| dc.description.abstract | Hydrogen and ammonia are the carbon-free fuels that have the potential to replace the fossil fuels in the near future. In addition, they can also act as energy carriers and storage media for many applications; particularly in the transportation sector, which contributes around 25% of the global greenhouse gas (GHG) emissions, and a substantial reduction to this share will undoubtedly achieve better environmental conditions. In this thesis, six novel integrated systems for powering vehicles are conceptually developed and introduced.All the system are thermodynamically modeled by applying energetic and exergetic approaches via the Engineering Equation Solver software (EES). The obtained results are validated by using energy and exergy analyses and available data from the literature. Moreover, exergoeconomic analysis has been carried out for the proposed systems. The Genetic Algorithm is utilized to optimize the introduced systems to achieve the optimum performance with the least possible cost for each system.
For the same power output of 118 kW, the overall energy and exergy efficiencies of system 1, which comprises Li-ion battery, PEMFC system and PV panels are found to be 45.9% and 46.4% at a fuel cell current density of 1150 mA/cm2 respectively. The energy and exergy efficiencies of system 2, which comprises Li-ion battery, PEMFC system, PV panels and AEC unit are found to be 47.5% and 47.4% at a fuel cell current density of 1150 mA/cm2 respectively. The overall energy efficiencies of systems 3, which comprises ammonia-hydrogen ICE and ammonia dissociation separation unit (ADSU) and system 4, which comprises ammonia-hydrogen ICE, ADSU and PEMFC system are obtained as 31% and 38.6% respectively. The overall exergy efficiencies of systems 3 and 4 are found to be 28.8% and 36.2% respectively. The overall energy and exergy efficiencies of system 5, which consists of ammonia-hydrogen ICE, thermoelectric generators (TEG) and AEC unit are found to be 31.1% and 28.9% respectively. The overall energy and exergy efficiency of system 6, which consists of Li-ion battery, gas turbine, TEG, organic Rankine cycle (ORC) and absorption chiller are found to be 32.3% and 29.2% respectively. | en |
