Component test facility for a 700 °C power plant (Comtes700)
The objective of Comtes700 was a test of components for the 700 °C power plant technology. A test facility of steam generator components up to a wall thickness of 50 mm was erected in an existing power plant. A partial steam flow from the host plant was heated up to 700 °C and operated for 22 400 hours. Compared to ferritic components, machining of nickel-based components lasted a minimum of four times longer. Maximum grain sizes in semi-finished products were achieved by a modified heat treatment. After adjustment of testing technology, overlaps of alloy 617B tubes were avoided.... Evaporator materials functioned satisfactorily during operation. Updated material properties and reduced mechanical loads restricted the reliability statement. Superheater materials only failed once in a dissimilar weld. Some superheater materials may not reach a lifetime of 200 000 hours due to fireside corrosion. Thick-walled components from 30 to 50 mm in wall thickness displayed a susceptibility to stress relaxation cracking in welds. Additional stresses were caused by two-phase flow and insufficient design of spray attemperator. A solution for the workshop and repair welds was to conduct different heat treatment procedures. Valves functioned satisfactorily but after dismantling some internal cracks were found which could be avoided by design changes. Steam parameter measurements were proved. Non-destructive testing for initial and periodic inspection was developed during the project, but without having a relevant acceptance criterion. The component test was designed, manufactured, erected and operated, but it revealed challenges which were partly solved. Additional research activities are necessary before construction and operation of a 700 °C power plant in the near future.
- Corporate author(s): Directorate-General for Research and Innovation (European Commission)
- Personal author(s): Ullrich, C; Polenz, S; Foß, K; Stolzenberger, Christian; Gierschner, G; Klauke, F; Rossberger, D; Krogh, O; Schmidt, G; Möbius, A; Tak, K. G; Billard, P; Ghiribelli, L; Madsen, J. L; Mohrmann, R; Huysmans, S; Hölzel, C; Jensen, S. A; Edelmann, H Themes: Industrial research and development, Basic metals industry, steel industry
- Subject: coal, industrial equipment, materials technology, power plant, research report, testing