Recovering the remaining cold energy from the regasification process is one of the key challenges of the overall LNG value chain. This paper aims to develop a cryogenic energy storage system (CES) integrated with LNG direct expansion regasification (LNG–CES) that can recover cold energy and store it as cryogenic energy using air as the working fluid. Cold energy of LNG is available in two forms: thermal energy by heat exchange and shaft work by expansion, while the cryogenic storage process requires compression and cooling. The supply and demand of LNG direct expansion and cryogenic energy storage processes are well balanced. Therefore, a combined LNG–CES process to store energy will prove efficient. This study proposes an industrial-feasible design for the LNG–CES process and energy optimization to maximize net power output from the process. Moreover, a novel process design is proposed to recover cold energy lost during LNG regasification more efficiently. Energy optimization results of the proposed design demonstrated an 11.04% increase in the net power generation from the feasible configuration of the base design. Additionally, the cause of this improvement was studied using thermodynamic analyses.
Bibliographical noteFunding Information:
This research was supported by Basic Science Research Program through the National Research Foundation of Korea , funded by the Ministry of Education (Grant Number: 2018R1 A6A3A03011666 ).
© 2019 Elsevier Ltd
All Science Journal Classification (ASJC) codes
- Civil and Structural Engineering
- Building and Construction
- Mechanical Engineering
- Industrial and Manufacturing Engineering
- Electrical and Electronic Engineering