一种低温堆核电站的动态数学模型

Dynamic mathematical model of low-temperature reactor of nuclear power plant

针对研发的采用一体化布置、全功率自然循环的低温核反应堆电站,建立了一个可用于大功率运行范围控制系统仿真的动态数学模型。模型采用了六组缓发中子动态方程(考虑了慢化剂温度和燃料温度反应性负反馈)、集中参数的堆芯传热模型以及自然循环流动模型,重点考虑了主回路自然循环对堆芯内冷却剂和燃料棒之间的传热系数、主换热器换热系数、主回路时间常数的影响。仿真结果表明,模型能够正确反映低温堆核电站的主要动态特性,可用于电站控制系统仿真。

This paper discusses the considerations in the modeling of a new type of nuclear power plant for its control system simulation in a wide power range. Using low-temperature reactor with many advanced features such as integrative disposition, natural circulation, this new type of nuclear power plant is developed by INET of Tsinghua University. Modeling methods such as point kinetic model with six-group delayed neutrons （considering the coolant temperature and fuel temperature negative feedback）, lumped reactor diathermanous model and natural circulation model are used. Special attention was paid to the natural circulation characteristics of primary loop, which affects diathermanous coefficient between the coolant and the fuel, the heat exchange coefficient of the primary heat exchanger and the time constant of primary loop. Simulation results showed that the model is accurate enough to describe the main dynamic characteristics and could be used in the simulation of control system.