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Viewing 151 to 180 of 21945
2017-03-28
Technical Paper
2017-01-0944
Ryuji Ando, Takashi Hihara, Yasuyuki Banno, Makoto Nagata, Tomoaki Ishitsuka, Nobuyuki Matsubayashi, Toshihisa Tomie
Abstract Modern diesel emission control systems often use Urea Selective Catalytic Reduction (Urea-SCR) for NOx control. One of the most active SCR catalysts is based on Cu-zeolite, specifically Cu-Chabazite (Cu-CHA), also known as Cu-SSZ-13. The Cu-SCR catalyst exhibits high NOx control performance and has a high thermal durability. However, its catalytic performance deteriorates upon long-term exposure to sulfur. This work describes our efforts to investigate the detailed mechanism of poisoning of the catalyst by sulfur, the optimum conditions required for de-sulfation, and the recovery of catalytic activity. Density functional theory (DFT) calculations were performed to locate the sulfur adsorption site within the Cu-zeolite structure. Analytical characterization of the sulfur-poisoned catalyst was performed using Extreme Ultraviolet Photoelectron Spectroscopy (EUPS) and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS).
2017-03-28
Technical Paper
2017-01-0943
Cory S. Hendrickson, Devesh Upadhyay, Michiel Van Nieuwstadt
Abstract Over the past decade urea-based selective catalytic reduction (SCR) has become a leading aftertreatment solution to meet increasingly stringent Nitrogen oxide (NOx) emissions requirements in diesel powertrains. A common trend seen in modern SCR systems is the use of "split-brick" configurations where two SCR catalysts are placed in thermally distinct regions of the aftertreatment. One catalyst is close-coupled to the engine for fast light-off and another catalyst is positioned under-floor to improve performance at high space velocities. Typically, a single injector is located upstream of the first catalyst to provide the reductant necessary for efficient NOx reduction. This paper explores the potential benefit, in terms of improved NOx reduction, control of NH3 slip or reduced reductant consumption, of having independently actuated injectors in front of each catalyst.
2017-03-28
Journal Article
2017-01-0942
Joseph R. Theis, Christine Lambert
Abstract Model low temperature NOx adsorbers (LTNA) consisting of Pd on a ceria/zirconia washcoat on monoliths were evaluated for low temperature NOx storage under lean conditions to assess their potential for adsorbing the cold-start NOx emissions on a diesel engine during the period before the urea/SCR system becomes operational. A reactor-based transient test was performed with and without C2H4, CO/H2, and H2O to assess the effects of these species on the NOx storage performance. In the absence of C2H4 or CO/H2, H2O severely suppressed the NOx storage of these model LTNAs at temperatures below 100°C, presumably by blocking the storage sites. When C2H4 was included in the feedgas, H2O still suppressed the NOx storage below 100°C. However, the C2H4 significantly increased the NOx storage efficiency above 100°C, attributable to the formation of alkyl nitrites or alkyl nitrates on the catalyst.
2017-03-28
Journal Article
2017-01-0940
Jesus Emmanuel De Abreu Goes, Louise Olsson, Malin Berggrund, Annika Kristoffersson, Lars Gustafson, Mikael Hicks
Abstract Even though substantial improvements have been made for the lean NOx trap (LNT) catalyst in recent years, the durability still remains problematic because of the sulfur poisoning and sintering of the precious metals at high operating temperatures. Hence, commercial LNT catalysts were aged and tested in order to investigate their performance and activity degradation compared to the fresh catalyst, and establish a proper correlation between the aging methods used. The target of this study is to provide useful information for regeneration strategies and optimize the catalyst management for better performance and durability. With this goal in mind, two different aging procedures were implemented in this investigation. A catalyst was vehicle-aged in the vehicle chassis dynamometer for 100000 km, thus exposed to real conditions. Whereas, an accelerated aging method was used by subjecting a fresh LNT catalyst at 800 °C for 24 hours in an oven under controlled conditions.
2017-03-28
Journal Article
2017-01-0939
Ashok Kumar, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Abstract Copper- and Iron- based metal-zeolite SCR catalysts are widely used in US and European diesel aftertreatment systems to achieve drastic reduction in NOx emission. These catalysts are highly selective to N2 under wide range of operating conditions. Nevertheless, the type of transition metal has a significant impact on the key performance and durability parameters such as NOx conversion, selectivity towards N2O, hydrothermal stability, and sensitivity to fuel sulfur content. In this study, we explained the differences in the performance characteristics of these catalysts based on their relative acidic-basic nature of transition metal present in these catalysts using practically relevant gas species present in diesel exhaust such as NO2, SOx, and NH3. These experiments show that Fe-zeolite has relatively acidic nature as compared to Cu-zeolite that causes NH3 inhibition and hence explains low NOx conversion on Fe-zeolite at low temperature under standard SCR conditions.
2017-03-28
Technical Paper
2017-01-0938
Gillis Hommen, Frank Kupper, Xander Seykens
Abstract This article describes a NOx sensor based urea dosing control strategy for heavy-duty diesel aftertreatment systems using Selective Catalytic Reduction. The dosing control strategy comprises of a fast-response, model-based ammonia storage control system in combination with a long-timescale tailpipe-feedback module that adjusts the dosing quantity according to current aftertreatment conditions. This results in a control system that is robust to system disturbances such as biased NOx sensors and variations in AdBlue concentrations. The cross-sensitivity of the tailpipe NOx sensor to ammonia is handled by a novel, smart signal filter that can reliably identify the contributions of NOx and NH3 in the tailpipe sensor signal, without requiring an artificial perturbation of the dosing signal.
2017-03-28
Journal Article
2017-01-0953
Jinyong Luo, Yadan Tang, Saurabh Joshi, Krishna Kamasamudram, Neal Currier, Aleksey Yezerets
Abstract Cu/CHA catalysts have been widely used in the industry, due to their desirable performance characteristics including the unmatched hydrothermal stability. While broadly recognized for their outstanding activity at or above 200°C, these catalysts may not show desired levels of NOx conversion at lower temperatures. To achieve high NOx conversions it is desirable to have NO2/NOx close to 0.5 for fast SCR. However even under such optimal gas feed conditions, sustained use of Cu/CHA below 200°C leads to ammonium nitrate formation and accumulation, resulting in the inhibition of NOx conversion. In this contribution, the formation and decomposition of NH4NO3 on a commercial Cu/CHA catalyst have been investigated systematically. First, the impact of NH4NO3 self-inhibition on SCR activity as a function of temperature and NO2/NOx ratios was investigated through reactor testing.
2017-03-28
Journal Article
2017-01-0952
Michael B. Hopka, David Bilby, Michiel Van Nieuwstadt
Abstract The resistive particulate matter sensor (PMS) is rapidly becoming ubiquitous on diesel vehicles as a means to diagnose particulate filter (DPF) leaks. By design the device provides an integrated measure of the amount of PM to which it has been exposed during a defined measurement period within a drive cycle. The state of the art resistive PMS has a large deadband before any valid output related to the accumulated PM is realized. As a result, most DPF monitors that use the PMS consider its output only as an indicator that a threshold quantity of PM has amassed rather than a real-time measure of concentration. This measurement paradigm has the unfortunate side effect that as the PM OBD threshold decreases, or the PMS is used on a vehicle with a larger exhaust volume flow, a longer measurement is required to reach the same PM sensor output. Longer PMS measurement times lead to long particulate filter monitoring durations that may reduce filter monitor completion frequency.
2017-03-28
Journal Article
2017-01-0951
Paul Mentink, Xander Seykens, Daniel Escobar Valdivieso
Abstract To meet future emission targets, it becomes increasingly important to optimize the synergy between engine and aftertreatment system. By using an integrated control approach minimal fluid (fuel and DEF) consumption is targeted within the constraints of emission legislation during real-world operation. In such concept, the on-line availability of engine-out NOx emission is crucial. Here, the use of a Virtual NOx sensor can be of great added-value. Virtual sensing enables more direct and robust emission control allowing, for example, engine-out NOx determination during conditions in which the hardware sensor is not available, such as cold start conditions. Furthermore, with use of the virtual sensor, the engine control strategy can be directly based on NOx emission data, resulting in reduced response time and improved transient emission control. This paper presents the development and on-line implementation of a Virtual NOx sensor, using in-cylinder pressure as main input.
2017-03-28
Technical Paper
2017-01-0949
Makoto Ito, Mitsuru Sakimoto, Zhenzhou Su, Go Hayashita, Keiichiro Aoki
Abstract New 2A/F systems different from usual A/F-O2 systems are being developed to cope with strict regulation of exhaust gas. In the 2A/F systems, 2A/F sensors are equipped in front and rear of a three-way catalyst. The A/F-O2 systems are ideas which use a rear O2 to detect exhaust gas leaked from three-way catalyst early and feed back. On the other hand, the 2A/F systems are ideas which use a rear A/F sensor to detect nearly stoichiometric gas discharged from the three-way catalyst accurately, and to prevent leakage of exhaust gas from the three-way catalyst. Therefore, accurate detection of nearly stoichiometric gas by the rear A/F sensor is the most importrant for the 2A/F systems. In general, the A/F sensors can be classified into two types, so called, one-cell type and two-cell type. Because the one-cell type A/F sensors don’t have hysteresis, they have potential for higher accuracy.
2017-03-28
Journal Article
2017-01-0947
Athanasios G. Konstandopoulos, Dimitrios Zarvalis, Leonidas Chasapidis, Danis Deloglou, Nickolas Vlachos, Adam Kotrba, Ginette Anderson
Abstract Evolving marine diesel emission regulations drive significant reductions of nitrogen oxide (NOx) emissions. There is, therefore, considerable interest to develop and validate Selective Catalytic Reduction (SCR) converters for marine diesel NOx emission control. Substrates in marine applications need to be robust to survive the high sulfur content of marine fuels and must offer cost and pressure drop benefits. In principle, extruded honeycomb substrates of higher cell density offer benefits on system volume and provide increased catalyst area (in direct trade-off with increased pressure drop). However higher cell densities may become more easily plugged by deposition of soot and/or sulfate particulates, on the inlet face of the monolithic converter, as well as on the channel walls and catalyst coating, eventually leading to unacceptable flow restriction or suppression of catalytic function.
2017-03-28
Journal Article
2017-01-0946
Nathan Ottinger, Yuanzhou Xi, Christopher Keturakis, Z. Gerald Liu
Abstract Low-temperature (T ≤ 200°C) NOx conversion is receiving increasing research attention due to continued potential reductions in regulated NOx emissions from diesel engines. At these temperatures, ammonium salts (e.g., ammonium nitrate, ammonium (bi)sulfate, etc.) can form as a result of interactions between NH3 and NOx or SOx, respectively. The formation of these salts can reduce the availability of NH3 for NOx conversion, block active catalyst sites, and result in the formation of N2O, a regulated Greenhouse Gas (GHG). In this study, we investigate the effect of hydrothermal aging on the formation and decomposition of ammonium nitrate on a state-of-the-art Cu/zeolite selective catalytic reduction (SCR) catalyst. Reactor-based constant-temperature ammonium nitrate formation, temperature programmed oxidation (TPO), and NO titration experiments are used to characterize the effect of hydrothermal aging from 600 to 950°C.
2017-03-28
Journal Article
2017-01-0945
Markus Dietrich, Carsten Steiner, Gunter Hagen, Ralf Moos
Abstract The radio-frequency (RF) or microwave-based catalyst state determination offers the opportunity to operate an automotive catalyst at its optimal point. This has already been proven for the oxidation state of TWCs, the soot loading state on DPFs/GPFs, and the ammonia storage state of vanadium and zeolite based SCR catalysts. However, the latter has only been demonstrated in laboratory scale with synthetic exhaust using gaseous ammonia. This work presents first results on an engine test bench with a serial-type zeolite-based SCR catalyst, using urea solution and the RF tool to detect the current ammonia loading in real time and to control directly the urea dosing system without any additional sensors. The original catalyst volume was reduced by 50 % to operate deliberately the SCR system under high space velocities and to challenge its function. Stationary conditions and operation points with continuously changing NOx emissions and space velocities were observed.
2017-03-28
Journal Article
2017-01-0926
Kentaro Iwasaki
Abstract The diesel particulate filter (DPF) has been used in the automobile industry for around a decade. As a key technology for emissions control the DPF design needs to be increasingly optimized to expand its function to deal with any emission not just particulate matter (PM). NOx emission regulations need to be met as well as CO2 targets through minimizing any fuel penalty. Cost is extremely important to deliver an effective after-treatment catalyst. Aluminum titanate and cordierite-based material DPFs are very cost effective in part because their properties allow monolith-manufacturing. Furthermore, geometrical design of the DPF channel structure can contribute to multi-functionalization of the DPF to provide further advantages. Square and asymmetric square-designed channel structures have been utilized on current after-treatment DPF systems.
2017-03-28
Journal Article
2017-01-0927
Carl Justin Kamp, Shawn Zhang, Sujay Bagi, Victor Wong, Greg Monahan, Alexander Sappok, Yujun Wang
Abstract Diesel engine exhaust aftertreatment components, especially the diesel particulate filter (DPF), are subject to various modes of degradation over their lifetimes. One particular adverse effect on the DPF is the significant rise in pressure drop due to the accumulation of engine lubricant-derived ash which coats the inlet channel walls effectively decreasing the permeability of the filter. The decreased permeability due to ash in the DPF can result in increased filter pressure drop and decreased fuel economy. A unique two-step approach, consisting of experimental measurements and direct numerical simulations using ultra-high resolution 3D imaging data, has been utilized in this study to better understand the effects of ash accumulation on engine aftertreatment component functionality.
2017-03-28
Technical Paper
2017-01-0924
Jan Schoenhaber, Nikolas Kuehn, Bastian Bradler, Joerg Michael Richter, Sascha Bauer, Bernd Lenzen, Christian Beidl
Abstract Recently, the European Union has adopted a new regulation on Real-Driving-Emissions (RDE) and also China is considering RDE implementation into new China 6 legislation. The new RDE regulation is focused on measuring nitrogen oxides (NOx) and particulate number (PN) emissions of both light-duty gasoline and diesel vehicles under real world conditions. A supplemental RDE test procedure was developed for European type approval, which includes on-road testing with cars equipped with portable emission measurement systems (PEMS). This new regulation will significantly affect the engine calibrations and the exhaust gas aftertreatment. In this study the impact of the new RDE regulation on two recent EU 6b certified turbocharged direct injected gasoline vehicles has been investigated. A comparison of several chassis dyno drive cycles with two new defined on-road RDE cycles was performed.
2017-03-28
Technical Paper
2017-01-0922
Akito Takayama, Takahiro Kurokawa, Hiroki Nakayama, Takuya Katoh, Makoto Nagata
Abstract A new Pd-Rh three-way catalyst (TWC) for close-coupled (CC) applications was developed to improve low temperature gas activity. In this study the TWC has a layered structure with Pd in the top layer and Rh in the bottom layer. The specific objectives of this study was to compare Ba and La additives to Pd in the top layer. Alumina was used for the Pd support and La or Ba were co-impregnated with Pd. The catalysts were engine aged at 950°C for 200 h and evaluated on a vehicle using the European NEDC test, for CO, HC and NOx performance. After this aging, the Pd-La catalyst showed higher gas performance than the Pd-Ba catalyst, especially in the cold start region. This improvement was correlated to the Pd particle size and the sintering suppression observed upon addition of La. Sintering suppression was also observed upon addition of Ba; however, the mechanism appears to be different from that of La addition.
2017-03-28
Journal Article
2017-01-0925
Tatsuro Sugino, Eriko Tanaka, Huong Tran, Norihiko Aono
Abstract Diesel particulate filters (DPFs) are an essential aftertreatment component for reducing the PM emissions of diesel engine vehicles. Installation of a DPF can achieve high filtration efficiency, but PM filtration also causes a high pressure drop due to deep bed filtration. Consequently, periodic PM regeneration is necessary to keep a low pressure drop, but this causes significant deterioration in fuel efficiency. Improving the efficiency of PM regeneration and keeping the pressure drop low are major challenges faced by DPF manufacturers in meeting future CO2 emissions regulations. This paper presents a novel morphological catalyst layer for DPFs, which is located in the surface of the inlet DPF channels and has been formed into a highly porous and three-dimensional meshwork shape. These features enhanced not only the prevention of deep bed filtration to reduce the pressure drop, but also the soot-catalyst contact for a faster PM regeneration rate.
2017-03-28
Technical Paper
2017-01-0923
Ed Szczepanski, Akinori Koda, Daniel Sweeney, Nick Polcyn, Mitsunori Ota
Tightening global emissions standards are driving automotive Original Equipment Manufacturer’s (OEM’s) to utilize Three Way Catalyst (TWC) aftertreatment systems that can perform with greater efficiency and greater measured control of Precious Group Metals (PGM) use. At the same time, TWC aftertreatment systems minimize exhaust system pressure drops. This study will determine the influence of catalyst substrate cell geometry on emission and PGM usage. Additionally, a study of lightoff and backpressure comparisons will be conducted. The two substrate configurations used are hex/750cpsi and square/750cpsi.
2017-03-28
Journal Article
2017-01-0920
Jean P. Roy, Ahmed Ghoniem, Robert Panora, Joseph Gehret, Bruce Falls, David Wallace, Daniel Ott
Abstract All vehicles sold today are required to meet emissions standards based on specific driving cycles. Emissions standards are getting tighter and the introduction of real driving tests is imminent, potentially calling for improved aftertreatment systems. A dual stage catalyst system, with exhaust temperature control, can provide a robust solution to meet challenging modes of operation such as rapid acceleration and other heavy-duty transients. The Ultera® technology, developed and successfully implemented on stationary natural gas CHP (Combined Heat and Power) engines, introduces a second stage catalyst downstream of a three-way catalyst. Air is injected between the two stages to provide oxygen required for the second stage reaction that removes additional CO and NMOG. Critical to the process is to avoid the reformation of NOx.
2017-03-28
Technical Paper
2017-01-0921
Bharadwaj Sathiamoorthy, Alex Graper, Andrew McIntosh, William Kaminski
Abstract The automotive aftermarket industry is an extremely cost competitive market to say the least. Aftermarket manufacturers are sought by customers primarily for their ability to replace an OES (Original Equipment Supplier) for a fraction of the cost. This forces the manufacturers to yield on performance abilities to get a share in the market place. The TWC system in gasoline vehicles not only acts as an emissions reduction device but is an integral part of the overall vehicle performance itself, especially since the introduction of OBD (On-Board Diagnostics) II systems in 1995. An inefficient catalyst not only leads to excessive tailpipe emissions but also acts detrimental to vehicle fueling and hence overall performance. The aftermarket catalyst industry which is regulated by EPA (United States Environmental Protection Agency) and CARB (California Air Resource Board) for gasoline engines is subject to meeting a mandatory performance standard for the same reason.
2017-03-28
Journal Article
2017-01-0935
Christoph Boerensen, Dirk Roemer, Christian Nederlof, Evgeny Smirnov, Frank Linzen, Felix Goebel, Brendan Carberry
Abstract The most significant challenge in emission control for compression ignited internal combustion engines is the suppression of NOx. In the US, NOx-levels have faced a progressive reduction for several years, but recently the introduction of the Real Driving Emissions legislation (RDE) in Europe has not only significantly increased the severity of the required emission reduction but now is in the advent of stretching technology to its limits. Emission control is based on engine-internal optimization to reduce the engine-out emissions in conjunction with aftertreatment technologies, that are either Selective Catalytic Reduction (SCR) or Lean NOx Trap (LNT) based systems. Due to its ability to control high amounts of NOx, SCR is widely used in heavy-duty applications and is becoming more popular in light-duty and passenger car applications as well.
2017-03-28
Technical Paper
2017-01-0936
Pavel Krejza, Jaroslav Pekar, Jiri Figura, Lukas Lansky, Dirk von Wissel, Tianran Zhang
Abstract The paper provides an overview of a developed methodology and a toolchain for modeling and control of a complex aftertreatment system for passenger cars. The primary objective of this work is to show how the use of this methodology allows to streamline the development process and to reduce the development time thanks to a model based semi-automatic control design methodology combined with piece-wise optimal control. Major improvements in passenger car tailpipe NOx removal need to be achieved to fulfil the upcoming post EURO 6 norms and Real Driving Emissions (RDE) limits. Multi-brick systems employing combinations of multiple Selective Catalytic Reduction (SCR) catalysts with an Ammonia Oxidation Catalysts, known also as Ammonia Clean-Up Catalyst (CUC), are proposed to cover operation over a wide temperature range. However, control of multi-brick systems is complex due to lack of available sensors in the production configurations.
2017-03-28
Technical Paper
2017-01-0932
Nehemiah S I Alozie, George Fern, David Peirce, Lionel Ganippa
Abstract The use of diesel particulate filter [DPF] has become a standard in modern diesel engine after treatment technology. However pressure drop develops across the filter as PM accumulates and this requires quick periodic burn-out without incurring thermal runaway temperatures that could compromise DPF integrity during operation. Adequate understanding of soot oxidation is needed for design and manufacture of efficient filter traps for the engine system. In this study, we have examined the impact of blending biodiesel on oxidation of PM generated from a high speed direct injection [HSDI] diesel engine, which was operated with 20% [B20] and 40% [B40] blends of two biodiesel fuels. The PM samples were collected from the engine exhaust using a Pall Tissuquartz filter, the oxidation characteristics of the samples were carried out using thermogravimetric analyzer [TGA]. The biodiesel oxidation data obtained from pure petrodiesel was compared against the fuel blends.
2017-03-28
Journal Article
2017-01-0930
Christine K. Lambert, Timothy Chanko, Mark Jagner, Jon Hangas, Xin Liu, James Pakko, Carl Justin Kamp
Abstract To meet future particle mass and particle number standards, gasoline vehicles may require particle control, either by way of an exhaust gas filter and/or engine modifications. Soot levels for gasoline engines are much lower than diesel engines; however, non-combustible material (ash) will be collected that can potentially cause increased backpressure, reduced power, and lower fuel economy. The purpose of this work was to examine the ash loading of gasoline particle filters (GPFs) during rapid aging cycles and at real time low mileages, and compare the filter performances to both fresh and very high mileage filters. Current rapid aging cycles for gasoline exhaust systems are designed to degrade the three-way catalyst washcoat both hydrothermally and chemically to represent full useful life catalysts. The ash generated during rapid aging was low in quantity although similar in quality to real time ash.
2017-03-28
Technical Paper
2017-01-0933
Yunhua Zhang, Diming Lou, Piqiang Tan, Zhiyuan Hu, Qian Feng
Abstract Biodiesel as a renewable energy is becoming increasingly attractive due to the growing scarcity of conventional fossil fuels. Meanwhile, the development of after-treatment technologies for the diesel engine brings new insight concerning emissions especially the particulate matter pollutants. In order to study the coupling effects of biodiesel blend and CCRT (Catalyzed Continuously Regeneration Trap) on the particulate matter emissions, the particulate matter emissions from an urban bus with and without CCRT burning BD0 and BD10 respectively was tested and analyzed using electrical low pressure impactor (ELPI). The operation conditions included steady state conditions and transient conditions. Results showed that the particulate number-size distribution of BD10 and BD0 both had two peaks in nuclei mode and accumulation mode at the conditions of idle, low speed and medium speed while at high speed condition the particulate number-size distribution only had one peak.
2017-03-28
Technical Paper
2017-01-0931
Michiel Van Nieuwstadt, Joseph Ulrey
Abstract While not commonly in production today, Gasoline Particulate Filters (GPFs) are likely to see widespread deployment to meet stringent EU6.2 and China particulate number (PN) standards. In many ways the operating conditions for GPFs are orthogonal to those of their diesel counterparts, and this leads to different and interesting requirements for the control strategy. We will present some generic system architectures for exhaust systems containing a GPF and will lay out an architecture for the GPF control strategy components which include: regeneration assist feature, soot estimation algorithm, GPF protection. The regeneration assist feature uses spark retard to increase exhaust temperature. The soot estimation algorithm describes how we can estimate soot from an open loop model or from a normalized pressure metric. The GPF protection feature controls oxygen flow to limit the soot burn rate.
2017-03-28
Technical Paper
2017-01-0928
Osama M. Ibrahim
Abstract Diesel oxidation catalysts with ultra-low NO2 emissions have been developed based on palladium-tungsten (Pd-W). The catalysts are supported by aluminum-yttrium oxides (Al2O3-Y2O3) nano-washcoat on sintered metal fibers. Elemental composition analysis was performed using Energy Dispersive Spectroscopy (EDS) to quantify the distribution of the Al2O3-Y2O3 nano-washcoats and Pd-W catalysts on the surface of the metal fibers. Initially, emissions measurements were conducted to evaluate the performance of Pd-W catalysts using small coated samples of sintered metal fibers. The results show that the catalysts selectively oxidize CO into CO2 and reduce NO2 into NO, resulting in over 90% reduction in CO emissions and up to 85% reduction in NO2 emissions. Scale-up of an Active Diesel Particulate Filter (ADPF) was then tested on a Cummins 5.9L ISB diesel engine using the US-FTP transient test cycle and the ISO 8178 8-mode test cycle.
2017-03-28
Technical Paper
2017-01-0929
Satoru Inoda, Yasutaka Nomura, Hirotaka Ori, Yuji Yabuzaki
Abstract In the near future, particulate number (PN) regulations, including the Euro 6 regulations, will be going into effective and becoming more stringent around the world targeted at gasoline engine vehicles. There is a type of particulate filter that has used for diesel engine vehicles, as a means to satisfy PN regulations. There are two types of particulate filters. One is a “bare” or “adding-type” GPF that is uncoated with catalyst, and the other is a replaceable-type GPF that is coated with catalyst. The replaceable-type GPF (coated GPF) has advantages in terms of cost-performance, installation space, and lower level of pressure drop, compared to the uncoated GPF. The three main functions required for a coated GPF are, an improvement of three-way catalytic performance, lowering of pressure drop, and PN filtration efficiency improvement.
2017-03-28
Technical Paper
2017-01-1217
Jiangong Zhu, Zechang Sun, Xuezhe Wei, Haifeng Dai
Abstract An alternating current (AC) heating method for a NMC lithium-ion battery with 8Ah capacity is proposed. The effects of excitation frequency, current amplitudes, and voltage limit condition on the temperature evolution are investigated experimentally. Current amplitudes are set to 24A(3C), 40(5C), and 64A(8C), and excitation frequencies are set to 300Hz, 100Hz, 30Hz, 10Hz, 5Hz, and 1Hz respectively. The voltage limitations are necessary to protect cells from overcharge and over-discharge. Therefore the voltage limit condition (4.2V/2.75V, 4.3V/2.65V, and 4.4V/2.55V) are also considered in depth to verify the feasibility of the AC heating method. The temperature rises prominently as the current increases, and the decrement of frequencies also lead to the obvious growth of battery temperature. The battery obtain the maximum temperature rise at 64A and 1Hz, which takes 1800s to heat up the battery from -25°C to 18°C.
Viewing 151 to 180 of 21945