Research On Interface Characteristics Of Liquid Lead-bismuth Eutectic Flow

Accelerator Driven subcritical System (ADS) is the concrete manifestation of the principle of Partitioning and Transmutation, is the terminal Processing equipment of Nuclear waste, is the only way for Sustainable development of the nuclear power plant. Liquid lead-bismuth eutectic (LBE) is important spallation target materials and candidate coolant materials in accelerator driven subcritical system, its thermal hydraulic characteristics are keys to understand ADS research and development. Interface Characteristics of Liquid Lead-bismuth Eutectic Flow have important effect on ADS, A series of thermal and mechanical phenomena related to Lead-bismuth Eutectic Flow interface characteristics, such as thermal stratification, flow induced vibration, are the research hot spot. Research on Interface Characteristics of Liquid Lead-bismuth Eutectic Flow will promote the ADS system further perfectly.By the calculation of scientific laws as well as fitting other scholars’experimental results, we tried to obtain the above thermodynamics physical properties. By the calculation, we got formula about characteristic temperatures, density, specific heat, viscosity and thermal conductivity of liquid lead-bismuth eutectic. And by fitting other scholars’experimental results, we got the fitting formula. Finally, by the contrast analysis, we found that the fitting formula and calculation formula agree well, and fitting formula more approaches the experimental value with a high accuracy, whose differential deviation is not over1%. And NCEPU-LBETP program bases on FORTRAN Language, realizes the calculation of characteristic temperatures, density, specific heat, viscosity and thermal conductivity of liquid lead-bismuth eutectic, and the calculating step sequence simplified greatly, the accuracy is improved.The emergence of Liquid lead-bismuth eutectic thermal stratification bring hidden dangers to the safe operation of the system, in order to ensure the safety of the ADS system, this paper presents the numerical simulation for thermal stratification of ADS LBE loop by using Computational Fluid Dynamics(CFD) method. The result shows that:With time, the thermal stratification phenomena of LBE heating section be stable constantly; fluid flow velocity, heating power have a significant impact on thermal stratification; the most serious area of thermal stratification exists in heating zone and the hierarchical state of thermal stratification is different; when the temperature difference in the loop is bigger, the velocity increase, the thermal stratification is more obvious; when the diameter is larger, velocity is reduced, the thermal stratification is not obvious; when the velocity is low, thermal stratification of local area tends to disappear; when the velocity is big, the temperature increase in maximum temperature difference of cross section; the counter-measure be given at the end. The mechanism of flow induced vibration of tube bundle in heat exchanger be analyzed, and on this basis, the judgment and vibration-proof measures are given.Finally, a design of LBE circulation loop and an experiment plan are proposed combine with actual conditions. This research work for subsequent lead bismuth test bench construction and lead bismuth circulation flow heat transfer experiment laid the foundation.