Chair:
Edson Bazzo
Departamento de Engenharia Mecânica
Universidade Federal de Santa Catarina
Luís E. Saraiva -
saraiva@upf.tche.br
Universidade de Passo Fundo,
Faculdade de Engenharia e Arquitetura
Campus Bairro São
José - 99001-970 - Passo Fundo - RS
Kamal A.R. Ismail - kamal@fem.unicamp.br
Universidade Estadual de
Campinas, Faculdade de Engenharia Mecânica, DETF
Cidade Universitária
Zeferino Vaz - 13083-970 - Campinas - SP
A non-tapered (internally cylindrical) axially rotating heat pipe is numerically studied. The governing equations for vapor and liquid flow through porous medium are simultaneously solved by the SIMPLE method. Temperature, pressure, axial, radial and tangencial velocities profiles are presented in terms of parameters like heat transfer rate and rotational speed.
Keywords: Rotating
heat pipes, Rotating flow, Phase change heat transfer.
PERFORMANCE ANALYSIS OF CAPILLARY PUMPS INTEGRATED TO FLAT SOLAR COLLECTORS
Edson Bazzo - ebazzo@emc.ufsc.br
Fernando Marcelo Pereira
Luciano Heinen
Gabriel I. Medina Tapia
- gabriel@emc.ufsc.br
Universidade Federal de
Santa Catarina
Departamento de Engenharia
Mecânica
88.040-900, Florianópolis
- SC
This paper presents the thermal
performance of a circumferentially grooved capillary pump integrated into
a solar plate collector. Experimental results are obtained for a solar
heating system in small scale, consisting of a circumferentially grooved
capillary pump mounted on a copper flat plate of 46 cm length and 6 cm
width. Tests carried out in the laboratory showed good agreement with theoretical
results, found out from analytical and numerical models. Heat loads capacities
up to 500 W/m 2 are expected.
Paulo Couto - couto@labsolar.ufsc.br
Federal University of Santa
Catarina - Department of Mechanical Engineering
P.O. Box 476 - Trindade
- 88040-900 - Florianopolis - SC - Brazil
Marcia B. H. Mantelli - marcia@labsolar.ufsc.br
Federal University of Santa
Catarina - Department of Mathematics
P.O. Box 476 - Trindade
- 88040-900 - Florianopolis - SC - Brazil
Cryogenic heat pipe is one of the satellite thermal control device, which is used mainly for the thermal control of optical surfaces, infrared scanning systems, or large super-conducting magnets in the space environment. Actually, researches are being conducted in including other applications of cryogenic heat pipes, such as the cooling of electronic de-vices, particularly in microgravity environments. The technology of cryogenic heat pipes is now under investigation on the Satellite Thermal Control Laboratory of the Federal Univer-sity of Santa Catarina. This paper presents a review of the cryogenic heat pipes researches available in the literature. A review of ground testing and microgravity experiments is pre-sented as well as their contributions.
Keywords: Heat Pipe, Cryogenics,
and Satellite Thermal Control.
Marco A. W. Cavalcanti -
cavalcanti@les.ufpb.br
Universidade Federal da
Paraíba, Laboratório de Energia Solar, CT/ CPGEM - DTM
Cx. P. 5115, CEP 58051-970,
João Pessoa, PB, Brasil
Valérie Sartre - sartre@genserver.cethil.insa-lyon.fr
Monique Lallemand - m.lal@genserver.cethil.insa-lyon.fr
INSA de Lyon, CETHIL - Equipe
Energétique et Thermique, UPRES A CNRS 5008, Villeurbanne, France
An experimental study is developed on the performance of a cylindrical two-phase closed thermosyphon, of the type Cu-R113, filled at 100 % of evaporator volume, operating at optimal inclination and vertical position. The optimal angle was previously determined by an experimental study. Four operating temperatures are investigated (60, 70, 80 e 90 ºC) and the power supplied at the evaporator is between 600 and 2200 W. The condenser and evaporator thermal performances are analyzed by the heat transfer coefficients evaluation on the condenser and evaporator as function of the thermal power. Finally, the thermosyphon global performance is analyzed by the global thermal resistance evaluation. Vertical and optimal inclination results are compared for operating temperature of 80 ºC.
Keywords: Two-phase thermosyphon,
Optimal angle, Condensation, Thermal resistance, Experimental study
STEADY STATE SIMULATION OF HEAT PIPES IN CRITICAL CONDITIONS OF HEAT FLUX AND ROTATION
Humberto Araujo Machado -
machado@univap.br
Universidade do Vale do
Paraíba, UNIVAP - IP&D
Av Shishima Hifume, 2911,
12244-000, São José dos Campos, SP, Brazil
Ricardo Fortes de Miranda-
rfmiranda@mecanica.ufu.br
Universidade Federal de
Uberlândia, Faculdade de Engenharia Mecânica
Campus Santa Mônica,
bloco 1M, 38400-902, Uberlândia, MG, Brazil.
Rotating circular heat pipes
have some important applications, as electric engines cooling, turbine
thermal control, etc. The effect of rotation in its work becomes important
in both critical cases, when the angular velocity or heat flux are too
large, compared to the heat transfer and fluid flow scales. In this work,
a steady rotating cylindrical heat pipe is simulated through the finite
volume method, coupling the vapor zone and porous media. Several values
for angular and linear Reynolds number, as functions of angular velocity
and heat flux, respectively, are showed, as well the effects of such variation
in the streamlines of the whole heat pipe dominium. A limit for heat pipe
operation, taking into account the losses
of heat exchange capacity,
is presented as a curve related to the Reynolds numbers, which can be useful
for heat pipe design.
Keywords: Rotating heat pipes,
Finite volume, Phase change in porous media