Method of predicting nitrogen dioxide emission from engine

Patent metadata

Field	Value
Publication number	US-10989701-B2
Application number	US-201816020633-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Nov 30, 2017
Publication date	Apr 27, 2021
Grant date	Apr 27, 2021

Abstract

A method of predicting nitrogen dioxide emission from an engine may include an initial nitrogen dioxide formation prediction operation of predicting an amount of nitrogen dioxide which is originally formed in the engine using a nitrogen dioxide formation model by an electronic control unit (ECU) while engine combustion is underway, a nitrogen dioxide reduction prediction operation of determining an amount of nitrogen dioxide which is reduced to nitrogen monoxide using a reverse reaction of the nitrogen dioxide formation model by the ECU based on the amount of formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation, and a final nitrogen dioxide emission determination operation of determining an amount of nitrogen dioxide which is ultimately generated by the engine by the ECU based on a difference between the amount of formed nitrogen dioxide and the amount of reduced nitrogen dioxide.

First claim

What is claimed is:

1. A method of predicting nitrogen dioxide emission from an engine, for predicting an amount of nitrogen dioxide (NO 2 ) among nitrogen oxides (NO x ) emitted from the engine, the method comprising:
an initial nitrogen dioxide formation prediction operation of predicting an amount of nitrogen dioxide which is originally formed in the engine using a nitrogen dioxide formation model by an electronic control unit (ECU) while engine combustion is underway,
a nitrogen dioxide reduction prediction operation of determining an amount of nitrogen dioxide which is reduced to nitrogen monoxide using a reverse reaction of the nitrogen dioxide formation model by the ECU based on the amount of formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation, and
a final nitrogen dioxide emission determination operation of determining an amount of nitrogen dioxide which is generated by the engine by the ECU based on a difference between the amount of the formed nitrogen dioxide and the amount of reduced nitrogen dioxide,
wherein the amount of the formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation is determined based on the amount of formed nitrogen monoxide using the following equation:

NO

2
,
formation

=

A
×

NO
Q

×

exp
⁡

(

B
T

)

,

⁢
and

wherein NO 2,formation is the amount of the formed nitrogen dioxide, A and B are constants, NO Q is the amount of nitrogen monoxide in the engine, and T is an in-cylinder temperature.

2. The method of claim 1 , wherein the amount of the formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation is determined based on an amount of formed nitrogen monoxide through at least one of the following reaction schemes:
NO+HO 2 ↔NO 2 +OH

NO+O 2 ↔NO 2 +O

2NO+O 2 ↔2NO 2

NO+OH↔NO 2 +H.

3. The method of claim 1 , wherein the in-cylinder temperature is one of a single flame temperature, a maximum in-cylinder temperature, and a predetermined temperature depending on a fuel-to-oxygen ratio immediately before main injection.

4. The method of claim 1 , wherein the amount of the formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation is predicted using an engine combustion pressure and an engine operating parameter.

5. The method of claim 1 , wherein the amount of the reduced nitrogen dioxide in the nitrogen dioxide reduction prediction operation is determined based on the amount of the formed nitrogen dioxide through a reverse reaction of one of the following reaction schemes:
NO+HO 2 ↔NO 2 +OH

NO+O 2 ↔NO 2 +O

2NO+O 2 ↔2NO 2

NO+OH↔NO 2 +H.

6. The method of claim 2 , wherein the amount of the reduced nitrogen dioxide in the nitrogen dioxide reduction prediction operation is predicted using the following equation:

NO

2
,
decompositon

=

NO

2
,
formation

×
E
×

exp
⁡

(

F
T

)

,

wherein NO 2,decomposition is the amount of the reduced nitrogen dioxide, E and F are constants and T is an in-cylinder temperature.

7. The method of claim 3 , wherein an HO 2 radical is determined from a fuel amount and an intake air amount.

8. The method of claim 4 , wherein the engine operating parameter includes at least one of a fuel amount, an engine speed (RPM), an air-fuel ratio (AF) and EGR.

9. The method of claim 6 , wherein an HO 2 radical is determined from a fuel amount and an intake air amount.

10. The method of claim 7 , wherein the HO 2 radical before formation of nitrogen dioxide is convened and applied based on the following equation:
(Fuel amount) C ×(Oxygen concentration of cylinder) D

(wherein C and D are constants).

11. The method of claim 9 , wherein the HO 2 radical before formation of nitrogen dioxide is converted and applied based on the following equation:
(Fuel amount) G ×(Oxygen concentration of cylinder) H

(wherein G and H are constants).

12. The method of claim 10 , wherein the amount of the formed nitrogen dioxide in the initial nitrogen dioxide formation prediction operation is determined based on the amount of formed nitrogen monoxide using the following equation:

NO

2
,
formation

=

A
×

NO
Q

×

exp
⁡

(

B
T

)

×

Q

main
+
post

C

×

Q

2
,
Q

D

,

wherein A, B, C, and D are constants, T is an in-cylinder temperature, Q main+post is a fuel amount, and O 2,Q is an oxygen amount.

13. The method of claim 11 , wherein the amount of the reduced nitrogen dioxide is determined by applying an in-cylinder environmental factor to the equation of claim 6 .

14. The method of claim 11 , wherein the amount of the reduced nitrogen dioxide in the nitrogen dioxide reduction prediction operation is predicted using the following equation:

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp
• Seoul Nat Univ R&Db Foundation

Inventors

• Han Kyoung-Chan
• Lee Jun-Yong
• Yu Jun
• Lee Kyoung-Min
• Min Kyoung-Doug
• Lee Seung-Ha
• Lee Young-Bok

Classifications

• F02D2250/36

  Control for minimising NOx emissions · CPC title

• F02D2041/1412

  using a predictive controller · CPC title

• F02D45/00 Primary

  Electrical control not provided for in groups F02D41/00 - F02D43/00 · CPC title

• F02D41/1401

  characterised by the control or regulation method (F02D41/1473, F02D41/1477 take precedence) · CPC title

• F02D41/0235

  in relation with the state of the exhaust gas treating apparatus (control of exhaust gas treating apparatus per se F01N) · CPC title