JP2000320823A - Fluidized bed abnormal combustion diagnosis method and fluidized bed abnormal combustion diagnosis device - Google Patents

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To detect abnormal combustion associated with the generation of coarse particles of a fluidized medium in a fluidized bed at an early stage, and to prevent the occurrence of wear and the like in a furnace, and to prevent the occurrence of wear and the like beforehand To provide a diagnostic method and device. SOLUTION: Differential pressure detectors 27 to 30 are provided in a fluidized bed boiler 2.
And temperature detectors 31 to 35, and a differential pressure signal and a temperature signal by these are sent to a signal processing unit 37 via a signal acquisition unit 36.
To calculate the average value, frequency distribution, peak value, and spectrum of the differential pressure vibration waveform, and register them in the normal state average value, frequency distribution, peak value, spectrum, If the difference between the two is greater than a predetermined value, it is determined that the combustion is abnormal, and displayed on the monitor 39.
A warning sound is generated from a speaker 40 to notify the occurrence of an abnormality. [Effect] Since the generation of coarse particles in the fluidized bed can be detected at an early stage, the occurrence of wear in the furnace can be easily suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for diagnosing abnormal combustion in a fluidized bed combustion apparatus, and more particularly to a method and apparatus for abnormal combustion diagnosis suitable for a fluidized bed coal combustion apparatus using limestone as a fluidized medium.

[0002]

2. Description of the Related Art A fluidized bed combustion apparatus in which solid particles are filled in a container to form a fluid medium, and air is blown from a lower portion of the container and burned is to easily maintain a uniform temperature distribution in the combustion bed. Therefore, it is known as a combustion device suitable for burning solid fuel such as coal and refuse.

[0003] In particular, a fluidized-bed coal combustion apparatus using limestone as a fluidizing medium can have a combustion temperature of 800 to 900 ° C, which is lower than the melting temperature of ash, and as a result, has the following characteristics. (a) Pulverized coal-fired boiler does not cause ash melting,
Restrictions by coal type are reduced. (b) Since the limestone fluid medium promotes desulfurization at the same time as combustion, the flue gas desulfurization device becomes unnecessary and the site area of the power plant can be reduced.

[0004] There are two types of fluidized bed combustion apparatuses for burning coal, an atmospheric pressure type and a pressurized type. And
One type of pressurized fluidized-bed combustion system is a coal-fired pressurized fluidized-bed combined power generation system, in which combustion is performed in a pressurized state, and a gas turbine can be driven by flue gas. Therefore, by combining power generation with a steam turbine, there is a feature that the efficiency is higher than that of an atmospheric pressure type fluidized bed combustion power generation system.

[0005] Fig. 8 shows an example of this coal-fired pressurized fluidized bed combined cycle power generation system. As shown in the figure, the system includes a fluidized bed boiler 2 installed in a pressure vessel 1 and a fluidized bed boiler 2 generated therein. A steam turbine 4 driven by the steam 3, a dust removing device including a cyclone 11 and a ceramic filter 12 for cleaning the combustion gas 5 generated in the fluidized bed boiler 2, and a gas turbine 6 driven by the cleaned combustion gas 15 Is the main part.

A fuel 7 made of a mixture of pulverized coal and water is introduced into the pressure vessel 1 and supplied into a fluidized bed 8 formed in the fluidized-bed boiler 2. In parallel with this, high-pressure air is supplied into the fluidized-bed boiler 2 from a compressor 9 driven by a gas turbine 6,
Thereby, fluidized bed combustion is maintained at a temperature of about 860 ° C. in the fluidized bed 8 formed in the fluidized bed boiler 2.

The inside of the fluidized-bed boiler 2 is vertically partitioned by an air distribution plate 21, and the fluidized medium 16 is supplied and filled in the upper part to form a fluidized bed 8, and the lower part is an air chamber. Then, fuel is supplied into the fluidized bed 8 and high-pressure air is supplied to the air chamber for combustion.

At this time, SO ₂ (sulfur dioxide) is generated by combustion.
Feature that is but occurs, by using the limestone particles as bed material 16 to form a fluidized layer 8 (also referred to as a bed material), absorption occurs SO ₂ by limestone, this result, flue gas desulfurization apparatus is not required Further, at this time, since the combustion temperature of the fluidized bed is lower than that of normal flame combustion, generation of NOx (nitride) is also suppressed, and therefore, the power generation system is generally in harmony with the environment. It is said that.

The heat generated in the fluidized bed 8 is
The heat transfer tube 10 installed in the inside is heated, and the heat transfer tube 1 is heated.
The water supplied in 0 is taken out as steam 3 and the steam turbine 4 is driven. On the other hand, the combustion gas 5 taken out of the fluidized bed boiler 2 is removed by a dust removal device comprising a cyclone 11 and a ceramic filter 12 used as a high-temperature filter, and separated into combustion ash 18 and a clean combustion gas 15. Is done.

[0010] Then, the gas turbine 6 is driven by the combustion gas 15, and thereafter, the combustion gas 15 is supplied to the denitration apparatus 1.
9. Exhaust gas 1 from the stack 13 after passing through the dust removal device 20
It is discharged into the atmosphere as 7. At this time, the gas turbine 6
The generator 14 is driven by the power generated in the above, and the compressor 9 is also driven by the gas turbine 6, and the high-pressure air produced by the compressor 9 is supplied to the fluidized-bed boiler 2 as described above. Will be.

[0011]

In the above prior art, no consideration is given to the detection of coarse particles of the fluidized medium in the fluidized bed, and there is a problem that abnormal combustion may occur. In the fluidized bed combustion apparatus, if the supply of fuel is unevenly distributed, an abnormally high temperature portion is generated. For this reason, for example, the coal debris and limestone react to cause a phenomenon that particles adhere to each other.

When this phenomenon progresses, massive coarse particles are generated, the size of which is increased from 10 mm to 20 mm, and these particles are combined to become larger.
Dispersion of the air flow is impeded, which leads to poor flow,
This is a vicious cycle in which abnormal combustion is further advanced.

Further, when the coarse particles are generated, a part of the passage portion of the supply air is blocked, and a region where the upward flow of the air is increased is generated, so that the heat transfer tubes and the dummy tubes are significantly worn. This may cause the heat transfer tube to blow.

[0014] As described above, the generation of coarse particles in the fluidized bed combustion apparatus causes poor flow and abnormal combustion, and the wear in the furnace proceeds. However, in the related art, the above-described problem occurs because the generation of coarse particles of the fluidized medium in the fluidized bed cannot be detected.

SUMMARY OF THE INVENTION An object of the present invention is to detect abnormal combustion associated with the generation of coarse particles of a fluidized medium in a fluidized bed at an early stage, thereby preventing the occurrence of wear and the like in a furnace in advance. An object of the present invention is to provide a diagnostic method and device.

[0016]

SUMMARY OF THE INVENTION The object of the present invention is to provide a method for diagnosing abnormal combustion in a fluidized bed combustion apparatus, wherein the average value of any one of the pressure differences and the temperature of each part, This is achieved by calculating a frequency distribution, an amplitude peak value, and a spectrum and comparing any of them with a preset reference value to determine abnormal combustion.

As a result, generation of coarse particles in the fluidized bed combustion device can be detected at an early stage, and as a result, the present invention operates as follows. By detecting the temperature at a predetermined height of the fluidized bed combustion device, a temperature change in the fluidized bed can be detected, but this is a temperature change near the detection point, and even if an abnormality near this point can be detected, If an abnormality occurs in a remote place,
It cannot always be detected.

Here, when coarse particles are generated, the apparent density of the fluidized bed decreases due to stagnation of bubbles around the coarse particles, and this decrease in density is caused by the presence of coarse particles. Appears as a change in differential pressure in the section. In addition, around the coarse particles, the movement and flow of the bubbles also change, so that the time series signal of the differential pressure changes, which is caused by the average value of the differential pressure vibration waveform, the frequency distribution, and the spectrum of the vibration waveform (frequency distribution). ) Can be detected by analyzing the change in detail.

Then, the detected result is compared with a reference value of an average value, a frequency distribution, and a frequency distribution registered in advance, so that an abnormality can be determined at an early stage. At this time, in particular, the bubble channeling appears as a decrease in the absolute value of the differential pressure and the amplitude of the vibration waveform. Therefore, these phenomena can also be specified by analyzing the differential pressure vibration waveform.

On the other hand, the presence or absence of coarse particles in the fluidized bed also affects the differential pressure in the fixed bed state. At this time, since the generated coarse particles act as obstacles to the air flow from the dispersion plate, the abnormality appears as an increase in the differential pressure, and therefore,
If a change in the differential pressure is tracked at the time of startup, an abnormality in the furnace can be detected at an early stage.

Further, the instantaneous fluctuation of the differential pressure vibration can be detected by analyzing the peak value thereof. This is achieved by setting a reference threshold value in advance in the abnormal combustion determination section, It is possible to prepare for abnormalities by leading to alarm notification.

By analyzing the vibration waveform of the differential pressure signal in this way, normal or abnormal flow is identified.
ADVANTAGE OF THE INVENTION According to this invention, abnormality can be discovered from the change of a fluid combustion state.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and apparatus for diagnosing abnormal fluidized-bed combustion according to the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 shows an embodiment of the present invention. This embodiment is directed to a fluidized-bed boiler 2 having a pressure vessel 1 (see FIG. 8) having a height of 7.0 m.
25 to 25 are pressure introduction valves, 26 to 30 are differential pressure detectors, 31 to 31
35 is a temperature detector, 36 is a signal acquisition unit, 37 is a signal processing unit, 38 is a signal determination unit, 39 is a monitor device, and 40 is a speaker.

The pressure introduction valves 22 to 26 are connected to the fluidized bed boiler 2
It is composed of a cock or the like having a sufficient pressure resistance to the internal pressure, and has a height of 0.7 m, 1.m from the furnace bottom L of the fluidized bed boiler 2 (where the air distribution plate 21 is located in FIG. 8).
It is installed at a total of five locations: 9 m, 3.0 m, and 4.0 m, and functions to extract the pressure inside the fluidized bed boiler 2 at each location.

The differential pressure detectors 27 to 30 are provided with two systems of pressure introduction parts, detect a pressure difference appearing between these pressure introduction parts, and function to generate an electric signal corresponding to the detected pressure difference. As shown in the drawing, a pressure introduction valve 22 and pressure introduction sections 23 to 26 installed at the bottom of the furnace of the fluidized-bed boiler 2 are provided.
Are respectively connected to the pressure introducing portions.

Accordingly, the differential pressure detector 27 is connected to the fluidized bed boiler 2
The height difference between the furnace bottom L of the fluidized-bed boiler 2 and the height of 1.9 m is detected by the pressure difference in this section. In the meantime, the differential pressure detector 29 is between the furnace bottom L of the fluidized bed boiler 2 and the height of 3.0 m, and the differential pressure detector 30 is between the furnace bottom L of the fluidized bed boiler 2 and 4.0 m. The sections between the heights are set as differential pressure measurement sections, pressure differences in those sections are detected, and electric signals (pressure signals) corresponding to these pressure differences are generated.

The temperature detectors 31 to 35 are constituted by a thermocouple type temperature sensor or the like, and are provided in a fluidized bed 0.05 m in height from the furnace bottom of the fluidized-bed boiler 2 and in a middle position of a differential pressure measurement section. Are mounted at positions of 0.4 m, 1.3 m, 2.4 m and 3.6 m, respectively, and serve to detect an ambient temperature in the fluidized bed boiler 2 and generate an electric signal (temperature signal).

The signal capturing section 36 includes four differential pressure detectors 27.
The pressure signals supplied in time series from 30 and the temperature signals supplied in time series from the five temperature detectors 31 to 35 are input and taken in at predetermined time intervals (sampling). At this time, the sampling period can be arbitrarily changed according to the operation state of the fluidized-bed boiler 2 or the like, whereby the change in the flow state is analyzed as an instantaneous value, or as an average value of a predetermined period. It is configured so that analysis can be selected.

The signal processing unit 37 analyzes the waveforms of the four pressure signals and the five temperature signals input from the signal acquisition unit 36, and calculates the average value, frequency distribution, peak value,
Works to calculate the spectrum. The signal determination unit 38
The waveform analysis result supplied from the signal processing unit 37 is compared with a predetermined judgment reference value registered in advance to determine whether or not the combustion is abnormal.

When the result of the determination is that the combustion is abnormal, the signal determination section 37 generates a predetermined abnormality signal so that the monitor 39 and the speaker 40 notify the abnormality. Here, the reference value used for the determination by the signal determination unit 38 is determined by the signal processing unit 3 when it is determined that the normal operation state is maintained during the operation of the fluidized-bed boiler 2.
7 is registered and used.

As a result, new reference values can be obtained one after another according to the accumulation of the operation time. Therefore, a plurality of these reference values are prepared in accordance with the operation conditions such as the difference in the particle size distribution of the fluid medium. Alternatively, selection and determination may be performed in accordance with actual operating conditions, or addition and updating may be performed.

Next, an abnormal combustion diagnosis operation according to this embodiment will be described. First, the signal processing unit 37 analyzes a frequency distribution from a change in differential pressure for each differential pressure measurement section. FIG.
Is an example of this frequency distribution analysis result. The analysis result of the differential pressure taken from the three differential pressure detectors 27 to 29 for 60 seconds is shown with the horizontal axis representing the differential pressure and the vertical axis representing the frequency. Here, the solid line is a normal waveform, and the broken line is an abnormal waveform.

In the case of FIG. 2, the differential pressure measurement section is 0 to 1.9.
m and 0 to 4.0 m, a difference appears between the solid line waveform and the broken line waveform, and it can be seen that the frequency distribution of the broken line is displaced to a lower differential pressure as compared with the normal case. This is because the coal debris and the limestone react with each other to generate massive coarse particles due to the sticking phenomenon between the particles, resulting in the stagnation of bubbles around the coarse particles, and thereby the apparent density of the fluidized bed. Attributable to the above decrease.

Moreover, in this case, in the differential pressure measurement section 0 to 0.
Since there is almost no deviation in the waveform at 7 m, it can be estimated that coarse particles have occurred in the upper differential pressure measurement section of 0.7 to 1.9 m. As described above, by comparing with the frequency distribution of the differential pressure in the normal state, it is possible to detect the abnormality due to the deviation from the normal value, and to estimate the position where the coarse particles exist from the differential pressure measurement section where the deviation appears. it can.

At this time, the signal judging section 38 displays the waveform shown in FIG. 2 on the monitor 39, and furthermore, a warning sound is generated from the speaker 40 when the waveform shift reaches a predetermined amount. As a result, according to this embodiment, when abnormal combustion occurs in the fluidized bed during operation, an audible notification is obtained from the speaker 40 and the monitor 39
The content of the occurrence of the abnormality can be easily known by the display. Therefore, according to this embodiment, it is possible to easily obtain an accurate grasp of the abnormal combustion appearing in the fluidized bed, and as a result, it is possible to take appropriate measures and sufficiently suppress the furnace wear.

FIG. 3 shows another example of the frequency distribution analysis results in the same differential pressure measurement section as in FIG. 2. In this case, the differential pressure measurement sections are 0 to 0.7 m, 0 to 1.9 m, and 0 to 4 m. In all the measurement sections of 0.0 m, the frequency distribution of the broken line is displaced from the solid line to the lower differential pressure, and the fluctuation range of the differential pressure is narrower in each waveform than in the normal case.

This indicates that a channeling portion of air was generated in the fluidized bed, and a path through which air could penetrate from the inside of the bed to the top of the bed was formed. This indicates that the fluctuation component of the differential pressure is suppressed because the rupture of is reduced, and this indicates that the fluctuation range of the differential pressure is reduced.

Thus, by analyzing the differential pressure measurement results one after another and comparing it with the frequency distribution of the differential pressure in the normal state, the deviation of the waveform from the normal value and the change in the differential pressure fluctuation width indicate the abnormal flow. It is possible to estimate the fluidized bed channeling phenomenon, which is one aspect of the present invention, and it is possible to reliably report abnormal combustion.

Next, another example of the abnormal combustion diagnosis method according to this embodiment will be described below. As is clear from FIG. 1, the signal processing unit 37 is configured to analyze also the temperature signals detected by the temperature detectors 31 to 35. In the diagnosis method described below, the analysis of this temperature signal is applied. It was done.

FIG. 4 shows, as an example, a change in temperature at a measurement height of 0.4 m, that is, an analysis result based on a temperature signal of the temperature detector 32. In this case, the measurement height is 0.4 m. Therefore, the temperature in the fluidized bed is detected. In this case, in a normal state, as shown by a solid line, the temperature is almost constant, and here, only a small change is observed at about 850 ° C.

On the other hand, when the uneven distribution of fuel occurs, the temperature locally changes in the furnace. For example, in FIG. 4, as indicated by a broken line, the temperature temporarily rises to 920 ° C. between 1 hour and 2 hours after the start of measurement, and therefore, in this case,
This indicates that the coal is unevenly distributed near the temperature detector 32. The threshold is set so that the temperature of 920 ° C. at this time is equal to or higher than the threshold in the normal state.

Thereafter, the temperature once decreases and then returns to the normal range. In this case, at this high temperature, the debris of the coal reacts with limestone, causing the particles to adhere to each other and coarsening. There is a risk that particles will be formed. Therefore, the signal processing unit 37 monitors the temperature signals from the temperature detectors 31 to 35, and when such an abnormal high temperature phenomenon occurs, thereafter, determines an abnormality by analyzing the differential pressure vibration waveform described with reference to FIG. Is configured to execute.

Therefore, according to this embodiment, when the coarse particles are formed by the above-described series of processing and there is a possibility of poor flow due to stagnation of the particles, it can be detected at an early stage. Abnormal combustion can be suppressed and furnace wear can be reliably suppressed.

By the way, depending on the cause of the abnormality, the determination method based on the frequency distribution of the differential pressure waveform described with reference to FIG.
In particular, abnormalities may not be diagnosed. However, even in this case, according to the spectrum analysis described with reference to FIG. 5 below, an abnormality may be determined in some cases. Therefore, by using them together, the diagnostic accuracy can be improved.

For example, even when the analysis result shown in FIG. 5 is obtained, in the diagnosis based on the frequency distribution of the differential pressure oscillation waveform shown in FIG. However, in FIG. 5, as shown by the solid line and the broken line, there is a remarkable difference between the normal state and the abnormal state, and the diagnosis can be easily obtained.

That is, FIG. 5 shows an example of the spectrum (frequency distribution) analysis result of the differential pressure vibration waveform, in which the differential pressure vibration waveform in the differential pressure measurement section 0 to 1.9 m is spectrum-analyzed, and the result is analyzed. , The frequency is plotted on the horizontal axis and the intensity of the differential pressure is plotted on the vertical axis. According to this figure, the peak of the frequency which is below 0.1 Hz in the normal spectrum, It is clearly shown that it has moved to around 0.6 Hz.

This is because coarse particles were formed,
This shows that bubbles rising in the fluidized bed were divided and became smaller. In other words, when coarse particles are formed,
The bubble diameter fluctuates around it, and this causes a change in the frequency component due to the vibration of the differential pressure, and the bubbles are divided and reduced, resulting in an increase in the frequency of the differential pressure vibration.

As described above, even if the bubbles do not reach the vicinity of the coarse particles, the spectrum of the vibration waveform appears only by a change in the bubble diameter. Therefore, as shown by the solid line in FIG. Can be detected at an early stage by comparing the spectrum with the spectrum, and therefore, according to this embodiment, abnormal combustion of the fluidized bed is suppressed, and furnace wear is surely suppressed. be able to.

At this time, the spectrum (frequency distribution) analysis of the differential pressure oscillation waveform is configured to be performed by the signal processing unit 37. At this time, a wavelet analysis that can precisely analyze a time series change is adopted. By doing so, it can be easily implemented.

The above is the method of diagnosing abnormal combustion during operation of the fluidized bed combustion apparatus. Here, the combustion operation by the fluidized bed is stopped, and the fluidized bed is in a fixed bed state. A method of diagnosing abnormalities at the time will be described. In this method, when the fluidized-bed boiler 2 is started, before the ignition in the furnace, a predetermined flow rate of air for measurement is sent into the furnace so that the fluidized bed has a fixed bed. When in the state, the differential pressure signal is taken in from the differential pressure detectors 27 to 29 to make a diagnosis.

FIG. 6 shows the differential pressure measured in each section of 0 to 0.7 m, 0 to 1.9 m, and 0 to 4.0 m with the fluidized bed in the above fixed bed state, that is, a differential pressure detector. 27, 28, 30
FIG. 7 is a characteristic diagram in which the vertical axis represents the differential pressure when the superficial velocity is plotted on the horizontal axis, which is an example of the result of analysis by the signal processing unit 37 based on the differential pressure signal supplied from.

Here, the superficial velocity [m / sec] refers to the rate of rise of air in the furnace (fluidized bed boiler 2), and the air flow rate A [m ³ / sec] and the cross-sectional area of the furnace By B [m ² ], A /
This is a numerical value given as B, and therefore, a signal representing the air flow rate A is input to the signal capturing unit 36 as shown in FIG. The signal representing the air flow rate A is supplied from an air flow rate detector (not shown).

In FIG. 6, the differential pressure characteristic at normal time shown by the solid line and the differential pressure characteristic shown by the broken line are:
There is a clear difference. That is, differential pressure measurement section 0
It can be seen that the characteristic pressure at 1.9 m and the differential pressure at the abnormal time indicated by the broken line in the differential pressure measurement section 0 to 4.0 m are higher than the differential pressure at the normal time indicated by the solid line.

This can be explained as follows. That is, in the fixed bed state, the coarse particles act as obstacles to the air flow, and the fluidized bed becomes poor in flow. This poor flow causes an increase in the differential pressure.

The signal processor 37 registers the normal differential pressure characteristics shown in FIG. 6 in advance and compares them with the differential pressure characteristics captured in the fixed layer state. Also, when the threshold value exceeds a predetermined threshold value set in advance, the speaker 40 is operated to thereby notify that there is a risk of abnormal combustion.

Therefore, according to this embodiment, when the fluidized bed boiler 2 is not operating, for example, immediately before startup, the condition of the fluidized bed is diagnosed in advance, and no coarse particles are formed in the fluidized medium. As a result, abnormalities in the furnace can be detected early and appropriate measures can be taken, abnormal combustion of the fluidized bed can be suppressed, and furnace wear can be reliably suppressed.

FIG. 7 is a flowchart showing the abnormal combustion diagnosis processing in the above embodiment. The differential pressure oscillation waveform (differential pressure signal) and the thermocouple temperature (temperature signal) monitored in the fluidized bed boiler 2 by the differential pressure detectors 27 to 30 and the temperature detectors 31 to 35 are converted into a signal capturing unit 36. Are subjected to A / D conversion, and then the signal processing unit 37 calculates an average value, a frequency distribution, a peak value, a spectrum, and the like.

Thereafter, in the signal determination section 38, a warning is first issued when the peak value exceeds a preset allowable threshold. If the peak value is within the allowable range, the average value, frequency distribution, and spectrum are then compared with their normal data to calculate the deviation, and if this is greater than the allowable value, a warning is automatically issued. It is emitted.

Therefore, in the above embodiment, the abnormal flow in the furnace, such as the detection of coarse particles, can be found at an early stage by this procedure, and as a result, appropriate measures can be easily taken to avoid a phenomenon leading to furnace wear. be able to.

Next, FIG. 9 shows a case where the above-described various abnormality diagnosis methods are applied to, for example, the fluidized bed power generation system shown in FIG.
(Personal computer) 42 is an A / D converter for interface, and the other configuration is the same as that of the embodiment of FIG. 1. Therefore, the personal computer 41 is composed of the signal processing unit 37 and the signal determination unit of FIG. The A / D converter 42 also corresponds to the signal acquisition unit 36.

In the embodiment shown in FIG. 9, the personal computer 41 uses any of the methods described with reference to FIGS. Program), and the differential pressure detector 2 is connected to the personal computer via the A / D converter 42.
7 to 30 and the temperature detectors 31 to 35, respectively, the differential pressure signal and the temperature signal are fetched, and the result of the combustion abnormality diagnosis is displayed on the monitor of the personal computer 25 as in the embodiment of FIG. This is to inform.

By the way, in the above description of the embodiment, the case where the signals from all four differential pressure detectors 27 to 30 and all five temperature detectors 31 to 35 are used will be described. Although not described, it is needless to say that any one of them can be arbitrarily selected and used, and it is only necessary to select one that gives a better diagnosis result and perform the diagnosis.

[0063]

According to the present invention, since the occurrence of coarse particles in the fluidized medium in the fluidized bed combustion apparatus is detected and abnormal combustion is determined, an accurate diagnosis of abnormal combustion can be made at an early stage. In addition, it can be easily obtained. Therefore, according to the present invention, the abnormal combustion appearing in the fluidized bed can be quickly and accurately grasped, and as a result, an appropriate countermeasure can be taken at an early stage, and the furnace wear can be sufficiently suppressed.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a fluidized bed abnormal combustion diagnosis method according to the present invention.

FIG. 2 is a characteristic diagram for describing a first example of an abnormal combustion diagnosis method according to one embodiment of the present invention.

FIG. 3 is a characteristic diagram for explaining a second example of the abnormal combustion diagnosis method according to one embodiment of the present invention.

FIG. 4 is a characteristic diagram for explaining a third example of the abnormal combustion diagnosis method according to one embodiment of the present invention.

FIG. 5 is a characteristic diagram for explaining a fourth example of the abnormal combustion diagnosis method according to one embodiment of the present invention.

FIG. 6 is a characteristic diagram for explaining a fifth example of the abnormal combustion diagnosis method according to the embodiment of the present invention.

FIG. 7 is a flowchart illustrating a processing procedure of an abnormal combustion diagnosis method according to an embodiment of the present invention.

FIG. 8 is a block diagram illustrating an example of a pressurized fluidized bed power generation system.

FIG. 9 is a configuration diagram showing one embodiment of a fluidized bed abnormal combustion diagnosis device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pressure vessel 2 Fluidized bed boiler 3 Steam 4 Steam turbine 5 Combustion gas 6 Gas turbine 7 Fuel 8 Fluidized bed 9 Compressor 10 Heat transfer tube 11 Cyclone 12 Ceramic filter 13 Stack 14 Generator 15 Cleaned combustion gas 16 Fluid medium 17 Exhaust gas 18 Combustion ash 19 Denitration device 20 Dedusting device 21 Air dispersion plate 22-26 Pressure introduction valve 27-30 Differential pressure detector 31-35 Temperature detector 36 Signal take-in unit 37 Signal processing unit 38 Signal determination unit 39 Monitor 40 Speaker 41 Personal computer (personal computer) 42 A / D converter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Tomohiko Miyamoto 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Inside the Hitachi Research Laboratory, Hitachi, Ltd. (72) Mamoru Mizumoto 7, Omikamachi, Hitachi City, Ibaraki No. 1-1 In Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Hisayuki Orita 7-1-1, Omikamachi, Hitachi City, Ibaraki Prefecture Inside Hitachi Research Laboratory, Hitachi, Ltd. (72) Katsuya Oki Kure City, Hiroshima Prefecture 6-9, Takaracho Babkotsuk Hitachi Kure Factory F-term (reference) 3K062 AA11 CA01 CB03 DA01 DA12 DB30 3K068 NA01 PB01 PB07

Claims (5)

[Claims] 1. A method for diagnosing abnormal combustion of a fluidized bed in a fluidized bed combustion apparatus, comprising the steps of:
A fluidized bed for calculating an abnormal combustion by calculating an average value, a frequency distribution, an amplitude peak value, and a spectrum of any one of them and comparing any of them with a preset reference value; Abnormal combustion diagnosis method. 2. A fluidized bed abnormal combustion diagnostic apparatus for a fluidized bed combustion apparatus, comprising: a signal capturing section for capturing a differential pressure and a temperature appearing in the fluidized bed combustion apparatus; and a time series signal captured by the signal capturing section. And a mean value, frequency distribution, and differential pressure waveform of the differential pressure waveform obtained by the signal processing unit.
A fluidized-bed abnormal combustion diagnostic device, comprising: a signal determination unit that compares one of an amplitude peak value and a spectrum with a reference value. 3. The apparatus according to claim 2, wherein the signal acquiring unit changes a signal acquiring time by changing a signal acquiring time.
A method for diagnosing abnormal fluidized-bed combustion, wherein the amount of data transferred to the signal processing unit can be arbitrarily changed. 4. The apparatus according to claim 2, wherein the reference value in the signal determination unit is updated as necessary.
A fluidized-bed abnormal combustion diagnostic device, which is configured to be addable. 5. The apparatus according to claim 2, further comprising at least one of a display unit and a notifying unit, wherein when it is determined that the combustion is abnormal, at least one of the content of the abnormal combustion and the notification of the occurrence of the abnormal combustion is obtained. A fluidized-bed abnormal combustion diagnosis apparatus characterized by having the above-described configuration.