Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p5
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 5/71)
Character Range: 220189–223361

dry air
              in which

              Ra = relative humidity of the intake air, %

              pa = saturation vapour pressure of the intake air, kPa pB = total barometric pressure, kPa

4.4.                            Calculation of the emission mass flow rates

              The emission mass flow rates (g/h) for each mode shall be calculated as follows, assuming the exhaust gas density to be 1,293 kg/m3 at 273 K (0 C) and 101,3 kPa:

                (1)    NOx mass = 0,001587 × NOx conc × KH,D × GEXHW

                (2)    COx mass = 0,000966 × COconc × GEXHW

                (3)    HCmass = 0,000479 × HCconc × GEXHW

              where NOx conc, COconc, HCconc (1) are the average concentrations (ppm) in the raw exhaust gas, as determined in Section 4.1.

              If, optionally, the gaseous emissions are determined with a full flow dilution system, the following formulae shall be applied:

                (1)    NOx mass = 0,001587 × NOx conc × KH,D × GTOTW

                (2)    COx mass = 0,000966 × COconc × GTOTW

                (3)    HCmass = 0,000479 × HCconc × GTOTW

              where NOx conc, COconc, HCconc (1) are the average background corrected concentrations (ppm) of each mode in the diluted exhaust gas, as determined in Annex III, Appendix 2, Section 4.3.1.1.

         (1) Based on C1 equivalent.

4.5.                            Calculation of the specific emissions

              The emissions (g/kWh) shall be calculated for all individual components in the following way:

              The weighting factors (WF) used in the above calculation are according to Section 2.7.1.

4.6.                            Calculation of the area control values

              For the three control points selected according to Section 2.7.6, the NOx emission shall be measured and calculated according to Section 4.6.1 and also determined by interpolation from the modes of the test cycle closest to the respective control point according to Section 4.6.2. The measured values are then compared to the interpolated values according to Section 4.6.3.

4.6.1.                        Calculation of the specific emission

              The NOx emission for each of the control points (Z) shall be calculated as follows:

4.6.2.                        Determination of the emission value from the test cycle

              The NOx emission for each of the control points shall be interpolated from the four closest modes of the test cycle that envelop the selected control point Z as shown in Figure 4. For these modes (R, S, T, U), the following definitions apply:

Speed(R)           =   Speed(T) = nRT
Speed(S)           =   Speed(U) = nSU
Per cent load(R)   =   Per cent load(S)
Per cent load(T)   =   Per cent load(U).

              The NOx emission of the selected control point Z shall be calculated as follows:

              and:
               where,

                      ER, ES, ET, EU = specific NOx emission of the enveloping modes calculated in accordance with Section 4.6.1.
              MR, MS, MT, MU = engine torque of the enveloping modes

        Figure 4

        Interpolation of NOx control