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对电子芯片在FC-72工质中浸没喷射沸腾换热进行了实验研究。通过干腐蚀技术在硅片表面加工出50μm×60μm,50μm×120μm(宽×高)的柱状微结构,硅片尺寸为10 mm×10 mm×0.5 mm,过冷度分别为25、35 K,喷射速度V_j分别为0.5、1.0、1.5 m/s。实验表明,临界热流密度随着喷射速度和过冷度的增加而增加,增加过冷度和喷射速度可减小气泡脱离时的尺寸,增加气泡脱离频率,因此提高了临界热流密度并且降低了壁面温度。此外,在单相对流换热区对流换热占据主导地位,热流密度随着壁面过热度线性增加;在核态沸腾换热区,对流换热与核态沸腾换热同时影响着换热过程。当喷射速度较小时,核态沸腾区曲线的斜率比单相对流区曲线的斜率大得多,显示出浸没喷射沸腾的优良换热性能。
Electronic chips in the FC-72 working medium immersed in boiling heat transfer were experimentally studied. The columnar microstructures of 50μm × 60μm, 50μm × 120μm (W × H) were fabricated on the surface of silicon wafer by dry etching. The dimensions of the silicon wafer were 10 mm × 10 mm × 0.5 mm and the undercooling were 25, 35 K, The jet velocity V_j is 0.5, 1.0, 1.5 m / s, respectively. The experimental results show that the critical heat flux density increases with the increase of injection velocity and supercooling degree. Increasing the supercooling degree and jet velocity can reduce the size of bubbles and increase the frequency of bubble detachment, so the critical heat flux density is increased and the wall surface temperature. In addition, the convective heat transfer dominated in the single-phase convection heat transfer zone, and the heat flux increased linearly with the superheat of the wall. In the nucleate boiling heat exchange zone, the convective heat transfer and the nucleate boiling heat transfer also affected the heat transfer process. When the jet velocity is small, the slope of the nibbling zone curve is much larger than the slope of the single-phase convection zone curve and shows the excellent heat transfer performance of submerged jet boiling.