Gasoline octane number
Gasoline octane number is a numerical indicator to measure the knocking resistance of gasoline in a cylinder. The high value indicates good antiknock. When the gasoline is normally burned in the cylinder, the flame propagation speed is 10-20 m/s, and in the case of knocking combustion, it can reach 1500-2000 m/s. The latter will cause the temperature of the cylinder to rise sharply, the combustion of gasoline is incomplete, and the machine vibrates strongly, which causes the output power to drop and the parts to be damaged. Isooctane, which has the same molecular equation as octane, has the least amount of blasting, and we set its octane number to 100. Often the standard isooctane number is 100, and the octane number of n-heptane is set to zero. The two standard fuels are mixed in different volume ratios to obtain a mixture of various shock resistance grades in the engine. Under the same conditions of work, compare with the fuel to be tested. The percentage of isooctane contained in the mixture having the same seismic resistance as the sample is the octane number of the sample. Gasoline has a large octane number, good shock resistance and good quality. Multiplying the percentage of different types of hydrocarbons in gasoline by their octane number adds up to the octane number of the gasoline.