Method of and System For Generating Power By Oxyfuel Combustion
First Claim
1. A method of generating power by oxyfuel combustion, the method comprising the steps of:
- (a) feeding carbonaceous fuel into a furnace;
(b) feeding oxidant gas into the furnace, wherein, in a first operating mode, the oxidant gas comprises a stream of substantially pure oxygen conveyed from an oxygen supply for combusting the fuel with the oxygen to produce exhaust gas comprising mainly carbon dioxide and water;
(c) discharging an exhaust gas stream from the furnace;
(d) dividing the exhaust gas stream in a final divider piece into a recycling portion and an end portion;
(e) recycling the recycling portion through a gas recycling channel to the furnace; and
(f) conveying the end portion through an outlet channel to final processing, wherein the method also comprises the steps of;
(g) dividing the exhaust gas stream in a first divider piece, arranged upstream of the final divider piece, into a first exhaust gas stream and a second exhaust gas stream;
(h) transferring heat from the first exhaust gas stream to gas in the gas recycling channel by a gas-gas heat exchanger to form a cooled first exhaust gas stream;
(i) transferring heat from the second exhaust gas stream to a flow of feedwater in a feedwater line by a first economizer to form a cooled second exhaust gas stream;
(j) combining the cooled first exhaust gas stream and the cooled second exhaust gas stream in a connecting piece arranged upstream of the final divider piece to form a combined exhaust gas stream; and
(k) conveying at least a portion of the combined exhaust gas stream through a second economizer arranged to transfer heat from the combined exhaust gas stream to the flow of feedwater in the feedwater line.
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Accused Products
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. A first economizer arranged in the second exhaust gas channel portion transfers heat from exhaust gas in the second exhaust gas channel portion to a flow of feedwater in a feedwater line, and a second economizer arranged in the exhaust gas channel system downstream of the connecting piece transfers heat from gas in the exhaust gas channel system to the flow of feedwater in the feedwater line.
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Citations
18 Claims
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1. A method of generating power by oxyfuel combustion, the method comprising the steps of:
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(a) feeding carbonaceous fuel into a furnace; (b) feeding oxidant gas into the furnace, wherein, in a first operating mode, the oxidant gas comprises a stream of substantially pure oxygen conveyed from an oxygen supply for combusting the fuel with the oxygen to produce exhaust gas comprising mainly carbon dioxide and water; (c) discharging an exhaust gas stream from the furnace; (d) dividing the exhaust gas stream in a final divider piece into a recycling portion and an end portion; (e) recycling the recycling portion through a gas recycling channel to the furnace; and (f) conveying the end portion through an outlet channel to final processing, wherein the method also comprises the steps of; (g) dividing the exhaust gas stream in a first divider piece, arranged upstream of the final divider piece, into a first exhaust gas stream and a second exhaust gas stream; (h) transferring heat from the first exhaust gas stream to gas in the gas recycling channel by a gas-gas heat exchanger to form a cooled first exhaust gas stream; (i) transferring heat from the second exhaust gas stream to a flow of feedwater in a feedwater line by a first economizer to form a cooled second exhaust gas stream; (j) combining the cooled first exhaust gas stream and the cooled second exhaust gas stream in a connecting piece arranged upstream of the final divider piece to form a combined exhaust gas stream; and (k) conveying at least a portion of the combined exhaust gas stream through a second economizer arranged to transfer heat from the combined exhaust gas stream to the flow of feedwater in the feedwater line. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 17)
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11. A system for generating power by oxyfuel combustion, the system comprising:
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a furnace for combusting carbonaceous fuel; an oxygen channel for feeding substantially pure oxygen from an oxygen supply into the furnace for combusting the fuel with the oxygen to produce exhaust gas comprising mainly carbon dioxide and water; an exhaust gas channel system connected to the furnace for discharging the exhaust gas from the furnace, wherein the exhaust gas channel system comprises an upstream channel, an outlet channel and a gas recycling channel, wherein the upstream channel is connected by a final divider piece to the gas recycling channel and the outlet channel, for recycling a recycling portion of the exhaust gas through the recycling channel to the furnace, and for conveying an end portion of the exhaust gas through the outlet channel for final processing, wherein 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 to transfer heat from exhaust gas in the first exhaust gas channel portion to gas in the gas recycling channel; a first economizer arranged in the second exhaust gas channel portion to transfer heat from exhaust gas in the second exhaust gas channel portion to a flow of feedwater in a feedwater line; and a second economizer arranged in the exhaust gas channel system downstream of the connecting piece to transfer heat from gas in the exhaust gas channel system to the flow of feedwater in the feedwater line. - View Dependent Claims (12, 13, 14, 15, 16, 18)
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Specification