Modeling and experimental study of nucleate boiling on a vertical array of horizontal plain tubes
- Department of Mechanical Engineering, Escola de Engenharia de Sao Carlos (EESC), University of Sao Paulo (USP), Av. Trabalhador SanCarlense 400, Centro, Sao Carlos, SP (Brazil)
- Escola Politecnica Superior, Universidade da Coruna, Mendizabal s/n Esteiro, 15403 Ferrol, Coruna (Spain)
- Centro Federal de Educacao Tecnologica de Minas Gerais - CEFETMG, Unidade Divinopolis, R. Monte Santo, 319, Divinopolis, MG (Brazil)
An investigation of nucleate boiling on a vertical array of horizontal plain tubes is presented in this paper. Experiments were performed with refrigerant R123 at reduced pressures varying from 0.022 to 0.64, tube pitch to diameter ratios of 1.32, 1.53 and 2.00, and heat fluxes from 0.5 to 40 kW/m{sup 2}. Brass tubes with external diameters of 19.05 mm and average roughness of 0.12 {mu}m were used in the experiments. The effect of the tube spacing on the local heat transfer coefficient along the tube array was negligible within the present range of experimental conditions. For partial nucleate boiling, characterized by low heat fluxes, and low reduced pressures, the tube positioning shows a remarkable effect on the heat transfer coefficient. Based on these data, a general correlation for the prediction of the nucleate boiling heat transfer coefficient on a vertical array of horizontal tubes under flooded conditions was proposed. According to this correlation, the ratio between the heat transfer coefficients of a given tube and the lowest tube in the array depends only on the tube row number, the reduced pressure and the heat flux. By using the proposed correlation, most of the experimental heat transfer coefficients obtained in the present study were predicted within {+-}15%. The new correlation compares reasonably well with independent data from the literature. (author)
- OSTI ID:
- 21116047
- Journal Information:
- Experimental Thermal and Fluid Science, Vol. 32, Issue 8; Other Information: Elsevier Ltd. All rights reserved; ISSN 0894-1777
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of heat exchanger tube parameters on nucleate pool boiling heat transfer in a scaled IRWST
Pressure drop, heat transfer, critical heat flux, and flow stability of two-phase flow boiling of water and ethylene glycol/water mixtures - final report for project "Efficent cooling in engines with nucleate boiling."