核化学与放射化学2026，Vol.48Issue(4)：372-383,12.DOI:10.7538/hhx.2026.48.04.0372
不同冷帽覆盖率下高放废液玻璃固化电熔炉熔化性能仿真模拟研究
Simulation Study on Performance of Joule-Heated Ceramic Electric Melter Under Different Cold Cap Coverages
摘要
Abstract
The safe and efficient immobilization of high-level liquid waste(HLLW)is a critical global challenge.Vitrification utilizing a continuous Joule-heated ceramic melter(JHCM)is currently the most effective technology for HLLW treatment.During operation,HLLW and glass-forming additives form a floating layer of unmelted batch materials,known as the cold cap,on the melt pool.The cold cap coverage rate significantly governs heat transfer dynamics,physical field distributions,and operational safety.Due to the extreme high-temperature and high-radiation environment inside the melter,directly obtaining internal physical field data is exceedingly difficult.Therefore,establishing an accurate predictive model for the melter's performance is crucial for ensuring safe operation.In this study,a comprehensive three-dimensional numerical simulation was conducted using COMSOL Multiphysics software to systematically investigate the impact of different cold cap coverage rates(25%,50%,75%,and 90%)on the JHCM's melting efficiency and safety.The computational model coupled fluid dynamics,heat transfer,electric fields,and Joule heat,utilizing approximately 200 000 mesh elements.The molten glass flow was treated as an incompressible Newtonian fluid in a laminar regime,whereas the plenum gas flow was simulated using a turbulent model.The simulation results demonstrate that as the cold cap coverage increases from 25%to 90%,the average temperature within the melt pool rises from 1 127℃to 1 241℃,an increase of approximately 10%.Conversely,the expanded cold cap effectively insulates the upper space,causing the average temperature in the plenum to drop drastically from 897℃to 635℃(a 30%reduction),and the exhaust gas pipeline temperature to decrease from 746℃to 501℃.These variations profoundly influence electrical and thermal distributions.Under a low coverage mode,the distributions of current density and Joule heat within the molten glass are notably heterogeneous.Excessive local current density concentrates near the electrodes(exceeding 5 000 A/m2),significantly exacerbating the risk of electrode ablation.In contrast,under high coverage conditions,the Joule heat distribution homogenizes remarkably,with regions exceeding 80 kW/m3 increasing to 54%of the pool volume.Energy distribution analysis shows that at 90%coverage,thermal energy dissipated into the plenum diminishes to 16.0 kW,compared to 73.5 kW at 25%coverage.Accordingly,heat flux from the melt pool to the cold cap escalates from 11.5 to 22.8 kW/m2.Consequently,the comprehensive melting efficiency of the melter undergoes a near-twofold enhancement,surging from 275.4 to 545.3 kg/(m2•d).In conclusion,maintaining high cold cap coverage optimizes internal multiphysics fields,mitigates electrode burnout risks,and maximizes vitrification efficiency.关键词
高放废液/玻璃固化/陶瓷电熔炉/冷帽/数值模拟Key words
high-level liquid waste/vitrification/Joule-heated ceramic melter/cold cap/numerical sim-ulation分类
化学化工引用本文复制引用
王磊,李立峰,贾子强,徐凯..不同冷帽覆盖率下高放废液玻璃固化电熔炉熔化性能仿真模拟研究[J].核化学与放射化学,2026,48(4):372-383,12.基金项目
国家自然科学基金项目(U2241290) （U2241290）
