JP2011075177A - Oxygen combustion boiler system and its starting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oxygen combustion boiler system capable of increasing concentration of carbon dioxide in an exhaust gas by reducing an amount of air used in starting, and preventing misfire of burner flame. <P>SOLUTION: This method of starting the burner of the oxygen combustion boiler system has a first process in which an ignition torch is formed in a furnace chamber, and oil drops or a flammable gas as a main fuel is burned near the burner or the ignition torch in the furnace chamber while using a gas mainly composed of the air as a susceptible gas for the combustion of the main fuel, a second process in which an air flow rate is reduced by adjusting a flow rate of the air used in the susceptible gas while increasing a ratio of a flow rate of a recirculation gas or high purity oxygen by adjusting a recirculation flow rate of a part of an exhaust gas or a flow rate of oxygen supplied from a high-purity oxygen manufacturing device, so that the susceptible gas is finally converted into a gas including the recirculation gas or the gas including high-purity oxygen as its main component, and a third process in which the main fuel is switched from the oil drops or the combustible gas to coal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oxyfuel boiler system and an operation method at the time of startup.

  In a thermal power plant having a boiler and a steam turbine as main components, the amount of carbon dioxide, which is one of the causes of global warming, is larger than other power generation methods. Therefore, a method of burning using high-purity oxygen instead of using air as a conventional combustion support gas when burning fuel in a boiler, that is, an oxyfuel combustion method has been proposed.

  With the oxyfuel combustion method, the carbon dioxide concentration in the exhaust gas can be increased, so there is no need to concentrate the carbon dioxide when recovering carbon dioxide from the exhaust gas, and the exhaust gas can be cooled as it is to liquefy and separate the carbon dioxide. This makes it easier to recover carbon dioxide. As a result, it contributes to the reduction of carbon dioxide emissions.

  For example, as disclosed in Patent Document 1, after starting an oxyfuel boiler facility, exhaust gas recirculated to the boiler body and oxygen from a high-purity oxygen production apparatus are supplied, and carbon dioxide in the exhaust gas The concentration of is increased.

  Moreover, in the pulverized coal fired boiler, oil droplets with good ignitability are supplied to the burner during start-up or low-load operation to burn the oil droplets, thereby assisting stable combustion of the pulverized coal.

  For example, as disclosed in Patent Document 2, at startup, a diesel oil ignition torch is used to fire up to 15% of the boiler load, after which the heavy oil burner is ignited and fired to 15 to 35% of the boiler load using only the heavy oil burner. After that, when the furnace temperature in the boiler furnace rises sufficiently, pulverized coal fuel is supplied from the pulverized coal machine to the pulverized coal supply pipe and pulverized coal burner to burn the pulverized coal, and finally the pulverized coal Switching to charcoal-only firing.

  In boiler combustion systems that use pulverized coal and oil or combustible gas as fuel, a coaxial combustion structure is often employed.

  For example, as disclosed in Patent Document 3, the coal burner and the oil burner are arranged coaxially, whereby the number of openings provided in the boiler furnace wall for installing the burner can be reduced, and the combustion air The supply system is simplified.

JP 2001-336736 A Japanese Patent Laid-Open No. 5-322114 JP-A-8-178261

  As described above, in the oxyfuel boiler system, instead of using air as the combustion support gas, the exhaust gas recirculated and the oxygen from the high-purity oxygen production device can be used to increase the carbon dioxide concentration in the exhaust gas. By cooling the exhaust gas, it is possible to liquefy and separate carbon dioxide, which is effective for reducing carbon dioxide emissions.

  However, at startup, the furnace chamber is filled with air, and the majority of the exhaust gas components become nitrogen. Therefore, even if the exhaust gas is recirculated as combustion support gas and supplied to the furnace, the concentration of carbon dioxide in the exhaust gas is increased. There is a problem that the burner flame may be misfired because the oxygen concentration in the supporting gas is reduced by recirculating the exhaust gas.

  As disclosed in Patent Document 1 as an example, at the time of start-up, the flow rate of air is adjusted so that the outlet oxygen concentration of the boiler body becomes equal to the outlet oxygen concentration set value so that the exhaust gas oxygen concentration does not become too low. By doing so, there is a technology to deal with the problem that the burner flame may be misfired. However, with this technology, until starting is completed, nitrogen derived from the air used as the combustion support gas will occupy the majority of the components in the exhaust gas, and there is a problem that the concentration of carbon dioxide in the exhaust gas cannot be increased. there were.

  Therefore, the problem to be solved by the present invention is to increase the carbon dioxide concentration in the exhaust gas by reducing the amount of air used when starting the oxyfuel boiler system, and to avoid misfire of the burner flame. An object of the present invention is to achieve both high concentration of carbon dioxide in exhaust gas and avoidance of misfire of a burner flame at the time of starting an oxyfuel boiler system.

  In order to achieve the above object, the furnace chamber has a plurality of stages of burners in the height direction, and forms an ignition torch by burning oil droplets or combustible gas in the furnace chamber, and oil droplets in the burner in the furnace chamber. Alternatively, combustible gas or pulverized coal is burned as the main fuel, and oxygen is mixed with a part of the exhaust gas from the furnace chamber outlet and recirculated to be used as a combustion support gas for the main fuel combustion. On the other hand, a method for starting an oxyfuel boiler system in which part or all of carbon dioxide is extracted from exhaust gas and recovered, and as a first procedure, after an ignition torch is formed in the furnace chamber, the vicinity of the burner in the furnace chamber and the ignition In the vicinity of the torch, an oil droplet or a combustible gas is used as a main fuel and combustion is performed using a gas having a main component as air as a combustion support gas for the combustion of the main fuel. One of the exhaust gases By adjusting the recirculation flow rate or the oxygen flow rate supplied from the high-purity oxygen production apparatus, the flow rate of recirculation gas or high-purity oxygen is increased, and the air flow rate used for the combustion support gas is adjusted. The flow rate of air is reduced, and finally the combustion support gas is made a gas mainly composed of a recirculation gas or a gas containing high-purity oxygen. As a third procedure, the main fuel is switched from oil droplets or combustible gas to coal. This is a method for starting a burner of an oxyfuel boiler system.

  ADVANTAGE OF THE INVENTION According to this invention, at the time of starting of an oxyfuel boiler system, the high concentration of the carbon dioxide in exhaust gas and the misfire avoidance of a burner flame can be made compatible.

Configuration of oxyfuel boiler system. Configuration of each system connected to the burner. The configuration of the burner installed in the furnace room. An example of the starting process of the independent burner of a comparative example. The process of starting a single burner according to this embodiment. An example of the starting process of the oxyfuel boiler system of a comparative example. The starting process of the oxyfuel boiler system according to this embodiment. The process of starting the oxyfuel boiler system according to this embodiment (Alternative Method 1). The process of starting the oxyfuel boiler system according to this embodiment (Alternative Method 2). The process of starting the oxyfuel boiler system according to the present embodiment (Alternative Method 3). Process of starting the oxyfuel boiler system according to the present embodiment (Alternative Method 4). Process of starting the oxyfuel boiler system according to the present embodiment (Alternative Method 5). The process of starting the oxyfuel boiler system according to this embodiment (Alternative Method 6). The figure which shows the procedure of combustion support gas switching. The figure which shows the oxyfuel boiler system provided with the control apparatus.

  Embodiments will be described below with reference to the drawings.

  In this embodiment, the furnace chamber has a plurality of stages of burners in the height direction, and an ignition torch is formed by burning at least one of oil droplets, combustible gas, or the like in the furnace chamber. Near and near the ignition torch, oil droplets, combustible gas, pulverized coal, or at least one of them is burned as main fuel, and the exhaust gas passing through the furnace chamber outlet is converted into a heat exchanger, an exhaust gas treatment device, or at least one of them. After passing through one, oxygen is mixed into a part of the exhaust gas and recirculated to use as a combustion support gas for the main fuel, and after increasing the carbon dioxide concentration for the remainder of the exhaust gas In an oxyfuel boiler system that compresses part or all of it and extracts and recovers carbon dioxide from exhaust gas, the first procedure is to form an ignition torch in the furnace chamber. After that, oil droplets or combustible gas or at least one of them is burned as main fuel in the vicinity of the burner in the furnace chamber and near the ignition torch, and the main component is air as the combustion support gas of the main fuel. As a second procedure, the recirculation gas is adjusted by adjusting at least one of the recirculation flow rate of the exhaust gas, the oxygen flow rate supplied from the high-purity oxygen production apparatus, or at least one of them to the combustion support gas. Alternatively, by increasing the flow rate of high purity oxygen or at least one of them and adjusting the flow rate of air used for the combustion support gas, the air flow rate is reduced, and finally the combustion support gas is recirculated gas or high flow rate. As a third procedure, the main fuel is changed from oil droplets or flammable gas to coal. A rolling method.

  Other examples are also described below.

〔Example〕
The concept relating to the oxyfuel boiler system will be described with reference to FIGS. The activation method will be described with reference to FIGS. 4 to 15 shown below using an example and a comparative example.

  FIG. 1 shows the configuration of an oxyfuel boiler system. In FIG. 1, 100 is a furnace chamber, 102 is a furnace outlet, and 103 is an exhaust gas transport pipe. The exhaust gas 99 passes from the furnace chamber 100 through the furnace outlet 102, is transported along the exhaust gas transport pipe 103, drops in temperature when passing through the heat exchanger 105, and nitrogen oxides when passing through the exhaust gas treatment device 107. Alternatively, harmful substances such as sulfur oxides or metal compounds, particulate matter such as moisture and ash and soot are removed, and the recirculation branch point 109 is reached. A part of the exhaust gas that has reached the recirculation branch point 109 branches to a recirculation gas supply system 90 described later, and the remaining exhaust gas is discharged out of the system through the flue 111. The mill 62 constitutes a primary gas supply system 60 (shown in FIG. 2) together with the pusher blower 141, the air transport pipe 61, the pulverized coal transport pipe 63 and the like, and is connected to the burner 150. The oxygen separator 72 constitutes an oxygen supply system 70 (shown in FIG. 2) together with the blower 71, the separated oxygen transport pipe 73, the high concentration oxygen intermediate tank 74, the high concentration oxygen transport pipe 75 and the like, and is connected to the burner 150. Yes. The air conveyance pipe 81 constitutes a secondary air supply system 80 (shown in FIG. 2) together with the forced air blower 141 and the heat exchanger 105 and is connected to the burner 150. The recirculation gas adjustment valve 91 constitutes a recirculation gas supply system 90 (shown in FIG. 2) together with the suction blower 92, the recirculation gas transport pipe 93, the heat exchanger 105, and the like, and is connected to the burner 150. The hydraulic pressure source 31 is connected to two systems of a load oil supply system 30a and a torch oil supply system 30b. The load oil supply system 30 a includes a load oil transport pipe 33 and an oil inlet valve 35, and is connected to the burner 150. The torch oil supply system 30 b includes a torch oil transport pipe 33 b and an oil inlet valve 35 b and is connected to the ignition torch 152 of the burner 150. A plurality (not shown) of burners 150 are installed in the furnace chamber 100. The burner 150 is provided with a temperature signal detector 153 that detects the temperature.

  FIG. 2 shows the configuration of each system connected to the burner 150. Although the number of the burners 150 is three, it is not limited to three but is an example representing a plurality. Each burner 150 is provided with a temperature signal detector 153, an ignition torch 152, an oil burner nozzle 155, a primary gas nozzle 156, and a secondary gas nozzle 157. The recirculation gas supply system 90 is connected to the secondary gas nozzle 157 of the burner 150. The oxygen supply system 70 is connected to the secondary gas nozzle 157 of each burner 150. The secondary air supply system 80 is connected to the secondary gas nozzle 157 of each burner 150. The primary gas supply system 60 is connected to the primary gas nozzle 156 of each burner 150. The oil supply system 30 includes two systems, a load oil supply system 30a and a torch oil supply system 30b. The load oil supply system 30 a is connected to the oil burner nozzle 155 of each burner 150. The torch oil supply system 30 b is connected to the ignition torch 152 of each burner 150.

  FIG. 3 shows the configuration of the burner installed in the furnace chamber. On the wall surface of the furnace chamber 100, three burners 150 per one wall surface are installed on two wall surfaces, and six burners 150 are installed per one step. Each of the burners 150 is ignited with a flame and the load is increased by an appropriate method to start the boiler.

  FIG. 4 shows an example of the process of starting the single burner of the comparative example. Activation of the burner is completed by proceeding in the order of the first procedure, the second procedure, and the third procedure. In the first procedure, the main fuel is ignited. Specifically, oil is supplied to the ignition torch 152 of the burner 150 by the torch oil supply system 30b to ignite the auxiliary flame 11, and oil is supplied to the oil burner nozzle 155 of the burner 150 by the load oil supply system 30a. The secondary air supply system 80 supplies air as a combustion support gas to the secondary gas nozzle 157 of the burner 150 to form an oil flame (combustion gas: air) 12. That is, according to the first procedure, the burner 150 is changed from the state a) to the state c). In the second procedure, the main fuel is switched from oil to coal. Specifically, the oil flame (combustion gas: air) 12 is maintained until the temperature signal detector 153 can confirm that the temperature condition becomes a condition capable of burning coal. Thereafter, pulverized coal is supplied to the primary gas nozzle 156 of the burner 150 by the primary gas supply system to form a coal flame (combustion gas: air) 13. That is, according to the second procedure, the burner 150 is changed from the state c) to the state 2). In the third procedure, the combustion supporting gas is switched from air to a gas composed of exhaust gas and oxygen. Specifically, a combustion support gas is supplied to the secondary gas nozzle 157 of the burner 150 by the secondary air supply system 80, the recirculation gas supply system 90, and the oxygen supply system 70, and a coal flame (combustion gas: air and recirculation gas). And oxygen) 14 are formed, the supply of air by the secondary air supply system 80 is stopped, and a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed. That is, according to the third procedure, the burner 150 is changed from the state d) to the state d).

  FIG. 5 shows the process of starting a single burner according to this embodiment. Activation of the burner is completed by proceeding in the order of the first procedure, the second procedure, and the third procedure. In the first procedure, the main fuel is ignited. Specifically, the burner 150 is changed from the state a) to the state c) by the same procedure as the first procedure in FIG. In the second procedure, the combustion supporting gas is switched from air to a gas composed of exhaust gas and oxygen. Specifically, an auxiliary flame is supplied to the secondary gas nozzle 157 of the burner 150 by the secondary air supply system 80, the recirculation gas supply system 90, and the oxygen supply system 70 to provide an oil flame (combustion gas: air and recirculation gas). And oxygen) 16, and then the supply of air by the secondary air supply system 80 is stopped to form an oil flame (combustion gas: recirculation gas and oxygen) 17. That is, according to the second procedure, the burner 150 is changed from the state c) to the state e). In the third procedure, the main fuel is switched from oil to coal. Specifically, the oil flame (combustion gas: recirculation gas and oxygen) 17 is maintained until the temperature signal detector 153 can confirm that the temperature condition becomes a condition capable of burning coal. Thereafter, pulverized coal is supplied to the primary gas nozzle 156 of the burner 150 by the primary gas supply system to form a coal flame (combustion gas: recirculation gas and oxygen) 15. That is, the burner 150 is changed from the state of e) to the state of f) by the third procedure. The point of the present embodiment is the second procedure in FIG. When the combustion-supporting gas is switched, exhaust gas is introduced into the burner flame, which may cause misfire. In the prior art, as described in the third procedure of FIG. 4, the combustion support gas is switched when burning with coal as the main fuel. According to the present invention, oil having better ignitability than coal is used as the main fuel. The misfire of the burner flame can be avoided by switching the combustion support gas when

  FIG. 6 shows an example of the starting process of the oxyfuel boiler system of the comparative example. First, as shown in state A), the auxiliary flame 11 is formed on the ignition torch 152 of each burner 150. Then, as in state B), oil is ignited as the main fuel in the uppermost burner to form an oil flame (combustion gas: air) 12, and it is confirmed that the temperature condition becomes a condition capable of coal combustion, state C In the uppermost burner, coal is ignited as main fuel to form a coal flame (combustion gas: air) 13 as shown in FIG. Then, as in state D), the oil is ignited as the main fuel in the middle burner to form an oil flame (supporting gas: air) 12, and it is confirmed that the temperature condition becomes a condition capable of coal combustion, state E) In this way, coal is ignited as the main fuel by the burner at the middle stage to form a coal flame (combustion gas: air) 13. Then, as shown in state F), the lower burner ignites the oil as the main fuel to form an oil flame (combustion gas: air) 12 and confirms that the temperature condition is such that coal combustion is possible, state G). As described above, the lower burner ignites coal as the main fuel to form a coal flame (combustion gas: air) 13. Then, as shown in state H), the combustion support gas of each burner is switched from air to a gas consisting of air, recirculation gas and oxygen to form a coal flame (combustion gas: air, recirculation gas and oxygen) 14, and finally Specifically, the combustion supporting gas is switched to a gas composed of recirculation gas and oxygen to form a coal flame (combustion gas: recirculation gas and oxygen) 15.

  FIG. 7 shows the starting process of the oxyfuel boiler system according to this embodiment. First, the state B) is realized by the same method as A) to B) in FIG. From state B), as shown in state J), oil is ignited as the main fuel in the middle burner to form an oil flame (combustion gas: air) 12 to form the main component of the combustion support gas of the main fuel combustion. This realizes a state in which the burner whose air is air is formed in two stages adjacent to each other in the vertical direction. After that, the combustion support gas of the upper burner of the two-stage burners is switched from air to a gas consisting of air, recirculation gas and oxygen, and oil flame (combustion gas: air and recirculation gas) as in state K). And oxygen) 16 are formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state L) to form an oil flame (combustion gas: recirculation gas and oxygen) 17. . Then, as in the state M), the lower burner ignites oil as the main fuel to form an oil flame (combustion gas: air) 12 so that the main component of the combustion support gas of the main fuel combustion is air. Is formed in two stages adjacent to each other in the vertical direction. After that, the combustion support gas of the upper burner of the two-stage burners is switched from air to a gas consisting of air, recirculation gas and oxygen, and oil flame (combustion gas: air and recirculation gas) as in state N). And oxygen) 16 are formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state O) to form an oil flame (combustion gas: recirculation gas and oxygen) 17. . Then, as shown in state P), the combustion gas of the lower burner is switched from air to a gas consisting of air, recirculation gas and oxygen to form an oil flame (combustion gas: air, recirculation gas and oxygen) 16; Finally, as shown in state Q), the combustion support gas is switched to a gas composed of recirculation gas and oxygen to form an oil flame (combustion gas: recirculation gas and oxygen) 17. Thereafter, the main fuel of each burner is switched from oil to coal, and a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed as in state I). The point of this embodiment is the process from state J) to L) and the process from state M) to O) in FIG. State J) realizes a state in which the burner whose main component of the combustion support gas of the main fuel is air is formed in two stages adjacent to each other in the vertical direction. Among them, in the processes K) to L) in which the gas containing exhaust gas is introduced into the upper stage (upper stage) burner, misfiring of the upper stage burner flame can be avoided by heating from the lower stage (middle stage) burner flame. Similarly, in the state M), a state is realized in which the burner whose main component of the combustion support gas of the main fuel is air is formed in two adjacent stages in the vertical direction. In the process N) to O) of introducing the gas containing exhaust gas into the upper stage (middle stage) burner among the above burners, misfire of the middle stage burner flame can be avoided by heating from the burner flame of the lower stage (lower stage) . In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided. Moreover, misfire of the burner flame can be avoided because the combustion-supporting gas is switched when oil having better ignitability than coal is used as the main fuel.

  FIG. 8 shows the starting process (Alternative Method 1) of the oxyfuel boiler system according to this embodiment. First, the state E) is realized by the same method as A) to E) in FIG. In the state E), the burner whose main component of the combustion supporting gas for the combustion of coal as the main fuel is air is formed in two stages adjacent to each other in the vertical direction. Of the two-stage burners, the combustion support gas of the upper stage (upper stage) burner is switched from air to a gas consisting of air, recirculation gas, and oxygen, and a coal flame (combustion gas: Air, recirculation gas, and oxygen) 14 are formed, and finally the combustion support gas is switched to a gas composed of the recirculation gas and oxygen as in the state S), and the coal flame (combustion gas: recirculation gas and oxygen). ) 15 is formed. Then, as shown in state T), the lower burner ignites oil as the main fuel to form an oil flame (combustion gas: air) 12 and the temperature signal detector 153 determines that the temperature condition becomes a condition capable of coal combustion. After confirmation, as shown in state U), coal is ignited as main fuel by a lower burner to form a coal flame (combustion gas: air) 13. This realizes a state in which the burner whose main component of the combustion supporting gas of coal as the main fuel is air is formed in two stages adjacent in the vertical direction. Of the two-stage burners, the combustion support gas of the upper stage (middle stage) burner is switched from air to a gas consisting of air, recirculation gas, and oxygen, and a coal flame (combustion gas: Air, recirculation gas and oxygen) 14 are formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state W), and coal flame (combustion gas: recirculation gas and oxygen). ) 15 is formed. Then, as shown in state X), the combustion gas of the lower burner is switched from air to a gas consisting of air, recirculation gas and oxygen to form a coal flame (combustion gas: air, recirculation gas and oxygen) 14. Finally, as shown in state I), the combustion gas of the lower burner is switched to a gas composed of recirculation gas and oxygen to form a coal flame (combustion gas: recirculation gas and oxygen) 15. The point of this embodiment is the process from state E) to S) and the process from state U) to W) in FIG. In the state E), a state is realized in which the burner whose main component of the combustion support gas of coal, which is the main fuel, is air is formed in two adjacent stages in the vertical direction. In the process R) to S) of introducing the gas containing exhaust gas into the upper stage (upper stage) burner among the above burners, misfiring of the upper stage burner flame can be avoided by heating from the lower stage (middle stage) burner flame. . Similarly, in the state U), a state is realized in which the burner whose main component of the combustion support gas of the main fuel is air is formed in two stages adjacent to each other in the vertical direction. In the process V) to W) in which the gas containing exhaust gas is introduced into the upper stage (middle stage) burner among the above burners, the misfire of the middle stage burner flame can be avoided by heating from the lower stage (lower stage) burner flame. . In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided.

  FIG. 9 shows the process of starting the oxyfuel boiler system according to this embodiment (Alternative Method 2). First, the state B) is realized by the same method as A) to B) in FIG. From state B), the combustion gas of the upper burner is switched from air to oxygen-rich air to form an oil flame (combustion gas: oxygen-rich air) 18, and the middle burner as in state J2). By igniting the oil as the main fuel and forming an oil flame (support gas: oxygen-rich air) 18, the burner whose main component of the support gas of the combustion of the main fuel is oxygen-rich air is vertically moved A state where two steps are formed adjacent to each other is realized. After that, the combustion gas of the upper (upper) burner of the two burners is switched from oxygen-rich air to gas consisting of air, recirculation gas, and oxygen, and an oil flame (support) as in state K2). Combustion gas: air, recirculation gas and oxygen) 16 is formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state L2), and an oil flame (combustion gas: recycle) Gas and oxygen) 17 are formed. Thereafter, as shown in the state M2), the main burner gas combusts the main fuel by igniting the oil as the main fuel in the lower burner and forming an oil flame (support gas: oxygen-rich air) 18. This realizes a state where two burners are formed adjacent to each other in the vertical direction. After that, the combustion support gas of the upper (middle) burner among the two burners is switched from air to a gas composed of air, recirculation gas and oxygen, and an oil flame (combustion gas: (Air, recirculation gas and oxygen) 16 is formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state O2), and an oil flame (support gas: recirculation gas and oxygen) ) 17 is formed. Then, as shown in state P), the combustion gas of the lower burner is switched from air to a gas consisting of air, recirculation gas and oxygen to form an oil flame (combustion gas: air, recirculation gas and oxygen) 16; Finally, as shown in state Q), the combustion support gas is switched to a gas composed of recirculation gas and oxygen to form an oil flame (combustion gas: recirculation gas and oxygen) 17. Thereafter, the main fuel of each burner is switched from oil to coal, and a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed as in state I). The point of this embodiment is the process from state J2) to L2) and the process from state M2) to O2) in FIG. In the state J2), a state is realized in which the burner whose main component of the combustion support gas of the main fuel is oxygen-rich air is formed in two stages adjacent to each other in the vertical direction. In the processes K2) to L2) of introducing the gas containing the exhaust gas into the upper stage (upper stage) burner among the above burners, misfiring of the upper stage burner flame can be avoided by heating from the lower stage (middle stage) burner flame. . Further, since the burner flame is formed by the oxygen-rich supporting gas, the heating function from the burner flame in the immediately lower stage (middle stage) is enhanced, so the process from state J) to L) in FIG. Compared with, the misfire of the upper burner flame can be avoided more. Similarly, in the state M2), a state is realized in which the burner whose main component of combustion supporting gas of the main fuel is oxygen-rich air is formed in two stages adjacent to each other in the vertical direction. Among the two stages of burners, the process of introducing gas containing exhaust gas into the upper stage (middle stage) burner N2) to O2) also causes the middle stage burner flame to be misfired by heating from the burner flame of the lower stage (lower stage). Can be avoided. Further, since the burner flame is formed by the oxygen-rich supporting gas, the heating function from the burner flame in the immediately lower stage (lower stage) is enhanced, so the process from state M) to O) in FIG. Compared with, misfire of the middle burner flame can be avoided more. In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided.

  FIG. 10 shows the starting process of the oxyfuel boiler system according to this embodiment (Alternative Method 3). First, the state E) is realized by the same method as A) to E) in FIG. In the state E), the burner whose main component of the combustion supporting gas for the combustion of coal as the main fuel is air is formed in two stages adjacent to each other in the vertical direction. Of the two-stage burners, the combustion support gas of the upper stage (upper stage) burner is switched from air to a gas consisting of air, recirculation gas, and oxygen, and a coal flame (combustion gas: In addition to forming air, recirculation gas and oxygen 14, the combustion gas of the lower stage (middle stage) burner is switched from air to oxygen-rich air, and a coal flame (combustion gas: oxygen-rich air) 19 is switched. Let it form. Thereafter, as shown in the state S2), the combustion gas of the upper stage (upper stage) burner is switched to a gas composed of recirculation gas and oxygen to form a coal flame (combustion gas: recirculation gas and oxygen) 15. Then, as shown in state T2), the lower burner ignites the oil as the main fuel to form an oil flame (support gas: oxygen-rich air) 18, and the temperature signal is detected when the temperature condition becomes a condition capable of coal combustion. After confirming with the vessel 153, the coal is ignited as main fuel with the lower burner as in the state U2) to form a coal flame (combustion gas: oxygen-rich air) 19. This realizes a state in which the burner whose main component of the combustion supporting gas of coal as the main fuel is air is formed in two stages adjacent in the vertical direction. Of the two-stage burners, the combustion support gas of the upper stage (middle stage) burner is switched from oxygen-rich air to gas consisting of air, recirculation gas, and oxygen. Combustion gas: air, recirculation gas and oxygen) 14 is formed, and finally the combustion support gas is switched to a gas composed of recirculation gas and oxygen as in state W2), and coal flame (combustion gas: recirculation) Gas and oxygen) 15 are formed. After that, as shown in state X), the combustion gas of the lower burner is switched from oxygen-rich air to gas consisting of air, recirculation gas and oxygen, and coal flame (combustion gas: air, recirculation gas and oxygen) 14 is changed. Finally, as shown in state I), the combustion gas in the lower burner is switched to a gas composed of recirculation gas and oxygen to form a coal flame (combustion gas: recirculation gas and oxygen) 15. The point of this embodiment is the process from state E) to S2) and the process from state U2) to W2) in FIG. In the state E), a state is realized in which the burner whose main component of the combustion support gas of coal, which is the main fuel, is air is formed in two adjacent stages in the vertical direction. In the processes R2) to S2) of introducing the gas containing the exhaust gas into the upper stage (upper stage) burner among the above burners, misfiring of the upper stage burner flame can be avoided by heating from the lower stage (middle stage) burner flame. . Further, in the process from R2) to S2), since the burner flame is formed by the oxygen-rich supporting gas, the heating function from the burner flame in the immediately lower stage (middle stage) is strengthened. Compared with the process from state R) to S), misfire of the upper burner flame can be avoided more. Similarly, in the state U2), a state is realized in which the burner whose main component of the combustion support gas of the main fuel is oxygen-rich air is formed in two stages adjacent to each other in the vertical direction. Of the two-stage burners, in the process V2) to W2) of introducing the gas containing exhaust gas into the upper (middle) burner, the middle burner flame is misfired by heating from the burner flame in the lower stage (lower stage). Can be avoided. Further, since the burner flame is formed by the oxygen-rich combustion support gas, the heating function from the burner flame in the lower stage (lower stage) is enhanced, so the process from state V) to W) in FIG. Compared with, misfire of the middle burner flame can be avoided more. In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided.

  FIG. 11 shows the starting process of the oxyfuel boiler system according to this embodiment (Alternative Method 4). First, the state B) is realized by the same method as A) to B) in FIG. From state B), as shown in state J), oil is ignited as the main fuel in the middle burner to form an oil flame (combustion gas: air) 12 to form the main component of the combustion support gas of the main fuel combustion. This realizes a state in which the burner whose air is air is formed in two stages adjacent to each other in the vertical direction. After that, the combustion support gas of the upper (upper) burner of the two burners is switched from air to a gas composed of air, recirculation gas and oxygen and having a higher oxygen concentration than air, as in state K). Oil flame (combustion gas: consisting of air, recirculation gas and oxygen is formed, and the oxygen concentration is higher than air) 20, and finally the support gas is recirculated from recirculation gas and oxygen as in state L) Then, an oil flame (combustion gas: recirculation gas and oxygen) 17 is formed. Then, as in the state M), the lower burner ignites oil as the main fuel to form an oil flame (combustion gas: air) 12 so that the main component of the combustion support gas of the main fuel combustion is air. Is formed in two stages adjacent to each other in the vertical direction. Thereafter, the combustion support gas of the upper (middle) burner of the two burners is switched from air to a gas composed of air, recirculation gas, and oxygen and having a higher oxygen concentration than air, as in state N3) An oil flame (combustion gas: consisting of air, recirculation gas, and oxygen is formed, and the oxygen concentration is higher than air) 20, and finally the support gas is recirculated from recirculation gas and oxygen as in state O) Then, an oil flame (combustion gas: recirculation gas and oxygen) 17 is formed. After that, as shown in state P3), the combustion gas of the lower burner is switched from air to a gas composed of air, recirculation gas, and oxygen, and the oxygen concentration is higher than that of air, and an oil flame (combustion gas: air and recirculation gas). And the oxygen concentration is higher than that of air) 20, and finally the combustion support gas is switched to a gas consisting of recirculation gas and oxygen as in state Q) to form an oil flame (combustion support gas: Recycle gas and oxygen) 17 are formed. Thereafter, the main fuel of each burner is switched from oil to coal, and a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed as in state I). The point of this embodiment is the process from state J) to L) and the process from state M) to O) in FIG. State J) realizes a state in which the burner whose main component of the combustion support gas of the main fuel is air is formed in two stages adjacent to each other in the vertical direction. Among them, in the processes K3) to L) of introducing the gas containing exhaust gas into the upper (upper) burner, misfiring of the upper burner flame can be avoided by heating from the lower (middle) burner flame. In addition, since the oxygen concentration of the supporting gas does not fall below the oxygen concentration of the air over the processes J) to L), the state L) is realized in a shorter time compared with the processes J) to L) of FIG. It is possible to increase the carbon dioxide concentration in the exhaust gas. Similarly, in the state M), a state is realized in which the burner whose main component of the combustion support gas of the main fuel is air is formed in two adjacent stages in the vertical direction. In the process N3) to O) of introducing the gas containing exhaust gas into the upper stage (middle stage) burner among the above burners, the misfire of the middle stage burner flame can be avoided by heating from the burner flame of the lower stage (lower stage) . In addition, since the oxygen concentration of the supporting gas does not fall below the oxygen concentration of the air from the processes M) to O), the state O) is realized in a shorter time than the processes M) to O) in FIG. It is possible to increase the carbon dioxide concentration in the exhaust gas. In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided.

  FIG. 12 shows the process of starting the oxyfuel boiler system according to this embodiment (Alternative Method 5). First, the state E) is realized by the same method as A) to E) in FIG. In the state E), the burner whose main component of the combustion supporting gas for the combustion of coal as the main fuel is air is formed in two stages adjacent to each other in the vertical direction. Thereafter, the combustion support gas of the upper (upper) burner of the two burners is switched from air to a gas composed of air, recirculation gas, and oxygen and having a higher oxygen concentration than air, as in state R3). A coal flame (combustion gas: consisting of air, recirculation gas, and oxygen is formed, and the oxygen concentration is higher than air) 21, and finally the support gas is recirculated from recirculation gas and oxygen as in state S) Then, a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed. Then, as shown in state T), the lower burner ignites oil as the main fuel to form an oil flame (combustion gas: air) 12 and the temperature signal detector 153 determines that the temperature condition becomes a condition capable of coal combustion. After confirmation, as shown in state U), coal is ignited as main fuel by a lower burner to form a coal flame (combustion gas: air) 13. This realizes a state in which the burner whose main component of the combustion supporting gas of coal as the main fuel is air is formed in two stages adjacent in the vertical direction. Thereafter, the combustion support gas of the upper (middle) burner of the two burners is switched from air to a gas composed of air, recirculation gas, and oxygen and having a higher oxygen concentration than air, as in state V3). A coal flame (combustion gas: consisting of air, recirculation gas and oxygen is formed, and the oxygen concentration is higher than air) 21, and finally the support gas is recirculated from recirculation gas and oxygen as in state W) Then, a coal flame (combustion gas: recirculation gas and oxygen) 15 is formed. After that, as shown in state X3), the combustion gas of the lower burner is switched from air to air, recirculation gas, and oxygen, and the oxygen concentration is higher than that of air, and coal flame (combustion gas: air and recirculation gas) (The oxygen concentration is higher than that of air) 21, and finally the combustion gas of the lower burner is switched to the gas consisting of recirculation gas and oxygen as shown in state I). (Fuel gas: recirculation gas and oxygen) 15 is formed. The point of this embodiment is the process from state E) to S) and the process from state U) to W) in FIG. In the state E), a state is realized in which the burner whose main component of the combustion support gas of coal, which is the main fuel, is air is formed in two adjacent stages in the vertical direction. In the processes R3) to S) of introducing the gas containing exhaust gas into the upper stage (upper stage) burner among the above burners, misfiring of the upper stage burner flame can be avoided by heating from the lower stage (middle stage) burner flame. . Further, since the oxygen concentration of the supporting gas does not fall below the oxygen concentration of the air from the steps E) to S), the state S) is realized in a shorter time than the steps E) to S) in FIG. It is possible to increase the carbon dioxide concentration in the exhaust gas. Similarly, in the state U), a state is realized in which the burner whose main component of the combustion combustion gas of coal as the main fuel is air is formed in two stages adjacent to each other in the vertical direction. In the process V3) to W) of introducing the gas containing the exhaust gas into the upper stage (middle stage) burner of the two stage burners, the middle stage burner flame is misfired by heating from the lower stage (lower stage) burner flame. Can be avoided. In addition, since the oxygen concentration of the supporting gas does not fall below the oxygen concentration of the air from the process U) to W), the state W) is realized in a shorter time than the processes U) to W) in FIG. It is possible to increase the carbon dioxide concentration in the exhaust gas. In addition, the amount of air supplied to the burner is reduced as compared with the process of FIG. 6, that is, the proportion of nitrogen in the exhaust gas is reduced. Therefore, the carbon dioxide concentration in the exhaust gas can be increased, and the misfire of the burner flame can be avoided.

  In the present embodiment, the carbon dioxide concentration in the exhaust gas can be increased most, and the misfire of the burner flame can be avoided by the same method as the process of starting the oxyfuel boiler system described in FIG.

  FIG. 13 shows the starting process of the oxyfuel boiler system according to this embodiment (Alternative Method 6). This starting process is an example in which the adjustment of the oxygen flow rate and the adjustment of the recirculation flow rate in the starting method shown in FIGS. 9 to 12 are applied to the embodiment of FIG. This activation method can be applied to both the comparative example of FIG. 4 and the embodiment of FIG.

  As a problem of switching combustion support gas, the supply of air is stopped and the combustion support gas is switched to a gas containing recirculation gas and oxygen to shorten the time required to form a flame (combustion gas: recycle gas and oxygen). There are challenges.

  The state G) of FIG. 13 is realized by the same method as A) to G) of FIG. In the state G), coal is ignited as main fuel by the upper, middle and lower burners to form a coal flame (combustion gas: air) 13. After that, as shown in state H2), the combustion support gas of the burner is switched from air to a gas composed of air, recirculation gas, and oxygen, and the oxygen concentration is higher than air, and coal flame (combustion gas: air and recirculation gas). And the oxygen concentration is higher than that of air) 21. Finally, as shown in state I), the combustion support gas is switched to a gas composed of recirculation gas and oxygen to form a coal flame (combustion gas: recirculation gas and oxygen) 15.

  FIG. 14 is a diagram illustrating a procedure for switching the combustion support gas. The specific procedure is as shown in FIG. The combustion support gas switching is started, and the flow rate of high-purity oxygen is increased by adjusting the oxygen flow rate as the first procedure. As a second procedure, the flow rate ratio of the recirculation gas is increased by adjusting the recirculation flow rate of a part of the exhaust gas. As a third procedure, the air flow rate is reduced by adjusting the air flow rate. Finally, the switching of the combustion support gas to the recycle gas or the gas containing high purity oxygen is completed. The second procedure and the third procedure may be reversed. 14, oil flame (supporting gas: air) 12, oil flame (supporting gas: composed of air, recirculation gas and oxygen, oxygen concentration is higher than air) 20, oil flame (supporting gas) The recycle gas and oxygen) 17 switching procedure is the same.

  Thus, after switching from the state where the gas whose main component is air is the supporting gas, after increasing the flow rate of high purity oxygen by adjusting the flow rate of oxygen supplied from the high purity oxygen production device, By adjusting the recirculation flow rate of a part of the exhaust gas, the flow rate of the recirculation gas is increased, and by adjusting the air flow rate used for the combustion support gas, the air flow rate is reduced and finally the combustion support gas is reduced. The starting method is to switch to a recirculated gas or a gas containing high purity oxygen.

  As shown in the graph showing the relationship between the oxygen concentration and the time in the figure showing the procedure for switching the combustion support gas in FIG. 14, when the oxygen flow rate is increased in advance at the start of the oxyfuel boiler system, a process such as a is performed. When the oxygen flow rate is not increased in advance, the process is as shown in b. The time t1 until the flame is stabilized and the switching of the support gas is completed in the process a in which the oxygen concentration is increased in advance is shorter than the time t2 in the process b. This is because the oxygen concentration of the supporting gas does not fall below the oxygen concentration of air over the processes G) to I) in FIG. 13, and therefore, compared with the time from the processes G) to I) in FIG. State I) can be realized in a short period of time, the supply of air is stopped, and the combustion support gas is switched to a gas containing recirculation gas and oxygen to form a coal flame (supporting gas: recirculation gas and oxygen) 15 Can be shortened.

  Moreover, the graph showing the relationship between burner temperature and time among the figures which show the procedure of the combustion support gas switching of FIG. 14 is demonstrated. When switching from a state where the gas whose main component is air is used as a combustion support gas at startup, the flow rate of high-purity oxygen is increased by adjusting the flow rate of oxygen supplied from the high-purity oxygen production device, and then the exhaust gas The timing of increasing the recirculation gas flow rate by adjusting the partial recirculation gas flow rate triggers a change in the temperature signal from the temperature signal detection means provided in at least one of the burner parts The startup method is As a method for detecting a change in the temperature signal, a method for detecting that the burner temperature reaches a predetermined value T1 when the oxygen concentration is increased as compared with air, or a case where the burner temperature T0 and oxygen before switching are increased. There is a method in which a difference in a predetermined value T1 of the burner temperature is preset and detected. As a result, it is possible to grasp that the oxygen concentration of the supporting gas is not lower than the oxygen concentration of the air without providing an oxygen concentration measuring device, and the time for forming the flame in which the supporting gas is switched can be shortened. .

  In addition, after switching from the state where the gas whose main component is air is used as the combustion support gas at startup, after increasing the flow rate of high purity oxygen by adjusting the oxygen flow rate supplied from the high purity oxygen production device By adjusting the recirculation gas flow rate of a part of the exhaust gas, increasing the flow rate of the recirculation gas and adjusting the air flow rate used for the combustion support gas, the timing to reduce the air flow rate, The starting method uses a change in the temperature signal from the temperature signal detecting means provided in at least one of them as a trigger. Since the flow rate of oxygen supplied from the oxygen production apparatus is increased in consideration of the decrease in the oxygen concentration due to the decrease in the air flow rate, the burner temperature T1 should be higher than the burner temperature when the flow rate of only the recirculation gas is increased. . This makes it possible to grasp that the oxygen concentration of the supporting gas does not fall below the oxygen concentration of the air without providing an oxygen concentration measuring device. The time for forming the switched flame can be shortened.

  The starting method of the oxyfuel boiler system of each embodiment described above can be performed by monitoring and commanding by a person in the central operation room, or by command reception based on data reception, data processing, and processing by the control device. The figure of the oxyfuel boiler system provided with the control apparatus in FIG. 15 is shown. The control apparatus 200 is provided in the oxyfuel boiler system of FIG. The control device 200 is connected to the temperature signal detector 153, the blower 71, the recirculation gas regulating valve 91, and the suction blower 92, receives measurement information from the temperature signal detector 153, and transmits an operation command to the target such as the blower 71. . In addition, although it is described here that it is connected only to a limited number of measuring instruments and operating machines, it is actually connected to all measuring instruments and operating machines provided in the oxyfuel boiler system. When the processing of FIG. 4 to FIG. 14 is performed by the control device 200, the control device can be implemented by a computer having a memory or a CPU, and the processing means as functions of the device is a program module. Yes, each function can be implemented by reading the module and causing the computer to execute it. The control device receives measurement data measured by the oxyfuel boiler system, executes the above-described startup method, and transmits a command to devices such as a valve and a blower of the oxyfuel boiler system.

  In addition, this invention is not limited to the Example of FIGS. 1-15 mentioned above, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  According to this embodiment, the concentration of carbon dioxide in the exhaust gas can be increased even when the oxyfuel boiler is started. It is possible to provide an oxyfuel boiler system in which exhaust gas can be cooled as it is to liquefy and separate carbon dioxide and carbon dioxide can be easily recovered.

11 Auxiliary flame 12 Oil flame (supporting gas: air)
13 Coal flame (supporting gas: air)
14 Coal flame (support gas: air, recirculation gas and oxygen)
15 Coal flame (combustion gas: recirculation gas and oxygen)
16 Oil flame (supporting gas: air, recirculation gas and oxygen)
17 Oil flame (support gas: recirculation gas and oxygen)
18 Oil flame (support gas: oxygen-rich air)
19 Coal flame (support gas: oxygen-rich air)
20 Oil flame (combustion gas: consisting of air, recirculation gas and oxygen, oxygen concentration is higher than air)
21 Coal flame (supporting gas: consisting of air, recirculation gas and oxygen, oxygen concentration is higher than air)
30 Oil supply system 30a Load oil supply system 30b Torch oil supply system 31 Hydraulic source 33 Load oil transport pipe 33b Torch oil transport pipe 35, 35b Oil inlet valve 60 Primary gas supply system 61 Air transport pipe 62 Mill 63 Pulverized coal transport pipe 70 Oxygen supply system 71 Blower 72 Oxygen separator 73 Separation oxygen transport pipe 74 High concentration oxygen intermediate tank 75 High concentration oxygen transport pipe 80 Secondary air supply system 81 Air transport pipe 90 Recirculation gas supply system 91 Recirculation Gas adjusting valve 92 Suction blower 93 Recirculation gas transport pipe 99 Exhaust gas 100 Furnace chamber 102 Furnace outlet 103 Exhaust gas transport pipe 105 Exhaust gas treatment device 109 Exhaust gas treatment device 109 Recirculation branch point 111 Flue path 141 Press blower 150 Burner 152 Ignition torch 153 Temperature Signal detector 155 Oil burner nozzle 156 Primary gas nozzle 157 Secondary gas nozzle
200 Controller

Claims (9)

It has a multi-stage burner in the height direction of the furnace chamber and forms an ignition torch by burning oil droplets or combustible gas in the furnace chamber, and oil droplets or combustible gas or pulverized coal is burned in the burner in the furnace chamber. Combusted as the main fuel, mixed with oxygen in a part of the exhaust gas from the furnace chamber outlet and recirculated and used as a combustion support gas for the combustion of the main fuel, part or all of the remaining exhaust gas A method for starting an oxyfuel boiler system that extracts and recovers carbon dioxide from exhaust gas,
As a first procedure, after forming an ignition torch in the furnace chamber, oil droplets or combustible gas is used as the main fuel in the vicinity of the burner in the furnace chamber and in the vicinity of the ignition torch, and the main component of the combustion support gas of the main fuel is Combustion using air gas,
As a second procedure, the flow rate ratio of the recirculation gas or high purity oxygen is increased by adjusting the recirculation flow rate of a part of the exhaust gas or the oxygen flow rate supplied from the high purity oxygen production apparatus to the combustion support gas. Meanwhile, by adjusting the air flow rate used for the combustion support gas, the air flow rate is reduced, and finally the combustion support gas is a gas mainly composed of a recirculation gas or a gas containing high-purity oxygen,
As a third procedure, the main fuel is switched from oil droplets or combustible gas to coal.
A method for starting a burner of an oxyfuel boiler system. The furnace chamber has a multi-stage burner in the height direction, and an ignition torch is formed by burning oil droplets or combustible gas in the furnace chamber, and oil droplets or combustible gas or pulverized coal is generated in the furnace chamber burner. Combusted as the main fuel, mixed with oxygen in a part of the exhaust gas from the furnace chamber outlet and recirculated and used as a combustion support gas for the combustion of the main fuel, part or all of the remaining exhaust gas In an oxyfuel boiler system that extracts and recovers carbon dioxide from exhaust gas,
At the time of start-up, the main fuel is burned, and the burner flame whose main component of the combustion support gas of the main fuel is air is formed in two or more stages adjacent in the vertical direction, Of the flames of the burner of two or more stages, the supporting gas of the flame of the burner other than the lowermost stage is changed from a gas mainly containing air to a gas mainly containing a recirculated gas or a gas containing high-purity oxygen. Switch,
A method for starting an oxyfuel boiler system. 3. A method for starting an oxyfuel boiler system according to claim 2, wherein a flame of a burner in which oil droplets or combustible gas is burned as a main fuel, and the main component of the combustion supporting gas of the main fuel combustion is air. In the state where two or more stages are formed adjacent to each other in the vertical direction, the flame-supporting gas of the burner flames other than the lowermost stage among the flames of the two or more stage burners is mainly composed of air. Switch from recirculation gas or gas containing high purity oxygen to the main component,
A method for starting an oxyfuel boiler system. 3. The start-up method for an oxyfuel boiler system according to claim 2, wherein pulverized coal is burned as a main fuel at the time of start-up, and the main component of the combustion-supporting gas of the main fuel is air. In the state where two or more stages are formed adjacent to each other in the vertical direction, the combustion-supporting gas of the burner other than the lowermost stage among the two or more stages is recirculated from the gas mainly composed of air. Or switch to a gas whose main component is a gas containing high-purity oxygen,
A method for starting an oxyfuel boiler system. 5. The method for starting an oxyfuel boiler system according to claim 2, 3 or 4, wherein oil droplets, combustible gas or pulverized coal is combusted as main fuel at the time of start-up, and combustion support gas for combustion of the main fuel. In the procedure of using a gas whose main component is air, the oxygen concentration of the combustion support gas is made higher than the oxygen concentration of air.
A method for starting an oxyfuel boiler system. The furnace chamber has a multi-stage burner in the height direction, and air is used to transport pulverized coal to the burner that leads to the furnace chamber, and an ignition torch is formed by burning oil droplets or combustible gas in the furnace chamber After burning oil droplets, combustible gas, or pulverized coal as the main fuel in the burner in the furnace chamber, and passing the exhaust gas from the furnace chamber outlet through the heat exchanger or the exhaust gas treatment device, a part of the exhaust gas Is used as a support gas for combustion of the main fuel by recirculating to the furnace chamber, and part or all of the oxygen supplied from the high-purity oxygen production apparatus is used as a part of the support gas, In the starting method of the oxyfuel boiler system that extracts and recovers carbon dioxide from the exhaust gas part or all of the remaining exhaust gas,
When switching from a state where the gas whose main component is air is a combustion support gas at startup, after increasing the flow rate of high purity oxygen by adjusting the oxygen flow rate supplied from the high purity oxygen production device, By adjusting the recirculation flow rate of a part of the exhaust gas, the flow rate of the recirculation gas is increased, and the air flow rate used for the combustion support gas is adjusted to reduce the air flow rate, and finally the support flow rate. Switch the fuel gas to recycle gas or gas containing high purity oxygen,
A method for starting an oxyfuel boiler system. In the start-up method of the oxyfuel boiler system according to claim 6, at the time of start-up, the oxygen flow rate supplied from the high-purity oxygen production apparatus is changed when switching from the state where the gas whose main component is air is used as the combustion support gas. After increasing the flow rate ratio of high-purity oxygen by adjusting, the timing for increasing the flow rate ratio of the recirculation gas by adjusting the recirculation flow rate of a part of the exhaust gas is set to at least one of the burner sites. Triggered by a change in temperature signal from the temperature signal detection means provided in
A method for starting an oxyfuel boiler system. 8. The oxygen combustion boiler system start-up method according to claim 6, wherein oxygen supplied from the high-purity oxygen production apparatus when switching from a state where a gas whose main component is air is used as a combustion-supporting gas at the time of start-up. After increasing the flow rate of high-purity oxygen by adjusting the flow rate, adjusting the recirculation flow rate of a part of the exhaust gas, increasing the flow rate rate of the recirculation gas and using the air used for the combustion support gas By adjusting the flow rate, the timing for reducing the air flow rate is triggered by a change in the temperature signal from the temperature signal detection means provided in at least one of the burner parts.
A method for starting an oxyfuel boiler system. A furnace chamber for burning fuel;
A combustion burner that is provided in a plurality of stages in the furnace chamber in the height direction and burns with oil droplets or combustible gas or pulverized coal as the main fuel;
An oxygen supply system for supplying oxygen from the high-purity oxygen production apparatus to the burner;
A primary gas supply system for supplying air to the burner;
An oil supply system for a torch for supplying oil droplets or combustible gas;
A recirculation gas supply system for recirculating a part of the exhaust gas from the furnace chamber outlet and supplying the burner as a combustion support gas for the main fuel;
After forming an ignition torch by burning oil droplets or combustible gas in the furnace chamber as a first procedure, oil droplets or combustible gas is used as the main fuel in the vicinity of the burner in the furnace chamber and in the vicinity of the ignition torch. As a second procedure, the combustion supporting gas is combusted using a gas whose main component is air, and as a second procedure, the combustion supporting gas is supplied from a part of the recirculation flow rate of the exhaust gas or a high-purity oxygen production apparatus. By adjusting the oxygen flow rate, the flow rate of recirculated gas or high-purity oxygen is increased, while the air flow rate used for the combustion support gas is adjusted to reduce the air flow rate, and finally the combustion support gas. And a control device that switches the main fuel from oil droplets or combustible gas to coal as a third procedure, as a gas mainly composed of recirculated gas or gas containing high-purity oxygen,
An oxyfuel boiler system characterized by that.

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