Dean Tomazic

Effects of Biodiesel Operation on Light-Duty Tier 2 Engine and Emission Control Systems

This paper documents the impact of biodiesel blends on engine-out emissions as well as overall system performance in terms of emissions control system calibration and overall system efficiency.

Development of a Diesel Passenger Car Meeting Tier 2 Emissions Levels

Increasing fuel costs, the need to reduce dependence on foreign oil as well as the high efficiency and the desire for superior durability have caused the diesel engine to again become a prime target for light-duty vehicle applications in the United States. In support of this the U.S. Department of Energy (DOE) has engaged in a test project under the Advanced Petroleum Based Fuels-Diesel Emission Control (APBF-DEC) activity to develop a passenger car with the capability to demonstrate compliance with Tier 2 Bin 5 emission targets with a fresh emission control catalyst system. In order to achieve this goal, a prototype engine was installed in a passenger car and optimized to provide the lowest practical level of engine-out emissions. While this optimized calibration proved capable of meeting Euro 4 emission regulations for nitrogen oxides (NO x ) on an engine-out basis, a further reduction of 85% in both NO x and particulate matter (PM) emissions was necessary to meet the stringent Tier 2 Bin 5 emission levels. The emission control system was subsequently optimized in the test cell under steady-state and transient conditions. A rapid warm-up strategy was developed to achieve the fastest possible catalyst light-off under cold start conditions. The catalyst performance was mapped and optimized under numerous load and speed conditions with different lean-rich modulation approaches. Finally, diesel particulate filter (DPF) regeneration as well as desulfurization strategies were developed under this project. Vehicle tests with development emission control systems proved that the combination of low engine-out emissions, in conjunction with a sophisticated regeneration strategy, were able to meet Tier 2 Bin 5 emission levels.

Biodiesel Effects on U.S. Light-Duty Tier 2 Engine and Emission Control Systems – Part 2

Raising interest in Diesel powered passenger cars in the United States in combination with the government mandated policy to reduce dependency of foreign oil, leads to the desire of operating Diesel vehicles with Biodiesel fuel blends. There is only limited information related to the impact of Biodiesel fuels on the performance of advanced emission control systems. In this project the implementation of a NOx storage and a SCR emission control system and the development for optimal performance are evaluated. The main focus remains on the discussion of the differences between the fuels which is done for the development as well as useful life aged components. From emission control standpoint only marginal effects could be observed as a result of the Biodiesel operation. The NOx storage catalyst results showed lower tailpipe emissions which were attributed to the lower exhaust temperature profile during the test cycle. The SCR catalyst tailpipe results were fuel neutral. The engine-out emissions formation showed increased NOx and decreased HC emissions with the Biodiesel blend. The observed effect specifically on NOx was up to 10% increase with the B20 blend. There was some impact on fuel economy which was attributed to higher combustion efficiency resulting in approximately 2% improved fuel economy with Biodiesel. There was no measurable impact of Biodiesel operation on the engine mechanics including fuel injection system.

DPF Regeneration-Concept to Avoid Uncontrolled Regeneration During Idle

Significant particulate emission reductions of diesel engines can be achieved using diesel particulate filters (DPFs). Ceramic wall flow filters with a PM efficiency of >90% have proven to be effective components in emission control. The challenge for the application lies with the development and adaptation of a reliable regeneration strategy. The main focus is emission efficiency over the legally required durability periods, as well as over the useful vehicle life. It will be shown, that new DPF systems are characterized by a high degree of integration with the engine management system, to allow for initiation of the regeneration and its control for optimum DPF protection. Using selected cases, the optimum combination and tuning will be demonstrated for successful regenerations, taking into account DPF properties. For example, high DPF durability, good DPF regenerability, and low system pressure drop are balanced with engine based parameters like air mass flow, exhaust gas temperature, and exhaust oxygen content. Advanced system control techniques, such as tuning and optimization will be presented and discussed. New possibilities of the application of new robust and cost effective DPF systems will be shown.

U.S. 2007 - Which Way to Go? Possible Technical Solutions

The exhaust emissions standards for heavy-duty (HD) truck engines in the U.S. are facing a severe reduction of both PM and NO x emission in the year 2007, making extensive exhaust aftertreatment inevitable. Although the final emission limit values for NO x (0.20 g/bhp-hr) and NMHC (0.14 g/bhp-hr) will see a phase-in between 2007 and 2010, the PM emission limits of 0.01 g/bhp-hr will already take full effect in 2007. Engine-out emissions in the range of EURO 5 / U.S. 2002/04 will be achievable through internal measures as described in this paper. To fulfill U.S. 2007 limits, a diesel particulate filter will be necessary. The final limits taking effect in 2010 will only be fulfilled through application of NO x and particulate aftertreatment. To achieve the low engine-out emission levels, this paper will focus on both internal measures (high-EGR combustion systems and partial homogenization) and external aftertreatment systems. These approaches will be assessed to determine combined solutions that reach the desired emission targets.

Waste Heat Recovery for Locomotive Engines Using the Organic Rankine Cycle

Locomotive engines are emitting high levels of exhaust gas emissions and substantial amount of particulates which is thought to have significant global warming potential. In the past years locomotive regulations have been implemented in the United States to control the emission in this application. Also it can be observed that engine emitted carbon dioxides (CO2) will be limited soon for all on-road engine categories to meet the Green House Gases (GHG) norms.Tier 4 standards apply to locomotives since the beginning of 2015 for newly built or remanufactured engines. NOx and particulate limits have been reduced by around 70% compared to the Tier 3 standards requiring significant advancements in engine technology and / or exhaust aftertreatment solutions. EGR technology is an option to reduce NOx emissions to Tier 4 locomotive standards indeed of its impact on engine fuel consumption as well as the emitted CO2 gas, which may be controlled either by future CO2 or fuel consumption standards.To cope with this challenge, new engine technology concepts need to be developed. A waste heat recovery system is a beneficial solution to recover the wasted energies from different heat sources in the engine. Especially the considerable amount of exergy in the exhaust gas (EGR and tailpipe), which results from its high temperature and mass flow, has significant recovery potential. By utilizing a waste heat recovery system a portion of this exergy can be converted into a usable form of power, which then will increase the effective power output of the engine system. A major challenge is to recover the wasted exhaust energy with the maximum possible system efficiency. In a Tier 4 locomotive engine, heat from the EGR system as well as the tailpipe waste heat can be recovered by using an Organic Rankine Cycle (ORC) waste heat recovery system.This paper will discuss the results of a waste heat recovery (ORC) system evaluation for locomotive applications. With the help of thermodynamic calculations the incremental power from ORC system as well as the fuel economy benefit will be evaluated and discussed. Additionally, a reasonable working fluid and the system layout, which are considered for thermodynamic calculations, will be reviewed.Copyright

Biodiesel Effects on Engine and Emission Control Systems

Raising interest in Diesel powered passenger cars in the USA in combination with the government mandated policy to reduce dependency of foreign oil, leads to the desire of operating Diesel vehicles with biodiesel fuel blends. There is only limited information related to the impact of biodiesel fuels on the performance of advanced emission control systems. In this project the implementation of a NOx storage and an SCR emission control system and the development for optimal performance were evaluated by FEV.

A concept for advanced DPF regeneration

Wall-flow, high-efficiency diesel particulate filters (DPF) have proven to significantly reduce the PM emissions of diesel engines and will be seen in rapidly increasing numbers of European diesel passenger cars. The challenges ahead for these “active” DPF systems are their enhanced cost-effectiveness while not compromising on vehicle/engine performance and emission safety.

A diesel engine concept to fulfil tier 2 bin 5 emission standards

Increasing fuel costs, the need to reduce dependency on foreign oil as well as the high efficiency and the desire for superior durability have caused the Diesel engine to again become a prime target for light-duty vehicle applications in the United States. In support of this, the U.S. Department of Energy (DOE) has engaged in a test project under the Advanced Petroleum Based Fuels-Diesel Emission Control (APBF-DEC) activity to develop a passenger car with the capability to demonstrate compliance with Tier 2 Bin 5 emission targets.