CFD model simulation and experimental testing of a household husky biomass cook stove

It is difficult to burn husky biomass in combustion cook stoves with smoke free operation, and as such their utilization needs improvised design configurations. Fine tuning the design configuration and testing in virtual reality through simulations saves lot of time, effort, and money. In this regard, this study aims to predict the performance of a household husky biomass cook stove using Computational fluid dynamic (CFD) simulation and it’s validation with experimental testing. The cook stove model was designed using CATIA V5R20 and ANSYS 19.2 was employed to simulate its performance. The wood-volatile-air materials were used from the ANSYS data/base for CFD simulation with naturally flowing atmospheric air. The design optimization of the cook stove was also done by changing the stove model geometry using the assumed fuel inlet diameters. The simulation results indicate that from the assumed fuel inlet diameters (6 mm, 7 mm, 8 mm, and 9 mm), the maximum temperature was observed at a fuel inlet diameter of 7 mm, which was 1016 K. These results also show that changing the fuel inlet diameter can affect the stove's efficiency. The experimental performance was evaluated by the water boiling test (WBT) version 4.2.3 using two pots of different sizes with coffee husk and rice husk biomass, while also employing the heterogeneous testing procedure (HTP) protocol with 3 L, 5 L, and 6.4 L for high, medium, and low-level test phases. A comparison of the CFD simulation with the experimental test result in terms of maximum heating efficiency showed 30% and 29% respectively resulting in a good agreement. The CFD model simulation was compared with the WBT experimental result considering the fact that the WBT (2014 version) is a more recent one than the HTP (2010 version) protocol. According to the WBT experimental findings, when utilizing coffee husk biomass and a 3.5-liter pot, the maximum thermal efficiency and time to boil water were determined to be 29% and 7.7 min, respectively, whereas for rice husk biomass, they were 28% and 8.4 min, respectively. The average specific fuel consumption of the improved biomass cook stoves described in the literature was 115 g/liter, compared to 98 g/liter for the husky biomass stove in this stud leading to a 14.78% reduction in specific fuel consumption. The relative error between the CFD simulation and experimental results at 3.33 % indicates a close agreement between the two, thus validating the simulation results.