Effects of Injection Timing and Exhaust Gas Recirculation on Emissions from a D.I. Diesel Engine

Robert C. Yu; Syed M. Shahed

doi:10.4271/811234

1981-10-01

Effects of Injection Timing and Exhaust Gas Recirculation on Emissions from a D.I. Diesel Engine 811234

Some results of a systematic study on the effects of injection timing retard and exhaust gas recirculation on emissions from a D.I. diesel engine are presented. The factors investigated include engine speed, fuel rate, injection timing, injection pressure, intake charge oxygen concentration, and type of diluent. The detailed mechanisms governing the formation and control of nitric oxide are studied analytically, using a previously developed diesel combustion model based on transient fuel-air mixing and Zeldovich nitric oxide reaction mechanisms.

The results show that exhaust gas recirculation and injection timing retard are both effective in reducing nitric oxide emissions at the expense of increasing smoke. The reduction of nitric oxide with exhaust gas recirculation and injection timing retard is mainly related to the decrease of local temperature and local atomic oxygen concentration. The local atomic oxygen concentration is a function of the local temperature and local molecular oxygen concentration. The results also indicate that the smoke-nitric oxide trade-off at constant charge-fuel ratio for the engine tested is fairly independent of exhaust gas recirculation rate, injection timing, injection pressure, engine speed and fuel rate.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Effects of Injection Timing and Exhaust Gas Recirculation on Emissions from a D.I. Diesel Engine 811234

SAE MOBILUS