Method for determining the low pressure exhaust gas recirculation mass flow in the air system of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9228508-B2
Application number	US-201213450747-A
Country	US
Kind code	B2
Filing date	Apr 19, 2012
Priority date	Apr 29, 2011
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

In a method for determining a low pressure exhaust gas recirculation mass flow {dot over (m)} Opt in the air system of an internal combustion engine ( 10 ) with low pressure exhaust gas recirculation, the determination of the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt involves a preliminary low pressure exhaust gas recirculation mass flow {dot over (m)} EGRLPDs which is determined from a function involving, in particular, the pressure p 42 upstream and the pressure p 12 downstream of a low pressure side exhaust gas recirculation valve EGRVIvLP ( 29 ), the temperature T EGRVIvPUs downstream of the low pressure side exhaust gas recirculation valve ( 29 ), and the geometry ar EGRVIvLP of the low pressure side exhaust gas recirculation valve ( 29 ). According to the invention, at least one mass balance based variable is also considered in the determination of the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt .

First claim

What is claimed is:

1. A method for determining a low pressure exhaust gas recirculation mass flow {dot over (m)} Opt in an air system of an internal combustion engine ( 10 ) with low pressure exhaust gas recirculation, determining by a controller the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt based on a preliminary low pressure exhaust gas recirculation mass flow {dot over (m)} EGRLPDs using a function involving a pressure p 42 upstream and a pressure p 12 downstream of a low pressure side exhaust gas recirculation valve EGRVIvLP ( 29 ), a temperature T EGRVlvPUs upstream of the low pressure side exhaust gas recirculation valve ( 29 ), and a geometry ar EGRVlvLP of the low pressure side exhaust gas recirculation valve ( 29 ), characterized in that the controller determines the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt using a mass balance based variable which is a modeled mass flow {dot over (m)} EGRLPPTN which involves mass flows on an air feed side of the air system;
wherein the controller determines the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt using a weighting of the preliminary low pressure exhaust gas recirculation mass flow {dot over (m)} EGRLPDs and the mass balance based mass flow {dot over (m)} EGRLPPTN ; and
wherein the controller controls a combustion of the internal combustion engine by controlling the low pressure exhaust gas recirculation based on the determined low pressure exhaust gas recirculation mass flow {dot over (m)} Opt .

2. The method according to claim 1 , characterized in that the mass flows on the air feed side of the air system includes at least one of a mass flow at the inlet of the internal combustion engine ( 10 ), a high pressure side exhaust gas recirculation mass flow, and a fresh air mass flow.

3. The method according to claim 1 , characterized in that the mass flows on the air feed side of the air system includes a mass flow at the inlet of the internal combustion engine ( 10 ).

4. The method according to claim 1 , characterized in that the mass flows on the air feed side of the air system includes a high pressure side exhaust gas recirculation mass flow.

5. The method according to claim 1 , characterized in that the mass flows on the air feed side of the air system includes a fresh air mass flow.

6. The method according to claim 1 , characterized in that the low pressure exhaust gas recirculation mass flow {dot over (m)} Opt is determined using the formula
{dot over (m)} Opt =C 1 *{dot over (m)} EGRLPDs +(1− C 1 )* {dot over (m)} EGRLPPTN

C 1 being a weighting factor.

7. The method according to claim 6 , characterized in that the weighting factor is selected as a function of standard deviations of the determination of the preliminary low pressure exhaust gas recirculation mass flow {dot over (m)} EGRLPDs and of the mass balance based mass flow {dot over (m)} EGRLPPTN , the value with the smaller standard deviation being given a higher weight.

8. The method according to claim 1 characterized in that the determination of the mass balance based mass flow {dot over (m)} EGRLPPTN involves:
a mass flow {dot over (m)} 22 at an inlet of the internal combustion engine ( 10 ), which is a function of the air consumption and/or an engine speed and/or an engine volume and/or a temperature at the inlet of the internal combustion engine ( 10 ) and/or a pressure at the inlet of the internal combustion engine ( 10 ), and/or
a measured or modeled high pressure exhaust gas recirculation mass flow {dot over (m)} EGRHP and/or
a measured or modeled fresh air mass flow {dot over (m)} 10 and/or
a dynamic correction variable

d
dt

⁢

M
21

,

 which is a function of a volume between a compressor ( 16 b ) and a throttle valve ( 18 ) of the air system.

9. The method according to claim 8 , characterized in that the mass flow {dot over (m)} 22 is measured.

10. The method according to claim 8 , characterized in that the mass flow {dot over (m)} 22 is modeled.

11. The method according to claim 8 , characterized in that the mass balance based mass flow {dot over (m)} EGRLPPTN is determined with the formula

m
.

EGRLPPTN

=

m
.

22

-

m
.

EGRHP

+

d
dt

⁢

M
21

-

m
.

10

.

12. The method according to claim 1 , characterized in that the preliminary low pressure exhaust gas recirculation mass flow {dot over (m)} EGRLPDs is determined with the formula

m
.

EGRLPDs

=

c
2

⁢

1

T
EGRVlvLPUs

*

p
42

*

ar
EGRVlvLP

*

ψ
⁡

(

p
12

p
42

)

.

13. A computer program which executes a method in accordance with claim 1 on an arithmetic unit or a controller.

14. A computer program product with program code stored on a machine readable carrier, for carrying out a method in accordance with claim 1 when the program is executed on an arithmetic unit or a controller.

15. A method for determining a low pressure exhaust gas recirculation mass flow {dot over (m)} Opt in an air system of an internal combustion engine ( 10 ) with low pressure exhaust gas recirculation, determining by a controller t

Assignees

• Blumendeller Wilhelm
• Bleile Thomas
• Sievert Arvid
• Hoerner Martin
• Huck Rene
• Bosch Gmbh Robert

Inventors

• Blumendeller Wilhelm
• Bleile Thomas
• Sievert Arvid
• Hoerner Martin
• Huck Rene

Classifications

• F02D41/0072

  Estimating, calculating or determining the EGR rate, amount or flow (sensors in EGR systems F02M26/45) · CPC title

• F02D21/08 Primary

  the other gas being the exhaust gas of engine · CPC title

• F02M26/05

  High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor · CPC title

• F02M26/25

  with coolers having bypasses · CPC title

• F02M26/24

  with two or more coolers · CPC title