Design and CFD Analysis of Food Dryer Using Solar Flat Plate Collector and Exhaust Gas with Finned Copper Tubes

To remove moisture direct, indirect mode solar drying methods are available. Indirect method, the crop is directly exposed to solar radiation. But in the case of incident method crop is placed in the closed system and solar radiation is absorbed by some transparent surface – usually, a solar collector where it is converted into heat by refraction in the system. But this method is applicable on sunny days only. So the exhaust gas was used as heat source for drying with the help of copper heat exchangers irrespective of seasons. This method has the capability of reducing the drying time by up to 50 percent compared to traditional drying. In order to obtain the best results, current work focuses on modeling and analysis of solar food dryer attached with the flat plate collector and exhaust gas heat exchanger. CFD Analysis of food dryer containing exhaust pipe heat exchanger with and without fins is carried out. The results are compared and the best heat transfer model is recommended. From the theoretical, Numerical and experimental validation, it was found that the output temperature of the Flat plate collector whose overall efficiency of 5.7 was compared in different cases. There was a gradual increase in output temperature when exhaust pipe was added and further step increase when exhaust pipe with fins was added. As a result of increased output temperature and moisture numerical rate was increased.