Avaliação energética de um sistema de refrigeração por absorção utilizando gás de aterro e gás natural

The current technological development made by the absorption refrigeration system is an economic and ambient alternative in comparison to the vapor cycle, possessing an advantage that uses thermal energy that is less noble. Chillers of absorption are used widely in the air conditioned industries, because they can be set in motion through hot water vapors that burn natural gas, solar energy, biomasses amongst others instead of electricity. These systems allow it to reduce the tips of electric demand and balance the rocking of energy demand. This work has had a main objective to simulate a absorption refrigeration cycle with lithium-water bromide solution using biogas of sanitary landfill, and mixtures of this with natural gas. These results shown to the energy viability of the system burning biogas and its mixtures with natural gas in the generator, when compared with equipments that uses traditional fuels (natural gas, oil diesel, amongst others), for operation the commercial chillers with 15 kW of the refrigeration capacity and temperature of the water in the entrance of 14°C and the exit of 7°C.

Um novo sistema de refrigeração com controle de temperatura, compressor aberto, máquina de indução trifásica com velocidade variável e correção ativa do fator de potência do estágio de entrada

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise térmica de sistema de refrigeração direta em fermentadores cilindrocônicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Modelagem e simulação numérica de um sistema de refrigeração por absorção utilizando o par H2O-LiBr

The term refrigeration solar refers to any air conditioning system that uses solar energy as a primary energy source. The use of solar radiation for cooling purposes is divided according to their technological possibilities which are distinguished from one another as the way that energy is involved in the cycle, work or heat. The first case is related to vapor compression cycles, in which the work input is provided by the photovoltaic conversion of solar energy into electrical energy. In the second case, an absorption refrigeration cycle is used and the thermal energy collected from the solar radiation is provided at the generator of this cycle.. In this work a system with an absorption cycle using the pair BrLi-water, using solar energy as input is modeled. It is considered a simple refrigeration cycle whose the equations of mass and energy conservation in each component are developed in order to obtain an algebraic equation set and a simulation routine using the EES software. Although the simulation operates under certain specified thermal load it is possible to estimate the necessary areas of heat exchangers and solar collectors

Modelagem e avaliação de um sistema de refrigeração por absorção para residências e instalações de pequeno porte

This work presents a study of the absorption refrigeration system and the modeling and evaluation of two cycles using the binary solutions water-lithium bromide and ammonia-water for an equipment to be used in small size plants like residences. The study and evaluation aims the complete understanding of all parts of the system and the influence of each one of them as well as the spread of the knowledge to raise the use of this type of equipment in all sizes in order to decrease the energetic consumption of plants of all scales and making viable the alternative sources. The study is done in each element of the cycle separately and in some auxiliary equipments required in the operation such as the main power source, the solar collector. The software used for modeling, with emphasis on thermal part, was the EES (Engineering Equation Solver), that permitted the thermal balance calculus and acquisition of the used fluids properties. The results obtained for the equipment shows the system is more complex than the widely used in business, however, it can be viable and represents an alternative to increase the energetic efficiency

Validação de sistema automatizado de refrigeração e congelação de sêmen ovino

Pós-graduação em Medicina Veterinária - FMVZ

Eficiência energética em sistemas de refrigeração industrial: estudo de caso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Eficiência energética aplicada na indústria de bebidas em sistemas de refrigeração e ar comprimido: estudo de casos

Pós-graduação em Engenharia Mecânica - FEG

Determinação da entropia de mistura amônia e água para aplicações em processos de refrigeração por absorção

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise exergética e ecológica de um sistema compacto de cogeração operando com gás de síntese

The aim of this work is to make a qualitatively and ecologically evaluation of a compact cogeneration system that operates with synthesis gas obtained from a gasifier. Using the Eucalyptus Biomass as fuel, that passes through a wood gasifier (Drowndraft type) and supply the internal combustion engine. The compact cogeneration system is composed of two heat exchangers, an energy generator connected to an internal combustion engine and an absorption refrigeration system. The complete system is installed in the laboratory from the Energy Department at the University of Guaratinguetá. By the analysis related to the First and Second Thermodynamic Laws applied in this system, was possible to identify the mass flows in each point, energetic efficiency, irreversibility and exergetic efficiency. The components that have the biggest irreversibilities are the gasifier, followed by the internal combustion engine, which should be focused in future improvements. The system efficiency in energetic basis is 51,84% and in exergetic basis is 22,78%. Using the ecologic efficiency methodology was possible to identify the emissions rates, the pollution indicator associated to the combustion of the synthesis gas in the internal combustion engine. The ecologic efficiency considering the energectic analysis is 91,73%, while considering the exergetic analysis, 83,65%. It is concluded that the use of the synthesis gas in a compact cogeneration system is viable from the technical and ecological point of view, making possible to generate energy for isolated communities and promoting the decentralized electricity generation

Comparação de modelos de custo dos produtos gerados em uma central de cogeração

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo da resistência ao desgaste e à corrosão de revestimentos metálico-cerâmicos aplicados na liga AA7050 mediante aspersão térmica oxicombustível de alta velocidade (HVOF)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Código computacional para análise de sistemas de cogeração com turbinas a gás

Pós-graduação em Engenharia Mecânica - FEG

Mapeamento energético de um edifício corporativo

Increasingly the business for large companies tend to sustainable actions. Such actions may have motivated social, environmental and economical too. Thus, the study of small actions or investments aimed at improving a product or a process may impact on financial return and even the exposure of a sustainable paper company, a fact that is increasingly wel l regarded in the market. This study presents proposals raised in the market and in the literature showing the cost of each investment, the payback over time and the benefits of each project to be implemented in a corporative building located in the city of São Paulo. It was analyzed the energy consumption, determining the amount of consumption of each device through measurement of some parameters such as voltage and operating current, and lifting nominal values supplied by the manufacturers. By understanding the conditions of each equipment and the processes involved, were raised possible energy improvements, focusing on the cooling system of the building, the tariff system and the installation of an energy management system

Avaliação do potencial de microgeração em despacho econômico para atendimento aos requisitos de etiquetagem de edifícios

The discussions about the energy rationalization are gaining more and more space on the everyday of engineers and other professionals in the field of energy. A greater focus is being tied to commercial buildings, because they are one of the biggest responsible for the high energetic expenditure according to the National Energetic Balance, especially by the use of air conditioners for the people’s thermal comfort. Such finding made INMETRO to develop a building labeling procedure through th National Program of Electric Energy Conservation in Buildings; by means of this systematic, the built areas are classified by levels that go from A(the best) to E(the worst), taking into account envelopment, illumination system and air conditioning. A bonus process based on water rationalization, use of renewable energy sources, cogeneration systems or technical innovations, allows the classification to be changed up to one level. A study made exactly on a commercial building, the building of Foundation for Technological and Scientific Development located inside of the College of Engineering of Guaratinguetá, sought to identify technical/economic alternatives for the building certification and appealed to the bonus based on water rationalization. The present study is based on analysis of deploying a cogeneration system formed by internal combustion engine and an absorption refrigeration system as bonus alternative, so that the costs are analyzed regarding energy consumption and use of the motor. With the calculations and results, the viability of the building to receive a bonus from INMETRO through its National Program for Energy Conservation in Buildings is studied and concluded from this study whether or not you can get a better level of energy efficiency for the building in question... (Complete abstract click electronic access below)