阅读说明：本技术 一种燃气喷射控制方法、装置及车辆 (Gas injection control method and device and vehicle ) 是由 潘永传 韩雨 曲业源 于 2021-09-17 设计创作，主要内容包括：本发明属于车辆技术领域,公开了一种燃气喷射控制方法、装置及车辆。燃气喷射控制方法包括判断发动机是否处于预设工况；如果发动机处于预设工况,则根据混合器入口处燃气压力变化率和燃气管容积对燃气喷射量进行修正,根据修正后的燃气喷射量进行燃气喷射；预设工况为发动机的空气进气压力变化率大于第一预设值,且发动机的转速变化率大于第二预设值。通过根据混合器入口处燃气压力变化率和燃气管容积对燃气喷射量进行修正,使修正后的燃气喷射量能够随着燃气管容积以及混合器入口处燃气压力的变化而变化,保证对于不同的发动机燃气系统管路布置方式,以及不同的混合器入口处燃气压力变化率,均能够提供准确的燃气喷射量。(The invention belongs to the technical field of vehicles and discloses a fuel gas injection control method, a fuel gas injection control device and a vehicle. The fuel gas injection control method comprises the steps of judging whether an engine is in a preset working condition or not; if the engine is in a preset working condition, correcting the gas injection quantity according to the gas pressure change rate at the inlet of the mixer and the volume of the gas pipe, and performing gas injection according to the corrected gas injection quantity; the preset working condition is that the change rate of the air inlet pressure of the engine is larger than a first preset value, and the change rate of the rotating speed of the engine is larger than a second preset value. Through revising the gas injection volume according to blender entrance gas pressure rate of change and gas pipe volume, the gas injection volume after making the correction can change along with the change of gas pipe volume and blender entrance gas pressure, guarantees to the engine gas system pipeline arrangement mode of difference to and different blender entrance gas pressure rate of change, the homoenergetic provides accurate gas injection volume.)

1. A gas injection control method characterized by comprising:

judging whether the engine is in a preset working condition or not;

if the engine is in a preset working condition, correcting the gas injection quantity according to the gas pressure change rate at the inlet of the mixer and the volume of the gas pipe, and performing gas injection according to the corrected gas injection quantity;

the preset working condition is that the change rate of the air inlet pressure of the engine is larger than a first preset value, and the change rate of the rotating speed of the engine is larger than a second preset value.

2. The gas injection control method according to claim 1, wherein the correcting the gas injection amount includes:

determining a basic fuel gas injection quantity, wherein the basic fuel gas injection quantity is in positive correlation with air intake quantity;

determining a first compensation amount, the determining the first compensation amount comprising determining a first expected compensation amount, the first expected compensation amount positively correlated to both the rate of change of gas pressure at the mixer inlet and the gas pipe volume, the first compensation amount equal to the first expected compensation amount;

the corrected gas injection amount is the basic gas injection amount plus the first compensation amount.

3. The gas injection control method of claim 2, further comprising, after determining the first expected compensation amount: and determining a first correction coefficient according to the rotating speed and load conditions of the engine, and multiplying the first expected compensation amount by the first correction coefficient to obtain a second expected compensation amount, wherein the first compensation amount is equal to the second expected compensation amount.

4. The gas injection control method of claim 3, further comprising, after determining the second expected compensation amount: and comparing the second expected compensation amount with a preset highest compensation amount, wherein if the second expected compensation amount is not less than the preset highest compensation amount, the first compensation amount is equal to the preset highest compensation amount.

5. The gas injection control method of claim 3, further comprising, after determining the second expected compensation amount: comparing the second expected compensation amount with a preset minimum compensation amount, and if the second expected compensation amount is not greater than the preset minimum compensation amount, the first compensation amount is equal to the preset minimum compensation amount.

6. The gas injection control method according to any one of claims 2 to 5, wherein the correcting the gas injection amount further includes:

and judging whether the engine is in a gas interruption and gas supply recovery mode, if so, determining a second compensation amount after determining the first compensation amount, wherein the corrected gas injection amount is equal to the sum of the basic gas injection amount, the first compensation amount and the second compensation amount.

7. The gas injection control method according to claim 6, wherein the determining a second compensation amount includes: and determining a second correction coefficient according to the rotating speed and the load condition of the engine, and multiplying the second correction coefficient by the basic fuel gas injection quantity to obtain a second compensation quantity.

8. The gas injection control method according to claim 1, wherein the performing of gas injection according to the corrected gas injection amount includes calculating a corrected power-on time of a gas injection valve according to the corrected gas injection amount, and controlling the gas injection valve to perform gas injection for the corrected power-on time.

9. A gas injection control device characterized in that gas injection is performed using the gas injection control method according to any one of claims 1 to 8.

10. A vehicle characterized by performing gas injection using the gas injection control method according to any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of vehicles, in particular to a fuel gas injection control method, a fuel gas injection control device and a vehicle.

Background

The current natural gas engine generally adopts a single-point injection mode, and the gas quantity control is mainly based on the air intake quantity. The accuracy of the fuel gas control is directly related to the air-fuel ratio of the engine, and the abnormal control of the air-fuel ratio easily causes the conversion of a three-way catalyst in an engine post-processing system to reduce the efficiency and influences the emission control. Due to the influence of design differences of a gas system, a certain volume exists between the outlet of an actual gas injection valve and a mixer, and the gas injection calculated based on the air quantity in the transient control process of the engine has certain delay, so that the transient control of the engine is influenced. Therefore, when the vehicle is in a state of rapid acceleration or rapid deceleration, it is necessary to compensate for the gas injection amount to meet the need for a rapid change in the air intake amount.

However, in the existing gas injection control method, when the pipeline arrangement of a gas system of an engine is changed, abnormal noise may occur in the air-fuel ratio control of the engine when a vehicle is accelerated and decelerated suddenly, the dynamic performance and the economical efficiency of the engine are affected, and meanwhile, abnormal emission control of the engine may be caused.

Disclosure of Invention

The invention aims to provide a gas injection control method, a gas injection control device and a vehicle, which can ensure that accurate gas injection quantity can be provided for different engine gas system pipeline arrangement modes and different gas pressure change rates at inlets of mixers.

In order to achieve the purpose, the invention adopts the following technical scheme:

a gas injection control method comprising:

judging whether the engine is in a preset working condition or not;

if the engine is in a preset working condition, correcting the gas injection quantity according to the gas pressure change rate at the inlet of the mixer and the volume of the gas pipe, and performing gas injection according to the corrected gas injection quantity;

the preset working condition is that the change rate of the air inlet pressure of the engine is larger than a first preset value, and the change rate of the rotating speed of the engine is larger than a second preset value.

Preferably, the correcting the fuel injection amount includes:

determining a basic fuel gas injection quantity, wherein the basic fuel gas injection quantity is in positive correlation with air intake quantity;

determining a first compensation amount, the determining the first compensation amount comprising determining a first expected compensation amount, the first expected compensation amount positively correlated to both the rate of change of gas pressure at the mixer inlet and the gas pipe volume, the first compensation amount equal to the first expected compensation amount;

the corrected gas injection amount is the basic gas injection amount plus the first compensation amount.

Preferably, after determining the first expected compensation amount, the method further includes: and determining a first correction coefficient according to the rotating speed and load conditions of the engine, and multiplying the first expected compensation amount by the first correction coefficient to obtain a second expected compensation amount, wherein the first compensation amount is equal to the second expected compensation amount.

Preferably, after determining the second expected compensation amount, the method further includes: and comparing the second expected compensation amount with a preset highest compensation amount, wherein if the second expected compensation amount is not less than the preset highest compensation amount, the first compensation amount is equal to the preset highest compensation amount.

Preferably, after determining the second expected compensation amount, the method further includes: comparing the second expected compensation amount with a preset minimum compensation amount, and if the second expected compensation amount is not greater than the preset minimum compensation amount, the first compensation amount is equal to the preset minimum compensation amount.

Preferably, the correcting the fuel injection amount further includes:

and judging whether the engine is in a gas interruption and gas supply recovery mode, if so, determining a second compensation amount after determining the first compensation amount, wherein the corrected gas injection amount is equal to the sum of the basic gas injection amount, the first compensation amount and the second compensation amount.

Preferably, the determining the second compensation amount includes: and determining a second correction coefficient according to the rotating speed and the load condition of the engine, and multiplying the second correction coefficient by the basic fuel gas injection quantity to obtain a second compensation quantity.

Preferably, the performing of the gas injection according to the corrected gas injection amount includes calculating a power-on time of the gas injection valve after correction according to the corrected gas injection amount, and controlling the gas injection valve to perform the gas injection according to the corrected power-on time.

A gas injection control device for performing gas injection using any one of the gas injection control methods described above.

A vehicle that performs gas injection using the gas injection control method of any one of the above.

The invention has the beneficial effects that:

the invention provides a fuel gas injection control method, which comprises the steps of judging whether an engine is in a preset working condition or not; and if the engine is in a preset working condition, correcting the gas injection quantity according to the gas pressure change rate at the inlet of the mixer and the volume of the gas pipe, and performing gas injection according to the corrected gas injection quantity. The preset working condition is that the change rate of the air inlet pressure of the engine is larger than a first preset value, and the change rate of the rotating speed of the engine is larger than a second preset value. Through revising the gas injection volume according to blender entrance gas pressure rate of change and gas pipe volume, the gas injection volume after making the correction can change along with the change of gas pipe volume and blender entrance gas pressure, guarantees to the engine gas system pipeline arrangement mode of difference to and different blender entrance gas pressure rate of change, the homoenergetic provides accurate gas injection volume.

Drawings

Fig. 1 is a flowchart of a fuel gas injection control method according to an embodiment of the present invention;

FIG. 2 is a flow chart of a fuel gas injection control method according to a second embodiment of the present invention;

FIG. 3 is a flow chart of a fuel gas injection control method according to a third embodiment of the present invention;

fig. 4 is a flowchart of a gas injection control method according to a fourth embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "connected," "connected," and "fixed" are to be construed broadly, e.g., as meaning permanently connected, removably connected, or integral to one another; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description of the present embodiment, the terms "upper", "lower", "right", etc. are used in an orientation or positional relationship based on that shown in the drawings only for convenience of description and simplicity of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used only for descriptive purposes and are not intended to have a special meaning.

Example one

As shown in fig. 1, the present embodiment provides a gas injection control method, including: and judging whether the engine is in a preset working condition or not. Specifically, the preset working condition is that the air inlet pressure change rate of the engine is larger than a first preset value, and the rotating speed change rate of the engine is larger than a second preset value.

And if the engine is in a preset working condition, correcting the gas injection quantity according to the gas pressure change rate at the inlet of the mixer and the volume of the gas pipe, and performing gas injection according to the corrected gas injection quantity. The gas injection quantity after correction can be changed along with the change of the gas pipe volume and the gas pressure at the inlet of the mixer, and the accurate gas injection quantity can be provided for different engine gas system pipeline arrangement modes and different gas pressure change rates at the inlet of the mixer.

Alternatively, the specific step of correcting the fuel injection amount includes:

first, a basic gas injection quantity is determined, which is positively correlated with the engine intake air quantity, and specifically, the basic gas injection quantity is calculated according to the air intake air quantity, the excess air coefficient and the required air-fuel ratio. Specifically, the method comprises the following steps:

M_fuel＝M_air/Lambda

wherein M is_fuelBased on the amount of gas injected, M_airLambda is the required air-fuel ratio for the air intake amount.

Then, a first compensation amount is determined, which includes determining a first expected compensation amount that positively correlates to both the rate of change of gas pressure at the mixer inlet and the gas line volume. Specifically, the method comprises the following steps:

dn₁＝VdP_i/RT

wherein n is₁For the first desired compensation, dn₁In the form of a derivative of the first desired compensation quantity, P_iFor gas pressure at the mixer inlet, dP_iIs a mixerThe gas pressure change rate at the opening, V is the volume of the gas pipe, R is an ideal gas constant, and T is the gas temperature.

The first expected compensation amount can be calculated by integrating the above formula with time, and the specific calculation method is common knowledge in the art and will not be described herein again. The first compensation amount is equal to the first expected compensation amount. The corrected gas injection amount is equal to the basic gas injection amount plus the first compensation amount.

And finally, calculating the corrected power-on time of the gas injection valve according to the corrected gas injection quantity, and controlling the gas injection valve to inject the gas according to the corrected power-on time.

Example two

The present embodiment provides a gas injection control method, as shown in fig. 2, in the first embodiment, after determining the first expected compensation amount, the method further includes determining a first correction coefficient according to a table look-up table of engine speed and load conditions, and multiplying the first expected compensation amount by the first correction coefficient to obtain a second expected compensation amount, specifically:

dn₂＝a₁×VdP_i/RT

wherein n is₂For the second desired compensation, dn₂In the form of a derivative of the second desired compensation quantity, P_iFor gas pressure at the mixer inlet, dP_iIs the rate of change of gas pressure at the mixer inlet, a₁Is a first correction factor, V is the gas pipe volume, R is the ideal gas constant, and T is the gas temperature.

The second expected compensation amount can be calculated by integrating the above formula with time, and the specific calculation method is common knowledge in the art and will not be described herein again.

The first amount of compensation is equal to the second expected amount of compensation. Therefore, the first compensation amount changes along with the change of the rotating speed and the load condition of the engine, the corrected fuel gas injection amount is equal to the basic fuel gas injection amount plus the first compensation amount, and the corrected fuel gas injection amount can better meet the requirements of the engine under different rotating speed and load conditions.

And finally, calculating the corrected power-on time of the gas injection valve according to the corrected gas injection quantity, and controlling the gas injection valve to inject the gas according to the corrected power-on time.

EXAMPLE III

The present embodiment provides a gas injection control method, as shown in fig. 3, on the basis of the second embodiment, after determining the second expected compensation amount, the method further includes: comparing the second expected compensation amount with a preset highest compensation amount, and if the second expected compensation amount is not less than the preset highest compensation amount, the first compensation amount is equal to the preset highest compensation amount; and comparing the second expected compensation amount with a preset minimum compensation amount, and if the second expected compensation amount is not greater than the preset minimum compensation amount, the first compensation amount is equal to the preset minimum compensation amount. Therefore, the situation that the driving experience is influenced due to the fact that the fuel gas injection quantity is changed too fast when the vehicle is accelerated or decelerated suddenly is avoided. The first compensation amount is equal to the second expected compensation amount if the second expected compensation amount is between the preset highest compensation amount and the preset lowest compensation amount.

And finally, calculating the corrected power-on time of the gas injection valve according to the corrected gas injection quantity, and controlling the gas injection valve to inject the gas according to the corrected power-on time.

Example four

In the present embodiment, as shown in fig. 4, the method for controlling gas injection according to the third embodiment further includes: and judging whether the engine is in the gas supply interruption and recovery mode, and if the engine is in the gas supply interruption and recovery mode, determining the first compensation amount and then determining the second compensation amount. The specific step of determining the second compensation amount comprises: and determining a second correction coefficient according to the table look-up of the rotating speed and the load condition of the engine, and multiplying the second correction coefficient by the basic fuel gas injection quantity to obtain a second compensation quantity. Specifically, the method comprises the following steps:

n_3＝a₂×M_fuel

wherein n is₃Is a second compensation amount, a₂Is the second correction coefficient, M_fuelIs the basic gas injection quantity.

And taking the sum of the basic fuel gas injection quantity, the first compensation quantity and the second compensation quantity as the corrected fuel gas injection quantity. When the engine is switched from the gas-cut state to the gas supply state, the required fuel injection compensation amount is larger, and the influence on the power performance and emission control of the engine due to the fact that the air-fuel ratio is too lean for a long time after the engine is switched to the gas supply state is avoided by increasing the second compensation amount.

And finally, calculating the corrected power-on time of the gas injection valve according to the corrected gas injection quantity, and controlling the gas injection valve to inject the gas according to the corrected power-on time.

The embodiment also provides a fuel gas injection control device, which uses the fuel gas injection control method to inject fuel gas.

The embodiment also provides a vehicle which uses the fuel gas injection control method to perform fuel gas injection.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Numerous obvious variations, adaptations and substitutions will occur to those skilled in the art without departing from the scope of the invention. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.