Thesis (M.S.M.E)--Baylor University, 2009. / Includes bibliographical references (p. 133-134).

Made available in DSpace on 2015-07-13T12:10:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-04. Added 1 bitstream(s) on 2015-07-13T12:25:41Z : No. of bitstreams: 1 000832971.pdf: 1514299 bytes, checksum: 29a4cd55e16ecdbaead264c825fb9957 (MD5) / A disponibilidade de luz solar, transformada em energia, pode ser capturada em quase todo o mundo. Desde a década de 1990 o mercado da utilização de energia solar vem crescendo, porém informações sobre estudos de caso para a avaliação da inserção de aquecedores solares de água nos domicílios populares brasileiros ainda são escassas. O presente trabalho visa contribuir para reduzir essa carência e tem como objetivo avaliar a viabilidade técnica e econômica da inserção de aquecedores solares de água nas residências populares no município de Tremembé, localizado no Vale do Paraíba, estado de São Paulo, Brasil. O município de Tremembé possui uma área de 192 km² e conta com uma população de 42.027 habitantes, sendo um total de 10.632 domicílios. A avaliação foi efetuada numa amostra setorial do total de domicílios, através de um plano amostral aleatório estratificado, metodologia que permite conhecer melhor as características próprias de cada setor do município estudado. A pesquisa de campo foi efetuada com o método survey, com o total de 360 questionários, os quais foram aplicados a um representante de cada família. Imagens com as descrições e atributos dos setores censitários do IBGE foram tratadas no formato de extensão kmz. Foi necessária a construção de um cadastro no programa Excel para inserir os dados colhidos em campo e esses dados foram sobrepostos aos layers das imagens tratadas. O resultado desta pesquisa mostrou aceitação generalizada da população à possibilidade de instalações e utilização de sistemas de aquecimento solar de água, especialmente nas áreas rurais, principalmente por apresentar custo reduzido de energia elétrica no pico e aponta para a redução da demanda na rede elétrica. A pesquisa comprova que com a utilização de energia solar, o município pode economizar 31.680.000 kWh/ano, o que corresponde a R$ 9.504.000,00 /ano / The availability of sunlight converted into energy can be captured throughout the world. Since the 1990s the market for the use of solar energy has been growing, but information on case studies to assess the inclusion of solar water heaters in the popular Brazilian households are still scarce. The present work aims at contributing to reduce this gap and aims to assess the technical and economic feasibility of integration of solar water heaters in low-income households in the municipality Tremembé, located in the Paraíba Valley, State of São Paulo, Brazil. Tremembé has an area of 192 km ² and has a population of 42,027 inhabitants, with 10,632 households. The evaluation has done on a sectorial sample of total households. Effected through a stratified aleatory sampling plan, as this methodology allows better understanding the characteristics of each sector of the municipality. The field research was conducted with the survey method, with 360 questionnaires, which have been applied to a representative of each family. Images with descriptions and attributes of the official census sectors of IBGE have been treated in the extension kmz format. It was necessary to build a register in Excel to insert the data collected in the field and these data were overlaid on the images Leyers treated. The result of this research showed widespread acceptance of the population the possibility of facilities and use of solar water heating systems, especially the rural areas, mainly by presenting reduced cost of electric power in peak and points to reduced demand in the power grid. The research proves that with the use of solar energy, the city may save 31, 68 million kWh/year, which corresponds to R$ 9,504,000.00/ year

Orientador: Vicente Luiz Scalon / Coorientador: Alcides Padilha / Banca: Ismael de Marchi Neto / Banca: Celso Luiz da Silva / Resumo: Atualmente, a aplicação da energia solar térmica para aquecimento de água é uma solução técnica e economicamente viável permitindo a redução do consumo de energia elétrica no setor residencial, comercial e industrial. Diante disto, se faz cada vez mais necessário o domínio de metodologias que permitam quantificar a energia térmica útil captada pelos coletores solares e determinar a sua eficiência na geração de água quente. Como uma forma de contribuir para esta meta, este trabalho desenvolve uma análise comparativa da captação de energia térmica no coletor solar plano. A partir de dados experimentais e teóricos, diferentes modelos para tratamento dos dados foram aplicados e comparados. A metodologia do trabalho consistiu em monitorar um sistema de aquecimento solar residencial, em condições reais de uso e, a partir dos dados obtidos, calcular e comparar a captação de energia térmica útil nos coletores solares baseando-se no balanço energético pela Primeira Lei da Termodinâmica e pelo Método de Eficiência Térmica Instantânea. A irradiação solar global incidente nas placas da placa solar plano também foi monitorada e, portanto, seu valor foi comparado ao modelo teórico. Por fim, a demanda mensal de energia térmica para consumo de água quente da residência também foi monitorada e comparada à captação mensal de energia. A aplicação mostrou coerência entre os resultados experimentais e teóricos em grande parte dos casos, algumas inconveniências em determinadas situações e oportuni... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Currently, the application of solar thermal energy for water heating is a technical and economically viable solution allowing the reduction of electricity consumption in the residential, commercial and industrial sector. Given this, it is increasingly the domain methodologies that enable more necessary to quantify the useful thermal energy captured by solar collectors and determine their efficiency in the generation of hot water. As a way to contribute to this goal, this paper develops a comparative analysis of thermal energy harvesting in flat solar collector. From experimental and theoretical data, different models for processing the data were applied and compared. The methodology of the study was to monitor a residential solar heating system in real conditions of use and, from the data calculate and compare the uptake of useful thermal energy in solar collectors based on the energy balance of the First Law of Thermodynamics and by the Instantaneous Thermal Efficiency Method. The global solar radiation incident on the places of the solar collector plane was also monitored and therefore its value was compared to the theoretical model. Finally, the monthly demand for hot water thermal energy consumption of the house was also monitored and compared to the monthly energy harvesting. The application showed consistency between experimental and theoretical results in most cases, some inconveniences in certain situations and opportunities for improvements, in what is considered good design practice, as highlighted in the work / Mestre

Thesis (MTech (Mechanical Engineering))--Cape Peninsula University of Technology, 2016. / South Africa has raised concerns regarding the development of renewable energy sources such as wind, hydro and solar energy. Integration of a combined photovoltaic and thermal system was considered to transform simultaneous energy into electricity and heat. This was done to challenge the low energy efficiency observed when the two solar energy conversion technologies are employed separately, in order to gain higher overall energy efficiency and ensure better utilization of the solar energy. Therefore, the notion of using a combined photovoltaic and thermal system was to optimize and to improve the overall PV panel efficiency by adding conversion to thermal energy for residential and commercial needs of hot water or space heating or space cooling using appropriate technology. The PV/T model constructed using water as fluid like the one used for the experimental work, presented a marginal increase in electrical efficiency but a considerable yield on the overall PV/T efficiency, because of the simultaneous operation by coupling a PV module with a thermal collectors.

Orientador: Teófilo Miguel de Souza / Coorientador: José Antonio Perrella Balestieri / Banca: José Feliciano Adami / Banca: Paulo Cesar Boggiani / Resumo: A disponibilidade de luz solar, transformada em energia, pode ser capturada em quase todo o mundo. Desde a década de 1990 o mercado da utilização de energia solar vem crescendo, porém informações sobre estudos de caso para a avaliação da inserção de aquecedores solares de água nos domicílios populares brasileiros ainda são escassas. O presente trabalho visa contribuir para reduzir essa carência e tem como objetivo avaliar a viabilidade técnica e econômica da inserção de aquecedores solares de água nas residências populares no município de Tremembé, localizado no Vale do Paraíba, estado de São Paulo, Brasil. O município de Tremembé possui uma área de 192 km² e conta com uma população de 42.027 habitantes, sendo um total de 10.632 domicílios. A avaliação foi efetuada numa amostra setorial do total de domicílios, através de um plano amostral aleatório estratificado, metodologia que permite conhecer melhor as características próprias de cada setor do município estudado. A pesquisa de campo foi efetuada com o método survey, com o total de 360 questionários, os quais foram aplicados a um representante de cada família. Imagens com as descrições e atributos dos setores censitários do IBGE foram tratadas no formato de extensão kmz. Foi necessária a construção de um cadastro no programa Excel para inserir os dados colhidos em campo e esses dados foram sobrepostos aos layers das imagens tratadas. O resultado desta pesquisa mostrou aceitação generalizada da população à possibilidade de instalações e utilização de sistemas de aquecimento solar de água, especialmente nas áreas rurais, principalmente por apresentar custo reduzido de energia elétrica no pico e aponta para a redução da demanda na rede elétrica. A pesquisa comprova que com a utilização de energia solar, o município pode economizar 31.680.000 kWh/ano, o que corresponde a R$ 9.504.000,00 /ano / Abstract: The availability of sunlight converted into energy can be captured throughout the world. Since the 1990s the market for the use of solar energy has been growing, but information on case studies to assess the inclusion of solar water heaters in the popular Brazilian households are still scarce. The present work aims at contributing to reduce this gap and aims to assess the technical and economic feasibility of integration of solar water heaters in low-income households in the municipality Tremembé, located in the Paraíba Valley, State of São Paulo, Brazil. Tremembé has an area of 192 km ² and has a population of 42,027 inhabitants, with 10,632 households. The evaluation has done on a sectorial sample of total households. Effected through a stratified aleatory sampling plan, as this methodology allows better understanding the characteristics of each sector of the municipality. The field research was conducted with the survey method, with 360 questionnaires, which have been applied to a representative of each family. Images with descriptions and attributes of the official census sectors of IBGE have been treated in the extension kmz format. It was necessary to build a register in Excel to insert the data collected in the field and these data were overlaid on the images Leyers treated. The result of this research showed widespread acceptance of the population the possibility of facilities and use of solar water heating systems, especially the rural areas, mainly by presenting reduced cost of electric power in peak and points to reduced demand in the power grid. The research proves that with the use of solar energy, the city may save 31, 68 million kWh/year, which corresponds to R$ 9,504,000.00/ year / Mestre

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / A solar desalination system basically has two components: the heating unit (solar collectors) and the desalination unit (tower). Among its main advantages, this device does not need electrical power to operate, since it is driven by thermosiphon. In its operation, brackish water is heated and it evaporates. The evaporated vapor rises and hits the coller walls of the above tray, where it condensates and drains through a specially designed geometry, structure to be finally by in a set of gutter. The already demineralized water flows through a main channel where it is stored in a container, outside the desalination tower. The resulting water from this process is pure and free from contamination, either microorganisms or salt. This study analyzes the performance of a desalination system with a desalination tower and a set of three solar collectors. The heat transfer medium between the collector and the tower was thermal oil flow, Lubrax Utile OT-100. The experimental results demonstrate the operation of this type of desalinator, since ideal conditions for its correct functioning was only achieved after the installation of a positive displacement pump, which that promoted the oil circulation. Thermocouples installed in the stages of tower registered the temperature increase throughout the day. Peaks of 77 ÂC were measured in the storage tank of the tower. The mean values of production per day were 25 liters of desalinated water with an average conductivity always less than 10 μS / cm Â, representing a salt removal efficiency greater than 99%. In performance calculation, the best result was obtained when the pumping system was combined with the use of a solar reflector, achieving GOR value of 2.85. / Um dessalinizador solar possui basicamente duas unidades: a unidade de aquecimento (coletora) e a unidade de dessalinizaÃÃo (torre). Apresenta entre suas principais vantagens o fato de nÃo precisar de energia elÃtrica para seu funcionamento, pois à acionada por termossifÃo. A operaÃÃo se dà pelo aquecimento da Ãgua salobra atà que esta comece a evaporar. O vapor, ao subir e encontrar com uma superfÃcie com temperatura inferior, condensa e escorre atravÃs de estruturas em uma geometria especialmente projetada para este fim e sà entÃo à coletada por um sistema de calhas. A Ãgua jà desmineralizada segue por uma calha principal onde escorre e à armazenada em um recipiente, jà fora da torre de dessalinizaÃÃo. A Ãgua resultante desse processo à praticamente pura e isenta de contaminaÃÃo, tanto por microrganismos como por sais e outros contaminantes. O presente trabalho analisa o desempenho do dessalinizador composto por uma torre de dessalinizaÃÃo e um conjunto composto por trÃs coletores solares acionados por Ãleo tÃrmico Lubrax Utile OT-100. Os resultados experimentais comprovam o funcionamento desse tipo de dessalinizador, visto que condiÃÃes ideais para seu correto funcionamento sà foram atingidas graÃas à instalaÃÃo de uma bomba de deslocamento positivo que promoveu a circulaÃÃo do Ãleo. Termopares instalados nos estÃgios da torre registraram o aumento de temperatura ao longo do dia. Picos de 77ÂC foram medidos no tanque de armazenamento da torre. Valores mÃdios de produÃÃo por dia sÃo de 25 litros de Ãgua, com uma condutividade mÃdia sempre inferior a 10 μS/cmÂ, o que representa uma eficiÃncia na remoÃÃo de sais superior a 99%. No cÃlculo de desempenho, o melhor resultado foi obtido quando o sistema de bombeamento foi combinado com o uso de um refletor solar, obtendo o valor do GOR (RazÃo de ganho de saÃda) de 2,85.

The ability to predict the future behavior of solar activity has become of extreme importance due to its effect on the near-Earth environment. Predictions of both the amplitude and timing of the next solar cycle will assist in estimating the various consequences of Space Weather. Several prediction techniques have been applied and have achieved varying degrees of success in the domain of solar activity prediction. These techniques include, for example, neural networks and geomagnetic precursor methods. In this thesis, various neural network based models were developed and the model considered to be optimum was used to estimate the shape and timing of solar cycle 24. Given the recent success of the geomagnetic precusrsor methods, geomagnetic activity as measured by the aa index is considered among the main inputs to the neural network model. The neural network model developed is also provided with the time input parameters defining the year and the month of a particular solar cycle, in order to characterise the temporal behaviour of sunspot number as observed during the last 10 solar cycles. The structure of input-output patterns to the neural network is constructed in such a way that the network learns the relationship between the aa index values of a particular cycle, and the sunspot number values of the following cycle. Assuming January 2008 as the minimum preceding solar cycle 24, the shape and amplitude of solar cycle 24 is estimated in terms of monthly mean and smoothed monthly sunspot number. This new prediction model estimates an average solar cycle 24, with the maximum occurring around June 2012 [± 11 months], with a smoothed monthly maximum sunspot number of 121 ± 9.

M.Ing. / A dissertation presented on the basic solar design principles such as sun-earth geometry, energy wavelengths, optics, incidence angles, parabolic collector configurations and design, materials for solar applications, efficiencies, etc to be considered in Solar Concentrating Collector design. These principles were applied in the design and fabrication of a prototype solar collector. The solar collector was tested to verify and correct mathematical models that were generated from existing literature; as well as for optimization work.

Global energy consumption has been increasing continuously every year. Many energy sources are utilized. Conventional fossil fuels are not sustainable, and their environmental impacts are more apparent than ever before. For heating purposes, most of the heat still comes from combustion of both non-renewable and renewable energy sources. According to IEA (2019), only 10% of heat supply in industrial sectors and buildings comes from renewable sources. Hence, 40% of the carbon emission in the energy sector comes from heat. Therefore, shifting from non-renewable to renewable energy sources is essential in reducing the environmental impact from heat production. Sweden has a long tradition of solar thermal in district heating for cities. Therefore, this study tried to look at the application of solar thermal energy for heat production to supply the District Heating (DH) system and compare its environmental performance to other types of energy sources. The system that was examined in this study is the solar thermal collector field from Absolicon in Härnösand. A Life Cycle Assessment (LCA) was conducted to evaluate the life cycle environmental impacts of this solar collector field. The assessment was done by collecting primary data provided by Absolicon and its suppliers and secondary data from the literatures. The results showed that Absolicon solar thermal collector field generated less overall environmental impacts than conventional energy sources in heat production. Moreover, the result for carbon footprint of the solar collector is 4.4 kg CO2/MWh, which is at least 3-4 times less lifetime emissions when compared to other solar energy technologies. / Den globala energiförbrukningen har ökat kontinuerligt varje år. Många energikällor används. Konventionella fossila bränslen är inte hållbara och deras miljöpåverkan är mer påtaglig än någonsin tidigare. För uppvärmningsändamål kommer det mesta av värmen fortfarande från förbränning av både icke-förnybara och förnybara energikällor. Enligt IEA (2019) kommer endast 10 % av värmeförsörjningen i industrisektorer och byggnader från förnybara källor. Därför kommer 40 % av koldioxidutsläppen i energisektorn från värme. Därför är en övergång från icke-förnybara till förnybara energikällor väsentligt för att minska miljöpåverkan från värmeproduktion. Sverige har en lång tradition av solvärme inom fjärrvärme för städer. Därför försökte denna studie titta på tillämpningen av solvärmeenergi för värmeproduktion för att försörja fjärrvärmesystemet (DH) och jämföra dess miljöprestanda med andra typer av energikällor. Systemet som undersöktes i denna studie är solfångarfältet från Absolicon i Härnösand. En livscykelanalys (LCA) genomfördes för att utvärdera livscykelns miljöpåverkan av detta solfångarfält. Bedömningen gjordes genom att samla in primärdata från Absolicon och dess leverantörer och sekundärdata från litteraturen. Resultaten visade att Absolicon solfångarfält genererade mindre total miljöpåverkan än konventionella energikällor vid värmeproduktion. Dessutom är resultatet för solfångarens koldioxidavtryck 4,4E kg CO2/MWhvilket är minst 3-4 gånger mindre livstidsutsläpp jämfört med andra solenergitekniker.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Solar energy is by far the greatest energy resource available to generate power. One of the difficulties of using solar energy is that it is not available 24 hours per day - some form of storage is required if electricity generation at night or during cloudy periods is necessary. If a combined cycle power plant is used to obtain higher efficiencies, and reduce the cost of electricity, storage will allow the secondary cycle to operate independently of the primary cycle. This study focuses on the use of packed beds of rock or slag, with air as a heat transfer medium, to store thermal energy in a solar thermal power plant at temperatures sufficiently high for a Rankine steam cycle. Experimental tests were done in a packed bed test section to determine the validity of existing equations and models for predicting the pressure drop and fluid temperatures during charging and discharging. Three different sets of rocks were tested, and the average size, specific heat capacity and density of each set were measured. Rock and slag samples were also thermally cycled between average temperatures of 30 ºC and 510 ºC in an oven. The classical pressure drop equation significantly under-predicts the pressure drop at particle Reynolds numbers lower than 3500. It appears that the pressure drop through a packed bed is proportional to the 1.8th power of the air flow speed at particle Reynolds numbers above about 500. The Effectiveness-NTU model combined with a variety of heat transfer correlations is able to predict the air temperature trend over the bed within 15 % of the measured temperature drop over the packed bed. Dolerite and granite rocks were also thermally cycled 125 times in an oven without breaking apart, and may be suitable for use as thermal storage media at temperatures of approximately 500 ºC. The required volume of a packed bed of 0.1 m particles to store the thermal energy from the exhaust of a 100 MWe gas turbine operating for 8 hours is predicted to be 24 × 103 m3, which should be sufficient to run a 25-30 MWe steam cycle for over 10 hours. This storage volume is of a similar magnitude to existing molten salt thermal storage. / AFRIKAANSE OPSOMMING: Sonenergie is die grootste energiebron wat gebruik kan word vir krag opwekking. ‘n Probleem met die gebruik van sonenergie is dat die son nie 24 uur per dag skyn nie. Dit is dus nodig om die energie te stoor indien dit nodig sal wees om elektrisiteit te genereer wanneer die son nie skyn nie. ‘n Gekombineerde kringloop kan gebruik word om ‘n hoër benuttingsgraad te bereik en elektrisiteit goedkoper te maak. Dit sal dan moontlik wees om die termiese energie uit die primêre kringloop te stoor, wat die sekondêre kringloop onafhanklik van die primêre kringloop sal maak. Dié gevalle studie ondersoek die gebruik van ‘n slakof- klipbed met lug as hitteoordragmedium, om te bepaal of dit moontlik is om hitte te stoor teen ‘n temperatuur wat hoog genoeg is om ‘n Rankine stoom kringloop te bedryf. Eksperimentele toetse is in ‘n toets-bed gedoen en die drukverandering oor die bed en die lug temperatuur is gemeet en vergelyk met voorspelde waardes van vergelykings en modelle in die literatuur. Drie soorte klippe was getoets. Die gemiddelde grootte, spesifieke hitte-kapasiteit en digtheid van elke soort klip is gemeet. Klip en slak monsters is ook siklies tussen temperature van 30 ºC en 510 ºC verkoel en verhit. Die klassieke drukverlies vergelyking gee laer waardes as wat gemeet is vir Reynolds nommers minder as 3500. Dit blyk dat die drukverlies deur ‘n klipbed afhanklik is van die lug vloeispoed tot die mag 1.8 as die Reynolds nommer groter as omtrent 500 is. Die ‘Effectiveness-NTU’ model gekombineerd met ‘n verskeidenheid van hitteoordragskoeffisiënte voorspel temperature binne 15 % van die gemete temperatuur verskil oor die bed. Doloriet en graniet klippe het 125 sikliese toetse ondergaan sonder om te breek, en is miskien gepas vir gebruik in ‘n klipbed by temperature van sowat 500 ºC Die voorspelde volume van ‘n klipbed wat uit 0.1 m klippe bestaan wat die termiese energie vir 8 ure uit die uitlaat van ‘n 100 MWe gasturbiene kan stoor, is 24 × 103 m3. Dit behoort genoeg te wees om ‘n 25 – 30 MWe stoom kringloop vir ten minste 10 ure te bedryf. Die volume is min of meer gelyk aan dié van gesmelte sout store wat alreeds gebou is.