Effect of EGR Coupled SCR on NOx Emission Characteristics of Heavy-Duty Diesel Engine
2022-01-0664
03/29/2022
- Event
- Content
- EGR and SCR has become an important technology to reduce NOx emission of heavy-duty diesel engine and meet increasingly stringent emission regulations. This paper studied on the effect of EGR coupled SCR on NOx emission characteristics of heavy-duty diesel engine based on engine bench test. The results showed that the NO emission reduction performance of EGR coupled SCR increased with the increase of engine load, and the increase slowed down after 75% load. EGR coupled SCR has little effect on NO2 emission reduction, the increase of engine speed can significantly improve the efficiency of NO2 emission reduction at 75% and 100% load. The effect of EGR coupled SCR on reducing NO became more and more significant with the increase of diesel engine load, but the effect was no longer significant when the reduction of NO emission exceeded a certain limit under the same working condition. EGR had better NOx reduction performance at 50% load of diesel engine when the valve opening was 25% and 50%, and the effect of SCR was not significant at this time. Compared with low load, increased valve opening of EGR or urea injection ammonia nitrogen ratio of SCR had a more obvious effect on NOx emission reduction at high load. SCR coupled with low valve opening EGR had a more significant effect on NOx emission reduction. The increase of the EGR valve opening and the SCR urea injection led to the increase of fuel consumption rate of diesel engine, but the influence of the two factors on the fuel consumption rate of diesel engine decreased gradually with the increase of diesel engine speed.
- Citation
- Lou, D., Kang, L., Tan, P., Hu, Z. et al., "Effect of EGR Coupled SCR on NOx Emission Characteristics of Heavy-Duty Diesel Engine," SAE Technical Paper 2022-01-0664, 2022, .