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Otimização de sistema de aquecimento solar de água em edificações residenciais unifamiliares utilizando o programa TRNSYS. ; Optimization of solar energy water heating systems in single-family residences using the TRNSYS program.

Lima, Juliana Benoni Arruda
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/12/2003 PT
Relevância na Pesquisa
46.11%
Os sistemas de aquecimento solar de água têm sido amplamente utilizados no Brasil para uso doméstico em residências unifamiliares, aproveitando a energia potencial da água do reservatório superior e o fenômeno da termossifonagem para a circulação da água quente. Entretanto estes sistemas de aquecimento de água normalmente são dimensionados através de tabelas fornecidas pelos fabricantes que indicam o número de placas em função do tamanho da família e do número de pontos de utilização de água quente. Esse dimensionamento é muito mais baseado na intuição e experiência dos fabricantes do que em dados científicos. Por isso este trabalho desenvolveu um modelo de otimização para projetos de sistemas de aquecimento solar de água, utilizando uma rotina de simulação numérica em longo prazo em regime transiente. O dimensionamento otimizado fornece a inclinação e a área da placa coletora que resultam no mínimo custo ao longo da vida útil do equipamento. Este custo engloba gastos com a instalação, manutenção e uso de energia auxiliar. O procedimento computacional foi executado com características específicas do projeto, tais como:condições climáticas locais, perfil de demanda de água quente, orientação da placa coletora e a temperatura desejada para o armazenamento da água quente. Foi estudado um sistema de aquecimento solar da água por termossifão com placas coletoras planas para o clima de São Paulo. Este modelo busca facilitar o dimensionamento dos sistemas de aquecimento solar de água para os projetistas...

Coeficiente de operación de un sistema formado por un refrigerador doméstico acoplado a un acumulador de agua caliente para la recuperación de energía

Souza, Luís M.P.; Scalon, Vicente L.; Padilha, Alcides
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 141-150
SPA
Relevância na Pesquisa
46.17%
An experimental apparatus containing a domestic refrigerator coupled to a vertical hot water storage tank was used for energy recovery. The original condenser of the refrigerator was maintained, but modified with a concentric tubes heat exchanger with countercurrent water and refrigerating gas flows. The coefficient of performance for the heat pump is calculated by the ratio of energy in the heat storage and the electric power consumed by the domestic refrigerator compressor. The results show that the increasing of hydrostatic pressure in the storage tank increases the water flow rate and the coefficient of performance. The proposed device also reduces the heat dissipation to the surroundings. This is more important in small confinements found in low-cost houses.

Integração de painéis solares térmicos na reabilitação de edifícios em Portugal para AQS e aquecimento ambiente; Integration os solar termal systems in building rehabilitation in Portugal for DHW production and space heating

Marques, Francisco José Carvalho
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Trabalho de Conclusão de Curso
Publicado em //2014 POR
Relevância na Pesquisa
55.9%
Dissertação de mestrado integrado em Engenharia Civil; A Diretiva n.º 2010/31/UE, do Parlamento Europeu e do Conselho, de 19 de maio de 2010 (EPBD-recast), transposta para o direito nacional pelo Decreto-Lei n.º 118/2013, de 20 de agosto, define como metas para 2020 a redução dos consumos energéticos em 20%, aumento em 20% da utilização de energias renováveis e redução em 20% das emissões de gases de efeito de estufa em relação aos níveis de 1990 e a obtenção de edifícios NZEB – Nearly Zero Energy Buildings (edifícios com necessidades quase nulas de energia). Apesar de a Diretiva impor estas metas para os edifícios novos ou para grandes obras de reabilitação de edifícios existentes, é essencial para Portugal atingir esses objetivos, intervir no edificado existente. A instalação de painéis solares térmicos aquando da realização de obras de reabilitação dos edifícios de habitação é importante para a obtenção de edifícios NZEB. No entanto, mais do que instalar é necessário integrar os painéis na envolvente do edifício (substituindo o/os componentes), minimizando o impacto estético, reduzindo os custos de implementação e valorizando os próprios edifícios. Em resposta a essas necessidades...

Avaliação de ciclo de vida de sistemas solares térmicos em edifícios; Life cycle assessment of solar hot water systems in buildings

Fernandes, Verónica Marisa Martins
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Trabalho de Conclusão de Curso
Publicado em //2014 POR
Relevância na Pesquisa
66.08%
Dissertação de mestrado integrado em Engenharia Civil; A presente dissertação aborda fundamentalmente conceitos de cariz ambiental e económico aplicados ao ciclo de vida de sistemas solares térmicos para águas quentes sanitárias. Com este trabalho pretende-se alertar os projetistas para a problemática atual das alterações climáticas, de forma a privilegiar o uso de energias renováveis, mais concretamente de energia solar. Para tal serão apresentados e discutidos conceitos e noções sobre a legislação e o mercado dos sistemas solares térmicos, assim como os principais componentes que constituem esses sistemas. No fim do estudo apresenta-se uma metodologia de avaliação de ciclo de vida de sistemas solares térmicos com base numa análise LCA e LCC, que desencadeou o desenvolvimento de um programa informático que tem como objetivo a integração mais rápida do sistema solar térmico na construção e, portanto, promover a sua sustentabilidade. O programa permite o cálculo dos potenciais impactes ambientais tais como aquecimento global, acidificação, eutrofização, destruição da camada de ozono, energia incorporada, etc., decorrentes do ciclo de vida do sistema solar térmico, os impactes desse sistema ao longo do tempo de vida do edifício e a sua viabilidade económica. Posteriormente...

The COOLSUN triple-technology approach to reach high solar fractions for space heating, space cooling and domestic hot water

Facão, Jorge; Lobato, António; Baldo, Catherine
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em //2013 ENG
Relevância na Pesquisa
96.2%
Within the framework of the COOLSUN project a triple-technology approach to reach high solar fractions for space heating, space cooling and domestic hot water preparation is being developed. The three core components are a thermo fluid with a low environmental impact and a boiling point above 200 °C, a high efficient adsorption chiller, and an advanced controller. System simulations modelling the transient behaviour of the entire application, i.e. building, hot water preparation and space heating/cooling, show that for Mediterranean locations the solar fraction reaches values up to 100 %; and even in Central Europe remarkable energy savings can be reached. The first prototype of the system is installed since spring 2013 in a building and monitored under real operation conditions.

New test methodologies to analyse direct expansion solar assisted heat pumps for domestic hot water 

Facão, Jorge; Carvalho, M. J.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
96.2%
Since there are not specific standards for testing direct expansion solar assisted heat pumps for domestic hot water, new testing methodologies are proposed supported by laboratory experiments. Two methodologies were developed for performance measurement: modified BIN method and long term performance prediction with a TRNSYS model validated with specific experimental conditions. The long term performance prediction is a methodology similar to the already obtained for solar thermal systems. A system was tested in Lisbon during one year, covering almost all possible local weather conditions. The hot water tapping test cycle used was in agreement with recent standards EN16147:2011 or EN15316-3-1:2007. The influence of average daily air temperature, dew point temperature and solar irradiation was analysed. The seasonal performance factor was calculated for two cities in Portugal (Lisbon and Porto) and for additional four cities in Europe (Davos, Athens, Helsinki and Strasburg). The establishment of a procedure to calculate the seasonal performance of this kind of systems is very important according to the directive 2009/28/EC of the European Parliament and of the Council.

The COOLSUN triple-technology approach to reach high solar fractions for space heating, space cooling and domestic hot water

Facão, Jorge; Lobato, António; Baldo, Catherine
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2014 ENG
Relevância na Pesquisa
96.2%
Within the framework of the COOLSUN project a triple-technology approach to reach high solar fractions for space heating, space cooling and domestic hot water preparation is being developed. The three core components are a thermo fluid with a low environmental impact and a boiling point above 200 °C, a high efficient adsorption chiller, and an advanced controller. System simulations modelling the transient behaviour of the entire application, i.e. building, hot water preparation and space heating/cooling, show that for Mediterranean locations the solar fraction reaches values up to 100 %; and even in Central Europe remarkable energy savings can be reached. The first prototype of the system is installed since spring 2013 in a building and monitored under real operation conditions.

Risk factors for contamination of domestic hot water systems by legionellae.

Alary, M; Joly, J R
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /08/1991 EN
Relevância na Pesquisa
56.21%
To assess risk factors associated with the contamination of the domestic environment by legionellae, 211 houses in the Quebec City area were randomly selected and water samples were collected from the hot water tank, the shower heads, and the most frequently used faucet. After centrifugation, concentrated samples were seeded in triplicate on BCYE and GPV media. Data on the characteristics of the hot water system and plumbing in the house and on the personal habits of the occupants were collected for each house. Among these 211 houses, hot water was provided by either an oil or gas heater in 33 and by an electric heater in 178. Legionellae were isolated from none of the samples from houses with oil or gas heaters and from 39% (69 of 178) of those with electric water heaters (P less than 0.0001). This association remained highly significant after control for water temperature and other variables in a stratified analysis. In the 178 houses with an electric heater, 12% of the faucets, 15% of the shower heads, and 37% of the water heaters were contaminated. Legionella pneumophila serogroups 2 and 4 were the most frequently isolated strains. Logistic regression showed that factors associated with electric water heater contamination were (i) location of the house in older districts of the city (P less than 0.0001)...

Presence of Thermophilic Bacteria in Laundry and Domestic Hot-Water Heaters

Brock, Thomas D.; Boylen, Kathryn L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1973 EN
Relevância na Pesquisa
56.15%
Thermophilic bacteria resembling Thermus aquaticus were isolated from hot water taken from domestic and commercial hot-water tanks. Cold water from the same locations never yielded thermophilic bacteria, suggesting that the bacteria were growing in the tanks. In contrast to the T. aquaticus isolates from hot springs, the present isolates were rarely pigmented. In general, the hotter sources more frequently yielded bacteria.

Total and Viable Legionella pneumophila Cells in Hot and Natural Waters as Measured by Immunofluorescence-Based Assays and Solid-Phase Cytometry ▿†

Parthuisot, N.; Binet, M.; Touron-Bodilis, A.; Pougnard, C.; Lebaron, P.; Baudart, J.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /09/2011 EN
Relevância na Pesquisa
46.24%
A new method was developed for the rapid and sensitive detection of viable Legionella pneumophila. The method combines specific immunofluorescence (IF) staining using monoclonal antibodies with a bacterial viability marker (ChemChrome V6 cellular esterase activity marker) by means of solid-phase cytometry (SPC). IF methods were applied to the detection and enumeration of both the total and viable L. pneumophila cells in water samples. The sensitivity of the IF methods coupled to SPC was 34 cells liter−1, and the reproducibility was good, with the coefficient of variation generally falling below 30%. IF methods were applied to the enumeration of total and viable L. pneumophila cells in 46 domestic hot water samples as well as in cooling tower water and natural water samples, such as thermal spring water and freshwater samples. Comparison with standard plate counts showed that (i) the total direct counts were always higher than the plate counts and (ii) the viable counts were higher than or close to the plate counts. With domestic hot waters, when the IF assay was combined with the viability test, SPC detected up to 3.4 × 103 viable but nonculturable L. pneumophila cells per liter. These direct IF methods could be a powerful tool for high-frequency monitoring of domestic hot waters or for investigating the occurrence of viable L. pneumophila in both man-made water systems and environmental water samples.

Legionella Infection Risk from Domestic Hot Water

Borella, Paola; Montagna, M. Teresa; Romano-Spica, Vincenzo; Stampi, Serena; Stancanelli, Giovanna; Triassi, Maria; Neglia, Rachele; Marchesi, Isabella; Fantuzzi, Guglielmina; Tatò, Daniela; Napoli, Christian; Quaranta, Gianluigi; Laurenti, Patrizia; Leo
Fonte: Centers for Disease Control and Prevention Publicador: Centers for Disease Control and Prevention
Tipo: Artigo de Revista Científica
Publicado em /03/2004 EN
Relevância na Pesquisa
55.99%
We investigated Legionella and Pseudomonas contamination of hot water in a cross-sectional multicentric survey in Italy. Chemical parameters (hardness, free chlorine, and trace elements) were determined. Legionella spp. were detected in 33 (22.6%) and Pseudomonas spp. in 56 (38.4%) of 146 samples. Some factors associated with Legionella contamination were heater type, tank distance and capacity, water plant age, and mineral content. Pseudomonas presence was influenced by water source, hardness, free chlorine, and temperature. Legionella contamination was associated with a centralized heater, distance from the heater point >10 m, and a water plant >10 years old. Furthermore, zinc levels of <20 μg/L and copper levels of >50 μg/L appeared to be protective against Legionella colonization. Legionella species and serogroups were differently distributed according to heater type, water temperature, and free chlorine, suggesting that Legionella strains may have a different sensibility and resistance to environmental factors and different ecologic niches.

A 40Kw roof mounted PV thermal concentrator system

Smeltink, J; Blakers, Andrew W; Coventry, J
Fonte: Universidade Nacional da Austrália Publicador: Universidade Nacional da Austrália
Tipo: Conference paper Formato: 2241804 bytes; 352 bytes; application/pdf; application/octet-stream
EN_AU
Relevância na Pesquisa
66.09%
The Australian National University, Centre for Sustainable Energy Systems (ANU-CSES) has developed a photovoltaic thermal (PV-T) concentrator system. This system is based on its Combined Heat and Power Solar (CHAPS) collector technology. This paper describes a roof mounted 40 kW PV-T concentrator system which was installed during 2003-4. The system comprises eight 24 metre long single axis tracking reflective solar collectors. Mirrors are used to focus light onto high efficiency monocrystalline silicon solar cells. The mirrors are constructed by laminating mirrored glass onto a metal backing, and provide a geometrical concentration ratio of 37x. Heat is removed from the solar cells using a fluid, which flows through a passage in the cell housings. The fluid is then passed through a heat exchanger to provide heat for domestic hot water and room heating. The collector movement is controlled by a microprocessor using an open loop time based algorithm. The annual output of the system is expected to be 50 MWHr of electricity and 100 MWHr of hot water.; no

Solar thermal energy: domestic hot water system; Energía solar térmica : sistema de agua caliente sanitaria

Rodríguez Salazar, César
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
ENG
Relevância na Pesquisa
66%
Ingeniería industrial

Diseño de instalación geotérmica para producción de ACS y calefacción por suelo radiante para vivienda unifamiliar en Torrelavega; Geothermal system design for production of hot wáter and underfloor heating for family housing in Torrelavega

Caviedes del Hoyo, Patricia
Fonte: Universidade de Cantabria Publicador: Universidade de Cantabria
Tipo: Trabalho de Conclusão de Curso
SPA
Relevância na Pesquisa
55.9%
Grado en Ingeniería de los Recursos Mineros

Analysis of the efficiency of solar collectors in the domestic warm water net in the context of the reduction of CO (subíndice 2) emission : influence of solar conditions in Poland in spring and summer time on the efficiency of the system of flat solar collections

Escudero Muñoz, Álvaro
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: info:eu-repo/semantics/bachelorThesis; info:eu-repo/semantics/masterThesis Formato: application/octet-stream; application/octet-stream; application/pdf
Publicado em //2009; 2009 ENG
Relevância na Pesquisa
45.96%
The purpose of this master thesis is to analyze which external agents can influence the radiation received in the solar collector, and how this radiation can be transformed into useful energy by heating water that will be used later for sanitary issues and for heating, ventilating and air conditioning of domestic houses. Also we will analyze the economic and environmental impact of investing in this kind of technologies, by calculating the amount of traditional fuels that we will not have to spend, and the reduction of C02 emissions that will lead us to undertake Kyoto Protocol. In order to do this analysis we will use software for forecasting direct, scattered and reflected radiation arriving to a certain location, in our case the city of Wroclaw. This software is called Solarsym and was developed in 2006 by the staff of the Institute of Thermal Engineering and Fluid mechanics and the Institute of Geography and Regional Development, both from the University of Wroclaw, in Poland. The calculation model was adapted to the data from climate station in Wroclaw so the results might be considered as correct for the climate area of Wroclaw and the surrounding area. The program also lets you carry out approximate calculations for any location in the polish. The variables that we will analyze are the mainly physical variables...

Evaluation of an Indirect Solar Assisted Heat Pump Water Heater in the Canadian Environment

ELLIOTT, BRYN DAVIS
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
76.12%
Solar Domestic Hot Water systems and air-source heat pumps offer the potential for energy savings in residential hot water production, however their performance is limited in cold climates, where the low ambient temperature reduces the collector efficiency or the heat pump coefficient of performance. Combining these systems into a Solar-Assisted Heat Pump can alleviate these limitations by reducing the required collector temperature and by providing an increased heat pump evaporator temperature. This study is a continuation of the development of an Indirect Solar-Assisted Heat Pump undertaken at the Queen’s University Solar Calorimetry Laboratory. Previously, a numerical study compared its performance to existing technology, and based upon this feasibility analysis, a prototype was constructed for controlled laboratory tests using simulated solar input. In the current study, the prototype was modified to include a novel hybrid collector such that its performance under actual weather conditions throughout the year could be assessed. On sunny days, the system experienced daily averaged collector efficiencies between 0.47 and 0.88, depending on the flow rate and season. Averaged heat pump coefficients of performance of 2.54 to 3.13 were observed. Overcast days experienced reduced coefficients of performance...

Preliminary Investigation into Solar Thermal Combi-system Performance

Lee, Elizabeth
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
66.15%
Solar thermal combi-systems use solar energy to provide thermal energy for space heating and domestic hot water. These systems come in many different designs and configurations, and their performance is dependent on many different factors such as location, solar collector type and orientation, and thermal storage size. In this study, two different combi-system configurations (a basic combi-system, and a single-tank combi-system) as well a stand-alone solar space heating system and a stand-alone solar domestic hot water system were investigated using TRNSYS models and simulations, and the thermal performances were compared using different combinations of solar collector and heat exchanger types, different locations, and a sensitivity analysis was performed using the basic solar combi-system. Using Toronto as the reference location, the performance of the solar stand-alone and combi-systems were compared using combinations of solar collector types (glazed vs. vacuum tube) and heat exchanger types (fixed effectiveness vs. natural convection). Each system combination was optimized for collector flow rate and tilt angle, and all systems were given the same solar collector area, thermal storage volume, and load profiles. This analysis revealed that the glazed type solar collector performed best when the heating load was continuous throughout the year...

Solar Hot Water Heater Augmented with PV-TEM Heat Pump

PRESTON, NATHANIEL
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
76.03%
Solar assisted heat pumps (SAHPs) can provide higher collector efficiencies and solar fractions when compared against standard solar hot water heaters. Vapour compression (VC) heat pumps require environmentally hazardous refrigerants and moving parts which increase maintenance costs and place limits on operating conditions. Thermoelectric modules (TEMs) use solid state electronics to pump heat without moving parts or refrigerants. This study investigated the performance of a SAHP system utilizing an array of thermoelectric modules as the heat pump. A component model was developed to simulate the TEM heat pump performance using TRNSYS software and results were compared against those determined experimentally. A simplified model was unable to accurately predict TEM performance. The model was therefore refined to incorporate empirically determined parameters. An apparatus was constructed to measure the performance of a small photovoltaic array driven TEM heat pump and simulation results using the component model were found to be in agreement. Several SAHP configurations were simulated using TRNSYS and compared with vapour compression SAHPs previously studied at the QSCL. The TEM ISAHP provided a Free Energy Ratio (FER) of 46% and a collector efficiency of 36% whereas the VC ISAHP provided 54% and 76% respectively. The photovoltaic (PV) driven ISAHP system was able to achieve a higher FER of 50% with the use of a 2 module PV array and a reduced thermal collector area. Further optimization is required to improve TEM heat pump performance in this configuration and reduce the photovoltaic array size. The use of a maximum power point tracker into the PV/TEM system should be investigated as panel efficiency losses reached up to 30% in the configuration studied. The possibility of incorporating combined PV/T modules could decrease costs and also warrants further study. Critical factors in the success of a TEM driven solar assisted heat pump will include the improvement of thermoelectric materials performance...

Appendicitis epidemic following introduction of piped water to Anglesey.

Barker, D J; Morris, J A; Simmonds, S J; Oliver, R H
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /06/1988 EN
Relevância na Pesquisa
46.07%
The extension of piped water supplies in Anglesey, North Wales, 30 years ago and the consequent introduction of domestic hot water systems was followed by an epidemic of appendicitis. This occurred while appendicitis rates were falling elsewhere in Britain. The diet of Anglesey is unremarkable. This is further evidence that epidemics of appendicitis occur during the transition to 'western' hygiene, an important component of which is the provision of domestic hot water systems and fixed baths.

EVALUATING ENERGY EFFICIENCY: A DOMESTIC SOLAR HOT WATER PROGRAM IN NORTHEAST FLORIDA

Moore, Ben
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' Project Formato: 911766 bytes; application/pdf
Publicado em 18/04/2007 EN_US
Relevância na Pesquisa
66.15%
Energy efficient technologies are a major tool for reducing electricity usage as well as greenhouse gas emissions. Nevertheless, serious market barriers impede the diffusion of these solutions. Many utilities offer programs and incentives to surmount these barriers. However, few empirical studies exist that quantitatively document the impacts of such initiatives. This project investigates a utility rebate program aimed at encouraging the adoption of domestic solar hot water (DSHW) systems in northeast Florida residences. Four years of household consumption, temperature, and one year of block group level demographic data is analyzed using multiple and multilevel, or hierarchical, regression analysis techniques. Four estimators are developed to estimate the causal impact of the program. The first estimator utilizes a random selection of non-participating households within the utility’s service territory and a subset of participating households for that year to establish control and treatment groups. The remaining estimators represent a random effects model, a fixed effects model, and a mediating multilevel model of the causal effect of the program for the years 2003 through 2006, respectively. These latter models derive control and treatment groups from pre- and post-treatment cohorts of program participants. Each estimator exhibits particular strengths and weaknesses. In aggregate...