When the passenger cars with diesel engines emerged, the popularity of diesel fuel has increased significantly. If earlier it was used mainly for construction and agricultural machinery, today, due to its technical characteristics, diesel fuel can be on par with gasoline.
The parameters of diesel fuel are the criteria by which it is classified. They characterize the different properties of fuel and their variation depending on conditions.
The classification of solar oil in the USSR was not as detailed as it is in Russia today. All fuel was divided into wither and arctic with indication of sulfur content and flash point (for summer fuel) and set point (for other types). For example, the indication 3 -0.05 (-25 ° C) corresponds to a winter DF with sulfur content of 50 mg / kg and set point of -25 ° C.
The modern classification is much more extensive. Quality certificates of diesel fuel normally include 15-20 key parameters. The main parameters are:
The main parameter of diesel fuel is the cetane number. This is a quality indicator obtained by motor tests. Cetane number indicates the time interval from the entry of fuel into the piston cylinder to the moment of its ignition, and shows its flammability.
For cars this parameter is normally in the range from 50 to 60. For heavy special purpose vehicles it starts from 40. In Russia, the GOST standard for diesel fuel provides the value of the CN from 45, in Europe – from 48.
A high cetane number is attributed to environmentally friendly and high-quality fuel. But if it exceeds 60, the engine power growth decreases, affecting the car’s performance.
2. Classification of diesel fuel by types.
Since January 2015, the classification by types coincides with the classification by the emission classes according to the European standard. Sulfur content is the main parameter for this classification.
Sulfur content indicates the following types and classes of diesel fuel:
- sulfur up to 350 mg / kg – emission class K3 (type I),
- sulfur up to 50 mg / kg – emission class K4 (type II),
- sulfur up to 10 mg / kg – emission class K5 (type III),
Classification by types is considered outdated and is no longer applied. Since 2016 in the Russian Federation it is permitted to produce and use diesel fuel of not less than K5 class.
Viscosity and density are important indicators of DF quality. They have a direct impact on feed, injection and filtering of fuel. Optimum viscosity provides good lubrication ability, and the density influences on consumption and efficiency.
Density of diesel fuel in accordance with GOST is in the range from 833 kg / cu. m (for the arctic) to 863 kg / cu. m. (for summer and off-season). Besides, the water content in the diesel fuel is limited to 200 mg / kg.
4. Division by seasons.
According to the climatic conditions where it is applied, DTs are divided into the following groups:
• summer (above 0 ° C),
• off-season (above -15 ° C, rare),
• Winter (above -20 ° C),
• Arctic (above -38 ° C).
5. Types and classes.
The modern GOST divides diesel fuel into groups according to the temperature conditions in the zones of use. Types of fuel for use in middle latitudes are determined by the maximum filtering temperature:
- A – +5⁰C,
- B – 0⁰C,
- C – -5⁰C,
- D – -10⁰C,
- E – -15⁰C,
- F – -20⁰C.
Classes of diesel fuel for cold climate shall have the following maximum filtering temperature:
- Class 0 – -20⁰C,
- Class 1 – -26⁰C,
- Class 2 – -32⁰C,
- Class 3 – -38⁰C,
- Class 4 – -44⁰C,
Diesel fuel standards are strictly regulated by GOSTs, because on the quality of fuel depend the performance of industrial, agricultural, military and other equipment.