PFBC power plant

Claim 1

A power plant burning fuel, primarily coal, in a fluidized bed of particulate material, at a pressure exceeding the atmospheric pressure, a so-called PFBC power plant, comprising a bed vessel (12) with a bottom (18, 30) with nozzles (22, 34) for supplying the bed vessel (12) with air for fluidization of the bed (38) of the particulate material and combustion of the fuel supplied to the bed (38), a gas turbine (106) driven by combustion gas from the bed vessel (12), and a compressor (112), suitably driven by said turbine (106), compressing fluidization air and combustion air, characterized in that the bed vessel (12) is divided into a first section (14) and a second section (16) by a vertical partition (17) reaching up to the upper wall of the bed vessel (12) so that freeboards (86 and 46, respectively) separated from each other are formed in said first section (14) and said second section (16), said first section (14) of the bed bessel (12) forms a gas generator in which a burnable gas is generated, the lower part of the partition (17) is provided with at least one opening (68) for transferring bed material from said first section (14) of the bed vessel (12) to said second section (16), the plant comprises a secondary combustion chamber (98) for combustion of the burnable gas generated in the gas generator, and the plant comprises a device for mixing the combustion gases generated in said secondary combustion chamber (98) and in said second section (16) before the gases are supplied to the turbine (106).