Концепція модернізації проточної частини парової турбіни серії K-300 для переходу на ультра-суперкритичні параметри пари

A concept of the K-300 series steam turbine flow part for transition to operation with ultra-supercritical initial steam parameters is described in the paper. A loop scheme with two-tier blades of the steam turbine flow part has been proposed for the first time in the world. The main turbine parameters, such as pressure and temperature at the inlet to the high-pressure cylinder (HPC), temperature of the intermediate superheat, temperature and mass flow rate at the outlet from the low-pressure cylinder, were selected. The turbine is designed to operate with initial parameters of fresh steam at a pressure of 35 MPa and a temperature of 700 °C with intermediate steam superheating to 700 °C. The flow part was divided into cylinders with a preliminary estimate of the number of HPC and intermediate-pressure cylinder (IPC) stages and determination of their axial dimensions. The feasibility of using a loop scheme with two-tier blades in HPC and IPC flow parts was substantiated, and thermal drop in stages were determined. The main geometric characteristics of the HPC and IPC stages were determined taking into account the loop scheme and two-tier blades. A three-dimensional model was developed and the flow in the turbine flow parts was calculated. The obtained results show a high internal efficiency of the new HPC and IPC flow parts of 94.18% and 94.5%, respectively. This will increase the efficiency of the power plant up to 49.2% and provide an increase in capacity by 80.64 MW.