3. Flue gas temperature

The definition of heat of combustion assumes that the reaction products (fumes) are at the same temperature (and pressure or volume) as the reactants. In practice, this temperature identity condition is rarely met. Similarly, in many applications (combustion in engines or power plants), the reactants are not at the standard temperature, but at any temperature, which may also be different for the fuel and the oxidizer. This means that the amount of heat Q released to the outside during combustion is no longer the opposite of the heat of combustion. The application of the relationship (1) , which translates the first principle of thermodynamics, is always possible and can be detailed, for example, for...