This master thesis presents a new technological combination of two environmentally friendly sources of energy in order to provide DHW, and space heating. Solar energy is used for space heating, and DHW production using PV modules which supply direct current directly to electrical heating elements inside a water storage tank. On the other hand a GSHP system as another source of renewable energy provides heat in the water storage tank of the system in order to provide DHW and space heating. These two sources of renewable energy have been combined in this case-study in order to obtain a more efficient system, which will reduce the amount of electricity consumed by the GSHP system.The key aim of this study is to make simulations, and calculations of the amount ofelectrical energy that can be expected to be produced by a certain amount of PV modules that are already assembled on a house in Vantaa, southern Finland. This energy is then intended to be used as a complement to produce hot water in the heating system of the house beside the original GSHP system. Thus the amount of electrical energy purchased from the grid should be reduced and the compressor in the GSHP would need fewer starts which would reduce the heating cost of the GSHP system for space heating and providing hot water.The produced energy by the PV arrays in three different circuits will be charged directly to three electrical heating elements in the water storage tank of the existing system to satisfy the demand of the heating elements. The excess energy can be used to heat the water in the water storage tank to some extent which leads to a reduction of electricity consumption by the different components of the GSHP system.To increase the efficiency of the existing hybrid system, optimization of different PV configurations have been accomplished, and the results are compared. Optimization of the arrays in southern and western walls shows a DC power increase of 298 kWh/year compared with the existing PV configurations. Comparing the results from the optimization of the arrays on the western roof if the intention is to feed AC power to the components of the GSHP system shows a yearly AC power production of 1,646 kWh.This is with the consideration of no overproduction by the PV modules during the summer months. This means the optimized PV systems will be able to cover a larger part of summer demand compared with the existing system.

Sunshine, air and water are the vital elements to the human. This study investigated the insolation and solar radiation in Kaohsiung city. Solar radiation on the horizontal and declined plane was calculated. Sun shadow model for urban buildings was constructed for computing accumulated sunshining hours. Horizontal and vertical building shadows were displayed in ArcGIS ¡V the GIS software. Raster-based data model was used to analyze the effect of sun shadow shading by neighbour buildings. And the effect of shadow shading for solar water heater was also investigated. According to the results, minor installation error of orientation and decline angles of solar panel will not cause major energy loss. And the distance between the buildings¡Bthe height difference and the orientation between buildings are most important factors which affect optimal installation location of the solar water heater. If there are buildings located to the south, southeast and southwest, and the stories difference between buildings is over three, the installing location should be moved toward north. If buildings are next to each others and the variation of height is large, the efficient of receiving solar radiation will be deteriorated. The larger is the distance between buildings, the better the energy received.

The purpose of this study is to investigate the performance of a spherical solar collector by using numerical and experimental methods. For this analysis, equations were obtained by choosing appropriate control volumes in the system and applying The First Law of Thermodynamics. The experiments were realized at four different mass flow rates and non-flow situation. For the numerical simulation of the system, a computer program in Mathcad was written. Another computer program in Mathcad was written for the variation of the absorbed solar radiation through out the day. Finally, the performance of the spherical solar collector is compared theoretically to that of flat plate solar collectors.

abstract: Improving the conditions of schools in many parts of the world is gradually acquiring importance. The Green School movement is an integral part of this effort since it aims at improving indoor environmental conditions. This would in turn, enhance student- learning while minimizing adverse environmental impact through energy efficiency of comfort-related HVAC and lighting systems. This research, which is a part of a larger research project, aims at evaluating different school building designs in Albania in terms of energy use and indoor thermal comfort, and identify energy efficient options of existing schools. We start by identifying three different climate zones in Albania; Coastal (Durres), Hill/Pre-mountainous (Tirana), mountainous (Korca). Next, two prototypical school building designs are identified from the existing stock. Numerous scenarios are then identified for analysis which consists of combinations of climate zone, building type, building orientation, building upgrade levels, presence of renewable energy systems (solar photovoltaic and solar water heater). The existing building layouts, initially outlined in CAD software and then imported into a detailed building energy software program (eQuest) to perform annual simulations for all scenarios. The research also predicted indoor thermal comfort conditions of the various scenarios on the premise that windows could be opened to provide natural ventilation cooling when appropriate. This study also estimated the energy generated from solar photovoltaic systems and solar water heater systems when placed on the available roof area to determine the extent to which they are able to meet the required electric loads (plug and lights) and building heating loads respectively. The results showed that there is adequate indoor comfort without the need for mechanical cooling for the three climate zones, and that only heating is needed during the winter months. / Dissertation/Thesis / Masters Thesis Architecture 2015

abstract: The complicated, unpredictable, and often chaotic hot water usage pattern of typical households severely limits the effectiveness and efficiency of traditional solar hot water heater systems. Similar to large scale concentrating solar power plants, the use of thermal energy storage techniques to store collected solar energy as latent heat has the potential to improve the efficiency of solar hot water systems. Rather than being used to produce steam to generate electricity, the stored thermal energy would be used to heat water on-demand well after the sun sets. The scope of this thesis was to design, analyze, build, and test a proof of concept prototype for an on-demand solar water heater for residential use with latent heat thermal energy storage. The proof of concept system will be used for future research and can be quickly reconfigured making it ideal for use as a test bed. This thesis outlines the analysis, design, and testing processes used to model, build, and evaluate the performance of the prototype system. The prototype system developed to complete this thesis was designed using systems engineering principles and consists of several main subsystems. These subsystems include a parabolic trough concentrating solar collector, a phase change material reservoir including heat exchangers, a heat transfer fluid reservoir, and a plumbing system. The system functions by absorbing solar thermal energy in a heat transfer fluid using the solar collector and transferring the absorbed thermal energy to the phase change material for storage. The system was analyzed using a mathematical model created in MATLAB and experimental testing was used to verify that the system functioned as designed. The mathematical model was designed to be adaptable for evaluating different system configurations for future research. The results of the analysis as well as the experimental tests conducted, verify that the proof of concept system is functional and capable of producing hot water using stored thermal energy. This will allow the system to function as a test bed for future research and long-term performance testing to evaluate changes in the performance of the phase change material over time. With additional refinement the prototype system has the potential to be developed into a commercially viable product for use in residential homes. / Dissertation/Thesis / Masters Thesis Engineering 2015

Este trabalho aborda o desenvolvimento de um sistema de controle de temperatura para um aquecedor de passagem de água a gás. O sistema de controle Controlgás é apresentado e comparado ao sistema de controle típico, usado em aquecedores de passagem convencionais. São apresentadas as características e objetivos do projeto Controlgás, o qual serviu de base para o desenvolvimento deste trabalho. É apresentada uma fundamentação teórica sobre técnicas de controle para compensação de variações paramétricas e de atrasos de transporte, bem como uma revisão sobre as principais soluções já desenvolvidas para o controle de temperatura da água em aquecedores de passagem. A bancada experimental, contendo o aquecedor e o sistema de controle, utilizada em trabalhos anteriores, foi reestruturada e instrumentada com sensores de temperatura na entrada e na saída de água e com sensores que detectam a presença de chama e de fluxo de água. Foi desenvolvida uma servo-válvula que permite a regulagem automática da vazão de gás. Desenvolveu-se um circuito de potência para o acionamento dos atuadores (solenoides e servo-válvula) da bancada, assim como algoritmos que geram os sinais adequados para seu funcionamento. Foi feita a identificação do processo e o modelo da servo-válvula foi obtido por meio da análise de ensaios experimentais. O modelo do sistema completo foi desenvolvido no programa Simulink, onde foram feitas simulações do comportamento dinâmico do sistema proposto. O sistema foi implantado experimentalmente e foi capaz de convergir para as temperaturas de referência durante os ensaios. / This work addresses the development of a temperature control system for a gas tankless water heater. The Controlgás control system is presented and compared to typical control systems used in regular tankless water heaters. The characteristics and objectives of Controlgás project, which formed the basis for the development of this work, are presented. A theoretical foundation on control techniques for compensation of parametric variations and transport delays is presented, as well as a review of the main solutions already developed for the control of water temperature on tankless water heaters. The experimental set containing the heater and the control system used in previous work was restructured and instrumented with temperature sensors at the water's input and output and with sensors which detect the presence of flame and the water flow. A servo-valve that allows automatic adjustment of the gas flow was developed. A power circuit was created to drive the actuators (solenoids and servo-valve) of the set, as well as algorithms that generate the appropriate signals for its operation. The process identification and the servo-valve‟s model were obtained through experimental analysis. The system‟s complete model was developed in Simulink, where simulations of the dynamic behavior of the proposed system were made. The system was implemented experimentally and was able to converge to the reference temperatures during the tests.

Este trabalho apresenta uma metodologia de avaliação da incerteza associada à medição do desempenho térmico de coletores solares térmicos, utilizados em aquecedores de água residenciais. A determinação desta grandeza tem influência direta na estimativa da fração solar obtida pelo sistema, e consequentemente no tempo de retorno sobre o investimento do mesmo. Coletores solares planos, construídos a partir de perfis de alumínio, com absorvedores metálicos, pintura preta não seletiva, tubulação interna de cobre, cobertura de vidro simples e isolante térmico na parte traseira, foram ensaiados individualmente em laboratório para determinação do seu desempenho. O procedimento adotado foi o indoor, onde os ensaios são realizados sob um simulador artificial de radiação solar, e envolveu a configuração da câmara de testes, estabilização das variáveis ambientais, ensaios das amostras, cálculo do desempenho térmico e estimativa da sua incerteza associada. Esta última levou em consideração as contribuições da instrumentação empregada, da estabilidade temporal das condições de contorno para realização das medições e do método estatístico utilizado na determinação da curva de desempenho térmico do coletor. Ao final do estudo foram ponderados os limites aceitos pelo programa de etiquetagem brasileiro de coletores em comparação com os resultados obtidos. / This work presents a methodology for assessing the thermal performance uncertainty of solar collectors used in residential water heaters. The uncertainty has a direct influence on the solar fraction prediction and consequently on its payback time. Flat solar collectors, built in aluminum frames, metallic absorber with non-selective black paint, copper pipes, single glass cover and thermal insulation on the back, were tested individually at the laboratory to measure their performance. The test procedure was the indoor, performed on an artificial solar simulator, and included the test chamber set-up, environmental variables control, sample testing, thermal performance calculating and its uncertainty estimate. The latter considered the instrumentation, temporal stability of variables and the statistical method used on the collectors thermal performance curve fitting. The study also compared the results obtained with the performance limits accepted by the Brazilian collector labeling program.

[pt] No presente trabalho calcula-se a eficiência de um aquecedor de água, sem evaporação, queimando gás combustível com composição química desconhecida. Faz-se a comparação dos resultados obtidos com duas normas que apresentam formas diferentes de cálculo, ASME (1) e NBS (2). Com os resultados finais, sugere-se um procedimento a ser seguido no cálculo de eficiência de aquecedores. / [en] In this research, the thermal efficiency of a sensible water heater is measured and calculated, burning fuel gas with unknown chemical composition. The experimental results are then compared with the calculated values, when using ASME(1) and NBS(2) standard procedures. Finally and procedure is suggested to calculate the thermal efficiency of such heaters.

Este trabalho aborda o desenvolvimento de um sistema de controle de temperatura para um aquecedor de passagem de água a gás. O sistema de controle Controlgás é apresentado e comparado ao sistema de controle típico, usado em aquecedores de passagem convencionais. São apresentadas as características e objetivos do projeto Controlgás, o qual serviu de base para o desenvolvimento deste trabalho. É apresentada uma fundamentação teórica sobre técnicas de controle para compensação de variações paramétricas e de atrasos de transporte, bem como uma revisão sobre as principais soluções já desenvolvidas para o controle de temperatura da água em aquecedores de passagem. A bancada experimental, contendo o aquecedor e o sistema de controle, utilizada em trabalhos anteriores, foi reestruturada e instrumentada com sensores de temperatura na entrada e na saída de água e com sensores que detectam a presença de chama e de fluxo de água. Foi desenvolvida uma servo-válvula que permite a regulagem automática da vazão de gás. Desenvolveu-se um circuito de potência para o acionamento dos atuadores (solenoides e servo-válvula) da bancada, assim como algoritmos que geram os sinais adequados para seu funcionamento. Foi feita a identificação do processo e o modelo da servo-válvula foi obtido por meio da análise de ensaios experimentais. O modelo do sistema completo foi desenvolvido no programa Simulink, onde foram feitas simulações do comportamento dinâmico do sistema proposto. O sistema foi implantado experimentalmente e foi capaz de convergir para as temperaturas de referência durante os ensaios. / This work addresses the development of a temperature control system for a gas tankless water heater. The Controlgás control system is presented and compared to typical control systems used in regular tankless water heaters. The characteristics and objectives of Controlgás project, which formed the basis for the development of this work, are presented. A theoretical foundation on control techniques for compensation of parametric variations and transport delays is presented, as well as a review of the main solutions already developed for the control of water temperature on tankless water heaters. The experimental set containing the heater and the control system used in previous work was restructured and instrumented with temperature sensors at the water's input and output and with sensors which detect the presence of flame and the water flow. A servo-valve that allows automatic adjustment of the gas flow was developed. A power circuit was created to drive the actuators (solenoids and servo-valve) of the set, as well as algorithms that generate the appropriate signals for its operation. The process identification and the servo-valve‟s model were obtained through experimental analysis. The system‟s complete model was developed in Simulink, where simulations of the dynamic behavior of the proposed system were made. The system was implemented experimentally and was able to converge to the reference temperatures during the tests.

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