公开(公告)号：US20240003534A1

公开(公告)日：2024-01-04

申请号：US18251811

申请日：2021-11-02

Applicant: Valmet Technologies Oy

Inventor： Juha HILJANEN ,  Pekka LEHTONEN ,  Pertti TAPIAINEN ,  Mikko VARONEN

IPC: F22B31/04 ,  F23C6/02 ,  F28D13/00 ,  F01D15/10 ,  H02K7/18

CPC classification number: F22B31/04 ,  F23C6/02 ,  F28D13/00 ,  F01D15/10 ,  H02K7/1823 ,  F23C10/10

Abstract: A method for heating a heat exchange medium in a fluidized bed boiler (100), the method comprising burning first fuel (165) in a first furnace (162) of the fluidized bed boiler (100) to produce first flue gas (163); recovering heat from the first flue gas (163) to a heat exchange medium using a first heat exchanger (310); conveying the heat exchange medium from the first heat exchanger (310) to a second heat exchanger (320), of which at least a part is arranged in contact with a fluidized bed of the fluidized bed boiler (100); burning second fuel (175) in a second furnace (172) of the fluidized bed boiler (100) to produce second flue gas (173); conveying the heat exchange medium from the second heat exchanger (320) to a third heat exchanger (330); and recovering heat from the second flue gas (173) to the heat exchange medium using the third heat exchanger (330). A fluidized bed boiler (100) for performing the method. A loopseal heat exchanger (400) that is, when installed in a loopseal of a circulating fluidized bed boiler, configured to burn second fuel (175) in a second furnace (172) of the loopseal heat exchanger (400) to produce second flue gas (173); convey the heat exchange medium from the second heat exchanger (320) to a third heat exchanger (330); and recover heat from the second flue gas (173) to the heat exchange medium using the third heat exchanger (330).