More flexible power plants

Conventional power plants are being started up and shut down more and more often in order to maintain power in the grid when energy feed from renewables fluctuates. This places the plant components under great stress, as they have to withstand temperature differences of several hundred degrees within periods as short as one hour. Up to now, there has not been any theoretical and experimental basis in order to calculate these stresses and their effects – which is where the THERRI research project comes in (THERRI stands for the German „thermal fatigue crack growth“).

Besides TÜV NORD GROUP, the departments of structural mechanics and technical thermodynamics at the University of Rostock, the research centre Forschungszentrum Jülich and the hard coal power plant in Rostock operated by KNG Kraftwerks- und Netzgesellschaft are also partners in the project.

The aim of the project is to make operation of thermal power plants much more flexible than is possible with the current calculation norms. Both inspection and maintenance should be orientated towards the new demands created by strongly fluctuating electricity generation. Comprehensive material trials at the research institutions in Rostock and Jülich form the basis of the project. During the trials, fracture mechanical characteristic values are determined in relation to the influence of the particular medium used and measurements of crack growth are taken under conditions which are similar to those found in everyday plant operation. The trials are accompanied by detailed simulation calculations (FEM, XFEM) of selected components of the Rostock power plant which are particularly susceptible to fatigue.

The research project is making an important contribution to improved cost-effectiveness of residual power plants and therefore to reduction of the cost of the energy changeover to renewables for energy suppliers and industrial companies. The Federal Ministry for Economic Affairs and Energy is funding the project.