高熔点物质与冷却剂相互作用的机理研究

Study on Mechanism of the Interaction Between Coolant and Melt With High Melting Point

高温熔融物与低温冷却剂间的相互作用是核反应堆严重事故下的重要现象,关于这一现象,国际上多年来开展了大量实验和数值研究。然而,熔融物与冷却剂热相互作用(FCI)的作用机理至今未能解明,数值模拟的分析结果同实验数据间仍存在较大差距。本研究通过建立中型熔融物与冷却剂相互作用实验台架,研究FCI影响因素及熔融物与冷却剂间的热相互作用机理。本文开展了以304不锈钢及钼铁为熔融物材料,水为冷却剂材料的热相互作用实验研究。该实验研究了高熔点物质质量、材料性质及冷却剂过冷度对热相互作用的影响,通过实验产物的形貌及尺寸分布分析,提出高熔点物质的凝固效应是决定相互作用强弱的重要机制,同时分析了在不同工况下的相互作用机理,为熔融物热能-机械能转化研究奠定基础。

The high temperature melt interacts with the low temperature coolant is the important phenomenon in nuclear reactor severe accident,which has been experimentally and numerically studied for many years.However,the mechanisms involved in the thermal interaction of coolant and melt have not been figured out so far and there still exists a broad gap between the simulated results and the experimental data.Therefore,a new facility for intermediate-scaled fuel coolant interaction（FCI）experiments has been set up,mainly focusing on the impact factors and thermal interaction mechanism of coolant and melt.In the present study,a series of tests using simulant materials（304SS or FeMo）have been carried out based on the new facility for FCI research.During the tests,the effects of initial mass,thermophysical properties of melt with high melting point and subcooling temeprature on thermal interaction have been studied.Based on the analysis of debris characteristics and size distribution,it has been determined that the solidification of melt with hight melting point is the significant impact factor which strongly influences the thermal interaction.Furthermore,interaction mechanisms have been discussed under different conditions.All the work is done for research on energy conversion process in the future.