The improvements made on a 2.0 litre indirect injection diesel engine to achieve 20 percent increase in power output and emissions lower than Bharat Stage II is presented. The improvements made are in four major areas, namely i) Auxiliary loss reduction, ii) combustion system redesign, iii) fuel injection equipment and iv) employment of after treatment devices EGR and Oxy-cat.
For auxiliary loss reduction, a thermal clutch in cooling fan is introduced to increase the net power output of the engine. Combustion system improvements include increase in swirl chamber volume ratio, optimization of glow- plug protrusion in pre- chamber, redesign of depth of clover shape and introduction of piston scoop. A different injection rate profile along with Load Dependent Timer Travel and Speed dependent Timer Travel Hysterisis controls are provided in the injection pump for lower emissions. To reduce the NOx and particulate emissions, a solenoid operated ON/OFF type EGR and an oxy-cat are used respectively.
The results show an improvement in power output of 20 percent and emissions lower than the Bharat stage II. The compression ratio is kept same, as the increase in prechamber volume is compensated by the reduction in volume of the clover shape on the piston crown.