Influence of Secondary Flow Generation on Heat Transfer inside the Fin Type Spiral Sub-Cooled Condenser by Experimental and CFD Analysis

摘要

This paper discusses the compact structure, innovative and unique approach of high performance spiral coil sub-cooled condenser for compact power plant/engine applications. The motivation behind this study is to reduce the engine emission by improving the coefficient of performance for air-conditioning unit. Since the air conditioning system is the most power consumption units after the power plant, so it significantly affects the fuel consumption and the hazardous gas emissions. In the air condition cycle, the condenser unit is addressed as one of the important devices, and thus, the author tried to reduce the energy consumption by improving the performance of the condenser. The most advantage points of this study is to use spiral coil sub-cooled condenser, which elaborates the effect of secondary flow generation inside the fluid and is known as the Dean’s effect. This results in the heterogeneous temperature distribution across the periphery of the tube and lead to a greater heat transfer. The heat transfer characteristics for the tube-fin type with spiral coil and square cross-section have been determined experimentally and then compared with of CFD analysis. During the bench tests, the experiments were performed at the various air velocities and the different mass flow rate of the refrigerant. The calorimeter was used to obtain the desired temperature along with the humidity level inside a control volume. These results showed that the spiral coil sub-cooled condenser provides to enhance the heat transfer characteristics on the refrigerant side. Additionally, the results from the CFD analysis revealed that the heat transfer coefficient for the spiral coil sub-cooled condenser on the refrigerant side was 1.96 times greater than the conventional type of sub-cooled condenser.