Multi-physical field simulation calculation and analysis of simulated high-level waste liquid spray calcination

by Yanmei CHENG, Kening LI, Xingyun JIA, Guoan YE

Aiming at the independent research and development of a simulated high-level waste liquid spray calcination transformation treatment test device, a three-dimensional multi-physical field model of spray calcination was established by means of finite element analysis method. In this paper, the simulated high-level waste liquid is a mixed solution of nitrate solution and sucrose. The main chemical components of nitrate dissolution are HNO₃ and NaNO₃. The process of evaporation and calcination of high-level waste liquid to form oxides is also called the pretreatment of high-level waste liquid or the conversion of high-level waste liquid. In this experiment, the atomized droplets sprayed at high speed are evaporated, dried and calcined in turn in the calciner to obtain the calcined product. The distribution law of temperature flow field and chemical reaction state and results inside the test device were revealed by simulation calculation. The results show that under the condition of multi-physical field coupling, the chemical reaction temperature has an effect on the yield of the product. The temperature is positively correlated with the product concentration, and the effect of temperature on the yield of NO₂ is greater than that of Na₂O. At the same time, in this chemical reaction, the concentration of reactants (NaNO₃ and HNO₃) had a positive correlation with the concentration of main products (NO₂ and Na₂O). However, the rate of increase in the concentration of the main products (NO₂ and Na₂O) decreased with the increase of the concentration of the reactants (NaNO₃ and HNO₃).