液化天然气在微通道内流动沸腾的气泡行为及蒸发薄液膜机理研究

液化天然气（LNG）在微通道内的流动沸腾换热机理是印刷电路板式换热器（PCHE）应用于浮式液化天然气（FLNG）系统亟待解决的关键问题，而气泡行为及气泡底层蒸发薄液膜的研究是揭示流动沸腾传热传质机理的重要理论基础。本项目拟针对LNG在PCHE内的气化过程，围绕非共沸混合工质在微通道内流动沸腾中微尺度效应作用下的气泡行为特性及蒸发薄液膜的传热传质机理两个关键科学问题，采用可视化实验、数值模拟及理论分析相结合的方法，研究温度滑移、传质阻力对气泡核化、生长、滑移、脱离、受限及拉长行为的影响机制，阐明气泡行为的微尺度效应；研究蒸发薄液膜的形态及换热特性，建立蒸发薄液膜传热传质模型，揭示LNG蒸发薄液膜的传热传质机理；阐明气泡行为与蒸发薄液膜传热传质机理之间的关联机制。研究成果对完善微通道内LNG流动沸腾换热理论体系具有重要作用，为推进PCHE应用于FLNG的国产化进程提供科学依据。

The flow boiling heat transfer mechanism of liquefied natural gas (LNG) in microchannels is a key issue to be solved in the application of printed circuit heat exchanger (PCHE) to floating liquefied natural gas (FLNG) systems. The study of bubble behavior and bubble bottom evaporating thin film is an important theoretical basis for revealing the heat and mass transfer mechanism of flow boiling. This project is aimed at the gasification process of LNG in PCHE. The bubble behavior under micro-scale effects and the heat and mass transfer mechanism of evaporating thin film in the flow boiling process of zeotropic mixtures in microchannels are two key scientific problems. Visual experiments, numerical simulation and theoretical analysis will be applied. The mechanism of temperature slip and mass transfer resistance on bubble nucleation, growth, slip, detachment, limitation and elongation behavior will be studied. The micro-scale effect of bubble behavior will be clarified in the project. The morphology, heat and transfer characteristics of the evaporating thin film will be studied, the heat and mass transfer model of which will be established. The heat and mass transfer mechanism of LNG evaporating thin film will be revealed. The correlation mechanism between the bubble behavior and the heat and mass transfer mechanism of evaporating thin film will be explained. The research results play an important role in perfecting the theoretical system of LNG flow boiling heat transfer in microchannels, and provide a scientific basis for promoting the application of PCHE to the localization of FLNG.