Electrochemical reductant generation while dosing DEF

Patent metadata

Field	Value
Publication number	US-10188986-B2
Application number	US-201514935094-A
Country	US
Kind code	B2
Filing date	Nov 6, 2015
Priority date	Nov 6, 2015
Publication date	Jan 29, 2019
Grant date	Jan 29, 2019

Abstract

A diesel exhaust fluid (DEF) doser includes a DEF inlet configured to receive DEF, a DEF outlet configured to spray DEF out of the DEF doser, and an electrochemical cell. The electrochemical cell is located between the DEF inlet and the DEF outlet and couplable to a power source. The electrochemical cell is configured such that, when DEF is flowing from the DEF inlet to the DEF outlet and when the electrochemical cell is coupled to the power source, the electrochemical cell causes an electrolytic reaction in the DEF flowing from the DEF inlet to the DEF outlet to produce gaseous products in the DEF flowing from the DEF inlet to the DEF outlet, and wherein the gaseous products comprise one or more of H2 or NH3.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A diesel exhaust fluid (DEF) doser, comprising:
a DEF inlet configured to receive DEF, wherein the DEF includes a solution of urea and water;
a DEF outlet configured to spray DEF out of the DEF doser; and
an electrochemical cell located between the DEF inlet and the DEF outlet and couplable to a power source, wherein the electrochemical cell is configured such that, when DEF is flowing from the DEF inlet to the DEF outlet and when the electrochemical cell is coupled to the power source, the electrochemical cell causes an electrolytic reaction in the DEF flowing from the DEF inlet to the DEF outlet to produce gaseous products in the DEF flowing from the DEF inlet to the DEF outlet, and wherein the gaseous products comprise one or more of H 2 or NH 3 , wherein the electrochemical cell comprises a compartment including a cathode and an anode electrode, wherein the compartment is configured to mix the gaseous products from the cathode and anode electrodes before the DEF outlet.

2. The DEF doser of claim 1 , further comprising a wave form generator configured to vary electrical power from the power source.

3. The DEF doser of claim 1 , wherein the anode and cathode electrodes are coupled to the power source, and wherein the anode and cathode electrodes line portions of the compartment.

4. The DEF doser of claim 3 , wherein at least one of the cathode and anode electrodes comprises at least one of platinum, palladium, nickel, rhodium, ruthenium, tungsten, or titanium.

5. The DEF doser of claim 3 , wherein at least one of the cathode and anode electrodes comprises a metal material of a porous sintered construction, the DEF doser further comprising:
a solid ionically conducting material located between portions of the two electrodes.

6. The DEF doser of claim 5 , wherein the ionically conducting material comprises a proton conducting material configured to be impregnated with hydrophilic mineral particles.

7. The DEF doser of claim 1 , wherein the power source is configured to activate the electrochemical cell with an applied voltage up to about 10V.

8. The DEF doser of claim 1 , further comprising a wave form generator, wherein the power source is configured to activate the electrochemical cell with a pulsed voltage in a range from about −10V to about 10V at a time interval between about 1 μs and about 1 ms.

9. The DEF doser of claim 8 , wherein a current density of the electrolytic reaction in the DEF flowing from the DEF inlet to the DEF outlet caused by the pulsed voltage is in a range from about 1 μA/cm 2 and about 1 mA/cm 2 .

10. The DEF doser of claim 1 , wherein the power source is configured to drive the electrochemical cell with a pulsed voltage that is timed based on a pulsed flow pattern of DEF spray out of the DEF outlet.

11. The DEF doser of claim 1 , wherein a droplet size of DEF spray out of the DEF outlet is controlled based on an applied voltage from the power source.

12. The DEF doser of claim 1 , wherein the electrochemical cell is configured such that a droplet size of DEF spray out of the DEF outlet when the electrolytic reaction occurs in the DEF flowing from the DEF inlet to the DEF outlet is smaller than a droplet size of DEF spray out of the DEF outlet when the electrolytic reaction does not occur.

13. The DEF doser of claim 1 , wherein the electrolytic reaction comprises electro-active vaporization, wherein the electro-active vaporization comprises water electrolysis in the DEF flowing from the DEF inlet to the DEF outlet and accelerated production of the gaseous products in the DEF flowing from the DEF inlet to the DEF outlet.

14. The DEF doser of claim 1 , wherein the electrochemical cell is configured such that an applied voltage to the electrochemical cell causes discharge of one or more DEF deposits at the DEF outlet.

15. The DEF doser of claim 1 , wherein the solution comprises 32.5% urea.

16. A diesel exhaust system, comprising:
a flow channel configured to direct diesel exhaust into a mixing chamber;
a diesel exhaust fluid (DEF) doser configured to spray DEF into the diesel exhaust in the mixing chamber, wherein the DEF includes a solution of urea and water; and
a power source coupled to the DEF doser and configured to provide an applied voltage to the DEF doser;
wherein the DEF doser comprises an electrochemical cell located between a DEF inlet and a DEF outlet, wherein the electrochemical cell is configured such that, when the applied voltage is provided by the power source, the electrochemical cell causes an electrolytic reaction in the DEF to produce gaseous products in the DEF before the DEF is sprayed into the mixing chamber, and wherein the gaseous products comprise one or more of H 2 or NH 3 , wherein the electrochemical cell comprises a compartment including a cathode and an anode electrode, wherein the compartment is configured to mix the gaseous products from the cathode and anode electrodes before the DEF outlet to dose the mixed gaseous products from the doser to the mixing chamber with diesel exhaust.

17. The diesel exhaust system of claim 16 , wherein the gaseous products produced in the electrolytic reaction cause the sprayed DEF to mix with the diesel exhaust in the mixing chamber more rapidly than sprayed DEF without the gaseous products mixed with the diesel exhaust in the mixing chamber.

18. The diesel exhaust system of claim 16 , further comprising a wave form generator configured to vary electrical power in the applied voltage from the power source to the DEF doser.

19. The diesel exhaust system of claim 16 , wherein the anode and cathode electrodes are coupled to the power source, and wherein the anode and cathode electrodes line portions of the compartment.

20. The diesel exhaust system of claim 19 , wherein at least one of the anode and cathode electrodes comprises a metal material of a porous sintered construction, and wherein the DEF doser further comprises a solid ionically conducting material located between portions of the anode and cathode electrodes.

21. The diesel exhaust system of claim 20 , wherein the ionically conducting material comprises a proton conducting material configured to be impregnated with hydrophilic mineral particles.

22. The diesel exhaust system of claim 16 , wherein the solution comprises 32.5% urea.

Assignees

• Goffe Randal A
• Paccar Inc

Inventors

• Goffe Randal A

Classifications

• B01D2251/2062

  Ammonia · CPC title

• F01N3/2066

  Selective catalytic reduction [SCR] · CPC title

• Y02T10/24

  Cross-Sectional Technologies · mapped topic

• F01N2610/02

  the substance being ammonia or urea · CPC title

• C25B9/04

  Chemistry & Metallurgy · mapped topic