CN219548957U

CN219548957U - Gas engine aftertreatment system, engine and vehicle

Info

Publication number: CN219548957U
Application number: CN202320041483.4U
Authority: CN
Inventors: 霍翠英; 刘伟达; 郑碧莹; 李俊普; 张言库
Original assignee: Weichai Power Co Ltd; Weichai Power Emission Solutions Technology Co Ltd
Current assignee: Weichai Power Co Ltd; Weichai Power Emission Solutions Technology Co Ltd
Priority date: 2023-01-03
Filing date: 2023-01-03
Publication date: 2023-08-18
Anticipated expiration: 2033-01-03

Abstract

The utility model discloses a gas engine aftertreatment system, an engine and a vehicle, relates to the technical field of vehicle aftertreatment, solves the problems of low space utilization rate and easiness in influence of working temperature of the existing aftertreatment system, improves the space utilization rate, and reduces the emission of pollutants, and the specific scheme is as follows: the device comprises a DOC catalyst, a urea injection device, a mixer and a particle collector which are connected in sequence, wherein an SCR catalyst is coated on the inner hole surface of the particle collector.

Description

Gas engine aftertreatment system, engine and vehicle

Technical Field

The utility model relates to the technical field of vehicle aftertreatment, in particular to a gas engine aftertreatment system, an engine and a vehicle.

Background

Three-way catalyst is installed in the three-way catalytic converter, and CH in tail gas of engine can be treated simultaneously ₄ Contaminants such as CO, NOx, etc., but NH as a byproduct is often produced ₃ The ammonia emission exceeds standard, and particulate matters in the tail gas cannot be treated, so that PN emission exceeds standard; secondly, the main components of the three-way catalyst are noble metals such as platinum, palladium, rhodium and the like, the cost is high, and a post-treatment system without rhodium noble metals is provided for solving the problems.

The inventor discovers that in the existing rhodium-free precious metal aftertreatment system (publication number: CN 216381563U), the SCR catalyst is independently arranged, a large amount of SCR carriers and arrangement spaces are often needed, the space utilization rate is not improved, and the SCR catalyst is easily affected by the working temperature, so that the emission of pollutants cannot be reduced.

Disclosure of Invention

Aiming at the defects existing in the prior art, the utility model aims to provide a gas engine aftertreatment system, an engine and a vehicle, wherein an SCR catalyst is coated on the inner hole surface of a particle catcher so as to save SCR carriers and arrangement space, and meanwhile, the SCR can better reach the working temperature due to higher temperature on the particle catcher, so that the emission of pollutants is reduced, and the problems of low space utilization rate and easiness in being influenced by the working temperature of the existing aftertreatment system are solved.

In order to achieve the above object, the present utility model is realized by the following technical scheme:

in a first aspect, an embodiment of the present utility model provides a gas engine aftertreatment system, including a DOC catalyst, a urea injection device, a mixer, and a particle trap, connected in sequence, wherein an inner bore of the particle trap is coated with an SCR catalyst.

As a further implementation, the DOC catalyst comprises a DOC catalyst, and the DOC catalyst is coated in a zoned manner.

As a further implementation, the DOC catalyst includes a first oxidation catalyst coated on an inner bore surface of the DOC carrier remote from the first portion of the urea injection device.

As a further implementation, the DOC catalyst further includes a second oxidation catalyst coated on an inner bore surface of the DOC carrier proximate to the second portion of the urea injection device.

As a further implementation, an air injection device is also included, the air injection device being connected between the mixer and the particle catcher.

As a further implementation, the particle trap further comprises an ammonia complement collector connected to the air outlet end of the particle trap.

As a further implementation, the DOC catalyst further includes cerium oxide, which is coated on the inner pore surface of the DOC carrier.

In a second aspect, embodiments of the present utility model provide an engine utilizing the gas engine aftertreatment system of the first aspect.

As a further implementation, the DOC catalyst is connected to the outlet end of the engine.

In a third aspect, embodiments of the present utility model provide a vehicle using the engine of the second aspect.

The beneficial effects of the utility model are as follows:

1) The SCR catalyst is coated on the inner hole surface of the particle catcher, so that the SCR carrier and arrangement space are saved, the space utilization rate is improved, meanwhile, the SCR can reach the working temperature better due to higher temperature on the particle catcher, and the emission of pollutants is reduced.

2) The aftertreatment system of the utility model realizes methane removal through the oxidation type DOC catalyst under the condition of equivalent ratio, and avoids the problem of short-term failure of the DOC catalyst under the condition of lean burn.

3) According to the utility model, the air injection device is introduced, so that the SCR reaction can smoothly occur, thereby removing NOx, avoiding the reaction of NOx by using a rhodium-gold catalyst in the traditional three-way catalyst, and effectively reducing the cost of a post-treatment system.

Drawings

The accompanying drawings, which are included to provide a further understanding of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain the utility model.

FIG. 1 is a schematic overall architecture of a gas engine aftertreatment system according to one or more embodiments of the present disclosure;

in the figure: the mutual spacing or size is exaggerated for showing the positions of all parts, and the schematic drawings are used only for illustration;

1, a DOC catalyst; 2. urea injection device; 3. a mixer; 4. an air injection device; 5. a particle catcher; 6. an ammonia collector.

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the utility model. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs.

As described in the background art, in the existing rhodium-free precious metal aftertreatment system, the SCR catalyst is independently arranged, a large amount of SCR carriers and arrangement spaces are often required, the space utilization rate is not improved, the SCR catalyst is easily affected by the working temperature, and therefore the problem that pollutant emission cannot be reduced is caused.

Example 1

In an exemplary embodiment of the present utility model, as shown in fig. 1, a gas engine aftertreatment system is provided, which includes a DOC catalyst 1, a urea injection device 2, a mixer 3 and a particle catcher 5, which are sequentially connected, wherein the DOC catalyst 1 is connected to an air outlet end of the engine, the urea injection device 2 is connected to the air outlet end of the DOC catalyst 1, the mixer 3 is connected to the air outlet end of the urea injection device 2, an SCR catalyst is coated on an inner hole surface of the particle catcher 5, and the particle catcher 5 is connected to the air outlet end of the mixer 3.

Through using the aftertreatment system in this embodiment, scribble the SCR catalyst and attach on the hole face of DPF carrier, carry out conversion treatment to NOx in the tail gas, the PM such as carbon granule in the DPF will tail gas is mended simultaneously and is made system PM and PN to satisfy emission requirement, in addition, scribble the SCR catalyst and attach on particle trap 5, can effectively save aftertreatment system's occupation space, realize tight coupling arrangement scheme as far as, space utilization has been promoted, and the last temperature of particle trap 5 is higher, can let the better operating temperature that reaches of SCR, reduce the emission of pollutant.

Specifically, the particle catcher 5 is a DPF, the utility model refers to a diesel engine, the DOC is diesel oxidation catalyst, and the device is arranged in the exhaust system of the diesel vehicle and can reduce the pollutant emission in the exhaust through various physical and chemical actions; SCR (Selective Catalytic Reduction) is a selective catalytic reduction method based on the principle of increasing N under catalytic action ₂ Is reduced in NH ₃ Is not limited. PN emissions refer to the mass/Particle Number (PN) of solid suspended particles in automobile exhaust emissions.

Specifically, the DPF in the present embodiment has a wall flow structure, so that particulate matters in the tail gas can be removed, and the PN emission meets the corresponding requirements.

The DOC catalyst is an oxidation type catalyst, and the DOC catalyst is coated in a partitioned manner, specifically comprises a first oxidation type catalyst, wherein the first oxidation type catalyst is coated on an inner hole surface of a first part of the DOC carrier far away from the urea injection device 2, and the first oxidation type catalyst is coated on the inner hole surface of the first part, so that hydrocarbon and carbohydrate can be removed, and harmful substances in tail gas can be removed.

The first oxidation catalyst comprises Pd metal. The first oxidation catalyst in this embodiment includes a large amount of Pd metal and a small amount of Pt metal, where the Pd metal can effectively perform a catalytic reaction on hydrocarbons (including methane) and carbohydrates (including nitric oxide) in the exhaust gas, so as to achieve the purpose of purifying the exhaust gas.

The DOC catalyst further comprises a second oxidation catalyst coated on the inner pore surface of the DOC carrier near the second part of the urea injection device 2. The second oxidation catalyst is coated on the inner hole surface of the second part, so that the generation of nitrogen oxides (including nitrogen dioxide) can be promoted, the passive regeneration function of soot on the DPF is further realized, and the operation efficiency of the DPF is improved.

The second oxidation catalyst comprises Pt metal. The second oxidation catalyst in this embodiment includes a small amount of Pd metal and a large amount of Pt metal, and the Pt metal can effectively catalyze the exhaust gas, thereby generating NO ₂ And is used for the purpose of passive regeneration of soot on the DPF.

The DOC catalyst also comprises cerium oxide, wherein the cerium oxide is coated on the inner pore surface of the DOC carrier. Cerium oxide is used as an oxygen storage material, can play a role in storing and releasing oxygen under lean-burn and rich-burn conditions, promotes the dispersion of a noble metal catalyst, and improves the operation efficiency of the DPF.

As shown in fig. 1, the aftertreatment system further comprises an air injection device 4, the air injection device 4 being connected between the mixer 3 and the particle catcher 5.

The air injection device 4 can add sufficient oxygen into the tail gas, so that the oxidation and combustion of harmful gases such as ammonia gas, carbon oxides and the like in the particle catcher 5 are facilitated, the conversion treatment of NOx in the tail gas is performed, meanwhile, the reaction of NOx by using a rhodium-gold catalyst in the traditional three-way catalyst is avoided, and the cost of a post-treatment system is effectively reduced.

As shown in fig. 1, the aftertreatment system further includes an ammonia slip 6, the ammonia slip 6 being connected to the exhaust end of the particle trap 5. The ammonia complement collector 6 is used for collecting or absorbing ammonia in the tail gas, so that the ammonia is prevented from being discharged to the atmosphere along with the tail gas, and the purification effect of the tail gas is improved.

Example 2

In an exemplary embodiment of the utility model, an engine is proposed comprising the aftertreatment system described in example 1, the DOC catalyst 1 being connected to the outlet end of the engine.

The SCR catalyst is coated on the inner hole surface of the DPF carrier, so that the function of synchronously treating oxynitride while treating particulate matters can be realized, PN emission is guaranteed, in addition, the SCR catalyst is coated on the particle catcher 5, the occupied space of a post-treatment system can be effectively saved, a tight coupling arrangement scheme is realized as much as possible, the space utilization rate is improved, the temperature on the particle catcher 5 is higher, the SCR can reach the working temperature better, and the emission of pollutants is reduced.

Example 3

In an exemplary embodiment of the present utility model, a vehicle is provided that includes the engine described in example 2.

The above description is only of the preferred embodiments of the present utility model and is not intended to limit the present utility model, but various modifications and variations can be made to the present utility model by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. The gas engine aftertreatment system is characterized by comprising a DOC catalyst, a urea injection device, a mixer and a particle catcher which are connected in sequence, wherein an SCR catalyst is coated on the inner hole of the particle catcher; the particle filter also comprises an air injection device which is connected between the mixer and the particle catcher.

2. The gas engine aftertreatment system of claim 1, wherein the DOC catalyst comprises a DOC catalyst, the DOC catalyst being zone coated.

3. The gas engine aftertreatment system of claim 2, wherein the DOC catalyst comprises a first oxidation catalyst coated on a bore surface of the DOC carrier remote from the first portion of the urea injection device.

4. A gas engine aftertreatment system according to claim 3 wherein the DOC catalyst further comprises a second oxidation catalyst coated on the inner bore surface of the DOC carrier adjacent the second portion of the urea injection device.

5. The gas engine aftertreatment system of claim 1, further comprising an ammonia slip connected to an outlet end of the particulate trap.

6. The gas engine aftertreatment system of claim 2, wherein the DOC catalyst further comprises cerium oxide coated on the inner bore surface of the DOC support.

7. An engine, characterized in that the gas engine aftertreatment system according to any one of claims 1-6 is utilized.

8. An engine according to claim 7, wherein the DOC catalyst is connected to the exhaust end of the engine.

9. A vehicle characterized in that an engine as claimed in claim 7 is utilized.