Analysis of Thermodynamic Efficiency of Small-Scale Natural Gas Liquefying Plant Operating on Medium-Pressure Cycle

Abstract

The sole Russian Federation LNG plant operating in Ekaterinburg on medium-pressure expander cycle (Claude cycle) allows utilization of the energy of pressure fall at a gas distributing station. The thermodynamic efficiency of the plant is 17.5%, which matches the current level of development in this category of cryogenic plants. Statistical entropy analysis showed that the major contribution to the nonequilibrity of the liquefaction process is made by remote mainline compressor (up to 40%) and turboexpander-compressor aggregate (up to 25%). This fact opens up possibilities of improving LNG plants further by switching to other methods of cold generation using, in particular, rotor wave cryogenerator