Gong Yaopeng, Zhang Li, Yuan Yidan, Guo Qiang, Ma Weimin, Huang Shanfang
Department of Engineering Physics, Tsinghua University, Beijing, China.
China Nuclear Power Engineering Co., Ltd (CNPE), Beijing, China.
Heliyon. 2023 Nov 17;9(12):e22424. doi: 10.1016/j.heliyon.2023.e22424. eCollection 2023 Dec.
Reliable thermophysical properties of core melt (corium) are essential for the accurate prediction of the severe accident progression in light water reactors. Zirconia is one of the most important materials in corium. Despite the high interest in the viscosity of molten zirconia, few experimental data have been reported due to its high melting temperature and high vapor pressure. In the present study, the viscosity of molten zirconia was measured using aerodynamic levitation, laser heating and droplet oscillation techniques. A material sample was levitated by argon gas flow in a conical nozzle and then melted into a droplet by laser beams. The initial quiescent droplet was forced to oscillate by the excitation of a loudspeaker, and the viscosity was deduced based on the characteristics of the droplet damped oscillation after the loudspeaker was turned off. The viscosity of molten alumina was first measured for verification of the measurement system. Afterwards the viscosity of molten zirconia was measured. The results showed that the viscosity of molten zirconia at melting temperature (2988K) was 12.87 ± 1.03 mPa s and decreased with increasing temperature. The measurement uncertainties are within 21 %.
堆芯熔体（熔堆）可靠的热物理性质对于准确预测轻水反应堆严重事故的发展进程至关重要。氧化锆是熔堆中最重要的材料之一。尽管人们对熔融氧化锆的粘度高度关注，但由于其熔点高和蒸气压高，鲜有实验数据报道。在本研究中，利用气动悬浮、激光加热和液滴振荡技术测量了熔融氧化锆的粘度。通过氩气流将材料样品悬浮在锥形喷嘴中，然后用激光束将其熔化成液滴。通过扬声器的激励使初始静止的液滴产生振荡，在扬声器关闭后，根据液滴阻尼振荡的特性推导出粘度。首先测量了熔融氧化铝的粘度以验证测量系统。随后测量了熔融氧化锆的粘度。结果表明，熔融氧化锆在熔化温度（2988K）下的粘度为12.87±1.03 mPa·s，并随温度升高而降低。测量不确定度在21%以内。
