基于多目标遗传算法的SCR系统氨覆盖率优化

Optimization of Ammonia Coverage Ratio in Selective Catalytic Reduction System Using a Multi-objective Genetic Algorithm

基于单状态选择催化还原(SCR)模型,应用多目标遗传算法对SCR系统进行优化。获得了最优氨覆盖率目标值,优化了SCR系统NOx排放和NH3泄漏之间的此消彼长(tread-off)的关系,分析了催化器温度、空速和SCR催化器入口NOx浓度对最优目标氨存储的影响。研究结果表明,催化器温度是最优氨覆盖率目标值的主要影响因素,最优氨覆盖率目标值随着温度的增大呈线性降低趋势。世界统一稳态测试循环(WHSC)和瞬态测试循环(WHTC)仿真结果表明,采用优化后的氨覆盖率图谱作为氨存储目标值,可在取得较低NOx排放的同时限制NH3泄漏。

Based on the one-state selective catalytic reduction(SCR) model, a multi-objective genetic algorithm is adopted for SCR system optimization. The optimal ammonia coverage ratio target value is obtained. The tread-off relationship between NOx emission and NH3 leakage in SCR system is optimized. The effect of catalyst temperature, space velocity and SCR catalyst inlet NOx concentration on optimal target ammonia storage is analyzed. The results show that the catalyst temperature has the main influence on the target value of the optimal ammonia coverage ratio, which decreases linearly with the increase of the temperature. The simulation results of the world harmonized stationary cycle(WHSC) and world harmonized transient cycle(WHTC) show that the optimal ammonia coverage ratio map as control set-point can achieve low NOx emission while restrict NH3 leakage.