Automotive exhaust emissions at low ambient temperature

Research output: Book/ReportReportProfessional

1 Citation (Scopus)

Abstract

Cold ambient conditions have a distinct impact on the total emission of the Finnish car park because climatic conditions in Finland are rather severe regarding the use of automobiles. In the present study, the exhaust emission characteristics of three automotive petrol engines with different fuel metering systems were evaluated. Experiments were carried out on an engine and exhaust system combination in a cold chamber at a constant ambient temperature ranging from +20 °C to -30 °C. Test procedures included either constant or variable load mode during a 30 minute run. The test results show that the use of the enrichment devices necessary during cold-start and warm-up period has a major impact on the total emissions during the test In the carburetted non-catalyst engines the share of the initial emissions during cold-start and warm-up phase was smaller than with the fuel-injected catalyst version. The catalytic converter equipped version was also found to be far more sensitive to the low ambient temperature than the normal carburetted versions without exhaust after treatment. The relative increase in CO and HC emissions when the ambient temperature was lowered was in case of the fuel-injected catalyst engine some 5 to 15 times greater than with the normal carburetted version of the same engine. Although the temperature of the converter rose quite quickly after the cold start it did not promote the conversion, because the enrichment circuit of the fuel injection system over riched the air-fuel mixture, thus optimising the driveability, but making the operation of the three-way catalytic converter impossible. The carburetted test engines were found to be quite sensitive to intake air temperature. The test results indicate that the emission behaviour of different fuel metering and emission control systems can be surprising at low ambient temperature. Standardised test procedures for exhaust emissions do not consider the effect of low ambient temperature. Hence, the results of this study indicate a clear need for developing emission test procedures also for low temperature operation of the automobiles.
Original languageEnglish
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Number of pages40
ISBN (Print)951-38-2948-0
Publication statusPublished - 1987
MoE publication typeD4 Published development or research report or study

Publication series

NameTutkimuksia / Valtion teknillinen tutkimuskeskus
PublisherVTT
Volume496

Fingerprint

Engines
Catalytic converters
Temperature
Automobiles
Low temperature operations
Catalysts
Exhaust systems (engine)
Air intakes
Emission control
Fuel injection
Railroad cars
Control systems
Networks (circuits)
Air
Experiments

Keywords

  • motor vehicle engines
  • low temperatures
  • exhaust emissions

Cite this

Laurikko, J., Nylund, N-O., & Sipilä, K. (1987). Automotive exhaust emissions at low ambient temperature. Espoo: VTT Technical Research Centre of Finland. Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports, No. 496
Laurikko, Juhani ; Nylund, Nils-Olof ; Sipilä, Kai. / Automotive exhaust emissions at low ambient temperature. Espoo : VTT Technical Research Centre of Finland, 1987. 40 p. (Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports; No. 496).
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abstract = "Cold ambient conditions have a distinct impact on the total emission of the Finnish car park because climatic conditions in Finland are rather severe regarding the use of automobiles. In the present study, the exhaust emission characteristics of three automotive petrol engines with different fuel metering systems were evaluated. Experiments were carried out on an engine and exhaust system combination in a cold chamber at a constant ambient temperature ranging from +20 °C to -30 °C. Test procedures included either constant or variable load mode during a 30 minute run. The test results show that the use of the enrichment devices necessary during cold-start and warm-up period has a major impact on the total emissions during the test In the carburetted non-catalyst engines the share of the initial emissions during cold-start and warm-up phase was smaller than with the fuel-injected catalyst version. The catalytic converter equipped version was also found to be far more sensitive to the low ambient temperature than the normal carburetted versions without exhaust after treatment. The relative increase in CO and HC emissions when the ambient temperature was lowered was in case of the fuel-injected catalyst engine some 5 to 15 times greater than with the normal carburetted version of the same engine. Although the temperature of the converter rose quite quickly after the cold start it did not promote the conversion, because the enrichment circuit of the fuel injection system over riched the air-fuel mixture, thus optimising the driveability, but making the operation of the three-way catalytic converter impossible. The carburetted test engines were found to be quite sensitive to intake air temperature. The test results indicate that the emission behaviour of different fuel metering and emission control systems can be surprising at low ambient temperature. Standardised test procedures for exhaust emissions do not consider the effect of low ambient temperature. Hence, the results of this study indicate a clear need for developing emission test procedures also for low temperature operation of the automobiles.",
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Laurikko, J, Nylund, N-O & Sipilä, K 1987, Automotive exhaust emissions at low ambient temperature. Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports, no. 496, VTT Technical Research Centre of Finland, Espoo.

Automotive exhaust emissions at low ambient temperature. / Laurikko, Juhani; Nylund, Nils-Olof; Sipilä, Kai.

Espoo : VTT Technical Research Centre of Finland, 1987. 40 p. (Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports; No. 496).

Research output: Book/ReportReportProfessional

TY - BOOK

T1 - Automotive exhaust emissions at low ambient temperature

AU - Laurikko, Juhani

AU - Nylund, Nils-Olof

AU - Sipilä, Kai

PY - 1987

Y1 - 1987

N2 - Cold ambient conditions have a distinct impact on the total emission of the Finnish car park because climatic conditions in Finland are rather severe regarding the use of automobiles. In the present study, the exhaust emission characteristics of three automotive petrol engines with different fuel metering systems were evaluated. Experiments were carried out on an engine and exhaust system combination in a cold chamber at a constant ambient temperature ranging from +20 °C to -30 °C. Test procedures included either constant or variable load mode during a 30 minute run. The test results show that the use of the enrichment devices necessary during cold-start and warm-up period has a major impact on the total emissions during the test In the carburetted non-catalyst engines the share of the initial emissions during cold-start and warm-up phase was smaller than with the fuel-injected catalyst version. The catalytic converter equipped version was also found to be far more sensitive to the low ambient temperature than the normal carburetted versions without exhaust after treatment. The relative increase in CO and HC emissions when the ambient temperature was lowered was in case of the fuel-injected catalyst engine some 5 to 15 times greater than with the normal carburetted version of the same engine. Although the temperature of the converter rose quite quickly after the cold start it did not promote the conversion, because the enrichment circuit of the fuel injection system over riched the air-fuel mixture, thus optimising the driveability, but making the operation of the three-way catalytic converter impossible. The carburetted test engines were found to be quite sensitive to intake air temperature. The test results indicate that the emission behaviour of different fuel metering and emission control systems can be surprising at low ambient temperature. Standardised test procedures for exhaust emissions do not consider the effect of low ambient temperature. Hence, the results of this study indicate a clear need for developing emission test procedures also for low temperature operation of the automobiles.

AB - Cold ambient conditions have a distinct impact on the total emission of the Finnish car park because climatic conditions in Finland are rather severe regarding the use of automobiles. In the present study, the exhaust emission characteristics of three automotive petrol engines with different fuel metering systems were evaluated. Experiments were carried out on an engine and exhaust system combination in a cold chamber at a constant ambient temperature ranging from +20 °C to -30 °C. Test procedures included either constant or variable load mode during a 30 minute run. The test results show that the use of the enrichment devices necessary during cold-start and warm-up period has a major impact on the total emissions during the test In the carburetted non-catalyst engines the share of the initial emissions during cold-start and warm-up phase was smaller than with the fuel-injected catalyst version. The catalytic converter equipped version was also found to be far more sensitive to the low ambient temperature than the normal carburetted versions without exhaust after treatment. The relative increase in CO and HC emissions when the ambient temperature was lowered was in case of the fuel-injected catalyst engine some 5 to 15 times greater than with the normal carburetted version of the same engine. Although the temperature of the converter rose quite quickly after the cold start it did not promote the conversion, because the enrichment circuit of the fuel injection system over riched the air-fuel mixture, thus optimising the driveability, but making the operation of the three-way catalytic converter impossible. The carburetted test engines were found to be quite sensitive to intake air temperature. The test results indicate that the emission behaviour of different fuel metering and emission control systems can be surprising at low ambient temperature. Standardised test procedures for exhaust emissions do not consider the effect of low ambient temperature. Hence, the results of this study indicate a clear need for developing emission test procedures also for low temperature operation of the automobiles.

KW - motor vehicle engines

KW - low temperatures

KW - exhaust emissions

M3 - Report

SN - 951-38-2948-0

T3 - Tutkimuksia / Valtion teknillinen tutkimuskeskus

BT - Automotive exhaust emissions at low ambient temperature

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Laurikko J, Nylund N-O, Sipilä K. Automotive exhaust emissions at low ambient temperature. Espoo: VTT Technical Research Centre of Finland, 1987. 40 p. (Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports; No. 496).