Advancement in infrared imaging technology has allowed the thermal imaging to detect and visualize several gases, mostly hydrocarbon gases. In addition, infrared cameras could potentially be used as a non-contact temperature measurement for gas and vapor. However, current application of infrared imaging techniques for gas measurements are still limited due to several uncertainties in their performance parameters. The aim of this research work was to determine the key factors in the application of infrared imaging technology for gas visualization and a non-contact temperature measurement. Furthermore, the concentration profile and emission rate of the gas are predicted by combining the application of the infrared imaging method with gas dispersion modeling. In this research, infrared cameras have been used to visualize liquefied natural gas (LNG) plumes from LNG spills on water. The analyses of the thermograms showed that the apparent temperatures were different from the thermocouple measurement which occurred due to the assumption of that the object emissivity was always equal to unity. The emissivity for pure methane gas and a mixture of methane and atmospheric gases were then evaluated in order to obtain the actual temperature distribution of the gas cloud. The results showed that by including the emissivity value of the gas, the temperature profile of the dispersed gas obtained from a thermal imaging measurement was in good agreement with the measurement using the thermocouples. Furthermore, the temperature distribution of the gas was compared to the concentration of a dispersed LNG vapor cloud to obtain a correlation between the temperature and the concentration of the cloud. Other application of infrared imaging technique was also conducted for leak detection of natural gas from a pipeline. The capability of an infrared camera to detect a fugitive gas leak was combined with the simulation of vapor discharge and dispersion in order to obtain a correlation between the emission rates and the sizes of the gas plume to the minimum detectable concentration. The relationship of the methane gas cloud size to the gas emission rate was highly dependent to the prevailing atmospheric condition. The results showed that the correlation were best to predict the emission rate less than 0.2 kg/s. At higher emission rate, the increase in gas release rate did not change the size of the cloud significantly.

In conventional remote sensing, visible-near infrared (VNIR) and shortwave infrared (SWIR) part of the electromagnetic spectrum (EMS) have been utilized for lithological discrimination extensively. Additionally, TIR part of the EM spectrum can also be utilized for discrimination of surface materials either through emissivity characteristics of materials or through radiance as in VNIR and SWIR. In this study, ASTER thermal multispectral infrared data is evaluated in regard to lithological discrimination and mapping through emissivity values rather than conventional methods that utilize radiance values. In order to reach this goal, Principle Component Analysis (PCA) and Decorrelation Stretch techniques are utilized for ASTER VNIR and SWIR data. Furthermore, the spectral indices which directly utilize the radiance values in VNIR, SWIR and TIR are also included in the image analysis. The emissivity values are obtained through Temperature-Emissivity Separation (TES) algorithm. The results of the image analyses, except spectral indices, are displayed in RGB color composite along with the geological map for visual interpretation. The results showed that utilizing emissivity values possesses potential for discrimination of organic matter bearing surface mixtures which has not been possible through the conventional methods. Additionally, PCA of emissivity values may increase the level of discrimination even further. Since the emissivity utilization is rather unused throughout in literature and new, further assessment of accuracy is highly recommended along with the field validations.

Cette thèse porte sur les propriétés thermooptiques de matériaux en émission et réflexion depuis les températures cryogéniques jusqu'aux très hautes températures. Afin de dégager des lois générales sur l’émission de rayonnement d’un solide, il faut connaitre les paramètres fondamentaux : indice complexe, fréquence de relaxation, fréquence plasma sur le domaine le plus large possible à la fois en température mais aussi en longueur d’onde. Dans ce but une partie importante du travail de thèse a consisté à développer des moyens de mesure qui permettent d’effectuer des spectres d’émission ou de réflexion de l’ultraviolet à l’infrarouge lointain et pour les températures de 40K à 3000K.Une fois cet objectif atteint, un des premiers résultats fondamentaux a été d’étudier le zirconium à haute température. La multiplicité des montages nécessaires pour couvrir le domaine de mesure a permis ensuite des applications industrielles très variées, depuis la détermination du facteur d’absorption solaire du Kapton à 77K pour un satellite jusqu'à la cartographie en émissivité et température d’un bain de soudage d’acier. A température proche de l’ambiante la détermination de l’efficacité d’un isolant à bulles métallisé a conduit à mesurer et introduire dans les calculs les propriétés des matériaux dans l’infrarouge lointain. / This study deals with the thermo-optical properties of materials by emission and reflection from cryogenic temperatures up to very high temperatures.To identify the general laws of radiative emission of a solid, some basic parameters should be known: complex index, relaxation frequency, plasma frequency in a wide range of both temperatures and wavelengths. For this purpose, an important part of this work was to develop means to measure emission or reflection spectra from the ultraviolet to the far infrared and for temperatures from 40K to 3000K.When this is achieved, one of the earliest fundamental results was the study of zirconium at high temperature. Various experimentation was then used for a wide variety of industrial applications: from the determination of solar absorptance of Kapton at 77K for a satellite to the cartographies of emissivity and temperature for a bath of welding steel. In order to determine the insulation effectiveness of a bubble plating film near ambient temperature, measurement and introduction of material properties in the far infrared in the calculations have been conducted.

Este trabalho apresenta a metodologia empregada para desenvolvimento e utilização de um equipamento para medir valores de emissividade hemisférica. O referido equipamento permite efetuar simultaneamente medidas de emissividade através do método calorimétrico e do método radiométrico. O calorímetro mede o fluxo de calor entre duas superfícies paralelas e horizontais, onde a superfície superior é aquecida por uma fonte de corrente elétrica de alta estabilidade. As temperaturas das duas superfícies são determinadas quando o sistema atinge o equilíbrio térmico. A superfície aquecida é protegida por uma guarda térmica fazendo com que toda a potência elétrica seja dissipada à superfície inferior, que por sua vez é refrigerada com um sistema que utiliza pastilhas Peltier. O fluxo de calor é medido e seu valor é utilizado em uma equação onde as emissividades de ambas as superfícies são participantes. O radiômetro utiliza sensores detectores térmicos que convertem em sinal elétrico o efeito de aquecimento decorrente da incidência deste fluxo de calor radiante entre as duas superfícies. A partir de experimentos com superfícies de emissividades conhecidas, parâmetros fixos do equipamento foram determinados estando o mesmo apto a medir superfícies com valores de emissividade desconhecidos. O trabalho analisa também os erros experimentais intrínsecos do instrumento. / This work presents the methodology used for development and use of an equipment to measure values of hemispherical emissivity. The equipment allows to make emissivity measurements simultaneously through the calorimetric method and of the radiometric method. The calorimeter measures the heat transfer between two parallel and horizontal surfaces, where the superior surface is heated up by a source of electric current of high sustainability. The temperatures of the two surfaces are determined when the system reaches the thermal equilibrium. The heated surface is protected by a thermal guard, wich makes all the eletrical power to be dissipated towards the inferior surface that is cooled by a Peltier system. The heat flux is measured and its value is used in an equation where the emissividades of both surfaces are important. The radiometer uses thermal detectors that convert in electric sign, the heating effect due to the incidence of this radiant heat flux between the two surfaces. Starting from experiments with surfaces of known emissivity, fixed parameters of the equipment were determined being the same capable to measure surfaces with unknown emissivity values. The work also analyzes the experimental intrinsic errors of the apparratus.

Este trabalho apresenta a metodologia empregada para desenvolvimento e utilização de um equipamento para medir valores de emissividade hemisférica. O referido equipamento permite efetuar simultaneamente medidas de emissividade através do método calorimétrico e do método radiométrico. O calorímetro mede o fluxo de calor entre duas superfícies paralelas e horizontais, onde a superfície superior é aquecida por uma fonte de corrente elétrica de alta estabilidade. As temperaturas das duas superfícies são determinadas quando o sistema atinge o equilíbrio térmico. A superfície aquecida é protegida por uma guarda térmica fazendo com que toda a potência elétrica seja dissipada à superfície inferior, que por sua vez é refrigerada com um sistema que utiliza pastilhas Peltier. O fluxo de calor é medido e seu valor é utilizado em uma equação onde as emissividades de ambas as superfícies são participantes. O radiômetro utiliza sensores detectores térmicos que convertem em sinal elétrico o efeito de aquecimento decorrente da incidência deste fluxo de calor radiante entre as duas superfícies. A partir de experimentos com superfícies de emissividades conhecidas, parâmetros fixos do equipamento foram determinados estando o mesmo apto a medir superfícies com valores de emissividade desconhecidos. O trabalho analisa também os erros experimentais intrínsecos do instrumento. / This work presents the methodology used for development and use of an equipment to measure values of hemispherical emissivity. The equipment allows to make emissivity measurements simultaneously through the calorimetric method and of the radiometric method. The calorimeter measures the heat transfer between two parallel and horizontal surfaces, where the superior surface is heated up by a source of electric current of high sustainability. The temperatures of the two surfaces are determined when the system reaches the thermal equilibrium. The heated surface is protected by a thermal guard, wich makes all the eletrical power to be dissipated towards the inferior surface that is cooled by a Peltier system. The heat flux is measured and its value is used in an equation where the emissividades of both surfaces are important. The radiometer uses thermal detectors that convert in electric sign, the heating effect due to the incidence of this radiant heat flux between the two surfaces. Starting from experiments with surfaces of known emissivity, fixed parameters of the equipment were determined being the same capable to measure surfaces with unknown emissivity values. The work also analyzes the experimental intrinsic errors of the apparratus.

Este trabalho apresenta a metodologia empregada para desenvolvimento e utilização de um equipamento para medir valores de emissividade hemisférica. O referido equipamento permite efetuar simultaneamente medidas de emissividade através do método calorimétrico e do método radiométrico. O calorímetro mede o fluxo de calor entre duas superfícies paralelas e horizontais, onde a superfície superior é aquecida por uma fonte de corrente elétrica de alta estabilidade. As temperaturas das duas superfícies são determinadas quando o sistema atinge o equilíbrio térmico. A superfície aquecida é protegida por uma guarda térmica fazendo com que toda a potência elétrica seja dissipada à superfície inferior, que por sua vez é refrigerada com um sistema que utiliza pastilhas Peltier. O fluxo de calor é medido e seu valor é utilizado em uma equação onde as emissividades de ambas as superfícies são participantes. O radiômetro utiliza sensores detectores térmicos que convertem em sinal elétrico o efeito de aquecimento decorrente da incidência deste fluxo de calor radiante entre as duas superfícies. A partir de experimentos com superfícies de emissividades conhecidas, parâmetros fixos do equipamento foram determinados estando o mesmo apto a medir superfícies com valores de emissividade desconhecidos. O trabalho analisa também os erros experimentais intrínsecos do instrumento. / This work presents the methodology used for development and use of an equipment to measure values of hemispherical emissivity. The equipment allows to make emissivity measurements simultaneously through the calorimetric method and of the radiometric method. The calorimeter measures the heat transfer between two parallel and horizontal surfaces, where the superior surface is heated up by a source of electric current of high sustainability. The temperatures of the two surfaces are determined when the system reaches the thermal equilibrium. The heated surface is protected by a thermal guard, wich makes all the eletrical power to be dissipated towards the inferior surface that is cooled by a Peltier system. The heat flux is measured and its value is used in an equation where the emissividades of both surfaces are important. The radiometer uses thermal detectors that convert in electric sign, the heating effect due to the incidence of this radiant heat flux between the two surfaces. Starting from experiments with surfaces of known emissivity, fixed parameters of the equipment were determined being the same capable to measure surfaces with unknown emissivity values. The work also analyzes the experimental intrinsic errors of the apparratus.

Orientador: Hilton Silveira Pinto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-06T03:42:16Z (GMT). No. of bitstreams: 1 Almeida_CarlosAlbertoSoaresde_D.pdf: 685356 bytes, checksum: 3eb22116a96bd0f7b5643e5620f19c26 (MD5) Previous issue date: 2001 / Resumo: Foram utilizadas séries de imagens diurnas e noturnas captadas pelos sensores AVHRR a bordo do satélite NOAA-14 para a obtenção dos valores finais de temperatura de superfície do dossel vegetativo. O processamento das imagens incluiu o geo-referenciamento e as correções quanto aos efeitos atmosféricos e de emissividade, para as quais se utilizou o método de correção split window. A equação de split window usada considerou o parâmetro de emissividade da superfície cultivada estimada diretamente no campo pelo método da caixa. Este método foi comparado a um método alternativo de estimativa de emissividade no campo baseado na proporção de cobertura vegetal e solo descoberto. Os dois métodos apresentaram resultados equivalentes quanto à estimativa de emissividade da superfície. A alta correlação entre a temperatura de superfície medida no campo e a obtida a partir das imagens indicou que as equações de split window usadas corrigiram satisfatoriamente as imagens quanto aos efeitos atmosféricos e de emissividade / Abstract: Diurnal and nocturnal image series have been used in this work. These images were processed on suitable software to the treatment of NOAA-AVHRR products, for Surface temperature final value obtaining. The processing work includes both the images geo-referencing and their atmospheric correction applying the "split window method". The split window equation used takes into account the crop surface emissivity parameter, estimated directly on the field by the "box method". This one was compared to an alternative emissivity estimate on the field method, which is based on the crop covering/bared soil relation. Both methods when compared presented similar results. A terrestrial radiometer was used to the surface temperature measurements carried out in situ, during the satellite passes. The correct surface temperature satellite data were submitted to a regression analysis against the terrestrial data about the same parameter. High association level between surface temperature measured at the field and the near air temperature was observed. The high correlation between surface temperature measured at the field and that one from the images shown that the split window equation corrected satisfactorily the atmosphere effects over the images / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / Em aplicaÃÃes prÃticas de energia solar ativa e passiva, ou para outros fins construtivos, o revestimento superficial do material que absorve a radiaÃÃo solar tem um papel importante no que concerne à absorÃÃo e à emissÃo de radiaÃÃo solar e tÃrmica, influenciando diretamente na relaÃÃo custo-benefÃcio do equipamento. Revestimentos superficiais para as placas absorvedoras de radiaÃÃo solar, ou superfÃcies seletivas, alteram as relaÃÃes de ganho e perda de energia do equipamento e, por isso, o desempenho dos diferentes revestimentos disponÃveis, seus tipos e custos, alÃm de Ãreas potenciais de aplicaÃÃo devem ser conhecidos. Em geral, coletores de placa plana sem superfÃcies seletivas operam em temperaturas inferiores a 100ÂC, sendo utilizados no aquecimento de Ãgua, em processos de secagem, etc. Existem aplicaÃÃes prÃticas como fogÃes solares, sistemas de refrigeraÃÃo, dessalinizadores tÃrmicos onde sÃo necessÃrias temperaturas muito elevadas que sà sÃo alcanÃadas pelo uso de superfÃcies seletivas. Para alta eficiÃncia, os coletores solares devem possuir um mÃximo de absorbÃncia no espectro solar enquanto mantÃm um mÃnimo de emitÃncia no infravermelho. Este trabalho apresenta um estudo comparativo de superfÃcies seletivas para coletores solares utilizadas nos maiores centros que utilizam energias renovÃveis. SÃo apresentadas as mediÃÃes experimentais da temperatura em placas absorvedoras e da radiaÃÃo solar global e direta incidente sobre as placas em funÃÃo do tempo. As amostras foram testadas nas condiÃÃes ambientais de Fortaleza. Os valores experimentais foram usados na determinaÃÃo dos valores para a emissividade, apÃs a realizaÃÃo de um balanÃo de energia em regime permanente nessas amostras. As temperaturas de estagnaÃÃo nas amostras foram tambÃm calculadas mostrando o desempenho desses materiais. SÃo tambÃm apresentadas as anÃlises microscÃpicas (microscÃpico eletrÃnico de varredura) das diferentes superfÃcies. Os resultados mostram claramente o desempenho das amostras quando expostas à radiaÃÃo solar e que o procedimento desenvolvido para esse trabalho pode ser utilizado na determinaÃÃo de um valor mÃdio para a emissividade tÃrmica a partir de mediÃÃes mais simples. / Em aplicaÃÃes prÃticas de energia solar ativa e passiva, ou para outros fins construtivos, o revestimento superficial do material que absorve a radiaÃÃo solar tem um papel importante no que concerne à absorÃÃo e à emissÃo de radiaÃÃo solar e tÃrmica, influenciando diretamente na relaÃÃo custo-benefÃcio do equipamento. Revestimentos superficiais para as placas absorvedoras de radiaÃÃo solar, ou superfÃcies seletivas, alteram as relaÃÃes de ganho e perda de energia do equipamento e, por isso, o desempenho dos diferentes revestimentos disponÃveis, seus tipos e custos, alÃm de Ãreas potenciais de aplicaÃÃo devem ser conhecidos. Em geral, coletores de placa plana sem superfÃcies seletivas operam em temperaturas inferiores a 100ÂC, sendo utilizados no aquecimento de Ãgua, em processos de secagem, etc. Existem aplicaÃÃes prÃticas como fogÃes solares, sistemas de refrigeraÃÃo, dessalinizadores tÃrmicos onde sÃo necessÃrias temperaturas muito elevadas que sà sÃo alcanÃadas pelo uso de superfÃcies seletivas. Para alta eficiÃncia, os coletores solares devem possuir um mÃximo de absorbÃncia no espectro solar enquanto mantÃm um mÃnimo de emitÃncia no infravermelho. Este trabalho apresenta um estudo comparativo de superfÃcies seletivas para coletores solares utilizadas nos maiores centros que utilizam energias renovÃveis. SÃo apresentadas as mediÃÃes experimentais da temperatura em placas absorvedoras e da radiaÃÃo solar global e direta incidente sobre as placas em funÃÃo do tempo. As amostras foram testadas nas condiÃÃes ambientais de Fortaleza. Os valores experimentais foram usados na determinaÃÃo dos valores para a emissividade, apÃs a realizaÃÃo de um balanÃo de energia em regime permanente nessas amostras. As temperaturas de estagnaÃÃo nas amostras foram tambÃm calculadas mostrando o desempenho desses materiais. SÃo tambÃm apresentadas as anÃlises microscÃpicas (microscÃpico eletrÃnico de varredura) das diferentes superfÃcies. Os resultados mostram claramente o desempenho das amostras quando expostas à radiaÃÃo solar e que o procedimento desenvolvido para esse trabalho pode ser utilizado na determinaÃÃo de um valor mÃdio para a emissividade tÃrmica a partir de mediÃÃes mais simples. / In practical applications of active and passive solar energy, or other construction purposes, the coating material which absorbs solar radiation has an important role as regards the absorption and emission of thermal radiation and, directly influencing the cost benefit the product. Surface coatings for solar radiation-absorbing plate or selective surfaces, changing the relationship of gain and loss of energy of the equipment and, therefore, the performance of the various coatings available types and their costs as well as potential areas of application should be known. In general, flat plate collectors operate without selective surfaces at temperatures below 100  C, and for the heating of water in drying processes, etc.. There are practical applications such as solar cookers, refrigeration systems, thermal desalination plants where they are needed at very high temperatures that are only achieved by the use of selective surfaces. For high efficiency, solar collectors should have a maximum absorbance in the solar spectrum while maintaining a minimum infrared emittance. This paper presents a comparative study of selective surfaces for solar collectors used in the larger centers that use renewable energy. Shows the experimental measurements of the temperature and the plates absorbing solar radiation and directly incident on the plates as a function of time. Samples were tested in environmental conditions in Fortaleza. The experimental values ​​were used in determining values ​​for the emissivity, after conducting an energy balance in steady state in these samples. The stagnation temperatures in the samples was also calculated showing the performance of these materials. Are also presented microscopic analysis (scanning electron microscopy) of different surfaces. The results clearly show the performance of samples when exposed to solar radiation and the procedure developed for this work may be used in determining an average value for the thermal emissivity measurements from simpler. / In practical applications of active and passive solar energy, or other construction purposes, the coating material which absorbs solar radiation has an important role as regards the absorption and emission of thermal radiation and, directly influencing the cost benefit the product. Surface coatings for solar radiation-absorbing plate or selective surfaces, changing the relationship of gain and loss of energy of the equipment and, therefore, the performance of the various coatings available types and their costs as well as potential areas of application should be known. In general, flat plate collectors operate without selective surfaces at temperatures below 100  C, and for the heating of water in drying processes, etc.. There are practical applications such as solar cookers, refrigeration systems, thermal desalination plants where they are needed at very high temperatures that are only achieved by the use of selective surfaces. For high efficiency, solar collectors should have a maximum absorbance in the solar spectrum while maintaining a minimum infrared emittance. This paper presents a comparative study of selective surfaces for solar collectors used in the larger centers that use renewable energy. Shows the experimental measurements of the temperature and the plates absorbing solar radiation and directly incident on the plates as a function of time. Samples were tested in environmental conditions in Fortaleza. The experimental values ​​were used in determining values ​​for the emissivity, after conducting an energy balance in steady state in these samples. The stagnation temperatures in the samples was also calculated showing the performance of these materials. Are also presented microscopic analysis (scanning electron microscopy) of different surfaces. The results clearly show the performance of samples when exposed to solar radiation and the procedure developed for this work may be used in determining an average value for the thermal emissivity measurements from simpler.

Dans les contacts fortement dissipatifs, la dissipation d'énergie par frottement conduit à des sollicitations thermiques très sévères qui peuvent avoir des répercussions conséquentes sur les performances, la durabilité des organes de friction, l'environnement ou la santé humaine. La connaissance des champs thermiques des surfaces de frottement est un enjeu de premier ordre. Dans le cas de mesures sans contact du rayonnement calorifique, elle s'avère difficile du fait de l'émissivité inconnue de ces surfaces, qui varie spatialement et temporellement lors du frottement. Les travaux ont concerné le développement d'une mesure de champs thermiques par thermographie bichromatique dont l'intérêt est d'accéder simultanément à la température et à l'émissivité de surface. Les difficultés résident dans le recalage spatial et temporel de deux imageurs infrarouges, la calibration en flux des caméras et la variation spectrale de l'émissivité. La technique développée a été appliquée à la mesure in situ des champs de température et d'émissivité d'un disque de frein pendant le freinage, et exploitée pour l'analyse des localisations thermiques induites par le frottement et de leurs interactions avec le circuit tribologique, tirant parti de la connaissance de l'évolution spatiale et temporelle de l'émissivité. / In highly dissipative contacts, the energy dissipated by friction leads to severe thermal loads which could have bad consequences on performances, on friction parts durability, on the environment or on human health. Therefore, knowledge of sliding surfaces thermal fields is a first-rate issue. Due to the lack of knowledge about the emissivity of those surfaces, which change both spatially and temporally during friction, measuring thermal fields is difficult. The work done concerned the development of thermal fields measurement by bispectral thermography, which allows to get simultaneously surface emissivity and temperature. The difficulties reside in the spatial and temporal images registration of two infrared cameras, in the camera flows calibration and in the spectral emissivity variation. The technique developed was applied to the in situ fields measurement of temperature and emissivity of a brake disc during braking. It was then used for analysis of thermal locations induced by friction and their interactions with the tribological circus, leveraging the knowledge of the spatial and temporal evolution of the emissivity.

The subject of this thesis is the incorporation of the contactless temperature measurement of surface temperatures among other methods of temperature measurement with the analysis of (individual) advantages and disadvantages. The study is focused on the measurement and finding alternative protective clingfilms for thermo camera “Flir SC2000” and possible ways of their usage.