EXPERIMENTAL STUDIES ON THE UTILIZATION OF ACETYLENE AND OXYGENATED BLENDS IN A DUAL FUEL ENGINE

Abstract

The energy requirement has increased multifold globally with the steep rise in industrialization and socio-economic growth. The various sectors that require energy are industry, transport, agriculture, domestic, and many others. However, the world's transportation depends heavily on petroleum fuels. Diesel engines are highly demanded because of their higher thermal efficiency and versatility. However, these engines emit harmful exhaust emissions such as carbon monoxide (CO), hydrocarbons (HC), oxides of nitrogen (NOx), particulate matter, and smoke while burning liquid diesel. Many engine scientists have recommended to utilize alternative fuels to tackle twin catastrophes i.e., environmental degradation and fossil fuel crisis. Hence, alternative fuels are getting more prominence as concerns over escalated exhaust emissions as well as replacement of petroleum fuels. Utilizing gaseous fuels is one of the most promising options to mitigate exhaust pollutants as well as to improve conventional engine performance without major modifications. Since they have higher auto-ignition temperature, higher calorific values, and clean-burning affinity, hence are suitable for compression ignition engines under dual fuel mode. In this regard acetylene has attractive combustion properties like hydrogen and the utilization of acetylene is not exhaustively explored in literature. Hence acetylene is utilized as a primary fuel in dual fuel engine to investigate the combustion, performance, and emission characteristics in the present study. In the first stage of the experiment, the optimized flow rate of acetylene is found by examining the engine characteristics. The flow rate of acetylene is varied from 2 LPM to 8 LPM in the step count of 2 LPM. It is noticed that when the acetylene is inducted at 4 LPM, brake thermal

Experimental Studies on the Utilization of Acetylene and Oxygenated blends in a Dual Fuel Engine Page vii efficiency (BTE) is comparable at 80% load as well as HC, CO emissions are reduced in comparison to pure diesel. However, the NOx level is increased in comparison to neat diesel. Furthermore, the experimental results are fed as input and targets in the ANN network to predict the accuracy of experimental results. Predicted results show that R values closer to unity and mean square error value approximately 0.001. In the second phase of the experimentation, oxygenated fuels, i.e., diesel/DEE and diesel/n-butanol blends, are utilized in the dual fuel engine at optimized induction rate (4 LPM) of acetylene gas. Again, the performance, combustion, and emission parameters are evaluated in a modified engine. It is observed that BDEE10 shows the highest brake thermal efficiency (BTE), i.e., 1.67% higher, whereas BBU10 shows 1.21% higher BTE compared to baseline diesel. Simultaneously, NOx emission is also reduced to a substantial level, i.e., 22% and 27% lower than neat diesel while utilizing BDEE10 and BBU10 blend under dual fuel mode of combustion. Moreover, HC and CO emissions are reduced at a significant rate while utilizing BDEE10 and BBU10 blend in dual fuel mode. Overall, it can be concluded that the performance of the acetylene fuelled engine can be improved by utilizing oxygenated blends up to 10%.