Exhaust Gas Recirculation

Diesel is going to be the fuel that will control the world just like gasoline is today. Clean diesel is something that seems unreachable but it is closer than people think. Diesels now are Cleaner than ever and it it going to out do any other form of power for cars. Although other fuels and forms of power produce no emissions, diesel engines can be made to produce less harmful pollutants and be more efficient. There may be a few negative characteristics about diesel engines. But, the positive characteristics that they have out weight the bad things about them. To keep the diesels clean the process of how they work needs to be known.

Gas engines are mainly used by the individual in personal vehicles whereas diesels are very popular in the commercial and industrial fields. Diesel engines are used by the navy in their ships and by the army in their tanks and big trucks. Some of the main reasons for choosing this engine are

I said earlier that the engine burns fuel and air to cause compression. With a high-burning gas injected into the engine, you gain instant horsepower***. Nitrous Oxide is a gas that burns hotter and faster than regular fuel. When it is directly injected into the cylinder, it burns at a greater rate to the fuel, increasing speed greatly. Through a switch on the wheel, a driver engages a certain amount of NOS**** from a tank in his car. Through a nozzle, the driver decides how much gas he wants then the burst is pressed. With this high-powered gas, too much can literally burn so hot that it melts your engine. These drivers take the risk of wanting too much speed and blowing their engine apart. A NOS boost can shake the welds off the engine and the driver out of the car; this is why it’s a blessing and a curse.

A. A gas engine uses spark to ignite gasoline while a diesel engine uses compressed air to ignite the diesel fuel.

When nitrous oxide is used in cars and rockets, it vaporizes, causing a significant cooling effect on the intake air. You increase the density of the air when the intake air pressure is reduced. This provides even more oxygen in the cylinder which is a good thing.

The reduction in mass flow rate causes the compressor pressure ratio and efficiency to drop [27]. As the mass flow rate is reduced, the turbine exhaust gas temperature increases to maintain energy balance [27]. The mass flow rate of helium can be decreased to a limit until either material restrictions at the turbine exit or heat exchanger inlet prohibit the higher temperatures [27] or the efficiency of the turbomachinery falls below an acceptable level.

Figs. 5(b) and (c) show the CO and THC emissions from the combustion of the four fuels under different BMEPs. The CO emissions from the combustion of all the four fuels decreased gradually with increasing BMEP. Under a small BMEP, the combustion temperature was generally low, and the CO emissions mainly came from the combustion in the cylinder low-temperature regions [43]; as the BMEP increased, the in-cylinder temperature increased and the CO emissions decreased. It can also be observed that CO emissions increased after the addition of n-butanol to pure diesel. This happens because n-butanol has a low cetane number and shows poor combustibility, and a larger portion of over-thin gas mixture was formed before the combustion, thus the combustion

With proposed rule BLM aims to reduce gas lost through venting, flaring and equipment leaks.

Nitrous oxide is an important green house gas. The global warming potential for nitrous oxide is 298 times higher than that of carbon dioxide over a 100-year time horizon (Ravishankara, Daniel and Portmann, 2009). Nitrous oxide is also contributing the third largest radiative forcing globally (Oenema et al., 1997). With the recent emphasis on control of global warming, ways to reduce nitrous oxide are highly sought.

This will be achieved by making the engine run more efficiently, thus using less fuel, thus emitting less waste. The Environmental Protection Agency states that about 29% of greenhouse gas emissions comes from transportation. If all vehicles are serviced regularly, this percent will decrease. The decrease in greenhouse gas emissions will slow global warming and make less pollution. This will help our desert environment by making the air cleaner.

Engineering: [a] diesel engine is an internal combustion engine in which the chemical energy of fuel is transformed into thermal energy of the cylinder charge, in consequence of the self-ignition and combustion of fuel in the engine cylinder after compression of the air charge in the cylinder (p1

Periodically, the engine switches to a richer air-fuel mixture that increases the content of unburned hydrocarbons (HC) in the exhaust. In the presence of the platinum catalyst in the LNT, the HC reacts with the NOX, converting everything to nitrogen, water and carbon dioxide. Once the NOX in the trap has been consumed the engine reverts to lean operation and the cycle starts over again.” (Motavalli 2015)

These types of engines can be found not only in cars and trucks, but in boats, lawn mowers and generators to name a few.

EGR as its name suggests recirculates part of the exhaust gas (cooled) back to the combustion chamber. This mixture of fresh air and recirculated exhaust reduces the concentration of oxygen and reduce combustion temperature. These mechanisms reduce NOx production at the expense of fuel efficiency and PM emission.

We, Manish Sharma, Anmol Verma, Manthan Kumar And Utkarsh Srivastava, students of B.Tech (2011-15) hereby declare that the project titled “Turbulence modeling of vehicle’s exhaust system to reduce the exhaust emissions” which is submitted by us to Department of MECHANICAL AND AUTOMATION, Amity School of Engineering and Technology, Amity University Uttar Pradesh, Noida, in partial fulfillment of requirement for the award of the degree of Bachelor of Technology in Mechanical And Automation , has not been previously formed the basis for the award of any degree, diploma or other similar title or recognition.