Thermal analysis of cooled supercritical steam turbine components

This paper describes thermal analysis methodology results for the supercritical steam turbines. The analysis presented here concerns the external cooling of the turbine components. Due to the supercritical parameters of the live steam, the inlet areas of the high and intermediate pressure parts are exposed to the steam at high temperature level. The design solutions applied to the turbines so far aim to protect the inlet areas. Basic solution incorporate protective screens, which are made of a material more resistant to the high temperature than the rest of the components. Additional protection is provided by the external cooling. The applications of both methods described above allow to increase the live steam temperature. The conducted analysis determined the temperature field in the steam, which cools the rotor, as well as the distribution of the temperature and stresses in the rotor. The obtained results were then applied to the investigations concerning the durability of the rotor.