Made available in DSpace on 2016-04-01T17:55:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-29. Added 1 bitstream(s) on 2016-04-01T18:00:55Z : No. of bitstreams: 1 000505950.pdf: 2040911 bytes, checksum: 6a6c3699938e4a1059984533329b05ad (MD5) / Devido à extrema necessidade de se diversificar as fontes de energia renováveis, torna-se necessário a busca por métodos de reciclagem de energia pela utilização de rejeitos térmicos de equipamentos. Assim, o aproveitamento desses rejeitos pode ser utilizado, como uma nova fonte de energia, para o aquecimento de água e armazenamento da mesma em reservatório para uso doméstico. Devido a isso, é proposta a construção de um aparato experimental de um reservatório de armazenamento térmico cilíndrico, onde o objetivo da pesquisa será o levantamento dos coeficientes de desempenho relativo aos refrigeradores convencional e modificado, além de realizar uma análise da armazenagem da água quente, através da técnica da estratificação térmica utilizando um refrigerador com condensador modificado. O rejeito térmico coletado, através do princípio do termosifão, será armazenado na forma de energia térmica. Os resultados mostraram que os coeficientes de desempenho dos sistemas, calculados pelas técnicas relativas às perdas térmicas teóricas e experimentais, apresentaram grande diferença. Observou-se o comportamento dinâmico das termoclinas, através do efeito da estratificação térmica e a evolução das temperaturas em função do tempo, mostrando maior viabilidade do refrigerador modificado, gerando assim maior conforto térmico aos usuários além de produzir água quente para uso doméstico. / Due to the extreme necessity to diversify renewable energy sources, the search for energy recycling methods through the utilization of thermal losses from equipment has become fundamental. Thus, these losses can be used as new source of energy for water heating and storage in Domestic Hot Water Storage Tanks (DHWST). For this reason, the construction of an experimental apparatus with a cylindrical thermal storage tank is proposed, in which the objective of the study will be a survey of the Coefficient of Performance concerning conventional and modified refrigerators, as well as to perform an analysis of hot water, through the thermal stratification technique using a refrigerator with a modified condenser. The collected thermal loss, as per the thermosiphon principle, will be stored as thermal energy. The results showed that the coefficient of performance for the systems, calculated using techniques for theoretical and experimental thermal losses, presented great differences. The dynamic behavior of the thermal distribution was observed through the thermal stratification effect and temperature evolution in terms of time, showing greater variability of the modified refrigerator generating more thermal comfort to users in addition to providing domestic hot water.

Sweden is only utilizing half of the available excess heat. To utilize more of the excess heat a seasonal thermal energy storage could be implemented to store excessed heat from the summer when the demand is lower to the winter when the demand is higher. This can be achieved by an integration of a seasonal thermal energy storage to the district heating system. A seasonal thermal energy storage may also reduce the need of the system’s peak load, which often is economically costly and adversely affect the environment. The purpose of the paper is to investigate the possibility for Skövde Värmeverk to implement a seasonal thermal storage. The paper is performed by a literature collection and calculations are made by software programs. The result shows that it is technically possible to implement a pit thermal energy storage and a borhole thermal energy storage, but no outcome shows a profitability within 20 years. A pit thermal energy storage can replace the system’s peak load up to 79 percent and a borhole thermal energy storage up to 2,8 percent. The most suitable case for Skövde Värmeverk is to install a pit thermal energy storage with a storage capacity of 4 GWh.

O desempenho das Máquinas de Medir a Três Coordenadas (MM3Cs) fica limitado por diversos fatores, que atuam de maneira conjunta gerando os denominados erros volumétricos. Para a temperatura de 20ºC os erros geométricos podem ser considerados constantes, uma vez que variam muito lentamente com o tempo. Porém, se a temperatura é alterada estes erros mudam em grandeza e comportamento, gerando os denominados erros térmicos. Alguns trabalhos têm sido desenvolvidos com o objetivo de estudar e modelar os erros térmicos, porém os resultados alcançados são, ainda, incipientes. Este trabalho apresenta o equacionamento das componentes do erro volumétrico das MM3Cs considerando as influências térmicas. A medelagem foi aplicada a uma MM3C do tipo \"Ponte Móvel\" e combina transformações homogêneas, técnicas de regressão e mínimos quadrados. As grandezas dos erros geométricos e das variações termicamente induzidas destes erros foram coletadas utilizando-se do interferômetro laser, do esquadro mecânico, do nível eletrônico, etc. Os valores das temperaturas foram monitorados através de termopares do tipo T (Cobre-Constantan). Verificou-se que a Máquina não experimenta deformações, além, das provocadas pela livre dilatação dos seus componentes. A partir do modelo proposto foram sintetizadas as componentes do erro volumétrico, os resultados foram discutidos e comparados com aqueles obtidos através da medição de um anel padrão, constatando-se a excelente capacidade do modelo na previsão do erro volumétrico da máquina. No caso, erros da ordem de grandeza de 10 &#956m foram reduzidos em pelo menos 75%, enquanto que para erros maiores que 10 &#956m a eficiência do modelo foi de 90%. / Performance of coordinate measuring machines (CMMs) is limited by numerous factors that operate simultaneously and generate volumetric errors. The most significant portion of the volumetric error is produced by geometric errors. At the temperature of 20ºC, geometric errors can be considered at steady states, once their variation in time is considerably slow. However, if temperature is modified, these errors change in magnitude and behaviour, generating the thermal induced errors. Some work has been developed aiming to study and model the thermal errors, but the achieved results are still incipient. This work presents the derivation of the components of the volumetric error considering its thermal influences. The method was employed and applied to moving bridge CMM and combines homogeneous transformation, regression techniques and least squares methods. The magnitudes of the geometric errors and its thermally induced variations were collected by means of a laser interferometer system, mechanical square, electronic level, etc. Temperature data were monitored by means of T-type thermocouples (copper-constantan). It was verified that the CMM was not susceptible to deformations other than the ones due to the dilatation of its components. From the proposed model, the components of volumetric error were synthesized; the results were discussed and compared to the ones obtained from the measurement of a ring plug, observing the outstanding ability of the model to predict the volumetric error of the machine. Errors of 10 &#956m in magnitude were reduced in at least 75%, whilst errors greater than 10 &#956m, presented a reduction efficiency of 90%. It was verified that the CMM was not susceptible to deformations other than the ones due to the dilatation of its components.

[pt] O presente trabalho descreve o desenvolvimento de um sistema de dessorção térmica aplicável a remediação de solos contaminados por compostos orgânicos. O sistema consiste de um bastonete térmico capaz de aquecer o solo através de um fluxo radial e de um oxidador térmico destinado ao tratamento das emissões gasosas. Fazem parte do sistema, como equipamentos acessórios, controladores de temperatura do tipo rampa patamar, isolantes térmicos de fibra cerâmica, membranas plásticas e amostradores de água e de gases. Estes últimos são utilizados para averiguar a eficiência do oxidador térmico. O sistema desenvolvido atingiu aos objetivos de projeto. O bastonete térmico foi capaz de aplicar temperaturas de até 600 ºC seguindo trajetórias de temperatura programadas. O mesmo pode-se afirmar do sistema de tratamento das emissões gasosas. O programa experimental realizado em um solo residual de gnaisse, obtido de um talude rodoviário da Rodovia Washington Luís, contaminado por óleo queimado, revelou que o sistema desenvolvido é capaz de reduzir a concentração de compostos orgânicos a um valor mínimo, bem abaixo dos limites estabelecido pelos órgãos ambientais nacionais e estrangeiros. O programa expôs a importância da aeração da matriz porosa durante o tratamento para impedir a formação de coque. As determinações analíticas revelaram que as emissões gasosas resultantes do aquecimento do solo residual contaminado com óleo queimado tratam-se de parafinas de olefinas. A duração do ensaio bem como o projeto do arranjo espacial da distribuição dos bastonetes em um sistema in situ de remediação pode ser determinada através do emprego da formulação de propagação de calor formulada por Stegemeier (1998). / [en] This dissertation refers to the development of an in situ system devised to remediate soils contaminated with organic compounds. The system consists basically of a thermal probe capable of heating the soil matrix through radial flow and a thermal oxidizer that treats the resulting gases emissions. The system clearly reached the design aims. The thermal probe consistently programed temperatures up to 6000C to the soil matrix following applied thermal paths. The thermal oxidizer was capable to heat gases emissions up to 9000C under prolonged exposure. The experimental program was carried out using a residual soil from gnaiss taken from a slope at Washington Luiz Roadway. This soil was contaminated with used oil and submitted to a series of tests in order to assess the efficiency of the system developed herein. The results suggest that thermal desorption was able to reduce the degree of contamination to levels well below the limits established by National and International Environmental Agencies. The results also revealed the importance of aeration during the process to avoid the formation of coke. Fingerprinting tests carried out on gases emissions revealed that they were composed mainly by olefins and paraffins. The design of an in situ system as well as the termination criteria for in situ thermal desorption treatment might well be accomplished using the heat propagation theory developed by Stegemeier (1998).

Les travaux menés durant cette thèse ont abouti à la fabrication d'un microsystème fluidique de détection de gaz innovant portatif, bas coût et incluant un pompage thermique. Le microcapteur de gaz utilisé est inséré dans un microcanal. Un chauffage intégré permet au microcapteur de bien fonctionner. Il permet aussi la création du phénomène de thermal creep qui est à l'origine de l'écoulement du gaz à détecter le long du canal vers le microcapteur. Le gradient de température le long du canal et les dimensions sont des paramètres essentiels de l'étude.Des simulations microfluidiques et thermiques ont permis de définir les dimensions du microcanal ainsi que les matériaux les plus adéquats. Deux types de microsystèmes ont ensuite été réalisés. Le dispositif de chauffage intégré a été calibré afin d'étudier le gradient thermique réel. Une étude des performances du microcapteur sous ammoniac a été réalisée. Nous avons pu notamment déterminer la température optimale de détection. Puis des tests dans une cellule de détection ont été réalisés avec le microsystème complet. / My thesis work led to develop an innovative fluidic microsystem for gas detection. It is portable, cheap and has an integrated thermal pumping. The gas microsensor used is inserted into a microchannel. Its integrated heater allows the well detection. It also allows the creation of thermal creep phenomenon, which is at the origin of the gas flow along the channel which will be detected by the microsensor. The choices of both microchannel dimensions and the temperature gradient are the most important parameters. Thus, microfluidic and thermal simulations were performed to define the microchannel dimensions and the most suitable materials natures. Two microsystems were processed with clean room technologies. The integrated heater was calibrated to study the real thermal gradient. A study of the performance of the microsensor was performed under ammonia. We could include determining the optimal temperature sensing. Then the microsystem was studed using in a special detection cell.

No description available.

Thermal bridging can be defined as the phenomenon where a structural element spanning the building envelope acts like a thermal pathway which collects and moves energy (heat) from the interior to the exterior of the structure. CFS construction, due to the high thermal conductivity of steel with respect to its surrounding structural components and repetitive nature of framing, is highly prone to thermal bridging. Thermal bridging significantly alters the thermal performance of wall assemblies. Hence, the objective of this research project was to quantify the magnitude of energy loss through cold-formed steel (CFS) stud wall assemblies at a component level to lay the groundwork for future works that promote sustainable, energy-efficient, and improved building design recommendations. Therefore, a parametric evaluation was performed using ISO 10211:2007, Annex A, conforming heat transfer software Blocon Heat3 version 8 to generate the data required for analysis. 80 unique wall assemblies and the impact of selected parameters on the overall thermal transmittance of the wall assembly were studied as part of the parametric evaluation. The key variables of the study are steel thickness, stud depth, stud spacing, cavity insulation R-value, external insulation thickness (R-value), and fastener diameter and length. Based on the results of the analysis, effects of increasing stud and track thickness, depth, and stud spacing have been discussed in the form of trends in overall heat flow and linear thermal transmittance coefficient values. Additionaly, effects of increasing external insulation have been discussed by addressing changes in heat flow.

Spacecraft testing includes acoustics, vibrations, and thermal vacuum. Cal Poly’s Space Environments Lab is equipped with multiple vacuum chambers, but no thermal vacuum chamber. The purpose of this thesis is to incorporate an ATS Chiller system with the HVEC vacuum chamber so students are able to experiment with a thermal vacuum chamber. The ATS Chiller had leaky pipes that needed to be refurbished and a shroud was implemented to improve thermal capabilities of the system. The full system was able to reach temperatures as low as -38ºC and as high as 58ºC at a pressure of 10-6 Torr. The ATS Chiller was able to absorb up to 500W of heat dissipation from a component mounted to the platen inside of the vacuum chamber. Thermal modeling of the apparatus was performed in Thermal Desktop. The model was incorporated with the test data to extract interface resistance information between connected surfaces. Another model is used to analyze a theoretical component inside the apparatus to evaluate mounting methods and determine theoretical temperatures of the component. The model adjusts for material properties, including thermal conductivity and emissivity to accurately simulate testing conditions within +/- 3ºC. Platen and shroud adjustments were able to accommodate a peak bake out temperature of 130±2.2℃ of any component without damage to the system. Three temperature cycles were performed by the thermal vacuum chamber to reach extreme temperatures of 58℃ and -38. A 300 Watt heater was used to simulate component heat dissipation for the duration of the test. Furthermore, this thesis lays out further possibilities for thermal testing using the HVEC Vacuum chamber and ATS chiller as a thermal vacuum chamber.

This thesis focuses on the development of an open source software capable of automatic face detection in an image captured by a thermal camera, followed by a temperature measuring. This software is supposed to aid in the COVID-19 pandemics. The developed software is independent of used thermal camera. In this thesis, I am using TIM400 thermal camera. The implementation of the face detection was achieved by an OpenCV module. The methods tested were Template Matching, Eigen Faces, and Cascade Classifier. The last-mentioned had the best results, hence was used in the final version of the software. Cascade Classifier is looking for the eyes and their surrounding area in the image, allowing the software to subsequently measure the temperature on the surface of one's forehead. One can therefore be wearing a face mask or a respirator safely. The temperature measuring works in real time and the software is able to capture several people at once. It then keeps a record of the temperature of each measured individual as well as the time of the measurement. The software as a whole is a part of an installation file compatible with the Windows operating system. The functionality of this software was tested – the video recordings are included in this thesis.

Aim of this work is a systematic investigation of the modes of thermal convection (onset of convection, stationary solutions, periodic solutions, chaotic states) in a material whose properties vary with depth like the material of Earth mantle; the problem was solved in Cartesian geometry. The Stokes equation set was consistently formulated in the spectral region not only horizontally but also vertically, and thus in the model consisting of layers with a constant viscosity but with general course of velocity and temperature in each layer. This equation set was solved with matrix method for each wave vector. Thermal equation was solved in the spatial domain and the transition of velocity and temperature between spectral and spatial domains was performed using the fast Fourier transform. This procedure allows a straightforward parallelization, thereby opening the possibility of not only two-dimensional but also three-dimensional modeling and modeling of chaotic regimes. On the basis of the numerical difficulties of method presented here an model investigated in finite elemens was used. The basic modes of thermal convection were then investigated using model assembled in the software Comsol. Powered by TCPDF (www.tcpdf.org)