Inproving the efficiency utilization  of fuel gas excess pressure in two-stage expander


The study considers the feasibility of applying the expander-generating units for the electric energy production instead of throttle pressure regulators. The research shows the importance of the influence of the operating parameters of the gas supply system and their changes in the electric energy quantitative estimation produced by the expander-generator unit. Such parameters are gas pressure in the supply pipeline and a gas flow rate through the expander. The study shows that the regulation of the expander-generator unit is provided in varying degrees of throttling the gas flow while reducing gas consumption. Periodic changes of pressure in the main gas pipeline and the gas flow result in the need to use the throttle gas regulator in front of the expander. Consequently, this fact reduces the efficiency of the expander-generator unit installed on gas-distributing stations or gas control point. The proposed series and parallel two-cylinder utilization expander unit provides the ability to limit the throttling process in the regulation of plant operation. As a result, this allows increasing the electric energy production and making a better use of the energy of excess gas pressure. Among the benefits of this study, by switching from a parallel circuit to a series circuit, there are additional electric energy generation and better utilization of energy excess gas pressure which are achieved under certain conditions.