What are the emission controls in diesel engine?
Three different emission control systems are examined as diesel oxidation catalyst (DOC) to control CO, and HC emissions, diesel particulate filter (DPF) to control PM emissions and selective catalytic reduction (SCR) to control NOx emissions.
What are the different methods to control exhaust emission in Si?
SI engine controls include: Air/fuel ratio control, spark timing control, idle speed control. Aftertreatment system controls include: thermal management to ensure rapid warm-up and high emission reduction efficiency; and air/fuel ratio control to ensure maximum conversion of the TWC.
What types of after treatment technologies are used on diesels to reduce emissions?
Generally speaking, the heavy duty diesel engine aftertreatment system has two primary components: the exhaust aftertreatment technology — which includes the diesel oxidation catalyst (DOC) and diesel particulate filter (DPF) — to reduce and mitigate PM; and a select catalytic reduction (SCR) system to reduce NOx …
How do diesel emission systems work?
Small quantities of diesel exhaust fluid (DEF) are injected into the exhaust upstream of a catalyst, where it vaporizes and decomposes to form ammonia and carbon dioxide. The ammonia (NH3) is the desired product which in conjunction to the SCR catalyst, converts the NOx to harmless nitrogen (N2) and water (H2O).
What causes high diesel emissions?
Abstract: Diesel engine emissions may increase as the engine deteriorates. Normal engine wear typically causes an increase of PM emissions and a decrease of NOx in mechanical engines. In engines with EGR or NOx aftertreatment, engine wear may also lead to increased NOx emissions.
How do diesel engines reduce NOx emissions?
NOx emission can be reduced by primary methods such as retard injection, fuel nozzle modification, change of compression ratio, water direct injection, water emulsification, exhaust gas recirculation (EGR) and secondary method such as selective catalytic reduction (SCR).
What are the various emissions in the exhaust of petrol and diesel engine?
Combustion-engine exhaust gases
| Compound | Petrol | Diesel |
|---|---|---|
| nitrogen oxides | < 0.25 | < 0.15 |
| carbon monoxide | 1 – 2 | < 0.045 |
| particulate matter | < 0.045 | |
| hydrocarbons | < 0.25 | < 0.03 |
What is diesel after treatment?
An aftertreatment system is a method or device for reducing harmful exhaust emissions from internal-combustion engines. In other words, it is a device that cleans exhaust gases to ensure the engines meet emission regulations.
How does DPF aftertreatment work?
The DPF comes after the DOC in the exhaust aftertreatment system. The DPF removes most of the particles (more than 99 %) from the exhaust gases. The exhaust gases pass through the filter, which collects particles from the gases. The particles eventually turn into a soot cake.
How does DEF reduce emissions?
Diesel Exhaust Fluid (DEF) is a solution of urea and water that’s injected into the exhaust stream of diesel vehicles to turn NOx gases (harmful emissions) into nitrogen and water. This system is called a Selective Catalytic Reduction (SCR) implemented by vehicle manufacturers to meet EPA emissions standards in 2010.
What is a emissions system?
WHAT DOES IT DO? Your car’s emission system controls the emissions, exhaust and pollutants (including gasoline vapors escaping from the fuel tank), using an array of sensors, computerized engine controls and the exhaust components.