基板温度对HFE7100液滴蒸发过程的影响研究

Influence of substrate temperature on HFE7100 droplet evaporation process

为探究基板温度对甲基九氟丁醚(HFE7100)液滴蒸发模式、形态参数及蒸发速率的影响,促进其在微尺度传热领域的应用,选用3种不同表面温度(20、30、40℃)的玻璃材料为基板,记录液滴蒸发过程中接触角、接触直径、润湿面积和液滴体积等参数的变化过程。结果表明:不同基板温度下,HFE7100的接触角和接触直径同时下降直至蒸发结束,液滴蒸发模式并非表现为混合蒸发模式;基板温度对HFE7100蒸发初始阶段形态参数影响显著,基板温度越高,HFE7100初始接触角越大,初始接触直径和润湿面积越小,初始形态参数变化速率越大;HFE7100液滴蒸发过程可分为三个阶段,第一和第三阶段蒸发速率较大,中间阶段蒸发速率较小,最大蒸发量发生在初始阶段,且基板温度越高,蒸发速率越大。

In order to investigate the effect of substrate temperature on evaporation model,morphology parameters and evaporation rate of droplet of butane,1,1,1,2,2,3,3,4,4-nonafluoro-4-methoxy(HFE7100),and to promote its application in microscale heat transfer.Three kinds of glass materials with different surface temperatures(20,30,40℃)were selected as substrates,the contact angle,contact diameter,wetting area,droplet residual volume and mass loss rate during droplet evaporation were recorded.The results show that the contact angle and contact diameter of HFE7100 decrease at the same time until the end of evaporation at different substrate temperatures,the droplet evaporation model is not a mixed evaporation model.The substrate temperature has a significant effect on the morphological parameters of HFE7100 during the initial evaporation stage,the higher the substrate temperature,the larger the initial contact angle,the smaller the initial contact diameter and wetting area,and the larger the change rate of initial morphological parameters.The evaporation process of HFE7100 droplets can be divided into three stages,in the first and the third stages,the evaporation rate is higher,and in the middle stage,the evaporation rate is lower,the maximum amount of evaporation occurs at the initial stage.And the higher the substrate temperature,the higher the evaporation rate is.