Full Answer
What is an aftertreatment system?
How Cummins Single Module Aftertreatment Technology Works. Play Video. The harmful emission gases in the exhaust stream move from the exhaust side of the turbo to the aftertreatment system (outlined in red). The Cummins Particulate Filter contains the Diesel Particulate Filter (DPF) which collects and oxidizes carbon to remove particulate matter (PM) …
What are the design requirements for aftertreatment systems?
· The main function of an aftertreatment system is to significantly reduce harmful emissions produced by diesel fuel powered equipment. It does so by targeting certain molecules present after diesel combustion and converting or processing them into less harmful byproducts. The targeted emissions include Particulate Matter (PM), Hydrocarbons (HC ...
What are the different parts of an engine aftertreatment system?
After-treatment systems such as EGR and SCR are widely accepted as the prime route for early Euro VI compliant applications. However, while these are proven paths to reducing NOx emissions, there are trade-offs associated with each approach. EGR limits combustion temperature by introducing cooled exhaust gas into the intake system, reducing NOx.
What are the 2013 multi-module aftertreatment aftertreatment video system component responsibilities?
Aftertreatment FAQ. What is a TLA? TLA stands for Top-Level-Assembly. This is the aggregation of welded components into an assembly on which removable components like sensors, dosing valve, access panels, v-band clamps are installed. What do the sizes / nomenclature mean?
What does an after treatment system include?
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 ...
What is DOC and DPF?
The exhaust aftertreatment devices that are applied to vehicles are Diesel Oxidation Catalysts (DOC), Diesel Particulate Filters (DPF) and Selective Catalytic Reduction (SCR) catalysts.
How does diesel after treatment work?
Instead, diesel exhaust aftertreatment systems reduce pollutants after they have been produced. The exhaust enters the diesel oxidizing catalyst (DOC) where HC and CO emission levels are reduced. This oxidizing process is similar to what occurred in the two-way catalysts on gas-powered cars of the mid-1970s.
What is a doc Cummins?
Diesel Particulate Filter. Cummins Emission Solutions' DPF is coupled with a Diesel Oxidation Catalyst (DOC). Together, those products are effective at removing 99 percent of PM soot from the exhaust system using wall- flow substrates.
Is the doc before or after the DPF?
The exhaust gas flows through the DOC's honeycomb structure which is coated with metal catalysts. CO and hydrocarbons get eliminated and turned into the less harmful water and CO2. Most of the manufacturers place the DOC before the DPF, this way the hydrocarbons filtered out by the DOC can't clog the DPF.
What is SCR on a diesel?
Selective Catalytic Reduction (SCR) is a proven and advanced active emissions control technology system that injects a liquid-reductant agent through a special catalyst into the exhaust stream of a diesel engine. The reductant source is usually automotive-grade urea, otherwise known as Diesel Exhaust Fluid (DEF).
What are the components of after treatment system in BS IV vehicle?
aftertreatment system consists of a fuel dosing system, mixing elements, fuel reformer, LNT, diesel particulate filter (DPF), and SCR catalyst arranged in series.
What is the purpose of DEF?
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.
How does a DPF regenerate?
DPF active regeneration Active regeneration happens when extra fuel is injected automatically as the filter reaches an approximately 45% full limit. The extra fuel raises the temperature of the exhaust and burns off the stored soot. Yet the journey has to be long enough to complete a full cycle.
What is a SCR filter?
Selective Catalytic Reduction of NOx (SCR deNOx) is a technology applied on diesel engines to reduce the NOx emissions, by injecting a urea-water solution (AdBlue) into the exhaust gas upstream of the SCR catalyst, generating ammonia (NH3).
Can a SCR be cleaned?
For SCR catalyst washing (and our other filter cleaning services), we have a success rate of 95 percent. In other words, we can usually clean your filters and return them to effective service, meaning that no replacement is necessary.
What precious metals are in a DPF?
This structure is covered with a layer of chemical catalyst that contains small amounts of precious metal, usually platinum or palladium, that interact with and oxidize pollutants in the exhaust stream (CO and unburned HCs), thereby reducing poisonous emissions.
What is the purpose of the doc?
In modern diesel aftertreatment systems, an important function of the DOC is to oxidize nitric oxide (NO) to nitrogen dioxide (NO2)—a gas needed to support the performance of diesel particulate filters and SCR catalysts used for NOx reduction.
What is a doc on a Peterbilt?
Exhaust from a diesel engine can be harmful to the environment and human health. So, to make the exhaust cleaner, manufacturers started adding an aftertreatment system to their trucks in 2007. This includes a Diesel Oxidation Catalyst (DOC) and Diesel Particulate Filter (DPF).
What does DPF stand for?
diesel particulate filterA diesel particulate filter, or DPF, is an exhaust aftertreatment device that traps particulate matter such as soot and ash.
Can a doc filter be cleaned?
Diesel particulate filters (DPF) work in conjunction with a diesel oxidation catalyst (DOC) in an exhaust system to reduce emissions and increase fuel efficiency. Both require regular cleaning to remove ash that builds up over time.
How does aftertreatment work?
An aftertreatment system is a method or device for reducing harmful exhaust emissions from internal-combustion engines to ensure the engines meet emission regulations.
What is aftertreatment system?
An aftertreatment system is a method or device for reducing harmful exhaust emissions from internal-combustion engines to ensure the engines meet emission regulations. Find out how an aftertreatment system works.
Emissions: Low Engine Temperatures
Particulate matter can be identified as the black soot that is exiting the exhaust pipes. It is the result of the partial combustion of hydrocarbons, engine oil and other additives present in fuel. Particulate matter is trapped in the Diesel Particulate Filter (DPF) by funneling the exhaust gases through a ceramic filter.
High Engine Temperatures
Finally, there is NOx, which is composed of Nitrogen Oxide (NO) and Nitrogen Dioxide (NO2). To reduce NOx, Diesel Exhaust Fluid (DEF) also known as AdBlue or Urea, is used in the aftertreatment system. DEF is composed of 32.5% urea (NH3) and demineralized water.
Optional: Emissions Regulations - On-Highway
As the world starts to see the negative impacts of vehicle emissions, countries realize that there must be significant changes made to vehicles to protect planet earth so that we may survive.
Off-Road Emission Overview – Off Road
The US government also required emissions regulations for off-road vehicles. The timing of the requirements was slightly behind the on-road vehicle standards but followed similar emissions regulations.
How Does KUS Come Into Play?
KUS DEF products focus on NOx conversion. They include DEF sending units, DEF tanks, DEF nozzles, DEF pump housings, and other accessories.
What is selective catalytic reduction?
Selective Catalytic Reduction (SCR) is another method, in addition to EGR, to reduce the level of NOx emissions. Rather than engine-out, SCR reduces tailpipe NOx emissions. In the presence of a catalyst, urea turns into ammonia and carbon dioxide, which then reacts with the NOx to create nitrogen and water vapour.
Is biodiesel a fuel injection system?
In addition, the introduction of bio-diesels is a cause of concern for fuel injection systems. The first generation of bio-diesels based on the esterisation of plant oils are subject to oxidation and deterioration with time.
Does exhaust throttling reduce air-fuel ratio?
Intake or exhaust throttling may reduce air–fuel ratio and increase the exhaust temperature for the aftertreatment system (e.g., DPF regeneration, SCR, LNT). Exhaust throttling generally produces less BSFC penalty than the pre-compressor intake throttling. However, any throttle valves placed in any part of the engine air system increase BSFC significantly, and their use should be avoided or minimized in engine system design. Although all the air control valves can achieve a wide range of controls of exhaust temperature and space velocity by adjusting the air flow rate, only VVA (e.g., early or late IVC, or cylinder deactivation) can achieve them without BSFC penalty. Early EVO and the valve events to obtain internal EGR may also increase the exhaust temperature. The benefit of exhaust temperature increase by VVA is especially important at light loads and during warm-up.
What is CAE in automotive?
CAE (computer assisted engineering) has become a popular tool for development of both the automotive catalyst and the total after-treatment system . This paper reports on using the CAE approach for modeling the DOC (diesel oxidation catalyst) + CSF (catalyzed soot filter) system. Two cases of modeling are shown here. One case is a modeling of DOC pre-cat in which the transient HC (and CO) gas performance is required. In this model, the parameters shown below are used; the random pore model for a gas diffusion, HC adsorption capacity as a function of temperature, HC desorption rate and HC reaction rate. Calculated catalyst performance correlated to the experimental results, thus validating the model. Another case is a modeling of DOC + CSF in which active regeneration of CSF is required. The CSF is used for diesel exhaust soot filtering, and the accumulated soot is periodically combusted to regenerate the CSF. Additional fuel is supplied to the DOC by post injection and/or fuel dosing into the exhaust pipe upstream of DOC and the resulting exotherm provides the heat for soot combustion on the CSF. In this study the uniformity of soot regeneration in the CSF was investigated as a function of fuel supply uniformity to the DOC.
What is CSF used for?
The CSF is used for diesel exhaust soot filtering, and the accumulated soot is periodically combusted to regenerate the CSF. Additional fuel is supplied to the DOC by post injection and/or fuel dosing into the exhaust pipe upstream of DOC and the resulting exotherm provides the heat for soot combustion on the CSF.
What is diesel oxidation catalyst?
Diesel oxidation catalysts reduce Particulate Matter (PM) through a chemical reaction that requires no cleaning or maintenance. In production since the early 1990’s, DOCs have been customized for the challenging demands of off-highway equipment and unique space constraints.
How many SCR systems are there?
Nearly 1 million selective catalytic reduction (SCR) systems and complementary components have been in use worldwide since 2005. SCR systems are an effective and reliable technology that reduces oxides of nitrogen (NOx) emissions for a broad range of off-highway applications and enables enhanced fuel economy.
What is SCR in automotive?
SCR systems are an effective and reliable technology that reduces oxides of nitrogen (NOx) emissions for a broad range of off-highway applications and enables enhanced fuel economy. Ideal for off-highway equipment, SCR systems are virtually maintenance-free with occasional dosing system filter maintenance depending on the application.
What is SCR in a system?
An SCR system is comprised of three main elements: SCR catalyst, urea dosing system and the aftertreatment control system. Our systems use a chemical reductant, in this case urea, which is called Diesel Exhaust Fluid (DEF) in North American or AdBlue in Europe.
What is Cummins control system?
Control systems by Cummins can be used as a stand-alone module to enhance engine control capabilities or integrated right into the engine control module. These systems monitor changes in pressure, temperature and oxides of nitrogen (NOx) while adjusting engine and aftertreatment operation for peak performance with the required emissions control.
How to service a DPF?
Further maintenance recommendations included the following: 1 Engine OEMs often require that when you service a DPF, you replace any of the gaskets or clamps that are used to hold that DPF in place. This will guarantee that you get a good seal of the DPF back in the system, and that there are no leaks in the system. 2 Activating parked regeneration in a safe place when automatic regeneration requirements cannot be met will help ensure overall health of the entire aftertreatment system. 3 It is extremely important to pay attention to the CEL/MIL lamps, which are put into place to notify the driver that actions need to be taken to ensure the health of the ATS. If ignored, damage to the system can occur, as well as derate conditions including torque and speed reductions. 4 It is important to know what kind of oil your engine requires, especially in light of the recent introduction of the American Petroleum Institute’s FA-4 and CK-4 categories. The engines will require the correct oil in order for the recommended DPF cleaning intervals to be correct.
What are the components of an engine aftertreatment system?
There are three components to the engine aftertreatment system: the diesel particulate filter (DPF), the diesel oxidation catalyst (DOC), and the selective catalytic reduction (SCR). The DPF has been the main focus of attention when problems come up, but it’s just as important to look at the DOC and SCR to make sure everything in ...
What is passive regeneration?
Passive regeneration occurs naturally in the truck. Under active regeneration, the DOC is part of the process to increase gas temperature. Basically, in most cases, fuel is consumed and used within the DOC. That increases the gas temperature, and that higher temperature gas enters the DPF and helps to burn off soot.”.
Does aftertreatment reduce emissions?
That increases the gas temperature, and that higher temperature gas enters the DPF and helps to burn off soot.”. Aftertreatment systems have led to a significant reduction in the emissions pouring from the engine.
What happens if you don't evaporate urea?
Boone explained that not completely evaporate the urea is a big problem that leaves a white deposit in the system, which can lead to additional backpressure.
How long does it take to service a Volvo aftertreatment system?
A good example of that is the Volvo aftertreatment system, which has a DPF that can be serviced in around 15 to 20 minutes, whereas a lot of the previous generation systems would take significantly longer. That all leads to more uptime for the vehicle, rather than having it sit in a shop.”. Advertisement.
What are the drawbacks of DPF?
Boone said that one of the DPF’s biggest drawbacks is that it adds a restriction to the system that wasn’t there prior to the use of a filter. It’s gathering soot, which has to be turned off, and it’s gathering ash, which has to be physically removed. All of this leads to an increase in the backpressure of the system.
About Cummins Emission Solutions
How An Aftertreatment Works
- An aftertreatment system is a method or device for reducing harmful exhaust emissions from internal-combustion engines to ensure the engines meet emission regulations. Find out how an aftertreatment system works
CORE Technologies
- Cummins’ leading aftertreatment technologies are designed around our proven core technologies. Building on thousands of hours of real-world experience and expertise of oxidation catalysts, particulate filters and SCR technology, our aftertreatment systems help optimize your entire engine system to operate more efficiently. Learn more about our Core...
Product Segments
- Cummins helps customers meet tomorrow's emissions standards today with innovative, flexible and integrated technology for light- medium-, heavy-duty and high-horsepower commercial on- and off-highway engine markets.
Aftertreatment Innovation
- At Cummins, our continuous improvement process demands that we look for new and innovative ways to make engines run cleaner, stronger and longer. Our continued commitment to meeting the highest standards and our innovative technologies set us apart from the competition. Find out more about our future technologies