The Research Of Primary Loop Model Of Advanced Pressurized Water Reactor Based On Modular Modeling

Nuclear power has no pollution,large capacity of single unit,close to the load center other advantages,which is the best choice for the Guarantee of our country energy supply.It is necessary to model the nuclear power unit,especially its one-loop system,to help study the network coordination of nuclear power and power grid,and ensure the stable operation of nuclear power in the power grid.AP1000,which is the representative of the advanced PWR nuclear power,has a loop variable,non-linear,difficult to obtain parameters and other characteristics.At present,the simulation model of nuclear power plant is mainly for the second generation or the second generation and half unit,and most of them are designed for the independent equipment and system.It is difficult to combine with the power system.Therefore,the research of model of the nuclear power is important for the protection of China's power grid and the energy supply of China.Based on a wide range of literature review,this paper deeply studies the operating characteristics of nuclear power plant.Based on the research and operatation of several nuclear power projects,this paper adopts a modular modeling method to establish a one-loop model of advanced PWR nuclear power unit.The main contents and achievements of this paper are as follows(1)The modular modeling method theory is analyzed and the primary loop of the advanced PWR nuclear power unit is divided into core and coolant system model,the coolant main pump flow calculation model.(2)The change of reactivity coefficient for neutron reactors is influenced by many factors.It is a typical multi-input,single-output nonlinear model,and the coupling between them is difficult to be modeled by lumped parameter method.The fuel temperature coefficient and the coolant temperature coefficient model is established by BP network.The results show that the neutron reactivity model based on BP neural network can accurately reflect the influence of various factors on neutron reactivity.(3)Taking the temperature feedback,the reactor and the coolant system model are set up,and the dynamic response characteristics of the reactor under the disturbance of the coolant temperature are simulated and analyzed.The results show that the reactor can maintain its stability under external small disturbance due to negative feedback effect such as its own temperature effect.(4)The third generation of advanced pressurized water reactor nuclear power unit coolant main pump using shielded motor,the main pump inertia is small,running the friction torque can not be ignored.Considering the friction torque during operation,the calculation model of the main pump flow of the coolant suitable for the third generation nuclear power unit is established.The dynamic response characteristics of the main pump under the voltage and frequency fluctuation of the grid are simulated and analyzed.The overall primary loop model of the advanced pressurized water reactor nuclear power plant is established.The steady-state running characteristics are analyzed and compared with the actual design parameters..Finally,the response characteristics of the output of a nuclear power plant in the power grid frequency disturbance are analyzed.