高压环境雾化钐铁液滴冷却过程的研究
发布时间：2019-04-04 08:59
【摘要】：通过建立高压环境下雾化液滴传热与冷却的理论模型,分析了钐铁合金液滴雾化凝固过程中的冷却阶段,重点讨论了环境压力和液滴尺寸对冷却行为的影响。分析结果表明,冷却过程中对流传热系数随环境压力的升高而增大,随液滴尺寸的减小而增大,尺寸越小,传热系数变化越明显;环境压力升高可使雾化液滴在0.000 2 s或更短的时间内以更大的对流传热系数进行热量传递;随环境压力的升高,液滴的冷却速率增大,形核过冷度也有缓慢增大的趋势,直径50μm以内的液滴的冷却速率达106K/s,形核过冷度达200℃以上。在实际的雾化过程中,环境压力通过减小液滴尺寸显著提高冷却速度,增大形核过冷度。
[Abstract]:Based on the theoretical model of heat transfer and cooling of atomized droplets in high pressure environment, the cooling stage during atomizing solidification of Sm-Fe alloy droplets was analyzed, and the effects of ambient pressure and droplet size on cooling behavior were discussed emphatically. The results show that the convective heat transfer coefficient increases with the increase of ambient pressure and with the decrease of droplet size. The smaller the size is, the more obvious the change of heat transfer coefficient is. The higher the environmental pressure, the higher the convective heat transfer coefficient of the atomized liquid droplets in 0.000 s or shorter time. With the increase of ambient pressure, the cooling rate of the droplets increases, and the nucleation undercooling degree increases slowly. The cooling rate of the droplets within 50 渭 m in diameter is up to 106 K / s, and the nucleation subcooling degree is over 200 鈩，
本文编号：2453665
[Abstract]:Based on the theoretical model of heat transfer and cooling of atomized droplets in high pressure environment, the cooling stage during atomizing solidification of Sm-Fe alloy droplets was analyzed, and the effects of ambient pressure and droplet size on cooling behavior were discussed emphatically. The results show that the convective heat transfer coefficient increases with the increase of ambient pressure and with the decrease of droplet size. The smaller the size is, the more obvious the change of heat transfer coefficient is. The higher the environmental pressure, the higher the convective heat transfer coefficient of the atomized liquid droplets in 0.000 s or shorter time. With the increase of ambient pressure, the cooling rate of the droplets increases, and the nucleation undercooling degree increases slowly. The cooling rate of the droplets within 50 渭 m in diameter is up to 106 K / s, and the nucleation subcooling degree is over 200 鈩，
本文编号：2453665
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