Commission Regulation (EU) 2017/2400Dangos y teitl llawn

5. Post-processing of measurement data

All calculations defined in this paragraph shall be performed specifically for each engine within one engine CO₂-family.

5.1 Calculation of engine work

Total engine work over a cycle or a defined period shall be determined from the recorded values of engine power determind in accordance with paragraph 3.1.2 and paragraphs 6.3.5. and 7.4.8. of Annex 4 to UN/ECE Regulation 49 Rev.06.

The engine work over a complete testcycle or over each WHTC-sub-cycle shall be determined by integrating of recorded values of engine power in accordance with the following formula:

where:

W_{act, i}

=

total engine work over the time period from t₀ to t₁

t₀

=

time at the start of the time period

t₁

=

time at the end of the time period

n

=

number of recorded values over the time period from t₀ to t₁

P_{k [0 … n]}

=

recorded engine power values over the time period from t₀ to t₁ in chronological order, where k runs from 0 at t₀ to n at t₁

h

=

interval width between two adjacent recorded values defined by

5.2 Calculation of integrated fuel consumption

Any recorded negative values for the fuel consumption shall be used directly and shall not be set equal to zero for the calculations of the integrated value.

The total fuel mass consumed by the engine over a complete testcycle or over each WHTC-sub-cycle shall be determined by integrating recorded values of fuel massflow in accordance with the following formula:

where:

Σ FC_{meas, i}

=

total fuel mass consumed by the engine over the time period from t₀ to t₁

t₀

=

time at the start of the time period

t₁

=

time at the end of the time period

n

=

number of recorded values over the time period from t₀ to t₁

mf_fuel,_{k [0 … n]}

=

recorded fuel massflow values over the time period from t₀ to t₁ in chronological order, where k runs from 0 at t₀ to n at t₁

h

=

interval width between two adjacent recorded values defined by

5.3 Calculation of specific fuel consumption figures

The correction and balancing factors, which have to be provided as input for the simulation tool, are calculated by the engine pre-processing tool based on the measured specific fuel consumption figures of the engine determined in accordance with paragraphs 5.3.1 and 5.3.2.

5.3.1 Specific fuel consumption figures for WHTC correction factor

The specific fuel consumption figures needed for the WHTC correction factor shall be calculated from the actual measured values for the hotstart WHTC recorded in accordance with paragraph 4.3.3 as follows:

• SFC_{meas, Urban} = Σ FC_{meas, WHTC-Urban} / W_{act, WHTC-Urban}

• SFC_{meas, Rural} = Σ FC_{meas, WHTC- Rural} / W_{act, WHTC- Rural}

• SFC_{meas, MW} = Σ FC_{meas, WHTC-MW} / W_{act, WHTC-M})

where:

SFC_{meas, i}

=

Specific fuel consumption over the WHTC-sub-cycle i [g/kWh]

Σ FC_{meas, i}

=

Total fuel mass consumed by the engine over the WHTC-sub-cycle i [g] determined in accordance with paragraph 5.2

W_{act, i}

=

Total engine work over the WHTC sub-cycle i [kWh] determined in accordance with paragraph 5.1

The 3 different sub-cycles of the WHTC – urban, rural and motorway – shall be defined as follows:

(1)

urban: from cycle start to ≤ 900 seconds from cycle start

(2)

rural: from > 900 seconds to ≤ 1 380 seconds from cycle start

(3)

motorway (MW): from > 1 380 seconds from cycle start to cycle end

5.3.2 Specific fuel consumption figures for cold-hot emission balancing factor

The specific fuel consumption figures needed for the cold-hot emission balancing factor shall be calculated from the actual measured values for both, the hotstart and coldstart WHTC test recorded in accordance with paragraph 4.3.3. The calculations shall be performed for both, the hotstart and coldstart WHTC separately as follows:

• SFC_{meas, hot} = Σ FC_{meas, hot} / W_{act, hot}

• SFC_{meas, cold} = Σ FC_{meas, cold} / W_{act, cold}

where:

SFC_{meas, j}

=

Specific fuel consumption [g/kWh]

Σ FC_{meas, j}

=

Total fuel consumption over the WHTC [g] determined in accordance with paragraph 5.2 of this Annex

W_{act, j}

=

Total engine work over the WHTC [kWh] determined in accordance with paragraph 5.1 of this Annex

5.3.3 Specific fuel consumption figures over WHSC

The specific fuel consumption over the WHSC shall be calculated from the actual measured values for the WHSC recorded in accordance with paragraph 4.3.4 as follows:

SFC_WHSC = (Σ FC_WHSC) / (W_WHSC)

where:

SFC_WHSC

=

Specific fuel consumption over WHSC [g/kWh]

Σ FC_WHSC

=

Total fuel consumption over the WHSC [g] determined in accordance with paragraph 5.2 of this Annex

W_WHSC

=

Total engine work over the WHSC [kWh] determined in accordance with paragraph 5.1 of this Annex

5.3.3.1 Corrected specific fuel consumption figures over WHSC

The calculated specific fuel consumption over the WHSC, SFC_WHSC, determined in accordance with paragraph 5.3.3 shall be adjusted to a corrected value, SFC_WHSC,corr, in order to account for the difference between the NCV of the fuel used during testing and the standard NCV for the respective engine fuel technology in accordance with the following equation:

where:

SFC_WHSC,corr

=

Corrected specific fuel consumption over WHSC [g/kWh]

SFC_WHSC

=

Specific fuel consumption over WHSC [g/kWh]

NCV_meas

=

NCV of the fuel used during testing determined in accordance with paragraph 3.2 [MJ/kg]

NCV_std

=

Standard NCV in accordance with Table 4 [MJ/kg]

Table 4

Standard net calorific values of fuel types

Fuel type / engine type	Reference fuel type	Standard NCV [MJ/kg]
Diesel / CI	B7	42,7
Ethanol / CI	ED95	25,7
Petrol / PI	E10	41,5
Ethanol / PI	E85	29,1
LPG / PI	LPG Fuel B	46,0
Natural Gas / PI	G25	45,1

5.3.3.2 Special provisions for B7 reference fuel

In the case that reference fuel of the type B7 (Diesel /CI) in accordance with paragraph 3.2 was used during testing, the standardization correction in accordance with paragraph 5.3.3.1 shall not be performed and the corrected value, SFC_WHSC,corr, shall be set to the uncorrected value SFC_WHSC.

5.4 Correction factor for engines equipped with exhaust after-treatment systems that are regenerated on a periodic basis

For engines equipped with exhaust after-treatment systems that are regenerated on a periodic basis defined in accordance with paragraph 6.6.1 of Annex 4 to UN/ECE Regulation 49 Rev.06, fuel consumption shall be adjusted to account for regeneration events by a correction factor.

This correction factor, CF_RegPer, shall be determined in accordance with paragraph 6.6.2 of Annex 4 to UN/ECE Regulation 49 Rev.06.

For engines equipped with exhaust after-treatment systems with continuous regeneration, defined in accordance with paragraph 6.6 of Annex 4 to UN/ECE Regulation 49 Rev.06, no correction factor shall be determined and the value of the factor CF_RegPer shall be set to 1.

The engine full load curve recorded in accordance with paragraph 4.3.1 shall be used for the denormalization of the WHTC reference cycle and all calculations of reference values performed in accordance with paragraphs 7.4.6, 7.4.7 and 7.4.8 of Annex 4 to UN/ECE Regulation 49 Rev.06.

In addition to the provisions defined in Annex 4 to UN/ECE Regulation 49 Rev.06 the actual fuel mass flow consumed by the engine in accordance with paragraph 3.4 shall be recorded for each WHTC hot start test performed in accordance with paragraph 6.6.2 of Annex 4 to UN/ECE Regulation 49 Rev.06.

The specific fuel consumption for each WHTC hot start test performed shall be calculated by the following equation:

SFC_{meas, m} = (Σ FC_{meas, m}) / (W_{act, m})

where:

SFC_{meas, m}

=

Specific fuel consumption [g/kWh]

Σ FC_meas,m

=

Total fuel consumption over the WHTC [g] determined in accordance with paragraph 5.2 of this Annex

W_{act, m}

=

Total engine work over the WHTC [kWh] determined in accordance with paragraph 5.1 of this Annex

m

=

Index defining each individual WHTC hot start test

The specific fuel consumption values for the individual WHTC tests shall be weighted by the following equation:

where:

n

=

the number of WHTC hot start tests without regeneration

n_r

=

the number of WHTC hot start tests with regeneration (minimum number is one test)

SFC_avg

=

the average specific fuel consumption from all WHTC hot start tests without regeneration [g/kWh]

SFC_avg,r

=

the average specific fuel consumption from all WHTC hot start tests with regeneration [g/kWh]

The correction factor, CF_RegPer, shall be calculated by the following equation: