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[F1ANNEX Xa U.K. CONFORMITY OF SIMULATION TOOL OPERATION AND OF CO 2 EMISSIONS AND FUEL CONSUMPTION RELATED PROPERTIES OF COMPONENTS, SEPARATE TECHNICAL UNITS AND SYSTEMS: VERIFICATION TESTING PROCEDURE
Textual Amendments
7. Test evaluation U.K.
The simulated fuel consumption shall be compared to the measured fuel consumption using the simulation tool.
7.1. Simulation of the fuel consumption U.K.
The input data and input information for the simulation tool for the verification test shall be the following:
The certified CO 2 emissions and fuel consumption related properties of the following components, separate technical units or systems:
engines;
transmissions;
torque converters;
other torque transferring components;
additional driveline components;
axles.
The input data set out in Table 4.
The power calculated by the simulation tool by the equations of longitudinal dynamics from the measured vehicle speed and road gradient course may be used for plausibility checks to test if the total simulated cycle work is similar to the measured value.
The simulation tool shall calculate the gears engaged during the verification test by calculating the engine speeds per gear at the actual vehicle speed and selecting the gear that provides the engine speed closest to the measured engine speed.
The measured wheel power shall replace in the verification test mode of the simulation tool the simulated power demand at the wheels. The measured engine speed and the gear defined in the verification test input data shall replace the corresponding simulation part. The standard fan power in the simulation tool shall be replaced by the fan power calculated from the measured fan speed in the simulation tool as follows:
where:
=
fan power to be used in the simulation for the verification test [kW]
=
measured rotational speed of the fan [1/s]
=
diameter of the fan [m]
=
generic parameters in the simulation tool:
=
7 320 W
=
1 200 rpm
=
810 mm
The steering pump, compressor and generator shall be attributed standard values in accordance with Annex IX.
All other simulation steps and data handling concerning axle, transmission and engine efficiency shall be identical to the application of the simulation tool to determine and declare the CO 2 emissions and fuel consumption of new vehicles.
The simulated fuel consumption value shall be the total fuel flow over the verification test relevant test distance, from the end of the zeroing after the warm up phase to the end of the test. The total verification test relevant test distance shall be calculated from the vehicle speed signal.
The results from the simulation tool for the verification test shall be calculated as follows:
where:
=
Verification test work calculated by the simulation tool for the complete fuel consumption measurement phase [kWh]
=
Fuel consumption simulated by the simulation tool over the complete fuel consumption measurement phase [g/kWh]
=
Simulation rate [Hz]
=
Instantaneous fuel consumption simulated by the simulation tool over the test [g/s]
7.2. Calculation of the measured fuel consumption U.K.
The measured fuel flow shall be integrated for the same time span as the simulated fuel consumption. The measured fuel consumption for the total test shall be calculated as follows:
where:
=
Fuel consumption measured by integrating fuel mass flow over the complete fuel consumption measurement phase [g/kWh]
=
Instantaneous fuel mass flow measured during the fuel consumption measurement phase [g/s]
=
Sampling rate [Hz]
=
Verification test work at the wheel calculated from the measured wheel torque and wheel rotational speeds over the complete fuel consumption measurement phase [kWh]
=
Positive power at the left (i = l) and right (i = 2) wheel calculated from the measured wheel torque and wheel rotational speeds at time step t where only power values greater zero are considered
=
instantaneously measured torque at the wheel ‘ i ’ in time step ‘ t ’ [Nm]
=
instantaneously measured rotational speed at the wheel ‘i’ in time step ‘t’ [min – 1 ]
The measured fuel consumption values shall be corrected for the net calorific value (NCV) as set out in point 3 of Annex V to calculate the verification test results.
where:
=
NCV of the fuel used in the verification test determined in accordance with point 3.2 of Annex V [MJ/kg]
=
Standard NCV in accordance with Table 4 of Annex V [MJ/kg]
=
Fuel consumption measured by integrating fuel mass over the complete fuel consumption measurement phase corrected for the test fuel NCV [g/kWh]
7.3. Pass/Fail check U.K.
The vehicle shall pass the verification test if the ratio of corrected measured fuel consumption to simulated fuel consumption is below the tolerances set out in Table 5.
In the case of a shorter run-in phase than 15 000 km the influence on the fuel efficiency of the vehicle may be corrected with the following evolution coefficient:
where:
=
Fuel consumption measured and corrected of a shorter run-in phase
=
run-in distance [km]
=
Evolution coefficient of 0,98
For vehicle odometer reading above 15 000 km, no correction shall be applied.
The ratio of measured and simulated fuel consumption for the total verification test relevant trip shall be calculated as verification test ratio in accordance with the following equation:
Where:
=
Ratio of fuel consumption measured and simulated in the verification testing procedure
For a comparison with the declared CO 2 emissions of the vehicle in accordance with Article 9, the verified CO 2 emissions of the vehicle are determined as follows:
where:
=
verified CO 2 emissions of the vehicle in [g/t-km]
=
declared CO 2 emissions of the vehicle in [g/t-km]
If a first vehicle fails the tolerances for C VTP , two more tests may be performed on the same vehicle or two more similar vehicles may be tested on request of the vehicle manufacturer. For the evaluation of the pass criterion set out in Table 5, the averages of the verification testing procedure ratio from the up to three tests shall be used. If the pass criterion is not reached, the vehicle fails the verification testing procedure.
Table 5
Pass fail criterion for the verification test
| C VPT | |
|---|---|
| Pass criterion for the verification testing procedure | < 1,075] |