Naphthenes groups have shaped molecule with the atomic arrangement of a closed chain (ring). When this closed chain containing only single bonds, is called cyclic hydrocarbon saturated hydrocarbons with the general formula CA. which has one double bond are called unsaturated cyclic CnH2.-21 mempunyi two double bonds are called unsaturated cyclic C.Fl 2n-4, and so on.
Fuel oil (BBM) can contain a group Napthanes Cyclo Pentane C6H12 C5HIO and Cyclohexance. Cyclo Pentane molecules with atoms C 10 H atoms can bind if there are only single bonds between carbon atoms are C5HIO, but if there is a double bond between carbon atoms, then only 8 H atoms that can be tied into C5H8.
Bonding molecules that have atoms form a closed chain (ring) is chemically more stable than the open-chain structure of gas. Therefore, the group napht henes more stable than those of paraffin. To changes in temperature, its chemical composition is not easily changed.
Aromatics group has a molecular composition of a closed chain (ring), but other than thenes group, the aromatics group contains a double bond between C atoms it.
Shaped molecule with the atomic structure of a closed chain (ring) with a benzene molecule core Iebih thermally stable than the simple ring-shaped atomic structure (uaphthenics).
Therefore, the aromatic hydrocarbon ignition requires a higher temperature in the combustion chamber compared with aliphatic hydrocarbon ignition.
In addition to the normal hydrocarbons, there is also a branch of hydrocarbons having a chain of open-tai (isomers) and a branch of the chain ring. Examples of hydrocarbons with a branched chain structure Uka is isooctane C5H18 which has a methyl group (CH3). Isooctane molecule is thermally more stable than the molecule with the atomic structure of the open-chain form, normal isooctane C8H +18
The time required for burning up diesel fuel in the combustion chamber cylinder diesel engine for fuel rapid N having a molecular weight also its density) is small compared with having a large molecular weight. Therefore, for high torque diesel engine required a lighter fuel than for diesel engines at low rpm.
Combustion of fuel in a diesel engine cylinder ignition occurs because there is (self ignition) fuel is sprayed into the cylinder chamber containing high-temperature compressed air. The ignition temperature alone, is the minimum temperature that can ignite a fuel. This temperature must be achieved during compression lang diesel engine approaching a blind eye to the point when the fuel is sprayed into the cylinder.
Fuel to be burned in a diesel engine cylinder needs to be filtered first so as not to clog the atomizer and also do not carry substances that can not be burned, which will cause the crust in the cylinder. The crust in the form of carbon deposits caused by incomplete combustion of the carbon.