CN116378802A

CN116378802A - Control method, device and medium for fuel injection quantity of engine

Info

Publication number: CN116378802A
Application number: CN202310253490.5A
Authority: CN
Inventors: 王国栋; 窦站成; 薛振涛; 张利君; 秦海玉; 姚亚俊; 褚国良; 李钊
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2023-03-13
Filing date: 2023-03-13
Publication date: 2023-07-04

Abstract

The disclosure relates to a method, a device and a medium for controlling fuel injection quantity of an engine, wherein the method comprises the following steps: detecting that the DPF needs to be regenerated, and respectively acquiring first temperatures measured by sensors positioned at the upstream of the DPF of each branch in the aftertreatment system, wherein the aftertreatment system comprises a plurality of branches; for each branch, performing closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch, and determining the first oil injection quantity of the branch according to a closed-loop control result; determining the required oil injection quantity of the branch according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch; and controlling the HC injection device to inject fuel to the DOC in each branch based on the fuel injection quantity required by each branch. The method and the device can reduce the conditions of carrier burning, burning and melting and the like caused by uneven fuel injection airflow into the DOC in the regeneration process in the prior art.

Description

Control method, device and medium for fuel injection quantity of engine

Technical Field

The disclosure relates to the technical field of engine aftertreatment, and in particular relates to a method, a device and a medium for controlling fuel injection quantity of an engine.

Background

At present, with the upgrading of the engine emission technology, the DPF (Diesel Particulate Filter, diesel particulate matter trap) technology is adopted, so that most of carbon smoke and other particulate matters in tail gas can be filtered, and the emission of the particulate matters is effectively reduced.

However, as the engine operating time increases, the carbon particles trapped in the DPF increase, which may lead to an increase in engine exhaust back pressure, worsening in-cylinder combustion, and deteriorating fuel consumption and emissions, which may affect engine dynamics and fuel economy. Thus, the DPF requires periodic active regeneration after a certain amount of carbon particulate accumulation has been reached. In the regeneration process, the engine sprays fuel oil or tail pipe after spraying fuel oil, for example HC (Hydrocarbon), the fuel oil oxidizes and releases heat in the DOC (Diesel Oxidation Catalysis, diesel oxidation catalyst) to generate high temperature, so that soot is oxidized and burned at high temperature to remove, and the DPF function is recovered.

However, due to uneven fuel injection airflow into the DOC in the regeneration process, higher temperature may occur in the DPF, and further carrier burning, burning and melting and the like may occur.

Disclosure of Invention

The invention provides a control method, a device and a medium for fuel injection quantity of an engine, which can reduce the conditions of carrier burning, burning and the like caused by uneven fuel injection airflow into a DOC in the regeneration process in the prior art.

According to a first aspect of an embodiment of the present disclosure, there is provided a method for controlling an engine fuel injection amount, the method including:

detecting that the DPF needs to be regenerated, and respectively acquiring first temperatures measured by a sensor positioned at the upstream of the DPF of each branch in the aftertreatment system, wherein the aftertreatment system comprises a plurality of branches, and each branch comprises a DOC, a sensor and the DPF;

for each branch, performing closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch, and determining the first oil injection quantity of the branch according to a closed-loop control result; the set DPF upstream temperature is determined according to a second temperature, exhaust gas mass flow and a first corresponding relation measured by a sensor on an exhaust pipe upstream of a DOC in the aftertreatment system, wherein the first corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow and the DPF upstream temperature;

determining the required oil injection quantity of the branch according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch, wherein the second oil injection quantity is determined based on the second temperature, the heat value of unit fuel combustion and the exhaust gas mass flow;

And controlling the HC injection device to inject fuel to the DOC in each branch based on the fuel injection quantity required by each branch.

According to the technical scheme provided by the embodiment of the disclosure, in the aftertreatment system with the plurality of branches, for each branch, closed-loop control is performed on the regeneration temperature according to the set upstream temperature of the DPF and the first temperature measured by the sensor at the upstream of the DPF of the branch, the first oil injection quantity of the branch is determined according to the closed-loop control result, and the required oil injection quantity of each branch is determined according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch. And the HC injection device is controlled to inject oil to the DOC in each branch based on the oil injection quantity required by each branch, so that the accurate control of the oil injection quantity of each branch is realized, the conditions of carrier burning and cracking, burning and melting and the like caused by uneven oil injection airflow to the DOC in the regeneration process in the prior art are reduced, and the reliability of DPF regeneration is further improved.

In one possible implementation, the determining the second fuel injection amount based on the second temperature, the heating value of unit fuel combustion, and the exhaust gas mass flow includes:

determining a heat quantity value required for regeneration based on the second temperature, the heat capacity of the exhaust gas and the exhaust gas mass flow, wherein the heat capacity of the exhaust gas is determined according to the second temperature and a second corresponding relation, and the second corresponding relation is a corresponding relation between each second temperature and the heat capacity of each exhaust gas;

And determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion and HC conversion efficiency, wherein the HC conversion efficiency is determined according to the second temperature, the exhaust gas mass flow rate and a third corresponding relation, and the third corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow rates and the HC conversion efficiencies.

In one possible implementation, the determining the heat value required for regeneration based on the second temperature, the heat capacity of the exhaust gas, and the exhaust gas mass flow rate includes:

determining a temperature difference between a set temperature and the second temperature, wherein the set temperature is greater than the second temperature;

and taking the product of the determined temperature difference, the heat capacity of the exhaust gas and the exhaust gas mass flow as the heat quantity value.

In one possible implementation manner, the determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion, and the HC conversion efficiency includes:

determining a first ratio of the heat value to the heat value of combustion of the unit fuel;

and taking the determined second ratio of the first ratio to the HC conversion efficiency as the second fuel injection quantity.

In one possible implementation manner, the determining the fuel injection quantity required by the branch according to the first fuel injection quantity, the second fuel injection quantity and the fuel injection boundary value of the branch includes:

if the sum of the first oil injection quantity and the second oil injection quantity of the branch is smaller than the oil injection boundary value, taking the sum as the oil injection quantity required by the branch;

and if the sum of the first oil injection quantity and the second oil injection quantity of the branch is greater than or equal to the oil injection boundary value, taking the oil injection boundary value as the oil injection quantity required by the branch.

According to the technical scheme provided by the embodiment of the disclosure, aiming at each branch in the aftertreatment system, the minimum value of the sum value of the first oil injection quantity and the second oil injection quantity of the branch and the oil injection boundary value is used as the main oil injection quantity of the branch, so that the oil injection quantity of the HC injection device injected to the DOC in each branch is ensured to be within the oil injection boundary value, the conditions of carrier burning, burning and the like caused by uneven oil injection airflow to the DOC in the regeneration process in the prior art can be reduced, and the reliability of DPF regeneration is improved.

In one possible implementation manner, the controlling the HC injection device to perform oil injection to the DOC in each branch includes:

If the aftertreatment system comprises two branches, acquiring a third temperature measured by a sensor positioned at the upstream of the DPF of the first branch in the aftertreatment system and a fourth temperature measured by a sensor positioned at the upstream of the DPF of the second branch in real time;

and controlling the fuel injection quantity of the HC injection device injected to the DOCs in the two branches based on the relation between the third temperature and the fourth temperature.

According to the technical scheme provided by the embodiment of the disclosure, aiming at the aftertreatment system with the two branches, according to the relation between the temperature measured by the sensor at the upstream of the DPF of the first branch and the temperature measured by the sensor at the upstream of the DPF of the second branch, the injection quantity of the HC injection device injected to the DOCs in the two branches is controlled, so that the fuel injected by the HC injection device to the DOCs in the two branches is more uniform, the active regeneration process of the DPF is controlled, and the reliability of DPF regeneration is improved.

In one possible implementation manner, the controlling the injection quantity of the HC injection device injected to the DOC in the two branches based on the relation between the third temperature and the fourth temperature includes:

if the third temperature is higher than the fourth temperature, reducing the fuel injection quantity of the HC injection device injected to the DOC in the first branch road, and increasing the fuel injection quantity of the HC injection device injected to the DOC in the second branch road;

If the third temperature is smaller than the fourth temperature, increasing the fuel injection quantity of the HC injection device injected to the DOC in the first branch road, and reducing the fuel injection quantity of the HC injection device injected to the DOC in the second branch road;

and if the third temperature is equal to the fourth temperature, keeping the fuel injection quantity of the HC injection device injected to the DOC in each branch circuit unchanged.

According to the technical scheme provided by the embodiment of the disclosure, aiming at the aftertreatment system with two branches, according to the magnitude relation between the temperature measured by the sensor at the upstream of the DPF of the first branch and the temperature measured by the sensor at the upstream of the DPF of the second branch, the fuel injection quantity of the HC injection device injected to the DOCs in the branches is respectively adjusted, so that the fuel injected by the HC injection device to the DOCs in the two branches is more uniform, the stability of the temperature at the upstream of the DPF of the branches is ensured, the active regeneration process of the DPF is controlled, and the reliability of DPF regeneration is improved.

According to a second aspect of the embodiments of the present disclosure, there is provided a control device of an engine fuel injection amount, the device including:

the acquisition module is used for detecting that the DPF needs to be regenerated and respectively acquiring first temperatures measured by a sensor positioned at the upstream of the DPF of each branch in the aftertreatment system, wherein the aftertreatment system comprises a plurality of branches, and each branch comprises a DOC, a sensor and the DPF;

The first determining module is used for carrying out closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch for each branch, and determining the first oil injection quantity of the branch according to a closed-loop control result; the set DPF upstream temperature is determined according to a second temperature, exhaust gas mass flow and a first corresponding relation measured by a sensor on an exhaust pipe upstream of a DOC in the aftertreatment system, wherein the first corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow and the DPF upstream temperature;

the second determining module is used for determining the fuel injection quantity required by the branch according to the first fuel injection quantity, the second fuel injection quantity and the fuel injection boundary value of the branch, wherein the second fuel injection quantity is determined based on the second temperature, the heat value of unit fuel combustion and the exhaust gas mass flow;

and the control module is used for controlling the HC injection device to inject oil to the DOCs in each branch circuit based on the oil injection quantity required by each branch circuit.

In one possible implementation manner, the first determining module is configured to:

In one possible implementation manner, the second determining module is configured to:

In one possible implementation, the control module is configured to:

According to a third aspect of the embodiments of the present disclosure, there is provided a control apparatus of an engine fuel injection amount, comprising: a processor; a memory for storing processor-executable instructions; the processor executes the executable instructions to realize the steps of the engine oil injection quantity control method.

According to a fourth aspect of the embodiments of the present disclosure, there is provided a computer-readable storage medium having stored thereon computer instructions which, when executed by a processor, implement the steps of the above-described method of controlling an engine fuel injection amount.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings that are needed in the description of the embodiments will be briefly described below, it will be apparent that the drawings in the following description are only some embodiments of the present disclosure, and that other drawings may be obtained according to these drawings without inventive effort to a person of ordinary skill in the art.

FIG. 1 is a schematic illustration of an application scenario shown according to an exemplary embodiment;

FIG. 2 is a flow chart illustrating a method of controlling an engine fuel injection amount according to an exemplary embodiment;

FIG. 3 is a specific flow chart illustrating a method of controlling an engine fuel injection amount according to an exemplary embodiment;

FIG. 4 is a schematic diagram illustrating a method of determining the amount of fuel injection required for a branch, according to an exemplary embodiment;

FIG. 5 is a flowchart illustrating a method of determining a second fuel injection amount according to an exemplary embodiment;

FIG. 6 is a flowchart illustrating a method of controlling an HC injection device to inject fuel into DOCs in various branches according to an exemplary embodiment;

FIG. 7 is a schematic diagram illustrating a method of controlling an HC injection device to inject fuel into DOCs in various branches according to an exemplary embodiment;

FIG. 8 is an engine aftertreatment system layout diagram shown in accordance with an exemplary embodiment;

FIG. 9 is a schematic diagram illustrating an engine fuel injection amount control apparatus according to an exemplary embodiment;

FIG. 10 is a schematic diagram of an electronic device showing a method of controlling an engine fuel injection amount according to an exemplary embodiment;

fig. 11 is a program product diagram showing a control method of an engine fuel injection amount according to an exemplary embodiment.

Detailed Description

For the purpose of promoting an understanding of the principles and advantages of the disclosure, reference will now be made in detail to the drawings, in which it is apparent that the embodiments described are only some, but not all embodiments of the disclosure. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the disclosure, are within the scope of the disclosure based on the embodiments in the disclosure.

Some words appearing hereinafter are explained:

1. the term "and/or" in the embodiments of the present disclosure describes an association relationship of association objects, which indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship.

2. The terms first, second and the like in the description and in the claims of the embodiments of the disclosure and in the above-described figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the disclosure described herein may be capable of operation in sequences other than those illustrated or described herein.

The application scenario described in the embodiments of the present disclosure is for more clearly describing the technical solution of the embodiments of the present disclosure, and does not constitute a limitation on the technical solution provided by the embodiments of the present disclosure, and as a person of ordinary skill in the art can know that, with the appearance of a new application scenario, the technical solution provided by the embodiments of the present disclosure is equally applicable to similar technical problems. In the description of the present disclosure, unless otherwise indicated, the meaning of "a plurality" is two or more.

At present, as the running time of the engine increases, carbon particles trapped by the DPF increase, so that the exhaust back pressure of the engine increases, the in-cylinder combustion is deteriorated, the fuel consumption and the emission are both poor, and the power performance and the fuel economy of the engine are affected. Thus, the DPF requires periodic active regeneration after a certain amount of carbon particulate accumulation has been reached. In the regeneration process, the engine sprays fuel oil or fuel oil after a tail pipe is sprayed in a cylinder, for example HC, the fuel oil oxidizes and releases heat in the DOC to generate high temperature, and soot is oxidized and burned at high temperature to remove the soot, so that the DPF function is recovered. However, due to uneven fuel injection airflow into the DOC in the regeneration process, higher temperature may occur in the DPF, and further carrier burning, melting and the like may occur.

In order to solve the problems, the disclosure provides a method, a device and a medium for controlling fuel injection quantity of an engine, which can reduce the conditions of carrier burning, burning and the like caused by uneven fuel injection airflow into a DOC in a regeneration process in the prior art.

Referring first to fig. 1, which is a schematic view of an application scenario of an embodiment of the present disclosure, including an aftertreatment system 11 and an electronic control unit (Electronic Control Unit, ECU) 12, wherein the aftertreatment system 11 is configured to send a first temperature upstream of the DPFs of each branch to the electronic control unit 12; the electronic control unit 12 is configured to determine an amount of fuel injection required by each branch based on a first temperature upstream of the DPF of each branch sent by the aftertreatment system 11, and control the HC injection device to inject fuel into the DOC in each branch.

In the embodiment of the disclosure, the electronic control unit 12 detects that the DPF needs to be regenerated, and obtains the first temperatures measured by the sensors located upstream of the DPFs of the various branches in the aftertreatment system 11 respectively, wherein the aftertreatment system 11 comprises a plurality of branches, and each branch comprises a DOC, a sensor and the DPF; for each branch, performing closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch, and determining the first oil injection quantity of the branch according to a closed-loop control result; wherein the set upstream temperature of the DPF is determined according to a second temperature, an exhaust mass flow rate, and a first correspondence relationship measured by a sensor on an exhaust line upstream of the DOC in the aftertreatment system 11, the first correspondence relationship being a correspondence relationship between each second temperature, each exhaust mass flow rate, and each upstream temperature of the DPF; determining the required oil injection quantity of the branch according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch, wherein the second oil injection quantity is determined based on the second temperature, the heat value of unit fuel combustion and the exhaust gas mass flow; based on the amount of fuel injection required for each branch, the HC injection device in the aftertreatment system 11 is controlled to inject fuel into the DOC in each branch.

In some embodiments, a method for controlling an engine fuel injection amount provided by the present disclosure is described below by way of specific embodiments, as shown in fig. 2, including:

step 201, detecting that DPF needs to be regenerated, and respectively acquiring first temperatures measured by sensors positioned at the upstream of DPF of each branch in the aftertreatment system;

wherein the aftertreatment system includes a plurality of legs, each leg including a DOC, a sensor, and a DPF.

The DPF filters and traps particulates in engine exhaust mainly through diffusion, deposition and impact mechanisms. As the exhaust gas flows through the trap, particulates in the exhaust gas are adsorbed onto the filter element of the filter body, leaving cleaner exhaust gas to be discharged into the atmosphere. Wall-flow ceramic honeycomb filters are currently in much use.

DOC is a honeycomb ceramic carrier coated with noble metal catalyst (such as Pt) for reducing the chemical reaction activation energy of HC, CO (carbon monoxide) and SOF (Soluble Orangic Fraction, organic soluble component) in the exhaust gas of engine, so that these substances can be oxidized with oxygen in the exhaust gas at lower temperature and finally converted into CO ₂ (carbon dioxide) and H ₂ O (water).

The basic working principle of the particulate matter trapping system is as follows: as engine exhaust flows through the DOC, CO and HC are first almost entirely oxidized to CO at temperatures of 200-600deg.C ₂ And H ₂ O, while NO (nitric oxide) is converted into NO ₂ (II)Nitrogen oxide). After the exhaust gas enters the DPF from the DOC, particles in the exhaust gas are adsorbed on a filter element of the filter body, cleaner exhaust gas is left to be discharged into the atmosphere, and the trapping efficiency of the DPF can reach more than 90 percent.

The exhaust particulate matter of an engine mainly comprises two components: unburned Soot (Soot), ash (ash), wherein particulate emissions are mostly composed of tiny particles of carbon and carbide. The Soot is a portion of the exhaust particulate matter that can be burned off by regeneration, and ash is a portion of the exhaust particulate matter that is not burned off.

With the lengthening of the working time, more and more particulate matters are accumulated on the DPF, so that the filtering effect of the DPF is affected, the exhaust back pressure is increased, the ventilation and combustion of an engine are affected, the power output is reduced, the oil consumption is increased, and therefore, how to timely eliminate the particulate matters on the DPF (DPF regeneration) is the key of the technology. DPF regeneration refers to the process that during long-term operation of the DPF, the back pressure of an engine is increased due to the gradual increase of particulate matters in a trap, so that the performance of the engine is reduced, and deposited particulate matters are removed periodically, so that the filtering performance of the DPF is recovered.

DPF regeneration has two methods, active regeneration and passive regeneration: active regeneration refers to the use of external energy to raise the temperature within the DPF to ignite and burn the particulate matter. When the differential pressure sensor detects that the back pressure of the DPF is overlarge, the accumulated carbon quantity carried by the DPF is considered to be reached, and the temperature in the DPF is increased by external energy, such as fuel oil injection and combustion before the DOC, so that the temperature in the DPF reaches a certain temperature, deposited particles are oxidized and combusted, and the purpose of regeneration is achieved. The DPF temperature rises above 550 ℃ to burn the trapped particulates therein, thereby restoring the trapping capacity of the DPF.

Passive regeneration refers to NO in the tail gas in a certain temperature range (generally 250 ℃ -450 ℃) ₂ Has strong oxidizing ability to the trapped particles, thus, NO can be utilized ₂ Removal of particulates in a particulate trap as an oxidizing agent and production of CO ₂ And NO ₂ And is reduced to NO, thereby achieving the purpose of removing particles.

Step 202, performing closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch for each branch, and determining the first oil injection quantity of the branch according to the closed-loop control result;

The set upstream temperature of the DPF is determined according to a second temperature, an exhaust gas mass flow and a first corresponding relation measured by a sensor on an exhaust pipe upstream of the DOC in the aftertreatment system, and the first corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow and the upstream temperature of the DPF. Wherein, the first correspondence may be a data table (Map).

When the first correspondence is a data table and includes 4 correspondences, as shown in table 1, the 4 correspondences are respectively: second temperature T ₁ And exhaust gas mass flow C ₁ Corresponding to the upstream temperature T of DPF _a The method comprises the steps of carrying out a first treatment on the surface of the Second temperature T ₁ And exhaust gas mass flow C ₂ Corresponding to the upstream temperature T of DPF _c The method comprises the steps of carrying out a first treatment on the surface of the Second temperature T ₂ And exhaust gas mass flow C ₁ Corresponding to the upstream temperature T of DPF _b The method comprises the steps of carrying out a first treatment on the surface of the Second temperature T ₃ And exhaust gas mass flow C ₃ Corresponding to the upstream temperature T of DPF _d 。

TABLE 1

Second temperature	Mass flow of exhaust gas	DPF upstream temperature
			T ₁	C ₁	T _a
T ₁	C ₂	T _b
			T ₂	C ₁	T _c
T ₃	C ₃	T _d

Based on the data in Table 1, if a second temperature T measured by a sensor located on the exhaust line upstream of the DOC in the aftertreatment system is obtained ₂ And exhaust gas mass flow C ₁ Then determining the corresponding DPF upstream temperature T _b 。

Step 203, determining the required oil injection quantity of the branch according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch;

Wherein the second fuel injection amount is determined based on the second temperature, a heating value per unit fuel combustion, and the exhaust gas mass flow rate. The fuel injection boundary value is set according to actual conditions.

And 204, controlling the HC injection device to inject fuel to the DOC in each branch circuit based on the fuel injection quantity required by each branch circuit.

Specifically, based on the amount of fuel injection required by each branch, the butterfly valve can be used to control the HC injection device to inject fuel to the DOC in each branch.

In the aftertreatment system with a plurality of branches, for each branch, the regeneration temperature is subjected to closed-loop control according to the set upstream temperature of the DPF and the first temperature measured by a sensor at the upstream of the DPF of the branch, the first oil injection quantity of the branch is determined according to a closed-loop control result, and the required oil injection quantity of each branch is determined according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch. And the HC injection device is controlled to inject oil to the DOC in each branch based on the oil injection quantity required by each branch, so that the accurate control of the oil injection quantity of each branch is realized, the conditions of carrier burning and cracking, burning and melting and the like caused by uneven oil injection airflow to the DOC in the regeneration process in the prior art are reduced, and the reliability of DPF regeneration is further improved.

The following describes in detail the specific steps of the method for controlling the fuel injection amount of the engine, as shown in fig. 3, including:

step 301, detecting that the DPF needs to be regenerated;

step 302, respectively acquiring first temperatures measured by sensors positioned upstream of DPFs of various branches in an aftertreatment system;

step 303, performing closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch for each branch, and determining a first oil injection quantity of the branch according to a closed-loop control result;

the closed loop control is a control mode for correcting according to a quota or a standard when the measured actual value deviates from the target value so as to gradually reach the target value. The present disclosure adjusts, for each leg in the aftertreatment system, the first amount of fuel injected into the DOC in that leg based on the temperature deviation between the set DPF upstream temperature (target regeneration temperature) and the first temperature (actual temperature) measured by the sensor upstream of the DPF in that leg, thereby controlling the first temperature in that leg to increase to the set DPF upstream temperature to meet the regeneration temperature demand at the time of DPF regeneration.

Therefore, the specific procedure of the above step 303 is as follows:

calculating a temperature deviation between a set DPF upstream temperature and a first temperature of the branch;

the temperature deviation is converted into a first injection quantity of the branch by means of a PI controller (Proportional Integral Controller, proportional-integral controller).

The specific method for converting the temperature deviation into the fuel injection quantity by using the PI controller is the prior art, and will not be described herein.

As shown in fig. 4, for each branch, the second temperature T measured by the sensor on the exhaust pipe upstream of the DOC in the aftertreatment system is determined based on the DPF upstream temperature set value Map, that is, the first correspondence ₁ Set DPF upstream temperature T corresponding to exhaust gas mass flow ₂ . The DPF upstream temperature T to be set ₂ With the first temperature T of the branch ₅₁ And subtracting to obtain a corresponding temperature deviation, and inputting the temperature deviation into a PI controller to obtain a first oil injection quantity of the branch circuit output by the PI controller.

Step 304, determining a second fuel injection amount based on the second temperature, the heating value of unit fuel combustion and the exhaust gas mass flow;

the execution sequence of the

above steps

304 and 303 may be set according to the actual situation. The second oil injection quantity corresponding to each branch is the same.

The specific process of step 304 is shown in fig. 5, and includes:

step 501, determining a heat value required for regeneration based on the second temperature, the heat capacity of the exhaust gas, and the exhaust gas mass flow;

the heat capacity of the exhaust gas is determined according to the second temperature and a second corresponding relation, and the second corresponding relation is a corresponding relation between each second temperature and the heat capacity of each exhaust gas. Wherein the second relationship may be a data table or Curve (CUR).

Wherein, based on the second temperature, the heat capacity of the exhaust gas, and the exhaust gas mass flow, a specific method of determining a heat quantity value required for regeneration is as follows:

The set temperature may be 600 ℃, or may be set to other values according to actual conditions.

Specifically, the heat value Q required for regeneration can be determined by the following formula:

Q＝c*m*(T _a -T _b )；

where c is the exhaust gas mass flow, m is the heat capacity of the exhaust gas, T _a Is a set temperature, T _b Is the second temperature.

Step 502, determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion, and the HC conversion efficiency.

The HC conversion efficiency is determined according to the second temperature, the exhaust gas mass flow rate and a third corresponding relation, and the third corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow rates and the HC conversion efficiencies.

The specific method for determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion and the HC conversion efficiency is as follows:

Specifically, the second injection amount q may be determined by the following formula:

q＝Q/M/p；

where Q is a heat value, M is a heat value per unit fuel combustion, and p is HC conversion efficiency.

Step 305, determining the required oil injection quantity of the branch according to the first oil injection quantity, the second oil injection quantity and the oil injection boundary value of the branch;

the above step 305 specifically includes the following cases:

As shown in fig. 4, for each branch, a sum of the first injection amount and the second injection amount is determined, and the minimum value between the sum and the injection boundary value is taken as the injection amount required for the branch.

And 306, controlling the HC injection device to inject fuel to the DOC in each branch circuit based on the fuel injection quantity required by each branch circuit.

When the aftertreatment system comprises two branches, in order to make the HC injected by the HC injection device to the DOCs in each branch more uniform, further control the active regeneration process of the DPF, improve the use reliability of the DPF, as shown in FIG. 6, the HC injection device is controlled to inject fuel to the DOCs in each branch by the following method:

step 601, acquiring a third temperature measured by a sensor positioned upstream of a DPF of a first branch in the aftertreatment system and a fourth temperature measured by a sensor positioned upstream of a DPF of a second branch in real time;

step 602, controlling the fuel injection quantity of the HC injection device injected to the DOCs in the two branches based on the relation between the third temperature and the fourth temperature.

The above-mentioned controlling the injection quantity of the HC injection device injected to the DOC in the two branches based on the relation between the third temperature and the fourth temperature specifically includes the following cases:

In the above-mentioned control HC injection device to the DOC oil injection in two branches, can utilize a butterfly valve to control HC injection device to the quantity of fuel injection of DOC injection in two branches; the two butterfly valves can also be used for respectively controlling the fuel injection quantity of the HC injection device injected to the DOC in each branch.

When the injection amount of the HC injection device to the DOC injection in the two branches is controlled by one butterfly valve, as shown in fig. 7, a third temperature T is obtained ₅₁ And a fourth temperature T ₅₂ Calculate the third temperature T ₅₁ And a fourth temperature T ₅₂ And determining the butterfly valve opening corresponding to the deviation based on the CUR, wherein the CUR comprises the corresponding relation between each deviation and each butterfly valve opening. Based on the determined butterfly valve opening and the determined butterfly valve opening boundary, the opening of the butterfly valve is adjusted, so that the adjustment of the injection quantity of the HC injection device injected to the DOC in each branch is realized. The present disclosure utilizes the relationship between the third temperature and the fourth temperature to continuously adjust the opening of the butterfly valve, thereby stabilizing the regeneration temperature in the DPF regeneration process.

When the first butterfly valve is used for controlling the fuel injection quantity of the HC injection device injected to the DOC in the first branch circuit and the second butterfly valve is used for controlling the fuel injection quantity of the HC injection device injected to the DOC in the second branch circuit, the fuel injection quantity of the HC injection device injected to the DOC in the two branch circuits is controlled based on the relation between the third temperature and the fourth temperature, and the method specifically comprises the following steps:

if the third temperature is higher than the fourth temperature, reducing the opening of a first butterfly valve, so as to reduce the injection quantity of the HC injection device injected to the DOC in the first branch, and increasing the opening of a second butterfly valve, so as to increase the injection quantity of the HC injection device injected to the DOC in the second branch;

If the third temperature is smaller than the fourth temperature, increasing the opening of a first butterfly valve, so as to increase the fuel injection quantity of the HC injection device injected to the DOC in the first branch, and reducing the opening of a second butterfly valve, so as to reduce the fuel injection quantity of the HC injection device injected to the DOC in the second branch;

and if the third temperature is equal to the fourth temperature, the opening degrees of the first butterfly valve and the second butterfly valve are kept unchanged, so that the fuel injection quantity of the HC injection device injected to the DOC in each branch is kept unchanged.

In order to further explain the technical ideas of the present disclosure, the technical scheme of the present disclosure will be described with reference to specific application scenarios.

Fig. 8 is a layout diagram of an engine aftertreatment system according to an embodiment of the disclosure, as shown in fig. 8, exhaust gas after TC (turbo Charger) is discharged after passing through an HC injection device 802, a two-way doc+dpf, a mixer, a urea injection device 809, a two-way SCR (Selective Catalytic Reduction ) +asc (Ammonia Slip Catalyst, ammonia oxidation catalyst). A temperature sensor 805 is provided upstream of the first DPF, a temperature sensor 806 is provided upstream of the second DPF, a differential pressure sensor 807 is provided in the first DPF, and a differential pressure sensor 808 is provided in the second DPF. In addition, NO is provided on the exhaust pipe upstream of the DOC _X A (nitrogen oxide) sensor 801, a temperature sensor 803, a butterfly valve 804 provided in the exhaust pipe upstream of the DOC, a temperature sensor 810 provided in the exhaust pipe upstream of the scr, and NO provided in the exhaust pipe downstream of the ASC _X Sensor 811, temperature sensor 812, and PM (Particulate Matter ) sensor 813.

The aftertreatment system disclosed by the disclosure is added with one DOC+DPF on the basis of the prior art, namely, two DOCs+DPF are arranged in parallel, so that the exhaust back pressure of an engine is reduced, the thermal efficiency of the engine is improved, the oil consumption is saved, and the use cost is reduced.

Based on the aftertreatment system in fig. 8, the specific procedure of the engine oil injection quantity control method is as follows:

when two DPFs need to be regenerated, the temperature T of the first branch, measured by the temperature sensor 805, is acquired ₅₁ And the temperature T of the second branch measured by the temperature sensor 806 ₅₂ The method comprises the steps of carrying out a first treatment on the surface of the Second temperature T measured based on temperature sensor 803 ₁ Determining the second fuel injection quantity A by the heat value of unit fuel combustion and the mass flow of waste gas ₁ 。

Based on the first correspondence, a second temperature T measured by the temperature sensor 803 is determined ₁ Set DPF upstream temperature T corresponding to exhaust gas mass flow ₂ The method comprises the steps of carrying out a first treatment on the surface of the For the first branch, the DPF upstream temperature T is set ₂ With temperature T ₅₁ Subtracting to obtain corresponding deviation, and inputting the deviationThe PI controller obtains a first oil injection quantity B of a first branch output by the PI controller ₁ The method comprises the steps of carrying out a first treatment on the surface of the Calculating a first fuel injection quantity B ₁ And a second fuel injection quantity A ₁ Sum value C of (C) ₁ Will sum to C ₁ And the minimum value between the injection boundary value D is used as the required injection quantity q of the branch ₁ The method comprises the steps of carrying out a first treatment on the surface of the Based on the required fuel injection quantity q of the first branch ₁ The opening degree of the butterfly valve 804 is adjusted to control the HC injection device 802 to inject fuel into the first DOC in the first branch.

For the second branch, the DPF upstream temperature T is set ₂ With temperature T ₅₂ Subtracting to obtain corresponding deviation, inputting the deviation into the PI controller to obtain a first oil injection quantity B of a second branch output by the PI controller ₂ The method comprises the steps of carrying out a first treatment on the surface of the Calculating a first fuel injection quantity B ₂ And a second fuel injection quantity A ₂ Sum value C of (C) ₂ Will sum to C ₂ And the minimum value between the injection boundary value D is used as the required injection quantity q of the branch ₂ The method comprises the steps of carrying out a first treatment on the surface of the Based on the amount q of fuel injection required by the second branch ₂ The opening degree of the butterfly valve 804 is adjusted to control the HC injection device 802 to inject fuel to the second DOC in the second branch.

In the process of injecting fuel into each branch by the HC injection device 802, the temperature T of the first branch measured by the temperature sensor 805 is obtained in real time ₅₁ And the temperature T of the second branch measured by the temperature sensor 806 ₅₂ The method comprises the steps of carrying out a first treatment on the surface of the If the temperature T ₅₁ Greater than temperature T ₅₂ The opening degree of the butterfly valve 804 is adjusted to reduce the injection quantity of the first DOC in the first branch road injected by the HC injection device 802 and increase the injection quantity of the second DOC in the second branch road injected by the HC injection device 802; if the temperature T ₅₁ Less than temperature T ₅₂ The opening degree of the butterfly valve 804 is adjusted to increase the fuel injection quantity of the HC injection device 802 injected to the first DOC in the first branch passage and reduce the fuel injection quantity of the HC injection device 802 injected to the second DOC in the second branch passage; if the temperature T ₅₁ Equal to temperature T ₅₂ The current opening degree of the butterfly valve 804 is kept unchanged, that is, the injection quantity of the HC injection device 802 injected to the DOC in each branch is kept unchanged.

In some embodiments, based on the same inventive concept, the embodiments of the present disclosure further provide a control device for an engine fuel injection amount, and since the device is a device in the method in the embodiments of the present disclosure and the principle of the device for solving the problem is similar to that of the method, the implementation of the device may refer to the implementation of the method, and the repetition is omitted.

As shown in fig. 9, the above device includes the following modules:

the acquisition module 901 is used for detecting that the DPF needs to be regenerated and respectively acquiring first temperatures measured by sensors positioned at the upstream of the DPF of each branch in the aftertreatment system, wherein the aftertreatment system comprises a plurality of branches, and each branch comprises a DOC, a sensor and the DPF;

A first determining module 902, configured to perform closed-loop control on the regeneration temperature according to the set DPF upstream temperature and the first temperature of the branch for each branch, and determine a first fuel injection amount of the branch according to a closed-loop control result; the set DPF upstream temperature is determined according to a second temperature, exhaust gas mass flow and a first corresponding relation measured by a sensor on an exhaust pipe upstream of a DOC in the aftertreatment system, wherein the first corresponding relation is a corresponding relation among the second temperatures, the exhaust gas mass flow and the DPF upstream temperature;

a second determining module 903, configured to determine an injection amount required by the branch according to a first injection amount, a second injection amount, and an injection boundary value of the branch, where the second injection amount is determined based on the second temperature, a heating value of unit fuel combustion, and the exhaust gas mass flow;

the control module 904 is configured to control the HC injection device to inject fuel to the DOC in each branch based on the fuel injection amount required by each branch.

As an alternative embodiment, the first determining module 902 is configured to:

As an alternative embodiment, the first determining module 904 is configured to:

As an alternative embodiment, the second determining module 903 is configured to:

As an alternative embodiment, the control module 904 is configured to:

In some embodiments, based on the same inventive concept, there is further provided in the embodiments of the present disclosure an engine oil injection amount control apparatus, which may implement the engine oil injection amount control function discussed above, referring to fig. 10, the apparatus includes a processor 101 and a memory 102, where the memory 102 is configured to store program instructions;

the processor 101 invokes the program instructions stored in the memory by running the program instructions to implement:

As an alternative embodiment, the determining the second fuel injection amount based on the second temperature, the heating value of unit fuel combustion, and the exhaust gas mass flow rate includes:

As an alternative embodiment, said determining a heat value required for regeneration based on said second temperature, a heat capacity of the exhaust gas and said exhaust gas mass flow comprises:

As an alternative embodiment, the determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion, and the HC conversion efficiency includes:

As an optional implementation manner, the determining the fuel injection quantity required by the branch according to the first fuel injection quantity, the second fuel injection quantity and the fuel injection boundary value of the branch includes:

As an optional implementation manner, the controlling the HC injection device to inject oil to the DOC in each branch circuit includes:

As an optional implementation manner, the controlling the injection quantity of the HC injection device injected to the DOC in the two branches based on the relation between the third temperature and the fourth temperature includes:

In some possible implementations, aspects of the present disclosure may also be implemented in the form of a program product, as shown in fig. 11, the computer program product 110 comprising computer program code which, when run on a computer, causes the computer to perform a method of controlling an engine oil injection amount as any of the foregoing discussion. Since the principle of the solution of the problem of the computer program product is similar to that of the control method of the fuel injection quantity of the engine, the implementation of the computer program product can be referred to the implementation of the method, and the repetition is omitted.

It will be apparent to those skilled in the art that embodiments of the present disclosure may be provided as a method, system, or computer program product. Accordingly, the present disclosure may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present disclosure may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, magnetic disk storage, optical storage, and the like) having computer-usable program code embodied therein.

The present disclosure is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A method for controlling an amount of fuel injected into an engine, the method comprising:

detecting that a Diesel Particulate Filter (DPF) needs to be regenerated, and respectively acquiring first temperatures measured by a sensor positioned at the upstream of DPFs of each branch in an aftertreatment system, wherein the aftertreatment system comprises a plurality of branches, and each branch comprises a Diesel Oxidation Catalyst (DOC), a sensor and the DPFs;

And controlling the hydrocarbon HC injection device to inject fuel to the DOC in each branch based on the fuel injection quantity required by each branch.

2. The method of claim 1, wherein the determining a second fuel injection amount based on the second temperature, a heating value of unit fuel combustion, and the exhaust gas mass flow rate comprises:

3. The method of claim 2, wherein the determining a heat value required for regeneration based on the second temperature, a heat capacity of the exhaust gas, and the exhaust gas mass flow rate comprises:

4. The method according to claim 2, wherein the determining the second fuel injection amount based on the heat value, the heat value of unit fuel combustion, and the HC conversion efficiency includes:

5. The method of claim 1, wherein the determining the amount of fuel injected required by the branch based on the first amount of fuel injected, the second amount of fuel injected, and the fuel injection boundary value for the branch comprises:

6. The method according to any one of claims 1 to 5, wherein controlling the HC injection device to inject fuel to the DOC in each branch includes:

7. The method according to claim 6, wherein the controlling the injection amount of the HC injection device to the DOC in the two branches based on the relation between the third temperature and the fourth temperature includes:

8. A control device for an engine fuel injection amount, characterized by comprising:

the acquisition module is used for detecting that the DPF needs to be regenerated, and respectively acquiring first temperatures measured by the sensors positioned at the upstream of the DPFs of each branch in the aftertreatment system, wherein the aftertreatment system comprises a plurality of branches, and each branch comprises an oxidation catalyst DOC, a sensor and the DPF;

And the control module is used for controlling the hydrocarbon HC injection device to inject fuel to the DOC in each branch circuit based on the fuel injection quantity required by each branch circuit.

9. A control apparatus for an engine fuel injection amount, characterized by comprising: a processor; a memory for storing processor-executable instructions; wherein the processor implements the steps of the method of any one of claims 1 to 7 by executing the executable instructions.

10. A computer readable and writable storage medium, on which computer instructions are stored which when executed by a processor implement the steps of the method of any one of claims 1 to 7.