Energy efficiency analysis of the radiative transfer of a real medium in thermoforming. (March 2023)

• Record Type: Journal Article
• Authors: Hedfi, Hachem; Erchiqui, Fouad; Kocaefe, Yasar; Naji, Hassane
• Is Part Of: International communications in heat and mass transfer. Volume 142(2023)
• Publication Date: 2023-03
• Subjects: Thermoforming -- Radiative absorption -- Exponential wide-band model -- Direct area exchange -- Monte Carlo method; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Heat -- Transmission; Mass transfer; Periodicals; 621.4022
• DOI: 10.1016/j.icheatmasstransfer.2023.106664
• Languages: English
• ISSNs: 0735-1933

Abstract

Abstract: Thermoforming involves warming thermoplastics using infrared sources to a desired state in an open oven at atmospheric pressure. The prediction of the distribution of the flux intercepted by the thermoplastic is generally modeled by assuming the surrounding medium transparent. It is within this framework that the present work is placed while aiming at the influence of the temperature and the humidity of the ambient air ( gas ) on the intercepted energy. To do this, the wide-band model is used to characterize the absorptivity of air vs. the temperature and absolute humidity at atmospheric pressure. The energy efficiency of the radiation emitted by a halogen source and intercepted by a flat surface has been characterized using the temperature of the source and the surrounding environment, humidity, and distance. The temperature of the considered source range 600 K–1500 K, while that of the humid air is in the range 400 K–1000 K for an absolute humidity range 10–80%. The absorptivity of the real gas is modeled by that of a gray gas and the surface-to-surface and volume-to-surface exchange areas are assessed via the Monte Carlo method. From this study, it appears that the error induced by the transparent medium assumption depends on the distance ( between lamp and receiver ), the lamp temperature, the gas temperature, and its humidity.