Document ID: chunk:federal_register_of_legislation:F2023C00229:reg:9:p16
Version: federal_register_of_legislation:F2023C00229
Segment Type: reg
Provision Reference: reg 9 (pt 16/71)
Character Range: 253181–256255

the cycle, kg t = cycle time, s
              Kv =  calibration coefficient of the critical flow venturi for standard conditions  pA = absolute pressure at venturi inlet, kPa
              T = absolute temperature at venturi inlet, K

              If a system with flow compensation is used (i.e. without heat exchanger), the instantaneous mass emissions shall be calculated and integrated over the cycle. In this case, the instantaneous mass of the diluted exhaust gas shall be calculated as follows:

              For the PDP-CVS system:

                        MTOTW,i = 1,293 × V0 × Np,i × (pB – p1) × 273 / (101,3 × T)

              where:

              MTOTW,i = instantaneous mass of the diluted exhaust gas on wet basis, kg Np,i = total revolutions of pump per time interval

         For the CFV-CVS system:

MTOTW,i = 1,293 × Δti × Kv × pA / T0,5
              where:

              MTOTW,i = instantaneous mass of the diluted exhaust gas on wet basis, kg

              Δti = time interval, s

              If the total sample mass of particulates (MSAM) and gaseous pollutants exceeds 0,5 % of the total CVS flow (MTOTW), the CVS flow shall be corrected for MSAM or the particulate sample flow shall be returned to the CVS prior to the flow measuring device (PDP or CFV).

4.2.                            NOx correction for humidity

              As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for ambient air humidity with the factors given in the following formulae:

                (a)    for diesel engines:

                (b)    for gas engines:

              where:

              Ha = humidity of the intake air water per kg 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

4.3.                            Calculation of the emission mass flow

4.3.1.                        Systems with constant mass flow

              For systems with heat exchanger, the mass of the pollutants (g/test) shall be determined from the following equations:

                (1)    NOx mass = 0,001587 × NOx conc × KH,D × MTOT W (diesel engines)

                (2)    NOx mass = 0,001587 × NOx conc × KH,G × MTOT W (gas engines)

                (3)    COmass = 0,000966 × COconc × MTOT W

                (4)    HCmass = 0,000479 × HCconc × MTOT W (diesel engines)

                (5)    HCmass = 0,000502 × HCconc × MTOT W (LPG fuelled engines)

                (6)    NMHCmass = 0,000516 × NMHCconc × MTOT W (NG fuelled engines)

(7)    CH4 mass = 0,000552 × CH4 conc × MTOT W (NG fuelled engines) where:
              NOx conc, COconc, HCconc (1), NMHCconc = average background corrected concentrations over the cycle from
                               integration (mandatory for NOx and HC) or bag measurement, ppm

              MTOTW = total mass of diluted exhaust gas over the cycle as determined in Section 4.1, kg KH,D = humidity correction factor for