5.3 Test fuel oils
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Statutory Documents - IMO Publications and Documents - International Codes - NOx Technical Code (2008) - Technical Code on Control of Emission of Nitrogen Oxides from Marine Diesel Engines - Chapter 5 - Procedures for NOx emission measurements on a test bed - 5.3 Test fuel oils

5.3 Test fuel oils

  5.3.1 Fuel oil characteristics may influence the engine exhaust gas emission; in particular, some fuel bound nitrogen can be converted to NOx during combustion. Therefore, the characteristics of the fuel oil used for the test are to be determined and recorded. Where a reference fuel oil is used, the reference code or specifications and the analysis of the fuel oil shall be provided.

  5.3.2 The selection of the fuel oil for the test depends on the purpose of the test. If a suitable reference fuel oil is not available, it is recommended to use a DM-grade (distillate) marine fuel specified in ISO 8217:2005, with properties suitable for the engine type. In case a DM-grade fuel oil is not available, a RM-grade (residual) fuel oil according to ISO 8217:2005 shall be used. The fuel oil shall be analysed for its composition of all components necessary for a clear specification and determination of DM- or RM-grade. The nitrogen content shall also be determined. The fuel oil used during the parent engine test shall be sampled during the test.

  5.3.3 The fuel oil temperature shall be in accordance with the manufacturer’s recommendations. The fuel oil temperature shall be measured at the inlet to the engine, or as specified by the manufacturer, and the temperature and location of measurement recorded.

  5.3.4 The selection of gas fuel for testing depends on the aim of tests. In case where an appropriate standard gas fuel is not available, other gas fuels shall be used with the approval of the Administration. A gas fuel sample shall be collected during the test of the parent engine. The gas fuel shall be analysed to give fuel composition and fuel specification.

  5.3.5 Gas fuel temperature shall be measured and recorded together with the measurement point position.

  5.3.6 Gas mode operation of dual fuel engines using liquid fuel as pilot or balance fuel shall be tested using maximum liquid-to-gas fuel ratio, such maximum ratio means for the different test cycle modes the maximum liquid-to-gas setting certified. The liquid fraction of the fuel shall comply with 5.3.1, 5.3.2 and 5.3.3.

Parent topic: Chapter 5 - Procedures for NOx emission measurements on a test bed
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