Jet Fuels Flashcards
What is the average fuel consumption of an average plane at crusing speed ?
15 000 L/h or 12 t/h for a boeing 747
How is the fuel burnt in a plane ?
Auto-ignition at high T and P
In jet fuel, what are the measures taken to prevent water contamination ?
- Floatinf arms in the tanks
- 2 micron water separator micro-filter
What are the three most importants specifications for jet fuels ?
- Volatility
- Resistance to low temperature
- Combustion quality
What are the ASTM specs for jet fuel ?
- 10% distilled : max 205°C
- FBP : 300°C
- Losses < 1.5%
What are the two specs used to monitor the distillation column ?
- Flash point of the kerosene cut (separation between gasoline and kerosene)
- Freezing point of the kerosene cut (separation btween kerosene and LGO)
What is the spec of jet fuel regarding flash point ?
Flash point > 38°C
Why is flash point important ?
It’s a safety spec to improve safety during storage and transport
What are the specs for smoke point in jet fuel
- smoke point > 25 mm or >18 mm if naphthalene under 3%
- aromatic content < 25%
What is the specification for the calorific value of jet fuel ?
LCV > 42 800 kJ/kg
Why is there a calorific spec on jet fuel ?
To enable the pilote to calculate the amount of fuel he will need and not take too much (it makes the plane heavier and we then increase fuel consumption)
What is the density spec of jet fuel ?
Density at 15°C between 0.775 and 0.840 kg/m3
What is the viscosity spec of jet fuel ?
Viscosity at -20°C < 8 cSt
What is the freezing point spec of jet fuel ?
Freezing point < -47°C
What affects the freezing point of jet fuel ?
The higher the n-paraffin content the higher the freezing point :(
