What is the formula of afbc boiler efficiency?

The formula for the efficiency of an AFBC (Atmospheric Fluidized Bed Combustion) boiler can be expressed as:

[ \text{Efficiency} (%) = \left( \frac{\text{Useful heat output}}{\text{Total heat input}} \right) \times 100 ]

In practical terms, this involves measuring the energy content of the flue gases, the heat losses, and the energy produced by the boiler, taking into account factors like unburned fuel and heat losses through radiation and convection.