DE10315148A1 - Operating supercharger for IC engine, has a compressor for compressing air and an exhaust gas turbocharger with a blower and a turbine - Google Patents

Abstract

A valve (13) for switching a flow path fits on a secondary (15) for a compressor (12) and this secondary links in the valve's first position, i.e. in the valve's first mode, to a primary (16) for a turbine (11). In the valve's second position, i.e. in the valve's second mode, the compressor's secondary links to the turbine's secondary (17). The compressor's primary (14) links to a blower's (10) primary (18). An independent claim is also included for a method for controlling an internal combustion engine.

Description

The The invention relates to an internal combustion engine with an exhaust gas turbocharger and a compressor according to the preamble of claim 1 and a control method therefor.

at an internal combustion engine is about an exhaust gas turbocharger determines the boost pressure. With a significant increase of the desired performance, the boost pressure is increased with a delay. Due to the desired performance, the injected is simultaneously Fuel quantity increased. Out the elevated Amount of fuel and the delayed Charging pressure buildup result in increased Emission values and an increased Turbidity.

A compressor improves the situation. This promotes an additional volume of air into the combustion chambers of the internal combustion engine in the event of a full load jump in the power requirement. With one from the DE 42 10 070 C1 Known solution, the compressor is arranged on the secondary side of the compressor, ie between the exhaust gas turbocharger and the internal combustion engine. The charge air is therefore first delivered by the compressor of the exhaust gas turbocharger and then compressed by the compressor.

With one from the DE 33 17 017 A1 known solution, a compressor is arranged on the primary side of the compressor, ie it is connected upstream of the exhaust gas turbocharger. In addition, a bypass flap is provided to bypass the compressor.

Both Common solutions from the prior art are that the compressor is designed as a so-called full flow compressor. With a full load jump the total air volume must pass through the compressor promoted become. Due to their design, full-flow compressors are therefore built in great Volume. The power requirement of one is also problematic Full flow compressor and the large wire cross sections.

The The invention is based on the object of a space-optimized and performance-optimized solution for one Internal combustion engine with an exhaust gas turbocharger and a compressor provide.

The Object is achieved by the features of claim 1 and a method solved for control according to claim 8. The configurations are in the subclaims shown.

The Invention provides that a valve for switching a flow path on the secondary side the compressor is arranged and in a first position of the Valve the secondary side of the compressor with the primary side the turbine is connected. In this first position of the valve is the one promoted by the compressor Air led to the turbine of the exhaust gas turbocharger. In a second position the valve becomes the secondary side of the compressor with the secondary side connected to the turbine, d. H. the air is directed past the turbine. alternative it is provided that in the second position of the valve the secondary side of the Compressor with the secondary side of the compressor is connected, the connecting line from Secondary valve of the compressor opens between the compressor and a charge air cooler. at this alternative is the primary side of the compressor is also connected to the secondary side of the compressor. The branch to the primary side the compressor is after the charge air cooler.

The The control method provides that starting from idle mode, a first mode is set if one that represents the desired performance Company size one exceeds the first limit. In the first mode, the air delivered by the compressor is then the primary side fed to the turbine. A second mode is then set if the state of the exhaust gas turbocharger representing Company size one exceeds the second limit. When the second mode is set, the air delivered by the compressor to the secondary side blown off the turbine or blown onto the secondary side of the compressor.

By the invention becomes a more spontaneous transition response from idle mode to a higher one Load level achieved. This results in reduced NOx values and a reduced turbidity. Since the control process is based on existing sensor signals recourse, can the control software into existing motor control software with little effort be involved. Overall, the invention offers the advantage that the compressor according to the invention only about a third of the size and power consumption a full flow compressor.

In the drawings are the exemplary embodiments presented the invention.

It demonstrate:

1 a system diagram;

2 a block diagram, first embodiment;

3 a block diagram, second embodiment;

4 a timing diagram;

5 a program schedule.

The 1 shows a system diagram of a drive unit consisting of an internal combustion engine 1 with an engine load 3 , The internal combustion engine 1 drives the engine load via a shaft 3 on. In a marine application, the engine load corresponds 3 for example a boat reversing gear with propeller. An exhaust gas turbocharger is used to charge the internal combustion engine 2 intended. As is known, includes the exhaust gas turbocharger 2 a compressor for compressing the intake air, a turbine for expanding the exhaust gas and a shaft for connecting the compressor to the turbine. The functionality of an exhaust gas turbocharger is assumed to be known in the rest of the text. In the internal combustion engine shown 1 the fuel is injected via a common rail system. This includes the following components: pumps 6 with suction throttle to deliver fuel from a fuel tank 5 , a rail 7 for storing the fuel and injectors 9 for injecting fuel from the rail 7 into the combustion chambers of the internal combustion engine 1 ,

The operating mode of the internal combustion engine 1 is controlled by an electronic control unit (EDC) 4 regulated. The electronic control unit 4 contains the usual components of a microcomputer system, for example a microprocessor, I / O modules, buffers and memory modules (EEPROM, RAM). In the memory modules are those for the operation of the internal combustion engine 1 relevant operating data applied in characteristic curves / characteristic curves. The electronic control unit calculates these 4 from the input variables the output variables. In 1 The following input variables are shown as examples: a rail pressure pCR, which is generated by means of a rail pressure sensor 8th is measured, an actual speed signal nMOT (IST) of the internal combustion engine 1 , an input variable E and a signal FW to specify the desired performance by the operator. In a ship application, this corresponds to the selector lever position. The input variable E includes, for example, the charge air pressure pLL and the speed nATL of the exhaust gas turbocharger 2 as well as the temperatures of the coolants / lubricants and the fuel.

In 1 are the output variables of the electronic control unit 4 a signal ADV to control the pumps 6 With suction throttle, a signal MOD for controlling a valve, a signal KP (optional) for activating / deactivating a compressor and an output variable A are shown. The output variable A represents the other control signals for controlling and regulating the internal combustion engine 1 , for example the start of injection SB and an injection duration SD.

The 2 shows a block diagram of the invention in a first embodiment. The block diagram includes the internal combustion engine as essential components 1 , the exhaust gas turbocharger 2 , a compressor 12 and a valve 13 , The compressor 12 is activated / deactivated via the signal KP. The switching status of the valve 13 is defined via the MOD signal. Of course, it is possible that the compressor cannot be activated separately, but is continuously in operation while the internal combustion engine is operating. The compressor 10 of the exhaust gas turbocharger 2 promotes on the primary side 18 Ambient air, pressure level pL. The compressed air, charge air, is on the secondary side 19 of the compressor 10 via an intercooler 21 and a charge air line 22 the combustion chambers of the internal combustion engine 1 fed. The exhaust gas from the internal combustion engine 1 is via an exhaust pipe to the primary side 16 the turbine 11 of the exhaust gas turbocharger 2 guided. Via a bypass 25 and a wastegate disposed therein 23 becomes the primary side with the secondary side 17 connected. The wastegate 23 and the valve 13 can be designed as a single unit in practice. This optimizes the installation space since only one actuator is required for this. The pressure level on the secondary side 17 the turbine 11 corresponds to the reference symbol pAB.

From the primary side 18 of the compressor 10 branches off a line leading to the primary side 14 of the compressor 12 leads. On the secondary side 15 of the compressor 12 is the valve 13 arranged. In a first position MOD1 of the valve 13 becomes the secondary side 15 of the compressor with the primary side 16 the turbine 11 connected. There is a connecting line for this 20 intended. The first position is also referred to as the first mode in the rest of the text. In a second position MOD2 of the valve 13 becomes the secondary side 15 of the compressor 12 over a line 24 with the secondary side 17 the turbine 11 connected. The second position is also referred to as the second mode in the text below.

When the compressor is deactivated 12 It must be ensured that there is no exhaust gas from the primary turbine 16 via line 20 flows back to the compressor side. To do this, either the valve 13 reversed to the second position (MOD2) or it becomes a check valve 26 intended.

To protect against compressor pumps 10 this can be done with an internal recirculation. Recirculation means that air from the secondary compressor 19 to the primary side compressor 18 is returned. This Rezir kulation can also be switchable.

As an alternative to the recirculation described above, a pipe 27 be provided which from the secondary side compressor 19 to the primary side turbine 16 leads. In this is a switchable valve 28 arranged. This version is in the 2 shown in dashed lines.

The arrangement has the following functionality:
In idle mode of the internal combustion engine 1 the first mode MOD1 is set when an operating variable representing the desired performance exceeds a first limit value. In the first mode MOD1 the valve picks up 13 the first position. The one from the compressor 12 Air extracted is therefore on the primary side 16 the turbine 11 guided. This increases the volume flow in front of the turbine. The second mode MOD2 is set when the state of the exhaust gas turbocharger 2 representative farm size exceeds a second limit. The second mode MOD2 is set if, for example, the charge air pressure pLL on the secondary side 19 of the compressor 10 exceeds the second limit. In the second mode MOD2 the valve takes off 13 the second position. The compressor therefore conveys the air to the secondary side of the turbine 11 , ie the pumped air is blown over.

The 3 shows a block diagram of the invention in a second embodiment. In contrast to the execution according to the 2 is the primary side 14 of the compressor 12 with the "charge air line 22 connected and the valve 13 is over the line 24 with the secondary side 19 of the compressor 10 connected. The administration 24 opens out between the compressor 10 and the charge air cooler 21 , The description of the applies to the functionality 2 , in the second mode the compressor 12 air is blown and the charge air cooler 21 flows through.

The junction of the line 20 in the primary side 16 the turbine 11 can be done in two ways. In the first embodiment, the compressed air is introduced directly into the exhaust gas. In the second embodiment, the compressed air is used to isolate the exhaust pipe and the exhaust gas turbocharger 2 used. From the DE 42 06 247 C1 a three-wall exhaust pipe is known. In this case, the air in the line 20 introduced into the insulating jacket between the exhaust duct and the outer water jacket. Due to the insulating effect of the inflowing air, the thermal energy remains in the exhaust gas or is absorbed by the inflowing air. So this is not removed from the water jacket. This increases the enthalpy of the air and the exhaust gas.

The 4 shows a timing diagram consisting of the sub-figures 4A to 4D. These each show over time: an engine speed setpoint nMOT (SW) ( 4A ), the mode MOD ( 4B ), the speed nATL of the exhaust gas turbocharger ( 4C ) and the charge air pressure pLL ( 4D ). As the operating variable, which represents the operator's desired performance, in 4A the engine speed setpoint nMOT (SW) is selected. In practice, the engine speed setpoint nMOT (SW) is determined from the desired performance via a corresponding characteristic curve or map. Of course, the desired performance can also be mapped using other operating variables, for example throttle valve information. The charge air pressure pLL in 4D represents a state variable of the exhaust gas turbocharger 2 , Instead of the charge air pressure pLL, the temperature of the charge air, the speed nATL of the exhaust gas turbocharger or variables derived therefrom can also be used. In 4C and 4D a curve according to the prior art is shown as a dashed line. The solid line indicates the course according to the invention.

At time t1, the internal combustion engine is in idle mode. The engine speed setpoint nMOT (SW) has the value n1, z. B. 600 revolutions. At time t2, the engine speed setpoint nMOT (SW) exceeds a limit value GW1. In response to this, the first mode is set, ie the signal MOD in 4B changes to 1. In the first mode MODI the valve takes 13 a first position. In this position the compressor 12 delivered air to the primary side of the turbine 11 guided. Due to the increased volume flow on the primary side of the turbine, the speed nATL begins to increase at time t2 at point A in the direction of point B. At time t3, the engine speed setpoint nMOT (SW) reaches the final value n2. Due to the increasing speed nATL of the exhaust gas turbocharger 2 along the line with the points AB the charge air pressure pLL in increases 4D along the solid line with points D and E. At time t5, the charge air pressure pLL exceeds a limit value GW2, point E.

In response to this, the second mode is set. The signal in 4B changes the level from 1 to 2. When the second mode MOD2 is set, the valve picks up 13 the second position. In this is the compressor 12 conveyed air to the secondary side 17 the turbine 11 or secondary side 19 of the compressor 10 guided, ie the air is blown or blown.

From the comparison of the solid lines to the dashed line in 4C and 4D it is clear that the response of the exhaust gas turbocharger is improved by the invention. In 4C a time t4 is shown as an example. At this time, a speed curve according to the invention (solid line) differs from a speed curve according to the prior art (dashed line) by a difference DIFF, corresponding to the distance between points B and C. The same applies to the charge air pressure pLL to this Time. As from the 4D It becomes clear that the charge air pressure pLL according to the invention already reaches the pressure level GW2 at time t5 in point E, in accordance with the prior art only at time t6 in point F.

In 5 a program flow chart for a method according to the invention is shown. At S1 the compressor is activated, e.g. B. with starting the internal combustion engine. As an alternative, the reference symbol S2a provides that the compressor 12 is then activated before the first mode MOD1 is set. At S2 it is checked whether the speed setpoint nMOT (SW) exceeds the first limit value GW1. If this is not the case, a waiting loop is run with S3. If it is determined in S2 that the speed setpoint nMOT (SW) has exceeded the limit value GW1, the first mode MOD1 is set in S4, causing the valve 13 occupies the first position. It is then checked at S5 whether the charge air pressure pLL is greater than the second limit value GW2. If this is not the case, a waiting loop is run through with S6. If the charge air pressure pLL exceeds the second limit value GW2, the second mode MOD2 is set in S7. Then the compressor at S8 12 disabled. This concludes the program flow chart.

For one Steps S1, S2a are omitted from the permanently operated compressor and S8. The sequence therefore also includes steps S2 to S7.

1

Internal combustion engine

2

turbocharger

3

engine load

4

electronic control unit (EDC)

5

Fuel tank

6

pump

7

Rail

8th

Rail pressure sensor

9

injector

10

compressor

11

turbine

12

compressor

13

Valve (3/2)

14

Primary side compressor

15

Secondary side compressor

16

Primary side turbine

17

Secondary turbine

18

Primary side compressor

19

Secondary compressor

20

connecting line

21

Charge air cooler

22

Charge-air line

23

wastegate

24

management

25

bypass line

26

check valve

27

management

28

Valve

Claims (10)

Internal combustion engine ( 1 ) with an exhaust gas turbocharger ( 2 ) for charging the internal combustion engine ( 1 ) which has a compressor ( 10 ) and a turbine ( 11 ) and with a compressor ( 12 ) for the compression of air, characterized in that a valve ( 13 ) for switching a flow path on the secondary side ( 15 ) of the compressor ( 12 ) is arranged and in a first position (MOD1) of the valve ( 13 ) the secondary side ( 15 ) of the compressor ( 12 ) with the primary side ( 16 ) the turbine ( 11 ) is connected. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to claim 1, characterized in that in a second position (MOD2) of the valve ( 13 ) the secondary side ( 15 ) of the compressor ( 12 ) with the secondary side ( 17 ) the turbine ( 11 ) is connected. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to claims 1 and 2, characterized in that the primary side ( 14 ) of the compressor ( 12 ) with the primary side ( 18 ) of the compressor ( 10 ) is connected. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to claim 1, characterized in that in a second position (MOD2) of the valve ( 13 ) the secondary side ( 15 ) of the compressor ( 12 ) with the secondary side ( 19 ) of the compressor ( 10 ) is connected. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to claim 4, characterized in that a connecting line ( 20 ) from the valve ( 13 ) to the secondary side ( 19 ) of the compressor ( 10 ) between the compressor ( 10 ) and an intercooler ( 21 ) flows out. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to claims 4 and 5, characterized in that the primary side ( 14 ) of the compressor ( 12 ) with a charge air line ( 22 ) which connects the charge air cooler ( 21 ) with the internal combustion engine ( 1 ) connects. Internal combustion engine ( 1 ) with exhaust gas turbocharger ( 2 ) and compressor ( 12 ) according to one of the previous claims, characterized in that a wastegate ( 23 ) to bypass the turbine ( 11 ) and the valve ( 13 ) structurally form a unit. Method for controlling an internal combustion engine ( 1 ) with a device designed according to claim 1, characterized in that starting from the idle mode, a first mode (MOD1) is set when an operating variable representing the desired performance (nMOT (SW)) exceeds a first limit value (GW1) (nMOT ( SW)> GW1) and in the first mode (MOD1) the compressor ( 12 ) conveyed air on the primary side ( 16 ) the turbine ( 11 ) is supplied. Method for controlling an internal combustion engine ( 1 ) according to claim 8, characterized in that the compressor ( 12 ) with starting the internal combustion engine ( 1 ) or setting the first mode (MOD1) is activated. Method for controlling an internal combustion engine ( 1 ) according to claim 8, characterized in that a second mode (MOD2) is set when one of the state of the exhaust gas turbocharger ( 2 ) representative operating variable (pLL) exceeds a second limit value (GW2) (pLL> GW2) and in the second mode (MOD2) that of the compressor ( 12 ) conveyed air to the secondary side ( 17 ) the turbine ( 11 ) is blown off or on the secondary side ( 19 ) of the compressor ( 10 ) is blown over.