In developing countries such as Guatemala, firewood is increasingly being used for cooking in most rural areas. Consequently, there is a shortage of firewood in these areas beca use trees do not grow at the same rate as they are consumed. Some authors report that 90% of the heat from firewood is lost during combustion. Several alternatives to open pit fires exist to reduce the amount of firewood used. However, these alternatives need to be evaluated to determine their efficiency. This project compared the time efficiency and volume of firewood used in the Finlandia style improved stoves, Josefina stoves, and open pit fires used by the majority of people in the Salitrón community of San Juan Ermita, Chiquimula.

In Mozambique, almost 80% of the population uses firewood for their energy needs,  however this use is not exclusive only to rural areas, observing the same in urban areas who not only use the wood and also charcoal stoves. Because of this situation, there is a huge devastation of the forest, which has caused the depletion of flora, thus missing native species without its due spare.  In Maputo, most households, the use of fire wood was replaced by charcoal because of high energetic intensity and also transportation and storing promptness. In 2011, three millions of sacs of charcoal have been in consumption, managing a market of $70 million in 2010 and 2012, the price rise a lot from 250 to 650 Meticais (200% more). In this context came the need, to evaluate the energy efficiency of charcoal stoves and their respective access by the population in Maputo in order to contribute to the reduction of excessive consumption of biomass. For it was made evaluation of energetic efficiency in ten stoves most used in the city of Maputo, We tested the quality of charcoal and found to demand access to its coal. The results showed that the charcoal tested is not the good quality because the values are outside the acceptable levels According to the literature. Energy efficiency evaluation noted that the most efficient stoves have been improved in spite of the water boiling test of the traditional stoves have been boil faster. There was also, that consumers prefer to buy products from day to day in establishments near to their residence and do not spend more money than 100.00 MTn (2 USD) every time moving to sales points. / I Mocambique använder nästan 80% av befolkningen ved för sina energibehov, men denna användning är inte exklusiv bara för landsbygdsområden, där man observerar samma i stadsområden som inte bara använder veden utan även koksugnar. På grund av den här situationen orsakas en enorm förödelse av skogen, vilket har orsakat utarmning av flora och inhemska arters fortplantning påverkas negativt. I de flesta hushåll i Maputo ersattes användningen av ved med träkol på grund av hög energiintensitet och snabbare transport och lagring. Under 2011 har tre miljoner säckar träkol konsumerats, vilket motsvarar en marknad på 70 miljoner dollar 2010 och 2012. Priset steg från 250 till 650 Meticais (mer än 200%) under denna period. I det här sammanhanget uppstod behovet att utvärdera energieffektiviteten hos ugnar för träkol och tillgången av sådana ugnar i Maputo för att bidra till minskningen av överdriven konsumtion av biomassa. För det gjordes utvärdering av energeffektiviteten i tio ugnar som mest används i staden Maputo. Kvaliteten på träkol testades och tillgången på träkol utvärderades. Resultaten visade att träkolet inte är av god kvalitet eftersom värdena ligger utanför acceptabla nivåer enligt litteraturen. Energieffektivitetsutvärderingen noterade att de mest effektiva ugnarna har förbättrats. Testen av de traditionella ugnarna visade att kokningstiden för vatten har kortats ner. Det visade sig också att konsumenter föredrar att köpa produkter från dag till dag i företag nära deras hemvist, och de spenderar inte mer än 100,00 MTn (2 USD) varje gång de flyttar till försäljningsställen.

The purpose of this study was to develop a framework for analysis and assessment of the cost of ownership and use of major cooking appliances. This involved an assessment of the monetary cost as well as the cost of human resources required to maintain and operate cooking systems. The goal was to provide information useful in making purchase decisions within a framework that can be used to organize information about cost beyond the initial purchase price. Five cooktops--conventional electric coil, induction, solid element with thermostatic control, solid element with thermal limiter, and gas--and a microwave oven were used to develop a decision-making matrix. Data were collected in the Virginia Polytechnic Institute and State University College of Human Resources household equipment laboratory. In addition, data were compiled from previous studies which included the same variables. One-way analysis of variance, Student-Newman-Keuls, and Tukey’s HDS techniques were used to analyze the data. Results were used to assign weights in the matrix used to develop a 10-point scale which represented the total cost of owning and using a cooking system in food preparation. The scale was then used to evaluate the appliances used in this study. Based on the matrix, the microwave oven received the highest score followed by gas, conventional electric coil, solid element with thermostatic control, solid element with thermal limiter, and induction cooktops. The cost of owning and using any of these appliances is not markedly different in terms of life expectancy, maintenance, energy, or cooking time. However, such factors as user interaction with the appliance, speed of heat-up, heat recover rate, retained heat, evenness of heating, cleaning time, and initial purchase price do vary and are likely to influence satisfaction with a cooking system. / Ph. D.

This thesis project made in collaboration with Stegia AB focuses on the development of an automated testing unit for control units in wood stoves. The reason behind this work is new laws regarding safety and performance for controlsystems in household appliances and an ambition to digitize the traditional woodstove. The current control units which are essential for managing functions andmonitoring different states in the stove also allow users to receive operational information via a mobile app. Throughout the testing it’s required to ensure that the produced control units perform as functionally desired. To meet these requirements each unit needs to undergo comprehensive functio-nal tests after assembly to guarantee flawless operation and the ability to handle the tasks they where designed for. This work aims to develop a test unit that can automate this process, improving both production reliability and efficiency. The project focuses on constructing a prototype that uses both hardware and software to perform automated tests that simulate various scenarios and loads that the control units might encounter. By examining how test automation should be carried out and exploring techniques such as Hardware in the Loop (HIL), it is possible to create environments similar to those in which the units will be used. This ensures that each component functions as it should during actual use in the stove. The conclusion of this work is that an automated testing unit is technically feasible and a prototype has been developed. With further development there is potential to standardize the testing process and leading to higher product quality and greater customer satisfaction. / Detta examensarbete som genomförts i samarbete med Stegia AB inriktar sig på utvecklingen av en automatiserad testenhet för styrenheter i braskaminer. Orsaken till att detta arbete genomförts grundar sig i nya lagar gällande säkerhet och prestanda för styrsystem i hushållsapparater samt en ambition att digitalisera den traditionella braskaminen. De nuvarande styrenheterna vilka är avgörandeför att hantera funktioner och övervaka olika tillstånd i braskaminen möjliggör även att användaren får driftsinformation i en mobil-app. För att göra detta möjligt krävs noggrann testning för att säkerställa att de styrenheter som produceras presterar enligt vad som funktionsmässigt önskas. För att möta dessa krav önskas att varje enhet skall kunna genomgå omfattande funktionstester efter montering för att garantera att de fungerar felfritt och kan hantera de uppgifter som de är designade för. Detta arbete syftar till att utveckla en testenhet som kan automatisera denna process vilket inte bara förbättrar tillförlitligheten i produktionen utan även effektiviserar hela produktionsprocessen. Projektet fokuserar på att konstruera en prototyp som använder både hårdvara och mjukvara för att utföra automatiserade tester som simulerar olika scenarion och belastningar som styrenheterna kan utsättas för. Genom att undersöka hur testautomatiersing bör utföras samt undersöka tekniker som Hardware inthe Loop (HIL) möjliggörs att skapa miljöer likt de som enheterna kommer att användas i. Detta i sin tur säkerställer att varje komponent fungerar som den ska under vid använding i braskaminen. Slutsatsen av detta arbete är att en automatiserad testenhet är tekniskt genomförbar och att en prototyp tagits fram. Med ytterligare utveckling finns potential att standardisera testprocessen vilket kan leda till högre produktkvalitet och större kundnöjdhet.

In 2011, Energy saving (mud) stoves were introduced in villages around the Kachung Forestplantation in rural Uganda as part of an effort to support local sustainable development. Initial fieldwork showedthat the stoves had not been adopted as much as the apparent benefits would suggest. This has been a commonissue with improved cooking stove projects around the world. In order to find out why the stoves are notadopted, 67 women in charge of the cooking were interviewed additionally participant observations of cooking,other daily work routines and building stoves conducted, as well as interviews with other relevant stakeholders.Results show that women struggle to find enough firewood and are bothered by the smoke produced whencooking, which makes them generally very interested in improved mud stoves. Indeed many women hadadopted a local version of the mud stove in order to ease the burden of firewood collection. The reason for notadopting a mud stove in general can be mainly attributed to work burden in constructing it. As for the moresophisticated energy saving mud stoves introduced, additional factors were that the implementation strategyshows weaknesses in how the knowledge on how to build the stove is supposed to spread. Further, the stoveintroduced is rather complex in the way it is supposed to be built, which makes it difficult to spread theknowledge of how to build it. The implementation strategy needs to be revised under consideration of the localcircumstances in order to achieve a higher adoption rate.

The recovery boiler in a pulp and paper mill plays a dual role of recovering pulping chemicals and generating steam for either chemical processes or producing electricity. The efficiency of producing steam in the recovery boiler is limited by the first melting temperature of ash deposits that accumulate on the superheater tubes. Above the first melting temperature, the molten salt reacts with the protective oxide film that develops and dissolves it. The most protective oxide is determined by evaluating how little it dissolves and how its solubility changes in the molten salt. Solubility tests were done on several protective oxides in a known salt composition from a recovery boiler that burns hardwood derived fuel. ICP-OES was used to measure concentration of dissolved metal in the exposure tests while EDS and XRD were used to verify chemical compositions in exposure tests. NiO was found to be the least soluble oxide while Cr₂O₃ and Al₂O₃ had similar solubility with Fe₂O₃ being less soluble than Cr₂O₃ but more soluble than NiO. Exposure tests with pure metals and selected alloys indicated that even though Fe₂O₃ has little solubility, it is not a protective oxide and causes severe corrosion in stainless steels. The change in performance of iron based alloys was due to the development of a negative solubility gradient for Fe₂O₃ where Fe₂O₃ precipitated out of solution and created a continuous leaching of oxide. Manganese was found to be beneficial in stainless steels but its role is still unknown. Nickel based alloys were found to be least corroded due to nickel's low solubility and because it did not form a negative solubility gradient.

In recent centuries the Swedish Tiled Stove has varied in its design with an aesthetic evolutionary history that has not only followed the architectural and artistic ideals but also the taste in stove design. The heat source has varied depending on the regional traditions and where it was located within the country, but the inside of the construction was of a similar five channel system. The purpose of this paper is to study and compare the design of tile matrices made by Emil Petterson with other Swedish stoves.  The following questions will be addressed: What characterized the production of a small scale tile stove workroom during the years 1900-50? Which main styles can be described as Emil Pettersson’s ideal while producing his matrices? And finally, is it possible to study the tile stove matrices as objects of historical and cultural significance, and what difficult methodological issues might occur in the doing of it?  To answer these questions I will present the results of the documentation of Pettersson’s tile matrices with detailed historical categorizations and schedules. The conclusion shows that Pettersson as a stove builder and -producer was characterized by eclectic ideals and a design shape based on more liberal interpretations of contemporary trends. The studying of tile stove matrices showed that, despite its difficulties regarding the inverted shapes, it is a barer of great historical and cultural value and that it plays a key part in the historical context of tile stove ovens.

This thesis is the result of nine weeks fieldwork in Babati and Bukoba districts in Northern Tanzania during spring 2012. The purpose of this thesis is to study why development projects on fuel-efficient stoves have had a limited adoption in these two regions and what obstacles and opportunities there are for further spread of fuel-efficient cooking stoves. Semi-structured interviews were the main method used for collecting the empirical data, which was then analysed from a socio-economic perspective with help from the framework of Sustainable Rural Livelihoods. The Results showed that people’s perceptions of fuel-efficient stoves are positive but that projects face many obstacles connected to socio-economic conditions. Knowledge on how to get stoves and access to financial capital is main obstacles for further spreading. Social networks and organisations are channels for information, but to spread outside these networks will need complementing strategies from organisations promoting fuel-efficient stoves. Important are also finding ways of making the financial aspect of adopting stoves less, like using materials with lower costs, using stove-models with low costs and training people in building stoves so re-investments are unnecessary and dependency of funding from organisations less. Gender is a factor affecting the adoption of fuel-efficient stoves, regarding access to assets and generated benefits. There is therefore an importance of involving gender throughout the different stages of the projects.

Made available in DSpace on 2014-12-17T15:01:15Z (GMT). No. of bitstreams: 1 JohnsonPM.pdf: 2529117 bytes, checksum: aa7070b9f8036203a44199f6a7119e3f (MD5) Previous issue date: 2007-10-31 / The present work presents a contribution in the study of modelings of transference of heat for foods submitted to the experimental tests in the considered solar oven, where the best modeling for the beefburger of chicken in study was evaluated, comparing the results, considering this food as a half-infinite(1er object considered model) and,after that, considered the chicken beefburger as a plain plate in transient regimen in two distinct conditions: not considering and another model considering the contribution of the generation term, through the Criterion of Pomerantsev. The Sun, beyond life source, is the origin of all the energy forms that the man comes using during its history and can be the reply for the question of the energy supplying in the future, a time that learns to use to advantage in rational way the light that this star constantly special tax on our planet. Shining more than the 5 billion years, it is calculated that the Sun still in them will privilege for others 6 billion years, or either, it is only in the half of its existence and will launch on the Earth, only in this year, 4000 times more energy that we will consume. Front to this reality, would be irrational not to search, by all means technical possible, to use to advantage this clean, ecological and gratuitous power plant. In this dissertation evaluate the performance of solar cooker of the type box. Laboratory of Solar Energy of the Federal University of the Great River of North - UFRN was constructed by the group (LES) a model of solar stove of the type box and was tested its viability technique, considering modeling foods submitted when baking in the solar oven, the cooker has main characteristic the easiness of manufacture and assembly, the low cost (was used material accessible composition to the low income communities) and simplicity in the mechanism of movement of the archetype for incidence of the direct solar light. They had been proposals modeling for calculations of food the minimum baking time, considering the following models of transference of heat in the transient state: object the halfinfinite, plain plate and the model of the sphere to study the necessary temperature for the it bakes of bread (considering spherical geometry). After evaluate the models of transmission of heat will be foods submitted you the processes of to it bakes of, the times gotten for the modeling with the experimental times of it bakes in the solar oven had been compared, demonstrating the modeling that more good that it portraies the accuracies of the results of the model / O presente trabalho apresenta uma contribui??o no estudo de modelagens de transfer?ncia de calor para os alimentos submetidos aos testes experimentais no forno solar proposto, onde foi avaliada a melhor modelagem para o bife de frango em estudo, comparando os resultados, considerando este alimento como um objeto semi-infinito (1o modelo proposto) e, em seguida, considerou o bife de frango como uma placa plana em regime transiente em duas condi??es distintas: n?o considerando e outro modelo considerando a contribui??o do termo de gera??o, atrav?s do Crit?rio de Pomerantsev. O Sol, al?m de fonte de vida, ? a origem de todas as formas de energia que o homem vem utilizando durante sua hist?ria e pode ser a resposta para a quest?o do abastecimento energ?tico no futuro, uma vez que aprendamos a aproveitar de maneira racional a luz que esta estrela constantemente derrama sobre nosso planeta. Brilhando a mais de cinco bilh?es de anos, calcula-se que o Sol ainda nos privilegiar? por outros seis bilh?es de anos, ou seja, ele est? apenas na metade de sua exist?ncia e lan?ar? sobre a Terra, s? neste ano, 4000 vezes mais energia que consumiremos. Frente a esta realidade, seria irracional n?o buscar, por todos os meios tecnicamente poss?veis, aproveitar esta fonte de energia limpa, ecol?gica e gratuita. Na presente disserta??o avalia-se o desempenho de um fog?o solar do tipo caixa. Foi constru?do pelo grupo (LES) Laborat?rio de Energia Solar da Universidade Federal do Rio Grande do Norte - UFRN um modelo de fog?o solar do tipo caixa e foi testada a sua viabilidade t?cnica, propondo modelagens para alimentos submetidos ao assamento no forno solar o fog?o tem caracter?sticas principais a facilidade de fabrica??o e montagem, o baixo custo (foi utilizada material comp?sito acess?vel ?s comunidades de baixa renda) e a simplicidade no mecanismo de movimenta??o do prot?tipo para incid?ncia da luz solar direta. Foram propostas modelagens para c?lculos do tempo m?nimo de cozimentos de alimentos, considerando os seguintes modelos de transfer?ncia de calor no estado transiente: objeto semiinfinito, placa plana e o modelo da esfera para estudar a temperatura necess?ria para o assamento de p?o (considerando geometria esf?rica). Ap?s avalia??o dos modelos de transmiss?o de calor para os alimentos submetidos aos processos de assamento, foram comparados os tempos obtidos pelas modelagens com os tempos experimentais de assamento no forno solar, explicitando a modelagem que melhor retrata a acur?cia dos resultados do modelo

[pt] Esta dissertação tem por objetivo avaliar metrologicamente os resultados dos ensaios de rendimento e consumo em aparelhos domésticos de cocção a gás e sua influência na classificação do Programa Brasileiro de Etiquetagem desses aparelhos. A avaliação de conformidade e como as diferentes altitudes influenciam nos ensaios, acompanhadas de suas incertezas de medição, provêm de dados históricos do início do Programa Brasileiro de Etiquetagem em fogões e aos constantes questionamentos sobre a representatividade dos resultados dos planos interlaboratoriais, o que motivou a realização do estudo. A metodologia utilizada fundamentou-se em pesquisa bibliográfica, documental e experimental, que teve por finalidade coletar dados dos ensaios de rendimento e consumo em duas cidades com diferentes altitudes, discussão da norma com detalhamento dos algoritmos e tratamento estatístico dos dados coletados, onde a abordagem proposta se baseia na avaliação da normalidade, tratamento de outliers, cálculo do rendimento reportado a partir da medida de posição inversamente ponderada pela medida de dispersão de cada queimador e desenvolvimento dos algoritmos do cálculo de incerteza dos ensaios de rendimento e consumo. Neste cenário, os resultados mostram que a média aritmética, atualmente usada no cálculo do rendimento dos quatro queimadores da mesa do fogão, pode ser substituída pela média ponderada por variâncias estatisticamente não compatíveis entre si. Conclui-se que a incerteza dos ensaios do rendimento e consumo não foi suficiente para colocar em risco a mudança de faixa de classificação da etiqueta de eficiência energética do produto; entretanto, se observa uma diferença entre os resultados ao nível do mar e em altitude acima do nível do mar, o que sugere estudos futuros mais detalhados sobre os algoritmos de correção da grandeza altitude. / [en] This dissertation aims to metrologically evaluate the results of performance and consumption tests on domestic gas cooking appliances and their influence on the classification of the Brazilian Labelling Program for these appliances. The compliance assessment and how the different altitudes influence the tests accompanied by their measurement uncertainties come from historical data from the beginning of the Brazilian Labelling Program on stoves and from the constant questions about the representativeness of the results of the interlaboratorial tests, which motivated the realization of the study. The methodology used was based on bibliographic, documentary and experimental research, which aimed to collect data from income and consumption tests in two cities with different altitudes, discussion of the standard with details of the algorithms and statistical treatment of the collected data. The approach proposal is based on the evaluation of normality, treatment of outliers, calculation of the reported yield from the position measurement inversely weighted by the measure of dispersion of each burner and development of the uncertainty calculation algorithms of the performance and consumption tests. In this scenario, the results show that the arithmetic mean, currently used in the calculation of the performance of the four burners on the stove table, can be replaced by the weighted average by variances that are not statistically compatible with each other. It is concluded that the uncertainty of the efficiency and consumption tests was not enough to put at risk the change in the classification range of the energy efficiency label of the product. However, there is a difference between the results at sea level and at altitude above sea level, which suggests more detailed future studies on the altitude correction algorithms.