System and method for low CO emission engine

Patent metadata

Field	Value
Publication number	US-11149617-B2
Application number	US-201716318123-A
Country	US
Kind code	B2
Filing date	Aug 18, 2017
Priority date	Aug 19, 2016
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

In one aspect, a system is provided and includes an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold. The system also includes a catalyst positioned downstream of the exhaust valve.

First claim

The invention claimed is:

1. A system, comprising:
an engine including an exhaust valve, an exhaust manifold downstream of the exhaust valve and a muffler downstream of the exhaust manifold;
a catalyst positioned downstream of the exhaust valve;
a fuel injector; and
a controller connected with the fuel injector, the controller comprising a processor connected to a memory device storing instructions which cause the processor to perform dithering to run the engine rich/lean for a determined period of time;
wherein a chamber is disposed upstream of the catalyst, the chamber sized for improved exhaust flow distribution to the catalyst, and a volume of the catalyst is 0.25 to 0.75 of a volume of the chamber.

2. The system of claim 1 , wherein the engine is a four-stroke gasoline engine.

3. The system of claim 1 , further comprising a portable generator configured to be powered by the engine.

4. The system of claim 3 , wherein the portable generator includes a frame at least partially supporting the engine and at least one wheel coupled to the frame.

5. The system of claim 3 , wherein the portable generator provides power less than or equal to 10 kilowatts.

6. The system of claim 3 , wherein the engine is between 80 cubic-centimeters and 224 cubic centimeters.

7. The system of claim 3 , wherein the engine is between 224 cubic-centimeters and 999 cubic centimeters.

8. The system of claim 3 , wherein the engine is less than 80 cubic-centimeters.

9. The system of claim 1 , wherein the catalyst is positioned in the muffler.

10. The system of claim 9 , wherein a cross-section of the muffler is oval shaped.

11. The system of claim 1 , further including an oxygen sensor positioned upstream of the catalyst.

12. The system of claim 1 , wherein the catalyst is one of a plurality of catalysts.

13. The system of claim 1 , wherein the determined period of time is on the order of seconds.

14. The system of claim 1 , wherein the instructions cause the processor to perform dithering to run the engine with a dithering frequency of 0.5 Hz to 4 Hz.

15. The system of claim 1 , wherein the instructions cause the processor to allow the catalyst to re-oxygenate and control chemical pollutants CO, NOx, and HC present in exhaust from the engine.

16. The system of claim 1 , wherein the instructions cause the processor to perform dithering to find a stoichiometric point of the engine.

17. The system of claim 1 , wherein the instructions cause the processor to control the rich/lean run of the engine along with the dithering speed and amplitude.

18. The system of claim 1 , wherein the muffler comprises double walls.

19. The system of claim 1 , further comprising a cylinder head connected to the exhaust manifold and an oxygen sensor positioned upstream of the exhaust manifold in the cylinder head.

20. The system of claim 1 , wherein the catalyst and the chamber are both disposed in the muffler.

21. The system of claim 1 , wherein an entrance cone is abutted against an entrance of the catalyst to funnel air to the catalyst.

22. The system of claim 21 , wherein the entrance cone and the catalyst are both disposed in the muffler.

23. The system of claim 20 , wherein an entrance cone is abutted against an entrance of the catalyst to funnel air to the catalyst, the entrance cone disposed in the muffler.

24. The system of claim 1 , wherein the catalyst includes a rare earth metal that absorbs oxygen and a wash coat to reduce pollutants including hydrocarbons, carbon monoxide, and nitrogen oxide.

Assignees

• Kohler Co

Inventors

• Pekrul Eric
• Radue Martin L

Classifications

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F01N3/18

  characterised by methods of operation; Control · CPC title

• F01N2340/02

  Distance of the exhaust apparatus to the engine or between two exhaust apparatuses · CPC title

• F01N13/06

  specially adapted for star-arrangement of cylinders, e.g. exhaust manifolds · CPC title

• F01N2430/06

  by varying fuel-air ratio, e.g. by enriching fuel-air mixture · CPC title