JP2010243016A - Oxygen burning boiler plant and method of operating the oxygen burning boiler plant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately control supply oxygen amount and oxygen concentration even when fuel amount supplied to burners is fluctuated, in an oxygen burning method. <P>SOLUTION: This oxygen burning boiler plant includes: a boiler for burning fuel by the burners by using gas containing oxygen having higher concentration than that in the air and gas containing carbon dioxide having higher concentration than that in the air to generate steam; an exhaust gas circulation means for using part of boiler exhaust gas as the gas containing carbon dioxide as circulating exhaust gas; and a carbon dioxide recovery means for recovering carbon dioxide in the boiler exhaust gas. The oxygen burning boiler plant further includes: a pulverized coal flowmeter for measuring the fuel amount supplied to the burners with respect to each burner or as a total value of the plurality of burners; and an oxygen supply amount determination means for controlling the amount of the gas containing oxygen having high concentration supplied to the burner, based on the fuel amount value measured by the pulverized coal flowmeter. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oxyfuel boiler plant and a method for operating an oxyfuel boiler plant.

  It has been pointed out that thermal power plants that have boilers and steam turbines as main components emit more carbon dioxide, which is a cause of global warming, than other power generation systems.

  Therefore, a method of burning with high-purity oxygen instead of using air as in the prior art when fuel is burned in a boiler has been proposed. Hereinafter, this method is referred to as oxygen combustion, and the combustion method using air is referred to as air combustion.

  In oxyfuel combustion, most of the exhaust gas becomes carbon dioxide, 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 carbon dioxide. It is one of the effective methods for reducing carbon dioxide emissions.

  In addition, since about 80% of nitrogen in the air is not supplied to the boiler, nitrogen oxide (thermal NOx) generated from nitrogen in the air is not generated, and a reduction effect of nitrogen oxide is also expected.

  In the oxyfuel boiler, when the fuel is burned only with oxygen, the flame temperature becomes too high and the burner and the boiler furnace wall surface may be damaged. Therefore, a method has been proposed in which a part of boiler exhaust gas is circulated, mixed with oxygen and burned.

  Patent Document 1 discloses a method for controlling the circulating gas flow rate of boiler exhaust gas so that the total heat recovery amount of the boiler becomes a target heat recovery amount, a system for supplying oxygen to the boiler main body by mixing oxygen with the circulating exhaust gas, and oxygen directly in the boiler main body. And a method for controlling the amount of heat collected in the boiler body by changing the flow rate of oxygen supplied to both systems.

  In addition, there has been proposed a method of starting with air combustion at the start and switching to oxyfuel combustion with a predetermined load. In Patent Document 2, the flow rate of the atmosphere is adjusted so that the outlet oxygen concentration of the boiler body becomes equal to the outlet oxygen concentration set value at the time of startup, and after the startup is completed, the outlet oxygen concentration of the boiler body is equal to the outlet oxygen concentration set value. A method is described in which the flow rate of oxygen supplied from the high-purity oxygen production apparatus is adjusted and the exhaust gas circulation flow rate is adjusted so that the inlet oxygen concentration of the boiler body becomes equal to the inlet oxygen concentration set value.

JP 2007-147162 A JP 2001-336736 A

  An oxyfuel boiler is one of the major differences from the air combustion system in that the amount of oxygen in the supply gas and the oxygen concentration can be changed independently. In addition, appropriately controlling these amounts leads to stable and safe operation of the plant.

  In particular, if the amount of supplied oxygen is too small relative to the amount of fuel added, it will cause incomplete combustion and misfire, and if it is too much, it will cause overheating due to a rise in flame temperature, which is an important factor. In addition, as is evident especially in boilers that use coal as fuel, even if the set value of the supplied fuel is constant, the amount of fuel actually injected into the boiler varies over time, so the amount of supplied oxygen is maintained appropriately. It is not easy to do. In the oxyfuel combustion method, the change in the oxygen amount also affects the oxygen concentration. Even when adjusting the exhaust gas circulation flow rate using the target heat recovery amount and the inlet oxygen concentration set value as an index as in the above-mentioned patent document, it is difficult to maintain the oxygen concentration at a predetermined target value or set value.

  When adjusting the exhaust gas circulation flow rate using the boiler heat recovery as an index, it is caused by combustion, gas flow, steam flow, heat transfer, etc. in the boiler from when the oxygen amount or oxygen concentration changes until the boiler heat recovery amount is affected. Therefore, it is not easy to maintain the heat recovery amount at the target value.

  An object of the present invention is to appropriately control the amount of oxygen supplied and the oxygen concentration even if the amount of fuel supplied to the burner fluctuates in the oxyfuel combustion system.

  The present invention provides a pulverized coal flow meter that measures the amount of fuel supplied to a burner as a total value for each burner or a plurality of burners, and a high concentration that is supplied to the burner based on the fuel amount value measured by the pulverized coal flow meter. And oxygen supply amount determining means for adjusting the amount of the gas containing oxygen.

  According to the present invention, in the oxyfuel combustion system, even if the amount of fuel supplied to the burner fluctuates, the amount of oxygen supplied and the oxygen concentration can be controlled appropriately.

It is a figure explaining the structure of the boiler plant which concerns on Example 1. FIG. It is a figure explaining the structure of the water / steam system in an Example. It is a figure explaining the burner arrangement example of the boiler furnace in an Example. It is a figure explaining the structure of the boiler plant which concerns on Example 2. FIG. It is a figure explaining the example of a change of main process amount.

  Hereinafter, each embodiment will be described with reference to the drawings.

  FIG. 1 shows the present embodiment by taking a power plant using coal as a fuel as an example. The control device 100 of the present embodiment receives process value measurement information from the control target plant, and uses this to perform a preprogrammed operation in the control device 100 and transmit an operation command signal (control signal) to the plant. To do. The plant controls the state of the plant by operating an actuator such as a valve opening or a damper opening in accordance with the received operation command signal.

  The present embodiment is a thermal power plant having a boiler 200 and a steam turbine 300 driven by steam generated by the boiler 200 as main components (a generator is not shown). The control device 100 receives the load request command 10 from the central power supply command station, and controls the plant to a designated load (power generation output) state based on this. By adjusting the valve opening degree of the steam control valve 254, the flow rate of the steam guided to the turbine 300 changes and the power generation output changes.

  In addition, the water / steam system includes a condenser 310 that cools the steam emitted from the steam turbine 300 into a liquid, and a water supply pump 320 that feeds water cooled by the condenser 310 back to the boiler 200 as boiler feed water. There is. Although not shown in the drawings, an actual plant also includes a feed water heater that preheats boiler feed water using a part of steam (extracted air) extracted from an intermediate stage of the steam turbine 300 as a heating source.

  On the other hand, the system of the combustion gas 380 discharged from the boiler includes a gas preheater 330, an exhaust gas treatment device 340 for purifying the exhaust gas, a carbon dioxide recovery device 350 for cooling and liquefying and recovering carbon dioxide in the exhaust gas, There is a chimney 370 that discharges a gas 351 mainly composed of nitrogen and oxygen after the carbon dioxide is recovered.

  In this embodiment, an air combustion boiler in which fuel is burned with air is burned using a gas containing high-purity oxygen instead of air, and a plant including an oxyfuel combustion boiler and an oxyfuel combustion boiler Is targeted.

  Therefore, as shown in FIG. 1, an oxygen production apparatus 360 for producing high-concentration oxygen by separating air into a nitrogen-based gas and an oxygen-based gas is provided. The oxygen production apparatus is a system in which air is cooled and separated using the difference between the boiling points of oxygen and nitrogen. This embodiment does not depend on the oxygen production method, and may be another method such as a membrane separation method that uses a difference in size between nitrogen molecules and oxygen molecules.

  In the oxygen production apparatus, the air 363 is separated into a high-purity oxygen gas 362 and a nitrogen-based gas 361, and the nitrogen-based gas 361 is discharged from the chimney 370 to the atmosphere.

  If combustion is performed using only high-purity oxygen instead of air, the temperature of the flame becomes too high, and there is a possibility that the burner or boiler wall surface that burns fuel may be damaged. Therefore, the high-purity oxygen 362 produced by the oxygen production apparatus 360 is mixed with the circulating exhaust gas 390 that is part of the exhaust gas discharged from the boiler and supplied to the burner 210.

  Circulating exhaust gas 390 takes out part of the gas after being purified by exhaust gas treatment device 340 and raises the temperature by gas preheater 330. The flow rate of the circulating exhaust gas is adjusted by changing the opening degree of the circulating exhaust gas flow rate adjustment valve 391 based on the valve opening degree command 22.

  The flow rate of the oxygen gas 362 supplied to the burner 210 can be adjusted by controlling the opening degree of the flow rate adjusting valve 211 based on the valve opening degree command 14 from the control device 100.

  Coal 400 as fuel is sent to the coal crusher 410 through the fuel supply amount adjustment valve 401. It becomes powder (pulverized coal) by the coal pulverizer 410, is transported by a part of the circulating exhaust gas 390, and is supplied to the burner 210. The flow rate of the pulverized coal is measured by the pulverized coal flow meter 420, and the amount of fuel actually supplied to the burner can be grasped. The amount of circulating exhaust gas sent to the coal pulverizer 410 can be adjusted by controlling the flow rate adjustment valve 213.

  Next, the configuration of the boiler will be described.

  Since the inside of the furnace that burns fuel becomes high temperature, there is a cooling wall called a water wall 230 that cools the entire wall surface and collects the heat of the combustion gas. In the boiler 200, there are other heat exchangers including a economizer 290, a primary superheater 280, a secondary superheater 240, a tertiary superheater 250, and a quaternary superheater 260. Is recovered to produce high-temperature steam.

  As shown in FIG. 2, as steam flow, the boiler feed water is first led to the economizer 290, and then the water wall 230, primary superheater 280, secondary superheater 240, tertiary superheater 250, quaternary. The temperature is raised in the order of the superheater 260, becomes main steam 251, and enters the steam turbine 300. In this cycle, the steam that has worked in the high-pressure steam turbine 300 becomes liquid in the condenser 310 and is sent again to the boiler by the feed water pump 320.

  Next, the configuration and function of the control device 100 according to the present embodiment will be described. The control device 100 controls the plant based on the load request command 10 from the central power supply command station. The reference fuel amount determination unit 11 calculates a fuel amount set in advance with respect to the load request command 10 and outputs the fuel amount as a reference fuel amount signal 12 to the fuel supply amount adjustment valve control unit 17. The fuel supply amount adjusting valve control means 17 compares the input reference fuel amount signal 12 with the measured value 421 of the pulverized coal flow meter 420, and the valve of the fuel supply amount adjusting valve 401 by proportional integral control based on the deviation amount. The opening command signal 18 is calculated and output to the fuel supply amount adjustment valve 401.

  The feed water flow rate determining means 15 calculates a feed water flow rate to the boiler that is set in advance with respect to the input load request command 10, and outputs the calculated feed water flow rate signal 19 to the feed water pump 320. The water supply pump 320 changes the amount of water supplied to the boiler by changing the rotation speed of the pump or the opening of the rotor blades based on the water supply flow rate signal 19.

  In the oxygen supply amount determination means 23, the reference oxygen amount determination means 13 calculates the reference oxygen amount signal 14 so that the ratio between the fuel amount and the oxygen amount set with respect to the measured value 421 of the pulverized coal flow meter 420 is obtained. . If the reference oxygen amount signal 14 is output to the supply oxygen flow rate adjustment valve 211 to adjust the oxygen flow rate, the ratio of the set fuel amount to the oxygen amount even if the amount of fuel actually supplied to the burner fluctuates. Oxygen can be supplied while maintaining Thereby, the combustion state of a desirable state can be maintained in the burner.

  The circulating exhaust gas amount adjusting means 16 calculates a reference circulating exhaust gas amount that is preset for the input load request command 10. In the condition comparison means 20, the measured value 263 of the steam temperature / pressure at the boiler outlet measured by the measuring instrument 262, the measured value 322 of the feed water temperature / pressure at the boiler inlet measured by the measuring instrument 321, and the feed water flow rate determining means 15. The heat absorption amount of the boiler is calculated using the feed water flow rate signal 19 determined in step (1). The calculated heat absorption amount is compared with a reference heat absorption amount set in advance with respect to the load request command 10, and a correction signal 25 for the circulation exhaust gas amount is calculated from the deviation amount by proportional-integral control to thereby adjust the circulation exhaust gas amount adjusting means. 16 is output.

  As a function of the circulating exhaust gas amount adjusting means 16, a signal obtained by adding the correction signal 25 to the reference circulating exhaust gas amount determined from the load request command 10 is created, and based on this, the opening command signal 22 of the circulating exhaust gas flow rate adjusting valve 391 is obtained. A method of creating is also conceivable. By doing so, the exhaust gas circulation flow rate, that is, the oxygen concentration can be controlled so as to maintain the desired boiler heat absorption amount even when the fuel heat generation amount changes due to the change in the fuel amount or the change of the coal type. Driving becomes possible.

  Further, in this embodiment, in order to maintain the oxygen concentration even if the fuel amount fluctuates, the circulating exhaust gas amount adjusting means 16 corresponds to the increase or decrease of the reference oxygen amount signal 14 determined based on the measured value 421 of the fuel amount. Then, a correction is made so that the opening degree command of the circulating exhaust gas flow rate adjustment valve 391 is increased or decreased in advance. That is, the opening degree command signal 22 of the circulating exhaust gas flow rate adjustment valve 391 is created by adding a correction signal 25 and a correction signal corresponding to the reference oxygen amount signal 14 to the reference circulating exhaust gas amount determined from the load request command 10.

  This makes it possible to stably maintain the oxygen concentration at the target value even with respect to time fluctuations in the fuel amount, and as a result, keep the heat load in the furnace and the amount of heat collected from the boiler within an appropriate range. Can do.

  In general, as shown in FIG. 3, a plurality of boiler burners are installed in the horizontal direction and in a plurality of stages in the height direction before and after the furnace. It is desirable to measure the flow rate of pulverized coal for each burner stage or for each burner and independently adjust the amount of oxygen and the amount of circulating exhaust gas.

  FIG. 5 shows an example of the behavior of the oxygen amount, fuel / oxygen ratio, circulating exhaust gas amount, and oxygen concentration according to this embodiment. This figure shows the case where the amount of fuel fluctuates with time under a constant load requirement. A broken line before application and a solid line after application.

  Since the load demand is constant before application, a certain amount of oxygen is supplied. For this reason, the fuel / oxygen ratio fluctuates in accordance with the fluctuation of the fuel amount, so that it is difficult to obtain a stable combustion state.

  Further, since the amount of circulating exhaust gas is controlled by feeding back the amount of heat collected from the boiler, a time delay occurs until the amount of heat collected is affected, and it is difficult to keep the oxygen concentration constant.

  On the other hand, by applying the present embodiment, it is possible to quickly cope with the fuel amount variation by measuring the fuel amount variation, and to maintain the fuel / oxygen ratio almost constant. Moreover, since the increase / decrease in the amount of oxygen is also quickly reflected in the amount of circulating exhaust gas, the oxygen concentration can be maintained substantially constant.

  As a result, a desirable combustion state can be maintained even if the amount of fuel fluctuates. Therefore, the possibility of overheating or misfire can be suppressed, and safe and stable operation can be realized.

  Compared with the air combustion method in which the fuel is burned with air, the oxyfuel combustion method does not input about 80% of the nitrogen in the air into the boiler. Therefore, nitrogen oxides (thermal NOx) derived mainly from nitrogen in the air Occurrence is eliminated and nitrogen oxide emissions are reduced. Further, since most carbon in the fuel becomes carbon dioxide by combustion, the exhaust gas becomes high-concentration carbon dioxide gas.

  Therefore, compared with the case of recovering carbon dioxide from air combustion type boiler exhaust gas, a process of concentrating carbon dioxide is unnecessary, and the system is suitable for recovering carbon dioxide.

  This example makes it possible to operate safely and stably, so it becomes a thermal power generation system that can be expected to significantly reduce carbon dioxide emissions, which is the greatest merit of the oxyfuel boiler system. It becomes possible to achieve both.

  Next, Example 2 will be described with reference to FIG.

  The difference from FIG. 1 is mainly the functions of the condition comparison means 20 and the oxygen supply amount determination means 23 in the control device 100. In the oxyfuel combustion method, if the amount of oxygen and the oxygen concentration are too large, the flame temperature during combustion becomes excessive, and the burner 210 and the water wall 230 may be overheated and damaged.

  Therefore, in this example, the metal temperature near the burner 210 is measured by the temperature measuring device 215. The measured temperature 216 is input to the condition comparison means 20. In the condition comparison unit 20, a deviation amount 26 between the temperature 216 and a preset allowable temperature is calculated and output to the oxygen supply amount determination unit 23.

  The oxygen supply amount determination means 23 includes an oxygen amount correction means 19 in addition to the reference oxygen amount determination means 13. The oxygen amount correction means 19 corrects the reference oxygen amount signal 14 based on the deviation amount 26 between the temperature 216 near the burner and the allowable temperature. When the temperature 216 is lower than the allowable temperature, the correction amount is set to zero. When the temperature exceeds the allowable temperature, the oxygen amount signal 21 is generated by adding a correction for decreasing the oxygen supply amount in proportion to the deviation amount 26.

  Thereby, it can prevent that the burner vicinity overheats and is damaged. However, if the oxygen supply amount is reduced too much, there is a possibility that a stable combustion state cannot be maintained. Therefore, the correction is performed within a preset range with respect to the reference oxygen amount signal 14.

  The corrected oxygen amount signal 21 is output to the circulating exhaust gas amount adjusting means 16 instead of the reference oxygen amount signal 14 in the first embodiment.

  In this example, the oxygen amount is corrected based on the deviation amount 26 between the temperature 216 near the burner and the allowable temperature, but the oxygen concentration may be changed by correcting the circulating exhaust gas amount. In this case, when the temperature 216 exceeds the allowable temperature, the oxygen concentration may be lowered by correcting the amount of circulating exhaust gas so as to increase.

  In this example, the temperature in the vicinity of the burner that is considered to be closest to the flame is measured, and this temperature is used as an index for correction. However, the metal temperature of the heat exchanger in the water wall or the boiler, the steam temperature in the heat transfer tube, or the gas temperature may be used as an index, and the measurement position is not limited. In addition, since the ratio of fuel to oxygen and the oxygen concentration also affect the composition of the combustion exhaust gas, measure the concentration of components in the exhaust gas such as nitrogen oxide concentration or sulfur oxide or carbon dioxide or carbon monoxide in the exhaust gas. It is also possible to adjust the amount of oxygen or the amount of circulating exhaust gas so that it approaches a desired value.

11 Reference fuel amount determination means 12 Reference fuel amount signal 13 Reference oxygen amount determination means 14 Reference oxygen amount signal 15 Supply water flow rate determination means 16 Circulating exhaust gas amount adjustment means 17 Fuel supply amount adjustment valve control means 18 Valve opening command signal 19 Supply water flow rate Signal 20 Condition comparison means 22 Opening command signal 23 Oxygen supply amount determination means 25 Correction signal 100 Controller 200 Boiler 210 Burners 211, 213 Flow rate adjusting valve 230 Water wall 240 Secondary superheater 250 Third superheater 251 Main steam 254 Steam control valve 260 4 superheater 262,321 temperature and pressure measuring instruments 263,322 measurements 280 primary superheater 290 economiser 300 steam turbine 310 condenser 320 feed pump 330 gas preheater 340 pollution control apparatus 350 CO ₂ Recovery device 351 Nitrogen / oxygen main gas 360 Oxygen production device 361 Nitrogen main gas 3 2 high-purity oxygen gas 363 air 370 chimney 380 exhaust 390 circulation exhaust gas 391 circulation flue gas flow rate regulating valve 392 air flow control valve 400 Coal 401 fuel supply amount adjusting valve 410 coal pulverizer 420 pulverized coal flowmeter 421 pulverized coal flow rate measurement value

Claims (8)

A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulation exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
The pulverized coal flow meter that measures the amount of fuel supplied to the burner as a total value of one or more burners, and the high amount supplied to the burner based on the fuel amount value measured by the pulverized coal flow meter An oxyfuel boiler plant comprising oxygen supply amount determination means for adjusting an amount of gas containing oxygen at a concentration. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulation exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
The pulverized coal flow meter that measures the amount of fuel supplied to the burner as a total value of one or more burners, and the high amount supplied to the burner based on the fuel amount value measured by the pulverized coal flow meter An oxygen supply amount determining means for adjusting the amount of gas containing oxygen at a concentration, and a circulating exhaust gas amount for adjusting the amount of the circulating exhaust gas using the amount of gas containing oxygen at a high concentration determined by the oxygen amount adjusting means An oxyfuel boiler plant characterized by comprising an adjusting means. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulation exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
A pulverized coal flow meter for measuring the amount of fuel supplied to the burner as a total value of one or more burners;
Heat absorption amount of the boiler, burner temperature, metal temperature at a predetermined position of the heat exchanger in the boiler, gas temperature at a predetermined position of the boiler, nitrogen oxide concentration or sulfur oxide or carbon dioxide in the exhaust gas of the boiler Alternatively, for at least one of the carbon monoxide, the condition comparison means for calculating a deviation amount from a predetermined condition value, and the high amount supplied to the burner based on the fuel amount value measured by the pulverized coal flow meter. An oxyfuel boiler plant comprising oxygen supply amount determination means for adjusting an amount of gas containing oxygen at a concentration. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulation exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
Based on a pulverized coal flow meter that measures the amount of fuel supplied to the burner as a total value for each burner or a plurality of burners, and a relationship set in advance corresponding to the fuel amount value measured by the pulverized coal flow meter Reference oxygen amount determining means for determining a reference amount of the gas containing the high concentration oxygen supplied to the corresponding burner;
Heat absorption amount of the boiler, burner temperature, metal temperature at a predetermined position of the heat exchanger in the boiler, gas temperature at a predetermined position of the boiler, nitrogen oxide concentration or sulfur oxide or carbon dioxide in the exhaust gas of the boiler Or, for at least one of carbon monoxide, a condition comparing means for calculating a deviation amount in comparison with a predetermined condition value;
Based on the deviation amount calculated by the condition comparison means, an oxygen amount correcting means for determining a correction value for the oxygen amount reference amount determined by the reference oxygen amount determining means, and correcting the oxygen amount reference amount with the correction value An oxygen combustion boiler plant comprising oxygen supply amount determination means for determining an added oxygen amount. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulation exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
Based on a pulverized coal flow meter that measures the amount of fuel supplied to the burner as a total value for each burner or a plurality of burners, and a relationship set in advance corresponding to the fuel amount value measured by the pulverized coal flow meter Reference oxygen amount determining means for determining a reference amount of the gas containing the high concentration oxygen supplied to the corresponding burner;
Heat absorption amount of the boiler, burner temperature, metal temperature at a predetermined position of the heat exchanger in the boiler, gas temperature at a predetermined position of the boiler, nitrogen oxide concentration or sulfur oxide or carbon dioxide in the exhaust gas of the boiler Or, for at least one of carbon monoxide, a condition comparing means for calculating a deviation amount in comparison with a predetermined condition value;
Based on the deviation calculated by the condition comparison unit, an oxygen amount correction unit that determines a correction value for the oxygen amount reference amount determined by the reference oxygen amount determination unit, and the high concentration determined by the oxygen amount correction unit An oxyfuel boiler plant comprising a circulating exhaust gas amount adjusting means for adjusting the amount of the circulating exhaust gas using an amount of a gas containing oxygen. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an operation method of an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulating exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
Adjusting the amount of the gas containing the high-concentration oxygen supplied to the burner based on a burner fuel amount value obtained by measuring the amount of fuel supplied to the burner as a total value of one or more burners. A method for operating an oxyfuel boiler plant. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an operation method of an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulating exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
Determining the amount of gas containing the high-concentration oxygen to be supplied to the corresponding burner based on a burner fuel amount value obtained by measuring the amount of fuel supplied to the burner as a total value of one or more burners; An operating method of an oxyfuel boiler plant, characterized in that the amount of the circulating exhaust gas is adjusted using the determined amount of gas containing high-concentration oxygen. A boiler that generates steam by burning a fuel with a burner using a gas containing oxygen at a higher concentration than in air and a gas containing carbon dioxide at a higher concentration than in air, and boiler exhaust gas as the gas containing carbon dioxide In an operation method of an oxyfuel boiler plant comprising exhaust gas circulation means for using a part of the exhaust gas as circulating exhaust gas, and carbon dioxide recovery means for recovering carbon dioxide in the exhaust gas of the boiler,
The gas containing the high-concentration oxygen supplied to the burner using a preset relationship with respect to the burner fuel amount value obtained by measuring the amount of fuel supplied to the burner as a total value of one or more burners. Determine the reference amount of
Heat absorption amount of the boiler, burner temperature, metal temperature at a predetermined position of the heat exchanger in the boiler, gas temperature at a predetermined position of the boiler, nitrogen oxide concentration or sulfur oxide or carbon dioxide in the exhaust gas of the boiler Alternatively, for at least one of the carbon monoxide, a deviation from a predetermined condition value is calculated, a correction amount for the gas amount containing the high concentration oxygen is calculated based on the deviation, and the reference amount and the An operation method of an oxyfuel boiler plant, wherein an amount of gas containing the high concentration oxygen supplied to the burner is determined from a correction amount.

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