Diesel oil is extracted from the oil, according to the different process of distillation process, can be divided into two major categories of light diesel and heavy diesel. Because of the high speed of the diesel engine, light diesel oil is light yellow to dark yellow, some slightly green, not easy to evaporate hair, feel some sticky.
A requirements for use of light diesel oil.
1 the ignition property of moderate ignition diesel oil is the ability of diesel and air to form combustible mixture to self ignited and burn. It is usually expressed as "Sixteen alkane".
As for the sixteen alkane value, it is not a unit, but a comparison value. It means that the combustion property of diesel is equivalent to the volume percentage of sixteen alkanes in the mixture of sixteen alkanes and a- methylnaphthalene. The combustion and starting properties of sixteen alkane are much better than that of the a- methyl naphthalene. It is assumed that the combustion performance of sixteen alkanes is 100 units, a- methylnaphthalene. It is a 0 unit. To synthesize a mixture of two different combustion properties with a different volume ratio, the sixteen alkane values from 0 to 100 are obtained. For example, the number 0 light diesel regulation should not be less than 50, indicating that its combustion performance is equivalent to a mixture of 50% sixteen alkanes and 50%a- methylnaphthalene. The value of sixteen alkanes is more. Large, better combustion performance. The sixteen alkane value of diesel engine used in engineering machinery diesel engine is generally good at 45 to 60. Low sixteen alkane value will cause the diesel engine to work rough and difficult to start in winter. The sixteen alkane value is too high, the diesel fuel in the combustor can not be fully mixed with the air, so the combustion is incomplete and the diesel engine exhausting is caused. Black smoke, power decline and fuel consumption increase.
2 the low temperature fluidity of the good low temperature flow diesel oil is expressed by the condensation point. The condensation point refers to the temperature of diesel engine cooling to the loss of flow. It is one of the important indicators of diesel oil.
3, there must be a certain viscosity. The aim is to ensure that the fuel injection pump plunger coupling is well lubricated under the premise of good spray and complete combustion.
4 the evaporation of the suitable evaporative diesel oil is distilled out of the temperature of the distillate of 50%, 90% and 95%. It reflects the performance of the diesel oil from the liquid to the gaseous state. The lower the temperature, the better the vaporization. But if the vaporization is too good, the evaporation rate of the diesel fuel in the combustion chamber is too fast, which will cause the high speed of diesel combustion and the increase of cylinder pressure. Too large and rough work. But the evaporation is too low, and the evaporation of diesel oil is difficult, it is difficult to mix with the air and can not form a good combustible mixture, resulting in incomplete combustion, increasing carbon accumulation, exhaust smoke and oil consumption, and difficult starting.
B domestic light diesel oil selection method of domestic light diesel oil brands and specifications, according to quality divided into excellent grade, first grade and qualified 名媛直播 three grades, according to the point of condensation, 10, O, -10, -20, -35, -50 and other six brands.
The main difference between the superior grade, first grade and qualified 名媛直播 of light diesel oil is the quantity of sulfur. Considering the current situation of diesel engine lubricating oil in our country, the diesel engine of engineering machinery should choose light diesel with sulfur content in 0.20/0~0.50/0. This is because the sulfur content of the diesel oil is too large, it will produce three sulfur oxide after burning, and produce corrosion in the case of water. A very strong sulphuric acid will seriously corrode the cylinder.
In order to ensure the normal operation of the diesel engine, the diesel oil with high condensing point can be chosen as far as possible in the case of temperature. The purpose is to improve the economic benefit. To this end, the diesel condensate point is usually about 5 C lower than the local minimum temperature. For example, when the ambient temperature is above 4~7 C, the diesel engine is selected and purchased to ensure the normal diesel engine to make the diesel engine. Similarly, -10 light diesel is suitable for use in areas with a minimum temperature above -5 C.
Different grades of light diesel oil are basically the same because of their performance indicators except the condensation point. Therefore, the oil unit can be used mixed without affecting the quality when the container is insufficient. However, it is necessary to use the diesel oil with the highest condensation point at this time as the reference. Otherwise, the diesel engine will not be suitable for the local environment temperature, so that the diesel engine can not be normal work.
