Simulation of coconut shell combustion in a grate-fired furnace using distributed pyrolysis products model.

CFD simulation has been proven to accelerate the construction process of better biomass furnace and to find the optimum condition of biomass combustion. Optimum furnace design and operating condition can lead to better energy conversion with less pollution level. This work is aiming to formulate CFD model that can accurately predict the biomass combustion behavior inside a grate-fired biomass furnace. CFD simulation results then compared with experiment result which has been conducted using coconut shell as fuel. The distributed pyrolysis products based on atom and heat balance is utilized in the current work. The distributed pyrolysis products model gives reasonably good estimation of the volatile matter components and its composition in different pyrolysis temperature condition. Accurate prediction of the biomass combustion behavior from the proposed CFD model are depicted by high degree of similarity of several combustion parameters compared to the experimental observation i.e., temperature throughout the furnace and CO2 level of flue gas. The experimental observation give the CO2 level percentage from flue gas of 9.59±0.35 while current simulation produce the CO2 level percentage of 9.85. The relative error of temperature in furnace and CO2 level between current work and experimental observation have reached to be below 3% which is acceptable. Moreover, the proposed CFD model allows to estimate parameters which are hard to observe experimentally e.g., temperature distribution, local oxygen content, and volatile matters conversion. The established model allows further biomass combustion simulation in combination with pollutant formation which finally can be exploited to design the better furnace and better combustion condition. [ABSTRACT FROM AUTHOR]