Abstract:
Thermal control is an important topic for thermal management of small electrical and electronic devices. Closed loop pulsating heat pipe (CLPHP) is emerging as the best solution for thermal control. The aim of this experimental study is to search a CLPHP of better thermal performance for cooling different electrical and electronic devices. In this experiment, methanol, ethanol and distilled water have been used as working fluid. The effect of using methanol, ethanol and distilled water as working fluids is studied on thermal performance in different filling ratios. A copper capillary tube has been used having the inner diameter of 2mm, outer diameter of 2.5mm and length of 300mm. The CLPHP has 7 loops where length of the evaporation section is 100mm, adiabatic section is 100mm and condensation section is 100mm. The experiment is done using FR of 28%-88% with 15% of interval varying heat input from 10 watt to 70 watt. The results are compared on the basis of evaporator temperature, condenser temperature and their differences, thermal resistance, heat transfer co-efficient, Nusselt Number, power input and effect of filling ratios. The results demonstrate methanol as the most suitable working fluid at 58% filling ratio. Because, methanol at 58% filling ratio yields the lowest thermal resistance and highest heat transfer coefficient. In case of ethanol and distilled water, optimum filling ratio is found 58% and 88% respectively.
Description:
First of all, we are grateful to the Almighty for giving us the courage and enthusiasm to complete the thesis work. The authors express their profound gratitude to Dr. Aloke Kumar Mozumder, Dept. of Mechanical Engineering, BUET and Brig Gen Md. Habibur Rahman, Head, Dept. of Mechanical Engineering, MIST for their constant & meticulous supervision, valuable suggestion and encouragement to carry out this work. For all this, the authors acknowledge their sincere gratitude to them.
We are also grateful to Lt Col Golam Saklayen, all of the staffs and lab assistants of applied fluid mechanics lab and heat transfer lab of MIST for their help in construction of the project work and give their valuable knowledge and time for completing our experiment. In addition to that, we would like to thank to one of our fellow; Atif Yasir for helping us.
Finally, we would like to thank everybody who supported us in any respect for the completion of the thesis.
