Heat Exchangers
Mostrando 25-36 de 98 artigos, teses e dissertações.
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25. CFD analysis of the pulverized coal combustion processes in a 160 MWe tangentially-fired-boiler of a thermal power plant
The strategic role of energy and the current concern with greenhouse effects, energetic and exergetic efficiency of fossil fuel combustion greatly enhance the importance of the studies of complex physical and chemical processes occurring inside boilers of thermalpower plants. The state of the art in computational fluid dynamics and the availability of commer
Journal of the Brazilian Society of Mechanical Sciences and Engineering. Publicado em: 2010-12
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26. Estimation of effective thermal conductivity enhancement using foam in heat exchangers based on a new analytical model
Thermal performance of open-cell metal foam has been investigated under low Reynolds number by comparing the heat transfer coefficient and thermal conductivity for the flow through a packed channel of high porosity metal foam to that of an open channel. In the case of Al-Air at porosity 0.971, the ratio of heat transfer coefficients is estimated to be 18.5 w
Brazilian Journal of Chemical Engineering. Publicado em: 2010-03
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27. Estudo comparativo entre sistemas de regaseificação de gás natural líquido / Comparative Study between liquid natural gas regasification systems
Este trabalho apresenta um estudo comparativo entre quatro sistemas de regaseificação de gás natural líquido. Os sistemas de regaseificação baseados em trocas térmicas com água do mar e com produtos de combustão de gás natural, utilizados industrialmente, são apresentados e discutidos. Outros dois sistemas alternativos são apresentados, um deles
Publicado em: 2010
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28. Evaluating humidity recovery efficiency of currently available heat and moisture exchangers: a respiratory system model study
OBJECTIVES: To evaluate and compare the efficiency of humidification in available heat and moisture exchanger models under conditions of varying tidal volume, respiratory rate, and flow rate. INTRODUCTION: Inspired gases are routinely preconditioned by heat and moisture exchangers to provide a heat and water content similar to that provided normally by the n
Clinics. Publicado em: 2009-06
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29. Optimal paths for minimizing lost available work during heat transfer processes with a generalized heat transfer law
A common of finite-time heat transfer processes between high- and low-temperature sides with a generalized heat transfer law [q ∝ (Δ(Tn ))m] are studied in this paper. The optimal heating and cooling configurations for minimizing lost available work are derived for the fixed initial and final temperatures of the working fluid of the system (low-temperatur
Brazilian Journal of Physics. Publicado em: 2009-03
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30. Transferencia de calor em um regenerador rotativo com perda de carga estabelecida nos dutos da matriz / Heat transfer in a rotary regenerator with fixed pressure drop
Heat transfer from a rotary regenerator subject to constant pressure drop constraints was examined. The optimal porosity and the corresponding maximum heat transfer were obtained considering smooth and equilateral triangular matrix ducts. The fluid flow and the heat transfer coefficient were obtained from correlations taking into account the matrix ducts ent
Publicado em: 2009
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31. Maximum power, ecological function and efficiency of an irreversible Carnot cycle: a cost and effectiveness optimization
In this work we include, for the Carnot cycle, irreversibilities of linear finite rate of heat transfers between the heat engine and its reservoirs, heat leak between the reservoirs and internal dissipations of the working fluid. A first optimization of the power output, the efficiency and ecological function of an irreversible Carnot cycle, with respect to:
Brazilian Journal of Physics. Publicado em: 2008-12
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32. Eficiência térmica de trocadores de calor compactos através de simulação numérica / Thermal efficiency of compact heat exchangers by numerical simulation
Um novo método numérico, para o cálculo da performance térmica de trocadores de calor com fluxos cruzados é apresentado. Dados referentes a efetividade - número de unidades de transferência (épsilon- NUT) para vários arranjos de escoamento, padronizados e complexos, foram obtidos usando esta metodologia. Os resultados foram validados através da com
Publicado em: 2008
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33. Study of hydrodynamics and heat transference from liquid whole egg through plate with three formats chevron / Estudo da hidrodinamica e transferencia de calor do ovo integral liquido atraves de placas com tres formatos chevron
At this work are showed the heat transference and hydrodynamics of liquid egg flow between ducts with corrugated walls, simulating plate heat exchangers. The contour conditions admitted was the constant temperature in the walls during the fluid heating. The whole egg rheology was experimentally determinated in a extend temperature range (289 ? 335K). The egg
Publicado em: 2008
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34. Inspeção de feixes tubulares de trocadores de calor
Decisions making related to the physical conditions of tubular bundles of heat exchangers involves an important subjective aspect due to the intrinsic difficulty of inspection of those components promoted by the complex lay-out of its tubes and consequent lack of visual access. Therefore, it is not unusual to occur failure of those equipments during the camp
Publicado em: 2008
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35. Efeitos dos filtros trocadores de calor e umidade sobre a mecânica respiratória / Effects of the heat and moiusture exchangers filters on respiratory mechanics
Os filtros HME são dispositivos que combinam propriedades de umidificação com propriedades de retenção bacterianas através de membranas que, desta forma, protegem pacientes mecanicamente ventilados. Objetivou-se analisar, em um modelo experimental, os efeitos de diferentes marcas de filtros HME, em diferentes tempos de uso, sobre a mecânica respirató
Publicado em: 2008
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36. Análise da prestação de serviços de caldeiraria na paradas programadas de manutenção de plantas industriais da refinaria Landulpho Alves: RLAM.
Maintenance turnarounds on industrial plants is an activity that strongly influences the business results of an oil refinery. So, the management of turnarounds should be analyzed under a strategic approach. Among the activities of maintenance that are carried through during a turnaround, the most important involve maintenance jobs on static equipments such a
Publicado em: 2008