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Technical Paper

Development of Fuel Cell Hybrid Vehicle by Toyota -Durability-

2009-04-20
2009-01-1002
Various issues must be resolved before sustainable mobility can be achieved, the most important of which are reacting to energy supply and demand, and lowering CO2 emissions. At present, the fact that the vast majority of vehicles run on conventional oil is regarded as a problem for which Toyota Motor Corporation (TMC) is developing various technological solutions. Fuel cell (FC) technology is one of the most promising of these solutions. A fuel cell is an extremely clean device that uses hydrogen and oxygen to generate power without emitting substances like CO2, NOx, or PM during operation. Its energy efficiency is high and it is widely expected to form the basis of the next generation of powertrains. Since 1992, TMC has been working to develop the main components of fuel cell vehicles, including the fuel cell itself, and the high pressure hydrogen tank and hybrid systems.
Journal Article

High-Efficiency and Low-NOx Hydrogen Combustion by High Pressure Direct Injection

2010-10-25
2010-01-2173
Hydrogen can be produced from various renewable energy sources, therefore it is predicted that hydrogen could play a greater role in meeting society's energy needs in the mid- to long-term. Conventional hydrogen engines have some disadvantages: higher cooling loss results in low thermal efficiency and abnormal combustion (backfire, pre-ignition, higher burning velocity) limits high load operation. Direct injection is an effective solution to overcome these disadvantages, but combustion methods that enable both high efficiency and low NOx have yet to be studied in enough detail. In this research, high-efficiency and low-NOx hydrogen combustion was investigated using a prototype high-pressure hydrogen injector (maximum 30 MPa). Experiments were carried out with a 2.2-liter 4-cylinder diesel engine equipped with a centrally mounted hydrogen injector, a toroidal shape combustion chamber, and a spark plug in the glow plug position.
Technical Paper

Feasibility Study of Exhaust Emissions in a Natural Gas Diesel Dual Fuel (DDF) Engine

2012-09-10
2012-01-1649
The Diesel Dual Fuel (DDF) vehicle is one of the technologies to convert diesel vehicles for natural gas usage. The purpose of this research was to study the possibility of a DDF vehicle to meet emission standards for diesel vehicles. This research was done for small passenger vehicles and commercial vehicles. The exhaust emissions compliance of such vehicles in a New European Driving Cycle (NEDC) mode which was composed of Urban Driving Cycles (UDC) and an Extra Urban Driving Cycle (EUDC) was evaluated. (see APPENDIXFigure A1) In this study, the passenger vehicle engine, compliant with the EURO4 standard, was converted to a DDF engine. Engine bench tests under steady state conditions showed similar result to previous papers. Total hydrocarbon (HC) emission was extremely high, compared to diesel engine. The NEDC mode emissions of the DDF vehicle were estimated based on these engine bench test results.
Technical Paper

Improvement of Adhesion Properties between Epoxy Resin and Primer and between Primer and Ni Plating in Hybrid Vehicle Power Semiconductor Module under High Temperature Conditions

2016-04-05
2016-01-0500
In this report, adhesion mechanism between epoxy resin and primer and between primer and Ni platting in Hybrid vehicle (HV) was investigated. Adhesion forces are thought to be a combination of mechanical bond forces (such as anchor effect), chemical bond forces and physical bond forces (such as hydrogen bonding and Van der Waals force). Currently there is insufficient understanding of the adhesion mechanism. In particular, the extent to which the three bond forces contribute to adhesion strength. So the adhesion mechanism of polyimide primers was analyzed using a number of different methods, including transmission electron microscope (TEM) and atomic force microscope (AFM) observation, to determine the contributions of the three bonding forces. Molecular simulation was also used to investigate the relationship between adhesion strength and the molecular structure of the primer.
Technical Paper

Colorimetric Sensor for Facile Identification of Methanol-Containing Gasoline

2017-03-28
2017-01-1288
Despite the fact that methanol is toxic to human health and causes serious damage to automobile engines and fuel system components, methanol-containing gasoline is becoming popular in some areas. Methanol demonstrates similar chemical properties to ethanol (which is already established as an additive to gasoline), so that it is difficult to identify methanol-containing gasoline without performing proper chemical analysis. In this study, we report a low-cost, portable, and easy-to-operate sensor that selectively changes color in response to methanol contained in gasoline. The colorimetric sensor will be useful for automobile users to avoid methanol-containing gasoline upon refueling.
Technical Paper

The Impact of RON on SI Engine Thermal Efficiency

2007-07-23
2007-01-2007
Recently, global warming and energy security have received significant attention. Thus an improvement of the vehicle fuel economy is strongly required. For engines, one effective way is to improve the engine thermal efficiency. Raising compression ratio [1] or turbo charging technologies have potential to achieve high thermal efficiency. However knock does not allow the high thermal efficiency. Knock depends on the fuel composition and the pressure and temperature history of unburnt end-gas [2-3]. For fuels, RON is well known for describing the anti knock quality. High RON fuels have high anti knock quality and result in higher thermal efficiency. This paper investigates the impact of high RON fuels on the thermal efficiency by using high compression ratio engine, turbo charged engine, and lean boosted engine [4]. Finally, it is shown that the high thermal efficiency can be approached with high RON gasoline and ethanol.
Technical Paper

Vegetable Oil Hydrogenating Process for Automotive Fuel

2007-07-23
2007-01-2030
From the viewpoint of primary energy diversification and CO2 reduction, interests of using Biomass Fuel are rising. Some kinds of FAME (Fatty Acid Methyl Ester), which are obtained from oil fats like vegetable oil using transesterification reaction with methanol, are getting Palm Oilpular for bio-diesel recently. In this study, we have conducted many experiments of palm oil hydrogenations using our pilot plants, and checked the reactivity and the pattern of product yields. As a result, we figured out that the hydrocarbon oil equivalent to the conventional diesel fuel can be obtained from vegetable oils in good yield under mild hydrogenation conditions. Moreover, as a result of various evaluations for the hydrogenated palm oil (oxidation stability, lowtemperature flow property, LCA, etc.), we found that the hydrogenated palm oil by our technology has performances almost equivalent to conventional diesel fuel.
Technical Paper

High Concentration Ethanol Effect on SI Engine Cold Startability

2007-07-23
2007-01-2036
From the energy security and CO2 discharge reduction point of view, much attention has been paid to the usage of biofuel, ethanol, as an alternative source of energy in the transportation industry. Yet, the major drawback in applying highly concentrated ethanol in the spark ignited internal combustion engines is cold start instability. This is due to the characteristics of ethanol, large latent heat required to vaporize. This paper investigates necessary conditions for the engine cold start, using highly concentrated ethanol. Tests performed with varieties of ethanol fuel, a relationship between cold startability lower temperature limit and reid vapor pressure was observed. A method to boost the vaporization, intake valve timing control is introduced to obtain high compression peak temperature.
Technical Paper

Feasibility Study of Ethanol Applications to A Direct Injection Gasoline Engine

2007-07-23
2007-01-2037
Feasibility studies concerning ethanol utilization in direct injection gasoline engines were conducted in order to clarify the effects of ethanol on engine performance, exhaust emissions and injector deposit formation. The investigation results indicate that E100 (100% ethanol fuel) can improve full load engine performance around whole engine speed range in a high compression ratio engine (ε=13:1), compared to that of a base compression ratio engine (ε=11.5:1) operated on a premium gasoline. This was caused by the volumetric efficiency (ηv) improvement and engine knock suppression in the high compression ratio engine. On the other hand, HC emissions remarkably increased under lower engine speeds at a full load condition. This phenomenon suggests that poor combustion occurred due to insufficient mixing of air and E100 fuel under these conditions, in which the amount of ethanol injected was too large and fluidity in the cylinder was weak.
Technical Paper

Study of Mileage-Related Formaldehyde Emission from Methanol Fueled Vehicles

1990-02-01
900705
In order to determine the main factors causing the mileage-related increase in formaldehyde emission from methanol-fueled vehicles, mileage was accumulated on three types of vehicle, each of which had a different air-fuel calibration system. From exhaust emission data obtained during and after the mileage accumulation, it was found that lean burn operation resulted in by far the highest formaldehyde emission increase. An investigation into the reason for the rise in engine-out formaldehyde emission revealed that deposits in the combustion chamber emanating from the lubricating oil promotes formaldehyde formation. Furthermore it was learnt that an increase in engine-out NOx emissions promotes partial oxidation of unburned methanol in the catalyst, leading to a significant increase in catalyst-out formaldehyde emission.
Technical Paper

Oxygen and Propellant Extraction from Martian Atmosphere: Feasibility Study of a Small Technological Demonstration Plant

2008-06-29
2008-01-1984
The sustainability of Martian outposts development is strongly based on the capability of achieving a high level of autonomy both in terms of operations management and of resources availability. In situ production of consumables is a key point to allow humans to work and live on Mars avoiding or limiting the need for re-supplies of materials from Earth. Required consumables can be produced in situ exploiting the locally available resources, but also by means of green-houses and waste recycle systems. Dedicated robotic missions for in situ demonstration of this type of technologies are a fundamental step of the Martian In Situ Resources Utilization (ISRU) development roadmap. This paper is focused on the extraction of oxygen and fuels (e.g. methane) from the Martian atmosphere, and presents a feasibility study for a small technological demonstration plant.
Technical Paper

GTL Fuel Impact on DI Diesel Emissions

2007-07-23
2007-01-2004
Reduction of exhaust emissions was investigated in a modern diesel engine equipped with advanced diesel after treatment system using a Gas-to-Liquid (GTL) fuel, a cleaner burning alternative diesel fuel. This fuel has near zero sulfur and aromatics and high cetane number. Some specially prepared GTL fuel samples were used to study the effects of GTL fuel distillation characteristics on exhaust emissions before engine modification. Test results indicated that distillation range of GTL fuels has a significant impact on engine out PM. High cetane number also improved HC and CO emissions, while these fuel properties have little effect on NOx emissions. From these results, it was found that low distillation range and high cetane number GTL fuel can provide a favorable potential in NOx/PM emissions trade-off. In order to improve the tail-pipe emissions in the latest diesel engine system, the engine modifications were carried out for the most favorable GTL fuel sample.
Technical Paper

Impact Study of High Biodiesel Blends on Performance of Exhaust Aftertreatment Systems

2008-10-06
2008-01-2494
Biodiesel Fuel (BDF) Research Work Group works on identifying technological issues on the use of high biodiesel blends (over 5 mass%) in conventional diesel vehicles under the Japan Auto-Oil Program started in 2007. The Work Group conducts an analytical study on the issues to develop measures to be taken by fuel products and vehicle manufacturers, and to produce new technological findings that could contribute to the study of its introduction in Japan, including establishment of a national fuel quality standard covering high biodiesel blends. For evaluation of the impacts of high biodiesel blends on performance of diesel particulate filter system, a wide variety of biodiesel blendstocks were prepared, ranging from some kinds of fatty acid methyl esters (FAME) to another type of BDF such as hydrotreated biodiesel (HBD). Evaluation was mainly conducted on blend levels of 20% and 50%, but also conducted on 10% blends and neat FAME in some tests.
Technical Paper

Effects of Bio-Fuels on Vehicle Performance: Degradation Mechanism Analysis of Bio-Fuels

2004-10-25
2004-01-3031
In recent years, alternative sources of fuel are receiving a lot of attention in the automotive industry. Fuels derived from an agricultural feedstock are an attractive option. Bio-fuels based on vegetable oils offer the advantage being a sustainable, annually renewable source of automobile fuel. One of key issues in using vegetable oil based fuels is its oxidation stability. Since diesel fuels from fossil oil have good oxidation stability, automobile companies have not considered fuel degradation when developing diesel engines and vehicles as compared with gasoline engines. This paper presents the results of oxidation stability testing on bio-fuels. Oxidation stability was determined using three test methods, ASTM D525, EN14112 and ASTM D2274. The effects of storage condition, bio-fuel composition and antioxidants on the degradation of bio-fuels were all investigated. ASTM D525 is an effective test method to determine the effects of storage condition on bio-fuels stability.
Technical Paper

The Effect of Ethanol Fuel on a Spark Ignition Engine

2006-10-16
2006-01-3380
Since ethanol is a renewable source of energy and it contributes to lower CO2 emissions, ethanol produced from biomass is expected to increase in use as an alternative fuel. It is recognized that for spark ignition (SI) engines ethanol has advantages of high octane number and high combustion speed and has a disadvantage of difficult startability at low temperature. This paper investigates the influence of ethanol fuel on SI engine performance, thermal efficiency, and emissions. The combustion characteristics under cold engine conditions are also examined. Ethanol has high anti-knock quality due to its high octane number, and high latent heat of evaporation, which decreases the compressed gas temperature during the compression stroke. In addition to the effect of latent heat of evaporation, the difference of combustion products compared with gasoline further decreases combustion temperature, thereby reducing cooling heat loss.
Technical Paper

Effects of RME30 on Exhaust Emissions and Combustion in a Diesel Engine

2008-10-06
2008-01-2499
Considering the popularity of biodiesel fuels for diesel vehicles, the impacts of rapeseed oil methyl ester (RME), which is the most utilized biodiesel fuel in Europe, on tailpipe emissions from a diesel passenger car was investigated. In this study, 30% RME blended diesel fuel (RME30) was used and the comparison of tailpipe emissions between RME30 and a reference diesel fuel was conducted using a test vehicle with the latest engine and aftertreatment system. The results of the investigation reveal that RME30 generates about the same amount of NOx in tailpipe emissions as diesel fuel, and less HC, CO, and PM. These phenomena occurred in spite of attaching catalysts to the test vehicle, and therefore suggesting that the NOx conversion efficiency of the catalysts for RME30 is equal to that for diesel fuel. The injection rate for RME30 was the same as that for diesel fuel.
Technical Paper

Hardfaced Valve and P/M Valve Seat System for CNG and LPG Fuel Engines

2005-04-11
2005-01-0718
When adapted for use in automotive engines, CNG and LPG are considered environmentally friendly compared to gasoline or diesel fuel. However, when these gaseous fuels are used, wear of the valve seat insert and valve face increases if materials meant for use with gasoline are adopted. In comparison to a gasoline engine, the oxide membrane that is formed on the sliding surfaces of the valve face and valve seat insert is limited. As a consequence, adhesion occurs and increased wear of these components is the result. Based on analysis materials that are more compatible with these gaseous fuels were developed.
Technical Paper

Oxidation Stability of Diesel/Biodiesel Blends: Impact of Fuels Physical-Chemical Properties over Ageing During Storage and Accelerated Oxidation

2015-09-01
2015-01-1930
Current and future engine technologies and fuels are mutually dependent. The increased use of alternative fuels has been linked to deterioration in performance of injectors, fuel filters and engines as a result of insoluble deposit formation. The present work aimed to study the impact of Diesel/biodiesel blends formulation (biodiesel feedstock and content) and temperature on the oxidation stability based on total acid number (TAN). The biofuels used in the fuel matrix were: rapeseed, soy and palm methyl esters (RME, SME and PME respectively). The Diesel/biodiesel blends were made with 0%v/v, 5%v/v, 10% v/v and 20%v/v of biodiesel blended with additive-free new Diesel. The oxidation stability of Diesel/biodiesel blends was to evaluate during 6 months fuels storage, under 20°C and 40°C, and fuels severe oxidation into a reactor vessel to better understand the parameters leading to fuel oxidation on-board.
Technical Paper

Effects of GTL Fuel Properties on DI Diesel Combustion

2005-10-24
2005-01-3763
Reduction of vehicle exhaust emissions is an important contributor to improved air quality. At the same time demand is growing for new transportation fuels that can enhance security and diversity of energy supply. Gas to Liquids (GTL) Fuel has generated much interest from governments and automotive manufacturers. It is a liquid fuel derived from natural gas, and its properties - sulphur free, low polyaromatics and high cetane number - make it desirable for future clean light-duty diesel engines. In this paper, the effects of distillation characteristics and cetane number of experimental GTL test fuels on direct injection (DI) diesel combustion and exhaust emissions were investigated, together with their spray behaviour and mixing characteristics. The test results show that the lower distillation test fuels produce the largest reductions in smoke and PM emissions even at high cetane numbers. This is linked to the enhanced air/fuel mixing of the lighter fuel in a shorter time.
Technical Paper

A Novel 1D Co-Simulation Framework for the Prediction of Tailpipe Emissions under Different IC Engine Operating Conditions

2019-09-09
2019-24-0147
The accurate prediction of pollutant emissions generated by IC engines is a key aspect to guarantee the respect of the emission regulation legislation. This paper describes the approach followed by the authors to achieve a strict numerical coupling of two different 1D modeling tools in a co-simulation environment, aiming at a reliable calculation of engine-out and tailpipe emissions. The main idea is to allow an accurate 1D simulation of the unsteady flows and wave motion inside the intake and exhaust systems, without resorting to an over-simplified geometrical discretization, and to rely on advanced thermodynamic combustion models and kinetic sub-models for the calculation of cylinder-out emissions. A specific fluid dynamic approach is then used to track the chemical composition along the exhaust duct-system, in order to evaluate the conversion efficiency of after-treatment devices, such as TWC, GPF, DPF, DOC, SCR and so on.
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