浸没燃烧蒸发过程单个气泡传热传质模型

浸没燃烧蒸发器是一种利用高温气体与低温液体直接接触传热的高效蒸发设备,其现有传热传质模型较为繁琐。该文从传质推动力角度出发建立了高温气泡在水中上升过程的传热传质模型,计算结果与文献报道的实验数据、模拟结果基本吻合。利用该模型计算可得出,浸没燃烧蒸发过程中,液体平衡温度随气体初始温度的升高或气泡内初始水蒸汽含量的增大而升高,接触时间在一定范围内的增加使得液体平衡温度随之降低,超出1 s后对液体平衡温度影响不大。

Heat and mass transfer modeling of a single bubble during submerged combustion evaporation

The submerged combustion evaporator is a high-efficiency equipment using direct contact heat transfer between superheated bubbles and the liquid. The mass transfer force concept was used to develop a model for the heat and mass transfer from a single superheated bubble rising in the water pool. The results agree well with experimental data. The results also show that during submerged combustion evaporation, the steady-state liquid temperature increases with the increasing initial gas temperature or with increasing initial water-vapor content in the superheated bubble. Increases of the direct contact time of up to 1 s reduce the steady-state liquid temperature, but have little influence on the steadystate liquid temperature beyond 1 s.