Steam generator with circulating atmosphere or pressurized turbulent layer firing, and method for control thereof

Claim 1

Steam generator with circulating atmospheric or pressurized fluidized bed furnace, comprising: a turbulence-type combustion chamber; flow-bed coolers and waste-heat steam generator; feed-water pre-heater surfaces, evaporator surfaces, super-heater surfaces and intermediate super-heater surfaces arranged in said fluidized bed furnace; said evaporator surfaces being distributed over a plurality of partial surfaces arranged in a flow-bed cooler or in said turbulence-type combustion chamber, a partial surface having flow therethrough taking place first at the tube side and being dimensioned for required low-load condition of the steam generator, said partial surface being heated only when said steam generator is operated at said low-load condition whereby the other partial surfaces can be bypassed; during rising load heating surfaces arranged in the flow-bed coolers being supplied with an increasing quantity of turbulence-layer solids and during falling load said heating surfaces being supplied with a decreasing quantity of turbulence-layer solids, said evaporator surfaces being feee of temperature radiants due to nonuniform distribution of water and steam mixture, said steam generator having means for being operable at minimum partial loads, deviations in heat absorption of the evaporator heating surfaces being correctable by means varying the supply of solid medium to the flow-bed cooler.