Modeling And Simulation Of Hualong-1 Nuclear Power Secondary Circuit

In recent years,China's nuclear power industry has developed rapidly.With the construction of “Hualong 1”and the successful development of CAP1400,China has become another nuclear power country with independent three-generation nuclear power technology and whole industry chain after the United States,France and Russia.The design and operation control of Hualong I is more complex than that of the second generation nuclear power plant by combining the active and passive methods.Therefore,it is of great practical significance to deeply grasp the dynamic characteristics of the second loop of “Hualong 1” and to provide boundary basis for the design of the first loop.The main work and conclusions of this paper are as follows:(1)Using APROS simulation platform,the second loop simulation model of “Hualong 1” is established,and the operation parameters of the main nodes of the second loop under three steady-state operating conditions are checked.(2)On the basis of steady-state check,the model of relevant automatic control system is established,and the transient analysis under normal and emergency conditions is carried out.The simulation results show that the equipment in the secondary circuit can correctly respond to the load changes in the conventional and emergency conditions,and realize stable operation after off-design conditions.(3)The model of the classical over-speed protection control system and the over-speed protection control system of million kilowatt nuclear power steam turbine under the condition of 100% FP load rejection to power supply is established,and the advantages and disadvantages of the two kinds of over-speed protection systems are compared.The results show that the control strategy of over-speed protection for million kilowatt nuclear power steam turbine reduces the flying time and the maximum flying speed of the rotor,and greatly reduces the risk of over-speed of the rotor.(4)Based on the control strategy of over-speed protection for million kilowatt nuclear power steam turbine,the effects of different valve time constants and loss of power time of solenoid valves on the thermal-hydraulic transient process of the secondary circuit under the condition of 100% FP load rejection to power supply are studied.The results show that different valve time constants and electromagnetic valve power loss time have great influence on the steam turbine power generation system,while the influence on other secondary auxiliary systems can be neglected.The dynamic simulation model established in this paper can accurately simulate the dynamic characteristics of the second loop of “Hualong 1” and has good engineering application value.The transient analysis results have guiding significance for the optimization design and control of nuclear island.At the same time,the research results of over-speed protection strategy for load rejection steam turbine can be used for reference for the control and commissioning of other similar units.