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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.
51

Energy Savings in CO2 Capture System through Intercooling Mechanism

Rehan, M., Rahmanian, Nejat, Hyatt, Xaviar, Peletiri, Suoton P., Nizami, A.-S. 12 March 2021 (has links)
Yes / It has been globally recognized as necessary to reduce greenhouse gas (GHG) emissions for mitigating the adverse effects of global warming on earth. Carbon dioxide (CO2) capture and storage (CCS) technologies can play a critical role to achieve these reductions. Current CCS technologies use several different approaches including adsorption, membrane separation, physical and chemical absorption to separate CO2from flue gases. This study aims to evaluate the performance and energy savings of CO2capture system based on chemical absorption by installing an intercooler in the system. Monoethanolamine (MEA) was used as the absorption solvent and Aspen HYSYS (ver. 9) was used to simulate the CO2capturing model. The positioning of the intercooler was studied in 10 different cases and compared with the base case 0 without intercooling. It was found that the installation of the intercooler improved the overall efficiency of CO2recovery in the designed system for all 1-10 cases. Intercooler case 9 was found to be the best case in providing the highest recovery of CO2(92.68%), together with MEA solvent savings of 2.51%. Furthermore, energy savings of 16 GJ/h was estimated from the absorber column alone, that would increase many folds for the entire CO2capture plant. The intercooling system, thus showed improved CO2recovery performance and potential of significant savings in MEA solvent loading and energy requirements, essential for the development of economical and optimized CO2capturing technology.
52

Toward Industrialized Retrofitting : Accelerating the Transformation of the Residential Building Stock in Sweden

Wang, Qian January 2013 (has links)
Energy utilization issues are becoming increasingly important around the world. Existing residential and building service sectors represent a large part of total energy utilization, and the corresponding operational costs and environmental impacts are high. Retrofitting is considered an effective way to accelerate the sustainable transformation of the existing building stock. In Sweden, 1945–1975 was a boom period for the construction of residential buildings. After 40–70 years of use, large contingents of buildings need to be systematically retrofitted. In the past, most Swedish buildings were retrofitted individually, and occasionally in small clusters. Cost-effective retrofitting for large-scale implementation has not yet been substantially attained. Standardizing and industrializing the retrofitting process is expected to produce the following benefits: availability of standardized toolkits based on building typologies; simplified and more efficient decision-making process; lower retrofitting costs; shorter project durations; greater resource-efficiency; lower environmental impact; and higher profitability.The overall aim of the present study is to contribute to the knowledge regarding industrialized retrofitting toolkits in Swedish residential buildings and evaluate the various toolkits. More specifically, the study aims to analyze the energy demand saving potential of different retrofitting measures and long-term profits based on the typology of residential buildings. Based on a systematic set of building properties and classification of existing residential types in Sweden, four slab houses (lamellhus) were selected as the major sub-types of building stock for the demonstration cases. The case buildings were constructed between 1945 and 1975 and are currently used as single-family houses, multi-family houses, or apartment blocks. The main approaches applied to model the retrofitting profits were Consolis Energy +, parametric-based sensitivity analysis, and life-cycle-based economic assessment.Based on the theoretical modeling and analytical results from the case studies, it was found that the energy-saving potential is strongly dominated by the building type, which affects the design of retrofitting toolkits and defines life cycle costs. The results show that improving the efficiency of heat recovery in exhaust ventilation systems is an effective retrofitting measure for energy demand savings in the studied building types. However, the efficiency of other measures is highly dependent on the typology of the buildings. From an economic perspective, toolkits that include all of the possible retrofitting measures may not lead to larger expected reduction in LCC compared to standard retrofits that only include the most sensitive parameters. In addition, the impacts of energy price changes to the LCC in the future are highly diverse in different types of residential buildings. Developing systematic retrofitting guidelines for Swedish residential buildings requires both further research and a close collaboration between all stakeholders involved in the retrofitting process. / <p>QC 20131118</p>
53

Sustainable lighting in offices : " How to save energy in officeswith a new lighting design ? "

Alsaeid, Khaled January 2019 (has links)
Sustainableefficient lighting is becoming seen as one of the mostimportant issues in the office environment In Sweden, energydemandfor lighting corresponds to 20 of the total electricity use in officebuildings 31 while lighting form on average 33 1 of the electricityconsumption in UK office buildingsThisthesis investigate how to make lighting in offices more sustainableand focus on energy efficiency, to save energy through creating guidelinesrelated to light source technologies lighting control systems and the userbehavior then apply those guidelines to an existing office throughsuggesting a new lighting designTheexisting office in this case is the ÅF company 10 th office floor locatedin Stockholm SwedenThisinvestigation methodology consist of 2 main parts literature review andProject ( study At the first part, methods used are a combination ofliterature review related to saving energy through sustainability in lightingand how light source technology lighting control systems and the effect ofuser behavior could help to create more energy efficient lighting systemsAtthe second part, methods used in the Project study analyzed throughqualitative methods through surveys in addition to quantitative methodthrough and personal observations The used methods helped to createguidelines for the new suggested lighting design for ÅF 10 th office floorpartTheResults shows that the new suggested lighting design saved up to31 96 than the current lighting situation3
54

Cooling, heating, and power systems energy performance and non-conventional evaluation based on energy use

Fumo, Nelson 09 August 2008 (has links)
Cooling, Heating and Power (CHP) systems have been recognized as a key alternative for thermal energy and electricity generation at or near end-user sites. CHP systems can provide electricity while recovering waste heat to be used for space and water heating, and for space cooling. Although CHP technology seems to be economically feasible, because of the constant fluctuations in energy prices, CHP systems cannot always guarantee economic savings. However, a well-designed CHP system can guarantee energy savings, which makes necessary the quantification of non-conventional benefits from this technology in order to offset any economic weakness that can arise as consequence of energy prices. Some aspects that could be included in a non-conventional evaluation are: building energy rating, emission of pollutants, power reliability, power quality, fuel flexibility, brand and marketing benefits, protection from electric rate hikes, and benefits from promoting energy management practices. This study focuses on two aspects: building energy rating and emission reduction of pollutants, related to CHP system energy performance. Two methodologies have been developed in order to estimate the energy related benefits from CHP technology. To determine the energy performance, a model has been developed and implemented to simulate CHP systems in order to estimate the building-CHP system energy consumption. The developed model includes the relevant variables governing CHP systems such as: type and size of the components, individual component efficiencies, system operating mode, operational strategy, and building demand for power, heating, and cooling. The novelty of this model is the introduction of the Building Primary Energy Ratio (BPER) as a parameter to implement a primary energy operational strategy, which allows obtaining the best energy performance from the building-CHP system. Results show that the BPER operational strategy always guarantees energy savings. On the other hand, results from a cost-oriented operational strategy reveal that for critical design conditions, high economic savings can be obtained with unacceptable increment of energy consumption. For Energy Star Rating and Leadership in Energy and Environmental Design (LEED) Rating, results show that CHP systems have the ability to improve both ratings.
55

Effects of Elevated CO<sub>2</sub> on Growth, Development, Nutrient Concentration and Insect Performance of Plants Grown at Sub-Optimal Temperature

Rodriguez, Wilmer Mauricio 21 March 2011 (has links)
No description available.
56

Increased sustainability in boating and leisure craft through re-manufacturing: A case study on a Railactuator

Hoang, Michael January 2022 (has links)
As environmental impact and environmental emissions are an important part of today's society, due to climate change, high demands are placed on material selection, how the product is recycled and how the product is remanufactured. Remanufacturing is by definition to manufacture an old product into a new product Remanufacturing is an important process to get a sustainable life in the industries, this is because of the increased consumption of products and technique that are thrown away near the products end-of-life. Remanufacturing is a process applied to a product or a part near its end-of-life to transform a used product to a like-new product. At present, remanufacturing is a process that is not used as much in the marine world as other transportation industries, such as automotive and rail. At present, the remanufacturing process is only applying on smaller structures such as engines, propeller shafts, compressors and pumps.  This project work aimed to investigate the effects of implementing remanufacturing into Onmar products. In order to study how remanufacturing affects a company, an analysis was carried out on the company's Rail actuator to study the effects of implementing remanufacturing into the product. Since there are high demands on how the product is designed, an analysis was carried out on how the rail actuator was designed to meet the criteria set. This resulted in two different covers being produced in order to meet the requirements needed to carry out remanufacturing on the product. By implementing remanufacturing on the rail actuator resulted in large savings on energy consumption, material recycling, manufacturing costs, raw materials and carbon dioxide emissions when manufacturing new material.
57

Investigating the Impact of Urban Tree Planting Strategies for Shade and Residential Energy Conservation

Hwang, Won Hoi 04 September 2015 (has links)
Expanding urbanization, characterized by increased impervious surfaces and decreased tree canopy, is contributing to rising urban temperatures. This trend has implications for energy consumption, which strategically placed trees can modify by casting shade upon building and ground surfaces. However, urban densification, a paradigm of modern residential land development, often constrains space for planting shade trees. Thus, the overall objective of this dissertation was to investigate shade tree planting strategies and their effects on residential cooling and heating energy conservation for dense urban neighborhoods in U.S. cities on a latitudinal gradient. The first study used a computer program called Shadow Pattern Simulator to examine the effects of tree form, tree placement, and sunlight exposure on shade provision for a residential structure model. Simulation results affirmed the conventional strategy in northern latitudes that recommends planting shade trees on the east or west aspect for maximizing beneficial shade while avoiding tree plantings on the south aspect to minimize any heating penalty of undesirable shade. However, in southern latitudes, planting trees on southerly aspect should not be discounted because the shorter heating season lessens the detrimental heating penalty while providing beneficial season shade. The second study, using an energy simulation program called EnergyPlus, evaluated the effect of a single shade tree upon the energy consumption of the structure model. This study affirmed that energy conservation benefits are influenced by the quantity as well as the quality of tree shade upon building surfaces. In addition, interactions between sun angle, tree form, and tree placement were observed to influence tree shade effects on annual energy consumption. In the third study, based on the first two studies, an alternative tree placement strategy, which reconfigured tree placement around the residential structure, was developed to maximize cooling and heating energy savings while attenuating space conflicts. The alternative strategy was found to be as effective as the conventional strategy while being more responsive to parcel or building orientations in dense urban neighborhoods. Overall, understanding the fundamental interactions between tree form, tree placement, and geographic settings is critical for improving energy conservation benefits of shade trees in dense urban settings. / Ph. D.
58

Vytvoření metodiky zavádění systému managementu hospodaření s energií ve výrobním podniku / Development and implementation of energy savings and energy management methodology in an industrial enterprise

Dudarev, Ivan Unknown Date (has links)
V současné době se problematika energetických úspor dostává do popředí zájmu jak na úrovni jednotlivých podniků, tak i na úrovni celého státu. Často bývá příčinou sporů ve vědeckých kruzích i mezi odborníky z praxe. Lidstvo tradičně začalo využívat energii z minerálních přírodních zdrojů, které však ve srovnání s obnovitelnými zdroji energie mají omezení. Výzkum a implementace moderních technologií jsou ztíženy otázkou investic a časově omezeny. Proto se evropská strategie energetické bezpečnosti zaměřuje na energetickou účinnost, která je jedním z nejefektivnějších způsobů zlepšení bezpečnosti spotřeby energie. Velké společnosti a podniky jsou jedním z hlavních spotřebitelů energie. Proto je tato vědecká práce zaměřena na problematiku úspor energie a zlepšování energetické účinnosti podniku. Těžiště práce spočívá ve vytvoření a zavedení metodiky pro úsporu energie a managementu hospodaření s energií ve výrobním procesu automobilového podniku. Dále je pro účely této práce vytvořen a popsán způsob vizualizace spotřeby energie v prostředí virtuální reality
59

Development and Implementation of Energy Savings and Energy Management Methodology in an Industrial Enterprise / Development and Implementation of Energy Savings and Energy Management Methodology in an Industrial Enterprise

Dudarev, Ivan January 2015 (has links)
V současné době se problematika energetických úspor dostává do popředí zájmu jak na úrovni jednotlivých podniků, tak i na úrovni celého státu. Často bývá příčinou sporů ve vědeckých kruzích i mezi odborníky z praxe. Lidstvo tradičně začalo využívat energii z minerálních přírodních zdrojů, které však ve srovnání s obnovitelnými zdroji energie mají omezení. Výzkum a implementace moderních technologií jsou ztíženy otázkou investic a časově omezeny. Proto se evropská strategie energetické bezpečnosti zaměřuje na energetickou účinnost, která je jedním z nejefektivnějších způsobů zlepšení bezpečnosti spotřeby energie. Velké společnosti a podniky jsou jedním z hlavních spotřebitelů energie. Proto je tato vědecká práce zaměřena na problematiku úspor energie a zlepšování energetické účinnosti podniku. Těžiště práce spočívá ve vytvoření a zavedení metodiky pro úsporu energie a managementu hospodaření s energií ve výrobním procesu automobilového podniku. Dále je pro účely této práce vytvořen a popsán způsob vizualizace spotřeby energie v prostředí virtuální reality
60

Probabalistic load modelling of electrical demand of residential water heating

Urban, Graeme John 03 1900 (has links)
Thesis (MScEng)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Energy efficiency and the move to renewable energy resources are of vital importance in growing profitable and sustainable economies. In recent years, greater emphasis has been placed on institutions, companies and individuals to reduce their electrical energy demand through energy management. In an attempt to reduce the demand, the electrical power utility in South Africa, Eskom, has introduced Demand Side Management programs and substantial increases in electricity tariffs. In addition to these, tax incentives have been offered to help off-set the capital costs associated with the investments made in replacing old electrical equipment with new electrically efficient equipment. Thus the need for accurate Measurement and Verification of electrical energy demand reduction, to substantiate fiscal claims, has become imperative. The main purpose of Measurement and Verification is to investigate the actual monetary performance of an energy savings project. Energy savings assessments, based on purely deterministic baseline demand, do not adequately represent the statistical nature of the savings impacts of many practical load systems, as disclosed in a reporting period. This thesis presents the development of a generic probabilistic methodology to determine the demand profiles of preand post-Energy Conservation Measures (ECMs) for practical load systems. The difference between the simulated demand of the pre- and post-ECMs for a particular set of variables represent the electrical demand impact. The electrical demand of the pre- and post-ECMs is defined in terms of Probability Density Functions, and derived using a multivariate kernel density estimation algorithm. The approach is tested using a simulation model of a waterheating geyser implemented in MATLAB. Three different ECMs are simulated using the geyser model and demand density estimation. The results of the demand impacts of the ECMs are presented and evaluated. With regards to possible future research this methodology could be applied to the evaluation of the demand impacts of heat pump technologies and solar water heaters. / AFRIKAANSE OPSOMMING: en die skuif na hernubare energiebronne is van deurslaggewende belang vir die ontwikkeling van winsgewende en volhoubare ekonomieë. Onlangs is meer klem geplaas op instansies, maatskappye en individue om hul aanvraag na energie te verminder met behulp van energiebestuur. In ‘n poging om die aanvraag te verlaag, het Eskom, Suid-Afrika se elektrisiteitsverskaffer, aansienlike elektrisiteitstariefverhogings ingelyf en Aanvraagbestuursprogramme van stapel gestuur. Bykomend hiertoe is belastingaansporings ook aangebied, waarteen kapitale kostes, geassosieer met die vervanging van ou elektriese toerusting met nuwe elektries doeltreffende toerusting, afgeset kan word. Derhalwe het die behoefte aan akkurate Meting en Verifikasie van elektriese energie aanvraagvermindering, om finansiële eise te staaf, noodsaaklik geword. Die hoofdoel van Meting en Verifikasie is om die werklike finansiële prestasie van energiebesparingsprojek te ondersoek soos bekend gemaak word tydens ’n verslagdoeningstydperk. Energiebesparingassesserings wat slegs gebaseer word op die suiwer deterministiese basislyn aanvraag na elektrisiteit, verteenwoordig nie die werklike statistiese aard van die besparingsimpakte van baie praktiese lasstelsels nie. Hierdie tesis stel die ontwikkeling van generiese waarskynlikheids-metodologie voor, om die voor- en na- Energiebesparings-maatreëls se aanvraagprofiele vir sulke praktiese lasstelsels, vas te stel. Die verskil tussen die gesimuleerde aanvraag van die voor- en na- Energiebesparings-maatreëls vir spesifieke stel veranderlikes verteenwoordig die elektriese aanvraag impak. Die voor- en na- Energiebesparings-maatreëls van die energieverbruik profieldata word gedefinieer in terme van Waarskynlikheidsdigtheidsfunksies en afgelei deur gebruik te maak van meerveranderlike kerndigtheidafskattingsalgoritme. Die benadering is getoets deur gebruik te maak van simuleringsmodel van warmwaterstelsel geïmplimenteer in MATLAB. Drie verskillende voor- en na- Energiebesparings-maatreëls is gesimuleer met behulp van die warmwaterstelselmodel en aanvraag digtheidafskatting. Die resultate van die elektriese aanvraag impakte van die voor- en na- Energiebesparings-maatreëls word vervolgens bespreek en geëvalueer. Met betrekking tot moontlike toekomstige navorsing kan hierdie metodologie toegepas word om die aanvraag impakte van hittepomp- en sonwaterverwarmingstegnologieë te evalueer.

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