针对Urea-SCR催化器储氨量计算问题,提出基于催化器下游NOx变化规律的计算方法,并分析对比其与质量守恒法的准确程度。在AVL台架上开展储氨特性试验并分析试验数据发现,添蓝溶液不足时,质量守恒法计算结果为负数且添蓝溶液过喷时其计算结果远大于变化规律法;相比质量守恒法,变化规律法排除了HC与NOx的反应以及添蓝溶液的沉淀与结晶对计算结果的影响,误差减少10%。
For the calculation of ammonia storage amount of Urea-SCR catalyst, this paper proposes the calculation method based on the change law of NOx at downstream of catalyst, and compare and analyze it's calculation accuracy with the mass conservation. The test for ammonia storage property is carried out on AVL bench, which shows that, when the Ad Blue injection is insufficient, the ammonia storage amount calculated by the method of mass conservation law is negative,when the Ad Blue injection is excessive, the ammonia storage amount calculated by the method of mass conservation law is much greater than the method of change law; compared with the mass conservation law, the method of change law eliminates the effect of HC and NOx reaction and Adblue's precipitation and crystallization on that calculation results, and the error rate is reduced by 10%.