances caused by switching mutations.

[0112] The core structure and functions of the module are as follows:

[0113] 1. Recovery condition judgment logic unit

[0114] The module continuously obtains the following information from the temperature control safety processing module:

[0115] Whether the current temperature of each monitoring point is stable within the safe setting range (for example: below 590°C and the slope is less than 1°C / min);

[0116] Whether all actuator states are restored to their initial settings (such as damper closed, water pump stopped);

[0117] Whether the abnormal status code has been cleared and the alarm has been released;

[0118] Whether the prediction model results are stable;

[0119] After the above recovery judgment logic is met, the module outputs the "recovery conditions met" flag and triggers the policy recovery process.

[0120] 2. Control strategy library and matching rule engine

[0121] The module has multiple built-in preset control strategies and is equipped with multi-dimensional matching rules. Typical strategies include:

[0122] High load stable recovery strategy: Applicable to rapid temperature control recovery when the load is still high;

[0123] Low-load slow start strategy: Applicable to scenarios with small load fluctuations, such as early morning start-up or nighttime maintenance.

[0124] Transition protection strategy: set temporary control band limit tightening, extend action cycle, and maintain observation window;

[0125] Manual confirmation strategy: manual instructions are accepted and confirmation by the DCS platform is required before recovery;

[0126] Strategy matching is determined by a logical scoring matrix, such as current thermal inertia parameters, equipment downtime, and predicted trend flatness, to determine the optimal recovery plan.

[0127] 3. Control parameter online adaptive adjustment unit

[0128] Based on the selected strategy, this module adjusts the control parameters in the temperature control safety processing module in real time, including:

[0129] Proportional P, integral I, and differential D values ​​in PID controller;

[0130] Control output upper and lower limits, slope constraint value;

[0131] Control cycle and dead zone range;

[0132] The regulation logic is based on the evaluation results of the previous response process (such as overshoot amplitude, stabilization time, and response delay), and adopts gradient step size limitation and safety range constraint to avoid overshoot or oscillation.

[0133] 4. Policy soft switching guarantee mechanism

[0134] In the process of switching the recovery control strategy, in order to avoid sudden changes in the system response, the module has a built-in slow transition mechanism:

[0135] The set target temperature is gradually corrected using linear interpolation;

[0136] A limited slow-start strategy is adopted for the control output, such as limiting not more than 25% in the initial stage;

[0137] The strategy switching process has a buffer period (e.g. 30 to 60 seconds), during which only major alarms are responded to to ensure a stable system transition;

[0138] The entire policy switching process is recorded and rollback is supported.

[0139] 5. Manual access and remote command interaction interface

[0140] The module receives control strategy confirmation commands or parameter download commands from the DCS platform or operator workstation through the communication and alarm module, suitable for manual takeover or semi-automatic recovery. To prevent unauthorized operation, this channel has an operation permission identification code and recovery process interlock logic to ensure closed-loop control process security.

[0141] 6. Policy recovery log and data trace mechanism

[0142] The module records each policy switch as a complete recovery event package, including:

[0143] Recovery trigger time and trigger reason;

[0144] Select the strategy number and name;

[0145] Comparison of PID parameters before and after recovery;

[0146] Control output trend curve;

[0147] Secondary alarm events (if any);

[0148] This data package is used for system self-learning, historical evaluation, or as an AI model training sample.

[0149] In summary, the intelligent strategy recovery module realizes an automated closed-loop control path for smooth recovery from the protection state to steady-state control, so that the device of the present invention can still maintain logical continuity, parameter optimality and response stability after thermal control intervention, and has high self-regulation, self-coordination and safety assurance capabilities.

[0150] Specifically, the communication and alarm module serves as the information exchange hub between the device and external systems (including the power plant DCS platform, data monitoring platform, and operation and maintenance terminals). It is primarily responsible for enabling real-time uploading of operating status, temperature data, and alarm information, as well as remote issuance of control instructions, policy instructions, and configuration commands. Furthermore, the module features local alarm functionality, a communication interruption self-diagnosis mechanism, and data cache redundancy, ensuring highly reliable information exchange even in complex industrial communication environments.

[0151] The specific structure and functions of this module are as follows:

[0152] 1. Industrial communication interface support unit

[0153] The communication module provides a variety of industrial fieldbus and standard communication protocol interfaces to adapt to different DCS system environments. The interface configuration is as follows:

[0154] Modbus TCP / IP (Ethernet): Supports connecting to the main control system as a Modbus Slave to upload temperature data, status code, alarm code, strategy number, etc.

[0155] OPC UA / OPC DA interface: supports device registration as a node to the OPC server of the power plant DCS, suitable for a wide range of deployment scenarios such as the Guodian Zhishen DCS;

[0156] Modbus RTU (RS-485): Suitable for serial data acquisition platforms or legacy I / O systems;

[0157] Optional extension protocols: such as PROFINET, CANopen, Ethernet / IP, etc., can be integrated through the communication module expansion board to meet customized requirements.

[0158] The communication protocol supports configurable parameters such as device address, baud rate, refresh cycle, timeout reconnection, etc., which facilitates on-site engineering debugging and system integration.

[0159] 2. Data mapping and information upload mechanism

[0160] The module can upload the following key data to the DCS master station or upper data server in real time:

[0161] Real-time master / standby temperature data, average temperature and heating slope;

[0162] Current strategy number and control mode flag;

[0163] The current status of the actuator (action / failure / no feedback);

[0164] System operation status code and fault status code;

[0165] The most recent alarm record (including type, time, and handling response);

[0166] The above data is uploaded using register mapping, structured data frames or OPC variable structures, and supports on-demand selection of upload cycles (such as 1s, 2s, 5s adjustable).

[0167] 3. Alarm output and hierarchical linkage mechanism

[0168] The module supports local and remote dual-level alarm logic:

[0169] Local alarm output: equipped with three-color high-brightness indicator lights and sound and light alarms, indicating normal (green), warning (yellow), and serious abnormality (red + buzzer);

[0170] Remote alarm linkage:

[0171] Write to the specified alarm register of DCS or DSS platform to trigger the main control system graphic linkage and alarm recording;

[0172] Optional configuration of platform alarm channels such as SMS, email, and WeChat enterprise push, relying on intranet API or third-party cloud gateway access;

[0173] Supports configuration of different alarm levels corresponding to different response time limits and linkage strategies (for example, serious alarms can be linked to emergency pump stop, remote interlocking, etc.).

[0174] 4. Remote control command receiving and parsing unit

[0175] This module supports the host system to send control commands and forward them to the corresponding functional modules, including:

[0176] Control strategy switching instructions (such as switching to manual takeover);

[0177] PID parameter remote setting instructions (such as online adjustment of P / I / D);

[0178] Module reset, cold start, and fault self-test start commands;

[0179] Actuator jog test command;

[0180] All instructions are equipped with permission verification and execution confirmation mechanisms to prevent false triggering or illegal instruction injection. Key control commands must be confirmed twice by the temperature control safety processing module before execution.

[0181] 5. Communication status monitoring and fault tolerance mechanism

[0182] To enhance the robustness of system operation, the module is equipped with the following communication guarantee functions:

[0183] Communication interruption detection (such as no data sent or received for more than 10 seconds) and automatic reconnection;

[0184] Communication channel redundancy mechanism, supporting dual network port / dual RS485 switching operation;

[0185] During disconnection, key data is cached locally in a ring storage area and retransmitted in batches after communication is restored;

[0186] Abnormal communication status will generate a "communication fault alarm code" and report it to the local interface and DCS platform to facilitate rapid response by operators.

[0187] 6. Data interface expansion and back-end access capabilities

[0188] The module reserves a spare Ethernet port and a RESTful interface to facilitate subsequent access to big data platforms, device management systems, or AI algorithm training platforms, enabling extended functions such as device health diagnosis, strategy optimization, and remote online upgrades.

[0189] In summary, the communication and alarm module realizes the full-process information management capability from data collection and upload, status alarm linkage, remote policy distribution to communication self-healing guarantee, providing stable support for remote access, main control system docking and operational reliability of the device in complex industrial sites.

[0190] Example 2

[0191] This embodiment provides a power plant temperature control system safety protection system constructed based on the temperature control system safety protection device described in Example 1. The system is aimed at key parts of the thermal power plant boiler and thermal system that are prone to temperature control anomalies. By regionalizing intelligent monitoring devices, integrating linkage response mechanisms and remote control interfaces, a multi-level intelligent temperature control protection system of "distributed on-site monitoring + central control linkage + prediction and early warning analysis" is constructed.

[0192] 1. Overall system structure

[0193] like Figure 2 As shown, the system mainly consists of the following parts:

[0194] 1. Multiple temperature control system safety protection device nodes (devices described in Example 1);

[0195] 2. Main control system platform (power plant DCS system, such as Guodian Zhishen WISE series);

[0196] 3. Data service and alarm analysis subsystem (DSS platform);

[0197] 4. Operation terminals of operation and maintenance personnel (such as duty station control screen, engineer station, tablet device);

[0198] 5. Communication network infrastructure (fiber optic ring network / industrial Ethernet).

[0199] Each protection device node is connected to the DCS master station via industrial Ethernet and synchronized with the DSS platform via OPC or Modbus interfaces for historical data synchronization and alarm trend analysis. The operator terminal uses the DCS platform to access temperature control status, issue policy switching or control confirmation commands, and implement manual system oversight and control access.

[0200] 2. Deployment Strategy and Functional Division

[0201] This system has been deployed on a 330MW drum boiler unit. The specific deployment strategy is as follows:

[0202] Arrange devices A1 and A2 on the left and right water-cooled walls of the boiler;

[0203] Arrange device A3 on the drum outlet and evaporation pipe;

[0204] Arrange device A4 in the front section of the superheater;

[0205] Arrange devices A5 and A6 at the economizer outlet and air preheater inlet;

[0206] Each device node operates independently, including temperature acquisition, abnormal trend identification, actuator linkage response, and data upload, providing local rapid response capabilities. The overall system forms a spatially distributed layout to ensure coverage of high thermal stress and high failure risk areas of the boiler thermal system.

[0207] 3. System linkage control mechanism

[0208] The overall operation process of the system is as follows:

[0209] 1. Each device node collects local measurement point temperature data in real time, performs sliding window analysis and AI trend prediction;

[0210] 2. After identifying temperature control anomalies or predicting risk trends, the node activates local spray, damper, or fan motion through the actuator control module;

[0211] 3. Generate alarm data at the same time and upload it to the DCS system master station and DSS platform through the communication module;

[0212] 4. The DCS system notifies operators through means such as changing the color of the graphical interface, pop-up alarm windows, and buzzer prompts;

[0213] 5. The DSS platform records alarm events and creates trend graphs for subsequent analysis and strategy optimization;

[0214] 6. If the alarm level is high, the DCS will automatically link other related control logics, such as reducing the coal feed rate and lowering the main steam temperature, to form an interlocking protection response;

[0215] 7. After the fault is resolved, the strategy recovery module gradually restores to the original control logic according to the operating conditions, and synchronously uploads the recovery log to the DCS for archiving.

[0216] 4. Remote Operation and Maintenance and Manual Takeover

[0217] This system supports the following operation and maintenance features:

[0218] The on-duty personnel can view the temperature data, alarm status and actuator action records of all device nodes through the DCS system;

[0219] The engineer station can issue a policy switching command (such as forcing the system into slow adjustment mode) or a manual takeover mode;

[0220] The device supports remote online debugging and inching testing, and maintenance personnel can initiate automated diagnosis through the platform;

[0221] All alarm events and response processes are recorded in the historical database and generated into reports for inspection and evaluation.

[0222] 5. System Deployment Effect and Summary

[0223] In this embodiment, the system successfully implemented early warning of temperature increases in the boiler's water-wall area during field deployment of a 330MW drum boiler. During one run, the temperature rise rate of the left wall water-cooling tube reached 3.7°C / min. The system issued a predictive warning 17 seconds in advance, enabling the spray valve to respond quickly and successfully avoiding temperature overshoot and a DCS high-temperature trip. DSS records show that the system's alarm accuracy exceeded 97%, with an intervention response time of less than 200ms, enhancing the proactive safety protection capabilities of the overall thermal control system.

[0224] The temperature control system safety protection system described in the present invention has the characteristics of scalable structure, complete control closed loop, and strong platform integration capability. It is suitable for the intelligent safety upgrade deployment of the boiler body and auxiliary thermal system of medium and large thermal power units.

[0225] Application Examples

[0226] The power plant temperature control system safety protection device and system described in this invention have been successfully deployed in a 330MW drum-type coal-fired generator unit. This unit uses the Guodian Zhishen WISE series DCS platform as its primary control system. The boiler is a natural circulation drum type with several typical high-thermal stress structural areas, including left and right water-cooled walls, evaporator tube bundles, drum outlet, economizer, and air preheater.

[0227] In the actual deployment process:

[0228] The system selects six key locations, including the left and right water-cooled walls of the boiler, the outlet of the steam drum riser, and the front wall of the superheater, to install the temperature control system safety protection device described in Example 1;

[0229] Each device node is connected to the factory industrial ring network via Ethernet and establishes communication with the DCS system via the Modbus TCP protocol. At the same time, historical trend data is connected to the DSS platform for data archiving and trend analysis.

[0230] Each device node realizes local independent operation, including temperature collection, LSTM trend prediction, main and standby channel switching, actuator linkage response and alarm output, etc.

[0231] The control execution end includes electric dampers, water spray valves, bypass cooling water pumps, etc., which are directly connected to the actuator control module, and the response delay does not exceed 150ms.

[0232] During a high-load operation, uneven heating occurred locally in the rising section of the left wall of the boiler. The temperature rise slope of the water-cooled wall measuring point briefly increased to 3.8°C / min, and the main channel thermocouple signal exhibited slight drift. The system quickly identified this and automatically switched to the backup channel. The AI ​​trend prediction model identified the abnormal temperature rise trend 17 seconds in advance. The control module linked the opening of the left damper and spray water valve and sent a critical alarm to the DCS system through the communication module. After the linked response, the temperature in this area was stabilized below 612°C, successfully preventing overheating of the water-cooled wall and tripping of the boiler thermal control system, and ensuring the continuous and stable operation of the unit.

[0233] Operational data evaluation shows that the device maintains an anomaly identification accuracy rate exceeding 96%, a linkage response time of less than 200ms, and a 100% strategy recovery success rate under typical complex boiler operating conditions, including high load, sudden temperature changes, and ash interference. The deployment of this system significantly enhances the power plant's temperature control system's early warning and fault suppression capabilities, as well as the visual management capabilities of the DCS platform. It provides a scalable engineering demonstration path for subsequent intelligent thermal control upgrades.

[0234] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A safety protection device for a temperature control system in a power plant, characterized in that: include: Redundant temperature acquisition module, used to collect data from the main channel and backup channel temperature sensors in multiple key parts of the power plant thermal system, and output stable and effective temperature data through the main and backup switching logic; A temperature control safety processing module is used to receive the temperature data uploaded by the redundant temperature acquisition module and execute an abnormality recognition logic. When it is determined that the temperature control is in an abnormal state, it generates a control instruction and an alarm signal; An actuator control and protection module is used to receive control instructions from the temperature control safety processing module, drive the on-site actuator to perform safety response actions such as spraying, damper adjustment or cooling pump start-up, and return to the execution state; An intelligent strategy recovery module, configured to determine whether recovery conditions are met after the abnormal state is resolved, generate a recovery control strategy and control parameters, and feed the recovery control strategy and control parameters back to the temperature control safety processing module; The communication and alarm module is used to establish a communication connection with the host computer system to achieve the upload of status data, the output of alarm events and the remote reception of control instructions.

2. The device according to claim 1, characterized in that The redundant temperature acquisition module includes: Each temperature monitoring point is equipped with a pair of main channel and backup channel sensors, the sensors are K-type thermocouples or PT100 platinum resistance; The acquisition module is equipped with sliding filtering and differential judgment logic, and automatically switches to the backup channel when an abnormality is detected in the main channel, and outputs the channel status flag.

3. The device according to claim 1, characterized in that The temperature control safety processing module includes: Embedded processor platform for performing data reception, cache management, state determination and prediction operations; The anomaly recognition logic includes fixed threshold judgment, slope analysis, and temperature trend prediction algorithm based on LSTM or SVM model to identify abnormal temperature trends or mutations.

4. The device according to claim 3, characterized in that After determining that the temperature control is in an abnormal state, the temperature control safety processing module simultaneously outputs a control instruction to the actuator control protection module and outputs an alarm data frame to the communication and alarm module. The data frame includes the alarm level, occurrence location, predicted trend and abnormality type.

5. The device according to claim 1, characterized in that The actuator control protection module includes: Multiple isolated control output channels are connected to on-site solenoid valves, damper actuators or cooling water pumps; Each output channel is equipped with a status feedback interface, and is provided with a control command response timeout judgment mechanism, an action failure flag and a control priority override logic.

6. The device according to claim 1, characterized in that The intelligent strategy recovery module includes: Strategy library and strategy matching logic, used to match recovery control strategies based on load status, trend curves, and historical operating conditions; The control parameter adjustment unit is used to adjust the PID parameters, control period and output upper and lower limits online. The parameter adjustment is limited to the set variation range to prevent over-adjustment.

7. The device according to claim 6, characterized in that The intelligent strategy recovery module is provided with a soft switching logic, uses an interpolation method to adjust the control setting value, and performs a slow-start limiting process on the control output during the strategy switching process.

8. The device according to claim 1, characterized in that The communication and alarm module supports Modbus TCP / IP, OPC UA and Modbus RTU communication protocols, has dual communication channel redundant switching capability, as well as local sound and light alarm and remote alarm information push functions.

9. A power plant temperature control system safety protection system, characterized in that: It comprises a plurality of temperature control system safety protection devices according to any one of claims 1 to 8, wherein the plurality of devices are respectively deployed at the water-cooled wall, drum outlet, economizer outlet and superheater front area of ​​the boiler, and are connected to the power plant DCS main control system and alarm analysis platform through the industrial communication network.

10. The system according to claim 9, characterized in that The system has the ability to identify distributed local temperature control anomalies and centralized remote linkage control. The DCS main control system is used for graphical interface monitoring, strategy intervention and interlocking control. The alarm analysis platform is used for alarm data archiving, trend graph generation and alarm record visualization.

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