OXIDIZATION CATALYST AND EXHAUST EMISSION CONTROL SYSTEM

• Main Authors: OKA KOHEI, KAMAKURA SATOSHI, HIDAKA MIYUKI, SHIBATA KEIKO, YAMAMOTO KAZUNARI, HASHIMOTO MUNEMASA
• Format: Patent
• Language: English; Japanese
• Published: 28.12.2017
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

PROBLEM TO BE SOLVED: To provide an exhaust emission control system capable of preventing excessive rise of a temperature of a selective reduction type catalyst device, avoiding irreversible deterioration causing structural destruction of the selective reduction type catalyst device and maintaining high exhaust emission control performance while enabling elongation of a service life of the selective reduction type catalyst device even during forced regeneration control of a collection filter device, and an exhaust emission control method.SOLUTION: In control of a supply amount Wu of a reduction solution U, when forced regeneration control of a collection filter device 30 is performed, in order to prevent a catalyst temperature Tc of a selective reduction type catalyst device 40 from reaching a preset upper limit temperature Tu or higher, the supply amount Wu of the reduction solution U supplied from a reduction solution supply device 41 is increased to exceed a minimum necessary amount Wb enabling reduction of nitrogen oxide in an exhaust gas G, and by using the reduction solution U, the selective reduction type catalyst device 40 is cooled.SELECTED DRAWING: Figure 1 【課題】捕集フィルター装置の強制再生制御時においても、選択還元型触媒装置の温度が過度に高くなることを防止して、選択還元型触媒装置の構造的な破壊を伴う不可逆的な劣化を回避して、選択還元型触媒装置の長寿命化を実現しつつ、高い浄化性能を維持できる排気ガス浄化システム、及び排気ガス浄化方法を提供する。【解決手段】還元用溶液Ｕの供給量Ｗｕの制御に際して、捕集フィルター装置３０の強制再生制御時に、選択還元型触媒装置４０の触媒温度Ｔｃが予め設定した上限温度Ｔｕ以上にならないように、還元用溶液供給装置４１から供給される還元用溶液Ｕの供給量Ｗｕを、排気ガスＧ中の窒素酸化物を還元できる必要最低限の量Ｗｂよりも増量して、この還元用溶液Ｕにより選択還元型触媒装置４０を冷却する。【選択図】図１