Method and control device for operating a common-rail fuel supply system

Patent metadata

Field	Value
Publication number	US-11220986-B2
Application number	US-202015931319-A
Country	US
Kind code	B2
Filing date	May 13, 2020
Priority date	May 15, 2019
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A method for operating a common-rail fuel supply system of an internal combustion engine includes determining, dependent on an operating point of the engine, a set point rate of delivery of the high-pressure pumping device, and a set point pressure for the pressure storage system under high pressure, determining, dependent on a deviation between the set point pressure and an actual pressure in the pressure storage system, for a first part quantity of the throttle valves a closed-loop control portion for the position of the respective throttle valve, and activating the first part quantity of the throttle valves with the closed-loop control portion in addition to open-loop control for only the respective throttle valve of the first part quantity of the throttle valves. The, or each, throttle valve of a second part quantity of the throttle valves is exclusively activated with the open-loop control portion.

First claim

We claim:

1. A method for operating a common-rail fuel supply system of an internal combustion engine configured as a diesel internal combustion engine of a ship, the common-rail fuel supply system having a low-pressure region ( 4 ), a high-pressure region ( 6 ) and a high-pressure pumping device ( 3 ) having at least two high-pressure pumps ( 2 ), with the help of which fuel from the low-pressure region ( 4 ) of the fuel supply system is deliverable into the high-pressure region ( 6 ) of the fuel supply system, wherein in the high-pressure region ( 6 ) between the high-pressure pumping device ( 3 ) and injectors ( 1 ) assigned to cylinders, a pressure storage system ( 7 ) that is under high pressure is provided, and wherein a rate of delivery of the high-pressure pumping device ( 3 ) is adjustable by way of throttle valves ( 13 ) upstream of the high-pressure pumps ( 2 ), the method comprising:
determining, dependent on a requested operating point of the internal combustion engine, a set point rate of delivery of the high-pressure pumping device ( 3 ), and a set point pressure for the pressure storage system ( 7 ) under high pressure,
determining, dependent on the set point rate of delivery of the high-pressure pumping device ( 3 ) for all throttle valves ( 13 ), a control portion for the position of the respective throttle valve ( 13 ), and activating the respective throttle valve ( 13 ) with the determined control portion,
determining, dependent on a deviation between the set point pressure and an actual pressure in the pressure storage system ( 7 ) under high pressure, for a first part quantity of the throttle valves ( 13 ) a closed-loop control portion for the position of the respective throttle valve ( 13 ), and activating the first part quantity of the throttle valves ( 13 ) with the closed-loop control portion in addition to open-loop control for only the respective throttle valve ( 13 ) of the first part quantity of the throttle valves ( 13 ), whereas the, or each, throttle valve ( 13 ) of a second part quantity of the throttle valves ( 13 ) is exclusively activated with the open-loop control portion, and
exchanging or replacing, the, or each, throttle valve ( 13 ) of the first part quantity of the throttle valves ( 13 ), with a throttle valve of the second part quantity of the throttle valves ( 13 ).

2. The method according to claim 1 , wherein the first part quantity of the throttle valves ( 13 ), which are activated with the open-loop control portion and the closed-loop control portion, comprises a single throttle valve for each cylinder bank.

3. The method according to claim 2 , wherein the exchanging or replacing is performed in a time-controlled manner.

4. The method according to claim 3 , wherein the exchanging or replacing is performed after expiration of a defined period of time.

5. The method according to claim 1 , wherein the exchanging or replacing is performed in an event-controlled manner.

6. The method according to claim 5 , wherein the exchanging or replacing is performed during an engine start.

7. The method according to claim 1 , further comprising determining the set point rate of delivery and the set point pressure dependent on a requested load of the internal combustion engine.

8. A common-rail fuel supply system of an internal combustion engine configured as a diesel internal combustion engine of a ship, comprises:
a low-pressure region ( 4 );
a high-pressure region ( 6 );
a high-pressure pumping device ( 3 ) comprising at least two high-pressure pumps ( 2 ) configured to deliver fuel from the low-pressure region ( 4 ) of the fuel supply system into the high-pressure region ( 6 );
a pressure storage system ( 7 ) under high pressure arranged in the high-pressure region ( 6 ) between the high-pressure pumping device ( 3 ) and injectors ( 1 ) assigned to cylinders of the internal combustion engine;
a plurality of throttle valves arranged upstream of the high-pressure pumps ( 2 ), and configured to adjust a rate of delivery of the high-pressure pumping device ( 3 ); and
a controller,
wherein the controller, dependent on a requested operating point of the internal combustion engine on the one hand, determines a set point rate of delivery of the high-pressure pumping device ( 3 ) and a set point pressure for the pressure storage system ( 7 ) under high pressure,
wherein the controller, dependent on the set point rate of delivery of the high-pressure pumping device ( 3 ), determines a control portion for the position of the respective throttle valve ( 13 ) for each throttle valve ( 13 ), with which the controller activates each throttle valve ( 13 ),
wherein the controller, dependent on a deviation between the set point pressure and an actual pressure in the pressure storage system ( 7 ) under high pressure, is configured to determine a closed-loop control portion for the position of the respective throttle valve ( 13 ) for a first part quantity of the throttle valves ( 13 ), with which the controller, in addition to open-loop control, activates the respective throttle valve ( 13 ) of the first part quantity of the throttle valves ( 13 ), whereas the controller activates the, or each, throttle valve ( 13 ) of a second part quantity of the throttle valves ( 13 ) exclusively with the open-loop control portion, and
wherein the controller controls exchanging or replacing, of the, or each, throttle valve ( 13 ) of the first part quantity of the throttle valves ( 13 ), with a throttle valve of the second part quantity of the throttle valves ( 13 ).

Assignees

• Man Energy Solutions Se

Inventors

• Meier Christian
• Seibt Marcus

Classifications

• F02M63/0056

  Throttling valves, e.g. having variable opening positions throttling the flow · CPC title

• F02M63/0225 Primary

  Fuel-injection apparatus having a common rail feeding several injectors (F02M63/0003 takes precedence); Means for varying pressure in common rails; Pumps feeding common rails · CPC title

• F02M2200/315

  for damping fuel pressure fluctuations · CPC title

• F02D19/0684

  High pressure fuel injection systems; Details on pumps, rails or the arrangement of valves in the fuel supply and return systems · CPC title

• F02M37/0064 Primary

  for engines being fed with multiple fuels or fuels having special properties, e.g. bio-fuels; varying the fuel composition (controlling engines working with pluralities of fuels F02D19/06) · CPC title