How does air fuel ratio affect the performance of the engine?

The cylinder temperature increases with increases of engine speed however temperature decreases with increases of air-fuel ratio. The volumetric efficiency increases with increases of engine speed and equivalent ratio.

What are the engine variables that affects formation of NOx in the exhaust of CI engines?

A. Diesel engines operate at a higher temperature and pressure than petrol engines. These conditions favour the production of NOx gases. The quantity depends on the volume and duration of the hottest part of the flame.

What is the effect of air fuel ratio on exhaust emission?

The results illuminated that, the CO emissions drop sharply when air/fuel mixture changed from rich to lean. Particularly, at full load the CO emission decreases by about 4 times when λ changed from 0.85 to 1.1, and it keeps decreasing to only about one-tenth at λ = 1.2.

What air fuel ratio is best for power?

For maximum reliability at full power, air/ fuel ratios from 10.5-12.5:1 are considered best, depending on the engine. Richer than around 10.5:1, you start to get noticeable black smoke from the exhaust and the car can struggle to run properly without misfiring.

What causes excessive NOx emissions?

High NOx emissions can occur when an engine’s air-fuel mixture is too lean. This could be caused by a problem with the vehicle’s oxygen sensor, malfunctioning air flow and coolant sensors or a leak in the fuel system.

What is the cause of formation of NOx in petrol engine?

NOx is produced from the reaction of nitrogen and oxygen gases in the air during combustion, especially at high temperatures. NOx gases are formed whenever combustion occurs in the presence of nitrogen – e.g. in car engines; they are also produced naturally by lightning.

What is best air fuel ratio for emissions?

14.7:1 ratio
The 14.7:1 ratio is perfect for idling and light throttle cruising conditions as it’s the most efficient mixture possible, meaning the best fuel economy and lowest emissions.

What is the effect of air fuel ratio and spark advance on NOx emission?

The results showed that equivalence ratio and engine load have the greatest impact on NOx emissions, followed by the intake gas temperature, and finally the engine speed and intake gas pressure have the least impact on NOx emissions.