Abstract:
Vapor compression refrigeration system was studied as it is the most widely used refrigeration system especially in small scale of refrigeration application such as in domestic application. Performance of the system becomes main issue and many researches are still ongoing to evaluate and improve efficiency of the system. By learning and understanding the basic vaporcompression refrigeration systems, the performance of refrigeration system can be determined using refrigerator test rig. This thesis deals with coefficient of performance testing under a vapor compression refrigerator using experimental setup for three different refrigerants. The main objective in this thesis was to obtain performance of the refrigeration system in term of refrigeration capacity, compressor work and coefficient of performance (COP) by determining three important parameters during operating mode which are temperature, pressure and refrigerant flowrate. The performance of the refrigerator test rig was analyzed using the actual pressure-enthalpy diagram of refrigeration cycle and by using the mathematical equation. This study may help the readers to analyze the performance of the refrigerator. Performance increases as the evaporating temperature increases, but reduces as the condensing temperature increases. We have found from the experiment that the average actual COP of R-12, R-22 and R-134a are 4.07, 3.97 and 3.80 respectively. Considering the overall assessment of the results and global warming potentials (GWPs) we can say that R134a will be a better alternative than other two refrigerants in the refrigeration system.
Description:
First of all, praise is due to almighty ALLAH with his compassion and mercifulness to allow us finalizing this undergraduate thesis. We express sincerest gratitude to our supervisor, Dr. Engr. Md. Shafiqul Islam, Principal Engineer & Project Director, Bangladesh Atomic Energy Commission, Dhaka, Bangladesh, who has supported us throughout our thesis with his patience and knowledge. We attribute the level of our Bachelor degree to his encouragement and effort and without him this thesis would not have been completed and written.
Our special thanks to all the lab assistants of Heat Transfer Lab of MIST who participated in maintenance related to experimental setup. We are grateful to MIST for funding. It would not be possible to complete this thesis without the financial co-operation of this organization. Finally, we thank our parents for supporting us throughout all our studies at University. We are also grateful to our friends for inspiring us in different stages of the thesis work.
The Authors Department of Mechanical Engineering, Military Institute of Science & Technology, Mirpur Cantonment, Dhaka-1216, Bangladesh. December, 2012.
