This study experimentally investigates the condensation of dielectric fluid HFE-7100 in a micro-channel heat sink with the hydraulic diameter of 1.21 mm. Tests are conducted at a fixed pressure of 110 kPa, with vapor mass quality (xin) ranging from 0.1 to 0.9, mass fluxes (G) from 150 to 250 kg·m−2·s−1, inclined angle (θ) from −90° to +90°. A novel trapezoid drainage design is proposed to enhance the condensation heat transfer by effectively entraining condensation film. When G is lower than 200 kg·m−2·s−1, the two phase heat transfer coefficient (htp) for the trapezoid drainage design exceeds the conventional rectangular micro-channel heat sink by 10–26% while the corresponding pressure drop is about 22–45% lower. When G is increased to 250 kg·m−2·s−1, the drainage design can still dramatically decrease the pressure drop, however, it shows a negative effect on htp when the xin is greater than 0.2. With inclined arrangements, the pressure drop would dramatically increase due to gravity effect. Besides, at the conditions of θ = −45° and −90°, the trapezoid drainage channel can improve the htp by 43–45% when G is lower than 200 kg·m−2·s−1. On the contrary, with the arrangement of θ = +45° and +90°, the trapezoid drainage channels may decrease the htp by 8–15%. This phenomenon is especially pronounced at a high xin. In addition, the heat transfer enhancement and deterioration are both analyzed based on stress distribution at vapor phase and condensation film.
|頁（從 - 到）||11-24|
|期刊||Experimental Thermal and Fluid Science|
|出版狀態||Published - 1 九月 2019|