Design and thermal-hydraulic analysis of supercritical steam generator in high-temperature gas-cooled reactor

The pressure and temperature of water in the steam generator in high-temperature gas-cooled reactor power plant can be increased to supercritical as the HTR-PM reactor, which was built by the Institute of Nuclear and New Energy Technology of Tsinghua University in China, provides helium up to 750degC and the design and fabrication of supercritical unit in China are sophisticated. Ten 252.9 MW(th) supercritical steam generators, which are exactly the same, including a main heating section and a reheating section, are designed to work with ten HTR-PM reactors and one supercritical turbine unit, and the thermal and hydraulic characteristics are analyzed. The supercritical steam generator is composed of 19 5-layer helically coiled tube components in both these two sections. The tube size, the component diameter and the tube sheet are quite similar with HTR-PM subcritical steam generator, while the total tube height is 6 m higher, so the damping devices might be necessary to be installed at the bottom of the supercritical steam generator to avoid swaying and vibration. The heat transfer coefficient of supercritical pressure water has a peak in the main heating section without any abrupt variation of the inside and outside wall temperatures. (author)