Abstract: A fluidized bed boiler has a heat exchanger with a front wall, a rear wall opposite to the front wall, and two side walls, formed as water tube panels. An inlet opening in a first section of an upper portion of the heat exchanger introduces hot particles from the fluidized bed boiler to the heat exchanger. Heat exchange surfaces for recovering heat from the particles and an outlet opening are arranged in a second section of the upper portion for returning cooled particles as an overflow from the heat exchanger back to the boiler. The heat exchanger further includes a partition wall between the first and the second sections of the upper portion of the heat exchanger. The partition wall extends from the front wall to a center section of the heat exchanger, and is formed by bending water tubes from at least one side wall of the heat exchanger.

Abstract: A method of generating power by oxyfuel combustion. Carbonaceous fuel and oxidant gas are fed into a furnace. In a first operating mode, the oxidant gas includes a stream of substantially pure oxygen conveyed from an oxygen supply for combusting the fuel with the oxygen to produce exhaust gas including mainly carbon dioxide and water. The exhaust gas is discharged from the furnace and is divided into a recycling portion and an end portion. The recycling portion is recycled to the furnace. Heat is transferred from the end portion to the stream of substantially pure oxygen by circulating a liquid heat transfer medium in a passage between an exhaust gas cooler and an oxygen heater.

Abstract: An oxyfuel combustion system for generating power that includes a furnace for combusting carbonaceous fuel and substantially pure oxygen to produce exhaust gas including mainly carbon dioxide and water. An exhaust gas channel system discharges the exhaust gas from the furnace. The exhaust gas channel system has an upstream channel, an outlet channel and a gas recycling channel. The upstream channel recycles a recycling portion of the exhaust gas through the recycling channel to the furnace, and conveys an end portion of the exhaust gas through the outlet channel for final processing. The upstream channel is divided between a first divider piece and a connecting piece into a first exhaust gas channel portion and a second exhaust gas channel portion. A gas-gas heat exchanger arranged in the first exhaust gas channel portion transfers heat from exhaust gas in the first exhaust gas channel portion to gas in the gas recycling channel.

Abstract: Carbonaceous fuel is combusted with an oxidant gas in a furnace of a boiler system to generate power. Oxidant gas is fed into the furnace for combusting the fuel to produce exhaust gas, the exhaust gas is discharged from the furnace via an exhaust gas channel, a stream of feedwater is conveyed from a final economizer arranged in the exhaust gas channel to evaporating and superheating heat exchange surfaces arranged in the furnace and in the exhaust gas channel for converting the feedwater to superheated steam, the superheated steam is converted in a high-pressure steam turbine for generating power, a first portion of steam is extracted from the high-pressure steam turbine for preheating the feedwater, a second portion of steam is conveyed from the high-pressure steam turbine to reheating heat exchange surfaces arranged in the exhaust gas channel for generating reheated steam, and the reheated steam is expanded in an intermediate pressure steam turbine for generating power.