This paper presents a methodology for obtaining the parameters of the equivalent circuit for an induction motor from the information on the nameplate and manufacturer catalog data sheet. The proposed method is straight and noniterative. The variation in rotor parameters for deep bars or double squirrel-cage rotors is modeled and presented as a function of […]
In an editorial of a recent issue of a known academic journal, Prof. Hartmut Michel affirmed that “…the production of biofuels constitutes an extremely inefficient land use… We should not grow plants for biofuel production.”, after comparing the area occupied with plants for bioenergy production with the one required for photovoltaic cells to supply the […]
A model proposal to determine the influence of wind over temperature measurements when conducting outdoor infrared (IR) themographic inspections is addressed in this paper. A wind velocity-dependent temperature reduction factor is developed and applied in order to estimate the target temperature in the absence of wind, which is considered as the worst case. The model […]
Liquid biofuels, as ethanol and biodiesel, supply 25% of the road transport fuel consumed in Brazil. Ethanol blending has been mandatory since 1931, pure ethanol has been used since 1975, and nowadays flex-fuel cars are widely used. In 2008, ethanol production reached 28 Mm³, but recently, government efforts to reduce gasoline prices have reduced the […]
This study aimed to evaluate the energy efficiency, thermal power and amount of volatiles released (CO2, CO and SO2) by three models of wood-metallic cookstoves into single-family residences in the city of Irati / PR, Brazil. All cookstoves had a low average energy efficiency from 2.9% ± 0.3 (stove 1), 2.6% ± 0.5 (stove 2) […]
Sugarcane produced in Brazil has several environmental advantages. However, burning residues, which leads to GHG and black carbon (BC) emissions, has been used to facilitate manual harvest. BC emissions have a net warming effect and cause health problems. Mechanized harvest without burning is gradually replacing manually harvested burned sugarcane. Global warming potential (GWP) and human […]
Increasing efficiency of electrical equipment is essential to national energy rationality, enabling energy consumption reduction and postponing inversion in distribution, transmission and generation, as well as mitigating environmental impacts associated with such activities. Considering such purposes, two actions have been promoted in Brazil: (a) minimum energy performance standards (MEPS) have been required for some appliances […]
A relevância da energia como um insumo para os processos produtivos é bastante conhecida. Sem energia, nada pode ser realizado, transportado ou processado. Sabe-se que boa parte da energia entregue às unidades produtivas é desperdiçada ou usada com baixa eficiência, sendo igualmente reconhecida a necessidade de se melhorar o rendimento dos processos energéticos no contexto […]
After decades of low cost energy, the oil shocks of the seventiesraised the price of energy and call the consumers attention to thelimits of conventional energy supply, fostering the increase of efficiency in energy systems and stimulating the development of avariety of new and alternative sources of energy. Then, between1985 and 2002 some years of […]
Desde 1995 o Brasil tem implementado o programa de etiquetagem energética Selo PROCEL para estimular os fabricantes a aumentarem a eficiência de muitos eletrodomésticos e equipamentos. Em 2003 os motores de indução começaram a receber o Selo PROCEL o que ajudou a ampliar a eficiência desses equipamentos devido aos limites de eficiência estabelecidos pelo programa […]