Heat Exchange from the Toucan Bill Reveals a Controllable Vascular Thermal Radiator

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Experimental analysis of heat recoveries with heat pipes operating in low inclination angle

Heat recovery devices are important in the optimization of thermal systems, since they can be used to reduce thermal losses to the environment. The use of heat pipes in these types of equipment can provide heat recoveries of higher efficiency, since both fluid flows are external and there are less contamination risks between the hot and cold fluids. The objective of this work is to study a heat recovery unit constructed with heat pipes and mainly, to analyze the influence of the inclination of the heat pipes on the performance of the equipment. For this analysis, a heat recovery unit was constructed which possesses 48 finned heat pipes in triangular geometry, the evaporator and condenser being of the same length. This unit was tested in an air-air system simulating a heat recovery process in which heat was supplied to the hot fluid by electrical resistances. The results have shown that there exists an inclination at which the system has a better performance, but for higher inclinations there is no significant increase of the efficiency of the system. This paper also presents the influence of inclination of heat pipes on effectiveness and NTU parameters which are important in heat exchanger design.

Tracheobronchial consequences of the use of heat and moisture exchangers in dogs

Purpose: To determine the effect of heat and moisture exchange (HME) on the tracheobronchial tree (TBT) using a unidirectional anesthesic circuit with or without CO2 absorber and high or low fresh gas flow (FGF), in dogs. Methods: Thirty-two dogs were randomly allocated to four groups: G1 (n = 8) valvular circuit without CO2 absorber and high FGF (5 L·min-1); G2 (n = 8) as G1 with HME; G3 (n = 8) circuit with CO2 absorber with a low FGF (1 L·min-1); G4 (n = 8) as G3 with HME. Anesthesia was induced and maintained with pentobarbital. Tympanic temperature (TT), inhaled gas temperature (IGT), relative (RH) and absolute humidity (AH) of inhaled gas were measured at 15 (control), 60, 120 and 180 min of controlled ventilation. Dogs were euthanized and biopsies in the areas of TBT were performed by scanning electron microscopy. Results: The G2 and G4 groups showed the highest AH (>20 mgH2O·L-1) and G1 the lowest (< 10 mgH2O·L-1) and G3 was intermediate (<20 mgH2O·L-1) (P < 0.01). There was no difference of TT and IGT among groups. Alterations of the mucociliary system were greatest in G1, least in G2 and G4, and intermediate in G3. Conclusion: In dogs, introduction of HME to a unidirectional anesthetic circuit with/without CO2 absorber and high or low FGF preserved humidity of inspired gases. HME attenuated but did not prevent alterations of the mucociliary system of the TBT.

Desenvolvimento de um circuito eletrônico experimental de anemômetro de fio quente

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reologia de vinhos tintos secos produzidos no Sul do Brasil

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Análise térmica de sistema de refrigeração direta em fermentadores cilindrocônicos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Equipamento de hipotermia para ser utilizado em tratamento muscular com lesões na fase aguda

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Desenvolvimento de um sistema de climatização via solo para galpões de frango de corte

Pós-graduação em Zootecnia - FCAV

Substituição do diesel usado nos queimadores industriais por álcool combustível

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise experimental e desenvolvimento de um modelo numérico simplificado para um trocador de calor compacto para resfriamento de componentes eletrônicos

Pós-graduação em Engenharia Mecânica - FEIS

Desenvolvimento experimental e simulação numérica de uma réplica térmica de placa de circuito impresso

Pós-graduação em Engenharia Mecânica - FEIS

Otimização ecológica dos ciclos ar-padrão Otto e Diesel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de cargas térmicas de uma aeronave e dimensionamento de um sistema de ar condicionado

This work deals with the thermal load study of a fictitious aircraft as well as scaling, in terms of the airflow and temperature of the air conditioning system, for heating and cooling of the its internal environment, aiming the thermal comfort of occupants. The first part is presented the techniques and methods utilized for modeling different heat exchanges that occur in the aircraft and then allowed to calculate the total heat load and the airflow and temperature necessary to comply with the requirements of the thermal comfort. Techniques to determine the basic parameters, as convection coefficient and global coefficient of heat exchange, are also presented. The work aims to develop a program, using a computational tool, to automate the calculations so that facilitate this study. It also allows to be used for other airplanes just changing parameters and the control variables related to the specific project. Finally the program performs calculations for a fictitious airplane, to analyze its functionality and the influence of parameters involved in the temperature controls. The program allowed analyzing the sensitivity of portions of the thermal load and the corresponding parameters of influence, as well as the scaling of the air conditioning in terms of airflow and temperature. It was considered, despite the simplifications, a good approximation to the actual values and then can be used in development of the other airplanes

Auditoria energética em caldeira de monóxido de carbono

Within the concepts of sustainability, energy audit magnified its importance in managing systems in industrial plants. Can reduce waste and save energy representative, the improvement and development of thermal and electrical systems can be very attractive to business. With the focus on a boiler generating steam, the energy audit aimed to increase efficiency and eliminate energy losses of the heat engine. The boiler in question is commonly called CO boiler because most of the calorific power provided comes from this. Using a fuel gas from the catalyst regeneration process, it has featured in the boiler power generation system of the refinery. Burning a mixture of gaseous components from discarded into the atmosphere, the heat engine can generate tons of steam just as the other boilers installed. The challenge was to work with this gas mixture and obtain maximum efficiency, reduce moisture and enjoy the warmth of the heat exchange have been studied and recommended. Every project, from evaluation of the variables in the composition of fuel gas, to the using of heat exchangers and refrigeration system are suitable for evaluation and improvements

Análise da troca de calor em sistemas de injeção de termoplásticos – um estudo de caso: polipropileno

The purpose of this work was to define the processes through which the cooling of thermoplastics parts occur inside the mold cavity in an injection process. The plastic materials have become more widespread in the automobile industry and, among its manufacturing processes, injection moulding develops quickly, allowing the manufacturing of quality parts in great volumes. Data was collected from the injection of Volkswagen Gol NF 23X (Gol Generation 5). Using approximated methods for calculation for the heat Exchange inside the mould, in the cooling system, the required water flow was determined to properly cool the parts. Comparing the obtained value with Project specifications, it was verified that the method, in spite of incurring in some mistakes, is efficient in determining the flow of cooling fluid and serves as a verification tool for the parameters defined on project, and can be applied to simple projects. The definition of the cooling system, in practice, is dependent on innumerable variables and each case must be approached in itself, since the parameters for one product may not be ideal for another