Navegando por Assunto "Thermal comfort"

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Acesso aberto (Open Access)
Análise computacional dos campos de velocidade e temperatura do ambiente interno da usina termelétrica Santana - Amapá
(Universidade Federal do Pará, 2008-08-07) OLIVEIRA FILHO, Álvaro Henriques de; SAID, Mounsif; http://lattes.cnpq.br/8493361134195157
The numerical simulation of the airflow in internal environments is in the present time the most appropriate method for analysis of thermal comfort indoors. The airflow in these environments is configured as a complex one, therefore, in general, it is a combination of free-shear flow (jet) and of wall-shear flow, moreover, these are governed by inertia and buoyancy forces, characterizing a situation of mixing convection. The combination of these mechanisms creates an airflow with complex characteristics, as recirculation zones, vortices, detachment and re-attachment of boundary layer amongst others. Therefore, the precision of the solution will be directly connected, mainly, with the ability of the adopted turbulence model to reproduce the turbulent characteristics of the airflow and thermal transfers. The main objective of the present work was the computational simulation of the internal thermal environment of the enclosure which shelters the generators and the Wärtzilä engines of the thermo-electric power plant of Santana in the state of Amapá (Brazil). The mathematical formulation based on the solution of the general equations of conservation includes an analysis of the principal models of turbulence applied to the airflow inside the enclosure, as well as the heat transfer processes associated. The finite-volume numerical method is used in the discretization of the conservation equations, through the Fluent-Airpak software, for the analysis of the distribution of air velocity and temperature fields. The correct use of the software was tested and validated by successfully simulating problems solved by other authors. The numerical results of the airflow in the enclosure were compared with the experimental data and presented a good agreement, by considering the complexity of the simulated problem and the limitations and difficulties found during measurements. Moreover, simulations are presented of strategies for improvement of the thermal environment, based on the actual reality and on the results of the numerical simulations. Finally, simulations of a prototype solution are presented with the reduction of the internal temperature in the enclosure. This solution allows an increase of the exposure time inside the enclosure, from 20 up to 30%, and improves the thermal comfort of the thermo-electric power plant.
Acesso aberto (Open Access)
A redução do consumo de energia elétrica em Manaus através de medidas de eficiência energética em climatização industrial
(Universidade Federal do Pará, 2011-02-28) SILVA, Jorge Lúcio da; BARREIROS, José Augusto Lima; http://lattes.cnpq.br/1246564618922453
The dissertation has as objective that is to evaluate the consumption of industrial electric industries in the Pole of Manaus – AM (PIM), through using the electric optimizing efficient energy with (EE), with based models comparison in the consumption of electricity consumed by the PIM. The study was based in accordance with national rules of industrial climate control technical standards established. It also measures the (EE) since it was used through replacement of the air conditioners window style of low efficiency, for equipments of high performance. The use of estimated thermal loads resulted in the application of electrical measurements, in which were obtained by evaluating the EE that allowed us to find mechanisms of linguistic variables that solved and enhance the capabilities of air conditioners, where they controlled both simultaneously the temperature, humidity, movement, and the purification of indoor air with in the Brazilian Television industry (IBT)To minimize the costs, we made analysis of programmed actions with calculation by tools through inference that provided the followings results: Control of the external sources of hot or cold, and verification of losses in the pipes and also losses in the environments, and adjust the temperature of thermal comfort, Such as environment and system utilization, and utilization control system for optimum use of equipment with thermo bank accumulation of ice or water which (EE)Measures have to be quantified of their consumption and savings to reduce electricity demand In their actual impacts of the company.Being so the results permitted a reduction of saving cost near about R$ 14.299,73 in actual eight months studied and representing a percentage of 7.32% savings for the company in its energy consumption amounting to a cost of R $ 1,787.46 a month showing real satisfactory outcome within the costs set by the IBT.