Search Results

Exhaust emissions were measured under real world urban driving conditions using a set of in-vehicle FTIR emission measurement system, which is able to measure 65 emission components simultaneously at a rate of 0.5 Hz. The test vehicle was a modern EURO4 emission compliant SI car equipped with temperature measurement along the exhaust pipe across the catalyst so as to match thermal characteristics to emission profiles. A free flow urban driving cycle was used for the test and four repeated journeys were conducted. The results were compared to EU emissions legislation. The results show that the warm up of the lubricating oil needed 15 minutes. The TWC needed about 200 seconds to reach full conversion efficiency. CO, THC and NOx emissions exceeded the EURO4 exhaust emission legislation. CO2 emissions were well above the type approval value of this vehicle.

A FTIR in-vehicle on-road emission measurement system was installed in a EURO 2 emissions compliant SI car to investigate exhaust emissions under different urban traffic conditions. The real time fuel consumption and vehicle traveling speed was measured and logged. The temperatures were measured along the exhaust pipe so as to monitor the thermal characteristics and efficiency of the catalyst. Two real world driving cycles were developed with different traffic conditions. One (WP cycle) was located in a quiet area with few traffic interference and the other one (HPL cycle) was in a busy area with more traffic variations. The test car was pre-warmed before each test to eliminate cold start effect. The driving parameters were analyzed for two real world cycles. The WP cycle had higher acceleration rate, longer acceleration mode and shorter steady speed driving mode and thus harsher than the HPL cycle.

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.

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.

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.

Regulated and non-regulated tailpipe exhaust emissions were measured under real world urban driving conditions using a set of in-vehicle FTIR emission measurement system, which is able to measure 65 emission components simultaneously at a rate of 0.5 Hz. A EURO3 emission compliant SI car was used as a probe vehicle. An urban driving cycle was used for the test and four repeated journeys were conducted. The results were compared to EU emissions legislation. The results show that the TWC needed approximately 200 seconds to reach full conversion efficiency. THC and NOx emissions exceeded the EURO 3 exhaust emission legislation. CO2 emissions were well above the type approval value of this type of the vehicle. Greenhouse gases (methane and nitrous oxide) and toxic hydrocarbons such as benzene were predominantly emitted during cold start period from 0 to 200 seconds of the engine start. The results had a reasonable repeatability for most of the emissions.

A Euro 2 SI (Spark Ignition) Mondeo was investigated for a fully warmed-up vehicle on a simple urban driving loop. Emissions were monitored using an on-board Horiba OBS (On-Board emission measurement System) 1300. 10 laps of a 0.6 km loop were driven by each driver and this involved 4 junctions per lap. Statistical analysis of 20 drivers was made over 27 repeat junction events for each driver. The statistical analysis of the data showed that for all drivers the CO₂, speed and throttle position were more typical Gaussian in their distribution. NOx and CO on the other hand were lognormal in their distribution. Acceleration, positive and negative throttle jerks (rate of change of throttle angle) were borderline Gaussian. HC (Hydrocarbon) emissions were not Gaussian and there was some evidence for a gamma distribution and for a lognormal distribution. Comparison of mean HC emissions between the drivers was therefore not reliable.

A method of cleaning lubricating oil on line was investigated using a fine bypass particulate filter followed by an infra red heater. Two bypass filter sizes of 6 and 1 micron were investigated, both filter sizes were effective but the one micron filter had the greatest benefit. This was tested on two nominally identical EURO 2 emissions compliance single decker buses, fitted with Cummins 6 cylinder 8.3 litre turbocharged intercooled engines and coded as Bus 4063 and 4070. These vehicles had emissions characteristics that were significantly different, in spite of their similar age and total mileage. Bus 4063 showed an apparent deterioration on emissions with time while Bus 4070 showed a stabilised trend on emissions with time for their baseline tests without the recycler fitted. Comparison was made with the emissions on the same vehicles and engines with and without the on-line bypass oil recycler. Engine exhaust emissions were measured about every 2000 miles.

This study uses on-board measurement systems to analyze emissions from a diesel engine vehicle during the cold start period. An in-vehicle FTIR (Fourier Transform Inferred) spectrometer and a Horiba on-board measurement system (OBS-1300) were installed on a EURO3 emission-compliant 1.8 TDCi diesel van, in order to measure the emissions. Both regulated and non-regulated emissions were measured, along with an analysis of the NO/NO₂ split. A VBOX GPS system was used to log coordinates and road speed for driving parameters and emission analysis. Thermal couples were installed along the exhaust system to measure the temperatures of exhaust gases during cold start. The real-time fuel consumption was measured. The study also looks at the influence of velocity on emissions of hydrocarbons (HCs) and NOx. The cold start period of an SI-engine-powered vehicle, was typically around 200 seconds in urban driving conditions.

The objective of this work was the development of an on-road in-vehicle emissions measurement technique utilizing a relatively new, commercial, portable Fourier Transform Infra-Red (FTIR) Spectrometer capable of identifying and measuring (at approximately 3 second intervals) up to 51 different compounds. The FTIR was installed in a medium class EURO1 spark ignition passenger vehicle in order to measure on-road emissions. The vehicle was also instrumented to allow the logging of engine speed, road speed, global position, throttle position, air-fuel ratio, air flow and fuel flow in addition to engine, exhaust and catalyst temperatures. This instrumentation allowed the calculation of mass-based emissions from the volume-based concentrations measured by the FTIR. To validate the FTIR data, the instrument was used to measure emissions from an engine subjected to a real-world drive cycle using an AC dynamometer.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined. A real world test cycle was used, based on an urban drive cycle that was similar to the ECE urban drive cycle. It was based on four laps of a street circuit and an emissions sample bag was taken for each lap. The bag for the first lap was for the cold start emissions. An in-vehicle direct exhaust dual bag sampling technique was used to simultaneously collect exhaust samples upstream and downstream of the three-way catalyst (TWC). The cold start tests were conducted over a year, with ambient temperatures ranging from - 2°C to 32°C. The exhaust system was instrumented with thermocouples so that the catalyst light off temperature could be determined. The results showed that CO emissions for the cold start were reduced by a factor of 8 downstream of catalyst when ambient temperature rose from -2°C to 32°C, the corresponding hydrocarbon emissions were reduced by a factor of 4.

The influence of ambient temperature on exhaust emissions for an instrumented Euro 1 SI car was determined for urban congested traffic conditions. In UK cities cold-starting vehicles directly into congested traffic conditions is a common occurrence that is not currently taken into account when modeling urban traffic pollution. In-vehicle emission samples were taken directly from the exhaust, upstream and downstream of the catalyst, using the bag sampling technique. The first bag was for the cold start emissions and approximately the first 1.1 km of travel. The following three bags were with a hotter catalyst. The cold start tests were conducted over a year, with ambient temperatures ranging from 2°C to 30°C. The results showed that CO emissions for the cold start were reduced by 70% downstream of the catalyst when the ambient temperature rose from 2°C to 30°C. The corresponding hydrocarbon emissions were reduced by 41% and NOx emissions were increased by 90%.

A method of cleaning diesel engine lubricating oil on-line was investigated using a bypass fine particulate filter followed by an infra-red heater to remove water vapour and light diesel fractions in the oil. The impact of this oil recycler on the gaseous and particulate emissions was investigated over a 300 hour oil age period. A Ford 1.8 litre IDI passenger car diesel engine was used with engine out emission sampled every 15-20 hours. The tests were carried out at 2500rpm (52% of the maximum speed) and 12.3 kW with 47 Nm load (43% of the maximum load and 29% of the maximum power). The EGR level at this condition was 15%. A stop start test cycle was used with a cold start each time and a typical test period of 2-3 hours. The results showed that the recycler had its greatest influence on emissions for fresh oil when there was a large reduction in particulate emissions due mainly to large reductions in the ash, carbon and unburned lubricating oil fractions.

This paper presents the emissions results and operational behavior of two hybrid vehicles over EU legislative Real Driving Emissions (RDE) and other on-road testing cycles. The behavior of one hybrid vehicle during real world driving is investigated, including analyses of air-fuel ratio and catalyst temperature changes, in order to elucidate the reasons for the emissions results seen in the other hybrid vehicle over an RDE cycle. It was observed that the catalyst cooled down over time when the hybrid vehicle SI (Spark Ignition) engine was turned off, meaning that when the engine restarted the catalyst efficiency was decreased until it was able to light-off once again. This leads to increases in the tailpipe emissions of CO, NOx and hydrocarbons after the engine restarts. In addition to this problem, the engine restarts demanded fuel enrichment, which resulted in incomplete combustion and further increases in CO and PN emissions.