Multi-objective optimization of series system for heat recovery: Technical and economic tradeoff

The refrigeration system on fishing vessels consumes a lot of fuel and increases carbon emissions. The absorption system for ice-making driven with the waste heat of the internal combustion engine is a feasible method to achieve "Nearly Zero Energy" freeze preservation. In this paper, firstly, the ammonia absorption cycle driven by the waste heat of the fishing boat was thermodynamically modeled, and it is found that the absorption chiller's performance is affected by the engine power, cooling water temperature. Secondly, by establishing a thermoeconomic model, taking the capital, operation cost into consideration, the thermal economy of the system is analyzed; finally, through the multi-objective of the genetic algorithm, Pareto optimal frontiers of the system were presented. Different clusters of the optimal results show that the investment payback time can reach 2.50 years and 2.58 years; with exergy efficiency 37.81% and 37.86%, respectively.