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Technical Paper

Analysis of car structures in future market and necessary policy for environment based on the vehicle performance and economic aspects

2000-06-12
2000-05-0382
Increasing CO2 emissions from vehicles is becoming a major concern in automotive society, and variety of future types of cars are intensively investigated. However it is not clear which level of performance and cost must be achieved for the future cars to be available in a market and how much percentage of cars is necessary to be replaced by the future cars for the conservation of environment. The objective of this paper is to evaluate the possibility of market growth of future cars, as hybrid cars, electric vehicles and fuel cell cars, based on the performance and economic aspects. This paper investigates the emission reduction potential of these vehicles, and also compares the composition of vehicle types and emissions for a variety of scenarios of consumer characteristics, economic growth, fuel price, performance of cars, and carbon tax control measures. A model of user preference of cars was established from the statistic analysis of past data.
Technical Paper

Global mobility on roads in the 21st century

2000-06-12
2000-05-0383
In future, there will be increasing demand for mobility and transportation especially in the newly industrialized countries where about half of the world''s population lives. This will enormously increase the number of vehicles in operation. The fact of such development taking place in the economically poorest countries of the world is alarming because these will not be able to apply strict emission and safety legislation as is practiced in the highly industrialized nations. Renewable energy must be developed and used to reduce exhaust emission even though fossil fuels will be available for decades in the future. Besides further reduction of required energy and increase of efficiency, intelligent traffic management systems will play a major role in tackling the challenges put by our demands for individual mobility.
Technical Paper

Exhaust emission control on Nissan engine Z24

2000-06-12
2000-05-0361
Automotive emissions are the most important sources for air pollution in the city of Tehran. In order to control and reduce air pollution in this city, it is important to reduce vehicular exhaust emission. Patrol and pick-ups with Japanese originality have assembly line in Iran. These vehicles which are more or less popular in Tehran, originally have old design and not able to fulfill any new emission regulations. In this paper, Nissan engine Z24, combustion chamber has been modified, the orifice and main metering system in carburetor has been changed fundamentally and unleaded gasoline has been introduced to the engine. Reasonable reduction in exhaust emission has been measured on dynamometer under different loads and speeds. The new findings have been recommended to local manufacturer for mass production. The new Iranian Nissan patrol and pick-up will fulfill the moderate regulation mainly ECE 15-04.
Technical Paper

Study on Intelligent Idling Stop System

2000-06-12
2000-05-0365
The “idling stop” of the vehicle, which is defined as no rotation of the engine when it stops, theoretically brings to reduce the fuel consumption (i.e. carbon dioxide) and the exhaust emissions. However, the idling stop practically has weak points as follows: 1. When the engine is restarted, much fuel is consumed. 2. When the engine is restarted, much the exhaust emissions are discharged. 3. While various electric devices work, the load of the battery is high. 4. The deterioration of the lubricating oil proceeds due to repeating start and stop. In order to overcome the above weak points the authors propose the new system called IISS.
Technical Paper

High Dynamic Range Operation Modes of Analyzers in R&D Applications

2000-06-12
2000-05-0349
Increasing requirements for the result quality of exhaust emission analyzers and state of the art analyzer technology require a new point of view regarding measuring range definitions and linearization procedures. To make best use of the power of this analyzer technology, linearizaton procedures need reconsideration. Although for certification the linearization procedures to be applied on an emission analyzer are define clearly, for research and development applications, no prescriptions are existing. Therefore non sophisticated routines, that assist the full potential of new analyzers may be employed.
Technical Paper

Design impacts on CVS systems meeting future requirements for equivalent zero emissions vehicles

2000-06-12
2000-05-0347
The latest legislation requires a dramatic reduction of motor vehicle exhaust emission. This is also a big challenge for emission measurement instrumentation, because of almost zero concentrations of certain components in the exhaust. For current measurement devices, which are recommended by the legislation, it is almost impossible to determine such low emission levels with adequate accuracy. The paper describes a new Constant Volume Sampling (CVS) system with reduced dilution, warming and quick flow rate changing capability. Possible solutions are discussed and the properties of data measured with test facilities which are prepared to cover S-ULEV and EURO IV applications are described. Also the selection of used materials is of rising importance. The tests were performed on a dynamic engine test bed which was equipped with such a CVS system and with emission analyzing systems for raw exhaust and diluted measurements.
Technical Paper

The development of warm-up control strategies for a methanol reformer fuel cell vehicle

2000-06-12
2000-05-0330
A fuel-cell-powered vehicle requires a plentiful supply of hydrogen to achieve good performance. This can be produced from methanol via an on-board reformer and gas clean-up unit. Since the reformer can take several minutes to reach its operating temperature, it is initially necessary to provide an alternative power source, such as a battery or ultra-capacitor, in order to drive the vehicle. This paper describes the use of a fuel cell vehicle simulation to predict behavior over a drive cycle from a cold start and to evaluate different warm-up control strategies in terms of performance and fuel efficiency.
Technical Paper

Characteristics of High-Pressure Spray and Exhaust Emissions in a Single- Cylinder Di Diesel Engine

2000-06-12
2000-05-0333
Regulations on exhaust emissions from light- and heavy-duty diesel engines have generated interest in high-pressure fuel injection systems. It has been recognized that high-pressure injection systems produce fuel sprays that may be more conductive to reducing exhaust emissions in direct-injection diesel engines. However, for such a system to be effective it must be matched carefully with the engine design and its operating parameters. A common-rail type of fuel injection system was investigated in the present study. The injection system utilizes an intensifier to generate injection pressures as high as 160 MPa. The fuel spray characteristics were evaluated on a test bench in a chamber containing pressurized nitrogen gas. The injection system was then incorporated in a single-cylinder diesel engine. The injection system parameters were adjusted to match engine specifications and its operating parameters.
Technical Paper

A study on the distribution of soot in cylinder of an optically accessible diesel engine using laser sheet

2000-06-12
2000-05-0334
In order to clarify the characteristics of soot formation and oxidation in cylinder of diesel engine, it is necessary to diagnose accurately for combustion of in-cylinder. The past techniques for soot measurement have limitations in providing the characteristics of soot in a diesel engine, whereas, laser-based 2D imaging diagnostics have the potential to provide better temporally and spatially resolved measurements of the soot distribution. The technique using laser sheet beam has been applied to an optically accessible diesel engine for the quantitative measurement of soot. The results provide the information for reduction of soot from diesel engine. We used both LIS and LII techniques simultaneously in this study. The images of LIS and LII show the quantitative distribution of the soot concentration in an optically accessible diesel engine. In this study, several results were obtained by the simultaneous measurement of LIS and LII techniques.
Technical Paper

Experimental Study on Diesel Nitrogen Oxide Reduction By Exhaust Gas Recirculation

2000-06-12
2000-05-0335
This paper concerns mainly with the research work of diesel nitrogen oxide reduction by Exhaust Gas Recirculation (EGR). Using exhaust gas cleaned by a high efficiency bag filter as EGR gas, a 1110 DI diesel engine test bed was set up, and tests were made to investigate the EGR effects on engine performances, including engine emissions and fuel economy. The results showed that the EGR could be used as an effective way to reduce diesel nitrogen oxides with very little economy penalty. When the engine works at low or moderate loads, 25 to 40 percent of the EGR rate is good for better trade-off of engine economy and emissions. The nitrogen oxide reduction efficiency can be as high as 50% to 60% based on emission concentrations, and can be even higher based on total exhaust gas emissions of nitrogen oxides. Larger EGR rate can attain higher nitrogen oxide reduction efficiency, but the engine economy, HC and CO emissions will worsen.
Technical Paper

Exhaust noise design based on psycho-acoustic parameters

2000-06-12
2000-05-0312
People make judgements of the sound produced by vehicles in a variety of situations and contexts. The most common type of assessment is an overall judgement of sound quality like pleasantness and sportiveness. From the car manufacturer''s point of view it is important to note that subjective judgements of sound influence the buyer''s opinion of the performance and value of the vehicle. Consequently, there is a need to quantify the subjective perception of the sound quality associated with a vehicle. This paper presents a study of the sound quality of vehicle exhaust noise based on the correlation between the subjective perception associated with this type of sound and measured psycho-acoustic parameters such as loudness, sharpness and roughness. The tailpipe noise of a selection of representative vehicles was recorded using an artificial head. A subjective evaluation of these sound recordings was made by a jury using standard relative techniques.
Technical Paper

Continuous measurement of soot and soluble organic fraction emission from advanced powertrain

2000-06-12
2000-05-0314
Particulate matter (PM) emission from vehicles is one of the biggest issues in terms of environmental protection and influence to human body. Thus, a variety of measurement technologies have been develop so far. Currently, a gravimetric method is most commonly used in the automotive industry, partially because it is specified in the regulations. This method uses a combination of a dilution tunnel and a filter that collects the PM from the diluted sample gas with subsequent weighting by a micro balance. However, since this technique is a batch measurement, it is impossible to determine at what point of the emissions test the Soot, SOF (Soluble Organic Fraction), and the total PM are emitted. Thus the demand for real-time PM measurement under transient test conditions has increased.
Technical Paper

EXHAUST EMISSION FROM DIESEL ENGINE DURING COLD START IN AMBIENT TEMPERATURE CONDITIONS

2000-06-12
2000-05-0316
This paper reviews the exhaust emissions from direct injection diesel engines in the initial period following startup. The tests were undertake in “cold start” mode (temperature of cooling water and lube oil equal ambient temperature) and “warm start” modes (after getting equilibrium state). Both results were compared. Exhaust emissions in the period of run from cold start to warmed-up is very important to satisfy present day standards worldwide.
Technical Paper

Three-way catalysts for partial lean-burn engine vehicle

2000-06-12
2000-05-0322
Emission of carbon dioxide from mobile sources seriously concerned to solve greenhouse effect and high price of gasoline in some countries have resulted in the development of lean-burn concept engine. In spite of many studies on the lean deNOx catalyst, we have no clear solution to obtain high fuel economy and high efficiency of NOx conversion in lean-burn application. This paper describes applicability and problems of NOx adsorber system to partial lean-burn vehicle, the development of three-way catalyst with improvement of washcoat technology based on three-way catalyst used for gasoline application, and comparison test results of evaluations is synthesized gas activity test, Federal Test Procedure (FTP) test, etc. This study shows improved three-way catalysts in partial lean- burn vehicle have max. 89% of NOx conversion in FTP without adding rich spike and regeneration functions to engine management system.
Technical Paper

The effect of engine misfire on catalytic converter and vehicle emissions

2000-06-12
2000-05-0325
A conventional automotive emission control system depends on the measurements provided by various sensors to control the air-fuel (A/F) ratio. Maintaining the A/F ratio close to stoichiometry permits catalytic converter to operate in an optimized efficiency, which reduces the exhaust emission. Malfunction resulted from engine misfire makes catalyst''s converting efficiency drop. Such a condition results in increased emissions as well as in damage to catalytic converters. So current researches are proceeded in response to the California OBD II (On-Board Diagnostics) and EOBD that will be adopted in Europe requirements for engine misfire detection in passenger vehicles. In this study, two methods to diagnose the misfire an approached: catalytic converter''s temperature measurement over the threshold exposure temperature to examine the catalyst''s damage, and the vehicle emission test over FTP-75 cycle by varying misfire rates.
Technical Paper

Scavenger free three-way catalyst with low hydrogen sulfide emission

2000-06-12
2000-05-0308
This study suggests new types of catalysts that show low hydrogen sulfide emission without scavenger such as NiO. Hydrogen sulfide can be reduced by changing the physicochemical properties of washcoat components. Synthesized gas activity tests were performed to investigate the effect of modified washcoat on hydrogen sulfide formation and catalytic activity. BET surface area tests, X- ray diffraction tests, and gas chromatography tests were also carried out to examine the characteristics of catalysts. Preparation methods for catalysts were focused on minimizing the adsorption of sulfur species on catalysts. The first approach is heat treatment of cerium oxide to reduce adsorption sites for sulfur compounds. But this leads to deterioration of CO and NOx conversion efficiencies. The second one is adding new types of promoters that increase thermal durability and dynamic oxygen storing function of cerium oxide.
Technical Paper

New ways of fluid flow control in automobiles: Experience with exhaust gas aftertreatmetn control

2000-06-12
2000-05-0299
Flow control by fluidic devices - without moving parts - offers advantages of reliability and low cost. As an example of their automobile application based on authors'' long-time experience the paper describes a fluidic valve for switching exhaust gas flow in a NOx absorber into a by-pass during regeneration phase. The unique feature here is the fluidic valve being of monostable and of axisymmetric design, integrated into the absorber body. After development in aerodynamic laboratory, the final design was tested on engine test stand and finally in a car. This proved that the performance under high temperature and pulsation existing in exhaust systems is reliable and promising. Fluidic valves require, however, close matching with aerodynamic load. To optimize the exhaust system layout for the whole load-speed range and reaching minimum counter- pressure, both the components of exhaust system and control strategy have to be properly adopted.
Technical Paper

Exhaust emissions from medium- and high-mileage in-service cars with three- way catalytic emissions control system driven under Nordic driving conditions

2000-06-12
2000-05-0295
Exhasut emissions were determined from a fleet of some 50 cars that have been in normal private ownership service in Finnish driving conditions. These represent typical Nordic climate with strongly varying ambient temperatures between summer and winter months. All cars were petrol-fuelled, and had an up-to-date emissions control system based on a three-way catalytic converter. Tested vehicles represented model years 1990 to 1996. They had odometer ratings at the time of testing ranging from a low of 10,000 km up to a high of 373,000 km. The emissions performance was assessed using U.S. FTP75 urban during schedule. Testing was carried out at normal ambient temperatures (+22...23° ...). The paper reports an assessment of typical emissions performance as a function of distance driven encountered from normal TWC cars that have been in day-to-day use under sometimes quite rigorous driving conditions.
Technical Paper

Research of Employing an Electrostatic Centrifugal Precipitator to Collect Diesel Particulate

2000-06-12
2000-05-0289
An electrostatic centrifugal precipitator (ESCP) has been developed to trap diesel particulate. In the ESCP, particulate is charged by a corona field, and moves to the surface of the collecting plate due to electrical force. Particulate deposited on the collecting plate is removed to a hopper by the shear force of exhaust gas. Test results show that the ESCP has high trap efficiency with very low pressure drop, and the efficiency varies with the inlet exhaust gas velocity and temperature. The highest temperature under which the ESCP can perform normally is limited by the high temperature electrical properties of the gas. Compared with a wall-flow type diesel particulate filter, the ESCP has many advantages such as very low pressure drop, low cost and no regeneration.
Technical Paper

Ways to meet future emission standards for heavy Sports Utility Vehicles - SUV

2000-06-12
2000-05-0288
Diesel engines belong to the most efficient power sources for any kind of on-road vehicle, but especially in Europe increasingly for passenger cars. However, more stringent exhaust emission regulations, which will come into force world-wide in industrialised countries during the first decade of the next century will require NOx and particulate emissions to be reduced by up to 60% and more from today's levels. To meet these future emission standards particularly for heavier passenger vehicles, such as SUVs, Pickup Trucks and Light Commercial Vehicles, as well as for heavy luxury class passenger cars, the application of new technologies including advanced exhaust gas aftertreatment systems will be indispensable, especially in view of maintaining the thermal efficiency of diesel engines relative to gasoline engines.
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