含添加剂雾滴蒸发速率的实验及数值模拟

Evaporation of a Small Water Droplet Containing Additive

为揭示含添加剂细水雾灭火机理和评价其灭火有效性,首先建立了抛光金属热表面雾滴蒸发实验台,选用分别含30％、60％质量分数的醋酸钾添加剂的水溶液和含30％、60％质量分数的碘化钠添加剂的水溶液作为研究介质,通过压电陶瓷雾滴发生器产生均匀的细水雾雾滴,观察雾滴在热金属表面的蒸发过程,实验过程中金属表面的温度控制在50～100℃．研究表明,在给定的温度条件下,含醋酸钾和碘化钠的水溶液的平均蒸发速率要比不含添加剂的纯水慢．在此基础上,建立了单个半球雾滴的传热传质蒸发模型并进行了数值模拟,在定性上与实验结果相一致．

An experimental study on the evaporation of a small water droplet containing an additive on a heated, polished staiuless-steel surface was performed. Solutions of water containing 30% （weight percentage） and 60% （weight percentage） of potassium acetate and sodium iodide respectively were used in the experiments. Surface temperatures used in the experiments ranged from 50℃ to 100 ~C. The average evaporation rates for the potassium acetate and sodium iodide solutions were found lower than that of pure water at a given surface temperature. A simple evaporation model was developed to interpret the experimented results,the simple analysis agrees qualitatively with trend of the experimental data.