JP2016186271A - Catalyst using exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a catalyst using exhaust emission control device that shortens time where catalyst temperature reaches activation temperature as much as possible to maintain an exhaust emission control rate at a high level even in a low load operation where an exhaust flow rate is low.SOLUTION: A catalyst using exhaust emission control device 100 cleans an exhaust gas discharged from an internal combustion engine 101 via an exhaust pipe 102 by a catalyst. The catalyst using exhaust emission control device 100 includes catalyst effective volume changing means 116 for changing a catalyst effective volume based on an exhaust flow rate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a catalyst-based exhaust purification device that purifies exhaust gas discharged from an internal combustion engine such as a diesel engine through an exhaust pipe with a catalyst.

As an exhaust gas purification device that purifies exhaust gas discharged into the atmosphere by removing harmful substances contained in exhaust gas discharged from an internal combustion engine such as a diesel engine mounted on an automobile through an exhaust pipe, Particulate matter (PM) contained therein is collected by a diesel particulate filter (DPF) to reduce the amount of particulate matter discharged into the atmosphere and installed in the front stage of the diesel particulate collection filter The oxidation catalyst (DOC) is used to oxidize nitric oxide (NO) contained in the exhaust to produce nitrogen dioxide (NO ₂ ), and the nitrogen dioxide collects it in the diesel particulate filter. 2. Description of the Related Art A catalyst-based exhaust purification device such as a diesel particulate filter device that burns and removes particulate matter is known (see, for example, Patent Document 1).

JP 2011-256848 A

  By the way, in the catalyst-based exhaust purification device, the catalyst volume is determined based on the exhaust flow rate during full load operation in order to maintain the exhaust purification rate at a high level even during full load operation where the exhaust flow rate is maximum. However, at the time of low load operation with a small exhaust flow rate, the amount of heat of the exhaust is small, so that the time until the catalyst temperature reaches the activation temperature becomes long, and there is a problem that the exhaust purification rate decreases.

  Therefore, an object of the present invention is to maintain the exhaust purification rate at a high level by shortening the time until the catalyst temperature reaches the activation temperature as much as possible even during low load operation with a small exhaust flow rate. The object is to provide a catalyst-based exhaust purification device.

  The present invention devised to achieve this object is a catalyst effective volume for changing the catalyst effective volume based on the exhaust flow rate in a catalyst-based exhaust gas purification apparatus that purifies exhaust gas discharged from an internal combustion engine through an exhaust pipe with a catalyst. It is a catalyst-based exhaust gas purification device provided with changing means.

  Preferably, the catalyst effective volume changing means is a shutter valve that is installed on the exhaust upstream side of the catalyst and whose opening is controlled based on the exhaust flow rate.

  According to the present invention, it is possible to use a catalyst capable of maintaining the exhaust purification rate at a high level by shortening the time required for the catalyst temperature to reach the activation temperature as much as possible even during low load operation with a small exhaust flow rate. An exhaust emission control device can be provided.

It is the schematic which shows the catalyst utilization exhaust gas purification apparatus which concerns on this invention.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the accompanying drawings.

  As shown in FIG. 1, the catalyst-based exhaust purification device 100 removes harmful substances contained in the exhaust discharged from the internal combustion engine 101 such as a diesel engine mounted on the automobile 200 through the exhaust pipe 102. This is a type of exhaust purification device that purifies exhaust discharged into the atmosphere.

  As the catalyst exhaust purification apparatus 100, for example, the particulate matter contained in the exhaust gas is collected by the diesel particulate filter 103 and the amount of particulate matter discharged into the atmosphere is reduced. Nitric oxide contained in the exhaust gas is oxidized by the oxidation catalyst 104 installed in the front stage of the collection filter 103 to generate nitrogen dioxide, and the nitrogen dioxide is collected by the diesel particulate collection filter 103. A diesel particulate filter device that burns and removes particulate matter that has been burned off may be used, but any device that purifies exhaust gas with a catalyst may be used.

  The internal combustion engine 101 is connected to an intake pipe 105 and is connected to an intake manifold 106 that branches intake air introduced into the internal combustion engine 101 through the intake pipe 105 to each combustion chamber of the internal combustion engine 101, and an exhaust pipe 102. An exhaust manifold 107 that joins exhaust exhaust discharged from each combustion chamber of the internal combustion engine 101 to the exhaust pipe 102 is provided.

  Since the intake manifold 106 and the exhaust manifold 107 are communicated with each other through an exhaust gas recirculation (EGR) pipe 108, the exhaust gas exhausted from the internal combustion engine 101 is circulated as the intake air introduced into the internal combustion engine 101 again. At this time, the exhaust gas is cooled through the exhaust gas recirculation cooler 109 installed in the exhaust gas recirculation pipe 108 and circulated as intake air.

  In the internal combustion engine 101, intake air is introduced into the internal combustion engine 101 through the intake pipe 105 and exhaust gas is discharged from the internal combustion engine 101 through the exhaust pipe 102 through a combustion stroke. At this time, the intake air introduced into the internal combustion engine 101 is purified through the intake air purification device 110 installed in the intake pipe 105 and exhausted to the atmosphere through the catalyst-based exhaust gas purification device 100 installed in the exhaust pipe 102. Exhausted exhaust is purified.

  In the automobile 200, since the supercharger 111 is installed between the intake pipe 105 and the exhaust pipe 102, the prime mover 112 of the supercharger 111 installed in the exhaust pipe 102 is discharged from the internal combustion engine 101. By being driven by exhaust gas, the compressor 113 of the supercharger 111 installed in the intake pipe 105 is driven, and the intake air introduced into the internal combustion engine 101 through the intake pipe 105 is supercharged.

  Further, the automobile 200 is discharged into the atmosphere through the exhaust pipe 102 by adding unburned fuel to the exhaust discharged into the atmosphere through the exhaust pipe 102 and oxidizing and burning the unburned fuel with the oxidation catalyst 104. In order to raise the exhaust temperature and raise the temperature of the diesel particulate filter 103 to a reproducible temperature and maintain the state, unburned fuel is added to the exhaust discharged into the atmosphere through the exhaust pipe 102. As a means, an exhaust pipe fuel injector 115 for injecting fuel in accordance with an instruction fuel injection amount by an internal combustion engine controller (ECU) 114 is mounted on the exhaust upstream side of the diesel particulate filter 103.

  The catalyst-based exhaust purification apparatus 100 according to a preferred embodiment of the present invention includes a catalyst effective volume changing unit 116 that changes the catalyst effective volume based on the exhaust flow rate. The catalyst effective volume changing unit 116 includes: The shutter valve 117 is installed upstream of the oxidation catalyst 104 and whose opening is controlled by the internal combustion engine controller 114 based on the exhaust flow rate.

  The opening of the shutter valve 117 is increased during high load operation with a large exhaust flow rate, and the opening is decreased during low load operation with a small exhaust flow rate. The opening degree is set to 100% during full load operation at which the exhaust flow rate becomes maximum.

  Thereby, since the catalyst effective volume can be changed based on the exhaust gas flow rate, even at the time of low load operation with a small exhaust gas flow rate, only a part of the oxidation catalyst 104 can be intensively heated, It is possible to maintain the exhaust purification rate at a high level by shortening the time until the catalyst temperature reaches the activation temperature as much as possible.

100 catalyst exhaust purification device 101 internal combustion engine 102 exhaust pipe 103 diesel particulate filter 104 oxidation catalyst 105 intake pipe 106 intake manifold 107 exhaust manifold 108 exhaust recirculation pipe 109 exhaust recirculation cooler 110 intake air purification apparatus 111 supercharging Engine 112 Motor 113 Compressor 114 Internal combustion engine controller 115 Exhaust pipe fuel injector 116 Catalyst effective volume changing means 117 Shutter valve 200 Automobile

Claims (2)

In a catalyst exhaust purification device that purifies exhaust gas discharged from an internal combustion engine through an exhaust pipe with a catalyst,
A catalyst-based exhaust purification device comprising catalyst effective volume changing means for changing the catalyst effective volume based on an exhaust gas flow rate.   2. The catalyst-based exhaust purification device according to claim 1, wherein the catalyst effective volume changing unit includes a shutter valve that is installed on the exhaust upstream side of the catalyst and whose opening is controlled based on an exhaust flow rate.

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