(ultra) Supercritical Thermal Power Units Of Steel Database Development And Its Application

With the energy crisis and the pollution of the environment global problems increasing, Ultra-supercritical (USC) fossil power plant,as the most mature and commercial technology at present,which has realized commercial operation, will have broad prospects in the coming decades. The application of this technology has become an effective way to achieve energy-saving and emission reduction in China.In this paper,the present situation and development trend of ultra-supercritical technology in the world are briefly introduced. And the development and application of advanced heat-resistant steels are clarified as the most important foundation for the development of USC power plants. The reasonable design and reliable operation of the USC power plant are severely influenced in our country due to the lag of domestic advanced heat resistant steel technology, the lack of sufficient basic data and experience of the material properties, the dispersion of the data and imperfect of the data sharing mechanism. The necessity and feasibility of developing domestic database of steel property for USC power plants are analyzed in this paper.Thanks to the development of computer technology and materials technology, the database related technologies has become an important branch of material science. The author used the Visual Basic 6.0 as the main tool and SQL Server 2000 as the backstage database to develop the property-database for steels used for USC power plants. The basic functions of the database are also briefly introduced in this paper. Based on Client/Server network structure, the fundamental functions of this system include data browse, inquiry, input, update, backup, drawing, comparative analysis, remote communication and so on. The source code of developed software is of 11089 lines and 1115 data record of steel properties had been input.The author comprehensively reviewed the properties of some advanced boiler steels for USC such as T/P92, T/P122, S30432 (Super304H), S31042 (HR3C) and 9Cr3W3Co by using our database. The creep rupture strength, corrosion-resistance and conventional strength of these steels and their welding parts were carefully compared. The isothermal curve method and Larson-Miller method were applied to reasonably extrapolate creep rupture strengths of these steels after 105 hours service. Meanwhile, allowable stress of these steel tubes and pipes and associated engineering concerns were also discussed.Finally, the creep and stress-rupture test in tension, the tensile testing at elevated temperature, the steam corrosion, ash corrosion test technology and the extrapolation method of creep rupture data in our country are discussed. The major cause of data dispersivity is analyzed in this paper. It proposed that the development and continuous improvement of "the property-database for steels used for USC power plants" is of great strategic significance, not only for the study and application of USC power plants, but also for the development and localization of entire heat resistant steel areas.