| Στήλη Α |
Κάντε την αντιστοιχία |
Στήλη B |
| 1. Kinematic viscosity |
| A. It is the ability to reduce friction between solid surfaces in relative motion. The fuel itself protects some moving parts of fuel pumps and injectors from wear. Higher viscosity fuels provide sufficient lubricity. To avoid excessive wear, the fuel must have some minimum level of lubricity. |
| 2. Oxidation stability |
| B. Its content of a marine fuel depends on the crude oil origin and the refining process. When a fuel burns, sulphur is converted into sulphur oxides. These oxides reach the lubricating oil via the blow-by gas. These oxides are corrosive to engine piston liners and must be neutralized by the cylinder lubricant. Marine engine lubricants are developed to cope with this |
| 3. Sulphur: |
| C. is a measure of a fuel’s ignition quality in compression-ignition engines. It denotes delay between fuel injection into the combustion chamber and the beginning of compression ignition (auto-ignition). So it is a more important for ignition quality of diesel fuel. The higher the value of cetane number of a fuel, easier will be the starting of the engine. |
| 4. Water content |
| D. This is defined as the ratio of the mass to the volume of the fuel. It is the weight of fuel in kilogram per litre of fuel at 15°C. The density is mainly expressed in kg/m3. |
| 5. Hydrogen sulfide |
| E. H₂S is a highly toxic gas and exposure to high vapor concentrations is hazardous and can be fatal in extreme cases. It is naturally present in crude oils and can be formed during the refining processes used to produce the fuel. H₂S can also evolve from the fuels in storage tanks, barges and customer tanks. |
| 6. Lubricity |
| F. Degradation of distillate fuels by oxidation can cause fuel stability problems. Unstable distillate fuels can form insoluble organic particles which may clog fuel filters, cause wear and contribute to injector deposits |
| 7. Cloud point |
| G. The percentage of water in the fuel can be translated into a corresponding energy loss for the customer. Water is removed onboard the vessel by centrifugal purification. If after purification, the water content remains too high, water vapor lock can occur and pumps can cut out. If water-contaminated fuel reaches the injectors, combustion can be erratic. Water in fuel that remains standing in lines for a longer period can cause corrosion |
| 8. Cetane number |
| H. It is the temperature at which the wax in the fuel forms a cloudy appearance. Above this temperature, the fuel turns to be turbid. This is important for the fuel consumption at winter. This formation of wax results in clogging of engine filters. It is also known as wax appearance point (WAP). Cloud point is measured at intervals of 2 or 3oF |
| 9. Specific gravity of liquid fuel. |
| I. It is the ratio of density of fuel with respect to that of water. It denotes ratio of mass to volume of fuel to that of water at a given temperature. The reference substance for liquid fuel is mainly water or liquid that is nearly water at 4°C. |
| 10. Density of liquid fuel. |
| J. It is a measure of the fluidity of the product at a certain temperature. The viscosity of a fuel decreases with increasing temperature. |
