The heat transfer and pressure drop characteristics of the mixture are the design basis of evaporators and optimization of Organic Rankine Cycle (ORC). As a promising mixture for ORC systems, R245fa/R141b with different mass fractions (1/0, 0.75/0.25, 0.5/0.5, 0.25/0.75 and 0/1) were selected as the working fluid. The heat transfer coefficient (HTC) and frictional pressure drop in a horizontal microfin tube with 8.6 mm equivalent diameter were measured. During the experimental tests, the saturation pressure is vary from 0.15 to 0.25 MPa (saturation temperature from 25.3 to 60.5 ℃), mass fluxes from 203.19 to 306.64 kg•m^-2 s^-1, and heat fluxes from 7 to 15 kW m^-2. Additionally, based on the empirical correlations in the literature, we developed a correlation with higher prediction accuracy. The results indicate that the HTC and pressure drop of R245fa/R141b increase with mass flux, while decrease with saturation pressure. The increase of the mass fraction of R245fa results in an increase of the HTC and friction pressure drop for R245fa/R141b. The correlation of Cavallini–Kattan are consistent with the experimental data of heat transfer with mean absolute deviations of 16.68%. When mass flux is less than 200 kg m^-2 s^-1 and vapor quality is less than 0.2, modified Dittus–Boelter correlation can predict 87.3% data points in the error range of ±30% with a MAD of 6.75%. As to frictional pressure drop, the deviations of ±10.34% experimental data are obtained by the modified Filho correlation.

混合物的传热和压降特性是蒸发器的设计基础和有机朗肯循环（ORC）的优化。作为ORC系统的有希望的混合物，选择了具有不同质量分数（1 / 0、0.75 / 0.25、0.5 / 0.5、0.25 / 0.75和0/1）的R245fa / R141b作为工作流体。测量了等效直径为8.6 mm的水平微翅片管的传热系数（HTC）和摩擦压降。在实验测试中，饱和压力是变化从0.15〜0.25兆帕（饱和温度从25.3至60.5℃），质量通量从203.19到306.64千克•米^-2小号^-1，和热通量从7到15千瓦米^{- 2}。此外，基于文献中的经验相关性，我们开发了具有较高预测精度的相关性。结果表明，R245fa / R141b的HTC和压降随质量通量而增加，而随饱和压力而降低。R245fa的质量分数的增加导致HTC的增加和R245fa / R141b的摩擦压降。Cavallini–Kattan的相关性与传热的实验数据一致，平均绝对偏差为16.68％。当质量通量小于200 kg m ^-2 s ^-1时当蒸气质量小于0.2时，修正的Dittus-Boelter相关性可以在±30％的误差范围内预测87.3％的数据点，而MAD为6.75％。关于摩擦压降，通过改进的菲尔霍相关性获得了±10.34％的实验数据的偏差。