DEVELOPMENT AND NO LOAD CHARACTERISATION OF A PASSIVE GREENHOUSE SOLAR MANURE DRYER
This study aimed to assess the performance of a locally fabricated passive solar greenhouse for poultry manure drying. A passive greenhouse solar manure dryer of about 21.31 m3 volume was fabricated with 5 mm thick transparent glass at Nsukka (longitude 7.390 N and latitude 6.860 E) in the southeast of Nigeria. The dryer was tested at no load with all the necessary physical parameters measured. The average values of the heat utilization factor and coefficient of performance of the dryer is 0.49 and 0.53 respectively. The dryer maximum stratification temperature of approximately 7 oC was observed between the topmost and the lowest trays. The maximum dryer temperature of 37.750 °C was obtained during the period due to cloudy sky. The daily average values of convective heat transfer coefficient and radiative heat transfer coefficient were 1.52 W/m2K, 5.8 W/m2K, and 1.6 W/m2K, 5.8 W/m2K for days one and two, respectively; it ranges from 5.4 W/m2 K to 6.2 W/m2K and 0.95 W/m2 K to 2.2 W/m2 K for radiative and convective heat transfer coefficient, respectively. From the obtained results, the dryer was estimated to be about 39.3% faster than the traditional open-sun drying method.
Keywords: Greenhouse, solar dryer, no-load testing, heat utilization factor, coefficient of performance.
