Summary:
0 Introduction Life-cycle management refers to the new technology that optimizes equipment operation and maintenance management based on the monitoring and evaluation of the status of the equipment with the objective of economically realizing the entire service life of the unit. The life span of a thermal power unit depends on the lifespan of its weakest part. Therefore, research and improvement of the life management of turbine rotors and cylinders is an important part of strengthening the life management of thermal power units.
Most of the previous turbine life management systems were two-tier application programs, namely only the data layer and the computing layer. This requires that the calculation program is installed on each client, the maintenance and use of the program is inconvenient, and it requires a lot of resources on the client. The author introduces Microsoft's ActiveX technology, plus a presentation layer, the program interface to be displayed is made ActiveX controls published on the Internet, so that only the calculation program is placed on the server, and the client does not need to install the calculation program, use the Web Browsers (such as Internet Explorer) can view the required program interface and overcome the shortcomings of the previous turbine life management program.
1 The overall content and structure of the system 1.1 The main contents of the system and the functional system mainly include three aspects:
a. The information library of the main components of the steam turbine: including the component code, the name of the component, the position of the component, and the degree of importance of the component, etc., for the user to conveniently browse and inquire through the Web page;
b. On-line monitoring system for the life status of turbine rotors: The temperature and thermal stress of the rotor during the operation of the unit (especially start-stop, variable load, etc.) are monitored so that the unit can operate at a reasonable level and the rotor is maximized. Service life
c. Turbine cylinder life status online monitoring system: The temperature and thermal stress of the cylinder are monitored during the operation of the unit (especially start-stop, variable load, etc.), so that the unit operates at a reasonable level to maximize the use of cylinders. life.
The functions that the entire system can achieve are:
a. Guide operation personnel to perform reasonable operations to achieve safety and efficiency;
b. Enable managers to understand the operation of the unit for a certain period of time;
c. Regularly evaluate the start-up and shutdown of the unit, run a reasonable assessment of the operation, and play a guiding role in the future operation and maintenance. For some places that do operate in accordance with the scheduling requirements and unreasonable, they can reflect to the dispatcher according to the operation curve and analysis report, in order to change The scheduling curve makes the operation more reasonable and economical.
1.2 The overall structure of the system design The system is a typical three-tier application, including the data layer, logic layer and presentation layer. Among them: The data layer uses SQLServer database to realize, mainly includes real-time database, historical database, abnormal data record database, start-up and shutdown process database, etc. The logic layer is a calculation program, it obtains data from the database, and the computer group starts and stops, The temperature field, stress value, life loss, and cumulative life loss of the rotor and cylinder when the load is changed, and the calculation result is saved in the database; the presentation layer is to display the interface into an ActiveX control and placed on the Web server. The client can use a web browser to view the temperature field and stress value of the rotor and cylinder when the unit is started or stopped or when the load is changed, and the life loss and cumulative life loss of the rotor and cylinder when each start and stop or load change. The overall structure of the system is shown in Figure 1.
2 Specific realization of system functions 2.1 Data layer implementation The data layer is stored on the database server and can be on the same computer as the computing server. It mainly stores data tables for collecting data, data tables that need to display data, and data of key data. Tables and data tables for exception data provide data for the computation and presentation layers.
2.2 The realization of the logic layer Modern stress analysis technology has been able to use a three-dimensional unsteady finite element method to analyze in detail the transient temperature distribution and stress of the rotor in the process of start-stop and variable load of steam turbine, and then determine according to the material and fatigue curve. Rotor life loss, but this exact analysis method can not meet the real-time operation requirements of the turbine in the actual operation of the power plant. For this purpose, a life loss monitoring system suitable for on-site use is composed of measuring point sensors, computers, and life analysis software. It is calculated in advance by the off-line turbine rotor finite element method to find out where the thermal stress is greatest and stress concentration. Coefficients, then on-line monitoring of the section with the largest stress, measuring the relevant parameters of the site, using a one-dimensional model for on-line stress calculation, and then using the stress concentration coefficient to modify the thermal stress, to obtain the corresponding thermal stress in the section at the moment Finally, the life loss is estimated from the fatigue curve of the material.
At present, there are three simplified formulas for on-line calculation of rotor thermal stress in China: one-dimensional analytical method, one-dimensional finite difference method, and control model method. The system uses a one-dimensional difference method for rotor thermal stress calculation [1]. The calculation program is stored on the calculation server and can complete functions such as data acquisition, stress calculation, life management, start-up instructions, and recall.
2.3 Presentation Layer Theory and System Implementation ActiveX technology is a technology that Microsoft provides to developers to integrate the computer desktop environment with the Internet and its numerous resources. It uses COM to allow components to interact in a network environment, regardless of the specific programming environment.
ActiveX includes both server-side and client-side technologies. Its main content is:
a. ActiveX controls: COM objects that are inserted into web pages and containers that support ActiveX.
b. ActiveX documents: Used to browse compound documents (non-HTML documents) such as Word documents, Excel documents, etc. in Web browsers and other ActiveX-enabled containers.
c. ActiveX Server Framework: Provides a series of functions and encapsulation classes for various aspects of Web server application design, such as server filters, HTML data flow control, and so on.
In layman's terms, ActiveX technology is to compile some interface programs or program blocks that need to be browsed according to the requirements of ActiveX. These programs are usually stored in the server as exe, dll, and OCX files. The biggest difference from other types of controls is that ActiveX controls can be embedded in Web pages. When a user accesses a Web page that has an ActiveX control embedded in it, ActiveX controls are downloaded to the client to run [2].
The development of ActiveX controls is not limited by language. Using VC, VB, Delphi, C++Builder can be used to develop ActiveX, and each has its own advantages and disadvantages. This article recommends using C++
Builder develops ActiveX controls, using C + + Builder can develop a control called ActiveForm, it is actually an ActiveX control, but ActiveForm itself is an ActiveX control container, its development process and the development of ordinary C + + Builder application The program is basically the same.
Using ActiveX controls usually encounter the following problems:
a. Usually ActiveX controls are relatively large, so when the page is opened, the download speed will be slow. In order to increase the download speed of ActiveX controls, ActiveX controls can be compressed into a CAB format, which can greatly reduce the size of ActiveX controls and increase downloads. speed. In C++Builder, simply use the UseCABfilecompression option in the WebDeploymentOptions dialog box.
b. Because ActiveX has some security risks, during the first ActiveX download, the browser may prevent it from downloading. The security level of the client browser needs to be set to “noneâ€.
3 Application Examples The application of this method is described by taking the turbine rotor life management system of a power plant in Shanghai as an example. This system is the most important and typical part of the entire turbine life management system.
The data layer adopts SQLServer7.0, which stores the collected data such as operating parameters, as well as the data to be displayed calculated by the calculation layer, such as the thermal stress of the inner and outer walls, and the life loss of the start and stop of the rotor.
The calculation layer uses VC programming to calculate the temperature field and thermal stress of the rotor using the one-dimensional difference method mentioned above through the data collected in the data layer, so as to further calculate the life loss and cumulative life loss of each start and stop of the rotor. , and save the results of the calculation to the database of the data layer.
Then use C++Builder to make the interface to be displayed as an ActiveX control, and display the data to be visually displayed in the form of numbers, curves, and bar graphs. Since most of the data to be displayed are dynamic, the interface needs to be constantly refreshed. The data in the system is updated with a timer. The data is updated from the database through the ADO interface. The screen is filled with the background color to cover the previous content. Redraw later.
After using C++Builder to complete an ActiveX control, it is usually necessary to wrap the ActiveX control, that is, embed it into the HTML file [3]. Here, CiasslD and Codebase of the OCX must be provided. When the client browses this page, it will first look up the ClasslD in the local registry. If it exists and the version is not updated, you do not need to download it. Otherwise, this control will be searched and downloaded according to the path specified by Codebase. When adjusting the size and position of the ActiveX control interface, you can use Microsoft's tool Microsoft ActiveX ControlPad for visual adjustments. When you need to update a control, you only need to put the new version you have made in the directory where the control was previously located, and the client will download it again.
The web server uses Microsoft's lis (Internet Information Service) server to place ActiveX-embedded HTML files in the server's corresponding virtual directory.
The implementation method of the machine life management system overcomes the disadvantages of the previous presentation layer being difficult to achieve or the Web page downloading speed being slow. Practice has proved that the ActiveX control developed by this method is simple and practical, stable operation, has played a certain role in extending the life of the unit, and also has certain reference value for the development of other e-commerce, industrial monitoring systems.
0 Introduction Life-cycle management refers to the new technology that optimizes equipment operation and maintenance management based on the monitoring and evaluation of the status of the equipment with the objective of economically realizing the entire service life of the unit. The life span of a thermal power unit depends on the lifespan of its weakest part. Therefore, research and improvement of the life management of turbine rotors and cylinders is an important part of strengthening the life management of thermal power units.
Most of the previous turbine life management systems were two-tier application programs, namely only the data layer and the computing layer. This requires that the calculation program is installed on each client, the maintenance and use of the program is inconvenient, and it requires a lot of resources on the client. The author introduces Microsoft's ActiveX technology, plus a presentation layer, the program interface to be displayed is made ActiveX controls published on the Internet, so that only the calculation program is placed on the server, and the client does not need to install the calculation program, use the Web Browsers (such as Internet Explorer) can view the required program interface and overcome the shortcomings of the previous turbine life management program.
1 The overall content and structure of the system 1.1 The main contents of the system and the functional system mainly include three aspects:
a. The information library of the main components of the steam turbine: including the component code, the name of the component, the position of the component, and the degree of importance of the component, etc., for the user to conveniently browse and inquire through the Web page;
b. On-line monitoring system for the life status of turbine rotors: The temperature and thermal stress of the rotor during the operation of the unit (especially start-stop, variable load, etc.) are monitored so that the unit can operate at a reasonable level and the rotor is maximized. Service life
c. Turbine cylinder life status online monitoring system: The temperature and thermal stress of the cylinder are monitored during the operation of the unit (especially start-stop, variable load, etc.), so that the unit operates at a reasonable level to maximize the use of cylinders. life.
The functions that the entire system can achieve are:
a. Guide operation personnel to perform reasonable operations to achieve safety and efficiency;
b. Enable managers to understand the operation of the unit for a certain period of time;
c. Regularly evaluate the start-up and shutdown of the unit, run a reasonable assessment of the operation, and play a guiding role in the future operation and maintenance. For some places that do operate in accordance with the scheduling requirements and unreasonable, they can reflect to the dispatcher according to the operation curve and analysis report, in order to change The scheduling curve makes the operation more reasonable and economical.
1.2 The overall structure of the system design The system is a typical three-tier application, including the data layer, logic layer and presentation layer. Among them: The data layer uses SQLServer database to realize, mainly includes real-time database, historical database, abnormal data record database, start-up and shutdown process database, etc. The logic layer is a calculation program, it obtains data from the database, and the computer group starts and stops, The temperature field, stress value, life loss, and cumulative life loss of the rotor and cylinder when the load is changed, and the calculation result is saved in the database; the presentation layer is to display the interface into an ActiveX control and placed on the Web server. The client can use a web browser to view the temperature field and stress value of the rotor and cylinder when the unit is started or stopped or when the load is changed, and the life loss and cumulative life loss of the rotor and cylinder when each start and stop or load change. The overall structure of the system is shown in Figure 1.
2 Specific realization of system functions 2.1 Data layer implementation The data layer is stored on the database server and can be on the same computer as the computing server. It mainly stores data tables for collecting data, data tables that need to display data, and data of key data. Tables and data tables for exception data provide data for the computation and presentation layers.
2.2 The realization of the logic layer Modern stress analysis technology has been able to use a three-dimensional unsteady finite element method to analyze in detail the transient temperature distribution and stress of the rotor in the process of start-stop and variable load of steam turbine, and then determine according to the material and fatigue curve. Rotor life loss, but this exact analysis method can not meet the real-time operation requirements of the turbine in the actual operation of the power plant. For this purpose, a life loss monitoring system suitable for on-site use is composed of measuring point sensors, computers, and life analysis software. It is calculated in advance by the off-line turbine rotor finite element method to find out where the thermal stress is greatest and stress concentration. Coefficients, then on-line monitoring of the section with the largest stress, measuring the relevant parameters of the site, using a one-dimensional model for on-line stress calculation, and then using the stress concentration coefficient to modify the thermal stress, to obtain the corresponding thermal stress in the section at the moment Finally, the life loss is estimated from the fatigue curve of the material.
At present, there are three simplified formulas for on-line calculation of rotor thermal stress in China: one-dimensional analytical method, one-dimensional finite difference method, and control model method. The system uses a one-dimensional difference method for rotor thermal stress calculation [1]. The calculation program is stored on the calculation server and can complete functions such as data acquisition, stress calculation, life management, start-up instructions, and recall.
2.3 Presentation Layer Theory and System Implementation ActiveX technology is a technology that Microsoft provides to developers to integrate the computer desktop environment with the Internet and its numerous resources. It uses COM to allow components to interact in a network environment, regardless of the specific programming environment.
ActiveX includes both server-side and client-side technologies. Its main content is:
a. ActiveX controls: COM objects that are inserted into web pages and containers that support ActiveX.
b. ActiveX documents: Used to browse compound documents (non-HTML documents) such as Word documents, Excel documents, etc. in Web browsers and other ActiveX-enabled containers.
c. ActiveX Server Framework: Provides a series of functions and encapsulation classes for various aspects of Web server application design, such as server filters, HTML data flow control, and so on.
In layman's terms, ActiveX technology is to compile some interface programs or program blocks that need to be browsed according to the requirements of ActiveX. These programs are usually stored in the server as exe, dll, and OCX files. The biggest difference from other types of controls is that ActiveX controls can be embedded in Web pages. When a user accesses a Web page that has an ActiveX control embedded in it, ActiveX controls are downloaded to the client to run [2].
The development of ActiveX controls is not limited by language. Using VC, VB, Delphi, C++Builder can be used to develop ActiveX, and each has its own advantages and disadvantages. This article recommends using C++
Builder develops ActiveX controls, using C + + Builder can develop a control called ActiveForm, it is actually an ActiveX control, but ActiveForm itself is an ActiveX control container, its development process and the development of ordinary C + + Builder application The program is basically the same.
Using ActiveX controls usually encounter the following problems:
a. Usually ActiveX controls are relatively large, so when the page is opened, the download speed will be slow. In order to increase the download speed of ActiveX controls, ActiveX controls can be compressed into a CAB format, which can greatly reduce the size of ActiveX controls and increase downloads. speed. In C++Builder, simply use the UseCABfilecompression option in the WebDeploymentOptions dialog box.
b. Because ActiveX has some security risks, during the first ActiveX download, the browser may prevent it from downloading. The security level of the client browser needs to be set to “noneâ€.
3 Application Examples The application of this method is described by taking the turbine rotor life management system of a power plant in Shanghai as an example. This system is the most important and typical part of the entire turbine life management system.
The data layer adopts SQLServer7.0, which stores the collected data such as operating parameters, as well as the data to be displayed calculated by the calculation layer, such as the thermal stress of the inner and outer walls, and the life loss of the start and stop of the rotor.
The calculation layer uses VC programming to calculate the temperature field and thermal stress of the rotor using the one-dimensional difference method mentioned above through the data collected in the data layer, so as to further calculate the life loss and cumulative life loss of each start and stop of the rotor. , and save the results of the calculation to the database of the data layer.
Then use C++Builder to make the interface to be displayed as an ActiveX control, and display the data to be visually displayed in the form of numbers, curves, and bar graphs. Since most of the data to be displayed are dynamic, the interface needs to be constantly refreshed. The data in the system is updated with a timer. The data is updated from the database through the ADO interface. The screen is filled with the background color to cover the previous content. Redraw later.
After using C++Builder to complete an ActiveX control, it is usually necessary to wrap the ActiveX control, that is, embed it into the HTML file [3]. Here, CiasslD and Codebase of the OCX must be provided. When the client browses this page, it will first look up the ClasslD in the local registry. If it exists and the version is not updated, you do not need to download it. Otherwise, this control will be searched and downloaded according to the path specified by Codebase. When adjusting the size and position of the ActiveX control interface, you can use Microsoft's tool Microsoft ActiveX ControlPad for visual adjustments. When you need to update a control, you only need to put the new version you have made in the directory where the control was previously located, and the client will download it again.
The web server uses Microsoft's lis (Internet Information Service) server to place ActiveX-embedded HTML files in the server's corresponding virtual directory.
The implementation method of the machine life management system overcomes the disadvantages of the previous presentation layer being difficult to achieve or the Web page downloading speed being slow. Practice has proved that the ActiveX control developed by this method is simple and practical, stable operation, has played a certain role in extending the life of the unit, and also has certain reference value for the development of other e-commerce, industrial monitoring systems.
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