(a) Oven characteristics. The oven used for termally stressing the test catalyst must be capable of maintaining a temperature of 500 [5 C and 1000 [10 C.
(b) Evaluation gas composition. (1) A synthetic exhaust gas mixture is used for evaluating the effect of thermal stress on catalyst conversion efficiency.
(1) A synthetic exhaust gas mixture is used for evaluating the effect of thermal stress on catalyst conversion efficiency.
(2) The synthetic exhaust gas mixture must have the following composition: ------------------------------------------------------------------------
Volume Parts per
Constituent percent million------------------------------------------------------------------------Carbon Monoxide \1\........................... 1 ...........Oxygen........................................ 1.3Carbon Dioxide................................ 9Water Vapor................................... 10Sulfur Dioxide................................ ........... 20Oxides of Nitrogen............................ ........... 280Hydrogen...................................... ........... 3500Hydrocarbon \1 2\............................. ........... 4000Nitrogen=Balance..............................------------------------------------------------------------------------\1\ Alternatively, the carbon monoxide and hydrocarbon proportions of
the mixture may be changed to 1.2% and 4650 ppm, respectively (using
on of these alternative concentrations requires that the other be used
simultaneously).\2\ Propylene/propane ratio=2/1. [61 FR 52102, Oct. 4, 1996; 62 FR 20066, Apr. 24, 1997]
Sec. Appendix A to Subpart D of Part 91--Tables
Table 1--Symbols Used in Subparts D and E----------------------------------------------------------------------------------------------------------------
Symbol Term Unit----------------------------------------------------------------------------------------------------------------AYM............................. Final weighted emission test g/kW-hr
results.C3 H8........................... Propane......................... ............................................CB.............................. Concentration of emission in ppm
background sample.CD.............................. Concentration of emission in ppm
dilute sample.CO.............................. Carbon monoxide................. ............................................CO2............................. Carbon dioxide.................. ............................................conc............................ Concentration (ppm by volume)... ppmDX.............................. Density of a specific emission g/m\3\
(XX).DXX............................. Volume concentration of a percent
specific emission (XX) on a dry
basis.DF.............................. Dilution factor of dilute
exhaust.D1.............................. Water vapor mixture percent
concentration.f............................... Engine specific parameter ............................................
considering atmospheric
conditions.GAIRD........................... Intake air mass flow rate on dry kg/h
basis.GFuel........................... Fuel mass flow rate............. kg/hGP.............................. Analyzer standard operating Pa
pressure.Gs.............................. Mass of carbon measured during a g
sampling period.H............................... Absolute humidity (water content gr/kg
related to dry air).H2.............................. Hydrogen........................ ............................................i............................... Subscript denoting an individual ............................................
mode.IT.............................. Indicated torque................ N-mK............................... Wet to dry conversion factor.... ............................................KH.............................. Humidity correction factor...... ............................................KV.............................. Calibration coefficient for ............................................
critical flow venturi.MX.............................. Molecular weight of a specific g/mole
molecule(XX).mass............................ Pollutant mass flow............. g/hMFUEL........................... Mass of fuel consumed during a g
sampling period.N............................... Pump revolutions during test revs
period.N2.............................. Nitrogen........................ ............................................NO.............................. Nitric oxide.................... ............................................NO2............................. Nitrogen dioxide................ ............................................NOX............................. Oxides of nitrogen.............. ............................................O2.............................. Oxygen.......................... ............................................O2 I............................ Oxygen concentration of the percent
burner air.P............................... Absolute pressure............... kPaPAUX............................ Declared total power absorbed by kW
auxiliaries fitted for the test.PB.............................. Total barometric pressure kPa
(average of the pre-test and
post-test values).Pdew............................ Test ambient saturation vapor kPa
pressure at the dew point.Pe.............................. Absolute pump outlet pressure... kPaPED............................. Pressure drop between the inlet kPa
and throat of metering venturi.Pi.............................. Pi=PM, i + PAUX,i............... ............................................
PM.............................. Maximum power measured at the kW
test speed under test
conditions.PP.............................. Absolute pump inlet pressure.... kPaPPI............................. Inlet pressure depression of kPa
venturi or pump.PPO............................. Pressure head at CVS pump outlet kPaPs.............................. Dry atmospheric pressure........ kPaPV.............................. Absolute venturi inlet pressure. kPaPwb............................. Saturated vapor pressure........ PaQC.............................. Volumetric flow rate of dilute m\3\/hr
exhaust through CVS at STP.QS.............................. Gas flow rate................... m\3\/minRSTP............................ Ideal gas constant at STP....... m\3\/moleR2.............................. Fuel carbon weight fraction..... g/gSTP............................. Standard temperature and ............................................
pressure.t............................... Elapsed time for test period.... sec.T............................... Absolute temperature at air C
inlet.Ta.............................. Ambient temperature............. CTEI............................. Air temperature in to metering C
venturi or flowmeter.TK.............................. Absolute temperature............ KTP.............................. Absolute pump inlet temperature. CTPI............................. Air temperature at CVS pump C
inlet.TPO............................. Air temperature at CVS pump C
outlet.TV.............................. Absolute venturi inlet C
temperature.VO.............................. Pump flow....................... m\3\/revW............................... Average mass flow of emissions.. g/hrWX.............................. Mass rate of specific emission g/hr
(XX).WXX............................. Volume concentration in exhaust ppm, ppmC, %
of specific emission (XX) on
wet basis.WF.............................. Weighing factor................. ............................................Z1.............................. Water concentration............. percent[alpha]......................... Fuel specific factor
representing the hydrogen to
carbon ratio.----------------------------------------------------------------------------------------------------------------
Table 2--Measurement Accuracy Calibration Frequency----------------------------------------------------------------------------------------------------------------
Permissible deviation from reading \1\
No. Item -------------------------------------------------- Calibration frequency
non-idle idle----------------------------------------------------------------------------------------------------------------1........... Engine speed........... [2%.................... [2%.................... Monthly.2........... Torque................. [5%.................... ....................... Monthly.3........... Fuel consumption....... [1%.................... [5%.................... Monthly.4........... Air consumption........ [2%.................... [5%.................... As required.5........... Coolant temperature.... [2 C................... Same................... As required.6........... Lubricant temperature.. [2 C................... Same................... As required.7........... Exhaust back pressure.. [5%.................... Same................... As required.8........... Inlet depression....... [5%.................... Same................... As required.9........... Exhaust gas temperature [15 C.................. Same................... As required.10.......... Air inlet temperature [2 C................... Same................... As required.
(combustion air).11.......... Atmospheric pressure... [0.5%.................. Same................... As required.12.......... Humidity (combustion [3.0%.................. Same................... As required.
air) (relative).13.......... Fuel temperature....... [2 C................... Same................... As required.14.......... Temperature with regard [2 C................... Same................... As required.
to dilution system.15.......... Dilution air humidity.. [3% absolute........... Same................... As required.16.......... HC analyzer............ [2% \2\................ Same................... Monthly.17.......... CO analyzer............ [2% \2\................ Same................... Monthly.18.......... NOX analyzer........... [2% \2\................ Same................... Monthly.19.......... NOX converter check.... 90%.................... Same................... Monthly.20.......... CO2 analyzer........... [2% \2\................ Same................... Monthly.----------------------------------------------------------------------------------------------------------------\1\ All accuracy requirements pertain to the final recorded value which is inclusive of the data acquisition
system.\2\ If reading is under 100 ppm then the accuracy shall be [2 ppm.
Table 3--Test Fuel Specifications------------------------------------------------------------------------
Procedure
Item Property Tolerance (ASTM) \1\------------------------------------------------------------------------Sulfur, ppm max.................. 1000 ........... D 2622Benzene, max. percent............ 1.5 ........... D 3606RVP, psi......................... 8.6 [0.6 D 323Octane, R+M/2.................... 89.9 [3.1 D 2699
D 2700
IBP, C........................... 32.8 [11.0 D 8610% point, C..................... 53.3 [5.5 D 8650% point, C..................... 101.7 [8.3 D 8690% point, C..................... 160.0 [11.1 D 86End Point, max. C................ 212.8 ........... D 86Phosphorus, g/l, max............. 0.02 ........... D 3231Lead, g/l, max................... 0.02 ........... ...........Manganese, g/l, max.............. 0.004 ........... ...........Aromatics, max. percent.......... 35 ........... D 1319Olefins, max. percent............ 10 ........... D 1319Saturates, percent............... remain ........... D 1319------------------------------------------------------------------------\1\ All ASTM Procedures in this table have been incorporated by
reference. See Sec. 91.6.
Sec. Appendix B to Subpart D of Part 91--Figures
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