Track: Energy

Abstract

The overall objective of this study was to minimize the environmental impact of agricultural operations by developing a system which uses engine waste heat for grain draining. Waste heat is drawn from the engine exhaust and the cooling system and used for heating drying air. The system heats ambient air to the desired drying temperature of 55⁰ C. This waste is used to supplement methane-based fuel which is the main energy source for cereal drying. Grain is normally harvested at a moisture content of 32% wet basis but can be higher or lower depending on factors such as the stage of maturity, season, weather pattern as well as drying facilities. For maize, the traditional approach is to leave the crop in the field until the moisture content has fallen to around 20%. Changes in weather patterns, however, have resulted in farmers’ inability to sufficiently dry their cereals leading to frequent cases infection with aflatoxins and consequent disposal of affected maize. In this study and analysis of a 223.71kW diesel engine with 81.33% of load, 599.9℃ exhaust temperature and 244 brake horsepower were used. The proposed heat exchanger was found to have effectiveness of 92% and 93% for energy from the exhaust and coolant, respectively. Energy harnessed from the coolant and exhaust was used to heat ambient air to 55⁰C which was then directed into the cereal dryer for maize gains drying. The dryer has a batch drying capacity of 40,000 kg for one drying operation in an hour and some of the exhaust air is redirected into the dryer as it was still considered to have sufficient heat to dry the maize in the chamber.