The effect of EGR rate on NOx reduction at various engine loads at average speed is shown in Figure 1. Under all loads, the amount of NOx decreases as the EGR rate increases. The graph also shows that the NOx reduction effect at a given EGR rate increases as engine load increases. EGR temperature can impact intake mixture temperature and therefore NOx emissions. Cooling the EGR would increase the temperature difference term in the heat absorption equation for the EGR. Now I will talk about bad or failing EGR symptoms. Say no to plagiarism. Get a tailor-made essay on “Why violent video games should not be banned”? Get the original essay The exhaust gas recirculation valve is a component commonly found on many road vehicles. It is part of the vehicle's exhaust gas recirculation (EGR) system, an emissions system designed to recirculate exhaust gases into the vehicle's intake to reduce cylinder temperatures and NOx emissions . The EGR valve is one of the main components that controls the flow and recirculation of these exhaust gases. When the valve is open, exhaust gases can pass through the vehicle's EGR system to help control vehicle emissions. When the EGR valve has a problem, it can cause problems with the flow and operation of the EGR system, which can lead to increased emissions and performance issues. Usually, a faulty or failing EGR valve will produce a few symptoms that can alert the driver to a potential problem. I will say one thing about engine performance issues and a problem related to rough idling. Engine Performance Issues – One of the first symptoms of a problem with the EGR valve is engine performance issues. A clogged or faulty EGR valve can disrupt the vehicle's air-fuel ratio, which can lead to engine performance issues such as reduced horsepower, acceleration, and even fuel efficiency. Rough Idle – One of the most common symptoms of a problem with the vehicle's EGR valve is rough idling. It is not uncommon for EGR valves to malfunction and get stuck in the open position. This can result in recirculation of exhaust gases, causing rough idling even when conditions are undesirable. Next 02 sensors and ways they may or may not affect automobile emissions. First I'll explain exactly what an 02 sensor is, what it does, and who created it. An oxygen probe (or lambda probe) is an electronic device that measures the proportion of oxygen (O2) in the gas or liquid analyzed. It was developed by the Robert Bosch GmbH company in the late 1960s under the leadership of Dr. Günter Bauman. Hydrocarbon emissions occur when fuel molecules in the engine do not burn or only partially burn. Hydrocarbons react in the presence of nitrogen oxides and sunlight to form ground-level ozone, a major component of smog. Ozone irritates the eyes, damages the lungs and worsens respiratory problems. This is our most widespread and intractable urban air pollution problem. A number of exhaust hydrocarbons are also toxic and can potentially cause cancer. Nitrogen Oxides (NOx) Under the high pressure and temperature conditions of an engine, nitrogen and oxygen atoms in the air react to form various oxidesof nitrogen, collectively called NOx. . Nitrogen oxides, like hydrocarbons, are precursors to the formation of ozone. They also contribute to the formation of acid rain. Carbon monoxide (CO) is a product of incomplete combustion and occurs when the carbon in the fuel is partially oxidized rather than completely oxidized to carbon dioxide (CO). Carbon monoxide reduces the flow of oxygen in the blood and is particularly dangerous for people with heart disease. Carbon Dioxide, In recent years, the U.S. Environmental Protection Agency (EPA) has begun to view carbon dioxide, a product of "perfect" combustion, as a pollution problem. Carbon dioxide does not directly harm human health, but it is a "greenhouse gas" that traps Earth's heat and contributes to global warming potential. Evaporative Emissions Hydrocarbon pollutants also escape into the air through fuel evaporation. With effective exhaust emission controls and current gasoline formulations, evaporative losses can account for the majority of total hydrocarbon pollution from current car models on hot days when ozone levels are the highest. Evaporative emissions occur in several ways: DIURNAL: Gasoline evaporation increases as temperatures rise during the day, heating the fuel tank and carrying away gasoline vapors. LOSS OF OPERATION: The hot engine and exhaust system can spray gasoline when the car is running. HOT DIP: The engine remains hot for some time after the car is stopped and gasoline evaporation continues when the car is parked. REFUELING: Gasoline vapors are still present in the fuel tanks. These vapors are vented when the tank is filled with liquid fuel. Si Engine Emissions SI engine emissions are divided into three categories: exhaust emissions, evaporative emissions, and crankcase emissions. The main constituents that contribute to air pollution are CO, NOx and HC from SI engine exhaust. Relative quantities depend on engine design and operating conditions but are in the range, NOx -> 500-1000 ppm (20 g/kg fuel), CO -> 122% (200 g/kg fuel) and HC -> 43000 ppm (25 g/kg of fuel). Fuel evaporation from the fuel tank and carburetor exists even after the engine is stopped and is unburned hydrocarbons. However, in most modern engines, these unburned, non-exhausted HCRs are effectively controlled by returning blown gases from the crankcase to the engine. Intake system by venting the fuel tank and a vapor-absorbing carbon canister which is purged as the engine runs. intake air during normal engine operation. The constituent of the order includes SO2 and lead compounds. Gasoline therefore rarely contains sulfur; SO2 is not a pollutant from SI engine exhaust. Gasoline contains lead in small proportions, but its effects are more serious on human health. The Delhi government has therefore restricted the use of unleaded petrol. One of the most important variables in determining SI emissions is the fuel-air equivalence ratio. The SI engine always operates at stoichiometric or slightly rich mixture. When the engine is started, the very rich mixture is provided because the vaporization is very slow. So, until the engine warms up and this enrichment is stopped, CO and HC emissions arehigh. Under part load conditions, the lean mixture can be used, which will reduce HC and CO emissions and moderate NOx emissions. Using recycled exhaust to dilute the engine intake mixture lowers the NOx level but deteriorates combustion quality. Exhaust gas recirculation (EGR). The method is used with stoichiometric mixtures in many engines to reduce emissions. The sources of pollution are mainly three in number as mentioned previously, engine exhaust gases (CO, NOx, HC), crankcase breather (HC) and direct evaporation of gasoline from the carburetor and tank of fuel, especially in hot weather (HC). Emissions from CI engines Diesel combustion is heterogeneous in nature, unlike spark ignition engines where the fuel mixture is predominantly homogeneous. In diesel engines, fuel is injected into a cylinder filled with high-temperature compressed air. Emissions are formed following the combustion of this heterogeneous air/fuel mixture depending on the conditions prevailing not only during combustion but also during expansion and especially before opening the exhaust valve. Mixture preparation during ignition delay, fuel ignition quality, residence time at different combustion temperatures, expansion duration and general engine design features play a very important role in the formation of emissions. Essentially, the concentration of different emission species in the exhaust gases is the result of their formation and reduction in the exhaust system. Incomplete combustion products formed in the early stages of combustion may be oxidized later during the expansion stroke. Mixing unburned hydrocarbons with oxidizing gases, elevated temperature in the combustion chamber, and adequate residence time for the oxidation process allows for more complete combustion. In most cases, once formed, nitric oxide (NO) is not broken down but its concentration may increase during the remainder of the combustion process if the temperature remains high. IV. Euro standards Exhaust gases from combustion engines mainly contain unburned hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx), which are mainly responsible for air pollution that leads to health risks and adverse effects on crops as well. the government. imposed emission standards that limit the amount of each pollution emitted by the engine into the atmosphere. The collection efficiency of these filters ranges from 50 percent to over 90 percent. Excellent filter efficiency has rarely been a problem with the various filter materials listed above, but work has continued with these materials, for example to (1) optimize high filter efficiency with low back pressure which accompanies it, (2) improve the radial flow of oxidation. through the filter during regeneration, and (3) improve the mechanical strength of filter designs. Fine particulate diesel exhaust gases enter the filter, but because the filter cell is capped at the opposite end, the exhaust gases cannot exit the cell. Instead, the exhaust gases pass through the porous walls of the cell. The particle is trapped on the cell wall. Exhaust gases exit the filter through the adjacent cell. XX. Using catalyst control and particulate filter in conjunction with other control strategies Slightly delaying injection timing or integrating exhaust gas recirculation (EGR) will reduce NOx emissions from diesel engines by..