UREA SCR SYSTEM, CONTROL DEVICE OF UREA SCR SYSTEM AND ESTIMATION METHOD OF ACCUMULATION AMOUNT OF WHITE PRODUCT

To provide a urea SCR system which can accurately estimate an accumulation amount of white products in an exhaust flow passage, a control device of the urea SCR system and an estimation method of the accumulation amount of the white products.SOLUTION: A urea SCR system 100 comprises a urea water injector 101, an SCR catalyst 102 and a control device 103. The control device 103 determines an addition accumulation amount in an exhaust flow passage 105 of white products on the basis of an addition amount of urea water, a temperature of exhaust emission, and a flow rate of the exhaust emission, determines a subtraction accumulation amount in the exhaust flow passage 105 of the white products on the basis of a current accumulation amount of the white products in the exhaust flow passage 105, the temperature of the exhaust emission and the flow rate of the exhaust emission, and sets a sum of the current accumulation amount of the white products in the exhaust flow passage 105, the addition accumulation amount of the white products in the exhaust flow passage 105, and the subtraction accumulation amount of the white products in the exhaust flow passage 105 to a novel accumulation amount of the white products in the exhaust flow passage 105, thus solving a problem.SELECTED DRAWING: Figure 1 【課題】白色生成物の排気流路に於ける堆積量を高精度に推定する事が可能な尿素ＳＣＲシステム、尿素ＳＣＲシステムの制御装置、及び白色生成物の堆積量の推定方法を提供する。【解決手段】尿素水インジェクタ１０１と、ＳＣＲ触媒１０２と、制御装置１０３と、を備え、制御装置１０３は、尿素水の添加量と排気の温度と排気の流量とを基に白色生成物の排気流路１０５に於ける加算堆積量を決定し、白色生成物の排気流路１０５に於ける現在の堆積量と排気の温度と排気の流量とを基に白色生成物の排気流路１０５に於ける減算堆積量を決定し、白色生成物の排気流路１０５に於ける現在の堆積量と白色生成物の排気流路１０５に於ける加算堆積量と白色生成物の排気流路１０５に於ける減算堆積量との和を白色生成物の排気流路１０５に於ける新規の堆積量とする尿素ＳＣＲシステム１００によって課題を解決する事が出来る。【選択図】図１