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Commercial vehicles require fast aftertreatment heat-up to move the SCR catalyst into the most efficient temperature range to meet upcoming NOX regulations while minimizing CO2. The focus of this paper is to identify the technology levers when used independently and also together for the purpose of NOX and CO2 reduction toward achieving 2027 emissions levels while remaining CO2 neutral or better. A series of independent levers including cylinder deactivation, LO-SCR, electric aftertreatment heating and fuel burner technologies were explored. All fell short for meeting the 2027 CARB transient emission targets when used independently. However, the combinations of two of these levers were shown to approach the goal of transient emissions with one configuration meeting the requirement. Finally, the combination of three independent levers were shown to achieve 40% margin for meeting 2027 transient NOx emissions while remaining CO2 neutral.

Diesel engine cylinder deactivation (CDA) can be used to reduce petroleum consumption and greenhouse gas (GHG) emissions of the global freight transportation system. Heavy duty trucks require complex exhaust aftertreatment (A/T) in order to meet stringent emission regulations. Efficient reduction of engine-out emissions require a certain A/T system temperature range, which is achieved by thermal management via control of engine exhaust flow and temperature. Fuel efficient thermal management is a significant challenge, particularly during cold start, extended idle, urban driving, and vehicle operation in cold ambient conditions. CDA results in airflow reductions at low loads. Airflow reductions generally result in higher exhaust gas temperatures and lower exhaust flow rates, which are beneficial for maintaining already elevated component temperatures. Airflow reductions also reduce pumping work, which improves fuel efficiency.

Increased demands for reduction of fuel consumption and CO2 emissions are driven by the global warming. To meet these challenges with respect to the passenger car segment the strategy of utilizing IC-engine downsizing has shown to be effective. In order to additionally meet requirements for high power and torque output supercharging is required. This can be realized using e.g. turbo-chargers, roots blowers or a combination of several such devices for the highest specific power segment. Both turbo-chargers and roots blowers can be strong sources of sound depending on the operating conditions and extensive NVH abatements such as resonators and encapsulation might be required to achieve superior vehicle NVH. For an efficient resonator tuning process in-duct acoustic source data is required. No published studies exists that describe how the gas exchange process for roots blowers can be described by acoustic sources in the frequency domain.

The vehicle air-conditioning system has significant impact on fuel economy and range of electric vehicles. Improving the fuel economy of vehicles therefore demand for energy efficient climate control systems. Also the emissions regulations motivate the reduced use of fuel for vehicle's cabin climate control. Solar heat gain of the passenger compartment by greenhouse effect is generally treated as the peak thermal load of the climate control system. Although the use of advanced glazing is considered first to reduce solar heat gain other means such as ventilation of parked car and recirculation of cabin air also have impetus for reducing the climate control loads.

Global environmental and economic concerns regarding increasing fuel consumption and greenhouse gas emission are driving changes to legislative regulations and consumer demand. As regulations become more stringent, advanced engine technologies must be developed and implemented to realize desired benefits. Discrete variable valve lift technology is a targeted means to achieve improved fuel economy in gasoline engines. By limiting intake air flow with an engine valve, as opposed to standard throttling, road-load pumping losses are reduced resulting in improved fuel economy. This paper focuses on the design and development of a switching roller finger follower system which enables two mode discrete variable valve lift on end pivot roller finger follower valvetrains. The system configuration presented includes a four-cylinder passenger car engine with an electro-hydraulic oil control valve, dual feed hydraulic lash adjuster, and switching roller finger follower.

Diesel exhaust aftertreatment systems are required for meeting Final Tier 4 emission regulations. This paper addresses an aftertreatment system designed to meet the Final Tier 4 emission standards for nonroad vehicle markets. The aftertreatment system consists of a fuel dosing system, mixing elements, fuel vaporizer, fuel reformer, lean NOx trap (LNT), diesel particulate filter (DPF), and an optional selective catalytic reduction (SCR) catalyst. Aftertreatment system performance, both with and without the SCR, was characterized in an engine dynamometer test cell, using a 4.5 liter, pre-production diesel engine. The engine out NOx nominally ranged between 1.6 and 2.0 g/kW-hr while all operating modes ranged between 1.2 and 2.8 g/kW-hr. The engine out particulate matter was calibrated to approximately 0.1 g/kW-hr for various power ratings. Three engine power ratings of 104 kW, 85 kW and 78 kW were evaluated.

Diesel exhaust aftertreatment systems are required for meeting both EPA 2010 and final Tier 4 emission regulations. This paper addresses aftertreatment system performance of a fuel reformer, lean NOx trap (LNT) and selective catalytic reduction (SCR) system designed to meet the EPA 2010 emission standards for an on-highway heavy-duty vehicle. The aftertreatment system consists of a fuel dosing system, mixing elements, fuel reformer, LNT, diesel particulate filter (DPF), and SCR for meeting NOx and particulate emissions. System performance was characterized in an engine dynamometer test cell, using a development, 13L, heavy-duty engine. The catalyst performance was evaluated using degreened catalysts. Test results show that system performance met the EPA 2010 emission standards under a range of test conditions that were reflective of actual vehicle operation.

On-board measurements of fuel consumption and vehicle exhaust emissions of NOx, HC, CO, CO2, and PM are being conducted for three types of commercially available city buses in Guangzhou, China. The selected vehicles for this test include a diesel bus with Eaton hybrid electric powertrain, a conventional diesel bus with automated mechanical transmission (AMT), and a LPG powered city bus with manual transmission (MT). All of the tested vehicles were instrumented with on-board measurements. Horiba OBS-2200 was used for measuring NOx, HC, and CO emissions; ELPI (Electrical Low Pressure Impactor) was used for PM measurement. The vehicles were tested at Hainan National Proving Ground in southern China. Test data of fuel consumption and exhaust emissions were analyzed. The city bus with Eaton hybrid electric powertrain demonstrated more than 27% fuel consumption reduction over the conventional diesel powered bus, and over 68% over the LPG bus.

The US Environmental Protection Agency (EPA)’s heavy duty diesel emission standard was tightened beginning from 2007 with the introduction of ultra-low-sulfur diesel fuel. Most heavy duty diesel applications were required to equip Particulate Matter (PM) after-treatment systems to meet the new tighter, emission standard. Systems utilizing Diesel Oxidation Catalyst (DOC) and Catalyzed-Diesel Particulate Filter (DPF) are a mainstream of modern diesel PM after-treatment systems. To ensure appropriate performance of the system, periodic cleaning of the PM trapped in DPF by its oxidation (a process called “regeneration”) is necessary. As a result, of this regeneration, DOC’s and DPF’s can be exposed to hundreds of thermal cycles during their lifetime. Therefore, to understand the thermo-mechanical performance of the DOC and DPF is an essential issue to evaluate the durability of the system.

An advanced exhaust aftertreatment system is characterized following end-of-life catalyst aging to meet final Tier 4 off-highway emission requirements. This system consists of a fuel dosing system, mixing elements, fuel reformer, lean NOx trap (LNT), diesel particulate filter (DPF), and a selective catalytic reduction (SCR) catalyst. The fuel reformer is used to generate hydrogen (H2) and carbon monoxide (CO) from injected diesel fuel. These reductants are used to regenerate and desulfate the LNT catalyst. NOx emissions are reduced using the combination of the LNT and SCR catalysts. During LNT regeneration, ammonia (NH3) is intentionally released from the LNT and stored on the downstream SCR catalyst to further reduce NOx that passed through the LNT catalyst. This paper addresses system durability as the catalysts were aged to 500 desulfation events using an off-highway diesel engine.

Eaton has developed a prototype hydraulic hybrid vehicle energy management system that substantially improves fuel economy and reduces harmful emissions. The system was developed cooperatively with the U.S. Environmental Protection Agency (EPA), Navistar Inc., and the U.S. Army. The system has demonstrated fuel economy improvements in real world use of up to 50 percent while simultaneously reducing carbon emissions by up to 30 percent. The first real world application of the technology will be in parcel delivery vehicles owned by United Parcel Service (UPS). The hybrid vehicle energy management system components will be described and principles of operation explained. Major properties of the system will be examined and it will be shown why the hydraulic hybrid system is well suited for the parcel delivery vehicle application. Several secondary beneficial properties of the system will also be discussed.

This paper addresses Hardware-In-the-Loop modeling and simulation for Diesel aftertreatment controls system development. Lean NOx Trap (LNT) based aftertreatment system is an efficient way to reduce NOx emission from diesel engines. From control system perspective, the main challenge in aftertreatment system is to predict temperature at various locations and estimate the stored NOx in LNT. Accurate estimation of temperatures and NOx stored in the LNT will result in an efficient system control with less fuel penalty while still maintaining the emission requirements. The optimization of the controls will prolong the lifespan of the system by avoiding overheating the catalysts, and slow the progressive process of component aging. Under real world conditions, it is quite difficult and costly to test the performance of a such complex controller by using only vehicle tests and engine cells.

Eaton has developed a prototype hydraulic hybrid vehicle energy management system that substantially improves fuel economy and reduces harmful emissions. The system was developed cooperatively with the U.S. Environmental Protection Agency (EPA), Navistar Inc., and the U.S. Army. The system has demonstrated fuel economy improvements in real world use of up to 50 percent while simultaneously reducing carbon emissions by up to 30 percent. The first real world application of the technology will be in parcel delivery vehicles owned by United Parcel Service (UPS). The hybrid vehicle energy management system components will be described and principles of operation explained. Major properties of the system will be examined and it will be shown why the hydraulic hybrid system is well suited for the parcel delivery vehicle application. Several secondary beneficial properties of the system will also be discussed.

In today’s highly competitive automotive environment people are always looking to develop processes that are fast, efficient, and effective. Moving testing from expensive prototype vehicles into the laboratory is an approach being implemented for many different vehicle subsystems. Specifically a process has recently been developed at General Motors that predicts exhaust back pressure performance for a running vehicle using laboratory testing and spreadsheet calculations. This paper describes the laboratory facility and procedure, the theory behind the calculations, and the correlation between vehicle test and laboratory based results. It also comments on the benefits of the process with respect to reduction in design iterations, quicker availability of results, and money savings.

General Motors recently demonstrated two driveable test vehicles powered by a Homogeneous Charge Compression Ignition (HCCI) engine. HCCI combustion has the potential of a significant fuel economy benefit with reduced after-treatment cost. However, the biggest challenge of realizing HCCI in vehicle applications is controlling the combustion process. Without a direct trigger mechanism for HCCI's flameless combustion, the in-cylinder mixture composition and temperature must be tightly controlled in order to achieve robust HCCI combustion. The control architecture and strategy that was implemented in the demo vehicles is presented in this paper. Both demo vehicles, one with automatic transmission and the other one with manual transmission, are powered by a 2.2-liter HCCI engine that features a central direct-injection system, variable valve lift on both intake and exhaust valves, dual electric camshaft phasers and individual cylinder pressure transducers.

Reducing Carbon Dioxide (CO2) emissions is one of the major challenges for automobile manufacturers. This is driven by environmental, consumer, and regulatory demands in all major regions worldwide. For conventional vehicles, a host of technologies have been applied that improve the overall efficiency of the vehicle. This reduces CO2 contributions by directly reducing the amount of energy consumed to power a vehicle. The hybrid electric vehicle (HEV) continues this trend. However, there are limits to CO2 reduction due to improvements in efficiency alone. Other major improvements are realized when the CO2 content of the energy used to motivate vehicles is reduced. With the introduction of Extended Range Electric Vehicles (E-REVs) and Plug-in HEVs (PHEVs), electric grid energy displaces petroleum. This enables the potential for significant CO2 reductions as the CO2 per unit of electrical energy is reduced over time with the improving mix of energy sources for the electrical grid.

Diesel engines offer better fuel economy compared to their gasoline counterpart, but simultaneous control of NOx and particulates is very challenging. The blended 2-way SCR/DPF is recently emerging as a compact and cost-effective technology to reduce NOx and particulates from diesel exhaust using a single aftertreatment device. By coating SCR catalysts on and inside the walls of the conventional wall-flow filter, the 2-way SCR/DPF eliminates the volume and mass of the conventional SCR device. Compared with the conventional diesel aftertreatment system with a SCR and a DPF, the 2-way SCR/DPF technology offers the potential of significant cost saving and packaging flexibility. In this study, an engine dynamometer test cell was set up to repeatedly load and regenerate the SCR/DPF devices to mimic catalyst aging experienced during periodic high-temperature soot regenerations in the real world.

Exhaust gas recirculation (EGR) is one of the key approaches applied to reduce emissions for an internal combustion engine. Recirculating a desired amount of EGR requires accurately estimating EGR mass flow. This can be calculated either from the gas flow equation of an orifice, or from the difference between charge air mass flow and fresh air mass flow. Both calculations need engine exhaust pressure as an input variable. This paper presents a method to estimate exhaust pressure for a variable geometry turbo charged diesel engine. The method is accurate and simple to fit production ECU application, therefore, saves cost of using a physical sensor.

An LNT + SCR diesel aftertreatment system was developed in order to meet the 2010 US HD EPA on-road, and tier 4 US HD EPA off-road emission standards. This system consists of a fuel reformer (REF), lean NOx trap (LNT), catalyzed diesel particulate filter (DPF), and selective catalytic reduction (SCR) catalyst arranged in series to reduce tailpipe nitrogen oxides (NOx) and particulate matter (PM). This system utilizes a REF to produce hydrogen (H2), carbon monoxide (CO) and heat to regenerate the LNT, desulfate the LNT, and actively regenerate the DPF. The NOx stored on the LNT is reduced by the H2 and CO generated in the REF converting it to nitrogen (N2) and ammonia (NH3). NH3, which is normally an undesired byproduct of LNT regeneration, is stored in the downstream SCR which is utilized to further reduce NOx that passes through the LNT. Engine exhaust PM is filtered and trapped by the DPF reducing the tailpipe PM emissions.

An advanced exhaust aftertreatment system is being developed using a fuel dosing system, mixing elements, fuel reformer, lean NOx trap (LNT), diesel particulate filter (DPF) and a selective catalytic reduction (SCR) catalyst arranged in series for both on- and off- highway diesel engines to meet the upcoming emissions regulations. This system utilizes a fuel reformer to generate hydrogen (H2) and carbon monoxide (CO) from injected diesel fuel. These reductants are used to regenerate and desulfate the LNT catalyst. NOx emissions are reduced using the combination of the LNT and SCR catalysts. During LNT regeneration, ammonia is intentionally released from the LNT and stored on the downstream SCR catalyst to further reduce NOx that passed through the LNT catalyst. This paper addresses LNT and SCR catalyst degradation as these were subjected to 150 desulfation events using a pre-production 2007 medium heavy-duty, on-highway diesel engine.