Thesis. 1978. Ph.D.--Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Ph.D.

The addressed topic is to investigate the power distribution at a base metal refinery and to identify the potential improvement in power consumption efficiency. The work included in this study revealed that the power consumption efficiency at the evaluated base metal refinery can be improved. The significance of this study relates to Eskom’s tariff increases and directive to mining and large industrial companies to reduce their power consumption as well as the recent incremental increase in power tariffs. Base metal refineries are substantial power consumers and will be required to evaluate the efficiency of their base metal production. A load study was conducted at a base metal refinery in order to determine the current power consumption at the various process areas. The measurements obtained from the load study formed the basis for calculations to determine the potential efficiency improvement. The load study revealed that the electro-winning area contributes to the majority of the power consumed (52% of total apparent power) at the refinery. The potential improvement in efficiency at the electro-winning process area was identified by means of evaluating the rectifier and rectifier transformer power consumption. Methods and technologies for the reduction in power consumption was consequently evaluated and quantified. The potential reduction in conductor losses by converting from global power factor correction to localised power factor correction for the major plant areas was furthermore identified as an area of potential efficiency improvement and consequently evaluated. The improvement in motor efficiency across the base metal refinery was identified by means of comparing the efficiency and power factor of high efficiency motors to that of the standard efficiency motors installed at the refinery. The work included in this study reveals that an improvement in power consumption efficiency is achievable at the evaluated base metal refinery. An efficiency improvement of 1.785% (real power reduction of 2.07%) can be achieved by implementing localised power factor correction and high efficiency motors. An average efficiency improvement of 1.282% (total real power reduction of 2.78%) can be achieved with the additional implementation of specialised, high efficiency rectifier transformer designs. The implementation of localised power factor correction as well as high efficiency motors was identified as short term efficiency improvement projects. A financial study was conducted in order to determine the cost and payback period associated with the reduction in real power consumption for implementation of the recommended efficiency improvement projects. The payback period, required to achieve an average efficiency improvement of 1.785%, was calculated to be approximately 4 years. The initial capital investment required to implement the efficiency improvement projects is about R22.5 million. The monthly electricity utility bill savings associated with the efficiency improvement projects is approximately R455,000. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.

M.Ing. (Engineering Management) / In January 2008, South Africa experienced a power crisis which changed how South Africa viewed its primary energy sector. South Africa largely depends on coal to generate 77% of the country’s energy needs. Eskom is the main electricity producer and the largest in Africa. Coal is the third largest exporter earner after gold and platinum and the second largest contributor to the South African export market after platinum (Falcon and Prevost, 2012). This highlights the importance of coal to the South African energy sector and economy. According to Geologist Chris Hartnady, the estimated coal production peak is in 2020, a period where most Eskom power station and mines would reach their lifespan (Davie, 2010). There are increased concerns about the quality of coal supplied to Eskom and the preference of coal producers to export coal to international markets. This could possibly compromise the supply of domestic coal. Historically, Eskom was supplied with lower grade coal and higher grade coal was exported. The increased demand for lower quality coal in the Asian markets has been an aggravating factor for the South African government to secure the security of coal supply to Eskom (Sapa, 2012). In March 2013, the South African government declared coal a strategic resource. This implies that the State has the right to regulate and restrict the export of coal to international markets. The available research conducted, by consulting economic firms such as the mineral advisory firm XMP consultants; suggest that the declaration of coal as a strategic resource will impact negatively on the South African economy in some ways and also influence investment attraction into the country (Booyens, 2013). This research seeks to analyse the consequences of declaring coal a strategic resource in South Africa. The enormities in the research subject title, “An analysis of the consequences of declaring coal a strategic resource in South Africa”, makes it extremely difficult to cover all aspects involved in a minor dissertation and to substantially quantify the results in monetary terms due to the facet of dynamic factors involved...

Thesis: M.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1980 / Includes bibliographical references. / by Akhil Gupta. / M.S. / M.S. Massachusetts Institute of Technology, Department of Mechanical Engineering

Power conservation has become a high priority to South African industries due to recent environmental assessments and electricity price hikes. This research aims to demonstrate to Industry the many simple and cost effective ways to increase their industrial efficiency with simple modifications, as well as making them more aware of common assembly errors that significantly increase power consumption. This has been accomplished with the design, construction and testing of a test rig capable of producing the desired test results which simulate Industry usage. A test rig was required to test certain energy efficient equipment. This dissertation contains an explanation of the tests required, as well as how they were conducted. These test requirements directed the design outcomes of the test rig. Due to the variety of equipment to be tested, and the accuracy required, the test rig had to be fully adjustable. The design process is explained in this dissertation, along with relevant theory with regard to the testing procedures. The testing procedures were designed to be as accurate as possible. The setup equipment and procedure is briefly explained to ensure an understanding of the capabilities of the test rig. This dissertation contains the results obtained from testing a variety of couplings, belts and motors under different conditions. The results obtained show the difference between the efficiency of a standard motor and that of a high efficiency motor. The efficiency comparison of the Poly V TM, Poly Chain® and SPB V-belts showed very distinct advantages and disadvantages of each belt. The coupling testing was conducted under conditions of misalignment, and resulted in distinct differences in the efficiencies of each coupling at different degrees of misalignments. The couplings tested were the Fenaflex®, the Quick-Flex®, and the Fenagrid® coupling. All results obtained were analyzed and discussed in the relevant sections. The results obtained showed that the high efficiency motor is significantly more efficient than the standard motor at full load, although at low loading, the motor efficiencies were very similar. The coupling tests showed the negative effects misalignment has on the efficiency of the Quick-Flex® and Fenagrid® coupling as well as the capability of the Fenaflex® coupling to withstand the effects of large misalignments without significant efficiency loss. v The belt testing revealed the advantages and disadvantages of each type of belt used. This showed that although the synchronous belt did not lose efficiency with decreased tension, it became unstable, and was difficult to keep on the pulley if not aligned correctly. The V-belts can handle low tension well. Prolonged use of the belts can cause them to stretch, lowering the tension into a “danger zone” that will cause the belts to slip. This slip can damage the belt and pulley. At the lower tension of the V-belt, although the efficiency increases slightly, the vibration of the slack side of the belt is significant, and can be dangerous as the belt could jump off the pulley. The Poly V TM belt has some of the advantages of the V-belt, except that it is unable to maintain its friction at low tension, as the belt width prevents it from being wedged into the grooves like the V-belt. The fluid coupling tests showed that the shock loading on a high inertia system can be significantly reduced with the aid of a fluid coupling. The reduced shock loading can reduce energy consumption, and increase the life of electric motors and the equipment that they drive by preventing excessive overloading. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2011.