Effects of operational parameters on liquid nitrogen spray cooling
Effects of operational parameters on liquid nitrogen spray cooling
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DOI：
10.1016/j.applthermaleng.2018.09.098
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发表时间：
2019-01
影响因子：
6.4
通讯作者：
Y. Ruan;Yu Hou;R. Xue;Gaoqiao Luo;K. Zhu;X. Liu;Liang Chen
中科院分区：
文献类型：
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作者：
Y. Ruan;Yu Hou;R. Xue;Gaoqiao Luo;K. Zhu;X. Liu;Liang Chen
为了确定设计参数对液氮喷雾冷却液滴蒸发和分布的影响，通过改变质量流量、流速、液滴直径、喷射方向和液滴速度进行了实验和数值研究。结果表明，反向喷射产生最高的液滴蒸发率，这是40%和10%，分别高于通过正向和横向喷射获得的蒸发率。在横向喷流中观察到反向旋转的涡对，通过对流混合改善了温度分布。减小液滴直径提供了比增加液滴速度更有效的增强蒸发的手段，并且通过将液滴直径从0.6 mm减小到0.2 mm观察到液滴蒸发的线性增加。研究结果为低温风洞液氮喷雾冷却系统的设计提供了指导。
To determine the influence of design parameters on droplet evaporation and distribution of liquid nitrogen (LN2) spray cooling, experimental and numerical studies are performed by varying the mass flow rate, flow velocity, droplet diameter, injection orientation, and droplet velocity. The results demonstrate that backward injection yields the highest droplet evaporation ratio, which is 40% and 10% higher than the evaporation ratios obtained through forward and transverse injections, respectively. Counter-rotating vortex pairs are observed in the transverse injection, which improves the temperature distribution via convective mixing. Reducing the droplet diameter provides a more effective means of enhancing the evaporation than increasing the droplet velocity, and a linear increase in the droplet evaporation is observed by reducing the droplet diameter from 0.6 to 0.2 mm. The results and findings provide guidelines for the design of LN2spray cooling systems for cryogenic wind tunnels.