Sensing, Actuation, and Embedded Control for a Custom SCR Nitrogen Oxides Emissions Reduction System

Diesel engines are the main power source for medium and heavy duty on road vehicles. With the rising standards for mileage of vehicles set by the Corporate Average Fuel Economy and the Environmental Protection Agency, diesel engines should soon be considered in lieu of gas engines. Despite advantages of diesel engines, diesel emissions include harmful gasses like carbon monoxide, nitrogen oxides and particulate matter. Selective Catalytic Reduction (SCR) systems have long been used to reduce diesel emissions from medium to heavy-duty diesel engines. Primary focus of this research effort is the implementation and improvement of a SCR system on light diesel engines. To improve efficiency we implemented a control law to limit the emissions within bounds ensuring low emissions for varied drive cycles. We developed a controller network using user datagram protocol to collect engine data using Arduino. The controller network establishes communication link between sensor data collection and a raspberry pi controller to enable full control over the test station

Technological approaches to improve the engine efficiency and to reduce pollutant emissions of automotive diesel engines.

The research work was mainly focused on the technological approach to improve engine efficiency and reduce pollutant emissions applicable to diesel engines which are very often incompatible were assessed through a set of full- scale tests on a real diesel engine in order to satisfy the new emissions limits. (1) The first strategy evaluated in this work to improve the engine efficiency was the reduction of the mechanical losses: through the incorporation of nanomaterials in the lubricant formulation. The effect of the lubricant oil additivated with MoS2 nanopowders was assessed through a set of full - scale tests on a real diesel engine – several engine points and cooling water temperatures were investigated for both a reference oil and a MoS2-additivated one. (2) Other strategy to reduce pollutant emissions included in this PhD thesis was the effects of using a 30% by volume blend of a renewable fuel, called Farnesane, and fossil diesel in a small Euro 5 displacement passenger car diesel engine. (3) And finally, the CeO2/BaO/Pt system was selected in order to perform an NO2-assisted soot oxidation, as a aftertreatment strategy to reduce pollutant emissions. The aim of such catalytic system is to couple the catalytic functionality for soot abatement during DPF regeneration, namely CeO2, and an embedded lean NOx trap (LNT) functionality given by BaO, for NOx storage, whose oxidation over Pt to form adsorbed nitrates is facilitated by the presence of CeO2 itself

Reduction of Particulate Matter Emissions in EU Inland Waterway Transport

In September 2014, the European Commission adopted a proposal on new requirements relating to emission limits and type-approval for non-road engines. The introduction of a new emission stage (Stage V) establishes extremely tight limits for particulate matter emissions for mobile non-road applications, including inland waterway vessels. These new emission limits will eventually require many ships to apply efficient exhaust gas after-treatment technology. The aim of this study was to find out which kinds of exhaust gas after-treatment solutions could fulfil these tightening particulate emission standards in EU inland navigation. A marine dual fuel engine was used as an example. The engine can be run both with gas and diesel fuel. The first part of the study consists of a literature review of various exhaust gas after-treatment technologies. This part serves as a general technology guide for particulate emission abatement from diesel engines. In the second part of the study, different supplier technologies and solutions were evaluated. The targets for particulate filtering system were defined and a specific inquiry was sent to potential suppliers. Based on the replies, passive diesel particulate filter systems with catalytic coating or/and an upstream diesel oxidation catalyst can be regarded as the primary choice for particulate emission control in inland navigation. This study was conducted as part of the EU Hercules-2 research and development programme, aimed at fostering environmentally sustainable and more efficient shipping.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Perovskite-Based Formulations as Rival Platinum Catalysts for NO_x Removal in Diesel Exhaust Aftertreatment

NOx removal is still a technological challenge in diesel engines. NOx storage and reduction (NSR), selective catalytic reduction (SCR), and combined NSR-SCR systems are the efficient approaches for diesel exhaust aftertreatment control. However, NSR and combined NSR-SCR technologies require high noble metal loadings, with low thermal stability and high cost. Recently, perovskites have gained special attention as an efficient alternative to substituting noble metals in heterogeneous catalysis. Up to date, few studies analyzed the application of perovskites in automobile catalytic converters. This chapter overviews recent research on development of novel perovskite-based catalysts as a component of single-NSR and hybrid NSR-SCR systems for NOx removal from diesel engine exhaust gases. Results in our laboratory are compared with similar work reported in the literature by other authors. Under realistic conditions, 0.5% Pd–30% La0.5Ba0.5CoO3/Al2O3 catalyst achieves NOx-to-N2 conversion higher than 92% when is coupled with an SCR catalyst placed downstream. The results show promise for a considerably higher thermal stability and lower cost diesel exhaust treatment system

Automotive Powertrain Control — A Survey

This paper surveys recent and historical publications on automotive powertrain control. Control-oriented models of gasoline and diesel engines and their aftertreatment systems are reviewed, and challenging control problems for conventional engines, hybrid vehicles and fuel cell powertrains are discussed. Fundamentals are revisited and advancements are highlighted. A comprehensive list of references is provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72023/1/j.1934-6093.2006.tb00275.x.pd

Supervisory control for emission compliance of heavy-duty vehicles

Heavy freight trucks globally contribute to a significant proportion of transport-related air pollution. The dominant air pollutants from heavy freight trucks with diesel engine and exhaust aftertreatment system (EATS) are CO2, hydrocarbons (HC), CO, particulate matter (PM), NOX (NO and NO2), and NH3. The greenhouse gas emission legislation limits the amount of CO2 emission, and Euro VI emission legislation limits the other dominant air pollutants. Emission legislation is gradually becoming more and more stringent to reach the long term goal of near-zero-emission. Several parties are working together to reduce the emissions, keeping both the short and long term goal in mind. Any step which results in ICE downsizing contributes to the reduction of all dominant emissions. But, with size and type of the ICE decided, there is a trade-off between NOX emission and other emissions: reduced NOX emission means reduced fuel efficiency (i.e. increased CO2, PM, and HC emissions). It is a challenge to fulfil the current emission legislation—especially real-driving NOX emission legislation—with existing control functionalities in the engine management system (EMS). However, better control of NOX emission is possible by exploiting predictive driving information and considering the coupling between the engine system and EATS. This work pursues this idea and concludes that fulfilling real-driving NOX emission legislation is possible, considering the coupling between the engine system and EATS while using predictive information. The work provides a mathematical formulation of the concept and then develops, evaluates, and implements an engine-EATS supervisor which optimizes total fuel consumption and fulfils both the world harmonized transient cycle (WHTC) based and real-driving NOX emission legislation. The developed supervisor is a distributed economic nonlinear model predictive controller (E-NMPC). This work develops and analyzes two different versions of the distributed E-NMPC based supervisory control algorithm. The more efficient one of the two is again compared for three variants. Considering the computation time of the three algorithms and processing speed of the existing EMS, one algorithm is selected for implementation. The supervisor performs much better compared to a baseline controller (optimized offline). Simulation results show that the supervisory controller has 1.7% less total fuel consumption and 88.4% less NH3 slip, compared to the baseline controller, to achieve the same real-driving NOX emission

Impact of potential engine malfunctions on fuel consumption and gaseous emissions of a Euro VI diesel truck

© 2019 Elsevier Ltd Although new vehicles are designed to comply with specific emission regulations, their in-service performance would not necessarily achieve them due to wear-and-tear and improper maintenance, as well as tampering or failure of engine control and exhaust after-treatment systems. In addition, there is a lack of knowledge on how significantly these potential malfunctions affect vehicle performance. This study was therefore conducted to simulate the effect of various engine malfunctions on the fuel consumption and gaseous emissions of a 16-tonne Euro VI diesel truck using transient chassis dynamometer testing. The simulated malfunctions included those that would commonly occur in the intake, fuel injection, exhaust after-treatment and other systems. The results showed that all malfunctions increased fuel consumption except for the malfunction of EGR fully closed which reduced fuel consumption by 31%. The biggest increases in fuel consumption were caused by malfunctions in the intake system (16%–43%), followed by the exhaust after-treatment (6%–30%), fuel injection (4%–24%) and other systems (6%–11%). Regarding pollutant emissions, the effect of engine malfunctions on HC and CO emissions was insignificant, which remained unchanged or even reduced for most cases. An exception was EGR fully open which increased HC and CO emissions by 343% and 1124%, respectively. Contrary to HC and CO emissions, NO emissions were significantly increased by malfunctions. The largest increases in NO emissions were caused by malfunctions in the after-treatment system, ranging from 38% (SCR) to 1606% (DPF pressure sensor). Malfunctions in the fuel injection system (24%–1259%) and intercooler (438%–604%) could also increase NO emissions markedly. This study demonstrated clearly the importance of having properly functioning engine control and exhaust after-treatment systems to achieve the required performance of fuel consumption and pollutant emissions

Review of thermal management of catalytic converters to decrease engine emissions during cold start and warm up

Catalytic converters mitigate carbon monoxide, hydrocarbon, nitrogen oxides and particulate matter emissions from internal combustion engines, and allow meeting the increasingly stringent emission regulations. However, catalytic converters experience light-off issues during cold start and warm up. This paper reviews the literature on the thermal management of catalysts, which aims to significantly reduce the light-off time and emission concentrations through appropriate heating methods. In particular, methods based on the control of engine parameters are easily implementable, as they do not require extra heating devices. They present good performance in terms of catalyst light-off time reduction, but bring high fuel penalties, caused by the heat loss and unburnt fuel. Other thermal management methods, such as those based on burners, reformers and electrically heated catalysts, involve the installation of additional devices, but allow flexibility in the location and intensity of the heat injection, which can effectively reduce the heat loss in the tailpipe. Heat storage materials decrease catalyst light-off time, emission concentrations and fuel consumption, but they are not effective if the engine remains switched off for long periods of time. The main recommendation of this survey is that integrated and more advanced thermal management control strategies should be developed to reduce light-off time without significant energy penalty

Control of NOx emissions from diesel engines using exhaust gas re-circulation

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The diesel engine currently accounts for 32 per cent of the new passenger car sales in Europe. In the US, diesel-power is responsible for 94 per cent of all freight movement. Comparing European Stage III standard petrol and diesel passenger car emissions, diesel NOx emissions are still considered a concern. This thesis investigates the mechanisms by which oxides of nitrogen are formed during diesel combustion. It reviews the current methods of controlling NOx emissions, such as retarding fuel injection timing, exhaust gas re-circulation (EGR), water injection and exhaust after-treatment. Modelling using a phenomenological model, is used to demonstrate the extended Zeldovich mechanism and formation trends, the effects of EGR and the significance of the Zeldovich mechanism rate constants. Modified Zeldovich rate constants are proposed to improve the correlation to measured data. Clearly, EGR is currently the most effective method of reducing NOx emissions from passenger car diesel engines. The way EGR works in suppressing NOx formation is reviewed in detail. Experimentation on a 1.8 litre inline 4-cylinder 4-valve per cylinder DI diesel with a variable nozzle turbine (VNT) turbocharger was used to demonstrate the concept of "additional" EGR on this small automotive engine. "Additional" EGR is the concept whereby a proportion of the EGR is added to the total charge, so that the volumetric efficiency increases as EGR is introduced. By using "additional" EGR, the benefits of lower NOx emissions combined with reduced particulates emissions and improved fuel consumption were clearly demonstrated at two test conditions. The reasons for achieving lower NOx emissions when using a VNT turbocharger and EGR have been explained. Finally, several methods of calculating EGR proportion were used and compared against true mass flow. The use of a CO2 balance was found to be the most accurate method.This study is funded by the Ford Motor Company