Optimization of Direct Charge Compression Ignition Engine by Varying Injection Timing and Injection Pressure

  • Sara Ngure Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology
  • Robert Kiplimo Department of Marine Engineering, Jomo Kenyatta University of Agriculture and Technology
  • Hiram Ndiritu Department of Mechanical Engineering, Jomo Kenyatta University of Agriculture and Technology

Abstract

The present work was directed towards optimizing a single cylinder,direct injection compression engine. This was done by developing atest rig which was set to operate on premixed mode. In order todevelop the rig, an electronic control unit was designed, assembledand incorporated in the set up. Further the exhaust gasrecirculation system(EGR) was designed, assembled and incorporatedinto the test rig. The objective of this work was to establish thatdirect injection compression engine can be set on a differentoperating mode for improved performance and reduced exhaustemissions. The electronic control unit facilitated the variation ofthe injection timing and the injection pressure. Injection timingwas varied from 240 to 360 at the interval of 30while injection pressure was varied from 180 bar to 230 bar at theinterval of 10 bar. In order to regulate the percentage of EGR, tworegulating valves were installed on the exhaust and recirculationlines respectively. The percentage of EGR was varied from 10% to30%. The performance and emission characteristics of the premixedcompression engine was investigated and the results compared withthose of direct injection compression engine. The results showedthat premixed charge compression engine has improved performance andreduced exhaust emissions of carbon monoxide (CO)andhydrocarbon(HC). There was improvement of 2.3 % in performance and7.6% in reduction of exhaust emissions of CO and HC. This was dueto better fuel mixing condition which was facilitated by theelectronic control unit incoorporated in the set up. The resultsalso showed that use of upto 20% EGR for medium to low loads leadsto better performance and reduced emissions of HC and CO. This showsthat, the performance and emission of an existing direct injectionengine can be improved by incooporating locally designed andassembled control unit as a subsystem. The data analyzed for asingle cylinder engine would be considered as a source ofinformation for applying this technology in multi-cylinder dieselequipment for minimum emissions and better fueleconomy.
Published
Dec 22, 2017
How to Cite
NGURE, Sara; KIPLIMO, Robert; NDIRITU, Hiram. Optimization of Direct Charge Compression Ignition Engine by Varying Injection Timing and Injection Pressure. JOURNAL OF SUSTAINABLE RESEARCH IN ENGINEERING, [S.l.], v. 4, n. 1, p. 23-32, dec. 2017. ISSN 2409-1243. Available at: <http://sri.jkuat.ac.ke/ojs/index.php/sri/article/view/616>. Date accessed: 18 aug. 2018.