Method of igniting a combustion chamber with a fluidized bed and a power plant for utilizing the method

Abstract

The invention relates to a method of igniting, upon start-up, a combustion chamber (8) in a power plant with combustion of fuel in a fluidized bed (14). The air flow through the nozzles (13) of the combustion chamber bottom (12) for fluidization of the bed (14) and for combustion of the fuel can be reduced upon start-up; bed material, which is heated to the ignition temperature of a start-up fuel, is transferred from a storage container (40) to the combustion chamber (8), and fuel is supplied to the bed (14). In those cases where the air flow has been reduced during the transfer of the bed material, it is increased again when the fuel is supplied. The invention also relates to a power plant having means for temporarily bypassing the nozzles (13) of the combustion chamber bottom (12) while transferring hot bed material from a storage container (40) to the combustion chamber (8), and a fuel system (30-38) for the supply of fuel to the combustion chamber (8). In a plant with a combustion chamber (8) enclosed in a pressure vessel (10), a connection with a valve (55) for by-passing the air flow may be provided between the space (11) in the pressure vessel and the freeboard (18) of the combustion chamber (8) for reducing the air flow through the bed. Further, control means (38, 80) are provided for carrying out the necessary operations of valves, and the like, during the start-up operation.

Dependencies are inferred from the claim text.