Advanced exergetic analysis of a refrigeration system for liquefaction of natural gas

Abstract

During the last years the total cost of LNG technology has decreased significantly due to improvements of the liquefaction process by developing new schematics with different mixtures as working fluids. However, many liquefaction plants, based on a three-cascade refrigeration system, are in operation in the world. In this paper, a three-cascade refrigeration system for liquefaction of natural gas is used as an example to apply the advanced exergetic analysis. With the aid of this analysis, the interactions among system components as well as the potential for improving the thermodynamic efficiency of components and of the overall system are revealed. The objective of this paper is to demonstrate (a) the potential for thermodynamic improvement of a three-cascade refrigeration system for liquefaction of natural gas, and (b) the capabilities associated with an advanced exergetic analysis.