本文選題：超聲波 + 凍結(jié)�。� 參考：《化工學(xué)報(bào)》2017年11期

【摘要】：超聲波液體輔助凍結(jié)在食品、海水淡化及冰蓄冷等方面的應(yīng)用得到了廣泛關(guān)注。結(jié)合聲場(chǎng)理論,在對(duì)液滴界面處熱質(zhì)傳遞分析的基礎(chǔ)上,建立了超聲波作用下的液滴冷卻凍結(jié)數(shù)學(xué)模型,討論了不同超聲波頻率、強(qiáng)度及作用時(shí)間對(duì)液滴界面處熱質(zhì)傳遞的影響,得到了超聲波作用下液滴的冷卻凍結(jié)規(guī)律。結(jié)果表明:超聲波作用下界面處的傳質(zhì)系數(shù)隨著超聲波強(qiáng)度的增加而增大,但隨超聲波頻率的增加而減小;在液滴冷卻凍結(jié)過(guò)程中,質(zhì)量傳遞與熱量傳遞的方向相同,液滴的冷卻凍結(jié)在超聲波作用下得到了強(qiáng)化。在超聲波頻率為20000 Hz(強(qiáng)度為400W?m-2),經(jīng)過(guò)相同的時(shí)間(60 s),超聲波作用下的液滴溫度比無(wú)超聲作用的溫度低2.0~2.5℃。研究將有助于深入理解超聲波輔助冷卻凍結(jié)機(jī)理,并為其工程應(yīng)用提供了指導(dǎo)和參考。
[Abstract]:Ultrasonic liquid-assisted freezing has been widely used in food, seawater desalination and ice storage. Based on the theory of sound field and the analysis of heat and mass transfer at the interface of liquid droplet, a mathematical model of cooling and freezing of droplet under the action of ultrasonic wave is established, and the different ultrasonic frequencies are discussed. The effect of intensity and time on the heat and mass transfer at the interface of droplet was studied and the cooling and freezing law of droplet under ultrasonic wave was obtained. The results show that the mass transfer coefficient at the interface increases with the increase of ultrasonic intensity, but decreases with the increase of ultrasonic frequency, and the direction of mass transfer and heat transfer is the same in the freezing process of droplet cooling. The cooling of droplets was strengthened by ultrasonic wave. When the ultrasonic frequency is 20000 Hz (intensity is 400 W / m ~ (-2), the droplet temperature under the same time (60 s), ultrasonic wave) is 2. 0 鈩，

本文編號(hào)：2081190