scholarly journals An overview of cold start emissions from direct injection spark-ignition and compression ignition engines of light duty vehicles at low ambient temperatures

2013 ◽  
Vol 154 (3) ◽  
pp. 96-103
Author(s):  
Piotr BIELACZYC ◽  
Andrzej SZCZOTKA ◽  
Joseph WOODBURN

Spark-ignition (SI) engines are highly susceptible to excess emissions when started at low ambient temperatures, a phenomenon which has been widely discussed in the literature. Direct injection diesel engines feature a markedly different fuelling and combustion strategy, and as such their emissions behaviour is somewhat different from gasoline engines. The excess emissions of diesel engines at low ambient temperatures should also differ. The aim of this study was to compare excess emissions of gaseous and solid pollutants over a legislative driving cycle (the New European Driving Cycle, NEDC) following cold start at a low ambient temperature for both engine types. This paper examines emissions at low ambient temperatures with a special focus on cold start; emissions are also compared to start-up at a higher ambient temperature (24 °C). The causes of excess emissions andfuel consumption are briefly discussed. A series of tests were performed on European Euro 5 passenger cars on a chassis dynamometer within an advanced climate-controlled test laboratory at BOSMAL Automotive Research and Development Institute, Poland. Emissions data obtained over the Urban Driving Cycle by testing at 24 °C and at -7 °C, are presentedfor a selection ofmodern Euro 5 gasoline and diesel vehicles representative of the European passenger carfleet. A full modal emissions analysis was also conducted at 24 °C and at -7 °C over the NEDC. Emissions andfuel consumption were substantially higher at -7 °C than at 24 °C.

2021 ◽  
Vol 11 (1) ◽  
pp. 425-434
Author(s):  
Jacek Pielecha ◽  
Kinga Skobiej ◽  
Karolina Kurtyka

Abstract In order to better reflect the actual ecological performance of vehicles in traffic conditions, both the emission standards and the applied emission tests are being developed, for example by considering exhaust emissions for a cold engine start. This article presents the research results on the impact of ambient temperature during the cold start of a gasoline engine in road emission tests. The Real Driving Emissions (RDE) tests apply to passenger cars that meet the Euro 6 emissions norm and they are complementary to their type approval tests. A portable emissions measurement system was used to record the engine and vehicle operating parameters, as well as to measure the exhaust emissions during tests. This allowed for parameters such as engine load, engine speed and vehicle speed to be monitored. The cold start conditions for two different temperatures (8°C and 25°C) were compared in detail. Moreover, the engine operating parameters, exhaust concentration values and road emissions for the 300 s time interval, were compared. The summary of the article presents the share of a passenger car’s cold start phase for each exhaust compound in the urban part of the test and in the entire Real Driving Emissions test depending on the ambient temperature.


2020 ◽  
Vol 181 (2) ◽  
pp. 24-30
Author(s):  
Karolina KURTYKA ◽  
Jacek PIELECHA

The implementation of the 3rd package of the RDE test procedure has extended the test method by considering emissions from a cold start period into the total exhaust emissions from a vehicle. The article presents the research results of exhaust emissions of a vehicle equipped with a gasoline engine. The tests were carried out at two different ambient temperatures, in line with the requirements of the RDE test procedure for passenger cars, meeting the Euro 6d-Temp emissions standard. The obtained results were analyzed, i.e. there were compared the engine and vehicle operating parameters and the values of road exhaust emissions during the cold start at two different ambient temperatures. The summary presents the shares of the cold start phase for each exhaust emission compound in the urban part of the test and the entire RDE test, depending on the ambient temperature (8ºC and 25ºC).


2014 ◽  
Vol 40 (3) ◽  
pp. 87-100 ◽  
Author(s):  
Piotr Bielaczyc ◽  
Andrzej Szczotka ◽  
Joseph Woodburn

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, NOx and CO2 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 NOx and CO2 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 significant 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.


2019 ◽  
Vol 179 (4) ◽  
pp. 160-168 ◽  
Author(s):  
Jacek PIELECHA ◽  
Jerzy MERKISZ ◽  
Karolina KURTYKA ◽  
Kinga SKOBIEJ

Modernization of passenger cars and constant development of existing legislation lead to a reduction of exhaust emissions from these vehicles. In accordance with package 3 of the RDE test procedure, the European Commission has extended testing methods by including exhaust emissions during a cold start. The article compares the research results on the impact of ambient temperature during the cold start of spark-ignition and compression-ignition engines in road emission tests. The tests were carried out in line with the requirements of the RDE test procedure for passenger cars meeting the Euro 6d-Temp emissions standard. The obtained results were analyzed, i.e. there were compared the engine and vehicle operation parameters and the values of road exhaust emissions, during the cold start of gasoline and diesel engines at the ambient temperature of approximately 25oC.The summary presents the share of cold start phase of a passenger car (at the ambient temperature of around 25oC) for each exhaust emission compound in the urban part of the test, and in the entire RDE test, depending on the engine type used.


2021 ◽  
Author(s):  
Joseph Woodburn

This paper reviews the emissions of reactive nitrogen compounds (RNCs) from modern vehicles fitted with spark ignition en-gines and three-way catalysts. Specific aspects of the pollutants involved – and their formation – are discussed. Cold start driving cycles are scenarios under which emissions of all four RNCs can be significant; the mechanisms behind emissions trends are ex-plored. Experimental data obtained from two vehicles tested over two different cold start driving cycles are presented and analysed. The use of gravimetric and molar metrics are explored. Ammonia, a species which is currently not regulated for passenger cars in any automotive market, is identified as forming the majority of the RNC emissions over the entire driving cycle. While ammonia emissions are strongly linked to aftertreatment system warmup and periods of high load, significant ammonia emissions were also measured under certain hot-running, low load conditions, and even at idle. For the majority of the duration of the test procedures employed, the RNC profile was dominated by ammonia, which accounted for between 69% and 86% of measured RNCs in the ex-haust gas. Emissions are compared to the available legislative precedents (i.e. emissions limits currently in force in various jurisdic-tions). Finally, possibilities for control of exhaust emissions of currently unregulated RNCs are briefly discussed.


Energy ◽  
2011 ◽  
Vol 36 (9) ◽  
pp. 5486-5496 ◽  
Author(s):  
J.V. Pastor ◽  
V. Bermúdez ◽  
J.M. García-Oliver ◽  
J.G. Ramírez-Hernández

2021 ◽  
pp. 1-11
Author(s):  
Dominik Appel ◽  
Fabian P. Hagen ◽  
Uwe Wagner ◽  
Thomas Koch ◽  
Henning Bockhorn ◽  
...  

Abstract To comply with future emission regulations for internal combustion engines, system-related cold-start conditions in short-distance traffic constitute a particular challenge. Under these conditions, pollutant emissions are seriously increased due to internal engine effects and unfavorable operating conditions of the exhaust aftertreatment systems. As a secondary effect, the composition of the exhaust gases has a considerable influence on the deposition of aerosols via different deposition mechanisms and on fouling processes of exhaust gas-carrying components. Also, the performance of exhaust gas aftertreatment systems may be affected disadvantageously. In this study, the exhaust gas and deposit composition of a turbocharged three-cylinder gasoline engine is examined in-situ upstream of the catalytic converter at ambient and engine starting temperatures of -22 °C to 23 °C using a Fourier-transform infrared spectrometer and a particle spectrometer. For the cold start investigation, a modern gasoline engine with series engine periphery is used. In particular, the investigation of the behavior of deposits in the exhaust system of gasoline engines during cold start under dynamic driving conditions represents an extraordinary challenge due to an average lower soot concentration in the exhaust gas compared to diesel engines and so far, has not been examined in this form. A novel sampling method allows ex-situ analysis of formed deposits during a single driving cycle. Both, particle number concentration and the deposition rate are higher in the testing procedure of Real Driving Emissions (RDE) than in the inner-city part of the Worldwide harmonized Light vehicles Test Cycle (WLTC). In addition, reduced ambient temperatures increase the amount of deposits, which consist predominantly of soot and to a minor fraction of volatile compounds. Although the primary particle size distributions of the deposited soot particles do not change when boundary conditions change, the degree of graphitization within the particles increases with increasing exhaust gas temperature.


2012 ◽  
Vol 134 (09) ◽  
pp. 38-41 ◽  
Author(s):  
Steve Ciatti

This article evaluates engine efficiency as a step towards improving fuel economy and emissions performance. Diesel engines tend to be very efficient; however, they have an emissions problem. They require complex and expensive equipment to meet pollution mandates. Spark ignition gasoline engines, on the other hand, do a much better job with emissions, but they are inherently less efficient. Thus, the research team at Argonne National Laboratory has decided to look for ways to combine the best characteristics of both. This new system is more like traditional diesel combustion than spark ignition, but uses a gasoline-like fuel and an innovative approach to combustion to minimize emissions. Diesel engines tend to run lean, meaning there is more oxygen in the mix than fuel, which reduces in-cylinder average temperatures. Research shows that gasoline spark engines have fatal efficiency flaws but comply easily and relatively inexpensively with emission requirements. Diesels are more efficient, but carry a heavy penalty for emission compliance. Different research teams’ challenge is to ensure robust, reliable operation during transient operation. The new system’s torque profile is essentially the same as that of a conventional diesel, and it provides excellent performance in the powerband where most people drive.


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