| Autor: |
Anugrah, T. V., Venugopal, Akash, Abinadh, M. P., Abhijith, S., Kumar, S. Sunil |
| Předmět: |
|
| Zdroj: |
AIP Conference Proceedings; 2024, Vol. 3134 Issue 1, p1-10, 10p |
| Abstrakt: |
Air-cooled condensers are cooling systems used in refrigeration and air-conditioning systems to cool hot vapour refrigerants. They use fans to blow air over hot refrigerant at higher pressure, which absorbs latent heat of evaporation from refrigerants and increases sensible heat for the cross-flowing air stream. Fins are used to increase the rate of heat transfer from the condenser tubes to the surrounding air through convection. Wavy fins can reduce the size of the condenser due to the use of shorter tubes, as they have more heat transfer rate compared to rectangular fins. In the present work airflow across both plain fin and wavy fin geometries is numerically investigated using Ansys Fluent 2022 and determined air-side heat transfer coefficients for both the geometries. Inside (Refrigerant) heat transfer coefficients were determined by standard correlations available in the literature. The overall length of the condenser tube is determined by dividing it into three sections: the de-superheating section, the condensation section, and the sub-cooling section. Correlations from the literature are then applied to these sections at a standard refrigerant mass flow rate in a 1.5 TR system. The overall heat transfer coefficient is obtained by using the air side heat transfer coefficient obtained from the Ansys numerical model and refrigerant side heat transfer coefficient determined by using standard correlations. The outlet temperature of the first unit at the inlet is determined in the first iteration and the inlet temperature of the next unit is assumed to be the outlet temperature of the preceding unit. The sum of the length of all three sections gives the overall condenser tube length. The calculations are done up to the saturation temperature while sizing the de-superheating section and a sub-cooling temperature of 5℃ is considered while sizing the sub-cooling section. The numerical model is validated with the experimental results available in the literature by comparing the air side heat transfer coefficient against various flow Reynolds numbers. The temperature plot and the velocity plots of the rectangular fin and wavy fin are compared. The condenser tube length obtained for wavy fin geometry is found to be considerably shorter than that containing rectangular fins for the same heat load. Hence the use of wavy fins over rectangular fins brought several advantages such as shorter condenser tube length, efficient heat transfer process, and lower cost of manufacture. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
