Refining and enhancing the steam cycle power generation process is essential to provide more efficient and cleaner power for the future.But keeping advanced technology operational in a cost-effective way sets the pace of change, writes Philippe Claeys.
Supercritical (SC) power stations are becoming more commonplace and the technology behind them is quickly developing into the norm for new projects in industrialized countries across the world.
In the past few years, new SC plants in China, India, Russia and South Africa have also come on line. Technological developments are expected to continue, with more and more new plants employing ultra-supercritical (USC) technology. Currently, there are USC plants in operation in Germany, Denmark and Japan, with a number of units under construction in China and India.
SC and USC technology improves thermal efficiency by converting water directly to steam, without the boiling phase. In this way, higher pressures and temperatures can improve the efficiency of the thermal cycle. Supercritical heating occurs around 221 bar, in comparison to conventional subcritical stations, which usually operate between 150-180 bar.
USC plants increase these pressures even further, resulting in improved efficiency in steam generation and a reduction in fuel consumption at the start of the combustion process.
Up to now, limitations in metallurgy have curbed the development of SC and USC power plants. However, companies such as Tyco Valves & Controls are investing in the research of nickel and chrome super alloys to engineer more robust components that can withstand higher operating pressures and temperatures. More……