PERFORMANCE ASSESSMENT OF INDIVIDUAL AND GROUPED WOOD BURNING STOVES

Abstract

In Ethiopia, Rural areas mostly used traditional wood burning stoves like open fire wood burning stoves for cooking, space heating and lighting. The use of these forms of energy is associated with environmental as well as human health impacts. Therefore, Improved /modified cook stove are required to alleviate these problems. In this study, an improved single and multiple wood burning stoves (double and triple) were designed, fabricated and tested to evaluate their performances and to compare them with the conventional charcoal burning stove. The energy efficiency and cooking times of each wood burning stove was determined indirectly by cooking 242 g rice in a pot and by measuring temperature of rice in the pot, stove body temperature and smoke outlet temperature every seven minutes. For each stove 350 g of ovendried wood was used. The tests were replicated five times. For comparison, three parameters (time of onset of cooking or time when the food temperature reaches 75oC, maximum temperature reached and effective times of cooking or time range of T ≥ 75oC) were considered. Comparisons of the three parameters were made by using one-way ANOVA followed by pair comparisons wherever the ANOVA showed significant differences. Besides, relative heat losses through the body of the stoves and the smoke outlets were determined by area calculation from the plots using Matlab software. The results showed no significant differences in time to reach 75oC and the maximum temperatures reached among treatments at p=0.05 level. In terms of effective cooking times there were significant differences between the fabricated and the conventional stove, but no differences between the former. The single stove exhibited higher stove body temperature of 17% and 16% than the double and the triple stoves, respectively. The double stove smoke outlets showed nearly 16% more heat loss than the single stove and about half as much over the triple stove. The use of fabricated stove has an advantage of almost doubling the effective cooking time as compared to the conventional stove.