Review and Assessment of Fuel Effects and Research Needs in Clean Diesel Technology

This paper reviews the current general understanding of fuel effects on combustion and emissions, fuel processing, and emission control technologies and assesses areas of opportunity in further research in clean diesel systems. The critical basic research areas identified focus on fundamental processes mat would develop a scientific knowledge base for the long-term development of clean diesel technology. The suggested approach, from a basic research perspective, will complement other pragmatic development programs in clean fuels production, application, engine and emission control technologies. Among areas suggested are: studies in developing basic data and modeling of fuel chemistry and emission mechanisms both in cylinder and during after-treatment, interactions of new fuel and engine technologies, gas-to-liquid fuel processing and utilization, and detailed particulate emission characterization and their health effects. The health effect benefits from clean fuels may be more than proportional to the reduction in mass emissions.

Performance and Exhaust Emissions of a Diesel Engine Running With DME

This research investigates engine performance and the potential of reducing exhaust emissions by using Dimethyl Ether (DME) which is an alternative fuel for diesel engines. The objective of this study it to evaluate (on the bed test) the performance and emissions reduction potential of an engine running with DME. A 4 cylinder passenger car HSDI Common Rail turbocharged diesel engine without specific modifications was used. The results obtained on this engine running with DME using diesel fuel as reference are encouraging. In the next steps of this study the injection rate will be adapted to DME operation and to the geometric and thermodynamic conditions of the combustion reaction. A study of the combustion reaction is also necessary in order to optimize the turbocharging system to exclusive DME operation.

Effect of Fuel Injection Timing Relative to Ignition Timing on the Natural-Gas Direct-Injection Combustion

Effect of fuel injection timing relative to ignition timing on natural gas direct-injection combustion was studied by using a rapid compression machine. The ignition timing was fixed at 80 ms from the compression start. When the injection timing was relatively earlier (injection start at 60 ms), the heat release pattern showed slower burn in the initial stage and faster burn in the late stage, which is similar to that of flame propagation of a premixed gas. In contrast to this, when the injection timing was relatively later (injection start at 75 ms), the heat release rate showed faster burn in the initial stage and slower burn in the late stage, which is similar to that of diesel combustion. The shortest duration was realized at the injection end timing of 80 ms (the same timing as the ignition timing) over the wide range of equivalence ratio. The degree of charge stratification and the intensity of turbulence generated by the fuel jet is considered to cause these behaviors. Earlier injection leads to longer duration of the initial combustion, whereas the later injection does longer duration of the late combustion. Earlier injection showed relatively lower CO emission while later injection produces relatively lower NOx emission. It was suggested that earlier injection leads to lower mixture stratification combustion and later injection leads to higher mixture stratification combustion. Combustion efficiency maintained high value over the wide range of equivalence ratio.

Combined Supercharging System: The Best Fit for Submarine Engines

The two types of supercharging processes, either with turbocharger or with mechanically driven compressor are the two systems known to be used on diesel engines for submarines. Each of these two systems has its own limitations. A two stage supercharging system has been investigated and developed by S.E.M.T. Pielstick. This system is based on a turbocharger used as a low-pressure stage combined with a high-pressure stage compressor which is mechanically driven by the engine. Test bench results are compared with those obtained with the classical systems. The new system with two-stage compression has an advantage particularly for the following main points: - specific power, - air and fuel specific consumptions, - capability to sustain high exhaust back pressures as well as low suction pressures and low sensitivity to their fluctuations, - safety against engine stalling in case of loss of submersion control.

Design Features of MAN B&W Medium Speed Diesel Engines Optimizing Life Cycle Costs

It is not only fuel and lube oil costs which determine life cycle costs of a diesel engine, but also maintenance costs and costs for replacements of wear components. All these costs are linked to the individual design of the engine and its capability to burn a variety of fuels, including low-priced heavy fuel oils. As an example, the paper describes several main components of MAN B&W medium-speed diesel engines (engine block, liner, piston) and how they contribute to lower life cycle costs by easier maintenance procedures, longer TBOs and longer life times. To achieve this is a challenging task for the engine manufacturer, since other strong market requirements such as reduced exhaust gas emissions or high power density have to be fulfilled simultaneously.

Diesel Engine Development for Low Emission Rail Traction Application

This paper describes the evolution of a family of modern four stroke high power density engines, the Ruston RK215 series, which has been developed to meet the specific needs of heavy duty rail traction application including the current EPA and UIC (European) emissions legislation. It discusses the extensive experience of Ruston in powering various locomotives including recent applications in overseas markets. The methodology adopted in the base engine design, to achieve high reliability and good component life is discussed with methods of validation and risk analysis during the design and development program. Specific reference is made to an emissions research program to ensure the engine will comply fully with future legislation.

Calibration of a Methodology to Determine Pollutant Production in Urban Areas and its Application to Real Situations

The paper illustrates a first calibration of the Danieli-d’Elia method for pollutant production determination in urban areas, as described in previous articles, and its application to measured road conditions in a Southern Italian City. In order to perform the calibration, the method was applied to UDC + EUDC driving cycles, theoretically obtained for a given vehicle, both catalysed and non-catalysed. Model predictions were then compared to law requirements for the relative model-year, obtaining the calibration. Next, it was also necessary to devise a procedure to filter the data, which was often subject to heavy electronic noise, causing unrealistic values of the acceleration, and this was also performed and applied to the different sets of experimental data. Once this was obtained, the comparison to real city pollutant production in various traffic and elevation conditions was performed. Finally, on the assumption that in real traffic the individual car’s kinematic conditions are conditioned by the presence of other cars, the measured kinematic diagrams were extended to different car typologies by changing engine speed in the appropriate manner, and consequently the torque. This allows the experimental measurement to be extended to the entire fleet of cars, running on a certain street at a given time, also taking into account velocity distributions, as will be shown.

Pollution Studies on Gasoline Engine With Electrically Heated Catalyst

The environmental pollution is one of the major strategic factors for decision-makers both in industry as well as in government. It has been established beyond doubt that the tailpipe emission shows significant effect on environment. It is clear that the vehicles form the predominant source of regulated and unregulated pollution. The environmental degradation all over the world has led to research, which resulted in the development of low emission vehicle and ultra low emission vehicle. In this work, performance of Low Mass Electrically Heated Metal Catalyst (LMEHMC) on the emission from SI engine has been experimentally investigated. Behaviors of chromium and copper oxides under various conditions were studied. It is found that the HC and CO emissions were reduced considerably when LMEHMC used with existing catalytic converter.

Reduction of NOx Emission From Diesel Engines Using Cu-ZSM-5 Catalyst

In this paper effect of on reduction a Cu-ZSM-5 catalyst of nitrogen oxides is investigated in a diesel engine. This research focuses to solve a problem that there is not enough THC to reduce nitrogen oxides in exhaust gas from a diesel engine. When diesel oil is directly supplied into the exhaust gas, the THC concentration sharply rises and the NOx conversion rate increases. The maximum NOx conversion rate reaches to 63% when the flow rate of diesel oil is 30 ml/min at a catalyst temperature 450 °C. The NOx reduction with less sacrifice of the specific fuel consumption is possible when the fuel is supplied into the exhaust pipe.

The GE/Jenbacher 1 MW Dual Speed Gas Engine Concept for the GE Rental Fleet

Jenbacher AG (JAG) has designed with General Electric (GE) a new container-based gas engine gen-set package for the GE rental fleet. All necessary system components like the natural gas engine, alternator, cooling fans, electrical units and auxiliaries are integrated in one 40-foot ISO container which is normally placed on a trailer truck. A unit weight of less than 53,000 lbs ensures easy transport from site to site. The gas and electricity connections are designed to ensure the lowest possible installation and setup times. The application of a closed loop cooling system inside the container has the advantage that no additional connections are necessary. Connections for heat recovery are integrated, and can easily be utilized if there is a demand. Another important feature is that the gen set is not influenced to a great extent by changes in environmental conditions. Ambient temperatures of up to 104°F (40°C) are still permissible without reduction of power output. Container insulation and exhaust gas silencer design are optimized to attain a noise level of 74 dB(A) at a distance of 7 m.