Diesel engine particle trap and non-road diesel engine compact post-processing system

Abstract

The utility model relates to a diesel engine particle trap and a non-road diesel engine compact post-processing system, and relates to the field of diesel engines, the diesel engine particle trap comprises a DPF carrier, and the surface of an air inlet duct of the DPF carrier is provided with an SCR coating and a DPF coating. The size of the post-processing system is reduced, and the adaptability of the whole vehicle is improved; according to the utility model, an SCR carrier and an SCR upstream exhaust temperature sensor are canceled, so that the design cost of the system is reduced.

Description

Technical Field

[0001] The utility model relates to the field of diesel engines, in particular to a diesel engine particle collector and a compact after-treatment system for non-road diesel engines. Background Art

[0002] DOC: Diesel catalytic oxidizer. Refers to a device installed in the exhaust system of a diesel vehicle engine that simultaneously reduces the emission of pollutants such as carbon monoxide (CO) and hydrocarbons (HC) in the exhaust through catalytic oxidation, and (or) converts nitrogen monoxide (NO) in exhaust pollutants into nitrogen dioxide (NO2). It includes a carrier and a coating. The DOC carrier is a honeycomb structure carrier covered with through holes, and common materials are ceramics, metals, etc.; the DOC coating is a liquid slurry, which is evenly coated on the surface of the DOC carrier pores. When the engine exhaust passes through the pores, a catalytic reaction occurs under the catalytic action of the coating. (See Figure 3a , 3b )

[0003] DPF: Diesel Particulate Filter. Refers to a filter installed in the exhaust system of a diesel vehicle engine that reduces particulate matter in the exhaust through the filtering properties of the inner wall of the carrier hole (with micropores). Usually there is only a carrier or a carrier and a coating. The DPF carrier is a honeycomb structure carrier in the form of cross-hole plugging, and common materials are ceramics, metals, silicon carbide, etc.; the DPF coating is a liquid slurry that is evenly coated on the surface of the DPF carrier intake channel. When the engine exhaust passes through the channel, a catalytic reaction occurs under the catalytic action of the coating; due to the cross-hole plugging, the airflow flows through the carrier in a wall flow manner for filtration to reduce particulate matter in the exhaust. In order to emphasize the solution coated with DPF coating, the industry usually refers to the DPF including DPF carrier and DPF coating as cDPF. (See Figure 4a , 4b )

[0004] SCR: Selective Catalytic Reduction. Refers to a catalytic converter installed in the exhaust system of a diesel vehicle engine, which converts toxic nitrogen oxides (NOx) in the exhaust into non-toxic nitrogen (N2) and water (H2O) through a selective catalytic reduction reaction to reduce the emission of nitrogen oxides (NOx). Among them, the converter using the metal oxide vanadium pentoxide (V2O5) as the active component of the catalyst is called a vanadium-based selective catalytic reduction converter, and the converter using a molecular sieve as the matrix is ​​called a molecular sieve selective catalytic reduction converter. It includes an SCR carrier and an SCR coating. The SCR carrier is a honeycomb structure carrier covered with through holes, and common materials are ceramics, metals, etc.; the SCR coating is a liquid slurry, which is evenly coated on the surface of the SCR carrier pores. The system also requires the addition of a substance that can produce a reducing agent (for example, a urea solution that can hydrolyze to produce NH3). When the engine exhaust passes through the pores, it undergoes a catalytic reaction with the reducing substance under the catalytic action of the coating. (See Figure 3a , 3b )

[0005] At present, the after-treatment system of non-road National IV emission diesel engines generally adopts the DOC+DPF+SCR technology route, such as Figure 1 In product development, the overall vehicle layout places higher demands on the dimensions of the after-treatment system, so it is necessary to integrate the catalytic unit in the system to reduce the system volume. Utility Model Content

[0006] The purpose of the utility model is to provide a diesel engine particulate filter and a compact after-treatment system for a non-road diesel engine, so as to reduce the volume of the system and lower the cost.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the utility model provides a diesel particulate filter and a compact after-treatment system for a non-road diesel engine. The diesel particulate filter includes a DPF carrier, and the surface of the air intake channel of the DPF carrier is provided with an SCR coating and a DPF coating.

[0008] Preferably, the DPF carrier is a honeycomb structure carrier in the form of cross-pore blocking.

[0009] Preferably, the DPF carrier is made of ceramic, metal or silicon carbide.

[0010] Preferably, the SCR coating and the DPF coating are liquid slurries.

[0011] Preferably, the DPF carrier comprises a plurality of plate-like structures parallel to each other, and the SCR coating and the DPF coating are located on surfaces of the plate-like structures close to each other.

[0012] Preferably, the diesel particulate filter described above further comprises a DOC and a mixer, the mixer is provided with a urea nozzle, two ends of the diesel particulate filter are connected with a pressure difference sensor, and the outlet end of the diesel particulate filter is also provided with a NOx sensor.

[0013] In summary, the utility model includes the following beneficial technical effects:

[0014] 1. The utility model reduces the volume of the post-processing system and improves the adaptability of the entire vehicle.

[0015] 2. The utility model eliminates the SCR carrier and the exhaust temperature sensor upstream of the SCR, thereby reducing the system design cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the DOC+DPF+SCR technical route for the existing non-road National IV emission diesel engine after-treatment system;

[0017] Figure 2 This is a schematic diagram of the DOC+SCRoF technical route of Example 2 of the present utility model;

[0018] Figure 3a A schematic diagram for showing airflow, carrier, and coating in DOC or SCR Figure 1 ;

[0019] Figure 3b A schematic diagram for showing airflow, carrier, and coating in DOC or SCR Figure 2 ;

[0020] Figure 4a A schematic diagram showing the airflow, carrier, and coating in cDPF Figure 1 ;

[0021] Figure 4b A schematic diagram showing the airflow, carrier, and coating in cDPF Figure 2 .

[0022] Figure numerals: 1. DOC; 2. DPF; 3. Mixer; 4. SCR; 5. Differential pressure sensor; 6. Urea nozzle; 7. NOx sensor; 8. SCRoF; 9. Airflow; 10. Carrier; 11. Coating. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] Embodiment 1:

[0025] The utility model discloses a diesel engine particulate filter. The utility model integrates DPF2 and SCR4, applies SCR coating on DPF carrier, eliminates SCR carrier, and realizes particulate matter capture and NOx reduction functions.

[0026] The utility model includes SCRoF8, which is a diesel particulate filter coated with a selective catalytic reduction coating (SCR coating), wherein the carrier 10 is a DPF carrier with a honeycomb structure in the form of cross-hole blocking; the coating 11 is a molecular sieve selective catalytic reduction SCR coating with a temperature-resistant design optimized; the optimized SCR coating is coated on the surface of the DPF carrier intake channel to achieve the functions of both SCR4 and DPF2.

[0027] Embodiment 2:

[0028] The utility model embodiment discloses a compact after-treatment system for non-road diesel engines, which adopts the diesel particulate filter in embodiment 1 and can simultaneously eliminate the SCR carrier and the SCR upstream temperature sensor, and is a DOC1+SCRoF8 technical route (such as Figure 2 ):

[0029] The mixer 3 and the urea nozzle 6 are arranged between DOC1 and SCRoF8 to ensure that urea flows into SCRoF8 as needed and evenly; two temperature sensors are arranged upstream of DOC1 (T4) and upstream of SCRoF8 (T5) for monitoring the gas temperature; the high and low pressure gas inlets of the differential pressure sensor 5 are arranged at both ends of SCRoF8 for monitoring the blockage of SCRoF8; a NOx sensor 7 is arranged downstream of SCRoF8 for monitoring the post-treatment efficiency.

[0030] This technical route can reduce the volume of the post-processing system while achieving design cost reduction.

[0031] Taking a 6.4L non-road National IV emission engine as an example, the utility model has the following effects:

[0032] The original DOC1+DPF2+SCR4 technical route is adopted. The DOC carrier specification is Φ10.5×3 inches, and the precious metal content of coating 11 is 2.25g; the DPF carrier specification is Φ10.5×5 inches, and the precious metal content of coating 11 is 0.75g, with a total precious metal content of 3g; the SCR carrier specification is Φ10.5×5 inches, and the SCR coating is applied. The mixer 3 and the urea nozzle 6 are arranged between DPF2 and SCR4; three temperature sensors are arranged at the upstream of DOC1 (T4), upstream of DPF2 (T5), and upstream of SCR4 (T6); the air intake of the differential pressure sensor 5 is arranged at both ends of DPF2; and a NOx sensor 7 is arranged downstream of SCR4.

[0033] After adopting the DOC1+SCRoF8 technical route, DOC1 uses the original configuration; the DPF carrier specification remains Φ10.5×5 inches, and the SCR coating replaces the original DPF coating, with a total coating 11 precious metal totaling 2.25g; the SCR carrier is cancelled; the mixer 3 and the urea nozzle 6 are arranged between DOC1 and SCRoF8; two temperature sensors are arranged upstream of DOC1 (T4) and upstream of SCRoF8 (T5); the air intake of the differential pressure sensor 5 is arranged at both ends of SCRoF8; a NOx sensor 7 is arranged downstream of SCRoF8. The engine emission test results meet the requirements, as shown in Table 1:

[0034]

[0035] Table 1

[0036] Compared with the original technical route, this proposal reduces the size of the carrier 10 and the coating by 38%, and reduces the precious metal content by 25%, which greatly reduces the installation space requirement of the after-treatment system in the vehicle, while achieving design cost reduction.

[0037] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A diesel particulate filter, characterized in that: The diesel particulate filter comprises a DPF carrier, the surface of the air inlet channel of the DPF carrier is provided with an SCR coating and a DPF coating, and the DPF carrier is a honeycomb structure carrier in the form of cross-hole blocking.

2. A diesel particulate filter according to claim 1, characterized in that: The DPF carrier is made of ceramic, metal or silicon carbide.

3. A diesel particulate filter according to claim 2, characterized in that: The SCR coating and the DPF coating are liquid slurries.

4. A diesel particulate filter according to claim 3, characterized in that: The DPF carrier comprises a plurality of plate-like structures parallel to each other, and the SCR coating and the DPF coating are located on surfaces of the plate-like structures close to each other.

5. A compact aftertreatment system for non-road diesel engines, characterized in that: The diesel particulate filter comprises the diesel particulate filter according to any one of claims 1 to 4, further comprising a DOC (1) and a mixer (3), wherein the mixer (3) is provided with a urea nozzle (6), pressure difference sensors (5) are connected to both ends of the diesel particulate filter, and a NOx sensor (7) is also provided at the outlet end of the diesel particulate filter.

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