Executive Summary :
|A clean, cost-effective, and versatile climate control system that can maintain temperatures in the range of 2-70?, humidity levels in the range of 5-95% (as per users’ requirement and end-application), and can work off-the-grid, is highly desirable for several agricultural storage and processing requirements. In this regard, the IITP in close collaboration with New Leaf Dynamic Technologies recently designed, developed and commercialized an off-the-grid refrigeration system for cold storage under the aegis of Uchhatar Avishkar Yojana (Project end date: August 16, 2018). This system incorporates a novel thermally-integrated biomass gasification and hot water generation (@40 liters/min with exit/output temperatures of 120°C) system with a thermal efficiency of 45% to power an adsorption-based refrigeration system. This is a completely environment-friendly unit with no greenhouse emissions, zero carbon footprint, and zero global warming potential. The unit is currently operational at various locations and provides 3.5 Ton (12 kW cooling) off-the-grid refrigeration using agricultural biomass waste/residue @ 10 kg/hr (calorific value of 19 MJ/kg with consumption @ 10 kg/hr implies 53 kW bioenergy), i.e., the overall efficiency of 23%. Investigators propose to extend this collaboration between IITP and New Leaf Dynamic Technologies to develop a more versatile climate control unit with independent temperature and humidity controls using the same biomass as the fuel. There are key engineering challenges that need to be addressed connected to the scaling up of the system. In addition, there are crucial manufacturing issues that require to be tackled. This calls for a concerted and timely effort. Investigators will incorporate an ultrasonic humidifier in the cold storage unit which will recirculate (spray) the condensate back into the room in order to maintain high humidity conditions. The system will thus be able to store perishables such as potatoes, which require low temperatures (2°C to 4°C), but at high humidity levels (90% relative humidity). Furthermore, when not in use during winters (and otherwise), the adsorption-based refrigeration subsystem can be turned off and the hot water from the thermally integrated biomass gasification and hot water generation subsystem (27 kW) can be routed through a radiator (space heating) which can facilitate drying/ripening of fruits and vegetables.