Numerical Study of CO and CO₂ Emissions From Rural Kitchen in Developing Countries

In this study the pattern and varying intensity of CO and CO₂ emission from different kinds of Biofuel used in the rural areas of developing countries have been investigated. A typical rural kitchen of dimension 3.0m × 1.5m × 2.2m is constructed with an improved concrete oven. We have measured the source concentration at the stove and used the value for the numerical model. In the current analysis it is observed that at closed ventilation condition, CO and CO₂ concentration exceeds safe limiting value. Even under the natural ventilation, it fails to keep the concentration below the safe threshold. However in forced ventilation system at 5m/s, the concentration level drops significantly. At the breathing point, for a source concentration of 338 PPM and without any ventilation, numerical results predict the CO concentration to be 70 PPM. Natural ventilation case shows no improvement while forced ventilation suppresses the concentration by 70%. On the other hand, for a no ventilation condition, CO₂ concentration is found to be as 2050 PPM when the source level concentration is 7100 PPM. Forced ventilation at 5m/s decreases the concentration to 750 PPM, well within the safe limit. High concentration was found to accumulate beneath the roof and on the top of the stove. It is then dispersed to the entire upper region of the kitchen. Deploying a duct in the exact spot shows that forced ventilation captures most of the fume and decreases dispersion along the roof. In no ventilation and natural ventilation cases, high concentration accumulation can be observed in the lower-left and lower-right corners, both in longitudinal and lateral planes which eventually affects the breathing zone concentration. On the other hand, for forced ventilation case, concentration at lower-left and lower-right corner is greatly reduced resulting low concentration at the breathing zone.