Abstract:
This thesis presents a method for improving the efficiency of a solid fuel-fired
water heater. In the proposed system, the porous materials was used to improve the heat transfer coefficient between the combustion zone and water tube bank. In addition, the combustion air waspre-heated to reach higher temperature. For this reason, the combustion efficiency of this combustor outperforms the conventional one. The porous medium used in this study are nuts with three different sizes: 8, 10 and 12 mm. The solid fuel used in this study is wood charcoal.
In this experimental study, the performance of combustor with and without
(conventional combustor) were compared. The best performance of the conventional combustor was used as the base case of study, then, the porous medium was installed to test the hypothesis that porous materials can improve the thermal efficiency. To figure out the best property of porous medium which suit well with this combustor, the pore sizes of porous materials were varied to determine the most appropriate size for maximizing the efficiency of the water heating system.
The results indicate that using of porous material can improve the efficiency of
the proposed system. The results also demonstrate that, among 3 sizes of porous medium: 8, 10 and 12 mm, using 10 mm nut size yields the highest thermal efficiency. An average combustion temperature of 1,020 ˚c, thermal efficiency about 60% and the maximum heating power about 45 kw were obtained using 10 mm nut size of porous medium