The Energy Density Of Diesel Is High
The main indicators of diesel are: flammability, evaporation, mobility, stability and corrosion and so on.
Diesel combustion of the level of a direct impact on the work of diesel engines. Cetane number is an important indicator of the ignition and combustion performance of diesel in the engine. The cetane number of the diesel fuel directly affects the combustion process of the fuel in the diesel engine.
Diesel oil has a high cetane number, its low ignition point, easy to spontaneous combustion in the diesel engine, the engine work smoothly. If the cetane number of diesel is too low, Biodiesel fuel is difficult to burn, will produce abnormal combustion, reduce the power of the engine. But the cetane number of diesel should not be too high, if too high, diesel can not be completely burned, fuel consumption increased.
The cetane number of diesel is related to its chemical composition. More oil information oil information oil technology, please pay attention to the public oil ring. Biodiesel The n-alkane has the highest cetane number, followed by the cycloalkane, and the polycyclic aromatic hydrocarbon has the lowest cetane number. Usually the cetane number of diesel fuel should be in the range of 45 ~ 60.
To make the engine start and work properly, the diesel is required to have good evaporation. But the evaporation can not be too strong, because the evaporation rate is too fast, burning will accumulate a lot of diesel, so that the engine work is not stable. At the same time, the evaporation is strong, that is, the fraction is light, the viscosity must be small, not only will increase the fuel pump wear, Biodiesel but also reduce the spray quality, so that the combustion process deteriorated. This means that the evaporation of diesel is too strong or too poor, that is, the fraction is too light or too heavy are not suitable. The evaporation of diesel fuel is mainly judged by the distillation range and the closed flash point.
① Distillation range
50% recovery temperature: the lower the temperature, indicating that the more light diesel components, the better the evaporation, Biodiesel so that diesel easy to start. Standard 50% of the provisions of the recovery temperature is not higher than 300 ℃.
90% recovery temperature and 95% recovery temperature: the lower the temperature, indicating that the less heavy components in diesel, diesel fuel can improve the performance and diesel engine power performance, Biodiesel reduce fuel consumption and reduce mechanical wear. The standard provides 90% recovery temperature and 95% recovery temperature of not higher than 355 ℃ and 365 ℃, respectively.
② flash point
The flash point of diesel is both a project to control the evaporation of diesel fuel and a project to ensure diesel stability. It is generally believed that light fuel in the storage and transportation, the flash point is higher than 35 ℃ is safe. The standard specifies that the flash point of diesel No. 0 is not less than 55 ° C.
Diesel is a mixture of light petroleum products and complex hydrocarbons (about 10 to 22 carbon atoms). For diesel fuel. Mainly by the distillation of crude oil, catalytic cracking, hot cracking.
The most important use of diesel is for diesel engines for vehicles and ships. Compared with gasoline, diesel energy density is high, fuel consumption is low. Biodiesel Diesel has a low energy consumption, so some small cars and even high-performance cars also switch to diesel.
Diesel is characterized by low self-ignition temperature, so the diesel engine does not require ignition devices such as spark plugs, which use compressed air to increase the air temperature, so that the air temperature exceeds the diesel spontaneous combustion test, then sprayed with diesel, diesel spray and air Mixed at the same time own ignition burning. From the performance point of view, the domestic traditional diesel engine has been giving people bulky, vibration and noise and emissions of serious pollution impression, so the basic domestic petrol engines are used, but in recent years, foreign well-known car dealers began to introduce some of the latest diesel engine technology To China, greatly improving the people on the diesel engine bias, Biodiesel such as FAW-Volkswagen has just launched TDI diesel engine Bora, its environmental protection, power and ride comfort are not inferior to the gasoline engine, but also has a unique diesel engine torque and ultra-low fuel consumption, the market The prospects are very promising.