摘要
很久以来,人们就认识到在液相中注入气泡可以产生强烈扰动,大在强化了对流传热和沸腾传热.不久前,C.F.Ma和Bergles侧进一步发现用异种气体快速冲击浸没在R-ll3中的微小加热壁面,其传热不但大为强化;而且可出现壁面温度低于液体冷却介质温度的“负温差传热”的奇异现象.此外,沈自求等最近亦发现,在蒸发过程中引入少量载气,可在气液界面上产生快速质量传递,使沸腾传热得到明显强化.此类现象的深入探讨对强化电子元件、蒸发器、原子能反应堆的传热均具有重要意义.
The heat transfer of a small heating device can be augmented by gas impingement in a liquid coolant bath. The mechanism of its heat transfer augmentation was studied. Theoretical analysis and experimental investigation showed that besides the increasing heat transfer by the agitation of liquid caused by gas jet impingement there existed a heat sink caused by liquid coolant vaporization at the impinging gas-liquid coolant interphase. Due to such a quick vaporisation, the temperature at the gas-liquid interphase dropped notably, increasing the effective heat transfer driving force and in turn the heat transfer. From such a point of view, a physical model of simultaneous heat and mass transfer was proposed to reveal the mechanism of this particular heat transfer phonomenon, and the convective heat transfer coefficient and mass transfer coefficient can be calculated.
出处
《化工学报》
EI
CAS
CSCD
北大核心
1990年第5期618-622,共5页
CIESC Journal
基金
国家自然科学基金资助项目