Energy and exergy audit of a solar grain dryer has been presented in this paper. The solar grain dryer is made up of a flat-plate solar collector and a convective drying chamber. The properties of the working fluid were measured at various energy input levels. Energy and exergy balance equations were written for the flat-plate solar collector, the convective drying chamber and the solar grain dryer. The audit performance equations were developed based on the energy and exergy balances in the solar grain dryer. The audit performance results show that the higher the energy loss and exergy destruction, the lower the values of energy and the exergy efficiencies in the solar grain dryer. The audit performance results obtained are useful for the design of an efficient grain solar dryer.
Keywords: energy audit, exergy audit, renewable energy, solar grain dryers, flat-plate collectors, convective drying chambers, solar energy, solar power