Research On Key Physical Properties In The Design Of Natural Gas Compressor

Natural gas compressor plays a important role in the industrial development of natural gas.It is widely used in industrial processes such as gas gathering,piping and pressurization.It makes a difference in the natural gas industry whether natural gas compressor be safe,economical and efficient.There is a certain gap between domestic compressor and foreign compressor in terms of service life,reliability,technical parameters and so on.One of the key issues to optimize the thermal design of natural gas compressor is to keep the calculation accuracy of natural gas physical properties.This paper researches around the accurate calculation of the physical parameters in the design process of natural gas compressor,including the p-V-T-x and V-L equilibrium parameters,in order to study the applicability of the cubic equations of state in calculating physical properties of natural gas mixture.The calculation models of SRK,PR and NB were established by using Fortran language in CVF platform.The calculation results were compared with the experimental data in compression factor,gas density and specific heat.According to literature,REFPROP developed by NIST is suitable for the calculation of the physical properties of hydrocarbon.The author reviewed a large number of literatures to collect experimental data to verify the accuracy of REFPROP in calculating natural gas properties.40 kinds of natural gas and 90 actual working conditions provided by the Shen Gu company were used to study the applicability of PR in predicting natural gas physical properties,in which REFPROP was used as the contrast data source.Viscosity is one of the important physical properties of natural gas.At present,there is no strict theory can make the viscosity as a function of temperature and pressure,and there are no binary regression models can accurately describe the relationship of viscosity with temperature and pressure because of the complication.In this paper,a new method is proposed to establish a function of viscosity with temperature and pressure in a suitable range(230K?T?450K,p?20MPa).It can accurately predict the viscosity of 17 natural gas pure components.