Valmet Technologies Oy

Pekka Lehtonen

Juha Ojanperä

Tero Luomaharju

Tero Heino

Mikko Varonen

Juha Hiljanen

Pertti Tapiainen

Pasi Yli-hemminki

Tuomas Kanniainen

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

Method for heating a heat exchange medium in a fluidized bed boiler, a fluidized bed boiler, and a loopseal heat exchanger

A heat exchanger () suitable for recovering heat from bed material of a fluidized bed boiler (). The heat exchanger () comprises first and second heat exchanger tubes () and first and second feeding chambers () configured to supply bed material to the first and second heat exchanger tubes (), respectively. The first heat exchanger tubes () are arranged on a first side of a plane (P) that intersects the first feeding chamber () and the second heat exchanger tubes () are arranged on a second side of the plane (P). The first feeding chamber () is configured to supply bed material to the second feeding chamber ().

Heat exchanger for a loopseal of a circulating fluidized bed boiler and a circulating fluidized bed boiler

A circulating fluidized bed boiler, comprising a furnace, a loopseal, and a loopseal heat exchanger arranged in the loopseal. The loopseal heat exchanger comprises at least an inlet chamber, a bypass chamber, and a first heat exchange chamber, heat exchanger pipes arranged in the first heat exchange chamber, and a primary particle outlet for letting out bed material from the first heat exchange chamber. The primary particle outlet has at least a first part and a second part separated from each other by a barrier element in such a way that the first part of the primary particle outlet has a first height and a first width, wherein a ratio of the first height to the first width is less than 0.5 or more than 2. Use of the circulating fluidized bed boiler such that fluidizing gas and bed material are let out from the first heat exchange chamber via the primary particle outlet.

Circulating fluidized bed boiler with a loopseal heat exchanger

A circulating fluidized bed boiler is described, comprising a furnace, a loopseal, and a loopseal heat exchanger arranged in the loopseal. The loopseal heat exchanger comprises walls limiting an interior of the loopseal heat exchanger, a first particle outlet for letting out particulate material from the loopseal heat exchanger, an inlet for receiving bed material, heat exchanger tubes arranged in the interior of the loopseal heat exchanger, and a first ash removal channel configured to let out ash from the loopseal heat exchanger. An ash cooler is configured to receive ash from the first ash removal channel. In the loopseal heat exchanger the first ash removal channel is arranged at a lower level than the first particle outlet.

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Tampere, Finland

Pekka Lehtonen