JP3917943B2 - Measurement system for unburned ash - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an unburned ash measurement system suitable for use in boilers such as thermal power plants.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, chemical analyzers and X-ray analyzers are well known as devices for measuring calorific value, unburnt components, and component composition of pulverized coal, fly ash (ash), cement raw materials, and the like. However, since these analyzers require a considerable amount of time (20 to 120 minutes) from taking a sample to obtaining an analysis result, the measurement results are used for boilers (in the case of a thermal power plant). When performing control, this time lag is large, which is a major obstacle to plant control.
[0003]
On the other hand, some X-ray analyzers and Γ-ray analyzers can measure in real time. However, in this case, the X-ray analyzer can measure only Ca in the case of a cement plant, and its performance is low. In addition, the Γ-ray analyzer has a problem that it is troublesome and expensive to handle.
[0004]
Therefore, in recent years, in cement plants, there is an increasing need for on-line measurement of cement components due to the need for improved management of cement quality, and it is desired to develop a quantifiable method that meets this need. It was recalled that a laser-induced breakdown spectroscopy (LIBS method) proposed in Japanese Patent Application Laid-Open No. 10-185817 (Patent Document 1) and the like was adopted to make it an apparatus.
[0005]
The LIBS method is implemented as shown in FIG.
That is, the measurement object exists (circulates) in the piping 01 of various plants and the like. Examples of measurement objects include pulverized coal, fly ash, and cement raw materials. A measurement window 03 having a purge air passage 03a is installed in the measurement field 02 of the pipe 01.
[0006]
The laser light output from the pulse laser device 05 constituting the LIBS device 04 is condensed on the measurement field 02 via the lens 06 and the measurement window 03. For this reason, the fine particles present in the measurement field 02 are turned into plasma, and plasma light is generated from the plasmad component material.
[0007]
The generated plasma light is output to the outside from the measurement window 03 of the measurement field 02, reflected by the mirror 07, further collected by the lens 08, and incident on the spectroscope 09. The spectroscope 09 splits plasma light having a wavelength of 190 nm to 500 nm (or a partial wavelength range within this range), and inputs the split light component to the CCD camera 010.
[0008]
The CCD camera 010 capable of high-speed gate detects the spectral plasma light dispersed by the spectroscope 09 and transfers a signal corresponding to the spectral plasma light to the computer 011. The CCD camera 010 is connected to the pulse laser device 05 via a synchronization line 012, and the gate control of the CCD camera 010 and the oscillation of the pulse laser device 05 are synchronized.
[0009]
The computer 011 performs an information processing operation on the transferred signal (having emission intensity information from each component), thereby generating a calorific value of pulverized coal, fly ash, cement raw material existing in the measuring field 02, Calculate fuel and component composition in real time.
[0010]
As described above, since the LIBS device 04 can measure the composition component of the measurement object in real time at the measurement site, the operation control of the plant or the like can be performed satisfactorily based on the measurement result.
[0011]
Then, an object of this invention is to provide the novel unburned ash content measurement system which can measure the unburned content in the ash in a boiler in real time using the LIBS apparatus mentioned above.
[0012]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-185817
[Means for Solving the Problems]
A first invention of the present invention that solves the above-described problems includes a first ejector that sucks a sample gas into a sampling line branched from a combustion gas line of a boiler,
A cyclone for separating and collecting ash from the sample gas sucked by the first ejector;
A second ejector disposed between the first ejector and the cyclone for sucking a sample gas sucked by the first ejector;
A third ejector that sucks the ash separated and collected by the cyclone is sequentially inserted from the upstream side of the line to the downstream side,
In the line between the cyclone and the third ejector, the ash flowing through the line is irradiated with a laser to make its composition component into plasma, and the plasma light generated from the plasma is incident on the spectrometer. It interposed a measuring device for measuring the unburned ash from the spectroscopic spectral light,
Furthermore, a switching valve is provided in the line between the second ejector and the cyclone, and a fourth ejector for supplying gas containing reference powder from the sample calibration means to the measuring device from the switching valve is provided. It is in the measurement system for unburned ash in ash.
[0015]
According to a second invention, in the first invention,
An unburned ash content measurement system is provided that includes a mass flow controller for adjusting the amount of air supplied to the second ejector.
[0016]
According to a third invention, in the first invention,
An unburned ash measurement system is provided in which a bypass line for supplying sample gas from the cyclone to the downstream side of the third ejector is provided, and a fifth ejector is provided in the bypass line.
[0017]
A fourth invention according to the first invention,
An unburned ash content measurement system comprising air supply means for supplying air for diluting CO ₂ concentration to a line for measuring unburned content in ash by the measuring device on the downstream side of the cyclone. is there.
[0018]
A fifth invention is a pulverized coal combustion system in which coal pulverized coal is supplied to each combustor and burned,
Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
An unburned ash measurement system in ash of the first to fourth inventions for measuring unburned content in ash in a combustion gas line from a combustor;
A pulverized coal combustion system comprising combustion control means for controlling combustion from a measurement result of the unburned ash measurement system.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an unburned ash content measurement system according to the present invention will be described in detail with reference to the accompanying drawings.
[0020]
[First Embodiment]
FIG. 1 is a schematic configuration diagram of an unburned ash measurement system showing a first embodiment.
As shown in FIG. 1, the unburned ash measurement system 10 according to the first embodiment includes a sample containing ash in a sampling line 12 branched from a combustion gas line 11 of a boiler (not shown). A first ejector 14 for sucking the gas 13;
A cyclone 16 for separating and collecting the ash 15 from the sample gas 13 sucked by the first ejector 14;
A second ejector 17 that is disposed between the first ejector 14 and the cyclone 16 and sucks the sample gas 13 sucked by the first ejector 14;
A third ejector 18 that sucks the ash 15 separated and collected by the cyclone 16 is sequentially inserted from the upstream side of the line to the downstream side, and in the line between the cyclone 16 and the third ejector 18. Then, the ash 15 flowing through the line is irradiated with laser light to make its composition component into plasma, the plasma light generated from the plasma is incident on the spectroscope, and the unburned content in the ash from the spectrum light dispersed by the spectroscope Is provided via a LIBS device 19 that measures the above.
[0021]
Further, a three-way switching valve 21 is provided in the line between the second ejector 17 and the cyclone 16, and the reference powder 23a from the sample calibration means 22 is supplied from the switching valve 21 to the LIBS device (Laser Induced Breakdown Spectroscopy) 19. A fourth ejector 23 for supplying a gas containing it is provided, and the system is calibrated every predetermined period.
This reference powder is a powder whose known unburned amount is used for calibration, so that calibration should be performed after a predetermined time (for example, once every two to three weeks or once a month). Yes.
[0022]
Further, a mass flow controller 24 for adjusting the supply amount of the air 20 to the second ejector 17 is provided. When the signal strength of the LIBS decreases, the mass flow controller 24 is adjusted to increase the supply amount of the air 20. The sample gas supply amount is increased so that the signal intensity can always be monitored.
This makes it possible to handle any type of boiler operation.
[0023]
In the present embodiment, the bypass line 31 for supplying the sample gas 11 from the cyclone 16 to the downstream side of the third ejector 18 is provided, and the fifth ejector 32 is provided in the bypass line 31, thereby providing the cyclone. The pressurization to the CO ₂ component in the sample gas supplied to 16 is suppressed.
[0024]
That is, since the fifth ejector 32 provided in the bypass line 31 is provided, the gas from the second ejector 17 is applied to the sampling tube 19a that performs LIBS measurement by forcibly sucking the gas with the fifth ejector 32. The supply of the sample gas 11 is eliminated, and the CO _{2 in} the gas is eliminated from being subject to pressure fluctuations.
As a result, in the second ejector 17, for example, when there is a sudden pressurization, the CO ₂ component is erroneously measured as the C (carbon) component by the LIBS device 19 to prevent erroneous fluctuation of the C concentration. I am doing so.
The gas from the third ejector 18 and the fifth ejector 32 is returned to the flue by the return pipe 37.
[0025]
As shown in FIG. 3, the air 20 is supplied into the sampling pipe 19a to rectify the flow of the ash when measuring the ash. Further, air 20 is separately supplied so as to prevent contamination of the transmission window 19b through which the laser light L is transmitted.
[0026]
In addition, an air supply means 33 is provided on the downstream side of the cyclone 16 to supply air for diluting the CO ₂ concentration to the measurement line of the LIBS device 19.
Thus, by supplying dilution air, the CO ₂ concentration is diluted to prevent the C concentration from fluctuating.
[0027]
A flow meter 35 is provided between the first ejector 14 and the second ejector 17 to measure the sampling flow rate.
[0028]
The three-way valve and the shutoff valve are constituted by, for example, electromagnetic valves, and are switched (opened / closed) as required by a control device (not shown). The first ejector 14, the third ejector 18, the fourth ejector 23, and the fifth ejector 32 are provided with a flow meter (not shown) to monitor the flow rate of the sample gas and ash flowing through the part. Yes.
[0029]
Further, the flow rate of the air 20 supplied from the air supply means 36 to be supplied to each ejector is adjusted by an air flow meter (not shown).
[0030]
As a result, the sample gas 11 sucked into the sampling line 12 by the first ejector 14 and the second ejector 17 is guided to the cyclone 16, where the ash content in the gas is separated and collected. The ash content separated and collected by the cyclone 16 is measured by the LIBS device 19 while the ash content reaches the third ejector 18 from the cyclone 16. In other words, the LIBS device 19 measures the C component derived from Si, Al, Ca, Fe and unburned components as the main components in the ash, and calculates the unburned content from the ratio of Si, Al, Ca, Fe and C. It is calculated.
[0031]
And in a boiler, based on the measurement result of the said LIBS apparatus 19, the combustion conditions in a boiler furnace are changed, for example, increasing / decreasing the grinding | pulverization amount of pulverized coal, and an unburned part is controlled.
[0032]
Next, when the LIBS device 19 is calibrated, the three-way valve that is the switching valve 21 is switched and the shut-off valve 25 is opened as shown in FIG.
[0033]
As a result, when a reference powder (for example, 2.0% unburned content) whose unburned content is known is supplied from the sample calibration means (feeder) 22, the sample powder is sucked by the fourth ejector 23 and guided to the cyclone 16, The unburned content in the reference powder can be measured and calibrated.
[0034]
At the time of this calibration, the sample gas from the sampling line does not go to the measurement line side by the valve 21, but is backflowed by the second ejector 17, the sample gas in the pipe is pushed back to the flue, and the sample line is washed.
[0035]
As a result, calibration of sample gas concentration measurement can be performed properly.
[0036]
[Second Embodiment]
FIG. 4 is a schematic configuration diagram of an unburned ash measurement system showing a second embodiment.
The unburned ash measurement system 10 showing the second embodiment is provided with a plurality of first ejectors 14 for sucking a sample gas 13 containing ash.
[0037]
As shown in FIG. 4, the unburned ash measurement system 10 according to the second embodiment includes ash in sampling lines 12A and 12B branched from combustion gas lines 11A and 11B of a boiler (not shown). The first ejectors 14A and 14B for sucking the sample gas 13 containing the cyclone 16; the cyclone 16 for separating and collecting the ash 15 from the sample gas 13 sucked by the first ejectors 14A and 14B; A second ejector 17 that is arranged between the ejectors 14A and 14B and the cyclone 16 and sucks the sample gas 13 sucked by the first ejectors 14A and 14B, and an ash component separated and collected by the cyclone 16 And a third ejector 18 for sucking 15 in order from the upstream side to the downstream side of the line, and the cyclone 16 and the third ejector 18 During this period, the ash 15 flowing through the line is irradiated with a laser to make its composition component into plasma, and plasma light generated from the plasma is incident on the spectroscope. It is provided with a LIBS device 19 for measuring the unburned amount.
[0038]
That is, when there are a plurality of boilers, the LIBS measurement system is used as a single unit, and the unburned content in the ash is measured by switching.
In the present embodiment, the first ejector 14A and the first ejector 14B are interposed in the sampling lines 12A and 12B from the two systems (system A and system B) of the combustion gas lines 11A and 11B, respectively. The supply flow path is switched.
[0039]
[Third Embodiment]
An outline of the boiler system is shown.
FIG. 5 illustrates a boiler combustion control system using this measuring apparatus.
As shown in FIG. 5, the boiler furnace 101 is provided with a plurality of burners 102, to which are connected pulverized coal supply pipes 103, and pulverized coal 104 is fed from a mill (pulverized coal machine) 105. Have been supplied.
[0040]
Further, the exhaust gas from the boiler furnace 101 is cleaned by an electrostatic precipitator 111 and a desulfurization / denitration device 112 interposed in the flue 110 and discharged to the outside.
The sampling line 11 branched from the flue 110 is provided with a LIBS system 10 for measuring unburned components in the ash.
[0041]
Then, the measurement result of the unburned carbon amount is sent to the control system 120 to control the rotation speed of the mill 105 and to instruct the supply amount of additional air.
[0042]
FIG. 6 shows the control state. In the figure, the left axis represents the amount of unburned carbon in fly ash (%), the right axis represents the unburned carbon set value (%) in fly ash, and the horizontal axis represents time (H).
As shown in FIG. 6, it can be seen that the amount of unburned carbon in the fly ash is set (broken line in the figure) to follow as indicated by the thick line in the figure.
[0043]
Needless to say, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.
[0044]
【The invention's effect】
As described above, according to the present invention, the first ejector that sucks the sample gas into the sampling line branched from the combustion gas line of the boiler, and the ash from the sample gas sucked by the first ejector. A cyclone to be separated and collected, a second ejector that is disposed between the first ejector and the cyclone and sucks the sample gas sucked by the first ejector, and is separated and collected by the cyclone. A third ejector for sucking the ash content is sequentially inserted from the upstream side of the line to the downstream side, and the ash content flowing through the line is irradiated with laser in the line between the cyclone and the third ejector. The composition component is turned into plasma, plasma light generated from the plasma is incident on the spectroscope, and the unburned matter in the ash is measured from the spectroscopic light dispersed by the spectroscope. Having interposed that measuring apparatus can measure the unburned ash in the boiler in real time.
[Brief description of the drawings]
1 is a schematic configuration diagram of an unburned ash measurement system according to a first embodiment;
FIG. 2 is a schematic configuration diagram at the time of calibration of the unburned ash measurement system according to the first embodiment.
FIG. 3 is a schematic configuration diagram of a sampling tube.
FIG. 4 is a schematic configuration diagram of an unburned ash measurement system according to a second embodiment.
FIG. 5 is a boiler system diagram.
FIG. 6 is a diagram showing a state of control.
FIG. 7 is an explanatory diagram of a LIBS apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Ash incombustible measurement system 11 Combustion gas line 12 Sampling line 13 Sample gas 14 1st ejector 15 Ash 16 Cyclone 17 2nd ejector 18 3rd ejector 19 LIBS apparatus

Claims (5)

A first ejector for sucking a sample gas into a sampling line branched from a combustion gas line of the boiler;
A cyclone for separating and collecting ash from the sample gas sucked by the first ejector;
A second ejector disposed between the first ejector and the cyclone for sucking a sample gas sucked by the first ejector;
A third ejector that sucks the ash separated and collected by the cyclone is sequentially inserted from the upstream side of the line to the downstream side,
In the line between the cyclone and the third ejector, the ash that flows through the line is irradiated with a laser to make its composition component into plasma, and the plasma light generated from the plasma is incident on the spectrometer. It interposed a measuring device for measuring the unburned ash from the spectroscopic spectral light,
Furthermore, a switching valve is provided in the line between the second ejector and the cyclone, and a fourth ejector for supplying gas containing reference powder from the sample calibration means to the measuring device from the switching valve is provided. A system for measuring unburned in ash. In claim 1,
An unburned ash measurement system, comprising a mass flow controller for adjusting an air supply amount to the second ejector. In claim 1,
An unburned ash measurement system in ash, wherein a bypass line for supplying sample gas from the cyclone to the downstream side of the third ejector is provided, and a fifth ejector is provided in the bypass line. In claim 1,
An unburned ash content measurement system comprising an air supply means for supplying air for diluting a CO ₂ concentration to a line for measuring unburned content in ash by the measuring device on the downstream side of the cyclone. A pulverized coal combustion system in which pulverized coal of coal is supplied to each combustor and burned,
Pulverizing means for pulverizing coal from the coal yard;
Pulverized coal supply pipe for supplying pulverized coal from the pulverizing means to a combustor;
An unburned ash measurement system in ash according to claims 1 to 4 , which measures unburned content in ash in a combustion gas line from a combustor;
A pulverized coal combustion system comprising combustion control means for controlling combustion from a measurement result of the unburned ash measurement system.

Images