Urea backflow prevention apparatus of scr and a control method thereof

Patent metadata

Field	Value
Publication number	US-2016131002-A1
Application number	US-201514788307-A
Country	US
Kind code	A1
Filing date	Jun 30, 2015
Priority date	Nov 11, 2014
Publication date	May 12, 2016
Grant date	—

Abstract

A urea backflow prevention apparatus of Selective Catalytic Reduction (SCR) system that injects a urea aqueous solution to an exhaust pipe may include a urea tank storing the urea aqueous solution, a nozzle being installed on the exhaust pipe and injecting the urea aqueous solution into the exhaust pipe, a supply pump pressurizing the urea aqueous solution in order to inject the urea aqueous solution from the nozzle to the exhaust pipe, a suction line supplying the urea aqueous solution stored in the urea tank to the supply pump by connecting the urea tank and the supply pump, a pressure line delivering the urea aqueous solution pressurized at the supply pump to the nozzle by connecting the supply pump and the nozzle, and a return line collecting urea aqueous solution not injected at the nozzle to the urea tank by connecting the supply pump and the urea tank.

First claim

What is claimed is:

1 . A urea backflow prevention apparatus of Selective Catalytic Reduction (SCR) system that injects a urea aqueous solution to an exhaust pipe, the urea backflow prevention apparatus of SCR comprising:
a urea tank storing the urea aqueous solution; a nozzle being installed on the exhaust pipe and injecting the urea aqueous solution into the exhaust pipe; a supply pump pressurizing the urea aqueous solution of the urea tank to inject the urea aqueous solution from the nozzle to the exhaust pipe; a suction line supplying the urea aqueous solution stored in the urea tank to the supply pump by connecting the urea tank and the supply pump; a pressure line connecting the supply pump and the nozzle and delivering the urea aqueous solution pressurized at the supply pump to the nozzle; and a return line collecting a urea aqueous solution not injected at the nozzle to the urea tank by connecting the supply pump and the urea tank.

2 . The urea backflow prevention apparatus of the SCR system of claim 1 , further comprising a shut-off valve disposed on the suction line and selectively opening the suction line.

3 . The urea backflow prevention apparatus of the SCR system of claim 2 , further comprising a urea detection device being provided in at least one of the supply pump and the pressure line, and detecting whether the urea aqueous solution exists in the at least one of the supply pump and the pressure line after an operation of the SCR system is terminated.

4 . The urea backflow prevention apparatus of the SCR system of claim 3 , further comprising a controller receiving a signal of whether the urea aqueous solution exists in the at least one of the supply pump and the pressure line from the urea detection device and transmits a signal for the shut-off valve to selectively open the suction line after the operation of the SCR system is terminated.

5 . The urea backflow prevention apparatus of the SCR system of claim 1 , wherein the urea tank comprises a ventilating opening opened to atmosphere.

6 . The urea backflow prevention apparatus of the SCR system of claim 2 , wherein the return line is formed to be shorter than the suction line so that a lower part of the return line is continuously positioned on a surface of the urea aqueous solution inside of the urea tank.

7 . A control method for a urea backflow prevention apparatus of Selective Catalytic Reduction (SCR), comprising:
an engine stop determination step by a controller of determining whether an engine of a vehicle is stopped; a urea collection step of collecting a urea aqueous solution inside of a pressure line, a supply pump and a suction line by operating the supply pump in a reverse direction, when the engine is determined to be stopped at the engine stop determination step; a urea collection completion determination step of determining whether the collection of the urea aqueous solution has been completed by the controller receiving a signal on whether the urea aqueous solution exists in at least one of the supply pump and the pressure line from a urea detection device, after the urea collection step; and a shut-off valve closure step of closing a shut-off valve by transmitting a signal from the controller to the shut-off valve, when it is determined by the controller that the collection of the urea aqueous solution has been completed, after the urea collection completion determination step.

8 . The control method for the urea backflow prevention apparatus of the SCR of claim 7 , further comprising an engine operation determination step of determining whether the engine is operated again by the controller, after the shut-off valve closure step.

9 . The control method for the urea backflow prevention apparatus of the SCR of claim 8 , further comprising a shut-off valve open step of opening the shut-off valve by transmitting a signal from the controller to the shut-off valve, when it is determined by the controller that the engine is operated again at the engine operation determination step.

Assignees

• Hyundai Motor Co Ltd

Inventors

• Yang Dae-Won
• Park Suk-Il

Classifications

• F01N3/208 Primary

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

• F01N3/2896

  Liquid catalyst carrier · CPC title

• F01N2610/1433

  Pumps · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F01N2610/1486

  Means to prevent the substance from freezing · CPC title