Entity

Time filter

Source Type


De Oliveira Costa L.,IAV Do Brazil Automotive Engineering | Santos R.S.,IAV Do Brazil Automotive Engineering
SAE Technical Papers | Year: 2011

Due to the independent operation of the NOx (Nitrogen Oxides) aftertreatment systems from the engine, the aim of the OBD system (OnBoard Diagnosis) is to guarantee the NOx and the Particulate Matter emissions stay within the emissions standards during all the vehicle useful life. In the case of heavy duty diesel vehicles, that use the SCR system (Selective Catalytic Reduction) as the NOx aftertreatment technology, the use of the NOx sensor in the exhaust pipe will be indispensable to control and to monitor the engine emissions. In parallel with these advances in the engine embedded technology for reduction of emissions, it is also advancing the use of biofuels such as biodiesel, which appears as a renewable and clean alternative because it is derived from organic mass and results lower concentrations of some pollutant gases in the exhaust gas in comparison to the fossil fuel. But recent studies are indicating that the NOx is the unique gas that results higher concentration in the exhaust gas when the engine using biodiesel instead of conventional diesel. Thus, using biodiesel, the vehicle will present a higher tendency of mistakes on emissions diagnosis by the OBD system, penalizing the vehicle user and damaging the progress of incentives for the biodiesel program. The subject of this paper is to study the operation of the SCR aftertreatment system when using conventional diesel and biodiesel, to explore the characteristics of the NOx sensor and to analyze its behavior of NOx detection in real applications with the engine using biodiesel, presenting adequate solutions to adapt the entire system. Copyright © 2011 SAE International. Source


De Oliveira Costa L.,IAV Do Brazil Automotive Engineering | Santos R.S.,IAV Do Brazil Automotive Engineering
SAE Technical Papers | Year: 2012

Due to the independent operation between the aftertreatment systems and the engine, the aim of the On Board Diagnostic System (OBD) is to ensure the engine emissions stay within the emissions standards during the whole vehicle useful life. In the case of the heavy duty diesel vehicles that use the Selective Catalytic Reduction System (SCR) or the Exhaust Gas Recirculation System (EGR) as the NOx aftertreatment technologies to meet the stringent emissions levels, the use of sensors in the exhaust pipe is required to control and to monitor the engine emissions. These are new and great challenges to the national diesel engine developers who are working with these systems to get the homologation certification. Accurate mathematic models within the automotive control strategies are becoming ever more important and are strongly used to monitor the NOx emissions directly (in case of SCR systems using the NOx sensor) or indirectly (in case of EGR systems using the Lambda sensor). The subject of this paper is to study the operation of the aftertreatment systems, to explore the charactheristics of the NOx and Lambda sensors and to analyse their behaviour in real applications, applying them into the emissions control and monitoring systems to achieve the legal requirements. Copyright © 2012 SAE International. Source


De Oliveira Costa L.,IAV Do Brazil Automotive Engineering | Godden J.E.,IAV Do Brazil Automotive Engineering | Amadio R.B.,IAV Do Brazil Automotive Engineering | Santos R.S.,IAV Do Brazil Automotive Engineering
SAE Technical Papers | Year: 2013

Emission standards are becoming more stringent and at the same time the standards for the On-Board Diagnostic System (OBD) are also continuously enhancing to ensure a more efficient and robust engine emissions monitoring system during the whole vehicle useful life and to improve the quality of the information delivered to the user. In the case of heavy duty diesel vehicles, the Brazilian standards are developed according to the existing European standards (Euro), for example the current standard in Brazil (so called Proconve P7) follows the same requirements of the Euro V with some minor differences. As a consequence, the applied technologies for exhaust gas after-treatment and sensing systems to meet the requirements are already used in European applications such as Selective Catalytic Reduction System (SCR), Exhaust Gas Recirculation (EGR), Diesel Particulate Filter (DPF) and Diesel Oxidation Catalyst (DOC), as well as temperature, NOx and differential pressure sensors. Considering that a possible future standard Proconve P8 will be based on the current European Euro VI, this paper is a case study of the OBD System, to compare its features in an engine certified as Euro VI and in an engine certified as Proconve P7 (Euro V), in order to identify the new challenges for a future Brazilian standard. The comparison of the requirements was performed and the behavior of the involved technologies were analyzed in real applications according to the homologation processes specified in each standard. © 2013 SAE INTERNATIONAL. Source

Discover hidden collaborations