Shaft seal pipeline temperature distributed monitoring and cooperative temperature control system
By dividing the shaft seal pipeline into heating sections and arranging temperature measuring points, and combining them with the DCS distributed control system, precise monitoring of the shaft seal pipeline temperature and coordinated control of the vacuum system are achieved. This solves the problems of insufficient temperature monitoring accuracy and high energy consumption in existing technologies, and improves the turbine's rapid start-up and shutdown capabilities and safety.
Patent Information
- Application Number
- CN202511618715.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-06
- Publication Date
- 2026-02-06
AI Technical Summary
The existing technology for monitoring the temperature of shaft seal pipelines is not accurate enough, and cannot accurately reflect the overall temperature field distribution. Furthermore, the temperature control operates independently from the vacuum system, resulting in temperature control lag and high energy consumption, which makes it difficult to meet the requirements for rapid start-up and shutdown of steam turbines.
A distributed temperature monitoring and collaborative temperature control system is adopted. By dividing the shaft seal pipeline into heating sections and arranging temperature measuring points, and combining the data fusion analysis with the DCS distributed control system, intelligent linkage between the shaft seal heating system and the vacuum pump system is realized, and a closed-loop control process is constructed.
It enables precise monitoring of shaft seal pipeline temperature, reduces energy consumption, improves the safety and rapid response capability of hot start-up, and adapts to the "day start-up and night stop" mode.
Smart Images
Figure CN121473933A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of turbine shaft seal temperature monitoring and control technology, and in particular to a distributed monitoring and collaborative temperature control system for shaft seal pipeline temperature. Background Technology
[0002] To improve efficiency, the steam seal tooth clearance of the D880 turbine in Unit 7 of the Zhenlian Gas Turbine Plant is designed to be relatively small. During hot startup, the shaft seal steam temperature needs to reach specific requirements. However, current technology involves a long shaft seal warm-up time, and auxiliary equipment needs to run continuously after shutdown to maintain vacuum, resulting in high energy consumption. Insufficient warm-up can lead to uneven expansion of the steam seal teeth due to temperature differences, potentially causing shaft seizure. Currently, peak-shaving gas turbines mostly adopt a "daytime start-night shutdown" mode, placing higher demands on the rapid start-up and shutdown and temperature control of the shaft seal system.
[0003] Currently, domestic monitoring of shaft seal temperature for SAIC D880 steam turbines primarily employs single-point temperature measurement, with temperature control and vacuum systems operating independently. Some technologies attempt to increase shaft seal temperature by adding heating devices, but these fail to establish a distributed temperature monitoring network or achieve coordinated operation between temperature control and the vacuum system, making it difficult to meet the requirements for rapid start-up and shutdown of the unit.
[0004] In other words, the existing technology has the following drawbacks: Insufficient temperature measurement accuracy: Single-point temperature measurement cannot accurately reflect the overall temperature field distribution of the shaft seal pipeline, resulting in heating blind spots and temperature control lag; Lack of coordinated control: Temperature control and vacuum system operate independently, vacuum withdrawal time is not optimized based on temperature data, and auxiliary equipment energy consumption is high; Low level of automation: It lacks an automatic diagnosis and compensation mechanism for temperature anomalies, making it difficult to adapt to the temperature control requirements of shaft seals under complex working conditions.
[0005] Therefore, it is necessary to provide a new distributed monitoring and collaborative temperature control system for shaft seal pipelines to solve the above-mentioned technical problems. Summary of the Invention
[0006] To address the aforementioned technical problems, this invention provides a distributed monitoring and collaborative temperature control system for shaft seal pipelines.
[0007] The distributed monitoring and collaborative temperature control system for shaft seal pipeline provided by this invention includes a turbine cylinder and a pipeline body connected to the cylinder, and further includes: The data acquisition and sensing unit includes a distributed monitoring device for shaft seal pipe temperature installed on the main body of the pipe and a vacuum-coordinated temperature control device installed on the turbine cylinder. The centralized monitoring and decision-making unit is a DCS distributed control system. The DCS distributed control system is signal-connected to the shaft seal pipe temperature distributed monitoring device and the vacuum collaborative temperature control device. The shaft seal pipe temperature distributed monitoring device is used to provide the DCS distributed control system with the temperature data of the main body of the pipe, while the vacuum collaborative temperature control device is used to provide the DCS distributed control system with the vacuum degree of the middle and low cylinders and the temperature difference between the upper and lower cylinders. An execution unit, which is signal-connected to the DCS distributed control system, includes a shaft seal heating system and a vacuum pump system, to utilize the DCS distributed control system to generate coordinated control commands for the shaft seal heating system and the vacuum pump system.
[0008] Preferably, the main body of the pipeline is divided into multiple independent heating sections, including four heating sections of the high-pressure front shaft seal pipeline and three heating sections of the high-pressure rear shaft seal pipeline.
[0009] Preferably, the distributed temperature monitoring device for the shaft seal pipeline includes temperature measuring points installed on the heating section, and at least one temperature measuring point is installed on each heating section. Multiple temperature measuring points are integrated and connected to a digital controller, which is used to connect to the DCS distributed control system.
[0010] Preferably, the temperature measuring point is a type K thermocouple.
[0011] Preferably, the digital controller is an AI-8 series digital controller.
[0012] Preferably, the vacuum-coordinated temperature control device includes a vacuum degree sensor and a temperature difference sensor. The vacuum degree sensor is installed on the cavity of the intermediate-pressure cylinder / low-pressure cylinder of the steam turbine, while the temperature difference sensor is symmetrically installed on the upper and lower parts of the steam turbine cylinder. The vacuum degree sensor and the temperature difference sensor are also connected to the DCS distributed control system.
[0013] A steam turbine, wherein the steam turbine is equipped with a distributed monitoring and collaborative temperature control system for shaft seal pipe temperature.
[0014] Compared with related technologies, the distributed monitoring and collaborative temperature control system for shaft seal pipelines provided by this invention has the following advantages: 1. By dividing the shaft seal pipeline into 7 independent heating sections and arranging distributed temperature measuring points, a complete temperature field monitoring network was constructed, overcoming the monitoring blind spots existing in traditional single-point temperature measurement, enabling the system to grasp the temperature distribution status of the entire pipeline in real time, and improving the accuracy of temperature monitoring of the shaft seal pipeline. 2. By integrating and analyzing distributed temperature field, vacuum degree and cylinder temperature difference data through the DCS distributed control system, intelligent linkage between shaft seal heating system and vacuum pump system is realized. The system can automatically determine the best time to withdraw vacuum based on temperature field uniformity, compress auxiliary machine running time to the theoretical minimum value, and effectively reduce energy consumption. 3. Distributed temperature monitoring, combined with upper and lower cylinder temperature difference monitoring, can promptly detect abnormal conditions such as local overcooling, overheating, or uneven expansion. Through precise temperature control in zones, it ensures that the steam seal teeth obtain uniform and stable thermal expansion conditions, fundamentally eliminating the risk of bearing seizure caused by uneven temperature and greatly improving the safety of hot start-up. 4. The fully automated "perception-decision-execution" closed-loop control process replaces the traditional start-up and shutdown mode that relies on manual experience, greatly shortening the preparation time of the shaft sealing system and enabling the unit to quickly respond to peak-shaving commands, perfectly adapting to the "daytime start-up and nighttime shutdown" operation mode. Attached Figure Description
[0015] Figure 1 A schematic diagram of the system operation flow structure of the distributed monitoring and collaborative temperature control system for shaft seal pipelines provided by the present invention; Figure 2 This is a schematic diagram of the data acquisition unit shown in this invention; Figure 3 This is a schematic diagram of the structure of the execution unit shown in this invention. Detailed Implementation
[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0017] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.
[0018] Please see Figures 1 to 3 The present invention provides a distributed monitoring and collaborative temperature control system for shaft seal pipeline temperature, which includes a turbine cylinder and a pipeline body, wherein the pipeline body is connected to the turbine cylinder. To monitor and control factors such as the vacuum level and temperature difference of the turbine cylinder and the temperature distribution of the main pipeline, it is also equipped with corresponding data acquisition and sensing units, centralized monitoring and decision-making units, and execution units.
[0019] It should be noted that for this system, the turbine cylinder block and the shaft seal pipeline body directly connected to it together form the basic structure. The connection and assembly between the two adopts the traditional precision installation to ensure the sealing between them (the structure, operating mechanism and assembly method of the device itself are not described in detail here). To achieve precise monitoring and intelligent control, the system integrates a complete automated control chain: the data acquisition and sensing unit, as the most basic detection item of the system, has a real-time monitoring function for both the pipeline body and the turbine cylinder. Specifically, for the turbine cylinder, it is used to sense the vacuum level inside the turbine cylinder in real time and also monitor the temperature difference between the upper and lower cylinders; while for the pipeline body, it is used to accurately monitor the temperature changes at various locations within the pipeline body, and the obtained data can be directly transmitted to the centralized monitoring and decision-making unit. For the centralized monitoring and decision-making unit, which is a DCS distributed control system, it can serve as the "intelligent hub" of the entire system. It continuously receives, aggregates and processes all sensor data. Through embedded control logic and algorithms, it makes a comprehensive judgment on the uniformity of the pipeline temperature field and the timing of vacuum establishment, and generates coordinated control commands to directly control the opening and closing of the execution unit. The actuator includes a shaft seal heating system and a vacuum pump system, serving as the final action carrier of the entire control system. The actuator has a real-time signal connection with the DCS distributed control system to receive signal commands from the DCS and respond promptly. In other words, the DCS distributed control system generates integrated linkage commands based on the fusion analysis of distributed temperature field, vacuum degree, and temperature difference data. The execution unit receives the signals and responds accordingly: on the one hand, the shaft seal heating system precisely adjusts the power output of each heating section according to the commands to achieve a rapid and uniform increase in pipeline temperature and ensure safe startup; on the other hand, the vacuum pump system performs start-up and shutdown operations according to the optimal timing determined by the commands, rather than operating independently. This minimizes unnecessary auxiliary machine energy consumption while ensuring unit safety. Ultimately, through the coordinated action of these two systems, the decision-making wisdom of the DCS is transformed into precise and energy-saving physical operations. Therefore, by constructing a closed-loop control system composed of a distributed sensor network, a DCS intelligent hub, and collaborative actuators, the turbine shaft sealing system has been upgraded from "experience-driven" to "data-driven intelligent." This system can accurately grasp the temperature field distribution and cylinder status across the entire pipeline, enabling differentiated and precise temperature control of the shaft sealing heating system. This fundamentally eliminates the risk of uneven expansion and shaft seizure caused by localized overcooling or overheating, greatly improving the safety of hot-state startup. Simultaneously, through intelligent linkage between temperature field data and the vacuum system, the system can accurately determine and automatically execute the optimal vacuum withdrawal time, compressing auxiliary machine operating time to the theoretical minimum. This effectively solves the energy consumption problem caused by maintaining vacuum in traditional modes, significantly reducing operating costs. Therefore, with its comprehensive status awareness, intelligent decision-making logic, and precise collaborative execution, the system fully meets the stringent requirements of the "daytime start-night shutdown" mode of peak-shaving units for rapid start-up and shutdown, safety and reliability, and energy saving and consumption reduction.
[0020] For the main body of the pipeline; The main body of the pipeline is divided into multiple independent heating sections, including four heating sections for the high-pressure front shaft seal pipeline and three heating sections for the high-pressure rear shaft seal pipeline.
[0021] It should be noted that the main body of the pipeline is structurally divided into multiple independent heating sections. Specifically, the high-pressure front shaft seal pipeline is divided into four heating sections, while the high-pressure rear shaft seal pipeline is divided into three heating sections. This precise zoning design allows the heating system to break through the traditional extensive mode of overall heating, thereby achieving precise and zoned management of the temperature along the shaft seal pipeline. It is like equipping the pipeline with an independently adjustable "segmented temperature control switch," thus ensuring uniform heating of the pipeline during start-up and shutdown. This effectively avoids the risk of end-heating blind spots and local overheating caused by a single heat source in long-distance pipelines, providing uniform and stable thermal expansion conditions for the steam seal teeth, and improving start-up safety and temperature control efficiency from the structural root.
[0022] For the data acquisition and sensing unit; Please see Figure 2 The data acquisition and sensing unit includes a distributed monitoring device for shaft seal pipe temperature installed on the main body of the pipe and a vacuum-coordinated temperature control device installed on the turbine cylinder. That is, the shaft seal pipeline temperature distributed monitoring device includes temperature measuring points installed on the heating section, and at least one temperature measuring point is installed on each heating section. Multiple temperature measuring points are integrated and connected to a digital controller, which is used to connect to the DCS distributed control system signal. The temperature measuring point is a K-type thermocouple, and the digital controller is an AI-8 series digital controller.
[0023] It should be noted that the data acquisition and sensing unit includes a distributed monitoring device for shaft seal pipe temperature installed on the main body of the pipe and a vacuum-coordinated temperature control device installed on the turbine cylinder, which are used to detect the temperature field of the main body of the pipe and the vacuum degree and temperature difference of the turbine cylinder, respectively. For the distributed temperature monitoring device for shaft seal pipelines, at least one temperature measuring point is first evenly distributed in each independent heating section. These temperature measuring points distributed in each heating section together form a dense temperature sensing network and are all integrated and connected to a digital controller. The digital controller serves as the data collection and preprocessing node for the field data. It establishes a stable signal connection with the upper-level DCS distributed control system through a standard communication protocol to realize the real-time remote transmission of monitoring data. The temperature measuring points use fast-response, high-temperature resistant K-type thermocouples, which can accurately capture rapid temperature changes; while the digital controller is preferably the AI-8 series, which, with its excellent multi-channel acquisition capability and anti-interference characteristics, ensures synchronous, stable and reliable acquisition and preliminary processing of distributed temperature field data, providing a precise and effective data foundation for the intelligent decision-making of DCS.
[0024] Please see Figure 2 The vacuum-coordinated temperature control device includes a vacuum degree sensor and a temperature difference sensor. The vacuum degree sensor is installed on the cavity of the intermediate-pressure cylinder / low-pressure cylinder of the steam turbine, while the temperature difference sensor is symmetrically installed on the upper and lower parts of the steam turbine cylinder. The vacuum degree sensor and the temperature difference sensor are also connected to the DCS distributed control system.
[0025] It should be noted that the vacuum-coordinated temperature control device mainly consists of a vacuum degree sensor and a temperature difference sensor. That is, the vacuum sensor is installed on the cavity of the intermediate pressure cylinder and / or low pressure cylinder of the steam turbine to monitor the establishment, maintenance and change of the vacuum state in the cylinder, and to provide direct data for judging the system vacuum dynamics; The temperature difference sensors are installed symmetrically on the upper and lower parts of the turbine cylinder. By continuously comparing the temperature readings of the upper and lower cylinders, the uniformity of the cylinder's thermal expansion is monitored in real time, effectively preventing the risk of thermal stress deformation caused by excessive temperature difference. Both types of sensors are connected to the DCS distributed control system via signal transmission, which allows the collected vacuum and temperature difference data to be transmitted to the central processing unit in real time. This provides essential operating condition data for the DCS to comprehensively analyze the shaft seal temperature field, optimize the vacuum pump start-stop logic, and ultimately generate coordinated control commands, thereby truly realizing deep linkage and safe regulation between temperature control and the vacuum system.
[0026] The specific operating procedure for this device is as follows: (1) After the system starts up, it first enters the full monitoring state, that is, the temperature sensors (K-type thermocouples) arranged on the 7 independent heating sections of the shaft seal pipeline start to work, collect the temperature data of each section in real time, and form a complete pipeline temperature field distribution map; at the same time, the vacuum sensor installed on the medium / low pressure cylinder of the steam turbine and the temperature difference sensor on the upper / lower part of the cylinder body start synchronously to monitor the vacuum condition in the cylinder and the uniformity of heating of the cylinder body, respectively. All these data are initially collected and processed by the digital controller on site and then transmitted to the DCS distributed control system. (2) The DCS distributed control system receives and integrates data from various sources, and analyzes and judges the data accordingly. The analysis includes: 1) Determine whether the entire pipeline has been safely and evenly heated to the predetermined temperature to avoid local overcooling or overheating and prevent shaft seizure; 2) Monitor the temperature difference between the upper and lower cylinders to ensure it is within a safe threshold and prevent equipment damage; 3) Determine the optimal start-up and shutdown times for the vacuum pump based on the current temperature field and cylinder safety conditions; (3) Based on the decision results, the DCS distributed control system issues coordinated control commands to the execution units: 1) For the shaft seal heating system: issue power adjustment commands to accurately supplement the heat in the low-temperature sections, ensuring that the entire pipeline is heated to the target state quickly and evenly; 2) For the vacuum pump system: When it is determined that the pipeline temperature field has reached the standard and the cylinder is safe, a command to stop the vacuum pump is issued, thereby accurately cutting off the operation of auxiliary equipment while ensuring safety, and achieving energy saving.
[0027] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A distributed monitoring and collaborative temperature control system for shaft seal pipeline temperature, comprising a turbine cylinder and a pipeline body connecting the cylinder, characterized in that, Also includes: The data acquisition and sensing unit includes a distributed monitoring device for shaft seal pipe temperature installed on the main body of the pipe and a vacuum-coordinated temperature control device installed on the turbine cylinder. The centralized monitoring and decision-making unit is a DCS distributed control system. The DCS distributed control system is signal-connected to the shaft seal pipe temperature distributed monitoring device and the vacuum collaborative temperature control device. The shaft seal pipe temperature distributed monitoring device is used to provide the DCS distributed control system with the temperature data of the main body of the pipe, while the vacuum collaborative temperature control device is used to provide the DCS distributed control system with the vacuum degree of the middle and low cylinders and the temperature difference between the upper and lower cylinders. An execution unit, which is signal-connected to the DCS distributed control system, includes a shaft seal heating system and a vacuum pump system, to utilize the DCS distributed control system to generate coordinated control commands for the shaft seal heating system and the vacuum pump system.
2. The distributed monitoring and collaborative temperature control system for shaft seal pipelines according to claim 1, characterized in that, The main body of the pipeline is divided into multiple independent heating sections, including four heating sections of the high-pressure front shaft seal pipeline and three heating sections of the high-pressure rear shaft seal pipeline.
3. The distributed monitoring and collaborative temperature control system for shaft seal pipelines according to claim 1, characterized in that, The distributed temperature monitoring device for the shaft seal pipeline includes temperature measuring points installed on the heating section, with at least one temperature measuring point installed on each heating section. Multiple temperature measuring points are integrated and connected to a digital controller, which is used to connect to the DCS distributed control system.
4. The distributed monitoring and collaborative temperature control system for shaft seal pipelines according to claim 3, characterized in that, The temperature measuring point is a type K thermocouple.
5. The distributed monitoring and collaborative temperature control system for shaft seal pipelines according to claim 3, characterized in that, The digital controller is an AI-8 series digital controller.
6. The distributed monitoring and collaborative temperature control system for shaft seal pipelines according to claim 1, characterized in that, The vacuum-coordinated temperature control device includes a vacuum degree sensor and a temperature difference sensor. The vacuum degree sensor is installed on the cavity of the intermediate-pressure cylinder / low-pressure cylinder of the steam turbine, while the temperature difference sensor is symmetrically installed on the upper and lower parts of the steam turbine cylinder. The vacuum degree sensor and the temperature difference sensor are also connected to the DCS distributed control system.
7. A steam turbine, characterized in that, The steam turbine is equipped with a distributed monitoring and collaborative temperature control system for shaft seal pipeline temperature as described in any one of claims 1-6.