阅读说明：本技术 发动机增压器瞬时超速保护方法及系统 (Instantaneous overspeed protection method and system for engine supercharger ) 是由 韩金辉 冯海浩 李丽丽 马广营 李丹 于 2020-12-03 设计创作，主要内容包括：本发明涉及一种发动机增压器瞬时超速保护方法及系统,其包括以下步骤：获取发动机的运行参数；获取增压器的实时进气压比；计算对应当前工况下增压器的最高限值压比,将所述最高限值压比与所述实时进气压比进行比较,若所述实时进气压比大于所述最高限值压比,则判定所述增压器处于超速状态；在判定出所述增压器处于超速状态时,控制放气阀开环；还包括电控单元ECU,所述电控单元ECU与放气阀电性连接,且其内部还预制存储有增压器的特性曲线MAP图；运行参数测量装置,其被设置成用于测量发动机的运行参数。本发明具有降低或避免发动机突变工况引起的增压器瞬时转速超限对增压器造成损害的效果。(The invention relates to an instantaneous overspeed protection method and system for an engine supercharger, which comprises the following steps: acquiring operating parameters of an engine; acquiring a real-time air inlet pressure ratio of a supercharger; calculating a maximum limit pressure ratio of the supercharger corresponding to the current working condition, comparing the maximum limit pressure ratio with the real-time air inlet pressure ratio, and if the real-time air inlet pressure ratio is greater than the maximum limit pressure ratio, judging that the supercharger is in an overspeed state; when the supercharger is judged to be in an overspeed state, controlling the open loop of a release valve; the electronic control unit ECU is electrically connected with the air release valve, and a characteristic curve MAP of the supercharger is prefabricated and stored in the electronic control unit ECU; an operating parameter measuring device is provided for measuring an operating parameter of the engine. The invention has the effect of reducing or avoiding damage to the supercharger caused by the fact that the instantaneous rotating speed of the supercharger is over-limited due to the sudden change of the working condition of the engine.)

1. An engine supercharger instantaneous overspeed protection method is characterized in that: the method comprises the following steps:

acquiring operating parameters of an engine;

acquiring a real-time air inlet pressure ratio of a supercharger;

calculating a maximum limit pressure ratio of the supercharger corresponding to the current working condition, comparing the maximum limit pressure ratio with the real-time air inlet pressure ratio, and if the real-time air inlet pressure ratio is greater than the maximum limit pressure ratio, judging that the supercharger is in an overspeed state;

and controlling the open loop of a release valve when the supercharger is judged to be in an overspeed state.

2. The engine supercharger transient overspeed protection method according to claim 1, characterized in that: the operating parameters include an engine intake air amount and an intake air pressure.

3. The engine supercharger transient overspeed protection method according to claim 1, characterized in that: the engine air intake is measured from a MAF flow meter.

4. The engine supercharger transient overspeed protection method according to claim 1, characterized in that: and calculating the highest limit pressure ratio according to the air inlet quantity of the engine.

5. The engine supercharger transient overspeed protection method according to claim 1, characterized in that: and obtaining a pressure ratio by dividing the pressure value of the air outlet of the supercharger by the pressure value of the air inlet during normal air inlet.

6. The engine supercharger instantaneous overspeed protection method according to claim 5, characterized in that: and calculating the real-time intake air pressure ratio according to the pressure ratio.

7. An engine supercharger instantaneous overspeed protection system, characterized in that: comprises that

The electronic control unit ECU is electrically connected with the air release valve, and a characteristic curve MAP of the supercharger is prefabricated and stored in the electronic control unit ECU;

an operating parameter measuring device is provided for measuring an operating parameter of the engine.

8. The engine supercharger transient overspeed protection system of claim 7, wherein: the electronic control unit ECU is also electrically connected with the parameter measuring device, and the parameter measuring device uploads measured data to the electronic control unit ECU in the form of electric signals.

9. The engine supercharger transient overspeed protection system of claim 7, wherein: the parameter measuring device includes at least:

the air inlet temperature/pressure sensor is arranged on an air inlet pipe of the engine, is positioned at the front end of the intercooler and is used for measuring the air inlet temperature of the air inlet pipe and the real-time air inlet pressure of the supercharger;

and the MAF flow meter is arranged on an air inlet end pipeline between the intercooler and the engine and is used for measuring the fresh air inflow of the engine.

10. The engine supercharger transient overspeed protection system of claim 7, wherein: the air release valve is of an electric control type.

Technical Field

The invention relates to the technical field of engines, in particular to an instantaneous overspeed protection method and an instantaneous overspeed protection system for an engine supercharger.

Background

This section provides background information related to the present disclosure only and is not necessarily prior art.

The conventional supercharger overspeed is a common supercharger problem in the operation process of an engine, and a certain rotating speed margin is usually kept in the model selection and calibration of the supercharger. However, unavoidable conditions such as sudden acceleration occur frequently during engine operation, and the occurrence of such conditions is highly likely to cause the instantaneous rotational speed of the supercharger to exceed the limit value. If the above conditions occur frequently or are continued for a long time, the service life of the supercharger is influenced, and the performance and the service life of the engine are seriously damaged.

Disclosure of Invention

The invention aims to at least solve the problem of how to avoid damage to a supercharger caused by the fact that the instantaneous rotating speed of the supercharger is over-limited due to the sudden working condition of an engine. The purpose is realized by the following technical scheme:

a first aspect of the present invention provides a method of transient overspeed protection of an engine supercharger, the method comprising the steps of:

acquiring operating parameters of an engine;

acquiring a real-time air inlet pressure ratio of a supercharger;

calculating a maximum limit pressure ratio of the supercharger corresponding to the current working condition, comparing the maximum limit pressure ratio with the real-time air inlet pressure ratio, and if the real-time air inlet pressure ratio is greater than the maximum limit pressure ratio, judging that the supercharger is in an overspeed state;

and controlling the open loop of a release valve when the supercharger is judged to be in an overspeed state.

According to the instantaneous overspeed protection method for the supercharger of the engine, for the EGR engine, firstly, the operation parameters of the engine are obtained, the real-time air inlet pressure of the supercharger is calculated according to the operation parameters, and then the real-time air inlet pressure ratio under the current working condition is calculated and obtained according to the real-time air inlet pressure. When the real-time air inlet pressure ratio is larger than the maximum limit pressure ratio under the working condition, the supercharger can be judged to be in an instantaneous overspeed state.

When the supercharger is in an overspeed state, the air release valve is switched to an open state, part of waste gas in front of the supercharger turbine is quickly bypassed, and the energy in front of the supercharger turbine is reduced, so that the pressure before inter-cooling is quickly reduced, the supercharger can be quickly far away from the overspeed state and returns to a safe operation area as far as possible, the damage of the instantaneous overspeed phenomenon generated when the supercharger suddenly changes working conditions to the performance and the service life of an engine is avoided or reduced, and the purpose of protecting the supercharger is achieved. The protection method can avoid or reduce damage to the supercharger caused by the fact that the instantaneous rotating speed of the supercharger is over-limited due to sudden change of working conditions of the engine.

In addition, the method for protecting the instantaneous overspeed of the engine supercharger can also have the following additional technical characteristics:

in some embodiments of the invention, the operating parameters include engine intake air quantity and intake air pressure.

In some embodiments of the invention, the engine air intake amount is measured based on a MAF flow meter.

In some embodiments of the invention, the maximum limit pressure ratio is calculated based on the engine intake air amount.

In some embodiments of the invention, the pressure ratio is derived from the pressure value at the outlet of the supercharger divided by the pressure value at the inlet for normal intake.

In some embodiments of the invention, the real-time intake air pressure ratio is calculated from the pressure ratio.

A second aspect of the present invention provides an engine supercharger transient overspeed protection system, comprising

The electronic control unit ECU is electrically connected with the air release valve, and a characteristic curve MAP of the supercharger is prefabricated and stored in the electronic control unit ECU;

an operating parameter measuring device is provided for measuring an operating parameter of the engine.

In some embodiments of the present invention, the ECU is further electrically connected to the parameter measuring device, and the parameter measuring device uploads the measured data to the ECU in the form of an electrical signal.

In some embodiments of the invention, the parameter measuring device comprises at least:

the air inlet temperature/pressure sensor is arranged on an air inlet pipe of the engine, is positioned at the front end of the intercooler and is used for measuring the air inlet temperature of the air inlet pipe and the real-time air inlet pressure of the supercharger;

and the MAF flow meter is arranged on an air inlet pipe between the intercooler and the engine and used for measuring the fresh air inlet quantity of the engine.

In some embodiments of the invention, the purge valve is electronically controlled.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like parts are designated by like reference numerals throughout the drawings. In the drawings:

FIG. 1 is a flow chart of an engine supercharger transient overspeed protection method of the present application;

FIG. 2 is a schematic diagram of an EGR engine intake and exhaust system configuration based on a MAF route according to the present application;

fig. 3 is a schematic diagram of a MAP of a characteristic curve of the supercharger of the present application.

Reference numerals:

1. an air inlet pipe; 2. a supercharger compressor; 3. an intercooler; 4. a MAF flow meter; 5. an intake throttle valve; 6. an intake air temperature/pressure sensor; 7. an engine; 8. a deflation valve; 9. a supercharger turbine; 10. an exhaust pipe; 11. a speed line.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1-2, according to an embodiment of the present invention, there is provided an engine supercharger transient overspeed protection method, comprising the steps of:

the operation parameters of the engine 7 are obtained, including the air inflow and the air inflow pressure of the engine 7, the air inflow of the engine 7 is measured according to the MAF flowmeter 4, and meanwhile, the maximum limit pressure ratio is calculated according to the air inflow of the engine 7. And the pressure ratio is obtained by dividing the pressure value of the air outlet of the supercharger compressor 2 by the pressure value of the air inlet during normal air inlet.

And acquiring the real-time intake air pressure ratio of the supercharger.

And calculating the maximum limit pressure ratio of the supercharger corresponding to the current working condition, comparing the maximum limit pressure ratio with the real-time air inlet pressure ratio, and judging that the supercharger is in an overspeed state if the real-time air inlet pressure ratio is greater than the maximum limit pressure ratio.

And when the supercharger is judged to be in an overspeed state, controlling the air release valve 8 to open loop. Part of the exhaust gas before the vortex is quickly bypassed, so that the energy before the vortex is reduced, and the intercooling front pressure is quickly reduced, so that the supercharger can be away from an overspeed state and return to a safe operation state as quickly as possible.

In this embodiment, according to the method for protecting instantaneous overspeed of the engine supercharger, the EGR engine 7 based on the MAF route first obtains the operation parameters of the engine 7, calculates the real-time intake pressure of the supercharger according to the operation parameters, and then calculates and obtains the real-time intake pressure ratio under the current working condition according to the real-time intake pressure. When the real-time air inlet pressure ratio is larger than the maximum limit pressure ratio under the working condition, the supercharger can be judged to be in an instantaneous overspeed state.

When the supercharger is in an overspeed state, the air release valve 8 is switched to an open state, part of exhaust gas in front of the supercharger turbine 9 is quickly bypassed, and energy in front of the supercharger turbine is reduced, so that the pressure before cold is quickly reduced, the supercharger can be quickly far away from the overspeed state and can be returned to a safe operation area, and damage to the supercharger caused by instantaneous supercharger speed overrun due to sudden working conditions of the engine 7 is avoided or reduced.

In another aspect of the invention, an engine 7 supercharger instant overspeed protection system is provided, comprising

The ECU is mainly used for calculating, processing and judging information input by the flow meter and various sensors according to programs and data in the memory of the ECU, and then outputting instructions. Meanwhile, the electronic control unit ECU is electrically connected to the air release valve 8, that is, the air release valve 8 is electrically controlled.

As shown in fig. 3, a MAP of a characteristic curve of the supercharger is also pre-stored in the electronic control unit ECU; in the MAP of the characteristic curve, the abscissa represents the fresh intake air flow of the engine 7, the ordinate represents the supercharger intake pressure ratio, different curve speed lines 11 are set in the coordinate system, and in the standard state, for different speed limit lines, the intake air flow and the intake pressure ratio have a one-to-one correspondence relationship, and the supercharger intake pressure ratio is calculated from the intercooling intake pressure.

An operating parameter measuring device arranged to measure an operating parameter of the engine 7. As shown in fig. 2, the parameter measuring device includes at least:

the air inlet temperature/pressure sensor 6 is arranged on the air inlet pipe 1, is positioned at the front end of the intercooler 3, and is used for measuring the air inlet temperature of the air inlet pipe 1 and the real-time air inlet pressure value of the supercharger;

a MAF flow meter 4 installed in the intake pipe 1 between the intercooler 3 and the engine 7 for measuring a fresh intake air amount of the engine 7;

which is installed in the intake pipe 1 between the MAF flow meter 4 and the engine 7, for measuring the intake air temperature and the intake air pressure of the engine 7, and calculating the total intake air amount of the engine 7.

Meanwhile, the electronic control unit ECU is also electrically connected with the parameter measuring device, and the parameter measuring device uploads measured data to the electronic control unit ECU in the form of electric signals.

The open-loop opening of the air release valve 8 can achieve the purpose of reducing the energy before the vortex more quickly and effectively, and if the overspeed risk is monitored, the open-loop control of the air release valve 8 can greatly improve the risk avoiding efficiency of the supercharger.

In the embodiment, according to the instant overspeed protection system of the engine supercharger, based on the principle of the MAF route, the fresh air inflow of the engine 7 can be directly measured by the MAF flow meter 4, and the fresh air inflow corresponding to the air inflow under any working condition has an air inflow pressure ratio under the unique maximum rotating speed limit value theoretically. For the EGR engine 7 of the MAF route, the air inlet temperature of the air inlet pipe 1 and the real-time air inlet pressure value of the supercharger can be measured based on the air inlet temperature/pressure sensor 6, and the real-time air inlet pressure ratio under the current working condition can be obtained through calculation. When the calculated maximum limit pressure ratio is smaller than the real-time calculated intake pressure ratio under the working condition, the supercharger can be judged to be in an instantaneous overspeed state.

When the electronic control unit ECU judges that the supercharger is in an overspeed state, the ECU gives an instruction to the electronic control air release valve 8 to the engine 7 of the supercharger matched with the electronic control air release valve 8, the electronic control air release valve 8 is rapidly controlled by switching open loops according to the corresponding electronic control air release valve 8 in the original closed loop state, part of exhaust gas in front of a supercharger turbine 9 is rapidly bypassed, and energy before vortex is reduced, so that pressure before inter-cooling is rapidly reduced, the supercharger can be rapidly far away from the overspeed state and returns to a safe operation area, and therefore damage to the performance and the service life of the engine 7 caused by an instant overspeed phenomenon occurring when the supercharger is in an instant sudden change working condition is avoided or reduced, and the purpose of protecting the. According to the system and the method for protecting the instantaneous overspeed of the engine supercharger, the damage to the supercharger caused by the instantaneous speed overrun of the supercharger, which is caused by the sudden change working condition of the engine 7, can be avoided or reduced.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.