Method pertaining to air removal from a liquid supply system and a liquid supply system

Patent metadata

Field	Value
Publication number	US-9624807-B2
Application number	US-201113806213-A
Country	US
Kind code	B2
Filing date	Jun 20, 2011
Priority date	Jun 21, 2010
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A method pertaining to a liquid supply system which supplies liquid to a feed device ( 230 ) via which liquid is supplied to at least one consumption point ( 250 ): Determining presence of air supplied upstream to the feed device ( 230 ), and, when presence of air is found, of reducing operating power of the feed device ( 230 ) compared with ordinary operation. Also a computer program product containing program code (P) for a computer ( 200; 210 ) for implementing the method. Also a device and a motor vehicle ( 100 ) which is equipped with the device.

First claim

The invention claimed is:

1. A method of operating a liquid supply system of an SCR exhaust system comprising:
providing a container, an electric pump and a supply line to supply liquid from the container to the electric pump via the supply line, the pump supplying the liquid back to the container and to the exhaust system via a dosing unit that includes a dosing valve;
operating the pump at a predetermined power level;
detecting presence of air supplied upstream of the pump with a pressure sensor, and determining presence of air supplied upstream of the pump with a control unit; and
operating the pump at a reduced power by reducing an operating power of the pump to a level below the predetermined level in response to detecting presence of air supplied upstream of the pump; and
maintaining the reduced operating power of the pump while supplying liquid to the exhaust system and back to the container via the dosing unit until no longer the detected presence of air is present.

2. A method according to claim 1 , wherein the desirable level corresponds to one of a predetermined operating power for the pump and a predetermined working pressure of the liquid supplied by the pump.

3. A method according to claim 1 , wherein the liquid is a reducing agent.

4. A method according to claim 1 , wherein the pump is a diaphragm pump.

5. A method according to claim 1 , further comprising reducing the operating power supplied to the pump by at least 40%, compared to the predetermined level.

6. A method according to claim 1 , further comprising increasing the reduced operating power supplied to the pump in at least one stage, or by ramping, to any suitable operating power.

7. A liquid supply system for supplying liquid to an exhaust system, the system comprising:
an electric pump operable to transmit liquid from a container and operable to supply liquid to the exhaust system via a dosing valve of a dosing unit, and from the dosing unit back to the container;
a liquid supply line connected to the electric pump and to the dosing unit to supply liquid from the pump to the exhaust system via the dosing valve;
another liquid supply line connected to the dosing unit and the container to supply liquid from the dosing unit to the container, and
a control device including a data processor is configured to determine the presence of air supplied upstream of the pump by detecting presence of air supplied upstream of the pump via a pressure sensor;
the control device is further configured to operate the pump at a predetermined power level;
the control device is further configured to reduce an operating power supplied to the electric pump to a level below the predetermined level in response to determination of the presence of air supplied upstream of the pump,
the control device is further configured to maintain the reduced operating power until no longer the determined presence of air is present while supplying liquid to the exhaust system and back to the container,
wherein the electric pump receives power at the predetermined level to supply liquid to the dosing valve via the supply line, and
the electric pump, the liquid supply line, the another liquid supply line and the dosing valve are connected in a configuration to supply liquid to the dosing valve via the liquid supply line, and to supply liquid to the container from the dosing unit via the another liquid supply line by the electric pump when the operating power supplied to the electric pump is reduced below the predetermined level.

8. A liquid supply system according to claim 7 , in which the desirable level corresponds to one of a predetermined operating power of the pump and predetermined working pressure of the liquid supplied by the pump.

9. A liquid supply system according to claim 7 , wherein the liquid is a reducing agent.

10. A liquid supply system according to claim 7 , wherein the pump is a diaphragm pump.

11. A liquid supply system according to claim 7 ,
wherein the control device reduces the operating power of the pump by at least 40% compared with the predetermined level.

12. A liquid supply system according to claim 7 , wherein the control device increases the reduced operating power supplied to the pump in at least one stage, or by ramping, to any suitable operating power.

13. A vehicle comprising a liquid supply system according to claim 7 and a motor vehicle.

14. A motor vehicle according to claim 13 , wherein the motor vehicle is selected from a group consisting of a truck, a bus and passenger car.

15. A system comprising the liquid supply system of claim 7 , wherein the system is an SCR system.

Assignees

• Eriksson Lars
• Carlsson Ulf
• Scania Cv Ab

Inventors

• Eriksson Lars
• Carlsson Ulf

Classifications

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• F01N2900/1822

  Pump parameters · CPC title

• F01N3/208 Primary

  Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent · CPC title

• F01N2610/1466

  Means for venting air out of conduits or tanks · CPC title

• F01N9/00 Primary

  Electrical control of exhaust gas treating apparatus (monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00) · CPC title