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Diesel engine ash emissions are composed of the non-combustible portions of diesel particulate matter derived mainly from lube oil, and over time can degrade diesel particulate filter performance. This paper presents results from a high temperature oxidation method (HTOM) used to estimate ash emissions, and engine oil consumption in real-time. Atomized lubrication oil and diesel engine exhaust were used to evaluate the HTOM performance. Atomized fresh and used lube oil experiments showed that the HTOM reached stable particle size distributions and concentrations at temperatures above 700°C. The HTOM produced very similar number and volume weighted particle size distributions for both types of lube oils. The particle number size distribution was unimodal, with a geometric mean diameter of about 23 nm. The volume size distribution had a geometric volume mean diameter of about 65 nm.

Diesel fuel injection systems are operating at increasingly higher pressure (up to 250 MPa) with smaller clearances, making them more sensitive to diesel fuel contaminants. Most liquid particle counters have difficulty detecting particles <4 μm in diameter and are unable to distinguish between solid and semi-solid materials. The low conductivity of diesel fuel limits the use of the Coulter counter. This raises the need for a new method to characterize small (<4 μm) fuel contaminants. We propose and evaluate an aerosolization method for characterizing solid particulate matter in diesel fuel that can detect particles as small as 0.5 μm. The particle sizing and concentration performance of the method were calibrated and validated by the use of seed particles added to filtered diesel fuel. A size dependent correction method was developed to account for the preferential atomization and subsequent aerosol conditioning processes to obtain the liquid-borne particle concentration.

Hydrogen was used to operate a single cylinder engine in homogeneous charge compression ignition (HCCI) mode. The engine was a modified 435 cm3 single cylinder air cooled Yanmar L100V direct injection (DI) compression ignition (CI) engine. The original diesel fuel injection system was removed and a hydrogen port fuel injection (PFI) system was added, along with a 1 kW intake air heater. The piston was modified from the original re-entrant bowl piston to a dish shaped piston, while maintaining the original 21.2:1 compression ratio. The engine speed was maintained at a constant 1800 RPM. Three hydrogen fueling conditions of 25, 30, and 35 slpm were investigated, which corresponded to an excess air ratio (λ) of roughly 4.38, 3.64, and 3.16, respectively The fuel conversion efficiency for the conditions tested ranged from 23% - 27%.

This study investigates the combustion and emissions of a compression ignition (CI) engine operating with mixtures of hydrogen (H₂) and carbon monoxide (CO) injected with the intake air. Hydrogen and carbon monoxide were chosen as the gaseous fuels, because they represent the main fuel component of synthesis gas, which can be produced by a variety of methods and feed stocks. However, due to varying feed stock and production mechanisms, syngas composition can vary significantly. It is currently unknown how a varying H₂/CO (syngas) ratio affects the cycle efficiency and gaseous emissions. The experiments were performed on an air-cooled, naturally aspirated, direct injection diesel engine. The engine was operated at 1800 RPM with a compression ratio of 21.2:1. Two load conditions were tested; 2 bar and 4 bar net indicated mean effective pressure (IMEPⁿ). For all test conditions the added syngas demonstrated lower cycle efficiency than the diesel fuel baseline.

Four-way, integrated, diesel emission control systems that combine selective catalytic reduction for NOx control with a continuously regenerating trap to remove diesel particulate matter were evaluated under real-world, on-road conditions. Tests were conducted using a semi-tractor with an emissions year 2000, 6-cylinder, 12 L, Volvo engine rated at 287 kW at 1800 rpm and 1964 N-m. The emission control system was certified for retrofit application on-highway trucks, model years 1994 through 2002, with 4-stroke, 186-373 kW (250-500 hp) heavy-duty diesel engines without exhaust gas recirculation. The evaluations were unique because the mobile laboratory platform enabled evaluation under real-world exhaust plume dilution conditions as opposed to laboratory dilution conditions. Real-time plume measurements for NOx, particle number concentration and size distribution were made and emission control performance was evaluated on-road.

This paper reports on the first phase of a project that explores the trends and dependencies of the input power to the major mechanically-driven accessories including hydraulic pumps, air compressor, air conditioning (AC) compressor, and alternator on a modern parallel hybrid city bus. In this first phase, the impact of accessory electrification is estimated by considering the near-elimination of accessory overdrive and parasitic loading. In addition to reducing accessory fuel consumption accessory electrification can also serve as a bridge to the eventual use of a diesel or fuel cell auxiliary power unit to generate electricity for accessories on transit buses. Data collection and processing methods of this study are described, the shortcomings of mechanically-driven accessories are discussed, and an estimation of savings for accessory electrification is performed.

Engine-out particle size distributions and soot mass emissions were measured from a gasoline direct injection (GDI) engine fueled by seven different gasoline formulations. Additionally, particle size distributions were simultaneously measured downstream of a catalyzed gasoline particulate filter (GPF) to determine the size resolved filtration efficiency. Stoichiometric, lean homogeneous, and lean stratified combustion modes were studied at four steady-state engine conditions. The particulate matter (PM) Index was calculated for each fuel as a function of the double bond equivalent and vapor pressure of the fuel components. There was generally poor correlation between particle number (PN)/PM mass emissions and the PM Index for steady state stoichiometric conditions with clean injectors, which emitted low particle concentrations.