A. Rehman

Homogeneous Charge Compression Ignition (HCCI) Combustion Engine- A Review

At present, it is highly required from the automobile sector to develop clean technologies with lower fuel consumption for ambient air quality improvement, green house gas reduction and energy security. Furthermore, due to continuously stringent emission legislation and the fast depletion of the primary energy resources, the development of new highly efficient and environment friendly combustion systems becomes of paramount importance and hence research need to be done in this area. One such combustion system is Homogeneous Charge Compression Ignition (HCCI) technology, which has the potential to reduce oxides of nitrogen (NOx) and particulate matter (PM) simultaneously maintaining the thermal efficiency at par with that of conventional diesel engine combustion. However, some issues such as combustion phasing control, controlled auto-ignition, operating range, homogeneous charge preparation, cold start, pressure rise rate and noise and emissions of unburned hydro carbon (UHC), and carbon monoxide (CO) need to be solved for successful operation and therefore commercial application of HCCI engine. Other similar combustion concepts, which can be considered as the extension of HCCI, are Low Temperature Combustion (LTC) and Stratified Charge Compression Ignition (SCCI). This paper reviews all the three advanced combustion concepts along with their merits and demerits.

CI engine performance characteristics and exhaust emissions with enzymatic degummed linseed methyl esters and their diesel blends

ABSTRACT This research paper deals with the comparative study of enzymatic degummed linseed methyl ester (EDLME), water degummed linseed methyl ester and non-degummed linseed methyl ester with their different diesel blends on performances parameters such as brake power and brake specific fuel consumption. Emissions characterization such as unburned hydrocarbon, carbon monoxide, nitric oxide, nitrogen dioxide and smoke opacity were also measured. It was found that the 25% blend of EDLME with diesel is the best alternative for the diesel fuel based on overall performance in terms of engine performance and emissions. Therefore, EDLME25 (25% blend of EDLME with 75% diesel) can be considered as an alternative fuel for diesel engines.

A Spray Pattern and Emission Characterisation of Enzymatic Degummed Linseed Methyl Ester on Diesel Engine

An experimental study on the characteristics of enzymatic degummed linseed methyl ester (EDLME) and Non-degummed linseed methyl ester (NDLME) spray is performed and compared with diesel spray using a single-cylinder compression ignition engine. The spray visualisation performance has been investigated on a single-hole nozzle under ambient conditions, and a high-speed camera (photron-SA5 FASTCAM) was used to capture images at a constant fuel injection pressure of 210 bar. This paper also deals with the influence of the EDLME properties on the spray and emission characteristics. On the basis of spray investigation for different diesel blends (25%, 50%, 75% and 100%) of EDLME and NDLME, fuels showed maximum spray cone angles and least spray penetration for EDLME25 as comparable to that of other blends. It was found that a decrease in spray cone angle is one of the main reasons for the increased NOX emissions.