Research On The Steam Generator Thermal-hydraulic Characteristics Impact Of Tube Rupture

Steam generator is a critical heat exchanger between the primary and secondary loop inthe pressurized water reactor nuclear power plant. It’s important part of nuclear power plantcan be safe and reliable operation. Nuclear power plant operation experience demonstrate thatSteam generator U-tube Rupture is one of the most frequently occurring accidents. When thesteam generator tube rupture occurs, resulting in the release of radioactive material into theatmosphere, pollute the environment; if the operator is not able to timely intervention of theaccident, the upgrade may result in an accident, causing melting heap danger. Therefore, thesteam generator tube rupture accident simulation, operating personnel to ensure timelyintervention in the prevention of a major nuclear accident is important.When the steam generator tube rupture occurs, a secondary side refrigerant flow, thenext state of normal operation, the secondary fluid mass, energy and momentum changed.Therefore, the steam generator tube rupture accident research, must be in good condition thesteam generator tube, operating on the basis of normal. In this paper, Daya Bay Nuclearsteam generator as the research object, the first state to establish a complete dynamicmathematical model of a steam generator, and on this basis, based on the lumped parametermethod to establish a one-dimensional drift tube rupture flow dynamic mathematical model.Using SIMULINK simulation module of the steam generator steady-state and dynamiccalculations, and different conditions, different locations and different leak flow tube ruptureaccident simulation.The steam generator at100%,70%,50%and30%levels of four kinds of conditions, thesteady-state operation results and the actual operating parameters controlled maximum errorof5%or less.100%of the steam generator consists of a step down to70%of the workingconditions working conditions, four kinds of working conditions the coolant temperature stepdecrease of5%with the coolant flow step increase of10%three kinds of disturbance dynamicsimulation, simulation results show that: Casual Add a steam generator with disturbances ofthe parameters have shown a reasonable trend.100%of the steam generator leaks positions different conditions of the four conditions(100%,70%,50%,30%) the same position and the same disclosure conditions different fromthe same for leaks leak flow simulation, the simulation results show that: when a leak occurs, the main parameters of the steam generator curve trend basically the same, but the response isdifferent amplitudes. When a leak occurs, with the primary fluid into the secondary side, thesecondary side pressure overall upward trend; steam production, vapor quality ratio and a sideoutlet temperature is decreased; water level is manifested in increased and then decreased, andultimately stabilize the water level in the vicinity before the accident.In summary, the successful application of this paper drift flow theory dynamic of steamgenerator tube rupture model, the study provides theoretical support for the steam generatortube rupture accident analysis.