纳入量子效应的变阱宽方阱链流体状态方程

Equation of state with quantum effects for square-well chain fluid with variable range

氦、氢等小分子物质在低温高密区常呈现出显著的量子效应,经典分子热力学方法难以精确描述.在统计缔合流体理论框架下,我们将表征量子效应的特征参数德布罗意波长引入修正经典方阱势能函数的作用范围,构建了新的可高精度描述具量子效应流体热力学性质的变阱宽方阱链状态方程(QSWCF-VR),将描述常规流体和具量子效应流体热力学性质的模型统一到同一理论框架.基于氦、氢、氘、氖纯组分气液平衡实验数据,获得了表征各纯物质特性的分子参数,并据此高精度预测了它们的完整相图和临界性质.本工作可为具量子效应流体热力学性质描述及氢能应用等提供理论支撑.

Some components with small molecular weight like helium, hydrogen and so on often exhibit significant quantum effects in the regions with low temperature and high density, which are difficult to accurately describe by the classical molecular thermodynamics models. To obtain a reliable model for this type fluid, the de Broglie wavelength was employed to characterize the quantum effects in this work. Based on the statistical associated fluid theory(SAFT), a novel molecular thermodynamic model(QSWCF-VR) that can accurately represent the phase behavior of fluids with quantum effects was then proposed through modifying the square-well width of the classical square-well potential with de Broglie wavelength. The presented model can be used for describing the thermodynamic properties of both conventional fluids and quantum-effect fluids. Based on the saturated vapor-liquid equilibrium experimental data of helium, hydrogen, deuterium, and neon, their molecular parameters characterizing the properties of each pure fluid are obtained, and their phase equilibrium, PVT curves and critical properties are then successfully predicted. The study will provide a theoretical support for the description of the thermodynamic properties of quantum-effect fluids.