Eventos Anais de eventos
ENCIT 2020
18th Brazilian Congress of Thermal Sciences and Engineering
Experimental evaluation of the heat transfer coefficient for convective condensation inside a horizontal conventional-sized channel
Submission Author:
Tiago Augusto Moreira , SP
Co-Authors:
Tiago Augusto Moreira, Gherhardt Ribatski
Presenter: Tiago Augusto Moreira
doi://10.26678/ABCM.ENCIT2020.CIT20-0117
Abstract
In refrigeration applications such as air-conditioning, domestic and industrial freezers, refrigerators and vending machines the largest amount of mass inside the system is verified at the condenser. Therefore, attention should be given to the optimization of such component focusing on the reduction of the refrigerant load associated to the increase of the system efficiency. Such optimization is achieved using accurate prediction methods for the heat transfer coefficient, which development rely on extensive databases due to their semi-empirical nature. In the present study, experiments for the heat transfer coefficient for convective condensation were performed in a 9.43 mm inner diameter channel for the R134a. Data was obtained at a saturation temperature of 35°C with mass velocity varying from 100 to 400 kg/m2s, heat fluxes from 10 to 40 kW/m2 and vapor qualities up to the unity. In general, the heat transfer coefficient increases with increasing mass velocity and vapor quality (except for G=100 kg/m2s). A negligible effect of heat flux was verified independent of mass velocity. The experimental results were compared against prediction methods available in literature, and a reasonable agreement was found.
Keywords
Heat transfer coefficient, convective condensation, Two-phase Flow
DOWNLOAD PDF VIEW PRESENTATION
