Name : Natashane McCook
Course : Power Plant Engineering
Lecture : Mr: E Thorpe
Title : Combustion
The term complete combustion generally is used in connection with the burning of hydrocarbons. Combustion is the process of burning that occurs when fuel, oxygen, and heat are simultaneously present. The result of complete combustion is the release of energy, carbon dioxide, and water vapor. If the hydrocarbon contains sulfur, sulfur dioxide also will be present. On the flip side, incomplete combustion results in some of the carbon atoms combining with only one oxygen atom to form carbon monoxide and other potentially harmful by-products. Usually, the combustion process is triggered by heating a hydrocarbon above its ignition temperature in an oxygen-rich environment. When the compound is heated, the chemical bonds of the hydrocarbon are split. The elements of the hydrocarbon then combine with the oxygen to form oxygen-containing compounds known as oxides. This rearrangement of hydrocarbon elements into oxides is accompanied by release of energy and heat. Complete combustion occurs when the fuel and oxygen are in the perfect combination, or ratio, to completely burn the fuel. This condition also is referred to as stoichiometric or zero excess air combustion. On the other hand, incomplete combustion may leave some of the fuel unused. The combustion process is extremely dependent on time, temperature, and turbulence. Time is important to combustion because if a fuel is not given a sufficient amount of time to burn, a significant amount of energy will be left in the fuel. Too much time to burn on the other hand will produce very long flames, which can be a function of bad mixing. The correct balance of time and mixing will achieve complete combustion, minimize flame impingement (boiler maintenance hazard), and improve combustion safety. In addition, a properly controlled combustion process strives to provide the highest...