Design, CFD modeling and prototype testing of husk biomass cook stove

Abstract

Around 2.7 billion people across the world consume solid biomass fuel for heating, cooking, and other daily energy demands. In developing countries, biomass fuels are mainly burned in open fields as waste materials. Some are used by traditional stoves, resulting in less energy efficiency and causing environmental air pollution, which leads to climate change. In Ethiopia, most of the available improved stoves were designed by considering only wood fuel, which is not suitable for using biomass like coffee husks and rice husks. The developed husk biomass cook stove is suitable for using such types of biomass. This research work aims to design and develop, CFD modeling, and prototype testing of husk biomass stove for cooking purposes. The husk biomass cook stove model was designed using CATIA V5R20 and imported to ANSYS 19.2 using CFD fluent for prediction of its performance. The water boiling test (WBT) and emission tests were conducted for stove evaluation. The experimental performance was evaluated and analyzed by the water boiling test version 4.2.3 spreadsheet using two pots with different sizes for coffee husk and rice husk biomass. The WBT experimental results indicate that the average thermal efficiency and time to boil water using coffee husk biomass and a 3.5-liter pot were 29% and 7.7 minutes, respectively, during the hot start phase. Using the rice husk biomass and a 3.5-liter pot, the average thermal efficiency and time to boil water were 28% and 8.4 minutes, respectively, during the hot start phase. The emission test results showed that the average CO emission was 229 ppm for the cold start phase, 220 ppm for the hot start phase, and 235 ppm for the simmering phase by using rice husk biomass. When coffee husk biomass was used, the average CO emission was 254 ppm during the cold start phase, 240 ppm during the hot start phase, and 262 ppm during the simmering phase. The international workshop agreement principle was conducted to classify the performance of the stove accordingly and the result indicates that the average indoor CO emissions were 0.186 g/min and 0.274 g/min using rice husk and coffee husk biomass, respectively. The relative error between the CFD and experimental results is 3.33 %. Finally, the total selling price of the fabricated husk biomass cook stove is 350 ETB