Method of controlling a combustion engine equipped with double supercharging

Patent metadata

Field	Value
Publication number	US-9879592-B2
Application number	US-201314427480-A
Country	US
Kind code	B2
Filing date	Aug 12, 2013
Priority date	Sep 11, 2012
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

The invention relates to a method for controlling a combustion engine ( 1 ) equipped with a supercharging system, comprising a turbocharger ( 2 ) and a mechanical compressor ( 3 ) and a bypass circuit disposed in parallel with the mechanical compressor comprising a controlled bypass valve ( 4 ). The method includes:
a) acquiring a boost pressure setpoint P sural sp ; b) converting the boost pressure setpoint P sural sp into an opening setpoint Bypass sp of the bypass valve ( 4 ) using a filling model modelling the filling of the supercharging boost volume between the intake valves of the engine ( 1 ) and the mechanical compressor ( 3 ) and bypass valve ( 4 ); and c) controlling the bypass valve ( 4 ) is according to the opening setpoint Bypass sp of the bypass valve.

First claim

The invention claimed is:

1. A method for controlling a combustion engine equipped with a supercharging system including a turbocharger and a mechanical compressor for compressing a gaseous mixture on an intake side of the engine and a bypass circuit disposed in parallel with the mechanical compressor including a controlled bypass valve, comprising:
a) acquiring a boost pressure setpoint;
b) converting the boost pressure setpoint into an opening setpoint of the bypass valve by use of a filling model modelling filling of a supercharging boost volume disposed between intake valves of the engine and the mechanical compressor and the bypass valve; and
c) controlling the bypass valve according to the opening setpoint of the bypass valve.

2. A method according to claim 1 , comprising determining:
a pressure and a temperature upstream of the mechanical compressor and a boost pressure and a boost temperature on an intake side of the engine; and wherein
the filling model modelling filling of the supercharging boost volume links the boost pressure to opening of the bypass valve by use of the pressure and the temperature upstream of the mechanical compressor and the boost temperature.

3. A method according to claim 2 , comprising:
determining the boost pressure and the boost temperature by use of pressure and temperature sensors disposed upstream of an intake manifold of the engine.

4. A method according to claim 3 , comprising:
determining the pressure and the temperature upstream of the mechanical compressor by use of pressure and temperature sensors disposed upstream of the mechanical compressor.

5. A method according to claim 3 , comprising:
determining the pressure and the temperature upstream of the mechanical compressor by using an estimator which is dependent on the boost pressure and the boost temperature.

6. A method according to claim 3 , comprising determining the filling model based on a filling equation expressing filling of the supercharging boost volume with a conservation-of-flow rate relationship:

P
.

sural

=

RT
sural

V
sural

⁢

(

D
cm

-

D
bp

-

D
asp

)

where {dot over (P)} sural is the first derivative of the boost pressure P sural with respect to time, R is the perfect gas constant, V sural is the supercharging boost volume, D cm is a flow rate arriving from the mechanical compressor, D bp is a flow rate leaving through the bypass valve which is a function of opening of the bypass valve and D asp is an aspirated flow rate flowing toward cylinders of the engine.

7. A method according to claim 6 , comprising determining the flow rate D bp flowing through the bypass valve determined from a pressure drop relationship:
D bp =A bp (Bypass)· f ( P avcm ,P sural ,T avcm )

where A bp (Bypass) is an area of opening of the bypass valve and f is the flow rate per unit area defined by a formula:

f
⁡

(

P
avcm

,

P
sural

,

T
avcm

)

=

P
sural

RT
avcm

⁢

{

(

P
avcm

P
sural

)

1
γ

⁢

2

γ
-
1

⁢

(

1
-

(

P
avcm

P
sural

)

γ
-
1

γ

)

if
⁢

⁢

(

P
avcm

Assignees

• Ifp Energies Now

Inventors

• Leroy Thomas
• Chauvin Jonathan
• Chasse Alexandre

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02B37/16

  by bypassing charging air · CPC title

• F02M26/06

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

• F02D21/08

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

• F02B29/0406

  Layout of the intake air cooling or coolant circuit · CPC title