LESS WEIGHT, LESS NOISE, MORE FLEXIBILITY, MORE EMISSIONS REDUCTIONS
As federal regulators create ever steeper hills for automakers to climb to meet tighter fuel-economy requirements and CO2 emissions standards, automakers have found new ways to calibrate engines, new materials from which to fashion vehicles and new alternative methods to power them.
These innovations, in turn, have required new approaches to emissions control systems to increase their effectiveness without increasing their weight, to improve performance while enhancing design flexibility.
On display during the 2015 North American International Auto Show are advancements from Faurecia Emissions Control Technologies that allow exhaust systems for cars and trucks to harmonize perfectly with the new regulations and new technologies that are driving the next generation of vehicles.
A FAMILY OF PRODUCTS TO REDUCE NOX EMISSIONS
The trend for automotive designers seeking to reduce emissions of nitrogen oxides (NOx) has been to bring the diesel’s selective catalytic reduction (SCR) catalyst as close as possible to the engine to improve light-off time. Faurecia is featuring a high-performance, very compact mixing design portfolio for increasingly popular diesel engines. These Faurecia-patented systems provide a much shorter catalyst light-off time during cold starts, allowing the engine to run more efficiently and generate fewer emissions.
Compact SCR BlueBox® Technology
The SCR BlueBox® enables close coupling in a compact system that is lighter than previous SCR devices. It offers better emissions control and potentially a lower cost. Raw emissions from the exhaust enter the SCR BlueBox® and go into a helical mixing chamber. There, Diesel Exhaust Fluid (DEF)—a mixture of urea and water—is sprayed into the chamber. SCR BlueBox® technology ensures exceptionally good mixing of the exhaust and fluid, resulting in thermal decomposition to drive out the water and chemical decomposition to produce ammonia. A principal advantage of SCR BlueBox® is that in a short package it very evenly distributes ammonia in the exhaust gas for highly efficient reduction of the nitrogen oxides to nitrogen and water.
One of the challenges of close coupling is managing urea deposits in the exhaust system. As a result of a thorough understanding and knowledge base relating to SCR, Faurecia’s SCR BlueBox® designs have very low deposit formation potential.
One strategy for calibrating engines for better fuel economy also leads to higher NOx output from the engine. To deal with those emissions, more DEF needs to be injected, which increases the risk of deposits. Faurecia, however, has improved the management of those deposits to minimize this issue.
Faurecia today has significantly expanded its experience and the range of engine sizes for which it has developed SCR BlueBox® technology. Faurecia now creates U-shaped and V-shaped SCR BlueBox® systems to accommodate the more compact, fuel-saving engine configurations in the latest vehicles. Such capabilities for offering improved NOx reduction in a portfolio of form factors are both an important and a difficult expertise to develop. Faurecia Emissions Control Technologies, however, has become a world leader in SC R innovation.
SCR-coated DPF: Combining Filtering with SCR
SCR-coated DPF combines the SCR catalyst with a porous filter substrate to offer both NOx reduction and a diesel particulate filter on a single brick. This industry leading technology contributes to less space consumption, lighter weight and reduced costs. Faurecia SCR BlueBox® technology has been developed as a SCR-coated DPF enabler to be compatible with SCRF, allowing automakers to incorporate all the advantages of a compact SCR system in a weight-saving package.
Faurecia’s entire compact mixing portfolio is applicable to transverse and longitudinal installations, making it especially appropriate to the newest diesel pickup trucks that favor longitudinal systems. These include light-duty diesel pickups that use an underfloor SCR BlueBox® layout.
Low pressure EGR Back-Pressure valve
The Back-Pressure Valve plays a key role in low pressure exhaust gas recirculation (EGR) systems to force exhaust gases back to the engine air intake. The low pressure EGR system allows up to 50 percent nitrogen oxides reduction for diesel engines.
Faurecia has developed its own Back-Pressure Valve leveraging its acoustic Electric Actuated Valve, which shares the same formed body process while offering several body diameters. Several actuator solutions are available combining smart and failsafe solutions in a compact package.
Gasoline Particulate Filter
Diesel vehicles have long been required to incorporate particulate filters to remove soot after it leaves the engine and before it can enter the environment. Now particulate filters are ready to be introduced in gasoline engines.
The particulate issue largely has emerged with the move toward gasoline direct injection systems, as well as governmental decisions to regulate tiny particulate matter.
The direct-injection engines emit higher volumes of particulates than standard gasoline engines and the Gasoline Particulate Filter (GPF) technology enables reduction of particulate emissions into the ambient air level.
In this context, Faurecia has developed, and is producing for a major automaker, the first GPF to be fitted optionally on a premium vehicle.
This vehicle equipped with a GPF will be compliant with the forthcoming Euro 6c (2017) regulation which imposes regulations on particulate numbers either for diesel or direct-injection gasoline engines.
A GPF will collect particulates on an ongoing basis and will regenerate more easily than a DPF (Diesel Particulate Filter) on a passive regeneration mode.
Faurecia is convinced that the Gasoline Particulate Filter will enable the industry to offer the fuel-efficiency of gasoline direct-injection engines while protecting the air quality of harmful ultra-fine particulates.
Ammonia Storage and Delivery System (ASDS)
Faurecia recently demonstrated the value of its Ammonia Storage and Delivery System (ASDS) for reducing NOx emissions in the toughest of conditions.
In place of the mixing process to generate ammonia from diesel exhaust fluid (DEF), ASDS delivers pure ammonia directly to an SCR catalyst in the exhaust line. ASDS stores ammonia as a solid in a metallic cartridge and releases it as a gas when the cartridge is heated. The ammonia becomes immediately available to the catalyst for NOx reduction.
ASDS OFFERS A NUMBER OF ADVANTAGES OVER CONVENTIONAL SCR SYSTEMS.
- ASDS requires less space because of its high ammonia-storage capacity.
- With a nearly zero wait time for ammonia availability, ASDS can improve NOx reduction at the lower exhaust temperatures typical of urban driving, because it enables a faster activation of NOx conversion.
- No deposits formed in the exhaust line, because ASDS does not require decomposition to produce ammonia.
- The ammonia will not freeze at low temperatures, unlike DEF.
- ASDS is a simple injection system that is easy to package.
At NAIAS 2015, Faurecia is exhibiting a portion of the exhaust system from a bus that participated in a test of ASDS during changing weather conditions in Buffalo, New York. Three buses equipped with ASDS were monitored between March and July 2014 under normal use conditions. Each day, measurements were made and compared to three reference buses using DEF on the same route. After 18,600 miles, the buses running with ASDS showed a 7-to-10-percent better NOx conversion compared with the conventional bus system.
Additionally, changeovers in the ammonia cartridge were shown to require less than one minute. Even more important, significantly lower maintenance and warranty costs can be anticipated because the formation of deposits in the exhaust system was eliminated.
Acoustic Performance and Sound Design
Faurecia has established its leadership in designing exhaust systems that not only eliminate unwanted noise but accomplish it with a minimum amount of mass. Through clever new systems, Faurecia is adding more capabilities to exhaust systems that weigh much less
Exhaust Dynamic Sound Technologies
Faurecia continues to advance its exhaust dynamic sound technologies to furnish the character and voice that each vehicle deserves. Diesel-powered cars that are replete with after-treatment devices for capturing emissions may generate very little or no exhaust sounds. On the road, drivers expect their high-horsepower car to produce a sound that matches all of its power, even if it has a four-cylinder engine. Too often, however, today’s cars emit little more than whooshes
Faurecia brings back the vehicle’s voice by placing a speaker at the end of the exhaust line, right next to the tailpipe. Enclosed in a housing of metal or plastic, the speaker responds to prompts from the car’s engine electronic control unit (ECU) and produces a very specific sound that corresponds to the vehicle’s speed and engine load. In this way, diesel cars can sound very much like their gasoline-powered counterparts.
Since this system can create virtually any sound, designers have new freedom to reshape the exhaust sound at any point in the design process, rather than finding themselves locked into one set of specifications at the beginning.
Similarly, vehicles that make too much noise can be transformed into much softersounding cars through exhaust dynamic sound technologies. Turbo-charged gasoline-powered cars often generate too rash exhaust noise, but Faurecia technology can cancel that unpleasant noise through a speaker at the tailpipe that emits frequencies exactly opposite to those being generated by the car at any point in time. The ECU consistently monitors noise frequencies at the tailpipe and synchronizes production of noise-cancelling waves.
Then, Faurecia technology can employ the ECU and the same speaker to generate a sound that gives character to the car without attracting unwanted attention.
Faurecia produces the entire exhaust sound system, from ECU to speaker and canning. Faurecia expects its exhaust dynamic sound technologies will begin appearing on premium and mainstream cars in the 2017 model year.
At NAIAS 2015, journalists will have the opportunity to test drive a vehicle equipped with exhaust dynamic sound technology right outside of Detroit’s Cobo Hall.
During NAIAS 2015, Faurecia Emissions Control Technologies is displaying four types of valves that it produces. These valves help automakers achieve more acoustic and back pressure targets with less weight. Key Faurecia innovations are represented in this exhibit by the adaptive valve and the electrically
In 2014, Faurecia celebrated a milestone in the industry’s adoption of its innovative adaptive valve, producing its one-millionth valve. This self activated valve, which is placed in front of the rear muffler, is composed of a tubular body and swiveling flap linked to an external coiled spring. The coiled spring keeps the flap closed, until the gas-flow increases and pressure builds into the exhaust pipe, forcing the flap to gradually open, hence letting the full-powered sound of the engine express itself. This type of valve can potentially help reduce the volume and the weight of the mufflers by up-to 30 percent while reducing
The Faurecia Electric Actuated Valve is situated behind the rear muffler. The flap position is controlled by the ECU, based on vehicle speed, engine load and calibration.
Compact exhaust heat recovery systems are not just for hybrids anymore. Faurecia originally developed its compact EHRS to enable gas-electric hybrid vehicles to warm up the passenger cabin quickly. As a result, the gasoline engine needs to run for less time, enabling the vehicle to switch over to its electric powertrain sooner and thereby improving fuel economy by up to 7 percent while reducing emissions.
Now the Faurecia compact EHRS harmonizes with conventional gasoline-powered vehicles as well. Faurecia has improved the system’s efficiency for such vehicles while maintaining its same small size.
Currently, Faurecia Emissions Control Technologies is working with its customers in North America on applications that use EHRS not only to heat the air inside the cabin but also to warm the engine or gearbox in cold weather. With what amounts to a “reverse radiator,” a heat exchanger is positioned inside the gas stream so that, as coolant runs through it, the gas heats the fluid to warm up the engine lubricant along with heating the cabin. Heating lubricant reduces the engine’s friction losses, thus generating fuel economy by around 2 percent on a conventional gasoline engine. Additionally, heating the cabin faster offers the opportunity either to improve passenger comfort or to downsize auxiliary heaters while having the same comfort, thus generating significant savings for the OEM. In another available configuration, the engine or the gearbox oil are routed through the heat exchanger directly, rather than plumbing the coolant system into the heat exchanger.
Moreover, Faurecia is preparing the next generation of exhaust heat recovery by working with its customers on Rankine and Thermo-Electric Generators that turn exhaust heat into mechanical or electrical power which could be directly used by the vehicle. Faurecia exhaust heat recovery systems are designed to produce heat more rapidly with systems that weigh less, an aspect of Faurecia’s “less is more” philosophy that automakers and consumers can warm up to quickly.