Fast fluidized bed boiler and a method of controlling such a boiler
AssigneeStudsvik Energiteknik AB
InventorLars A. Stromberg
Life of this patent
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Abstract
A completely cooled fast fluidized bed boiler comprises a reactor (4) having a bottom section (3), an integrated primary non-centrifugal mechanical particle separator (5), a gas pass (7) containing convective heat exchangers (10), and means (6,8,9) for controllably recirculating separated particles into the reactor bottom section (3). Reactor (4), separator (5) and gas pass (7) are built as an integrated unit within one and the same cooling system. The boiler is controlled by maintaining the bed temperature substantially constant or within a relatively narrow temperature interval by regulating the recirculation rate dependent on boiler load. For regulating the recirculation rate a non-mechanical valve, preferably a so-called L-valve (8), is used.
Claims35
Fast fluidized bed boiler comprising a vertical reactor having a bottom section, a primary particle separator, a gas pass containing convective heat exchangers, and optionally a secondary particle separator, means for recirculating separated particles into the reactor bottom section, the boiler being a completely cooled and integrated design, the integrated primary particle separator being a non-centrifugal mechanical separator of a general labyrinth type, the reactor and the primary particle separator and the gas pass containing convective heat exchangers being built as a unit within one and the same cooling system.
A method of controlling a cooled fast fluidized bed boiler, the boiler comprising a reactor, a primary particle separator, a gas pass, and a bottom section of the reactor, the method comprising the steps of maintaining the temperature of the bed material of the reactor substantially constant or within a relatively narrow temperature interval by regulating the recirculation flow of separated particles dependent on the boiler load, thereby varying the particle density of the reactor and thus the heat transfer to the cooled walls of the reactor.
An apparatus for controlling a cooled first fluidized bed boiler, the boiler comprising a reactor having cooled walls, a primary particle separator, a gas pass, and means for recirculating separated particles into a bottom section of the reactor, the apparatus including means for sensing the boiler load, and means for controlling said means for recirculating separated particles dependent on the boiler load sensed, and thereby the recirculation rate such that the temperature of the bed material of the reactor is maintained substantially constant or within a relatively narrow temperature interval.
Dependencies are inferred from the claim text.