Design and optimization of cryogenic process

Abstract

Refrigeration system is widely used in the industry, especially in cryogenic process. The main problem of refrigeration system is high energy consumption from shaft work resulting in high operation cost. To minimize the amount of shaft work, it is accomplished by a combination of pinch and exergy analysis. The strength of pinch analysis is graphical representation by using simple diagrams of composite curves and grand composite curve for process modifications. However, limitation of pinch analysis is that it only deals with thermal system, not including power or shaft work. Exergy analysis is a tool to utilize power or shaft work and identify thermodynamic imperfection of process. Both strengths are combined to help improve process efficiency. In this study, this methodology is applied for case study of LNG to improve processes such a reducing shaft work and increasing the exergy efficiency. Furthermore, the cascade refrigeration system is designed by mathematical programming.