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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.
1

The sputtering of zinc oxide thin films for spectrally selective solar energy material applications

Figgures, Christopher Colin January 1989 (has links)
No description available.
2

Solar Heat in Industrial Processes : Integration of Parabolic Trough Solar Collectors Dairy Plants and Pharmaceutical Plants

Al-Hasnawi, Hassan January 2016 (has links)
The industry sector accounts for a high share of the final energy consumption, with industries in EU-28accounting for a quarter of the final energy demand. Studies also show that 45 % of the industrial heatdemand in EU-27 is in a temperature range that can be supplied with present day solar collectors. Despitethis large potential, solar heat faces obstacles hindering its growth in the industrial sector. The mostsignificant obstacle is the low insight of the industrial system designs and energy demands. Those arecrucial factors for the feasibility and dimensioning of solar heating systems. Three case studies aretherefore conducted in dairy and pharmaceutical plants in order to review the most promising integrationpoints for parabolic trough solar collectors in terms of annual heat demand, temperature level andintegration effort. Two case studies are performed in dairy plants and one in a pharmaceutical plant, alllocated in Sweden. The analyses comprised reviewing energy mappings, process and instrumentationdiagrams of processes and boiler systems, and hourly energy demand data. Simulations have beencarried out with Polysun for the processes with hourly energy data available.Four integration points have been determined to be high priority solar heat integration points in dairyplants, when considering annual thermal energy demand, temperature levels and integration effort.Those are the low pressure steam line, heating of feedwater, clean in place systems and pasteurizers.Solar heat integration concepts have been presented for all the aforementioned heat sinks andsimulations have been conducted for the low pressure steam line and heating of feedwater. A significantamount of excess heat is produced as a result of fluctuating heat demands and peak solar heat productionhours. Further investigation should be carried out, in order to review the potential of supplying excessheat to other heat sinks. Despite the reviewed potential of the clean in place systems and pasteurizers,lack of the hourly energy demand has hindered further analyses of those systems. It is thereforerecommended to conduct energy measurements before taking further measures.Two integration points have been identified in the pharmaceutical plant, namely autoclaves andmultiple-effect distillers. Solar steam generation concepts have been presented for both processes. Theautoclaves are provided with 4,5 bar steam intermittently, as they work with batches and can have ondutyand off-duty intervals ranging from 3-30 minutes. The multiple-effect distillers are providedwith 7 bar steam, which is of rather high pressure for the solar collectors model on which thesimulations are based. The heat demand of the distillers is more or less constant.It was generally easier to acquire data for the integration points at the supply level. For instance, all heatsinks at the supply level had energy demand data available, contrary to the process level. This inclinesadditional focus on integration to the supply level, if the extent of the feasibility study is to be kept to aminimum.
3

Äldreboendet på Zakrisdal : En studie om solvärme med säsongslagring / Home for elderly at Zakrisdal : A study about solar heat with seasonal heat storage

Skantz, Christoffer January 2008 (has links)
<p>A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?</p>
4

Äldreboendet på Zakrisdal : En studie om solvärme med säsongslagring / Home for elderly at Zakrisdal : A study about solar heat with seasonal heat storage

Skantz, Christoffer January 2008 (has links)
A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?
5

MILJÖCERTIFIERING MED MILJÖBYGGNAD : FÖRSLAG FÖR LÖSNING AV PROBLEMET MED UPPFYLLNAD AV KRAVEN PÅ DAGSLJUS OCH SOLVÄRMELAST / ENVIRONMENTAL CERTIFICATION WITH MILJÖBYGGNAD : PROPOSAL FOR SOLUTION OF THE PROBLEM WITH FULFILLMENT OF THE CLAIMS OF DAYLIGHT AND SOLAR HEAT LOAD

Johansson, Pontus, Alvarsson, Daniel January 2015 (has links)
Syfte: I dagens samhälle har det blivit mer intressant att bygga med en miljö-certifiering, detta leder till att byggentreprenörer ställs inför tekniska svårigheter vid både projektering och produktion för att kraven ska uppfyllas. I denna rapport kommer svårigheterna med solvärmelast och dagsljus behandlas då de kan vara ett problem. Målet med denna rapport är att ”Belysa hur kraven på dagsljus och solvärmelast enligt miljöcertifieringssystemet Miljöbyggnad kan lösas”. Metod: Kvalitativ data samlades in via intervjuer för att få svar på frågeställningarna. Intervjuerna genomfördes i huvudsak på plats hos respektive persons företag. En hög validitet uppnåddes genom att intervjufrågorna strukturerades och hade koppling till frågeställningar och mål. Reliabiliteten stärktes genom att intervjuerna spelades in och det gick att hitta samband mellan svaren. Resultat: Kravnivåerna i Miljöbyggnad är BBR:s krav i grunden för de flesta indikatorer vilket motsvarar BRONS-nivån i Miljöbyggnad. För indikatorn dagsljus skulle SILVER vara lite bättre än BRONS och för GULD krävs datorsimuleringar samt enkätundersökning eller egendeklaration. För Indikatorn solvärmelast finns inget grundkrav i BBR då det endast står att solvärmetillskottet ska begränsas. När kravnivåerna för solvärmelast togs fram användes persienner för att ta reda på rimliga nivåer. Det kan uppstå problem med att uppfylla kraven för solvärmelast och dagsljus om arkitekten inte har tillräcklig kunskap om Miljöbyggnad. Placering av byggnader och fönster är också problematiskt eftersom byggnader inte bör ligga för nära varandra för att tillräckligt med dagsljus ska komma in i byggnaden. Mycket fönster i söderriktning kan innebära mycket solinstrålning vilket kan ge problem med att klara solvärmelasten. De lösningar som denna rapport har fått fram är att det ska finnas en dialog mellan ansvariga i projekten för att hitta pareto-optimala lösningar. Det går att sänka kravet på en indikator och höja kravet på en annan för att sammanlagt få det byggnadsbetyg som önskas. Solvärmelastens krav kan lösas med hjälp av olika sorters solskydd. Det går även att ändra fönstrets typ, storlek eller antal. Konsekvenser: Den slutsats som går att dra efter att arbetet blivit färdigställt, är att fönster påverkar indikatorerna solvärmelast och dagsljus mest. För att båda de kraven ska bli uppfyllda och få ett högt betyg, är det lämpligt att använda solskydd för att minska solvärmelasten. En rekommendation är också att beställarens arkitekt detaljberäknar indikatorerna innan förfrågningsunderlaget går ut, då det oftast är i början av byggprocessen som de större problemen kan undvikas. Begränsningar: Arbetet begränsas till att behandla indikatorerna solvärmelast och dagsljus i miljöcertifieringssystemet Miljöbyggnad. Lösningar för kravnivåerna detaljstuderas inte. Undersökningsstrategin begränsas till att bara innehålla en kvalitativ metod. Nyckelord: Dagsljus, Fönster, Miljöbyggnad, Solvärmelast / Purpose: Society has become more interested in building with an environmental certification system, which leads to that building engineers are facing technical difficulties in both planning and production to meet the requirements. This thesis addresses the technical difficulties with solar heat load and daylight in the environmental certification system Miljöbyggnad. The purpose of this thesis is to “Illustrate how the demands of daylight and solar heat load in Miljöbyggnad can be solved”. Method: Qualitative data were collected through interviews to obtain answers concering the issues. The interviews essentially took place at each person’s company. High validity was achieved by the interview questions that were structured and linked to the issues and the purpose of this thesis. To increase the reliability, interviews were recorded and it was possible to find correlations between the answers. Findings: The BRONZE level in Miljöbyggnad is basically BBR:s requirements for most of the indicators. The SILVER level for the indicator daylight were supposed to be better than BRONZE and GOLD requires simulations and pleased residents. It is not possible to find requirements for solar heat load in BBR. When the requirements for this indicator in Miljöbyggnad was set, sun-blinds were used. There may be problems in meeting the requirements for solar heat load and daylight if the architects do not have the sufficient knowledge of Miljöbyggnad. The placement of buildings and windows are also problematic because the distance between the buildings can affect daylight problems. If there are a lot of windows in the south direction, the solar gain may cause difficulty to solve the requirements for solar heat load. The solutions this thesis submits are, to have a dialogue between the involving people in the projects to find pareto-optimal solutions. It is possible to reduce the require-ments for one indicator and raise the requirements for another to get the total building-rating as required. The requirements for solar heat load can be solved by using different kinds of shading devices. It is possible to change the type of windows, size of the windows and the amounts of windows. Implications: The conclusions are that the windows affect the indicators solar heat load and daylight very much. To solve the requirements and get a high rating on both indicators, it is appropriate to use any kind of shading devices. We also recommend that the architect calculates the indicators in detail before the tender document is ready, to avoid major problems. Limitations: To limit the extensive work it was necessary to focus on the indicators solar heat load and daylight in the environmental certification system Miljöbyggnad. The solutions for the indicators levels were not studied in details. The investigation method was limited to only use qualitative interviews. Keywords: Daylight, Miljöbyggnad, Solar heat load, Windows
6

Metal Thermoelectrics: An Economical Solution to Large Scale Waste Heat Recovery

Henderson, Erik January 2017 (has links)
No description available.
7

Design and performance evaluation of a HYDROSOL space heating and cooling system

Terblanche, Johann Pierre 03 1900 (has links)
Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Space heating and cooling, as required for chicken poultry farming, is an energy intensive operation. Due to the continuous rise in the prices of fossil fuel, water and electricity, there is a need to develop renewable and sustainable energy systems that minimise the use of fuel or electricity, for heating, and water, for cooling of air. The HYDROSOL (HYDro ROck SOLar) system, developed at Stellenbosch University, is such a renewable energy system that potentially provides a low cost solution. Instead of using conventional gas and electricity heaters for the heating of air during winter, the HYDROSOL system collects solar heat, stores it in a packed bed of rocks and dispatches the heat as required. During hot summer days, when cooling is needed, the rocks are cooled during the night when the ambient temperatures are low and/ or by evaporative cooling by spraying water onto them. During the day, hot air is then cooled when it passes through the colder rocks with minimal water consumption compared to current systems. In this thesis, a prototype of the HYDROSOL system is presented, designed and built for experimental testing. A transient 2-D thermo flow model is developed and presented for the analytical and experimental performance evaluation of this system for solar heating and night air cooling operation. This model is used to conduct a parametric study on HYDROSOL to gain a better understanding of the operation and control of the system. The HYDROSOL concept is intended to be used for heating and cooling of residential buildings, office suites, warehouses, shopping centres, food processing industries e.g. drying of foods, and various agricultural industries e.g. greenhouses. In this thesis, a HYDROSOL system is developed mainly for poultry broiler houses in South Africa focussing on convective dry cooling, charging the rock bed with night-time ambient air, and convective heating, harvesting solar heat during the day, with different modes of operation available. / AFRIKAANSE OPSOMMING: Ruimte verhitting en verkoeling, soos benodig vir hoender pluimvee boerdery, is ‘n energie intensiewe bedryf. As gevolg van die voortdurende styging in fossiel brandstof-, water- en elektrisiteitpryse, het ‘n behoefte ontstaan om hernubare en volhoubare energie-stelsels te ontwikkel wat minder brandstof of elektrisiteit, vir verhitting, en water, vir verkoeling van lug, gebruik. Die HYDROSOL (HYDro ROck SOLar) stelsel, wat ontwikkel is by die Universiteit van Stellenbosch, is ‘n hernubare energie-stelsel wat ‘n potensiële lae koste oplossing bied. In plaas daarvan om konvensionele gas en elektrisiteit verwarmers vir verhitting van lug gedurende die winter te gebruik, maak HYDROSOL gebruik van son warmte, stoor dit in `n gepakte bed van klip en onttrek die warmte soos benodig. Gedurende die warm somer dae wanneer verkoeling benodig word, word die klippe gedurende die nag, met kouer omgewings lug en/of met verdampingsverkoeling, deur water op die klippe te spuit, afgekoel. Gedurende die dag word warm lug afgekoel deur die lug oor die koue klippe te forseer met minimale waterverbruik in vergelyking met huidige stelsels. ‘n Prototipe van die HYDROSOL word voorgestel, ontwerp en gebou vir eksperimentele doeleindes. ‘n 2-D tyd afhanklike termo- vloei model word voorgestel vir die analitiese en eksperimentele verrigting evaluering vir son verhitting en nag lug verkoeling. Hierdie model word gebruik om ‘n parametriese studie te doen om die werking en beheer van HYDROSOL beter te verstaan. Die HYDROSOL stelsel is bedoel om die verwarming en verkoeling vereistes van residensiële geboue, kantoor areas, pakhuise, winkelsentrums, voedsel verwerking nywerhede, soos bv. die droging van voedsel, en verskeie landboubedrywe, soos bv. kweekhuise, te bevredig. In hierdie tesis word ‘n HYDROSOL stelsel, hoofsaaklik vir pluimvee kuikenhuise in Suid- Afrika, ondersoek en fokus op die droë verkoeling, deur die rotsbed te laai gedurende die nag, asook droë- verhitting, wat gebruik maak van son energie gedurende die dag en kan beheer word op verskillende maniere.
8

Glass as a Building Element – A Sustainable Approach: A Study of an Existing Academic Building

Jori, Swapnil Shriram 2010 December 1900 (has links)
In the aspects of global sustainability, buildings are known to be one of the largest energy consumers. Though sustainable building construction through technological advances is helping in achieving environment friendly buildings, a considerable amount of energy is also being consumed by existing buildings. While many factors at all different stages of building life are responsible for this, the building material is one of the most important considerations. Glass being the most sensitive building material can lead to high energy consumption in the building if used in an improper way. This study takes this factor into account, and tries to investigate the potential of energy savings in buildings through the simple and basic considerations in design. An energy analysis model of an existing academic building in College Station, Texas was developed using Design Builder computer simulation software. This model was then analyzed for the total amount of energy consumption in the base case. The existing building model was then modified by replacing the glass used for external fenestrations. Latest building codes and standards for the site location, glass properties, and parametric simulation results were taken into consideration. Again the model was simulated for annual energy consumption and the results are noted. This formed the first option for the retrofitting scenario. A hypothetical redesign scenario was also established in which the revision of building orientation was taken into consideration. The building was re-oriented to suit the weather conditions and recommendations by Advanced Energy Design Guidelines (30 percent energy savings over ASHRAE Standard 90.1-1999). The building was then simulated for annual energy consumption. A comparative analysis was performed between the three cases and the study concluded by showing 23 percent savings in the annual fuel consumption, 23.35 percent reduction in CO2 emission of the building and 25 percent reduction in annual solar heat gain under Modified case 1. Modified case 2, however, did not show any further savings due to the form of the building (almost square). However, modified case 1 settings emitted 31.8 percent more CO2 over the Energy Star office building in Texas. This methodology sets up a set of guidelines which can be followed while investigating a building for minimum annual energy consumption.
9

Solar heat pump systems for heating applications : Analysis of system performance and possible solutions for improving system performance

Poppi, Stefano January 2017 (has links)
Solar heat pump systems (SHPs) are systems that combine solar energy and heat pumps. SHPs have been investigated for several decades and have been proven to increase the share of renewable energy and reduce electric energy demand in residential heating applications. Many solar thermal heat pump systems have become market-available in recent years; however these systems are still not widely employed in the residential sector. This is due mainly to the high initial costs (investment and installation costs) of solar thermal heat pump systems, which limits their cost-effectiveness. Enhancing cost-effectiveness of solar thermal heat pump systems is necessary for a more effective and broader market penetration. In this thesis, solar thermal and photovoltaic systems combined with heat pumps for heating applications are treated. The overall aims of the thesis are to: 1) investigate techno-economics of SHPs and 2) investigate possible solutions for improving system performance of a reference solar thermal and heat pump system for residential heating applications. In the first part of the thesis, the influence of climatic boundary conditions on economic performance of SHPs has been investigated by means of: a) an economic comparison of SHPs found in the relevant literature and b) system simulations of the reference solar thermal heat pump system. In the second part of the thesis, potential solutions for improving system performance of the reference solar thermal heat pump system with limited change in system’ costs are investigated. A systematic approach was used for investigating cost-effectiveness of the system improvements in the reference system. Based on results of the cost-effectiveness analysis, some of the investigated system improvements were chosen for being included in the design of a novel solar thermal and air source heat pump system concept. The novel system was designed for a house standard with relatively high operating temperatures (55°C/45°C) in the space heating distribution system and for high space heating demand (123 kWh/m2·year). Finally, the thesis ends with a cost-effectiveness analysis of the novel system. / <p>QC 20170918</p> / MacSheep / iNSPiRe
10

Data Analysis in Energy

Sun, Qiancheng 20 December 2022 (has links)
No description available.

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