Refine Your Search



Search Results

Technical Paper

Impact of Ambient Temperatures on VOC Emissions and OFP during Cold Start for SI Car Real World Urban Driving

New EU environmental law requires 31 ozone precursor VOCs (Volatile Organic Compounds) to be measured for urban air quality control. In this study, 23 out of the 31 ozone precursor VOCs were measured at a rate of 0.5 HZ by an in-vehicle FTIR (Fourier Transform InfraRed) emission measurement system along with 15 other VOCs. The vehicle used was a EURO2 emission compliant SI car. The test vehicle was driven under real world urban driving conditions on the same route by the same driver on different days at different ambient temperatures. All the journeys were started from cold. The VOC emissions and OFP (Ozone Formation Potential) as a function of engine warm up and ambient temperatures during cold start were investigated. The exhaust temperatures were measured along with the exhaust emissions. The temperature and duration of light off of the catalyst for VOCs was monitored.
Technical Paper

Comparison of Real World Emissions in Urban Driving for Euro 1-4 Vehicles Using a PEMS

An on-board emission measurement system (PEMS), the Horiba OBS 1300, was installed in Euro 1-4 SI cars of the same model to investigate the impact of vehicle technology on exhaust emissions, under urban driving conditions with a fully warmed-up catalyst. A typical urban driving loop cycle was used with no traffic loading so that driver behavior without the influence of other traffic could be investigated. The results showed that under real world driving conditions the NOx emissions exceeded the legislated values and only at cruise was the NOx emissions below the legislated value. The higher NOx emissions during real-world driving have implications for higher urban Ozone formation. With the exception of the old EURO1 vehicle, HC and CO emissions were under control for all the vehicles, as these are dominated by cold start issues, which were not included in this investigation.
Technical Paper

Comparison of Exhaust Emissions and Particulate Size Distribution for Diesel, Biodiesel and Cooking Oil from a Heavy Duty DI Diesel Engine

Rape oil, as used in fresh cooking oil (FCO), and the methyl ester derived from waste cooking oil (WCOB100) were tested as 100% biofuels (B100) on a heavy duty DI diesel engine under steady state conditions. The exhaust emissions were measured and compared to those for conventional low sulphur (<50ppm) diesel fuel. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Euro2 Phaser Engine, fitted with an oxidation catalyst. The engine out gaseous emissions results for WCOB100 showed a large decrease in CO and HC emissions, but a small increase in NOx emissions compared to diesel. However, for FCO the CO and HC increased relative to WCOB100 and CO was higher than for diesel, indicating deterioration in fuel/air mixing. The particulate matter (PM) emissions for WCOB100 were similar to those for diesel at the 23kw condition, but greatly reduced at 47kw. The FCO produced higher engine out PM at both power conditions due to a higher volatile organic fraction (VOF).
Journal Article

Temperature Programmed Oxidation as a Technique for Understanding Diesel Fuel System Deposits

The fuel injection equipment (FIE) has always been paramount to the performance of the Diesel engine. Increasingly stringent emissions regulations have dictated that the FIE becomes more precise and sophisticated. The latest generation FIE is therefore less tolerant to deposit formation than its less finely engineered predecessors. However, the latest emissions regulations make it increasingly difficult for engine manufacturers to comply without the use of exhaust aftertreatment. This aftertreatment often relies on catalytic processes that can be impaired by non-CHON (carbon, hydrogen, oxygen and nitrogen) components within the fuel. Fuel producers have therefore also been obliged to make major changes to try and ensure that with the latest technology engines and aftertreatment systems the fuel is still fit for purpose. However, there has recently been a significant increase in the incidence of reported problems due to deposit build-up within vehicle fuel systems.
Technical Paper

The Influence of Lubricating Oil Age on Oil Quality and Emissions from IDI Passenger Car Diesels

Two Ford IDI passenger car diesel engines, 1.6 and 1.8 litres, were tested over a 100 hour lube oil ageing period with engine out emission samples every 15 hours. The 1.6 litre engine was tested with 5% EGR and the 1.8 litre engine with 15% EGR. Comparison was also made with previous work using an older Petter AA1 engine. The three engines had different dependencies of particulate emissions on the lube oil age. The 1.6 litre engine increased the particulates from 1 to 2.5 g/kg of fuel, whereas the 1.8 litre engine first decreased the particulate emissions from 3 to 1 g/kg over 50 hours of oil age and then they increased to 2 g/kg at 100 hours. This was similar to the previous work on the Petter AA1 engine, where the emissions first decreased and then increased as the oil aged. For the 1.8 litre engine the lube oil fraction of the VOF was high with fresh oil and decreased with time for the first 50 hours and then remained steady.
Technical Paper

The Composition of Spark Ignition Engine Steady State Particulate Emissions

The contribution of spark ignition engine particulate emissions to total particulate emissions and the published data on SI engine emission levels are reviewed. There is a wide spread of published data and the worst SI engines would exceed the future diesel particulate emissions regulations. However, most modern SI engines with a catalyst will easily meet the future diesel particulate emissions regulations, although their particulates emissions are a significant fraction of these regulations. Steady state lambda 1 results are presented for a Ford Zetec SI engine at conditions representative of the urban driving cycle at 5 and 10kW power output and also at WOT. The impact of a cold start and EGR at the two low power conditions was also investigated. The particulate emissions for petrol were of the order of 5% of the future (2005) diesel emissions regulations and were approximately 20 mg/kg fuel (about 2 mg/mile or 1.3 mg/km).
Technical Paper

The Role of Lubricating Oil in Diesel Particulate and Particulate PAH Emissions

The role of lubricating oil in total particulate emmissions and in terms of polycyclic aromatic compounds (PAC) associated with the solvent organic fraction (SOF) of the particulate are investigated. Analysis of unused lubricating oil shows negligible concentrations of PAC. Used lubricating oil from a modified Perkins 4.236 Diesel engine, showed significant concentrations of PAC had accumulated in the oil in the form of PAC from unburnt fuel. Analysis of the oil was by gas chromatography using simultaneous parallel triple detection, allowing analysis of polycyclic aromatic hydrocarbons (PAH), nitrogen containing PAH (PANH) and sulphur containing PAH (PASH). Motoring the engine in the absence of fuel enabled the contribution of lubricating oil to the exhaust particulate and particulate PAC emission to be determined.
Technical Paper

The Aging of Lubricating Oil, The Influence of Unburnt Fuel and Particulate SOF Contamination

The role of lubricating oil as a sink for polycyclic aromatic compounds (PAC) and alkanes derived from unburnt fuel is described for two different oils used in two different DI diesel engines. The diesel engines used were, an older technology Petter AV1 single cylinder mine pumping engine and a Perkins 4.236 current technology engine. Analysis of the oil was by gas chromatography using simultaneous parallel triple detection, allowing analysis of hydrocarbons and nitrogen and sulphur containing compounds. Analysis of unused lubricating oil showed negligible concentrations of PAC and low molecular weight alkanes (< C20). The oil from each engine was analysed periodically during use and showed a rapid and significant accumulation of hydrocarbons which reached significant concentrations after only 10 hours use. The older technology engine showed a much higher accumulation rate.
Technical Paper

Practical Experience of Fitting DPFs to Buses in Chile

Continuing research into the effect of vehicle emissions is driving legislation, which is increasingly being enacted to encourage the retrofitting of emissions control devices. Of particular concern are emissions of diesel particulate matter and nitrogen oxides. More recently the adverse effects of nitrogen dioxide in particular, have been highlighted. A programme of work is underway in Santiago to demonstrate the suitability of retrofitting diesel particulate filters (DPF) to urban buses. This paper presents data, including regulated and unregulated emissions, from a bus fitted with a DPF that relies on a fuel borne catalyst (FBC) to facilitate regeneration of the DPF.
Technical Paper

The Emerging Market for Biodiesel and the Role of Fuel Additives

With growing concern over greenhouse gases there is increasing emphasis on reducing CO2 emissions. Despite engine efficiency improvements plus increased dieselisation of the fleet, increasing vehicle numbers results in increasing CO2 emissions. To reverse this trend the fuel source must be changed to renewable fuels which are CO2 neutral. A common route towards this goal is to substitute diesel fuel with esterified seed oils, collectively known as Fatty Acid Methyl Esters. However a fundamental change to the fuel chemistry produces new challenges in ensuring compatibility between fuel and engine performance/durability. This paper discusses the global situation and shows how fuel additives can overcome the challenges presented by the use of biodiesel.
Technical Paper

Condensable and Gaseous Hydrocarbon Emissions and Their Speciation for a Real World SI Car Test

Condensable and gaseous hydrocarbon emissions and speciation of the hydrocarbons have been investigated using a EURO1 emissions compliant SI (Spark Ignition) car. Exhaust gas samples were simultaneously collected upstream and downstream of the catalyst using a system containing cold ice trap, resin, particulate filter block and Teflon gas sampling bag. GC (Gas Chromatography) was employed to analyze for hydrocarbons and 16 of the more significant hydrocarbons are reported. The test was carried out using both cold start and hot start driving cycles. Results show that the benzene and toluene were major species emitted from the tailpipe under cold start conditions. Methylnaphthalene was a dominated hydrocarbon under hot start conditions. The cold start had significant influence on hydrocarbon emissions. The catalyst out benzene emissions for cold start was thirty times higher than that for hot start.
Technical Paper

Study of the Emissions Generated at Intersections for a SI Car under Real World Urban Driving Conditions

A precision in-vehicle tail-pipe emission measurement system was installed in a EURO1 emissions compliant SI car and used to investigate the variability in tail-pipe emission generation at an urban traffic junction. Exhaust gas and skin temperatures were also measured along the exhaust pipe of the instrumented vehicle, so the thermal characteristics and the efficiency of the catalyst monitored could be included in the analysis. Different turning movements (driving patterns) at the priority T-junction were investigated such as straight, left and right turns with and without stops. The test car was hot stable running conditions before each test, thereby negating cold start effects. To demonstrate the influence of the junction on tail-pipe emissions and fuel consumption, distance based factors were determined that compared the intersection drive-through measurements with steady speed (state) runs. Fuel consumption was increased at intersections by a factor of 1.3∼5.9.
Technical Paper

Metal Emissions, NO2 and HC Reduction from a Base Metal Catalysed DPF/FBC System

Due to concerns over NO2 emissions from platinum catalysts a base metal catalysed diesel particulate filter (DPF) has been developed and used in combination with fuel borne catalysts (FBC). Results are presented showing reductions in HC, NOX, NO2, and PAH emissions along with an assessment of the emissions of metals used in the FBC and the catalysed DPF. This data is used to show the likely reduction in overall iron and other metal emissions as a result of using the catalysed DPF/FBC system. A similar system has also been assessed for durability for over 2000 hours when fitted to a bus in regular service in Switzerland.
Technical Paper

Study of Emission and Combustion Characteristics of RME B100 Biodiesel from a Heavy Duty DI Diesel Engine

A rapeseed methyl ester biodiesel RMEB100 was tested on a heavy duty DI diesel engine under steady state conditions. The combustion performance and exhaust emissions were measured and compared to a standard petroleum derived diesel fuel. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Phaser Engine, with emission compliance of EURO 2, fitted with an oxidation catalyst. The exhaust samples were taken both upstream and downstream of the catalyst. Particulates were collected and analysed for VOF, carbon and ash. A MEXA7100 gas analysis system was used for legislated gas analysis such as CO, CO2, NOx and total hydrocarbons. A FTIR analysis system was deployed for gaseous hydrocarbon speciation, which is capable of speciating up to 65 species. The results showed a significant reduction in total particulate mass, particulate VOF, CO, THC and aldehydes when using RMEB100.
Technical Paper

Investigation of Aldehyde and VOC Emissions during Cold Start and Hot Engine Operations using 100% Biofuels for a DI Engine

Aldehydes and other Volatile Organic compounds (VOC) are assessed under cold start and steady state conditions using a Perkins Phaser 6 litre diesel engine. A comparison is made between petroleum diesel fuel (PD), 100% biodiesel (WME) and 100% rapeseed oil (RSO). A Temet FTIR was used to determine aldehydes including formaldehyde, acetaldehyde and acrolein. The diesel engine was cold started at room temperature using a step start up procedure that kept the power output constant at two steady state conditions: 23kW and 47kW. Very little difference was observed between petroleum diesel and biodiesel aldehyde emissions at either steady state conditions or during cold start. There was, however, an increase in aldehydes at steady state for rapeseed oil, particularly at low load, but only for from ∼10ppm to 25 ppm for formaldehyde (i.e. 0.12g/kWh to 0.37g/kWh). During cold start conditions, the emissions were significantly higher for rapeseed oil than for petroleum diesel.
Technical Paper

The Use of a Water/Lube Oil Heat Exchanger and Enhanced Cooling Water Heating to Increase Water and Lube Oil Heating Rates in Passenger Cars for Reduced Fuel Consumption and CO2 Emissions During Cold Start.

Lubricating oil takes all of the NEDC test cycle time to reach 90°C. Hence, this gives high friction losses throughout the test cycle, which leads to a significant increase in the fuel consumption. In real world driving, particularly in congested traffic, it is shown that lube oil warm-up is even slower than in the NEDC. Euro 1, 2 and 4 Ford Mondeo water and oil warm up rates in real world urban driving were determined and shown to be comparable with the results of Kunze et al. (2) for a BMW on the NEDC. This paper explores the use of forced convective heat exchange between the cooling water and the lube oil during the warm-up period. A technique of a step warm-up of the engine at 32 Nm at 2000 rpm (35% of peak power) was used and the engine lube oil and water temperature monitored. It was shown that the heat exchanger results in an increase in lube oil temperature by 4°C, which increased to 10°C if enhanced heat transfer to the water was used from an exhaust port heat exchanger.
Technical Paper

Reduction of Exhaust Emissions by a Synthetic Lubricating Oil with Higher Viscosity Grade and Optimized Additive Package for a Heavy Duty DI Diesel Engine Test

A 10W-50 G4 synthetic lubricating oil (EULUBE oil) was tested on a heavy duty DI diesel engine under two steady state conditions. The exhaust emissions were measured and compared to a 10W-30 CF semi-synthetic lubricating oil. The EULUBE oil contained the friction reduction additive to improve the fuel economy. The engine used was a 6 cylinder, turbocharged, intercooled Perkins Phaser Engine, with emission compliance of EURO 2, fitted with an oxidation catalyst. The exhaust samples were taken both upstream and downstream of the catalyst. Gaseous and particulates emissions were measured. Particulate size distribution was measured using ELPI and SMPS. The particulate samples were analysed for VOF, carbon and ash. A MEXA7100 gas analysis system was used for legislated gas analysis such as CO, CO2, NOx and total hydrocarbons. The results showed a significant reduction by synthetic lubricating oil in gaseous hydrocarbon emissions, total particulate mass, particulate carbon and ash.
Technical Paper

Chassis Dynamometer Evaluation of On-board Exhaust Emission Measurement System Performance in SI Car under Transient Operating Conditions

A commercial on-board exhaust emissions measurement system, the Horiba OBS-1300, was evaluated in a series of chassis dynamometer test trails. A EURO 1 (petrol) SI passenger car, operated under normal and rich combustion conditions, and a combination of static and transient sampling provided a wide range of measurement conditions for the evaluation exercise. The chassis dynamometer facility incorporated an ‘industry standard’ measurement system comprising MEXA-7400 gas analyzer and CVS bag sampling system which were used as ‘benchmarks’ for the evaluation of both OBS-1300 component (exhaust flow meter and species analyzer) measurements and ‘daughter’ emission measurements for regulated gas-phase species (CO, CO2, HC and NOx). Trials demonstrated very good to reasonable agreement for exhaust flow and CO, CO2 and HC concentration measurements during static (R2 ≈ 0.97, 0.99, 0.99 and 0.97, respectively) and transient (R2 ≈ 0.88, 0.96, 0.95 and 0.86, respectively) testing.
Technical Paper

The Effect of DI Nozzle Fouling on Fuel Spray Characteristics

The atomisation characteristics of DI diesel engine fuel injection nozzles have been the subject of intensive study over the last decade. Much of this work has been related to clean, single hole nozzles spraying into quiescent air, at either ambient conditions or elevated pressures and temperatures. Experience shows that fuel injector nozzles may foul very rapidly in field service, and that this might have a significant effect on the performance of the engine particularly with regard to emissions. The build up of material on the injector nozzle can be controlled by the addition of suitable fuel additives. This paper describes test procedures developed to assess deposit build up and to indicate the efficacy of keep clean additives. The paper then goes on to describe high speed photographic techniques for studying the fuel spray characteristics of clean and fouled injectors in a firing engine.
Technical Paper

The influence of PAH contamination of Lubricating Oil on Diesel Particulate PAH Emissions

The influence of contamination of lubricating oil on the emissions of total particulate, particulate polycyclic aromatic hydrocarbons (PAH) and unburnt fuel and gaseous emissions have been investigated for a modified Perkins 4.236 D.I. diesel engine. The emissions during fuel firing and motoring in the absence of fuel are compared. The results showed that the exhaust particulate during both firing and motoring were not affected by lubricating oil contamination. Emission of PAH during fuel firing and motoring increase with oil contamination which in turn reflects the build up of PAH with oil age. Some of the particulate PAH are biologically active. The contribution of oil derived PAH increase with age. Comparison of the gaseous emissions during fuel firing and during motoring also showed an increase in UHC with age of lubricating oil.