Journal Press India^®

Author Details ( * ) denotes Corresponding author

Low grade thermal energy is often required in the agricultural products, the conventional fuels most commonly used are diesel, petrol, bio-diesel, CNG, LPG, electricity, wood, agro waste etc. are available very costly day by day and are getting in the rural areas. The alternative is to use the solar energy thermal storage systems based on water is air required as a basic components in the low grade thermal energy utilization. A simple thermal analysis for open and close loop packed bed collector cum storage system has been carried out to study the performance of the system using different type of thermal energy storage materials such as rocks, pebbles, glass piece, stone pieces and fired brick. The effect of various parameter of packed bed, diameter of packed bed, porosity and mass flow rate on the volumetric heat transfer co-efficient, heat flux, efficiency of the system has been studied in details and time dependent periodic thermal model was developed. It was observed that fire brick gives better thermal energy storage effect than other storage material and hence it is recommended for open loop and close loop solar crop drying systems in the rural areas

Keywords

Low cost solar system; Thermal energy storage systems; Flow through the porous media; Solar thermal system design

1. Dunkle RV, “Randomly packed particle bed regenerator and evaporative coolers”, Trans. Inst. of Engg. (Australia) Page 117, 1972
2. Lof, GOG, “Unsteady state heat transfer between air and loose solids”, Journals of Industrial and Engg Chemistry, 40 Page 1061, 1948
3. R. S. Mishra, “Design, development and techno-economic evaluation of hybrid solar air heating cum storage system for space heating and crop drying”, proceeding, eight, national conference of mechanical engineers, University of Roorkee, Page 24-32, 1992
4. R. S. Mishra, “Evaluation of thermal performance of ventilating Trombe wall for porous and non-porous Ninth”, National conference on mechanical engineering, IIT Kanpur, Page 175-181, 1993
5. R. S. Mishra, “Thermal performance of thermal energy storage rock bed systems”, international conference on advances in mechanical and industrial engineering, University of Roorkee, Page 553-565, 1997
6. R. S. Mishra, “Evaluation of thermal performance of low cost rock bed thermal energy storage system for space heating and crop drying”, International conference on, Research and Development (Vision - 21st century), Page 235-243, 1999
7. Schumann, “Heat transfer in liquid flowing through porous prism”, Journal of heat transfer, Frankin Institute, Vol. 204,Page 405, 1929