超声波对池沸腾换热影响

Pool Boiling Under Ultrasonic Wave

对不同超声强度和辐射距离条件下过冷池沸腾换热特性进行了实验研究。超声波有效强化了沸腾起始段换热,对高热流密度沸腾传热也有一定的强化作用。超声辐射距离越近,强度越大,强化传热效果越好。对单相对流和沸腾起始区传热,超声波强化传热机理为空化作用;高热流密度沸腾时超声波对强化传热的主要机理是声流作用。得到了传热实验关联式。

Subcooled pool boiling heat transfer was experimentally studied under different ultrasonic intensity and emission distance.The results indicate that the ultrasonic wave can enhance the heat transfer under natural convection and initial boiling region and has a benefit to pool boiling heat transfer under high heat flux.Moreover,the closer emission distance to the heat surface is and the greater the ultrasonic intensity is,the better the enhancement heat transfer is.The mechanism of enhancement heat transfer under natural convection and initial boiling region is the cavitation influence,and the acoustic flow induced by the ultrasonic wave becomes domain mechanism under high heat flux pool boiling.Two correlations were proposed to predict the heat transfer coefficient under the two corresponding conditions.