JP7007217B2 - Boiler equipment, power generation equipment, and method for predicting the amount of stuck matter - Google Patents

Description

The present invention relates to boiler equipment and power generation equipment using carbon-based fuel, and a method for predicting the amount of deposits produced in these equipment, which can be used to predict the differential pressure of exhaust gas.

Conventionally, boiler equipment using carbon-based fuel represented by coal has a boiler that produces steam that is the driving force for power generation by burning carbon-based fuel, and nitrogen oxides (NO _X ) emitted from the boiler are ammonia. It is equipped with a denitration device that denitrates in the presence of (NH ₃ ), and the like. In this type of boiler equipment, if unreacted NH ₃ leaks to the downstream side of the denitration device, ammonium sulfate compounds such as aluminum ammonium sulfate (NH ₄ Al (SO) ₂ ) are generated from the NH ₃ as an element, and denitration is performed. It may condense at low temperatures downstream of the device. Further, ash adheres to such a condensate and becomes a fixed substance, which causes an increase in pressure loss (differential pressure) of exhaust gas.

If the differential pressure rises excessively, there is a high possibility that the equipment will be overloaded. On the other hand, cleaning the flow path to remove the adhered matter involves stopping the operation of the equipment, so cleaning cannot be performed more frequently than necessary. From such a background, it has been desired to predict the formation state of the adhered matter and, by extension, the differential pressure so that the flow path can be washed at an appropriate timing. In this regard, in Patent Document 1, the differential pressure of the air preheater, which is arranged on the downstream side of the denitration device and preheats the combustion air in the boiler by using the residual heat of the exhaust gas, is measured, and the leaked _NH3 concentration and the like are measured. A method of predicting the upward tendency of the differential pressure with correction is proposed.

Japanese Patent No. 2710985

However, in the prior art including Patent Document 1, only a method of predicting the differential pressure after operating the boiler equipment has been established, and the differential pressure is predicted only when a fuel having a proven record of use is used. I couldn't. Therefore, a method that can predict the amount of deposits produced without operating the boiler equipment and, by extension, the differential pressure has been desired so that it can be used even when fuel that has not been operated in the boiler equipment is used.

The present invention has been made in view of such circumstances, and the boiler equipment and the boiler equipment which can predict the amount of deposits produced even if the fuel has not been operated in the boiler equipment and can also be used for the prediction of the differential pressure. It is an object of the present invention to provide a power generation facility and a method for predicting the amount of fixed matter produced.

Aspects of the present invention for solving the above problems include a boiler that burns a carbon-based fuel to emit exhaust gas containing nitrogen oxide (NO _X ) and sulfur oxide (SO _X ), and a boiler downstream of the boiler. It is a boiler facility provided with a denitration device for denitrifying nitrogen oxide (NO _X ) in the exhaust gas in the presence of ammonia (NH ₃ ), and the carbon-based fuel to be used is analyzed. The amount of the N component, the amount of the S component, and the amount of the ash obtained from the carbon-based fuel were obtained in advance, and the amount of the N component, the amount of the S component, and the amount of the ash obtained in advance were obtained . Based on the amount of ammonia (NH ₃ ) leaked to the downstream side of the denitration device, a prediction that predicts the amount of deposits produced on the downstream side of the denitration device when the carbon-based fuel is burned in the boiler. It is in a boiler facility characterized by being equipped with a system.

According to this aspect, since the above prediction system is provided, the amount of N component (N component amount) and the amount of S component (S component) obtained in advance without actually operating the boiler equipment with the fuel are provided. The amount of adhered matter can be predicted based on the amount) and the amount of ash (amount of ash). The prediction result can also be used for the prediction of the differential pressure.

Here, it is preferable that the ash content contains an aluminum (Al) component, and the adhered substance is one in which the ash content is attached to a ammonium sulfate compound produced by containing the Al component. In such an embodiment, the ammonium sulfate compound produced containing the Al component is typical as a compound that causes a sticky substance. Therefore, according to such an embodiment, a ammonium sulfate compound (NH4 Al _{(SO) 2 ,} etc.) having a typical composition that causes a sticking substance is targeted, and the boiler equipment is solidified without actually operating the boiler equipment with the fuel. The amount of kimono produced can be predicted accurately.

Further, the ash content contains a calcium (Ca) component, and it is preferable that the prediction system predicts the amount of the adhered substance in consideration of the decomposition rate of the ammonium sulfate compound by the Ca component. According to this, since the decomposition rate of the ammonium sulfate compound by the Ca component is taken into consideration, the amount of the adhered matter produced can be predicted more accurately.

Further, it is preferable that the prediction system predicts the amount of the adhered substance in consideration of the consumption rate of the S component by the Ca component in the exhaust gas. According to this, since the consumption rate of the S component due to the Ca component is taken into consideration, the amount of the adhered matter produced can be predicted more accurately.

Further, it is preferable that the prediction system predicts the amount of the adhered matter produced in consideration of the oxidation rate of sulfur dioxide (SO ₂ ) by the denitration device. According to this, since the oxidation rate of SO ₂ by the denitration device is taken into consideration, the amount of the adhered matter can be predicted more accurately.

Further, the boiler equipment is provided on the downstream side of the denitration device with an air preheater that preheats the combustion air in the boiler by utilizing the residual heat of the exhaust gas, and the prediction system is equipped with the air preheating. It is preferable to predict the amount of the adhered matter produced in the vessel. According to this, it is possible to accurately predict the amount of the adhered matter generated in the middle temperature portion and the low temperature portion of the air preheater where the adhered matter is likely to be generated without actually operating the boiler equipment with the fuel.

Further, the prediction system obtains the effective diameter of the flow path through which the exhaust gas can pass based on the predicted amount of the adhered matter, and is based on the calculated effective diameter of the flow path and the flow rate of the exhaust gas. , It is preferable to predict the differential pressure on the upstream side and the downstream side of the flow path. According to this, since the prediction result of the amount of the adhered matter is used, the above-mentioned is based on the amount of N component, the amount of S component and the amount of ash obtained in advance without actually operating the boiler equipment with the fuel. The differential pressure can be predicted.

Another aspect of the present invention for solving the above problems is the boiler equipment according to any one of claims 1 to 7, a steam turbine in which steam generated in the boiler is introduced to obtain a driving force, and the above. It is a power generation facility characterized by being equipped with a generator that obtains electric power by driving a steam turbine.

According to such an embodiment, since the above-mentioned boiler equipment is provided, it is possible to provide a power generation equipment capable of predicting the amount of a compound that causes a sticking substance without actually operating the boiler equipment with the fuel. The prediction result can also be used for the prediction of the differential pressure.

Yet another aspect of the present invention that solves the above problems is a boiler that burns a carbon-based fuel to emit exhaust gas containing nitrogen oxides (NO _X ) and sulfur oxides (SO _X ), and the boiler. A carbon-based fuel that is used in a boiler facility equipped with a denitration device that is installed on the downstream side and denitrifies nitrogen oxides (NO _X ) in the exhaust gas in the presence of ammonia (NH ₃ ), and is planned to be used. The amount of the N component, the amount of the S component, and the amount of the ash obtained by the analysis are obtained in advance, and the amount of the N component, the amount of the S component, and the ash content obtained in advance are obtained. Based on the amount and the amount of ammonia (NH ₃ ) leaked to the downstream side of the denitration device, the amount of deposits produced on the downstream side of the denitration device when the carbon-based fuel is burned in the boiler is predicted. It is in the method of predicting the amount of adhered matter produced, which is characterized by the above.

According to this aspect, since the above prediction system is provided, the amount of N component (N component amount) and the amount of S component (S component) obtained in advance can be obtained without actually operating the boiler equipment with the fuel. The amount of adhered matter can be predicted based on the amount) and the amount of ash (amount of ash). The prediction result can also be used for the prediction of the differential pressure.

Here, it is preferable to use data containing an aluminum (Al) component as the ash content. In such an embodiment, the ammonium sulfate compound produced containing the Al component is typical as a compound that causes a sticky substance. Therefore, according to such an embodiment, it is possible to accurately predict the amount of the deposited substance produced in the ammonium sulfate compound having a typical composition that causes the adhered substance, without actually operating the boiler equipment with the fuel.

Further, the effective diameter of the flow path through which the exhaust gas can pass is obtained based on the predicted amount of the adhered matter, and the upstream side of the flow path and the flow rate of the exhaust gas are calculated based on the calculated effective diameter and the flow rate of the exhaust gas. It is preferable to predict the differential pressure on the downstream side. According to this, since the prediction result of the amount of the adhered matter is used, the above-mentioned amount of N component, S component amount and ash content obtained in advance can be used without actually operating the boiler equipment with the fuel. The differential pressure can be predicted.

The schematic diagram which shows the structural example of the boiler equipment which concerns on Embodiment 1. The schematic diagram which shows the structural example of the air preheater in the boiler equipment which concerns on Embodiment 1. FIG. The conceptual diagram explaining an example of the transition of the differential pressure in the boiler equipment which concerns on Embodiment 1. FIG. The figure which shows the configuration example of the prediction system which concerns on Embodiment 1. The figure explaining the flow of the formation of the fixed substance in Embodiment 1. FIG. The time chart diagram which shows the application example using the prediction system which concerns on Embodiment 1. The schematic diagram of the combined cycle power generation facility which concerns on Embodiment 3.

An embodiment of the present invention will be described with reference to the drawings. The following embodiment is an aspect of the present invention and can be arbitrarily modified within the scope of the present invention. In each figure and description, the same member is designated by the same reference numeral, and the description thereof is omitted as appropriate. In each figure, the scale and shape of each part may be set for convenience in order to facilitate explanation.

(Embodiment 1)
As shown in FIG. 1, the boiler equipment 20 includes a boiler 1, a denitration device 3 connected to the boiler 1 by an exhaust passage 2, an air preheater 5 connected to the denitration device 3 by an exhaust passage 4, and air preheating. It is equipped with a prediction system 30 (see FIG. 4) that can predict the differential pressure between the exhaust upstream side and the exhaust downstream side of the vessel 5 (hereinafter, may be simply referred to as “differential pressure”). In the figure, solid arrows indicate the flow of exhaust gas and air.

The boiler 1 burns a carbon-based fuel represented by coal (“Fuel” in the figure) to generate steam that is a driving force for power generation. The carbon-based fuel may be any fuel containing carbon within the scope of the present invention, and hydrocarbon-based materials such as wood and biomass, and hydrocarbon-based gases such as natural gas and city gas can also be used. The denitration device 3 denitrifies NO _X in the exhaust gas Gs0 discharged from the boiler 1 in the presence of NH ₃ by an ammonia reduction method (selective catalytic reduction method). The air preheater 5 preheats the combustion air (air Air1) in the boiler 1 by utilizing the residual heat of the exhaust gas Gs1 that has passed through the denitration device 3.

The flow of exhaust gas and air in the boiler equipment 20 is as follows. That is, the coal crushed by the crusher 6 is supplied into the boiler 1 together with the air through the burner group 7 arranged so as to face the boiler 1. The high-temperature exhaust gas Gs0 generated by the combustion of coal is discharged from the boiler 1 and guided to the exhaust passage 2. In the exhaust passage 2, NH ₃ is supplied from the NH ₃ supply unit 8 into the exhaust gas Gs 0, and NO _X is decomposed into H ₂ O and N ₂ by the denitration device 3. The exhaust gas Gs1 that has passed through the denitration device 3 is guided to the exhaust passage 4 at a high temperature and flows into the air preheater 5.

In the air preheater 5, heat exchange is performed between the high-temperature exhaust gas Gs1 and the air flowing in facing the exhaust gas Gs1. The air Air 1 pushed in from the push-in ventilator 9 is preheated by the air preheater 5 and then supplied into the boiler 1 through the burner group 7 (combustion air Air 2 in the boiler 1). Further, a part of the air Air1'pushed from the primary ventilator 10 is preheated by the air preheater 5 (air Air2'), and the rest is supplied to the crusher 6 as it is.

The exhaust gas Gs2 that has passed through the air preheater 5 is guided to the exhaust passage 11. Exhaust gas Gs2 is drawn in by an attracting ventilator 12 arranged in the middle of the exhaust passage 11, and is less than a specified level in a dust removing device, a desulfurizing device, etc. (not shown) arranged on the exhaust upstream side or the exhaust downstream side of the attracting ventilator 12. After being purified to the above, it is finally released from the chimney 13 into the atmosphere. The inducer ventilator 12 may be arranged in the middle of the dust remover, the desulfurization device, or the like, or on the downstream side of the exhaust gas thereof.

Here, as shown in FIGS. 2A to 2B, the air preheater 5 includes a cylindrical rotor 5a, a heat transfer element 5b filled in each radial partition wall of the rotor 5a, and a rotor 5a. It is provided with a rotating shaft 5c that supports the shaft. In the rotor 5a, for example, a first density portion 5d, a second density portion 5e, and a third density portion 5f filled with a heat transfer element 5b at a predetermined density are sequentially provided along a rotation shaft 5c in three stages. It has a structure.

The third density portion 5f has a smaller filling density of the heat transfer element 5b than the first density portion 5d and the second density portion 5e. The filling densities of the heat transfer elements 5b of the first density portion 5d and the second density portion 5e are the same, but may be different. The rotor 5a is surrounded by a casing (not shown), a rotating shaft 5c is arranged along the flux of exhaust gas and air, and the rotor 5a can rotate about the rotating shaft 5c by a driving force of a motor (not shown) or the like. It has become.

Exhaust gas Gs1 flows in from one surface of the rotor 5a (first density portion 5d side), and air Air1 and air Air1'inflow from the other surface of the rotor 5a facing the exhaust gas Gs1 (third density portion 5f side). While rotating the rotor 5a around the rotating shaft 5c, the heat of the heat transfer element 5b heated by the exhaust gas Gs1 is used to preheat the air Air1 and the air Air1'. The 1st density part 5d side where the high temperature exhaust gas Gs1 flows in becomes high temperature (high temperature part), and the 3rd density part 5f side where the air Air1 and the air Air1'inflow become the 1st density part 5d and the 2nd density part 5e. The temperature is lower than that (low temperature part).

In the boiler equipment 20 as described above, if unreacted NH ₃ leaks to the downstream side of the exhaust of the denitration device 3, sulfur dioxide compounds such as aluminum ammonium sulfate (NH ₄ Al (SO) ₂ ) will be generated with the NH ₃ as an element. It is generated and may be condensed in the above-mentioned medium temperature part (second density part 5e of the rotor 5a of the air preheater 5) and low temperature part (third density part 5f of the rotor 5a of the air preheater 5) of the air preheater 5. There is. As ash adheres to this and becomes a sticky substance, which narrows the flow path of the exhaust gas and causes an increase in pressure loss (differential pressure), as shown in FIG. 3, as the operating time t elapses, the air preheater 5 The differential pressure ΔP on the exhaust upstream side and the exhaust downstream side increases (differential pressure ΔP2 at time point t2> differential pressure ΔP1 at time point t1).

On the other hand, since the transition of the differential pressure ΔP differs depending on the coal type, when the coal type is changed at time point t2, even if the operating conditions of the equipment are basically the same, the differential pressure ΔP depends on the changed coal type. Is it a large rise (dotted line: Case 1 in FIG. 3) or is it only a small rise (dotted chain line: Case 2 in FIG. 3), or is the differential pressure ΔP significantly falling (broken line: Case 3 in FIG. 3)? It is different whether it stays at (two-dot chain line: Case 4 in FIG. 3).

Previously, only a method for predicting such a differential pressure ΔP was established after operating the boiler equipment. On the other hand, in the present embodiment, even if the coal type has not been operated in the boiler equipment 20, it is possible to predict the amount of the adhered matter that causes the flow path of the exhaust gas to be narrowed, and the prediction result is the differential pressure ΔP. It can be used to predict. Of course, according to the present embodiment, it is possible to predict the amount of adhered matter generated for the coal type having an operation record in the boiler equipment 20, and also to predict the differential pressure ΔP.

FIG. 4 shows a configuration example of the prediction system 30 according to the present embodiment in functional blocks. The prediction system 30 includes a microcomputer having a known configuration, and each means is realized by executing a program by the microcomputer. The prediction system 30 is provided with storage means and the like (not shown), and the calculation results and detection results of each means are stored.

The prediction system 30 includes a data reading means 31, a leak _NH3 amount estimation means ₃₂ , an SO3 production amount estimation means 33, a sulfurized compound production amount prediction means 34, a adhered matter production amount prediction means 35, and a differential pressure prediction means. Means 36 and. Since the ammonium sulfate compound that causes the deposit is produced by a reaction containing NH ₃ and SO ₃ contained in the exhaust gas when coal is burned as elements, in the present embodiment, the amount of the deposit is _AK or the difference. To predict the pressure ΔP, the prediction result of the total amount of ammonium sulfate compound produced _ANS3 is used. Then, in order to predict the total amount of ammonium sulfate compound produced _ANS3 , first, the total amount of _NH3 produced _AN and the _total amount of SO3 produced _AS5 are estimated.

The data reading means 31 reads the fuel property data 31a, the equipment operation data 31b, and the fixed physical property data 31c input to the input unit 37 by the equipment operator, and transmits these to each means. These data can be obtained in advance by analyzing the coal to be used, based on the examples of other coals in the past, or referring to the equipment conditions, without operating the boiler equipment 20. The input unit 37 is, for example, a personal computer used by the equipment operator, which is connected to the prediction system 30 by wire or wirelessly.

The fuel property data 31a is the N component amount R1, the S component amount R2, and the ash content R3 obtained when an analysis experiment or the like is performed on the coal to be used in advance. In the present embodiment, assuming that the ash contains an aluminum (Al) component, the Al component amount R4 corresponding to the amount of the Al component can also be input to the input unit 37. Since the Al component is typical as a metal component constituting the ammonium sulfate compound, by taking such an Al component into consideration, the ammonium sulfate compound (NH ₄ Al (NH 4 Al (NH 4 Al)) having a typical composition that causes a sticking substance is taken into consideration. It will be possible to predict the amount of adhered substances produced for SO ₄ ) ₂ etc.).

In rare cases where the Al component is insufficient and the formation of the ammonium sulfate compound is inhibited, the ash usually contains a sufficient amount of the Al component, and the input of the Al component amount R4 may be unnecessary. .. The Al component is an example of the metal component constituting the ammonium sulfate compound, and if there is a metal component that substitutes for the Al component, the metal component can be a component constituting the ammonium sulfate compound.

Further, in the present embodiment, assuming that the ash contains a calcium (Ca) component, the Ca component amount R5 corresponding to the amount of the Ca component can also be input to the input unit 37. By considering the Ca component, it becomes possible to consider the consumption rate of the S component by the Ca component and the decomposition rate of the ammonium sulfate compound by the Ca component, as described later, so that the amount of the adhered substance produced can be more accurate. You will be able to predict.

Further, the above equipment operation data 31b shows the oxidation rate R6 of SO ₂ by the denitration device 3 (the rate at which SO ₂ is oxidized to SO ₃ by the denitration device 3) and the consumption rate R7 of the S component by the Ca component (Ca component). The rate at which SO ₃ in the exhaust gas is consumed by the reaction with the Ca component) and the decomposition rate of the ammonium sulfate compound by the Ca component R8 (the rate at which the sulfur dioxide compound once produced by the reaction with the Ca component is decomposed). Input of some or all of the equipment operation data 31b can be omitted, but by inputting these, factors affecting the formation of ammonium sulfate compounds can be taken into consideration.

Further, the above-mentioned fixed material property data 31c has an ash adhesion ratio R9 (ratio of the amount of ash attached per unit amount of the sulphate compound) and a density R10 of the fixed substance (solid formed by ash adhering to the sulphate compound). The density of the kimono). When the ash adhesion ratio R9 is large and the ratio of the sulfur compound to the adhered material is negligible, the density R10 of the adhered matter can be substantially approximated to the density of the ash content, and the density R10 of the adhered matter is treated as the ash content density. be able to. As the fixed physical property data 31c, a fixed value stored in advance may be used, and in this case, the input thereof can be unnecessary.

The leak NH ₃ amount estimation means 32 leaks NH ₃ amount (NH ₃ generation) when NH ₃ leaks to the exhaust downstream side of the denitration device 3 without reacting in the control of supplying NH ₃ from the NH ₃ supply unit 8. Estimate the total amount _AN ). Since the leak NH ₃ varies depending on the operating conditions of the denitration device (NO _X amount in exhaust gas Gs0, ratio of NH ₃ to NOx, etc.) and the deterioration status of the denitration catalyst, the amount of N component read from the data reading means 31. The amount of leak _NH3 can be estimated based on R1 and the like.

Most of the S component becomes SO ₂ due to the combustion of coal, but a part of it becomes SO ₃ when oxygen is excessive at the time of combustion. Therefore, the SO ₃ production amount estimation means 33 estimates the SO ₃ production rate (the ratio of the S component of coal produced as SO ₃ ) based on such combustion conditions and the like. Then, the SO ₃ generation amount estimation means 33 estimates the SO ₃ production amount AS1 in the boiler 1 based on the estimated SO ₃ generation rate and the _S component amount R2 read from the data reading means 31. Assuming that all S components other than SO ₃ are SO ₂ , the SO ₂ production rate can be estimated from the above SO ₃ production rate, and the SO ₂ production amount can also be estimated based on this.

In addition, the fluctuation amount according to the fluctuation of various conditions can be ignored in the NH ₃ generation total amount AN estimated by the leak _{NH 3} quantity estimation means 32 and the SO ₃ generation rate estimated by the SO ₃ generation amount estimation means 33. In some cases, a fixed value may be used.

SO ₃ is produced not only by the boiler 1 but also by the oxidation of SO ₂ by the denitration device 3. An increase in SO ₃ leads to an increase in the amount of ammonium sulfate compound produced. On the other hand, SO ₃ reacts with Ca contained in ash to produce calcium sulfate (CaSO ₄ ), which consumes a part of it. Consumption of SO ₃ leads to a decrease in the amount of ammonium sulfate compound produced. Therefore, the SO ₃ production amount estimation means 33 is based on the above SO ₂ production amount and the oxidation rate R6 of SO ₂ read from the data reading means 31, and the SO ₂ oxidation amount _AS2 (SO ₂ by the denitration device 3). Estimate the amount of SO ₃ newly produced by oxidation). The SO ₂ oxidation amount _AS2 and the _SO3 production amount _AS1 described above are summed to estimate the _total SO3 amount _AS3 (formula (1) below).

SO ₃ total amount _AS3 = ₍ SO3 production amount _AS1 ) ₊ (SO2 oxidation amount _AS2 ) ... (1)

Then, the SO ₃ generation amount estimation means 33 is based on the above SO ₃ total amount AS 3 and the consumption rate R7 of the _S component read from the data reading means 31, and the SO ₃ consumption amount _{AS 4} (Ca component is SO). The amount of SO ₃ consumed by reacting with ₃ to produce Ca SO ₄ ) is estimated. Based on these, the SO ₃ production amount estimation means 33 subtracts the SO ₃ consumption amount _{AS 4} from the SO ₃ total amount _AS 3 to estimate the final SO ₃ production total amount _{AS 5} (see the following equation (2)). ..

Total amount of SO ₃ generated _AS5 = (total amount of SO _{3 AS3} )-(SO3 consumption amount _AS4 ) ... ( ₂ )

The ammonium sulfate compound production amount predicting means 34 is based on the NH ₃ total production amount AN estimated by the leak _{NH 3} production amount estimation means 32 and the SO ₃ production total amount _{AS 5} estimated by the SO ₃ production amount estimation means 33. The amount of ammonium sulfate compound produced, _ANS1 , is estimated. Then, based on the above-mentioned amount of ammonium sulfate compound produced A _NS1 and the decomposition rate R8 of the ammonium sulfate compound read from the data reading means 31, the amount of decomposition of the ammonium sulfate compound A _NS2 (Ca component reacts with the ammonium sulfate compound to CaSO ₄ ). The amount of the ammonium sulfate compound decomposed by the formation of the compound) is estimated. Further, the decomposition amount A _NS2 of the ammonium sulfate compound is subtracted from the amount of ammonium sulfate compound produced A _NS1 to estimate the final total amount of ammonium sulfate compound produced A _NS3 (see the following formula (3)).

Total amount of ammonium sulfate compound produced A _NS3 = (Amount of ammonium sulfate compound produced A _NS1 )-(Amount of decomposition of ammonium sulfate compound A _NS2 ) ... (3)

The flow up to the above is summarized in FIG. 5 (a). Combustion of coal makes the N component NO _X. NH ₃ is supplied to NO _X and decomposed into N ₂ and H ₂ O by the denitration device 3. On the other hand, a part of the supplied NH ₃ may leak to the exhaust downstream side of the denitration device 3 without reacting ( _{NH 3} total amount of production AN).

In addition, the S component becomes _SOX due to the combustion of coal. Most of SO _X is SO ₂ , but it becomes SO ₃ slightly when oxygen is excessive at the time of combustion (SO ₃ production amount _{AS 1} ). A part of SO ₂ is also oxidized to SO ₃ by the subsequent denitration device 3 (SO ₂ oxidation amount _AS2 ). On the other hand, when the Ca component in the ash reacts with SO ₃ , Ca SO ₄ is generated, which consumes SO ₃ (SO ₃ consumption _{AS 4} ). Therefore, the amount of SO ₃ obtained by subtracting the SO ₃ consumption amount _{AS 4} from the total amount of the SO ₃ production amount _{AS 1} and the SO ₂ oxidation amount _AS 2 (SO ₃ total amount _AS 3) flows into the air preheater 5 ( Total amount of SO ₃ produced _AS5 ).

Ammonium sulfate compound (NH ₄ Al (SO ₄ ) ₂ ) is produced by the reaction of NH ₃ , SO ₃ and Al components (amount of ammonium sulfate compound produced _ANS 1). On the other hand, the Ca component of the ash reacts with the ammonium sulfate compound to form CaSO ₄ , which decomposes the ammonium sulfate compound (decomposition amount of the ammonium sulfate compound A _NS2 ). The amount of ammonium sulfate compound thereafter becomes the final total amount of ammonium sulfate compound produced _ANS3 .

The prediction system 30 of the present embodiment uses the prediction result of the total amount of ammonium sulfate compound produced _ANS3 as described above to predict the amount of adhered material _AK , and further predicts the differential pressure ΔP. That is, the fixed substance production amount predicting means 35 estimates the fixed substance production amount _AK by multiplying the total amount of sulfurized compound produced _ANS3 predicted above by the ash adhesion ratio R9 read from the fixed material property data 31c. do. Then, the differential pressure predicting means 36 estimates the volume _VK of the fixed matter based on the amount of the fixed matter produced _AK predicted above and the density R10 of the fixed matter read from the fixed material property data 31c.

For example, if the ammonium sulfate compound (NH ₄ Al (SO ₄ ) ₂ ) is condensed and ash adheres to it, and the adhered substance is the medium temperature part of the air preheater 5, the flow path diameter D ₀ of the exhaust gas in the medium temperature part The flow path length L ₀ is known at the time of design. Assuming that a fixed substance having a volume of _VK is generated over the flow path length L ₀ at the flow path diameter D ₀ , the thickness d of the fixed substance in the low temperature portion can be roughly calculated, and the flow path diameter D ₀ is solid. By subtracting the thickness d of the kimono, the effective diameter of the flow path that can pass through the medium temperature portion (effective flow path diameter D ₁ ) can be roughly calculated (see FIG. 5 (b)).

Then, the differential pressure predicting means 36 predicts the differential pressure ΔP based _on the effective flow path diameter D1 obtained above and the flow rate Q of the exhaust gas scheduled during operation. The flow rate Q of the exhaust gas scheduled at the time of operation can be obtained in advance without operating the boiler equipment 20 by referring to the past operating conditions of the boiler 1.

In this respect, the differential pressure predicting means 36 simply obtains the differential pressure ΔP as _a function of the effective flow path diameter D1 and the flow rate Q of the exhaust gas (see the following equation (4)). In order to predict the differential pressure ΔP, parameters _other than the effective flow path diameter D1 and the flow rate Q of the exhaust gas may be considered, but if the function based on the following equation (4) is followed, the differential pressure ΔP can be easily obtained. Can be predicted.

Differential pressure ΔP = f (Q (exhaust gas flow rate), D ₁ (effective flow path diameter)) ... (4)

The total amount of ammonium sulfate compound produced A _NS3 and the amount of adhered substance _AK also include the concept of minus (decrease or decomposition). If the total amount of ammonium sulfate compound produced _ANS3 is positive in the above formula (3), the amount of ammonium sulfate compound is increased, the amount of adhered material _AK is also positive, and the volume _VK of the adhered material is also positive. The degree to which the effective flow path diameter D ₁ is reduced can be estimated depending on the degree of the positive value, and the degree of increase in the differential pressure ΔP can be predicted accordingly.

On the other hand, if the total amount of ammonium sulfate compound produced _ANS3 is negative in the above formula (3), the ammonium sulfate compound is reduced and decomposed, the amount of adhered material _AK is also negative, and the volume _VK of the adhered material is also negative. It becomes. The degree of recovery (expansion) of the effective flow path diameter D ₁ can be estimated from the degree of the negative value, and the degree of decrease of the differential pressure ΔP can be predicted accordingly. Further, the degree of increase or decrease of the differential pressure ΔP can be predicted according to the increase or decrease of the flow rate Q of the exhaust gas.

According to the boiler equipment 20 and the method for predicting the amount of fixed matter produced described above, the amount of N component R1, the amount of S component R2 and the amount of ash derived from the carbon fuel obtained by analyzing the carbon fuel to be used are obtained. Acquire R3 in advance. Therefore, even if the boiler equipment 20 is not actually operated with the fuel, the amount of adhered matter _AK can be predicted based on the previously acquired N component amount R1, S component amount R2, and ash content R3. Then, the effective flow path diameter D ₁ through which the exhaust gas can pass is obtained based on the predicted amount of the adhered substance _AK , and the differential pressure ΔP can be predicted based on the effective flow path diameter D ₁ and the flow rate Q of the exhaust gas.

In addition, in the present embodiment, the amount of adhered matter _AK produced by the air preheater 5 is predicted. According to this, it is possible to predict the amount of adhered matter _AK produced in the middle temperature portion and the low temperature portion of the air preheater 5 where the adhered matter is likely to be generated, even if the boiler equipment 20 is not actually operated with the fuel. .. Of course, the place where the amount of the fixed substance is predicted is not limited to the air preheater 5, and if there is a place where the sulfur compound is generated and condensed on the downstream side of the exhaust of the denitration device 3, the fixed substance is targeted at that place. Can be predicted, and thus the differential pressure ΔP can be predicted.

(Embodiment 2)
FIG. 6 is a time chart diagram for explaining an application example using the above prediction method. FIG. 6A is an example of fuel usage plan data DATA input to the prediction system 30. The usage plan data DATA includes a future period and fuel according to that period. Here, coal a is used in the future period Ta, coal b is used in the next period Tb, coal c is used in the next period Tc, and coal d is used in the next period Td. The usage plan to use is represented. Although not shown, the usage plan data DATA also includes usage plans after the period Td.

In the usage plan data DATA, a plurality of future periods may or may not be continuous. However, continuous pressure is preferable because the differential pressure can be predicted without interruption. Here, it is planned to use different coals depending on the period, but the same coal may be used repeatedly at intervals.

Of the coals a to d, for example, coal b and coal c are coals for which the boiler equipment 20 has not been operated. However, the prediction method described in the first embodiment can be applied not only to coal a and coal d having an operation record, but also to coal b and coal c having no operation record. For each of the coals a to d and the boiler equipment 20 scheduled to be operated, the fuel property data 31a, the equipment operation data 31b and the fixed physical property data 31c are input to the input unit 37, and is shown in FIG. 6 (b). As you can see, the future differential pressure ΔP can be predicted without actually operating the boiler equipment 20 with the coal (dotted lines from period Ta to period Td in the figure).

In particular, in this example, since it can be predicted that the differential pressure ΔP will increase during the period Tb in which the coal b is used, it is possible to carry out careful operation so that the differential pressure ΔP does not become too large during the period Tb. As a result, it is possible to reliably prevent an excessive load from being applied to the equipment. Further, since it can be predicted that the differential pressure ΔP will decrease during the period Tc in which the coal c is used, it is expected that the chances of allowing the operation will increase further after the period Tb, and the operating time t of the boiler equipment 20 will be further increased. It will be easier to secure.

As shown in FIG. 6 (c), when a predetermined start condition (start) is satisfied, based on the initial differential pressure ΔP _start at the time of differential pressure prediction at that time and the differential pressure change rate according to the coal a. The future differential pressure in the period Ta is actually measured (solid line in the period Ta in the figure). Then, the predicted differential pressure at the end of the period Ta becomes the initial differential pressure ΔP _start at the start of the next continuous period Tb. The future differential pressure in the period Tb is actually measured based on the initial differential pressure ΔP _start and the differential pressure change rate according to the coal b (solid line in the period Tb in the figure).

Here, if there is a slight deviation between the actual differential pressure and the predicted differential pressure, the deviations will accumulate. At the end of the period Ta (at the start of the period Tb), a deviation ΔD1 (actual differential pressure> predicted differential pressure) occurs, and at the end of the period Tb (at the start of the period Tc), a deviation ΔD2 occurs. (ΔD2> ΔD1).

For example, at the end of the period Ta (at the start of the period Tb), the deviation ΔD1 does not exceed the predetermined allowable value ΔD _lim , but at the end of the period Tb (at the start of the period Tc), the deviation ΔD2 is the allowable value ΔD. It may exceed _lim . At this time, the prediction system 30 detects that the deviation ΔD1 exceeds the allowable value ΔD _lim , starts from the initial differential pressure ΔP _start at the start of the period Tc, and predicts the differential pressure ΔP again. That is, at the end of the period Tb (at the start of the period Tc), the predicted transition of the differential pressure is updated. The update of the differential pressure prediction is reflected in the subsequent period as well (FIG. 6 (d)).

The relationship between the lengths of the periods in the usage plan data DATA and the transition of the predicted differential pressure are not limited to the example shown in FIG. Further, the usage plan data DATA can be stored in a storage means (not shown) in the prediction system 30 shown in FIG. 4, but may be stored in a place other than that.

(Embodiment 3)
FIG. 7 is a schematic system diagram showing an overall configuration example of the power generation facility 50 according to the present embodiment. The power generation facility 50 includes the boiler facility 20 described in the first embodiment, a steam turbine 51 in which steam generated in the boiler 1 is introduced to obtain a driving force, and a generator 52 in which power is obtained by driving the steam turbine 51. It is equipped.

In the power generation facility 50, steam is generated by the combustion of the carbon-based fuel in the boiler 1. Such steam is introduced into the steam turbine 51 to obtain a driving force for the generator 52. Electric power is obtained by driving the generator 52. The exhaust steam of the steam turbine 51 is condensed and restored by the condenser 53, and the condensed water from the condenser 53 is supplied to the boiler 1 by driving the water supply pump 54.

According to the power generation facility 50 according to the present embodiment, since the boiler facility 20 of the first embodiment is provided, the carbon-based fuel to be used is analyzed without actually operating the boiler facility 20 with the fuel. The obtained N component amount R1, S component amount R2 and ash content R3 derived from the carbon-based fuel are obtained in advance, and the adhered substance is based on the previously obtained N component amount R1, S component amount R2 and ash content R3. The amount of production _AK can be predicted. The prediction result can also be used for the prediction of the differential pressure ΔP.

(Other embodiments)
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, in FIG. 4, each means of the prediction system 30 is described by dividing it into functional blocks, but some or all of these means may be configured as one. Further, the prediction system 30 may be partially or wholly configured integrally with the boiler equipment 20. Further, the fuel may contain a carbon-based fuel other than coal within the scope of the present invention. Furthermore, fuels other than carbon-based fuels may be contained within the scope of the present invention.

1 ... Boiler, 2 ... Exhaust passage, 3 ... Condenser, 4 ... Exhaust passage, 5 ... Air preheater, 5a ... Rotor, 5b ... Heat transfer element, 5c ... Rotating shaft, 5d ... First density part (high temperature part) 5, 5e ... 2nd density part, 5f ... 3rd density part (low temperature part), 6 ... crusher, 7 ... burner group, 8 ... NH ₃ supply part, 9 ... push-in blower, 10 ... primary blower, 11 ... Exhaust passage, 12 ... Condenser, 13 ... Chimney, 20 ... Boiler equipment, 30 ... Prediction system, 31 ... Data reading means, 31a ... Fuel property data, 31b ... Equipment operation data, 31c ... Fixed physical property data, 32 ... Leak NH ₃ amount estimation means, 33 ... SO ₃ production amount estimation means, 34 ... sulfur compound production amount prediction means, 35 ... adhered matter production amount prediction means, 36 ... differential pressure prediction means, 37 ... input unit, 50 ... power generation equipment , 51 ... steam turbine, 52 ... generator, 53 ... condenser, 54 ... water supply pump, Air1 ... combustion air (air), Air1'... air, AiR2 ... combustion air (air), AiR2'... air, Fuel ... Carbon-based fuel, Gs0, Gs1, Gs2 ... Exhaust gas

Claims (11)

A boiler that burns carbon-based fuel to emit exhaust gas containing nitrogen oxides (NO _X ) and sulfur oxides (SO _X ),
A boiler facility provided on the downstream side of the boiler and equipped with a denitration device for denitrifying nitrogen oxides (NO _X ) in the exhaust gas in the presence of ammonia (NH ₃ ).
The amount of N component, the amount of S component and the amount of ash obtained by analyzing the carbon-based fuel to be used are obtained in advance, and the amount of the N component obtained in advance, The downstream side of the denitration device when the carbon-based fuel is burned in the boiler based on the amount of the S component, the amount of the ash, and the amount of ammonia (NH ₃ ) leaked to the downstream side of the denitration device. Boiler equipment characterized by being equipped with a prediction system that predicts the amount of solidified matter produced in the plant. The ash contains an aluminum (Al) component and
The boiler equipment according to claim 1, wherein the adhered substance is one in which the ash content is attached to the ammonium sulfate compound produced containing the Al component. The ash contains a calcium (Ca) component and
The boiler equipment according to claim 2, wherein the prediction system predicts the amount of the adhered product in consideration of the decomposition rate of the ammonium sulfate compound by the Ca component. The boiler equipment according to claim 3, wherein the prediction system predicts the amount of the adhered matter in consideration of the consumption rate of the S component by the Ca component in the exhaust gas. The prediction system according to any one of claims 1 to 4, wherein the prediction system predicts the amount of the adhered matter in consideration of the oxidation rate of sulfur dioxide (SO ₂ ) by the denitration device. Boiler equipment. The boiler equipment is provided on the downstream side of the denitration device with an air preheater that preheats the combustion air in the boiler by utilizing the residual heat of the exhaust gas.
The boiler equipment according to any one of claims 1 to 5, wherein the prediction system predicts the amount of the adhered matter produced by the air preheater. The prediction system is
The effective diameter of the flow path through which the exhaust gas can pass is obtained based on the predicted amount of the adhered matter, and the upstream side of the flow path is based on the calculated effective diameter of the flow path and the flow rate of the exhaust gas. The boiler equipment according to any one of claims 1 to 6, wherein the differential pressure on the downstream side is predicted. The boiler equipment according to any one of claims 1 to 7 and the boiler equipment.
A steam turbine in which steam generated in the boiler is introduced to obtain driving force, and
A generator that obtains electric power by driving the steam turbine, and
A power generation facility characterized by being equipped with. A boiler that burns carbon-based fuel to emit exhaust gas containing nitrogen oxides (NO _X ) and sulfur oxides (SO _X ),
It is used in a boiler facility provided on the downstream side of the boiler and equipped with a denitration device for denitrifying nitrogen oxides (NO _X ) in the exhaust gas in the presence of ammonia (NH ₃ ).
The amount of N component, the amount of S component, and the amount of ash obtained by analyzing the carbon-based fuel to be used are obtained in advance, and the amount of the N component obtained in advance, the above. Based on the amount of S component, the amount of ash, and the amount of ammonia (NH ₃ ) leaked to the downstream side of the denitration device, on the downstream side of the denitration device when the carbon-based fuel is burned in the boiler. A method for predicting the amount of fixed matter produced, which comprises predicting the amount of fixed matter produced. The method for predicting the amount of adhered matter produced according to claim 9, wherein a ash containing an aluminum (Al) component is used. The effective diameter of the flow path through which the exhaust gas can pass is obtained based on the predicted amount of the adhered matter, and the upstream side and the downstream side of the flow path are based on the calculated effective diameter and the flow rate of the exhaust gas. The method for predicting the amount of adhered matter produced according to claim 9 or 10, wherein the differential pressure is predicted.

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