超亲水乳突对冷凝传热的影响

Effect of Super-hydrophilic Mastoid on Condensation Heat Transfer

为强化冷凝传热,促使冷凝液快速脱离是重要途径。以微米级电解铜粉为材料,烧结制备了超亲水乳突结构,测试了超亲水乳突在不同角度下的吸液性能,并通过蒸汽冷凝实验,研究了超亲水乳突对冷凝传热的影响。实验结果表明,超亲水乳突表面的针状凸起增大了乳突的粗糙度,进而增大了超亲水乳突内的毛细吸力,吸液性能优越。因此应用超亲水乳突后,促进了冷凝表面冷凝液的脱离,从而强化了蒸汽冷凝传热。其中,应用超亲水乳突的超疏水表面表现出最高的传热系数。当过冷度ΔT=2.5 K时,传热系数是亲水铜表面的5.6倍。

It is an important way to enhance the condensation heat transfer by promoting the rapid separation of condensed liquid from condensing surface.Using micron-level electrolytic copper powder as the material,a super-hydrophilic mastoid was prepared by sintering technology,and the liquid absorption performance of the super-hydrophilic mastoid at different angles was tested.The effect of super-hydrophilic mastoid on the heat transfer coefficient was studied through the steam condensation experiment.The experimental results show that the needle-shaped protrusions on the surface of the super-hydrophilic mastoid increase the roughness of the mastoid,which in turn increases the capillary force in the super-hydrophilic mastoid,and the mastoid has superior liquid absorption performance.Therefore,the application of super-hydrophilic mastoid can promote the separation of condensed liquid from condensing surface,thereby enhancing the condensation heat transfer.Among them,the superhydrophobic surface using super-hydrophilic mastoid showed the highest heat transfer coefficient.When the supercooling degreeΔT=2.5 K,the heat transfer coefficient is 5.6 times that of the hydrophilic copper surface.