BRAKE THERMAL EFFICIENCY AND HEAT ANALYSIS OF A DIESEL ENGINE POWERED BY KHAYA-SENEGALENSIS BIODIESEL FUEL BLENDS
In this study, the brake thermal efficiency and heat analysis of a compression ignition engine powered by Khaya senegalensis biodiesel and its blends were experimentally investigated. The performance of the engine was evaluated by running a 2.5 kW, single cylinder, 4 stroke, air cooled, diesel engine test rig model TD111 (Petter AA1) with Khaya senegalensis biodiesel (B100) and its blends with diesel fuel (D100) of varying proportion from 10% to 50% (B10 to B50) at different engine load levels from 25% to 100% of the engine capacity (1000 g to 4000 g) at constant speed of 1500 rpm. The time taken by the engine to consume 8ml of the fuel was recorded, the torque produced by the engine, exhaust gas temperature, engine block surface temperature, barometric pressure and the ambient temperatures were also recorded. Other performance parameters of the engine were calculated from the experimental values. The maximum value of BTE was obtained at 75% engine load, with Khaya senegalensis biodiesel fuel blend (B10) having the highest value of 29.65% followed by B20 with 29.53%. The maximum value of heat supplied by the fuel (Qf ) to the engine occur at 100% engine load with Khaya senegalensis biodiesel fuel blend (B30) having the highest value of 23.34MW followed by B20 with 23.20 MW. The heat lost through the exhaust gas is at its lowest value at 100% engine load with B10 having the lowest value of 21.94% followed by B30 with 22.21% and the lowest value of heat loss to friction, lubrication and other mechanical activities (Qunacc) by the engine occur at 62.5% engine load with B10 having the highest value of 46.97% followed by B20 with 41.85%. Considering the low value of BTE of the engine running on biodiesel fuel blends, there is need to modify the engine design in order to improve the BTE of the engine.
Authors : Y.J. Soja, H. Dandakouta and R.I. Ejilah
Category : Open Access Volume (Issue) : 3(1) Date Uploaded : 25th March 2018