Ultimate analysis is a technique used in chemistry and engineering to determine the elemental composition of a substance, typically a fuel or other organic material.
RAF stands for "reactive air fuel" and is a measure of the ratio of air to fuel in a combustion process. It is an important factor in determining the efficiency and emissions of a fuel combustion process.
RGF stands for "relative gas factor" and is a measure of the amount of gas produced during a combustion process. It is used to determine the energy content and efficiency of a fuel.
Excess air refers to the amount of air in a combustion process that is above the theoretical amount needed for complete combustion. This excess air can affect the efficiency and emissions of the process.
Ultimate analysis is used to determine the elemental composition of a fuel, which is then used to calculate the theoretical amount of air needed for complete combustion. From this, the excess air can be determined and used to calculate the RAF and RGF values for a combustion process.