Diesel Exhaust Fluid Dosing System for Diesel Engine Aftertreatment Module

• US 20160160725A1
• Filed: 12/05/2014
• Published: 06/09/2016
• Est. Priority Date: 12/05/2014
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Hudgens, Jason, Fahrenkrug, Matthew, Cassidy, Theron, Cole, Brian, Dea, Kevin
• Granted Patent: US 9,512,763 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01N 2570/14 Nitrogen oxides
• CPC Class Codes: F01N 2590/08 for heavy duty applications, e.g. trucks, buses, tractors, locomotives
• CPC Class Codes: F01N 2610/02 the substance being ammonia or urea
• CPC Class Codes: F01N 2610/14 Arrangements for the supply of substances, e.g. conduits
• CPC Class Codes: F01N 2610/1453 Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
• CPC Class Codes: F01N 2610/1486 Means to prevent the substance from freezing
• CPC Class Codes: F01N 3/2066 Selective catalytic reduction [SCR]
• CPC Class Codes: F01N 3/2892 Exhaust flow directors or the like, e.g. upstream of catalytic device
• CPC Class Codes: F01N 3/2896 Liquid catalyst carrier
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A dosing system for dosing diesel exhaust fluid (DEF) into an inlet of a selective catalytic reduction (SCR) aftertreatment module of a diesel engine is described. The dosing system may comprise a DEF supply line configured to deliver the DEF from a pump to a first injector and a second injector at the inlet. The DEF supply line may include a tri-axis connector configured to split the DEF from the pump into two portions each exiting one of a first outlet port and a second outlet port, a first delivery conduit configured to deliver the DEF exiting the first outlet port to the first injector, and a second delivery conduit configured to deliver the DEF exiting the second outlet port to the second injector. The first injector and the second injector may dose the same quantity of the DEF into the inlet of the aftertreatment module.

Claims

1. A dosing system for dosing diesel exhaust fluid (DEF) into an inlet of a selective catalytic reduction (SCR) aftertreatment module of a diesel engine, comprising:

a pump configured to pump the DEF from a supply tank;

a first injector and a second injector configured to dose the DEF into the inlet of the SCR aftertreatment module; and

a DEF supply line configured to deliver the DEF from the pump to the first injector and the second injector, the DEF supply line including;

a tri-axis connector having a first outlet port and a second outlet port, the tri-axis connector being in fluid communication with the pump and configured to split the DEF from the pump into two portions each exiting one of the first outlet port and the second outlet port;

a first delivery conduit in fluid communication with the first outlet port and configured to deliver the DEF exiting the first outlet port to the first injector; and

a second delivery conduit in fluid communication with the second outlet port and configured to deliver the DEF exiting the second outlet port to the second injector, the first delivery conduit and the second delivery conduit being configured such that the first injector and the second injector dose a same quantity of the DEF into the inlet.

2. The dosing system of claim 1, wherein a dosing variance between the first injector and the second injector does not exceed 10%.

3. The dosing system of claim 1, wherein the first delivery conduit has a length L1 and the second delivery conduit has a length L2, and wherein L1 is equal to L2.

4. The dosing system of claim 1, wherein the tri-axis connector is a T-connector.

5. The dosing system of claim 1, wherein the tri-axis connector is a Y-connector.

6. The dosing system of claim 1, wherein the dosing system further comprises a heating system configured to heat the DEF in the DEF supply line, and wherein the tri-axis connector is configured to provide a clearance for the heating system.

7. The dosing system of claim 6, wherein the heating system includes a plurality of electrical circuits configured to heat separate portions of the DEF supply line, and wherein the plurality of electrical circuits are powered by a power driver.

8. The dosing system of claim 6, wherein the heating system includes a plurality of electrical circuits configured to heat separate portions of the DEF supply line, and wherein the plurality of electrical circuits are powered by a plurality of power drivers.

9. The dosing system of claim 8, wherein the DEF supply line further includes a supply conduit configured to receive the DEF from the pump, and wherein the tri-axis connector further includes an inlet port in fluid communication with the supply conduit and is configured to receive the DEF from the supply conduit.

10. The dosing system of claim 9, wherein the supply conduit is heated by a first electrical circuit powered by a first power driver, and wherein the tri-axis connector, the first delivery conduit, and the second delivery conduit are heated by a second electrical circuit powered by a second power driver.

11. A diesel engine system, comprising:

at least one combustion chamber;

an exhaust line; and

a selective catalytic reduction (SCR) aftertreatment module in fluid communication with the exhaust line and including an inlet, an SCR catalyst downstream of the inlet, and a dosing system configured to dose diesel exhaust fluid (DEF) into the inlet, the dosing system including

a pump configured to pump the DEF from a supply source,

a first injector and a second injector mounted on a top of the inlet and being configured to inject the DEF into the inlet, and

a DEF supply line mounted on a side of the SCR aftertreatment module and being configured to deliver the DEF from the pump to the first injector and the second injector, the DEF supply line including

a tri-axis connector having a first outlet port and a second outlet port, the tri-axis connector being in fluid communication with the pump and configured to split the DEF from the pump into two portions each exiting one of the first outlet port and the second outlet port,

a first delivery conduit in fluid communication with the first outlet port and configured to deliver the DEF exiting the first outlet port to the first injector, and

a second delivery conduit in fluid communication with the second outlet port and configured to deliver the DEF exiting the second outlet port to the second injector, the first delivery conduit and the second delivery conduit being configured such that the first injector and the second injector dose a same quantity of the DEF into the inlet.

12. The diesel engine system of claim 11, wherein a dosing variance between the first injector and the second injector does not exceed 10%.

13. The diesel engine system of claim 11, wherein the first delivery conduit has a length L1 and the second delivery conduit has a length L2, and wherein L1 is equal to L2.

14. The diesel engine system of claim 11, wherein the tri-axis connector is a T-connector.

15. The diesel engine system of claim 11, wherein the tri-axis connector is a Y-connector.

16. The diesel engine system of claim 11, wherein the dosing system further comprises a heating system configured to heat the DEF in the DEF supply line, and wherein the tri-axis connector is configured to provide a clearance for the heating system.

17. The diesel engine system of claim 16, wherein the heating system includes a plurality of electrical circuits configured to heat separate portions of the DEF supply line, and wherein the plurality of electrical circuits are powered by a plurality of power drivers.

18. The diesel engine system of claim 17, wherein the DEF supply line further includes a supply conduit configured to receive the DEF from the pump, and wherein an inlet port of the tri-axis connector is in fluid communication with the supply conduit and is configured to receive the DEF from the supply conduit.

19. The diesel engine system of claim 18, wherein the supply conduit is heated by a first electrical circuit powered by a first power supply, and wherein the tri-axis connector, the first delivery conduit, and the second delivery conduit are heated by a second electrical circuit powered by a second power supply.

20. A method for dosing diesel exhaust fluid (DEF) into an inlet of a selective catalytic reduction (SCR) aftertreatment module of a diesel engine, comprising:

splitting a flow of the DEF from a pump into two portions with a tri-axis connector, the two portions each exiting one of a first outlet port and a second outlet port of the tri-axis connector;

flowing the DEF exiting the first outlet port through a first delivery conduit;

flowing the DEF exiting the second outlet port through a second delivery conduit;

heating the DEF flowing through the tri-axis connector, the first delivery conduit, and the second delivery conduit with a heating system, the tri-axis connector being configured to provide a clearance for the heating system;

delivering the DEF from the first delivery conduit to a first injector;

delivering the DEF from the second delivery conduit to a second injector; and

dosing the DEF into the inlet of the SCR aftertreatment module with the first injector and the second injector, the first injector and the second injector dosing a same quantity of the DEF into the inlet.