Modeling and Research of Gas Transportation Unit Operation Modes

The main objective of this paper is to describe the methodic and the software developed by authors, which has aimed to simulate operation modes of a centrifugal gas compressor and associated equipment. In this paper, the computer-based design and the analysis of control systems for centrifugal gas compressors are presented. The structure of the mathematical models and the solution methods are discussed. A Visual Basic-based application has been built to solve the system dynamics and to generate the model in installation executable format. The application allows simulating the behavior of a gas compression network through an individual simulation of each component in the network like gas compressor, valve, heat-exchanger, gas-liquid separator, pipe line. Flow through the system elements is modeled as a multi-component compressible gas flow and the Redlich-Kwong Equation of State is used to solve the mass conservation equation. Based on the centrifugal gas compressor theory an anti-surge control strategy has been applied to the model in order to predict and control surge cases. The one-stage gas compression model has been used to verify how the software responds to changes in the suction and discharge conditions.