System Simulation for 700°C Class High Temperature Ultra Supercritical Steam Power Plant with Cooling Technology

High efficiency pulverized coal power plant technology, especially the system simulation and design for high temperature steam turbines, is discussed. It is believed that a 700-deg C class steam turbine system will be realized with Ni-based super alloys. The super alloys are more expensive than current materials like 12%Cr steels though its high temperature strength is excellent. In addition, the size of the alloys is limited for the current design. Therefore, it is necessary to study new design concept to utilize the super alloys. The key concept is the optimized combination of steam turbine cooling and the super alloys. In this paper, the development of a simulation technique and the application of the gas turbine cooling technique to the high temperature steam turbine design are discussed. The simulation software is specially designed to integrate the entire system simulation and the detailed design of components to evaluate the system performance with the cooled steam turbines. The results of calculation are assessed by taking the other calculations with a similar steam condition into consideration.