CN116625697A

CN116625697A - Method and device for measuring accumulated carbon of diesel engine, electronic equipment and storage medium

Info

Publication number: CN116625697A
Application number: CN202310907758.2A
Authority: CN
Inventors: 解礼兵; 李世峰; 陈旭东; 刘典云; 郑永明; 曾夏寒; 李�瑞
Original assignee: Cnr Automobile Inspection Center Kunming Co ltd
Current assignee: Cnr Automobile Inspection Center Kunming Co ltd
Priority date: 2023-07-24
Filing date: 2023-07-24
Publication date: 2023-08-22
Anticipated expiration: 2043-07-24
Also published as: CN116625697B

Abstract

The invention discloses a method and a device for measuring accumulated carbon of a diesel engine, electronic equipment and a storage medium. The method comprises the following steps: acquiring a plurality of groups of test data sets obtained by bench test of the diesel engine at the altitude to be tested; screening a plurality of screening rotational speeds and screening torques from a plurality of groups of test data sets; combining the screening rotational speed and the screening torque into a plurality of independent working conditions, wherein each independent working condition comprises a screening rotational speed and a screening torque; generating a carbon accumulating steady-state test cycle comprising a plurality of steady-state conditions based on the plurality of independent conditions, and generating a carbon accumulating transient test cycle comprising a plurality of transient conditions; and performing carbon accumulation measurement according to the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle. The invention rapidly generates the carbon accumulating steady-state test cycle with a plurality of steady-state working conditions and the carbon accumulating transient-state test cycle with a plurality of transient working conditions, so as to be used for rapidly verifying the performance of the DPF product and pushing the test process.

Description

Method and device for measuring accumulated carbon of diesel engine, electronic equipment and storage medium

Technical Field

The invention relates to the technical field of data processing, in particular to a method and a device for measuring accumulated carbon of a diesel engine, electronic equipment and a storage medium.

Background

Diesel engines are widely applied to the fields of traffic, navigation, aerospace and the like due to good dynamic property, fuel economy and working stability, but the pollutant emission is also a major difficult problem to be solved urgently, and particularly, the emission of NOx and PM accounts for more than 90% of the emission of automobiles, so that the pollutant emission is required to be treated and limited when the dynamic property of the diesel engines is utilized. With the development of science and technology, the emissions of carbon monoxide (CO), hydrocarbon (HC), nitrogen oxides (NOx) and Particulate Matters (PM) in automobile exhaust gas have reached a low level, but the PM amount is small and the hazard is large. PM is identified as the first kind of cancerogenic substances of current human beings, and the cancerogenic substances comprise various harmful substances such as aldehydes, aromatic hydrocarbons, dry soot, water and the like which are incompletely combusted by fuel oil, and the harmful substances are easy to form aerosol with dust and water in air, so that secondary pollution to the environment is caused. With the tightening and gradual implementation of emission regulations of automobiles, a great number of purification technologies and devices are applied to make an important contribution to automobile emission reduction, an oxidation catalyst (Diesel Oxidation Catalyst, DOC) is used for removing CO and HC, a wall-flow type particle trap (Diesel Particulate Filter, DPF) is used for removing PM, a selective catalytic reducer (Selective Catalytic Reduction, SCR) is used for removing NOx, and an ammonia oxidation catalyst (Ammonia Slip Catalyst, ASC) is used for removing NH3. The automobile exhaust emission is obviously influenced by the performance stability of the aftertreatment device, and the oxidation conversion efficiency of the DOC, the trapping and regeneration efficiency of the DPF and the catalytic reduction efficiency of the SCR all need to reach more than 90 percent, so that the emission of various pollutants of the automobile exhaust can be ensured to reach a lower level.

At present, DPF is a main device for reducing the emission of diesel particulate matters, can remove more than 90% of PM of diesel engines, is widely applied to road and non-road mobile machinery, but has crucial stable performance and service life. The DPF includes two processes of trapping and regenerating particulate matters, and relates to trapping efficiency and regeneration efficiency of the DPF, and the accumulated carbon amount of the DPF has a great influence on regeneration time, regeneration efficiency, engine performance and the like, so that the determination of the accumulated carbon amount at the regeneration time of the DPF is very important. However, due to the application of the purification technology in the engine, the emission of the original particulate matters of the engine is low at present, which results in an increase of the carbon accumulating cost of the DPF, especially the carbon accumulating time. Therefore, in the DPF design process, rapid carbon accumulation and accurate adjustment of the DPF are important preconditions for rapid positioning of regeneration time.

The prior art carbon accumulation measuring method adopts a transient working condition and a steady-state working condition to carry out DPF carbon accumulation of fixed duration, then carries out DPF weighing and calculates the carbon accumulation amount, but the prior carbon accumulation measuring method has more complicated procedures and more time consumption, and is not beneficial to the rapid development of DPF products and the determination of regeneration time.

Disclosure of Invention

Based on the above, it is necessary to provide a method, a device, an electronic apparatus and a storage medium for measuring the carbon accumulation of a diesel engine, aiming at the technical problems that the procedures of the prior art carbon accumulation measuring method are complex and time-consuming.

The invention provides a method for measuring accumulated carbon of a diesel engine, which comprises the following steps:

acquiring a plurality of groups of test data sets obtained by bench test of a diesel engine at an altitude to be tested, wherein each group of test data sets comprises a soot emission amount and one or more corresponding test data;

screening a plurality of screening rotational speeds and screening torques from a plurality of groups of the test data groups;

combining the screening rotational speed and the screening torque into a plurality of independent working conditions, wherein each independent working condition comprises the screening rotational speed and the screening torque;

generating a carbon accumulating steady-state test cycle comprising a plurality of steady-state conditions based on the plurality of independent conditions, and generating a carbon accumulating transient test cycle comprising a plurality of transient conditions;

and performing carbon accumulation measurement according to the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle.

Further, selecting a screening rotational speed and a screening torque from a plurality of sets of test data sets specifically includes:

if the diesel engine has no exhaust gas recirculation, then:

from a plurality of groups of test data groups, taking the range of main oil injection quantity of which the carbon smoke emission quantity meets the preset carbon smoke emission quantity screening condition as a main oil injection quantity range to be tested, and taking the range of oil injection pressure of which the carbon smoke emission quantity meets the preset carbon smoke emission quantity screening condition as an oil injection pressure range to be tested;

Selecting one or more groups of test data groups with main oil injection quantity within the main oil injection quantity range to be tested and oil injection pressure within the oil injection pressure range to be tested from multiple groups of test data groups as data groups to be tested, taking the rotating speed in the data groups to be tested as screening rotating speed and the torque in the data groups to be tested as screening torque; or alternatively

If the diesel engine is equipped with exhaust gas recirculation, then:

from a plurality of groups of test data groups, taking the range of main oil injection quantity of which the soot discharge quantity meets the preset soot discharge quantity screening condition as the range of main oil injection quantity to be tested, taking the range of oil injection pressure of which the soot discharge quantity meets the preset soot discharge quantity screening condition as the range of oil injection pressure to be tested, and taking the range of EGR valve opening of which the soot discharge quantity meets the preset soot discharge quantity screening condition as the range of EGR valve to be tested;

and selecting one or more groups of test data groups with main oil injection quantity within the main oil injection quantity range to be tested, oil injection pressure within the oil injection pressure range to be tested and EGR valve opening within the EGR valve range to be tested as the data groups to be tested, taking the rotating speed in the data groups to be tested as the screening rotating speed, and taking the torque in the data groups to be tested as the screening torque.

Further, the combination of the screening rotational speed and the screening torque into a plurality of independent working conditions specifically includes:

combining each screening rotating speed with each screening torque respectively to obtain a plurality of independent working conditions;

acquiring an external characteristic curve of the diesel engine;

screening all independent working conditions: and if the screening torque corresponding to the screening rotational speed in the independent working condition is larger than the maximum allowable torque corresponding to the same rotational speed in the external characteristic curve, eliminating the independent working condition containing the screening torque.

Further, the generating a carbon accumulating steady-state test cycle comprising a plurality of steady-state working conditions specifically comprises:

obtaining a soot emission measured value obtained by bench test of each independent working condition;

sequencing according to the measured value of the carbon smoke emission of each independent working condition;

setting the operation time length of each independent working condition as follows:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j The exhaust rate of soot in the jth independent condition, M is the number of independent conditions, q _s,i For the ith independent operating mode soot emission measurement, q _exh,i For the i-th independent operating mode instantaneous exhaust volume flow, T _{Total (S)} For a total length of time of operation;

constructing a plurality of working condition units, wherein each working condition unit comprises a plurality of independent working conditions;

and randomly arranging a plurality of working condition units to obtain a plurality of sequenced working condition units, generating a carbon accumulating steady-state test cycle according to the arrangement sequence of the working condition units, wherein the independent working condition is a steady-state working condition of the carbon accumulating steady-state test cycle.

Further, the generating a carbon accumulating transient test cycle including a plurality of transient conditions specifically includes:

setting the operation time length of each independent working condition as follows:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j The exhaust rate of soot in the jth independent condition, M is the number of independent conditions, q _s,i For the ith independent operating mode soot emission measurement, q _exh,i Instantaneous exhaust volumetric flow for the ith independent operating condition;

combining the independent working conditions into a carbon accumulating transient test cycle according to the sequencing order;

setting transition working conditions between two adjacent independent working conditions, wherein the transition working conditions comprise transition rotating speed and transition torque;

An initial idle speed working condition is set before the first independent working condition of the carbon accumulating transient test cycle, an end idle speed working condition is set after the last independent working condition, and the transient working conditions of the carbon accumulating transient test cycle comprise the independent working condition, the transition working condition and the idle speed working condition.

Still further, the setting of the transition condition between two adjacent independent conditions specifically includes:

setting a transition condition between the ith independent condition and the (i+1) th independent condition:

calculating the time coefficient of the transition working conditionSetting the operation time of the transition working conditionWherein t is _s,i For the operation duration of the ith independent working condition, t _s,i+1 The operation time length of the (i+1) th independent working condition is the operation time length;

if the time coefficient of the transition working condition is smaller than 1, setting the transition rotating speed of the transition working conditionSetting transition torque of transition working condition>Wherein a is _S1 Is a first rotation speed coefficient S _i Screening rotating speed for the ith independent working condition, a _T1 To screen the torque coefficient, T _i The screening torque of the ith independent working condition is obtained, and t is the time in the transition working condition;

if the time coefficient of the transition working condition is more than or equal to 1, setting the transition rotating speed of the transition working condition Setting transition torque of transition working condition>Wherein a is _S2 A is the second rotation speed coefficient _T2 Is the maximum allowable torque coefficient, b _S B is the third rotation speed coefficient _T And t is the time in the transition working condition.

Furthermore, the step of setting a start idle speed working condition before the first independent working condition of the carbon accumulating transient test cycle and setting an end idle speed working condition after the last independent working condition specifically comprises the following steps:

setting the running time of the initial idle working condition asWherein t is _s,1 The operation time is the operation time of the first independent working condition;

initial idle speed setting initial idle working conditionSetting an initial idle torque for an initial idle conditionWherein a is _S1 A is a first rotation speed coefficient _T1 To screen the torque coefficient, t1 isTime in the initial idle condition;

setting the operation time of ending the idle speed working condition asWherein t is _s,M The operation time of the last independent working condition is the operation time of the last independent working condition;

end idle speed setting end idle conditionSetting end idle torque of end idle condition +.>Wherein S is _M For the last screening rotating speed of the independent working condition, T _M Screening torque for the last independent working condition, t ₂ And (5) the time in the ending idle working condition is the time.

The invention provides a device for measuring accumulated carbon of a diesel engine, which comprises:

the system comprises a test data acquisition module, a test data acquisition module and a test data processing module, wherein the test data acquisition module is used for acquiring a plurality of groups of test data groups obtained by bench test of a diesel engine under an altitude to be tested, and each group of test data groups comprises a soot emission amount and one or more corresponding test data;

the screening module is used for screening a plurality of screening rotating speeds and screening torques from a plurality of groups of test data groups;

the combination module is used for combining the screening rotating speed and the screening torque into a plurality of independent working conditions, and each independent working condition comprises the screening rotating speed and the screening torque;

the cycle generation module is used for generating a to-be-detected working condition of the carbon accumulating steady-state test cycle and a to-be-detected working condition of the carbon accumulating transient-state test cycle based on a plurality of independent working conditions, wherein the to-be-detected working condition comprises a to-be-detected rotating speed calculated according to a screening rotating speed and a to-be-detected torque calculated according to a screening torque;

and the test module is used for executing carbon accumulation measurement based on the rotating speed to be tested and the torque to be tested of the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle in sequence.

The present invention provides an electronic device including:

at least one processor; the method comprises the steps of,

a memory communicatively coupled to at least one of the processors; wherein,,

the memory stores instructions executable by at least one of the processors to enable the at least one processor to perform a diesel engine carbon deposit measurement method as previously described.

The present invention provides a storage medium storing computer instructions that, when executed by a computer, are operable to perform all the steps of a diesel engine carbon deposit measurement method as described hereinbefore.

According to the invention, proper rotating speed and torque are screened out from test data, combined into a plurality of independent working conditions, and based on the independent working conditions, a carbon accumulating steady-state test cycle of a plurality of steady-state working conditions and a carbon accumulating transient test cycle comprising a plurality of transient working conditions are rapidly generated, so that the method is used for rapidly verifying the performance of a DPF product and promoting the test process. Meanwhile, the invention can predict the accumulated carbon amount of the DPF in real time, reduce the carrier damage rate in the DPF performance verification process, reduce the time cost of DPF product development and improve the product development efficiency.

Drawings

FIG. 1 is a flowchart of a method for measuring accumulated carbon of a diesel engine according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for measuring accumulated carbon in a diesel engine according to another embodiment of the present invention;

FIG. 3 is a schematic diagram of an exemplary speed-torque footprint of the present invention;

FIG. 4 is a schematic illustration of an exemplary condition removal of the present invention;

FIG. 5 is a flowchart of a method for measuring accumulated carbon of a diesel engine according to a preferred embodiment of the present invention;

FIG. 6 is a schematic diagram of a device for measuring accumulated carbon in a diesel engine according to the present invention;

fig. 7 is a schematic diagram of a hardware structure of an electronic device according to the present invention.

Detailed Description

Specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Wherein like parts are designated by like reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the drawings, and the words "inner" and "outer" refer to directions toward or away from, respectively, the geometric center of a particular component.

Fig. 1 is a flowchart of a method for measuring accumulated carbon of a diesel engine according to an embodiment of the present invention, including:

Step S101, a plurality of groups of test data sets obtained by bench test of a diesel engine under an altitude to be tested are obtained, wherein each group of test data sets comprises a carbon smoke emission amount and one or more corresponding test data;

step S102, screening a plurality of screening rotational speeds and screening torques from a plurality of groups of test data groups;

step S103, combining the screening rotating speed and the screening torque into a plurality of independent working conditions, wherein each independent working condition comprises the screening rotating speed and the screening torque;

step S104, generating a carbon accumulating steady-state test cycle comprising a plurality of steady-state working conditions based on a plurality of independent working conditions, and generating a carbon accumulating transient test cycle comprising a plurality of transient working conditions;

step S105, performing carbon accumulation measurement according to the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle.

In particular, the invention may be applied to electronic devices, such as computers, having processing capabilities.

Specifically, step S101 is first performed to acquire a test data set. The test data set includes one or more test data obtained from bench testing of the diesel engine at the altitude to be tested.

Specifically, testing a diesel engine based on a gantry that includes an altitude simulation system will result in multiple sets of test data.

In some embodiments, the bench test is a bench universal test.

Wherein each set of test data comprises a soot emission and one or more test data corresponding to the soot emission.

In some embodiments, each set of test data sets includes: soot emissions, main injection, injection pressure, rotational speed, and torque.

In some embodiments, each set of test data sets includes: soot emissions, main injection quantity, injection pressure, EGR valve opening, rotational speed, and torque.

Then, step S102 is executed to screen out a plurality of screening rotational speeds and screening torques from the plurality of sets of test data. Specifically, for a diesel engine without EGR, screening an air inlet boundary of high emission of engine soot, screening fuel injection parameters of high emission of engine soot based on a fuel injection system, and determining a control area of air inlet and fuel injection parameters, so that a plurality of screening rotational speeds and screening torques are screened out in a test data set.

And then, executing step S103, and combining the screening rotating speed and the screening torque into a plurality of independent working conditions. Specifically, each of the independent operating conditions includes one of the screening rotational speeds and one of the screening torques. Each independent working condition can be adopted (S _i ，T _i ) Representation, wherein S _i For the ith screening rotational speed, T _i Torque is screened for the ith.

Then step S104 is executed to generate a carbon accumulating steady-state test cycle including a plurality of steady-state conditions and a carbon accumulating transient-state test cycle including a plurality of transient conditions based on a plurality of the independent conditions.

Specifically, a plurality of independent working conditions are sequentially arranged to form a carbon accumulating steady-state test cycle or a carbon accumulating transient test cycle, wherein the independent working conditions are steady-state working conditions in the carbon accumulating steady-state test cycle or transient working conditions in the carbon accumulating transient test cycle.

And finally, executing step S105, and executing carbon accumulation measurement according to the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle.

According to experimental requirements, the carbon accumulating measurement can adopt a carbon accumulating steady-state test cycle, a carbon accumulating transient-state test cycle or a carbon accumulating steady-state test cycle.

And in the carbon accumulation measurement process, the working conditions of the corresponding cycles are sequentially taken out, the carbon accumulation measurement is carried out by adopting the rotating speed and the torque recorded by the working conditions, and the accumulated carbon emission of the corresponding test cycles is recorded and calculated by adopting the carbon smoke sampling equipment. And generating the optimal carbon accumulating test working condition, and calculating the predicted carbon accumulating amount and the corresponding carbon accumulating time of the test cycle.

According to the invention, proper rotating speed and torque are screened out from test data, combined into a plurality of independent working conditions, and based on the independent working conditions, a carbon accumulating steady-state test cycle of a plurality of steady-state working conditions and a carbon accumulating transient test cycle comprising a plurality of transient working conditions are rapidly generated, so that the method is used for rapidly verifying the performance of a DPF product and promoting the test process. Meanwhile, the invention can predict the accumulated carbon amount of the DPF in real time, reduce the carrier damage rate in the DPF performance verification process, reduce the time cost of DPF product development and improve the product development efficiency. The invention finally forms a DPF carbon accumulating circulation unit, one circulation unit is a steady-state/transient working condition, the carbon accumulating calculation value of the DPF carbon accumulating circulation unit can be obtained through testing (the calculation method refers to the national six-emission standard of heavy vehicles), the optimal DPF carbon accumulating circulation (comprising one or more circulation units) can be determined according to the customer requirements (carbon accumulating amount and carbon accumulating time), and the carbon accumulating circulation formed in this way is more fit with the carbon accumulating process of the DPF in the actual running of the whole vehicle.

Fig. 2 is a flowchart of a method for measuring accumulated carbon of a diesel engine according to another embodiment of the present invention, including:

step S201, a plurality of groups of test data sets obtained by bench test of the diesel engine under the altitude to be tested are obtained, wherein each group of test data sets comprises a carbon smoke emission amount and one or more corresponding test data.

Step S202, screening a plurality of screening rotational speeds and screening torques from a plurality of groups of the test data groups.

In one embodiment, the selecting the screening rotational speed and the screening torque from the plurality of sets of test data sets specifically includes:

if the diesel engine has no exhaust gas recirculation (Exhaust Gas Recirulation, EGR), then:

If the diesel engine is equipped with exhaust gas recirculation, then:

And step S203, respectively combining each screening rotating speed with each screening torque to obtain a plurality of independent working conditions.

And step S204, obtaining an external characteristic curve of the diesel engine.

Step S205, screening all independent working conditions: and if the screening torque corresponding to the screening rotational speed in the independent working condition is larger than the maximum allowable torque corresponding to the same rotational speed in the external characteristic curve, eliminating the independent working condition containing the screening torque.

Step S206, generating a carbon accumulating steady-state test cycle comprising a plurality of steady-state working conditions and generating a carbon accumulating transient test cycle comprising a plurality of transient working conditions based on a plurality of independent working conditions.

In one embodiment, the generating a carbon accumulating steady state test cycle including a plurality of steady state conditions specifically includes:

In one embodiment, the generating a carbon-accumulating transient test cycle including a plurality of transient conditions specifically includes:

In one embodiment, the setting a transition condition between two adjacent independent conditions specifically includes:

calculating the time coefficient of the transition working condition Setting the operation time of the transition working conditionWherein t is _s,i For the ith independent conditionT _s,i+1 The operation time length of the (i+1) th independent working condition is the operation time length;

if the time coefficient of the transition working condition is more than or equal to 1, setting the transition rotating speed of the transition working conditionSetting transition torque of transition working condition>Wherein a is _S2 A is the second rotation speed coefficient _T2 Is the maximum allowable torque coefficient, b _S B is the third rotation speed coefficient _T And t is the time in the transition working condition.

In one embodiment, the setting of the initial idle speed condition before the first independent condition and the ending idle speed condition after the last independent condition of the carbon accumulating transient test cycle specifically includes:

Initial idle speed setting initial idle working conditionInitial idle speed for setting initial idle speed working conditionTorque momentWherein a is _S1 A is a first rotation speed coefficient _T1 In order to screen the torque coefficient, t1 is the time in the initial idle working condition;

Step S207, performing carbon accumulation measurement according to the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle.

Specifically, step S201 is first performed to obtain a plurality of test data sets obtained by bench testing a diesel engine at an altitude to be tested. Each set of the test data sets includes a soot emission and a corresponding one or more test data.

Then, step S202 is executed to screen out a plurality of screening rotational speeds and screening torques.

If the diesel engine has no exhaust gas recirculation, then:

If the diesel engine is equipped with exhaust gas recirculation, then:

According to the embodiment, the main fuel injection quantity, the fuel injection pressure and the opening degree of the EGR valve are screened, the proper rotating speed and torque are determined to serve as working conditions, the working conditions are high-carbon-smoke emission working conditions, and the actual carbon accumulating time of the DPF is shortened as much as possible by constructing a carbon accumulating test cycle of high carbon smoke.

Specifically, a suitable split value may be selected as a target value according to the SOOT emission amount of the engine in all tests, and the SOOT emission amount selection condition may be a root > target value, where root is the SOOT emission amount.

For example, the soot emission amount of all tests is screened, and a 90% -100% split value is selected as a target value S90. The SOOT emission screening condition may be a root > S90.

The related parameters are preset as follows:

intake boundary: h represents altitude, unit: m; t represents the intake air temperature in units of: the temperature is lower than the temperature; RH represents intake air humidity in units: the%;

Oil injection parameters: pf represents injection pressure, unit: kPa; mf represents the main injection amount, unit: mg/hub;

EGR parameters: v (V) _EGR Represents EGR valve opening degree, unit: the%;

soot: SOOT stands for SOOT emission, unit: mg/m ³ ；

Rotational speed/torque: speed stands for rotational Speed, unit: r/min; torque stands for Torque, unit: nm;

control region screening conditions:

target value: the SOOT > S90, and the 90% split value of the engine is selected as a target value S90 according to the universal SOOT emission of the engine.

Boundary of variables: a represents an upper limit and b represents a lower limit;

i.e. the control area is a<i<b, where i= H, T, RH, pf, mf, V _EGR ；

Test procedure:

1. altitude and intake parameter determination: h=1900 m (optionally any value of 0-5000 m), t=25 ℃ (optionally 10-40 ℃), rh=40% (0-100%).

2. Fuel injection boundary determination: and screening out the boundary of the oil injection parameters (main oil injection quantity and oil injection pressure) according to an objective function (high soot emission value, FSN is more than or equal to 0.2). The FSN is a smoke degree parameter measured by a soot testing device (filter paper smoke meter, AVL415 SE) used in the bench test process, and the collected value represents the smoke degree of the exhaust.

Specifically, the soot emission amount screening condition is set to S90 <SOOT<S100. From the test data set, the main injection quantity Mf and the injection pressure Pf which meet the soot emission screening conditions are selected. Determining the range (a) of the main injection quantity Mf conforming to the soot discharge quantity screening condition _M ,b _M ) As the range of main fuel injection quantity to be measured. Determining a range (a) of the injection pressure Pf conforming to the soot emission amount screening condition _P ,b _P ) As the range of injection pressure to be measured.

For a diesel engine without EGR, the main injection quantity directly determines engine torque at different speeds, and the injection pressure directly influences the formation of soot, so that the speed torque conditions determined by the main injection quantity and the injection pressure are both high soot emission conditions. The rotational speed-torque footprint at the fuel injection boundary can be determined directly: and selecting one or more groups of test data groups with main oil injection quantity within the main oil injection quantity range to be tested and oil injection pressure within the oil injection pressure range to be tested from the plurality of groups of test data groups as the data groups to be tested, taking the rotating speed in the data groups to be tested as the screening rotating speed, and taking the torque in the data groups to be tested as the screening torque.

For diesel engines equipped with EGR, it is also necessary to determine the EGR valve boundaries: and (3) screening out the boundary of the EGR valve according to an objective function (high soot emission value, FSN is more than or equal to 0.2).

Specifically, the soot emission amount screening condition is set to S90<SOOT<S100. From the test data set, selecting an EGR valve opening V meeting the soot emission screening conditions _EGR . Determining an EGR valve opening V that meets soot emission screening conditions _EGR Range of Mf (a _E ,b _E ) As the EGR valve range to be measured.

Finally, determining a rotating speed-torque coverage area under the boundary of the fuel injection and the EGR valve: the main oil injection quantity directly determines the engine torque at different rotating speeds, the oil injection pressure and the EGR valve opening degree directly influence the formation of soot, and the main oil injection quantity, the oil injection pressure and the EGR opening degree under high soot are screened in the mode, so that the rotating speed torque working conditions determined by three key parameters are all high soot emission working conditions. As shown in fig. 3: the intersection of the first control region 301, which determines the rotational speed and torque from the fuel injection boundary, and the second control region 302, which determines the rotational speed and torque from the ERG boundary, is the rotational speed-torque footprint.

Specifically, from a plurality of groups of test data groups, selecting one or more groups of test data groups with main fuel injection quantity within the main fuel injection quantity range to be tested, fuel injection pressure within the fuel injection pressure range to be tested and EGR valve opening within the EGR valve range to be tested as a data group to be tested, taking the rotating speed in the data group to be tested as a screening rotating speed, and taking the torque in the data group to be tested as a screening torque.

In addition, since the test data set includes the rotational speed and the torque corresponding to the soot emission amount, the corresponding rotational speed and torque can be determined directly from the soot emission amount.

In some embodiments, selecting the screening rotational speed and the screening torque from the plurality of test data sets specifically includes:

and selecting one or more groups of test data groups with the carbon smoke emission meeting the preset carbon smoke emission screening conditions from the multiple groups of test data groups as a data group to be tested, taking the rotating speed in the data group to be tested as the screening rotating speed, and taking the torque in the data group to be tested as the screening torque.

After determining the screening rotational speed and the screening torque, step S203 is executed, where each screening rotational speed and each screening torque are respectively combined, so as to obtain a plurality of independent working conditions.

Specifically, the screening rotating speed and the screening torque are subjected to orthogonal treatment to form independent working conditions.

In some embodiments, the torque will be screenedScreening->And performing halving treatment, for example, performing 100 halving treatment, so as to form an orthogonal working condition table of independent operation working conditions, as shown in table 1.

TABLE 1 independent operating condition orthogonality table

And then, executing steps S204 to S205 to screen the independent working conditions, and removing unreasonable working conditions such as low-speed high-load working conditions. In particular, the method comprises the steps of,

Step S204 is first performed to obtain an external characteristic curve of the diesel engine. An external characteristic 41 is shown in fig. 4. The external characteristic is obtained from the mechanical properties of the engine. Each engine has a corresponding external characteristic. The outer characteristic curve represents the maximum allowable torque value of the engine at different rotational speeds.

Step S205 is then executed to screen all independent conditions: and if the screening torque corresponding to the screening rotational speed in the independent working condition is larger than the maximum allowable torque corresponding to the same rotational speed in the external characteristic curve, eliminating the independent working condition containing the screening torque. As shown in fig. 4, the independent operation 42 other than the outer characteristic 41 is removed.

In some embodiments, if the screening torque corresponding to the screening rotational speed in the independent working condition is greater than the maximum allowable torque corresponding to the same rotational speed in the external characteristic curve, the screening torque in the independent working condition is modified to be the maximum allowable torque.

After all the independent working conditions are obtained, step S206 is executed to generate a carbon accumulating steady-state test cycle including a plurality of steady-state working conditions and a carbon accumulating transient-state test cycle including a plurality of transient working conditions based on a plurality of the independent working conditions.

Carbon accumulating steady-state test cycle:

setting the operation time length of each independent working condition as follows:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j Carbon for the j independent working conditionSmoke discharge rate, M is the number of independent working conditions, q _s,i For the ith independent operating mode soot emission measurement, q _exh,i For the i-th independent operating mode instantaneous exhaust volume flow, T _{Total (S)} For a total length of time of operation;

The present embodiment provides a method of generating a carbon accumulating steady-state test cycle. The generation method of the carbon accumulation steady-state test cycle of the embodiment screens the high-carbon soot discharge working conditions, and according to the generation method (by the carbon soot discharge ratio, the operation time of each working condition is given, namely, the higher the carbon soot discharge is, the longer the operation time is), the carbon accumulation working condition of the high carbon soot can be obtained.

Specifically, the above conditions are ranked according to the soot emission ratio (or directly according to the soot emission measurement), and the operating duration of each individual condition is calculated based on the soot emission rate and the total operating duration of each individual condition:

wherein,,is the firstSoot emission measurements for i independent conditions, unit: />，/>The instantaneous exhaust volume flow is the i independent working condition, unit: />，/>Is the soot emission rate of the ith independent working condition, unit: />，m _s,j Soot emission rate in units of j independent operating mode: />，/>Is the soot emission coefficient of the ith independent working condition,is the running time of the ith independent working condition, unit: />，T _{Total (S)} To run the total duration, units: s, M is the number of independent working conditions.

The total operation time length is preset according to experimental requirements. Preferably, the total time period T is operated _{Total (S)} 1800s. M is the number of independent operating conditions, preferably M is 100.

And then constructing a plurality of working condition units, wherein each working condition unit comprises a plurality of independent working conditions.

In some embodiments, when M is even, the ith operating mode unit is formed by combining the ith independent operating mode and the ith+M/2 th independent operating mode, and when M is odd, M-1 independent operating modes are selected to form the operating mode unit, for example, the last independent operating mode is not used to form the operating mode unit, and then the ith operating mode unit is formed by combining the ith independent operating mode and the ith+M/2 th independent operating mode.

Specifically, taking M as an even number as an example, M independent working conditions in the orthogonal table are divided into M/2 working condition units. For example, 100 independent operating modes are divided into 50 operating mode units. Each working condition unit comprises 2 independent working conditions, wherein the ith working condition unit is formed by combining the ith independent working condition and the ith+M/2 independent working conditions. The working condition unit has the structure of (S _i ,T _i ;S _i+M/2 ,T _i+M/2 ) Wherein S is _i Screening rotating speed T for ith independent working condition _i The screening torque for the ith independent operating mode. For example, for 100 independent operating conditions, where the structure of the ith operating condition element is (S _i ,T _i ;S _i+50 ,T _i+50 ). For example, for 101 individual operating conditions, 100 individual operating conditions are selected for the formation of the operating condition unit, the structure of the ith operating condition unit being (S _i ,T _i ;S _i+50 ,T _i+50 ）。

Finally, all the working condition units are arranged and combined randomly to form the carbon accumulating steady-state test cycle (Carbon deposition steady test cycle, CDSC) containing the independent working conditions. Each independent working condition is a steady-state working condition of the carbon accumulating steady-state test cycle.

Carbon accumulation transient test cycle:

The embodiment provides a generation method of a carbon accumulating transient test cycle. Requirements for transient condition generation: the principle of continuous change of the rotating speed and the torque is that the continuous change of adjacent working condition points is carried out in a linear or nonlinear mode, the switching duty ratio of high and low load working conditions is higher, and the generated transient working conditions are selected from the independent working conditions. According to the generation method of the carbon accumulation transient test circulation, high-carbon-smoke-emission working conditions are screened, and according to the generation method (through the carbon smoke emission ratio, the operation time of each working condition is given, namely, the higher the carbon smoke emission is, the longer the operation time is), the carbon accumulation working condition of high carbon smoke can be obtained. Compared with a steady-state working condition, the transient working condition considers the process that the actual running working condition of the whole vehicle is continuous change of the engine speed and the torque, and is relatively fit with the actual process.

Specifically, for a plurality of independent working conditions, for example 100 independent working conditions, the operation duration of each independent working condition is set by adopting the mode of the carbon accumulating steady-state test cycle for each independent working condition:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j The exhaust rate of soot in the jth independent condition, M is the number of independent conditions, q _s,i For the ith independent operating mode soot emission measurement, q _exh,i For the i-th independent operating mode instantaneous exhaust volume flow, T _{Total (S)} For the total duration of operation.

And sequentially combining the sequenced independent working conditions into a carbon accumulating transient test cycle, adding a transition working condition between each independent working condition, and performing transition on the transition working condition in a linear and nonlinear mode, wherein the transient working conditions of the carbon accumulating transient test cycle comprise the independent working conditions and the transition working conditions.

calculating the time coefficient of the transition working conditionSetting the operation time of the transition working condition Wherein t is _s,i For the operation duration of the ith independent working condition, t _s,i+1 The operation time length of the (i+1) th independent working condition is the operation time length;

if the time coefficient of the transition working condition is smaller than 1, setting the transition rotating speed of the transition working conditionSetting transition torque of transition working condition>Wherein a is _S1 Is a first rotation speed coefficient S _i Is the firstScreening rotating speed of i independent working conditions, a _T1 To screen the torque coefficient, T _i The screening torque of the ith independent working condition is obtained, and t is the time in the transition working condition; />

Specifically, a time coefficient is given to adjacent independent working conditions, and if the time coefficient is more than 1, the adjacent independent working conditions are in nonlinear transition, so that larger change is given; if the coefficient is less than 1, the adjacent independent working conditions are in linear transition, and the transition working condition time comprises the ending time of the previous independent working condition and the starting time of the next independent working condition in the adjacent independent working conditions.

The time coefficient of the transition working condition between the ith independent working condition and the (i+1) th independent working condition is as follows:the operating time of the transitional mode ∈>Wherein->A time coefficient t of a transition condition between the ith independent condition and the (i+1) th independent condition _w,i,i+1 The operation time length t of the transition working condition between the ith independent working condition and the (i+1) th independent working condition _s,i For the operation duration of the ith independent working condition, t _s,i+1 For the operation duration of the i+1st independent operating mode,m is the number of independent working conditions. For the case of 100 independent operating conditions +.>。

Transition working condition structure

For linear transitions:

transition rotation speed of transition working condition；

Transition torque for transition conditions；

Wherein a is _S1 A is a first rotation speed coefficient _T1 In order to screen the torque coefficient, the torque coefficient is determined by the rotational speed and the torque of adjacent independent working conditions, S _i Screening rotating speed T for ith independent working condition _i The screening torque for the ith independent working condition, t is the time in the transition working condition,

when (when)，/>、/>；

When (when)，/>、/>。

For nonlinear transitions:

transition of transition conditionsRotational speed；

Transition torque for transition conditions；

Wherein a is _S2 A is the second rotation speed coefficient _T2 Is the maximum allowable torque coefficient, b _S B is the third rotation speed coefficient _T Is a third torque coefficient, is determined by the rotational speed torque of adjacent independent working conditions, t is the time in the transition working conditions, 。

When (when)，/>、/>；

When (when)，/>、/>。

And finally, adding an idle working condition at the head and the tail, wherein the idle working condition and the adjacent independent working condition are in linear transition, the time is half of the running time of the adjacent independent working condition, and finally, the carbon accumulating transient test cycle (Carbon deposition Transient test cycle, CDTC) is obtained.

initial idle speed setting initial idle working conditionSetting an initial idle torque for an initial idle conditionWherein a is _S1 A is a first rotation speed coefficient _T1 In order to screen the torque coefficient, t1 is the time in the initial idle working condition;

After the relevant carbon accumulating steady-state test cycle and the carbon accumulating transient-state test cycle are generated, step S207 is executed to execute carbon accumulating measurement.

Specifically, the working conditions of the carbon accumulating steady-state test cycle or the carbon accumulating transient test cycle are subjected to rack pretreatment, and working condition points with the temperature discharge exceeding 300 ℃ are eliminated. If the steady-state working conditions are eliminated, the rest working conditions with higher soot emission are screened for filling. And if a certain point of the transient working condition is eliminated, smoothly transitioning the adjacent working conditions.

For the carbon accumulating steady-state test cycle, sequentially taking out steady-state working conditions of the carbon accumulating steady-state test cycle in the carbon accumulating measurement process, and performing carbon accumulating measurement by adopting the rotating speed and the torque recorded by the steady-state working conditions to execute the running time recorded by the steady-state working conditions;

and for the carbon accumulating transient test cycle, sequentially taking out an initial idle speed working condition, a transient working condition, a transition working condition, an end idle speed working condition and the like of the carbon accumulating transient test cycle in the carbon accumulating measurement process, and executing the running time recorded by the working condition by adopting the rotating speed and the torque recorded by each working condition to perform carbon accumulating measurement.

The invention combines a plurality of screening rotating speeds and screening torques into a plurality of working conditions, eliminates unreasonable working conditions therein, can rapidly and accurately generate a carbon accumulating steady-state test cycle of a plurality of steady-state working conditions and a carbon accumulating transient test cycle comprising a plurality of transient working conditions, and is used for rapidly verifying the performance of DPF products and propelling test processes. The transition working condition of the carbon accumulating transient test cycle gives consideration to the linear and nonlinear conditions, and the test diversity is increased. Meanwhile, the invention can predict the accumulated carbon amount of the DPF in real time, reduce the carrier damage rate in the DPF performance verification process, reduce the time cost of DPF product development and improve the product development efficiency.

Fig. 5 is a flowchart showing a method for measuring accumulated carbon of a diesel engine according to a preferred embodiment of the present invention, including:

step S501, selecting an altitude requirement based on an altitude simulation system;

step S502, setting an oil injection boundary of high carbon smoke, and determining a first control area of rotating speed and torque according to the oil injection boundary;

step S503, setting an ERG boundary of high carbon smoke, and determining a second control area of the rotating speed and the torque according to the ERG boundary;

step S504, taking the intersection of the first control area and the second control area to generate an independent carbon accumulating working condition;

step S505, eliminating unreasonable torque rotation speed;

step S506, generating a carbon accumulating steady-state test cycle;

step S507, generating a carbon accumulating transient test cycle;

step S508, forming a circulation working condition of unit soot emission based on the carbon accumulating steady-state test circulation and/or the carbon accumulating transient test circulation;

step S509, according to the carbon accumulating requirement (altitude, carbon accumulating amount) of the customer, the circulating working condition of the unit soot emission amount is circularly executed until the test requirement is met, and the carbon accumulating time and the actual carbon accumulating amount are obtained.

Wherein, step S501 to step S507 generate a carbon accumulation steady-state test cycle and a carbon accumulation transient test cycle through independent working conditions, and then execute step S508 to form a cycle working condition of unit soot emission. Specifically, the cycle condition of the unit soot emission can be a carbon accumulating steady-state test cycle, a carbon accumulating transient test cycle, or a combination of the carbon accumulating steady-state test cycle and the carbon accumulating transient test cycle. The cycle condition of the unit soot emission is a test cycle, for example, 1g of soot emission is tested in a test. And then, according to the test requirement, executing the circulation working condition of the multi-unit soot emission to obtain the carbon accumulating time and the actual carbon accumulating amount.

Based on the same inventive concept, fig. 6 is a schematic diagram of a carbon accumulation measuring device of a diesel engine according to the present invention, including:

the test data acquisition module 601 is configured to acquire a plurality of groups of test data sets obtained by bench test of a diesel engine under an altitude to be tested, where each group of test data sets includes a soot emission amount and one or more corresponding test data;

a screening module 602, configured to screen a plurality of screening rotational speeds and screening torques from a plurality of sets of the test data sets;

a combining module 603, configured to combine the screening rotational speed and the screening torque into a plurality of independent working conditions, where each of the independent working conditions includes one of the screening rotational speed and one of the screening torque;

the cycle generating module 604 is configured to generate a to-be-tested working condition of the carbon accumulating steady-state test cycle and a to-be-tested working condition of the carbon accumulating transient test cycle based on a plurality of independent working conditions, where the to-be-tested working conditions include a to-be-tested rotating speed calculated according to a screening rotating speed and a to-be-tested torque calculated according to a screening torque;

the test module 605 is configured to perform carbon accumulation measurement sequentially based on the rotational speed to be measured and the torque to be measured of the working condition to be measured of the carbon accumulation steady-state test cycle and/or the carbon accumulation transient test cycle.

if the diesel engine has no exhaust gas recirculation, then:

If the diesel engine is equipped with exhaust gas recirculation, then:

In one embodiment, the combining the screening rotational speed and the screening torque into a plurality of independent working conditions specifically includes:

Acquiring an external characteristic curve of the diesel engine;

setting the operation time length of each independent working condition as follows:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j The exhaust rate of the soot is the j independent working condition, M is independentNumber of vertical conditions, q _s,i For the ith independent operating mode soot emission measurement, q _exh,i For the i-th independent operating mode instantaneous exhaust volume flow, T _{Total (S)} For a total length of time of operation;

if the time coefficient of the transition working condition is more than or equal to 1, setting the transition rotating speed of the transition working conditionSetting transition torque of transition working condition>Wherein a is _S2 A is the second rotation speed coefficient _T2 Is the maximum allowable torque coefficient, b _S B is the third rotation speed coefficient _T Is a third torque coefficient, t is the transition workTime in the situation.

The specific manner in which the various modules perform the operations in the apparatus of the above embodiments have been described in detail in connection with the embodiments of the method, and will not be described in detail herein.

Fig. 7 is a schematic diagram of a hardware structure of an electronic device according to the present invention, including:

at least one processor 701; the method comprises the steps of,

a memory 702 communicatively coupled to at least one of the processors 701; wherein,,

The memory 702 stores instructions executable by at least one of the processors to enable the at least one processor to perform a diesel engine carbon deposit measurement method as previously described.

One processor 701 is illustrated in fig. 7.

The electronic device may further include: an input device 703 and a display device 704.

The processor 701, the memory 702, the input device 703 and the display device 704 may be connected by a bus or other means, in the figures by way of example.

The memory 702 is used as a non-volatile computer readable storage medium for storing a non-volatile software program, a non-volatile computer executable program, and modules, such as program instructions/modules corresponding to the method for measuring carbon deposit in a diesel engine in an embodiment of the present application, for example, the method flows shown in fig. 1 and 2. The processor 701 executes various functional applications and data processing by running nonvolatile software programs, instructions, and modules stored in the memory 702, that is, implements the diesel engine carbon deposit measurement method in the above-described embodiment.

Memory 702 may include a storage program area that may store an operating system, at least one application program required for functionality, and a storage data area; the storage data area may store data created according to use of a diesel engine carbon deposit measurement method, or the like. In addition, the memory 702 may include high-speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 702 may optionally include memory remotely located relative to processor 701, which may be connected via a network to a device performing the diesel engine carbon deposit measurement method. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 703 may receive input user strokes and generate signal inputs related to user settings and function control of the diesel engine carbon deposit measurement method. The display device 704 may include a display apparatus such as a display screen.

The diesel engine carbon deposit measurement method of any of the method embodiments described above is performed when executed by the one or more processors 701, with the one or more modules stored in the memory 702.

An embodiment of the invention provides a storage medium storing computer instructions that, when executed by a computer, perform all the steps of a diesel engine carbon deposit measurement method as described above.

The foregoing examples illustrate only a few embodiments of the invention and are described in detail herein without thereby limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A method for measuring cumulative carbon of a diesel engine, comprising:

2. The method for measuring cumulative carbon of a diesel engine according to claim 1, wherein selecting a screening rotational speed and a screening torque from a plurality of sets of the test data sets, specifically comprises:

if the diesel engine has no exhaust gas recirculation, then:

If the diesel engine is equipped with exhaust gas recirculation, then:

3. The method for measuring carbon deposit of a diesel engine according to claim 1, characterized in that said combining said screening rotational speed and said screening torque into a plurality of independent operating conditions comprises:

acquiring an external characteristic curve of the diesel engine;

4. The method for measuring the cumulative carbon of the diesel engine according to claim 1, wherein the generating of the cumulative carbon steady-state test cycle comprising a plurality of steady-state conditions comprises:

5. The method for measuring carbon deposit in a diesel engine according to claim 1, characterized in that said generating a carbon deposit transient test cycle comprising a plurality of transient conditions, in particular comprises:

setting the operation time length of each independent working condition as follows:，/>wherein t is _s,i For the operation duration of the ith independent working condition, m _s,i Soot emission rate, m, for the ith independent operating mode _s,j The exhaust rate of soot for the jth independent condition, M being the independent conditionQuantity, q of _s,i For the ith independent operating mode soot emission measurement, q _exh,i Instantaneous exhaust volumetric flow for the ith independent operating condition;

6. The method for measuring carbon deposit of diesel engine according to claim 5, characterized in that said setting a transition condition between two adjacent independent conditions, in particular, comprises:

calculating the time coefficient of the transition working conditionSetting the operation duration of the transitional working condition +.>Wherein t is _s,i For the operation duration of the ith independent working condition, t _s,i+1 The operation time length of the (i+1) th independent working condition is the operation time length;

if the time coefficient of the transition working condition is smaller than 1, setting the transition rotating speed of the transition working conditionSetting transition torque of transition working condition>Wherein a is _S1 Is a first rotation speed systemNumber S _i Screening rotating speed for the ith independent working condition, a _T1 To screen the torque coefficient, T _i The screening torque of the ith independent working condition is obtained, and t is the time in the transition working condition;

7. The method for measuring carbon accumulation in a diesel engine according to claim 5, wherein a start idle condition is set before a first one of the independent conditions of the carbon accumulation transient test cycle, and an end idle condition is set after a last one of the independent conditions, specifically comprising:

setting an operation time for ending an idle operationIs thatWherein t is _s,M The operation time of the last independent working condition is the operation time of the last independent working condition;

8. A diesel engine carbon deposit measuring device, characterized by comprising:

9. An electronic device, comprising:

at least one processor; the method comprises the steps of,

a memory communicatively coupled to at least one of the processors; wherein,,

the memory stores instructions executable by at least one of the processors to enable the at least one of the processors to perform the diesel engine carbon deposit measurement method of any one of claims 1 to 8.

10. A storage medium storing computer instructions which, when executed by a computer, are adapted to carry out all the steps of a method for measuring carbon build up in a diesel engine as claimed in any one of claims 1 to 8.