Appendix 7 - Checklist for an engine parameter check method
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Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code - Technical Code on Control of Emission of Nitrous Oxides from Marine Diesel Engines - Appendix 7 - Checklist for an engine parameter check method

Appendix 7 - Checklist for an engine parameter check method

 (Refer to 6.2.3.5 of the NOx Technical Code)

  1 For some of the parameters listed below, more than one survey possibility exists. In such cases, as a guideline, any one of, or a combination of, the below listed methods may be sufficient to show compliance. Approved by the Administration, the ship operator, supported by the engine manufacturer, may choose what method is applicable.

  • .1 parameter "injection timing"

    • .1 fuel cam position (individual cam or camshaft if cams are not adjustable),

      • optional (dependent on design): position of a link between the cam and the pump drive,
      • optional for sleeve-metered pumps: VIT index and cam position or position of the barrel, or
      • other sleeve metering device;

    • .2 start of delivery for certain fuel rack positions (dynamic pressure measurement);

    • .3 opening of injection valve for certain load points, e.g., using a Hall sensor or acceleration pick-up;

    • .4 load-dependent operating values for charge air pressure, combustion peak pressure, charge air temperature, exhaust gas temperature versus graphs showing the correlation with NOx. Additionally, it shall be ensured that the compression ratio corresponds to the initial certification value (see 1.7);

      Note To assess the actual timing, it is necessary to know the allowable limits for meeting the emission limits or even graphs showing the influence of timing on NOx, based on the test-bed NOx measurement results.

  • .2 parameter "injection nozzle"

    • .1 specification and component identification number

  • .3 parameter "injection pump"

    • .1 component identification number (specifying plunger and barrel design)

  • .4 parameter "fuel cam"

    • .1 component identification number (specifying shape)

    • .2 start and end of delivery for a certain fuel rack position (dynamic pressure measurement)

  • .5 parameter "injection pressure"

    • .1 only for common-rail systems: load-dependent pressure in the rail, graph showing the correlation with NOx

  • .6 parameter "combustion chamber"

    • .1 component identification numbers for the cylinder head and piston head

  • .7 parameter "compression ratio"

    • .1 check for actual clearance

    • .2 check for shims in piston rod or connecting rod

  • .8 parameter "turbocharger type and build"

    • .1 model and specification (identification numbers)

    • .2 load-dependent charge air pressure, graph showing the correlation with NOx

  • .9 parameter "charge air cooler, charge air pre-heater"

    • .1 model and specification

    • .2 load-dependant charge air temperature corrected to reference conditions, graph showing the correlation with NOx

  • .10 parameter "valve timing" (only for 4-stroke engines with inlet valve closure before BDC)

    • .1 cam position

    • .2 check actual timing

  • .11 parameter "water injection" (for assessment: graph showing the influence on NOx)

    • .1 load-dependent water consumption (monitoring)

  • .12 parameter "emulsified fuel" (for assessment: graph showing the influence on NOx)

    • .1 load-dependent fuel rack position (monitoring)

    • .2 load-dependent water consumption (monitoring)

  • .13 parameter "exhaust gas recirculation" (for assessment: graph showing the influence on NOx)

    • .1 load-dependent mass flow of recirculated exhaust gas (monitoring)

    • .2 CO2 concentration in the mixture of fresh air and recirculated exhaust gas, i.e., in the "scavenge air" (monitoring)

    • .3 O2 concentration in the "scavenge air" (monitoring)

  • .14 parameter "selective catalytic reduction" (SCR)

    • .1 load-dependent mass flow of reducing agent (monitoring) and additional periodical spot checks on NOx concentration after SCR (for assessment, graph showing the influence on NOx)

  2 For engines with selective catalytic reduction (SCR) without feedback control, optional NOx measurement (periodical spot checks or monitoring) is useful to show that the SCR efficiency still corresponds to the state at the time of certification regardless of whether the ambient conditions or the fuel quality led to different raw emissions.

Parent topic: NOx Technical Code - Technical Code on Control of Emission of Nitrous Oxides from Marine Diesel Engines
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