CN114810392B - Method and related device for determining fuel gas demand of engine - Google Patents
Method and related device for determining fuel gas demand of engine Download PDFInfo
- Publication number
- CN114810392B CN114810392B CN202210499943.8A CN202210499943A CN114810392B CN 114810392 B CN114810392 B CN 114810392B CN 202210499943 A CN202210499943 A CN 202210499943A CN 114810392 B CN114810392 B CN 114810392B
- Authority
- CN
- China
- Prior art keywords
- excess air
- set value
- closed
- nitrogen oxide
- engine
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/0025—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
- F02D41/0027—Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures the fuel being gaseous
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1438—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor
- F02D41/1444—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases
- F02D41/146—Introducing closed-loop corrections using means for determining characteristics of the combustion gases; Sensors therefor characterised by the characteristics of the combustion gases the characteristics being an NOx content or concentration
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/14—Introducing closed-loop corrections
- F02D41/1401—Introducing closed-loop corrections characterised by the control or regulation method
- F02D2041/1409—Introducing closed-loop corrections characterised by the control or regulation method using at least a proportional, integral or derivative controller
Abstract
The application discloses a method and a related device for determining the gas demand of an engine, which are used for acquiring a nitrogen oxide measured value and a nitrogen oxide set value of a lean-burn gas engine; obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide; acquiring an excess air coefficient measured value and an excess air coefficient set value; correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value; obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value; and determining the fuel gas demand according to the second closed loop factor. Therefore, the phenomenon of large difference value of the second closed loop factors obtained through two closed loop PID control can not occur, so that the gas demand quantity is ensured to meet the actual demand of the lean-burn gas engine, and the stability of the lean-burn gas engine is ensured.
Description
Technical Field
The invention relates to the technical field of engines, in particular to a method for determining the fuel gas demand of an engine and a related device.
Background
The engine can continuously adjust the fuel gas demand, so that the fuel and air entering the engine can be fully combusted, and the combustion stability of the engine is ensured.
In the related art, a measured value of Nitrogen Oxide (NOX) is generally obtained through a sensor, and a gas demand is determined according to a difference between the measured value of NOX and a set value. However, this approach can only guarantee the stability of the engine to a certain extent.
Disclosure of Invention
In view of the above, the present application provides a method and related device for determining the fuel gas demand of an engine, which are used for improving the stability of the engine.
Based on this, the embodiment of the application discloses the following technical scheme:
in one aspect, an embodiment of the present application provides a method for determining a fuel gas demand of an engine, the method including:
acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine; the target engine is a lean-burn gas engine;
obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide;
acquiring an excess air coefficient measured value and an excess air coefficient set value;
correcting the excess air factor set value according to the first closed loop factor to obtain a corrected excess air factor set value;
obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value;
and determining the fuel gas demand according to the second closed-loop factor.
Optionally, the obtaining, by a second pid controller, a second closed loop factor according to the corrected excess air ratio set point and the excess air ratio measured value includes:
determining an excess air ratio difference value according to the corrected excess air ratio set value and the excess air ratio measured value;
and inputting the excess air coefficient difference value into the second proportional-differential integral controller, and obtaining a second closed-loop factor by adjusting the proportional-differential integral parameter of the second proportional-differential integral controller to meet the excess air coefficient preset condition.
Optionally, the method further comprises:
acquiring the rotation speed of the target engine and the air inlet pressure of the downstream of a throttle valve of the target engine;
and if the rotating speed meets the rotating speed condition and the air inlet pressure meets the pressure condition, acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at the target engine.
Optionally, the method further comprises:
and if the excess air ratio measured value is greater than or equal to 1.2, executing the step of correcting the excess air ratio set value according to the first closed loop factor to obtain a corrected excess air ratio set value.
In another aspect, the present application provides a method for determining a fuel gas demand of an engine, the method comprising:
acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine;
determining a nitrogen oxide difference value according to the nitrogen oxide measured value and the nitrogen oxide set value;
obtaining a first closed-loop factor according to the ratio of the nitrogen oxide difference value to the nitrogen oxide set value;
and determining the fuel gas demand according to the first closed-loop factor.
In another aspect the present application provides an apparatus for determining the fuel gas demand of an engine, the apparatus comprising: the device comprises an acquisition unit, a closed-loop control unit, a correction unit and a determination unit;
the acquisition unit is used for acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine; the target engine is a lean-burn gas engine;
the closed-loop control unit is used for obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide;
the acquisition unit is also used for acquiring an excess air coefficient measured value and an excess air coefficient set value;
the correction unit is used for correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value;
the closed-loop control unit is further used for obtaining a second closed-loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value;
the determining unit is used for determining the gas demand according to the second closed-loop factor.
In another aspect the present application provides an apparatus for determining the fuel gas demand of an engine, the apparatus comprising: the device comprises an acquisition unit, a calculation unit, a closed-loop control unit and a determination unit;
the acquisition unit is used for acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine;
the calculating unit is used for determining a nitrogen oxide difference value according to the nitrogen oxide measured value and the nitrogen oxide set value;
the closed-loop control unit is used for obtaining a first closed-loop factor according to the ratio of the nitrogen oxide difference value to the nitrogen oxide set value;
the determining unit is used for determining the gas demand according to the first closed-loop factor.
In another aspect, the present application provides a computer device comprising a processor and a memory:
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is configured to perform the method of the above aspect according to instructions in the program code.
In another aspect the present application provides a computer readable storage medium for storing a computer program for performing the method of the above aspect.
In another aspect, embodiments of the present application provide a computer program product or computer program comprising computer instructions stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device performs the method described in the above aspect.
The technical scheme has the advantages that:
for a lean-burn gas engine, acquiring a nitrogen oxide measurement value and a nitrogen oxide set value thereof; obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide; acquiring an excess air coefficient measured value and an excess air coefficient set value; correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value; obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient test value; and determining the fuel gas demand according to the second closed loop factor. Therefore, according to the characteristic that the measured value of the nitrogen oxide is reduced as the excess air coefficient of the lean-burn gas transmitter is increased, the excess air coefficient set value is corrected through the first closed-loop factor, and then the second closed-loop factor is obtained through the proportional-differential integral controller again, so that the second closed-loop factor obtained through two closed-loop PID control cannot have the phenomenon of large difference, the gas demand is ensured to meet the actual demand of the lean-burn gas engine, and the stability of the lean-burn gas engine is ensured.
Drawings
In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a flow chart of a method for determining fuel gas demand of an engine according to an embodiment of the present application;
FIG. 2 is a schematic diagram of the relationship between excess air ratio and NOx according to the embodiment of the present application;
FIG. 3 is a flow chart of yet another method for determining engine gas demand provided by an embodiment of the present application;
FIG. 4 is a flow chart of another method for determining fuel gas demand of an engine according to an embodiment of the present application;
FIG. 5 is a schematic diagram of an engine fuel gas demand determining apparatus according to an embodiment of the present disclosure;
FIG. 6 is a schematic diagram of yet another engine fuel gas demand determination apparatus provided in an embodiment of the present application;
fig. 7 is a block diagram of a computer device according to an embodiment of the present application.
Detailed Description
In order to make the present application solution better understood by those skilled in the art, the following description will clearly and completely describe the technical solution in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
According to research analysis, as the measured value of NOX and the preset unit of NOX value are parts per million (parts per million, ppm), in the process of determining the gas demand according to the difference value of the NOX measured value, the difference value only remains the value, and no unit is reserved, so that when the value of the difference value is larger, the determined gas demand is larger, the change of the gas demand is larger, and unstable phenomena such as ignition failure of an engine point easily occur. In addition, since NOX value changes are a slow process, rapid adjustments in fuel demand over large periods can also lead to engine instability.
Based on this, the embodiment of the application provides a method for determining the fuel gas demand of an engine, which aims at a lean-burn gas engine, and obtains a nitrogen oxide measurement value and a nitrogen oxide set value of the lean-burn gas engine; obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide; acquiring an excess air coefficient measured value and an excess air coefficient set value; correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value; obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value; and determining the fuel gas demand according to the second closed loop factor. Therefore, according to the characteristic that the measured value of the nitrogen oxide is reduced as the excess air coefficient of the lean-burn gas transmitter is increased, the excess air coefficient set value is corrected through the first closed-loop factor, and then the second closed-loop factor is obtained through the proportional-differential integral controller again, so that the second closed-loop factor obtained through two closed-loop PID control cannot have the phenomenon of large difference, the gas demand is ensured to meet the actual demand of the lean-burn gas engine, and the stability of the lean-burn gas engine is ensured.
A method for determining a fuel gas demand of an engine according to an embodiment of the present application will be described with reference to fig. 1. Referring to fig. 1, a flowchart of a method for determining a fuel gas demand of an engine according to an embodiment of the present application may include S101-S106.
S101: a nox measurement and a nox setpoint for a target engine are obtained.
The target engine is a lean-burn gas engine. In contrast to lean combustion, which is an amount of air required for the engine to burn just the fuel into the cylinder, lean combustion is an amount of air into the cylinder that is much larger than the amount of air theoretically combusting the fuel into the cylinder, and the actual amount of air is excessive.
Due to the characteristics of the lean-burn gas engine, the related art determines the gas demand by the difference between the measured value and the set value of NOX. However, this approach does not guarantee the stability of the lean-burn gas engine. Based on the above, the technical scheme of the application is provided.
The NOx measured value is an actual value of NOx obtained through a sensor, and the NOx set value is determined in advance according to the actual working condition of a target engine, such as the required torque, the required rotating speed and the like of the engine.
S102: and obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide.
As one possible implementation, a difference between the NOX measurement value and the NOX setting value, or a ratio obtained by dividing the difference by the NOX setting value, is determined, and the ratio is input to a Proportional-Integral-Derivative (PID) controller, and by adjusting the PID parameter, the NOX measurement value and the NOX setting value of the engine are converged to obtain a first closed-loop factor.
S103: and acquiring an excess air ratio measured value and an excess air ratio set value.
Wherein the ratio of the mass flow of fresh air actually entering the cylinder to participate in combustion to the mass flow of air theoretically required to combust the fuel entering the cylinder is also known as lambda. The air excess coefficient measured value is an actual value of the air excess coefficient obtained by a sensor, and the air excess coefficient set value is determined in advance according to the actual working condition of the target engine, such as the required torque, the required rotating speed and the like of the engine.
The embodiment of the present application does not specifically limit the precedence relationship between S103 and S101, and those skilled in the art may set the precedence relationship according to actual needs.
S104: and correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value.
Referring to fig. 2, a schematic diagram of an association relationship between an excess air ratio and NOX is provided in an embodiment of the present application. As can be seen from fig. 2, NOX decreases as the excess air ratio increases when the excess air ratio is greater than 1.1. When the excess air ratio is greater than 1.1, the characteristics of the lean-burn gas engine are met, or the lean-burn gas engine is in a linear relationship region where the excess air ratio increases and the NOX decreases, so the set value of the excess air ratio can be corrected by the first closed-loop factor.
As one possible implementation, the corrected excess air ratio setpoint may be obtained by adding the first closed loop factor to the excess air ratio setpoint.
S105: and obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value.
Therefore, compared with the method for directly determining the fuel gas demand by directly utilizing the first closed-loop factor, the method has the advantages that the first closed-loop factor is obtained according to the NOX measured value and the set value, and because the NOX and the fuel gas demand have no direct linear relation, the fuel gas demand obtained through the first closed-loop factor is not very accurate, and the output factor fluctuation is large when the engine runs under all working conditions because the deviation between the NOX measured value and the NOX set value is too large, so that the correction of the feedforward fuel gas demand is too large or too small, and the engine problem is caused. Based on this, since the excess air ratio has a linear relation with NOX emission (particularly when the excess air ratio is greater than 1.2), the stability of NOX closed-loop can be improved better by correcting the excess air ratio set point to obtain the second closed-loop factor.
The NOx closed loop is that a NOx measured value measured by a NOx sensor and a NOx set value are subjected to PID closed loop, a closed loop factor (a first closed loop factor) is output, and then the feedforward calculated gas demand is corrected after being processed, so that the gas combustion condition in the cylinder can be directly influenced due to the quantity of the gas demand entering the cylinder, and further NOx emission is influenced. The NOX closed loop factor either indirectly or directly modifies the feed-forward calculated gas demand to change the lambda value in the cylinder and vary NOX emissions.
As a possible implementation manner, a difference value between the corrected excess air coefficient set value and the excess air coefficient measured value may be determined, so as to obtain an excess air coefficient difference value, and then the excess air coefficient difference value is input into a second PID controller, and the second closed loop factor is obtained by adjusting the PID parameter of the second PID controller to meet the excess air coefficient preset condition.
The preset conditions of the excess air ratio may be set according to actual needs of those skilled in the art, for example, the output closed loop factor may be used to adjust the feed-forward gas demand, so that the excess air ratio measurement value converges on the corrected excess air ratio set value, i.e. the excess air ratio difference is as small as possible.
S106: and determining the fuel gas demand according to the second closed loop factor.
Firstly, according to working conditions, such as data of required torque, required rotating speed, excessive air coefficient set value, stoichiometric air-fuel ratio and the like of an engine, the feedforward required fuel gas quantity can be calculated, but due to errors of components such as engine air control, fuel gas control and the like, the feedforward required fuel gas quantity cannot accurately enter a cylinder to burn, and the excessive air coefficient measured value in the combusted exhaust gas is consistent with the excessive air coefficient set value, or the NOx measured value and the NOx set value have certain deviation, so that a NOx closed loop is needed, and the excessive air coefficient closed loop is corrected on the basis of the feedforward fuel gas required quantity.
According to the technical scheme, for the lean-burn gas engine, the nitrogen oxide measured value and the nitrogen oxide set value are obtained; obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide; acquiring an excess air coefficient measured value and an excess air coefficient set value; correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value; obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value; and determining the fuel gas demand according to the second closed loop factor. Therefore, according to the characteristic that the measured value of the nitrogen oxide is reduced as the excess air coefficient of the lean-burn gas transmitter is increased, the excess air coefficient set value is corrected through the first closed-loop factor, and then the second closed-loop factor is obtained through the proportional-differential integral controller again, so that the second closed-loop factor obtained through two closed-loop PID control cannot have the phenomenon of large difference, the gas demand is ensured to meet the actual demand of the lean-burn gas engine, and the stability of the lean-burn gas engine is ensured.
In order to make the technical solution provided by the embodiments of the present application clearer, a method for determining the fuel gas demand of the engine provided by the embodiments of the present application will be described with reference to fig. 3 by way of an example.
S301: the rotation speed of the target engine and the intake air pressure downstream of the throttle valve of the target engine are acquired. The execution subject of the embodiments of the present application may be an electronic controller unit (Electronic Control Unit, ECU) of a vehicle. The ECU detects a fluctuation in the rotational speed of the engine, an exhaust temperature of the engine, and the like.
S302: and if the rotating speed meets the rotating speed condition and the air inlet pressure meets the pressure condition, acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at the target engine.
The pressure condition and the rotating speed condition are used for judging whether the current target engine is in a normal state or not, such as in an engine exhaust temperature normal range, no sensor self-diagnosis fault exists, and no actuator self-diagnosis fault exists. If the engine is in a normal state, the subsequent judgment is significant. For example. If the exhaust temperature is too low, the engine may be in a misfire condition, or the engine misfire may be determined based on the misfire detection of the rotational speed fluctuation, at which time none of the target engines is in a normal state.
It should be noted that the pressure condition and the rotation speed condition may be set by those skilled in the art according to the target engine, and the present application is not particularly limited.
As a possible implementation manner, the target engine is in a normal state and needs to be in a steady-state working condition. The steady-state working condition is that the rotation speed of the engine fluctuates within a certain range, and the pressure measured by an air inlet pressure sensor at the downstream of a throttle valve of the engine is within a certain range. It will be appreciated that the steady state condition in the embodiments of the present application is a quasi-steady state, not an absolute steady state.
S303: and obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide.
S304: and acquiring an excess air ratio measured value and an excess air ratio set value.
S305: and if the excess air coefficient measured value is greater than or equal to 1.2, correcting the excess air coefficient set value according to the first closed loop factor to obtain a corrected excess air coefficient set value.
Note that, since the kind of lean-burn gas engine is high, the peak in fig. 2 is slightly different for different kinds of lean-burn gas engines, and when the excess air ratio measurement value is 1.2 or more, the probability that the excess air ratio and NOX are in the linear region is higher.
S306: and determining an excess air ratio difference value according to the corrected excess air ratio set value and the excess air ratio measured value.
S307: and inputting the excess air coefficient difference value into a second proportional-differential integral controller, and obtaining a second closed-loop factor by adjusting the proportional-differential integral parameter of the second proportional-differential integral controller to meet the excess air coefficient preset condition.
S308: and determining the fuel gas demand according to the second closed loop factor.
The relevant points can be seen in the foregoing S101-S106, and will not be described here again.
The embodiment of the application also provides a method for determining the fuel gas demand of the engine, and the method is described below with reference to fig. 4.
S401: a nox measurement and a nox setpoint for a target engine are obtained.
S402: and determining a nitrogen oxide difference value according to the nitrogen oxide measured value and the nitrogen oxide set value.
S403: and obtaining a first closed-loop factor according to the ratio of the nitrogen oxide difference value to the nitrogen oxide set value.
Thus, by dividing the difference by the nox setting value, the problem of larger values caused by the fact that the subsequent calculation is not performed in units in the related art can be reduced. Thereby guaranteeing that the gas demand accords with the actual demand of engine, guarantees the stability of engine.
S404: the fuel gas demand is determined based on the first closed loop factor.
In addition to the method for determining the fuel gas demand of the engine, the embodiment of the application also provides a device for determining the fuel gas demand of the engine, as shown in fig. 5, wherein the device comprises: an acquisition unit 501, a closed-loop control unit 502, a correction unit 503, and a determination unit 504;
the acquiring unit 501 is configured to acquire a measured value of nitrogen oxide and a set value of nitrogen oxide for a target engine; the target engine is a lean-burn gas engine;
the closed-loop control unit 502 is configured to obtain a first closed-loop factor through a first proportional-differential integral controller according to a difference between the measured value of the nitrogen oxide and the set value of the nitrogen oxide;
the acquiring unit 501 is further configured to acquire an excess air ratio measurement value and an excess air ratio set value;
the correction unit 503 is configured to correct the excess air factor set value according to the first closed loop factor, so as to obtain a corrected excess air factor set value;
the closed-loop control unit 502 is further configured to obtain a second closed-loop factor through a second pid controller according to the corrected excess air ratio set point and the excess air ratio measured value;
the determining unit 504 is configured to determine a fuel gas demand according to the second closed loop factor.
As a possible implementation manner, the closed-loop control unit 502 is configured to:
determining an excess air ratio difference value according to the corrected excess air ratio set value and the excess air ratio measured value;
and inputting the excess air coefficient difference value into the second proportional-differential integral controller, and obtaining a second closed-loop factor by adjusting the proportional-differential integral parameter of the second proportional-differential integral controller to meet the excess air coefficient preset condition.
As a possible implementation manner, the obtaining unit 501 is further configured to obtain a rotation speed of the target engine and an intake air pressure downstream of a throttle valve of the target engine;
the device further comprises a judging unit, wherein the judging unit is used for acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine if the rotating speed meets the rotating speed condition and the air inlet pressure meets the pressure condition.
As a possible implementation manner, the device further includes a judging unit, configured to execute the step of correcting the excess air ratio setting value according to the first closed-loop factor to obtain a corrected excess air ratio setting value if the excess air ratio measurement value is greater than or equal to 1.2.
According to the technical scheme, for the lean-burn gas engine, the nitrogen oxide measured value and the nitrogen oxide set value are obtained; obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide; acquiring an excess air coefficient measured value and an excess air coefficient set value; correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value; obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient set value; and determining the fuel gas demand according to the second closed loop factor. Therefore, according to the characteristic that the measured value of the nitrogen oxide is reduced as the excess air coefficient of the lean-burn gas transmitter is increased, the excess air coefficient set value is corrected through the first closed-loop factor, and then the second closed-loop factor is obtained through the proportional-differential integral controller again, so that the second closed-loop factor obtained through two closed-loop PID control cannot have the phenomenon of large difference, the gas demand is ensured to meet the actual demand of the lean-burn gas engine, and the stability of the lean-burn gas engine is ensured.
In addition to the method for determining the fuel gas demand of the engine, the embodiment of the application also provides a device for determining the fuel gas demand of the engine, as shown in fig. 6, wherein the device comprises: an acquisition unit 601, a calculation unit 602, a closed-loop control unit 603, and a determination unit 604;
the acquiring unit 601 is configured to acquire a measured value of nitrogen oxide and a set value of nitrogen oxide for a target engine;
the calculating unit 602 is configured to determine a nox difference value according to the nox measurement value and the nox setting value;
the closed-loop control unit 603 is configured to obtain a first closed-loop factor according to a ratio of the nox difference value to the nox set point;
the determining unit 604 is configured to determine a fuel gas demand according to the first closed loop factor.
Thus, by dividing the difference by the nox setting value, the problem of larger values caused by the fact that the subsequent calculation is not performed in units in the related art can be reduced. Thereby guaranteeing that the gas demand accords with the actual demand of engine, guarantees the stability of engine.
The embodiment of the present application further provides a computer device, referring to fig. 7, which shows a structural diagram of the computer device provided in the embodiment of the present application, as shown in fig. 7, where the device includes a processor 710 and a memory 720:
the memory 710 is used for storing program codes and transmitting the program codes to the processor;
the processor 720 is configured to execute any of the methods for determining engine gas demand provided in the above embodiments according to instructions in the program code.
An embodiment of the present application provides a computer readable storage medium for storing a computer program for executing any one of the methods for determining a fuel gas demand of an engine provided in the above embodiment.
Embodiments of the present application also provide a computer program product or computer program comprising computer instructions stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions so that the computer device performs the method of determining the engine gas demand provided in various alternative implementations of the above aspects.
It should be noted that, in the present description, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system or device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the relevant points refer to the description of the method section.
It should be understood that in this application, "at least one" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.
It is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software modules may be disposed in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (7)
1. A method of determining a fuel gas demand of an engine, the method comprising:
acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine; the target engine is a lean-burn gas engine;
obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide;
acquiring an excess air coefficient measured value and an excess air coefficient set value;
correcting the excess air factor set value according to the first closed loop factor to obtain a corrected excess air factor set value;
obtaining a second closed loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value;
and determining the fuel gas demand according to the second closed-loop factor.
2. The method of claim 1, wherein deriving a second closed loop factor from the corrected excess air ratio setpoint and the excess air ratio measurement by a second pid controller comprises:
determining an excess air ratio difference value according to the corrected excess air ratio set value and the excess air ratio measured value;
and inputting the excess air coefficient difference value into the second proportional-differential integral controller, and obtaining a second closed-loop factor by adjusting the proportional-differential integral parameter of the second proportional-differential integral controller to meet the excess air coefficient preset condition.
3. The method according to claim 1, wherein the method further comprises:
acquiring the rotation speed of the target engine and the air inlet pressure of the downstream of a throttle valve of the target engine;
and if the rotating speed meets the rotating speed condition and the air inlet pressure meets the pressure condition, acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at the target engine.
4. A method according to any one of claims 1-3, characterized in that the method further comprises:
and if the excess air ratio measured value is greater than or equal to 1.2, executing the step of correcting the excess air ratio set value according to the first closed loop factor to obtain a corrected excess air ratio set value.
5. An engine gas demand determining apparatus, comprising: the device comprises an acquisition unit, a closed-loop control unit, a correction unit and a determination unit;
the acquisition unit is used for acquiring a nitrogen oxide measured value and a nitrogen oxide set value aiming at a target engine; the target engine is a lean-burn gas engine;
the closed-loop control unit is used for obtaining a first closed-loop factor through a first proportional-differential integral controller according to the difference value between the measured value of the nitrogen oxide and the set value of the nitrogen oxide;
the acquisition unit is also used for acquiring an excess air coefficient measured value and an excess air coefficient set value;
the correction unit is used for correcting the excess air coefficient set value according to the first closed-loop factor to obtain a corrected excess air coefficient set value;
the closed-loop control unit is further used for obtaining a second closed-loop factor through a second proportional-differential integral controller according to the corrected excess air coefficient set value and the excess air coefficient measured value;
the determining unit is used for determining the gas demand according to the second closed-loop factor.
6. A computer device, the device comprising a processor and a memory:
the memory is used for storing program codes and transmitting the program codes to the processor;
the processor is configured to perform the method of any of claims 1-4 according to instructions in the program code.
7. A computer readable storage medium, characterized in that the computer readable storage medium is adapted to store a computer program adapted to perform the method of any of claims 1-4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210499943.8A CN114810392B (en) | 2022-05-09 | 2022-05-09 | Method and related device for determining fuel gas demand of engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210499943.8A CN114810392B (en) | 2022-05-09 | 2022-05-09 | Method and related device for determining fuel gas demand of engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114810392A CN114810392A (en) | 2022-07-29 |
| CN114810392B true CN114810392B (en) | 2023-07-18 |
Family
ID=82512873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210499943.8A Active CN114810392B (en) | 2022-05-09 | 2022-05-09 | Method and related device for determining fuel gas demand of engine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114810392B (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6598584B2 (en) * | 2001-02-23 | 2003-07-29 | Clean Air Partners, Inc. | Gas-fueled, compression ignition engine with maximized pilot ignition intensity |
| WO2011048707A1 (en) * | 2009-10-23 | 2011-04-28 | トヨタ自動車株式会社 | Air/fuel ratio control device for internal-combustion engine |
| SE538381C2 (en) * | 2013-04-30 | 2016-06-07 | Scania Cv Ab | Fuel quality detection method and system |
| KR102474612B1 (en) * | 2018-05-03 | 2022-12-06 | 현대자동차주식회사 | Method of nitrogen oxide in engine reflecting travel distance |
| US10697340B1 (en) * | 2019-01-31 | 2020-06-30 | Hyundai Motor Company | After treatment system and after treatment method for lean-burn engine |
-
2022
- 2022-05-09 CN CN202210499943.8A patent/CN114810392B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN114810392A (en) | 2022-07-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4314573B2 (en) | Multi-cylinder internal combustion engine cylinder-by-cylinder air-fuel ratio calculation device | |
| US6742379B2 (en) | Intake air oxygen concentration sensor calibration device and method | |
| US7877192B2 (en) | Control for an internal-combustion engine | |
| JP4251081B2 (en) | Control device for internal combustion engine | |
| US7654252B2 (en) | Air-fuel ratio control system and method for internal combustion engine | |
| EP3467284A1 (en) | Control device and control method for internal combustion engine | |
| JP4364777B2 (en) | Air-fuel ratio control device for internal combustion engine | |
| US7742870B2 (en) | Air-fuel ratio control device of internal combustion engine | |
| US5605132A (en) | Control method and controller for engine | |
| US20130184973A1 (en) | Fuel injection amount control apparatus for an internal combustion engine | |
| JP5741499B2 (en) | Air-fuel ratio variation abnormality detection device | |
| CN107542589B (en) | Air-fuel ratio controller for internal combustion engine and method for controlling air-fuel ratio of internal combustion engine | |
| CN114810392B (en) | Method and related device for determining fuel gas demand of engine | |
| JP5796592B2 (en) | Cylinder air-fuel ratio variation abnormality detection device | |
| JP2927074B2 (en) | Air-fuel ratio control device for internal combustion engine | |
| JP5606425B2 (en) | Control device for internal combustion engine and degradation diagnosis method for catalytic converter | |
| CN113431690A (en) | Control method and device of engine management system | |
| JP3409877B2 (en) | Control method and control device for lean burn engine | |
| US8726637B2 (en) | Air-fuel ratio control system for internal combustion engine | |
| US6901920B2 (en) | Engine control apparatus having cylinder-by-cylinder feedback control | |
| JP2012077719A (en) | Control device of internal combustion engine | |
| JP4270112B2 (en) | Control device for internal combustion engine | |
| JPH07269407A (en) | Engine misfire detecting device | |
| JPS63201356A (en) | Exhaust gas recirculation control device for diesel engine | |
| JPH0432939B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |