The Effect of Ambient Temperature on Cold Start Urban Traffic Emissions for a Real World SI Car

Andrews, Gordon E.; Zhu, Grant; Li, Hu; Simpson, Alex; Wylie, J. A.; Bell, MC; Tate, James

doi:10.4271/2004-01-2903

Cited by 49 publications

(34 citation statements)

References 14 publications

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“…However, the excess emissions for the second phase (the EUDC) were around 13%, indicating that the ambient temperature still had an effect on fuel consumption (and therefore on CO 2 emissions), despite the engine being more or less fully warmed up by the time the second phase started. HC and PM showed very large increases during both phases; CO and NO x only showed a large increase during the fi rst phase (the UDC); deterioration in emissions of CO 2 and PN and in the fuel consumption were less dramatic. The elevated emissions of HC and CO during the fi rst phase strongly suggest combustion diffi culties and rich operation.…”

Section: Hc and Co Emissions Results From Mpi And Disi Vehicles Obtainementioning

confidence: 97%

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Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

Bielaczyc¹,

Szczotka²,

Woodburn³

2014

Archives of Environmental Protection

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Keywords: Cold start, low ambient temperature, direct and indirect injection spark ignition engine, exhaust emissions.Abstract: SI engines are highly susceptible to excess emissions when started at low ambient temperatures. This phenomenon has multiple air quality and climate forcing implications. Direct injection petrol engines feature a markedly different fuelling strategy, and so their emissions behaviour is somewhat different from indirect injection petrol engines. The excess emissions of direct injection engines at low ambient temperatures should also differ. Additionally, the direct injection fuel delivery process leads to the formation of PM, and DISI engines should show greater PM emissions at low ambient temperatures. This study reports on laboratory experiments quantifying excess emissions of gaseous and solid pollutants over a legislative driving cycle following cold start at a low ambient temperature for both engine types. Over the legislative cycle for testing at -7°C (the UDC), emissions of HC, CO, NO x and CO 2 were higher when tested at -7°C than at 24°C. Massive increases in emissions of HC and CO were observed, together with more modest increases in NO x and CO 2 emissions. Results from the entire driving cycle showed excess emissions in both phases (though they were much larger for the UDC). The DISI vehicle showed lower increases in fuel consumption than the port injected vehicles, but greater increases in emission of HC and CO. DISI particle number emissions increased by around 50%; DISI particle mass by over 600%. The observed emissions deteriorations varied somewhat by engine type and from vehicle to vehicle. Excesses were greatest following start-up, but persisted, even after several hundred seconds' driving. The temperature of the intake air appeared to have a limited but signifi cant effect on emissions after the engine has been running for some time. All vehicles tested here comfortably met the relevant EU limits, providing further evidence that these limits are no longer challenging and need updating.

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Section: Hc and Co Emissions Results From Mpi And Disi Vehicles Obtainementioning

confidence: 97%

“…Overall, in the last 13 years, maximum permissible emissions from SI engines have decreased by around 40%; emissions limits for CI engines are now roughly 80% lower than they were. (Note that these reductions are for regulated emissions and do not include CO 2 , which has its own legislation).…”

Section: Archives Of Environmental Protection Vol 40 No 3 Pp 86 -1mentioning

confidence: 99%

Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

Bielaczyc¹,

Szczotka²,

Woodburn³

2014

Archives of Environmental Protection

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“…For cold start emission control it is the light off of the first brick that is important, but having both bricks active is important in terms of achieving the best catalyst conversion efficiency. (30), in which authors reported that the HC and CO emissions were strongly depending on thermal warm up processes of engine and exhaust system and affected by ambient temperatures. Figures 27 and 28 show the HC and CO emissions as a function of warm up process and comparisons between winter and summer.…”

Section: Catalyst Inlet Gas Temperatures and Energy Gain -mentioning

confidence: 99%

Impact of Ambient Temperatures on Exhaust Thermal Characteristics during Cold Start for Real World SI Car Urban Driving Tests

Andrews

Zhu

et al. 2005

SAE Technical Paper Series

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Thermal characteristics of SI engine exhaust during cold start and warm up period were investigated for different ambient temperatures (-2 to 32 °C). A Euro 1 emission compliance SI car was tested using a real world urban driving cycle to represent typical city driving patterns and simulate ECE15 urban driving cycle. The test car was equipped with 27 thermocouples along the engine and exhaust pipes so as to measure metal and exhaust gas temperatures along the engine, exhaust and catalyst. The characteristics of thermal properties of engine, exhaust system and catalyst were studied as a function of warm up time and ambient temperature. The temperature and time of the light-off of catalyst were investigated so as to evaluate the effect of thermal properties of the catalyst on emissions.The results show that the coolant water reached the full warm up about 5 minutes in summer and 9 minutes in winter after a cold start. Lubricating oil reached the full warm up in 10 minutes in summer and 14 minutes in winter after a cold start. The light-off time of TWC was about 3 minutes in summer and 6 minutes in winter in terms of catalyst substrate temperatures. The determination of catalyst light off has been studied and discussed in terms of catalyst substrate temperatures and gas temperatures. The ambient temperature had little influence on engine out exhaust gas temperatures. The heat loss from the engine out to the catalyst was at highest level in the first 5~6 minutes and after this point the heat available at the catalyst was relatively stable.The thermal properties of the engine and exhaust system had significant influence on emissions. The results indicate that in some urban driving conditions such as short journeys in cities especially under cold weather conditions, the function of catalysts for emission reductions is very limited. INTRODUCTIONIt is well known that a SI engine in cold conditions has much higher exhaust emissions than one that is fully warmed up (1-8). The new European passenger car emissions regulations has removed the first 40 seconds of idle period for the ECE driving cycle, in recognition of the importance of the cold start emissions. The new regulations also include -7°C tests for HC and CO emissions at cold start. It has to be addressed that Euro 1 cars were not developed to pass this cold test since developed prior to new -7°C regulation, and yet Euro 1 cars do cold starts at low temperatures in the real world. Extensive research had been undertaken in the past to investigate the influence of ambient temperature on exhaust emissions (2-8), normally using legislated test cycles and CVS test procedures. It was found that exhaust emissions could be drastically increased, relative to 25°C, at cold ambient conditions. For instance, the hydrocarbon emissions were found increase by 650% at -20°C and carbon monoxide emissions by 800% (8).A satisfactory cold start is very difficult to achieve at subzero ambient temperature conditions in terms of the SI Car Urban Driving Tests

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“…This demonstrated that hydrocarbon emissions were not as sensitive as CO emissions to engine temperatures. Li et al [6,[29][30][31][32] investigated cold start emissions from SI passenger cars and a light duty diesel van and reported a greater increase in CO emissions than hydrocarbon emissions when the temperature of the engine in a vehicle was lower.…”

Section: Hydrocarbon Emissionsmentioning

confidence: 99%

Emissions from a HGV Using Used Cooking Oil as a Fuel under Real World Driving Conditions

Hadavi

Dizayi

et al. 2015

SAE Technical Paper Series

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To maximize CO2 reduction, refined straight used cooking oils were used as a fuel in Heavy Goods Vehicles (HGVs) in this research. The fuel is called C2G Ultra Biofuel (C2G: Convert to Green Ltd) and is a fully renewable fuel made as a diesel replacement from processed used cooking oil, used directly in diesel engines specifically modified for this purpose. This is part of a large demonstration project involving ten 44-tonne trucks using C2G Ultra Biofuel as a fuel to partially replace standard diesel fuels. A dual fuel tank containing both diesel and C2G Ultra Biofuel and an on-board fuel blending system-Bioltec system was installed on each vehicle, which is able to heat the C2G Ultra Biofuel and automatically determine the required blending ratio of diesel and C2G Ultra Biofuel according to fuel temperature and engine load. The engine was started with diesel and then switched to C2G Ultra Biofuel under appropriate conditions. Exhaust emissions were measured using PEMS (Portable Emission Measurement Systems) on one of the trucks under real world driving conditions. Comparisons of emissions between neat diesel mode and blended fuel mode were made. The results show that C2G Ultra Biofuel can reduce particulate matter (PM) and CO emissions significantly compared to the use of pure diesel.

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The Effect of Ambient Temperature on Cold Start Urban Traffic Emissions for a Real World SI Car

Cited by 49 publications

References 14 publications

Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

Impact of Ambient Temperatures on Exhaust Thermal Characteristics during Cold Start for Real World SI Car Urban Driving Tests

Emissions from a HGV Using Used Cooking Oil as a Fuel under Real World Driving Conditions

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