Published 8 issues per year
ISSN Print: 1065-5131
ISSN Online: 1563-5074
Indexed in
FALLING FILM EVAPORATION OF PURE REFRIGERANT HCFC123 IN A PLATE-FIN HEAT EXCHANGER
ABSTRACT
In the present study, the characteristics of heat transfer and flow patterns are investigated experimentally for the falling film evaporation of pure refrigerant HCFC123 in a vertical rectangular channel with a serrated-fin surface. The refrigerant liquid is supplied to the channel through 37 holes of a distributor. The liquid flowing down vertically is heated electrically from the rear wall of the channel and evaporated. To directly observe the flow patterns during the evaporation process, a transparent vinyl chloride resin plate is placed as the front wall. The experimental parameters are as follows: the mass velocity G = 28−70 kg/(m2·s), the heat flux q = 20−50 kW/m2, and the pressure P ≈ 100 kPa. It is clarified that the heat transfer coefficient α depends on G and q in the region of vapor quality x ≥ 0.3 while there is little influence of G and q in the region x ≤ 0.3. From the direct observation using a high-speed video camera and a digital still camera, flow patterns are classified into five typical patterns: plane liquid film, wavy liquid film, liquid film accompanied with a dry patch, liquid film accompanied with dripping, and liquid film accompanied with mist. Then the relation between heat transfer and flow pattern is clarified. The results of heat transfer characteristics are also compared with some previous correlation equations.
-
Zhou Yuanyuan, Yu Jianlin, Numerical Analysis of Heat Transfer Characteristics of a Falling Film Type Plate-Fin Condenser/Reboiler, Journal of Heat Transfer, 138, 8, 2016. Crossref
-
Saha Sujoy Kumar, Ranjan Hrishiraj, Emani Madhu Sruthi, Bharti Anand Kumar, Round Tubes Having Plain-Plate Fins, in Heat Transfer Enhancement in Externally Finned Tubes and Internally Finned Tubes and Annuli, 2020. Crossref
-
Zhou Yuanyuan, Yu Jianlin, Gao Ming, An experimental study of falling film evaporation in vertical channels with perforated fins of a plate-fin heat exchanger, Chemical Engineering and Processing - Process Intensification, 145, 2019. Crossref
-
Li Xiaohuan, Fang Xiande, Luo Zufen, Xu Lu, Shang Hongfeng, A New Correlation of Heat Transfer Coefficients for Flow Boiling in Serrated Channels, Journal of Thermal Science and Engineering Applications, 14, 4, 2022. Crossref
-
Ohara Junichi, Evaporation Heat Transfer of HFO-1233zd (E) in Falling Film Type Plate-fin Evaporator, Marine Engineering, 56, 3, 2021. Crossref