| dc.description.abstract | This thesis presents novel engine systems using alternative fuels for aviation, rail, and marine transportation as follows: (i) alternative powering systems, such as fuel cells, on-board hydrogen production (ii) alternative fuel choices with hydrogen, methane, methanol, ethanol, and dimethyl ether; and (iii) different methods for waste retrieval energy, such as absorption refrigeration systems, desalination system, and thermoelectrical generators. The systems are analyzed by three methods: thermodynamic, exergoenvironmental, and exergoeconomic analyses. Besides, the multi-objective particle swarm optimization (MOPSO) is applied for different operating conditions to choose the optimal design characteristic of the transportation systems. For aviation transportation, the base turbofan produces a power of 9144 kW and thrusting energy of 38 MW, with 43.4% and 52% energetic and exergetic efficiency, respectively, under cruising conditions. However, the maximum power of SOFC-turbofan is 48MW, including 7.3 MW of turbofan power, 39.8 MW of thrust energy, and 0.94 MW of the SOFC. The overall energetic and exergetic efficiencies of the hybrid turbofan are 48.1% and 54.4%, respectively. For rail transportation, the traditional rail engine produces a power of 3355 kW with 45 % energetic and 57% exergetic efficiency. A new design of gas turbine combined with SOFC and PEMEC produces about 5590 kW with 90% energy efficiency and 50% exergy efficiency. This engine is optimized to produce a power of 7502 kW with exergetic efficiency of 82% with reducing specific fuel and product exergy cost to 11.5 $/GJ and 14.5$/GJ, respectively. For marine transportation, the traditional marine engine produces a power of 10,524 kW with 23% energetic efficiency. However, a stream Rankine cycle combined with a hybridized gas turbine produces a power of 15546 kW with 61% energetic efficiency and 43% exergetic efficiency. This engine is optimized to produce a power of 16725 kW with exergetic efficiency of 70% and reducing specific fuel and product exergy cost of 18 and 28 $/GJ, respectively. In addition, all five fuel blends in the eight engines were able to reduce carbon emissions by more than 60% compared to traditional fuels. Also, the specific fuel consumption was reduced by 10-20% compared to the utilization of traditional fuels. | en |
