Directive 2005/55/EC of the European Parliament and of the Council (repealed)Show full title

[F1 5. CALCULATION OF THE GASEOUS EMISSIONS U.K.

5.1. Data Evaluation U.K.

For the evaluation of the gaseous emissions, the chart reading of the last 30 seconds of each mode shall be averaged and the average concentrations (conc) of HC, CO and NO _x during each mode shall be determined from the average chart readings and the corresponding calibration data. A different type of recording can be used if it ensures an equivalent data acquisition.

For the NO _x check within the control area, the above requirements apply for NO _x only.

The exhaust gas flow q _mew or the diluted exhaust gas flow q _mdew , if used optionally, shall be determined in accordance with section 2.3 of Appendix 4 to this Annex.

5.2. Dry/Wet Correction U.K.

The measured concentration shall be converted to a wet basis according to the following formulae, if not already measured on a wet basis. The conversion shall be done for each individual mode.

c _wet = k _w × c _dry

For the raw exhaust gas:

or

where:

p _r

=

water vapour pressure after cooling bath, kPa,

p _b

=

total atmospheric pressure, kPa,

H _a

=

intake air humidity, g water per kg dry air,

k _f

=

0,055584 × w _ALF – 0,0001083 × w _BET – 0,0001562 × w _GAM + 0,0079936 × w _DEL + 0,0069978 × w _EPS

For the diluted exhaust gas:

or,

For the dilution air:

K _Wd = 1 – K _W1

For the intake air:

K _Wa = 1 – K _W2

where:

H _a

=

intake air humidity, g water per kg dry air

H _d

=

dilution air humidity, g water per kg dry air

and may be derived from relative humidity measurement, dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the generally accepted formulae.

5.3. NO _x correction for humidity and temperature U.K.

As the NO _x emission depends on ambient air conditions, the NO _x concentration shall be corrected for ambient air temperature and humidity with the factors given in the following formulae. The factors are valid in the range between 0 and 25 g/kg dry air.

(a)

for compression ignition engines:

with:

T _a

=

temperature of the intake air, K

H _a

=

humidity of the intake air, g water per kg dry air

where:

H _a may be derived from relative humidity measurement, dewpoint measurement, vapour pressure measurement or dry/wet bulb measurement using the generally accepted formulae.

(b)

for spark ignition engines

k _h.G = 0,6272 + 44,030 × 10 ^–3 × H _a - 0,862 × 10 ^–3 × H _a ²

where:

H _a may be derived from relative humidity measurement, dew point measurement, vapour pressure measurement or dry/wet bulb measurement using the generally accepted formulae.

5.4. Calculation of the emission mass flow rates U.K.

The emission mass flow rate (g/h) for each mode shall be calculated as follows. For the calculation of NO _x , the humidity correction factor k _h,D , or k _h,G , as applicable, as determined according to section 5.3, shall be used.

The measured concentration shall be converted to a wet basis according to section 5.2 if not already measured on a wet basis. Values for u _gas are given in Table 6 for selected components based on ideal gas properties and the fuels relevant for this Directive.

(a)

for the raw exhaust gas

m _gas = u _gas × c _gas × q _mew

where:

u _gas

=

ratio between density of exhaust component and density of exhaust gas

c _gas

=

concentration of the respective component in the raw exhaust gas, ppm

q _mew

=

exhaust mass flow rate, kg/h

(b)

for the diluted gas

m _gas = u _gas × c _gas,c × q _mdew

where:

u _gas

=

ratio between density of exhaust component and density of air

c _gas,c

=

background corrected concentration of the respective component in the diluted exhaust gas, ppm

q _mdew

=

diluted exhaust mass flow rate, kg/h

where:

The dilution factor D shall be calculated according to section 5.4.1 of Appendix 2 to this Annex.

5.5. Calculation of the specific emissions U.K.

The emissions (g/kWh) shall be calculated for all individual components in the following way:

where:

m _gas is the mass of individual gas

P _n is the net power determined according to section 8.2 in Annex II.

The weighting factors used in the above calculation are according to section 2.7.1.

Table 6

Values of u _gas in the raw and dilute exhaust gas for various exhaust components

Notes:
u values of raw exhaust based on ideal gas properties at λ = 2, dry air, 273 K, 101,3 kPa u values of dilute exhaust based on ideal gas properties and density of air u values of CNG accurate within 0,2 % for mass composition of: C = 66 – 76 %; H = 22 – 25 %; N = 0 – 12 % u value of CNG for HC corresponds to CH 2,93 (for total HC use u value of CH 4 ).
Fuel		NO x	CO	THC/NMHC	CO 2	CH 4
Diesel	Exhaust raw	0,001587	0,000966	0,000479	0,001518	0,000553
	Exhaust dilute	0,001588	0,000967	0,00048	0,001519	0,000553
Ethanol	Exhaust raw	0,001609	0,00098	0,000805	0,001539	0,000561
	Exhaust dilute	0,001588	0,000967	0,000795	0,001519	0,000553
CNG	Exhaust raw	0,001622	0,000987	0,000523	0,001552	0,000565
	Exhaust dilute	0,001588	0,000967	0,000584	0,001519	0,000553
Propane	Exhaust raw	0,001603	0,000976	0,000511	0,001533	0,000559
	Exhaust dilute	0,001588	0,000967	0,000507	0,001519	0,000553
Butane	Exhaust raw	0,0016	0,000974	0,000505	0,00153	0,000558
	Exhaust dilute	0,001588	0,000967	0,000501	0,001519	0,000553

5.6. Calculation of the area control values U.K.

For the three control points selected according to section 2.7.6, the NO _x emission shall be measured and calculated according to section 5.6.1 and also determined by interpolation from the modes of the test cycle closest to the respective control point according to section 5.6.2. The measured values are then compared to the interpolated values according to section 5.6.3.

5.6.1. Calculation of the Specific Emission U.K.

The NO _x emission for each of the control points (Z) shall be calculated as follows:

m _NOx,Z = 0,001587 × c _NOx,Z × k _h,D × q _mew

5.6.2. Determination of the Emission Value from the Test Cycle U.K.

The NO _x emission for each of the control points shall be interpolated from the four closest modes of the test cycle that envelop the selected control point Z as shown in Figure 4. For these modes (R, S, T, U), the following definitions apply:

Speed(R) = Speed(T) = n _RT

Speed(S) = Speed(U) = n _SU

Per cent load(R) = Per cent load(S)

Per cent load(T) = Per cent load(U).

The NO _x emission of the selected control point Z shall be calculated as follows:

and:

where:

E _R , E _S , E _T , E _U = specific NO _x emission of the enveloping modes calculated in accordance with section 5.6.1.

M _R , M _S , M _T , M _U = engine torque of the enveloping modes.

5.6.3. Comparison of NO _x Emission Values U.K.

The measured specific NO _x emission of the control point Z (NO _x,Z ) is compared to the interpolated value (E _Z ) as follows:]

Textual Amendments

F1 Substituted by Commission Directive 2005/78/EC of 14 November 2005 implementing Directive 2005/55/EC of the European Parliament and of the Council on the approximation of the laws of the Member States relating to the measures to be taken against the emission of gaseous and particulate pollutants from compression-ignition engines for use in vehicles, and the emission of gaseous pollutants from positive ignition engines fuelled with natural gas or liquefied petroleum gas for use in vehicles and amending Annexes I, II, III, IV and VI thereto (Text with EEA relevance).