Abstract:At present, the winter heating system in northern China mainly relies on coal-fired boilers,which is one of the air pollution sources there. As clean energy, nuclear energy can reduce air pollutant emissions and thus can be considered to replace the traditional coal-fired boiler heating system. A more energy-efficient winter heating operation mode, such as intermittent heating which is a common mode at the beginning and end of the heating season, has always been one of the research topics in the heating research area. This study aims to explore the feasibility of intermittent heating operation mode for nuclear heating. Based on the MATLAB/Simulink software platform and using DeST software, the thorough heating system models of the 49-2 pool type heating reactor was established and verified by experimental data, including core models, circuit models, thermal disturbance models and other important models. Then, through simulation, the changes of reactor reactivity and circuit temperatures in intermittent heating model were studied in detail. An intermittent heating operation mode that is suitable for the 49-2 pool type heating reactor is proposed. It takes advantage of the low heat load of the buildings during the day to ensure that the hourly temperature indoor meets its design requirements, and in the meantime can reducing the temperature difference between day and night, improving thermal comfort as well as saving operating costs. Intermittent heating mode is feasible for the 49-2 pool type heating reactor.