由于多相流的复杂性和缺乏对各相界面传热传质和动力学行为的微观认识及定量描述等原因，多相流和沸腾传热，成为当前多相流研究领域的重要课题。三元非共沸制冷剂R417A作为当前R22的替代品，在流动和换热性能上与R22还存在一定的差异，研究其在蒸发器中的沸腾换热，可以为今后替代制冷剂和相应的蒸发器的研制提供理论依据。本文对替代制冷剂R417A在水平管内沸腾换热的性能进行了数值模拟和理论分析。 首先，基于管内气液两相流的流动与换热机理，运用Fluent软件构建水平光滑管和内螺纹管模型，并进行网格划分，通过热力学和流体力学分析完成边界条件的设定以及湍流模型和多相流模型的选取。 其次，通过模拟计算，得到了管内制冷剂R417A流动沸腾换热过程中温度场、速度场和换热系数的分布及变化规律。通过改变入口边界条件，模拟出了质量流速、热流密度、蒸发温度和干度对沸腾换热的影响规律：随着制冷剂质量流速和换热密度的增加，换热系数明显增大；蒸发温度对换热系数的影响不是很明显；随着干度的增加，换热系数先是增大到最大值，随后出现管壁干燥、换热系数迅速降低的换热恶化现象，内螺纹强化管中换热系数高峰值对应的干度有向较大值的方向移动的趋势。 第三，比较了光滑管和内螺纹管换热性能和压降，分析了模拟结果。分析认为，内螺纹管能强化换热不单是微肋造成的面积增大所引起，还有螺纹结构所引起的湿润面积的增大、沸腾点和汽化核心的增多、扰动作用及紊流效应的增强、毛细湿润现象及对流体的旋转作用等因素。压降增大是由于螺纹管形成的二次流、摩擦的增大及流型的影响。 最后，将数值模拟结果与实验结果进行比较，并分析了两者的误差。结果表明数值模拟结果与实验结果比较吻合，进一步验证了数值模拟的可靠性。

As the complexity of multiphase flow and lack of micro-understanding and quantitative description of the interface heat transfer and dynamic behavior, multiphase flow and boiling heat transfer has become an important issue on multiphase flow research. As the alternative to R22 at present, there are some differences between ternary non-azeotropic refrigerant R417A and R22 in the flow and heat transfer performance and study of boiling heat transfer on R417A in the evaporator can provide the theoretical basis for the development of replacement refrigerants and the corresponding evaporators in the future.This article has conducted the numerical simulation and theoretical analysis on boiling heat transfer performance of the refrigerant R417A in horizontal tubes. Firstly, based on flow and heat transfer mechanism of gas-liquid two-phase flow in tubes, the computing models of a horizontal smooth tube and an internally grooved tube were built using Fluent software, and meshed. The boundary conditions were set and turbulence model and the multiphase flow model were selected through the analysis of thermodynamics and fluid dynamics. Secondly, through simulation, obtained the distribution and variation law of the temperature field, velocity and heat transfer coefficient on flow boiling heat transfer of refrigerant R417A in tubes. By changing the boundary conditions, simulated the influence laws of the mass flow rate, heat flux, evaporating temperature and dryness on the boiling heat transfer : As the increase of the refrigerant mass flow rate and heat transfer density, the heat transfer coefficient increased significantly; the influence of evaporation temperature on the heat transfer coefficient was not very obvious; with the increased dryness, heat transfer coefficient firstly increases to a maximum, and when wall turned dry, heat transfer coefficient fell quickly and heat transfer performance deteriorated. There was a trend that peak of heat transfer coefficient moved to the corresponding peak dryness in the internally grooved tube. Thirdly, heat transfer performance and pressure drop were compared in the smooth tube and the internally grooved tube and the results were analyzed. The reasons that the internally grooved tube can enhance heat transfer are not only area increase caused by micro-fin, but the thread structure can increase wetting area increases, the boiling point and vaporization core, effects of disturbance and turbulence, capillary and wetting phenomena and rotating fluid. The increased pressure drop is mainly due to the secondary flow, friction increases and the effects of boiling heat transfer flow caused by the formation of the internally grooved tube. Finally, numerical simulation and experimental results were compared and the causes of errors are analyzed. The results showed that simulation results coincided with the experimental results, and further verified the reliability of the numerical simulation.