Atualmente um dos grandes responsáveis pela emissão de CO2 (Dióxido de Carbono) são os veículos movidos a motor de combustão interna, em sua maioria os automóveis. Pesquisas recentes têm mostrado maneiras de aumentar a eficiência dos automóveis por meio do aproveitamento do calor de exaustão para geração de energia elétrica, com consequente redução no consumo de combustível. Esta dissertação tem por objetivo apresentar um estudo de viabilidade técnica de um gerador termoelétrico aproveitando o calor residual dos gases de exaustão de um motor de combustão interna para geração de energia elétrica. O trabalho apresenta o modelamento matemático e a implementação de um protótipo para realização dos ensaios para a obtenção de resultados experimentais. O protótipo foi montado utilizando módulos termolétricos cujo princípio de funcionamento é baseado nos efeitos Seebeck e Peltier, que devido ao conceito de reversibilidade podem funcionar como geradores elétricos, aquecedores ou refrigeradores. Por meio das equações teóricas e dos resultados dos ensaios experimentais foi possível avaliar o desempenho do sistema de geração de energia elétrica, determinar o comportamento dos principais parâmetros envolvidos e finalmente concluir sobre a exequibilidade e viabilidade do projeto. / Currently one of the most responsible for CO2 (Carbon Dioxide) emissions are vehicles powered by internal combustion engine, in their majority the automobiles. Recent research has shown ways to improve the efficiency of automobiles through the use of exhaust heat to generate electric power, with consequent reduction in fuel consumption. This paper aims to present a technical feasibility study of a thermoelectric generator using the residual heat from exhaust gases of an internal combustion engine to generate electric power. The paper presents the mathematical modeling and implementation of a prototype for tests to obtaining experimental results. The prototype was assembled using thermoelectric modules whose operating principle is based on the phenomena called Seebeck and Peltier Effects, which due to the concept of reversibility can act as electric generators, heaters or coolers. Through the theoretical equations and experimental results it was possible to evaluate the performance of electric power generation system, determine the behavior of the main parameters and finally conclude on the feasibility and viability of the project.

ELECTRA is a Swedish training reactor concept that will use fourth generation nuclear reactor technology, and is cooled by natural circulation of liquid lead. During a fuel inspection the reactor vessel has to be emptied on metal coolant and the power must be shutoff, this can lead to a meltdown. By calculating the produced residual heat in the fuel pins during the power shutdown and coolant drainage, the cladding temperature could be calculated. The potential usage of argon, helium or nitrogen gas as an emergency coolant during loss of lead was investigated. The gas coolant will unavoidably contain small amounts of water vapour which can have a negative impact on the core. This matter was examined with a literature study on the effect of water vapour on the cladding surface; FeCrAl, an iron- base alloy with high aluminium and chromium content.  The burnup simulation code Serpent was used for calculating the residual heat. The results indicated that just after five days of shutdown the residual heat decreased to 31 W/pin and continued to progressively decrease in the coming days. It was evaluated that the residual heat developed in the core would not exceed 600°C.  Calculations on the emergency gas coolant showed that nitrogen gas offered the best solution on terms of thermal decrease and cost-effectiveness. While helium cooling was the recommended option due to its inertness.  The literature study done on the oxidizing effect of water vapour on FeCrAl, shows little impact due to the high oxidation resistance of this alloy as a result of the high aluminium and chromium percentage.

ELECTRA is a Swedish training reactor concept that will use fourth generation nuclear reactor technology, and is cooled by natural circulation of liquid lead. During a fuel inspection the reactor vessel has to be emptied on metal coolant and the power must be shutoff, this can lead to a meltdown. By calculating the produced residual heat in the fuel pins during the power shutdown and coolant drainage, the cladding temperature could be calculated. The potential usage of argon, helium or nitrogen gas as an emergency coolant during loss of lead was investigated. The gas coolant will unavoidably contain small amounts of water vapour which can have a negative impact on the core. This matter was examined with a literature study on the effect of water vapour on the cladding surface; FeCrAl, an iron- base alloy with high aluminium and chromium content.  The burnup simulation code Serpent was used for calculating the residual heat. The results indicated that just after five days of shutdown the residual heat decreased to 31 W/pin and continued to progressively decrease in the coming days. It was evaluated that the residual heat developed in the core would not exceed 600°C.  Calculations on the emergency gas coolant showed that nitrogen gas offered the best solution on terms of thermal decrease and cost-effectiveness. While helium cooling was the recommended option due to its inertness.  The literature study done on the oxidizing effect of water vapour on FeCrAl, shows little impact due to the high oxidation resistance of this alloy as a result of the high aluminium and chromium percentage.

ELECTRA is a Swedish training reactor concept that will use fourth generation nuclear reactor technology, and is cooled by natural circulation of liquid lead. During a fuel inspection the reactor vessel has to be emptied on metal coolant and the power must be shutoff, this can lead to a meltdown. By calculating the produced residual heat in the fuel pins during the power shutdown and coolant drainage, the cladding temperature could be calculated. The potential usage of argon, helium or nitrogen gas as an emergency coolant during loss of lead was investigated. The gas coolant will unavoidably contain small amounts of water vapour which can have a negative impact on the core. This matter was examined with a literature study on the effect of water vapour on the cladding surface; FeCrAl, an iron- base alloy with high aluminium and chromium content.  The burnup simulation code Serpent was used for calculating the residual heat. The results indicated that just after five days of shutdown the residual heat decreased to 31 W/pin and continued to progressively decrease in the coming days. It was evaluated that the residual heat developed in the core would not exceed 600°C.  Calculations on the emergency gas coolant showed that nitrogen gas offered the best solution on terms of thermal decrease and cost-effectiveness. While helium cooling was the recommended option due to its inertness.  The literature study done on the oxidizing effect of water vapour on FeCrAl, shows little impact due to the high oxidation resistance of this alloy as a result of the high aluminium and chromium percentage.

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Norrbotten är ett län med stora ytor och en liten befolkning. Regionen är dock långt ifrån att vara självförsörjande på livsmedel. Detta beror till stor del på det karga klimatet som inte tillåter god skörd av många stapelvaror. Detta förvärras av att det finns ett ointresse att producera livsmedel hos befolkningen i övrigt. För att ändå kunna föda befolkningen måste hundratusentals ton livsmedel importeras varje år, inte bara från övriga Sverige utan också resten av Europa och världen. Samtidigt finns det många stora industrier i länet och nästan varje större tätort har ett fjärrvärmesystem. Dessa anläggningar producerar stora mängder restvärme som till viss del tas tillvara på, men mycket går till spillo. I Luleå Energis fall är nästan all fjärrvärme producerad av restgaser från SSABs ståltillverkning, vilket innebär att värmen redan är en form av restenergi. Luleå Energi har en ambition att bidra till att restvärme nyttjas ytterligare i samhället än den redan görs, en idé är att använda den till odling. Under hösten 2019 utfördes ett examensarbete på Luleå Energi, där designen för en lämplig odlingsenhet togs fram. Det är från denna odlingsenhet som detta examensarbete tar avstamp. Energiberäkningar och diskussion med sakkunniga visar att det är möjligt att nyttja lågvärdig värme till odlingsenheten. Det kräver heller inte några komplicerade värmekomponenter för att uppnå en god uppvärmning. Implementering av returvärmebaserad uppvärmning i en odlingsenhet som ställs upp centralt i Luleå tätort hoppas väcka intresse hos befolkningen till odling, men även nyttjande av restvärme då odlingsenheten tar sin värme från fjärrvärmereturen. Odlingsenheten är alltså ämnad att tackla två problem med livsmedelsförsörjningen, dels ointresset samt det karga klimatet. En livscykelanalys visar att odlingsenheten även är hållbar på andra sätt, då den kräver mindre resurser och kortare transportsträckor, däremot är koldioxidutsläppen något högre. Effekten av att odlingsenhetens nyttjande av fjärrvärmereturen skulle sänka dess temperatur var dock försumbar om inte tusentals odlingsenheter utplaceras. / Norrbotten county has a small population but a large area, however it is far from being self-sufficient on food. This is in big part due to the rugged and cold climate, which prevents ample harvest of many staple foods. Food production is exacerbated by disinterest by the population at large. To still have enough, hundreds of thousands of tonnes of food is imported from the rest of Sweden, Europe and the world. At the same time, there are quite a few large industries in the county, and almost every large town has their own district heating network. These facilities produce enormous amounts of residual heat, some of this heat is made use of but alot also goes to waste. The heat in Luleå Energi's district heating network is mainly produced by residual gases from steel production at SSAB, therefore the heat is already a form of residue. Luleå Energi has an ambition to contribute to a much wider use of residual heat in society, one idea is to use it for cultivation. During the fall of 2019, a master thesis handling the design of a suitable cultivation unit was presented. From that thesis, this work has its basis. Litterature study, energy calculations, and discussion with experts show that it is possible to use residual heat for this cultivation unit. Using this heat also does not require any complicated heating system to get a good effect. Implementation of residual-based heating in a cultivation unit placed in central Luleå is hoped to awaken interest within the population for cultivation, but also interest in use of residual heat, as the cultivation unit uses heat from the return flow from the district heating network. The cultivation is as such meant to combat two problems regarding food production, both the disinterest and the climate. A life cycle analysis also show that the cultivation unit is sustainable in other ways, as it requires less resources and less transport, however the carbon emissions are somewhat higher. The presumed effect that the cultivation units use of the return flow would lower its temperature, was negligible however, unless thousands of cultivation units would be placed.

L'objectif de cette étude consiste à développer une approche permettant d'économiser de l'énergie de haut niveau thermique dans le procédé de la distillation atmosphérique du pétrole. Cette approche repose sur le fait que l'installation de plusieurs flashs sur le train de préchauffage de ce procédé associée à un choix approprié du plateau d'alimentation des vapeurs résultantes à la colonne de distillation, provoque une diminution de la chaleur apportée à ce train de préchauffage. Le déficit de chaleur de haut niveau thermique ainsi créé est causé par la réduction des débits des reflux latéraux de la colonne de distillation et il est compensé par de la chaleur de bas niveau thermique apportée par les effluents résiduaires disponibles dans toute la raffinerie. Cette approche peut être appliquée aux nouveaux procédés comme à l'expansion des procédés existants et l'économie d'énergie de haut niveau thermique dans le four peut atteindre les 21%. Une réduction équivalente des gaz à effet de serre est aussi observée / The objective of this thesis is to demonstrate, on thermodynamic grounds, that introducing a flash in the preheating train of an atmospheric oil distillation process , together with an appropriate feeding of the resulting vapors into the column, could potentially bring substantial energy savings by reducing the duty of the preheating furnace and by reducing the distillation column irreversibilities. This idea has been expended by showing how this can be done while keeping the throughput and the product characteristics unchanged. The outcome is that placing several flashes after the heat exchangers and feeding the corresponding vapor streams to the appropriate trays of the column, reduces the pumparound flows and then the heat brought to the preheating train. The resulting heat deficit may then be compensated in additional heat exchangers by using low level heat recuperated from the products of the distillation and/or imported from other processes. The use of this residual heat reduces the furnace duty by approximately an equivalent amount and could be as high as 21%. The approach can be applied in the design of news processes or in the revamping of existing ones

This dissertation is divided into three parts. The first part deals with the use of waste heat in the theoretical plane, where methods and possibilities of using this heat are described. Part Two, which is computational, deals with the suggestion of heating industrial halls with an adjacent, mostly office, building in two variants, then it goes on to also deal with the concept of equal pressure forced ventilation, a proposal of air curtains and preparation of hot water, where the heat source is a boiler. In the last part an experiment took place which investigated the conversion efficiency of thermal to electric energy.