Post-processing method and device for gasoline engine, vehicle and storage medium

Abstract

The invention relates to a gasoline engine aftertreatment method and device, a vehicle and a storage medium, and the method comprises the steps that under the condition that the oil-gas ratio is larger than a preset threshold value, whether the nitrogen oxide concentration is larger than or equal to a first concentration threshold value or not, and / or whether the pressure difference is larger than a first pressure difference threshold value or not, and / or whether the gasoline engine is in a power point working condition or not are judged; if yes, whether the temperature is larger than or equal to a preset temperature threshold value is judged; and if the temperature is larger than or equal to the preset temperature threshold value, it is determined that the gasoline engine is in a regeneration working condition, the gasoline engine is controlled to stop, a bypass valve is controlled to be fully opened, a control valve is controlled to be fully opened, a secondary air valve is controlled to be fully opened, and secondary air is introduced into a particulate filter for particulate matter regeneration. Therefore, the problems that forcible conversion of the enrichment working condition is needed, the system size is large and the control difficulty is high in the prior art are solved, the conversion effect of harmful gas can be improved, emission of the harmful gas is reduced, and meanwhile the application difficulty is small.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a gasoline engine post-processing method, device, vehicle, and storage medium. Background Art

[0002] Lean-burn technology, with its advantages of high fuel economy, high thermal efficiency, and low conventional emissions, is considered one of the important technical routes for the future development of gasoline engines. However, due to the combustion of a mixture that deviates from the theoretical air-fuel ratio, the traditional TWC (Three-Way Catalytic Converter) experiences oxygen inhibition, which sharply reduces the conversion rate of NOx (Nitrogen Oxides) in the exhaust of lean-burn engines, making NOx emission control a limiting factor in the development of lean-burn engine technology.

[0003] Currently, the conversion efficiency of NOx and THC in gasoline engine aftertreatment systems needs to be further improved to control emissions.

[0004] In related technologies, stoichiometric combustion gasoline engines mainly adopt the EGR+TWC+GPF technical route, which uses EGR technology to reduce the combustion temperature in the cylinder and reduce the engine's original NOx emissions. At the same time, TWC is used to process the NOx, THC, and CO in the exhaust gas under the stoichiometric ratio. However, this solution is only applicable to stoichiometric combustion gasoline engines and is not applicable to lean-burn gasoline engines.

[0005] In the scheme applicable to lean-burn gasoline engines, in order to control NOx emissions, the relevant technologies also set up a NOx trap or a catalytic reducer; (1) Setting up a NOx trap can chemically store NOx in the exhaust of the lean-burn engine in alkaline earth compounds in the form of nitrates or nitrites. However, the NOx trap has an upper limit on the storage capacity. At this time, the combustion system needs to switch to rich combustion to achieve the regeneration of the NOx trap, which places high demands on the engine control system and will cause local over-concentration in the cylinder, affecting the engine combustion efficiency. Therefore, this scheme is not conducive to the engine thermal efficiency and control system design; (2) Setting up a catalytic reducer converts NOx into ammonia and water in the form of a chemical reaction by introducing additional reducing agents. However, the selective catalytic reducer needs to be regularly filled with reducing agents, and the reducing agent injection system is complex to control. In addition, the reducing agent injection system is large in size, has high requirements on the overall vehicle layout, and is difficult to apply. Summary of the Invention

[0006] The present application provides a gasoline engine post-processing method, device, vehicle and storage medium to solve the problems of related technologies requiring forced conversion to enriched operating conditions, large system size and difficulty in control. It can improve the conversion effect of harmful gases, reduce the emission of harmful gases, and has low application difficulty.

[0007] In a first aspect, an embodiment of the present application provides a gasoline engine aftertreatment method, wherein an exhaust manifold of the gasoline engine is connected to a secondary air valve and one end of a particulate trap, respectively; the other end of the particulate trap is connected to one end of a control valve and one end of a bypass valve, respectively; and the other end of the control valve is connected to one end of a lean NOx trap, wherein the method comprises the following steps: Determine whether the oil-gas ratio is greater than a preset threshold; If the oil-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition; If the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in the power point operating condition, determining whether the temperature is greater than or equal to a preset temperature threshold; If the temperature is greater than or equal to the preset temperature threshold, the gasoline engine is determined to be in a regeneration condition, the gasoline engine is controlled to shut down, the bypass valve is controlled to be fully opened, the control valve is controlled to be fully opened, and the secondary air valve is controlled to be fully opened to introduce secondary air into the particulate filter for particulate matter regeneration.

[0008] Optionally, in some embodiments, after determining whether the oil-gas ratio is greater than the preset threshold, the method includes: If the oil-gas ratio is less than or equal to the preset threshold, the gasoline engine is determined to be in a mass ratio operating condition, the bypass valve is controlled to be fully opened, the control valve is controlled to be fully closed, and the secondary air valve is controlled to be fully closed.

[0009] Optionally, in some embodiments, after determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, the method further includes: If the nitrogen oxide concentration is less than the first concentration threshold, and the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in the power point operating condition, then the gasoline engine is determined to be in a lean burn operating condition, the bypass valve is controlled to be fully closed, the control valve is controlled to be fully open, and the secondary air valve is controlled to be fully closed.

[0010] Optionally, in some embodiments, after determining that the gasoline engine is in a regeneration operating state, controlling the gasoline engine to stop, controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration, the following steps are included: Obtaining a new nitrogen oxide concentration, and determining whether the new nitrogen oxide concentration is less than the first concentration threshold; If the new nitrogen oxide concentration is less than the first concentration threshold, determining whether a restart signal of the gasoline engine is received; If a restart signal of the gasoline engine is received, the step of determining whether the oil-gas ratio is greater than a preset threshold is executed again.

[0011] Optionally, in some embodiments, after determining whether the temperature is greater than or equal to the preset temperature threshold, the method further includes: If the temperature is lower than the preset temperature threshold, the electric heater is turned on, and it is re-determined whether the temperature is higher than or equal to the preset temperature threshold until the temperature is higher than or equal to the preset temperature threshold, at which time the electric heater is stopped, wherein the electric heater is arranged between the exhaust manifold and one end of the particulate filter.

[0012] A second embodiment of the present application provides a gasoline engine aftertreatment device, wherein the exhaust manifold of the gasoline engine is connected to one end of a secondary air valve and a particulate trap, respectively; the other end of the particulate trap is connected to one end of a control valve and one end of a bypass valve, respectively; and the other end of the control valve is connected to one end of a lean NOx trap, wherein the device comprises: The first judgment module is used to judge whether the oil-gas ratio is greater than a preset threshold; a second judgment module, configured to judge, when the oil-gas ratio is greater than the preset threshold, whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition; a third judgment module, configured to judge whether the temperature is greater than or equal to a preset temperature threshold when the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in the power point operating condition; The control module is used to determine that the gasoline engine is in a regeneration operating state when the temperature is greater than or equal to the preset temperature threshold, control the gasoline engine to stop, and control the bypass valve to fully open, control the control valve to fully open, and control the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration.

[0013] Optionally, in some embodiments, after determining whether the oil-gas ratio is greater than the preset threshold, the first determination module includes: The first control unit is used to determine that the gasoline engine is in a quantitative ratio operating condition when the oil-gas ratio is less than or equal to the preset threshold, control the bypass valve to be fully opened, control the control valve to be fully closed, and control the secondary air valve to be fully closed.

[0014] Optionally, in some embodiments, after determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, the third judgment module further includes: The second control unit is used to determine that the gasoline engine is in a lean burn operating condition when the nitrogen oxide concentration is less than a first concentration threshold, the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in the power point operating condition, control the bypass valve to be fully closed, control the control valve to be fully open, and control the secondary air valve to be fully closed.

[0015] Optionally, in some embodiments, after determining that the gasoline engine is in a regeneration operating state, controlling the gasoline engine to stop, controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration, the control module includes: an acquiring unit, configured to acquire a new nitrogen oxide concentration and determine whether the new nitrogen oxide concentration is less than the first concentration threshold; a first determining unit, configured to determine whether a restart signal of the gasoline engine is received when the new nitrogen oxide concentration is less than the first concentration threshold; The second judgment unit is configured to, upon receiving a restart signal of the gasoline engine, re-execute the step of judging whether the oil-gas ratio is greater than a preset threshold.

[0016] Optionally, in some embodiments, after determining whether the temperature is greater than or equal to the preset temperature threshold, the third determination module includes: A heating unit is used to turn on the electric heater when the temperature is lower than the preset temperature threshold, and re-determine whether the temperature is higher than or equal to the preset temperature threshold until the temperature is higher than or equal to the preset temperature threshold, and then stop the electric heater, wherein the electric heater is arranged between the exhaust manifold and one end of the particulate filter.

[0017] A third aspect of the present application provides a vehicle, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the gasoline engine post-processing method as described in the above embodiment.

[0018] A fourth embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the post-processing method of a gasoline engine as described in the above embodiment.

[0019] Thus, by determining whether the oil-gas ratio is greater than a preset threshold, and if the oil-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, and if the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in a power point operating condition, determining whether the temperature is greater than or equal to a preset temperature threshold, and if the temperature is greater than or equal to the preset temperature threshold, determining that the gasoline engine is in a regeneration operating condition, controlling the gasoline engine to shut down, and controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration. This solves the problems of related technologies requiring forced conversion to an enriched operating condition, large system size, and high control difficulty, thereby improving the conversion effect of harmful gases and reducing harmful gas emissions, while also being easy to apply.

[0020] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic diagram of the principle of a gasoline engine after-treatment system provided according to one embodiment of the present application; Figure 2 This is a flow chart of a gasoline engine post-processing method according to an embodiment of the present application; Figure 3 This is a flow chart of a gasoline engine post-processing method according to one embodiment of the present application; Figure 4 Schematic diagram of a post-processing device for a gasoline engine according to an embodiment of the present application; Figure 5 A schematic structural diagram of a vehicle provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0022] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0023] The following describes a gasoline engine post-treatment method, device, vehicle, and storage medium according to an embodiment of the present application with reference to the accompanying drawings. To address the issues mentioned in the background art above, such as the need for forced conversion to a rich operating mode, large system size, and difficulty in control, the present application provides a gasoline engine post-treatment method. In this method, by determining whether the fuel-gas ratio is greater than a preset threshold, if the fuel-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating mode, if the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or if the gasoline engine is in a power point operating mode, determining whether the temperature is greater than or equal to a preset temperature threshold, and if the temperature is greater than or equal to the preset temperature threshold, determining that the gasoline engine is in a regeneration mode, controlling the gasoline engine to shut down, controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration. Therefore, the problems of related technologies requiring forced conversion to enriched conditions, large system size and difficult control can be solved, which can improve the conversion effect of harmful gases, reduce the emission of harmful gases, and at the same time reduce the difficulty of application.

[0024] It should be noted that the post-processing method of the gasoline engine of the embodiment of the present application adopts a gasoline engine post-processing system, such as Figure 1 As shown, the after-treatment system of the gasoline engine of the embodiment of the present application includes: a gasoline engine 1, an exhaust manifold 2, an electric heater 3, a particulate filter 4, a lean-burn nitrogen oxide filter 5, a three-way catalytic converter 6, a secondary air valve 7, a pressure difference sensor 8, a temperature sensor 9, a NOx concentration sensor 10, a control valve 11, a bypass valve 12 and an electronic control unit 13, wherein the gasoline engine 1 and the electric heater 3 and the particulate filter 4 are physically connected through the intake manifold 2, the secondary air valve 7 and the electric heater 3 are physically connected, and the electric heater 3 and the particulate filter 4 are tightly coupled; the particulate filter 4 is physically connected to the bypass valve 12 and the control valve 11 through pipelines respectively; the bypass valve 12 and the three-way catalytic converter 6 are physically connected through pipelines; the control valve 11, the lean-burn nitrogen oxide filter 5 and the three-way catalytic converter 6 are physically connected through pipelines. The electronic control unit 13 is connected to the secondary air valve 7, the bypass valve 12, and the control valve 11 through wires for electrical signals; the electronic control unit 13 is connected to the pressure difference sensor 8, the temperature sensor 9, and the NOx concentration sensor 10 through wires for electrical signals.

[0025] Preferably, a coated CGPF after-processor is used in the particulate filter 4, and the catalyst formula in the lean-burn nitrogen oxide trap 5 uses Pt; the catalyst formula of the three-way catalytic converter 6 uses Pt precious metal catalyst, avoiding the use of Pd and Rh precious metal catalysts; the exhaust pipe uses a pipe that has been insulated to avoid a drop in exhaust temperature and affect the catalyst efficiency.

[0026] The gasoline engine 1 and the exhaust manifold 2 constitute an engine module, which is used to generate the original exhaust gas of the engine; the particulate filter 4 and the pressure difference sensor 8 constitute a particulate filter module, which is used to control PM and PN in the original exhaust gas of the engine; the electric heater 3, the secondary air valve 7 and the temperature sensor 9 constitute a temperature control module, which is used to detect the exhaust temperature and control it to reach the target temperature, thereby regenerating the particulate filter 4 and generating CO; the lean-burn nitrogen oxides filter 5, the bypass valve 12, the control valve 11 and the NOx concentration sensor 10 constitute a NOx filter module, which is used to capture NOx in the exhaust and switch between the equivalence ratio operating condition, the lean-burn operating condition and the regeneration operating condition; the three-way catalytic converter 6 processes CO, HC and NOx emissions in the exhaust gas; the electronic control unit 13 is an electronic control unit module.

[0027] It should be noted that the electric heater 3, secondary air valve 7, particulate filter 4, lean-burn nitrogen oxide filter 5, three-way catalytic converter 6, differential pressure sensor 8, temperature sensor 9, NOx concentration sensor 10, control valve 11 and bypass valve 12 and corresponding connection structures mentioned in the embodiment of the present application are not limited to specific forms, including: carrier shape, volume, mesh size, pore size, porosity, etc.; coupled carrier or separated carrier; catalyst formula of the carrier; shape and structure of the sensor, shape and structure of the valve, etc., gasoline engine mode, traditional gasoline engine or hybrid gasoline engine; number of gasoline engine cylinders; port injection or direct injection; spark plug ignition or pre-combustion chamber ignition and other factors.

[0028] Specifically, Figure 2 A schematic flow chart of a gasoline engine post-processing method provided in an embodiment of the present application.

[0029] like Figure 2 As shown, the post-processing method of the gasoline engine includes the following steps: In step S101 , it is determined whether the oil-gas ratio is greater than a preset threshold.

[0030] Among them, the oil-gas ratio is the ratio of the actual air-fuel ratio to the theoretical air-fuel ratio, namely lambda. The preset threshold value can be pre-set by the user, obtained through a limited number of experiments, or obtained through a limited number of computer simulations. No specific limitation is made here. Preferably, the preset threshold value is 1.

[0031] Specifically, before determining whether the oil-gas ratio is greater than a preset threshold, the embodiment of the present application can obtain the oil-gas ratio of the combustion mixture, the pressure difference at both ends of the particulate filter, the temperature at the output end of the particulate filter, and the nitrogen oxide concentration at the output end of the lean-burn nitrogen oxide filter, so as to determine the current operating condition of the gasoline engine through the oil-gas ratio, pressure difference, temperature and nitrogen oxide concentration.

[0032] Optionally, in some embodiments, after determining whether the oil-gas ratio is greater than a preset threshold, it includes: if the oil-gas ratio is less than or equal to the preset threshold, determining that the gasoline engine is in a quantitative ratio operating condition, controlling the bypass valve to be fully open, controlling the control valve to be fully closed, and controlling the secondary air valve to be fully closed.

[0033] Specifically, combined Figure 3 As shown, when the electronic control unit 13 determines that lambda>1 is not, it is an equivalence ratio condition, the engine burns the oil-air mixture with lambda=1, the bypass valve 12 is fully open, and the secondary air valve 7 and the control valve 11 are fully closed. The post-processing path is the particulate filter 4 and the three-way catalytic converter 6. The particulate filter 4 processes PN in the exhaust gas, and the three-way catalytic converter 6 processes CO, HC and NOx in the exhaust gas.

[0034] In step S102, if the oil-gas ratio is greater than the preset threshold, it is determined whether the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in the power point operating condition.

[0035] The first concentration threshold and the first pressure difference threshold may be preset by a user, obtained through a limited number of experiments, or obtained through a limited number of computer simulations, which are not specifically limited here.

[0036] Specifically, when the electronic control unit 13 determines that lambda>1 is yes, it needs to continue to determine whether the NOx concentration exceeds the first concentration threshold Climit, whether the pressure difference P exceeds the first pressure difference threshold Plimit, and whether the gasoline engine is in the power point operating condition.

[0037] Optionally, in some embodiments, after determining whether the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, it also includes: if the nitrogen oxide concentration is less than the first concentration threshold, and the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in a power point operating condition, then the gasoline engine is determined to be in a lean burn condition, the bypass valve is controlled to be fully closed, the control valve is controlled to be fully open, and the secondary air valve is controlled to be fully closed.

[0038] Specifically, combined Figure 3As shown, if the nitrogen oxide concentration is less than the first concentration threshold, and the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in the power point operating condition, it is determined that the gasoline engine is in a lean burn operating condition, the bypass valve is controlled to be fully closed, the control valve is controlled to be fully open, and the secondary air valve is controlled to be fully closed, then it is a lean burn operating condition, the engine module burns the oil-air mixture with lambda>1, the secondary air valve 7 and the bypass valve 12 are fully closed and the control valve 11 is fully open, and the post-processing path is the particulate filter 4, the lean burn nitrogen oxide filter 5, and the three-way catalytic converter 6. The particulate filter 4 processes PN in the exhaust, the lean burn nitrogen oxide filter 5 processes NOx in the exhaust, and the three-way catalytic converter 6 processes CO and HC in the exhaust.

[0039] In step S103, if the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in the power point operating condition, it is determined whether the temperature is greater than or equal to the preset temperature threshold.

[0040] The preset temperature threshold may be pre-set by a user, obtained through a limited number of experiments, or obtained through a limited number of computer simulations, and is not specifically limited here.

[0041] Specifically, when the electronic control unit 13 determines that lambda>1 is yes, it determines whether the NOx concentration exceeds the threshold value C limit , whether the pressure difference P exceeds the threshold P limit and whether the gasoline engine is in the power point working condition. If any one of them is yes, then continue to determine whether the temperature T after the particulate filter 4 exceeds the threshold T limit .

[0042] Optionally, in some embodiments, after determining whether the temperature is greater than or equal to a preset temperature threshold, the method includes: if the temperature is less than the preset temperature threshold, turning on the electric heater, and re-determining whether the temperature is greater than or equal to the preset temperature threshold, until the temperature is greater than or equal to the preset temperature threshold, and stopping the electric heater, wherein the electric heater is arranged between the exhaust manifold and one end of the particulate collector.

[0043] Specifically, if the temperature is lower than the preset temperature threshold, the electric heater 3 is turned on to perform heating until the temperature is higher than or equal to the preset temperature threshold.

[0044] In step S104, if the temperature is greater than or equal to the preset temperature threshold, the gasoline engine is determined to be in a regeneration condition, the gasoline engine is controlled to shut down, the bypass valve is controlled to be fully opened, the control valve is controlled to be fully opened, and the secondary air valve is controlled to be fully opened to introduce secondary air into the particulate filter for particulate matter regeneration.

[0045] Optionally, in some embodiments, after determining that the gasoline engine is in a regeneration condition, controlling the gasoline engine to stop, controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration, it includes: obtaining a new nitrogen oxide concentration, and determining whether the new nitrogen oxide concentration is less than a first concentration threshold; if the new nitrogen oxide concentration is less than the first concentration threshold, determining whether a gasoline engine restart signal is received; if a gasoline engine restart signal is received, re-executing the step of determining whether the oil-gas ratio is greater than a preset threshold.

[0046] Specifically, combined Figure 3 As shown, if any one of the following conditions is true: the nitrogen oxide concentration is greater than or equal to the first concentration threshold, or the pressure difference is greater than the first pressure difference threshold, or the gasoline engine is in a power point operating condition, and the temperature is greater than or equal to the preset threshold, the gasoline engine is determined to be in a regeneration condition, the engine is shut down, the bypass valve 12 is fully closed, the control valve 11 is fully opened, the secondary air valve 7 is opened, the introduced secondary air enters the particulate filter 4, and undergoes an oxidation reaction with the previously captured carbon particles, consuming the carbon particles, and the generated CO is at a suitable temperature threshold T. limit The particulate matter will not be oxidized by oxygen on a large scale and will immediately enter the lean NOx trap 5 to react with the previously captured NOx under the catalyst to consume the NOx. The particulate trap 4 and the lean NOx trap 5 will achieve cooperative regeneration. The particulate matter will then enter the three-way catalytic converter 6 to process the CO, HC and NOx that have not yet reacted until the NOx concentration C is lower than the threshold C. limit After regeneration is complete, the engine restarts.

[0047] During the actual implementation process, the secondary air valve 7 introduces secondary air before the particulate filter 4, and undergoes an oxidation reaction with the carbon particles in the particulate filter 4. The generated CO then enters the lean-burn nitrogen oxide trap 5 to achieve coordinated regeneration. In addition, the embodiment of the present application can specifically design the carbon load of the particulate filter 4 and the NOx load of the lean-burn nitrogen oxide trap 5 according to the actual lean-burn usage of the engine to achieve optimal volumetric coordination between the two. Moreover, when performing regeneration conditions, there is no need to enrich or adjust the conditions, and the coordinated regeneration of carbon particles and NOx proceeds naturally.

[0048] In summary, the embodiment of the present application designs a solution of secondary air + electric heater + particulate filter + lean-burn nitrogen oxide filter + three-way catalytic converter, which solves the after-treatment problem of hybrid-specific lean-burn gasoline engines. Specifically, under the lambda=1 working condition, by closing the LNT passage valve and bypassing the TWC at the same time, a GPF+TWC solution is implemented to treat carbon particles under the equivalence ratio, as well as HC, CO and NOx; under the lean-burn working condition of lambda>1, by opening the LNT passage valve and closing the bypass at the same time, a GPF+LNT+TWC solution is implemented to achieve carbon particle and NOx capture, and HC and CO oxidation; under the regeneration working condition, by opening the LNT passage valve and closing the bypass at the same time, the secondary air valve is opened, the EHC starts to heat, and the EHC+secondary air+GPF+LNT+TWC solution is implemented to achieve the coordinated regeneration of carbon particles in the GPF and NOx in the LNT. The main process is that when it is identified that one of the three conditions, namely, the carbon load reaches the threshold, the NOx load reaches the threshold, or the power point operating condition, there is no need to enrich or adjust the operating condition. The EHC is first used to heat the exhaust temperature to the threshold, and then secondary air is introduced in front of the GPF to cause insufficient oxidation and regeneration reaction of carbon particles in the GPF, producing CO, consuming the carbon particles in the GPF, and then the CO enters the LNT to reduce NOx and generate nitrogen.

[0049] According to the gasoline engine post-treatment method proposed in an embodiment of the present application, by determining whether the oil-gas ratio is greater than a preset threshold, if the oil-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, if the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in a power point operating condition, determining whether the temperature is greater than or equal to a preset temperature threshold, and if the temperature is greater than or equal to the preset temperature threshold, determining that the gasoline engine is in a regeneration operating condition, controlling the gasoline engine to shut down, and controlling the bypass valve to fully open, the control valve to fully open, and the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration. This solves the problems of related technologies requiring forced conversion to an enriched operating condition, large system size, and high control difficulty, thereby improving the conversion efficiency of harmful gases and reducing harmful gas emissions, while also being simple to apply.

[0050] Next, the post-processing device of a gasoline engine proposed according to an embodiment of the present application will be described with reference to the accompanying drawings.

[0051] Figure 4 It is a block diagram of a post-processing device of a gasoline engine according to an embodiment of the present application.

[0052] like Figure 4As shown, the post-processing device 10 of the gasoline engine includes: a first judgment module 100 , a second judgment module 200 , a third judgment module 300 and a control module 400 .

[0053] The first judgment module 100 is used to judge whether the oil-gas ratio is greater than a preset threshold.

[0054] The second judgment module 200 is used to judge whether the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition when the oil-gas ratio is greater than a preset threshold.

[0055] The third judgment module 300 is used to determine whether the temperature is greater than or equal to a preset temperature threshold when the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in a power point operating condition.

[0056] The control module 400 is used to determine that the gasoline engine is in a regeneration operating state when the temperature is greater than or equal to a preset temperature threshold, control the gasoline engine to shut down, control the bypass valve to fully open, control the control valve to fully open, and control the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration.

[0057] Optionally, in some embodiments, after determining whether the oil-gas ratio is greater than a preset threshold, the first determination module 100 includes: a first control unit.

[0058] Among them, the first control unit is used to determine that the gasoline engine is in a quantity ratio operating condition when the oil-gas ratio is less than or equal to a preset threshold, control the bypass valve to be fully opened, control the control valve to be fully closed, and control the secondary air valve to be fully closed.

[0059] Optionally, in some embodiments, after determining whether the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, the third judgment module 300 further includes: a second control unit.

[0060] Among them, the second control unit is used to determine that the gasoline engine is in a lean burn condition when the nitrogen oxide concentration is less than the first concentration threshold, the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in a power point operating condition, control the bypass valve to be fully closed, control the control valve to be fully opened, and control the secondary air valve to be fully closed.

[0061] Optionally, in some embodiments, after determining that the gasoline engine is in a regeneration condition, controlling the gasoline engine to shut down, controlling the bypass valve to be fully opened, controlling the control valve to be fully opened, and controlling the secondary air valve to be fully opened to introduce secondary air into the particulate collector for particulate matter regeneration, the control module 400 includes: an acquisition unit, a first judgment unit, and a second judgment unit.

[0062] The acquiring unit is configured to acquire a new nitrogen oxide concentration and determine whether the new nitrogen oxide concentration is less than a first concentration threshold.

[0063] The first judgment unit is configured to judge whether a gasoline engine restart signal is received when a new nitrogen oxide concentration is less than a first concentration threshold.

[0064] The second judgment unit is configured to, upon receiving a restart signal of the gasoline engine, re-execute the step of judging whether the oil-gas ratio is greater than a preset threshold.

[0065] Optionally, in some embodiments, after determining whether the temperature is greater than or equal to a preset temperature threshold, the third determination module 300 includes: a heating unit.

[0066] Among them, the heating unit is used to turn on the electric heater when the temperature is lower than a preset temperature threshold, and re-determine whether the temperature is greater than or equal to the preset temperature threshold until the temperature is greater than or equal to the preset temperature threshold, and then stop the electric heater. The electric heater is arranged between the exhaust manifold and one end of the particulate filter.

[0067] It should be noted that the above explanation of the embodiment of the post-processing method of the gasoline engine is also applicable to the post-processing device of the gasoline engine of this embodiment, and will not be repeated here.

[0068] According to the gasoline engine post-treatment device proposed in an embodiment of the present application, by determining whether the oil-gas ratio is greater than a preset threshold, if the oil-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than the first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, if the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or if the gasoline engine is in a power point operating condition, determining whether the temperature is greater than or equal to a preset temperature threshold, and if the temperature is greater than or equal to the preset temperature threshold, determining that the gasoline engine is in a regeneration operating condition, controlling the gasoline engine to shut down, and controlling the bypass valve to fully open, the control valve to fully open, and the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration. This solves the problems of related technologies requiring forced conversion to an enriched operating condition, large system size, and high control difficulty, thereby improving the conversion efficiency of harmful gases and reducing harmful gas emissions, while also being simple to apply.

[0069] Figure 5 A schematic diagram of the structure of a vehicle provided in an embodiment of the present application. The vehicle may include: Memory 501 , processor 502 , and computer programs stored in the memory 501 and executable on the processor 502 .

[0070] When the processor 502 executes the program, the gasoline engine post-processing method provided in the above embodiment is implemented.

[0071] Furthermore, the vehicle further comprises: The communication interface 503 is used for communication between the memory 501 and the processor 502 .

[0072] The memory 501 is used to store computer programs that can be run on the processor 502 .

[0073] The memory 501 may include a high-speed RAM (Random Access Memory) memory, and may also include a non-volatile memory, such as at least one disk memory.

[0074] If the memory 501, processor 502, and communication interface 503 are implemented independently, the communication interface 503, memory 501, and processor 502 can be connected to each other via a bus and communicate with each other. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. Buses can be divided into address buses, data buses, control buses, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0075] Optionally, in a specific implementation, if the memory 501, the processor 502 and the communication interface 503 are integrated on a chip, the memory 501, the processor 502 and the communication interface 503 can communicate with each other through an internal interface.

[0076] The processor 502 may be a CPU (Central Processing Unit), or an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present application.

[0077] An embodiment of the present application further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned gasoline engine post-processing method.

[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0079] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this application, "N" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0080] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0081] It should be understood that various parts of the present application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiment, the N steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one of the following technologies known in the art or a combination thereof can be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application-specific integrated circuit having a suitable combination of logic gate circuits, a programmable gate array, a field programmable gate array, etc.

[0082] Those skilled in the art will understand that all or part of the steps in the method of the above embodiment can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiment.

[0083] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A post-processing method for a gasoline engine, characterized in that: The exhaust manifold of the gasoline engine is connected to one end of a secondary air valve and a particulate trap, respectively; the other end of the particulate trap is connected to one end of a control valve and one end of a bypass valve, respectively; the other end of the control valve is connected to one end of a lean nitrogen oxide trap, wherein the method comprises the following steps: Determine whether the oil-gas ratio is greater than a preset threshold; If the oil-gas ratio is greater than the preset threshold, determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition; If the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in the power point operating condition, determining whether the temperature is greater than or equal to a preset temperature threshold; If the temperature is greater than or equal to the preset temperature threshold, the gasoline engine is determined to be in a regeneration condition, the gasoline engine is controlled to shut down, the bypass valve is controlled to be fully opened, the control valve is controlled to be fully opened, and the secondary air valve is controlled to be fully opened to introduce secondary air into the particulate filter for particulate matter regeneration.

2. The method according to claim 1, characterized in that After determining whether the oil-gas ratio is greater than the preset threshold, the method includes: If the oil-gas ratio is less than or equal to the preset threshold, the gasoline engine is determined to be in a mass ratio operating condition, the bypass valve is controlled to be fully opened, the control valve is controlled to be fully closed, and the secondary air valve is controlled to be fully closed.

3. The method according to claim 1, characterized in that After determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, the method further includes: If the nitrogen oxide concentration is less than the first concentration threshold, and the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in the power point operating condition, then the gasoline engine is determined to be in a lean burn operating condition, the bypass valve is controlled to be fully closed, the control valve is controlled to be fully open, and the secondary air valve is controlled to be fully closed.

4. The method according to claim 1, wherein After determining that the gasoline engine is in a regeneration operating state, controlling the gasoline engine to stop, controlling the bypass valve to fully open, controlling the control valve to fully open, and controlling the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration, the method includes: Obtaining a new nitrogen oxide concentration, and determining whether the new nitrogen oxide concentration is less than the first concentration threshold; If the new nitrogen oxide concentration is less than the first concentration threshold, determining whether a restart signal of the gasoline engine is received; If a restart signal of the gasoline engine is received, the step of determining whether the oil-gas ratio is greater than a preset threshold is executed again.

5. The method according to claim 1, wherein After determining whether the temperature is greater than or equal to the preset temperature threshold, the method includes: If the temperature is lower than the preset temperature threshold, the electric heater is turned on, and it is re-determined whether the temperature is higher than or equal to the preset temperature threshold until the temperature is higher than or equal to the preset temperature threshold, at which time the electric heater is stopped, wherein the electric heater is arranged between the exhaust manifold and one end of the particulate filter.

6. A post-processing device for a gasoline engine, characterized in that: The exhaust manifold of the gasoline engine is connected to one end of the secondary air valve and the particulate trap respectively, the other end of the particulate trap is connected to one end of the control valve and one end of the bypass valve respectively, and the other end of the control valve is connected to one end of the lean-burn nitrogen oxide trap, wherein the device includes: The first judgment module is used to judge whether the oil-gas ratio is greater than a preset threshold; a second judgment module, configured to judge, when the oil-gas ratio is greater than the preset threshold, whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition; a third judgment module, configured to judge whether the temperature is greater than or equal to a preset temperature threshold when the nitrogen oxide concentration is greater than or equal to the first concentration threshold, and / or the pressure difference is greater than the first pressure difference threshold, and / or the gasoline engine is in the power point operating condition; The control module is used to determine that the gasoline engine is in a regeneration operating state when the temperature is greater than or equal to the preset temperature threshold, control the gasoline engine to stop, and control the bypass valve to fully open, control the control valve to fully open, and control the secondary air valve to fully open to introduce secondary air into the particulate filter for particulate matter regeneration.

7. The device according to claim 6, characterized in that After determining whether the oil-gas ratio is greater than the preset threshold, the first determination module includes: The first control unit is used to determine that the gasoline engine is in a quantitative ratio operating condition when the oil-gas ratio is less than or equal to the preset threshold, control the bypass valve to be fully opened, control the control valve to be fully closed, and control the secondary air valve to be fully closed.

8. The device according to claim 6, characterized in that After determining whether the nitrogen oxide concentration is greater than or equal to a first concentration threshold, and / or whether the pressure difference is greater than a first pressure difference threshold, and / or whether the gasoline engine is in a power point operating condition, the third determination module further includes: The second control unit is used to determine that the gasoline engine is in a lean burn operating condition when the nitrogen oxide concentration is less than a first concentration threshold, the pressure difference is less than or equal to the first pressure difference threshold, and the gasoline engine is not in the power point operating condition, control the bypass valve to be fully closed, control the control valve to be fully open, and control the secondary air valve to be fully closed.

9. A vehicle, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the gasoline engine post-processing method according to any one of claims 1 to 5.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The program is executed by a processor to implement the gasoline engine post-processing method according to any one of claims 1 to 5.

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