# Commission Delegated Regulation (EU) 2017/654 of 19 December 2016 supplementing Regulation (EU) 2016/1628 of the European Parliament and of the Council with regard to technical and general requirements relating to emission limits and type-approval for internal combustion engines for non-road mobile machinery, Division 2.1.5.2: Calculated values

Extent: E+W+S+N.I.

The component specific factor, u gas,i, may be calculated by the density ratio of the component and the exhaust gas or alternatively by the corresponding ratio of molar masses [equations (7-11) or (7-12)]:
u gas, i = M gas ∕ M e, i × 1000
(7-11)
or
u gas, i = ρ gas ∕ ρ e, i × 1000
(7-12)
where:
M gas molar mass of the gas component [g/mol]
M e, i instantaneous molar mass of the wet raw exhaust gas [g/mol]
ρ gas density of the gas component [kg/m3]
ρ e,i instantaneous density of the wet raw exhaust gas [kg/m3]
The molar mass of the exhaust gas, M e,i shall be derived for a general fuel composition CH α O ε N δ S γ under the assumption of complete combustion, and shall be calculated by means of equation (7-13):
M e,i = 1 + q mf,i q maw,i q mf,i q maw,i × α 4 + ε 2 + δ 2 12,011 + 1,00794 × α + 15,9994 × ε + 14,0067 × δ + 32,065 × γ + H a × 10 − 3 2 × 1,00794 + 15,9994 + 1 M a 1 + H a × 10 − 3
(7-13)
Where:
qm f, i instantaneous fuel mass flow rate on wet basis [kg/s]
qm aw, i instantaneous intake air mass flow rate on wet basis [kg/s]
α molar hydrogen-to-carbon ratio [-]
δ molar nitrogen-to-carbon ratio [-]
ε molar oxygen-to-carbon ratio [-]
γ atomic sulphur-to-carbon ratio [-]
H a intake air humidity [g H2O/kg dry air]
M a dry intake air molecular mass = 28,965 g/mol
The instantaneous raw exhaust gas density ρ e, i [kg/m3] shall be calculated by means of equation (7-14):
ρ e, i = 1000 + H a + 1000 × q m f, i ∕ q m ad, i 773,4 + 1,2434 × H a + k f × 1000 × q m f, i ∕ q m ad, i
(7-14)
where:
qm f, i instantaneous fuel mass flow rate [kg/s]
qm ad, i instantaneous dry intake air mass flow rate [kg/s]
H a intake air humidity [g H2O/kg dry air]
k f combustion additional volume [m3/kg fuel] [see equation (7-5)]

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Source: https://www.legislation.gov.uk/eur/2017/654/annex/VII/division/2/division/2.1/division/2.1.5/division/2.1.5.2 (the official version)
Page: https://openlegislation.uk/eu-regulation-2017-654/annex-VII/division-2/division-2.1/division-2.1.5/division-2.1.5.2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.