JP4119624B2 - 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 method (LIBS method) proposed in Japanese Patent Application Laid-Open No. 10-185817 etc. was adopted to make a device.
[0005]
For example, the LIBS method is implemented as shown in FIG.
That is, a measurement object exists (circulates) in the piping 1 of various plants and the like. Examples of measurement objects include pulverized coal, fly ash, and cement raw materials. A measurement window 3 having a purge air passage 3a is installed in the measurement field 2 of the pipe 1.
[0006]
The laser beam output from the pulse laser device 5 constituting the LIBS device 4 is condensed on the measurement field 2 via the lens 6 and the measurement window 3. For this reason, the fine particles present in the measurement field 2 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 3 of the measurement field 2, reflected by the mirror 7, further condensed by the lens 8, and incident on the spectroscope 9. The spectroscope 9 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 10.
[0008]
The CCD camera 10 capable of high-speed gate detects the spectral plasma light dispersed by the spectroscope 9 and transfers a signal corresponding to the spectral plasma light to the computer 11. The CCD camera 10 is connected to the pulse laser device 5 via a synchronization line 12, and the gate control of the CCD camera 10 and the oscillation of the pulse laser device 5 are synchronized.
[0009]
The computer 11 performs an information processing operation on the transferred signal (having light emission intensity information from each component), thereby calculating the calorific value of the pulverized coal, fly ash, cement raw material existing in the measurement field 2, Calculate fuel and component composition in real time.
[0010]
As described above, since the LIBS device 4 can measure the composition component of the measurement object in real time at the measurement site, the operation control of the plant and 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]
[Means for Solving the Problems]
The system for measuring unburned ash in ash according to the present invention that solves the above problems includes a first ejector that sucks sample gas into a sampling line branched from a combustion gas line of a boiler, and a sample sucked by the first ejector. A cyclone that separates and collects ash from the gas and a second ejector that sucks the ash separated and collected by the cyclone are sequentially inserted from the upstream side of the line to the downstream side, and the cyclone and the second During the line with the ejector, the ash flowing through the line is irradiated with a laser to make its composition component into plasma, the plasma light generated from the plasma is incident on the spectroscope, and from the spectral light that has been dispersed by the spectroscope It is characterized by interposing a measuring device that measures the unburned content in the ash.
[0013]
The sampling line upstream of the first ejector is separated into two systems through a valve device, and a flow meter is installed in one of them.
[0014]
The first ejector is provided in two stages in the sampling line, and a shutoff valve for shutting off the line when necessary is provided in the line between the two ejectors.
[0015]
A line is branched from a sampling line downstream of the second ejector via a valve device, and a second cyclone for separating and collecting ash is interposed in the branch line.
[0016]
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.
[0017]
[Example]
FIG. 1 is a schematic configuration diagram of an unburned ash measurement system showing an embodiment of the present invention, FIG. 2 is a diagram for explaining the operation, FIG. 1 (a) is a diagram for explaining a flow path in a normal mode, and FIG. FIG. 3 is a diagram for explaining the operation, FIG. 3A is a diagram for explaining the flow channel in the purge mode, and FIG. 3B is a diagram for explaining the channel in the sample mode.
[0018]
As shown in FIG. 1, first ejectors 20a and 20b for sucking sample gas containing ash into a main sampling line A branched from a combustion gas (exhaust gas) line of a boiler (not shown) through a valve device as appropriate. The first cyclone 21 that separates and collects ash from the sample gas sucked by the first ejectors 20a and 20b, and the second ejector that sucks the ash separated and collected by the first cyclone 21 22 are sequentially inserted from the upstream side of the line to the downstream side, and the composition component is obtained by irradiating the ash flowing through the line in the line between the first cyclone 21 and the second ejector 22 with a laser. LIBS (Laser Induced Br) that converts plasma into plasma and emits plasma light generated from the plasma into the spectroscope and measures the unburned content in the ash from the spectroscopic light spectrally separated by the spectroscope. eakdown Spectroscopy) device 4 is interposed. The gas component centrifuged by the first cyclone 21 is the first sub-sampling line A.₁And is joined into the main sampling line A downstream of the second ejector 22.
[0019]
Further, in the middle of the main sampling line A upstream of the first ejectors 20a and 20b, the second sub-sampling line A is passed through the three-way valves 23a and 23b.₂Are separately formed, and this second sub-sampling line A₂A flow meter 24 for measuring the flow rate of the sample gas is interposed in the middle of the process.
[0020]
Further, the first ejectors 20a and 20b are provided in two stages, front and rear, and the main sampling line A between the front ejector 20a and the rear ejector 20b is shut off when necessary. A valve 25 is interposed.
[0021]
Further, from the main sampling line A downstream of the second ejector 22, a third sub-sampling line A is passed through a three-way valve 26._ThreeIs branched, and this third sub-sampling line A_ThreeA second cyclone 28 that separates and collects ash is contained therein together with a pot 29. Third sub-sampling line A_ThreeThe downstream end is connected to the main sampling line A downstream of the three-way valve 26 via a shutoff valve 27 that shuts off the line when necessary.
[0022]
The three-way valves 23a, 23b, 26 and the shut-off valves 25, 27 are constituted by electromagnetic valves, for example, and are switched (open / closed) according to various modes to be described later by a control device (not shown). In addition, flow meters (not shown) are installed at five locations of the first ejectors 20a and 20b, the second ejector 22, the first cyclone 21 of the main sampling line A, and the LIBS device 4 measurement section, and the sample gas flowing through the portions. And the ash flow rate is monitored appropriately.
[0023]
Because of such a configuration, first, in the normal mode shown in FIG. 2A, the three-way valves 23a, 23b, and 26 are switched to the main sampling line A side, and the shut-off valve 25 is opened while the shut-off valve 27 is opened. Is closed.
[0024]
Thus, the sample gas sucked into the main sampling line A by the first ejectors 20a and 20b is guided to the first cyclone 21, where the ash content in the gas is separated and collected. The separated and collected ash is sucked by the second ejector 22 and then the first sub-sampling line A₁It merges with the gas that has passed through and is discharged out of the main sampling line A.
[0025]
The ash content separated and collected by the first cyclone 21 is measured by the LIBS device 4 while the ash content from the first cyclone 21 reaches the second ejector 22. In other words, the LIBS device 4 measures the C component caused by Si, Al, Ca, Fe and the 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.
[0026]
In the boiler, based on the measurement result of the LIBS device 4, for example, pulverized coalGrinding degreeBy changing the combustion conditions in the boiler furnace, etc.Control unburnt.
[0027]
Next, in the flow rate measurement mode shown in FIG. 2B, the three-way valves 23a and 23b are connected to the second sub-sampling line A.₂The rest is the same as the state of FIG.
[0028]
As a result, the sample gas sucked by the first ejectors 20a and 20b becomes the second sub-sampling line A.₂And the flow rate is measured by the flow meter 24 and guided to the first cyclone 21.
[0029]
As a result, the unburned component in the ash can be measured while monitoring the flow rate of the sample gas. This flow rate measurement mode is normally operated for about one hour, and further operation is avoided because it causes the clogging of the flow meter 24 and the like.
[0030]
Next, in the purge mode shown in FIG. 3A, the shutoff valve 25 is closed, and the three-way valves 23a, 23b, and 26 are switched to the main sampling line A side, while the shutoff valve 27 is closed.
[0031]
As a result, the air introduced from the former ejector 20a flows back through the main sampling line A upstream of the ejector 20a (see the arrow in the figure), and the ash adhering to the pipe inner wall of the same line, the components of the three-way valves 23a, 23b, etc. The air introduced from the ejector 20b at the subsequent stage is purged from the main sampling line A and the first sub-sampling line A downstream of the ejector 20a.₁And purge the ash adhering to the inner wall of the pipe and parts of various equipment.
[0032]
In this purge mode, the second sub-sampling line A is switched by switching the three-way valves 23a, 23b, 26 and the shut-off valve 27 in reverse.₂And the third sub-sampling line A_ThreeAshes can also be purged. In addition, it is preferable that this purge mode is automatically set when a system error occurs.
[0033]
Finally, in the sample mode shown in FIG. 3B, the three-way valves 23a and 23b are switched to the main sampling line A side to open the shut-off valve 25, while the three-way valve 26 is connected to the third sub-sampling line A._ThreeAnd the shut-off valve 27 is opened.
[0034]
Thus, the sample gas sucked into the main sampling line A by the first ejectors 20a and 20b is guided to the first cyclone 21, where the ash content in the gas is separated and collected. The separated and collected ash is sucked by the second ejector 22 and then the third sub-sampling line A_ThreeThen, the ash content in the gas is separated again by the second cyclone 28 and collected in the pot 29. The gas components separated by the second cyclone 28 are joined to the main sampling line A through the shut-off valve 27.
[0035]
After operating for about 2 hours in the mode, the ash collected and acquired in the pot 29 is subjected to component analysis by a chemical analyzer or an X-ray analyzer, and unburned components are measured. The measurement result and the measurement result of the LIBS device 4 are compared, and if the measurement value is different, the measurement value of the LIBS device 4 may be calibrated. This can be done while the LIBS device 4 is measuring.
[0036]
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.
[0037]
【The invention's effect】
As described above, according to the first aspect of 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 sample gas sucked by the first ejector A cyclone that separates and collects ash from the gas and a second ejector that sucks the ash separated and collected by the cyclone from the upstream side to the downstream side of the line, and the cyclone and the second ejector; In the ash line, the ash flowing through the line is irradiated with a laser to make its composition component into plasma, the plasma light generated from the plasma is incident on the spectroscope, and the spectral light spectrally separated by the spectroscope Since a measuring device for measuring the unburned portion of the boiler is installed, the unburned portion in the ash in the boiler can be measured in real time.
[0038]
According to the invention of claim 2, since the sampling line upstream of the first ejector is separated into two systems via a valve device, and a flow meter is installed in one of them, the flow rate of the sample gas is monitored. Unburned content in ash can be measured.
[0039]
According to the invention of claim 3, the first ejector is provided in two stages in the sampling line, and a shut-off valve for interrupting the line when necessary is provided in the line between the two ejectors. The ash remaining in the sampling line can be periodically purged by effectively using the introduction air of the first ejector.
[0040]
According to the invention of claim 4, the line is branched from the sampling line downstream of the second ejector via the valve device, and the second cyclone for separating and collecting ash is interposed in the branch line. The measurement value of the LIBS device can be calibrated in real time, and the reliability of the LIBS device can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an unburned ash measurement system showing an embodiment of the present invention.
2A and 2B are operation explanatory views, in which FIG. 2A is a flow path explanatory view in a normal mode, and FIG. 2B is a flow path explanatory view in a flow rate measurement mode.
3A and 3B are operation explanatory views, in which FIG. 3A is a flow path explanatory view in a purge mode, and FIG. 3B is a flow path explanatory view in a sample mode.
FIG. 4 is an explanatory diagram of a LIBS apparatus.
[Explanation of symbols]
1,1a, 1b Piping
2 Measuring field
3 Measurement window
3a Purge air passage
4 LIBS equipment
5 Pulse laser equipment
6 Lens
7 Mirror
8 Lens
9 Spectrometer
10 CCD camera
11 Computer
12 Sync line
20a First (previous) ejector
20b First (second stage) ejector
21 First cyclone
22 Second ejector
23a, 23b Three-way valve
24 Flow meter
25 Shut-off valve
26 Three-way valve
27 Shut-off valve
28 Second Cyclone
29 pots

Claims (4)

A first ejector that sucks sample gas into a sampling line branched from a combustion gas line of a boiler, a cyclone that separates and collects ash from the sample gas sucked by the first ejector, and a cyclone that separates the sample gas A second ejector that sucks the collected ash is sequentially inserted from the upstream side of the line to the downstream side, and a laser is applied to the ash that flows through the line in the line between the cyclone and the second ejector. Irradiate it to make its composition component into plasma, make plasma light generated from the plasma incident on the spectroscope, and install a measuring device that measures the unburned content in ash from the spectral light dispersed by the spectroscope A characteristic measurement system for unburned ash. 2. The unburned ash measurement system according to claim 1, wherein a sampling line upstream of the first ejector is separated into two systems via a valve device, and a flow meter is installed in one of them. 3. The first ejector is provided in two stages in a sampling line, and a shut-off valve is provided in a line between the two ejectors to shut off the line when necessary. An unburned ash measurement system in ash. A line is branched from a sampling line downstream of the second ejector via a valve device, and a second cyclone for separating and collecting ash is disposed in the branch line. 3. An unburned ash measurement system in ash according to 3.

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