Reducing Cold-Start Emissions by Catalytic Converter Thermal Management

This paper presents and discusses experimental data obtained during test simulating the test cycle ECE-15 for a relatively simple method for the reduction of pollutant emissions during a cold start. During a cold start the volume of the exhaust gases is considerably smaller than the ones under full load. Therefore, only a small portion of the catalyst active surface is used to process the gases at the cold start phase. After the light-off at the initial surface the exhaust gases pass from the total catalytic surface which is already pre-heated from the first phase. The experimental results presented here indicate that there is a reduction of the pollutant emissions during the cold start of an engine. The developed system uses the 20% of the catalyst active surface during start-up and the rest of the catalyst surface after this phase, controlled by a proper automation system. At the cold start phase the system focusing the gas flow towards the center core of the monolith, so there is a quicker warm-up of the catalyst and a faster initiation of catalysis in this area. So when the remaining ceramic body of the catalytic converter is used, it is already warmed and the catalysis starts almost immediately.

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Optimization of Catalytic Converter Design to Improve Under-Hood Thermal Management

10.4271/2019-01-1263 ◽

2019 ◽

Cited By ~ 2

Author(s):

Alaa El-Sharkawy ◽

Dipan Arora ◽

Michael W. Huxford

Keyword(s):

Thermal Management ◽

Catalytic Converter ◽

Converter Design

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Experimental Analysis of Telescopic Catalytic Converter in a Petrol Engine to Reduce Cold Start Emission

International Journal of Engineering Research in Africa ◽

10.4028/www.scientific.net/jera.25.28 ◽

2016 ◽

Vol 25 ◽

pp. 28-35

Author(s):

M. Ganesan ◽

S. Sendilvelan

Keyword(s):

Thermal Degradation ◽

Thermal Loading ◽

Catalytic Converter ◽

Cold Start ◽

Spark Ignition Engine ◽

Air Injection ◽

Injection System ◽

Engine Operation ◽

Hot Air ◽

Off Time

Control of harmful emissions during cold start of the engine has become a challenging task over the years due to the ever increasing stringent emission norms. Positioning of the catalytic converter closer to the exhaust manifold is an efficient way of achieving rapid light-off temperature. On the other hand, the resulting higher thermal loading under high-load engine operation may substantially cause thermal degradation and accelerate catalyst ageing. The objective of the present work is to reduce the light-off time of the catalyst and at the same time to reduce the thermal degradation and ageing of the catalyst to the minimum possible extent. In the present work two innovative approaches namely Parallel Catalytic Converter System (PCCS) and Telescopic Catalytic Converter System (TCCS) have been adopted to reduce the light-off time of the catalyst. The tests were conducted on a 4 cylinder Spark Ignition Engine under cold start condition. It was established that considerable reduction in the light-off time was achieved by using TCCS. Further reduction in the light-off time was achieved by using pre catalysts (40%vol. & 20%vol.) and hot air injection. It has been found that 13% reduction in CO light-off time was achieved with pre-catalyst (40%vol.), 50% reduction with pre-catalyst (20%vol.) and 66% reduction with hot air injector system, when compared to TCCS. Also 14% reduction in HC light-off time was achieved with pre-catalyst (40%vol.), 43% reduction with pre-catalyst (20%vol.) and 63% reduction with hot air injection system, when compared to TCCS. It was also established that light-off time of TCCS can be brought down to 10 seconds using hot air injection.

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Startup and Idle Emissions Analysis of a 2009 VW Jetta Using PEMS SemtechD

ASME 2012 Internal Combustion Engine Division Spring Technical Conference ◽

10.1115/ices2012-81170 ◽

2012 ◽

Author(s):

Michael V. Johnson ◽

Samuel Duncan ◽

Steven S. McConnell

Keyword(s):

Fuel Consumption ◽

Measurement System ◽

Catalytic Converter ◽

Cold Start ◽

Idle Time ◽

Initial Assessment ◽

Ambient Temperatures ◽

Time Period ◽

Startup Time ◽

Total Hydrocarbons

A 2009 Volkswagen Jetta was tested using a Portable Emissions Measurement System (PEMS) SemtechD emissions analyzer to determine when the emissions and fuel consumption will be the smallest in regards to startup vs. idle emissions. An idle time equivalent was calculated to determine when idle emissions became equal to startup emissions at four different ambient temperatures for a cold start. The mass of Total Hydrocarbons (THC) emitted limited the idle time equivalent to less than the startup time for all ambient temperatures. The temperature of the Catalytic Converter (CC) was monitored to determine how quickly the car cools down and therefore, how beneficial it is to turn the car off after a certain time period. For the temperature range tested, it was more beneficial for reduced emissions to turn off the car compared to idling by a factor of at least four. The data suggests a trend that idling would never be the best option; however, more testing needs to be done with a greater range of CC cool down temperatures to confirm this initial assessment.

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The analysis of heating process of catalytic converter using thermo-vision

Combustion Engines ◽

10.19206/ce-116864 ◽

2015 ◽

Vol 162 (3) ◽

pp. 41-51

Author(s):

Barbara WORSZTYNOWICZ ◽

Andrzej UHRYŃSKI

Keyword(s):

Cylinder Head ◽

Test Bench ◽

Catalytic Converter ◽

Exhaust System ◽

Cold Start ◽

Spark Ignition ◽

Spark Ignition Engine ◽

Heating Process ◽

Idle Speed ◽

Heat State

The article tackles the issues related to a process of heating of three way catalytic converter during the cold start and the heating of the spark ignition engine. The measurements on the test bench were performed, taking into consideration how engine works directly after the start, on the idle speed and under the load, during which the temperature of the exhaust gases in the exhaust system and coolant on the cylinder head were measured. At the same time the track of the heat state of the catalytic converter was monitored using thermo-vision camera. The results of the measurements were presented as charts and selected thermo-grams, qualitatively representing the issue of heating of the catalytic converter.

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Exhaust gas treatment for reducing cold start emissions of a motorcycle engine fuelled with gasoline-ethanol blends

Journal of Energy in Southern Africa ◽

10.17159/2413-3051/2015/v26i2a2199 ◽

2017 ◽

Vol 26 (2) ◽

pp. 84 ◽

Cited By ~ 1

Author(s):

A. Samuel Raja ◽

A. Valan Arasu

Keyword(s):

Traffic Congestion ◽

Catalytic Converter ◽

Cold Start ◽

Exhaust Gas ◽

Gas Temperature ◽

Gas Treatment ◽

Single Cylinder ◽

Hc Emissions ◽

Ethanol Blends ◽

Exhaust Gas Temperature

In countries like India, transportation by a two wheeled motorcycle is very common owing to affordable cost, easy handling and traffic congestion. Most of these bikes use single cylinder air cooled four-stroke spark ignition (SI) engines of displacement volume ranging from 100 cm3 to 250 cm3. CO and HC emissions from such engines when started after a minimum stop-time of 12 hours or more (cold-start emissions) are higher than warmed-up emissions. In the present study, a 150 cm3 single cylinder air cooled SI engine was tested for cold start emissions and exhaust gas temperature. Different gasoline-ethanol blends (E0 to E20) were used as fuel expecting better oxidation of HC and CO emissions with additional oxygen present in ethanol. The effect of glow plug assisted exhaust gas ignition (EGI) and use of catalytic converter on cold start emissions were studied separately using the same blends. Results show that with gasoline-ethanol blends, cold start CO and HC emissions were less than that with neat gasoline. And at an ambient temperature of 30±1°C, highest emission reductions were observed with E10. EGI without a catalytic converter had no significant effect on emissions except increasing the exhaust gas temperature. The catalytic converter was found to be active only after 120 seconds in converting cold start CO, HC and NOx. Use of a catalytic converter proves to be a better option than EGI in controlling cold start emissions with neat gasoline or gasoline-ethanol blends.

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