阅读说明：本技术 一种氧化剂主导的dpf主动再生装置及其控制方法 (DPF active regeneration device with leading oxidant and control method thereof ) 是由 姚超捷 谭丕强 胡志远 楼狄明 张允华 房亮 于 2021-07-05 设计创作，主要内容包括：本发明涉及一种氧化剂主导的DPF主动再生装置及其控制方法,装置包括DPF、NO-(x)存储单元、控制单元、传感器单元和阀门单元；DPF的入口连接有尾气管,NO-(x)存储单元的入口通过尾气支管连通至DPF入口侧的尾气管,NO-(x)存储单元的出口通过尾气支管连通至DPF入口侧的尾气管,NO-(x)存储单元用于存储或释放NO-(x)气体；阀门单元设置在尾气支管与NO-(x)存储单元之间,用于控制进出NO-(x)存储单元的尾气流量。与现有技术相比,本发明在DPF入口侧设置了NO-(x)存储单元,能够存储释放NO-(x)气体,在尾气排放时,NO-(x)存储单元吸收存储尾气中的NO-(x)气体,在进行DPF再生时,释放NO-(x)存储单元中的NO-(x)气体作为氧化剂进行DPF主动再生,成本低而且可以主动控制。(The invention relates to an oxidant-dominant DPF active regeneration device and a control method thereof, wherein the device comprises a DPF and NO x The device comprises a storage unit, a control unit, a sensor unit and a valve unit; the inlet of DPF is connected with tail gas pipe, NO x The inlet of the storage unit is communicated to a tail gas pipe on the inlet side of the DPF through a tail gas branch pipe, and NO x The outlet of the storage unit is communicated to a tail gas pipe on the inlet side of the DPF through a tail gas branch pipe, and NO x Storage unit for storing or releasing NO x A gas; the valve unit is arranged between the tail gas branch pipe and NO x Between memory cells for controlling in and out NO x The exhaust flow of the storage unit. Compared with the prior art, the invention is arranged at the inlet side of the DPFIs provided with NO x Storage unit capable of storing and releasing NO x Gas, at exhaust emission, NO x The storage unit absorbs and stores NO in the tail gas x Gas, during DPF regeneration, releasing NO x NO in memory cell x The gas is used as an oxidant to carry out DPF active regeneration, the cost is low, and the DPF can be actively controlled.)

1. An active regeneration device of DPF (diesel particulate filter) with leading oxidant is characterized by comprising DPF (1) and NO_xThe device comprises a storage unit (2), a control unit (3), a sensor unit and a valve unit;

the inlet of DPF (1) is connected with a tail gas pipe (4) and NO_xThe inlet of the storage unit (2) is communicated to a tail gas pipe (4) at the inlet side of the DPF (1) through a tail gas branch pipe (5), NO_xThe outlet of the storage unit (2) is communicated to a tail gas pipe (4) at the inlet side of the DPF (1) through a tail gas branch pipe (5), and the NO is_xThe storage unit (2) is used for storing or releasing NO_xA gas;

the valve unit is arranged between the tail gas branch pipe (5) and NO_xBetween the memory cells (2) for controlling the access to NO_xThe exhaust gas flow of the storage unit (2);

the control unit (3) is in communication connection with the sensor unit and the valve unit.

2. An oxidant dominated DPF active regeneration device as claimed in claim 1, wherein the valve unit comprises a first valve flap (6) and a second valve flap (7), the first valve flap (6) being set to NO_xThe second valve plate (7) is arranged on the tail gas branch pipe (5) at the inlet side of the storage unit (2)_xAn exhaust branch pipe (5) on the outlet side of the storage unit (2).

3. An active regeneration device of an oxidant dominated DPF as claimed in claim 1 where the sensor unit comprises a temperature sensor group (8) and NO_xA concentration sensor group (9), the temperature sensor group (8) being arranged at NO_xAn inlet of the storage unit (2), an inlet of the DPF (1) and an outlet of the DPF (1) for measuring the exhaust gas temperature, the NO_xThe concentration sensor group (9) is arranged in NO_xIn the exhaust gas pipe (4) before the inlet side of the storage unit (2) for measuring NO in the exhaust gas_xAnd (4) concentration.

4. An oxidant dominated DPF active regeneration device according to claim 3 where the sensor unit further comprises a set of pressure sensors arranged at the inlet and outlet of the DPF (1) for measuring the pressure difference of the DPF (1).

5. An oxidant dominated DPF active regeneration device as claimed in claim 1 wherein said NO is_xThe storage unit (2) is configured to adsorb NO at low temperature₂Releasing NO at high temperature₂。

6. An oxidant dominated DPF active regeneration device as claimed in claim 1 wherein said control unit (3) is further communicatively connected to the engine ECU (10), the control unit (3) obtaining engine operating conditions and engine exhaust flow through the engine ECU (10).

7. A control method for controlling an oxidant dominated DPF active regeneration device according to any one of claims 1-6, comprising the steps of:

s1, obtaining NO_xLatest NO in memory cell (2)_xStorage amount if NO_xIf the storage amount is less than the preset storage threshold, executing step S2, otherwise, executing step S3;

s2, entering NO_xStorage mode, calculating the opening of valve unit, and regulating inlet and outlet NO_xExhaust gas flow of storage cell (2), exit NO_xUpdating NO after storage mode_xStorage amount, repeating step S1;

s3, entering DPF regeneration mode and releasing NO_xNO in the memory cell (2)_xGas DPF regeneration to renew NO_xStorage amount, exit NO_xStep S1 is repeated after the pattern is stored.

8. The control method according to claim 7, wherein in step S2, when NO is present_xThe execution time of the storage mode being greater than a preset cycle period or NO_xWhen the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode; in step S3, when the execution time of the DPF regeneration mode is greater than the preset cycle period or NO_xWhen the storage amount is smaller than a preset storage threshold value, the DPF regeneration mode is exited; the preset cycle period is 50 ms-1000 ms.

9. A control method according to claim 8, characterized in that NO_xThe control process of the storage mode is as follows:

s21, obtaining the latest NO_xStorage amount if NO_xThe execution time of the storage mode being greater than the cycle period or NO_xIf the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode, otherwise, executing step S22;

s22, acquiring the temperature of the tail gas, and if the temperature of the tail gas is higher than a preset adsorption temperature threshold value, closing the valve unit to obtain NO_xThe storage unit (2) is independent, the step S21 is repeated, otherwise, the temperature is based on the temperature of the tail gasDegree, NO_xStorage amount and NO_xMemory MAP of memory cell (2) to obtain current NO_xExpected adsorption capacity;

s23, obtaining NO in tail gas_xConcentration and exhaust flow of the engine, based on NO_xExpected amount of adsorbed, NO_xConcentration and exhaust flow calculation of entering NO_xAn optimum exhaust gas flow rate of the storage unit (2);

s24, calculating the opening degree of the valve unit based on the optimal tail gas flow, controlling the valve unit to execute, and updating NO_xStorage amount, step S21 is repeated.

10. A control method according to claim 8, characterized in that the control procedure of the DPF regeneration mode is as follows:

s31, obtaining the latest NO_xStorage amount if DPF regeneration mode is performed for more than a cycle period or NO_xIf the storage amount is smaller than the preset storage threshold value, the DPF regeneration mode is exited, otherwise, the step S32 is executed;

s32, detecting whether the DPF needs to be regenerated, if not, repeating the step S31, otherwise, executing the step S33;

s33, calculating the expected NO of DPF_xDemand, exhaust gas temperature and latest NO_xStorage, calculating NO at the current exhaust temperature_xThe memory cell (2) releases NO_xRate of gas, if NO_xThe release of gas can satisfy the expected NO_xTriggering DPF regeneration when demand is required, calculating the opening degree of the valve unit, controlling the valve unit to execute, and updating NO_xAnd (4) storing the memory, repeating the step S31, and otherwise, directly repeating the step S31.

Technical Field

The invention relates to the field of power machinery and engineering, in particular to an oxidant-dominant DPF active regeneration device and a control method thereof.

Background

Diesel engines (diesel engines) are widely used in the fields of transportation, agricultural machinery, engineering machinery, and the like due to their excellent power performance and economy. However, diesel engines produce more particulate matter and Nitrogen Oxides (NO)_x) The emission causes great pollution to the atmospheric environment and also causes great threat to the health of residents.

A diesel particulate trap (DPF) is capable of trapping particulate matter in exhaust gas, thereby preventing the particulate matter from being discharged into the atmosphere. However, since the DPF continuously accumulates particulate matter during use to increase exhaust back pressure and affect normal operation of the diesel engine, it is necessary to perform DPF regeneration operation in which the particulate matter in the DPF is burned to reduce the amount of DPF carbon and restore the exhaust back pressure to normal. Generally, the DPF regeneration process includes active regeneration and passive regeneration, wherein the active regeneration increases the temperature of the particulate matters trapped in the DPF in an oil injection heating mode, so that combustible substances such as soot, organic matters and the like in the particulate matters are oxidized; passive regeneration, where the combustion temperature of the particulate matter is reduced by the addition of a catalyst, and is thereby oxidized.

However, both of these approaches have problems and difficulties, and the active regeneration involves oil injection, which may affect the engine oil consumption and even cause thermal runaway of the DPF, causing the DPF to burn through; passive regeneration uses catalysts that are expensive and do not allow active control of regeneration timing and rate.

Disclosure of Invention

It is an object of the present invention to overcome the above-mentioned deficiencies of the prior art by providing an oxidant-dominated solutionDPF active regeneration device and control method thereof, wherein NO is arranged at DPF inlet side_xStorage unit capable of storing and releasing NO_xGas, at exhaust emission, NO_xThe storage unit absorbs and stores NO in the tail gas_xGas, during DPF regeneration, releasing NO_xNO in memory cell_xThe gas is used as an oxidant to carry out DPF active regeneration, the cost is low, and the DPF can be actively controlled.

The purpose of the invention can be realized by the following technical scheme:

an active regeneration device of DPF with leading oxidant comprises DPF and NO_xThe device comprises a storage unit, a control unit, a sensor unit and a valve unit;

the inlet of DPF is connected with tail gas pipe, NO_xThe inlet of the storage unit is communicated to a tail gas pipe on the inlet side of the DPF through a tail gas branch pipe, and NO_xThe outlet of the storage unit is communicated to a tail gas pipe on the inlet side of the DPF through a tail gas branch pipe, and the NO is_xStorage unit for storing or releasing NO_xA gas;

the valve unit is arranged between the tail gas branch pipe and NO_xBetween memory cells for controlling in and out NO_xAn exhaust flow rate of the storage unit;

the control unit is in communication connection with the sensor unit and the valve unit.

Furthermore, the valve unit comprises a first valve plate and a second valve plate, and the first valve plate is arranged on NO_xThe second valve gate valve plate is arranged on the exhaust branch pipe on the inlet side of the storage unit_xOn the exhaust manifold on the outlet side of the storage unit.

Further, the sensor unit comprises a temperature sensor group and NO_xA concentration sensor group arranged at NO_xAn inlet of the storage unit, an inlet of the DPF and an outlet of the DPF for measuring the exhaust gas temperature, said NO_xConcentration sensor group arranged in NO_xIn the exhaust pipe before the inlet side of the storage unit for measuring NO in the exhaust gas_xAnd (4) concentration.

Further, the sensor unit further includes a pressure sensor group disposed at an inlet and an outlet of the DPF for measuring a pressure difference of the DPF, estimating a carbon loading in the DPF based on the pressure difference of the DPF, and performing active regeneration when the carbon loading reaches a certain amount.

Further, said NO_xThe storage unit is configured to adsorb NO at low temperature₂Releasing NO at high temperature₂。

Further, NO_xThe internal carrier and catalyst of the storage unit can be selected from PNA, LNT, etc. for storing and releasing NO_xCan also be composed of metal oxide, NO_xThe memory cell is capable of adsorbing NO at low temperatures₂And/and NO₂React to absorb NO₂Releasing NO at high temperature/in the dry state₂。

Further, the control unit is in communication connection with an engine ECU, and the control unit obtains the working condition of the engine and the exhaust flow of the engine through the engine ECU.

A control method for controlling an oxidant dominated DPF active regeneration device as described above, comprising the steps of:

s1, obtaining NO_xLatest NO in memory cell_xStorage amount if NO_xIf the storage amount is less than the preset storage threshold, executing step S2, otherwise, executing step S3;

s2, entering NO_xStorage mode, calculating the opening of valve unit, and regulating inlet and outlet NO_xExhaust flow of storage cell, Exit NO_xUpdating NO after storage mode_xStorage amount, repeating step S1;

s3, entering DPF regeneration mode and releasing NO_xNO in memory cell_xGas DPF regeneration to renew NO_xStorage amount, exit NO_xStep S1 is repeated after the pattern is stored.

Further, in step S2, when NO is present_xThe execution time of the storage mode being greater than a preset cycle period or NO_xWhen the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode; in step S3, when the execution time of the DPF regeneration mode is greater than the preset cycle period or NO_xWhen the storage amount is smaller than a preset storage threshold value, the DPF regeneration mode is exited; the preset cycle period is 50 ms-1000 ms.

Further, NO_xThe control process of the storage mode is as follows:

s21, obtaining the latest NO_xStorage amount if NO_xThe execution time of the storage mode being greater than the cycle period or NO_xIf the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode, otherwise, executing step S22;

s22, acquiring the temperature of the tail gas, and if the temperature of the tail gas is higher than a preset adsorption temperature threshold value, closing the valve unit to obtain NO_xThe storage unit is independent and step S21 is repeated, otherwise, based on the temperature of the exhaust gas, NO_xStorage amount and NO_xMemory MAP of memory cell to obtain current NO_xExpected adsorption capacity;

s23, obtaining NO in tail gas_xConcentration and exhaust flow of the engine, based on NO_xExpected amount of adsorbed, NO_xConcentration and exhaust flow calculation of entering NO_xOptimal exhaust flow of the storage unit;

s24, calculating the opening degree of the valve unit based on the optimal tail gas flow, controlling the valve unit to execute, and updating NO_xStorage amount, step S21 is repeated.

Further, the control procedure of the DPF regeneration mode is as follows:

s31, obtaining the latest NO_xStorage amount if DPF regeneration mode is performed for more than a cycle period or NO_xIf the storage amount is smaller than the preset storage threshold value, the DPF regeneration mode is exited, otherwise, the step S32 is executed;

s32, detecting whether the DPF needs to be regenerated, if not, repeating the step S31, otherwise, executing the step S33;

s33, calculating the expected NO of DPF_xDemand, exhaust gas temperature and latest NO_xStorage, calculating NO at the current exhaust temperature_xMemory cellReleasing NO_xRate of gas, if NO_xThe release of gas can satisfy the expected NO_xTriggering DPF regeneration when demand is required, calculating the opening degree of the valve unit, controlling the valve unit to execute, and updating NO_xAnd (4) storing the memory, repeating the step S31, and otherwise, directly repeating the step S31.

Compared with the prior art, the invention arranges NO at the inlet side of the DPF_xStorage unit capable of storing and releasing NO_xGas, at exhaust emission, NO_xThe storage unit absorbs and stores NO in the tail gas_xGas, during DPF regeneration, releasing NO_xNO in memory cell_xThe gas is used as an oxidant to carry out DPF active regeneration, the cost is low, active control can be realized, the thermal runaway problem of the existing DPF active oil injection regeneration is solved, and the catalyst cost of DPF passive regeneration and the problem of incapability of active control are solved.

Drawings

FIG. 1 is a schematic diagram of an active regeneration device for an oxidant dominated DPF;

FIG. 2 is a flow chart of a control method;

reference numerals: 1. DPF, 2, NO_xStorage unit, 3, control unit, 4, exhaust pipe, 5, exhaust branch pipe, 6, first valve plate, 7, second valve plate, 8, temperature sensor group, 9, NO_xConcentration sensor group, 10, engine ECU.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. Parts are exaggerated in the drawing where appropriate for clarity of illustration.

Example 1:

an active regeneration device for an oxidizer-dominated DPF is shown in FIG. 1 and comprises DPF1, NO_xA storage unit 2, a control unit 3, a sensor unit and a valve unit; the inlet of DPF1 is connected with tail gas pipe 4, NO_xThe inlet of the storage unit 2 is connected to the exhaust pipe 4 on the inlet side of the DPF1 through an exhaust branch pipe 5, NO_xThe outlet of the storage unit 2 is connected to an exhaust pipe 4 on the inlet side of the DPF1 through an exhaust branch pipe 5, and NO_xThe storage unit 2 is used for storing or releasing NO_xA gas; the valve unit is arranged between the tail gas branch pipe 5 and NO_xBetween the memory cells 2 for controlling the access to NO_xThe exhaust gas flow of the storage unit 2; the control unit 3 is in communication with the sensor unit and the valve unit.

NO_xThe storage unit 2 is configured to adsorb NO at low temperature₂Releasing NO at high temperature₂. In particular, NO_xThe internal carrier and catalyst of the storage unit 2 can be selected from PNA, LNT, etc. for storing and releasing NO_xThe carrier and catalyst of the post-processor, or metal oxide such as MgO, NO_xThe memory cell 2 is capable of adsorbing NO at low temperatures₂And/and NO₂React to absorb NO₂Releasing NO at high temperature/in the dry state₂。

The working principle of the application is as follows: utilization of NO in exhaust emission process_xThe storage unit 2 adsorbs and stores a part of NO_xGas, during DPF regeneration, releasing NO_xNO in the memory cell 2_xGases, increasing NO of exhaust entering DPF1_xConcentration to thereby pass NO₂Oxidizing soot in DPF1 allows for better active regeneration of DPF 1.

Wherein the sensor unit comprises a temperature sensor group 8 and NO_xConcentration sensor group 9 and temperature sensor group 8 are arranged in NO_xAn inlet of the storage unit 2, an inlet of the DPF1 and an outlet of the DPF1 for measuring exhaust gas temperature, NO_xThe concentration sensor group 9 is arranged at NO_xIn the exhaust pipe 4 before the inlet side of the storage unit 2 for measuring NO in the exhaust gas_xAnd (4) concentration.

The sensor unit further comprises a set of pressure sensors arranged at the inlet and outlet of the DPF1 for measuring the pressure difference of the DPF1, estimating the carbon loading in the DPF1 from the pressure difference of the DPF1, and requiring active regeneration when the carbon loading reaches a certain amount.

The valve unit comprises a first valve flap 6 and a second valve flap 7, the first valve flap 6 is arranged in NO_xOn the exhaust branch pipe 5 on the inlet side of the storage unit 2, a second valve plate 7 is provided on NO_xOn the exhaust branch pipe 5 on the outlet side of the storage unit 2.

According to NO_xThe material and the characteristics of the storage unit 2 can be used for calibrating NO through basic experiments_xStorage MAP of the storage unit 2, i.e. adsorption or release of NO at different temperatures_xThe amount of gas.

The opening degree of the first valve sheet 6 and the second valve sheet 7 is changed to adjust the NO entering_xThe exhaust gas flow rate of the storage unit 2 is combined with the exhaust gas flow rate of the engine and NO in the exhaust gas_xConcentration and opening degree of the first valve flap 6 and the second valve flap 7 according to NO at the current temperature_xThe stored MAP of the memory cell 2 can be estimated from NO_xNO adsorbed by the memory cell 2_xGas, regulating valve opening and accumulating current NO_xThe method for storing the data is not described in detail herein, and can be understood by practitioners in the relevant industries.

The control unit 3 is also connected in communication with an engine ECU10, and the control unit 3 acquires the operating condition of the engine and the exhaust gas flow rate of the engine through an engine ECU 10.

A control method, as shown in fig. 2, comprising the steps of:

s1, obtaining NO_xLatest NO in memory cell 2_xStorage amount if NO_xIf the storage amount is less than the preset storage threshold, executing step S2, otherwise, executing step S3;

s2, entering NO_xStorage mode, calculating the opening of valve unit, and regulating inlet and outlet NO_xExhaust gas flow of the storage cell 2, Exit NO_xUpdating NO after storage mode_xStorage amount, repeating step S1;

s3, entering DPF regeneration mode and releasing NO_xNO in the memory cell 2_xGas DPF regeneration to renew NO_xStorage amount, exit NO_xStep S1 is repeated after the pattern is stored.

In step S2, when NO is present_xThe execution time of the storage mode being greater than a preset cycle period or NO_xWhen the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode; in step S3, when the execution time of the DPF regeneration mode is greater than the preset cycle period or NO_xWhen the storage amount is smaller than a preset storage threshold value, the DPF regeneration mode is exited; the preset cycle period is 50 ms-1000 ms.

Wherein NO_xThe control process of the storage mode is as follows:

s21, obtaining the latest NO_xStorage amount if NO_xThe execution time of the storage mode being greater than the cycle period or NO_xIf the storage capacity is not less than the preset storage threshold, the NO is exited_xStoring the mode, otherwise, executing step S22;

s22, acquiring the temperature of the tail gas, and if the temperature of the tail gas is higher than a preset adsorption temperature threshold value, closing the valve unit to obtain NO_xThe storage unit 2 is independent and the step S21 is repeated, otherwise, based on the temperature of the exhaust gas, NO_xStorage amount and NO_xMemory MAP of memory cell 2 to obtain current NO_xExpected adsorption capacity;

s23, obtaining NO in tail gas_xConcentration and exhaust flow of the engine, based on NO_xExpected amount of adsorbed, NO_xConcentration and exhaust flow calculation of entering NO_xOptimum exhaust gas flow of the storage unit 2;

s24, calculating the opening degree of the valve unit based on the optimal exhaust gas flow and controlling the valve unit to execute, wherein the opening degree can be calculated according to NO in the exhaust gas_xConcentration, into NO_xExhaust gas flow and NO of storage cell 2_xThe adsorption capacity of the storage unit 2 is given NO_xMultiplying the storage rate by the time interval to obtain the NO in the time interval_xStorage amount, update NO_xStorage amount, step S21 is repeated.

The control process of the DPF regeneration mode is as follows:

s31, obtaining the latest NO_xStorage amount if DPF regeneration mode is performed for more than a cycle period or NO_xIf the storage amount is smaller than the preset storage threshold value, the DPF regeneration mode is exited, otherwise, the step S32 is executed;

s32, detecting whether the DPF1 needs to be regenerated according to the pressure difference of the DPF1, if not, repeating the step S31, otherwise, executing the step S33;

s33, calculating the expected NO of DPF1_xDemand, exhaust gas temperature and latest NO_xStorage, calculating NO at the current exhaust temperature_xMemory cell 2 releasing NO_xRate of gas, if NO_xThe release of gas can satisfy the expected NO_xThe required quantity triggers DPF regeneration, calculates the opening degree of the valve unit and controls the valve unit to execute, and NO is carried out similarly_xMultiplying the storage rate by the time interval to obtain NO_xStorage amount, update NO_xAnd (4) storing the memory, repeating the step S31, and otherwise, directly repeating the step S31.

In this embodiment, a master function, NO, is set_xStorage function and DPF regeneration function, the main function being a self-loop process, in NO_xRespectively entering NO under different storage quantities_xThe storage function and the DPF regeneration function are two sub-functions.

In NO_xIn the storage function, if the temperature of the exhaust gas is too high, the exhaust gas passes through NO_xThe memory cell 2 will cause NO_xMemory cell 2 releasing NO_xGas, then the first valve sheet 6 and the second valve sheet 7 are closed, NO_xThe memory unit 2 becomes an independent module. If the exhaust gas temperature is low, e.g. during cold start of the engine the exhaust gas temperature is low and NO_xIf the emission is high, the first valve sheet 6 and the second valve sheet 7 are completely opened, and the tail gas flows through NO_xMemory cell 2, NO therein_xGas NO_xThe storage unit 2 adsorbs and stores. Generally, the tail gas temperature and NO need to be balanced_xRegulating the heat-dissipating capacity of the memory cell 2 into NO_xOff-gas of storage unit 2Flow rate of tail gas to NO_xHeating of memory cell 2 and NO_xThe heat dissipation of the storage unit 2 is relatively balanced, so that NO can be adsorbed_xA gas.

In the DPF regeneration function, when DPF regeneration is needed, NO can be heated if the current exhaust temperature_xThe memory cell 2 is caused to release NO_xGas and NO_xNO released from the memory cell 2_xThe gases make NO in the exhaust entering the DPF1_xWhen the concentration meets the DPF active regeneration effect, active regeneration is triggered, and NO in tail gas is used as fuel_xGas and NO_xNO released from the memory cell 2_xThe gas acts as an oxidant to actively regenerate the DPF.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.