Nissan Diesel Motor Co., Ltd.

Ud Trucks Corporation

Waseda University

Tokyo Roki Co., Ltd.

Nobuhiko Masaki

Kiminobu Hirata

Masakazu Yano

Isamu Kanaya

Hisashi Akagawa

Kouji Masuda

Yuji Yajima

Jin Kusaka

Hideaki Kato

Hiroki Ueno

Tatsuji Miyata

Daisuke Shirai

Hitoshi Hiramoto

Koutarou Honda

Naobumi Yamada

Takayuki Adachi

Tomoko Amemiya

Yasumasa Notake

Keishi Takada

Takeshi Mende

Fumiyuki Tsurumi

Shinya Obana

An engine exhaust purification device comprises: a selective reduction type NOx catalyst; an oxidation catalyst disposed on an upstream side of the NOx catalyst; a reducing agent adding device which adds an NOx reducing agent to an exhaust gas of an engine; a control device which controls the reducing agent adding device; and an NOratio calculation device which estimates an NOratio of the exhaust gas flowing into the NOx catalyst. The NOratio of the exhaust gas flowing into the NOx catalyst is calculated by a catalytic reaction model where the oxidation reaction of NO in the oxidation catalyst is numerically formulated, and the NOratio is reflected to calculate an amount of ammonia adsorbed on the NOx catalyst by a catalytic reaction model where a chemical reaction concerned with the reduction of NOx in the NOx catalyst is numerically formulated.

Engine exhaust purification device

In order to maintain a high NOx purification rate of a NOx reduction catalytic converter even in the case in which an NOx emission amount from an engine changes suddenly, in an exhaust emission purifying apparatus for an engine that reduces and purifies NOx in exhaust gas using ammonia generated from an injection-supplied urea aqueous solution, after engine starting, when an exhaust temperature exceeds a predetermined temperature T (step S), an amount of urea aqueous solution corresponding to an actual engine operating state is injection-supplied (steps Sto S). On the other hand, at a change of the transmission speed ratio based on a driver's shift operation, an engine operating state after the change of the transmission speed ratio is predicted (steps S, S), and an amount of urea aqueous solution corresponding to the predicted engine operating state is injection-supplied before the change of the transmission speed ratio is completed (steps S, S).

Exhaust emission purifying apparatus for engine

In an exhaust filter, a urea hydrolysis catalyst is supported on a first portion of an inner wall of a cell passage on the inlet side, and a first NOx reducing catalyst is supported on a second portion of the inner wall of the inlet-side passage downstream of the first portion. A second NOx reducing catalyst is supported on a third portion of an inner wall of a cell passage on the outlet side where the third portion overlaps with the first portion in a direction of intersection with the exhaust flow into the exhaust filter or is downstream of the first portion. An oxidation catalyst is supported on a fourth portion of the inner wall of the outlet-side passage downstream of the third portion where the fourth portion overlaps with the second portion in the direction of intersection or is downstream of the second portion.

In an exhaust emission purifying apparatus for an internal combustion engine, for adding a reducing agent for NOto the exhaust gas to thereby purify NOin the exhaust gas, the mixing of the reducing agent injected by an injection nozzle with the exhaust gas is accelerated. To this end, in the apparatus of the present invention, the injection nozzle for the urea water is disposed to be opposite to the flow of the exhaust gas, or to face upward in a vertical direction.

Exhaust emission purifying apparatus for internal combustion engine

In an exhaust gas purification apparatus for an engine includes a bubble generation device, the bubble generation device for mixing nano-sized to micro-sized bubbles into a liquid reducing agent or a precursor thereof injection-supplied from an injection nozzle is disposed in a reducing agent supply system running from a reducing agent tank to the injection nozzle. When the liquid reducing agent or the precursor thereof is injection-supplied from the injection nozzle, the liquid reducing agent or the precursor thereof is divided by bubbles, and the bubbles are radically inflated and burst by a pressure change and a temperature change at the time of injection-supplying, so that microparticulation of the liquid reducing agent or the precursor thereof is facilitated.

Exhaust gas purification apparatus for engine

An exhaust gas pressure P, exhaust gas temperatures Tand Ton upstream and downstream of a DPF, a rotation speed Ne, a load Q, and an intake flow rate F as various operating conditions are read, and an amount of PM generated for short time &#x394;t is obtained to be added to a PM deposited amount m, and thus, to obtain an initial deposited amount. Exhaust gas properties and a space velocity SV are obtained based on various operating conditions, and the PM deposited amount m after a lapse of the short time &#x394;t is estimated from a PM deposited amount estimation equation 'm=m&#xb7;exp(&#x2212;B&#xb7;&#x394;t)' having been derived considering the exhaust gas properties and the space velocity SV. When the PM deposited amount m is equal to or more than a predetermined value, a forced regeneration processing in the DPF is executed, and thereafter, the PM deposited amount m is reset to 0.

Apparatus for and method of purifying exhaust gas

In order to suppress deposition of constituent of a reducing agent (dissolved matter) in an exhaust passage of an engine enhancing an elimination rate of NOx even when temperature of an exhaust emission from the engine is low, an exhaust emission purifying apparatus is provided with an electro-generative-heat carrier provided on an upstream side of an injection nozzle that supplies the reducing agent into the exhaust emission on upstream side of a reduction catalyst in an exhaust pipe, the exhaust emission being heated to a temperature equal to or higher than a melting point of the dissolved matter whereby deposition of the dissolved matter on an inner wall surface of the exhaust pipe is suppressed to effectively use the supplied reducing agent for catalytic reduction reaction, even when the exhaust emission temperature is lower than the melting point of the dissolved matter of the reducing agent.

In relation to an exhaust gas purification system that mixes a liquid reducing agent with air and injection-supplies this mixture into an exhaust gas flowing on an upstream side of a reduction catalyst () to thereby effect reduction purification of NOx in exhaust gas, a technical attention is directed to the relation of respective elements of; the travel distance, the fuel consumption, the air consumption, or the running time and the like, and the liquid reducing agent consumption, to constitute a configuration such that a continual monitor as to whether the injection condition of liquid reducing agent is normal or abnormal is executed by judging whether or not the amount of liquid reducing agent consumed for a predetermined travel distance, a predetermined fuel consumption, a predetermined air consumption, or a predetermined running time, is within a predetermined range.

Apparatus for judging condition of injection of reducing agent incorporated in exhaust gas purification system

An exhaust emission purifying apparatus has a NOx reduction catalytic converter in an exhaust passage of an engine, for purifying nitrogen oxides in the exhaust gas by reduction with urea aqueous solution; an injection nozzle injecting the urea solution toward an exhaust upstream side of the converter in the exhaust passage; and fins disposed on an exhaust upstream side of an injection position of the urea solution in the injection nozzle, for generating a spiral swirling flow of the gas swirling about a center corresponding to the central axis of an exhaust pipe. The swirling flow generated in the exhaust gas prior to the injection-supply of the urea aqueous solution promotes mixing of the solution with the gas to thereby promote the hydrolysis of the urea solution. And the exhaust gas and ammonia generated from the urea solution are uniformly mixed together.

An exhaust emission purifying apparatus of the present invention has a casing that includes therein a plurality of layered passages which is formed by partitioning an inside of the casing to thereby allow an exhaust passage from an exhaust emission inlet to an exhaust emission outlet to be folded in its direction once or more, a reduction catalyst that reductively purifies NOx by using a reducing agent, a nozzle that injects the reducing agent or a precursor thereof to an exhaust upstream side of the reduction catalyst, and a filter (DPF) that collects PM suspended in an exhaust emission. The reduction catalyst and the filter are disposed in the different layered passages. Consequently, a more compact exhaust emission purifying apparatus having both NOx removal function and PM collection function can be provided.

Exhaust emission purifying apparatus

For preventing clogging in an injection nozzle for supplying a reducing agent to exhaust gas flow on an upstream side of a reducing catalyst and for improving the efficiency of NOx purification processing, the injection nozzlehas a tip end portionprovided with a ring shaped protruding ridgedisposed on an outer peripheral surface of an exhaust gas downstream side end portion of the tip end portionthat is arranged substantially in parallel with an exhaust gas flow direction A inside an exhaust pipethe ring shaped protruding ridgebeing provided with injection hole or holesdrilled outward from the central axis of the injection nozzleso that the reducing agent is ejected on the exhaust gas upstream side of the reduction catalyst, from the injection holesThe injection holesdo not directly open on a wide outer peripheral surface of the injection nozzleand then when injection stops, the reducing agent does not become attached to or does not remain around the injection holesor the remaining amount thereof becomes small, so that clogging of the injection holesof the injection nozzleis prevented, and the efficiency of NOx purification processing is improved.

Exhaust gas purification apparatus of engine

An exhaust emission purifying apparatus for an engine having: a reduction catalytic converter disposed in an exhaust system of the engine, for reductively purifying nitrogen oxides in the exhaust emission with a reducing agent; an injection nozzle for injection-supplying the reducing agent to an exhaust upstream side of the reduction catalytic converter in an exhaust pipe of the exhaust system; and a reducing agent supply device supplying the reducing agent to the injection nozzle, in which a recess portion is formed on an inner wall on a lower portion of the exhaust pipe, by concaving a site to which at least the reducing agent injection-supplied from the injection nozzle is attached, and also, a bottom wall of the recess portion is made detachable.

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Ageo, Japan

Nobuhiko Masaki