热管堆固态堆芯三维核热力耦合方法与分析

Coupled Three-dimensional Neutronic/Thermal-mechanical Analysis of Heat Pipe Cooled Reactor Solid-state Core

有别于传统堆芯,热管冷却反应堆(简称热管堆)固态堆芯具有高温热膨胀效应,该特性产生了中子物理/热工/力学(简称核热力)相互耦合的效应。本文根据固态堆芯热膨胀反应性反馈机制与热管传热过程,建立固态堆芯三维动态几何的核热力耦合方法。应用核热力耦合方法,对KRUSTY热管堆进行稳态分析。结果表明,正常工况下,堆芯从冷态到热态变化过程中,核热力反应性反馈约为-850 pcm,其中堆芯热膨胀效应约占总反馈的90%。核热力耦合分析表明,热膨胀效应是固态堆芯负反馈与自稳调节的主导效应,但另一方面,显著的热应力将威胁堆芯完整性从而影响反应堆安全。在热管堆的设计和运行过程中应重点关注固态堆芯材料的力学性能。

The heat pipe cooled reactor solid-state core,which expands at high temperatures,distinguishes the heat pipe cooled reactor from the traditional reactor.This feature introduces the coupling effect of neutronic/thermal-mechanic(N/T-M).The coupled neutronic,thermal-mechanical,and heat pipe heat transfer(N/T-M/HP)strategy was developed.The coupled N/T-M/HP method was applied to the KRUSTY heat pipe cooled reactor.A steady-state normal operating case was simulated to show the redundancy and reliability of the solid-state core.For the normal case,the thermal-mechanical feedback is about-850 pcm from the cold state to the hot state.Analyses show that thermal expansion dominates the inherent safety and self-regulation,and yet threatens the core mechanical safety.Therefore,the mechanical performance of the solid-state core should be carefully analyzed during design and operation.