JP2011021496A - Exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heat an exhaust emission control device by heat of an engine body. <P>SOLUTION: A first aftertreatment device 306 and a second aftertreatment device 308 are connected to each other through an exhaust emission communication section 310 so that the first aftertreatment device 306 and second aftertreatment device 308 are arranged along the separate surfaces S4, S5 of the engine body 100. Thereby, both the first aftertreatment device 306 and second aftertreatment device 308 are brought into contact with the engine body 100 or sufficiently approach the engine body, and engine exhaust heat is efficiently taken into the exhaust emission control device 300 and utilized. Accordingly, the aftertreatment device 306 and second aftertreatment device 308 are always maintained at activation temperature, and purifying efficiency is improved. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an exhaust gas purification device used in an internal combustion engine such as a gasoline engine or a diesel engine, and relates to an exhaust gas purification device that purifies particulates (particulate matter) and nitrogen oxides (NOx).

Engine exhaust gas regulations are becoming stricter year by year, and exhaust gas purifying devices that are aftertreatment devices are required to purify both particulates and nitrogen oxides.
For example, in a diesel engine, a DPF (Diesel Particulate Filter) is used for collecting particulates, and a DeNOx catalyst such as a NOx purification catalyst or a NOx occlusion purification catalyst is used to reduce nitrogen oxide (NOx). Is adopted.

When such a first post-processing device for particulate processing and a second post-processing device for NOx are provided in the exhaust gas pipe of the engine, the exhaust gas pipe becomes long.
In addition, since the exhaust gas purification device cannot obtain sufficient purification performance when the temperature is lowered, generally, the exhaust gas purification device is brought into contact with the surface of the engine body and the exhaust gas purification device is heated by the heat of the engine body.

  In view of this, the exhaust gas purifying apparatus described in Patent Document 1 shortens the overall length by curving the exhaust gas pipe line in a U-shape.

JP 2005-155404 A

  Although the exhaust gas purification apparatus of Patent Document 1 has a substantially rectangular parallelepiped shape as a whole, although the overall length of the exhaust gas conduit is suppressed, a rectangular parallelepiped storage space is required, and the arrangement thereof is extremely limited. . For this reason, the exhaust heat of the engine body cannot be fully utilized.

  An exhaust gas purifying device according to a first aspect of the present invention includes a first aftertreatment device for collecting particulates (particulate matter) disposed in an exhaust gas passage of an engine body, and for reducing nitrogen oxides (NOx). A second aftertreatment device, and an exhaust gas communication portion that communicates the first aftertreatment device and the second aftertreatment device, and the first aftertreatment device and the second aftertreatment device are engine-operated. It is characterized by being arranged along two adjacent surfaces of the main body.

  An exhaust gas purification apparatus according to a second aspect of the present invention further comprises injection means for supplying and supplying a reducing agent for the second post-treatment device, and the first post-treatment device is disposed in the exhaust gas passage more than the second post-treatment device. It arrange | positions in the upstream and the said injection means is arrange | positioned in the downstream rather than the 1st post-processing apparatus, It is characterized by the above-mentioned.

  According to a third aspect of the present invention, there is provided an exhaust gas purifying device comprising: an engine fan disposed on the engine body so as to face one surface (referred to as a first surface); and at least a back surface (second surface) of the first surface. The first post-processing apparatus or the second post-processing apparatus is arranged along the line.

  According to a fourth aspect of the present invention, there is provided an exhaust gas purification apparatus, wherein the first post-treatment device, the second post-treatment device, and the exhaust gas communication portion are fastened in a separable manner.

  The exhaust gas purifying apparatus according to the present invention can be compactly configured while heating the apparatus for collecting particulates (particulate matter) and the apparatus for reducing nitrogen oxides (NOx) with the heat of the engine body. .

The front view which shows the industrial vehicle carrying the engine provided with the exhaust-gas purification apparatus by this invention. The conceptual diagram which shows the planar structure of the upper turning body in the industrial vehicle of FIG. FIG. 3 is a perspective view showing an engine provided with a first embodiment of an exhaust gas purifying apparatus according to the present invention. (A) is a front view of the exhaust gas purification apparatus of FIG. 3, (b) is a side view. The perspective view which shows the connection state of the exhaust gas purification apparatus of FIG. The perspective view which shows the engine provided with 2nd Embodiment of the exhaust-gas purification apparatus by this invention. (A) is a front view of the exhaust gas purification apparatus of FIG. 6, (b) is a side view. The perspective view which shows the connection state of the exhaust gas purification apparatus of FIG.

  Embodiments of an exhaust gas purification apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

-First embodiment-
The exhaust gas purification device is provided, for example, in the engine main body 100 mounted on the industrial vehicle shown in FIGS. 1 and 2. The industrial vehicle has a traveling body 200 and an upper revolving body 202 that is turnably mounted on the traveling body 200, and the engine body 100 is provided in the upper revolving body 202.

  In the upper swing body 202, a cab 204, a fuel tank 206, a hydraulic oil tank 208, and a swing device 210 are provided, a counterweight 212 is provided at the rearmost part of the upper swing body 202, and a front 214 is provided at the frontmost part. The engine body 100 is disposed in front of the counterweight 212. A hydraulic pump 102 is connected to the engine body 100. In addition to these many devices, the upper swing body 202 is provided with a hydraulic hose connecting the devices, electrical wiring, a jig for fixing them, and the like, and the space around the engine is narrow.

  As shown in FIGS. 3 and 4, an engine fan 110 that air-cools the engine body 100 is provided on one side surface (hereinafter, referred to as a first surface) S1 of the engine body 100, and a side surface on the back side of the first surface S1. (Hereinafter, it is referred to as the second surface.) S2 is provided with a flywheel 108 for stabilizing the engine output. An EGR pipe 328 of an exhaust gas recirculation system (EGR) is provided above the second surface S2. The EGR pipe 328 introduces exhaust gas exhausted to the exhaust manifold 350 protruding from the upper surface of the engine surface S4 into the intake pipe line 360. A turbocharger 106 driven by exhaust gas is connected to the exhaust manifold 350. The turbocharger 106 sends compressed air into the intake manifold 360. The exhaust gas exhaust line of the turbocharger 106 is connected to the exhaust gas purification device 300 via the exhaust gas intake unit 304. Exhaust gas discharged from the turbocharger 106 is purified through the exhaust gas purification device 300 and released from the exhaust gas discharge unit 312 to the atmosphere.

  The exhaust gas purification apparatus 300 will be described in detail with reference to FIGS. 3 and 4. The exhaust gas purification apparatus 300 includes a first post-treatment device 306 for collecting particulates (particulate matter) and a second post-treatment device 308 for reducing nitrogen oxides (NOx). The first post-treatment device 306 is disposed on the upstream side of the exhaust gas, and is disposed horizontally so as to contact the side surface S4 of the engine body 100. The second post-processing device 308 is disposed on the exhaust gas downstream side, and is disposed so as to contact the upper surface S5 of the engine body 100. The first post-treatment device 306 and the second post-treatment device 308 are connected by an exhaust gas communication unit 310.

  A reducing agent injection nozzle (which supplies and supplies a reducing agent (urea water or the like) for the second post-treatment device 308 to the exhaust gas communication section 310 that connects the first post-treatment device 306 and the second post-treatment device 308. Injection means) 326, and a reducing agent pump 322 is connected to the reducing agent injection nozzle 326. A reducing agent tank 324 is connected to the reducing agent pump 322. The reducing agent pump 322 and the reducing agent tank 324 are disposed close to or in close contact with the upper surface S5 of the engine body 100. The reducing agent pump 322 supplies the reducing agent stored in the reducing agent tank 324 to the reducing agent injection nozzle 326.

  As shown in FIG. 5, the first post-treatment device 306 is disposed on the downstream side of the exhaust gas intake unit 304 and is disposed on the downstream side of the catalyst conduit 314 and the catalyst conduit 314 containing the oxidation catalyst. And a DPF (Diesel Particulate Filter) 316. The catalyst conduit 314 and the DPF 316 are connected by a screw member 330 at the flange 328.

  As shown in FIG. 5, the second post-treatment device 308 is disposed on the downstream side of the exhaust gas communication unit 310 and has a first catalyst pipe 318 in which a NOx catalyst is accommodated, and a downstream of the first catalyst pipe 318. And a second catalyst conduit 320 containing an oxidation catalyst therein. The first catalyst conduit 318 and the second catalyst conduit 320 are connected by a screw member 330 at a flange 328.

  The exhaust gas communication section 310 includes an inlet section 310A provided in the first post-processing apparatus 306, an outlet section 310B provided in the second post-processing apparatus 308, and a communication section 310C that connects the inlet section 310A and the outlet section 310B. The inlet portion 310A and the communication portion 310C, and the outlet portion 310B and the communication portion 310C are connected by a screw member 330 at the flange 328, respectively.

An operation of the exhaust gas purifying apparatus by the exhaust gas purifying apparatus 300 configured as described above will be described.
The exhaust gas discharged from the engine body 100 to the exhaust manifold 350 drives the turbocharger 106, and the turbocharger 106 compresses the intake gas and introduces it into the intake manifold 360. The exhaust gas that has driven the turbocharger 106 flows into the exhaust gas purification device 300 and is exhausted after removing particulate matter and nitrogen oxides.

  In the first post-treatment device 306, CO and HC are removed by the oxidation catalyst in the oxidation catalyst pipe 314, and particles are removed by the DPF pipe 316 in which the DPF is accommodated. Since both the oxidation catalyst and the DPF are activated as the temperature rises, the exhaust gas purification function of the first aftertreatment device 306 is improved by heating the oxidation catalyst pipe 314 and the DPF pipe 316 with the heat of the engine body. be able to.

  The exhaust gas from which CO, HC, and particles have been removed by the first post-treatment device 306 flows into the communication pipe 310, where urea water is injected from the injection nozzle 326 into the exhaust gas. Exhaust gas sprayed with urea water flows into the Nox catalyst pipe 318 and is reduced to reduce Nox. Further, the exhaust gas flows into the oxidation catalyst pipe 320, CO and HC are further removed, and the exhaust gas is discharged from the exhaust gas discharge unit 312 to the atmosphere.

  The reducing agent pump 322 and the reducing agent tank 324 are heated by the heat of the engine body 100, and the reducing agent can be easily melted even in a low temperature environment and can be effectively mixed into the exhaust gas from the injection nozzle 326. . As a result, NOx in the exhaust gas can be efficiently removed in the Nox catalyst conduit 318.

The exhaust gas purifying apparatus using the exhaust gas purifying apparatus 300 configured as described above has the following effects.
(1) A first post-treatment device 306 for collecting particulates (particulate matter) and a second post-treatment device 308 for nitrogen oxide (NOx) reduction are arranged on two adjacent surfaces S4 of the engine body 100. Arranged along S2 respectively. Therefore, the exhaust gas purification apparatus 300 can remove particulates, CO, HC, and nitrogen oxides (NOx) from the exhaust gas while being activated by receiving heat from the engine body 100, and the exhaust gas. Without increasing the size of the gas purification device 300, it is possible to keep harmful substances in the exhaust gas within the standard values of the regulations. Further, even in a working machine having a small engine surrounding space such as a hydraulic excavator, the exhaust gas purifying device 300 that clears the legal regulation reference value can be disposed compactly around the engine body 100.

(2) The first post-treatment device 306 and the second post-treatment device 308 are arranged along the separate surfaces S4 and S5 of the engine body 100. Therefore, exhaust gas purification device 300 can be accommodated in a narrow space around engine body 100. In addition, since the second post-processing device 308 is disposed on the surface S5 that is different from the surface S4 on which the first post-processing device 306 is disposed, the first post-processing device 308 is matched to the position of the turbocharger 106. The arrangement of 306 can be freely set.

(3) An injection nozzle 326 for supplying urea water (reducing agent) for removing Nox in the second post-treatment device 308 is disposed in the exhaust gas communication unit 310, and the Nox is disposed upstream of the second post-treatment device 308. Since the oxidation catalyst pipe 320 is provided at the rear stage of the catalyst pipe 318, Nox, CO and HC can be effectively removed. That is, when urea water is injected into the exhaust gas, the exhaust gas temperature decreases. Therefore, when the oxidation catalyst pipe line 320 is arranged in the previous stage, there is a possibility that CO and HC cannot be sufficiently removed by the oxidation catalyst.

(4) The reducing agent pump 322 and the reducing agent tank 324 are disposed in close contact with the upper surface S5 of the engine body 100. Therefore, even in a low-temperature environment, the reducing agent can be easily melted and effectively mixed into the exhaust gas, and can come into contact with the exhaust gas to efficiently remove NOx. Moreover, crystallization of the reducing agent can be prevented.

(5) The first post-treatment device 306 and the second post-treatment device 308, the catalyst pipe 314 and the DPF 316, the NOx catalyst first catalyst pipe 318 and the oxidation catalyst second catalyst pipe 320 are formed by the flange 228. It is fastened with a bolt fastening mechanism. Therefore, each can be disassembled only by loosening the bolts, and the decomposability and maintainability of the exhaust gas purification device 300 are improved.

-Second Embodiment-
Next, a second embodiment of the exhaust gas purifying apparatus according to the present invention will be described with reference to FIGS. In the figure, the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the exhaust gas purifying apparatus according to the second embodiment, the second aftertreatment device 308 is disposed close to or in close contact with the EGR pipe 328 along the side surface S2 of the engine body 100. As shown in FIGS. 6 and 7, the second post-processing device 308 is horizontally disposed at substantially the same height as the first post-processing device 306 along the side surface S <b> 2 adjacent to the EGR pipe 328. . The exhaust gas communication part 310 connects the first post-treatment device 306 and the second post-treatment device 308 along the side surface S4.

  An exhaust manifold 350 projects from the engine body 100 on the upper part of the side surface S4 which is orthogonal to the side surface S2. Between the engine fan 110 and the second aftertreatment device 308, the engine body 100, the exhaust manifold 350, and the first aftertreatment device 306 are interposed.

  As described above, since the second post-processing device 308 is disposed close to or in close contact with the EGR pipe 328 along the side surface S2 of the engine body 100, it is heated by the heat of the EGR pipe 328 or the heat of the engine body. . Further, the engine main body 100, the EGR pipe 328, the exhaust manifold 350, and the first post-processing device 306 block the cooling air of the engine fan 110, so that the cooling air does not directly hit the second post-processing device 308. The second post-processing device 308 in the first embodiment is disposed on the upper surface S5 of the engine main body 100 and is heated by the heat of the engine, but is cooled by the cooling air of the engine fan 110. For this reason, the heat of the engine cannot be sufficiently used for improving the purification efficiency. In that respect, the second post-treatment device 308 according to the second embodiment is not cooled by the cooling air from the fan, and can use the heat of the engine and the heat of the EGR pipe 328 more effectively. The effect of further increasing the purification efficiency can be obtained.

  Note that the first post-processing device 306 can be disposed along the side surface S2 instead of the second post-processing device 308. In this case, the arrangement position of the second post-processing device 308 may be any of the side surface S4 and the upper surface S5 adjacent to the side surface S2 of the engine body.

  Further, the present invention can also be applied to a diesel engine that does not employ an EGR system. Therefore, the exhaust gas purification device according to the present invention includes a first aftertreatment device for collecting particulates (particulate matter) disposed in the exhaust gas passage of the engine body, and a nitrogen oxide (NOx) reduction. Any configuration may be adopted as long as the exhaust gas purifying device is provided with a minimum configuration in which the second aftertreatment device is disposed along two adjacent surfaces of the engine body.

DESCRIPTION OF SYMBOLS 100 Engine main body 110 Engine fan 300 Exhaust gas purification apparatus 304 Exhaust gas intake part 306 1st post-processing apparatus 308 2nd post-processing apparatus 310 Exhaust gas communication part 326 Reducing agent injection nozzle 328 EGR piping

Claims (4)

A first aftertreatment device for collecting particulate (particulate matter) disposed in an exhaust gas passage of the engine body;
A second aftertreatment device for reducing nitrogen oxides (NOx);
An exhaust gas communication portion for communicating the first post-treatment device and the second post-treatment device;
With
An exhaust gas purifying apparatus, wherein the first aftertreatment device and the second aftertreatment device are arranged along two adjacent surfaces of the engine body. The exhaust gas purification device according to claim 1,
An injection means for supplying and supplying a reducing agent for the second aftertreatment device;
The first aftertreatment device is disposed upstream of the second aftertreatment device in the exhaust gas passage,
An exhaust gas purifying apparatus, wherein the injection means is disposed downstream of the first post-treatment device. The exhaust gas purification apparatus according to claim 1 or 2,
The engine body includes an engine fan disposed opposite to one surface (first surface) and at least the first post-processing device or the second surface along the surface (second surface) on the back side of the first surface. 2. An exhaust gas purifier having an aftertreatment device. The exhaust gas purification apparatus according to any one of claims 1 to 3,
The exhaust gas purifying apparatus, wherein the first aftertreatment device, the second aftertreatment device, and the exhaust gas communication portion are connected to each other so as to be separable.

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