Submitted by (lucia.rodrigues@ufrpe.br) on 2016-10-14T11:39:21Z No. of bitstreams: 1 Tatiana Patricia Nascimento da Silva.pdf: 1324693 bytes, checksum: 31662474b4f5103f7a070cf7f5439bb7 (MD5) / Made available in DSpace on 2016-10-14T11:39:21Z (GMT). No. of bitstreams: 1 Tatiana Patricia Nascimento da Silva.pdf: 1324693 bytes, checksum: 31662474b4f5103f7a070cf7f5439bb7 (MD5) Previous issue date: 2013-02-25 / This research was conducted with the objective of analyzing quantitative and qualitative aspects of the poultry houses in terms of thermal efficiency and typology of built environments, with emphasis on productive performance. The first step was a survey of the main typological characteristics of the region where it was evaluated 68 sheds on 27 farms in the period May 2011 to April 2012, which allowed the removal of the constructive features of the aviaries in mesoregion of Pernambuco. For the second stage we selected five sheds with different typological characteristics, to determine the thermal efficiency of the system-poultry shed by means of thermal comfort indices (radiant heat load index, globe temperature and humidity and specific enthalpy) and the balance energy (sensible and latent exchanges) based on the performance of broilers. As a result of the first stage, the constructive characteristics were most evident width of 10-12 m (56%), length of 100-120 m (59%), with a slight separation between warehouses (<30 m) below the ceiling recommended (<3 m), eaves between 1 and 1.25 m (40%) low walls and high (> 0.2 m). As for natural cooling, most installations presented coverage natural lawn type (56%), no lining (96%) and louver (100%), cover with ceramic tile (93%), reflective paint on the roof (97%) and oriented east / west (89.7%). For artificial cooling, the primary heating source is wood hoods (71%), positive pressure ventilation (68%), fogging at high pressure (57%). As for the equipment presented to most feeders (54%) and drinkers (65%) commuting, axial fans (100%), the bed was used by most rice straw (56%) and yellow curtain (65%). In the second phase of this work, the thermal comfort indices showed no significant difference between the sheds (P <0.05). Environmental variables showed variations during the day, and the hours of 09 am to 15:00, showed mean values above the thermal comfort zone. As the energy balance, trade sensitive significant difference among the five sheds, as the times the effect was significant (P <0.05). The sensitive exchanges showed variation between the sheds. The data showed an increase in trade latent from the fourth week, but these values were lower than is thermal stress conditions, except for 3 who shed the seventh week exceeded trade exchanges latent sensitive. With respect to production performance, we note that there was no significant difference between 1 and 4 to shed the weight gain, mortality, feed intake and feed conversion. Including this last variable Shed 3. For other sheds the difference was significant at the 5% level of probability. Overall, it can be observed that the values found for the production indices remained below the tracks taken as optimal for cutting poultry industry. / Esta pesquisa foi conduzida com o objetivo de analisar aspectos quantitativos e qualitativos das instalações avícolas, em termos de eficiência térmica e tipologia dos ambientes construídos, com ênfase no desempenho produtivo das aves. Na primeira etapa foi realizado um levantamento das principais características tipológicas da região onde foi avaliados 68 galpões, em 27 granjas, no período de maio de 2011 a abril de 2012, o que permitiu o levantamento das características construtivas dos aviários na Mesorregião do Agreste pernambucano. Para a segunda etapa foram selecionados cinco galpões com características tipológicas distintas, para determinação da eficiência térmica no sistema ave-galpão, por meio dos índices de conforto térmico (carga térmica radiante, índice de temperatura de globo e umidade e entalpia específica) e do balanço de energia (trocas sensíveis e latentes) com base no desempenho de frangos de corte. Como resultado da primeira etapa, as características construtivas mais evidentes foram largura de 10-12 m (56%), comprimento de 100-120 m (59%), com pequeno afastamento entre galpões (< 30 m), pé-direito abaixo do recomendado (<3 m), beirais entre 1 e 1,25 m (40%) e muretas altas (> 0,2 m). Quanto à climatização natural, a maioria das instalações apresentou cobertura natural tipo gramado (56%), ausência forro (96%) e lanternim (100%), cobertura com telha cerâmica (93%), pintura reflexiva no telhado (97%) e orientação leste/oeste (89,7%). Para a climatização artificial, a principal fonte de aquecimento foi campânulas a lenha (71%), ventilação a pressão positiva (68%), nebulização a alta pressão (57%). Quanto aos equipamentos à maioria apresentaram comedouros (54%) e bebedouro (65%) pendulares, ventiladores axiais (100%), a cama utilizada pela maioria foi palha de arroz (56%) e cortina amarela (65%). Na segunda etapa do desse trabalho, os índices de conforto térmicos não apresentaram diferença significativa entre os galpões (P<0,05). As variáveis ambientais apresentaram variações ao longo do dia, sendo que os horários das 09 às 15:00, mostraram valores médios acima da zona de conforto térmico. Quanto o balanço de energia, as trocas sensíveis apresentaram diferença significativa entre os cinco galpões, quanto aos horários o efeito foi significativo (P<0,05). As trocas sensíveis apresentaram variação entre os galpões. Os dados mostraram que houve aumento das trocas latentes a partir da quarta semana, porém esses valores ficaram abaixo do que representa condições de estresse térmico, com exceção do galpão 3 que na sétima semana as trocas latentes ultrapassaram as trocas sensíveis. Com relação ao desempenho produtivo, nota-se que não houve diferença significativa entre o galpão 1 e 4 para as variáveis ganho de peso, mortalidade, consumo de ração e conversão alimentar. Incluindo nessa última variável o galpão 3. Para os demais galpões a diferença foi significativa ao nível de 5% de probabilidade. No geral, pode-se observar que os valores encontrados para os índices produtivos se mantiveram abaixo das faixas tidas como ideais para a indústria de aves de corte.

O etanol (álcool etílico) tem sido cada vez mais estudado e testado como combustível alternativo para substituição do uso de alguns derivados de petróleo em motores de combustão interna. O presente trabalho procura abordar o emprego do etanol na forma vaporizada em motores do ciclo Otto, objetivando a obtenção de melhores níveis de rendimento térmico total. Deste modo, um motor para teste de octanagem (motor CFR) foi equipado com um vaporizador de álcool instalado no coletor de escapamento, e após uma série de ensaios, várias análises puderam ser feitas. Essas considerações procuraram se ater a aspectos como rendimento térmico, relação ar/combustível, ângulo de avanço da centelha, temperatura de escape, assim como potência e eficiência volumétrica, levando em conta, sempre, a sua influência no funcionamento geral do motor. Ficou constatado que o motor movido a etanol vaporizado apresenta rendimento consideravelmente maior, menor consumo de combustível e funcionamento mais suave que aqueles verificados quando o mesmo motor e alimentado com álcool líquido. / The ethanol (ethyl alcohol) has been studied more and more as alternative fuel to replace some petroleum derivatives for internal combustion engines. The attached study examines the application of vaporized ethanol for Otto cycle engines, searching for better levels of total thermal efficiency. Therefore, an engine for test of octane number (CFR motor) was equipped with an alcohol vaporizer installed inside the escape pipe, and after many experiences, several analysis were made. The various analysis included aspects as thermal efficiency, air/fuel ratio, advance ignition, escape temperature, power and volumetric efficiency, always considering their influence on the operation of the engine. It was confirmed that the engine moved by vaporized ethanol presents higher thermal efficiency, smaller fuel consumption and smoother working than in case of alimentation by liquid alcohol.

O álcool etílico ou etanol vem se tornando, neste novo século, uma importante referência para estudos e aplicações que procuram um combustível alternativo ao uso de derivados de petróleo em motores de combustão interna. Neste trabalho, o uso do etanol vaporizado pelos gases de escape em motores do ciclo Otto busca a obtenção de melhores níveis de rendimento térmico e emissões de poluentes. Assim sendo, um motor de 1.0 litro foi montado em laboratório com um trocador de calor instalado ao lado do coletor de escapamento, e uma série de testes foram feitos, possibilitando uma cuidadosa análise quanto a rendimento térmico, relação ar/álcool, ângulo de avanço da centelha, temperatura de escape e gases de emissão, entre outros aspectos. Conclui-se que o motor a álcool vaporizado, em certos regimes de funcionamento, apresenta rendimento maior e emissões menores que aqueles verificados no motor a álcool líquido. / The ethyl alcohol or ethanol is becoming, in this new century, an important reference for studies and applications that search for an alternative fuel to be used in internal combustion engines, replacing oil derivatives. In this study, an Otto cycle engine is fueled with ethanol vaporized by the exhaust gases, aiming for better levels of thermal efficiency and exhaust emissions. Therefore, a 1.0 liter engine with a heat exchanger connected to the exhaust manifold was prepared in a test bench, and several tests were made, which allowed a criterious analysis about air/alcohol ratio, spark ignition time, exhaust temperature and exhaust emissions, and others. It was concluded that the engine fueled with vaporized alcohol presents, in some operation points, higher thermal efficiency and less emissions compared to the case of engine fueled with liquid alcohol.

This diploma thesis deals with the problems associated with acquisition of experimental data from technological unit for biomass combustion with nominal capacity of 1 MW, with regard to determination of thermal efficiency. In the introduction part, parameters of currently available biomass-based fuels as well as of those with large potential in the future are summarized. Further, a review in the field of biomass combustion technology is given. Biomass boilers are compared according to their technical parameters, function and benefits and drawbacks. In theoretical part methods for determination of thermal efficiency by direct method, indirect method and modified indirect method are described. Main parameters influencing resultant values of efficiency are included into the analysis. In final part an evaluation of real operational data from prototype unit combusting wooden chips is made. Recommendations for further experimental data gathering and their processing with the aim to evaluate thermal efficiency are suggested.

Many industrial processes have low-temperature waste heat sources that cannot be efficiently recovered. Low grade waste heat has generally been discarded by industry and has become an environmental concern because of thermal pollution. This has led to the lookout for technologies which not only reduce the burden on the non-renewable sources of energy but also take steps toward a cleaner environment. One approach which is found to be highly effective in addressing the above mentioned issues is the Organic Rankine Cycle (ORC), which can make use of low- temperature waste heat to generate electric power. Similar in principle to the conventional cycle, ORC is found to be superior performance-wise because of the organic working fluids used in the cycle. The focus of this study is to examine the ORC using different types of organic fluids and cycle configurations. These organic working fluids were selected to evaluate the effect of the fluid boiling point temperature and the fluid classification on the performance of ORCs. The results are compared with those of water under similar conditions. In order to improve the cycle performance, modified ORCs are also investigated. Regenerative ORCs are analyzed and compared with the basic ORC in order to determine the configuration that presents the best thermal efficiency with minimum irreversibility. The evaluation for both configurations is performed using a combined first and second law analysis by varying certain system operating parameters at various reference temperatures and pressures. A unique approach known as topological method is also used to analyze the system from the exergy point of view. Effects of various components are studied using the exergy-wheel diagram. The results show that ORCs using R113 as working fluid have the best thermal efficiency, while those using Propane demonstrate the worse efficiency. In addition, results from these analyses demonstrate that regenerative ORCs produce higher efficiencies compared to the basic ORC. Furthermore, the regenerative ORC requires less waste heat to produce the same electric power with a lower irreversibility.

Heat sinks are used mainly to take away the excessive heat which are produced in a component. This transfer of heat enables a smooth operation of the system with the heat generating component. The efficiency of heat sink is often dependent on the amount of heat it can take away within the smallest duration of time. Several designs and manufacturing techniques have been developed to improve this performance of heat sinks. This project aims at building a test rig which can be used to test the efficiency of heat sinks. The test rig should be designed to be modular, i.e. it should be able to test heat sinks of different sizes and also adhering to the design requirements. The project started with a broad information search on heat sinks and different testing methods. A system architecture was formulated for this test rig as a beginning stage and to find the different architectural components. The main principal components were selected fulfilling the design requirements. A chiller with pump, a flow meter with controller, temperature and pressure sensors and piping’s including a flexible pipe were the main components of the system created. When the specific components were chosen, the design was embodied and the components were arranged in a compact manner as a SolidEdge CAD-model. After several design iterations, a final design was selected. The experimental test rig was then built in the flow lab. The built experimental test setup is able to be adjusted to install heat sinks of different sizes making it modular in design. Future work to improve the performance of the test rig is also suggested. / Värmesänkor, som exempelvis kylflänsar, används främst för att transportera bort värme som orsakas av förluster i en komponent. Denna värmeöverföring möjliggör en smidig drift av systemet där den värmegenererande komponenten ingår. Värmesänkans effektivitet beror på hur mycket värmeeffekt den kan transportera bort. Flera olika konstruktioner och tillverkningstekniker har utvecklats för att förbättra värmesänkors kylprestanda. Målet med detta projekt är att bygga en testrigg som kan användas för att testa kylflänsars effektivitet. Testriggen ska utformas så att den är modulär, dvs. den ska kunna användas för att testa kylflänsar av olika storlekar. Projektet startade med en bred informationssökning om kylflänsar och olika testmetoder. En systemarkitektur skapades som ett början och för att hitta systemets olika principkomponenter. De viktigaste huvudkomponenterna som uppfyllde designkraven valdes sedan. En kylare med pump, en flödesmätare med regulator, temperatur- och tryckgivare och rörledningar, inklusive ett flexibelt rör var de viktigaste komponenterna i det system som skapades. De specifika komponenterna valdes sedan och de representerades och arrangerades på ett kompakt sätt som en system-CAD-modell i SolidEdge. Efter flera iterationer valdes en slutlig konstruktion, och den experimentella testriggen byggdes sedan i flödeslaboratoriet. Den experimentella testriggen kan justeras för att installera kylflänsar av olika storlekar, vilket innebär att den, i viss mån, är modulär. Framtida arbeten för att förbättra testriggens prestanda föreslås också.

Desde meados do século XX, métodos analíticos, numéricos e experimentais foram utilizados para quantificar a eficiência térmica na soldagem a arco, isto é, a razão entre a energia do arco elétrico e a energia que é entregue ao material durante a soldagem. Conhecendo-se a eficiência térmica, as dimensões da chapa e as propriedades térmicas do metal de base, torna-se possível prever as taxas e tempos de resfriamento a partir de modelo analíticos. Consequentemente, permitindo a previsão das transformações de fase, garantindo que os valores das propriedades da junta soldada se enquadrem dentro de um intervalo desejado. Os modelos de previsão de taxa de resfriamento derivados a partir dos modelos analíticos de Rosenthal são validos apenas no regime quase estacionário. Todavia, estes modelos costumam ser utilizados com pouco critério, mesmo em situações em que este regime não é alcançado. Portanto, para o desenvolvimento de modelos mais precisos e acurados para previsões das taxas de resfriamento, torna-se necessário entender como os termos do balanço de energia se desenvolvem durante a soldagem, até atingir o regime quase estacionário. Este trabalho tem como objetivo desenvolver um entendimento mais abrangente dos fatores que impactam nos valores de taxas de resfriamento em juntas soldadas. Realizaram-se ensaios de calorimetria com nitrogênio líquido para diferentes tempos de soldagem, como também, foram coletados ciclos térmicos em diferentes posições ao longo do cordão, buscando entender como as variações no balanço de energia, ao longo da soldagem, impactam no material. A partir da Metodologia de Superfície de Resposta, foram obtidos os modelos empíricos da energia entregue ao material e da eficiência térmica do arco. Um novo entendimento acerca do balanço de energia na soldagem foi alcançado, servindo de base para o desenvolvimento e validação de um modelo preditivo de taxa de resfriamento, válido para diferentes condições de fluxo de energia no material. / Since the early 20th century, numerical and experimental methods have been used to quantify the thermal arc efficiency in welding, i.e., the ratio between the electric arc energy and the energy delivered to the material during welding. Knowing the thermal arc efficiency, the sample dimensions and the thermal properties of the base metal, it is possible to predict the cooling rates by analytical models. Consequently, allowing the prediction of phase transformations in the material, ensuring that values of welded joint properties are within a desired range. Cooling rate prediction models derived from Rosenthal\'s analytical models are valid only in quasi-stationary state. However, these models are used with little criterion, even in situations where this state is not achieved. Therefore, to development of more accurate and precise models for the prediction of cooling rate it become necessary to understand the evolution of the energy balance during the welding until the quasi-stationary state was reached. This work aims to develop a more comprehensive understanding of the factors that affect the cooling rate in welded joints. Calorimetry tests with liquid nitrogen were carried out for different welding times, and thermal cycles were collected at different positions along the weld bead, to understand how the variations in the energy balance during the welding affect the material. From the Response Surface Methodology, the empirical models of delivered energy and the thermal arc efficiency were obtained. A new understanding about the energy balance in the welding was found, that was used for the development and validation of a predictive model of cooling rate, valid for different condition of energy flow in the material.

Desde meados do século XX, métodos analíticos, numéricos e experimentais foram utilizados para quantificar a eficiência térmica na soldagem a arco, isto é, a razão entre a energia do arco elétrico e a energia que é entregue ao material durante a soldagem. Conhecendo-se a eficiência térmica, as dimensões da chapa e as propriedades térmicas do metal de base, torna-se possível prever as taxas e tempos de resfriamento a partir de modelo analíticos. Consequentemente, permitindo a previsão das transformações de fase, garantindo que os valores das propriedades da junta soldada se enquadrem dentro de um intervalo desejado. Os modelos de previsão de taxa de resfriamento derivados a partir dos modelos analíticos de Rosenthal são validos apenas no regime quase estacionário. Todavia, estes modelos costumam ser utilizados com pouco critério, mesmo em situações em que este regime não é alcançado. Portanto, para o desenvolvimento de modelos mais precisos e acurados para previsões das taxas de resfriamento, torna-se necessário entender como os termos do balanço de energia se desenvolvem durante a soldagem, até atingir o regime quase estacionário. Este trabalho tem como objetivo desenvolver um entendimento mais abrangente dos fatores que impactam nos valores de taxas de resfriamento em juntas soldadas. Realizaram-se ensaios de calorimetria com nitrogênio líquido para diferentes tempos de soldagem, como também, foram coletados ciclos térmicos em diferentes posições ao longo do cordão, buscando entender como as variações no balanço de energia, ao longo da soldagem, impactam no material. A partir da Metodologia de Superfície de Resposta, foram obtidos os modelos empíricos da energia entregue ao material e da eficiência térmica do arco. Um novo entendimento acerca do balanço de energia na soldagem foi alcançado, servindo de base para o desenvolvimento e validação de um modelo preditivo de taxa de resfriamento, válido para diferentes condições de fluxo de energia no material. / Since the early 20th century, numerical and experimental methods have been used to quantify the thermal arc efficiency in welding, i.e., the ratio between the electric arc energy and the energy delivered to the material during welding. Knowing the thermal arc efficiency, the sample dimensions and the thermal properties of the base metal, it is possible to predict the cooling rates by analytical models. Consequently, allowing the prediction of phase transformations in the material, ensuring that values of welded joint properties are within a desired range. Cooling rate prediction models derived from Rosenthal\'s analytical models are valid only in quasi-stationary state. However, these models are used with little criterion, even in situations where this state is not achieved. Therefore, to development of more accurate and precise models for the prediction of cooling rate it become necessary to understand the evolution of the energy balance during the welding until the quasi-stationary state was reached. This work aims to develop a more comprehensive understanding of the factors that affect the cooling rate in welded joints. Calorimetry tests with liquid nitrogen were carried out for different welding times, and thermal cycles were collected at different positions along the weld bead, to understand how the variations in the energy balance during the welding affect the material. From the Response Surface Methodology, the empirical models of delivered energy and the thermal arc efficiency were obtained. A new understanding about the energy balance in the welding was found, that was used for the development and validation of a predictive model of cooling rate, valid for different condition of energy flow in the material.

The aim of this diploma thesis is to theoretically, practically and experimentally explore different ways of waste heat utilization in the building industry. The work is divided into three basic passages. In the first part I analyze the theoretical nature of the various physical processes in recovery and is there a practical use. More emphasis is placed on heat recovery from wastewater, as I am using this way of recuperation in other parts of this diploma thesis. In the second point, I apply the use of heat from waste water when designing a technical solu-tion for the reconstruction of the heating system of the clinic. The design is solved in two variants. The first suggested location lokali- them, recuperative, shower exchanger operation rehabilitation, bath and massage. In the second variant, central recovery is envisaged using a heat exchanger in the accumulator well and water-water heat pump. Based on the technical and economic evaluation, the first option was selected. The second variant is ineffective and remains only in the case study. In the last section, I experimentally investigate the thermal efficiency and the relative savings of the heat exchanger, which is designed in the first variant of the second part. Measurement, processing of results and evaluation I made for laboratory conditions and for real conditions with the showering person. Finally, I appreciate the eco-nomic benefits of this facility.

The master's thesis deals with district heat exchangers in a thermal steam cycle of combined heat and power plants and with types of condensate cascades in the multilevel heating systems. Calculation of the thermal efficiency of electricity generation is provided for the investigated thermal cycle, which was modified for three different types of cascades. Besides that, a comparison of useful electric power and electricity generation through one year period of working is made. A significant part of the work is devoted to the design of district heat exchangers, including the calculation of thermal power and heat transfer area. Main dimensions are proposed for each exchanger together with a basic drawing.