DPF passive regeneration calibration technology based on efficient aftertreatment

Abstract

The invention discloses a DPF passive regeneration calibration technology based on efficient aftertreatment, and belongs to the technical field of DPF regeneration of non-road national fourth diesel engines. The method comprises the following steps: acquiring regeneration core parameters from a tail gas detection range, wherein the core parameters comprise a DPF front-end real-time temperature T4, a DPF rear-end temperature T5, a DPF real-time carbon loading capacity C, an engine real-time rotating speed n and an engine real-time load rate lambda; passive regeneration is used as a core regeneration mode, dependence on active regeneration is greatly reduced, and the passive regeneration does not need additional intervention of a system, so that additional fuel consumption generated in the active regeneration process is reduced, and the fuel economy of the engine is remarkably improved; meanwhile, the reduction of the active regeneration frequency also reduces the repeated impact and loss of the high temperature on the DPF carrier, the DOC and other post-processing parts, prolongs the service life of the post-processing system, reduces the fault probability of the parts, further improves the operation reliability of the whole machine, and reduces the maintenance cost and shutdown loss of a user.

Description

TECHNICAL FIELD

[0001] The application relates to the field of DPF regeneration technology of non-road state IV diesel engines, in particular to a DPF passive regeneration calibration technology based on high-efficiency aftertreatment. BACKGROUND

[0002] Non-road state IV diesel engines are mainly applied to the fields of non-road mobile machines such as engineering machinery, agricultural machinery and generator sets, and exhaust emission thereof needs to meet the national fourth-stage emission standard (non-road state IV standard); at present, the mainstream exhaust treatment technology route in the field is a combination technology of an exhaust gas recirculation device (EGR), an intake throttle valve, a diesel oxidation catalyst (DOC) and a particulate filter (DPF), wherein the EGR device reduces the engine combustion temperature by returning part of the exhaust gas to the intake system, so as to control the generation of nitrogen oxides (NOx); the DOC is used for oxidizing hydrocarbons and carbon monoxide in the exhaust gas, and the DPF filters the fine particulate matter (PM) in the exhaust gas through diffusion deposition, inertial deposition and linear interception and is a key component for purifying particulate matter emission of diesel engines.

[0003] During the working process of the DPF, soot particles are continuously collected, and when the particles accumulate to a certain degree, the exhaust resistance of the engine is increased, and then the power performance and the economy are reduced, so the particles need to be removed through a "regeneration" process - the regeneration is divided into passive regeneration and active regeneration, the passive regeneration does not need external intervention and is realized by using the low-temperature combustion reaction of carbon particles and NOx on the surface of the DPF carrier, the required temperature is low but the efficiency is not high; the active regeneration needs to create a high-temperature condition by system intervention (such as additional heating, adjustment of the fuel injection amount, etc.) to promote the combustion of the particles, and although the particles can be quickly removed, additional energy is consumed.

[0004] The existing DPF regeneration technology of non-road state IV diesel engines mainly adopts active regeneration, and only simple passive regeneration is supplemented, the role of the passive regeneration can only slightly prolong the interval of the active regeneration, and the frequency of the active regeneration cannot be fundamentally reduced; frequent starting of the active regeneration not only significantly increases the fuel consumption of the engine, but also affects the power output stability of the engine due to high-temperature intervention, and meanwhile shortens the service life of the DPF, the DOC and other aftertreatment components.

[0005] In view of the above technical defects, a solution is provided. SUMMARY

[0006] The purpose of the application is to provide a DPF passive regeneration calibration technology based on high-efficiency aftertreatment, so as to solve the problems.

[0007] To achieve the above object, the present application provides the following technical solutions: a DPF passive regeneration calibration technology based on efficient post-processing, determining a detection target and a data acquisition device to build an exhaust gas detection range, comprising the following method steps;

[0008] S1, obtaining regeneration core parameters from the exhaust gas detection range, the core parameters including a DPF front end real-time temperature T4, a DPF rear end temperature T5, a DPF real-time carbon load C, an engine real-time speed n and an engine real-time load rate λ, obtaining a regeneration database by combining a history database with the regeneration core parameters;

[0009] S2, obtaining the regeneration core parameters and extracting the DPF front end real-time temperature T4 for data processing, obtaining a deviation value ΔT by combining a pre-stored passive regeneration optimal temperature 350℃ with the DPF front end real-time temperature T4, judging whether the deviation value ΔT meets a preset temperature deviation range to obtain a temperature judgment result;

[0010] S3, obtaining the engine real-time speed n and the engine real-time load rate λ, additionally collecting a remote post-injection hydrocarbon real-time injection amount Q to obtain a hydrocarbon maximum allowable leakage amount Qmax(n, λ) under load, combining corresponding pre-stored data retrieved from the regeneration database to analyze the ratio to obtain a hydrocarbon leakage risk judgment result;

[0011] S4, obtaining a joint analysis of the temperature judgment result and the hydrocarbon leakage risk judgment result, obtaining a required intake throttle valve maximum opening degree signal and a hydrocarbon leakage risk correction signal;

[0012] S5, obtaining the DPF real-time carbon load C and combining a pre-stored threshold value in the regeneration database for joint analysis, combining an intake throttle valve opening degree adjustment amount to generate a passive regeneration normal instruction, a passive regeneration reinforcement instruction and an active regeneration warning signal.

[0013] Further, the processing process of the regeneration core parameters in the S1 step is as follows:

[0014] The K-type thermocouple sensor installed at the DPF front end in the exhaust gas detection range collects the DPF front end real-time temperature T4, and the rear end thermocouple sensor collects the DPF rear end temperature T5, a preset carbon load threshold value obtained by taking the history database as a sample is retrieved, and a differential pressure model is constructed by combining the preset carbon load threshold value with the DPF front end real-time temperature T4 and the DPF rear end temperature T5 to obtain the DPF real-time carbon load C;

[0015] Based on the engine ECU reading engine real-time speed n and engine real-time load rate λ in the exhaust gas detection range, the real-time injection amount Q of the post-injection hydrocarbon is obtained through the feedback signal of the post-injection actuator, and the maximum allowable leakage amount Qmax(n, λ) of the hydrocarbon under load is obtained by bench test in the range of n=800-3000rpm, λ=20%-100%, and is pre-stored in the form of two-dimensional data table; obtain the detection data of the same type target in nearly one year, and combine the regeneration core parameters obtained in this exhaust gas detection range to jointly construct the regeneration database.

[0016] Further, the analysis process of the temperature judgment result in the S2 step is as follows:

[0017] The core parameters are obtained, and the real-time temperature T4 of the front end of the DPF is extracted for data processing. The real-time temperature T4 of the front end of the DPF is subjected to window sliding average filtering processing, the window size is 5 unit sampling points, the instantaneous fluctuation is removed, the filtered temperature T4 filter value is obtained, the pre-stored passive regeneration optimal temperature 350℃ is called and analyzed in combination with the temperature T4 filter value, and the deviation value ΔT is obtained.

[0018] Further, the pre-stored preset temperature deviation range is called and compared with the deviation value ΔT, the preset temperature deviation range includes temperature and engine real-time speed n, and is divided into two grades according to the historical database, specifically, when the engine real-time speed n≥1500rpm in the preset temperature deviation range, the temperature is [-25℃, 25℃], which is marked as the first grade, and when the engine real-time speed n≤1500rpm in the preset temperature deviation range, the temperature is [-30℃, 30℃], which is marked as the second grade;

[0019] If the deviation value ΔT is in the normal range, a temperature compliance signal is generated; if the deviation value ΔT is less than -30℃, a temperature low signal is generated; if the deviation value ΔT is greater than 30℃, a temperature high signal is generated.

[0020] Further, the analysis process of the carbon hydrogen leakage risk judgment result in the S3 step is as follows:

[0021] The engine real-time speed n, the engine real-time load rate λ and the real-time injection amount Q of the hydrocarbon are obtained, the pre-stored bilinear interpolation model is called, and the maximum allowable leakage amount Qmax(n, λ) of the hydrocarbon under load is obtained by substituting the engine real-time speed n and the engine real-time load rate λ.

[0022] Further, the record data of the same type as the exhaust gas detection range target is extracted from the historical database, the pre-stored rotation speed pre-stored interval value and the load pre-stored interval value are called, the record data is calibrated to obtain the calibrated pre-stored interval value, and the corresponding high-low grade rpn limit and high-low grade load limit are extracted from the historical database;

[0023] If the engine real-time rotation speed n and the engine real-time load rate λ exceed the calibrated pre-stored interval value, when the engine real-time rotation speed n > high rpn, the value n = high rpm corresponding to Qmax is taken, when the engine real-time rotation speed n < low rpn, the value n = low rpm corresponding to Qmax is taken, when the engine real-time load rate λ < low load grade limit value, the value λ = low load grade limit value corresponding to Qmax is taken, when the engine real-time load rate λ > high load grade limit value, the value λ = high load grade limit value corresponding to Qmax is taken, and the formula is used to reserve two decimal places; if K ≤ 0.9, a low hydrocarbon leakage risk signal is generated; if 0.9 < K ≤ 1, a medium hydrocarbon leakage risk signal is generated; and if K > 1, a high hydrocarbon leakage risk signal is generated

[0024] Further, the joint analysis process of the temperature judgment result and the hydrocarbon leakage risk in the S4 step is as follows:

[0025] The dynamic data of the engine real-time rotation speed n and the engine real-time load rate λ along the time line, and the current opening θ of the intake throttle valve in the exhaust gas detection range are obtained, the proportional coefficient Kp and the integral coefficient Ki calibrated by the historical database and the pre-stored proportional coefficient are called, when n ≥ 2000 rpm, Kp can take the value of 0.5% / ℃, and Ki can take the value of 0.02 mg / s·℃; when 1200 rpm ≤ n < 2000 rpm, Kp = 0.6% / ℃ and Ki = 0.03 mg / s·℃; and when n < 1200 rpm, Kp = 0.7% / ℃ and Ki = 0.04 mg / s·℃.

[0026] Further, the temperature judgment result and the hydrocarbon leakage risk judgment result are obtained, if the temperature is low and needs to be raised and the hydrocarbon leakage risk is low / medium, the formula is used to analyze to obtain the maximum opening signal of the intake throttle valve opening adjustment amount ; if the hydrocarbon leakage risk is high, the formula is used to analyze to obtain the carbon hydrocarbon leakage risk correction signal of the intake throttle valve opening adjustment amount

[0027] Further, the analysis process of the DPF passive regeneration state signal in the S5 step is as follows:

[0028] Based on the DPF real-time carbon load C obtained in the exhaust gas detection range, the calibrated carbon load threshold value is called by jointly analyzing the historical database and the pre-stored corresponding threshold value ​Calibrating carbon load threshold The threshold value comprises a high value and a low value, if the real-time carbon load C of the DPF is less than or equal to the low value, a passive regeneration normal instruction is generated in combination with a temperature meeting signal; if the low value is less than the real-time carbon load C of the DPF and less than or equal to the high value, a passive regeneration enhanced instruction is generated in combination with the temperature meeting signal; if the real-time carbon load C of the DPF is greater than the high value, a passive regeneration early warning signal is generated regardless of the temperature state.

[0029] The beneficial effects of the present application are:

[0030] 1. The present application can more fully utilize the hydrocarbons in the original exhaust tail gas to raise the temperature at the front end of the DPF, stably control the temperature at the front end of the DPF at about 350 degrees Celsius, which is the highest passive regeneration efficiency, realize efficient passive regeneration under all working conditions of the engine, quickly remove the soot particles in the DPF in a regeneration mode, reduce the accumulation speed of the particles, effectively prolong the interval time of active regeneration, and even do not need to start active regeneration under most conventional working conditions, fundamentally solve the core problem of high frequency of active regeneration in the prior art, greatly improve the passive regeneration efficiency, and significantly prolong the interval of active regeneration.

[0031] 2. The present application preacquires the maximum allowable leakage amount of the hydrocarbons under different speed and load combination working conditions through bench tests, constructs a complete basic database, combines a bilinear interpolation model, realizes real-time calculation of the reasonable injection amount of the hydrocarbons under the current working condition, and accurately controls the injection scale of the remote post-injection system, which not only guarantees the requirement of temperature rise of the DPF under small load working conditions, but also avoids the problem of leakage of the hydrocarbons due to insufficient oxidation, ensures that the engine emission always meets the non-road national standard IV, takes into account the regeneration effect and environmental protection requirements, accurately controls the hydrocarbon emission, and avoids the risk of leakage. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0033] Figure 1 The present application is a method flowchart;

[0034] Figure 2 The present application is a regeneration control schematic diagram. DETAILED DESCRIPTION

[0035] With reference to the accompanying drawings on the basis of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0036] Embodiment one: please refer to Figure 1 - Figure 2 As shown in the figure, the embodiment is a DPF passive regeneration calibration technology based on efficient post-processing, which determines the detection target and data acquisition equipment to build an exhaust gas detection range, including the following method steps.

[0037] S1, obtain regeneration core parameters from the exhaust gas detection range, the core parameters including DPF front end real-time temperature T4, DPF rear end temperature T5, DPF real-time carbon load C, engine real-time speed n and engine real-time load rate λ, obtain a regeneration database by combining the regeneration core parameters with the historical database, and the processing process of the regeneration core parameters is as follows:

[0038] The K-type thermocouple sensor installed at the front end of the DPF in the exhaust gas detection range collects the real-time temperature T4 at the front end of the DPF, and the rear-end thermocouple sensor collects the real-time temperature T5 at the rear end of the DPF, the sampling frequency is 1 Hz, and the data accuracy is ±1℃; the preset carbon load threshold obtained by taking the historical database as a sample is called, and the differential pressure model is constructed by combining the preset carbon load threshold with the real-time temperature T4 at the front end of the DPF and the real-time temperature T5 at the rear end of the DPF, to obtain the real-time carbon load C of the DPF, and the model is , wherein k1 and k2 are pre-stored bench calibration coefficients, k1 can be 0.2 g / (L·kPa), k2 can be 0.1 g / L, and are obtained by fitting 20 sets of bench test data from a 40-60 kW non-road national fourth diesel engine with a DOC+DPF-400 type post-processing system, the bench test conditions cover n=800-3000 rpm and λ=20%-100%, and the goodness of fit R²=0.98; The differential pressure between the front and rear ends of the DPF is , P4 is the pressure at the front end of the DPF, which is collected by a pressure sensor installed beside the T4 sensor, model PTX5072, range 0-100 kPa, accuracy ±0.2 kPa; P5 is the pressure at the rear end of the DPF, which is collected by a pressure sensor of the same type installed beside the T5 sensor;

[0039] The engine ECU reads the engine real-time speed n and engine real-time load rate λ in the exhaust gas detection range; the resolution is 10 rpm and 1% respectively; the real-time injection amount Q of the post-injection hydrocarbon is obtained through the feedback signal of the post-injection actuator, and the accuracy is 0.1 mg / s; Qmax(n, λ) is obtained by bench test in the range of n=800-3000 rpm, λ=20%-100%, and is pre-stored in the form of two-dimensional data table;

[0040] The same type of target near 1 year detection old data is obtained, which is summarized as a historical database, and combined with the regeneration core parameters obtained in this exhaust gas detection range to jointly construct a regeneration database. It should be noted that the same type of target range refers to the equipment consistent with the current detection target power segment and aftertreatment type. The current detection target is a 50kW non-road state IV diesel engine matched with a certain type of loader, the power segment can be 40-60kW, and the aftertreatment type can be DOC+DPF. The old data of the historical database comes from the equipment operation and maintenance records of the enterprise MES system and the annual emission detection report of the third party detection agency. The equipment operation and maintenance records contain regeneration parameters after each start, and the data amount is not less than 50 sets of equipment for 12 months of continuous records.

[0041] S2, obtain the regeneration core parameters and extract the real-time temperature T4 of the DPF front end for data processing, retrieve the pre-stored passive regeneration optimal temperature 350℃ and analyze the deviation value ΔT combined with the real-time temperature T4 of the DPF front end, judge whether the deviation value ΔT conforms to the preset temperature deviation range, and obtain the temperature judgment result; the analysis process of the temperature judgment result is as follows:

[0042] Obtain the core parameters and extract the real-time temperature T4 of the DPF front end for data processing, perform window sliding average filtering processing on the real-time temperature T4 of the DPF front end, the window size is 5 unit sampling points, and the instantaneous fluctuation is removed to obtain the filtered temperature T4 filter value, retrieve the pre-stored passive regeneration optimal temperature 350℃ and analyze the deviation value ΔT combined with the temperature T4 filter value. It should be noted that the details of the sliding average filtering operation, such as the sampling frequency of 1 Hz, 5 unit sampling points corresponding to a 5 second time window, the window sliding mode is to remove the oldest 1 old sampling value every time 1 DPF front end real-time temperature T4 sampling value is added, and the arithmetic mean of the 5 values is recalculated as the temperature T4 filter value; for example, the original value of the DPF front end real-time temperature T4 is 328℃, 330℃, 329℃, 331℃ and 330℃, the temperature T4 sampling value=(328+330+329+331+330) / 5=329.6℃, , is in [-25℃, 25℃], and a temperature compliance signal is generated;

[0043] The preset temperature deviation range and the deviation value AT are combined for comparison processing. The preset temperature deviation range contains the temperature and the engine real-time speed n, and is divided into two grades according to the historical database. Specifically, when the engine real-time speed n in the preset temperature deviation range is greater than or equal to 1500 rpm, the temperature is [-25℃, 25℃], and is marked as the first grade; and when the engine real-time speed n in the preset temperature deviation range is less than 1500 rpm, the temperature is [-30℃, 30℃], and is marked as the second grade.

[0044] When the engine real-time speed n is greater than or equal to 1500 rpm, the high-speed interval;

[0045] The temperature meets the standard range: [-25℃, 25℃], the deviation value AT is in the normal range, and a temperature meeting signal is generated;

[0046] The temperature is low trigger threshold: if the deviation value AT is less than -30℃, lower than this value, a temperature is low and needs to be raised signal is generated, because the high-speed exhaust air speed is fast, a lower temperature is needed to intervene;

[0047] The temperature is high trigger threshold: if the deviation value AT is greater than 25℃, higher than this value, a temperature is high and needs to be controlled signal is generated, to avoid high temperature damage to the DPF carrier;

[0048] When the engine real-time speed n is less than 1500 rpm, the low-speed interval:

[0049] The temperature meets the standard range: [-30℃, 30℃], the low-speed exhaust air speed is slow, and a slightly wide temperature fluctuation is allowed;

[0050] The temperature is low trigger threshold: if the deviation value AT is less than -35℃, lower than this value, a temperature is low and needs to be raised signal is generated, because the low-speed carbon hydroxide oxidation rate is slow, a lower temperature is needed to strengthen the temperature rise;

[0051] The temperature is high trigger threshold: if the deviation value AT is greater than 30℃, a temperature is high and needs to be controlled signal is generated, and the ECU will also trigger a temporary instruction of reducing the intake throttle opening degree by 5%, to avoid the DPF carrier overtemperature, and the carrier tolerance upper limit is 600℃.

[0052] S3, the engine real-time speed n and the engine real-time load rate λ are obtained, the remote post-injection carbon hydrocarbon real-time injection amount Q is additionally collected, the maximum allowed leakage amount Qmax(n, λ) of carbon hydrocarbon under load is obtained, the corresponding pre-stored data is retrieved from the regeneration database, and the ratio of the two is analyzed to obtain a carbon hydrocarbon leakage risk judgment result; the analysis process of the carbon hydrocarbon leakage risk judgment result is as follows:

[0053] The engine real-time speed n, the engine real-time load rate λ and the real-time injection amount Q of the injected hydrocarbon are obtained, the pre-stored bilinear interpolation model is called, the engine real-time speed n and the engine real-time load rate λ are substituted to obtain the maximum allowable leakage amount Qmax(n, λ) of the hydrocarbon under load. It should be noted that the real-time injection amount Q of the injected hydrocarbon is obtained by analyzing the feedback current of the post-injection actuator, the model of the injection actuator is: electric DP4-12V, and the analysis formula is Q=0.05×I-0.1, wherein I represents the feedback current, for example, when I=100mA, Q=0.05×100-0.1=4.9mg / s.

[0054] The record data of the same type as the target of the exhaust gas detection range in the historical database is extracted, the pre-stored speed pre-stored interval value and the load pre-stored interval value are called, the speed pre-stored interval value and the load pre-stored interval value are calibrated with the record data, the pre-stored interval value is calibrated, the corresponding high-low grade rpn limit and high-low grade load limit are extracted from the historical database, and it should be noted that the calibrated speed pre-stored interval is 800-3000rpm, the high rpn limit=3000rpm, and the low rpn limit=800rpm; the calibrated load pre-stored interval is 20%-100%, the high load limit=100%, and the low load limit=20%, and the limit value is from the coverage interval statistics of the same type target 95% working condition in the historical database;

[0055] If the engine real-time speed n and the engine real-time load rate λ exceed the calibrated pre-stored interval value, when the engine real-time speed n>high rpn, the value n=high rpm corresponding Qmax is taken, and when the engine real-time speed n<low rpn, the value n=low rpm corresponding Qmax is taken.

[0056] When the engine real-time load rate λ<low load limit value, the value λ=low load limit value corresponding Qmax is taken, and when the engine real-time load rate λ>high load limit value, the value λ=high load limit value corresponding Qmax is taken.

[0057] The formula is used, and two decimal places are retained; if K≤0.9, a low hydrocarbon leakage risk signal is generated, the generated low hydrocarbon leakage risk signal is transmitted to the DPF regeneration control module of the engine ECU, the transmission delay is ≤100ms, and if a temperature is low and needs to be warmed up at the same time signal is received, the intake throttle valve opening adjustment amount , the remote post-injection hydrocarbon injection amount increment ΔQ is analyzed according to the S4 step.

[0058] If 0.9<K≤1, a medium hydrocarbon leakage risk signal is generated.

[0059] If K > 1, a high carbon hydrogen leakage risk signal is generated, and a yellow risk warning light of the instrument is triggered to be always on, prompting the driver that the current carbon hydrogen leakage is out of the regulation, and immediately recording the current n, λ, Q data, with the accuracy of n to 1 rpm, λ to 0.1%, and Q to 0.01 mg / s, and locking and storing, which cannot be covered by subsequent data, and when reading through the special calibration software, it is marked as a high-risk calibration sample; and the current n, λ, Q data are recorded for subsequent calibration.

[0060] Embodiment two

[0061] S4, the temperature judgment result and the carbon hydrogen leakage risk judgment result are combined and analyzed to obtain the required intake throttle valve maximum opening signal and the carbon hydrogen leakage risk correction signal, and the combined analysis process of the temperature judgment result and the carbon hydrogen leakage risk is as follows:

[0062] The dynamic data of the engine real-time speed n and the engine real-time load rate λ along the time line are obtained, the dynamic data of the engine real-time speed n and the load rate λ are collected for 1 value every 50 ms, and 10 values are continuously collected as a group of dynamic data for judging the stability of the working condition, if the fluctuation of the 10 values is ≤5%, it is determined as a stable working condition, otherwise it is determined as a transient working condition, and the Kp and Ki are suspended in the transient working condition, and the current opening θ of the intake throttle valve and the real-time injection amount Q of the carbon hydrogen compound are maintained, and the current opening θ of the intake throttle valve in the exhaust gas detection range is adjusted, and the proportional coefficient Kp and the integral coefficient Ki obtained by calibrating the pre-stored proportional coefficient through the historical database are called, and it should be noted that the initial value of Kp and Ki comes from the bench test, and the calibration process is to adjust the intake throttle valve opening adjustment amount The adjustment effect data, if the temperature T4 filter value after adjustment reaches 350℃ for >30 seconds, Kp increases by 5%; if the temperature T4 filter value after adjustment overshoots >10℃, Kp decreases by 5%; for example, in the historical data, n=1800rpm, λ=50% working condition, initial Kp=0.6% / ℃, when the temperature rising time is 35 seconds, after calibration, Kp=0.63% / ℃, and the temperature rising time is shortened to 28 seconds;

[0063] When n≥2000rpm, Kp can be 0.5% / ℃, and Ki can be 0.02mg / s・℃; when 1200rpm≤n<2000rpm, Kp=0.6% / ℃, Ki=0.03mg / s・℃; when n<1200rpm, Kp=0.7% / ℃, Ki=0.04mg / s・℃.

[0064] The temperature judgment result and the carbon hydrogen leakage risk judgment result are obtained, if the temperature is low and the carbon hydrogen leakage risk is low / medium, the formula 、 is used to analyze the intake throttle valve opening adjustment amount The maximum opening signal of the intake throttle valve ensures ,The maximum opening signal of the intake throttle valve ensures , The maximum opening signal of the intake throttle valve ensures is expressed as a filtered temperature deviation value, is expressed as a remote post-injection hydrocarbon injection amount increment, and the maximum opening signal is generated, transmitted to the intake throttle valve actuator, and the intake throttle valve actuator model is Bosch BV6-12V. The actuator changes the opening at an adjustment rate of 2% / s, for example =12%, it takes 6 seconds to adjust to the position; after reaching the position, the actuator feedback voltage signal 5V is at the position, 0V is not at the position to the ECU, and the ECU stops adjusting after receiving the position signal;

[0065] If the risk of hydrocarbon leakage is high, the formula is used to analyze the intake throttle valve opening adjustment amount The risk correction signal of hydrocarbon leakage is obtained, where 0.8 represents the risk correction coefficient, for example, n=1800rpm (Kp=0.6% / ℃), T= -20℃, when the risk is medium =0.6×20=12%, and when the risk is high =12×0.8=9.6%.

[0066] S5, obtain the real-time carbon load C of the DPF and jointly analyze it with the pre-stored threshold value in the regeneration database, combine the intake throttle valve opening adjustment amount, generate passive regeneration normal instruction, passive regeneration reinforcement instruction and active regeneration warning signal, realize passive regeneration calibration control, and the analysis process of the DPF passive regeneration state signal is as follows:

[0067] Based on the real-time carbon load C of the DPF obtained within the exhaust detection range, the calibrated carbon load threshold value is obtained by jointly analyzing the historical database and the pre-stored corresponding threshold value The calibrated carbon load threshold value contains a high value and a low value. It should be noted that the low value of the calibrated carbon load threshold value The high value can be 5g / L, and the numerical value is derived from the recommended threshold value provided by the DPF carrier manufacturer +1000 hour durability test data correction. The recommended threshold value is 2.8g / L for the low value and 4.8g / L for the high value. It is found that when C>5g / L, the DPF back pressure exceeds 5kPa, affecting the engine power, so the high value is set to 5g / L.

[0068]

[0069] If the low value < DPF real-time carbon load C < high value, the passive regeneration reinforcement instruction is generated in combination with the temperature compliance signal, the current intake throttle valve current opening degree θ and the real-time hydrocarbon compound injection amount Q are maintained, but the carbon load detection frequency is increased from 1 Hz to 2 Hz, and the real-time carbon load decrease is monitored;

[0070] If the DPF real-time carbon load C > high value, regardless of the temperature state, the active regeneration warning signal is generated, and the current intake throttle valve opening degree θ and the hydrocarbon compound real-time injection amount Q control instructions are generated according to S4 adjustment amount, the instrument triggers the red warning light (flashing, frequency 1 Hz) + buzzer (interval 2 seconds, 1 time), prompting the driver to complete the active regeneration preparation within 30 minutes;

[0071] The current intake throttle valve opening degree θ is adjusted to the current intake throttle valve opening degree θ + intake throttle valve opening degree adjustment amount Δθ, and the real-time hydrocarbon compound injection amount Q is adjusted to the real-time hydrocarbon compound injection amount Q + intake throttle valve opening degree adjustment amount ΔQ, if allowed.

[0072] In combination with embodiment one and embodiment two, the present application takes passive regeneration as the core regeneration mode, greatly reduces the dependence on active regeneration, and passive regeneration does not require additional intervention of the system, thereby reducing the additional fuel consumption generated in the active regeneration process, significantly improving the fuel economy of the engine; at the same time, the reduction of active regeneration frequency also reduces the repeated impact and wear of high temperature on the DPF carrier, DOC and other aftertreatment components, prolongs the service life of the aftertreatment system, reduces the component failure probability, and thus improves the reliability of the whole machine operation, reduces the maintenance cost and downtime loss of the user.

[0073] Through the synergistic effect of improving passive regeneration efficiency, controlling hydrocarbon leakage, and improving economy and reliability, the defects of the existing non-road national four diesel engine DPF regeneration technology are solved comprehensively - not only the core problem of frequent active regeneration is solved, but also the risk of emission exceeding the standard is avoided, and the energy saving and consumption reduction and component protection requirements are also considered.

[0074] The above content is only an example and description of the structure of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the structure of the invention or exceed the scope defined by the present claims, which should belong to the protection scope of the present application.

[0075] In the description of the specification, reference to "one embodiment", "an example", "a specific example" or the like means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. The appearances of the phrases "in one embodiment", "an example", "a specific example" or the like in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples.

[0076] The preferred embodiments of the application disclosed above are only to help explain the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments. Obviously, many modifications and variations can be made in light of the contents of the specification. The specification selects and specifically describes these embodiments in order to better explain the principles and practical application of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. A DPF passive regeneration calibration technique based on high efficiency post-processing, characterized in that, The method comprises the following steps of: S1, obtaining the regeneration core parameters from the exhaust detection range, the core parameters including the real-time temperature T4 at the front end of the DPF, the temperature T5 at the rear end of the DPF, the real-time carbon load C of the DPF, the real-time engine speed n and the real-time engine load rate λ, obtaining the historical database and the regeneration core parameters to jointly construct a regeneration database; S2, obtaining the regeneration core parameters and extracting the real-time temperature T4 at the front end of the DPF for data processing, calling the pre-stored passive regeneration optimal temperature 350 DEG C and the real-time temperature T4 at the front end of the DPF to jointly analyze the deviation ΔT, judging whether the deviation ΔT meets the preset temperature deviation range, and obtaining the temperature judgment result; S3, obtaining the real-time engine speed n and the real-time engine load rate λ, additionally collecting the real-time injection amount Q of the remote post-injection hydrocarbon, obtaining the maximum allowable leakage amount Qmax (n, λ) of the hydrocarbon under load, calling the corresponding pre-stored data from the regeneration database, analyzing the ratio of the two, and obtaining the hydrocarbon leakage risk judgment result; S4, jointly analyzing the temperature judgment result and the hydrocarbon leakage risk judgment result, obtaining the required intake throttle valve maximum opening signal and the hydrocarbon leakage risk correction signal; S5, obtaining the real-time carbon load C of the DPF and jointly analyzing the pre-stored threshold value in the regeneration database, combining the intake throttle valve opening adjustment amount, generating passive regeneration normal instructions, passive regeneration reinforcement instructions and active regeneration warning signals.

2. The DPF passive regeneration calibration technique based on high-efficiency post-processing according to claim 1, characterized in that, The processing process of the regeneration core parameters in the S1 step is as follows: Based on the K-type thermocouple sensor installed at the front end of the DPF in the exhaust detection range, the real-time temperature T4 at the front end of the DPF and the rear-end thermocouple sensor are collected, the preset carbon load threshold value obtained by taking the historical database as a sample is called, and the differential pressure model is constructed by combining the preset carbon load threshold value, the real-time temperature T4 at the front end of the DPF and the rear-end temperature T5 of the DPF, to obtain the real-time carbon load C of the DPF; Based on the engine ECU in the exhaust detection range, the real-time engine speed n and the real-time engine load rate λ are read, the real-time injection amount Q of the post-injection hydrocarbon is obtained through the feedback signal of the post-injection executor, the maximum allowable leakage amount Qmax (n, λ) of the hydrocarbon under load is obtained by bench test in the range of n=800-3000rpm and λ=20%-100%, and is pre-stored in the form of a two-dimensional data table; the detection old data of the same type target in nearly one year is obtained, which is summarized as a historical database, and the regeneration database is jointly constructed by combining the regeneration core parameters obtained in this exhaust detection range.

3. The DPF passive regeneration calibration technique based on high-efficiency post-processing of claim 1, wherein, The analysis process of the temperature judgment result in the S2 step is as follows: The core parameters are obtained, the real-time temperature T4 at the front end of the DPF is extracted for data processing, the real-time temperature T4 at the front end of the DPF is subjected to window sliding average filtering processing, the window size is 5 unit sampling points, the instantaneous fluctuation is removed, the filtered temperature T4 filter value is obtained, the pre-stored passive regeneration optimal temperature 350 DEG C is called, and the temperature T4 filter value is jointly analyzed to obtain the deviation ΔT.

4. The DPF passive regeneration calibration technique based on high-efficiency post-processing according to claim 2, characterized in that, The preset temperature deviation range is combined with the deviation value ΔT for comparison processing. The preset temperature deviation range contains temperature and engine real-time speed n, and is divided into two grades according to the historical database. Specifically, when the engine real-time speed n in the preset temperature deviation range is greater than or equal to 1500 rpm, the temperature is [-25℃, 25℃], which is marked as the first grade; and when the engine real-time speed n in the preset temperature deviation range is less than 1500 rpm, the temperature is [-30℃, 30℃], which is marked as the second grade. If the deviation value ΔT is in the normal range, a temperature compliance signal is generated; if the deviation value ΔT is less than -30℃, a temperature low signal is generated; and if the deviation value ΔT is greater than 30℃, a temperature high signal is generated.

5. The DPF passive regeneration calibration technique based on high-efficiency post-processing of claim 1, wherein, The analysis process of the carbon and hydrogen leakage risk judgment result in the S3 step is as follows: The engine real-time speed n, engine real-time load rate λ and real-time hydrocarbon injection amount Q are obtained, and a pre-stored bilinear interpolation model is called to obtain the maximum allowable leakage amount Qmax(n, λ) of hydrocarbons under load by substituting the engine real-time speed n and the engine real-time load rate λ.

6. The DPF passive regeneration calibration technique based on high-efficiency post-processing according to claim 5, characterized in that, The record data of the same type as the target of this exhaust detection range in the historical database is extracted, and the pre-stored speed pre-stored interval value and load pre-stored interval value are called to calibrate the speed pre-stored interval value and load pre-stored interval value with the record data, so as to obtain the calibrated pre-stored interval value, and the corresponding high-low grade rpn limit and high-low grade load limit are extracted from the historical database. If the engine real-time speed n and the engine real-time load rate λ exceed the calibration pre-stored interval value, when the engine real-time speed n>high rpn, the value n=Qmax corresponding to high rpm is taken, when n<low rpn, the value n=Qmax corresponding to low rpn is taken, when the engine real-time load rate λ<low load level limit value, the value λ=Qmax corresponding to low load level limit value is taken, when the engine real-time load rate λ>high load level limit value, the value λ=Qmax corresponding to high load level limit value is taken, the formula , two decimal places are reserved; if K≤0.9, a low hydrocarbon leakage risk signal is generated; if 0.9<K≤1, a medium hydrocarbon leakage risk signal is generated; if K>1, a high hydrocarbon leakage risk signal is generated.

7. The DPF passive regeneration calibration technique based on high-efficiency post-processing of claim 1, wherein, The joint analysis process of the temperature judgment result and the carbon and hydrogen leakage risk in the S4 step is as follows: The dynamic data of the engine real-time speed n and the engine real-time load rate λ along the time line, and the current opening degree θ of the intake throttle valve in the exhaust detection range are obtained, and the proportional coefficient Kp and the integral coefficient Ki calibrated by the historical database and the pre-stored proportional coefficient are called. When n is greater than or equal to 2000 rpm, Kp can be 0.5% / ℃ and Ki can be 0.02 mg / s・℃; when 1200 rpm≤n<2000 rpm, Kp=0.6% / ℃ and Ki=0.03 mg / s・℃; and when n<1200 rpm, Kp=0.7% / ℃ and Ki=0.04 mg / s・℃.

8. The DPF passive regeneration calibration technique based on high-efficiency post-processing according to claim 7, characterized in that, The temperature determination result and the hydrocarbon leakage risk determination result are obtained, if the temperature is low and the hydrocarbon leakage risk is low / medium, the intake throttle valve opening adjustment amount is obtained by formula analysis to obtain the maximum opening signal; if the hydrocarbon leakage risk is high, the intake throttle valve opening adjustment amount is obtained by formula analysis to obtain the hydrocarbon leakage risk correction signal.

9. The DPF passive regeneration calibration technique based on high-efficiency post-processing of claim 1, wherein, The analysis process of the DPF passive regeneration state signal in the S5 step is as follows: Based on the exhaust detection range, the real-time carbon load C of the DPF is obtained, and the calibrated carbon load threshold obtained by joint analysis of the historical database and the pre-stored corresponding threshold is called The calibrated carbon load threshold Contains high and low values. If the real-time carbon load C of the DPF is less than or equal to the low value, the passive regeneration normal instruction is generated in combination with the temperature compliance signal. If the low value is less than the real-time carbon load C of the DPF and the real-time carbon load C of the DPF is less than or equal to the high value, a passive regeneration strengthening instruction is generated in combination with the temperature compliance signal; and if the real-time carbon load C of the DPF is greater than the high value, a passive regeneration strengthening instruction is generated regardless of the temperature state.

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