Numerical Analysis of the Thermal Performance in Traditional and Developed Shapes of Thermosyphon

Abstract

In recent years, the research in renewable energy is remarkably increased to reduce the reliance on fossil fuels. Solar energy took the lead among the other sources of renewable energy due to its availability everywhere and the feasibility of its use for various circumstances. Thermosyphon is one of the most successful systems for solar energy conversion. In the present study, a CFD code is employed to analyze the natural convection phenomenon which is inherent in the performance of a thermosyphon system. A steal pipe of 25 mm internal diameter and 1250 mm length is considered as the condenser of the thermosyphon. Water jacket is used to cool the condenser with an internal diameter that is five times that of the condenser. Two types of pipes are considered in the present study, namely; straight and helical pipes. The case of helical pipe assumes five different numbers to turns, which are; 10, 20, 30, 40 and 45 turns. A solar heat flux of 500 W/m2 and above is used in the analysis. The results obtained from the numerical analysis showed that the helical pipe is more efficient than the straight pipe in heating the water inside the condenser jacket for the same operating conditions. The ratios of increase in jacket water temperature of the five cases of the helical pipe to that of the straight pipe were 23.8%, 36.5%, 42.1%, 45.3% and 46.2%, respectively.