摘要:
In an exhaust emission purifying apparatus for an internal combustion engine, for adding a reducing agent for NOx to the exhaust gas to thereby purify NOx in 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.
摘要:
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 (20) 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.
摘要:
A DPF disposed in an exhaust passage of a diesel engine is coated with a selective reducing catalyst, for selectively reducing and purifying NOx by using a reducing agent, and a thin film, having fine pores of size for allowing passage of the NOx and preventing passage of PM, in this order. In regeneration treatment of a DPF, the thin film prevents direct transmission of combustion heat of the PM to the selective reducing catalyst and suppresses a temperature rise of the selective reducing catalyst to thereby suppress deterioration of an active component.
摘要:
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.
摘要:
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 nozzle 14 has a tip end portion 18 provided with a ring shaped protruding ridge 19 disposed on an outer peripheral surface of an exhaust gas downstream side end portion of the tip end portion 18 that is arranged substantially in parallel with an exhaust gas flow direction A inside an exhaust pipe 13, the ring shaped protruding ridge 19 being provided with injection hole or holes 20 drilled outward from the central axis of the injection nozzle 14, so that the reducing agent is ejected on the exhaust gas upstream side of the reduction catalyst, from the injection holes 20. The injection holes 20 do not directly open on a wide outer peripheral surface of the injection nozzle 14, and then when injection stops, the reducing agent does not become attached to or does not remain around the injection holes 20, or the remaining amount thereof becomes small, so that clogging of the injection holes 20 of the injection nozzle 14 is prevented, and the efficiency of NOx purification processing is improved.
摘要:
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.
摘要:
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 nozzle 14 has a tip end portion 18 provided with a ring shaped protruding ridge 19 disposed on an outer peripheral surface of an exhaust gas downstream side end portion of the tip end portion 18 that is arranged substantially in parallel with an exhaust gas flow direction A inside an exhaust pipe 13, the ring shaped protruding ridge 19 being provided with injection hole or holes 20 drilled outward from the central axis of the injection nozzle 14, so that the reducing agent is ejected on the exhaust gas upstream side of the reduction catalyst, from the injection holes 20. The injection holes 20 do not directly open on a wide outer peripheral surface of the injection nozzle 14, and then when injection stops, the reducing agent does not become attached to or does not remain around the injection holes 20, or the remaining amount thereof becomes small, so that clogging of the injection holes 20 of the injection nozzle 14 is prevented, and the efficiency of NOx purification processing is improved.
摘要:
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.
摘要:
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 NO2 ratio calculation device which estimates an NO2 ratio of the exhaust gas flowing into the NOx catalyst. The NO2 ratio 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 NO2 ratio 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.
摘要:
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 S1), an amount of urea aqueous solution corresponding to an actual engine operating state is injection-supplied (steps S3 to S5). 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 S2, S6), 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 S7, S8).