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Division 2.1.5.2 Calculated values

United Kingdom

Original text. Later amendments are not shown.

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):

    F1 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)]

    • Annotations

    Textual amendments

    F1

    Substituted by Commission Delegated Regulation (EU) 2018/989 of 18 May 2018 amending and correcting Delegated Regulation (EU) 2017/654 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 (Text with EEA relevance).