Design And Online Simulation Of Level Control System For Steam Generator

Safety is the foundation of the existence and development of nuclear power station. Steam Generator(SG) is the key equipment connecting the primary circuit and secondary circuit, used to transfer the heat which the coolant brings out from the reactor core to the secondary circuit. So it’s very important to control the SG water level in a reasonable position. Nonlinearity, high complexity, phenomenon of "expansion" and "contraction", and the impact of various factors have always made water level control of SG a serious puzzle.This paper firstly introduces the characteristics of automation control in nuclear power station and the importance of water level control of SG. Elaborating the difficulties in water level measurement and control, factors that affect the water level, and system control method of SG water level. Then giving the design of SG’s water level regulating system in a way of PID cascade. In addition, modeling the process system, establishing the mathematical models of the control object(the SG’s water level).Next elaborating online simulation system’s structure and key technologies based on the real-time data, including system hardware configuration, virtual DCS and simulation, interactive accomplishment between systems and real-time data, etc. And based on the mathematical model,conducting experiments on system simulation, then according to the Nichols chart and simulation results,do some adjustment to the PID Parameter to make it work in a proper way. Finally, based on the security incident caused by a valve failure of steam condenser discharge on the Ling Ao Unit 3 Nuclear Power Station, the paper do certain online simulation on the transient analysis and real-time data,to verify the fidelity of the online simulation system and process trend of the transient development.