阅读说明：本技术 发动机及其增压系统 (Engine and supercharging system thereof ) 是由 陈栋栋 彭丽娟 杜星新 张萍 王新校 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种发动机及其增压系统,其中,发动机的增压系统包括进气管道、排气管道、旁通管道和旁通阀。进气管道连接压气机和发动机本体,排气管道连接发动机本体和涡轮机。旁通管道进气端与进气管道连接,出气端与排气管道连接。旁通阀设置在旁通管道上,且控制旁通管道通气量。本申请通过在合适的工况下根据需求适当打开某一开度,让增压后的进气在压差作用下旁通到排气侧,旁通后将使得排气流量及能量增加,这将使得涡轮机输出功率增加,由于发动机喘振余量增加、空燃比增加,发动机便可增加喷油量从而获取到更高的扭矩输出,且不会造成增压器喘振的问题,进而增压器的可靠性提高。(The invention discloses an engine and a supercharging system thereof, wherein the supercharging system of the engine comprises an air inlet pipeline, an exhaust pipeline, a bypass pipeline and a bypass valve. The air inlet pipeline is connected with the air compressor and the engine body, and the air outlet pipeline is connected with the engine body and the turbine. The inlet end of the bypass pipeline is connected with the inlet pipeline, and the outlet end of the bypass pipeline is connected with the exhaust pipeline. The bypass valve is arranged on the bypass pipeline and controls the ventilation volume of the bypass pipeline. This application is through properly opening a certain aperture according to the demand under suitable operating mode, lets the air intake after the pressure boost bypass to the exhaust side under the pressure differential effect, will make behind the bypass exhaust flow and energy increase, this will make turbine output increase, because engine surge allowance increases, air-fuel ratio increases, thereby the engine alright increase oil spout volume acquires higher torque output, and can not cause the problem of booster surge, and then the reliability of booster improves.)

1. A supercharging system for an engine, comprising:

an air inlet duct (7) connecting the compressor (4-1) and the engine body;

an exhaust pipe (8) connecting the engine body and the turbine (4-2);

the air inlet end of the bypass pipeline is connected with the air inlet pipeline (7), and the air outlet end of the bypass pipeline is connected with the exhaust pipeline (8);

a bypass valve (5) disposed on the bypass conduit and controlling the amount of ventilation in the bypass conduit.

2. Supercharging system according to claim 1, characterized in that the bypass line serves for conveying charge air through an intercooler to the exhaust line (8).

3. Supercharging system for an engine according to claim 2, characterized in that the charge air cooler comprises a main charge air cooler (2) arranged on the inlet duct (7) and a bypass charge air cooler (3) mounted on the bypass duct, the inlet of which is located upstream of the main charge air cooler (2).

4. Supercharging system for an engine according to claim 3, characterized in that the bypass charge air cooler (3) is located upstream of the bypass valve (5).

5. Supercharging system for an engine according to claim 3, characterized by further comprising an on-off valve for opening and closing the bypass intercooler (3).

6. Supercharging system according to claim 2, characterized in that the charge air cooler is located on the intake conduit (7) and the inlet of the bypass conduit is located downstream of the charge air cooler.

7. The supercharging system of an engine according to any of claims 1 to 6, characterized by further comprising a controller (9) that controls the opening and closing of the bypass valve (5).

8. Supercharging system for an engine according to claim 7, characterized in that the bypass valve (5) comprises a pneumatic valve and further comprises an electrical pressure regulating valve (6) connecting the bypass valve (5) and the controller (9).

9. Supercharging system for an engine according to claim 7, characterized in that the controller (9) controls the bypass valve (5) to open by a preset angle when the engine speed and/or the fuel injection quantity exceed a preset value.

10. The supercharging system of an engine according to claim 9, characterized in that when there is a difference between the temperature difference between the average exhaust gas temperature and the supercharged temperature and a target temperature difference, the controller (9) adjusts the opening degree of the bypass valve (5) by means of a PI algorithm until the actual temperature difference equals the target temperature difference, completing closed-loop control.

11. An engine comprising a supercharging system, wherein the supercharging system is as claimed in any one of claims 1 to 10.

Technical Field

The invention relates to the technical field of engines, in particular to a supercharging system of an engine. The invention also relates to an engine comprising the supercharging system.

Background

The air inlet bypass technology is characterized in that a bypass pipe is connected from the air inlet downstream of a compressor of a supercharger to the exhaust upstream of a turbine, and a corresponding heating device and an electric control valve are added, so that the purposes of bypassing the air inlet to the exhaust and heating are achieved.

However, the bypass intake air is heated for providing more energy to the turbine, but in practical application, many working conditions cause the problem of overheating of the turbine, which is very unfavorable for the reliability of the supercharger, and further causes the reliability of the supercharger to be reduced.

Therefore, how to improve the reliability of the supercharger is a technical problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The invention aims to provide a supercharging system of an engine, so as to improve the reliability of a supercharger. It is another object of the present invention to provide an engine including the supercharging system described above.

To achieve the above object, the present invention provides a supercharging system of an engine, comprising:

an air inlet pipeline connecting the compressor and the engine body;

an exhaust duct connecting the engine body and the turbine;

the air inlet end of the bypass pipeline is connected with the air inlet pipeline, and the air outlet end of the bypass pipeline is connected with the exhaust pipeline;

and the bypass valve is arranged on the bypass pipeline and controls the ventilation quantity of the bypass pipeline.

Preferably, the bypass duct is for conveying intercooler air to the exhaust duct.

Preferably, the intercooler comprises a main intercooler arranged on the air inlet pipeline and a bypass intercooler arranged on the bypass pipeline, and the air inlet of the bypass pipeline is positioned at the upstream of the main intercooler.

Preferably, the bypass intercooler is located upstream of the bypass valve.

Preferably, the system further comprises a switch valve for opening and closing the bypass intercooler.

Preferably, the intercooler is located on the intake duct, and the intake of the bypass duct is located downstream of the intercooler.

Preferably, the control device also comprises a controller for controlling the opening and closing of the bypass valve.

Preferably, the bypass valve is a pneumatic valve, and further comprises an electric pressure regulating valve connecting the bypass valve and the controller.

Preferably, the controller controls the bypass valve to open by a preset angle when the engine speed and/or the fuel injection amount exceed preset values.

Preferably, when the difference value exists between the temperature difference between the average exhaust temperature and the supercharged temperature and the target temperature difference, the controller adjusts the opening of the bypass valve through a PI algorithm until the actual temperature difference is equal to the target temperature difference, and closed-loop control is completed.

An engine comprising a supercharging system, the supercharging system being as claimed in any one of the preceding claims.

In the above technical solution, the engine supercharging system provided by the present invention includes an intake duct, an exhaust duct, a bypass duct, and a bypass valve. The air inlet pipeline is connected with the air compressor and the engine body, and the air outlet pipeline is connected with the engine body and the turbine. The inlet end of the bypass pipeline is connected with the inlet pipeline, and the outlet end of the bypass pipeline is connected with the exhaust pipeline. The bypass valve is arranged on the bypass pipeline and controls the ventilation volume of the bypass pipeline.

As can be seen from the above description, in the supercharging system of the engine provided by the present application, by appropriately opening a certain opening degree according to the requirement under the appropriate working condition, the supercharged intake air is bypassed to the exhaust side under the action of the pressure difference, and the exhaust flow and energy are increased after bypassing, which will increase the output power of the turbine, because the power consumed by the compressor is the power output by the turbine (after mechanical loss is removed), namely the power of the compressor is correspondingly increased at the moment, the air inlet flow is increased, namely, the operating condition drop point of the engine on the characteristic curve of the compressor moves towards the direction of larger air inlet flow and far from surge, because the surge margin of the engine is increased and the air-fuel ratio is increased at the moment, the fuel injection quantity of the engine can be increased, so that higher torque output can be obtained, the problem of supercharger surge can not be caused, and the reliability of the supercharger is improved.

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 structural diagram of a supercharging system according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another supercharging system provided by an embodiment of the present invention;

wherein in FIGS. 1-2: 1. an engine body; 2. a main intercooler; 3. bypassing an intercooler; 4. a supercharger; 4-1, a gas compressor; 4-2, a turbine; 5. a bypass valve; 6. an electrical pressure regulating valve; 7. an air intake duct; 8. an exhaust duct; 9. and a controller.

Detailed Description

The core of the invention is to provide a supercharging system of an engine to improve the reliability of a supercharger. Another core of the present invention is to provide an engine including the supercharging system described above.

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and embodiments.

Please refer to fig. 1 and fig. 2.

In one embodiment, the supercharging system for an engine according to an embodiment of the present invention includes an intake conduit 7, an exhaust conduit 8, a bypass conduit, and a bypass valve 5. Wherein the supercharging system may be used in a diesel engine. An air inlet pipe 7 connects the compressor 4-1 and the engine body 1, and an exhaust pipe 8 connects the engine body and the turbine 4-2. The inlet end of the bypass pipeline is connected with the inlet pipeline 7, and the outlet end of the bypass pipeline is connected with the exhaust pipeline 8. The bypass valve 5 is arranged on the bypass pipeline and controls the ventilation volume of the bypass pipeline, wherein the bypass valve 5 can be specifically an electromagnetic valve.

In order to avoid gas backflow, a one-way valve is arranged on the bypass pipeline, so that gas in the bypass pipeline can flow to the exhaust pipeline 8 as far as possible.

When the engine works specifically, the bypass valve 5 can be opened by a preset angle according to the condition that the average effective pressure of the engine is smaller than a preset value or the air pressure in the air inlet pipeline 7 is higher than the preset value of the air pressure in the air outlet pipeline 8. The angle at which the bypass valve 5 is opened depends on the actual engine operating requirements and is not specifically limited in this application.

As can be seen from the above description, in the supercharging system of the engine provided in the embodiment of the present application, the bypass valve 5 is appropriately opened by a certain opening degree according to the requirement under the appropriate working condition, the supercharged intake air is bypassed to the exhaust duct 8 under the action of the pressure difference, the exhaust flow and energy are increased after bypassing, which increases the output power of the turbine 4-2, the power consumed by the compressor 4-1 is the output power of the turbine 4-2 (after mechanical loss is removed), that is, the power of the compressor 4-1 is correspondingly increased at this time, the intake flow is increased, that is, the operating point of the engine on the characteristic curve of the compressor 4-1 is moved toward the direction of larger intake flow and away from surge, and because the engine margin is increased and the air-fuel ratio surge is increased at this time, the engine can increase the fuel injection flow to obtain higher torque output, the low-speed large torque of the engine can be effectively improved, the problem of surge of the supercharger 4 can not be caused, and the reliability of the supercharger 4 is improved.

In order to further improve the engine exhaust system reliability, a bypass line is preferably used to convey charge air through the charge air cooler to the exhaust line 8. The fresh air with controllable bypass temperature can also properly reduce the exhaust temperature, thereby achieving the purpose of improving the reliability of the exhaust system.

In one embodiment the charge air cooler comprises a main charge air cooler 2 arranged in an inlet duct 7 and a bypass charge air cooler 3 mounted in a bypass duct having an inlet upstream of the main charge air cooler 2.

In particular, the bypass intercooler 3 is located upstream of the bypass valve 5.

Further, the supercharging system also comprises a switch valve for opening and closing the bypass intercooler 3. The intake air downstream from the compressor 4-1 of the supercharger 4 is bypassed to the exhaust gas upstream from the turbine 4-2. The purpose of the bypass intercooler 3 is to cool the bypassed gas, which is beneficial to properly reduce the temperature of the total exhaust gas flowing into the turbine 4-2 and ensure that the turbine 4-2 is not overheated. By setting the switch valve, the bypass intercooler 3 can be selectively turned on or off according to actual conditions.

In another embodiment the charge air cooler is located in the inlet duct 7 and the inlet of the bypass duct is located downstream of the charge air cooler. As shown in the following, the arrangement mode omits the situation that an intercooler is separately arranged on the bypass pipeline, so that the arrangement is easier and the economical efficiency is better.

For automatic control, the supercharging system preferably also comprises a controller 9 which controls the opening and closing of the bypass valve 5.

Specifically, the bypass valve 5 is an air-operated valve, and further includes an electric pressure regulating valve 6 connecting the bypass valve 5 and a controller 9, and the controller 9 drives the electric pressure regulating valve 6 to control the opening degree of the bypass valve 5.

Specifically, when the engine speed or the fuel injection amount exceeds a preset value, the controller 9 controls the bypass valve 5 to open a preset angle. Of course, the controller 9 may control the bypass valve 5 to open according to the engine speed and the fuel injection amount exceeding the preset values while satisfying the corresponding preset values.

Further, when the difference between the temperature difference between the average exhaust temperature and the supercharged temperature and the target temperature difference exists, the controller 9 adjusts the opening degree of the bypass valve 5 through a PI algorithm until the actual temperature difference is equal to the target temperature difference, and then closed-loop control is completed.

The application provides open-loop and ECU software control strategy based on temperature difference closed loop, and open-loop (feedforward) control is carried out to the operating mode (rotational speed, fuel injection quantity) of engine operation, and closed-loop control is carried out to the temperature difference (the temperature difference value before whirlpool temperature and after pressurization) in the operation process, and when the engine runs to the operating mode that needs the air inlet bypass, at first open-loop opening degree opens bypass valve 5, and PI closed-loop control is carried out to the target temperature difference at the same time, until the temperature difference reaches the target value, corresponding 5 final opening degrees of bypass valve are obtained.

Taking a certain working condition (A100) as an example, when the bypass valve 5 is fully closed, the average effective pressure is 2.9MPa, the pressure after supercharging is 200kPa, the average exhaust pressure is 100kPa, the temperature after supercharging is 165 ℃, the average exhaust temperature is 550 ℃, and the intake flow is 1700 kg/h; when 15% of opening degree in the bypass valve 5 is given and the oil injection amount is calibrated again, the average effective pressure is 4.3MPa, the pressure after pressurization is 300kPa, the average pressure of exhaust gas is 200kPa, the temperature after pressurization is 230 ℃, the average temperature of exhaust gas is 830 ℃, and the flow of inlet gas is 2300 kg/h; if the surge margin and the average effective pressure at the moment both meet the design requirements, the corresponding opening of the bypass valve 5 is 15 percent, namely the final setting result of the open-loop control.

Closed-loop control conditions and specific steps: still taking a certain working condition (a100) as an example, as shown by the above parameters, the bypass valve 5 is opened from closing to 15% and the fuel injection amount is calibrated, the temperature difference is changed from 385 ℃ (550 minus 165) to 600 ℃ (830 minus 230), the temperature difference is taken as a closed-loop target, the open-loop opening is taken as a feedforward, when the actual temperature difference and the target temperature difference have a deviation, the opening of the bypass valve 5 is adjusted through a PI algorithm until the actual temperature difference is equal to the target temperature difference, closed-loop control is completed, and the closed-loop control is mainly aimed at solving the problem of poor consistency possibly existing in the open-loop control. In the process of closed-loop control, the open-loop opening degree is used as feedforward, so that consistency control is more reasonable.

The final opening of the bypass valve 5 is not limited to 15% during the specific operation of the engine, but depends on the specific requirements of the engine.

The application provides an engine, which comprises a supercharging system, wherein the supercharging system is any one of the supercharging systems. The foregoing describes a specific structure of the supercharging system, and the present application includes the supercharging system described above, and also has the technical effects described above.

In particular, the engine may be a diesel engine.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

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.