Apparatus and method for detecting urea deposit formation

Patent metadata

Field	Value
Publication number	US-10550744-B2
Application number	US-201515127988-A
Country	US
Kind code	B2
Filing date	Apr 1, 2015
Priority date	Apr 2, 2014
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

An apparatus for detecting urea deposits in an exhaust pipe of an internal combustion engine is provided, where the urea is introduced into the exhaust pipe in an aqueous urea solution via a nozzle. The apparatus comprises at least one radiation receiver which, in use, is located within the exhaust pipe downstream of the nozzle. The apparatus further comprises an electronic control unit in communication with the receiver, wherein the receiver communicates radiation data to the control unit which allows the control unit to establish whether deposits have formed within the exhaust pipe. A control valve is also provided which controls flow of the solution to the nozzle in response to signals from the control unit. A method of detecting urea deposits in an exhaust pipe of an internal combustion engine is also provided, as in an automotive vehicle incorporating the aforementioned apparatus.

First claim

The invention claimed is:

1. An apparatus for detecting urea deposits forming on an inner wall of an exhaust pipe of an internal combustion engine, the urea being introduced into the exhaust pipe in an aqueous urea solution via a nozzle, and the apparatus comprising:
at least one radiation receiver located within the exhaust pipe downstream of the nozzle;
an electronic control unit in communication with the at least one radiation receiver, wherein the at least one radiation receiver communicates radiation data to the electronic control unit, and wherein the electronic control unit determines whether urea deposits have formed on the inner wall of the exhaust pipe based on the radiation data communicated from the at least one radiation receiver; and
a control valve controlling flow of the aqueous urea solution to the nozzle in response to signals from the electronic control unit, wherein the electronic control unit communicates signals to the control valve to change the flow of the aqueous urea solution to the nozzle to decompose the urea deposits in response to determining that urea deposits have formed on the inner wall of the exhaust pipe.

2. The apparatus of claim 1 , further comprising at least one radiation transmitter located within the exhaust pipe upstream of the at least one radiation receiver, wherein the electronic control unit is in communication with the at least one radiation transmitter and the at least one radiation receiver.

3. The apparatus of claim 2 , wherein the at least one radiation transmitter and the at least one radiation receiver respectively transmit and receive acoustic waves travelling within the exhaust pipe.

4. The apparatus of claim 2 , wherein the at least one radiation transmitter and the at least one radiation receiver respectively transmit and receive acoustic waves travelling along the surface of the exhaust pipe.

5. The apparatus of claim 2 , wherein the at least one radiation transmitter and the at least one radiation receiver respectively transmit and receive electromagnetic waves.

6. The apparatus of claim 1 , wherein the engine includes an engine controller adapted to control the engine, and wherein the electronic control unit can communicate with the engine controller such that it can instruct the engine controller to increase exhaust gas temperature within the exhaust pipe to decompose the urea deposits in response to determining that urea deposits have formed on the inner wall of the exhaust pipe.

7. The apparatus of claim 1 , further comprising at least one environmental sensor located within the exhaust pipe, wherein the at least one environmental sensor is in communication with the electronic control unit such that the electronic control unit may adjust the calibration of the apparatus in response to environmental data received from the at least one environmental sensor.

8. The apparatus of claim 7 , wherein the at least one environmental sensor is selected from the group consisting of a temperature sensor and a pressure sensor.

9. The apparatus of claim 1 , wherein the electronic control unit includes a memory adapted to store data relating to one or more performance conditions or parameters at which it is established that urea deposits were forming in the pipe.

10. A method of detecting urea deposits on an inner wall of an exhaust pipe of an internal combustion engine, wherein urea is introduced into the exhaust pipe in an aqueous urea solution via a nozzle, the method comprising the steps of:
providing a control valve for controlling flow of the aqueous urea solution to the nozzle;
receiving transmitted radiation through at least one radiation receiver located within the exhaust pipe at a location downstream of the nozzle;
communicating data regarding the received radiation from the at least one radiation receiver to an electronic control unit;
establishing whether urea deposits have formed on the inner wall of the exhaust pipe based on the communicated data from the at least one radiation receiver; and
instructing the control valve to adjust the flow of the aqueous urea solution to the nozzle to decompose the urea deposits in response to determining that urea deposits have formed on the inner wall of the exhaust pipe.

11. The method of claim 10 , further comprising the step of transmitting the radiation from at least one radiation transmitter located at a location within the exhaust pipe upstream of the at least one radiation receiver, wherein the at least one radiation receiver is receiving radiation transmitted from the at least one radiation transmitter.

12. The method of claim 11 , wherein the radiation transmitted and received is acoustic waves travelling within the exhaust pipe.

13. The method of claim 11 , wherein the radiation transmitted and received is acoustic waves travelling along the surface of the exhaust pipe.

14. The method of claim 11 , wherein the radiation transmitted and received is electromagnetic waves.

15. The method of claim 10 , wherein the engine includes an engine controller and the method further comprises the step of the electronic control unit instructing the engine controller to increase exhaust gas temperature within the exhaust pipe to decompose the urea deposits in response to determining that urea deposits have formed on the inner wall of the exhaust pipe.

16. The method of claim 10 , further comprising the initial steps of:
calibrating the electronic control unit, wherein the at least one radiation receiver receives radiation transmitted by the at least one radiation transmitter when the pipe is initially clear of urea deposits, and communicating calibration data from the at least one radiation receiver to the electronic control unit; and
storing the calibration data in the electronic control unit so that the electronic control unit can compare the calibration data with real-time data received from the at least one radiation receiver to establish when urea deposits have formed within the pipe.

17. The method of claim 16 , wherein at least one environmental sensor is located within the exhaust pipe, the method further comprising the step of the electronic control unit adjusting the calibration data received in response to environmental data received from the at least one environmental sensor.

18. The method of claim 17 , wherein the at least one environmental sensor provides environmental data selected from the group consisting of temperature data and pressure data.

19. The method of claim 10 , further comprising the steps of:
the electronic control unit recording one or more performance conditions or parameters at which it is established that urea deposits have formed within the pipe; and
communicating one or more control signals to the control valve to ensure such conditions or parameters are not replicated in the future.

20. An automotive vehicle comprising the apparatus of claim 1 .

Assignees

• Caterpillar Inc
• Perkins Engines Co Ltd

Inventors

• Silver Ronald
• Reid Benjamin
• Steffen Thomas

Classifications

• F02D2200/08

  Exhaust gas treatment apparatus parameters · CPC title

• F01N3/208 Primary

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

• F01N3/2066 Primary

  Selective catalytic reduction [SCR] · CPC title

• F01N2550/05

  Systems for adding substances into exhaust · CPC title

• F01N13/008

  Mounting or arrangement of exhaust sensors in or on exhaust apparatus (sensor arrangements for engine control F02D41/1439) · CPC title