Dept. of Mechanical Eng., College of Engineering, Shiraz Branch, Islamic Azad University, Shiraz, I. R. of Iran
Fridges are used in various industries, and heat exchanger is one of the main components of these systems; therefore, efficiency analysis of these systems is very important. In many fridges, frost over the heat exchanger tubes or pipes affects the system operation and reduces heat transfer between the refrigerant and ambient, so defrosting systems are usually used to enhance heat transfer. Designing defrosting systems requires sufficient information about frost formation processes. Therefore, the objective of this study is experimental investigation of frost formation over a heat exchanger pipe in a pilot fridge. To do this, some steps are considered. For distinct cases, experiments are done to collect database for frost parameters under desired conditions. Then, based on experimental measurements some correlations are proposed for practical applications of frost growth and defrosting process over heat exchanger tubes.