No description available.

No description available.

The purpose of this project was to optimise a diesel engine converted to operate on natural gas, to suit the requirements for: low emissions, a high efficiency and sufficient power delivery within the constraints of cogeneration (combined heat and power) systems. Cogeneration Installations seek to improve the efficiency of power generation by utilising waste heat from the prime mover, as well as the production of electricity. Many small scale systems are based on open chamber gas engines, and, to reduce the payback time for the installation, the overall engine efficiency is of prime importance. Stationary engines can be subject to strict standards for emissions, the greatest challenge being presented by the control of NO emissions. The main difficulty is that the highest efficiency operating point of a spark ignition engine is also the point of maximum NO emissions. The extent of this problem was analysed by conducting tests across the entire operating map of the baseline engine at the required speed of 1500 rpm. The solution, in the form of a new high compression ratio combustion system was based on the following: An extensive literature review, the previous Brunel experience with gas engines, an evaluation of the baseline combustion and emissions performance, and the predictions of the Integrated Spark Ignition engine Simulation (ISIS) thermodynamic model. Tests were conducted on the new Fast Bum High Compression Ratio combustion system at compression ratios of 15:1 and 13:1, which demonstrated an extended lean burn capability such that an operating point was identified, that satisfied the conflicting requirements of: low emissions (less than 1g NOx/kWh or 360mg/m3), and a high brake efficiency (above 30%), as well as particular cogeneration criteria. The bmep was mostly above 6 bar. After further tuning and calibration with experimental data, the ISIS model was used to predict the engine power output, efficiency and emissions (NOx and CO) for the compression ratio of 15:1, across the entire operating map for both naturally aspirated and turbocharged configurations. The naturally aspirated results showed good agreement with the results of the experimental 15:1 FBHCR combustion system. The turbocharged engine was simulated with a bmep of 10 bar. The results identified much larger operating areas and all emissions limits were met above a brake efficiency of 36%. The conclusions are, that an open chamber fast bum high compression ratio combustion system can achieve very low emissions, particularly of NOx, and a high efficiency by having the capability of operating with lean enough mixtures. Further improvement in the efficiency is likely if other engine parameters (such as the valve timing) were to be optimised for 1500 rpm. The results from the turbocharged simulation show that turbocharging, whilst restoring the output can also achieve low emissions, and a higher efficiency than a naturally aspirated engine.

Today's societies are critically dependent on the reliable supply of electricity. The reliable operation of large synchronous generators in power stations is therefore of paramount importance. Thus, power utilities are most keenly concerned in taking measures to avoid catastrophic failures and to minimise the impact of generator outages due to faults. Each generator constitutes one of the most expensive single pieces of equipment in the power station. Although they are mostly reliable and generally require minimal maintenance, faults can and do occur with varying degrees of consequences ranging from minor outages to catastrophic failures. / When faults occur, cause-effect relationships need to be identified systematically. This is necessary for having a better understanding of the fault formation mechanisms so that preventive measures can be taken, although sometimes the immediate pressures for returning a generator to service may impede a thorough investigation. / This thesis is borne of the Author's experiences in dealing with large synchronous generators of various sizes and designs. The purpose of this thesis is to report on practical problems in the operation of large synchronous generators and offer advice on remedy. It presents carefully documented cases of faults. These vary from fractured stator conductors and core overheating to cracking of rotor retaining rings and winding short circuits. Symptoms of various faults are discussed along with the extent of damage and remedial solutions. Emphasis is placed on being able to prevent the fault recurrence and prolong the mean time between failures (MTBF). / Thesis (MEngineering(Research))--University of South Australia, 2006.

Since the 1980s, approximately 10 MWp photovoltaic (PV) power has been installed in off-grid areas in Indonesia for powering lighting, water pumping, communications, health clinics, etc. However, PV energy systems (PVES) have yet to prove their sustainability and remain inaccessible to many remote Indonesian communities. The objective of this interdisciplinary thesis is to draw on social and engineering perspectives to address sustainability issues related to off-grid PVES delivery in Indonesia. By employing the Brundtland definition of sustainability, off-grid PVES delivery is analysed with respect to its institutional, financial, technical, social and ecological sustainability. In parallel, the thesis also investigates PVES Accessibility, Availability and Acceptability (3A), referring to the three energy goals proposed by the World Energy Council. The concepts of Sustainable Development, Social Capital, and Diffusion of Innovation are employed to examine the potential for off-grid PVES to contribute to improving the sustainability of remote Indonesian communities. The I3A (Implementation, 3A) Sustainable PVES Delivery framework is proposed to investigate PVES sustainability and the extent to which local communities can continue to socially innovate to meet their evolving needs beyond initial project completion. Sound project management (PM) is essential as off-grid PVES projects can only access limited resources (time, funds, and scope) and project failure can undermine a community???s capacity to innovate. The research methodologies include literature research, qualitative field research in villages where PVES has been installed and interviews with a wide range of PVES stakeholders in Indonesia. The I3A framework is tested against three off-grid PVES case studies from Lampung, West Java and NTT Provinces and is also proposed as a design tool. A key conclusion is that, to be sustainable and equitable, off-grid PVES projects should be implemented in an institutional framework that provides sound project management and addresses PVES accessibility (financial, institutional and technological), availability (technical quality and continuity) and acceptability (social and ecological). The overall objectives are to acknowledge the interests of all stakeholders, maximise equity, assure PVES continuity, and institutionalize PVES by utilizing and enhancing preexisting community resources to leave the community with the capacity to socially innovate. While this might be regarded as idealistic, enhanced local autonomy and capability will be essential in the context of the energy security and climate change challenges that humanity now faces.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: photovoltaic; solar satellite; optimize; dc-dc. Includes bibliographical references (leaves 51).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 53-56). Also available via the Internet.

Thesis (Ph.D.) - University of Glasgow, 2008. / Includes bibliographical references. Print version also available.

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 154-159).

Thesis (Ph.D.)--University of Texas at Arlington, 2009.