Top Banner
Effect of Exhaust Gas Recirculation (EGR) on Performance and Emission characteristics of CI Engine Prepared by Sangeeta Das Enroll. no – 140370711008 Guided by Prof.Imran M Molvi. Mechanical Deptt.
23

EGR Technology

Sep 18, 2015

Download

Documents

Sangeeta Das

A presentation on Effect of Exhaust Gas Re-circulation (EGR) on Performance
and Emission characteristics of CI Engine.
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript

Slide 1

Effect of Exhaust Gas Recirculation (EGR) on Performanceand Emission characteristics of CI Engine

Prepared by Sangeeta DasEnroll. no 140370711008

Guided byProf.Imran M Molvi.Mechanical Deptt.The presentation is aimed at :Comparing the experimental works of various authors on effect of exhaust gas recirculation on reduction of exhaust temperature.

To study the effect of ECR on increase in particulate matter emission and probable means to reduce that.

Vehicular Nox emissions are regulated by stringent Environmental Legislations.NOx formation is a highly temperature dependent .In diesel Engines Engine Temp reaches upto 2000 Deg K, leading to Nox formation.To Control Nox emission exhaust temp Control can be obtained by late injection of fuel into combustion chamber.:- This decreases fuel efficiency.Better method to reduce the exhaust gas temperature is exhaust gas recirculation (ECR).ECR Technology reduces Nox emissions but increase unburned hydrocarbons and particulate matter in the exhaust.

IntroductionThe three most popular theory for Nox reduction by EGR technology are:-Increased ignition delay and reduction in max Temp achieved.Increased heat capacity of the non-reacting matter during combustion, thus lowering exhaust temperature.Dilution of inlet gas with inert gas reducing the adiabatic flame temperature.At reduced loads, EGR is more effective as at higher loads particulate matter production is more pronounced.

ContdECR can be calculated from:

Contd

Increasing EGR increases the specific heat of intake charge as exhaust gas has higher specific heat than fresh air.

The exhaust temp thus decreases with same heat release in the combustion chamber.B Jothithirumal et al investigated the effect of different quantities of exhaust gas recirculation on exhaust gas temp.

The experiment is conducted using 4 stroke 2 cylinder constant speed compression ingnition engine.

Literature Review of the 1st PaperExperimental Setups B Jothithirumal et al

ContdEGR system utilised: Long route Hot EGR system.Air box installed to measure the volumetric intake of air.Modifications made to control the discharge pulsations and measure EGR flowrate,.Engine Test Conducted at speed of1500 RPM at various loads and EGR openings.The exhaust gas opacity was measured by smoke opacity meter.The engine was run at different loads at 1500 rpm with different EGR rated (0-100%)

Results B Jothithirumal et al The Brake Thermal efficiency is slightly higher in Max EGR opening for all load conditions

Results B Jothithirumal et al Nox is comparatively less in 25% EGR valve opening

Results B Jothithirumal et al PM drastically increase when ECR is implemented for all load conditions.

Work of Jaffar Hussain Et al involved study of performance and emmission characteristics of engines under different EGR rates.

The experiment is carried out with three cylinder, air cooled and constant speed direct injection compression ignition engine.Literature Review of the 2nd PaperExperimental Setups Hussain Et al The experiment was carried out with following setup:

ContdThe Engine was coupled to an ac generator connected to a variable resistive load. Air cooling is achieved by not providing insulation in EGR recirculation line. Suitable modifications were made to control the EGR flow, dampen the engine pulsations and measure EGR flowrate.The exhaust gas opacity was measured by smoke opacity meter.The engine was run at different loads at 1500 rpm with different EGR rated (0-25%)

Results and discussionsThermal Efficiency is slightly increased at Lower ECR rates because of reburning of hydrocarbons

Thermal efficiency of Diff ECR RatesResults and discussionsThermal Efficiency is slightly increased at Lower ECR rates because of reburning of hydrocarbons

Thermal efficiency of Diff ECR RatesResults and discussionsExhaust Gas temp increases with load

Results and discussionsAs the EGR rate is incresed Volumetric efficiency increases.

Results and discussionsAs higher EGR rates hydrocarbon in exhaust gas increases.

Results and discussionsFig above shows the major benefit of diesel engines, decreasing the NOx emissions

Conclusion and Discussions

Both the studies observed that, EGR is a useful technology to reduce NOx emissions as it decreases the effective discharge tem.Hussain Et al observed a slight increase in Thermal efficiency and thus decrease in fuel consumption with the cold EGR setup, while B Jothithirumal et al didnt find significant change in brake thermal efficiency at lo EGR opening rates with long loop high temp EGR setup.Both the findings points to wards the fact that at lower EGR rates of 15-25%, Nox reduction is significant without much effect o engine performance.At higher EGR openings and at high loads particulate matter formation and smoke opacity increases.

Combined impact of Biodiesel an Exhaust gas recirculation on NOX emissions in CI Diesel Engines.-References

Effect of Exhaust gas recirculation on performance and emission characteristics of Three cylinder direct injection compression ingnition engine.

Performance analysis of Double Pipe Heat Exchanger with Annular Twisted Tape Inserts :-S.S.Pachegaonkar,S.G.Taji,Narayan Sane .Experimental studies on effect of coil wire insert on heat transfer enhancement and friction factor of Double Pipe Heat Exchanger :-Prof.S.S.Choudhari,prof.Taji s.G.References