EXPERIMENTAL INVESTIGATIONS OF EFFECTS OF COOLING/NON COOLING OF EGR ON TWO LEVEL OF COMPRESSION RATIO IN A COMMON RAIL DIESEL ENGINE

Abstract

EGR cooling is followed for many years and proven as an efficient technique for reducing NOx-PM emissions. EGR cooling helps in emission reduction of NOx and PM. But, it brings associated issues like cooler fouling; misfiring in cold condition, if cooling is not bypassed, during cold start. Also, it increases HC and CO emissions thus leading to increased loading of diesel oxidation catalyst. In the present study, two engine operating points were chosen from EUDC part of modified NEDC cycle for India. The two set of compression ratios were prepared. The NOx-PM along with HC and CO emissions were measured with 18.5CR. The emissions with cooled EGR were taken first which form the base optimization. The cooler was removed from the EGR circuit and same measurements were done. In the third step, the increased NOx due to non-cooled EGR was brought to the original value by increasing the Injection rail pressure and EGR rates simultaneously. In this process, the PM emission was found to be increasing marginally from its optimized value. The same experimentation was repeated for the 16.5 compression ratio. Both the compression ratios exhibit the similar trends of emissions. The magnitude of NOx PM, HC and CO differs for both the compression ratios. In order to meet the baseline optimized NOx-PM emissions with prime objective to get rid of EGR cooler and gain cost saving, reduced compression ratio found to be promising solution. There was marginal increase in CO and HC emission with this approach.

Keywords

Dates

  • Submission Date2013-08-04
  • Revision Date2014-07-20
  • Acceptance Date2015-12-24
  • Online Date2015-02-08

DOI Reference

10.2298/TSCI130804013G

References

  1. Dr. Peter L. Herzog, Combustion development directions for HSDI engine, Symposium of Automotive technology, India, 2005, pp.31-40
  2. F. Mallamo et. al., Effect of compression ratio and injection pressure on emissions and fuel consumption of a small displacement common rail diesel engine, SAE world congress, 2005-01-0379, 2005
  3. ***,Susumu Niinai available at <www.mazda.com/ mazdaspirit/skyactiv/engine/skyactive.html>
  4. O. Laguitton et. al., The effect of compression ratio on exhaust emissions from a PCCI diesel engine, Conversion & Management, 48 (11) (2007). pp. 2918-2924.
  5. B. Mahr, Future and Potential of Diesel Injection Systems, THIESEL Conference on Thermo- and Fluid-Dynamic Proceeding
  6. Yoshinori Iwabuchi et.al., Trial of New Concept Diesel Combustion System - Premixed Compression-Ignited Combustion, SAE world congress, 1999-01-0185,1999
  7. Wu, K., Effects of compression Ratio on Combustion characteristics of a Direct-Injection Diesel Engine, SAE world congress, 872056, 1987
  8. John B. Heywood, Internal Combustion engine fundamental, McGraw Hill Inc., New York USA, 1988, p.490.
  9. Jan-Ola Olsson et.al., The Effect of Cooled EGR on Emissions and Performance of a Turbocharged HCCI Engine, SAE world congress, 2003-01-0743, 2003
  10. R.S.G. Baert et.al., Efficient EGR Technology for Future HD Diesel Engine Emission Targets, SAE world congress, 1999-01-0837, 1999
  11. Andrew Nicol, Heavy-Duty Diesel Engine Trends to Meet Future Emissions Standards (EuroVI), Report No. RD07/413401.1, AECC Technical Seminar on Heavy-Duty Vehicle Emissions (EuroVI) Brussels, Ricardo, 2007.
  12. Gajarlawar Nilesh et.al., Investigation of effect of Pilot Injection with change in level of compression ratio in a common rail Diesel engine, Thermal Science, Vol.17 (2012) ,1., pp. 71-80
  13. Radivoje B.P., et.al., Benefits and Challenges of Variable Compression Ratio at Diesel engines, Thermal Science, vol. 14 (2010), 4., pp. 1063-1073
  14. ***, www.avl.com/ama-i60-exhaust-measurement-system
  15. ***, www.avl.com/indicom-indicating-software