Simulation Modeling Of Operating Characteristics And Control Strategy Research Of Condenser In Nuclear Power Plant

As the proportion of nuclear power generation has increased year by year,the demand for integrating nuclear power plants into the power grid for peak shaving has also increased.When nuclear power plants participate in power grid peak shaving,the safe operation of various equipment is particularly important.The condenser is one of the important auxiliary machines in the nuclear power plant.Its normal operation affects the working efficiency of the steam turbine unit and the safe of the entire nuclear power plant.Therefore,it is very necessary to effectively control the pressure of the condenser.At present,although domestic research on condensers is relatively mature,research on condensers in specific nuclear power plants is still relatively limited.This paper takes the condenser of the 900 MW unit of Daya Bay Nuclear Power Plant as the research object,establishes a lumped parameter model of sub-steps,and tries to improve the condenser pressure control system by using more mature intelligent control algorithms.This paper is introduced the structure,working principle and performance indicators of the condenser that affect the operating characteristics of the condenser,and then derives the steadystate mathematical model based on the heat transfer characteristics.Based on the actual design parameters of the Daya Bay Nuclear Power Plant,the characteristics of the steady-state are simulated and calculated.The calculated results are more consistent with the actual operating data of the reference object.Based on the equations of conservation of mass and energy,the lumped parameter method is used to establish the dynamic mathematical model of condenser heat transfer,and the heat transfer characteristics of each link are expressed by differential equations.The dynamic mathematical model of condenser established in this paper is included the mathematical model of cooling water disturbance response,the mathematical model of steam load disturbance response and the mathematical model of condenser pressure disturbance response.On the Matlab/Simulink simulation platform,the real-time simulation of the dynamic characteristics of the model proved that the mathematical model of the built condenser can well reflect the characteristics of the actual nuclear power plant operation,and the error of the calculation results is small.The model is reliable and effective.We can carry out follow-up related research work on this model.Predictive control is an advanced control algorithm suitable for process control.According to the heat transfer hysteresis characteristics of the condenser,a dynamic matrix predictive controller for condenser pressure is designed.Aiming at the disadvantage that the traditional PID controller cannot tune parameters online in real time,the fuzzy RBF neural network in the intelligent algorithm is selected,and the fuzzy RBF neural network controller and the adaptive fuzzy neural network controller are designed.The verification is carried out when the steam load changes step by step.The results show that the control effect of the fuzzy RBF neural network PID controller is the most ideal,the adjustment time is almost short,and the overshoot is small.The control effect of the fuzzy RBF neural network PID controller is second,and the control effect of the dynamic matrix predictive controller is slightly worse than the above two intelligent controllers.Aiming at the situation of large load fluctuation,this paper is introduced the idea of coordinated control based on the original control strategy,and designs a coordinated control system for condenser pressure in nuclear power plants.The coordinated control system can significantly improve the dynamic characteristics and control performance of the system.The research results of this paper have certain theoretical guiding significance and value for engineering practice,and can provide experience and reference for subsequent related research,and lay a good foundation for the study of condenser operating characteristics.