JPH0678543B2 - Coal gasifier slag tap monitoring method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is used in a device for melting ash in a coal gasification furnace to slag it and discharging it to the outside of the system, measuring the slag discharge amount, and monitoring the slag flowing state. A method and apparatus.

[Conventional technology]

Coal is a useful energy source with abundant reserves, but its treatment method is difficult because it contains ash (alumina, silica, etc.) and harmful metals of more than 10% and its application range has been narrowed.
However, in a spouted bed coal gasifier, etc., coal can be processed at high temperatures, ash can be melted, and harmful metals can be taken out of the system as slag that is difficult to elute. Promising use in the field. Therefore, the stable downflow technology of slag is an indispensable technology for coal gasifiers and the like. The measurement of the amount of slag flowing down is being studied for the purpose of this stable flow down.

In JP-A-57-67689, the amount of slag accumulated in the lower part of the furnace is detected by measuring the differential pressure between the top and bottom of the slag tap, and the slag flow rate is controlled by the burner combustion amount in the lower part of the furnace and the amount of gas extracted from the lower part of the furnace. did.

In Japanese Unexamined Patent Publication No. 58-49789, the opening area of the slag tap is detected from the captured image brightness distribution, and the oxidizer supply rate of the gasification furnace is changed to control the slag flow rate so that the opening area is appropriate.

[Problems to be solved by the invention]

The above conventional technique has a problem that the state of the slag tap cannot be accurately grasped.

In Japanese Patent Laid-Open No. 58-49789, the opening area of the slag tap was detected and the slag downflow state was measured.However, since the opening area is detected only from the brightness distribution, the slag adheres near the slag tap and the opening area changes. It was not possible to distinguish between the case where the opening area was changed and the case where the opening area was changed due to a trouble such as the breakage of the slag tap. For this reason, it is difficult to operate the furnace because it is not possible to accurately grasp the slug flow-down situation, especially in an unstable state at the time of load fluctuation and start-stop.

The object of the present invention is to destroy slag taps, stop slag flow down,
It is an object of the present invention to provide a method and apparatus for detecting conditions such as slag tap blockage before they occur and accurately monitoring them.

[Means for solving problems]

The present invention can accurately calculate the open area of the slag tap and the slag adhesion amount by image-processing the temperature distribution obtained by imaging the slag tap of the coal gasification furnace with a radiation thermometer, and the slag flowing state can be calculated from these. And a method and apparatus for diagnosing and monitoring.

Slag is dropped from the slag tap at the bottom of the furnace.
The temperatures of the slag tap openings, the slag that is flowing down, and the slag that has adhered and solidified to the slag tap are significantly different.
The temperature of the slag tap opening is the temperature of the flame. The temperature of the flowing slag is at least above the melting point, but much lower than the temperature of the flame. In addition, the temperature of the slag that has adhered and solidified is below the melting point.

Therefore, when an image of the vicinity of the slag tap is taken with a radiation thermometer, the slag tap opening, the slag flowing down, and the slag adhered and solidified to the slag tap are shown at different temperatures. By subjecting this to image processing, it is possible to detect the area of the slag that is flowing down, the slag tap opening, and the area of the slag that has adhered and solidified to the slag tap.

[Action]

The diagnostic results shown below can be provided by detecting and evaluating the areas of the slag flowing down, the slag tap openings, and the areas of the slag adhered and solidified to the slag tap, respectively.

(1) If there is no open hole and no molten slag is present, it is in a closed state.

(2) There is an open hole, but when there is no molten slag, the flow is stopped.

(3) When the solidified slag exists in the initial slag tap opening portion without the opening portion, there is a risk of blockage.

(4) When the molten slag fills the initial slag tap opening portion without the opening portion, the load is excessive.

(5) If the molten slag is outside the initial slag tap opening, there is a risk of slag tap breakage.

As described above, by obtaining the temperature distribution of the slag tap 34 in detail, it is possible to diagnose the slag flow-down state and prevent the risk of blockage or destruction from occurring.

Example 1 FIG. 1 is a block diagram of the coal gasification furnace used in this example.

The whole consists of a coal gasifier and a slag flow rate measurement and monitoring device applied to the coal gasifier. The coal supply amount control device 21 and the gasifying agent supply amount control device 22 are connected to a coal burner 33. Inside the gasification furnace 31, there is a gasification chamber 32,
The lower part of the gasification chamber 32 is connected to a slag cooling chamber 36 via a slag tap 34. The slag cooling chamber 36 is connected by a viewing window 35. Camera 40 of slag flow rate measurement and monitoring device
Is installed. The camera 40 is connected to the image conversion device 23, the image processing device 24, and the monitoring device 25.

Next, the operation will be described. 80w for coal 11 less than 200mesh
Pulverize to t% and make pulverized coal. The coal 11 is supplied to the coal burner 33 of the gasification furnace 31 whose supply amount is measured and controlled by the coal supply amount control device 21. The gasifying agent 12 such as air, oxygen and water vapor is supplied to the coal burner 33 of the gasification furnace 31 together with the coal 11 after the supply amount is measured and controlled by the gasifying agent supply amount control device 22. Coal supplied to coal burner 33
11 and the gasifying agent 12 are fed from the tip of the coal burner 33 to the gasification chamber 32.
Is sprayed on. In the gasification chamber 32, the coal 11 and the gasifying agent 12 react to generate high temperature heat. This heat reacts with the carbon contained in the coal 11 and the oxygen contained in the gasifying agent 12 to form a combustible product gas 14 containing carbon dioxide and carbon monoxide as main components.
It occurs when is generated. Generated gas 14 is gasifier outlet 39
More discharged.

After this high temperature, the temperature inside the gasification chamber 32 rises to about 1600 ° C. About 10% of the ash contained in coal 11 is alumina,
It contains silica as its main component and melts at high temperatures around 1600 ° C. When the ash is melted, it becomes a liquid slag 13. The slag 13 adheres to the wall surface of the gasification chamber 32 and flows into the slag tap 34 by gravity. Below the slag tap 34 is a slag cooling chamber 36, in which water is stored. Slug 13 is 1600
Although it is a high temperature of about 0 ° C, it enters the slag cooling chamber 36 at a low temperature with the slag tap 34 as a boundary, and drops into the accumulated water. 100 even if the high temperature slag 13 at 1600 ℃ is high
When dropped in water at about ℃, it is cooled rapidly and crushed finely due to its thermal shock. This shredded slag
13 is discharged from the slag extraction port 38 to the outside of the gasification furnace 31.

The fiber 50 is installed at a position where the slag tap 34 on which this slag drops can be imaged, and the slag tap 40 is set with the radiation thermometer 40.
Obtain the temperature distribution of 34.

The fiber 50 is an image fiber by stacking tens of thousands of optical fibers 50 made of a material such as quartz glass. Since it is exposed to high temperatures, it should be cooled appropriately using a water cooling tube or the like.

An infrared radiation thermometer or the like is used as the radiation thermometer 40.
An infrared radiation thermometer detects the intensity of infrared light emitted depending on the temperature of a substance and converts it into temperature. Therefore, when this is used, the fiber 50 made of a material that transmits infrared light (silicon fluoride, etc.) is used.

The temperature distribution obtained by the apparatus of Example 1 is shown in FIG.

FIG. 2 shows a sectional view of the slag tap 34 of the gasification furnace 31 and its temperature distribution.

The coal ash slag 13 generated at high temperature in the gasification chamber 32 is the gasification chamber.
It adheres to the inner wall of 32. Since the inner wall of the gasification chamber 32 has a low temperature, the slag 13 solidifies to form a solidified slag layer 61. A molten slag layer 62 is formed on the surface of the solidified slag layer 61. The thickness of the solidified slag layer 61 and the molten slag layer 62 is the amount of coal 11 supplied,
It depends on the supply amount of the gasifying agent 12 and the temperature of the gasification chamber 32. The solidified slag layer 61 and the molten slag layer 62 flow to the upper surface of the slag tap 34 and are discharged from the slag tap 34. The result of measuring the temperature of the lower surface of the slag tap 34 with a radiation thermometer is shown as the temperature distribution in the lower part of FIG.

Since a high-temperature flame in the gasification chamber 32 is observed from the opening of the slag tap 34, the temperature is extremely high. This portion is measured as a portion having an inner diameter smaller than d ₁ . The molten slag layer 62 is at least at a temperature at which the slag is molten, and therefore is a portion having a melting point or higher in the temperature distribution. This portion is measured as a portion having an inner diameter larger than d _{1 and} smaller than d ₂ . The solidified slag layer 61 is a portion in which the slag is not melted, and therefore is a portion having a melting point or lower in the temperature distribution. This part is measured as a part having an inner diameter larger than d _{2 and} smaller than d ₃ . Assuming that the inner diameter of the slag 13 when it is not flowing down is d ₃ , the areas of the solidified slag layer 61, the molten slag layer 62, and the open hole portions of the slag tap are shown as follows.

Suragutatsupu opening portion area = A molten slag layer 62 cross sectional area = B-A solidified slag layer 61 cross sectional area = C-B ^{_{where, A = πd 1 2/4}} , B = πd 2 2/4, C = πd 3 2 /Four.

From these, the diagnostic results as shown in Table 1 are obtained.

(1) There is no open hole portion and no molten slag layer 62 exists.
All slag taps 34 are filled with solidified slag 61.
Therefore, it represents a completely closed state.

(2) Shows a state in which it is not flowing down. However, since the solidified slag 61 is attached to the holes of the slag tap 34, it is necessary to be careful when the slag 13 starts to flow down.

(3) Shows a state where the material is not flowing down. Nothing is attached to the slag tap 34 hole, which is in good condition. But the gasification chamber
When the temperature of 32 is low, it means that the slag 13 is not produced.

(4) The molten slag layer 62 and the solidified slag layer 61 are provided in the slag tap 34 hole, although there is no open portion. Therefore, it is not flowing down, but it is in a dangerous state that may cause blockage.

(5) Slag 13 is flowing down stably, but slag tap
Since the solidified slag 61 is attached to the 34 holes, the solidified slag 61
There is a need to be careful not to keep confidential.

(6) Slag 13 is flowing down stably, and slag tap 34
Nothing is attached to the holes, indicating a good condition.

(7) There is no open hole, but the slag tap 34 hole is filled with the molten slag layer 62. More slag 13 than the capacity of the slag tap 34 is flowing out, and there is a possibility of destroying the slag tap 34.

(8) The molten slag layer 62 is located outside the holes in the slag tap 34. Therefore, it indicates that the slag tap 34 has been destroyed.

As described above, by obtaining the temperature distribution of the slag tap 34 in detail, it is possible to diagnose the slag flow-down state and prevent the risk of blockage or destruction from occurring.

[Embodiment 2] FIG. 3 is a configuration diagram of a gasification furnace used in this embodiment. The difference between the second embodiment and the first embodiment is that in the first embodiment, the infrared radiation thermometer 40 is used for measuring the temperature distribution near the slag tap 34.
However, the second embodiment uses a two-wavelength thermometer 41 instead of the infrared radiation thermometer 40. The two-wavelength thermometer 41 calculates the temperature by imaging one screen separately with different wavelengths and comparing the brightness at each wavelength, and the accuracy is higher than that of the infrared thermometer 41. Are better. As the wavelength can be selected as
A material such as quartz glass, which allows good transmission of visible wavelengths, is used.

The effect peculiar to this embodiment is that the two-wavelength thermometer 41 is used, so that the measurement accuracy of the temperature distribution can be improved, and the fiber made of a material that does not transmit infrared light can also be used.

[Third Embodiment] A third embodiment will be described with reference to FIG. The difference between the third embodiment and the first embodiment is that the first embodiment only monitors and issues an alarm. However, in the third embodiment, a control device 27 is newly provided and a monitoring device is provided.
The point is to control the coal supply amount and the gasifying agent supply amount according to the analysis results of 25. The current values of the coal supply amount and the gasifying agent supply amount shown in Table 1 determined by the monitoring device 25 are the control device 27.
Sent to. The control device 27 controls the coal supply amount control device 21 and the gasifying agent supply amount control device 22 in order to make the appropriate coal supply amount and gasification agent supply amount according to the signal sent.

The effect peculiar to the present embodiment is that the control device 27 constantly controls the supply amount of coal and the supply amount of gasifying agent, so that the slag 13 can be dripped more stably.

[Fourth Embodiment] In the case where the image processing technology is further improved in the future, not only the temperature distribution of the slag tap 34 but also the slag tap in the first embodiment will be described.
It is possible to analyze 34 surface states.

Example 4 is shown in FIG. The basic configuration is similar to that of the first embodiment. The difference from the first embodiment is that in addition to the image processing device 25, a surface state analysis device 28 is installed, and a physical property information output device is provided.
This is the point where 29 is newly provided. The surface condition taken by the surface condition analyzer 28 is sent to the physical property information output device 29. The physical property information output device 29 receives these signals and calculates and outputs the physical properties of the solidified slag layer 61 and the molten slag layer 62.

The effect peculiar to the present embodiment is that it is possible to detect the fluctuation of the ash physical properties of the supplied coal, which can calculate and output the physical properties of the solidified slag layer 61 and the molten slag layer 62, and the cause of clogging.

〔The invention's effect〕

According to the present invention, it is possible to measure the dropping frequency of molten slag, the size of the droplet, and the slag flow amount, and to grasp the slag flow state and the furnace state, so that stable furnace operation can be performed.

[Brief description of drawings]

FIG. 1 is a system diagram of the first embodiment, FIG. 2 is a sectional view of the vicinity of the slag tap of the first embodiment, a temperature distribution, and FIG. 3 is a second embodiment.
4 is a system diagram of the third embodiment, and FIG. 5 is a system diagram of the fourth embodiment. 11 …… Coal, 12 …… Gasifying agent, 13 …… Slag, 14 …… Production gas, 21 …… Coal supply amount control device, 22 …… Oxidant supply amount control device, 23 …… Image recording device, 24 ...... Image processing device, 25 …… Monitoring device, 27 …… Control device, 28 …… High-speed image processing device, 31 …… Gasification furnace, 32 …… Gasification chamber, 33 …… Coal burner, 34 …… Slag tap , 35 …… Peep window, 36 ……
Slag cooling chamber, 38 ... Generated gas outlet, 39 ... Slag outlet, 40 ... Infrared radiation thermometer, 41 ... Two-wavelength radiation thermometer,
50 …… Fiber.

Claims (2)

[Claims] 1. In a slag flow method of a coal gasifier in which coal ash is melted at a high temperature and discharged as slag, the temperature distribution near the slag tap where the slag flows down is measured, and the slag is inside the slag tap hole. The portion below the pour point of the fixed slag, the region up to the portion where a further rapid temperature rise occurs below the pour point of the slag is the molten slag, the inside of the molten slag is determined as the open hole portion, the open area of the slag tap A method for monitoring a coal gasifier slag tap, which calculates the occupied area of solidified slag and molten slag and diagnoses the slag dropping state in the slag tap. 2. A temperature distribution measuring device for measuring a temperature distribution of a slag tap in a slag flow-down device of a furnace which melts coal ash at high temperature and discharges it as slag out of the system, and processes the temperature distribution obtained by the device. Slag tap, solidified slag,
An apparatus for monitoring a coal gasifier slag tap comprising an image processing apparatus for detecting an occupied area of molten slag, a slag tap based on a result detected by the image processing apparatus, and a monitoring apparatus for diagnosing a slag dropping state.