- freely available
Energies 2017, 10(10), 1639; doi:10.3390/en10101639
2. Materials and Methods
3.1. Effect of Fuel Composition
3.2. Effect of Injection Gaps
- The results showed that the fuel composition had a significant impact on the global reactivity index that later affect the combustion performance with higher pressure and THR, shorter duration, and higher combustion efficiency as compared to diesel combustion.
- The combustion performance deteriorated with higher CNG percentages in the mixture because of the low reactivity of CNG.
- 60/40 diesel/CNG composition shows the best output when compared to other mixture compositions as it produces higher combustion output and shorter combustion duration, even though it shows long combustion delay.
- The primary reason for the diesel/CNG mixture better combustion output is the distributed diesel droplet caused by CNG injection that became multiple ignition points that significantly shortened the combustion duration.
- The gap between the injections of the diesel and the CNG was found to have a diverse effect relative to the mixture compositions.
- For high diesel percentage, the injection gaps show less effect to the combustion phasing, yet it has a significant effect on the combustion output. The combustion efficiency is reduced, and the combustion delay is longer with the increase of injection gap.
- In contrary, for the lower diesel percentage, injection gaps show a significant effect on the combustion phasing with a longer injection gap having longer combustion duration. Despite its effect on the combustion phasing, injection gap shows less effect on the combustion output.
- Mixture composition and injection gap are capable of controlling the combustion output and phasing as it generally creating various global and local reactivity index.
Conflicts of Interest
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|Fuels||Injector Delivery Rate (g/s)|
|Diesel||4.2 @ 3 bar|
|CNG||7.2 @ 7.5 bar|
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