摘要:
An exhaust manifold of an engine is connected to a three way (TW) catalyst, and the TW catalyst is connected to an NH.sub.3 adsorbing and oxidizing (NH.sub.3 -AO) catalyst, such as the Cu-zeolite catalyst. The engine performs the lean and the rich operations alternately and repeatedly. When the engine performs the rich operation, the TW catalyst synthesizes NH.sub.3 from NO.sub.x in the inflowing exhaust gas, and the NH.sub.3 is then adsorbed in the NH.sub.3 -AO catalyst. Next, when the engine performs the lean operation, NO.sub.x passes through the TW catalyst, and the adsorbed NH.sub.3 is desorbed and reduces the inflowing NO.sub.x. When the rich operation is in process, or is to be started, the exhaust gas temperature flowing into the NH.sub.3 -AO catalyst is detected. If the temperature is equal to or higher than the upper threshold representing the rich endurance temperature, the lean or the stoichiometric operation is performed.
摘要:
A three-way catalyst (8a) is connected to a first cylinder group 1a. The exhaust gas of the first cylinder group (1a), which has passed through the three-way catalyst (8a), and the exhaust gas of a second cylinder group (1b) are introduced to an exhaust gas purifying catalyst (14). The second cylinder group (1b) performs the lean operation. The first cylinder group (1a) performs the rich operation to synthesize NH.sub.3 from NO.sub.X in the exhaust gas of the first cylinder group (1a) in the three-way catalyst (8a). In the exhaust gas purifying catalyst (14), NO.sub.X in the exhaust gas of the second cylinder group 1b is purified by NH.sub.3 from the three-way catalyst (8a). The amount of HC flowing to the three-way catalyst (8a) is obtained. When the HC amount exceeds a predetermined amount, the first cylinder group 1a must perform the lean operation temporarily, to thereby maintain the excellent catalytic activity of the three-way catalyst (8a).
摘要:
An exhaust gas purifying catalyst, for reducing nitrogen oxides and ammonia in an exhaust gas of an internal combustion engine, in an oxidizing atmosphere, is provided. The exhaust gas purifying catalyst comprises a first catalyst having zeolite carrying platinum and copper thereon. Preferably, the exhaust gas purifying catalyst further comprises a second catalyst having zeolite carrying copper thereon. Preferably, the second catalyst is arranged upstream of the first catalyst, with respect to the exhaust gas flow.
摘要:
A device for purifying the exhaust gas of an engine having a plurality of cylinders divided into first and second cylinder groups, the first and the second cylinder groups being connected to first and second exhaust passage, respectively, and performing a lean operation, comprises an NH.sub.3 synthesizing catalyst arranged in the first exhaust passage, and an exhaust gas purifying catalyst arranged in an interconnecting passage, which interconnects the first passage downstream of the NH.sub.3 synthesizing catalyst and the second exhaust passage, for purifying the inflowing NO.sub.X and NH.sub.3. An additional engine performing a rich operation is provided and the exhaust gas thereof is fed to the first exhaust gas passage upstream of the NH.sub.3 synthesizing catalyst to make the exhaust gas air-fuel ratio of the exhaust gas flowing into the NH.sub.3 synthesizing catalyst rich, to thereby synthesize NH.sub.3 therein. An amount of NH.sub.3 or NO.sub.X flowing into the exhaust gas purifying catalyst is obtained, and the additional engine is controlled in accordance with the obtained NH.sub.3 or NO.sub.X amount to control the amount of the reducing agent flowing to the exhaust gas purifying catalyst.
摘要:
An engine (1) has first and second cylinder groups (1a) and (1b). The first cylinder group (1a) is connected to a three way (TW) catalyst (8a). The second group (1b) and the TW catalyst (8a) are connected, via an interconnecting duct (13) to an NH.sub.3 adsorbing and oxidizing (NH.sub.3 -AO) catalyst (14a). The first group (1a) performs the rich operation, and the second group (1b) performs the lean operation. In the TW catalyst (8a), NO.sub.x exhausted from the first group (1a) is converted to NH.sub.3, and the NH.sub.3 reduces the NO.sub.x exhausted from the second group (1b) in the NH.sub.3 -AO catalyst (14a). A NO.sub.x occluding and reducing (NO.sub.x -OR) catalyst (11a) is arranged in the exhaust passage between the second group (1b) and the interconnecting duct (13), to thereby suppress the NO.sub.x amount flowing into the NH.sub.3 -AO catalyst (14a).
摘要:
An exhaust manifold (7) of an engine (1) is connected to a three way (TW) catalyst (8a), and the TW catalyst (8a) is connected to an NH3 adsorbing and oxidizing (NH3-AO) catalyst (10a). The engine (1) performs the lean and the rich engine operations alternately and repeatedly. When the engine (1) performs the rich operation and thereby the exhaust gas air-fuel ratio of the exhaust gas flowing into the TW catalyst (8a) is made rich, NOx in the inflowing exhaust gas is converted to NH3 in the TW catalyst (8a). The NH3 is then adsorbed in the NH3-AO catalyst (10a). Next, when the engine (1) performs the lean operation and thereby the exhaust gas air-fuel ratio of the exhaust gas flowing into the TW catalyst (8a) is made lean, NOx in the exhausted gas passes through the TW catalyst (8a), and flows into the NH3-AO catalyst (10a). At this time, NH3 adsorbed in the catalyst (10a) is desorbed therefrom, and reduces the inflowing NOx.
摘要:
In the present invention, the exhaust gas from the engine is divided into a first and a second branch exhaust passages after it passes through a three-way reducing and oxidizing catalyst, and the two branch exhaust passages merge into an exhaust gas outlet passage. In the first branch exhaust passage, an oxidizing catalyst is disposed, and in the exhaust gas outlet passage, a denitrating and oxidizing catalyst is disposed. NO.sub.x in the exhaust gas from the engine is all converted to N.sub.2 and NH.sub.3 by the three-way reducing and oxidizing catalyst and a part of the NH.sub.3 generated by the three-way catalyst flows into the first branch exhaust passage and is converted to NO.sub.x again by the oxidizing catalyst. The amount of NO.sub.x produced by the oxidizing catalyst and the amount of NO.sub.x flowing through the second branch exhaust passage is determined by the flow distribution ratio of the first and the second branch exhaust passages. In this invention, the flow ratio is determined in such a manner that the amount of the NO.sub.x produced by the oxidizing catalyst and the amount of the NH.sub.3 passing through the second branch exhaust passage are stoichiometric to produce N.sub.2 and H.sub.2 O. Therefore, when these exhaust gases flow into the denitrating and oxidizing catalyst after they mix with each other in the exhaust gas outlet passage, all the NO.sub.x and the NH.sub.3 are converted to N.sub.2 and H.sub.2 O by the denitrating and oxidizing catalyst without producing any surplus NO.sub.x or NH.sub.3.
摘要:
To provide an exhaust gas purifying system for an internal combustion engine capable of executing an optimal regenerative operation by predicting a temperature of an absorbent based on running state information.There are predicted the amount of nitrogen oxides (NO.sub.x) to be absorbed by an absorbent 125 incorporated in a catalyst 124 and the temperature of the absorbent, based on the running state information obtained from a car navigation system 141 or traffic information service receiver 142, and the regenerative operation schedule is determined based on the prediction. Thus, the regenerative operation is conducted at the timing where NO.sub.x has been duly absorbed by the absorbent and the absorbent temperature is lower than a predetermined temperature, so that the leakage of NO.sub.x into the exterior of a vehicle can be restrained.
摘要:
An apparatus for controlling auxiliary equipment driven by an internal combustion engine, which can suppress the deterioration of a specific fuel consumption by controlling the auxiliary equipment based on running environment information provided from a car navigation system or the like. Namely, this apparatus predicts the future maximum output of the internal combustion engine and a running load thereof according to running environment information and vehicle information. Further, if the maximum output is larger than the running load, the auxiliary equipment (for example, a light and an air conditioner) are directly driven by the internal combustion engine. Moreover, surplus energy is stored in an energy storing device. When the maximum output is nearly equal to the running load and that the specific fuel consumption is deteriorated when driving the auxiliary equipments, they are driven by using the energy stored in the energy storing device. Consequently, the deterioration of the fuel consumption ratio due to the operations of the accessories is suppressed.
摘要:
In the present invention, a NO.sub.x absorbent is used for removing the NO.sub.x in the exhaust gas. The NO.sub.x absorbent absorbs NO.sub.x in the exhaust gas when the air-fuel ratio of the exhaust gas is lean, and releases the absorbed NO.sub.x and reduces it to nitrogen when the air-fuel ratio of the exhaust gas is rich or stoichiometric. To prevent the NO.sub.x absorbent from being saturated with the absorbed NO.sub.x, the NO.sub.x absorbent must be regenerated periodically by causing the NO.sub.x in the absorbent to be released and reduced. However, it is found that when the regenerating process by supplying a rich air-fuel ratio exhaust gas to the NO.sub.x absorbent is carried out at high NO.sub.x absorbent temperature, a part of NO.sub.x flows out from the NO.sub.x absorbent at the beginning of the regenerating process without being reduced. In the present invention, this outflow of NO.sub.x is suppressed by, for example, carrying out the regenerating process only when the temperature of the NO.sub.x absorbent is lowered to a predetermined temperature. This predetermined temperature is set low enough to ensure that the amount of the outflow of NO.sub.x is minimized.