HC injection quantity control method and system for external DPF system

Abstract

The present invention provides a HC injection amount control method and system for an external DPF system, the method comprising collecting the DPF front row temperature and rear row temperature of the external DPF system; collecting DPF pressure difference data DP and determining the carbon load Cm within the calibration unit time Δt0; calculating the basic injection amount; adjusting the calibration unit time in real time to obtain the adjusted unit time according to the DPF temperature rise difference and the pressure difference data DP; determining the injection amount correction coefficient according to the DPF front row temperature; outputting the corrected HC injection amount according to the adjusted unit time and the injection amount correction coefficient; when the DPF rear row temperature reaches above the preset temperature and lasts for a period greater than or equal to the time period tov, the DPF pressure difference data DP is less than the set pressure difference threshold, regeneration is completed, and the regeneration mode is exited. The present invention realizes closed-loop feedback control through the temperature and pressure difference of the DPF downstream exhaust temperature feedback, adjusts the injection amount in real time, prevents the occurrence of overheating, insufficient temperature rise within unit time, and other situations, and achieves accurate regeneration effects under different working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of diesel engine emission control, in particular to DPF regeneration technology, and in particular to a HC injection amount control method and system for an external DPF system. Background Art

[0002] During the combustion process, diesel engines produce a large amount of pollutants such as particulate matter and nitrogen oxides, which pose a serious threat to the environment and human health. In order to reduce the pollutants emitted by diesel engines, especially the emission of particulate matter, diesel particulate filters (DPF, diesel carbon particle filter, trap, filter) are widely used. The function of the DPF system is to collect and capture diesel combustion exhaust particulate matter. When the captured particulate matter accumulates to a certain extent, the ECU driving computer will perform "filter regeneration" by controlling the hydrocarbon injection system (HC) to spray diesel into the engine exhaust pipe, and burn the carbon particles in the filter into carbon dioxide and discharge it to purify the filter to maintain the filtering function. This process is called the regeneration process, which converts the particulate matter captured by the DPF system into harmless substances.

[0003] During the regeneration process, the DPF system will sinter and oxidize the accumulated particulate matter to restore its emission performance. The DPF regeneration process needs to be performed regularly, and its regeneration efficiency is affected by many factors, such as particulate matter load, fuel injection amount, etc. In order to ensure the effective regeneration of the DPF, the injection amount needs to be controlled and adjusted.

[0004] In the prior art, some vehicles are equipped with an external DPF active regeneration system that cannot obtain engine operating parameters, resulting in a greatly reduced accuracy of HC injection required for regeneration or only quantitative and timed output.

[0005] For example, without the engine operating conditions and parameters, the control algorithm for DPF regeneration injection is usually based on some empirical models or rules. For complex operating conditions or system changes, the control accuracy of the algorithm is greatly limited, and the DPF regeneration injection cannot be accurately controlled and adjusted. In addition, in the absence of engine operating condition information, adaptive adjustment is impossible. In particular, when the DPF is severely clogged, it may not be possible to adjust the regeneration injection in time to effectively clean the filter. Summary of the invention

[0006] In view of the defects and shortcomings of the prior art, the purpose of the present invention is to provide a HC injection amount control method and system for an external DPF system, which does not require access to diesel engine operating parameter information, collects feedback data through system sensors to perform HC adaptive control, and adjusts and corrects the HC injection amount in real time according to the pressure difference change rate and temperature range in the exhaust gas.

[0007] According to a first aspect of the present invention, a HC injection quantity control system for an external DPF system is provided, comprising:

[0008] Collect the DPF front temperature T5 and DPF rear temperature T6 corresponding to the external DPF system;

[0009] Collecting DPF pressure difference data DP, and determining the carbon load Cm within a calibration unit time Δt0 according to the pressure difference data DP;

[0010] Calculate the basic injection amount Fue0 required for carbon load regeneration;

[0011] According to the DPF temperature rise difference ΔT and the DPF pressure difference data DP, the calibration unit time Δt0 is adjusted in real time to obtain the adjusted unit time Δt;

[0012] Determine the fuel injection amount correction coefficient σ according to the temperature range of the DPF front row temperature T5;

[0013] Based on the basic injection amount Fue0, the corrected HC injection amount Fue is output according to the adjusted unit time Δt and the injection amount correction coefficient σ;

[0014] When the DPF rear temperature T6 reaches above the preset temperature Tov and lasts for a period greater than or equal to the set time period tov, and the DPF pressure difference data DP is less than the set pressure difference threshold DPov, regeneration is completed and the regeneration mode is exited.

[0015] In an optional embodiment, determining the carbon loading Cm within the basic calibration time Δt0 according to the pressure difference data DP includes:

[0016] According to the collected DPF differential pressure data DP of the external DPF system, the average differential pressure data within the basic calibration time Δt0 is determined, and the corresponding carbon loading Cm is obtained by looking up the carbon loading lookup table of the external DPF system which is pre-calibrated according to the average differential pressure data;

[0017] The carbon loading lookup table is pre-calibrated according to different carrier volume parameters and average pressure difference data of the external DPF system.

[0018] In an optional embodiment, the calculation of the basic fuel injection amount Fue0 required for carbon load regeneration includes:

[0019] Fue0=(Q / t)*λ s *Cm

[0020] Among them, Q represents the transferred energy, t represents the unit time, and λ s represents thermal conductivity, and Cm represents the aforementioned carbon loading.

[0021] In an optional embodiment, adjusting the calibration unit time Δt0 in real time according to the DPF temperature rise difference ΔT and the DPF pressure difference data DP to obtain the adjusted unit time Δt includes:

[0022] The adjusted unit time Δt is negatively correlated with the DPF temperature rise difference ΔT and the DPF pressure difference data DP, that is, as the DPF temperature rise difference ΔT and the DPF pressure difference data DP increase, the adjusted unit time Δt decreases.

[0023] In an optional embodiment, adjusting the calibration unit time Δt0 in real time according to the DPF temperature rise difference ΔT and the DPF pressure difference data DP to obtain the adjusted unit time Δt includes:

[0024] When the DPF temperature rise difference ΔT≤20°C, the change of the DPF pressure difference data DP is not considered, and Δt=Δt0 is maintained, which is recorded as Δt1;

[0025] When the DPF temperature rise difference is 20°C<ΔT≤50°C, according to different intervals of the DPF pressure difference data DP, adjust so that Δt=(0.5-1)*Δt0, recorded as Δt2;

[0026] When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.16-0.33)*Δt0, which is recorded as Δt3.

[0027] In an optional embodiment, the Δt0 is set to 30s.

[0028] In an optional embodiment, when the DPF temperature rise difference is 20°C<ΔT≤50°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.5-1)*Δt0, specifically including:

[0029] When the DPF pressure difference data DP is below 140kpa, Δt2 = 30s;

[0030] When the DPF pressure difference data DP exceeds 140kpa and is below 245kpa, Δt2 = 20s;

[0031] When the DPF pressure difference data DP exceeds 245kpa, Δt2=15s;

[0032] When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.16-0.33)*Δt0, specifically including:

[0033] When the DPF pressure difference data DP is below 245kpa, Δt3=10s;

[0034] When the DPF pressure difference data DP exceeds 245kpa, Δt3=5s.

[0035] In an optional embodiment, determining the fuel injection amount correction coefficient σ according to the temperature range in which the DPF front row temperature T5 is located includes:

[0036] When T5 is in the range of <330℃, determine the injection amount correction coefficient σ1;

[0037] When T5 is in the range of 330-480℃, determine the injection amount correction coefficient σ2;

[0038] When T5 is in the range of 480-550℃, determine the injection quantity correction coefficient σ3.

[0039] In an optional embodiment, based on the basic fuel injection amount Fue0, according to the adjusted unit time Δt and the fuel injection amount correction coefficient σ, the corrected HC fuel injection amount Fue is output, including:

[0040] When T5 is in the range of <330℃, the corrected HC injection amount Fue1 is outputted = σ1Fue0;

[0041] When T5 is in the range of 330-480℃, the corrected HC injection amount Fue2 is outputted = σ2Fue0;

[0042] When T5 is in the range of 480-550°C, the corrected HC injection amount Fue3 is output as σ3Fue0.

[0043] In an optional embodiment, the HC injection amount control method includes:

[0044] When T5 is within the range of <330°C, the corrected HC injection amount Fue1 is outputted starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt1 time period at intervals of Δt1, wherein σ1≤2.5;

[0045] When T5 is within the range of 330℃~480℃, the corrected HC injection amount Fue2 is outputted, starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt2 time period at intervals of Δt2, where σ2≤2;

[0046] When T5 is within the range of 480°C to 550°C, the corrected HC injection amount Fue3 is outputted starting from the basic injection amount Fue0, and is injected at intervals of Δt3. The corrected HC injection amount is outputted within each Δt3 time period, wherein σ3≤1.5.

[0047] In an optional embodiment, the preset temperature Tov is set to 550° C., the set time period tov is set to 20 min, and the pressure difference threshold DPov is set to 8 kPa.

[0048] According to a second aspect of the present invention, a HC injection quantity control system for an external DPF system is provided, comprising:

[0049] one or more processors;

[0050] The memory stores operable instructions, which, when executed by the one or more processors, enable the one or more processors to perform operations, including the process of executing the aforementioned HC injection amount control method for an external DPF system.

[0051] According to a third aspect of the present invention, a computer-readable medium storing software is provided, wherein the software includes instructions executable by one or more computers, and when the instructions are executed by the one or more computers, the process of the HC injection quantity control method for an external DPF system is performed.

[0052] It should be understood that all combinations of the aforementioned concepts and the additional concepts described in more detail below can be considered as part of the inventive subject matter of the present disclosure as long as such concepts are not mutually inconsistent. In addition, all combinations of the claimed subject matter are considered as part of the inventive subject matter of the present disclosure.

[0053] The foregoing and other aspects, embodiments and features of the present invention can be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the present invention, such as the features and / or beneficial effects of the exemplary embodiments, will be apparent from the following description or learned from the practice of the specific embodiments according to the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The accompanying drawings are not intended to be drawn to scale. In the accompanying drawings, each identical or nearly identical component shown in each figure may be represented by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings.

[0055] Figure 1 is a flow diagram of a method for controlling an HC injection amount of an external DPF system according to an embodiment of the present invention.

[0056] Figure 2 is based on Figure 1 A schematic diagram of a HC injection amount correction process of a specific example of the method. DETAILED DESCRIPTION

[0057] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0058] Various aspects of the present invention are described in this disclosure with reference to the accompanying drawings, in which many illustrative embodiments are shown. The embodiments of the present disclosure are not necessarily intended to include all aspects of the present invention. It should be understood that the various concepts and embodiments introduced above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed by the present invention are not limited to any implementation. In addition, some aspects disclosed by the present invention can be used alone or in any appropriate combination with other aspects disclosed by the present invention.

[0059] Combination Figure 1 As shown, the HC injection amount control method for an external DPF system according to an embodiment of the present invention includes:

[0060] Step S101, collecting the DPF front row temperature T5 and the DPF rear row temperature T6 corresponding to the external DPF system;

[0061] Step S102, collecting DPF pressure difference data DP, and determining the carbon load Cm within a calibration unit time Δt0 according to the pressure difference data DP;

[0062] Step S103, calculating the basic fuel injection amount Fue0 required for carbon load regeneration;

[0063] Step S104, adjusting the calibration unit time Δt0 in real time according to the DPF temperature difference ΔT (ΔT=T6-T5) and the pressure difference data DP to obtain the adjusted unit time Δt;

[0064] Step S105, determining the fuel injection amount correction coefficient σ according to the temperature range where the DPF front row temperature T5 is located;

[0065] Step S106, based on the basic fuel injection amount Fue0, output the corrected HC fuel injection amount Fue according to the adjusted unit time Δt and the fuel injection amount correction coefficient σ;

[0066] Step S107: When the DPF rear temperature T6 reaches a preset temperature Tov or above and lasts for a period greater than or equal to the set time period tov, and the DPF pressure difference data DP is less than the set pressure difference threshold DPov, regeneration is completed and the regeneration mode is exited.

[0067] In an optional embodiment, determining the carbon loading Cm within the basic calibration time Δt0 according to the pressure difference data DP includes:

[0068] According to the collected DPF differential pressure data DP of the external DPF system, the average differential pressure data within the basic calibration time Δt0 is determined, and the corresponding carbon loading Cm is obtained by looking up the carbon loading lookup table of the external DPF system which is pre-calibrated according to the average differential pressure data;

[0069] The carbon loading lookup table is pre-calibrated according to different carrier volume parameters and average pressure difference data of the external DPF system.

[0070] In an optional embodiment, the calculation of the basic fuel injection amount Fue0 required for carbon load regeneration includes:

[0071] Fue0=(Q / t)*λ s *Cm

[0072] Among them, Q represents the transferred energy, t represents the unit time, and λ s represents thermal conductivity, and Cm represents the aforementioned carbon loading.

[0073] In an optional embodiment, adjusting the calibration unit time Δt0 in real time according to the DPF temperature rise difference ΔT and the DPF pressure difference data DP to obtain the adjusted unit time Δt includes:

[0074] The adjusted unit time Δt is negatively correlated with the DPF temperature rise difference ΔT and the DPF pressure difference data DP, that is, as the DPF temperature rise difference ΔT and the DPF pressure difference data DP increase, the adjusted unit time Δt decreases.

[0075] In an optional embodiment, adjusting the calibration unit time Δt0 in real time according to the DPF temperature rise difference ΔT and the DPF pressure difference data DP to obtain the adjusted unit time Δt includes:

[0076] When the DPF temperature rise difference ΔT≤20°C, the change of the DPF pressure difference data DP is not considered, and Δt=Δt0 is maintained, which is recorded as Δt1;

[0077] When the DPF temperature rise difference is 20°C<ΔT≤50°C, according to different intervals of the DPF pressure difference data DP, adjust so that Δt=(0.5-1)*Δt0, recorded as Δt2;

[0078] When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.16-0.33)*Δt0, which is recorded as Δt3.

[0079] In an optional embodiment, the Δt0 is set to 30s.

[0080] In an optional embodiment, when the DPF temperature rise difference is 20°C<ΔT≤50°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.5-1)*Δt0, specifically including:

[0081] When the DPF pressure difference data DP is below 140kpa, Δt2 = 30s;

[0082] When the DPF pressure difference data DP exceeds 140kpa and is below 245kpa, Δt2 = 20s;

[0083] When the DPF pressure difference data DP exceeds 245kpa, Δt2=15s;

[0084] When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt=(0.16-0.33)*Δt0, specifically including:

[0085] When the DPF pressure difference data DP is below 245kpa, Δt3=10s;

[0086] When the DPF pressure difference data DP exceeds 245kpa, Δt3=5s.

[0087] In an optional embodiment, determining the fuel injection amount correction coefficient σ according to the temperature range in which the DPF front row temperature T5 is located includes:

[0088] When T5 is in the range of <330℃, determine the injection amount correction coefficient σ1;

[0089] When T5 is in the range of 330-480℃, determine the injection amount correction coefficient σ2;

[0090] When T5 is in the range of 480-550℃, determine the injection quantity correction coefficient σ3.

[0091] In an optional embodiment, based on the basic fuel injection amount Fue0, according to the adjusted unit time Δt and the fuel injection amount correction coefficient σ, the corrected HC fuel injection amount Fue is output, including:

[0092] When T5 is in the range of <330℃, the corrected HC injection amount Fue1 is outputted = σ1Fue0;

[0093] When T5 is in the range of 330-480℃, the corrected HC injection amount Fue2 is outputted = σ2Fue0;

[0094] When T5 is in the range of 480-550°C, the corrected HC injection amount Fue3 is output as σ3Fue0.

[0095] In an optional embodiment, the HC injection amount control method includes:

[0096] When T5 is within the range of <330°C, the corrected HC injection amount Fue1 is outputted starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt1 time period at intervals of Δt1, wherein σ1≤2.5;

[0097] When T5 is within the range of 330℃~480℃, the corrected HC injection amount Fue2 is outputted, starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt2 time period at intervals of Δt2, where σ2≤2;

[0098] When T5 is within the range of 480°C to 550°C, the corrected HC injection amount Fue3 is outputted starting from the basic injection amount Fue0, and is injected at intervals of Δt3. The corrected HC injection amount is outputted within each Δt3 time period, wherein σ3≤1.5.

[0099] From the above embodiments of the present invention, the HC injection amount control method for an external DPF system proposed by the present invention does not need to access the engine operating information, and controls the HC injection amount by collecting feedback data from its own sensors in combination with a calculation model, thereby achieving accurate control and adjustment of the DPF regeneration injection amount when accurate engine operating information cannot be obtained.

[0100] During the adjustment process, an automatic injection amount correction control algorithm is adopted, and the pressure difference value fed back by the pressure difference sensor is used to calculate the unit time, and the basic HC injection amount required for DPF regeneration is obtained. According to the calculation of the closed-loop control algorithm, the HC injection amount is adjusted and injected in different temperature intervals according to the pressure difference change and temperature interval in the exhaust gas, so that the temperature is raised to the regeneration temperature interval. The present invention performs closed-loop feedback control within a set interval through the temperature feedback of the exhaust temperature downstream of the DPF, adjusts the injection amount in real time, prevents the occurrence of overheating, insufficient temperature rise per unit time, etc., and uses the change in exhaust temperature and pressure difference to compensate for the HC injection amount, and finally achieves accurate regeneration effect under different working conditions.

[0101] {Example 1}

[0102] Combination Figure 2 As shown, we describe the process of the aforementioned embodiment in more detail with reference to a specific example.

[0103] exist Figure 2 In the example shown, the carbon loading amount is determined by looking up a table based on the collected DPF pressure difference data DP of the external DPF system.

[0104] DP data is the pressure difference data fed back by the pressure difference sensor, in hPa. From this, the average pressure difference data within the time period of Δt0 (the basic setting is 30s) can be calculated. Then, according to the average pressure difference data, the calibrated lookup table is looked up (adjustable for different carrier volumes) to obtain the carbon loading Cm at the current carbon loading level, in g.

[0105] In step S104, the temperature difference before and after the DPF carrier is determined in real time. The larger the temperature difference, the greater the DPF pressure difference. The unit time needs to be shortened relative to the initially set Δt0 (i.e., the calibrated time MAP). In this way, the basic injection quantity control can be adjusted according to the actual carbon loading.

[0106] Among them, in different temperature ranges, the adaptive correction coefficients σ1, σ2, and σ3 are all selected under different temperature sections. The purpose is to adjust the injection amount in different temperature ranges to prevent the temperature of carrier regeneration from being too high.

[0107] Combined with the above-mentioned adjusted unit time, T5 temperature rise is corrected per unit time in different temperature intervals, that is, gradually multiplied and increased. In this embodiment, the upper limit of the cumulative multiplication of the correction coefficient per unit time is set to 2.5, 2, and 1.5 respectively.

[0108] When the temperature data of the DPF rear temperature T6 is greater than or equal to the preset temperature threshold Tov=550℃, the duration ti is greater than or equal to the set tov=20min, and the pressure difference DP is less than the set DPov (8kap, the value can be adjusted for different vehicles), the regeneration is completed and the regeneration mode is exited.

[0109] If the duration is still not reached after 35 minutes, the regeneration mode will be exited and regeneration will be performed again when the power is next turned on. If regeneration is completed, the regeneration model will be turned on again after driving for 4 hours (the time varies for different vehicles) to request regeneration.

[0110] {Example 2}

[0111] The HC injection quantity control method for an external DPF system according to the above embodiment of the present invention is also configured as an HC injection quantity control system for an external DPF system, and the HC injection quantity control system for an external DPF system includes: one or more processors and a memory.

[0112] The memory is used to store operable instructions, which, when executed by the one or more processors, enable the one or more processors to perform operations, including the process of executing the HC injection amount control method for an external DPF system of the aforementioned embodiment.

[0113] {Example 3}

[0114] The HC injection amount control method for an external DPF system according to the above embodiment of the present invention is also configured with a computer-readable medium storing software, wherein the software includes instructions that can be executed by one or more computers, and when the instructions are executed by the one or more computers, the process of the HC injection amount control method for an external DPF system of the above embodiment is performed.

[0115] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A method for controlling the HC injection amount of an external DPF system, characterized in that: include: Collect the DPF front temperature T5 and DPF rear temperature T6 corresponding to the external DPF system; Collect DPF pressure difference data DP, and determine the carbon load within the calibration unit time Δt0 based on the pressure difference data DP Cm ; Calculate the basic injection amount Fue0 required for carbon load regeneration; According to the DPF temperature rise difference ΔT and the DPF pressure difference data DP, the calibration unit time Δt0 is adjusted in real time to obtain the adjusted unit time Δt, ΔT = T6 - T5; Determine the fuel injection amount correction coefficient σ according to the temperature range of the DPF front row temperature T5; Based on the basic injection amount Fue0, the corrected HC injection amount Fue is output according to the adjusted unit time Δt and the injection amount correction coefficient σ; When the DPF rear temperature T6 reaches a preset temperature Tov or above and lasts for a period greater than or equal to the set time period tov, and the DPF pressure difference data DP is less than the set pressure difference threshold DPov, regeneration is completed and the regeneration mode is exited; The method of adjusting the calibration unit time Δt0 in real time according to the DPF temperature rise difference ΔT and the DPF pressure difference data DP to obtain the adjusted unit time Δt includes: When the DPF temperature rise difference ΔT≤20℃, the change of DPF pressure difference data DP is not considered, and Δt = Δt0 is maintained, which is recorded as Δt1; When the DPF temperature rise difference is 20℃<ΔT≤50℃, according to the different intervals of the DPF pressure difference data DP, adjust Δt =(0.5-1)*Δt0, recorded as Δt2; When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt =(0.16-0.33)*Δt0, recorded as Δt3.

2. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: The carbon loading within the basic calibration time Δt0 is determined according to the pressure difference data DP Cm ,include: According to the collected DPF differential pressure data DP of the external DPF system, the average differential pressure data within the basic calibration time Δt0 is determined, and the corresponding carbon loading is obtained by looking up the carbon loading lookup table of the external DPF system which has been calibrated in advance according to the average differential pressure data. Cm ; The carbon loading lookup table is pre-calibrated according to different carrier volume parameters and average pressure difference data of the external DPF system.

3. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: The adjusted unit time Δt is negatively correlated with the DPF temperature rise difference ΔT and the DPF pressure difference data DP, that is, as the DPF temperature rise difference ΔT and the DPF pressure difference data DP increase, the adjusted unit time Δt decreases.

4. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: The Δt0 is set to 30 s.

5. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: When the DPF temperature rise difference is 20℃<ΔT≤50℃, according to the different intervals of the DPF pressure difference data DP, adjust so that Δt = (0.5-1)*Δt0, specifically including: When the DPF pressure difference data DP is below 140kpa, Δt2=30s; When the DPF pressure difference data DP exceeds 140kpa and is below 245kpa, Δt2=20s; When the DPF pressure difference data DP exceeds 245kpa, Δt2=15s; When the DPF temperature rise difference is 50°C<ΔT≤300°C, according to different intervals of the DPF pressure difference data DP, adjustment is made so that Δt = (0.16-0.33)*Δt0, specifically including: When the DPF pressure difference data DP is below 245kpa, Δt3=10s; When the DPF pressure difference data DP exceeds 245kpa, Δt3=5s.

6. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: Determining the fuel injection amount correction coefficient σ according to the temperature range where the DPF front row temperature T5 is located includes: When T5 is in the range of <330℃, determine the injection amount correction coefficient σ1; When T5 is in the range of 330-480℃, determine the injection amount correction coefficient σ2; When T5 is in the range of 480-550℃, determine the injection quantity correction coefficient σ3.

7. The HC injection amount control method for an external DPF system according to claim 6, characterized in that: Based on the basic injection amount Fue0, according to the adjusted unit time Δt and the injection amount correction coefficient σ, the corrected HC injection amount Fue is output, including: When T5 is within the range of <330℃, the corrected HC injection amount Fue1=σ1Fue0 is output; When T5 is in the range of 330-480℃, the corrected HC injection amount Fue2=σ2Fue0 is output; When T5 is in the range of 480-550℃, the corrected HC injection amount Fue3=σ3Fue0 is output.

8. The HC injection amount control method for an external DPF system according to claim 7, characterized in that: The HC injection amount control method includes: When T5 is within the range of <330°C, the corrected HC injection amount Fue1 is outputted starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt1 time period at intervals of Δt1, wherein σ1≤2.5; When T5 is within the range of 330℃~480℃, the corrected HC injection amount Fue2 is outputted, starting from the basic injection amount Fue0, and the corrected HC injection amount is outputted in each Δt2 time period at intervals of Δt2, where σ2≤2; When T5 is within the range of 480°C to 550°C, the corrected HC injection amount Fue3 is outputted starting from the basic injection amount Fue0, and is injected at intervals of Δt3. The corrected HC injection amount is outputted within each Δt3 time period, wherein σ3≤1.

5.

9. The HC injection amount control method for an external DPF system according to claim 1, characterized in that: The preset temperature Tov is set to 550° C., the preset time period tov is set to 20 min, and the pressure difference threshold DPov is set to 8 kPa.

10. A HC injection quantity control system for an external DPF system, characterized in that: include: one or more processors; A memory storing operable instructions, wherein when the instructions are executed by the one or more processors, the one or more processors are caused to perform operations, wherein the operations include the process of executing the HC injection quantity control method for an external DPF system as described in any one of claims 1 to 9.

11. A computer-readable medium storing software, characterized in that: The software includes instructions that can be executed by one or more computers, and when the instructions are executed by the one or more computers, the process of the HC injection amount control method for an external DPF system as described in any one of claims 1 to 9 is performed.

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