Document ID: chunk:federal_register_of_legislation:F2023L00129:reg:10:p126
Version: federal_register_of_legislation:F2023L00129
Segment Type: reg
Provision Reference: reg 10 (pt 126/150)
Character Range: 1074426–1077691

kg
              D is the dilution factor
              Optionally, the u factor may be calculated with equation 57 in paragraph 8.5.2.3.1. of Annex 4 by using a CO2 molar mass (MCO2) of 44.01 g/mol.
              CO2 background correction shall be applied in accordance with paragraph 8.5.2.3.2. of Annex 4.
              3.3. Calculation of brake specific emissions
              The cycle work needed for the calculation of brake specific CO2 emissions shall be determined in accordance with paragraph 7.8.6. of Annex 4.
              3.3.1. WHTC
              The brake specific emissions eCO2 (g/kWh) shall be calculated as follows:
              Where:
              mCO2, cold is the CO2 mass emissions of the cold start test, g/test
              mCO2, hot is the CO2 mass emissions of the hot start test, g/test
              Wact, cold is the actual cycle work of the cold start test, kWh
              Wact, hot  is the actual cycle work of the hot start test, kWh
3.3.2. WHSC
              The brake specific emissions eCO2 (g/kWh) shall be calculated as follows:
              Where:
              mCO2   is the CO2 mass emissions, g/test
              Wact  is the actual cycle work, kWh
 4.  Determination of fuel consumption
              4.1. Measurement
              Measurement of the instantaneous fuel flow shall be done by systems that preferably measure mass directly such as the following:
              (a) Mass flow sensor;
              (b) Fuel weighing;
              (c) Coriolis meter.
              The fuel flow measurement system shall have the following:
                  (a) An accuracy of ±2 per cent of the reading or ±0.3 per cent of full scale whichever is better;
              (b) A precision of ±1 per cent of full scale or better;
              (c) A rise time that does not exceed 5 s.
              The fuel flow measurement system shall meet the linearity requirements of paragraph 9.2. and Table 7 of Annex 4.
              Precautions shall be taken to avoid measurement errors. Such precautions shall at least include the following:
                  (a) The careful installation of the device according to the instrument manufacturers" recommendations and to good engineering practice;
                  (b) Flow conditioning as needed to prevent wakes, eddies, circulating flows, or flow pulsations that affect accuracy or precision of the fuel flow system;
                  (c) Account for any fuel that bypasses the engine or returns from the engine to the fuel storage tank.
              4.2. Data evaluation
              The relevant data shall be recorded and stored in accordance with paragraph 7.6.6. of Annex 4.
              4.3. Calculation of cycle averaged fuel consumption
              The mass of fuel (g/test) shall be determined by the sum of the instantaneous values over the cycle, as follows:
              Where:
              qmf,i is the instantaneous fuel flow, kg/s
              f is the data sampling rate, Hz
              n is the number of measurements
              4.4. Calculation of brake specific fuel consumption
              The cycle work needed for the calculation of the brake specific fuel consumption shall be determined in accordance with paragraph 7.8.6. of Annex