【摘要】 熔盐堆仿真试验装置的堆舱内传热过程分析是熔盐堆热工水力分析中的重要环节，堆舱内的空气传热过程复杂，空气辐射传热、自然对流和导热三种换热方式同时出现并相互耦合在一起。为了更详细地研究熔盐堆堆舱内的空气传热以及验证计算流体（Computational Fluid Dynamic,CFD）方法应用于熔盐堆堆舱热分析的准确性，本文以钍基熔盐堆缩比仿真试验装置（简称“仿真堆”）为研究对象，装置的总加热功率为370 kW，分别建立该试验装置上/下堆舱的三维计算模型，运用ANSYS软件对仿真堆上/下堆舱传热进行了数值模拟分析和实验验证。模拟结果表明，上/下堆舱内的空气温度分布比较均匀，上堆舱内存在较多涡流；仿真堆压力容器壁面的热量主要是通过辐射传递到下堆舱内，且随着压力容器壁面温度的升高，辐射和对流的换热功率的增加速率逐渐增大，但辐射换热功率增加更快；实验验证发现：上/下堆舱内所选温度测点的CFD计算值与实验值符合较好，两者的最大偏差分别为9.6%和4.3%，满足工程计算的误差要求，验证了CFD分析方法用于熔盐堆堆舱热分析的准确性和可行性，为2 MW液态钍基熔盐实验堆安全评审中所提出的CFD软件适用性提供了论证依据，为后续百兆瓦级熔盐堆堆舱的热工水力分析提供参考依据。更多还原

【Abstract】 [Background] Molten salt pebble-bed reactor is a new type of reactor with a complicated heat transfer process in the reactor cavity, the verification of the reliability and accuracy for the Computational Fluid Dynamics(CFD) software applied to the heat transfer process analysis in the reactor cavity of molten salt reactor(MSR) is crucial. Therefore, a simulated experimental facility for 2 MWt solid fuel Thorium Molten Salt Reactor(simulated reactor) is set up, and the experimental data from different experiment conditions are verified by FLUENT software of CFD. [Purpose] The study aims to understand the heat transfer process in the reactor cavity of MSR in detail, and to validate the reliability and accuracy of CFD method for the heat analysis for the reactor silo of MSR. [Methods] First, a one-fourth scale three-dimensional calculation model for the reactor cavity of simulated MSR was established, meshed the calculation model and performed the mesh independence analysis. Subsequently, based on the experimental data, a UDF(User-Defined Function) was programmed to define the temperature boundary condition at the interface between the upper and lower reactor cavity models. Finally, the heat transfer process in the upper and lower reactor cavity of simulated reactor was analyzed using the CFD method and verified against the experiment data under 5 experimental conditions. [Results] The calculation results indicate that the temperature distribution of the air in the upper and lower reactor cavity is fairly uniform, with many eddy zones present in the upper reactor cavity. As the wall temperature of the pressure vessel increases, the increase rate of heat transfer power due to both radiation and convection gradually accelerates, with radiation heat transfer power increasing more rapidly. The calculated values obtained by CFD are almost consistent with the experimental values, the largest deviations for upper and lower reactor cavity are 9.6% and 4.3%, respectively. Consequently, the CFD verification results for all temperature measuring points are fairly ideal and meet the deviation tolerances for engineering calculations. [Conclusions] This study verifies the accuracy of CFD analysis method when applied to the heat analysis for the reactor cavity of molten salt reactor, providing an important reference for subsequent thermal hydraulic analysis of the reactor cavity of a 100 MW molten salt reactor.更多还原