Invited Speaker


Dr. Nethaji N

Dr. Nethaji N

Department of Mechanical Engineering, Government Polytechnic College
Speech Title: Design and Construction of Hybrid Solar Farm Cooler for Preservation of Farm Perishables

Abstract: During the calendar year 2023 alone, the volume of Tomato production in India was estimated to have amounted to over 20 million metric tons. However, in India, due to a lack of proper storage and transportation facilities, about 20-40% of tomatoes are wasted (Statista Inc. Aug 24, 2023). Similarly India's flower production was estimated to amount to nearly 3 million metric tons in the year 2023. Here also the wastage was around 30-40% (Statista Inc. Aug 24, 2023) due to the same reasons. This research work aims to preserve and extend the shelf life of farm produce like Tomato, flowers, vegetables and other perishables when they are abundant but market price is lower. To achieve this, a Hybrid cold storage is built in the farm itself by running a Solar operated DC Inverter Vapour Compression Refrigeration system inside the red brick-sand structure which reduces the heat load on the storage unit by Evaporative cooling. As air in tropical regions are of lesser in humidity, the air flowing over the brick and sand structure continuously carry away the water vapour from the surface of the brick wall, which is permeable to water, which in return is poured periodically from the top of the wall gaps to achieve the optimum DBT and RH in the storage space. To achieve maximum permeability and hence the evaporation rate the gap between the inner and outer brick walls are filled with coarse river sand of permeability 1- 0.1×10-3ms-1. Generally, the ripened tomatoes can be stored in this type of cold storage for up to 2 to3 weeks at a temperature of 12°C- 16°C with a relative humidity of 85-90%. This results in significant reduction of wastage and also remunerative prices for farmers, when the market price is better. Thereby we can save about 9000 million Indian Rupees (112.5 million USD) per year as of 2023 Statistics when we take average Tomato price Rupees. 15.00 / kg results in significant saving of 0.01 % on India’s GDP( 1720 Lakh millions Rupees as of 2023-2024, National Statistical Office (NSO, India,12-04-2024).