ABSTRACT In this study, soybean biodiesel and mixtures with diesel are used as fuel in a diesel engine that drives a centrifugal pump. The consumption useful work rate, the reversible work rate, and the efficiency of the second law of thermodynamics were calculated by means of energetic and exergetic analyses. The soybean biodiesel was produced using ethanol with a proportion of 33% v/v and the catalyst NaOH (1%), thus obtaining a yield of 90,63%. The fuels used were pure diesel (B0); 25% soybean biodiesel and 75% diesel (B25); 50% soybean biodiesel and 50% diesel (B50); 75% soybean biodiesel and 25% diesel (B75); and soybean biodiesel (B100). The density and kinematic viscosity were within the limits established by the National Petroleum, Natural Gas, and Biofuels Agency. A value of 39 017 kJ.kg-1 was obtained for the highest heating value of the soybean biodiesel (B100). A 32,05% maximum second-law efficiency was obtained in the case of soybean biodiesel at maximum pump speed and at 9,2 m2/h. The B50 fuel obtained a 29,78% maximum second-law efficiency when the centrifugal pump operated at 2 733 rpm and at a maximum flow rate.

RESUMEN En este estudio se utilizan el biodiésel de soya y mezclas con diésel como combustible en un motor diésel que impulsa una bomba centrífuga. La tasa de trabajo útil de consumo, la tasa de trabajo reversible y la eficiencia de la segunda ley de la termodinamica se calcularon mediante análisis energético y exergético. El biodiésel de soya se produjo utilizando etanol en la proporción de 33 % v/v y el catalizador NaOH (1 %), obteniendo un rendimiento de 90,63 %. Los combustibles utilizados fueron diésel (B0); 25 % de biodiésel de soya y 75 % de diésel (B25); 50 % biodiésel de soya y 50 % de diésel (B50); 75 % de biodiésel de soya y 25 % de diésel (B75); y biodiésel de soya (B100). La densidad y la viscosidad cinemática estuvieron dentro de los límites establecidos por la Agencia Nacional de Petróleo, Gas Natural y Biocombustibles. Se obtuvo un valor de 39 017 kJ.kg-1 para el mayor poder calorifico del biodiésel de soya (B100). Se obtuvo 32,05 % de eficiencia máxima de la segunda ley en el caso del biodiésel de soya a la máxima velocidad de bombeo y a 9,2 m2/h. El combustible B50 obtuvo 29,78 % de eficiencia máxima de la segunda ley cuando la bomba centrífuga operó a 2 733 rpm y al caudal máximo.

Visando uma análise da evolução microestrutural e da resistência à corrosão do metal de solda em aço AISI 317L, obtido pelo processo GTAW, realizou-se a avaliação do efeito de exposições prolongadas a 550°C, através de tratamentos térmicos por 200h, 300h e 400h. Após cada tratamento foi efetuada uma caracterização microestrutural por microscopia eletrônica de varredura (MEV). Em seguida, foram realizados testes de polarização eletroquímica de reativação cíclica (PERC), para avaliar o grau de sensitização das amostras. Os resultados obtidos indicaram que o aumento do tempo de exposição promoveu a formação progressiva de fases intermetálicas, comprometendo a resistência à corrosão intergranular do metal de solda. Tais resultados contribuirão para uma melhor previsão do comportamento de soldas em aço AISI 317L, durante a operação dos equipamentos da indústria de processo.

Aiming at an analysis of the microstructural evolution and corrosion resistance of the weld metal in steel AISI 317L, obtained by GTAW process, conducted to evaluate the effect of prolonged exposure at 550 ° C by thermal treatment for 200h, 300h and 400h. After each treatment microstructural characterization was performed by scanning electron microscopy (SEM). Double loop electrochemical polarization reactivation tests (DL-EPR) were performed to evaluate the degree of sensitization of the samples. The results indicated that increasing the exposure time at 550 ºC promoted the progressive formation of intermetallic phases, which caused corrosion decay of the weld metal. These results contribute to a better prediction of the behavior of AISI 317L welded joins during operation of the process equipment industry.

The ability of Monte Carlo simulation and Latin Hypercube Sampling methods in estimating the productivity of the Shielded Metal Arc Welding (SmAW) applied in works of industrial piping assembly based on small samples is evaluated. The study was conducted by analyzing a sample collected from assembly operations done at refinery Duque de Caxias, Rio de Janeiro in Brazil. The ControlTub 5.3 software was used for data acquisition and MathWorks in the simulation step. For data analysis the results were compared using the proposed simulation methods. Then the similarities and differences between the methods to estimate the process productivity in analysis were evaluated. The results demonstrated the feasibility of applying the methods of Monte Carlo Simulation and Latin Hypercube Sampling in estimating productivity considering a welding process of industrial pipes.

Se evalúan los métodos de simulación de Monte Carlo e Hipercubo Latino para estimar la productividad del proceso de soldadura eléctrica por electrodo revestido (shielded metal arc welding) en las obras de montaje de tuberías industriales considerando pequeñas muestras. El estudio se realizó mediante el análisis de una muestra recogida en el ámbito de las obras en la Refinería Duque de Caxias, Estado de Río de Janeiro en Brasil. Se utilizó el programa ControlTub 5.3 para la adquisición de los datos y el programa de MathWorks para la simulación, Para el análisis de los datos se comparó los resultados obtenidos mediante los métodos estudiados. Posteriormente, se evaluaron las similitudes y diferencias entre estos métodos en la estimación de la productividad del proceso. Los resultados demostraron la viabilidad de aplicar los métodos de simulación de Monte Carlo e Hipercubo Latino en la estimación de la productividad en el proceso de soldadura de tuberías industriales.