Publication

Electrochemical Application For
Advanced Energy System Labortary.

Journal

Optimal design of organic Rankine cycle recovering LNG cold energy with finite heat exchanger size
Author
Choi Hong Wone
Co-author
Na Sun Ik, Hong Sung Bin, Chung Yoong, Kim Min Soo, Kim Dong Kyu*
Journal
Energy
Status
Published
Vol
217
Year
2021

An optimization study, under a size constraint, was carried out for an organic Rankine cycle (ORC) combined with an LNG regasification plant for recovering LNG cold energy. Typically, many researchers approached to an optimization problem by assuming pinch point or minimum approach temperature difference. As a different point of view, the size constraint was considered in that resources such as thermal energy and equipment size are limited in a real problem. Given this situation, adequate allocation of finite resources is an important issue for the system to maximize performance. Thus, the aim of this study is to understand how to properly utilize the resources when LNG cold energy and total conductance of heat exchangers are limited. Accordingly, the influences of heat duty allocation, UA allocation, and superheating a turbine's intake on net power were mainly taken into account. Results indicate that, when total conductance for system design increases, the ORC should take more heat duty and total conductance should be weighted to an evaporator. In most cases, the size of heat exchangers should be weighted in the order of evaporator, condenser, and trim heater, provided that total conductance for system design is sufficiently available.