Influence of High Frequency Supply Power on Discharge of HLLW Cold Crucible Glass Solidification

The melting and discharging of glass from cold crucible high level radioactive waste liquid is a key step in its solidification process, and the high frequency supply power is one of the important factors affecting the discharging. In order to explore the influence of high frequency supply power on the discharging of the engineering prototype of the \phi 650 mm cold crucible, improve the reliability and stability of the cold crucible discharging, a multi-physics coupling simulation study on the temperature field, electromagnetic field, and stirring flow field of a cold crucible using high frequency supply power as the experimental variable to simulate the temperature field distribution before discharge was conducted. A verification experiment was carried out to initiate the melting and discharging of glass beads, measure the temperature of the glass liquid in the cold crucible, and verify the simulation results. Different high frequency supply power simulations were conducted to predict the optimal high frequency supply power to ensure smooth discharge. The results indicate that a relatively ideal discharge condition with a waiting time of 42 min and an average discharge rate of 2.52 kg/min is obtained in the verification experiment of starting glass working condition. The required high frequency supply power is 360 kW. The measured temperatures at two different stirring blade stations under this condition are 1 365 ℃ and 1 387 ℃, respectively, which are in good agreement with the simulation prediction results. The temperature near the bottom discharge port of the crucible is predicted to be around 1 000 ℃ through the simulation temperature field. By changing the physical parameters of the glass to simulate the optimal high frequency supply power under stable operating conditions, the simulation shows that the required power is maintained at around 290 kW, and the predicted power is in good agreement with the experimental data. On this basis, the prediction of cold crucible discharge power and emergency plan design under abnormal stirring failure conditions were carried out. The study shows that high frequency supply power of about 360 kW is required under this abnormal condition. Therefore, the simulation model of cold crucible discharge established in this paper can predict the optimal discharge power under startup and stable conditions, and can predict the optimal high frequency supply power under various conditions that may arise in the future (different glass qualities, different stirring conditions, different component glasses, abnormal conditions, etc.) by adjusting simulation parameters.