Experimental Investigation on Influence of Injection Pressure on Gaseous Hydrogen Supplemented SVO operated IDI CI Engine

Abstract

Massive exploitation of fossil fuels and troubling environmental destruction is driving the researchers to learn of alternative fuels. Jatropha Curcas is one of the choices for ultimately fulfilling the specifications, aside from their negative aspects. In these line(s) preheated Jatropha straight vegetable oil SVO at 90 0C has been considered as a pilot fuel with supplementation of gaseous hydrogen by 5 percent of total energy, in order to overcome the demerits of using the direct use of Jatropha SVO in the selected engine. Single-cylinder, 4 Stroke, water-cooled, naturally aspired, constant speed, 7.35 kW power, in-direct injection (IDI) compression Ignition (CI) engine was selected for the experimentation with static advancement of injection timing to 220 bTDC. The influence of variation of injection pressures for the above said parameters on thermal performance, combustion characteristics and engine-out emissions were analysed. Injection pressure of 235 bar shows more reliable performance with a marginal penalty on emissions of NOx and HC, when compared to conventional diesel operation. Brake Thermal Efficiency of 31.76% was identified at 235 bar injection pressure which is 1.15% higher than the conventional diesel operation. The maximum cylinder pressure of 56.79 bar was recorded with an enhanced diffusion combustion phase of the differential heat release rate (DHRR). Smoke and CO were reduced to 27.4 HSU and 0.06 % by volume, which is 4.6 HSU and 0.01% by volume lesser than the conventional diesel operation. Whereas, NOx and HC were recorded as 492 ppm and 8 ppm at this optimised injection pressure which is marginally increased when compared to conventional diesel operation. In overall, advancing the static injection timing to 20, increasing the injection pressure to 235 bar for a 90 0C preheated Jatropha Curcas straight vegetable oil supplemented with gaseous hydrogen at 5 % of total energy shown better performance when compared to conventional diesel operation.