Pulverized combustion vs Circulating Fluidized Bed combustion

The thermal efficiency of steam generators can be usually determined using the Input-output method (efficiency is determined as the ratio of heat absorbed by the working fluids) and Heat loss method (determination of all accountable heat losses, heat credits and the heat in the fuel). The two are methods are equally acceptable. For CFB combustion dissociation calcium carbonate or calcium hydride involves endothermic reaction, for which the input of energy is required. In CFB boiler quantity of ash entering and being extracted from the boiler will be reached, because the CFB furnace holds significant amounts of inert material. Therefore, the calculation of losses due to the quantities of extracted ash (bed draw-down) shall be based on the mass flow of ash entering the boiler, thus ignoring any quantities of ash extracted accidentally. Boiler efficiency is formed by considering losses relative to ideal products, so for CFB boiler losses must be corrected with heat credit due to heat receiving in sulfatation and heat credit to incomplete decarbonation. Keywords efficiency; losses; heat; input-output method; heat loss metho