Development of an Advanced Solar-hybrid Adsorption Cooling System for Decentralised Storage of Agricultural Products in India

Agricultural products play a significant role and could yield substantial amount of foreign exchange for a tropical country like India. However, in India 30% of the agricultural products are spoiled in storage and transit. In this present investigation, funded by EC (DG-XII), TERI (Tata Energy Research Institute) and DLR (German Aerospace Establishment) have jointly designed and tested a solar-hybrid methanol/silicagel based adsorption cooling system for its possible application for decentralised cold storage of agricultural products in India where electricity is either not available or not reliable. A 10 kW (2.9 TR) system (for 100 t of agro-products, 240 mP3P in volume) has been designed and preliminary testing has been completed successfully. Methanol/silica gel working pair has been used in the adsorption refrigeration unit. It is operating with a very low (75-80 C) generation outlet temperature and rejecting heat at near ambient. This 10 kWBthB capacity cooling unit has offered cooling with a coefficient of performance (COP) for cooling of 0.3 to maintain a cold storage at 1 to 3C and cooling density of 100 W/kg silicagel at an evaporator temperature of 0C. The system is designed as a stand alone solar and waste heat driven cold storage with a dual-fuel engine, which generates 5 kWBeB electricity side by side. It has been estimated that the pay back period of such a system will be about 5 years with a 30-50% increment in electricity purchase rate of Indian State Electricity Board.