Comparison of different modeling approaches for minichannel evaporators under dehumidification

• Published in: Heat and mass transfer 2019-10, Vol.55 (10), p.2901-2919
• Main Authors: Hassan, Abdelrahman Hussein, Martínez-Ballester, Santiago, Gonzálvez-Maciá, José
• Format: Article
• Language: English
• Subjects: Air temperature; Carbon dioxide; Comparative studies; Dehumidification; Engineering; Engineering Thermodynamics; Evaporation; Evaporators; Heat and Mass Transfer; Industrial Chemistry/Chemical Engineering; Latent heat; Original; Thermodynamics
• ISSN: 0947-7411; 1432-1181
• DOI: 10.1007/s00231-019-02622-0

This paper firstly presents a comprehensive minichannel evaporator model (MCHX-1D-MB) based on fin theory coupled with the moving boundary technique along fin height. To validate the presented model, experimental data for R-134a and R-744 (CO 2 ) minichannel evaporators were used. The proposed model successfully predicted the cooling capacity of R-134a and CO 2 evaporators with mean absolute error values of ±1.8 and ± 4.3%, respectively. Regarding the outlet air temperature, the mean absolute errors in the estimated results were ± 0.43 and ± 0.9 °C for R-134a and CO 2 evaporators, respectively. Finally, to evaluate the impact of widely used assumption of cut fin on the air-side performance of minichannel evaporators, another model was developed (MCHX-1D-CF). The comparative study revealed that the most remarkable deviations between the two models appear when the evaporator operates under partially wet conditions, which were up to ≈12% in the latent heat transfer rate.