System and method for low CO emission engine
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.
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.