Hybrid Modelling-based Economic Performance Diagnosis for Nuclear Second-Loop System

Nuclear power is gradually rising in China as a clean, efficient, safe and reliable power generation energy source. Most of the major losses in the relative internal efficiency of the second circuit of the nuclear power unit originate from the nuclear turbine stage group and reheat heating process. For the energy loss problem occurring in the nuclear turbine stage group and return heaters, this paper establishes a variable operating condition regression model of the nuclear turbine stage group based on a hybrid modelling method combining mechanism modelling and data modelling, and verifies the performance diagnosis method for the high-pressure cylinder stage group 1 and stage group 2, which belongs to the early fault diagnosis and provides guidance for the guidance for subsequent operation optimization.