Performance analysis of a novel multimode electricity-cooling cogeneration system (ECCS) driven by exhaust from a marine engine

Abstract

Multiple operating modes and flexible outputs are typical characteristics of multimode electricity-cooling cogeneration systems (ECCS). The present study proposes an innovative multimode ECCS driven by exhaust gas from marine engines and presents a corresponding thermodynamic system model. The thermodynamic performance, distribution region of operating modes, and exergoeconomic performance of the system are comprehensively investigated under various operational conditions. A novel comprehensive evaluation index, namely, the system net output per unit total mass flow rate (NOPF), is introduced to ensure that the analysis of system performance remains unaffected by the variations in the mass flow rate of the working fluid. The findings indicate that the operational modes exhibit diverse responses to influencing variables, while the distribution region of the operational modes is more sensitive to the separation ratio of the working fluid flow rate (X). Under the electricity-cooling generation mode of the system, the maximum NOPF reaches 156.01 kJ·kg-1. Furthermore, the proposed system achieves a peak exergy efficiency (ηex) of 13.83%, concurrently decreasing the electricity production cost (EPC) to a mere 0.0981 Dollar·kWh-1. Finally, this study offers new research insights that can inform future regional analyses of other multimodal and multigeneration systems.