(a) Oven characteristics. The oven used for thermally 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: ------------------------------------------------------------------------
Parts
Constituent Volume per
percent million------------------------------------------------------------------------Carbon Monoxide...................................... 1 .......Oxygen............................................... 1.3 .......Carbon Dioxide....................................... 3.8 .......Water Vapor.......................................... 10 .......Sulfer dioxide....................................... ........ 20Oxides of nitrogen................................... ........ 280Hydrogen............................................. ........ 3500Hydrocarbon *........................................ ........ 4000Nitrogen = Balance------------------------------------------------------------------------\*\ Propylene/propane ratio = 2/1.
(c) Phase 2 engines. The catalyst thermal stress test is not required for engine families certified to the Phase 2 standards. [60 FR 34598, July 3, 1995, as amended at 64 FR 15243, Mar. 30, 1999]
Sec. Appendix A to Subpart D of Part 90--Tables
Table 1--Symbols Used in Subpart D------------------------------------------------------------------------
Symbol Term Unit------------------------------------------------------------------------CO Carbon monoxide.........................CO2 Carbon dioxide..........................NO Nitric oxide............................NO2 Nitrogen dioxide........................NOX Oxides of nitrogen......................O2 Oxygen..................................conc Concentration (ppm by volume)........... ppmf Engine specific parameter considering
atmospheric conditions.FFCB Fuel specific factor for the carbon
balance calculation.FFD Fuel specific factor for exhaust flow
calculation on dry basis.FFH Fuel specific factor representing the
hydrogen to carbon ratio.FFW Fuel specific factor for exhaust flow
calculation on wet basis.GAIRW Intake air mass flow rate on wet basis.. kg/hGAIRD Intake air mass flow rate on dry basis.. kg/hGEXHW Exhaust gas mass flow rate on wet basis. kg/hGFuel Fuel mass flow rate..................... kg/hH Absolute humidity (water content related gr/kg
to dry air).
i Subscript denoting an individual mode...KH Humidity correction factor..............L Percent torque related to maximum torque percent
for the test mode.mass Pollutant mass flow..................... g/hnd, i Engine speed (average at the i'th mode 1/min
during the cycle).Ps Dry atmospheric pressure................ kPaPd Test ambient saturation vapor pressure kPa
at ambient temperature.P Gross power output uncorrected.......... kWPAUX Declared total power absorbed by kW
auxiliaries fitted for the test.PM Maximum power measured at the test speed kW
under test conditions.Pi Pi = PM, i + PAUX, i....................PB Total barometric pressure (average of kPa
the pre-test and post-test values).Ra Relative humidity of the ambient air.... percentT Absolute temperature at air inlet....... CTbe Air temperature after the charge air C
cooler (if applicable) (average).Tclout Coolant temperature outlet (average).... CTDd Absolute dew point temperature.......... CTd, i Torque (average at the i'th mode during N-m
the cycle).TSC Temperature of the intercooled air...... CTref Reference temperature................... CVEXHD Exhaust gas volume flow rate on dry m\3\/h
basis.VAIRW Intake air volume flow rate on wet basis m\3\/hPB Total barometric pressure............... kPaVEXHW Exhaust gas volume flow rate on wet m\3\/h
basis.WF Weighing factor.........................WFE Effective weighing factor...............------------------------------------------------------------------------
Table 2--Measurement Calibration Accuracy and Frequency----------------------------------------------------------------------------------------------------------------
Permissible deviation from reading *
No. Item ---------------------------------------------- Calibration frequency
Non-idle Idle----------------------------------------------------------------------------------------------------------------1......... Engine speed............. [2 %..................... Same............. Monthly or within one month
prior to the certification
test.2......... Torque................... [2 %..................... ................. Monthly or within one month
prior to the certification
test.3......... Fuel consumption......... [2 %..................... [5%.............. Monthly or within one month
prior to the certification
test.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 air) [3.0 %................... Same............. As required.
(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 % **.................. Same............. Monthly or within one month
prior to the certification
test.17........ CO analyzer.............. [2 % **.................. Same............. Monthly or within one month
prior to the certification
test.18........ NOX analyzer............. [2 % **.................. Same............. Monthly or within one month
prior to the rtification
test.19........ NOX converter check...... 90 %..................... Same............. Monthly or within one month
prior to the certification
test.20........ CO2 analyzer............. [2 % **.................. Same............. Monthly or within one month
prior to the certification
test.----------------------------------------------------------------------------------------------------------------\*\ All accuracy requirements pertain to the final recorded value which is inclusive of the data acquisition
system.\**\ If reading is under 100 ppm then the accuracy shall be [2 ppm.
Table 3--Test Fuel Specifications----------------------------------------------------------------------------------------------------------------
Item Property Tolerances Procedure (ASTM) \1\----------------------------------------------------------------------------------------------------------------Sulfur, ppm max..................... 339...................... ......................... D 2622-92
Benzene, max. %..................... 1.5...................... ......................... D 3606-92RVP, psi............................ 8.7...................... [0.2..................... D 5191-93aOctane, R+M/2....................... 87.3..................... [0.5..................... D 2699-92
D 2700-92IBP, C.............................. 32.8..................... [11.0.................... D 86-9310 % point, C....................... 53.3..................... [5.5..................... D 86-9350 % point, C....................... 103.3.................... [5.5..................... D 86-9390 % point, C....................... 165.6.................... [5.5..................... D 86-93End Point, max. C................... 212.8.................... ......................... D 86-93Phosphorus, g/liter, max............ 0.02..................... ......................... D 3231-89Lead, g/liter, max.................. 0.02..................... ......................... ....................Manganese, g/liter, max............. 0.004.................... ......................... ....................Aromatics, %........................ 32.0..................... [4.0..................... D 1319-89Olefins, %.......................... 9.2...................... [4.0..................... D 1319-89Saturates, %........................ Remainder................ ......................... D 1319-89----------------------------------------------------------------------------------------------------------------\1\ All ASTM procedures in this table have been incorporated by reference. See Sec. 90.7.
Sec. Appendix B to Subpart D of Part 90--Figures
[GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT] [GRAPHIC(S) NOT AVAILABLE IN TIFF FORMAT]