how to check engine efficiency

Answer

I would carry out an engine performance test at steady load.

Record:

1. Engine rpm.
2. Shaft/indicated power.
3. Fuel consumption.
4. Fuel density and calorific value.
5. Pmax​.
6. Pcomp​.
7. indicated mean effective pressure.
8. exhaust temperatures.
9. scavenge pressure and temperature.
10. turbocharger rpm.
11. ambient/sea-water conditions where needed.
12. ship speed, draft and weather for propulsion assessment.

Then calculate SFOC and thermal efficiency and compare with:

• maker's baseline;
• sea-trial results;
• previous performance reports.

Oral answer:

I will check engine efficiency by taking a performance test at stable load. I determine actual engine power and fuel mass consumption, calculate SFOC and brake thermal efficiency using the fuel LCV, and compare them with maker or sea-trial reference data. At the same time I analyze indicator cards, Pmax, compression pressure, exhaust temperatures, scavenge pressure and turbocharger parameters to identify where efficiency is being lost.”