阅读说明：本技术 一种燃气轨压调节方法及系统 (Gas rail pressure adjusting method and system ) 是由 李旭 苏东超 刘世通 赵晓 于 2020-07-08 设计创作，主要内容包括：本发明公开了一种燃气轨压调节方法及系统,确定获取到的车辆运行状态参数是否符合预设切换条件,若不符合,根据当前的工况使用预定义的燃油轨压设定值,使燃气调压模块根据当前采集到燃油共轨管上的燃油轨压值调节燃气轨压,若符合,计算燃气轨压需求值,并根据燃气轨压偏差和燃气轨压需求值,计算当前所需的燃油轨压设定值,使燃气调压模块根据当前采集到燃油共轨管上的燃油轨压值调节燃气轨压。通过上述方案,燃气调压模块根据当前采集到燃油共轨管上的燃油轨压值调节燃气轨压,由于当前所需的燃油轨压设定值大于或等于当前燃油轨压,从而稳定了轨压波动,避免出现燃气调压模块将燃气泄放到燃气供给系统的回气管路中造成燃气浪费的情况。(The invention discloses a fuel gas rail pressure adjusting method and a fuel gas rail pressure adjusting system, which are used for determining whether an acquired vehicle running state parameter meets a preset switching condition, if not, using a predefined fuel oil rail pressure set value according to the current working condition to enable a fuel gas pressure adjusting module to adjust the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on a fuel oil common rail pipe, if so, calculating a fuel gas rail pressure requirement value, and calculating the currently required fuel oil rail pressure set value according to the fuel gas rail pressure deviation and the fuel gas rail pressure requirement value to enable the fuel gas pressure adjusting module to adjust the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe. Through above-mentioned scheme, the gas pressure regulating module is according to the fuel rail pressure value regulation gas rail pressure on the fuel common rail pipe of gathering at present, because the current required fuel rail pressure setting value is greater than or equal to current fuel rail pressure to stablize the rail pressure fluctuation, avoided appearing the gas pressure regulating module and released the gas and cause the extravagant condition of gas in the return gas pipeline of gas feed system.)

1. A fuel gas rail pressure adjusting method is applicable to a diesel fuel and gas dual-fuel engine, and comprises the following steps:

acquiring vehicle running state parameters;

determining whether the vehicle running state parameters meet preset switching conditions;

if the current working condition is not met, the predefined fuel rail pressure set value is used according to the current working condition, so that the fuel pressure regulating module regulates the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe;

if the fuel gas rail pressure requirement value is met, calculating a fuel gas rail pressure requirement value, and calculating a currently required fuel oil rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure requirement value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe.

2. The method of claim 1, wherein prior to causing the gas pressure regulation module to regulate the gas rail pressure based on the fuel rail pressure value, further comprising:

and limiting the change rate of the currently required fuel rail pressure set value to obtain a continuously stable fuel rail pressure value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure value.

3. The method of claim 1, wherein the vehicle operating state parameters include a gas injection amount, an accelerator pedal opening value, and an engine speed, and the determining whether the vehicle operating state parameters satisfy a preset switching condition includes:

when the gas injection amount is smaller than a preset minimum injection amount, the accelerator pedal opening value is smaller than a preset minimum accelerator value and the engine rotating speed is larger than a preset minimum rotating speed, the vehicle operating parameters meet preset switching conditions;

and when the vehicle operation parameter does not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed value, the vehicle operation parameter does not meet the preset switching condition.

4. The method of claim 1, wherein the calculating a gas rail pressure demand and the calculating a currently required fuel rail pressure set value based on a pre-obtained gas rail pressure deviation and the gas rail pressure demand comprises:

freezing the rail pressure of the fuel gas, and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas;

acquiring fuel rail pressure and fuel rail pressure deviation;

determining a first fuel gas rail pressure demand initial value based on the fuel gas rail pressure and the fuel gas rail pressure deviation;

judging whether the first fuel gas rail pressure demand initial value is smaller than the fuel gas rail pressure demand maximum value or not;

if so, determining that the initial value of the first fuel gas rail pressure requirement is kept unchanged;

if not, determining the maximum fuel gas rail pressure requirement value as the initial first fuel gas rail pressure requirement value;

acquiring the time that the vehicle operation parameters meet the preset switching conditions;

judging whether the time is greater than a preset time or not;

if yes, freezing the first gas rail pressure requirement initial value determined at the moment, and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value;

if not, continuously judging whether the fuel rail pressure is greater than the first fuel rail pressure requirement initial value or not;

if yes, determining the fuel gas rail pressure requirement value based on the current fuel oil rail pressure and the fuel gas rail pressure deviation;

if not, determining that the first fuel gas rail pressure requirement initial value is equal to the fuel gas rail pressure requirement value;

and determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

5. A gas rail pressure regulation system, the system comprising:

the acquisition unit is used for acquiring vehicle running state parameters;

the determining unit is used for determining whether the vehicle running state parameters meet preset switching conditions;

the first adjusting unit is used for using a predefined fuel rail pressure set value according to the current working condition if the fuel rail pressure set value does not meet the preset working condition, so that the fuel pressure adjusting module adjusts the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe;

and the second adjusting unit is used for calculating a fuel gas rail pressure required value if the fuel gas rail pressure required value is met, and calculating a currently required fuel oil rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure required value, so that the fuel gas pressure adjusting module adjusts the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe.

6. The system of claim 5, further comprising:

and the limiting unit is used for limiting the change rate of the currently required fuel rail pressure set value to obtain a continuously stable fuel rail pressure value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure value.

7. The system according to claim 5, wherein the determining unit is specifically configured to:

when the gas injection amount is smaller than a preset minimum injection amount, the accelerator pedal opening value is smaller than a preset minimum accelerator value and the engine rotating speed is larger than a preset minimum rotating speed, the vehicle operating parameters meet preset switching conditions; and when the vehicle operation parameter does not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed value, the vehicle operation parameter does not meet the preset switching condition.

8. The system of claim 5, wherein the second conditioning unit comprises:

the first determining module is used for freezing the rail pressure of the fuel gas and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas;

the first acquisition module is used for acquiring fuel rail pressure and fuel rail pressure deviation;

the second determining module is used for determining a first fuel gas rail pressure demand initial value based on the fuel oil rail pressure and the fuel gas rail pressure deviation;

the first judgment module is used for judging whether the first fuel gas rail pressure demand initial value is smaller than the fuel gas rail pressure demand maximum value or not;

the third determining module is used for determining that the initial value of the first fuel gas rail pressure requirement keeps unchanged if the first fuel gas rail pressure requirement is positive;

the fourth determining module is used for determining the maximum value of the gas rail pressure demand as the initial value of the first gas rail pressure demand if the maximum value of the gas rail pressure demand is not the first value;

the second acquisition module is used for acquiring the time elapsed after the vehicle operation parameters meet the preset switching conditions;

the second judging module is used for judging whether the time is greater than the preset time or not;

the fifth determining module is used for freezing the first gas rail pressure requirement initial value determined at the moment and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value if the first gas rail pressure requirement initial value is determined at the moment;

the third judgment module is used for continuously judging whether the fuel rail pressure is larger than the first fuel rail pressure requirement initial value or not if the fuel rail pressure is not larger than the first fuel rail pressure requirement initial value;

a sixth determining module, configured to determine the gas rail pressure demand value based on the current fuel rail pressure and the gas rail pressure deviation if the fuel rail pressure demand value is positive;

a seventh determining module, configured to determine that the first fuel gas rail pressure demand initial value is equal to the fuel gas rail pressure demand value if the first fuel gas rail pressure demand initial value is not equal to the fuel gas rail pressure demand value;

and the eighth determining module is used for determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

Technical Field

The invention relates to the technical field of engines, in particular to a gas rail pressure adjusting method and system.

Background

A High Pressure Direct Injection (HPDI) engine is a diesel-ignited diesel-fueled dual fuel engine.

The HPDI engine includes a two-way fuel and gas feed system. The fuel supply system consists of a high-pressure oil pump, a fuel common rail pipe and a fuel injector. The fuel gas supply system comprises a fuel gas pressure regulating module, a fuel gas common rail pipe and a fuel injector. The fuel gas pressure regulating module regulates fuel gas rail pressure according to fuel oil rail pressure, so that the regulated fuel gas rail pressure is always lower than the fuel oil rail pressure.

When the engine runs under load, if the accelerator pedal is suddenly loosened to zero opening at the moment, the fuel rail pressure is suddenly increased and then rapidly reduced due to the reaction lag of the high-pressure oil pump, and the fuel gas pressure regulating module discharges the fuel gas into a gas return pipeline of a fuel gas supply system, so that the problem of fuel gas waste is caused.

Disclosure of Invention

In view of the above, the invention discloses a method and a system for regulating fuel gas rail pressure, wherein a fuel gas pressure regulating module regulates the fuel gas rail pressure according to a fuel gas rail pressure value acquired currently on a fuel gas common rail pipe, and because a currently required fuel gas rail pressure set value is greater than or equal to the current fuel gas rail pressure, rail pressure fluctuation is stabilized, and the situation that fuel gas is discharged into a return gas pipeline of a fuel gas supply system by the fuel gas pressure regulating module to cause fuel gas waste is avoided.

In order to achieve the purpose, the technical scheme is as follows:

the invention discloses a gas rail pressure adjusting method which is suitable for a diesel oil and gas dual-fuel engine, and the method comprises the following steps:

acquiring vehicle running state parameters;

determining whether the vehicle running state parameters meet preset switching conditions;

if the current working condition is not met, the predefined fuel rail pressure set value is used according to the current working condition, so that the fuel pressure regulating module regulates the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe;

if the fuel gas rail pressure requirement value is met, calculating a fuel gas rail pressure requirement value, and calculating a currently required fuel oil rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure requirement value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe.

Preferably, before making the gas pressure regulating module adjust the gas rail pressure according to the fuel rail pressure value, still include:

and limiting the change rate of the currently required fuel rail pressure set value to obtain a continuously stable fuel rail pressure value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure value.

Preferably, the vehicle operation state parameters include a gas injection amount, an accelerator pedal opening value and an engine speed, and the determining whether the vehicle operation state parameters satisfy a preset switching condition includes:

when the gas injection amount is smaller than a preset minimum injection amount, the accelerator pedal opening value is smaller than a preset minimum accelerator value and the engine rotating speed is larger than a preset minimum rotating speed, the vehicle operating parameters meet preset switching conditions;

and when the vehicle operation parameter does not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed value, the vehicle operation parameter does not meet the preset switching condition.

Preferably, the calculating a fuel gas rail pressure demand value and calculating a currently required fuel oil rail pressure set value according to a fuel gas rail pressure deviation obtained in advance and the fuel gas rail pressure demand value includes:

freezing the rail pressure of the fuel gas, and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas;

acquiring fuel rail pressure and fuel rail pressure deviation;

determining a first fuel gas rail pressure demand initial value based on the fuel gas rail pressure and the fuel gas rail pressure deviation;

judging whether the first fuel gas rail pressure demand initial value is smaller than the fuel gas rail pressure demand maximum value or not;

if so, determining that the initial value of the first fuel gas rail pressure requirement is kept unchanged;

if not, determining the maximum fuel gas rail pressure requirement value as the initial first fuel gas rail pressure requirement value;

acquiring the time that the vehicle operation parameters meet the preset switching conditions;

judging whether the time is greater than a preset time or not;

if yes, freezing the first gas rail pressure requirement initial value determined at the moment, and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value;

if not, continuously judging whether the fuel rail pressure is greater than the first fuel rail pressure requirement initial value or not;

if yes, determining the fuel gas rail pressure requirement value based on the current fuel oil rail pressure and the fuel gas rail pressure deviation;

if not, determining that the first fuel gas rail pressure requirement initial value is equal to the fuel gas rail pressure requirement value;

and determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

The invention discloses in a second aspect a gas rail pressure regulating system, the system comprising:

the acquisition unit is used for acquiring vehicle running state parameters;

the determining unit is used for determining whether the vehicle running state parameters meet preset switching conditions;

the first adjusting unit is used for using a predefined fuel rail pressure set value according to the current working condition if the fuel rail pressure set value does not meet the preset working condition, so that the fuel pressure adjusting module adjusts the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe;

and the second adjusting unit is used for calculating a fuel gas rail pressure required value if the fuel gas rail pressure required value is met, and calculating a currently required fuel oil rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure required value, so that the fuel gas pressure adjusting module adjusts the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe.

Preferably, the method further comprises the following steps:

and the limiting unit is used for limiting the change rate of the currently required fuel rail pressure set value to obtain a continuously stable fuel rail pressure value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure value.

Preferably, the determining unit is specifically configured to:

when the gas injection amount is smaller than a preset minimum injection amount, the accelerator pedal opening value is smaller than a preset minimum accelerator value and the engine rotating speed is larger than a preset minimum rotating speed, the vehicle operating parameters meet preset switching conditions; and when the vehicle operation parameter does not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed value, the vehicle operation parameter does not meet the preset switching condition.

Preferably, the second adjusting unit includes:

the first determining module is used for freezing the rail pressure of the fuel gas and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas;

the first acquisition module is used for acquiring fuel rail pressure and fuel rail pressure deviation;

the second determining module is used for determining a first fuel gas rail pressure demand initial value based on the fuel oil rail pressure and the fuel gas rail pressure deviation;

the first judgment module is used for judging whether the first fuel gas rail pressure demand initial value is smaller than the fuel gas rail pressure demand maximum value or not;

the third determining module is used for determining that the initial value of the first fuel gas rail pressure requirement keeps unchanged if the first fuel gas rail pressure requirement is positive;

the fourth determining module is used for determining the maximum value of the gas rail pressure demand as the initial value of the first gas rail pressure demand if the maximum value of the gas rail pressure demand is not the first value;

the second acquisition module is used for acquiring the time elapsed after the vehicle operation parameters meet the preset switching conditions;

the second judging module is used for judging whether the time is greater than the preset time or not;

the fifth determining module is used for freezing the first gas rail pressure requirement initial value determined at the moment and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value if the first gas rail pressure requirement initial value is determined at the moment;

the third judgment module is used for continuously judging whether the fuel rail pressure is larger than the first fuel rail pressure requirement initial value or not if the fuel rail pressure is not larger than the first fuel rail pressure requirement initial value;

a sixth determining module, configured to determine the gas rail pressure demand value based on the current fuel rail pressure and the gas rail pressure deviation if the fuel rail pressure demand value is positive;

a seventh determining module, configured to determine that the first fuel gas rail pressure demand initial value is equal to the fuel gas rail pressure demand value if the first fuel gas rail pressure demand initial value is not equal to the fuel gas rail pressure demand value;

and the eighth determining module is used for determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

According to the technical scheme, the vehicle running state parameters are obtained, whether the vehicle running state parameters meet the preset switching conditions or not is determined, if not, the predefined fuel rail pressure set value is used according to the current working condition, the fuel gas rail pressure is adjusted by the fuel gas pressure adjusting module according to the currently acquired fuel rail pressure value on the fuel common rail pipe, if yes, the fuel gas rail pressure required value is calculated, the currently required fuel rail pressure set value is calculated according to the fuel gas rail pressure deviation and the fuel gas rail pressure required value, and the fuel gas rail pressure is adjusted by the fuel gas pressure adjusting module according to the currently acquired fuel rail pressure value on the fuel common rail pipe. Through above-mentioned scheme, the gas pressure regulating module is according to the fuel rail pressure value regulation gas rail pressure on the fuel common rail pipe of gathering at present, because the current required fuel rail pressure setting value is greater than or equal to current fuel rail pressure to stablize the rail pressure fluctuation, avoided appearing the gas pressure regulating module and released the gas and cause the extravagant condition of gas in the return gas pipeline of gas feed system.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic flow chart of a method for adjusting rail pressure of a fuel gas according to an embodiment of the present invention;

FIG. 2 is a flowchart illustrating a method for determining whether a vehicle operating condition parameter meets a predetermined switch condition according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a gas rail pressure adjusting system according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As is known in the art, HPDI engines include a two-way fuel and gas supply system. The fuel supply system consists of a high-pressure oil pump, a fuel common rail pipe and a fuel injector. The fuel gas supply system comprises a fuel gas pressure regulating module, a fuel gas common rail pipe and a fuel injector. The fuel gas pressure regulating module regulates fuel gas rail pressure according to fuel oil rail pressure, so that the regulated fuel gas rail pressure is always lower than the fuel oil rail pressure.

When the engine runs under load, if the accelerator pedal is suddenly loosened to zero opening at the moment, the fuel rail pressure is suddenly increased at the moment due to the reaction lag of the high-pressure oil pump, and the fuel gas pressure regulating module discharges the fuel gas into a return gas pipeline of a fuel gas supply system, so that the problem of fuel gas waste is caused.

In order to solve the problem, the invention discloses a fuel gas rail pressure adjusting method and a fuel gas rail pressure adjusting system. The specific implementation is specifically illustrated by the following examples.

As shown in fig. 1, which is a schematic flow chart of a fuel gas rail pressure adjusting method disclosed in an embodiment of the present invention, the fuel gas rail pressure adjusting method is suitable for a diesel fuel and fuel gas dual-fuel engine, and the fuel gas rail pressure adjusting method mainly includes the following steps:

s101: and acquiring vehicle running state parameters.

The vehicle running state parameters comprise gas injection quantity, an accelerator pedal opening value, engine rotating speed and the like.

S102: and determining whether the vehicle running state parameters meet preset switching conditions, if not, executing S103, and if so, executing S104.

The above S102 relates to a process of determining that the vehicle operation state parameter meets the preset switching condition, as shown in fig. 2.

In fig. 2, when the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value, and the engine speed is greater than the preset minimum speed, the vehicle operation parameters meet the preset switching conditions.

And when the vehicle operation parameters do not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed, the vehicle operation parameters do not meet the preset switching condition.

S103: and (4) using a predefined fuel rail pressure set value according to the current working condition, so that the fuel pressure regulating module regulates the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe.

The fuel rail pressure set value is set by a technician according to actual conditions, and the invention is not particularly limited.

The fuel rail pressure value is acquired through a rail pressure sensor arranged on the fuel common rail pipe and is used for representing the current pressure value in the fuel common rail pipe.

The gas rail pressure is acquired through a rail pressure sensor arranged on the gas common rail pipe and is used for representing the pressure in the current gas common rail pipe.

S104: and calculating a fuel gas rail pressure requirement value, and calculating a currently required fuel oil rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure requirement value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe.

And calculating according to the gas supply pressure and the gas rail pressure to obtain the gas rail pressure deviation.

The fuel gas pressure regulating module is used for regulating the mechanical pressure regulating device of the fuel gas rail pressure according to the fuel gas rail pressure, so that the regulated fuel gas rail pressure is always lower than the fuel gas rail pressure.

When the engine operates with load, if the accelerator pedal is suddenly loosened to zero opening at the moment, the fuel rail pressure is suddenly increased and then rapidly reduced due to the reaction lag of the high-pressure oil pump, the fuel rail pressure is adjusted by the fuel pressure adjusting module according to the currently acquired fuel rail pressure value on the fuel common rail pipe, and the adjusted fuel rail pressure is always lower than the fuel rail pressure so as to stabilize the fuel rail pressure.

According to the pre-acquired gas rail pressure deviation and the gas rail pressure required value, a currently required fuel rail pressure set value is calculated, and the gas pressure regulating module regulates the gas rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe, so that the situation that the gas pressure regulating module discharges gas into a gas return pipeline of a gas supply system to cause gas waste is avoided.

In step S104, a process of calculating a currently required fuel rail pressure set value according to the pre-obtained fuel rail pressure deviation and the pre-obtained fuel rail pressure required value, and enabling the fuel pressure regulating module to regulate the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe is performed, as shown in a1-a 13.

A1: and freezing the rail pressure of the fuel gas, and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas.

A2: and acquiring the deviation of the fuel rail pressure and the fuel rail pressure.

And calculating according to the gas supply pressure and the gas rail pressure to obtain the gas rail pressure deviation.

A3: and determining a first fuel gas rail pressure demand initial value based on the fuel gas rail pressure and the fuel gas rail pressure deviation.

And calculating according to the fuel rail pressure and the fuel rail pressure deviation to obtain a first fuel rail pressure demand initial value.

A4: and judging whether the initial value of the first fuel gas rail pressure requirement is smaller than the maximum value of the fuel gas rail pressure requirement.

A5: and if so, determining that the initial value of the first fuel gas rail pressure requirement is kept unchanged.

A6: if not, determining the maximum value of the fuel gas rail pressure demand as a first fuel gas rail pressure demand initial value.

A7: and acquiring the time elapsed after the vehicle operation parameters meet the preset switching conditions.

And acquiring the time elapsed after the vehicle operation parameters meet the preset switching conditions through the timer.

A8: and judging whether the time is greater than the preset time.

The preset time may be 3 seconds, 10 seconds, etc., and the specific preset time is determined, which is not limited in the present invention.

A9: and if so, freezing the first gas rail pressure requirement initial value determined at the moment, and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value.

A10: if not, continuously judging whether the fuel rail pressure is greater than the first fuel rail pressure requirement initial value or not.

A11: if yes, determining a fuel gas rail pressure requirement value based on the current fuel oil rail pressure and fuel gas rail pressure deviation.

A12: if not, determining that the first fuel gas rail pressure demand initial value is equal to the fuel gas rail pressure demand value.

A13: and determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

The embodiment of the invention discloses a fuel gas rail pressure adjusting method, which comprises the steps of obtaining vehicle running state parameters, determining whether the vehicle running state parameters meet preset switching conditions, using a predefined fuel gas rail pressure set value according to the current working condition if the vehicle running state parameters do not meet the preset switching conditions, enabling a fuel gas pressure adjusting module to adjust fuel gas rail pressure according to the currently acquired fuel gas rail pressure value on a fuel gas common rail pipe, calculating a fuel gas rail pressure required value if the vehicle running state parameters meet the preset switching conditions, calculating the currently required fuel gas rail pressure set value according to the pre-acquired fuel gas rail pressure deviation and the fuel gas rail pressure required value, and enabling the fuel gas pressure adjusting module to adjust the fuel gas rail pressure according to the currently acquired fuel gas rail pressure value on the fuel gas. Through above-mentioned scheme, the gas pressure regulating module is according to the fuel rail pressure value regulation gas rail pressure on the fuel common rail pipe of gathering at present, because the current required fuel rail pressure setting value is greater than or equal to current fuel rail pressure to stablize the rail pressure fluctuation, avoided appearing the gas pressure regulating module and released the gas and cause the extravagant condition of gas in the return gas pipeline of gas feed system.

In another example scenario, another gas rail pressure adjustment method is disclosed, as shown in B1-B4.

B1: and acquiring vehicle running state parameters.

B2: and determining whether the vehicle running state parameters meet preset switching conditions.

B3: if the fuel rail pressure does not meet the preset value, the predefined fuel rail pressure set value is used according to the current working condition, the change rate of the currently required fuel rail pressure set value is limited, and the fuel rail pressure set value which is continuously stable is obtained, so that the fuel pressure regulating module regulates the fuel rail pressure according to the continuously stable fuel rail pressure set value.

B4: if the fuel gas rail pressure set value meets the requirement, the fuel gas rail pressure required value is calculated, the currently required fuel oil rail pressure set value is calculated according to the fuel gas rail pressure deviation and the fuel gas rail pressure required value which are obtained in advance, the change rate of the currently required fuel oil rail pressure set value is limited, the fuel oil rail pressure set value which is continuously stable is obtained, and the fuel gas pressure regulating module is used for regulating the fuel gas rail pressure according to the continuously stable fuel oil rail pressure set value.

And calculating according to the gas supply pressure and the gas rail pressure to obtain the gas rail pressure deviation.

The situation that the fuel rail pressure set value changes suddenly is prevented by limiting the change rate of the currently required fuel rail pressure set value, so that the continuously stable fuel rail pressure set value is obtained.

In the embodiment of the invention, the change rate of the currently required fuel rail pressure set value is limited to obtain the continuously stable fuel rail pressure set value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure set value, and the condition that the fuel gas pressure regulating module discharges the fuel gas into a gas return pipeline of a fuel gas supply system to cause fuel gas waste is avoided.

Based on the gas rail pressure adjusting method disclosed by the embodiment, the embodiment of the invention also correspondingly discloses a gas rail pressure adjusting system, and as shown in fig. 3, the gas rail pressure adjusting system mainly comprises:

an obtaining unit 301, configured to obtain a vehicle operating state parameter.

The vehicle running state parameters comprise gas injection quantity, an accelerator pedal opening value, engine rotating speed and the like.

A determining unit 302, configured to determine whether the vehicle operating state parameter meets a preset switching condition.

Further, the determining unit 302 is specifically configured to, when the gas injection amount is smaller than a preset minimum injection amount, the accelerator pedal opening value is smaller than a preset minimum accelerator value, and the engine speed is greater than a preset minimum speed value, meet the preset switching condition for the vehicle operation parameter; when the vehicle operation parameters do not meet any condition that the gas injection amount is smaller than the preset minimum injection amount, the accelerator pedal opening value is smaller than the preset minimum accelerator value and the engine rotating speed is larger than the preset minimum rotating speed value, the vehicle operation parameters do not meet the preset switching condition.

And the first adjusting unit 303 is configured to use a predefined fuel rail pressure setting value according to the current working condition if the fuel rail pressure value does not match the predefined fuel rail pressure setting value, so that the fuel pressure adjusting module adjusts the fuel rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe.

The fuel rail pressure value is acquired through a rail pressure sensor arranged on the fuel common rail pipe and used for representing the pressure value in the current fuel common rail pipe.

The gas rail pressure is acquired through a rail pressure sensor arranged on the gas common rail pipe and is used for representing the pressure in the current gas common rail pipe.

And the second adjusting unit 304 is used for calculating a gas rail pressure requirement value if the fuel rail pressure requirement value is met, and calculating a currently required fuel rail pressure set value according to the pre-acquired gas rail pressure deviation and the gas rail pressure requirement value, so that the gas pressure adjusting module adjusts the gas rail pressure according to the currently acquired fuel rail pressure value on the fuel common rail pipe.

And calculating according to the gas supply pressure and the gas rail pressure to obtain the gas rail pressure deviation.

The fuel gas pressure regulating module is used for regulating the mechanical pressure regulating device of the fuel gas rail pressure according to the fuel gas rail pressure, so that the regulated fuel gas rail pressure is always lower than the fuel gas rail pressure.

When the engine runs with load, if the accelerator pedal is suddenly released to zero opening at the moment, the fuel rail pressure is suddenly increased at the moment due to the reaction lag of the high-pressure oil pump, and the adjusted fuel rail pressure is always lower than the fuel rail pressure, so that the fuel rail pressure is stabilized.

Further, the second adjusting unit 304 includes:

the first determining module is used for freezing the rail pressure of the fuel gas and determining the maximum value of the rail pressure demand of the fuel gas based on the rail pressure of the frozen fuel gas.

The first acquisition module is used for acquiring fuel rail pressure and fuel rail pressure deviation.

And the second determination module is used for determining a first fuel gas rail pressure demand initial value based on the fuel gas rail pressure and the fuel gas rail pressure deviation.

And the first judgment module is used for judging whether the first fuel gas rail pressure requirement initial value is smaller than the fuel gas rail pressure requirement maximum value or not.

And the third determining module is used for determining that the initial value of the first fuel gas rail pressure requirement is kept unchanged if the first fuel gas rail pressure requirement is positive.

And the fourth determining module is used for determining the maximum value of the gas rail pressure demand as the initial value of the first gas rail pressure demand if the maximum value of the gas rail pressure demand is not the first value.

And the second acquisition module is used for acquiring the time elapsed after the vehicle operation parameters meet the preset switching conditions.

And the second judging module is used for judging whether the time is greater than the preset time.

And the fifth determining module is used for freezing the first gas rail pressure requirement initial value determined at the moment and determining that the frozen first gas rail pressure requirement initial value is equal to the gas rail pressure requirement value.

And the third judgment module is used for continuously judging whether the fuel rail pressure is greater than the first fuel rail pressure requirement initial value or not if the fuel rail pressure is not greater than the first fuel rail pressure requirement initial value.

And the sixth determining module is used for determining the gas rail pressure demand value based on the current fuel rail pressure and the gas rail pressure deviation if the fuel rail pressure demand value is positive.

And the seventh determining module is used for determining that the first fuel gas rail pressure requirement initial value is equal to the fuel gas rail pressure requirement value if the first fuel gas rail pressure requirement initial value is not equal to the fuel gas rail pressure requirement value.

And the eighth determining module is used for determining the currently required fuel rail pressure set value based on the fuel rail pressure deviation and the fuel rail pressure required value.

Optionally, the method further includes: a limiting unit.

And the limiting unit is used for limiting the change rate of the currently required fuel rail pressure set value to obtain a continuously stable fuel rail pressure value, so that the fuel gas pressure regulating module regulates the fuel gas rail pressure according to the continuously stable fuel rail pressure value.

The embodiment of the invention discloses a fuel gas rail pressure adjusting system, which is used for obtaining vehicle running state parameters, determining whether the vehicle running state parameters meet preset switching conditions, if not, using a predefined fuel oil rail pressure set value according to the current working condition, enabling a fuel gas pressure adjusting module to adjust fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on a fuel oil common rail pipe, if so, calculating a fuel gas rail pressure requirement value, and according to the pre-obtained fuel gas rail pressure deviation and the fuel gas rail pressure requirement value, calculating the currently required fuel oil rail pressure set value, and enabling the fuel gas pressure adjusting module to adjust the fuel gas rail pressure according to the currently acquired fuel oil rail pressure value on the fuel oil common rail pipe. Through above-mentioned system, the gas pressure regulating module is according to the fuel rail pressure value regulation gas rail pressure on the fuel common rail pipe of gathering at present, because the current required fuel rail pressure setting value is greater than or equal to current fuel rail pressure to stablize the rail pressure fluctuation, avoided appearing the gas pressure regulating module and released the gas and cause the extravagant condition of gas in the return gas pipeline of gas feed system.

While, for purposes of simplicity of explanation, the foregoing method embodiments have been described as a series of acts or combination of acts, it will be appreciated by those skilled in the art that the present invention is not limited by the illustrated ordering of acts, as some steps may occur in other orders or concurrently with other steps in accordance with the invention. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and modules referred to are not necessarily required by the invention.

It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other. For the system-class embodiment, since it is basically similar to the method embodiment, the description is simple, and for the relevant points, reference may be made to the partial description of the method embodiment.

The steps in the method of each embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be 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. Also, 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 an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. 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 invention. Thus, the present invention 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.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.