状态方程参数化耦合制冷工质热导率性质预测模型

A Prediction Model of Refrigerant Thermal Conductivity Coupled with the Standardized Equation of the State Parameterization Scheme

针对准确的制冷工质热导率性质有益于制冷热泵系统的设计和优化,引入标准化参数化方案,得到扰动链统计缔合流体理论状态方程(PC-SAFT)的输入参数,结合剩余熵标度理论(RES),预测了包括氢氟烯烃(HFOs)、氢氟烃(HFCs)、烷烃(HCs)和CO_(2)(R744)在内的11种常见制冷工质的热导率性质,使用自助法,获得了标准化参数化方案与常规参数化方案输入参数的不确定度,并展开不确定度分析。通过与文献实验结果及已报道热导率性质模型比对,所提热导率性质模型与实验数据的总体平均相对偏差为3.32%。结果表明:所提热导率性质预测模型的整体表现优于常规参数化热导率模型和CE参考项热导率模型,且标准化参数化方案有潜力为混合工质体系的研发和推广提供可靠的基础物性数据;两种参数化方案输入参数在不确定度范围内波动时,对气相迁移性质的预测影响程度相似,但标准化参数化方案在液相迁移性质的预测上表现更优;此外,基于标准化参数化方案预测迁移性质需特别关注偏心因子的精度。

The accurate and reliable prediction of the refrigerant thermal conductivity is beneficial to the design and optimization of refrigeration and heat pump systems.In this paper,the standardized parameterization scheme was introduced to obtain the input parameters of the perturbed-chain statistical association fluid theory EOS(PC-SAFT).The residual entropy scale theory(RES)was adopted to predict the thermal conductivity of 11 common refrigerants,including hydrofluoroolefin(HFOs),hydrofluorocarbon(HFCs),alkanes(HCs),and CO_(2)(R744).The bootstrap method was used to calculate the uncertainty of input parameters for both standardized parameterization schemes and conventional parameterization schemes.Meanwhile,an uncertainty analysis was conducted.Through the comparison of differences among the experimental data,the proposed model,as well as the reported thermal conductivity models,the overall average relative deviation between the thermal conductivity prediction model proposed in this paper and the experimental data was 3.32%.The results showed that the overall performance of the proposed model was better than that of the conventional parameterization and CE reference term methods.Moreover,this standardized parameterization scheme had the potential to provide reliable basic physical property data for the development and promotion of mixed refrigerant systems.When the input parameters of the two parameterization schemes fluctuated within the uncertainty range,the standardized parameterization scheme achieved better performance in predicting liquid phase transport properties despite a similar degree of influence on the prediction of vapor phase transport properties.Furthermore,special attention should be paid to the accuracy of the acentric factor regarding the prediction of transport properties based on standardized parameterization schemes.