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64-427: Until 2010 this engine was a dual overhead cam design with one cam actuating the injectors and the other the valve train. This injection system is known as HPI (high pressure injection) where the injectors are cam-actuated to create injection pressure. The fuel system uses an Integrated Fuel System Module (IFSM) with a lift pump, gear pump, pressure regulators, shutoff valve, metering and timing actuators to deliver fuel to

128-411: A diesel exhaust fluid (DEF - composed of urea and water) injection system: holding tank, pump, controller, and injector and an SCR catalyst brick. DEF is heated, pumped and injected into a decomposition tube which then reacts with the exhaust reducing NOX. The ISX15 CM2250 and CM2350 has eliminated the injector camshaft due to the advent of the common rail fuel system in which the fuel is pressurized from

192-558: A cold engine. Moreover, the EGR valve was controlled, in part, by vacuum drawn from the carburetor's venturi, which allowed more precise constraint of EGR flow to only those engine load conditions under which NO x is likely to form. Later, backpressure transducers were added to the EGR valve control to further tailor EGR flow to engine load conditions. Most modern engines now need exhaust gas recirculation to meet NO x emissions standards. However, recent innovations have led to

256-468: A cool, dry, and well-ventilated area that is out of direct sunlight. Bulk volumes of DEF are compatible for storage within polyethylene containers ( HDPE , XLPE ), fiberglass reinforced plastic ( FRP ), and steel tanks. DEF is also often handled in intermediate bulk containers for storage and shipping. DEF is offered to consumers in a variety of quantities ranging from containers for single or repeated small usage, up to bulk carriers for consumers requiring

320-465: A diesel reduces the specific heat ratio of the combustion gases in the power stroke . This reduces the amount of power that can be extracted by the piston, thereby reducing the thermodynamic efficiency. EGR also tends to reduce the completeness of fuel combustion during the power stroke. This is plainly evident by the increase in particulate emissions that corresponds to an increase in EGR. Particulate matter (mainly carbon and also known as soot) that

384-608: A frozen tank at a core temperature of −15 °C (5 °F) must become available within 20 minutes when starting the engine at −15 °C (5 °F). Typically, the frozen DEF is melted by heat from the engine, e.g. engine coolant passing through the DEF tank, governed by a thermostatic coolant control valve. This method may take significant time before the SCR exhaust cleaning system is fully operational, often up to an hour. Another method to thaw DEF (and thus allow for full SCR operation)

448-569: A high pressure, multiple piston pump, transferred through tubing to a rail where fuel is stored under extremely high pressures up to 35,000 psi. In 2023, Cummins unveiled the X10 and X15N engines. The X10 is slated to replace the X12 and L9 in the truck market as it was made to serve both heavy duty and medium duty truck applications. The X15N is a CNG version of the X15, and is expected to release in 2025 with

512-465: A large amount of DEF. As of 2013, many truck stops have added DEF pumps. These are usually adjacent to fuel pumps so the driver can fill both tanks without moving the truck. In Europe, increasing numbers of fuel stations offer dispensers that pump Diesel Exhaust Fluid rather than the traditional method of using disposable, single-use plastic containers. These pumped dispensers are often targeted at commercial vehicles but are now also starting to emerge as

576-448: A mixture of nitrogen and oxygen is subjected to high temperature, the lower combustion chamber temperatures caused by EGR reduces the amount of NO x that the combustion process generates. Gases re-introduced from EGR systems will also contain near equilibrium concentrations of NO x and CO; the small fraction initially within the combustion chamber inhibits the total net production of these and other pollutants when sampled on

640-413: A move that now impacts 40% of registered vehicles. Diesel vehicles made since 2015 were required to be fitted with SCR systems. The South Korean government started rationing urea solution, and banned its resale as panic buying by drivers exacerbated an acute shortage that could cause transport and industry to grind to a halt. A KC-330 Cygnus was sent to import Diesel exhaust fluid from Australia to ease

704-494: A reduction in fuel efficiency due to the back pressure created. Diesel particulate filters come with their own set of very specific operational and maintenance requirements. Firstly, as the DPF captures the soot particles (which are made far more numerous due to the use of EGR), the DPF itself progressively becomes loaded with soot. This soot must then be burned off, either actively or passively. At sufficiently high temperatures,

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768-534: A shortage of DEF in South Korea was continuing and brought havoc to its economy. As most of the urea used is supplied by China, imports have slowed since China introduced mandatory inspections of urea exports in September. Nearly 97% of South Korea's urea imports came from China between January and September. In 2015, South Korea had made it mandatory for diesel cars to use urea solutions to control emissions,

832-440: A solution for the growing number of passenger cars that require DEF by volume. At airports, where DEF can sometimes be required for diesel ground service vehicles, its labelling and storage must be carefully managed to avoid accidentally servicing jet aircraft with DEF instead of fuel system icing inhibitor , a mistake that has been blamed for multiple in-flight engine failure and grounding incidents. As of December 2021 ,

896-444: A spark-ignition engine, an ancillary benefit of recirculating exhaust gases via an external EGR valve is an increase in efficiency, as charge dilution allows a larger throttle position and reduces associated pumping losses. Mazda's turbocharged SkyActiv gasoline direct injection engine uses recirculated and cooled exhaust gases to reduce combustion chamber temperatures, thereby permitting the engine to run at higher boost levels before

960-686: A supply shortage of the key material used in diesel vehicles. In early December 2021, the Australian National Road Transport Association also raised concerns about a shortage of DEF in the country due to the shortage of urea in China. China capped exports to protect its domestic supplies and rising DEF prices. By mid-December, there was approximately 7 weeks' supply of AdBlue left in Australia. On 14 December, Australian company IOR stated that it would build

1024-528: A time average. Chemical properties of different fuels limit how much EGR may be used. For example methanol is more tolerant to EGR than gasoline. The first EGR systems were crude; some were as simple as an orifice jet between the exhaust and intake tracts which admitted exhaust to the intake tract whenever the engine was running. Difficult starting, rough idling, reduced performance and lost fuel economy inevitably resulted. By 1973, an EGR valve controlled by manifold vacuum opened or closed to admit exhaust to

1088-488: A typical automotive spark-ignited (SI) engine, 5% to 15% of the exhaust gas is routed back to the intake as EGR. The maximum quantity is limited by the need of the mixture to sustain a continuous flame front during the combustion event; excessive EGR in poorly set up applications can cause misfires and partial burns. Although EGR does measurably slow combustion, this can largely be compensated for by advancing spark timing. The impact of EGR on engine efficiency largely depends on

1152-490: Is a 32.5% solution of urea, (NH 2 ) 2 CO . When it is injected into the hot exhaust gas stream, the water evaporates and the urea thermally decomposes to form ammonia ( NH 3 ) and isocyanic acid (HNCO): The isocyanic acid reacts with the water vapor and hydrolyses to carbon dioxide and ammonia: Overall, thus far: Ammonia, in the presence of oxygen and a catalyst, reduces two different nitrogen oxides: The overall reduction of NO x by urea

1216-432: Is a liquid used to reduce the amount of air pollution created by a diesel engine. Specifically, DEF is an aqueous urea solution made with 32.5% urea and 67.5% deionized water . DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides ( NO x ) in the diesel exhaust emissions from a diesel engine . In the international standard defining DEF ( ISO 22241), it

1280-459: Is a reduction in engine longevity. For example, because the EGR system routes exhaust gas directly back into the cylinder intake without any form of filtration, this exhaust gas contains carbon particulates . And, because these tiny particles are abrasive, the recirculation of this material back into the cylinder increases engine wear. This is so because these carbon particles will blow by the piston rings (causing piston-cylinder-interface wear in

1344-420: Is also omitted at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle. Since the EGR system recirculates a portion of exhaust gases, over time the valve can become clogged with carbon deposits, which will prevent it from operating properly. Clogged EGR valves can sometimes be cleaned, but replacement is necessary if the valve is faulty. Because diesel engines depend on

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1408-400: Is clear, non-toxic and safe to handle. Since urea has corrosive impact on metals like aluminium, DEF is stored and transported in special containers. These containers are typically made of stainless steel. Vehicles' selective catalytic reduction (SCR) systems and DEF dispensers are designed in a manner that there is no corrosive impact of urea on them. It is recommended that DEF be stored in

1472-494: Is effectively countered by the DPF, which collects these and in the end will burn those unburnt particles during regeneration, converting them into CO2 and water vapour emissions, that - unlike NOx gases - have no negative health effects. Modern cooled EGR systems help reduce engine wear by using the waste heat recouped from the recirculated gases to help warm the coolant and hence the engine block faster to operating temperature. This also helps lower fuel consumption through reducing

1536-501: Is exposure of the oil to high temperatures. Although engine manufacturers have refused to release details of the effect of EGR on fuel economy, the EPA regulations of 2002 that led to the introduction of cooled EGR were associated with a 3% drop in engine efficiency, thus bucking the trend of a 0.5% annual increase. Diesel exhaust fluid Diesel exhaust fluid ( DEF ; also known as AUS 32 and sometimes marketed as AdBlue )

1600-402: Is made and distributed for retail sale by Prime Lubes, Inc. Diesel engines are typically operated with a lean burn air-to-fuel ratio ( over-stoichiometric ratio) to ensure the full combustion of soot and to prevent them from exhausting unburnt fuel. The excess air leads to the generation of NO x , which are harmful pollutants , from nitrogen in the atmosphere. SCR is used to reduce

1664-438: Is not burned in the power stroke represents wasted energy. Because of stricter regulations on particulate matter (PM), the soot-increasing effect of EGR required the introduction of further emission controls in order to compensate for the resulting PM emission increases. The most common soot-control device is a diesel particulate filter (DPF) installed downstream of the engine in the exhaust system. This captures soot but causes

1728-548: Is referred to as AUS 32 (aqueous urea solution 32%). DEF is also sold as AdBlue, a registered trademark of the German Association of the Automotive Industry . Several brands of SCR systems use DEF: BlueHDI is used by PSA Group vehicles including Peugeot , Citroën , and DS Automobiles brands; BlueTec by Daimler AG ; and FLENDS (Final Low Emission New Diesel System) by UD Trucks . Blue Sky DEF

1792-589: Is slower than standard SCR, and ammonium nitrate can form and temporarily deactivate the catalytic converter. DEF freezes at −11 °C (12 °F). For the SCR exhaust cleaning system to function at low temperatures, a sufficient amount of the frozen DEF must be melted in as short time as possible, preferably on the order of minutes. For example, 2010 EPA emissions requirements require full DEF coolant flow within 70 minutes. In Europe, Regulation (EC) No 692/2008 specified in Annex XVI point 10 that DEF from

1856-542: Is system of injected urea that reduces the emissions of a diesel engine. The Cummins ISX is required to have inhibitors in place for certain failures of the DEF system. When the DEF tank is low or empty, the ISX cuts power by twenty five percent. Power cuts and driver warnings are also used when the DEF system has been tampered with or is not functioning properly. Cummins has corrected several malfunctions and conducted customer based research of several million miles of on road use of

1920-471: Is then: The ratio between NO 2 and NO determines which reactions take place and how fast. The highest conversion rates are achieved if equal amounts of NO 2 and NO are present, especially at temperatures between 200 °C and 350 °C. If there is more NO than NO 2 , fast SCR and standard SCR take place sequentially. If there is more NO 2 than NO , fast SCR and NO 2 SCR take place sequentially, however, NO 2 SCR

1984-581: Is to integrate an electric heater into the DEF tank. This heater must be sized, positioned, and powered adequately to rapidly melt sufficient frozen DEF. It should preferably be self regulating not to overheat if (part of) the heater is outside of the liquid. It should also preferably be self regulating to eliminate any complicated sensor and temperature regulating systems. Furthermore, the heater should not exceed 50–60 °C (122–140 °F), as DEF begins to decompose at around 60 °C (140 °F). PTC heaters are often used to achieve this. The urea solution

Cummins X-series engine - Misplaced Pages Continue

2048-519: The Cummins ISX by the EPA for natural gas usage that yielded results of major NOx emissions reduction. The configuration boasts ninety percent lower NOx emissions than the current EPA standard. This makes the Cummins ISX that burns natural gas one of the cleanest running diesel engines in the world. The ISX also utilizes a DPF , or diesel particulate filter, required by the EPA. The DPF filters out

2112-434: The Cummins ISX to make the DEF system as functional as possible. The system is also required to de-rate power given any problems in order to reduce emissions to an absolute minimum. In early ISX engines an anti backlash gear train is used. The anti backlash gears allow the engine to operate with minimal gear rattle. Cummins uses a gear train in the front of the engine which is inherently noisy. The anti backlash gearing makes

2176-726: The Cummins Signature was released to the Australian market to replace the out going N14. The Signature was produced up until 2003, In 2003 the highly popular Oceania exclusive was released this being the Gen 2 Cummins Signature. It built upon and improved on the original Cummins Signature. 2008 saw the third Signature revision this was the Signature EGR which utilized the same technology as the ISX EGR range. 2012 brought along

2240-463: The DPF by burning diesel fuel directly in the oxidation catalyst in order to significantly increase exhaust-gas temperatures through the DPF to the point where PM is incinerated by the residual oxygen in the exhaust. Because diesel fuel and engine oil both contain nonburnable (i.e. metallic and mineral) impurities, the incineration of soot (PM) in the DPF leaves behind a residue known as ash. For this reason, after repeated regeneration events, eventually

2304-547: The DPF must either be physically removed and cleaned in a special external process, or it must be replaced. As noted earlier, the feeding of the low-oxygen exhaust gas into the diesel engine's air intake engenders lower combustion temperatures, thereby reducing emissions of NO x . By replacing some of the fresh air intake with inert gases EGR also allows the engine to reduce the amount of injected fuel without compromising ideal air-fuel mixture ratio, therefore reducing fuel consumption in low engine load situation (for ex. while

2368-558: The DPF needs to be regularly removed and cleaned for the Cummins ISX. An ash-less oil could mean that cleaning would be unnecessary, but can inhibit lubrication properties. A zero-phosphorus oil has been studied and found to be ideal for DPF systems and lubrication. The oil displays passing results for both piston deposits and oil consumption, which means the DPF system would be optimized with use of zero-phosphorus, ultra low sulfur oil. The Cummins ISX also utilized DEF, or diesel exhaust fluid , in later models when EPA requirements changed. DEF

2432-436: The Gen 2 EGR line. Exhaust gas recirculation In internal combustion engines , exhaust gas recirculation ( EGR ) is a nitrogen oxide ( NO x ) emissions reduction technique used in petrol/gasoline , diesel engines and some hydrogen engines . EGR works by recirculating a portion of an engine's exhaust gas back to the engine cylinders . The exhaust gas displaces atmospheric air and reduces O 2 in

2496-701: The ISX CM871, this engine featured a Diesel Particulate Filter (DPF) which trapped the particulate matter or "soot" produced in the engine. With the help of the Diesel Oxidation Catalyst (DOC) the soot trapped in the DPF is oxidized and turned to ash during a process called regeneration. In motorhomes this was available as a 600 or 650 HP version. The current EPA 2010 version known as ISX15 CM2250 features enhanced exhaust gas recirculation, diesel particulate filter and selective catalytic reduction (SCR), also known as urea injection . SCR consists of

2560-427: The air-fuel mixture must be enriched to prevent engine knocking . In a gasoline engine, this inert exhaust displaces some amount of combustible charge in the cylinder, effectively reducing the quantity of charge available for combustion without affecting the air-fuel ratio. In a diesel engine, the exhaust gas replaces some of the excess oxygen in the pre-combustion mixture. Because NO x forms primarily when

2624-503: The amount of NO x released into the atmosphere. DEF from a separate tank is injected into the exhaust pipeline, and the exhaust heat decomposes it to ammonia. Within the SCR catalyst , the NO x are reduced by the ammonia into water and nitrogen , which are both nonpolluting. The water and nitrogen are then released into the atmosphere through the exhaust. SCR was applied to automobiles by Nissan Diesel Corporation , and

Cummins X-series engine - Misplaced Pages Continue

2688-425: The combustion chamber. Reducing the amount of oxygen reduces the amount of fuel that can burn in the cylinder thereby reducing peak in-cylinder temperatures. The actual amount of recirculated exhaust gas varies with the engine operating parameters. In the combustion cylinder, NO x is produced by high-temperature mixtures of atmospheric nitrogen and oxygen, and this usually occurs at cylinder peak pressure. In

2752-488: The combustion temperatures. In modern diesel engines , the EGR gas is usually cooled with a heat exchanger to allow the introduction of a greater mass of recirculated gas. However, uncooled EGR designs do exist; these are often referred to as hot-gas recirculation (HGR). Cooled EGR components are exposed to repeated, rapid changes in temperatures, which can cause coolant leak and catastrophic engine failure. Unlike spark-ignition engines , diesel engines are not limited by

2816-415: The development of engines that do not require them. The 3.6 Chrysler Pentastar engine is one example that does not require EGR. The exhaust gas contains water vapor and carbon dioxide which both have lower heat capacity ratio than air. Adding exhaust gas therefore reduces pressure and temperature during the isentropic compression in the cylinder, thereby lowering the adiabatic flame temperature . In

2880-497: The engine less noisy due to the reduced rattle while in operation. The anti backlash gear train comes at a cost of efficiency. The Cummins ISX 15 model equipped with anti backlash gearing suffers a friction loss. The gears must overcome more friction throughout their moving range than a standard gear. A standard gear in a Cummins ISX 15 needs to overcome 0.75 Newton meters of torque, while the anti backlash gearing needs to overcome approximately 5 Newton meters of torque. Starting in 1998

2944-636: The first practical product " Nissan Diesel Quon " was introduced in 2004. With the cooperation of the oil and chemical industry, a 1,300-station infrastructure to supply DEF was prepared by September 2005 in Japan. In 2007, the United States Environmental Protection Agency (EPA) enacted requirements to significantly reduce harmful exhaust emissions. To achieve this standard, Cummins and other diesel engine manufacturers developed an aftertreatment system that includes

3008-431: The form of an undesirable positive-feedback loop, will worsen as the engine ages. For example, as the piston rings progressively wear out, more crankcase oil will get into the exhaust stream. Simultaneously, more fuel and soot and combustion byproducts will gain access to the engine oil.) The end result of this recirculation of both exhaust gas and crankcase oil vapour is again an increase in soot production, which however

3072-402: The heat of compression to ignite their fuel, they are fundamentally different from spark-ignited engines. The physical process of diesel-fuel combustion is such that the most complete combustion occurs at the highest temperatures. Unfortunately, the production of nitrogen oxides ( NO x ) increases at high temperatures. The goal of EGR is thus to reduce NO x production by reducing

3136-539: The injectors. It has a one piece valve cover that is either plastic or on older models a chrome plated steel cover otherwise known as the Signature 600 or ISX CM570. In 2002, the ISX CM870 brought cooled exhaust gas recirculation (EGR) which takes exhaust gas and recirculates it back into the intake of the engine lowering the combustion chamber temperatures limiting the formation of NOx. In 2008, Cummins unveiled

3200-502: The intake tract only under certain conditions. Control systems grew more sophisticated as automakers gained experience; Volkswagen's "Coolant Controlled Exhaust Gas Recirculation" system of 1973 exemplified this evolution: a coolant temperature sensor blocked vacuum to the EGR valve until the engine reached normal operating temperature . This prevented driveability problems due to unnecessary exhaust induction; NO x forms under elevated temperature conditions generally not present with

3264-453: The latter is only there to reduce oil vapor emissions, and can be present on engines with or without any EGR system. However, the tripartite mixture resulting from employing both EGR and PCV in an engine (i.e. exhaust gas, fresh air, and oil vapour) can cause the buildup of sticky tar in the intake manifold and valves. This mixture can also cause problems with components such as swirl flaps , where fitted. (These problems, which effectively take

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3328-400: The more stringent 2010 EPA regulations, which reduced NO x levels even further. In 2008, the concerns about compliance shifted to the infrastructure for DEF distribution. The injection rate of DEF into the exhaust depends on the specific after-treatment system, but is typically 2–6% of diesel consumption volume. This low dosing rate ensures long fluid refill intervals and minimizes

3392-458: The need for a contiguous flamefront. Furthermore, since diesels always operate with excess air, they benefit (in terms of reduced NO x output) from EGR rates as high as 50%. However, a 50% EGR rate is only suitable when the diesel engine is at idle, since this is when there is otherwise a large excess of air. Because modern diesel engines often have a throttle, EGR can reduce the need for throttling, thereby eliminating this type of loss in

3456-422: The nitrogen dioxide component of NO x emissions is the primary oxidizer of the soot caught in the DPF at normal operating temperatures. This process is known as passive regeneration, and it is only partially effective at burning off the captured soot. And, especially at high EGR rates, the effectiveness of passive regeneration is further reduced. This, in turn, necessitates periodic active regeneration of

3520-471: The process) and then end up in the crankcase oil, where they will cause further wear throughout the engine simply because their tiny size passes through typical oil filters. This enables them to be recirculated indefinitely (until the next oil change takes place). Exhaust gas—which consists largely of nitrogen, carbon dioxide , and water vapor—has a higher specific heat than air, so it still serves to lower peak combustion temperatures. However, adding EGR to

3584-574: The same performance as the X15. Slated to replace X12 in Vocational & Regional Haul Slated to replace L9 Built off the X12 block The Cummins ISX diesel engine can be run in a dual fuel configuration, meaning it can properly operate on diesel fuel and natural gas . The burning of a natural gas alternative preserves diesel thermal efficiencies. The more efficient engine can produce less emissions in turn. The ISX can achieve this by altering ignition delay and injection timing. By examining

3648-424: The same way that it does for spark-ignited engines. In a naturally aspirated (i.e. nonturbocharged) engine, such a reduction in throttling also reduces the problem of engine oil being sucked past the piston rings into the cylinder and causing oil-derived carbon deposits there. (This benefit only applies to nonturbocharged engines.) In diesel engines in particular, EGR systems come with serious drawbacks, one of which

3712-417: The solid particles in the engine's exhaust, reducing tailpipe emissions. The DPF does have to be regularly maintained, however, because of its intricate design. The emissions control system will institute a filter regeneration which burns off the particulates. Any non-combustible materials found in lubrication additives will remain in the DPF, which can cause problems with back pressure and efficiency. This means

3776-401: The specific engine design, and sometimes leads to a compromise between efficiency and NO x emissions. In certain types of situations, a properly operating EGR can theoretically increase the efficiency of gasoline engines via several mechanisms: EGR is typically not employed at high loads because it would reduce peak power output. This is because it reduces the intake charge density. EGR

3840-405: The start of combustion (SOC), the engine's computer is able to employ a predictive ignition delay correlation. The predictive characteristics of the engine maximize both efficiency and useful power for the given fuel source. Compensations are made for the natural gas so that the power band and operating range are still functional for customers, while reducing emissions. Testing has also been done with

3904-402: The tank's size and intrusion into vehicle packaging space. An electronic control unit adjusts the addition of fluid in accordance with parameters such as NO x level in the exhaust gas (before catalytic converter, after catalytic converter, and possibly between catalytic converters if there is more than one), current ammonia filling level, engine operating temperature and speed. DEF

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3968-436: The time after cold starts during which the engine controller has to inject somewhat larger amounts of fuel into the cylinders to counter the effects of fuel vapor condensation on cylinder walls and lowered combustion effectiveness because of the engine block still being below ideal operating temperature. Lowering combustion temperatures also helps reducing the oxidization of engine oil, as the most significant factor affecting that

4032-515: The use of a diesel particulate filter (DPF). As the DPF does not function with low-sulfur diesel fuel, diesel engines that conform to 2007 EPA emissions standards require ultra-low-sulfur diesel (ULSD) fuel to prevent damage to the DPF. After a brief transition period, ULSD fuel became common at fuel pumps in the United States and Canada. The 2007 EPA regulations were meant to be an interim solution to allow manufacturers time to prepare for

4096-452: The vehicle is coasting or cruising). Power is not reduced by EGR at any times, as EGR is not employed in high load engine situations. This allows engines to still deliver maximum power when needed, but lower fuel consumption despite large cylinder volume when partial load is sufficient to meet the power needs of the car and the driver. EGR has nothing to do with oil vapor re-routing from a positive crankcase ventilation system (PCV) system, as

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