Traduction de «Diluted exhaust gas » (Anglais → Français) :

‘particulate pollutants’ means components of the exhaust gas which are removed from the diluted exhaust gas at a maximum temperature of 325 °K (52 °C) by means of the filters described in the test procedure for verifying average tailpipe emissions.

The following formulae shall be applied: where conc e,i = instantaneous concentration of the respective pollutant measured in the diluted exhaust gas (ppm) conc d = concentration of the respective pollutant measured in the dilution air (ppm) u = ratio between density of the exhaust component and density of diluted exhaust gas, as reported in Table 4, point 2.1.2.1 M TOTW,i = instantaneous mass of the diluted exhaust gas (section 2.2.1) (kg) M TOTW = total mass of diluted exhaust gas over the cycle (section 2.2.1) (kg) DF = dilution factor as determined in point 2.2.3.1.1.

where G EDFW ,i = instantaneous equivalent diluted exhaust mass flow rate (kg/s) G EXHW ,i = instantaneous exhaust mass flow rate (kg/s) q i = instantaneous dilution ratio G TOTW ,I = instantaneous diluted exhaust mass flow rate through dilution tunnel (kg/s) G DILW ,i = instantaneous dilution air mass flow rate (kg/s) f = data sampling rate (Hz) n = number of measurements (b) where M f = particulate mass sampled over the cycle (mg) r s = average sample ratio over the test cycle where where M SE = sampled exhaust mass over the cycle (kg) M EXHW = total exhaust mass flow over the cycle (kg) M SAM = mass of diluted exhaust gas passing the particu ...[+++]late collection filters (kg) M TOTW = mass of diluted exhaust gas passing the dilution tunnel (kg) NOTE: In case of the total sampling type system, M SAM and M TOTW are identical.

2.2.1. Determination of the Diluted Exhaust Gas Flow PDP-CVS system The calculation of the mass flow over the cycle, if the temperature of the diluted exhaust is kept within ± 6 K over the cycle by using a heat exchanger, is as follows: M TOTW = 1,293 x V0 x NP x (pB - p1 ) x273 / (101,3 x T) where M TOTW = mass of the diluted exhaust gas on wet basis over the cycle V0 = volume of gas pumped per revolution under test conditions (m³/rev) NP = total revolutions of pump per test pB = atmospheric pressure in the test cell (kPa) p1 = pressure drop below atmospheric at the pump inlet (kPa) T = average temperature of the diluted exhaust gas at ...[+++]pump inlet over the cycle (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.

Calculation of the Mass Flow The particulate mass MPT (g/test) shall be calculated as follows: PT where: Mf = particulate mass sampled over the cycle (mg) MTOTW = total mass of diluted exhaust gas over the cycle as determined in section 2.2.1 (kg) MSAM = mass of diluted exhaust gas taken from the dilution tunnel for collecting particulates (kg) and, Mf = Mf,p + Mf,b , if weighed separately (mg) Mf,p = particulate mass collected on the primary filter (mg) Mf,b = particulate mass collected on the back-up filter (mg) If a double dilution system is used, the mass of the secondary dilution air shall be subtracted from the total mass of the do ...[+++]uble diluted exhaust gas sampled through the particulate filters.

The tracer gas concentrations (CO2 or NOx) are measured in the raw exhaust gas, the diluted exhaust gas, and the dilution air with the exhaust gas analyser(s) EGA, and the dilution ratio is calculated from the values so measured.