Real thermodynamic energy and enthalpy on High Pressure Pneumatic System Based on Improved Virial Equation

摘要

This paper proposes an approach to calculate the specific thermodynamic energy and specific enthalpy of real gas. In the high-pressure air pneumatic system, the thermodynamic properties of the air which regarded as ideal gas would produce a large deviation to the actual value, thus seriously reducing the authenticity of the pneumatic parameters. In view of this, the specific residual thermodynamic energy and specific residual enthalpy of the high-pressure air were presented on the basis of modified corresponding state equation and virial equation which truncated to the third virial coefficient. In the specific enthalpy calculation for real gas, a difficult part of integration can be avoided by judiciously using advised residual functions. The true thermal physical property parameters of pneumatic system were obtained under the conditions of the wide variations of temperature and pressure.