Materials issues in coal-fired combined cycle power generation systems: Laboratory versus plant testing

The successful development of coal-fired combined cycle power generation systems require that all component parts are manufactured from appropriate materials and that these materials give predictable in-service performance. High temperature corrosion resulting from coal-derived particulates, deposition and gaseous species, is potentially life limiting for many components in these systems. Realistic laboratory test methods are outlined for gasifier and gas turbine environments and these have been combined with a materials assessment method based on accurate dimensional metrology. Such tests have allowed the production of models of materials performance as well as accurate comparisons between laboratory and plant derived data, These initial models predict the performance of materials well in the gas turbine environment, but tend to under-predict the damage observed in real gasifier environments. The differences found between materials performances observed in re:al plant environments and predicted from the models are being used to optimise the on-going model development and laboratory testing.