ABSTRACT

Energy efficient and environmentally friendly shipping have been primary concerns for the maritime industry. One of the alternatives to overcome these issues onboard is organic Rankine cycle (ORC) waste heat recovery system (WHRS). In this study, a transcritical ORC WHRS for a marine diesel engine is investigated at different engine operating loads by thermodynamic and environmental analysis. The engine exhaust gas is used as the waste heat source and R152a is selected as the working fluid. The energetic, exergetic and environmental parameters are analysed and the performance optimisation is conducted by using genetic algorithm. The results indicate that by employing the ORC system onboard, it is possible to increase the overall thermal efficiency of the ship power generation system by more than 2.5% and the system can save up to 678.1 tonnes CO₂ per year when the system is operated at the optimal conditions.

摘要

节能环保的航运一直是海运业的主要关注点。船上克服这些问题的替代方案之一是有机朗肯循环 (ORC) 废热回收系统 (WHRS)。在这项研究中，通过热力学和环境分析，研究了在不同发动机工作负载下用于船用柴油发动机的跨临界 ORC WHRS。以发动机废气作为余热源，选用R152a作为工质。分析了能量、热能和环境参数，并利用遗传算法进行了性能优化。结果表明，通过在船上采用ORC系统，可以将船舶发电系统的整体热效率提高2.5%以上，系统可以节省高达678.1吨的CO当系统在最佳条件下运行时，每年₂次。