圆柱定程干涉法测量混合工质气相声速的探索

The investigation on the speed of sound measurements with fixed-path resonator is one of the essential methods for the research on the thermophysical properties of working fluids. The mixtures are considered as potential alternatives for working fluids. This project focuses on developing the technologies of the speed of sound measurements by fixed-path cylindrical resonator as an accurate method for the measurements of the speed of sound of mixtures. The theoretical correction models of non-ideal perturbations caused by molecular relaxation and boundary layer effect in the measurements of speed of sound of the mixtures are established. The reliability of the correction models are verified by measurement of speed of sound of CO2, He/Xe mixtures and so on. The methods of mixture concentration control, measurement and analysis are developed and the design of experimental system is improved. The control methods and measurement processes of the measurement are optimized. The fixed-path cylindrical resonator is developed as an effective method for measuring the speed of sound of gaseous mixtures. Based on those experimental system improvements, the speed of sound of HFO/HC mixtures, such as HFO1234yf/isobutane、HFO1234ze(E)/isobutane and so on, will be measured with high accuracy, and the ideal gas specific heat, the virial coefficients and the relative thermal properties will be derived by fitting the acoustic data. The parameters of the potential function of square-well and Lennard-Jones model will be also determined. The state of equations of the mixtures of HFO/HC will be established based on the measurements. This study will provide theoretical bases for the investigation and application of the HFO/HC mixtures as alternative working fluids.

圆柱定程干涉法测量气相声速是工质热物性研究的重要方法。混合工质是极具潜力的工质替代方案。本项目探索解决圆柱定程干涉法应用于混合工质气相声速测量过程中的关键瓶颈。建立混合工质气相声速测量中分子弛豫、边界层效应引起的声学非理想因素的理论修正模型，并采用CO2、He/Xe等工质气相声速的测量验证模型的可靠性；开发混合工质组分浓度控制与测量分析方法，改进实验系统设计，优化控制方法与测量流程，将圆柱定程干涉法发展为混合工质气相声速精密测量的有效方法。在此基础上，开展HFO/HC类环保混合工质(HFO1234yf/异丁烷、HFO1234ze(E)/异丁烷等)的气相声速测量，推导获得混合工质理想气体比热、维里系数等热物性基础数据，并回归方阱势能和Lennard-Jones等势能模型参数，建立混合工质的通用状态方程，为HFO/HC类替代工质的深入研究和工程实践提供理论基础。

声速体现了介质的膨胀和压缩特性，是工质最基本的热力学性质，对于动力循环系统设计开发、工质热物性规律揭示具有非常重要的意义和价值。混合工质气相声速高精度测量是工质声速测量的热点和难点。本项目针对低密度区和高密度区流体声速测量的关键瓶颈，建立了适用于低密度区气相声速测量的圆柱定程干涉法和高密度区声速测量的双反射脉冲法，开展了具有应用前景的Xe、HFO1234yf、HFO1243zf纯净物及He+Xe、HFO1234yf+HC600a混合工质的气相声速测量及H2O液相声速的实验研究，并开发了惰性气体二元混合物及HFO/HC类工质的高精度的热力学性质计算模型，揭示了惰性气体、HFO/HC类混合工质的物性物性规律。将圆柱定程干涉法发展成为了混合工质气相声速测量的有效方法。.项目的主要成果为：建立了混合工质气相声速测量中分子弛豫、边界层效应引起的声学非理想因素修正，完善了混合工质圆柱定程干涉法气相声速测量理论模型，开发了混合工质组分浓度控制及测量分析方法，解决了混合工质气相声速测量的关键瓶颈，建立了混合工质的气相声速测量系统；获得了国际第二套简单分子Xe、He-Xe混合工质及HFO1234yf、HFO1243zf和国际首套HFO1234yf+HC600a混合体系的气相声速基础数据，获得了Xe、HFO1234yf、HFO1243zf的声速维里系数、维里系数、定压比热容、分子势能模型参数；建立了惰性气体二元混合工质的维里系数等高精度热力学性质计算模型，实现了惰性气体族及其二元混合物的热力学性质高精度计算；建立了高密度流体声速测量方法，开发了国内首套双脉冲反射法高密度流体声速测量系统，发展了高密度流体声速测量方法。研究成果将为新一代环保混合工质的热力循环系统设计开发、惰性气体及新型混合工质物性规律的深入研究奠定基础。.在项目的资助下，项目负责人获得了国家科学技术进步奖一等奖，发表学术期刊论文11篇，被SCI收录6篇，相关研究成果将在空天动力系统、航空航天气动热力学等研究领域应用。