BSc Thesis

"Heat Transfer Characteristics of Closed Loop Heat Pipe for Different Working Fluid & Fill Ratio"

Bachelor of Science Thesis Work (2021)

Abstract

Pulsating heat pipes (PHP) have created a newer arena and promising possibilities as passive devices for heat transfer applications, especially suited for thermal management of electronics. One of the main problems faced in the thermal management of modern small-scale electronic devices is that they have very high-power density resulting in higher heat dissipation rate. Pulsating heat pipes (PHP) can be installed inside the motherboard which can remove almost 100% of the dissipated heat. This study focuses on the effect of the filling ratio at different heat inputs to heat transfer characteristics of a Closed Loop Pulsating Heat Pipe (CLPHP) using conventional working fluids with and without insert. Different working fluids namely distilled water, ethanol, methanol and acetone have been used for experimentation. A closed loop pulsating heat pipe made of copper with 2 mm ID and 3 mm OD is used in the present study to evaluate the heat transfer performance. Closed loop pulsating heat pipe is designed and fabricated with proper facility for changing the filling ratio and heat input. Experiments are then conducted with different filling ratios ranging from 20% to 80% and heat input ranging from 10W to 90W. The main target of this study was to find out an optimum fluid as well as optimum value for filling ratio for which heat transfer from evaporator section to condenser section is maximum. Heat transfer capability of different working fluids is also compared. The optimum value for filling ratio is found to lie between 50% to 60%.