直接接触式蓄冷中相变问题的物理模型

基于直接接触式蓄冷中的相变现象,提出了考虑扩散相汽泡晃动的物理模型,并分析了其在连续相中生长问题;物理模型综合考虑了直接接触式蓄冷中扩散相两相汽泡在连续相中流动、换热及晃动的实际情况,其分析解与实验数据吻合较好;得到的分析解预示了各种因素对两相汽泡生长换热的影响:m越大,两相汽泡增长越慢,汽泡的增长速率在其开始阶段特快,而后迅速下降。相对于m来说,Pef对两相汽泡的生长的影响要小,Pef越大,汽泡增长越慢;有关理论模型将在新建的直接接触式蓄冷实验台上作进一步验证。

A Theoretical Study on Phase Change in Direct Contact Thermal Storage

On the basis of phase change properties in direct contact thermal storage, this paper presents a new physical model with consideration of its swashing and effects on heat transfer and analyses the problem of bubble growth in a continuous liquid. The proposed model is satisfactory to meet the results of testing on the spot. The model shows the influences of mass and Pef on the bubble growth in gas and liquid. The rate of the bubble growth slows down with mass increase. At the beginning, the bubble growth is much faster and then it decreases rapidly. The influences of Pef on the bubble growth are smaller than that of the mass. The larger the Pef, the slower the bubble growth.