The energy efficiency of a solar greenhouse for biomass drying

Abstract

Solar energy is a renewable, inexhaustible and clean source, it is becoming the main target of several applications, both domestic or industrial, cutting costs on electrical and thermal demands when compared with conventional sources. In the case of solar chamber, which makes use of incident solar radiation, it creates a favorable microclimate for drying inputs for reducing humidity to prevent the spread of biodegradable agents, on agricultural, forestry, and other products. With the objective to verify the energy efficiency of a prototype of the Greenhouse model, a solar chamber was built, where energy data and environmental variables were daily monitored in the drying process. For the determination of energy efficiency the ratio between converted energy into heat by the received energy was used. It was found that the chamber presented a daily energy gain of 220141,7 kJ, a daily thermal efficiency of 13,96% and up to 3 pm in 24,19%. The percentage difference in this efficiency is attributed to the chamber structure, which transmits and absorbs a higher percentage of solar energy during the day, but at night due to its transmissibility, emissivity properties, in addition to small structural failures that favor greater energy losses.