摘要:
In a power generation facility (10) wherein a fluidized bed combustion unit (12) produces steam to power a steam turbine generator (32), a heat recovery steam generator (20) produces steam for the steam turbine generator. Electrical power from the steam turbine generator is conducted to a motor (40) that drives and air compressor (36). The air compressor provides pressurized air back to the fluidized bed combustion unit (12) to promote fuel combustion. Flue gas from the heat recovery steam generator is selectively conducted to a CO2 capture unit (18) and then to a gas expander (42) that assists the motor in driving the air compressor (36). A heat exchanger (46) that is upstream of the CO2 Capture Unit and a heat exchanger (56) that is downstream of the CO2 Capture Unit and upstream of the air expander have thermal fluid sides that are connected in a closed circuit. The heat exchangers (46 and 56) convey heat away from the CO2 Capture Unit and provide heat to flue gas flowing to the gas expander to avoid icing conditions in the gas expander and acid condensation in the air emission stack.
摘要:
A method for enhancing furnace efficiency of a fluidized bed boiler is provided. The fluidized bed boiler includes a boiler body for carrying out fuel combustion in a fluidized bed thereof; a fluidized gas inlet for inputting an oxygen-containing fluidized gas into the boiler body to fluidize a boiler bed and facilitate the fuel combustion; a steam outlet for outputting a steam resulting from the fuel combustion from the boiler body; and a flue-gas exhaust for emitting a flue gas resulting from the fuel combustion from the boiler body. The method includes steps of: detecting an oxygen concentration of the flue gas; feeding a portion of the flue gas back to the fluidized gas inlet; and dynamically adjusting a flow rate of the feeding fluidized gas according to oxygen concentrations of the flue gas and the feeding fluidized gas to achieve automatic control of the fluidized bed boiler.
摘要:
A combustor 110 is operative to effect therewith the combustion of fossil fuel 114′ in order to thereby both heat to a working fluid 102 and generate a flue gas 104. An air preheater 144 receives the flue gas 104 generated in the combustor 110. A blower 180 causes air 188 to flow to the air preheater 144 when operating in an air fired mode, and causes both O2 and recycled flue gas 188′ to flow when operating in the O2 firing mode. The air preheater 144 is operative to transfer heat from the flue gas 150 received thereby to the air 188 that is received when operating in an air fired mode or to both the received O2 and the recycled flue gas 188′ that is received when operating in the O2 firing mode in order to thereby effect a preheating of the air 188 or of both the O2 and recycled flue gas, 188′ depending upon the specific nature of the mode of operation thereof, and to thereby effect therewith a cooling of the flue gas received thereby. The preheated air 142 or both the preheated O2 and the recycled flue gas 142′, depending upon the specific nature of the mode of operation, is caused to flow from the air preheater 144 to the combustor 110 in order to thereby effect therewith a fluidization of the fossil fuel 114′.
摘要:
A pyrolysis apparatus comprises a furnace (1) operating by fluidized bed combustion, a pyrolyzer (4) and flow paths, which connect the furnace (1) and the pyrolyzer (4) for arranging the circulation (C) of carrier material of the fluidized bed combustion between the furnace and the pyrolyzer The apparatus also comprises a supply inlet (14) for supplying fuel to be pyrolyzed to the pyrolyzer (4), fluidizing gas supply means (5) arranged in the pyrolyzer for fluidizing the mixture of carrier material and fuel, and an outlet (6) for taking condensible gaseous substances separated from the fuel to be pyrolyzed out of the pyrolyzer (4), and a condenser for condensing the condensible gaseous substances. The carrier material circulation is arranged at the furnace (1) by a cocurrent principle along the flow path of hot flue gases, which comprises a separator (3) located higher than the pyrolyzer (4), which separator is arranged to separate carrier material from flue gases, while the circulation also comprises a connecting conduit (11) between the separator (3) and the pyrolyzer (4) for moving the carrier material by gravity to the pyrolyzer (4), and a return path (12) between the pyrolyzer (4) and the furnace (1) for returning the carrier material to the furnace (1). The outlet (6) is arranged in the chamber formed by the pyrolyzer (4) in its upper part in a space above the fluidized mixture of carrier material and fuel in order to remove the condensible gaseous substances from the pyrolyzer.
摘要:
The invention comprising a drying and sorting apparatus for preparation of solid fuel and other solid materials having substantial surface moisture. Ambient air/gas is preheated by indirect heat exchange or other unfired means sufficiently to provide heat needed by the downstream process. The air/gas is then passed up vertically through a bed containing the solid materials, heating and fluidizing them along with the surface moisture. When in a fluidized state, the smaller/lower density particles rise to the top of the bed. At least a portion of the surface moisture on the particles is evaporated. The quantity and temperature of the air/gas flow is sufficient to retain the evaporated surface moisture in the vapor phase. Feedstock of solid materials is added to an intermediate location of the bed. The larger/more dense fluidized particles are removed from bottom location/s of the bed. The smaller/less dense fluidized particles are removed from top location/s of the bed. The temperature and vapor holding capacity of the air/gas leaving the bed is substantially higher than at ambient conditions. The air/gas is again heated by indirect or unfired means downstream of the bed for reducing relative humidity of the air/gas substantially below saturation prior to passage through a bag house for fine particle collection after which the air/gas along with the superheated water vapor is discharged to atmosphere. An optional mechanical solids separator can be installed between the bed and after bed heater.
摘要:
The invention comprising a drying and sorting apparatus for preparation of solid fuel prior to firing in a combustion furnace. Unsaturated air/gas is passed through a bed containing a mixture of solid fuel and inert material particles, fluidizing them. The unsaturated air/gas is the drying vehicle. When in a fluidized state, the lighter organically derived solid fuel particles separate from the heavier inert material particles. The air/gas is admitted to the bed directionally in a manner which drives the mixture in a retraceable path to outlet points downstream of the point of feedstock entry, the heavier inert material settling at the bottom and the lighter solid fuel particles rising in the bed. Means are provided in the sorter floor for selectively concentrating and directing the solid inert material to the collection point transversely to the direction of particle flotation.
摘要:
An overall process of cooling, dust removal, tar removal and heat recovery of high temperature gas generated in coal gasification furnaces, and apparatuses employed therefor are provided. In this process, specific apparatuses such as fluidized bed-cooler, fluidized bed-combustion furnace for regenerating granules, granular bed filter, gas cooler and, tar scrubber are successively and effectively employed. During the process, high, medium and low pressure steam, for example, are recovered by heat exchange in these apparatuses.
摘要:
The invention comprises a dense pack heat exchanger for a steam generator having a circulating fluidized bed combustion system whereby a bed of solid particles comprising fuel and inert material is entrained in the furnace gas stream. Means are provided for collecting high temperature bed solid particles downstream of the furnace. The dense pack heat exchanger directs the hot collected particles down over heat transfer surface, such surface being a portion of the steam generator fluid circuits. Flow is induced by gravity means. The dense compaction of the solid particles around the fluid heat exchange circuits results in high heat transfer rates as the fluid cools the compacted solid material. The heat exchange surface is arranged to facilitate flow of the solid particles through the heat exchanger.
摘要:
A method and associated apparatus for carrying out fluidized bed combustion and transferring heat produced thereby to a boiler includes providing a fluidized bed of particulate matter and introducing fuel particles thereinto, causing a portion of the fluidized bed constituents to flow upwardly through a heat exchanger which is essentially free of any obstructions to said flow, and reintroducing the portion of fluidized bed constituents which flow through the heat exchanger, back into the fluidized bed. As preferably embodied, the portion of fluidized bed constituents flows into an inlet at the bottom of the heat exchanger from a quiescent zone adjacent the combustion bed and a gas having a combustible component is introduced into the heat exchanger. Advantageously, additional fuel particles are also introduced into the heat exchanger to flow upwardly therethrough. Also advantageously, the cross-sectional area of the flow path provided in the heat exchanger is proportioned to provide an essentially uniform temperature profile across the flowing particles at any position in the heat exchanger.