Diesel fuel is ... Types, grades, brands, classes of diesel fuel

Diesel fuel - this is an old enough, but still in demand type of fuel for piston diesel engines. And if earlier the scope of its application was limited due to poor quality and toxic combustion products, now more and more cars are equipped with diesel engines, and scientists are working to improve performance and make diesel fuel environmentally safe.

What is diesel fuel

Diesel fuel is a heavy oil fraction, the basis of which are hydrocarbons with a high boiling point of 200-350 ° C. Used as a fuel in diesel engines and gas diesel engines.

Why in diesel? Because unlike gasoline engines, in which a mixture of gasoline and air is ignited from a spark, in a diesel piston engine, the fuel spontaneously ignites under strong compression.

Externally, diesel fuel is a liquid with a greater viscosity than gasoline, the color of which can be yellow and brown in different shades. The color is affected by the resin in the composition of the fuel.

When burned, any fuel produces energy. Diesel fuel, in addition to this main task, performs several more important functions in the engine. It lubricates the friction surfaces in the fuel injectors and pumps, cools the combustion chamber walls and regulates the exhaust parameters on the engines.

Use of diesel fuel

Marine and river vessels, diesel locomotives, military and agricultural machinery, trucks - virtually all heavy transport operates on diesel engines.

The last decades popular in the developed countries of Europe is a passenger car that operates on diesel fuel. The fuel consumption by 40% in the diesel engine is less, and the tractive effort, power, patency and safety of exhaust gases are greater than in the gasoline.

Diesel fuel is economical in operation and at cost fuel. It is used in diesel generators of stationary and mobile power stations, in boilers of autonomous heating systems.

Solar oil, which is popularly called simply solar oil, is a residual diesel fuel with a high viscosity and a boiling point of up to 400 ° C. This type of fuel is used for low-speed engines on water and railway transport, tractors. In addition, the carpentry impregnates the skin in the leather industry. Solar oil is a part of the lubricating-cooling liquid in the processing of metals by cutting and hardening liquid during their heat treatment.

Main characteristics

Cetane number (the main parameter of diesel fuel) characterizes the inflammability of the fuel. It determines the period of burning delay of the working mixture, that is, the time that passes between the injection of fuel into the cylinder and the beginning of its combustion. The shorter this time interval, the cetane number is higher, and the warm-up time of the engine is less. True, this increases smoke exhaust, which becomes critical for cetane number above 55.

For the injection and fuel injection processes, its viscosity is important, on which the lubricating characteristics also depend

Density of diesel fuel depends on its efficiency and economy, because the higher the density, the more energy is generated during combustion.

An important characteristic is the amount of sulfur that diesel contains. These are sulfur compounds, which reduce the corrosion resistance of the fuel system.

The quality of diesel fuel is also indicated by the limiting filterability temperature, that is, the temperature at which the diesel fuel is so thick that it no longer passes at all or very slowly passes through the filter with certain dimensions.

It is below the cloud point, that is, the temperature at which paraffin, which is contained in the fuel, begins to crystallize.

Types of diesel fuel

Until 2015, diesel fuel in Russian standards was divided into types. In the state standard, put into effect in January 2015, the division coincides with the division into ecological classes in accordance with the European standard and occurs depending on the sulfur content of the fuel. The sulfur content of not more than 350, 50 and 10 mg / kg corresponds to species I, species II and species III according to the obsolete and ecological classes K3, K4 and K5 according to the new state standard, respectively.

It is not recommended to use fuel in which high sulfur content, as this increases harmful emissions into the atmosphere, accelerates corrosion and wear of the fuel system elements, respectively, increases the cost of frequent replacement of filters and oil. As a rule, the improvement of some properties leads to the deterioration of others. Reducing the sulfur content is a reduction in the lubricating properties of diesel fuel. Therefore, to preserve one of the main functions, various additives are added to the fuel.

Varieties of diesel fuel

The grades of diesel fuel differ in temperature, below which fuel can not be used. As a criterion, the limiting filterability temperature is used. And according to the grades, summer and off-season diesel fuel is broken with this index not lower than -20 ° С.

Variety A is characterized by a temperature of at least 5 ° C above zero. For each next grade B, C, D, E and F, the indicator is reduced by 5 ° C.

An example is diesel EURO, grade C, species II and III, or in a new version of ecological classes K4 and K5 with a filterability temperature of up to five degrees below zero and sulfur content of not more than 50 and 10 milligrams per kilogram of fuel.

Classes of diesel fuel

The division into diesel fuel classes for winter or cold climate occurs not only according to the filterability temperature, the second characteristic is the cloud point temperature. In winter and arctic diesel fuel, at low temperatures, paraffin crystallization begins, which worsens performance.

If the designation of diesel fuel after the designation of DTs is not a letter, but a figure, then this fuel is winter or arctic.

Stamps of diesel fuel

According to the physicochemical properties, performance characteristics and application conditions, diesel fuel is divided into four types, which are marked with capital letters of the alphabet:

- Summer (L), which includes grades of fuel A, B, C, D with a limiting filterability temperature from +5 to -10 ° C. This diesel can be used at temperatures not lower than 0 ° С.

- Inter-season (E), grades E and F, with temperatures of -15 and -20 ° C, respectively, is used in autumn, when the air temperature ranges from +5 to -5 ° C.

- Winter (З), which is divided into classes 0 to 3 and a filterability temperature in the range from -20 to -38 ° С and is used at air temperature not lower than minus 20 ° С.

- Class A (class A) fuel with a filterability limit temperature minus 44 ° C and ambient temperature down to minus 50 ° C (in documents, a negative value is often accompanied by the word "minus" rather than an icon to avoid inaccuracies).

Marking of fuel

Diesel fuel brands include the name (DT), grade or class, depending on the conditions of use and the ecological class. That is, the mark specifies only two parameters: the sulfur content and the limiting filterability temperature.

Today, it is possible to find signs for new and obsolete, for example, DT winter EURO 5 grade F, which stands for winter diesel fuel with a sulfur content of not more than 50 mg / kg and a filterability limit temperature of minus 20 ° C, that is, the most used in conditions Russian winter with high requirements for fuel economy.

So far, this marking of L-0,2-62, that is, a summer fuel of the highest grade, indicating the amount of sulfur (200 mg / kg) and a flash-point of 62 ° C, is also found. The flash point is not the main indicator, but with equal other characteristics, fuel with a higher temperature is considered to be the best for fire safety purposes.

How to store diesel fuel

For an ordinary consumer who has a personal car with a diesel engine, the issue of storing diesel fuel is not worth it.

But for industries where fuel is bought in bulk and stored for a long time, the storage problem is very urgent.

Storage of diesel fuel is possible at a temperature of 20 ° C during the year and at temperatures above 30 ⁰ C from six months to a year in sealed containers, protected from direct sunlight.

During storage, the fuel should not come into contact with copper, brass or zinc, so that fuel is not clogged by products of chemical reactions with these metals. In addition, it must be protected from moisture and dust and should not have additives that can disintegrate during storage. For example, in diesel fuels with a high environmental class additives are added to increase the lubricating characteristics, which decompose very quickly.

The efficiency of this fuel is high, the scope of its use is steadily growing. There are new brands of diesel fuel and new sources of its production. Now there are new developments, and diesel fuel is produced not only from oil. Maybe the future belongs to diesel fuel from vegetable oils.