CN219472184U - Exhaust system - Google Patents

Abstract

The utility model discloses an exhaust system which comprises a first catalyst and a second catalyst which are connected, wherein a first oxygen sensor is arranged at the inlet of the first catalyst, a second oxygen sensor is arranged at the outlet of the first catalyst, the exhaust system further comprises a gas supplementing device, the inlet of the second catalyst is connected with the gas supplementing device, and tail gas sequentially passes through the first oxygen sensor, the first catalyst and the second oxygen sensor and then is merged into gas supplemented by the gas supplementing device and then enters the second catalyst. The oxygen supplying device is characterized by further comprising a controller, wherein the first oxygen sensor and the second oxygen sensor are connected with the input end of the controller, and the output end of the controller is connected with the oxygen supplying device to control the operation of the oxygen supplying device. The controller is an automobile ECU. The utility model has simple structure, adopts the structure of two catalytic converters and two oxygen sensors, adds an electric control air supplementing system, and accurately controls the lambda value of tail gas entering the front-stage catalytic converter and the rear-stage catalytic converter, thereby playing the role of catalytic conversion to the greatest extent, reducing the content of noble metals and saving the cost.

Description

Exhaust system

Technical Field

The utility model belongs to the technical field of engines, and particularly relates to an exhaust system.

Background

Along with the increasing strictness of automobile emission regulations, the oxygen storage capacity of the catalyst determines how much of the pollutant emission amount of the catalyst is needed under transient working conditions, in particular, the catalyst is an essential important part in a modern engine management system, is arranged in an automobile exhaust system, and can perform oxidation-reduction chemical reaction on harmful gases such as CO, HC, NOx generated by engine combustion under the catalytic action of noble metals such as platinum, rhodium and palladium to convert the harmful gases into CO2 and H2O, N2 when the working temperature of the catalyst reaches more than 300 ℃, so that tail gas is purified. In the prior art, the conversion efficiency of the three-way catalyst is generally improved by enlarging the size of the catalyst and increasing the content of noble metal, the production consistency of emission is poor, the cost is high, and the noble metal content of one three-way catalyst meeting the European emission regulation is generally more than 50g/ft 3. It is therefore important to obtain an exhaust system that overcomes the above-mentioned drawbacks.

Disclosure of Invention

In order to solve at least one technical problem, the utility model provides an emission system for electrically controlling air supplement in the middle of a double-channel oxygen sensor controlled double-stage catalyst, which comprises a first catalyst and a second catalyst which are connected, wherein a first oxygen sensor is arranged at the inlet of the first catalyst, a second oxygen sensor is arranged at the outlet of the first catalyst, the emission system further comprises an air supplement device, the air supplement device is connected at the inlet of the second catalyst, and tail gas sequentially passes through the first oxygen sensor, the first catalyst and the second oxygen sensor and then is merged into air supplemented by the air supplement device and then enters the second catalyst.

The oxygen supplying device is characterized by further comprising a controller, wherein the first oxygen sensor and the second oxygen sensor are connected with the input end of the controller, and the output end of the controller is connected with the oxygen supplying device to control the operation of the oxygen supplying device. The controller is an automobile ECU.

The air supplementing device is an air electromagnetic valve, and the air electromagnetic valve is connected to the inlet of the second catalyst through an air supplementing pipe. The air filter is characterized by further comprising an air filter, wherein an outlet of the air filter is connected with an inlet of the air electromagnetic valve.

The second catalyst is externally provided with a silencer. Wherein the first catalyst is a low mesh single oxidation catalyst.

Compared with the prior art, the utility model has the advantages that: the utility model has simple structure, adopts the structure that two catalysts are added with two oxygen sensors, and an electric control air supplementing system is added, the tail gas of the engine firstly passes through the first oxygen sensor, the first oxygen sensor transmits a lambda value signal of the tail gas to the controller, the controller controls the oil quantity of an engine oil sprayer through the lambda value, then the tail gas passes through the first catalyst to carry out temperature rising and preliminary conversion, the tail gas is discharged from an outlet of the first catalyst, the second oxygen sensor transmits the lambda value, a large amount of oxygen is consumed by the catalytic conversion in the first catalyst, the lambda value of the tail gas is higher than the optimal conversion window value (the window value range is 0.995-1.005) of the second catalyst, the controller, namely the ECU of the automobile, controls the air solenoid valve to work according to the lambda value of the second oxygen sensor, the lambda value of the air is supplemented by the air supplementing pipe, the tail gas mixed with fresh air enters the second catalyst to carry out conversion purification, and then is discharged through an inner pipeline of the silencer, and the lambda value is controlled to carry out conversion on the lambda value because the tail gas entering the front-stage catalyst and the rear-stage catalyst, so that the precious metal content is reduced to the precious metal content is exerted to the maximum extent.

The definition of the lambda value is: the oxygen mass ratio actually required to burn 1kg of gasoline is that theoretically required to burn 1kg of gasoline completely, i.e., λ=actual air amount/theoretical air amount; when lambda > 1, the combustible mixture is lean, and oxygen remains after combustion; when lambda < 1, the combustible mixture is rich and no oxygen remains after combustion. When λ=1, the gasoline is completely burned and the oxygen is just completely consumed.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

reference numerals: 1-a first catalyst; 2-a second catalyst; 3-a first oxygen sensor; 4-a second oxygen sensor; 5-an air supplementing pipe; 6-a controller; 7-a muffler; 8-an air solenoid valve; 9-air cleaner.

Detailed Description

The utility model will be described in detail below with respect to certain specific embodiments thereof in order to better understand the utility model and thereby to more clearly define the scope of the utility model as claimed. It should be noted that the following description is only some embodiments of the inventive concept and is only a part of examples of the present utility model, wherein the specific direct description of the related structures is only for the convenience of understanding the present utility model, and the specific features do not naturally and directly limit the implementation scope of the present utility model.

Referring to the drawings, the utility model adopts the following technical scheme that the exhaust system comprises a first catalyst 1 and a second catalyst 2 which are connected end to end in sequence, namely, an outlet of the first catalyst 1 is connected with an inlet of the second catalyst 2 through a connecting pipeline, a first oxygen sensor 3 is fixed at the inlet of the first catalyst 1, a second oxygen sensor 4 is fixed at the outlet of the first catalyst 1, the exhaust system further comprises a gas supplementing device, the inlet of the second catalyst 2 is connected with the gas supplementing device, and tail gas sequentially passes through the first oxygen sensor 3, the first catalyst 1 and the second oxygen sensor 4 and then enters the gas supplemented by the gas supplementing device and then enters the second catalyst 2.

The device further comprises a controller 6, the first oxygen sensor 3 and the second oxygen sensor 4 are connected with the input end of the controller 6, and the output end of the controller 6 is connected with the air supplementing device to control the air supplementing device to work. The controller 6 is an automobile ECU.

Wherein the first oxygen sensor 3 and the second oxygen sensor 4 may transmit signals to the ECU of the automobile through wires or wirelessly.

The air supplementing device is an air electromagnetic valve 8, and the air electromagnetic valve 8 is connected to the inlet of the second catalyst 2 through an air supplementing pipe 5. Also comprises an air filter 9, wherein the outlet of the air filter 9 is connected with the inlet of the air solenoid valve 8.

The second catalyst 2 is externally fixed with a muffler 7 of the motor vehicle itself, such as an automobile or a motorcycle. Wherein the first catalyst 1 is a low-cost oxidation catalyst.

Compared with the prior art, the utility model has the advantages that: the utility model has simple structure, adopts the structure of two catalysts and two oxygen sensors, and adds an electric control air supplementing system, the tail gas of the engine firstly passes through a first oxygen sensor 3, the first oxygen sensor 3 transmits lambda value signals of the tail gas to a controller 6, the controller 6 controls the oil quantity of an engine oil injector through lambda value, then the tail gas passes through a first catalyst 1 to carry out temperature rise and primary conversion, the tail gas is discharged from an outlet of the first catalyst 1, and the second oxygen sensor 4 transmits lambda ₂ The value, due to the consumption of a large amount of oxygen by the catalytic conversion in the first catalytic converter 1, results in a lambda value of the exhaust gas higher than the optimal conversion window value of the second catalytic converter 2; the controller 6, namely the ECU of the automobile controls the air electromagnetic valve 8 to work according to the lambda value of the second oxygen sensor 4, air is supplemented through the air supplementing pipe 5, the lambda value of the gas entering the second catalyst 2 is regulated, the tail gas mixed with fresh air enters the second catalyst 2 for conversion and purification, and then is discharged through the inner pipeline of the silencer 7, and the lambda value is accurately controlled due to the tail gas entering the front-stage catalyst and the rear-stage catalyst, so that the catalytic conversion effect can be exerted to the greatest extent, the noble metal content is reduced, and the cost is saved.

The above description is not intended to limit the utility model to the particular embodiments disclosed, but to limit the utility model to the particular embodiments disclosed, as many variations, modifications, additions and substitutions are possible, without departing from the scope and spirit of the utility model as disclosed in the accompanying claims.

Claims (6)

1. An exhaust system, characterized by: including first catalyst converter (1) and second catalyst converter (2) that link to each other, the entrance of first catalyst converter (1) is equipped with first oxygen sensor (3), the exit of first catalyst converter (1) is equipped with second oxygen sensor (4), still includes the air supplement unit, air supplement unit is connected to the entrance of second catalyst converter (2), and tail gas is incorporated behind air supplement unit benefit gas after first oxygen sensor (3), first catalyst converter (1), second oxygen sensor (4) in proper order and is got into second catalyst converter (2).

2. The exhaust system of claim 1, wherein: the device further comprises a controller (6), wherein the first oxygen sensor (3) and the second oxygen sensor (4) are connected with the input end of the controller (6), and the output end of the controller (6) is connected with the air supplementing device to control the air supplementing device to work.

3. The exhaust system of claim 1, wherein: the air supplementing device is an air electromagnetic valve (8), and the air electromagnetic valve (8) is connected to the inlet of the second catalyst (2) through an air supplementing pipe (5).

4. An exhaust system according to claim 3, characterized in that: the air filter device further comprises an air filter (9), and an outlet of the air filter (9) is connected with an inlet of the air solenoid valve (8).

5. The exhaust system of claim 1, wherein: a silencer (7) is arranged outside the second catalyst (2).

6. An exhaust system according to claim 2, characterized in that: the controller (6) is an automobile ECU.