Study on NOx emissions from a national V heavy-duty diesel engine

Detail components of nitrogen oxides (NOx) emissions, which is including NO, NO2, and N2O, from a national V heavy-duty diesel engine with selective catalytic reduction (SCR) were studied under different operating conditions by using Fourier transform infrared spectrum (FTIR) technology. Results show that compared to the engine without SCR, descent of NOx emissions from the engine with SCR on different load are different and the higher load, the more drop. NO and NO2 emissions from the engine with SCR have an varying degrees of decline, N2O emissions raise more than 50% as a result of SCR side reaction exists. N2O emissions ascends with the increase of the load, and this is because increasing exhaust temperature leads to higher oxidation reaction rate of NH3 to N2O.