This work is part of the dynamic of proposing a solution to the problem of access to electricity in Chad, which has a rate of access to electricity of 3%. N’Djamena has significant solar potential that can be harnessed to generate electricity. In this paper, we present a theoretical study of the performances of the Dish/Stirling system with the purpose of producing electricity, based on a mathematical model taking into account each of the subparts of the system (concentrator, solar cavity receiver, and Stirling engine). Hydrogen is preferred to helium as the working fluid for operating the Stirling engine at high temperatures. This coupled model made it possible to estimate the monthly average of the electric power produced by this modular system and also its overall solar electricity yield.

This study presents an experimental investigation and thermodynamic 0D modeling of the combustion of a compression-ignition engine, fueled by an alternative fuel based on neem biodiesel (B100) as well as conventional diesel (D100). The study highlights the effects of the engine load at 50%, 75% and 100% and the influence of the heat loss models proposed by Woschni, Eichelberg and Hohenberg on the variation in the cylinder pressure. The study shows that the heat loss through the cylinder wall is more pronounced during diffusion combustion regardless of the nature of the fuels tested and the load range required. The cylinder pressures when using B100 estimated at 89 bars are relatively higher than when using D100, about 3.3% greater under the same experimental conditions. It is also observed that the problem of the high pressure associated with the use of biodiesels in engines can be solved by optimizing the ignition delay. The net heat release rate remains roughly the same when using D100 and B100 at 100% load. At low loads, the D100 heat release rate is higher than B100. The investigation shows how wall heat losses are more pronounced in the diffusion combustion phase, relative to the premix phase, by presenting variations in the curves.

The present work investigates experimentally and numerically the combustion of methane coupled to biodiesel and diesel in dual fuel mode. The engine used is a single-cylinder Lister-Petter_01005299_TS1 modified for bi-fuel operation with a pre-chamber in the intake to allow methane to enter with the air. For this, we use three distinct fuels, conventional D100 diesel, B100 biodiesel and methane. The first two fuels are first burned independently under the same conditions independently under the same conditions using the double Wiebe phase. The numerical results obtained of this first combustion of B100 and D100 compared to the measured results show an agreement of 2% and 1.07% respectively for biodiesel and diesel allowing the validation of the numerical code. Next, we add methane to the air during the intake phase for the previously tested D100 and B100 fuels used as a pilot fuel in order to observe the impact of methane on cylinder pressure, nitrogen oxide emissions and heat release. The combustion model used is a two-zone 0D, one representing the burnt gases and the other the unburnt gases. The results showed a decrease in cylinder pressure and a large reduction in nitrogen oxide emissions of about 26.67% and about 48.76% when burning B100 biodiesel at medium load. The results also showed that the addition of methane to the air reduces the overall heat release of both fuels around TDC by 10.76% and 5.4% for biodiesel and diesel, respectively. But that in the diffusion phase, dual fuel combustion shows a higher heat release for diesel. It was also observed that peak pressures were reduced by 2.35% in the case of diesel compared to 7.45% for biodiesel.

This article analyses numerically the simultaneous influence of the compression rate, fuel nature and the advanced injection of fuel on maximum cylinder pressure during the combustion phrase with the help of the Python Spyder calculation code. Indeed, several authors have shown that the combustion of biofuels which make it possible to compensate for fossil and exhaustible resources, presents a cylinder pressure higher by about 3.5% compared to that of conventional diesel D100. This increase in pressure can be reduced by the means of controlling parameters making it possible to preserve the life of the engine and also reduce nitrogen oxides (NO x) and particular matter (PM). This article has two objectives which are: putting in place a numerical tool for the evaluation and simulation of thermal engines and the influence of control parameters on cylinder pressure. The single zone 0D combustion model which considers only the physical phenomena and considers the mixed fuel as a perfect gas is used. The fuel used is the Neem biofuel produced by Doctor Merlin Ayissi of the University of Douala and the D100 diesel fuel. The results are obtained from three fuel injection angles of 20˚, 13˚ and 10˚ before the TDC (Top Dead Centre) and three values of the engine compression rates of 15, 20 and 25. The delay in combustion is characteristic of the fuel used as illustrated by the cetane number. The results show that the cylinder pressure increases with increasing compression rate and a very high advanced injection. It also shows that the pressure is high when diesel D100 is used instead of D100 biodiesel.