Impact of geometrical surface modification on spray cooling heat transfer performance with liquid nitrogen: An experimental investigation. (March 2022)

• Record Type: Journal Article
• Authors: Yu, Yunxing; Qiu, Yinan; Liu, Jing; Chen, Jianye; Ding, Yue; Xie, Junlong
• Is Part Of: Cryogenics. Volume 122(2022)
• Publication Date: 2022-03
• Subjects: Liquid nitrogen -- Spray cooling -- Spray morphology -- Straight-grooved surface -- Heat flux -- Cryogenic; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2022.103438
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: An apparatus for liquid nitrogen spray cooling was built. Liquid nitrogen jet spray morphology was observed. Straight-grooved surface improved spray cooling performance compared to plain surface. Influences of groove width and depth on spray cooling were studied. Abstract: In this study, an experimental study on the spray cooling using liquid nitrogen (LN2 ) as the coolant was studied. Accordingly, an open-cycle experimental setup for cryogenic spray cooling was built. Investigation of spray cooling heat transfer performance on both plain and straight-grooved surfaces was carried out. The spray morphology was captured using the visual technique in the cryogenic system and the spray angles under different injection pressures were obtained. Additionally, a parametric study of heat transfer characteristics on the straight-grooved surfaces was carried out. The results have shown that the spray angle, at first, increases as with the inlet pressure, which is followed by a decrease. The straight-grooved surface significantly improved the spray cooling heat transfer compared to its plain counterpart by the maximum improvement rate of 64.2%. However, temperature uniformity was poorer. As the groove depth increases, the heat flux experiences increases at first, followed by a decrease. Finally, it was observed that the increase in groove width reduces the heat flux.