带开槽结构的多孔表面沸腾换热的双孔隙模型

Dual porous model for boiling heat transfer on porous surfaces with vapor channels

为研究开槽对多孔表面沸腾传热过程的影响 ,把不均匀多孔结构内的两相流动和传热视为在大尺度上的均匀介质内的流动和传递过程 ,用一种当量的双孔隙方法导出了双孔隙多孔介质汽液两相流动的一维模型 ,分析了双孔隙结构介质两相流动特性 ,讨论了结构参数对毛隙压力作用下的沸腾传热的影响。确立了最佳开槽密度与多孔层高度、渗透率和流体物性的关系 。

A onedimensional dual porous model was proposed to model the effects of channels in the porous coating on boiling heat transfer on coated porous surfaces. The result shows that boiling heat transfer on capillary porous coated surfaces with vapor channels can be enhanced by channels in the porous coatings. The vapor escapes from the open channels while liquid is sucked into the porous matrix to form a structured vaporliquid twophase flow pattern. The model shows that the dry out condition is affected by the size and density of the channels. The maximum dry out heat flux is achieved at a specific channel density which depends on the channel size that affect the vapor flow resistance.