CN211623528U - SMC quaternary catalytic converter for gasoline engine - Google Patents

Abstract

The utility model relates to a four-element catalytic converter of SMC for gasoline engine includes preceding stage catalyst converter and back-end catalyst converter that communicate each other, preceding stage catalyst converter includes preceding stage shell body (101), back-end catalyst converter includes back-end shell body (201), the parcel has preceding stage TWC ceramic carrier (102) and preceding stage SMC carrier (103) in preceding stage shell body (101), and preceding stage SMC carrier (103) are located the front end of preceding stage TWC ceramic carrier (102); two rear-stage TWC ceramic carriers (202) are arranged in the rear-stage outer shell (201), and a rear-stage SMC carrier (203) is clamped between the two rear-stage TWC ceramic carriers (202). The utility model relates to a SMC quaternary catalytic converter for gasoline engine, it has the cold start reaction of low temperature fast, the yields is high and the effectual advantage of difficult jam again of granule entrapment.

Description

SMC quaternary catalytic converter for gasoline engine

Technical Field

The utility model relates to a quaternary catalytic converter based on SMC technique make, be applied to automobile engine on, and can satisfy six emission standard in state belongs to motor vehicle exhaust processing technology field.

Background

At present, with the gradual code adding of the environmental protection policy, the national six standards are to be enforced comprehensively; compared with the national five standards, the core points of the national six standards are as follows:

and national sixth a: the CO (carbon monoxide) emission limit is reduced by 50%; and B, national six: THC (total hydrocarbons) and NMHC (non-methane total hydrocarbons) emission limits are reduced by 50%; NOx emission limit is reduced by 42%; the treatment requirements for Particulate Matter (PM) are increased and the emission limit is reduced by 33%.

Meanwhile, for gasoline engines, more than 70% of Hydrocarbon (HC) emissions are emitted at the time of cold start. There are two main reasons for the high initial emissions:

firstly, the catalyst can not react when not reaching the ignition temperature;

secondly, when the engine is started, the engine is in a cold state and is in an oil-rich working condition, and the combustion process is incomplete due to oxygen deficiency.

The technical route adopted today is the front-stage high-number thin-walled ceramic supported catalyst TWC + the post-stage particle capture GPF.

The advantages are that:

firstly, the low-temperature cold start effect is obvious by adopting a high-number thin-wall ceramic carrier;

and secondly, the collection of the PM by adopting the GPF can meet the requirement of the national 6 emission standard.

But it has disadvantages as well:

one, high-count thin-wall ceramic carriers are expensive (only NGK and Corning can be produced at present), have low thermal shock resistance, low strength and high packaging requirements, and particularly, packaging equipment needs to be greatly improved or the problem of high damage rate in production and later use can be solved.

Secondly, the volume of the hot end accounts for a larger displacement ratio, and the requirement on anti-aging performance is higher;

thirdly, the GPF catalytic coating process has problems, and the durability requirement is difficult to guarantee; the regeneration performance has problems, and the later stage has blockage hidden trouble.

For this reason, a new catalytic converter is needed.

Disclosure of Invention

An object of the utility model is to overcome above-mentioned not enough, provide a low temperature cold start reaction fast, yields height and granule entrapment are effectual and difficult SMC quaternary catalytic converter for gasoline engine who blocks up again.

The purpose of the utility model is realized like this:

the SMC quaternary catalytic converter for the gasoline engine comprises a front-stage catalyst and a rear-stage catalyst which are communicated with each other, wherein the front-stage catalyst comprises a front-stage outer shell, the rear-stage catalyst comprises a rear-stage outer shell, a front-stage TWC ceramic carrier and a front-stage SMC carrier are wrapped in the front-stage outer shell, and the front-stage SMC carrier is positioned at the front end of the front-stage TWC ceramic carrier; and two rear-stage TWC ceramic carriers are arranged in the rear-stage shell, and a rear-stage SMC carrier is clamped between the two rear-stage TWC ceramic carriers.

The utility model relates to a SMC quaternary catalytic converter for gasoline engine, preceding stage TWC ceramic carrier and back level TWC ceramic carrier are honeycomb ceramics.

The utility model relates to a SMC quaternary catalytic converter for gasoline engine, above-mentioned ceramic honeycomb's mesh number is 600 meshes, and the wall thickness is 5-6mm, and domestic can the large production supply to five standard stages in the country have fully been used, the technology is mature.

The utility model relates to a SMC quaternary catalytic converter for gasoline engine, preceding stage SMC carrier are provided with two or polylith that pile up each other.

The utility model relates to a SMC quaternary catalytic converter for gasoline engine, back level SMC carrier are provided with the combination in the different apertures of the polylith that piles up each other.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model discloses preceding stage catalyst converter adopts the SMC carrier to compound in the front end of TWC ceramic carrier to utilize SMC carrier (metal sponge carrier) heat conductivity high, melt the high, the high characteristic of intensity, avoid TWC ceramic carrier direct and high temperature tail gas contact, prevent that it from appearing burning and melting the phenomenon, and TWC ceramic carrier adopts the thick wall mode, very big improvement and the yields when installing; the rear-stage catalyst adopts a mode that two TWC ceramic carriers clamp an SMC carrier to replace a conventional particle trap GPF, so that the function of the conventional particle trap GPF can be realized, and holes on the TWC ceramic carriers adopt a straight hole mode, so that the manufacturing difficulty is reduced (the risk of blockage is reduced), and PM (carbon) particles and S-containing impurities are combusted in the SMC carrier in the middle in the particle trapping process, so that compared with the conventional structure, the blockage caused by accumulation in the TWC ceramic carriers is avoided; simultaneously, no matter the SMC carrier in preceding stage catalyst converter or the back-end catalyst converter all adopts the polylith mode of laminating, and the diameter variation in size of the honeycomb holes on the SMC carrier of difference to realize the seizure of different diameter particles, effectually prevent that it from taking place to block up.

Drawings

Fig. 1 is a schematic structural diagram of a preceding-stage catalyst of an SMC quaternary catalytic converter for a gasoline engine of the present invention.

Fig. 2 is a schematic structural diagram of a rear-stage catalyst of the SMC quaternary catalytic converter for the gasoline engine of the present invention.

Wherein:

the SMC carrier is a metal sponge carrier.

TWC ceramic supports.

A front-stage outer shell 101, a front-stage TWC ceramic carrier 102 and a front-stage SMC carrier 103;

a rear stage outer casing 201, a rear stage TWC ceramic carrier 202, a rear stage SMC carrier 203.

Detailed Description

Referring to fig. 1 and 2, the SMC quaternary catalytic converter for the gasoline engine of the present invention includes a front catalyst and a rear catalyst which are communicated with each other, the front catalyst includes a front shell 101, a front TWC ceramic carrier 102 and a front SMC carrier 103 are wrapped in the front shell 101, and the front SMC carrier 103 is located at the front end of the front TWC ceramic carrier 102; the rear-stage catalyst comprises a rear-stage outer shell 201, two rear-stage TWC ceramic carriers 202 are arranged in the rear-stage outer shell 201, and a rear-stage SMC carrier 203 is clamped between the two rear-stage TWC ceramic carriers 202;

further, the front-stage TWC ceramic carrier 102 and the rear-stage TWC ceramic carrier 202 are both made of honeycomb ceramics, the mesh number of the honeycomb ceramics is 600 meshes, and the wall thickness is 5-6 mm;

further, the preceding-stage SMC carrier 103 is provided with two or more pieces stacked on each other;

further, the rear-stage SMC carrier 203 is provided with a plurality of pieces stacked one on another;

the specific parameters of the preceding stage catalyst are as follows:

the diameter of the honeycomb ceramic is 118.4 multiplied by 80/0.88L, and the mesh number/wall thickness: 600 meshes/5 mm;

SMC φ 118.4 × 10 × 2/0.22L, 30PPI (preamble);

total volume: 1.1L; the total specification size is as follows: phi 118.4 is multiplied by 100;

furthermore, the aperture of the two SMC sponge metal catalysts is 30PPI, the reaction time is shortened by about 12 seconds compared with that of a 750-mesh honeycomb ceramic catalyst under the condition of the same content and proportion of noble metal, and the ignition temperature is reduced by about 20 ℃.

Further, the prior TWC ceramic carrier 102 is a honeycomb ceramic, which adopts a specification of 600/5, and has been well-established through the mass production inspection of the national 5 standard catalyst. The 750-mesh thin-wall ceramic carrier has low thermal shock resistance, low strength and high packaging requirements, and particularly packaging equipment needs to be greatly improved or upgraded; the problem of high damage rate exists in production and later use.

Secondly, the specific parameters of the rear-stage catalyst are as follows:

the honeycomb ceramic is phi 132 multiplied by 38 multiplied by 2/1.04L, mesh number/wall thickness: 600 meshes/5 mm;

SMC φ 132 × 10 × 2/0.28L, 50PPI (middle);

phi 132X 1.8X 2/0.05L, 100PPI (middle);

total volume: 1.37L; the total specification size is as follows: phi 132 x 100;

further, an SMC combination is arranged between the two honeycomb ceramic catalysts (the pore diameter of the 2 SMC sponge metal catalysts is 30-50 PPI; the pore diameter of the 2 SMC sponge metal catalysts is 100 PPI), and the central temperature of the TWC after ignition is very high; the ignition temperature point of the PM particles can be satisfied.

Furthermore, the rear-stage catalyst adopts SMC combination as a carrier; preparing noble metal, rare earth metal and transition metal as coating material; further catalytically oxidizing CO and HC; simultaneously collecting PM particles, and carrying out 4-level catalytic oxidation treatment to ensure that the PM particles are ignited, oxidized, combusted and decomposed; the conversion rate of PM particles can reach more than 80%.

Further, the sponge metal catalyst can avoid the blocking of PM at the later stage. The GPF catalytic coating process has problems, so that the durability requirement is difficult to ensure; the regeneration performance has problems, and the later stage has blockage hidden trouble.

To sum up, the utility model discloses a SMC quaternary catalytic converter improvement point:

1. adopting iron-chromium-aluminum (0CR21AL6) sponge metal as a carrier; the original high-mesh thin-wall ceramic carrier is replaced by the sponge metal with larger pore diameter, so that the method can be realized by utilizing the domestic low-mesh thin-wall ceramic carrier, not only the cost is reduced, but also the assembly yield is effectively improved (the high-mesh thin-wall ceramic carrier has low structural strength, is easy to break during assembly, and is easy to break when an automobile is too bumpy during use, especially in off-road occasions);

2. adopting a coating technology of iron-chromium-aluminum (0CR21AL6) sponge metal; and a multi-stage SMC technology is adopted, sponge metal with small pore diameter is adopted in the middle part for collecting PM, and PM particles are ignited, oxidized, combusted and decomposed through single-stage or multi-stage catalytic oxidation treatment.

3. The catalytic conversion performance of the engine on pollutants such as carbon monoxide (CO), Hydrocarbon (HC), nitrogen oxide (NOx), soot and Particulate Matters (PM) such as soluble organic matters (SOF) and sulfate attached to the soot under the condition of low-temperature cold start is improved; meets the more strict emission standard requirements of more than 6 countries;

4. the product has the characteristics of stronger shock resistance, high-temperature oxidation resistance, long service life and the like;

5. higher thermal conductivity, larger adsorption capacity and higher chemical activity.

6. The low-temperature cold start effect of the sponge metal is more obvious;

7. the catalytic conversion performance of PM far exceeds the requirement of 6 standard (33%) of China; the later-period blockage hidden danger does not exist;

8. the packaging equipment does not need to be modified.

Specifically, the sponge metal is a metal material with a porous structure containing a certain amount, pore size and porosity, and is a new material which is developed rapidly in the current material science. The manufacturing principle is that the required metal is plated on a special high polymer material framework with a three-dimensional net structure, such as polyurethane, polyester aminoethyl and other materials (commonly called sponge), after plating, the high polymer material and the reduced metal oxide in the sponge are burnt out, and finally the sponge metal product is prepared through chemical heat treatment and forming.

The sponge metal catalyst can be prepared by loading the active component containing noble metal on the sponge metal carrier, has the characteristics of good heat conduction performance, high mechanical impact resistance, high aperture ratio and the like, has good low-temperature cold start performance, and is particularly suitable for being used in strong absorption and heat release reaction systems and strong vibration environments.

Compared with the prior plate-shaped honeycomb metal carrier, the plate-shaped honeycomb plate has poor firmness of combination with the active coating and the catalytic component due to smooth surface of the matrix alloy, and is a main technical obstacle for practical application of the plate-shaped honeycomb metal carrier catalyst; in addition, the base alloy has large thermal expansion coefficient, poor thermal matching performance with the surface catalytic coating, poor thermal shock resistance and easy shedding of the catalytic coating. The structural form of the sponge metal is loose and porous, the sponge metal is formed by connecting three-dimensional multilayer three-dimensional framework ribs of a columnar structure, the catalytic coating slurry is sprayed around the columnar body of the sponge metal to form a wrapping structure which is completely different from a corrugated flaky plane structure, and the problem of the cohesive force between the catalytic coating and a metal carrier is solved.

Simultaneously, the framework rib of sponge metal is hollow structure, and has a plurality of perforation on the lateral wall of framework rib, and catalyst coating gets into the hollow inner chamber of framework rib through the perforation on the framework rib, is connected with outward appearance catalyst coating, and the coating combines more firmly inside and outside.

In addition, the sponge metal is loose and porous, has larger specific surface area than the honeycomb ceramic carrier, has quick thermal conductivity, high strength and high temperature resistance (the melting point temperature reaches 1100 ℃), and has better comprehensive performance than the honeycomb ceramic.

Finally, the aperture of the sponge metal can be set according to the emission parameters of the original vehicle, the structural combination of the sponge metals with different apertures is adopted, the problem of strength reduction of high-mesh honeycomb ceramics caused by thinning of channel walls is avoided, and the sponge metal carrier has the function of replacing the high-mesh honeycomb ceramics and becomes the best choice for the vehicle catalytic coating carrier.

Such as: the SMC carrier may specifically adopt the following physical characteristics:

pore diameter: 0.1mm to 10mm (5 to 130ppi), porosity: 95 to 98 percent

The through hole rate: not less than 98%, volume density: 0.1-0.8g/cm3

Tensile strength: 8-50MPa, compressive strength: not less than 250KPa (compression to 50% pressure value)

Mechanical strength: 2-7MPa, heat transfer coefficient: > 3w/(m2k), thickness: 1.0mm-15 mm.

In addition: it should be noted that the above-mentioned embodiment is only a preferred embodiment of the present patent, and any modification or improvement made by those skilled in the art based on the above-mentioned conception is within the protection scope of the present patent.

Claims (5)

1. The utility model provides a SMC quaternary catalytic converter for gasoline engine includes preceding stage catalyst and back-stage catalyst that communicate each other, preceding stage catalyst includes preceding stage shell body (101), back-stage catalyst includes back-stage shell body (201), its characterized in that:

a front-stage TWC ceramic carrier (102) and a front-stage SMC carrier (103) are wrapped in the front-stage outer shell (101), and the front-stage SMC carrier (103) is positioned at the front end of the front-stage TWC ceramic carrier (102); two rear-stage TWC ceramic carriers (202) are arranged in the rear-stage outer shell (201), and a rear-stage SMC carrier (203) is clamped between the two rear-stage TWC ceramic carriers (202).

2. The SMC quaternary catalytic converter for a gasoline engine as claimed in claim 1, wherein: the front-stage TWC ceramic carrier (102) and the rear-stage TWC ceramic carrier (202) are both made of honeycomb ceramics.

3. An SMC quaternary catalytic converter for a gasoline engine as set forth in claim 2, wherein: the honeycomb ceramic has a mesh size of 600 meshes and a wall thickness of 5-6 mm.

4. The SMC quaternary catalytic converter for a gasoline engine as claimed in claim 1, wherein: the pre-SMC carrier (103) is provided with two or more pieces stacked on each other.

5. The SMC quaternary catalytic converter for a gasoline engine as claimed in claim 1, wherein: the succeeding-stage SMC carrier (203) is provided with a plurality of blocks which are stacked on each other.

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