首页|Effects of temperature and inlet humidity on the particle size distributions of PbTe doped lead-bismuth eutectic aerosols
Effects of temperature and inlet humidity on the particle size distributions of PbTe doped lead-bismuth eutectic aerosols
Wang, Dr. JQ Wang, Mr. Jiaqing Wang, Dr. Haixia Fu, Ms. Xuewei Wu, Mr. Wenhao Xu¹˒, Mr. Mengzhuo Yu, Prof. Jie
Effects of temperature and inlet humidity on the particle size distributions of PbTe doped lead-bismuth eutectic aerosols
Effects of temperature and inlet humidity on the particle size distributions of PbTe doped lead-bismuth eutectic aerosols
摘要
The size distribution of aerosols formed from species released by lead-bismuth eutectic (LBE) is an important input for evaluating particle transport and filtration in nuclear facilities. In this study, PbTe-doped LBE was used as a nonradioactive surrogate system. Outlet particle size distributions were measured using a scanning mobility particle sizer (SMPS) at 400-800 °C and inlet relative humidities (RH in ) of 5%, 40%, and 60%, and interpreted together with characterization of the source-pool surface and downstream deposits. Within the 15-30 min comparison window, the total particle number concentration ranged from approximately 2 × 10⁴ to 9 × 10⁸ cm⁻³, and the geometric mean diameter (GMD) ranged from approximately 27 to 77 nm. At 400-600 °C, increasing temperature under low-and intermediate-humidity conditions increased the number concentration, decreased the GMD, and narrowed the distribution, indicating an enhanced small-particle mode. From 700 to 800 °C, the GMD increased from approximately 29-42 to 60-77 nm at all three humidities, indicating a shift toward larger particles. The direction of the humidity effect on number concentration reversed at the tested temperature of 700 °C: high humidity increased the number concentration by approximately two to four orders of magnitude at 400-600 °C, whereas the ordering became 5% > 40% > 60% RH in at 700 °C. At 800 °C, the number concentrations approached 10⁸ cm⁻³ at all humidities. Increasing the temperature from 500 to 700 °C was accompanied by relative Te depletion at the source-pool surface, relative Te enrichment at the deposit surface, and pronounced flake-like and block-like structures. These observations support downstream migration of Tecontaining species and their contribution to deposit formation. The results identify distinct temperature regimes characterized by enhancement of a small-particle mode and a shift toward larger particles, together with a reversal of the humidity effect between 600 and 700 °C. They provide an experimental basis for selecting condition-specific particle size distributions for transport and filtration models of LBE-related aerosols.