【摘要】 随着电动汽车和电子设备的快速发展，利用绝缘工质的浸没式相变冷却技术因在温控性能、集成化等方面优势明显逐渐受到关注，对该技术在低温工况下应用的需求也在不断增加。但目前关于绝缘冷却工质的沸腾传热基本机理尤其是低温工况下的研究较少。本文使用饱和压力(温度)可控的气密性实验系统，在低饱和压力条件下研究液层静压对Novec 7100在光滑铜表面的沸腾传热特性的影响。实验发现，临界热流密度随饱和压力的下降先降低后上升的特殊趋势。在饱和压力低于8.8 kPa后，池沸腾过程出现间歇性沸腾和自发过冷沸腾两种特殊的换热模式，临界热流密度会随液位高度增加而升高。当饱和压力为0.741 kPa时，23 mm和35 mm液位高度的临界热流密度值相差最大，约39 k W/m~2。更多还原

【Abstract】 With the development of electric vehicles and electronic devices, the two-phase immersion cooling technology using dielectric coolants has gradually attracted attention due to its significant advantages in temperature control performance and integration. The demand for the application of this technology in low-temperature conditions is also increasing. However, there is currently limited research on the boiling heat transfer of dielectric coolants, especially at low temperatures. This study investigates the effect of liquid static pressure on the boiling heat transfer characteristics of Novec 7100 on a smooth copper surface under low saturation pressure conditions using an airtight experimental system with controllable saturation pressure(temperature). The experiment reveals a unique trend of critical heat flux decreasing first and then increasing with decreasing saturation pressure. After the saturation pressure drops below 8.34 kPa, the pool boiling process exhibits “intermittent boiling” and “self-induced subcooled boiling” as two distinct heat transfer modes, and the critical heat flux increases with the liquid height. When the saturation pressure is 0.741 kPa, the critical heat flux values at liquid levels of 23 mm and 35 mm show the greatest difference, approximately39 k W/m~2.更多还原