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This study explores ways to determine the energy efficiency of a pyrometallurgical ore reduction plant and measures to improve it. The feasibility of building a commercial plant - that is more energy efficient, has a low energy cost, and can operate independently and cost-effectively of external electricity supply - is determined. The need for energy efficiency is expanded to three questions: how should the energy efficiency of the plant be determined, what is the efficiency of the existing plant and to what level it can be improved. Literature and other relevant sources were consulted. Twenty potential energy conservation measures were identified through a literature study. A multi-criteria decision-making approach resulted in the selection of ten measures for conceptual implementation. The measures ranged from high-efficiency motors, solar power, heat recovery with thermal oil and various heat engines, to pressure recovery with turbo-generators. A case study approach was followed with the energy efficiency of an existing prototype plant the subject being studied. The energy usage of the existing plant and feasible measures to improve the performance were empirically observed. The impact of these measures was modelled and the results of the conceptual implementation determined. Two measures that were implemented during the study are also described and the results reported. The study found that the energy efficiency of the plant could be determined by the ratio of product exergy to input energy. By incorporating a number of energy conservation measures conceptually the internal efficiency of the prototype plant was conceptually improved from the current 17% to 22% and as a result externally supplied electricity reduced by 47%. The results were extrapolated to a future commercial plant and energy efficiencies of 26% on-grid and 21% off-grid predicted. This study suggests that a significant improvement in energy efficiency and energy cost can be achieved by integrating appropriate energy conservation measures into the existing and future plants. / MIng (Mechanical Engineering), North-West University, Potchefstroom Campus, 2014

This study determined winter and summer shading coefficients for six commonly used landscape trees in Tucson using a photographic dot-matrix method. Tree types were developed from this data reflecting canopy density, shape, and foliage periods, then applied to SPS and MICROPAS computer programs to model effects of tree shade on annual energy loads for three residential construction types. Statistical analysis showed pruning to have a significant effect for 5 of the 6 species tested. Significant differences were also found among species and within species due to seasonal effects in foliage density. Shading scenarios manipulated the number and location of tree types were modeled. Greatest net annual savings were from 3 African sumac trees located on the west side of a masonry house typical of the 1950s (121). Shade from tree species found to have significantly different shading coefficients (10%) did not substantially increase energy savings ($5-12).

This study evaluated the effects of public postings on energy conservation behavior at a public university, using a multiple baseline design across three settings; bathrooms break rooms, and conference rooms. The behavior of building occupants was recorded to assess the frequency at which those individuals would turn lights off upon exiting an unoccupied room. The independent variables implemented by experimenters (light-switch plate stickers and laminated signs) had little to no effects on cumulative instances of lights turned off however, the installation of motion sensor lights produced better results. Across all conditions, lights were turned off most frequently in conference rooms (65% of observations) followed by break rooms (9% of observations), and bathrooms (3% of observations).

Energy is essential to economic prosperity and quality of life. However it can have detrimental effects on the environment if not used properly. Moreover, if energy resources are scarce in a given country, then its use will impose economic and financial burdens on the national economy. The cement industry is energy-intensive, which adds a micro dimension to the macro issues mentioned above. Reducing energy consumption without due consideration to production requirements is not an optimal situation. What is needed is to arrive at a situation whereby energy is used rationally. The concept of rational use of energy has two embedded principles. The first is increased energy-use efficiency and the second is environmental protection. Jordan Cement Factories (JCF), located in a developing country where energy resources are not indigenously available and, therefore, costly energy requirements are imported, have realised the importance of addressing the energy management and conservation issues. This thesis describes the efforts initiated and conducted by the author, to address the research problem of improving energy usage through the application of effective management techniques aimed at reducing energy consumption per unit of cement produced. This present research has been concerned with energy management and efficient use of energy. The Jordan Cement Factories were used as a vehicle to demonstrate the proposed research methodology that aimed at improving energy consumption and thus operational efficiency. The methodology is based on establishing statistically significant relationships between interacting problem factors, and assessing the economic impact of improving these factors. Economic evaluation entailed the development of economic models and an application methodology combined with illustrative case studies. Consequently, the problem of energy management has been presented in a wider perspective that addressed the whole management system at the organisation. Towards that end, it was first necessary to show the significance of energy cost with respect to the overall manufacturing costs. The analysis of production costs, which demonstrated the significance of energy costs, was followed by the investigation and examination of the basic management factors that have direct impact on energy consumption at the JCF. Among these factors are, for instance, production line availability, production rate, average number of stoppages, and average duration of stoppages. These factors were determined using preliminary data analysis and the experience and technical knowledge of the researcher. The statistical analysis proved the existence of strong relationships between energy consumption and management factors. Several models were developed for a set of selected production lines, in the JFC at Fuhais and Rashadiya plants. These statistical models were generated using actual data for electrical energy and fuel consumption. The derived models have demonstrated the existence of strong relationships between energy consumption and management control factors; for instance, the values of R2 range from 60% to 90%. This implies that an equivalent percentage of the variations in energy consumption can be attributed to the selected management factors. The economic model developed in this research is concerned with demonstrating that effective management practices associated with proper maintenance and housekeeping can result in highly significant savings in energy usage. Although a simplistic methodology was used to evaluate the economic impact of any improvement programme, the economic treatment showed that the cost of improvement is actually negligible compared to the realisable savings in energy usage. The research has dealt with the details of developing a coherent energy management model whose objective is to establish transformational management processes of certain high-level management factors into daily operations and controls. The high-level management .factors are the same factors used as independent variables in the statistical and economic models, which statistically proved to be the major factors affecting the energy consumption at JCF. The research has also presented a detailed analysis of the organisational and procedural aspects of energy management with concentration on management functions, especially planning, controlling, executing, organising, and auditing. A detailed mapping and analysis of these functions as the main components of an Energy Management System (EMS) resulted in establishing job descriptions, organisational charts, work instructions and procedures for all-important functions of the EMS. The type of work described in this thesis could be extrapolated for application in other industries, particularly energy-intensive ones, to arrive at the objective of rational use of energy at the national and international levels. Comprehensive studies would need to be carried out for each type of industry prior to implementation. The cost benefit analysis presented in this research proved, beyond any doubt, the importance of implementing the EMS in JCF. As a result of this implementation it is demonstrated that huge annual savings were realised. Finally, as a result of improving energy control factors, introducing energy conservation measures and employing management techniques at JCF to guarantee the effectiveness of all such activities, resulted in an annual savings amount to about USS 3.5 million. Therefore, if the same or similar actions are undertaken by all cement, or other highly energy intensive industries then the savings could reach billions of dollars.

Les transferts de chaleur constituent la base de nombreux processus industriels qui sont présents dans notre vie quotidienne. L’intensification de ces échanges et l’amélioration du rendement sont devenues aujourd’hui une problématique majeure dans le monde industriel, des organismes de réglementation mais aussi de la société dans son ensemble, qui prend conscience de l’épuisement progressif des ressources énergétiques et qui se soucie de l’avenir en matière énergétique. Face à ces enjeux énergétiques et environnementaux, Le défi technologique réside dans le développement de nouveaux processus pour une meilleure gestion de l’énergie. Ce travail de thèse s’inscrit dans ce cadre, et concerne particulièrement les problèmes liés à l’intensification des échanges thermiques dans les échangeurs de chaleur. Les améliorations des échanges thermiques dites ‘passives’ sont une voie déjà largement élaborée et atteignent leurs limites. De nouvelles stratégies d’optimisation doivent donc être étudiées. Une de ces stratégies consiste à améliorer les propriétés thermiques des fluides caloporteurs utilisés dans les systèmes thermiques, notamment dans les échangeurs de chaleur. Des progrès importants en chimie ont permis dès la fin des années 90 de synthétiser des particules de taille nanométrique, qui, dispersées dans un liquide porteur, constituent des nanofluides. Leur synthèse répond au besoin d’améliorer les propriétés thermiques des fluides caloporteurs en y insérant une phase solide de conductivité thermique très élevée. Le fil directeur de ce travail consiste donc à caractériser de manière approfondie le comportement thermique et rhéologique des nanofluides à base de nanotubes de carbone NTC utilisés tout au long de ce travail afin de quantifier les principaux paramètres influençant leurs propriétés thermo-physiques et les phénomènes physiques régissant l’intensification des transferts thermiques induits par ces nanofluides. Une analyse des travaux de recherche antérieurs a été menée dans le but de s’affranchir des différents paramètres qui peuvent influencer le comportement thermique et rhéologique des nanofluides dont on citera les paramètres liés à la composition des nanofluides (fraction volumique des NTC, type de surfactant, rapport d’aspect des NTC), la température, le fluide de base… Suite à cette étude, nous avons mené une étude expérimentale sur les propriétés thermo-physiques des nanofluides testés (conductivité thermique, viscosité dynamique, masse volumique) et sur les performances thermiques dans un échangeur de chaleur. Nous avons présenté également une analyse des résultats de façon à étudier l’influence des paramètres évoqués ci-dessus. Les résultats obtenus sont comparés et discutés vis-à-vis des modèles classiques existants, en proposant des améliorations et des interprétations selon les tendances obtenues. Les résultats prometteurs de cette étude sont très encourageants et montrent que l’utilisation des nanofluides à base de nanotubes de carbone offre clairement une amélioration des performances thermiques par rapport aux fluides de base classiques. Les nanofluides à base de NTC peuvent constituer ainsi un débouché prometteur des transferts thermiques et présentent de bonnes perspectives et développement. / Heat transfer is one of the most important industrial processes in our daily lives. Nowadays, the intensification of the heat transfer and the improving of the energy efficiency have become a major problem in industry, regulatory agencies, and also the society that becomes conscious of the progressive exhaustion of the world’s energy resources and cares about the future of energy. Due to these energy and environmental issues, the technological challenge is to develop new processes for better energy management. This work fits in that context and applies particularly the problems associated to the improvements of heat exchanger’s energy efficiency. The conventional methods for increasing the heat transfer in heat exchangers have already been extensively explored and have reached their objective limits. There is therefore an urgent need for new strategies with improved performances. The novel concept of improving the thermal properties of the working fluids used in thermal system, especially in heat exchangers, has been proposed as a means of meeting these challenges. The innovative concept of nanofluids heat transfer fluids consisting of suspended of nanoparticles with very high thermal conductivities has been proposed for these challenges. The aim of this work is therefore to characterize profoundly the thermal and the rheological behavior of nanofluids containing carbon nanotubes CNTs used throughout of this work. This is in order to quantify the main parameters influencing their thermophysical properties and physical phenomena governing the intensification of heat transfer induced by these nanofluids. An analysis of previous researches has been conducted for the purpose of establishing various parameters that may influence the thermal and rheological behavior of nanofluids, which including the parameters related to the composition of nanofluids (volume fraction of CNTs, type of surfactant, aspect ratio of CNTs), the temperature, the base fluid... Following this study, experiments have been carried out on the thermal physical properties of tested nanofluids (thermal conductivity, dynamic viscosity, density) and thermal performances in a heat exchanger. Analyses of the results have been presented in order to study the influence of the abovementioned parameters. The results obtained are compared and discussed vis-à-vis the existing conventional models, suggesting improvements and interpretations according to the trends obtained. The promising results of this study are very encouraging and show that the use of nanofluids containing carbon nanotubes clearly improved the thermal performances compared to the conventional base fluids. The CNT-based nanofluids can thus be a promising candidate for heat transfer and presents good perspective and development.

Atualmente, diante dos possíveis riscos de falta no fornecimento de energia elétrica no Brasil, surge a necessidade de se educar os consumidores a utilizar corretamente a energia elétrica, pois é mais barato conservar energia do que produzi-Ia. Na busca de solucionar a má utilização da energia elétrica em um campus universitário, levantam-se as características da instalação existente por meio de um equipamento registrador/medidor de grandezas elétricas. De posse destes dados, descrevem-se os problemas de consumo e de dimensionamento dos equipamentos encontrados nas instalações internas, a fim de se apontarem soluções técnicas viáveis para que se possa ter o uso racional de energia elétrica, as quais também poderão ser utilizadas em quaisquer outros centros consumidores. Além disto, abordam-se aspectos relativos ao gerenciamento das instalações existentes, visando-se o correto uso da energia elétrica, independentemente das condições em que se encontram as instalações. E dentro do possível, analisam-se as medidas sugeridas, o que demonstra a viabilidade das mudanças, frente à manutenção dos gastos existentes. / Due to the current possible risks to electric energy supply in Brazil, there is the need of making the consumers aware of how to use electric energy correctly, because it is cheaper to conserve energy than to produce it. Seeking to correct the use of electric energy in a university campus, characteristics of the existent installation were researched by means of recording/measuring equipment of electric variables. With this data provided is described the problems of consumption and use of the equipment found in the intemal facilities, with the purpose of aiming at viable technical solutions as to the rational use of electric energy, not only locally but in any other consumer centers. Furthermore, some aspects related to the management of the existent facilities were approached with a view to using electric energy correctly, independently of the conditions which of facilities are met. Suggested measures are analyzed for the sake of evaluating the viability the proposed changes, with regard to the maintenance of the existent expenses.

Energy e ciency is a critical constraint in wireless sensor networks. Wireless sensor networks (WSNs) consist of a large number of battery-powered sensor nodes, connected to each other and equipped with low-power transmission radios. Usually, the sensor nodes closer to the sink are more likely to become overloaded and subject to draining their battery faster than the nodes farther away, creating a funneling e ect. The use of a mobile device as a sink node to perform data gathering is a well known solution to balance the energy consumption in the entire network. To address this problem, in this work we consider the use of an UAV as a mobile sink. An unmanned aircraft vehicle (UAV) is an aircraft without a human pilot on-board, popularly known as a Drone. In this thesis, besides the use of the UAV as a mobile sink node, we propose an UAV-aided algorithm for data gathering in wireless sensor networks, called Humming- bird. Our distributed algorithm is energy-e cient. Rather than using an arbitrary path, the UAV implements an approximation algorithm to solve the well-known NP- Hard problem, the Traveling Salesman Problem (or TSP), to setup the trajectory of node points to visit for data gathering. In our approach, both the path planning and the data gathering are performed by the UAV, and this is seamlessly integrated with sensor data reporting. The results, using ns-3 network simulator show that our algorithm improves the network lifetime compared to regular (non-UAV) data gathering, especially for data intensive applications. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Este trabalho aborda dois assuntos básicos da construção de um modelo sustentável de desenvolvimento: a minimização de resíduos sólidos urbanos e a conservação de energia. Enquanto a minimização de resíduos sólidos urbanos se relaciona com a utilização racional de recursos materiais e contribui para solucionar o problema da escassez de áreas para deposição final de lixo dos grandes centros urbanos, a conservação de energia contribui para compensar, até certa extensão, a falta de investimentos no setor elétrico para o pleno atendimento da demanda, sem restringir o crescimento econômico do país. Existem diversas maneiras de se tratar adequadamente os resíduos sólidos urbanos. Por exemplo, podemos citar a compostagem de material orgânico, a reciclagem de materiais, a incineração de lixo e a redução na fonte. Neste trabalho, cada uma destas técnicas é explicada com a relacionada à conservação de energia, com ênfase à demonstrar a necessidade de uma abordagem sistêmica desses temas, no contexto da busca do desenvolvimento sustentável. / This paper focuses two topics related to the construction of a sustainable development model: the minimization of urban solid wastes and the energy conservation. The minimization of urban wastes is related to the efficient utilization of resource materials and contributes to solve the problem of shortage of available garbage disposal areas in great urban centers. Energy conservation, on the other hand, can be an alternative, when the lack of investment in the electrical sector would otherwise restrict the continued economic growth of the country. There are many ways of adequately handling urban solid wastes. For example, one can list the compost of organic materials, the recycling of materials, the incineration of materials and the reduction of the amount of waste generated. In this work, each of these techniques is evaluated and connected to the conservation of energy, in a attempt to show that it is necessary an integrated consideration of these to construct a to sustainable development model.

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