Experimental study on the influence of urea injection strategy of the emission performance for diesel engine
PENG Tao
YU Daoguang
CUI Yuanying
ZHANG Gecheng
SUN Ke
BAI Shuzhan
Abstract：To improve NOx conversion efficiency and reduce ammonia leakage,the influence of heterogeneous flow injection of urea at different space velocity and temperatures on NOx conversion efficiency,ammonia storage and ammonia leakage are investigated experimentally.The diesel engine used in the experiment employed an exhaust aftertreatment system with selective catalytic reduction(SCR)technology.The experimental results show that for a fixed air flow,the extent of ammonia leakage is related to changes in temperature.As the temperature increases,the catalytic reduction reaction accelerates and the ammonia leakage decreases.The temperature has a great influence on the catalytic reduction reaction rate.At a flow velocity of 10 000 h-1,the reaction rate of SCR at high temperature is much higher than that at low temperature.The flow velocity has a weak influence on the reaction rate.When the flow velocity changes from 10 000 h-1 to 40 000 h-1 at the same temperature,the average reaction rate within the SCR remained largely unchanged.However,increasing the flow velocity can accelerate the leakage of ammonia,thereby mitigating the benefits associated with the NOx conversion.
Keywords：diesel engineammonia leakconversion efficiencyreaction rateflow velocity
Publication Date：2025-03-30
Online Publishing Date：2026-05-22(First online date of this platform, not the publication date of the document)
Pages：7( 67-72,85 )