Mbiza Herbert; Chigumira Igenatious
Kwekwe Polytechnic, 1 Railway Ave, Box 399, Kwekwe
Research based STEMatised TVET innovations are the only solutions to solve the current socio-economic problems bedeviling Zimbabwe. A sustainable prototypical solid biomass fired stove integrated with a thermosiphonic water heating system has been designed for domestic use using locally available materials. Water carrying heat exchangers were embedded in the base of a biomass stove to absorb waste heat. The base plates of the stove are impregnated with washed river sand to increase heat retention. The water gets heated and flows into the storage tank through a closed loop thermosiphonic process. Water temperatures of 95℃ were achieved on the prototype stove with a base area of 500 mm by 300 mm and a 16 〖dm〗^3 water reservoir. The heat absorption efficiency and energy use is 75% more than the normal open fire, which is commonly used in most rural homesteads, as the design uses a dual absorption principle. Heat is used for direct heating at the top of the fireplace and waste heat is conducted into the base and chimney, being absorbed by the heat exchanger. The solid biomass fired stove integrated with a thermosiphonic water heating system finds useful application in both rural and urban setups in Zimbabwe and other Sub-Saharan African countries where electric access is only 17%, the lowest worldwide. Fire wood is mostly the source of energy for cooking and heating in most rural and urban areas. This paper proffers an alternative solution to sustainable energy use for rural and urban communities at a low cost.
Keywords: Thermosiphon; Heating system; Solid biomass