Fuels And Additives

Question 1

What are hydrocarbons?

Answer 1

Fuels for internal combustion engines are basically substances that can be made to vaporise and burn

Question 2

What is crude oil?

Answer 2

It’s found it’s earths crust and hydrocarbons are processed from it

Question 3

What dose LPGstand for?

Answer 3

Liquefied petroleum gas

Question 4

What are bio fuels?

Answer 4

Alcohols (methanol and Ethanol) are produced from vegetable matter

Question 5

How would you describe crude oil?

Answer 5

Unprocessed oil

Question 6

What dose crude oil contain?

Answer 6

Hundreds of different types of hydrocarbon all mixed together

Question 7

What is fraction distillation?

Answer 7

Is used for separating a mixture of substances with narrow differences

Question 8

What is cracking?

Answer 8

Breaking large hydrocarbons into smaller pieces

Question 9

What is unification?

Answer 9

The combination of smaller hydrocarbons to make larger ones

Question 10

What is alteration?

Answer 10

The structures of molecules in one fraction are rearranged to produce another

Question 11

What are some properties of good fuel?

Answer 11

High calorific value 
High octane number 
Low freezing point 
High latent heat 
Easy evaporation 
High flash point 
High density 
Must not absorb water

Question 12

What are the side effects of having a RICH fuel mixture?

Answer 12

High power

Less efficient combustion

Question 13

What are the side effects of having a WEAK fuel mixture?

Answer 13

Lower power
More efficient combustion
Lower fuel consumption

Question 14

What is detonation?

Answer 14

When burning takes place in many parts of the combustion chamber almost at same time and a powerful shockwave occurs

Question 15

What dose detonation cause?

Answer 15

Knocking

Pinking

Question 16

What are the effects of detonation?

Answer 16

Erosion and burning
Damage
Power loss
Pre ignition

Question 17

What factors could affect detonation?

Answer 17

Poor fuel quality 
High compression ratio 
Ignition timing 
Under heavy load 
Accusation of carbon

Question 18

What is pre ignition?

Answer 18

It’s the ignition of the mixture before the spark at the spark plug, it is ignited by some hot spot in the cylinder

Question 19

What are the effects of pre ignition?

Answer 19

Seizure - due to high cylinder pressure oil tends to be forced out the piston grooves and then ignites

Question 20

Effects affecting pre ignition?

Answer 20

Carbon deposits

Detonation - heavy detonation causes local overheating giving rise to pre ignition

Question 21

What is the octane number?

Answer 21

It’s a measure of a fuels resistance to detonation

Question 22

What is flash point?

Answer 22

Lowest temp at which vapours ignite in air when exposed to a flame

Question 23

What is volatility?

Answer 23

The ability of the fuel to change into a vapour form

Question 24

What is the cetane number?

Answer 24

For diesel only

It’s readiness for self ignition

Question 25

What is calorific value?

Answer 25

The amount of heat generated by a complete combustion of a unit mass of fuel

Question 26

What other products of combustion can be produced when the combustion is incomplete?

Answer 26

Hydrocarbons
Oxides of nitrogen
Carbon dioxide

Question 27

How are vehicles emissions controlled?

Answer 27

By relevant euro standards

Question 28

What is used to prevent the oxidation and deterioration of fuels in storage

Answer 28

Inhibitors