engine technology trends final/enginetechnologytrends... · 2012-05-21 · engine technology trends...

Engine Technology Trends

V a l v o l i n e T e c h n i c a l S e r v i c e s

The Driver of Engine Technology Changes Three main factors drive the engine technology changes. These are as given below:

The most important factor now behind engine technology changes is stringent emission legislation. Let’s talk about auto emissions. The fuel gets combusted inside combustion chamber of IC (Internal Combustion) engine and forms CO2, CO, Sulfur Oxide, NOx, PM etc, and most of the combustion byproducts have adverse affects on both human being and the environment.

IC Engine & Environment

Impact of emission on Human beings and Environment. According to the WHO, 800,000 people die prematurely due to urban air pollution. Diesel and petrol motor vehicles are a major source of emissions of particulate matter. Let’s discuss the impact of each emission gas on human being and environment. Carbon Monoxide Carbon monoxide (CO) is an odourless, colourless gas. This gas is toxic to humans and can be lethal at high doses. CO is emitted from a number of sources and the impact CO derived directly from vehicle emissions has on human health is an area of ongoing research.

Changing Emission Legislation

Increased Fuel Economy

Durability under severe operating condition



Carbon Dioxide Carbon Dioxide (CO2) is an odourless, colourless and main greenhouse gas causes global warming. The below picture shows that greenhouse gas absorbs sun light radiation and the remaining radiation does not have sufficient energy to penetrate the atmospheric layer and that comes back to earth and raises the global temperature.

Hydrocarbons There are two main types of hydrocarbon, the lighter fuel type and the heavier engine oil type. Hydrocarbons can help promote the formation of ground level ozone, which is a key ingredient in photochemical smog. At high levels, ground level ozone can disrupt photosynthesis in plants, causing damage to plants and ecosystems. It also leads to human health problems such as:

Allergy problems; Lowered resistance to respiratory infections; respiratory problems.

Some heavier hydrocarbons, such as benzene and formaldehyde, are toxic and may be carcinogenic. Hydrocarbons are emitted to the environment from a number of sources. The impact on human health of hydrocarbons derived directly from vehicle emissions is an area of ongoing research.



It also causes Ozone layer depletion, and harmful Sun rays enters atmosphere and causes lethal multiple problem of human being. Nitrogen Oxide Nitrogen oxide emissions include nitric oxide (NO) and nitrogen dioxide (NO2). Nitric oxide (NO) is a colourless and odourless greenhouse gas, while nitrogen dioxide (NO2) is a highly toxic greenhouse gas. Nitrogen oxides can contribute to acid rain and global warming. They are highly active ozone precursors and play an important role in smog formation. At high levels, ground level ozone can disrupt photosynthesis in plants, causing damage to plants and ecosystems. At high levels it can also lead to human health problems such as:

Allergy problems; Lowered resistance to respiratory infections; Respiratory problems.

Nitrogen oxides are emitted to the environment via a number of sources. The impact on human health and the environment of nitrogen oxides derived directly from vehicle emissions is an area of ongoing research. Particulate Matter



Diesel particulate matter (DPM), as defined by the EPA regulations and sampling procedures, is a complex aggregate of solid and liquid material. Its origin is carbonaceous particles generated in the engine cylinder during combustion. The primary carbon particles form larger agglomerates and combine with several other, both organic and inorganic, components of diesel exhaust. Generally, DPM is divided into three basic fractions

Human health can be negatively affected by particulates—especially by fine particulates that can be carried deep into the lungs. Possible health problems include:

Respiratory disease; Heart disease; Cancer.

Particulates are emitted to the environment via a number of sources. The impact on human health and the environment of particulates derived directly from vehicle emissions is an area of ongoing research Engine Technology Changes The main factor driving new diesel engine design is concern over the environmental impact of diesel engine emissions. The US Environment Protection Agency (EPA) adopted new emission standards for heavy duty diesel truck and bus engines in 1997 with the aim of reducing nitrogen oxide (NOx) emissions to 2 grams per brake horsepower hour (g/bhp-hr) by model year 2004. In 1998 the major U.S. manufacturers signed consent decrees with the EPA requiring them to meet these new emissions standards by 2002. Most manufacturers, including Cummins, Mack, Volvo and Detroit Diesel, have chosen to meet this requirement by developing EGR engines Environmental regulation will continue to drive innovation in the next few years. The EPA has proposed new limits on diesel fuel sulfur levels beginning in 2006 and consumer demand for longer



lasting oils and concern over increased sump temperatures will likely lead to even tougher emission standards in the future Auto Emissions Technologies and Norms in India Most of the Car manufacturers in India have foreign collaboration for new Technologies. This is however, not true for heavy vehicles, buses, truck and smaller number of tractor-trailers. But Vehicular technologies in India have seen improvements in recent years after the European model of emission norms has been adopted for passenger Cars, LCV’s, buses and Heavy Duty trucks Vehicular emission norms for new vehicles were notified for the first time in India in 1991. The emission norms were revised in 1996. India 2000 (Euro 1 equivalent, Bharat Stage 1) vehicle emission norms were introduced for new vehicles from April 2000. Bharat Stage II (Euro II equivalent) emission norms for new cars were introduced in Delhi from the year 2000 and extended to other 3 metro cities in the year 2001. The emission norms for CNG and LPG vehicles were notified in the year 2000 and 2001 respectively. The implementation schedule of EU emission standards in India is summarized in Table

Indian Emission Standards (4-Wheel Vehicles)

Standard Reference Date Region

India 2000 Euro 1 2000 Nationwide

Bharat Stage II Euro 2 2001 NCR*, Mumbai, Kolkata, Chennai

2003.04 NCR*, 11 Cities†

2005.04 Nationwide

Bharat Stage III Euro 3 2005.04 NCR*, 11 Cities†

2010.04 Nationwide

Bharat Stage IV Euro 4 2010.04 NCR*, 11 Cities†

National Capital Region (Delhi) † Mumbai, Kolkata, Chennai, Bangalore, Hyderabad, Secunderabad, Ahmedabad, Pune,

Surat, Kanpur and Agra



EU Emission norms for Heavy Duty Diesel Engines EU Emission Standards for HD Diesel Engines, g/kWh Tier CO HC NOx PM Smoke Euro I 4.5 1.1 8 0.612 Euro II 4 1.1 7 0.15 Euro III 2.1 0.66 5 0.1 0.8 Euro IV 1.5 0.46 3.5 0.02 0.5 Euro V 1.5 0.46 2 0.02 0.5 Euro VI 1.5 0.13 0.4 0.01

The below graphs collected from Cummins Inc shows the trend of reduction of both PM and NOx with EURO Norm.

Emission can be reduced by taking integral system approach among Engine Design, Advanced Emission Control System/ After Treatment Devices and High Quality Fuel/ Lubricants.



Design Changes to meet stringent Emission Norms Engine design changes and a significant reduction in the sulphur content of diesel fuel were sufficient to meet stringent emissions requirements. The below picture shows how the sulfur in fuel gets reduced with stringent emission requirement.



Exhaust Emission Fuel

However for stringent emission requirement, vehicle manufacturers will introduce new exhaust after-treatment systems for vehicles because changes in engine design alone will not be sufficient to meet the dramatic reduction in permissible emissions. These new exhaust after-treatment systems will be coupled with engine design changes such as the greater use of exhaust gas recirculation (EGR) engines and improvements to fuel injection, combustion timing, and turbo-charging. There is trade off type relation between PM and NOx in auto emission. The complete combustion happens when combustion temperature is high, but on the other side the high combustion temperature influences NOx formation.

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1994

1998

2002

2007

2010 00..00

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PPMM ((gg//hhpp--hhrr))

UULLSSDD 1155 PPPPMM

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11

Control StrategiesE

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Combustion Temperature

PM NOx

Limit

Engine design has been modified over time and also After Treatment Devices (ATD) has been added into engine to control emission. The below graph shows how the emission has been improved by addition of different engine technology.

The USA EPA 2007 compliant heavy-duty highway engine has been reducing the harmful pollutant gasses by more than 90 percent. Sulfur in diesel fuel is much lowered to enable modern pollution-control technology to be effective on these trucks and buses. EPA 2007 is requiring a 97 percent reduction in the sulfur content of highway diesel fuel from its current level of 500 parts per million (low sulfur diesel, or LSD) to 15 parts per million (ultra-low sulfurdiesel, or ULSD). ULSD enables advanced pollution control technology for cars, trucks, and buses so that engine manufacturers can meet the 2007 emission standard.

The USA EPA 2007 emission norm has great impact both on environment and human health as given below:

2.6 million tons of smog-causing nitrogen oxide emissions will be reduced each year. Soot or particulate matter will be reduced by 110,000 tons a year. An estimated 8,300 premature deaths, 5,500 cases of chronic bronchitis and 17,600 cases of

acute bronchitis in children will be prevented annually. An estimated 360,000 asthma attacks and 386,000 cases of respiratory symptoms in

asthmatic children will also be avoided every year.



1.5 million lost work days, 7,100 hospital visits and 2,400 emergency room visits for asthma will be prevented.

Impact on Heavy Duty Diesel Engine Design The below graph shows how the emissions gets reduced by adaptation of different new engine technology.

Let us talk about different available emission reduction engine technology in brief. Turbocharger and Intercoolers The power that can be developed by an internal combustion engine is limited by the amount of fuel that can be burned during each cycle. It is relatively easy to supply more fuel to the cylinders but this extra fuel must be matched by an increased supply of air if it is to be burned completely and efficiently. Supercharging is a way of increasing the amount of air in the cylinders of an engine, by supplying it at a higher pressure, thus making it possible to burn more fuel.

The air for supercharging is supplied by a blower or compressor which may be driven by the engine, by a separate motor or, as in the most frequently used method, by a turbine powered by the engine’s exhaust gases. This latter method of supercharging is known as turbocharging.



Vehicle manufacturers develop new engine designs to meet stricter government emissions and fuel efficiency regulations. These new designs can have a significant impact on lubricant performance In the turbocharged engine, the exhaust gases from the engine are directed into a gas turbine. This essentially consists of a set of angled blades mounted around a shaft. The pressure of the gases on the vanes forces the shaft to rotate. The turbine in turn drives a compressor mounted on the same shaft. Compressed air is produced and is fed to the engine cylinders, enabling them to burn more fuel. The turbocharged engine is highly efficient. When more fuel is injected, the energy of the exhaust gases increases. This immediately increases the output of compressed air. Conversely, when less fuel is injected, the output of compressed air decreases. Output is therefore closely matched to engine demands at a wide range of speeds Turbochargers operate at a much higher temperatures in gasoline engines than in diesel engines. The lubricating oils in turbocharged gasoline engines must be able to operate at these higher temperatures.

Variable Geometry Turbocharger (VGT) Variable Geometry Turbine technology is the next generation in turbocharger technology where the turbo uses variable vanes to control exhaust flow against the turbine blades. We know the problem with the turbocharger that big turbos do not work well at slow engine speeds, while small turbos are fast to spool but run out of steam pretty quick. This device allows the engine cylinders to be filled efficiently at all engine speeds, by constantly regulating the flow of exhaust gas. A turbocharger equipped with Variable Turbine Geometry has little movable vanes which can direct exhaust flow onto the turbine blades. The vane angles are adjusted via an actuator. The angle of the vanes varies throughout the engine RPM range to optimize turbine behaviour.



Due to use of VGT, engine always gets optimum air quantity for complete combustion, and it reduces emission. Fuel Injection in Diesel Engine The equipment of a diesel engine is precision made to deliver, at exactly the right time in the engine cycle, precisely metered quantities of fuel each containing droplets of the ideal size for efficient combustion. The equipment basically consists of a pump and an injector for each cylinder. The delivery of fuel from the pump to the injectors is controlled by an injection timing device operated by a camshaft or gear system driven from the engine. The fuel may be injected directly into the cylinder at the top of the compression stroke (a direct injection or DI engine), or be injected into a pre-combustion chamber before entering the cylinder through a narrow passage (an indirect injection or IDI engine). DI engines used to be noisy, so IDI was used to slow down the explosion, despite the consequent loss of efficiency. However, newer DI engines use other techniques such as two-stage injection and electronic control to produce a smoother, quieter engine with no loss of efficiency. Precision control of the fuel injection system enables the start and end of fuel injection to be carefully controlled. Injection timings have been retarded to reduce nitrogen oxide (NOx) emissions and injection pressures have been increased to improve combustion and reduce emissions of particulates. Over the last decade, a new fuel injection technology – the Diesel Common Rail System – has become widely used. It is now generally recognised as the future of diesel in passenger cars, trucks, buses, and other vehicles and equipment fitted with high-speed diesel engines. The system essentially consists of :

• A low-pressure electrical supply pump that delivers fuel from the tank to a main high-pressure injection pump with pressure regulator and inlet metering valve; • A ‘fuel manifold’ common to all injectors (the ‘common rail’) that contains a reserve of fuel at



very high-pressure (2000 bar and above), which is continuously monitored by close-circuit sensors; • Injectors controlled by a solenoid valve that inject precise amounts of fuel into the combustion chambers; • A Diesel Control Unit (DCU), which controls injector fuel flow, timing and rail pressure while continuously monitoring engine operating conditions.

High-Pressure Common Rail

High-Pressure PumpECU

Fuel Return to Tank

Common Rail

Injectors

Spill Control Valve

Common Rail Injection System The main advantages of the Diesel Common Rail System are:

Lower Engine Emission Enhanced Reliability and performance Less Engine Noise Better Fuel Econimy More Power available

PILOT INJECTION Sometimes called "pre-ignition", pilot injection eliminates the combustion spikes that cause the "rattle" traditionally associated with diesel engines, especially at idling speeds. Pilot injection introduces a



small quantity of fuel into the combustion chamber prior to the main power-inducing explosion. This injection takes place within a few ten-thousandths of a second of the main explosion and results in a smoother combustion cycle and reduced clatter. Pilot injection has two other significant advantages. The system enhances the engine's cold-start capability, so that diesels can now function at temperatures as low as minus 40 degrees Fahrenheit. Pilot injection also helps reduce nitrous-oxide emissions by lowering peak combustion temperatures. Direct Gasoline Injection (DGI)

DGI improves performance of engine. Ensure operation at part-load with a wide-open throttle valve in the inlet manifold, avoiding the considerable pumping losses of today's conventional port- injection systems.

With DGI systems, gasoline is injected directly into the combustion chamber, with throttle action initially controlling fuel delivery rather than intake airflow. Mixture turbulence and swirl rate can be enhanced by precise positioning of the injector nozzle, with fuel droplets impacting on a specially-contoured piston crown.

Injection pressures of up to 1,740 psi (120 bar) — compared to the usual 55 psi (3.8 bar) of a typical indirect-injection gasoline engine — provide much-finer fuel atomization. And higher compression ratios are possible since DGI reduces the knock tendency, thus enhancing thermal efficiency.

DGI helps engine downsizing for a given performance. DGI's increased power potential, smaller engine size, as well as fewer cylinders, helps to achieve fuel economy target.

The “lean” air/fuel mixture inherent to DGI operation, with its surplus of oxygen, upsets the stoichiometric (14.7:1) air-fuel mixture ratio needed for complete combustion. It increases generation of Nitrogen Oxides (NOx).

The common solution is a new type of NOx “reservoir” catalytic converter that temporarily absorbs excess NOx during times when the engine operates in lean-burn mode, then releases it periodically to react with other exhaust components, forming harmless nitrogen.



Unfortunately, sulfur in gasoline can poison these catalysts and drastically reduce their effectiveness. To guarantee emissions-compliance, DGI engines require sulfur-free (10 parts per million or less) gasoline.

Retarded Injection The Nitrogen with atmospheric air gets induced during suction stroke, and due to very high temperature during combustion stroke it gets oxidized and forms NOx which is toxic in nature. Now to meet stringent emission norms, NOx has to be reduced. Retarded Injection is one way to reduce NOx. Due to Retarded Injection, the combustion temperature is reduced, and not enough to oxidize N2 MULTIVALVE TECHNOLOGY Most modern turbo diesels engine feature four valves per cylinder — two inlet and two exhaust. This allows the fuel-injection nozzle to be positioned in the center of the combustion chamber, producing more efficient, symmetrical combustion. Power is increased, while harmful emissions are reduced. Variable Valve Timing (VVT)

Variable Valve Timing, often abbreviated to VVT, is a type of piston engine technology that deliberately delivers inconsistent timing of the intake and/or exhaust valves. The benefit of this is improved gas mileage and flexibility for an engine to deliver peak performance over a variety of driving conditions. For example, traditional piston engines often are required to sacrifice low-end torque for high-end power (or vice versa). A VVT engine more easily accommodates both of these preferred performance conditions.

As with traditional piston engines, VVT engines use cams on a camshaft to drive the flow of air into the intake and exhaust valves. The timing of this valve lift directly affects how much air is taken in during each engine cycle. At times when the engine requires more air flow (for example high speeds or acceleration), a traditional piston engine often does not allow enough air to flow during each cycle, resulting in lower output performance. Conversely, a traditional piston engine that has been designed to feature longer exhaust and intake cycles will result in reduced fuel efficiency at slower speeds.

There are several proprietary VVT engine technologies that work slightly differently to prolong exhaust and intake cycles at high speeds and reduce cycles at slow speeds. The three major solutions to varying the valve timing of an engine are as follows:

The actual timing of the intake or exhaust valves are slowed or sped up as needed Two sets of cam lobes are utilized and switched between as needed Timing and lift is continuously altered for maximum efficiency (called continuous variable valve

timing)



Rise of Piston Ring The fuel in between top piston ring and piston crown does not get combusted due to insufficient temperature, and forms PM which has adverse effect on both human being and environment. Now to meet stringent emission norms, PM has to be reduced. Higher Piston Ring engine technology is one way to reduce PM emission. Due to rise in top piston ring, the dead are gets reduced and reduces the formation of PM.

ConventionalPiston RingPositioning

ReducedDead Air Space

TWO PIECE PISTON By using Two Piece Piston (Aluminum Skirt and Steel core), the over all weight of engine gets reduced which reduces fuel consumption or increases mileages, and indirectly it reduces emissions.



Standard Piston

Articulated Piston Positive Crankcase Ventilation (PCV) System Due to high temperature, the fuel gets evaporated, and both blow by gas (unburned/ partially hydrocarbon) and evaporated fuel expelled from the fuel tank to atmosphere and causes emission. Now PCV system into advanced engine enables the evaporated fuel/ blow by gas back into combustion chamber and prevents emission.



Exhaust Gas Recirculation (EGR) The Nitrogen in atmosphere gets inducted into combustion chamber during suction stroke, and at high temperature during combustion it reacts with Oxygen and forms NOx which is toxic in nature and has adverse affect on both human being and atmosphere. The generation of NOx is temperature dependent, if the combustion temperature can be lowered then NOx formation can be reduced to a great extent. EGR is most promising advanced engine technology to reduce NOx emission. It recycles a fraction of exhaust gas by EGR valve into the engine’s intake system. The exhaust gas is depleted of Oxygen, and lower Oxygen content slow down combustion process which leads to reduced pick temperature. The lower pick temperature reduces NOx formation.



Diesel Oxygen Catalyst (DOC)

The diesel oxidation catalyst, sometimes called a 2-way oxidation catalyst, it removes carbon monoxide and hydrocarbons to a great extent. It can also substantially reduce diesel particulate matter. It is used mainly in diesel engine, but it can also be used for lean burn petrol (Spark Ignition) engine.

System performance

It is an extremely cost effective, reliable and flexible approach to reducing diesel exhaust emissions. Because of the relatively small size of the oxidation catalyst, the complete exhaust system is usually a direct replacement for the original which simplifies design and fitment, lowering the cost.



It is a ‘fit and forget’ solution requiring no maintenance, and housed in stainless steel it has a long life expectancy. The system does not require ultra low sulphur diesel and is resistant to ash produced by the burning of engine oil, making it suitable for a wide variety of vehicles or where ultra low sulphur diesel (50 ppm) is not available.

Two-way Catalytic Converter

A two-way catalytic converter has two simultaneous tasks:

1. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2 2. Oxidation of unburnt hydrocarbons (unburnt and partially-burnt fuel) to carbon dioxide and

water: CxH2x+2 + [(3x+1)/2] O2 → xCO2 + (x+1) H2O (a combustion reaction)

This type of catalytic converter is widely used on diesel engines to reduce hydrocarbon and carbon-monoxide emissions. They were also used on gasoline engines in U.S. market automobiles until 1981. Because of their inability to control nitrous oxide NOx, they were superseded by three-way converters.

Three-way Catalytic Converter

Since 1981, three-way catalytic converters have been used in vehicle emission control systems in North America and many other countries on road-going vehicles. A three-way catalytic converter has three simultaneous tasks:

1. Reduction of nitrogen oxides to nitrogen and oxygen: 2NOx → xO2 + N2 2. Oxidation of carbon monoxide to carbon dioxide: 2CO + O2 → 2CO2 3. Oxidation of unburnt hydrocarbons (HC) to carbon dioxide and water: CxH2x+2 + [(3x+1)/2]O2 →

xCO2 + (x+1)H2O

These three reactions occur most efficiently when the catalytic converter receives exhaust from an engine running slightly above the stoichiometric point. This point is between 14.6 and 14.8 parts air to 1 part fuel, by weight, for gasoline. The ratio for Auto gas (or liquefied petroleum gas (LPG)), natural



gas and ethanol fuel is slightly different, requiring modified fuel system settings when using those fuels. Generally, engines fitted with 3-way catalytic converters are equipped with a computerized closed-loop feedback fuel injection system using one or more oxygen sensors, though early in the deployment of three-way converters, carburetors equipped for feedback mixture control were used.

While a three-way catalyst can be used in an open-loop system, NOx reduction efficiency is low. Within a narrow fuel/air ratio band surrounding stoichiometry, conversion of all three pollutants is nearly complete. However, outside that band, conversion efficiency falls very rapidly. When there is more oxygen than required, the system is said to be running lean (as all the fuel got burnt, the emission of CO and hydrocarbons are minimized) and thereby, the reduction of NOx is favored, at the expense of CO and hydrocarbons. When there is excessive fuel, the engine is running rich; the reduction of CO and hydrocarbons is favored, at the expense of NOx.

Selective Catalytic Reduction Technology (SCR) Selective catalytic reduction (SCR) systems are NOx removal devices. The key benefit of SCR is its ability to maximize fuel efficiency while reducing NOx. SCR can offer this benefit because it is able to effectively counteract the high NOx levels produced by optimizing combustion for maximum fuel efficiency. SCR systems remove nitrogen oxide (NOx) emissions from diesel exhaust by using a solution of urea as an ammonia source for the reduction of the nitrogen oxides to nitrogen. The process starts with a diesel oxidation catalyst (DOC), which converts much of the NO to NO2 and removes hydrocarbons. The higher proportion of NO2 lowers the temperature required for the next stage of the reaction. In the next stage, a urea solution is injected into the SCR system in the presence of a hydrolysis catalyst, which generates ammonia. The SCR catalyst (often vanadium) then uses ammonia as a reducing agent to convert the nitrogen oxides to nitrogen and water. In the final stage, an oxidation catalyst is often used to remove any un-reacted ammonia to prevent it from escaping. SCR systems require a higher temperature to operate. Because of this and the operational economics of SCR, it is primarily suited for long-haul heavy duty diesel applications



Exhaust gasEngine

Ureatank

ControlUnit

Mixing

SCR Catalyst

HydrolysisCatalyst

OxidationCatalyst

Ureainjection

pmNO

NO2 Urea

Pre-oxidationCatalyst

N2

H2O

NOx

NOx

Ammonia

Reducing pm,Building NO2 Reducing NOx to

N2 and H2O

Convertingurea intoammonia

Preventingammonia-slip

Diesel Particulate Filter (DPF) DPFs capture particulates in diesel exhaust and prevent their discharge from the exhaust pipe. DPFs require elevated temperatures to regenerate (or burn off) these collected particulates and soot. There are various methods of raising the DPF temperature including electrical heating and fuel burners.



Catalysed DPFs In catalysed DPFs (cDPF), the surface of the inner walls of the honeycombed filter is coated with a catalyst such as platinum, palladium, and rhodium to promote oxidation of the particulates. This helps reduce the temperature required to burn off particulates and soot. Fuel additive-catalysed DPFs In fuel additive-catalysed DPF systems, an additive is held in a separate tank from which it is dispersed into the fuel. This additive is trapped with the particulates and lowers the temperature required for soot burning. However, the ash from the additive remains in the filter after the particulates have burnt off, thereby contributing to the ash build-up in the filter Continuously Regenerating Traps (CRTs) A CRT aftertreatment device combines a diesel oxidation catalyst (DOC) with a DPF to lower the temperature required to burn off particulates. CRTs operate on the principle that particulates can be oxidised and burned off at lower temperatures if they are in the presence of NO2. For this reason, the DOC is used to convert more nitrogen oxides to NO2 before the exhaust enters the DPF



Have a look into engine technology for EURO IV engine of different OEMs.

OEM Engine Technology

Oxidation Catalyst

SCR DPF

CAT CGI No No Yes

Cummins EGR Yes Yes Yes

Int’l (Navistar) Heavy & Cooled EGR

Yes No Yes

Mack EGR Yes Yes Yes

Volvo EGR Yes Yes Yes

DDC, MB EGR Yes Yes Yes

TATA MOTORS

EGR Yes Yes No

ASHOK LEYLAND

EGR Yes Yes No

engine technology trends final/enginetechnologytrends... · 2012-05-21 · engine technology trends...

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