Simulation on NOx emission of SCR system with PODE/methanol blend fuel
1. School of Automotive and Traffic Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. Wuxi Henghe EP Tech Co., Ltd., Wuxi, Jiangsu 214174, China; 3. State Key Laboratory of Power System of Tractor, Luoyang, Henan 471039, China
Abstract： To control the NOx emission of polyoxymethylene dimethyl ethers (PODE)/methanol blend fuel, the simulation model of selective catalytic reduction (SCR) system was established based on Converge software, and the influence of SCR system on the NOx emission of PODE/methanol blend fuel was investigated by numerical simulation. The results show that with the increasing of n(NH3)/n(NOx), NH3 distribution uniformity, velocity distribution uniformity and NOx conversion efficiency of SCR system are increased firstly with latter decreasing, while the leakage of NH3 is increased gradually. When the n(NH3)/n(NOx) is 1.3, the γNH3 reaches the highest value of 0.988 with the maximum μν value of 0.983 and the NOx conversion efficiency of 81.4%. Mixers can effectively improve the performance of SCR system. According to the optimization of SCR mixer by orthogonal experiment, the optimal scheme is obtained with the mixer blade number of 16, the blade inclination of 30° and the blade width of 16 mm, and the optimization scheme is verified by bench test. The NOx conversion efficiency of the optimized SCR system is 75.4% ，and the leakage of NH3 is reduced by 9.6×10-7 for the diesel engine at 1 800 r·min-1 and 100% load.
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