Optimal working fluids and economic estimation for both double stage organic Rankine cycle and added double stage organic Rankine cycle used for waste heat recovery from liquefied natural gas fueled ships

• Published in: Energy conversion and management 2021-08, Vol.242, p.114323, Article 114323
• Main Authors: Lim, Tae-Woo, Choi, Yong-Seok, Hwang, Da-Hye
• Format: Article
• Language: English
• Subjects: Computational fluid dynamics; Economic analysis; Economic models; Exergy; Exhaust gases; Exhaust systems; Heat exchanger; Heat recovery; Heat transfer; Heat transfer area; Liquefied natural gas; Natural gas; Organic Rankine cycle; Payback periods; Performance evaluation; Rankine cycle; Ships; Waste heat; Waste heat recovery; Working fluid; Working fluids
• ISSN: 0196-8904; 1879-2227
• DOI: 10.1016/j.enconman.2021.114323

•Double stage organic Rankine cycle can recover waste heat from duel fuel engine.•Working fluids R123, R141b, R601, R245fa, R236ea and R1233zd are used.•Power and payback period are 1840 kW and 4.22 years for R123-R245fa, respectively. Double and added double stage organic Rankine cycle systems are configured to recover exhaust gas waste heat of dual fuel engines. To evaluate the performance of the models proposed here, energy, exergy and economic analyses are performed. Several working fluids are evaluated for recommendation for double and added double stage organic Rankine cycle systems. In the double stage organic Rankine cycle, cycle 1 and cycle 2 are connected in parallel. Working fluids R123, R141b, and R601 are used in cycle 1, and R245fa, R236ea, and R1233zd in cycle 2. In the double stage organic Rankine cycle, the working fluid combinations of R601-R1233zd, R601-R245fa and R123-R245fa show better performance when considering power, heat transfer area and payback period, which are 1760 kW, 2108.9 m2 and 4.21 year, respectively for R601-R245fa. In the added double stage organic Rankine cycle, cycle 1 and cycle 2 are connected in two stages and cycle 1 and cycle 3 in parallel. The net power of the working fluid combinations of R123-R245fa and R123-R1233zd are 1799 kW and 1782 kW, respectively, which are higher than those of the others. Further, for R123-R245fa, the heat transfer area and payback period are 3352 m2 and 6.20 year, respectively, which is better compared to those of other working fluid combinations.