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The independent steering and driving vehicle: design, energy efficiency and parking analysis. / CUHK electronic theses & dissertations collectionJanuary 2010 (has links)
After describing the development of the ISDV, this thesis studies the energy management which can improve the energy efficiency. It is shown that the traditional electric vehicle (EV) is not capable of managing the energy required for one driving cycle because it has only a single traction motor. This thesis proposes and examines a new way to manage electrical energy in which torque is distributed among different in-wheel motors to achieve a higher level of overall energy efficiency, which has been enhanced and demonstrated in various driving cycles. / Thereafter, the thesis studies two aspects of benefits the ISDV can bring to parking. One is in space efficiency, defined as the ratio of the total space occupied by the vehicle in its final parked state over the whole area covered by the parking lot. Comparison of the ISDV and traditional vehicles in parking proves that the ISDV afford a higher level of space efficiency. The other aspect is the parking time. It is tested experimentally in the hardware-in-loop (HIL) system, and the motions of traditional vehicles, the zero radius turning motion, and the free motion of the ISDV are compared. The less time for parking demonstrates the easiness to steer the ISDV. / Throughout the history of human civilization, vehicles have played a significant role by connecting people in various locations. They have thus boosted the progress of civilization and made our lives more convenient. However, as the number of vehicles on the road has increased, the convenience, which vehicles provide, has gradually turned into inconvenience in three respects: 1) the energy consumed by vehicles accounts for a large proportion of total energy consumption, which is in an ever-increasing trend; 2) more parking space is needed, a significant proportion of which is not for parking itself but for enabling the vehicle to be navigated to its final parking slot; 3) the effort required to park a car is also troublesome, causing the driver to spend much more time in a crowded parking lot. / To alleviate these three problems, I develop a methodology to design an independent steering and driving vehicle (ISDV). It brings together the robotic technologies of steer-by-wire, drive-by-wire, four-wheel-independent-steering, and four-wheel-independent-driving. All four wheels of the ISDV can be steered independently, so that vehicle rotation and translation can be decoupled from each other. Omni-directional motions such as zero radius turning (ZRT) and lateral parking (LP) are realized, thereby enhancing the agility of the vehicle. In contrast with omni-directional wheeled mobile robots, this vehicle is targeted at serving as a human carrier or even as a vehicle carrier in the future. / Qian, Huihuan. / Adviser: Yangsheng Xu. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 149-159). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.
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Quantificação e correlação das variáveis do ciclo de vida energético da edificação: energia incorporada na envolvente arquitetônica e consumo energético pelo comportamento térmico, caso de estudo: moradia / Quantification and correlation of lifecycle building energyvariables: energy embodied in the architectural envelope and energy consumption for its thermal behavior, case study: residential houseQuiroa Herrera, Jaime Andrés 25 February 2013 (has links)
No presente trabalho se analisou o consumo energético de uma moradia social, para isto se calculou a energia incorporada nos materiais construtivos utilizados no projeto da moradia analisada e o consumo energético provocado pelo comportamento térmico da envolvente térmica da edificação estudando como a mudança dos materiais construtivos como: telhados e paredes modificam o valor da energia incorporada e o consumo de energia elétrica pelo comportamento térmico, uma vez que se considera possível que o consumo energético por motivos térmico seja maior que a energia incorporada. Para o calculo da energia incorporadados materiais construtivos que compõem a envolvente, foram utilizados coeficientes de energia incorporada propostos por Tavares, (2006), Graf; Tavares, (2010), Lobo, (2010). A pesquisa foi enfocada ao setor habitacional por ser um dos setores que apresentam maior consumo de energia, enfocando-se especificamente à moradia social. A metodologia para avaliar o consumo energético da edificação no período de análise, se divide em quatros etapas: 1) Quantificação de materiais da envolvente 2) Cálculo de energia incorporada 3) Cálculo de gasto energético nos períodos de 1 e 40 anos realizado por meio de simulações no software Energy Plus 4) Cálculo dos coeficientes de correlação das variáveis.Tomaram-se as cidades de São Carlos, SP e Belém, PA, como exemplos de análise. A primeira cidade participa com 11% no rubro de condicionamento ambiental no setor residencial e segunda participa com 40%. Os resultados foram trabalhados e analisados com gráficos de Excel, para a posterior análise e conclusão. Identificou-se um coeficiente de correlação que indica uma forte correlação entres as variáveis analisadas no presente. O que indica que existe uma relação entre a quantidade de energia incorporada nos materiais e no consumo energético operacional pelo comportamento térmico destes. / In this study were analyzed the energy consumption of a housing, for it is calculated the embodied energy of construction materials, and energy consumption caused by the thermal behavior of the building envelope. It was change the building materials in the building, modifying the value of embodied energy and electricity consumption, since it is possible that the energy consumption of thermal behavior can be higher than the energy embodied. To calculate the embodied energy, were used a embodied energy coefficients proposed by Tavares, (2006), Graf; Tavares, (2010)Lobo, (2010).(TAVARES, SERGIO FERNANDO, 2006). This research is focus to residential sector as one of the sectors with higher energy consumption, focusing specifically on social housing. The methodology to evaluate energy consumption in the building during the period of analysis is divided into three steps: 1) Quantification of the materials 2) Calculate the embodied energy 3) Calculate the consumption of energy in the period of 40 years, made by simulations in Energy Plus software 4) Calculate the correlation ship between the variables analyzed. It follows the cities of São Carlos, SP and Belem, PA as examples of analysis; the first city participates with 11% in the energy consumption used in environmental conditioning in the residential sector and the second city participates with 40%. Changes were made in the materials of walls and roofs, trying to identify the differences of embodied energy and electricity consumption. The data obtained were worked in Excel spread sheets for further analysis and conclusion of the data. It was identified a strongly correlation coefficient between the analyzed variables.
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The conserving communityMancke, Carol Jane January 1975 (has links)
Thesis. 1975. B.S.--Massachusetts Institute of Technology. Dept. of Urban Studies and Planning. / Bibliography: leaves 72-73. / by Carol J. Mancke. / B.S.
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Estudo do consumo de energia elétrica em máquinas-ferramentas / Assessment of energy consumption in machine toolsDanilo Henrique Pelegrino 21 June 2018 (has links)
Para lidar com o aumento dos custos de energia nos sistemas de produção e ações para minimizar impactos ambientais relacionados à geração de eletricidade através de combustíveis fósseis, o tema \"consumo de energia\" tornou-se um dos mais discutidos na indústria nos últimos anos (LI, 2015). Portanto, a redução do consumo de energia elétrica nos processos de fabricação é assunto fundamental para o segmento industrial nos dias atuais. Tal ação requer conhecimento sobre as demandas de energia de máquinas e todos os equipamentos envolvidos em um processo. Reduzir o consumo de energia nos processos de usinagem pode melhorar significativamente a produção de um modo sustentável (SCHUDELEIT; ZÜST; WEGENER, 2017). Para diminuir a demanda energética em processos de usinagem particularmente em máquinas-ferramentas (MFs), dados de consumo de energia devem ser obtidos para ajudar no planejamento de processos e também contribuir para melhorar a eficiência energética da máquina como um todo. Além disso, para atender à crescente demanda do mercado por máquinas mais eficientes e a competitividade global no setor de manufatura, fabricantes de MFs estão enfrentando grandes desafios para melhorar a produtividade e reduzir o consumo de energia (BEN JDIDIA et al., 2018). Considerando o aumento do preço da energia e a sustentabilidade industrial, o presente trabalho apresenta um estudo detalhado do consumo de energia em um centro de torneamento e sugere estratégias para reduzir o consumo de energia nas MFs. Os resultados obtidos, até agora, indicam que adaptar o comportamento operacional das MFs por meio de modos de operação inteligentes, adaptando a demanda de energia aos requisitos do processo específico parece ser um bom procedimento para reduzir o consumo de energia, tornando os processos e máquinas mais eficientes, melhorando assim a sustentabilidade dos processos de usinagem. / To deal with rising energy costs in production system and significant demands for minimizing environmental impacts related to the electricity generation using fossil fuels, the theme \"energy consumption\" has become one of the most discussed topics in the manufacturing industry in recent years (LI, 2015). Therefore, the reduction of energy consumption in manufacturing processes is a fundamental issue for the industrial segment nowadays. Such subject requires knowledge about the energy requirements from machines and all the involved equipment. Reducing energy consumption in machining processes can significantly improve sustainability in manufacturing (SCHUDELEIT; ZÜST; WEGENER, 2017). To reduce energy demand in machining processes, particularly in machine tools (MTs), energy consumption data must be obtained to help process-planning and contribute to improve machine efficiency. Moreover, to meet growing market demand for more efficient machines and global competitiveness in the manufacturing sector, MTs manufacturers are facing major challenges to improve productivity and reduce energy consumption (BEN JDIDIA et al., 2018). Considering the increasing energy requirements and industrial sustainability, the present research presents a comprehensive study of energy consumption in a Two-spindle Turning center and suggests strategies to reduce energy consumption in MTs as a whole. The results obtained, so far, indicates that optimizing the operational behavior of MTs through smart operation modes by adapting the power demand to the current production requirements seems to be a good procedure to reduce the energy consumption, making the processes and machines more efficient as well as improving environmental performance of machining processes.
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Análise das condições de iluminação das bibliotecas públicas municipais na cidade de São Paulo: diretrizes para um melhor aproveitamento da luz natural e redução do uso da iluminação artificial / The analysis on the lighting condition in public libraries in the city of São Paulo: guidelines for best natural lighting utilization and reduction of the artificial lighting useSandra Regina Pinto 22 July 2008 (has links)
As bibliotecas públicas subordinadas à Secretaria Municipal de Cultura da cidade de São Paulo foram objeto de estudo desta pesquisa, que levantou e analisou os dados cadastrais das 60 bibliotecas, levantou e analisou os dados sobre iluminação natural, artificial e consumo de energia para este uso final de uma amostra de 15 bibliotecas e elaborou um projeto de retrofit para um caso. O levantamento dos dados cadastrais, dos dados sobre os sistemas de iluminação e consumo de energia foi realizado com o auxílio de fichas de campo desenvolvidas para sistematizar a coleta das informações durante as vistorias. Foram atualizadas as plantas de arquitetura, tabuladas as contas de energia e calculados os valores de consumo médio mensal, específico e desagregado, potência instalada, densidade de potência da iluminação e despesa com energia elétrica de 15 bibliotecas selecionadas como amostra do universo. Como um diagnóstico preliminar desta amostra, observou-se o predomínio de equipamentos ineficientes no sistema de iluminação artificial e o uso final em iluminação representou o maior percentual no consumo total de energia elétrica das bibliotecas. Para a elaboração do projeto de retrofit foi escolhida a biblioteca que apresentou o maior percentual de consumo desagregado em iluminação dentre os casos estudados e, para tanto, foi atualizado o levantamento energético e as análises sobre iluminação natural e artificial foram aprofundadas por meio de medições e simulações computacionais. As principais diretrizes que nortearam o desenvolvimento deste projeto foram a utilização de um sistema de iluminação artificial complementar à luz natural, a adequação dos valores de iluminância às necessidades visuais de cada ambiente e a adoção de equipamentos eficientes. A utilização de um sistema de iluminação artificial composto por equipamentos tecnologicamente eficientes possibilita a diminuição no consumo de energia numa edificação, sendo que reduções significativas podem ser alcançadas quando tal sistema for usado de maneira complementar à luz natural e com acionamento automático. Diante do repertório construído, foram definidas algumas diretrizes para o melhor aproveitamento da luz natural e redução do uso da iluminação artificial. / The public libraries controlled by São Paulo City Culture Bureau were the target of this survey, which raised and analysed registered data from 60 libraries, raised and analysed natural and artificial lighting data and the energy consumption for this latter purpose out of a sample of 15 libraries and prepared a retrofit project for one case. Raising registered data, lighting system data and energy consumption was carried out by using survey cards developed to systematise the data collection during the research. Architectural plans were updated, the energy bills were listed and calculated were the average monthly consumption values, specific and disaggregated, installed power, density of lighting power and electric energy expenditure of 15 selected libraries as a universe sample. As a preliminary diagnosis of such sample, we observed the predominance of inefficient equipments in the artificial lighting system and the final lighting use represented the major percentage of the libraries overall electric consumption. In order to prepare the retrofit project, we chose the library presenting the major percentage of disaggregated lighting consumption amongst all studied cases and, to such, we updated the energy survey and the analysis of natural and artificial lighting was deepened by means of measurements and computer simulation. The main principles guiding the development of this project were the application of an artificial lighting system complementary to daylighting, the adequacy of illuminance values to the visual needs of each room and the adoption of efficient equipments. The application of an artificial lighting system composed of technologically efficient equipments allows the reduction in the energy consumption in a building, being such reduction significant and achievable when that system is used in a complementary way with daylighting and with automatic operation. Before this so constructed repertory, we defined some guidelines for best daylighting utilization and reduction of the artificial lighting use.
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Leitura automatizada de medidores de consumo de energia elétrica eletromecânicos. / Automated reading of eletromechanical electric energy consumption meter.José Walter Parquet Bizarria 02 June 2006 (has links)
BIZARRIA, J. W. P. Leitura automatizada de medidores de consumo de energia elétrica eletromecânicos. 2006. 255 f. Tese (Doutorado) - Escola Politécnica, Universidade de São Paulo, São Paulo, 2006. Este trabalho aborda o projeto conceitual de um sistema voltado para a leitura automatizada de medidores de consumo de energia elétrica eletromecânicos, residenciais, com transdutores por indução acoplados a registradores mecânicos ciclométricos, sendo esse sistema denominado de Sistema Automatizado para Leitura de Medidores Eletromecânicos (SALME). Nessa abordagem, são explorados conceitos que visam contribuir para a evolução desse tipo de medidor e de outros, aos quais esses conceitos possam ser estendidos. Os elementos desse sistema oferecem contribuição voltada para a busca de soluções dos atuais problemas existentes, principalmente no que se refere à automatização dos processos de aquisição de dados do consumo de energia elétrica, e no combate às fraudes. O SALME está fundamentado numa arquitetura de sistema distribuído que separa o medidor em duas unidades: uma destinada para a medição do consumo; outra para a visualização dos dados referentes à leitura do medidor. O modelo de aplicação dessa arquitetura prevê a instalação da unidade de medição no âmbito da via pública, sendo a unidade de visualização instalada no âmbito da unidade consumidora. A instalação da unidade de medição no âmbito da via pública dificulta a implementação e utilização de circuitos não autorizados, que impeçam ou interfiram na medição dos corretos valores de consumo de energia elétrica, a serem utilizados para a cobrança desse insumo. A instalação da unidade de visualização no âmbito da unidade consumidora proporciona ao consumidor a leitura do medidor, prevista para esse tipo de aplicação. Nesse sistema, a leitura do medidor é automatizada, de forma que a aquisição dos dados de leitura dos consumos pode ser realizada no âmbito da via pública, por meio do uso de coletores de dados ou por interligação a sistemas de comunicação que utilizam redes de longa distância. Para a comunicação com os coletores de dados, é prevista a utilização da radiação infravermelha como meio de comunicação sem fio. A automatização da leitura dos medidores é fundamentada no conceito de leitura eletrônica do registrador mecânico ciclométrico, sendo exploradas abordagens que envolvem: a conversão optoeletrônica analógica; a aquisição e o processamento de imagens, e a conversão optoeletrônica digital. Os resultados obtidos nos ensaios práticos efetuados com os protótipos dos elementos do SALME foram satisfatórios, sendo validados os princípios de funcionamento desses elementos, ratificando os conceitos propostos, mostrando que os objetivos previstos neste trabalho foram alcançados em toda a sua plenitude. / BIZARRIA, J. W. P. Automated reading of electromechanical electric energy consumption meter. 2006. 255 f. Thesis (Doctoral) - Escola Politécnica, Universidade de São Paulo, São Paulo, 2006. This work embodies a conceptual design of a system focalized in automatic reading of electromechanical electric energy consumption meter, residential, with inductive transducers coupled together with cyclic mechanical registers, being that system called by Automated System for Reading of Electromechanical Meter (ASREM). On that approach are explored concepts that aim to contribute for evolution of that type of meter and others of which those concepts can be extended. The elements of that system offer contribution dedicated for the search of solutions of the current problems, mainly referring to automation of data acquisition processes of electric power consumption, and against to swindle. ASREM is based on architecture of distributed system that splits the meter into two units, being one destined to consumption measurement and other for visualization of the data related to the meter reading. The model of application of that architecture, foresees the installation of a measurement unit in the ambit of public electrical network, being the unit of visualization installed in the ambit of consumer demand. The installation of measurement unit in the ambit of public electrical network, obstructs the implementation and use of non authorized circuits that prevent or interfere in the measurement of correct values of electric power consumption to be utilized for the collection of that tariff. The installation of unit for visualization in the ambit of consumer demand, provides to the consumer the reading of the meter foreseen for that type of application. On that system the reading of the meter is automated, so that the acquisition of the reading data of the consumptions it can be accomplished in the ambit of public electrical network, by means of usage either by data collectors or by interconnection to communication systems that use long distance networks. For the communication with the data collectors that is forecasted the utilization of infrared radiation as a mean of wireless communication. The automation of meters reading is based on concept of electronic reading of the cyclic mechanical register, being explored approaches that involve: the analogical optoelectronic conversion, acquisition and image processing, and digital optoelectronic conversion. The results obtained in the practical tests performed with the prototypes of ASREM elements, were satisfactory, being validated the principles of operation of those elements, ratifying the proposed concepts, showing that the objectives foreseen in this work were fully reached.
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Diretrizes para o design de dispositivos visuais para apresentação do consumo de energia em residênciasMoura, Paula Kvitko de January 2018 (has links)
O consumo de energia total residencial mundial aumentou 23% na última década e deverá aumentar mais 48% até 2040. Uma estratégia para a economia de energia é a mudança do comportamento dos usuários por meio da apresentação do feedback do consumo. O feedback pode ser apresentado em dispositivos visuais que são aparelhos eletrônicos que medem o consumo de eletricidade das casas e repassam esta informação aos usuários com a intenção de reduzi-lo. Pesquisas anteriores mostram que prover feedback com uso destes dispositivos pode gerar uma redução de 5 a 20% do consumo. No entanto, existem poucas pesquisas sobre o design de tais dispositivos que abordem a preferência e o entendimento do conteúdo (dados que podem ser apresentados no dispositivo) e do modo de apresentação (formato de apresentação do conteúdo). Estudos sugerem que as decisões de design variam conforme o tipo de usuário (crianças, adultos e idosos) e o contexto cultural no qual o dispositivo está inserido. Este trabalho explora os tipos de informações (ex.: consumo instantâneo, consumo por aparelho, etc.) e o formato da informação (numérico, analógico e ambiental) de um dispositivo visual mais adequado ao contexto brasileiro, considerando o tipo de usuário. Com base nos resultados de 7 grupos focados realizados com 50 participantes (20 crianças, 20 adultos e 10 idosos), foram desenvolvidos diretrizes e modelos conceituais para cada tipo de usuário Todos os participantes consideraram o consumo instantâneo importante. Entretanto, para idosos não é necessário apresentar esta informação visto que eles não gostariam de interagir com o dispositivo mais de uma vez ao dia, ao contrário dos adultos e crianças. Para aumentar o conhecimento do uso de energia dos usuários e encorajar a mudança de comportamento, também deve ser apresentada as informações de consumo cumulativo, consumo por aparelhos e dicas. Adultos e idosos preferem comparação histórica ao contrário das crianças que preferem informações que gerem a competição, como a comparação normativa. As informações sobre a preferência e o entendimento são importantes para o desenvolvimento de interfaces de dispositivos visuais que atendam aos requisitos dos usuários. Além disso, como os dispositivos visuais ainda não estão amplamente inseridos no Brasil, este trabalho pode contribuir para que o seu design proporcione o aumento da redução do consumo de energia. / The residential energy consumption in the world has increased by 23% in the past decade and is expected to rise 48% until 2040. One strategy to save energy is to change user behavior by presenting feedback on energy consumption. The feedback can be presented in electronic in-home displays which measure the household energy consumption and pass this information to users with the intention of reducing consumption. Previous research has shown that providing feedback can lead to reductions of 5 to 20%. However, there is still limited research on the design of such devices. The design of visual devices involves decisions regarding the preference and understanding of information types (data that can be displayed in a device) and information formats (ways to present different information types). Studies suggest that design decisions vary according to the type of user (children, adults and elderly) and the cultural context in which the device is inserted. This work explores the information formats (e.g. real-time consumption, consumption of each appliance, etc.) and the information formats (numerical, analogue and ambient) of an in-home display suited to the Brazilian context, considering the type of user Based on the results of 7 focus groups totaling 50 participants (20 children, 20 adults and 10 elderly), guidelines and prototypes were developed for each type of user. All participants considered real-time consumption important. However, it is not necessary to present this information for the elderly since they would not want to interact with the display more than once a day, unlike adults and children. Cumulative consumption, disaggregation by appliance and tips should also be presented for all type of users to increase awareness of energy usage and encourage behavior change. Adults and the elderly prefer historical comparison on contrary to children who prefer information that generates competition, such as normative comparison. Information about user preference and understanding is important for the development of in-home displays interfaces that meet user requirements. In addition, since in-home displays are not yet extensively adopted in Brazil, this work can contribute to the design of such displays that to further reduce the energy consumption.
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Multi-scale analysis of the energy performance of supermarketsSpyrou, Maria S. January 2015 (has links)
The retail sector accounts for more than 3% of the total electricity consumption in the UK and approximately 1% of total UK CO2 emissions. The overarching aim of this project was to understand the energy consumption of the Tesco estate (the market leader), identify best practice, and find ways to identify opportunities for energy reduction. The literature review of this work covered the topic of energy consumption in the retail sector, and reviewed benchmarks for this type of buildings from the UK, Europe and the US. Related data analysis techniques used in the industry or presented in the literature were also reviewed. This revealed that there are many different analysis and forecasting techniques available, and that they fall into two different categories: techniques that require past energy consumption data in order to calculate the future consumption, such as statistical regression, and techniques that are able to estimate the energy consumption of buildings, based on the specific building's characteristics, such as thermal simulation models. These are usually used for new buildings, but they could also be used in benchmarking exercises, in order to achieve best practice guides. Gaps in the industry knowledge were identified, and it was suggested that better analytical tools would enable the industry to create more accurate energy budgets for the year ahead leading to better operating margins. Benchmarks for the organisation's buildings were calculated. Retail buildings in the Tesco estate were found to have electrical intensity values between 230 kWh/m2 and 2000 kWh/m2 per year. Still the average electrical intensity of these buildings in 2010-11 was found to be less than the calculated UK average of the 2006-07 period. The effect of weather on gas and electricity consumption was investigated, and was found to be significant (p < 0.001). There was an effect related to the day-of-the-week, but this was found to be more related to the sales volume on those days. Sales volume was a proxy that was used to represent the number of customers walking through the stores. The built date of the building was also considered to be an interesting factor, as the building regulations changed significantly throughout the years and the sponsor did not usually carry out any fabric work when refurbishing the stores. User behaviour was also identified as an important factor that needed to be investigated further, relating to both how the staff perceives and manages the energy consumption in their work environment, as well as how the customers use the refrigeration equipment. Following a statistical analysis, significant factors were determined and used to create multiple linear regression models for electricity and gas demands in hypermarkets. Significant factors included the sales floor area of the store, the stock composition, and a factor representing the thermo-physical characteristics of the envelope. Two of the key findings are the statistical significance of operational usage factors, represented by volume of sales, on annual electricity demand and the absence of any statistically significant operational or weather related factors on annual gas demand. The results suggest that by knowing as little as four characteristics of a food retail store (size of sales area, sales volume, product mix, year of construction) one can confidently calculate its annual electricity demands (R2=0.75, p < 0.001). Similarly by knowing the size of the sales area, product mix, ceiling height and number of floors, one can calculate the annual gas demands (R2=0.5, p < 0.001). Using the models created, along with the actual energy consumption of stores, stores that are not as energy efficient as expected can be isolated and investigated further in order to understand the reason for poor energy performance. Refrigeration data from 10 stores were investigated, including data such as the electricity consumption of the pack, outside air temperature, discharge and suction pressure, as well as percentage of refrigerant gas in the receiver. Data mining methods (regression and Fourier transforms) were employed to remove known operational patterns (e.g. defrost cycles) and seasonal variations. Events that have had an effect on the electricity consumption of the system were highlighted and faults that had been identified by the existing methodology were filtered out. The resulting dataset was then analysed further to understand the events that increase the electricity demand of the systems in order to create an automatic identification method. The cases analysed demonstrated that the method presented could form part of a more advanced automatic fault detection solution; potential faults were difficult to identify in the original electricity dataset. However, treating the data with the method designed as part of this work has made it simpler to identify potential faults, and isolate probable causes. It was also shown that by monitoring the suction pressure of the packs, alongside the compressor run-times, one could identify further opportunities for electricity consumption reduction.
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A performance and energy evaluation of a fertiliser-drawn forward osmosis (FDFO) systemLambrechts, Rhynhardt January 2018 (has links)
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Globally, water is considered an essential resource as it sustains human, animal and plant life. Water is not only essential for all forms of life but imperative for economic growth. The world’s population is increasing at a disquieting rate, which will result in an increased demand for fresh water and food security. The agricultural industry is the main consumer of global freshwater and utilises fertilisers in order to meet food demands. The demand for water in South Africa (SA) has increased considerably due to the rapid expansion of the agricultural industry, and of the municipal and industrial sectors. Agricultural developments in SA are affected greatly as the country is facing a current drought crisis as a result of low rainfall and large water demands. With an abundance of saline water globally, desalinisation will be a major contributor to solving the global freshwater crisis. With limited fresh water resources accompanied by the agricultural industry as a major consumer, alternative measures are required to desalinate water specifically for agricultural use. Forward osmosis (FO) is a membrane technology that gained interest over the past decade because it has several advantages over pressure-driven membrane processes such as reverse osmosis (RO). FO technology is based on the natural osmotic process which is driven by a concentration gradient between two solutions separated by a semi-permeable membrane. Naturally, water will permeate through the membrane from a solution of low solute concentration or low osmotic pressure (OP) known as a feed solution (FS) to a solution of a higher concentration or higher OP also known as a draw solution (DS). Whilst various research studies have contributed to several advances in FO, several process limitations such as reverse solute flux (RSF), concentration polarisation (CP) and membrane fouling remain problematic, hindering FO for large-scale applications. Further investigation is therefore warranted and crucial in order to understand how to mitigate these limitations to develop/improve future processes. The aim of this study was to evaluate a fertiliser-drawn forward osmosis (FDFO) system by investigating the effects of membrane orientation, system flow rate, DS concentration, and membrane fouling on an FDFO systems performance and energy consumption. The FS used was synthetic brackish water with a sodium chloride (NaCl) content of 5 g/L whereas a potassium chloride (KCl) synthetic fertiliser was used as a DS. The membrane utilised was a cellulose triacetate (CTA) membrane and was tested in forward osmosis mode (FO mode) and pressure retarded osmosis mode (PRO mode) whilst the system flow rate was adjusted between 100, 200 and 400 mL/min. Additionally, the DS concentration was altered from 0.5, 1 and 2 M KCl, respectively. Experiments were performed using a bench scale FO setup which comprised of an i) FO membrane cell, ii) a double head variable peristaltic pump for transporting FS and DS’s respectively, iii) a digital scale to measure the mass of the DS, iv) a magnetic stirrer to agitate the FS, v) two reservoirs for the FS and DS, respectively, vi) a digital multiparameter meter to determine FS electrical conductivity (EC) and vii) a digital electrical multimeter to measure system energy consumption. Each experiment comprised of seven steps i) pre-FDFO membrane control, ii) membrane cleaning, iii) FDFO experiment, iv) post-FDFO membrane control, v) membrane cleaning, vi) membrane damage dye identification and vii) membrane cleaning. Pre- and post-FDFO membrane control experiments operated for 5 h whilst each membrane cleaning procedure operated for 30 min. The FDFO experiment operated for 24 h whilst the membrane damage dye identification operated until a minimum of 10 mL water was recovered. The process parameter which largely contributed to a beneficial system performance and specific energy consumption (SEC) was the increase in DS concentration. Water fluxes increased approximately threefold from a DS concentration increase from 0.5 to 1 M, followed by an additional 30 to 50 % rise in water flux at a DS concentration increase 1 to 2 M. SEC decreased by 58 and 53 % for FO and PRO modes, respectively, with a DS concentration increase from 0.5 to 1 M. An additional 35 and 37 % SEC reduction for FO and PRO modes was obtained for a DS concentration increase from 1 to 2 M. Altering the membrane from FO to PRO did not contribute to a beneficial system performance nor did it improve SEC. However, at a DS concentration of 0,5 M, the PRO mode obtained a 5.3 % greater water recovery compared to the FO mode. Conversely, at a DS concentration of 1 and 2 M, the FO mode achieved 5.4 and 7.0 % greater water recoveries compared to the PRO mode. The increase in flow rate also did not increase system performance significantly, however, a fluctuation in system SEC was observed. Throughout the study, no membrane fouling was observed, however, possible minute traces of membrane fouling could be observed from the membrane surface electron microscope (SEM) images. Additionally, minor changes in post- FDFO membrane control water recovery results were noticed which support the possible occurrence of membrane fouling during the FDFO experiment.
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Experimental investigation on activation power requirement for CNTs-based sensors. / 對碳納米管微傳感器激勵功率需要的實驗研究 / Dui tan na mi guan wei chuan gan qi ji li gong lu xu yao de shi yan yan jiuJanuary 2009 (has links)
Ouyang, Mengxing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 83-88). / Abstracts in English and Chinese. / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Background and Motivation --- p.1 / Chapter 1.2 --- Objectives --- p.2 / Chapter 1.3 --- Contributions --- p.3 / Chapter 1.4 --- Organization of the Dissertation --- p.3 / Chapter 2. --- CNTs and Their Application as Sensors --- p.5 / Chapter 2.1 --- Introduction to CNTs --- p.5 / Chapter 2.2 --- CNTs Based Sensors --- p.8 / Chapter 3. --- F-CNTs Based Ethanol Sensors --- p.10 / Chapter 3.1 --- Introduction --- p.10 / Chapter 3.1.1 --- Carbon Nanotube Alcohol Sensors --- p.11 / Chapter 3.1.2 --- CNTs Sensor Configuration --- p.12 / Chapter 3.1.3 --- Activation of CNTs Sensor --- p.13 / Chapter 3.1.4 --- Functionalization of CNTs --- p.14 / Chapter 3.2 --- Fabrication of F-CNTs Based Ethanol Sensors --- p.16 / Chapter 3.2.1. --- Fabrication of f-CNTs --- p.16 / Chapter 3.2.2. --- Fabrication of Sensing Elements by DEP Manipulation --- p.17 / Chapter 3.2.3. --- Experimental Setup --- p.19 / Chapter 3.2.4. --- Mechanism of Ethanol Sensor --- p.20 / Chapter 3.3 --- Characterization of F-CNTs Based Ethanol Sensors --- p.21 / Chapter 3.3.1. --- I-V Characteristics --- p.21 / Chapter 3.3.2. --- Thermal Sensitivity --- p.22 / Chapter 3.3.3. --- Stability --- p.23 / Chapter 3.3.4. --- FFT and Spectral Analysis --- p.23 / Chapter 3.4 --- Performance of F-CNTs Based Ethanol Sensors --- p.26 / Chapter 3.4.1. --- Typical Response --- p.26 / Chapter 3.4.2. --- Selectivity --- p.27 / Chapter 3.4.3. --- Towards Low Concentration --- p.28 / Chapter 3.4.4. --- Towards Realistic application --- p.29 / Chapter 3.5 --- Constant Power Configuration --- p.32 / Chapter 3.5.1. --- Constant Power Circuit for Ethanol Detection --- p.32 / Chapter 3.5.2. --- Sensor Response versus Power --- p.35 / Chapter 3.5.3. --- Responsivity --- p.37 / Chapter 3.5.4. --- Noise --- p.38 / Chapter 3.5.5. --- Sensitivity --- p.39 / Chapter 3.5.6. --- Dynamic Response --- p.41 / Chapter 3.6 --- Comparison between F-MWNTs and MWNTs --- p.43 / Chapter 3.6.1. --- I-V Characteristics --- p.43 / Chapter 3.6.2. --- Cycling Response --- p.44 / Chapter 3.6.3. --- Dynamic Response --- p.46 / Chapter 3.6.4. --- Sensor Performance under Different Power --- p.48 / Chapter 3.7 --- Summary --- p.53 / Chapter 4. --- EG-CNTs Based Flow Sensors --- p.55 / Chapter 4.1 --- Introduction to CNTs Flow Sensors --- p.55 / Chapter 4.2 --- EG-CNTs and Their Applications --- p.56 / Chapter 4.2.1 --- Intro to EG-CNTs Sensor --- p.56 / Chapter 4.2.2 --- Fabrication of EG-CNTs Sensor --- p.57 / Chapter 4.2.3 --- Experimental Characterization --- p.59 / Chapter 4.2.3.1. --- I-V Characteristics --- p.59 / Chapter 4.2.3.2. --- Thermal Sensitivity --- p.61 / Chapter 4.2.3.3. --- Humidity responsivity --- p.63 / Chapter 4.2.3.4. --- Stability --- p.65 / Chapter 4.2.3.5. --- Hysteresis --- p.66 / Chapter 4.2.4 --- Summary --- p.68 / Chapter 4.3 --- Fabrication of EG-CNTs Flow Sensor --- p.70 / Chapter 4.3.1. --- Fabrication Procedure --- p.70 / Chapter 4.3.2 --- Experimental Setup --- p.73 / Chapter 4.4 --- Characterization of EG-CNTs Flow Sensor --- p.74 / Chapter 4.4.1. --- Typical Response --- p.74 / Chapter 4.4.2. --- Power Consumption --- p.75 / Chapter 4.4.3. --- Repeatability --- p.77 / Chapter 4.4.4. --- Flow Sensitivity --- p.78 / Chapter 4.5 --- Summary --- p.79 / Chapter 5. --- Conclusion --- p.80 / Chapter 6. --- Bibliography --- p.83
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