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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Evaluation of energy usage in the chemical industry and effective measures to reduce energy losses

Crespo, Raul Jose, January 2009 (has links)
Thesis (M.S.)--Mississippi State University. Department of Mechanical Engineering. / Title from title screen. Includes bibliographical references.
22

Ranking of Energy Saving Devices for Smart Homes according to their Payback Time

Felderer, Astrid, Brandtweiner, Roman, Hoeltl, Andrea January 2018 (has links) (PDF)
This paper discusses the average energy savings of various smart devices in connection with their average price. By calculating the devices' payback times, a ranking of the tools can be given. The whole study focuses on the average household within the EU-28 in terms of climate as well as in terms of user behaviour. The purpose of the research was to provide a win-win situation for users' wallets and the environment by showing the device which suits both players best. As a result of the research, it was found that the greatest reduction in energy consumption can be reached by an interaction of the smart device and the inhabitants of a smart home. By giving users feedback on their energy consumption through smart meters, average savings of 7.5% are reached. As a smart meter is available for about Euro 80, it has a payback time of only 4.24 months.
23

Gaming at work to save energy - Supporting behavioural change of occupants through cooperative games

Luo, Yi January 2018 (has links)
Commercial buildings are one of the main contributors to energy consumption while both energy management and occupants’ consumption behaviour play crucial roles in how energy is consumed. This study explored the energy awareness of occupants in a commercial building with the goal to investigate how increased awareness could support behaviour change. For this purpose, a cooperative gamified visualization of energy consumption data, “EnerSpace”, is designed, implemented and evaluated. 8 occupants participated in this study who experienced a one-week baseline period and a one-week “EnerSpace” game period. In EnerSpace, the participants were divided into two teams and powered a spaceship with their energy saving respectively on a resource exploitation trip to Mars. Each participant had an avatar in the spaceship who introduced the participant’s personal consumption data. The energy conservation of the participants affects the moving speed of the spaceship and the living condition of their avatars. Participants were rewarded by a postcard sent by the avatars when reaching a destination. The results showed that the participants 1) decreased their energy consumption, 2) reported a fun and engaging experience with EnerSpace, and 3) felt motivated for energy conservation by different motives. This study indicated a potential for energy saving in a commercial building using a cooperative game. / Kommersiella byggnader är en av de främsta bidragsgivarna till energiförbrukningen, medan både energihantering och passagerarnas konsumtionsbeteende spelar en viktig roll i hur energi förbrukas. Denna studie undersökte medvetenheten om passagerare i en kommersiell byggnad med målet att undersöka hur ökad medvetenhet kunde stödja beteendets förändring. I detta syfte utformas, implementeras och utvärderas en kooperativ gammal visualisering av energiförbrukningsdata, "EnerSpace". 8 personer deltog i den här studien som upplevde en veckors baslinjeperiod och en veckas "EnerSpace" spelperiod. I EnerSpace delades deltagarna i två lag och drev ett rymdskepp med respektive energibesparing på en resursutnyttjandesresa till Mars. Varje deltagare hade en avatar i rymdskeppet som introducerade deltagarens personliga konsumtionsdata. Deltagarnas energibesparande påverkar rymdskeppens rörelsehastighet och deras avatars levnadsförhållande. Deltagarna belönades med ett vykort skickat av avatarer när de kom till en destination. Resultaten visade att deltagarna 1) minskade sin energiförbrukning, 2) rapporterade en rolig och engagerande erfarenhet av EnerSpace, och 3) kände sig motiverade för energibesparing med olika motiv. Denna studie indikerade en potential för energibesparing i en kommersiell byggnad med hjälp av en kooperativ gammal visualisering.
24

Investigation of the process energy demand in polymer extrusion: A brief review and an experimental study

Abeykoon, Chamil, Kelly, Adrian L., Brown, Elaine C., Vera-Sorroche, Javier, Coates, Philip D., Harkin-Jones, E., Howell, Ken B., Deng, J., Li, K., Price, M. 17 October 2014 (has links)
Yes / Extrusion is one of the fundamental production methods in the polymer processing industry and is used in the production of a large number of commodities in a diverse industrial sector. Being an energy intensive production method, process energy efficiency is one of the major concerns and the selection of the most energy efficient processing conditions is a key to reducing operating costs. Usually, extruders consume energy through the drive motor, barrel heaters, cooling fans, cooling water pumps, gear pumps, etc. Typically the drive motor is the largest energy consuming device in an extruder while barrel/die heaters are responsible for the second largest energy demand. This study is focused on investigating the total energy demand of an extrusion plant under various processing conditions while identifying ways to optimise the energy efficiency. Initially, a review was carried out on the monitoring and modelling of the energy consumption in polymer extrusion. Also, the power factor, energy demand and losses of a typical extrusion plant were discussed in detail. The mass throughput, total energy consumption and power factor of an extruder were experimentally observed over different processing conditions and the total extruder energy demand was modelled empirically and also using a commercially available extrusion simulation software. The experimental results show that extruder energy demand is heavily coupled between the machine, material and process parameters. The total power predicted by the simulation software exhibits a lagging offset compared with the experimental measurements. Empirical models are in good agreement with the experimental measurements and hence these can be used in studying process energy behaviour in detail and to identify ways to optimise the process energy efficiency.
25

Homo Colossus Energy Calculator / Homo Colossus Energikalkylator

Helander, Hugo, Tegelmo, Linus January 2020 (has links)
This thesis covers the creation of a series of questions that have the purpose of estimating the amount of energy that an individual uses over the course of a year. These questions are designed for a kiosk in an exhibition environment, and they will be used for an environmental project called Homo Colossus which will be presented at different exhibitions. The foundational energy values used in this thesis are from David JC MacKay. The main problem explored throughout this thesis is how we can, with as few questions as possible, give someone an estimation of their yearly energy consumption. To achieve this, we interviewed people with relevant experience and conducted a questionnaire to test the questions. The results from the test led to minor alterations in our questionnaire structure. / Denna uppsats handlar om skapandet av en samling frågor som har syftet att uppskatta mängden energi som en individ använder över ett år. Dessa frågor är designade för en kiosk i en utställningsmiljö, och kommer att användas för ett projekt som kallas för ‘Homo Colossus’ som kommer att presenteras på diverse utställningar. Huvudkällan för energivärdena i denna uppsats kommer ifrån David JC MacKay. Huvudfrågan som denna uppsats täcker är hur vi kan, med så få frågor som möjligt, ge en uppskattning av någons årliga energikonsumtion. För att uppnå detta, så intervjuade vi personer med relevant erfarenhet och skapade ett frågeformulär för att testa frågorna. Resultatet från testet ledde till små förändringar i strukturen av frågeformuläret.
26

Improvisatory home heating : the gap between intended and actual use of radiators and TRVs

Osz, Katalin January 2016 (has links)
Ongoing modification and change is core to how domestic and built environments function. Thus occupants domestication and development of home heating practices around low-carbon technologies is likely to exceed what building engineering sciences have the ability to plan ahead for. Yet, environmental policies and low -carbon industry approaches to sustainable energy consumption are characterised by a high degree of technological determinism. Disciplinary approaches to sustainable energy consumption tend to separate home heating into stable, routine interaction with control points, environmental factors and socio-demographic drivers. Framing low-carbon technical change in isolation from domestic environments often leads to a gap between intended and actual use of technologies. By focusing on TRVs (thermostatic radiators valve) and radiators, this thesis takes an interdisciplinary turn to jointly examine the social and environmental elements of households energy use. A turn to sensory ethnography and practice-place relationships offers a way to better understand how people use energy for space heating in relation to the buildings they live in and how improvisatory uses of technologies emerge from flows of material, domestic, sensory and physical contingencies of the home. Combining home video tours with building energy monitoring in eight homes, the thesis demonstrates that home heating is a place-event of the home because heating systems and energy consumption are woven into the fabric of everyday life. Environmental elements show that the social and technical are inseparable in energy used for space heating and individual elements imply that the domestication of technologies is highly unpredictable. The thesis synthesises findings into a taxonomy table of irregular radiator and TRV use. On the one hand, irregularities indicate that improvisatory uses of technologies are productive sources of sustainable change because they can be potential sites for co-design. On the other hand, the interwoven character of the social and technical in households energy use critically challenges how environmental policy, low-carbon industry and disciplinary approaches frame intervention into sustainable energy consumption. The thesis argues for the value of logic of intervention and sustainable change that is collaborative, system-focused and gradually uncovers interrelationships.
27

Darstellung und Einfluss von durchbrochener Bewölkung auf den Ertrag von Photovoltaik-Anlagen und dessen Prognose

Göhler, R., Raabe, Armin, Zimmer, Janek 03 November 2017 (has links)
Due to the significant increase of ’renewable energy’ to the total energy the highly fluctuating energy supply, which is due to the constitutional conditions of production among others from photovoltaic systems, becomes a growing problem. As a result, many engineering firms and companies dedicate themselves to the so-called power prediction by which it should be possible to integrate a fast changing energy supply into a necessarily continuous energy supply. The Ingenieurbüro für Last- und Energiemanagement (LEM-Software) used a neural network for this prediction of performance of photovoltaic systems. This networks learn from past knowledge a mathematical patern that can be used for forecasting. Based on this, this article deals with a new parameter for the network which characterizes the probability of broken cloud effects. The global radiation forecast in the surrounding area is analyzed for this index. It turns out that this inhomogeneous index is a better indicator than the standard deviation. A first application shows a slight improvement in the forecast result. However, the time limit for application of the neural network is too short for a final evaluation. / Aufgrund des steigenden Anteils ’erneuerbarer Energie’ an der Energieversorgung wird die stark schwankende Energiezufuhr, bedingt durch die naturgegebenen Produktionsbedingungen unter anderem von Photovoltaik-Anlagen, zu einem immer größeren Problem. Infolge dessen widmen sich viele Ingenieurbüros und Firmen sogenannten Leistungsprognosen, mit deren Hilfe es gelingen soll, eine schnell wechselnde Energiebereitstellung in eine notwendigerweise kontinuierliche Energieversorgung zu streichen. Das Ingenieurbüro für Last- und Energiemanagement (LEM-Software) verwendet für diese Vorhersagen der Leistung von Photovoltaik-Anlagen ein künstliches neuronales Netzwerk (KNN). Dieses erlernt aus vergangenen Verhältnissen ein mathematisches Muster, welches für die Prognose angewendet werden kann. Aufbauend darauf befasst sich dieser Artikel mit einem Inhomogenitätsindex f¨ur das Netzwerk, welcher die Wahrscheinlichkeit für das Auftreten schnell wechselnder Bewölkung und von Broken-Cloud-Effekten charakterisiert. Für den Index wird die Globalstrahlungsvorhersage in der näheren Umgebung analysiert. Dabei stellt sich heraus, dass dieser Inhomogenitätsindex ein besserer Indikator als die Standardabweichung ist. Eine erste Anwendung zeigt eine leichte Verbesserung des Prognoseergebnisses, allerdings ist der Zeitraum für die Anwendung des KNN zu kurz für eine abschließende Bewertung.
28

The energy consumption mechanisms of a power-split hybrid electric vehicle in real-world driving

Lintern, Matthew A. January 2015 (has links)
With increasing costs of fossil fuels and intensified environmental awareness, low carbon vehicles, including hybrid electric vehicles (HEVs), are becoming more popular for car buyers due to their lower running costs. HEVs are sensitive to the driving conditions under which they are used however, and real-world driving can be very different to the legislative test cycles. On the road there are higher speeds, faster accelerations and more changes in speed, plus additional factors that are not taken into account in laboratory tests, all leading to poorer fuel economy. Future trends in the automotive industry are predicted to include a large focus on increased hybridisation of passenger cars in the coming years, so this is an important current research area. The aims of this project were to determine the energy consumption of a HEV in real-world driving, and investigate the differences in this compared to other standard drive cycles, and also compared to testing in laboratory conditions. A second generation Toyota Prius equipped with a GPS (Global Positioning System) data logging system collected driving data while in use by Loughborough University Security over a period of 9 months. The journey data was used for the development of a drive cycle, the Loughborough University Urban Drive Cycle 2 (LUUDC2), representing urban driving around the university campus and local town roads. It will also have a likeness to other similar driving routines. Vehicle testing was carried out on a chassis dynamometer on the real-world LUUDC2 and other existing drive cycles for comparison, including ECE-15, UDDS (Urban Dynamometer Driving Schedule) and Artemis Urban. Comparisons were made between real-world driving test results and chassis dynamometer real-world cycle test results. Comparison was also made with a pure electric vehicle (EV) that was tested in a similar way. To verify the test results and investigate the energy consumption inside the system, a Prius model in Autonomie vehicle simulation software was used. There were two main areas of results outcomes; the first of which was higher fuel consumption on the LUUDC2 compared to other cycles due to cycle effects, with the former having greater accelerations and a more transient speed profile. In a drive cycle acceleration effect study, for the cycle with 80% higher average acceleration than the other the difference in fuel consumption was about 32%, of which around half of this was discovered to be as a result of an increased average acceleration and deceleration rate. Compared to the standard ECE-15 urban drive cycle, fuel consumption was 20% higher on the LUUDC2. The second main area of outcomes is the factors that give greater energy consumption in real-world driving compared to in a laboratory and in simulations being determined and quantified. There was found to be a significant difference in fuel consumption for the HEV of over a third between on-road real-world driving and chassis dynamometer testing on the developed real-world cycle. Contributors to the difference were identified and explored further to quantify their impact. Firstly, validation of the drive cycle accuracy by statistical comparison to the original dataset using acceleration magnitude distributions highlighted that the cycle could be better matched. Chassis dynamometer testing of a new refined cycle showed that this had a significant impact, contributing approximately 16% of the difference to the real-world driving, bringing this gap down to 21%. This showed how important accurate cycle production from the data set is to give a representative and meaningful output. Road gradient was investigated as a possible contributor to the difference. The Prius was driven on repeated circuits of the campus to produce a simplified real-world driving cycle that could be directly linked with the corresponding gradients, which were obtained by surveying the land. This cycle was run on the chassis dynamometer and Autonomie was also used to simulate driving this cycle with and without its gradients. This study showed that gradient had a negligible contribution to fuel consumption of the HEV in the case of a circular route where returning to the start point. A main factor in the difference to real-world driving was found to be the use of climate control auxiliaries with associated ambient temperature. Investigation found this element is estimated to contribute over 15% to the difference in real-world fuel consumption, by running the heater in low temperatures and the air conditioning in high temperatures. This leaves a 6% remainder made up of a collection of other small real-world factors. Equivalent tests carried out in simulations to those carried out on the chassis dynamometer gave 20% lower fuel consumption. This is accounted for by degradation of the test vehicle at approximately 7%, and the other part by inaccuracy of the simulation model. Laboratory testing of the high voltage battery pack found it constituted around 2% of the vehicle degradation factor, plus an additional 5% due to imbalance of the battery cell voltages, on top of the 7% stated above. From this investigation it can be concluded that the driving cycle and environment have a substantial impact of the energy use of a HEV. Therefore they could be better designed by incorporating real-world driving into the development process, for example by basing control strategies on real-world drive cycles. Vehicles would also benefit from being developed for use in a particular application to improve their fuel consumption. Alternatively, factors for each of the contributing elements of real-world driving could be included in published fuel economy figures to give prospective users more representative values.
29

Wachstumspotentiale erneuerbarer Energien und ihre Implikationen für Klimaschutz, Versorgungssicherheit und Wettbewerbsfähigkeit /

Herholz, Ute. January 2006 (has links) (PDF)
Univ., Diss.--Hamburg, 2005. / Zsfassung in dt. Sprache.
30

Proposta de uma metodologia para avaliação das perdas comerciais dos sistemas eletricos : o caso Manaus / Proposal of methodology for avaliation of the commercials losses of the electrical systems : the Manaus case

Vieiralves, Eduardo de Xerez 29 August 2005 (has links)
Orientador: Moacyr Trindade de Oliveria Andrade / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-05T19:49:11Z (GMT). No. of bitstreams: 1 Vieiralves_EduardodeXerez_M.pdf: 1874956 bytes, checksum: 4f79bc70e42ae0c47e0a35cde1327ad1 (MD5) Previous issue date: 2005 / Resumo: O equilíbrio econômico-financeiro garantido pelo contrato de concessão firmado pelas concessionárias junto ao poder concedente, tem como prerrogativa uma gestão atuante por parte do agente prestador do serviço, o que evidencia o seu controle técnico e comercial, bem como a promoção do desenvolvimento tecnológico dos serviços concedidos. Neste contexto, é de suma importância que a receita da concessionária, fruto de sua gestão na aquisição da energia a ser utilizada, bem como sua efetiva disponibilidade, seja dirigida ao mercado e aos consumidores com a qualidade requerida, a preços compatíveis com a renda média da população regional e com um percentual de perdas compatível com a tecnologia disponível. O controle das perdas técnicas e comerciais, em empresas do setor elétrico é fundamental para a consecução dos objetivos das concessionárias e da população a ser atendida. A falta de efetivo controle das perdas gera desperdício, ineficiência e redunda em custos elevados. Na região amazônica, as fontes energéticas são suportadas por parques térmicos que queimam material fóssil. Nessas condições o desperdício energético provoca, adicionalmente, danos desnecessários à natureza. As emissões de material particulado e de gases do efeito estufa, na condição de grandes perdas comerciais das empresas do setor elétrico, são mais elevadas, o que fatalmente vai agravar as condições ambientais da vida das gerações futuras. Na região Norte do Brasil, os sistemas elétricos isolados, em função do tipo das fontes energéticas e das grandes distâncias envolvidas, apresentam altos custos de operação e manutenção. As empresas apresentam índices de perdas elevadíssimos, que inviabilizam totalmente o negócio, razão pela qual, até hoje, vários são os mecanismos de subsídios associados ao mesmo, visando a viabilização do serviço de energia elétrica. O presente trabalho visa analisar a situação das perdas comerciais na região, dando ênfase ao ¿Caso Manaus¿, procurando identificar as suas causas e efeitos, tanto para a sociedade em geral como para os empresários do setor. Mais especificamente, se abordará o estudo de caso da empresa Manaus Energia S/A, por ser a maior dos sistemas isolados e por apresentar índices de perdas muito acima do admissível e da média das concessionárias do Setor Elétrico Nacional / Abstract: The financial-economical equilibrium guaranteed by the concession contract made by the concessionaries before the granting power, has as a prerogative an acting management by the service agent owner. That evidences its technical and commercial control, as well as the promotion of the technological development of the granted services. In such a context, it is of great importance that the concessionary receipt, product of its management in the acquisition of the energy to be used, as well as in its effective availability, be driven towards the market and the consumers with the quality requested with compatible prices at the middle income of the local population and with a loss percentage balanced to the technology available. The control of such technical and commercial loss in the companies of the electric field is fundamental to the accomplishment of the concessionary objectives and to the population attending.The lack of an effective control about the loss generates waste, non-efficiency and leads to elevated costs. In the Amazon area, the energetic sources are supported by thermic park which burn fossil matter. Besides, in such conditions the energetic waste provokes unnecessary waste to the nature. The emissions of particled material and gases from the greenhouse effect, in the condition of great commercial losses of the electric field companies are higher what will worsen the environmental conditions of the future generations life. In Brazil north region, the isolated electric systems due to the kind of the energetic sources and the great distances involved, lead to high costs of operation and maintenance. The companies show very high losses rates which make the business completely unfeasible, that is the reason, nowadays, due to many are the resources of subsidies associated attempting the availability of the electric energy service. The present work aims to analyze the state of the commercial losses in the region, emphasizing ¿Manaus case¿, searching the causes and effects identification, to the society in general, as to the sector entrepreneurs. More specifically, there will be approached the case study of Manaus Energia S/A company, for being the biggest of the isolated systems and for presenting a loss rate much higher from the admissible and the average of the National Electric Sector concessionaries / Mestrado / Energia Eletrica / Mestre em Engenharia Mecânica

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