圆形浸没射流冲击驻点时射流速度对传热影响的实验研究

EXPERIMENTAL STUDY OF EXIT VELOCITY EFFECT ON HEAT TRANSFER WITH IMPINGING SUBMERGED CIRCULAR JETS AT STAGNATION POINT

以R113为工质系统地实验研究了圆形浸没射流冲击驻点时的传热情况 ,实验涉及单相对流传热、沸腾起始温度、核沸腾传热和临界热流密度等 .结果表明 :出口速度对沸腾起始温度和核沸腾传热没有影响 ;速度增加 ,单相对流传热和临界热流密度提高 ,而温度过头值减小 .当出口速度超过 10m·s-1后 ,高速射流冲击驻点的核沸腾曲线需要修正才能位于相应过冷度下池核沸腾曲线的延长线上 .

Experimental study was performed systematically to investigate heat transfer characteristics at the stagnation point from a simulated microelectronic chip of 5 mm×5 mm with impinging submerged circular jet, using R113 as the working fluid. Included are single-phase convective heat transfer, incipient boiling superheating, nucleate boiling heat transfer and burnout. The results showed that exit velocity had no influence on incipient boiling point and fully-developed nucleate boiling heat transfer curves, and that single-phase convective heat transfer coefficient and critical heat flux increased with enhanced jet exit velocity, while temperature overshoot decreased. While exit velocity was beyond 10 m&middots-1, the high heat flux portions of impingement boiling curves needed to be corrected in order to align with pool boiling curves at the same fluid subcooling.