The theoretical amount of air in combustion is referred to as what?

The theoretical amount of air required for combustion is referred to as stoichiometric air. This term specifically denotes the precise amount of air that must be mixed with fuel for complete combustion to occur, ensuring that all fuel is consumed and theoretically producing no excess fuel or unburned hydrocarbons. This concept is crucial in understanding the efficiency of combustion processes, as operating with stoichiometric air maximizes energy output and optimizes fuel use.

In combustion systems, if the actual air supplied exceeds the stoichiometric amount, it is termed excess air. While this may support more complete combustion, it also may lead to energy losses as unburned fuel or increased flue gas temperatures. Actual air pertains to the real, measured amount of air supplied but does not convey the ideal relationship between air and fuel. Operational air refers to the air supplied for practical operation, which may vary greatly from the theoretical model. Each of these terms relates to combustion efficiency, but stoichiometric air is the foundational concept for defining the ideal air requirement for complete combustion.