摘要:
An exhaust purification apparatus comprises an ammonia selective reduction-type NOx catalyst that selectively reduces NOx within exhaust gas by using ammonia as a reducing agent, a urea-water supply device that supplies urea-water into the exhaust gas existing upstream of the ammonia selective reduction-type NOx catalyst, and a control unit. The control unit controls the urea-water supply device so that the urea-water is intermittently supplied according to predetermined supply duration time and predetermined supply suspension time when the urea-water is supplied from the urea-water supply device for the purpose of providing ammonia to the ammonia selective reduction-type NOx catalyst.
摘要:
An exhaust purification apparatus for an engine has a first casing (17) that is interposed in an exhaust path (13); a second casing (23) that is set downstream of the first casing (17) and contains an exhaust purification device (24); a connecting pipe (22, 41, 51) that connects the first casing and the second casing (23) to each other and includes an insertion portion that is inserted in the first casing (17); and an injection nozzle (27, 52) that has a tip end inserted in the connecting pipe (22, 41, 51) and injects an auxiliary agent from the tip end. The insertion portion of the connecting pipe (22, 41, 51) is provided with a plurality of through-holes (22a, 41a, 41b, 51a) connecting the inside and the outside of the connecting pipe (22, 41, 51), so that the exhaust gas contained in the first casing (17) is introduced into the connecting pipe (22, 41, 51) through the through-holes and guided towards the second casing (23).
摘要:
An exhaust purification apparatus for an engine has a first casing (17) that is interposed in an exhaust path (13); a second casing (23) that is set downstream of the first casing (17) and contains an exhaust purification device (24); a connecting pipe (22, 41, 51) that connects the first casing and the second casing (23) to each other and includes an insertion portion that is inserted in the first casing (17); and an injection nozzle (27, 52) that has a tip end inserted in the connecting pipe (22, 41, 51) and injects an auxiliary agent from the tip end. The insertion portion of the connecting pipe (22, 41, 51) is provided with a plurality of through-holes (22a, 41a, 41b, 51a) connecting the inside and the outside of the connecting pipe (22, 41, 51), so that the exhaust gas contained in the first casing (17) is introduced into the connecting pipe (22, 41, 51) through the through-holes and guided towards the second casing (23).
摘要:
An agitating device for agitating the exhaust gas of an engine includes a base plate having a plurality of through holes that are defined by radially extending spoke portions and a ring-like rim portion and are arranged in a circular pattern in a circumferential direction of the base plate, and a plurality of fins expanding from the respective spokes on a slant with respect to the base plate. The base plate is fixed in the exhaust passage by the rim portion being jointed to the exhaust passage at welded portions. The welded portions are each disposed in an area between respective two adjacent spoke portions in the circumferential direction of the base plate, and an outer edge of the rim portion positioned on the outer side of the rim portion in extending directions of the spoke portions is located next to the exhaust passage with a gap provided therebetween.
摘要:
An exhaust gas purifying system reliably detects an amount of accumulated particulates, lengthens forced regeneration intervals, and improves fuel efficiency. The exhaust gas purifying system comprises: a particulate filter 22 disposed in an exhaust system of an internal combustion engine 2 and collecting particulates from exhaust gas, and an NO2 generating unit 21 upstream of or in the particulate filter 22; a discharged particulate amount calculating unit A1 calculates an amount Me of discharged particulates on the basis of an excess air ratio λ; a burnt particulate amount calculating unit A2 calculates an amount Mb of burnt particulates on the basis of the temperature of exhaust gas in front of the particulate filter or the temperature of the particulate filter; and a particulate accumulation amount calculating unit calculates an amount Ma of accumulated particulates on the basis of the amount Me of discharged particulates or the amount Mb of burnt particulates.
摘要:
An exhaust gas purifying system reliably detects an amount of accumulated particulates, lengthens forced regeneration intervals, and improves fuel efficiency. The exhaust gas purifying system comprises: a particulate filter 22 disposed in an exhaust system of an internal combustion engine 2 and collecting particulates from exhaust gas, and an NO2 generating unit 21 upstream of or in the particulate filter 22; a discharged particulate amount calculating unit A1 calculates an amount Me of discharged particulates on the basis of an excess air ratio λ; a burnt particulate amount calculating unit A2 calculates an amount Mb of burnt particulates on the basis of the temperature of exhaust gas in front of the particulate filter or the temperature of the particulate filter; and a particulate accumulation amount calculating unit calculates an amount Ma of accumulated particulates on the basis of the amount Me of discharged particulates or the amount Mb of burnt particulates.
摘要:
An exhaust emission control system of an internal combustion engine capable of post injection is disclosed which provides control such that the injection timing in sub injection is set to a point earlier than the target injection timing when the sub injection is started, and the injection timing in the sub injection is then delayed to the target injection timing. This realizes the post injection under the optimum conditions and enables an efficient rise in the exhaust temperature while inhibiting deterioration of the drivability due to a rapid change in torque.
摘要:
An exhaust emission control system of an internal combustion engine is provided which controls the oxygen concentration of exhaust passing through the exhaust emission control device according to the flow rate of exhaust flowing through an exhaust passage when the exhaust emission control device is regenerated, so that the regeneration is completed within a short period of time while the filter is prevented from being damaged by melting during the regeneration. This improves the exhaust emission control performance and reliability of the filter.
摘要:
A NOx catalyst for selectively reducing NOx in exhaust gas by adsorbing ammonia is provided at an exhaust system of an engine, ammonia or urea water is supplied to the NOx catalyst by reducing agent supplying means, a consumption amount of ammonia adsorbed to the NOx catalyst is derived by consumption amount deriving means based on an exhaust amount of NOx exhausted from the engine detected or estimated by NOx exhaust amount deriving means and an actual NOx cleaning rate by the NOx catalyst derived by actual NOx cleaning rate deriving means, an actual adsorption amount of ammonia adsorbed to the NOx catalyst is derived in accordance with an addition amount of ammonia and the consumption amount of ammonia by adsorption amount deriving means and the reducing agent supplying means is controlled by controlling means in accordance with the actual adsorption amount.
摘要:
An exhaust purification device for an engine comprises a catalyst device that purifies the exhaust gas of the engine by using an additive; a venturi-shaped mixing chamber that is disposed upstream from the catalyst device and extends from a taper portion with a diameter tapering downstream to continue to a constricted portion with a minimum diameter and then to a flared portion with a diameter that is increased in the downstream direction; a swirl-generating device that is disposed in vicinity of a most upstream section of the taper portion of the mixing chamber and generates a swirling flow in the exhaust gas; and an additive-injection device that is disposed upstream from the constricted portion of the mixing chamber and downstream from the swirl-generating device, and injects the additive into the mixing chamber.