Fast and simple calculation of thermodynamic properties of refrigerant using quadrilateral interpolation from preprocessed thermodynamic table.

Modern thermal energy systems are required for being smarter and more intelligent in connection with information and communication technology (ICT) to perform multiple functions. To achieve this goal, a number of complicated property calculations are essential. The refrigerant property calculation program REFPROP developed by NIST is most popularly used, however, direct use of REFPROP for low-end ICT devices are too heavy to be equipped. In this manner, an alternative computational method to calculate refrigerant property from thermodynamic tables is developed. As two steps of the procedure, machine-friendly thermodynamic tables are generated from REFPROP first, and then quadrilateral interpolation is carried out for intermediate properties. The results showed competitiveness of the interpolation method compared with the original calculation from REFPROP. From the research, the generation of thermodynamic tables is found to be important to increase its accuracy and reliability of property calculation.

为实现多重功能，现代热能系统需结合信息与通信技术（ICT）向智能化方向发展。为达成该目标，需开展大量复杂的物性计算工作。由美国国家标准与技术研究院（National Institute of Standards and Technology, NIST）开发的制冷剂物性计算程序REFPROP是目前应用最为广泛的工具，但直接将REFPROP部署于低端ICT设备时，其运算负载过高，难以适配。为此，本研究开发了一种基于热力学表格的制冷剂物性替代计算方法。该方法包含两个核心步骤：首先基于REFPROP生成面向机器读取的热力学表格，随后通过四边形插值算法求取中间物性参数。结果表明，该插值方法与REFPROP原生计算结果相比具备竞争力。经本研究验证，热力学表格的规范化生成对提升物性计算的精度与可靠性具有重要意义。