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Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural

Abstract

A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, and dimensional parameters of the convection. The results showed that the highest heat transfer value occurred when both a specific position and a specific channel opening were used. The experiments pointed out that the radiation contribution must be considered in heat transfer calculations. The conclusions showed that different channel openings can improve the heat transfer  More>>
Publication Date:
Jul 01, 1997
Product Type:
Thesis/Dissertation
Report Number:
ETDE-BR-0198
Reference Number:
EDB-01:043379
Resource Relation:
Other Information: TH: Tese (Ph.D.); 136 refs., 122 figs., 14 tabs.; PBD: 1997
Subject:
42 ENGINEERING; NATURAL CONVECTION; HEAT EXCHANGERS; TEMPERATURE DEPENDENCE; OPTIMIZATION; FREEZERS; EMISSIVITY; THERMAL RADIATION; THERMAL TESTING; SIMULATION; EXPERIMENTAL DATA
OSTI ID:
20128694
Research Organizations:
Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia
Country of Origin:
Brazil
Language:
Portuguese
Other Identifying Numbers:
TRN: BR01E0885
Availability:
Available to ETDE participating countries only(see www.etde.org); commercial reproduction prohibited; OSTI as DE20128694
Submitting Site:
BR
Size:
193 pages
Announcement Date:

Citation Formats

Rocha, Alan Carlos Bueno da. Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural. Brazil: N. p., 1997. Web.
Rocha, Alan Carlos Bueno da. Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural. Brazil.
Rocha, Alan Carlos Bueno da. 1997. "Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural." Brazil.
@misc{etde_20128694,
title = {Analysis and optimization of the heat transfer coefficient of a finned heat exchanger submitted to natural convection; Analise e otimizacao do coeficiente de transferencia de calor de um trocador aletado submetido a conveccao natural}
author = {Rocha, Alan Carlos Bueno da}
abstractNote = {A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, and dimensional parameters of the convection. The results showed that the highest heat transfer value occurred when both a specific position and a specific channel opening were used. The experiments pointed out that the radiation contribution must be considered in heat transfer calculations. The conclusions showed that different channel openings can improve the heat transfer coefficient in this heat transfer exchanger. (author)}
place = {Brazil}
year = {1997}
month = {Jul}
}