热管反应堆堆芯缩比模块瞬态特性分析

热管堆具有长寿期、高可靠性等优势，是当下空间核反应堆的研究焦点之一。为研究热管堆瞬态过程中的核热耦合现象，本文基于半物理仿真技术，搭建了针对热管反应堆堆芯缩比模块的核热耦合实验平台，通过实验模块测量了堆芯缩比模块的温度分布，在仿真模块中基于点堆模型计算了输出功率随时间的变化情况。通过耦合实验模块和仿真模块，探索了瞬态条件下堆芯缩比模块核热耦合特性，分析了引入不同初始反应性时堆芯温度、加热功率和剩余反应性的瞬态演变过程，揭示了系统热容量造成的温度迟滞变化效应，即热惯性现象。结果表明，堆芯缩比模块的热惯性随引入的初始反应性的增大及初始功率水平的增加而减小，且与基体材料的热扩散率呈反比。

Analysis of Transient Characteristic of Heat Pipe Reactor Core Scaled Model

Heat pipe reactor has the advantages of long life and high reliability, which is one of the research focuses of space nuclear reactor.In order to study neutronics and thermal-hydraulics coupling phenomenon in the transient process, based on the semi-physical simulation technology, experiment platform of neutronics and thermal-hydraulics coupling was set up in view of the heat pipe reactor core scaled model. The temperature distribution of the core scaled model was measured by the experiment module, and the output power was calculated by the simulation module. The transient response characteristics of core scaled model was explored through the experiment module and the simulation module. The transient change process of temperature, power and excess reactivity with the different initial reactivity insertions was studied, which revealed the temperature hysteresis characteristics of system due to the capability of heat capacity, namely the phenomenon of thermal inertia. The results show that the thermal inertia of the core scaled model decreases with the increase of the initial reactivity and the initial power level and is inversely proportional to the thermal diffusivity of the substrate.