4E analysis of a novel proton exchange membrane fuel cell/engine based cogeneration system with methanol fuel for ship application

Abstract

Cleaner fuels and more efficient systems are important for achieving green, low-carbon ships. In this paper, a novel proton exchange membrane fuel cell/engine based cogeneration system with methanol fuel (MPEC system) for ship application is proposed. By the online catalytic reforming process of methanol, the obtained hydrogen through reforming can provide sufficient high heating value fuel to the MPEC system. The energy efficiency, exergy efficiency, economy and environment (4 E) analysis method is adopted for the comprehensive performance analysis of the MPEC system. The results show that the proposed MPEC system can achieve cogeneration efficiency and power generation efficiency as high as 81.84% and 50.46%, respectively, which performs that the generation efficiency is improved by 19.55% compared to the single engine, and the biggest exergy loss process occurs at the engine. The total life cycle carbon emission and levelized cost of energy of the MPEC system are 344.938 g/kWh and 0.1411 $/kWh, separately. Moreover, the effects of various parameters on the MPEC system performance are analyzed, mainly including steam carbon ratio, current density, etc. Overall, a low-carbon power system with high efficiency and good load performance is achieved by combining high-efficiency fuel cell with a powerful engine.