Study on the Performance and Emissions of a Compression Ignition Engine Fuelled with Fischer-Tropsch Diesel Fuel

Abstract

Fischer-Tropsch (F-T) diesel fuel is characterized by a high cetane number, a nearzero sulphur content, and a very low aromatic level. In the present paper, the performance and emissions of an unmodified single-cylinder direct injection diesel engine operating on F-T diesel fuel are studied and compared with those of conventional diesel fuel operation. The results show that F-T diesel fuel exhibits a slightly longer injection delay and injection duration, displays an 18.7 per cent average shorter ignition delay, and has a lower peak value of premixed burning rate and a higher peak value of diffusion burning rate than conventional diesel fuel. The engine with F-T diesel fuel has a slightly lower peak combustion pressure and a far lower rate of pressure rise, and consequently a lower mechanical load and combustion noise compared with conventional diesel fuel. In addition, the brake specific fuel consumption is lower and the brake fuel conversion efficiency is higher for F-T diesel fuel operation. The CO 2 , HC, CO, NO x , and smoke emissions with F-T diesel fuel are reduced at all operating conditions when compared with conventional diesel fuel. On average, NO x and smoke emissions are reduced by 16.7 and 40.3 per cent respectively with F-T diesel fuel. The study demonstrates that F-T diesel fuel is an excellent clean alternative fuel for diesel engines.

Influence of gas-to-liquid (GTL) fuel in the blends of Calophyllum inophyllum biodiesel and diesel: An analysis of combustion–performance–emission characteristics

“…The test results for G20 revealed increased BTE values of approximately 1.62% values than diesel. This trend is also supported by other studies [22,46]. The lower BTE of the other two blends can be ascribed to the combined effect of their lower calorific value and higher kinetic viscosity.…”

“…Thus, a decrease was observed in the peak combustion pressure in the cylinder. The decreased maximum pressure of G20 can initiate smooth combustion, which can cause diminution in combustion noise [46].…”

“…However, the peak was higher and the duration was longer than those of diesel in diffusion burning zone. The higher CN of GTL fuel caused a smaller ignition delay, which yielded a diminution in both the mass of injected fuel and the rate of evaporation of fuel prior to ignition [22,46]. As a result, G20 demonstrated a low burning rate and small amount of energy released during the premixed combustion phase.…”

“…Since the G20 contains a higher calorific value, it requires a comparatively smaller quantity of fuel per stroke to produce the same power compared with diesel and two other blends [47,48]. G20 also demonstrated lower in-cylinder pressure and lower pressure rise rate, which could assist in compensating for mechanical losses and leads towards better combustion [46]. The higher BSFC values of the other two blends can be ascribed to the volumetric effect of the constant fuel injection rate, associated with their higher kinematic viscosity values.…”

“…Lower fuel consumption is required to overcome the mechanical losses associated with engine during medium-high speed operation compared with the lower speed operation. At the top dead center, a high level of spontaneous premixing occurs, which induces a faster rate of combustion [46]. At high speed, all fuels demonstrated low BTE.…”