State-of-the-art ultra-supercritical variable pressure once-through boiler with improved dynamic characteristics and reliability by reducing mass velocity of furnace wall

Abstract

The ultra-supercritical variable pressure operation once-through boiler with vertical furnace waterwall can be expected to improve load change characteristics and reliability by reducing the mass velocity of furnace wall tubes. On the other hand, when the mass velocity is lowered, there is a concern to suppress excessive temperature rise of furnace wall tubes due to heat transfer deterioration or departure from nucleate boiling. We tackled these issues and succeeded in improving the load change characteristics and reliability of the boiler. This report introduces the analysis/experiment and design technique applied to solve the problems, and the latest ultra-supercritical variable pressure once-through boiler put on the market using them.