Thermo-economic optimization and environmental analysis of a waste heat driven multi-ejector chiller for maritime applications

Waste heat recovery from cruise ship engines is an attractive solution to mitigate the significant environmental impact of such systems. In this paper, a novel thermo-economic-environmental analysis is conducted on a waste heat driven multi-ejector compressor assisted chiller employed for air conditioning on a cruise ship ongoing in the Baltic Sea. Each component is modelled using validated sub-models, and a multi-objective optimization of several independent variables is performed to optimize the system design and find the best trade-off between nominal performance and investment costs. The proposed system is then compared to a traditional electric chiller by simulating their performance during the entire cooling season. The thermo-economic-environmental analysis results point out that the hybrid cycle allows higher performance, especially with a cold storage tank, payback period between 4 and 14 years (depending on the fuel prices, varying between 1.5 €·kg−1 and 3.0 €·kg−1) and pollutant emissions reduction up to 70 % compared to the baseline electric chiller.