Hydraulic generator water guide crank arm displacement monitoring system

Abstract

The application discloses a water guide crank arm displacement monitoring system of a hydro-generator, which comprises a data acquisition module, a monitoring protection module and a data processing module, wherein the data acquisition module comprises a displacement sensor installed on a water guide crank arm of the hydro-generator; the data acquisition module is used for collecting displacement data of the water guide crank arm; the monitoring protection module is used for pre-processing the displacement data and outputting a shutdown signal when it is determined that the displacement of the water guide crank arm exceeds an upper limit of shutdown; and the data processing module is used for determining the displacement reason of the water guide crank arm according to the displacement data. The water guide crank arm displacement monitoring system provided by the application can not only avoid the occurrence of a heavy loss accident, but also effectively improve the equipment utilization rate due to the continuous online monitoring, the reduction of unit test time, equipment maintenance and the number of unplanned shutdowns.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water turbine generator monitoring, in particular to a water guide arm displacement monitoring system for water turbine generator. BACKGROUND

[0002] The rotating part of the water guide mechanism mainly includes: control ring, double-layer connecting plate, main and auxiliary arm, expansion pin (for connecting the main arm with the movable guide vane shaft) and connecting column pin, eccentric pin (for adjusting the vertical gap of the movable guide vane) and other components; the execution part mainly includes: 24 movable guide vanes. According to the structural analysis, the movable guide vane arm is installed at the upper end of the guide vane shaft, and the guide vane arm is connected with the control ring through connecting rods in sequence, and the length of each connecting rod is adjusted to make each vane run synchronously, so as to ensure that each guide vane can be closed synchronously. At present, the nut of the guide vane arm locking pin of the water guide mechanism is loose or the locking force is insufficient during maintenance, which directly leads to the abnormal phenomenon that the movable guide vane of the unit water guide mechanism sinks and the end face gap distribution relationship changes (note: the upper end face gap increases and the lower end face gap decreases). In this case, the sinking of the movable guide vane will cause the lower end face gap of the movable guide vane to decrease, and when the gap is 0 mm, the bottom ring upper surface and the movable guide vane lower end face will be seriously scratched during the movement of the movable guide vane (the adjustment movement of the movable guide vane during the operation of the unit). In severe cases, the movable guide vane of the unit will not be able to adjust, forcing the unit to lose control, causing great damage to the unit and affecting the safe and stable operation of the unit.

[0003] With the development of the power industry and technological progress, especially the rise of the "unattended (less attended)" operation and management mode of hydropower plants (stations), the improvement of the comprehensive automation level of hydropower stations and the application of computer monitoring systems and automation systems, the reliable operation and comprehensive automation level of the power station unit have been greatly improved. However, the safety and stability monitoring and protection of the water turbine generator unit, which is the main production equipment of the hydropower station, still remains at a relatively low level and relies mainly on the subjective visual inspection of the regular patrol and inspection of the operating personnel.

[0004] In order to ensure the safe and stable operation of the unit, according to the analysis of the current problem, it is urgently needed to monitor the guide vane arm in real time online. The guide vane arm gap displacement caused by the loosening of the nut is monitored through the installation of the water guide arm support displacement detection system. Through the displacement data analysis and judgment, the equipment is in normal state, critical state and fault state, and diversified information and trend change analysis information are provided according to the design structure. Through long-term online monitoring data, the fault trend and maintenance suggestions can be made in advance to realize the "condition-based maintenance" or "predictive maintenance" of the equipment. In order to avoid the expansion of the displacement accident of the unit, which will inevitably cause irreparable loss.

[0005] Therefore, it is urgent to add a water guide crank arm displacement state detection system to each unit to perform real-time monitoring and protection and early maintenance prediction. SUMMARY

[0006] The present application aims to at least partly solve one of the above technical problems. To this end, the present application proposes a water guide crank arm displacement monitoring system for a hydroelectric generator, comprising a data acquisition module, a monitoring and protection module, and a data processing module, wherein the data acquisition module comprises a displacement sensor installed on the water guide crank arm of the generator;

[0007] The data acquisition module is configured to acquire displacement data of the water guide crank arm.

[0008] The monitoring and protection module is configured to pre-process the displacement data and output a shutdown signal when it is determined that the displacement of the water guide crank arm exceeds an upper limit of shutdown.

[0009] The data processing module is configured to determine the cause of the displacement of the water guide crank arm based on the displacement data.

[0010] Preferably, the data acquisition module further comprises a motion sensor configured to acquire the running stroke and state of the servomotor piston rod of the hydroelectric generator; and the data processing module is further configured to determine the running trend of the hydroelectric generator based on the running stroke and state of the servomotor piston rod of the hydroelectric generator.

[0011] Preferably, the data acquisition module acquires an analog displacement signal of the water guide crank arm through the displacement sensor, converts the displacement analog signal into a corresponding displacement digital signal, and obtains the displacement data of the water guide crank arm.

[0012] Preferably, the monitoring and protection module is further configured to output an alarm signal and alarm information when it is determined that the displacement of the water guide crank arm exceeds an upper limit of alarm.

[0013] Preferably, the data processing module is further configured to perform data verification and digital filtering on the displacement data; and calculate the characteristic frequency value, the water guide crank arm displacement value, and the displacement trend of the water guide crank arm of the hydroelectric generator based on the displacement data.

[0014] Preferably, the data processing module is further configured to perform correlation analysis on the displacement amplitude of the water guide crank arm, the rotation speed of the hydroelectric generator, and the load of the hydroelectric generator based on the displacement data.

[0015] Preferably, the system further comprises a storage and communication module configured to store the running data of the hydroelectric generator and transmit the running data through a communication network.

[0016] The operation data comprises displacement data of the water guide crank arm, displacement change trend data of the water guide crank arm, and operation condition data of the hydro-generator.

[0017] Preferably, the interface display module is further configured to display the displacement amount of each water guide crank arm in the hydro-generator, the alarm upper limit and the shutdown upper limit, display the displacement fluctuation value of each water guide crank arm and the sensor signal parameter in a data table form, display the installation position of each displacement sensor, display the change trend of the displacement amount of each water guide crank arm in real time, and display the alarm signal and alarm information output by the detection protection module.

[0018] Preferably, the sensitivity of the displacement sensor, the shutdown upper limit, the alarm upper limit and the analog-digital signal conversion channel parameter are set according to the monitoring requirement.

[0019] Preferably, the displacement sensor is installed at the connection between the upper end surface of the water guide crank arm and the guide vane arm, and the sensing end of the probe of the displacement sensor is located on the central axis of the upper end surface of the water guide crank arm.

[0020] Compared with the prior art, the present application has the following advantages:

[0021] 1. Through the online state monitoring of the unit equipment, the operation condition of the unit is monitored and analyzed in real time, the operation condition of the unit is reasonably adjusted, the safe operation level of the equipment is improved, the water guide crank arm displacement overrun alarm and safety shutdown protection of the unit are realized, and the occurrence of a heavy loss accident is avoided.

[0022] 2. The continuous online monitoring is adopted, the unit test time, the equipment maintenance and the number of unplanned shutdowns are reduced, and the equipment utilization rate is effectively improved.

[0023] 3. The early fault identification is adopted to guide the equipment maintenance, the fault cause of the unit is detected in operation, the maintenance time and the maintenance cost are reduced, and the maintenance and repair plan (such as replacement of damaged parts, balance treatment and gap adjustment, etc.) is reasonably arranged.

[0024] 4. The present application can realize the analysis of the unit adjustment parameters, performance, and the characteristics and change trend of the unit unbalance force, optimize the operation mode of the unit, and prolong the service life of the equipment.

[0025] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be achieved and obtained by the structure particularly pointed out in the written description and the accompanying drawings.

[0026] The technical solutions of the present application will be further described in detail below with the help of the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application, and together with the description serve to explain the application, and should not be considered as limiting the application in any way. In the drawings:

[0028] Figure 1 It is a schematic diagram of water guide crank arm displacement monitoring system of hydroelectric generator.

[0029] Figure 2 It is a schematic diagram of displacement monitoring sensor installation position.

[0030] The preferred embodiments of the present application will be described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described here are only used to explain and illustrate the present application, and are not used to limit the present application.

[0031] As shown in Figure 1 The water guide crank arm displacement monitoring system of hydroelectric generator provided by the present application comprises a data acquisition module, a monitoring protection module and a data processing module, wherein the data acquisition module comprises a displacement sensor installed on the water guide crank arm of the generator.

[0032] The data acquisition module is used for acquiring displacement data of the water guide crank arm.

[0033] The monitoring protection module is used for pre-processing the displacement data and outputting a shutdown signal when it is determined that the displacement of the water guide crank arm exceeds the upper limit of shutdown.

[0034] The data processing module is used for determining the displacement reason of the water guide crank arm according to the displacement data.

[0035] In some embodiments of the present application, the data processing module is a data analysis processing host or a data acquisition and analysis workstation. The data acquisition and analysis workstation is an industrial computer capable of adapting to the real-time acquisition, real-time analysis and display of the running speed requirement, has a fast operation speed and can adapt to the harsh environment such as strong magnetic field, strong electric field and strong interference in the hydropower plant. The water guide crank arm displacement monitoring system of each unit is independently set and mutually constitutes a local area network for monitoring and analyzing the whole station, and can also interface with the data of other devices and systems in the power station. In order to facilitate installation and use, the data acquisition and analysis workstation uses an integrated industrial computer.

[0036] In some embodiments of the present application, the data acquisition module is composed of a signal acquisition processing lower computer and displacement sensing sensors and signal transmission devices. In this embodiment, according to the water guide assembly structure, one displacement sensor is installed at each water guide arm, and the signals are transmitted to the signal acquisition processing lower computer through signal cables and then transmitted to the water guide arm displacement state detection system host computer in the centralized monitoring room through communication. In order to meet the requirements of data acquisition accuracy and sampling rate, when selecting a data acquisition board, the analog-to-digital conversion accuracy, analog-to-digital conversion time, channel number and signal input range need to be considered. On the basis of this detection, a motion sensor for detecting the running stroke and state of the servomotor piston rod can also be added to provide more comprehensive detection for the displacement analysis of the running trend of the whole machine.

[0037] In some embodiments of the present application, the monitoring protection module can provide reliable power supply and power supply monitoring for the state monitoring sensors, and perform preprocessing of the collected data, including data screening, data verification, data monitoring and alarm when data transmission is abnormal. At the same time, when the displacement value of the unit exceeds the limit, the monitoring protection device outputs an alarm signal to remind the operation and maintenance personnel to check the unit and determine the cause of the displacement expansion; when the water guide arm locking pin bolt of the unit is loose and the displacement exceeds the dangerous (shutdown) upper limit, the monitoring protection device outputs a shutdown signal to protect the unit equipment from permanent damage or expansion of the accident.

[0038] In some embodiments of the present application, the water guide arm displacement monitoring system of the hydroelectric generator adopts modular design. In this embodiment, the data acquisition module can realize continuous data acquisition of 32 channels, and can realize data acquisition at certain points at fixed time and fixed points through DMA mode data transmission. The data buffer mode is adopted to store the memory image or array, which is convenient for real-time data analysis. The data processing module can realize the following functions:

[0039] 1. Data rationality check and digital filtering are performed on the collected input signals to remove high-order harmonics, which facilitates the use of the signals for display and displacement analysis;

[0040] 2. The characteristic frequency value of the unit is calculated, and the characteristic value of the unit is calculated according to the analysis requirements;

[0041] 3. The peak value and average value of the water guide arm displacement of each monitoring part of the unit are calculated;

[0042] 4. The overall structure of the water guide arm displacement signal of the unit is analyzed, for example, the change trend of the water guide arm displacement signal of the unit with time is analyzed;

[0043] 5. The correlation analysis of the water guide arm displacement amplitude, the speed of the hydroelectric generator and the load of the hydroelectric generator is performed to facilitate the analysis of the displacement reason of the water guide arm of the unit.

[0044] In some embodiments of the present application, the water guide arm displacement monitoring system further comprises an interface display module, and the functions of the interface display module include but are not limited to: displaying the displacement of each water guide arm in the hydroelectric generator, the upper limit of alarm and the upper limit of shutdown; displaying the displacement fluctuation value of each water guide arm and the sensor signal parameter in the form of a data table; displaying the installation position of each displacement sensor; displaying the change trend of the displacement of each water guide arm in real time; and displaying the alarm signal and alarm information output by the detection protection module.

[0045] In some embodiments of the present application, the water guide arm displacement monitoring system further comprises a storage communication module for storing the operation data of the hydroelectric generator and transmitting the operation data through a communication network; and the operation data mentioned herein includes the displacement data of the water guide arm, the displacement change trend data of the water guide arm and the operation condition data of the hydroelectric generator. It can be understood that the data obtained through the data acquisition module and the data processing module are applied in real time on one hand and stored in a historical database on the other hand, so as to facilitate long-term data analysis and accumulation. For the displacement and other parameters in typical unit operation conditions such as over-limit alarm state, start-up and shutdown process and load rejection state, continuous collection is required and storage into a typical database is required, so as to facilitate further data analysis. In some embodiments of the present application, in a stable condition, the system performs online automatic storage according to the change of equal-time parameters; in a transition process and an abnormal process, the system records in a condition starting and stopping mode. In order to consider the expansion of system software functions in the future and the interface with the computer monitoring system of the power station or the power plant system, the computer of the monitoring system in the present application is configured with a network communication card in terms of hardware, and an open database is adopted in terms of database and is set as a shared attribute.

[0046] In another embodiment of the present application, the data processing module is composed of a unit displacement analysis module, a state analysis display module, a data storage module, a data communication module and other sub-modules, and in this embodiment, the water guide arm displacement monitoring system further comprises a system software module, which can be used by a user to manage and configure parameters of other modules in the system, including setting the sensitivity of the displacement sensor, setting the shutdown upper limit parameter, setting the alarm upper limit parameter and setting the analog-digital signal conversion channel parameter.

[0047] Figure 2The displacement sensor installation schematic diagram is given for some embodiments of the present application, in which, according to the structural features of the hydroelectric generator set, the measuring point of the water guide crank arm is arranged at the joint seam of the crank arm guide vane arm, and the end face joint seam displacement trajectory diagram and the radial position diagram of the guide vane shaft of the section part can be obtained through the displacement sensor signal. The displacement sensor for measuring the water guide crank arm is directly installed above the support adjusting seat (base) through a specially designed support adjusting seat (base), and the sensing end of the sensor probe is opposite to the relative end surface of the measuring point. When installing, the installation base plate should be bolted or welded on the corresponding end plate, and at the same time, the gap between the front end of the sensor support adjusting seat and the opposite end surface should be kept between 0-40mm to facilitate the installation and adjustment of the sensor. In order to ensure the accuracy of the measurement, the orientation and detection surface of the sensor probe should also be ensured when installing the sensor adjusting seat. In order to ensure the accuracy of the measurement, the sensor probe should also be perpendicular to the measuring plate when installing the sensor bearing adjusting seat. At the same time, when measuring the horizontal displacement, the measuring plate should be in a vertical position, and when measuring the vertical position, the measuring plate should be in a horizontal position. Moreover, the distance between the sensor and the measured surface needs to be adjusted, which not only ensures that the key phase block does not collide with the probe, but also ensures that the key phase measurement block maintains sufficient displacement measurement distance through the probe.

[0048] The water guide crank arm displacement monitoring system given by the present application has the following advantages:

[0049] 1. Real-time monitoring of the stability of the hydraulic unit. Due to the characteristics of the hydraulic unit in operation, the operation mode of the power system, the operation characteristics and working condition parameters of the unit, and the correlation between the measuring points, etc., the parameters of each module in the system can be set online to meet the safety protection shutdown of the unit, avoid the false tripping and frequent alarm of the simple control protection device for the water guide crank arm displacement protection of the hydraulic unit, and also can alarm or protect the shutdown when the water guide crank arm displacement of the unit exceeds the limit, to avoid further damage to the unit equipment.

[0050] 2. Real-time acquisition, real-time state display, real-time digital display, real-time trend curve analysis, and timed data storage of the unit water guide crank arm displacement, to establish a complete state monitoring real-time database and historical database of the unit. According to years of monitoring data, the change of state data can be analyzed and compared to find the fault of the unit and arrange the maintenance reasonably. In stable working condition, the parameters are stored automatically according to the same time; in transition process and abnormal process, the monitoring data are recorded by condition starting and stopping, which ensures the completeness, accuracy and effectiveness of the monitoring data, and fully retains the complete information of the unit state characteristics. The local workstation has the function of storing high-speed sampling information, which can be used for the storage of typical working condition data, the test of transition process and the function of accident recall.

[0051] 3. Based on the system, a distributed real-time monitoring network and a background state analysis and diagnosis workstation can be established to form a unit state monitoring network of the whole power plant. The operation, maintenance and repair of the unit can be supported by various application software modules of the system. The system can provide various standard data interface modes for the computer monitoring of the power plant, and can conveniently exchange data and realize operation control with the real-time monitoring system of the power plant.

[0052] In conclusion, the present application has the following advantages: through online state monitoring of the unit equipment, real-time monitoring and analysis of the operation condition of the unit, reasonable adjustment of the operation condition of the unit, improvement of the safe operation level of the equipment, realization of the over-limit alarm and safe shutdown protection of the water guide crank arm displacement of the unit, and avoidance of the occurrence of heavy loss accidents. Continuous online monitoring is adopted, the test time of the unit, the equipment maintenance and the number of unplanned shutdowns are reduced, and the equipment utilization rate is effectively improved. Early fault identification is adopted to guide the equipment maintenance, the fault causes of the unit can be detected during operation, the maintenance time and maintenance cost are reduced, the maintenance and repair plan can be reasonably arranged, the adjustment parameters, performance and characteristics and variation trend of the unbalance force of the unit can be analyzed, the operation mode of the unit is optimized, and the service life of the equipment is prolonged.

[0053] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application belong to the scope of the claims of the present application and the equivalent technologies thereof, the present application also intends to include these modifications and variations.

Claims

1. A displacement monitoring system for a water guide boom of a hydro-generator, characterized in that, include: The system includes a data acquisition module, a monitoring and protection module, and a data processing module, wherein the data acquisition module includes a displacement sensor installed on the generator water guide crank arm; The data acquisition module is used to acquire the displacement data of the water guide crank arm; The monitoring and protection module is used to preprocess the displacement data and output a stop signal when it is determined that the displacement of the water guide crank arm exceeds the stop limit. The data processing module is used to determine the cause of the water guide crank arm displacement based on the displacement data; The data acquisition module further includes a motion sensor for acquiring the travel stroke and operating status of the relay piston rod of the hydro-generator; the data processing module is also used to determine the operating trend of the hydro-generator based on the travel stroke and operating status of the relay piston rod. The data acquisition module acquires the simulated displacement signal of the water guide arm through a displacement sensor, and converts the simulated displacement signal into a corresponding digital displacement signal to obtain the displacement data of the water guide arm. The displacement sensor is installed at the connection between the upper end face of the water guide arm and the guide vane arm, with the sensing end of the displacement sensor probe located on the central axis of the upper end face of the water guide arm. The measurement point where the displacement sensor is installed is arranged at the closing joint of the guide vane arm, with the sensing end of the displacement sensor probe facing the opposite end face surface of the measurement point. The data processing module is further configured to: perform data verification and digital filtering on the displacement data; and calculate the characteristic frequency value of the hydro-generator, the displacement value of the water guide arm, and the displacement change trend of the water guide arm based on the displacement data. The data processing module is also used to perform correlation analysis on the displacement amplitude of the water guide arm, the rotational speed of the turbine generator, and the load of the turbine generator based on the displacement data.

2. The displacement monitoring system for the water guide arm of a hydro-generator as described in claim 1, characterized in that, The monitoring and protection module is also used to output an alarm signal and alarm information when it is determined that the displacement of the water guide crank arm exceeds the alarm limit.

3. The displacement monitoring system for the water guide arm of a hydro-generator as described in claim 2, characterized in that, It also includes: a storage and communication module, used to store the hydro-generator operating data and transmit the operating data through a communication network; The operational data includes: displacement data of the water guide crank arm, displacement change trend data of the water guide crank arm, and operating condition data of the hydro-generator.

4. The displacement monitoring system for the water guide arm of a hydro-generator as described in claim 3, characterized in that, Also includes: The interface display module is used to display the displacement, alarm limit, and shutdown limit of each water guide crank arm in the hydro-generator. The displacement fluctuation value and sensor signal parameters of each water guide crank are displayed in tabular form; the installation position of each displacement sensor is displayed; and the displacement trend of each water guide crank is displayed in real time. The display shows the alarm signals and alarm information output by the monitoring and protection module.

5. The displacement monitoring system for the water guide arm of a hydro-generator as described in claim 4, characterized in that, The sensitivity of the displacement sensor, the shutdown limit, the alarm limit, and the analog-to-digital signal conversion channel parameters are set according to monitoring requirements.

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