Farrukh Khalid

Energetic and exergetic analyses of a hydrogen-fuelled HCCI engine for environmentally benign operation

In this paper, combined first and second law approach is applied to investigate the effects of percent excess air and ambient temperature on the energy and exergy efficiency of the hydrogen-fuelled homogeneous charge compression ignition engine. A maximum energy efficiency of 45% and an exergy efficiency of 37% are obtained at the excess air of 25%. A narrow range of 42–40% energy efficiency and a wide range of 25–45% exergy efficiency were achieved between the 20–40% excess air and an ambient temperature of 300 K. Close range of variation for energy efficiency (48–44%) and exergy efficiency (32–36%) were achieved between the ambient temperatures of 13°C and 41°C. Exergy analysis indicates that 52% of the fuel hydrogen exergy is destroyed due to various irreversible processes of the engine, around 40% is available as a useful work output, and 7.83% is lost via engine exhaust.

3.16 Thermal Energy Production

This contribution outlines and discusses the importance of thermal energy and its applications. Various forms of thermal energy are presented and discussed from energy, economic and environmental points of view. In order to provide a good understanding of the technical presentations of the options for thermal energy, illustrative examples are provided. Furthermore, various case studies on various systems (single to multigeneration) through tidal and getothermal are presented to highlight the importance of the subject and illustrate how the system performance is affected by changing state properties and operating conditions. In addition, the use of wind energy for thermal energy production is also described.

3.8 Ocean (Marine) Energy Production

This contribution outlines and discusses the importance of ocean (marine) energy and its applications for energy production. Various forms of ocean energy are presented and discussed from energy, economic, and environmental points of view. In order to provide a good understanding of the technical presentations of the options for ocean energy, illustrative examples are provided. Furthermore, a set of different case studies are included on analyses of the utilization of ocean thermal energy conversion (a type of ocean energy) for multigeneration incorporating other renewable energy sources (solar and geothermal). In addition, salinity gradient energy (a new type of ocean energy) is also described.