MEPC 39/6/1

ANNEX

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1.5 Except as otherwise specified, all results of calculations required by this appendix shall be recorded in the engine's test report in accordance with section 5.10 of this Code.

2 METHOD 1, CARBON BALANCE

2.1 This method includes six steps that shall be used in the calculation of the exhaust gas concentrations with regard to the fuel characteristics.

2.2 The given formulae of Method I are only valid in the absence of oxygen in the fuel.

2.3 First step: Calculation of the stoichiometric air demand

2.3.1 Process of complete combustion:

C+O2→CO2(1-1)

4H+O2→2H2O(1-2)

S+O2→SO2(1-3)

STOLAR=(BET/12.011+ALF/(4・1.00794)+GAM/32.060)・31.9988/23.15(1-4)

2.4 Second step : Calculation of the excess-air factor based on complete combustion and the CO2-concentration

EAFCDO=((BET・10・22.262/(12.011・1000))/(CO2D/100)+STOLAR・0.2315/1.42895-BET・10・22.262/(12.011・1000)-GAM・10・21.891/(32.060・1000))/(STOEAR・(0.7685/1.2505+0.2315/1.42895))(1-5)

2.5 Third step: Calculation of the hydrogen-to-carbon ratio

HTCRAT=ALF・12.011/(1.00794・BET) (1-6)

2.6 Fourth step: Calculation of the dry hydrocarbon-concentration based on the ECE R49-procedure with respect to fuel characteristics and air fuel ratio

2.6.1 The conversion of dry to wet concentration is given by:

concwet=concdry・(1-FFH・(fuel consumption/dry air consumption)) (1-7)

Total wet exhaust volume=Nitrogen of combustion air+

excess oxygen+

argon of the combustion air+

water of the combustion air+

water of the comustion process+

CO2 of the combustion process+

SO2 of the combustion process+(1-9)

MEPC 39/6/1

ANNEX

Page 63

where:

MVH2O=22.401dm3/mol

MVCO=22.262dm3/mol

MVSO2=21.891dm3/mol

2.6.2 The formula results:

and

FFH=(0.111127・ALF)/(0.773329+0.0555583・ALF-0.000109・BET-0.000157・GAM)・(GFUEL/GAIRD)) (1-12)

2.6.3 The excess air factor is defined as:

lv=air consumption/(fuel consumption・stoichiometric air demand) (1-13)

EAFCDO=GAIRD/(GFUEL・STOIAR) (1-14)

GAIRD=EAFCDO・GFUEL・STOIAR(1-15)

CWET=CDRY・(1-FFH・GFUEL/GAIRD)

=CDRY・(1-FFH・GFUEL/(EAFCDO・GFUEL・STOIAR))

=CDRY・(1-FFH・(EAFCDO・STOIAR)

CDRY=CWET・(1-FFH/(EAFCDO・STOLAR)) (1-16)

=CWET・EAFCDO・STIKAR/(EAFCDO・STOLAR-FFH) (1-17)

HCD=HCW・EAFCDO・STOIAR/(EAFCDO・STOLAR-FFH) (1-18)

2.7 Fifth step: Calculation of the excess air factor based on the US Federal Register [ 86.345-79]procedure

EXHCPN=(CO2D/100)+(COD/10 6)+(HCD/10 6) (1-19)

Iv=EAFEXH=(1/EXHCPN-COD/(10 6・EXHCPN))-0.75・HTCRAT/

(3.5/(COD/10 6・EXHCPN)+((1-3.5)/(1-HCD/(10 6・EXHCPN)))))/(4.77・(1+HTCRAT/4)) (1-20)

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