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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

Approaches to energy efficiency in China’s large-scale public building

Yu, Wenhe January 2010 (has links)
In recent years, the energy shortage has become a barrier to social development as there is a shortage of resources, especially non-renewable resources. In order to improve the current situation of human settlement for future generations, a series of environmental protection activities and rational utilizations of natural resources have been carried out at a global level on the theme of "Sustainable Development". Along with the quantitative growth of Chinese public buildings, especially the Large-Scale Public Buildings, the levels of energy consumption are rising and this phenomenon has been seen as a key point of energy management from a national view. This paper discusses the realities of energy consumption and the energy-saving policies of public buildings in the world’s major developed countries, and sums up the current condition of Chinese energy consumption in relation to public buildings. With regard to these factors, this paper tries to find approaches for solving the existing problems in each construction section. Less developed construction technology in China leads to a waste of materials and labor force. There is a lack of professional personnel to handle the operational management and a lack of consideration for energy efficiency in the designing process. There is not a suitable framework for compiling statistics and data on energy consumption. There are still many management problems such as inadequate policy standards in operability or implementation, unclear positioning in governmental management, ineffective incentive or punitive mechanisms, and a defective state system which results directly in an undeveloped service system for energy efficiency. Based on all of the problems listed above, this paper suggests solutions in four areas, namely Policy, Energy Statistics, Management and Education, in order to give academic support for the overhaul of Large-Scale Public Buildings towards greater energy efficiency in China.
22

Approaches to energy efficiency in China’s large-scale public building

Wenhe, Yu January 2010 (has links)
In recent years, the energy shortage has become a barrier to social development as there is a shortage of resources, especially non-renewable resources. In order to improve the current situation of human settlement for future generations, a series of environmental protection activities and rational utilizations of natural resources have been carried out at a global level on the theme of "Sustainable Development". Along with the quantitative growth of Chinese public buildings, especially the Large-Scale Public Buildings, the levels of energy consumption are rising and this phenomenon has been seen as a key point of energy management from a national view. This paper discusses the realities of energy consumption and the energy-saving policies of public buildings in the world’s major developed countries, and sums up the current condition of Chinese energy consumption in relation to public buildings. With regard to these factors, this paper tries to find approaches for solving the existing problems in each construction section. Less developed construction technology in China leads to a waste of materials and labor force. There is a lack of professional personnel to handle the operational management and a lack of consideration for energy efficiency in the designing process. There is not a suitable framework for compiling statistics and data on energy consumption. There are still many management problems such as inadequate policy standards in operability or implementation, unclear positioning in governmental management, ineffective incentive or punitive mechanisms, and a defective state system which results directly in an undeveloped service system for energy efficiency. Based on all of the problems listed above, this paper suggests solutions in four areas, namely Policy, Energy Statistics, Management and Education, in order to give academic support for the overhaul of Large-Scale Public Buildings towards greater energy efficiency in China. / www.ima.kth.se
23

Simulation of Indoor Radon and Energy Recovery Ventilation Systems in Residential Buildings

Akbari, Keramatollah January 2015 (has links)
This study aims to investigate the effects of ventilation rate, indoor air temperature, humidity and using a heat recovery ventilation system on indoor radon concentration and distribution. Methods employed include energy dynamic and computational fluid dynamics simulation, experimental measurement and analytical investigations. Experimental investigations primarily utilize a continuous radon meter and a detached house equipped with a recovery heat exchanger unit. The results of the dynamic simulation show that the heat recovery unit is cost-effective for the cold Swedish climate and an energy saving of about 30 kWh per  floor area per year is possible, while it can be also used to lower radon level. The numerical results showed that ventilation rate and ventilation location have significant impacts on both radon content and distribution, whereas indoor air temperature only has a small effect on radon level and distribution and humidity has no impact on radon level but has a small impact on its distribution.
24

Assessing energy and thermal comfort of domestic buildings in the Mediterranean region

Georgiou, Georgios January 2015 (has links)
Nowadays, buildings are responsible for the 40% of energy consumption in the European Union, with energy up to 68% being coherent with thermal loads. Acknowledging the great potential of building sector, a substantial amount of the current building inventory must be refurbished, based on the trade-offs between energy and thermal comfort. To this effect, this study investigates the impact of retrofitting measures in residential envelope for areas experience Mediterranean climate. Seven detached houses, located in Cyprus, were modelled, investigating 253 parameters of envelope interventions and also, 7,056 combinations of these measures. In general, the findings revealed a seasonal performance variation of interventions with regards to the outdoor climate. The application of roof insulation determined as the most economic viable solution during retrofitting (single interventions), achieving a reduction up to 25% of annual energy consumption with enhancement of the indoor thermal environment. In the perspective of synergies between interventions, the application of roof and external walls thermal insulation with upgrade of glazing system with double Low-E demonstrated exemplary levels of performance decreasing on average energy consumption up to 38%.The findings of this research will contribute on the development of guidelines for designers and house builders for a perceptual retrofitting of existing residential envelopes in Cyprus and also, for countries experiencing the Mediterranean climate.
25

Antecedents of energy literacy and energy saving behaviour : a mixed methods approach

van den Broek, Karlijn Lisette January 2016 (has links)
Energy conservation can mitigate significant issues such as climate change and fuel poverty, yet the determinants of this behaviour are poorly understood. It is important to understand the antecedents of energy conservation in order to effectively stimulate this behaviour in society. Traditional models have focused on normative and intentional processes to explain environmental behaviour, but have proven largely unsuccessful for predicting energy use. Considering that day-to-day energy behaviour is likely to be habitual and context dependent, models such as the Comprehensive Action Determination Model (CADM, Klöckner & Blöbaum, 2010), which have integrated these factors with more traditional antecedents of behaviour, may better account for people’s actions. The early research in this thesis tests the application of this model to energy saving behaviour using a mixed-methods approach. Findings show that such a model is suitable to account for the drivers of energy behaviour, particularly because of the important role of habits and situational influences on this behaviour. Although this model can successfully predict daily energy behaviours that involve the routine curtailment of household energy use, one-off energy efficiency investment behaviours are unlikely to be determined by the variables considered by the CADM. That is, these behaviours may be more dependent on people’s understanding of the energy consumption in their household, or their energy literacy. Therefore, the second part of this thesis investigates the cognitive processes that inform conscious energy judgements to explore the antecedents of this energy literacy. The studies in this thesis uncover an unprecedented variety of energy judgement heuristics in this decision-making process, and these heuristics are further investigated, again using various methods. This thesis concludes that, to maximally facilitate energy conservation, the habitual and situational antecedents of energy saving behaviour, as captured in such frameworks as the CADM, need to be considered alongside the cognitive processes that shape people’s energy literacy when designing effective energy conservation interventions that target both routine and non-routine actions.
26

Interactions in Collective Fish Swimming / Interactions des poissons en nage collective

Ashraf, Intesaaf 04 April 2018 (has links)
Le banc de poisson est un exemple typique d’auto organisation de groupe. Ce système implique des interactions complexes d’individus dans un milieu fluide et fait l’objet de nombreuses recherches multidisciplinaire théoriques, numériques ou expérimentales.Plusieurs hypothèses ont déjà été formulées pour expliquer la formation de ces bancs: la fuite face à des prédateurs, l’optimisation dans la recherche de nutriments ou encore l’économie d’énergie. Dans la plupart des recherches, les travaux se concentrent sur ce que les poissons devraient faire pour optimiser une tâche plutôt que sur des observations directes. Cela conduit à des différences dans les conclusions issus du travail des physiciens théoriciens ou ingénieurs avec ce qui est observé dans la nature par les biologistes. Dans ce travail, nous apportons, basées sur des observations directes tetra Hemigrammus bleheri, de nouveaux éléments sur les interactions des poissons lors de la nage collective comme le phénomène de burst-and-coast ou la synchronisation des cinématiques entre plus proches voisins. Enfin, nous démontrons que les bancs de Hemigrammus bleheri privilégient la configuration en ligne plutôt que celle en diamant souvent mise en avant dans la littérature / Fish school is the classical example of self-emergent system of collective behavior in animal locomotion, which involves complex interactions between individuals and has drawn fascination of numerous multidisciplinary analytical, numerical and experimental researches. Various reasons have been cited for the formation of fish school such as evading predators, enhancing foraging success or advantage in terms of energy consumption. However, most of the works primary focus on what fish should do in a school instead of what fish really do, leading to discrepancies between the works of theoretical physicists and engineers and what is observed in the nature by biologists. This thesis is an attempt to bridge this gap. In this work, we investigate the swimming dynamics of the red nose tetra fish Hemigrammus bleheri in a controlled experiment. The tetra fish are observed to swim using a burst-and-coast strategy, which could be for the purpose of active flow sensing. We also address the case of red nose tetra fish Hemigrammus bleheri swimming in groups in a uniform flow, giving special attention to the basic interactions and cooperative swimming of a single pair of fish. We first bring evidence of synchronization of the two fish, where the swimming modes are dominated by "out of phase" and "in phase" configurations. At last, we challenge the question of energy benefit by discussing the channeling effect versus the vortex interaction hypothesis (Weihs, Nature 241:290-291, 1973) about diamond shape. We provide the experimental observation that fish prefer inline formation or phalanx formation over the diamond shape while swimming in a school
27

Energy survey and saving in the ICA maxi Gävle.

DANIERE, Sébastien January 2009 (has links)
<p>Due to the global warming of the atmosphere it is now time to decrease the consumption of energy. One of the most important consumer is the commercial building area and especialy the supermarket. After a survey of the total consumption and a division into unit process it is possible to find some measures to decrease the global consumption of energy (in the lighting, cooling/freezing and space heating processes).</p>
28

ANALISYS AND ENERGY SAVING MEASURES OF KASTVALLEN ICE HOCKEY RINK ARENA

Igual Bueno, Mario, Bielsa Azcona, Jose Enrique January 2012 (has links)
Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SEK. The aim of this project is reducing the amount of the electricity and heat invoice promoting smart energy improvements. The improvements proposals can be divided in three sections; energy savings of the changing rooms, efficiency increase of the compressors and dehumidifier energy savings. For heat the tap water and the changing room’s ventilation it is suggested to take profit from the heat released at the condenser and so reduce its heat load requirements. For this proposal two different configurations are studied. In order to increase the efficiency of the compressors the possibility of reducing the condenser temperature will be studied. Three proposals will be studied to carry out this commitment; Installing a condensing temperature control, installing a evaporate cooler and having a snow storage. Finally, one of the largest consumers of electricity in Kastvallen ice hockey rink is the dehumidifier. The current dehumidifier works with a desiccant wheel. The desiccant material extract the moisture from the processed air flow, after that the desiccant has to be reactivated with ‘fresh air’. This reactivation air needs to be heated 95ºC, so the waste air released after the reactivation of the desiccant is air at high temperature. The first proposal is preheat the reactivation air with the hot waste air in order to reduce the heating requirements, conducting this proposal the total money saved each year would be 41811 SEK with a Pay-back around 1 year. The second step is studied the possibility of heating the air with district heating, taking into account that district heating is three times cheaper than electricity, conducting this proposal the total money saved each year would be 45629 SEK with a Pay-back around 1 year. The last proposal is to combine preheating and heating with district heating, conducting this proposal the total money saved each year would be 61553 SEK with a Pay-back around 1.6 years. All the previous energy improvements proposals are studied with empirical and analytical methods and using the knowledge gained during the previous years of studies. The study concludes that the best proposal for the dehumidifier is combine the preheating and heating with district heating. In addition of the money saved, this measure allows to save 2.71 Tm of CO2 each year. For the refrigeration cycle, the study concludes that installing a controlled temperature control is the best option if the price of that is lower than 334726 SEK. If not the best option is heating the rooms and the ventilation with the condenser of the refrigeration cycle. These measures could reduce between 8% and 20% of the total energy invoice plus a considerable reduction of CO2 emissions. Evaporative cooling and snow storage would be studying after with the data of the first year of the condensing temperature control; if it is installed.
29

Development of the Japanese Energy Saving Technology during 1920–1960 : The Iron and Steel Industry

KOBORI, Satoru 01 1900 (has links)
Comments and Discussion : Minoru Sawai
30

Energy survey and saving in the ICA maxi Gävle.

DANIERE, Sébastien January 2009 (has links)
Due to the global warming of the atmosphere it is now time to decrease the consumption of energy. One of the most important consumer is the commercial building area and especialy the supermarket. After a survey of the total consumption and a division into unit process it is possible to find some measures to decrease the global consumption of energy (in the lighting, cooling/freezing and space heating processes).

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