Investigation of the thermal characteristics of condensers in nuclear power plant by simulation with zoning model

Abstract

For the simulation of condensers in a nuclear power plant, in general two approaches can be used, the lumped parameter model and the numerical method. The lumped parameter method is simple and rapid thus widely used in real-time simulations. The numerical method can provide more detailed information and achieve higher accuracy in comparison with the lumped model, but increases implementation complexity and computational cost. In real-time simulations of nuclear power plants, to solve the problem of uneven distribution of thermal parameters in condensers, which is not feasible for the lumped parameter method, a new method for the simulation of condensers was proposed in this research. The method divides the shell side and tube side of the condenser to different zones, and apply the lumped parameter method in each zone. The mass flow between zones in the model are calculated as flow nets. A posteriori testing has been conducted for the proposed model, thermal parameters in each zone are simulated and the results are verified with experimental benchmark data from an actual condenser. The comparison confirms that the proposed method is highly accurate not only in different steady state operations, the responses of each zone in dynamic-state operations are consistent with theoretical analyses as well. Unlike previous works, the model made it possible to get the distributions of thermal parameters in a condenser through real-time simulations on the actual working processes.