This work concerns the energy efficiency study and analysis of a gas roasting oven developed by a local craftsman. The oven energy efficiency was determined by the Water Boiling Test (WBT) method. The temperatures of the walls as well as the ambient temperature were recorded to evaluate the heat losses by convection towards the environment. The energy balance of the oven then allows to calculate the heat losses from the fumes. The results show that the heat losses by fumes through the chimney are the greatest (50% of the energy consumed). Losses through the walls are relatively low (15%). The oven efficiency is around 35%, which is relatively low. These results show that optimization work must be carried out in order to improve the energy efficiency of the equipment.

This work is devoted to the evaluation of the performance of a typical fired-wood oven commonly used in the rotisserie sector in Burkina Faso. The methodology used is based on the energy balance of the oven. For this purpose, 20 liters of water were heated up to 90 °C. The difference in water temperature at the start and at the end of the experiment makes it possible to calculate the amount of energy consumed by the load. The temperatures of the walls as well as that of the ambient were recorded to evaluate the losses by convection towards the environment. The losses through the fumes have been estimated from the energy balance. The results show that the dominant losses are those of fumes (about 55 % of the energy consumed). The losses through the walls are relatively large (26 %). The efficiency of the oven is around 19 %, which is very low. These results show that these equipment are inefficient and contribute significantly to the waste of wood at the national level.

This work is devoted to a numerical study of the energy savings achieved by an oven insulated with terracotta bricks compared to an uninsulated oven. The numerical methodology is based on the nodal method and the transfer equations were obtained by making an energy balance on each node. The equations were then discretized using an implicit scheme with finite differences and solved by the Gauss algorithm. Numerical results validated by the experiment show that the insulation of the oven with terracotta bricks considerably reduces the energy losses through the walls, but the reduction level varies according to the thickness of the bricks. The optimal thicknesses of the bricks are between 3 and 4 cm, which corresponds to energy savings of between 60 to 70% compared to the uninsulated oven. The energy saved increases the energy efficiency of the oven from 15-17% to 25-29%.

This work concerns a numerical study of heat transfers in a typical roasting oven in Burkina Faso. The numerical methodology is based on the nodal method and the heat transfer equations have been established by performing a heat balance on each node. The equations obtained were then discretized using an implicit finite difference scheme and solved by the Gauss algorithm. The numerical results validated by the experiment show that the heat transfers within the oven are mainly influenced by the gas flow, the ambient temperature, the flame extinction time and the wind speed. Increasing gas flow rate and increasing ambient temperature increase the oven cavity temperature. The increase in wind speed causes a significant drop in the oven cavity temperature after the first 15 minutes of operation. Beyond a wind speed of 3m/s, we observe a convergence of the oven cavity temperatures towards a limit value. Regardless of the time the flame is extinguished, the gas flow rate, the ambient temperature and the wind speed, the oven cavity temperature drops rapidly towards the ambient temperature.

This work is devoted to an experimental study of charcoal savings achieved by an isolated barbecue oven with terracotta bricks compared to the same non-insulated oven. The methodology is based on the simultaneous monitoring of ovens temperatures at the grills level using thermocouples and an infrared imaging camera. The results show that for the same quantity of charcoal used, the temperatures reached in the grill of the insulated oven are above those of the non-insulated oven and the energy losses to the outside environment are very significant in the non-insulated oven. As a result, with a reduction in the amount of charcoal by 35%, the insulated oven achieves the same performance as the non-insulated one. These results highlight the importance of insulating barbecue ovens, particularly with terracotta bricks in reducing of charcoal consumption in Burkina Faso, and consequently in the safeguard of forest resources.