What is the ignition point of diesel fuel?
2 Answers
Diesel fuel has an ignition point of 220°C. The flash point of diesel is above 55°C. Diesel is a light petroleum product, a complex mixture of hydrocarbons (with carbon atoms numbering approximately 10-22). It serves as fuel for diesel engines. Diesel is primarily produced by blending diesel fractions obtained through processes such as crude oil distillation, catalytic cracking, thermal cracking, hydrocracking, and petroleum coking. It can also be produced from shale oil processing and coal liquefaction. Classification of engines: Based on the power source, automotive engines can be categorized into diesel engines, gasoline engines, electric vehicle motors, and hybrid systems, among others. Principle of engines: Common gasoline and diesel engines are both types of reciprocating piston internal combustion engines, which convert the chemical energy of fuel into the mechanical energy of piston motion to deliver power output. Gasoline engines feature high rotational speed, light weight, low noise, easy starting, and low manufacturing costs. Diesel engines have a higher compression ratio, superior thermal efficiency, and better economic performance and emission characteristics compared to gasoline engines.
The ignition point of diesel depends on the situation. What we usually refer to as the ignition point is actually closer to the 'flash point'—the temperature at which diesel vapor briefly ignites when an open flame is brought near the surface. Diesel's flash point is generally above 55°C, making it much safer than gasoline at room temperature. Truck driver Lao Zhang told me that what they should be most wary of is the autoignition point: diesel can spontaneously combust in air without an open flame at around 220°C, but under high pressure in the cylinder, the actual autoignition temperature drops to about 315°C—this is the principle behind diesel engine compression ignition. In winter, some vehicle owners find cold starts difficult because the cylinder compression temperature doesn't reach the autoignition point. The 'No Smoking or Open Flames' warning on fuel storage tanks is definitely not just for show.
