Skip to content
Extra Form
Abstract The dual mixed refrigerant (DMR) cycle, which pre-cools natural gas with the mixed refrigerants and then liquefies the natural gas with another set of mixed refrigerants, is well known for having the highest efficiency among the liquefaction cycles. Its possible application to LNG FPSO is also extensively investigated. In this study, the optimal operating conditions, such as the equipment's flow rate, pressure, temperature, and refrigerant composition per flow of the DMR cycle, were determined in consideration of power efficiency. To determine the optimal operating conditions, a mathematical model was formulated based on the mathematical model of the single mixed refrigerant (SMR) cycle with additional consideration of tees, phase separators, and common headers. In the mathematical model, the 227 operating conditions were defined as unknowns and 196 equality constraints related to the thermodynamics for the equipment were formulated. Further, the 15 given variables related to the natural gas, compressor efficiency and seawater coolers were used. This mathematical model can be regarded as the optimization problem, in which the number of unknowns is larger than the total number of equality constraints and given variables. To obtain the optimal operating conditions, the minimization of the required power for the compressors at the cycle was defined as an objective function. Moreover, set as design variables were the 16 operating conditions, such as flow rate, pressure, temperature and composition of the main and precooling refrigerant, natural gas temperature after precooling, and flow rate ratio for the tee. In addition, the temperature conditions for the equipment’s operation were used as inequality constraints. The optimal operating conditions were then obtained by using a hybrid optimization method that consists of the genetic algorithm (GA) and sequential quadratic programming (SQP). The calculation results show that the required power at the obtained conditions was decreased by 34.5% compared with that of the relevant patent obtained in 2001, and 1.2% compared with the corresponding value from the past relevant study carried out in 2008.
Publication Date 2011-06-19

Kyu-Yeul Lee, Ju-Hwan Cha, Joon-Chae Lee, Myung-Il Roh, Ji-Hyun Hwang, "Determination of the Optimal Operating Condition of Dual Mixed Refrigerant Cycle at the Pre-FEED Stage of LNG FPSO Topside Liquefaction Process", Proceedings of ISOPE(International Society of Offshore and Polar Engineers) 2011, Maui, USA, pp. 151-158, 2011.06.19-24


List of Articles
번호 분류 제목 Publication Date
61 International Conference Luman Zhao, Myung-Il Roh, Seung-Ho Ham, "Hardware-In-the-Loop Simulation for the Design and Testing of an Active Compensation System on an Offshore Supply Vessel", Proceedings of SUTTC 2016, Beijing, China, 2016.09.26-30 file 2016-09-29
60 International Conference Seung-Ho Ham, Myung-Il Roh, Hye-Won Lee, Jung-Woo Hong, "Dynamic Motion Analysis of a Drilling Rig Connected with Flexible Risers based on Flexible Multibody Dynamics", Proceedings of SUTTC 2016, Beijing, China, 2016.09.26-30 file 2016-09-29
59 International Conference Ki-Su Kim, Myung-Il Roh, Seung-Ho Ham, "Ship Route Planning Considering the Effects of Sea State and the Fuel Consumption", Proceedings of PRADS 2016, Copenhagen, Denmark, 2016.09.04-09.08 file 2016-09-07
58 International Conference Seung-Ho Ham, Myung-Il Roh, Hye-Won Lee, Jeong-Woo Hong, "Multi-physics Simulation Framework for Design and Production of Ships and Offshore Plants", Proceedings of PRADS 2016, Copenhagen, Denmark, 2016.09.04-09.08 file 2016-09-07
57 International Conference Dong-Hoon Jeong, Myung-Il Roh, Seung-Ho Ham, Woo-Young Choi, Chan-Young Lee, Kyung-Min Seo, Dong-Chul Lee, "Simulation-Based Performances Analysis for Naval Ships at the Initial Design Stage", Proceedings of ISOPE 2016, Rhodes, Greece file 2016-06-30
56 International Conference Sung-Min Lee, Myung-Il Roh, Ki-Su Kim, Seung-Ho Ham, Shin-Hyung Kim, Jin-Ho Hwang, "Lug Arrangement Design Based on the Optimization Technique and the Dynamic Analysis for Safe Block Lifting in Shipbuilding", Proceedings of ISOPE 2016, Rhodes, Greece file 2016-06-30
55 International Conference Luman Zhao, Myung-Il Roh, Seung-Ho Ham, "Hardware-In-the-Loop Simulation for a Heave Compensator of an Offshore Support Vessel", Proceedings of OMAE 2016, Busan, Korea, pp. 1-5, 2016.06.19-24 file 2016-06-20
54 International Conference Ki-Su Kim, Myung-Il Roh, Sung-Kyoon Kim, "An Arrangement Design Framework for Ships and Offshore Plants Based on Expert System and Optimization Technique", Proceedings of OMAE 2016, Busan, Korea, pp. 1-5, 2016.06.19-24 file 2016-06-20
53 International Conference Seung-Ho Ham, Myung-Il Roh, Hye-Won Lee, Dong-Hoon Jeong, "Physics-based Simulation Considering Collision During Production and Installation of Ships and Offshore Plants", Proceedings of ICCGS 2016, Ulsan, Korea, 2016.06.15-18 file 2016-06-16
52 International Conference Myung-Il Roh, Seung-Ho Ham, Ki-Su Kim, Luman Zhao, "Integrated Simulation Based on Multiphysics Analysis, Virtual Reality, and Hardware for Offshore Installation, Operation, and Maintenance", OTC Asia 2016, 2016.03.22-26 file 2016-03-23
Board Pagination Prev 1 ... 3 4 5 6 7 8 9 10 11 12 ... 14 Next
/ 14

Powered by Xpress Engine / Designed by Sketchbook

sketchbook5, 스케치북5

sketchbook5, 스케치북5

나눔글꼴 설치 안내


이 PC에는 나눔글꼴이 설치되어 있지 않습니다.

이 사이트를 나눔글꼴로 보기 위해서는
나눔글꼴을 설치해야 합니다.

설치 취소