波纹板强化换热装置中带水膜饱和烟气对流传热的实验研究

为了探讨糖厂的烟气水膜除尘耦合换热技术实施的可行性,建立了带水膜湿烟气与空气之间的换热实验装置,进行带水膜湿烟气的对流传热实验研究。在该换热装置中,烟气在矩形通道中流动并喷入雾化热水,通过换热面加热另一侧的空气,同时,在烟气侧通道安装波纹板强化单元,以强化热质传递。实验确定最佳液气比,通过改变波纹板峰高、波纹段高、段数及烟气流速,研究带水膜饱和烟气的对流传热系数。结果表明:饱和烟气对空气的换热量显著;最佳液气比为3.3~4.2 L/m~3;烟气流速和波纹板添加段数的增加显著增大对流传热系数。回归了最佳液气比下的传热准则关联式。

Experimental Study of the Convective Heat Transfer of Saturated Flue Gases with Water Film in aHeatExchangerIntensified Corrugated Plates

A heat exchange devise in whichthe air was heated by flue gases saturated by spraying hot waterwas established.Corrugated plates were equipped in the flue gases duct to intensify the saturation of the gases and convective heat transfer. Experiments were performed toinvestigate the heat transfer performance and the effects of flue gases velocity, water load, parameters of corrugatedplates including the peak height,the plate length,and the number of segments on theconvective heat transfer coefficients of saturated flue gases with water film. Theresults shown that the heat transfer rate between flue gases and the air was significant;the optimum ratio of liquid to gas is 3.2-4.5 L/m3; the heat transfer coefficientwas greatly enhanced by the increase of flue gases velocity, the increase of peak height and number of segments. A dimensionless number correlation formula for the convective heat transfer coefficients of saturated flue gases with water film is established by regression of the experimental data.