Germany has embarked on a new testing regime on power plant components to reflect more frequent start-up and shutdown cycles with their associated stresses.
The State of North Rhine Westphalia (NRW) in Germany has commissioned TÜV Rheinland Werkstoffprüfung (materials testing department) with the development, production and trial operation of testing equipment used to characterise materials used in flexible power plants. “The new technology enables long-term testing of materials in power plant operation,” said Dr Ansgar Kranz, authorised officer in the TÜV Rheinland material testing department. “This results in improved calculation models for the prediction of the remaining lifetime of flexible power plants,” he said.
To ensure constant network stability, conventional power plants must react more flexibly to offset irregularities from the growing supply of electrical power from renewable power sources. As a result, gas and coal-fired power stations are no longer continuously operating in basic mode, but rather go through the process of start-up and shutdown more frequently. Consequently, the number and extent of load changes increase and components are exposed to extreme temperature fluctuations more often, especially in the water-steam cycle. Therefore, this is where the creep-fatigue-mechanism should be explored. For this purpose, a cost-effective testing technology is in development to measure the long-term impact of this mechanism on materials.
“Such a precise assessment of the expected lifetime of critical components is urgently needed for safety reasons and to determine the economic viability of a plant,” says Dr. Ansgar Kranz, who is working with partners RWE Generation SE and StandZeit GmbH to carry out the project on behalf of the NRW Ministry for Innovation, Science and Research (MWIF). As cooperation partners, RWE has provided power plant data, while StandZeit has lent its support in the manufacture and integration of measuring and control technology.