Commission Regulation (EU) 2017/2400Show full title

1. Fan

The engine torque shall be measured at engine motoring with and without fan engaged with the following procedure:

(i)

Install the fan according to product instruction before the test starts.

(ii)

Warm up phase: The engine shall be warmed up according to the recommendation of the manufacturer and by practicing good engineering judgement (eg operating the engine for 20 minutes at mode 9, as defined in Table 1 of paragraph 7.2.2. of Annex 4 to UN/ECE Regulation 49 Rev.06).

(iii)

Stabilization phase: After the warm-up or optional warmup step (v) is completed the engine shall be operated with minimum operator demand (motoring) at engine speed n_pref for 130 ± 2 seconds with the fan disengaged (n_{fan_disengage} < 0,25 * n_engine * r_fan) The first 60 ± 1 seconds of this period are considered as a stabilization period, during which the actual engine speed shall be held within ±5 min^{– 1} of n_pref.

(iv)

Measurement phase: During the following period of 60 ± 1 seconds the actual engine speed shall be held within ± 2 min^{– 1} of n_pref and the coolant temperature within ± 5 °C while the torque for motoring the engine with the fan disengaged, the fan speed and the engine speed shall be recorded as an average value over this period of 60 ± 1 seconds. The remaining period of 10 ± 1 seconds shall be used for data post-processing and storage if necessary.

(v)

Optional warmup phase: Upon manufacturer's request and according to good engineering judgement step (ii) can be repeated (e.g. if the temperature has dropped more than 5 °C)

(vi)

Stabilization phase: After the optional warm-up is completed the engine shall be operated with minimum operator demand (motoring) at engine speed n_pref for 130 ± 2 seconds with the fan engaged (n_{fan_engage} > 0,9 * n_engine * r_fan) The first 60 ± 1 seconds of this period are considered as a stabilization period, during which the actual engine speed shall be held within ± 5 min^{– 1} of n_pref.

(vii)

Measurement phase: During the following period of 60 ± 1 seconds the actual engine speed shall be held within ± 2 min^{– 1} of n_pref and the coolant temperature within ± 5 °C while the torque for motoring the engine with the fan engaged, the fan speed and the engine speed shall be recorded as an average value over this period of 60 ± 1 seconds. The remaining period of 10±1 seconds shall be used for data post-processing and storage if necessary.

(viii)

Steps (iii) to (vii) shall be repeated at engine speeds n_95h and n_hi instead of n_pref, with an optional warmup step (v) before each stabilization step if needed to maintain a stable coolant temperature (± 5 °C), according to good engineering judgement.

(ix)

If the standard deviation of all calculated C_i according to the equation below at the three speeds n_pref, n_95h and n_hi is equal or higher than 3 percent, the measurement shall be performed for all engine speeds defining the grid for the fuel mapping procedure (FCMC) according to paragraph 4.3.5.2.1.

The actual fan constant shall be calculated from the measurement data according to the following equation:

where:

C_i

fan constant at certain engine speed

MD_{fan_disengage}

measured engine torque at motoring with fan disengaged (Nm)

MD_{fan_engage}

measured engine torque at motoring with fan engaged (Nm)

n_{fan_engage}

fan speed with fan engaged (min^{– 1})

n_{fan_disengage}

fan speed with fan disengaged min^{– 1})

r_fan

fan ratio

If the standard deviation of all calculated C_i at the three speeds n_pref, n_95h and n_hi is less than 3 %, an average value C_avg-fan determined over the three speeds n_pref, n_95h and n_hi shall be used for the fan constant.

If the standard deviation of all calculated C_i at the three speeds n_pref, n_95h and n_hi is equal or higher than 3 %, individual values determined for all engine speeds according to point (ix) shall be used for the fan constant C_ind-fan,i. The value of the fan constant for the actual engine speed C_fan, shall be determined by linear interpolation between the individual values C_ind-fan,i of the fan constant.

The engine torque for driving the fan shall be calculated according to the following equation:

M_fan = C_fan · n_fan ² · 10^{– 6}

where:

M_fan

engine torque for driving fan (Nm)

C_fan

fan constant C_avg-fan or C_ind-fan,i corresponding to n_engine

The mechanical power consumed by the fan shall be calculated from the engine torque for driving the fan and the actual engine speed. Mechanical power and engine torque shall be taken into account in accordance with paragraph 3.1.2.