Pressurized fluidized bed combustion system including control of temperature of flue gases entering a high temperature filter

摘要

A pressurized fluidized bed combustion system includes a pressure vessel, a furnace section within the pressure vessel for forming high temperature, high pressure gases and for generating steam, a compressor for providing compressed combustion air for the furnace section, a filter for cleaning the high temperature, high pressure flue gases formed in the furnace section, a gas turbine for generating power from the gases formed in the furnace section and cleaned in the filter, a steam turbine cycle for generating power from the steam generated in the furnace section, a heat recovery section, connected to the steam turbine cycle, for recovering heat from the gases exhausted from the gas turbine and for supplying the heat to feedwater provided for the steam generation in the furnace section, and an inlet duct for the filter. The inlet duct is connected between a gas discharge channel in the furnace section and a gas inlet channel in the filter. The inlet duct includes a first gas duct, a second gas duct, a first branch, connecting the gas discharge channel in the furnace section with the first and second gas ducts, for dividing the flow of gases from the furnace section into a first gas flow and a second gas flow, a second branch, connecting the first and second gas ducts with the gas inlet channel in the filter, for recombining the first and second gas flows and a gas cooler in the second gas duct for decreasing temperature of the second gas flow.