In this study, thin liquid film boiling heat transfer characteristics of R134a on a plain and two finned tubular surfaces were experimentally investigated. The dependence of heat transfer coefficient (HTC) on the composite effects of microstructure and hydrophobic coating was characterized. It is found that HTC increases monotonously with increasing heat flux until reaching a threshold heat flux (THF), beyond which the HTC starts to descend. The THF is highest for the plain surface and lowest for the boiling-enhanced surface due to the effect of reentrant cavities. The boiling-enhanced surface shows larger HTC under low heat fluxes (less than 60 kW m⁻²) compared with the condensation-enhanced counterpart, whereas the latter one is superior when the heat flux exceeds 60 kW m⁻². Hydrophobic coating can substantially intensify the liquid film boiling heat transfer on boiling-enhanced finned surface with reentrant cavities. The intensification of heat transfer is more prominent in cases of high heat flux.

在这项研究中，通过实验研究了R134a在平面和两个翅片管形表面上的薄膜沸腾沸腾传热特性。表征了传热系数（HTC）对微观结构和疏水涂层复合效应的依赖性。发现HTC随着热通量的增加而单调增加，直到达到阈值热通量（THF），超过此阈值HTC开始下降。由于凹腔的作用，四氢呋喃在平整​​表面上最高，而在沸腾增强表面上最低。与凝结增强的对应物相比，在低热通量（小于60 kW m ^-2）下，沸腾增强的表面显示出更大的HTC ，而当热通量超过60 kW m ^-2时，沸腾增强的表面表现出更高的HTC。。疏水涂层可以显着增强具有凹腔的沸腾增强翅片表面上的液膜沸腾传热。在高热通量的情况下，传热的增强更为显着。