The ENVADA Online monitoring and fault diagnosis system contains the products and services provided by ENVADA and her companion. The aim of the system is to help the client create a safe and comfortable production and live space so as to make the client not worrying the safe problem of their device any longer. This solution is for power industry. How to solve the problem of safety of production and fault prediction is introduced hereafter.
This is one of complete sets of guides introducing ENVADA’s solutions for the good of clients and some successful examples through the cooperation between ENVADA and other companies.
1. Power industry present development trend
The rapid economy development puts forward higher and higher demands, e.g. protecting environment, improving efficiency, decreasing cost and so on, to power industry. Power industry developing at a high speed is facing multiple challenges. The company of power industry must ensure safety and reliability of operation of unit in the complete production period.
The continual safe operation of unit is the first task of power industry. To complete this task, the unit must always be in a good condition. The unexpected accident, tear and wear rate and life prediction of unit should be understood in advance. Therefore, the company should be able to predict various conditions that the unit may produce so as to take suitable measures in advance to ensure continual safe operation of unit.
2. Solving your problem is our aim
To complete the task of continual safe operation of unit, the unit must always be in a good condition. Therefore, the forward real-time online monitoring is required so as to understand possible condition and time of occurrence of fault through variety of operation parameters of unit before the fault occurs. Because the random fault occurs abruptly, it would produce the largest damage and cause the hardest loss so how to avoid the occurrence of random fault of unit should be firstly considered. The technique of automatic online monitoring mode is advanced in comparison with online measuring and offline analysis monitoring mode as well as periodic monitoring mode so it can prevent the occurrence of abrupt fault of unit and no special expert is needed to operate in the site. To predict the fault of unit, which has much to do with time, and to change the maintenance mode of unit are mainly take into attention here. The technique develops on the basic of state monitoring and fault analysis and is a key to complete that advanced predict maintenance substitutes preventative maintenance based on time.
The vibration signal is most widely used among many signals reflecting the state of unit. Because the vibration is often the main cause of fault of unit, the signal of vibration commonly reflects variety of fault of unit. The signal of vibration contains variety of rich messages. Measuring vibration of unit is convenient and generally without any effect on normal operation of unit. The necessity and meaning installing rotating machinery vibration monitoring and fault diagnosis system are as follows：
1． The data record and signal analysis are able to provide powerful evidence for accident analysis after the accident occurs so as to save time judging the fault and to decrease the loss caused by stop of unit.
2． The occurrences of many faults have a developing procedure from light to hard. The trend analysis and the measurement of abnormal signal are able to find the potential fault of device early so as to take measures in advance, to avoid or decrease the occurrence of accident, to extend the life of unit and to improve usable time of unit.
3． By analyzing the state of unit is able to determine the best suitable time of maintenance and the project of maintenance, to prompt the transformation of maintenance mode from accident maintenance mode and periodic maintenance mode to condition maintenance mode, to avoid unnecessary stop of unit, to speed up the maintenance to decrease the time of stop of unit and save the cost of maintenance.
4． The application of fault diagnosis expert system is able to solve the problem of lack of expert in the site, to make best of rich experience of the expert in vibration monitoring domain so as to improve the level of fault diagnosis and to produce great social and economical benefits.
5． The vibration measuring technology is an essential tool for dynamic balance of rotator in the site.
Online monitoring technology is able to monitor and analyze the state of machinery. By monitoring and analyzing the state of fault of unit and the development of fault in real time is not only able to understand the fault and the fault extent of unit at any time but also to predict what time the fault of device would reach a danger extent and the unit should be stopped for maintenance so as to apply advanced predict maintenance, which is used to substitute the traditional preventative maintenance based on time, to the unit and to provide scientific guarantee for continual safe operation of unit.
3. EN8000 feature and advantage---Our product ensures safety of your device
The EN8000 large-scale rotating machinery vibration monitoring and fault diagnosis expert system made in ENVADA is designed and produced to meet above demands. It is able to provide continual protection for your unit.
EN8000 system construction
The EN8000B system is composed of the acquisition station (intelligent data acquisition box, that is called the lower computer) and the workstation (the upper computer). The two parts are connected through the network. The acquisition station is used to sample, analyze, store and display variety of signals. But it is only able to execute some simple analysis, such as waveform, spectrum and trend. Other complex analysis and fault diagnosis would be executed by the workstation. This kind of division simplifies the operation in the acquisition to the maximum so as to ensure reliability sampling and storing data.
The workstation can be any computer using Windows Operating System in a control room or an office and even in a long distance place. If the workstation has been connected with the acquisition station through network and the EN8000B workstation software has been installed on it, the workstation can monitor the state of unit in the site in real time, can execute fault analysis and diagnosis to history data, can backup history data, can edit system parameters, can upgrade system program and so on.
If there are many points measured, e.g. the number of acquisition station is more than 4, or there are many workstations working at the same time, a data server should be installed to improve the processing performance of system. The data server is used to receive, process and store real time data come from the acquisition station and to provide data processing service for the workstation at the same time.
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EN8000 system feature
The hardware of system adopts module construction so it has high reliability and easy of installation, maintenance and replacement. A vibration module has 4-path; an analog module and a switching module all have 32-path. These modules can be combined in any mode. If there were a fault in some channel or some module, it would not affect normal working of other channel or other module. Therefore, the client can substitute the module, which has a fault, to solve the fault (ENVADA will provide some backup module).
The EN8000diagnosis knowledge base is an open construction so the client can add the experience and knowledge accumulated in operation and maintenance in a long period into it.
The EN8000 system has some special functions besides variety of vibration graphs and spectrums that a common vibration analysis system can provide, such as follows：
◇Shaft system movement imitation
◇Relevant trend analysis (horizontal ordinate and vertical ordinate at option，time segment at any setup)
◇Many dynamic balance calculation methods
◇Complete database management
◇Remote diagnosis and analysis, etc.
The EN8000 system adopts Windows 2000 Operating System and has rich functions, such as real-time multitask, virtual memory, file management, network management. The main software of EN8000 system is developed in Delphi 6.0 programming environment and has powerful functions of graph display, database management, network communication, etc. The software has a powerful second developing ability and is well compatible with other system. It adopts a pull-down menu so friendly to client and easy of operation. It has complete functions especially designed to process the signals of fault diagnosis of rotating machinery and a perfect function of fault diagnosis expert system.
EN8000 system function
1. Real-time continual data sampling and displaying function
l Complete and reliable function acquiring the signal of site.
l All vibration signals of device can be continually and synchronously sampled and stored in a complete period at very high speed.
l Accurately sampling the rotating speed and the procedural parameter of state of device at high speed.
l Displaying the state of operation of device dynamically.
2. Flexible and convenient configuration software
The configuration software is available so the real-time monitoring display can be conveniently combined in any configuration to meet user’s requirements and to improve working efficiency.
3. Acknowledging the state of device automatically
l Normal operation state.
l Start/stop state.
l No-load state, vibration abnormal state, etc.
4. Forming variety of complete databases automatically to recall the accident
l History database：Hour, day, month and year database.
l Event database：Start/stop, abnormal variation, alarming event, etc.
5. Complete vibration analysis function available
l Time domain analysis：Waveform, orbit of shaft center, position of shaft center, shaft system movement imitation.
l Frequency domain analysis：Spectrums, fall graph, reverse spectrum, envelope spectrum, detailed spectrum, phase graph, wavelet transformation.
l Varying speed procedure：Baud graph, polar graph, cascade graph.
l Trend and relevant trend analysis.
l Comparison analysis.
6. Complete fault diagnosis expert system available
The system has a knowledge base being able to suit for different objects diagnosed and is able to manage the diagnosis knowledge base. It has a powerful ability acquiring the sign of fault automatically and can diagnose common vibration fault of device automatically or in a dialogue mode.
7. Many balance calculation methods available
l Least square method influence coefficient calculation and dynamic balance calculation.
l Harmonic component method influence coefficient calculation and dynamic balance calculation.
l Vector addition, remain vibration estimation, etc.
8. Powerful network function available
The system adopts the TCP/IP communication protocol and uses Winsock programming. It provides a rapid, safe and reliable remote service network interface to complete remote monitoring and fault diagnosis.
9. The hardware of system adopts a modularized collecting and distributing master-slave construction and has high reliability and easy of maintenance.
10. All application software are researched by ENVADA and are compatible with other systems so they can perfectly meet user’s special demands in time.
4. Actual case：Nayong Power Plant 4×300MW Units in Guizhou Province China
1. Introduction
The Nayong Power Plant belongs in Guizhou Power Company. She is to the southwest of Nayong County and at a distance 33km from Nayong and 70km from Liupanshui. The No.213 state way is around the east of the plant so the road construction is convenient. There is no railroad in the county. The nearest railroad station is the Lanba in Shuicheng that is at a distance 42km from the plant.
The Nayong Power Plant is a large-scale power plant that is near to the Nayong coalmine so she can make use of anthracite coal produced by Nayong County and alleviates the limitation of Nayong coal production because of transportation condition. The establishment of the power plant promotes the development of local coal industry and the development of local economy. The power produced by the plant will be put into Guizhou power network so as to not only meet the load demand of Guizhou power network and improve the reliability and quality of operation of power network but also provide power to around province through the power network. The capacity of the power plant is 1200MW (4×300MW) and will be an important power plant in Guizhou Province China.
The boilers of 4X300MW Units will need coal of 513.2t/h according to design coal so the coal per year needed is about 3,080,000t. It is all transported through road so the maximum number of tipper lorry used to delivery coal to the plant would be 1232 if a tipper lorry can delivery 10t.
The turbine is a sub-critical, once intermediate reheat, single shaft, HP and MP in a vat, two vats and two off-steam, condensing turbine. Its rated power is 300MW and main steam flow is 937.86t/h and the maximum continual power is 336.323MW.
The maximum continual output power of generator is 333MW; the rated power is 300MW，the rated power factor is 0.85. The generator adopts H2O-H-H cooling mode. The EN8000 systems of 8 sets installed on 1#~4#turbine generator units, 4×300MW，in August 2002.
2. EN8000 system construction
The EN8000 vibration monitoring and fault diagnosis system of turbine generator unit is composed of hardware and software. The former is composed of the high-speed intelligent data acquisition box (lower computer) and the engineer workstation (upper computer) and accessories. The two parts are connected through a network. The latter is composed of three parts: data sampling software, database software and analysis and diagnosis software. The data sampling software is used to sample data. It can automatically acknowledge the states of start/stop of unit, speeding/lowering rotating speed and normal/abnormal of unit and can execute the work of sampling data according to the state of unit, e.g. in a stable operating state, the data acquisition box will sample the data in timer mode and in a speeding/lowering rotating speed state, it will sample the data according to the variation of rotating speed. The database software is used to store the data. It can store the data to different database according different states of unit so as to make the later analysis convenient. The analysis and diagnosis software is used to online or off line analyze variety of data so as to judge the operation state of unit and to give the cause of fault of unit and processing advice automatically. The EN8000 system has a powerful vibration analysis and fault diagnosis function.
The configuration is the same for 4 turbine generator units in Nayong Power Plant. A turbine generator and its accessory devices are individually equipped with a high-speed intelligent data acquisition box. Two acquisition boxes are placed in a standard case. There are two acquisition boxes, a CRT displayer and their wiring terminals in the case. The unit equipped with an engineer workstation. The CRT displayer is used to display main monitoring graph and variety of analysis data graph and list of unit. The data sampling system (lower computer) of each unit connects with the engineer workstation (upper computer) through Ethernet and can send the data to the remote diagnosis system of ENVADA or the local network of the plant or the network of Guizhou Power Company through MODEM remote log-in. The 4 cases of lower computer of system are installed in the electric device room. The distribution project of the upper computer, displayer, printer and so on may be determined according to the condition of site.
