Understanding and improving the 9-coefficient pressure viscosity temperature (PVT) model

International Conference on Compressors and their Systems 2019

Barthel, Anthony J.^1 ; Majurin, Julie^1

CPI Fluid Engineering, Midland

MI, United States^1

关键词: Input datas;    Instrument setup;    Mixed refrigerants;    Model accuracy;    Operating condition;    Pressure-viscosity;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/604/1/012033/pdf
DOI  :  10.1088/1757-899X/604/1/012033

来源: IOP

【 摘 要 】

Data describing the physical properties of a mixed refrigerant-lubricant blend is necessary for compressor and system design and is measured using a pressure, viscosity, temperature (PVT) instrument setup. Measurements are taken at discrete conditions and refrigerant concentrations and a model is regressed which can describe pressure (refrigerant solubility), working viscosity, and density across the range of interest. Understanding the applicability of the model is crucial in choosing a suitable lubricant, since the tested conditions are unlikely to exactly match all operating conditions of interest. This paper describes how the PVT model is created, and how choices in input data can affect the resulting model. Emphasis is placed on the range over which PVT models are valid and what can be done to increase model accuracy.