JPH0621429B2 - Recovery Boiler Bed Top Temperature Measuring Device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus used for operation control of a recovery boiler in a pulp production process, and particularly to a top temperature of a char bed formed in the recovery boiler. Relates to a device for measuring.

[Conventional technology]

Generally, in a pulp production process, a recovery boiler is used which burns black liquor discharged as waste liquid from the chip cooking process to generate steam used for power generation and the like, and recovers a raw material of chemicals for chip cooking. In this recovery boiler, when the black liquor is injected into the furnace by the black liquor injection mechanism, the black liquor is suspended and dried to form a char bed at the bottom of the furnace, and steam is generated by burning the char bed. The drug raw material is recovered by the generation reaction and the reduction reaction generated at that time.

In recent years, energy saving, labor saving, and the like have been demanded in the pulp production process as well, but for this purpose, it is an issue to stabilize the operation of the recovery boiler and improve the thermal efficiency. In order to realize these, in the past, in order to control the level of the top of the char bed to exist within a certain range, it has sensitivity in the short wavelength band (about 0.5 μm).
The radiation thermometer of the table was fixed at the upper and lower limits of the range, and it was detected whether or not the top was within the range, and in the case of no, predetermined control was performed.

[Problems to be solved by the invention]

However, in the conventional device, two radiation thermometers monitor a specific level and determine whether the level is above or below this level to obtain an index of the charbed level control. It is difficult to accurately and reproducibly measure the level of the top of the char bed whose shape and level change accordingly, because the temperature difference between the upper and lower radiation thermometers is small. Furthermore, it was not considered to measure the top temperature and use it as an index for controlling the combustion of the char bed.

Moreover, since the radiation thermometer of the conventional device was used that has sensitivity in the short wavelength band, it was affected by the radiation of the gas body, and the temperature of the char bed itself could not be measured, It was in the form of measuring the temperature of the gas body around it, and it was impossible to measure the temperature of the top of the charbed itself.

In this way, the top temperature, which is usually the maximum temperature of the char bed and is important as a representative index for grasping the combustion state of the entire char bed, could not be measured, so it was not possible to accurately grasp the combustion state in the furnace. However, it was difficult to stabilize the boiler operation and improve the efficiency.

Therefore, the present invention provides a char bed top temperature measuring device for a recovery boiler, which can measure the top temperature of a char bed easily and with high accuracy and can stabilize the operation of the recovery boiler and improve efficiency. The purpose is to do.

[Means for solving problems]

The present invention, in order to solve the above problems and achieve the object,
A radiation thermometer, which has sensitivity in the wavelength band that is not easily affected by the radiation of the gas inside the recovery boiler, is installed on the furnace wall of the recovery boiler, and the viewpoint of this radiation thermometer is scanned vertically with respect to the char bed by the scanning mechanism. The top temperature measuring means measures the top temperature of the char bed based on the radiant energy intensity distribution along the scanning line of the radiation thermometer scanned by the scanning mechanism.

[Action]

According to the present invention, the charbed surface temperature along the scanning line of the radiation thermometer is accurately detected by taking such means, and the charbed top temperature is measured based on the charbed surface temperature.

〔Example〕

FIG. 1 is a system diagram showing the configuration of an embodiment of the present invention.
In the figure, 10 is a recovery boiler, and this boiler 1
A char bed 11 is formed at the furnace bottom of No. 0 by floating and drying the black liquor sprayed by a black liquor spraying mechanism (not shown). Reference numeral 12 denotes a radiation thermometer, which converts the radiation energy detector 13 provided on the outer wall surface of the recovery boiler 10 and the radiation energy intensity detected by this radiation energy detector 13 into temperature data. Temperature signal transmitter 14 that transmits every moment
It is composed of and. The radiant energy detector 13 detects the radiant energy within the viewpoint, and in particular, in order to distinguish between the radiant energy due to the charbed and the radiant energy due to the gas inside the boiler,
It is set to have sensitivity in a wavelength band that is less likely to be affected by the radiation of the gas body.

FIG. 2 is a diagram showing the relationship between the measured wavelength (horizontal axis) and the extinction coefficient (vertical axis) as the radiant energy intensity in the in-reactor gas body A and the char bed B. As is clear from the figure, since the extinction coefficient of the in-furnace gas body A becomes smaller than that of the char bed B in the vicinity of the measurement wavelength of 3.7 μm, detection with this far infrared measurement wavelength of 3.8 μm If a vessel is used, detection can be performed in a state in which it is unlikely to be affected by the in-furnace gas body A. Although the extinction coefficient of the in-furnace gas body A becomes smaller than that of the char bed B even at the measurement wavelength of 5 μm or more, the detector for the measurement wavelength of 5 μm or more requires special specifications and becomes expensive, which is not preferable. Appropriate.

Further, in FIG. 1, the radiant energy detector 13
Can be scanned in the vertical direction with respect to the char bed 11 by the scanning mechanism 15, and the scanning angle of the viewpoint of the radiant energy detector 13 is detected by the position signal transmitter 16 and is momentarily as angle data. It has been sent. As the scanning mechanism 15, means for scanning only the viewpoint of the radiant energy detector 13 with a fan-shaped body, or means for providing a rail in the vertical direction to scan the radiant energy detector 13 itself along the rail, and the like. Conceivable.

On the other hand, the temperature data transmitted from the temperature signal generator 14 and the angle data transmitted from the position signal generator 16 are given to the data processing unit 17. Then, the data processing unit 17 obtains temperature data corresponding to the scanning angle of the viewpoint of the radiant energy detector 13, and the temperature data corresponding to this scanning angle is sequentially stored in the storage unit 18 and smoothed as necessary. After the conversion processing is performed, it is displayed on the display 19 such as a CRT. Reference numeral 20 denotes a top temperature measuring section of the char bed 11, which measures the top temperature of the char bed 11 based on the data stored in the storage section 18 and outputs it as a char bed top temperature signal S. Has become.

FIG. 3 is a block diagram showing a specific configuration of the top temperature measuring section 20. In the figure, the temperature data corresponding to the scanning angle of the viewpoint of the radiant energy detector 13 stored in the storage unit 18 is subjected to a predetermined smoothing process by the smoothing circuit 21, and then the peak temperature detector 22. , The edge sample temperature detector 23, and the temperature change rate detector 24, and the detectors 22 to 24 measure the top temperature of the char bed 11. Then, the selector 25 selects and outputs any one of the top temperatures of the charbed tops measured by the detectors 22 to 24.

The peak temperature detector 22 sequentially compares the temperature data stored in the storage unit 18 and outputs the maximum temperature data as the temperature of the top of the char bed. Normally, the surface temperature of the char bed 11 becomes higher as it goes up. Therefore, the radiant energy detector 1
When 3 is scanned in the vertical direction with respect to the char bed 11,
As shown in FIG. 4, the detected temperature along one scanning line gradually rises, and when the viewpoint of the radiant energy detector 13 deviates from the char bed 11, the wavelength band of this radiant energy detector 13 radiates the gas in the furnace. Since the wavelength band is set so as not to be easily affected by, the detected temperature drops sharply. Therefore, it is generally considered that the peak temperature T1 of the temperature data stored in the storage unit 18 is the top temperature of the char bed 11.

However, if the combustion state locally becomes violent in the abdomen or the like of the char bed 11, this portion becomes the highest temperature. At this time, the temperature data stored in the storage unit 18 is the fifth data.
As shown in the figure, the peak temperature T1 is char bed 1
It does not have a top temperature of 1. In such a case, the edge sample temperature detector 23 detects the edge sample temperature and outputs the edge sample temperature as the top temperature of the char bed 11. That is, the peak temperature T1 is held from the temperature data stored in the storage unit 18,
A predetermined comparison α (40
<Α <100)% is multiplied to obtain the slice level temperature T2, and the temperature at an angle lower than the angle corresponding to the slice level temperature T2 by a predetermined angle β °, that is, the edge sample temperature T3 is called the charbed. Detect as the top temperature.

On the other hand, as described above, since the radiant energy detector 13 has sensitivity in the wavelength band that is not easily affected by the radiation of the gas in the furnace, when the viewpoint is scanned in the vertical direction with respect to the char bed 11, Charbed 1 is the detected temperature
When it deviates from 1, it drops sharply. Therefore, in the temperature change rate detector 24, the change rate of the temperature data stored in the storage unit 18 is calculated, and the higher temperature when the negative temperature change rate becomes the maximum is taken as the char bed top temperature. Output.

In the present apparatus configured as described above, the radiant energy detector 13 is attached to the char bed 11 by the scanning mechanism 15.
Scan in the vertical direction. Then, the temperature data with respect to the scanning angle of the viewpoint of the radiant energy detector 13 is stored in the storage unit 18 and displayed on the display unit 19. The operator looks at the temperature data displayed on the display unit 19,
Peak temperature detector 22, edge sample temperature detector 2
3. It is judged by which of the temperature change rate detectors 24 the temperature detected by the detector is appropriate as the temperature of the top of the char bed, and the selector 25 selects the temperature. That is, when the temperature data displayed on the display 19 is such that it gradually rises as the scanning angle rises and sharply falls at a predetermined angle as shown in FIG. 4, the peak temperature detector The temperature detected at 22 is output as the temperature of the top of the char bed.

On the other hand, when the temperature data has a bump-shaped bulge as shown in FIG. 5, the temperature detected by the edge sample temperature detector 23 or the temperature change rate detector 24 is used as the temperature of the top of the char bed. Output. In this case, if the temperature data suddenly drops when the viewpoint of the radiant energy detector 13 deviates from the char bed 11, the temperature detected by the edge sample temperature detector 23 will be almost the same as the temperature of the top of the char bed. However, if the falling slope of the temperature data is gentle, the temperature detected by the edge sample temperature detector 23 is likely to have an error. Therefore, the temperature detected by the temperature change rate detector 24 is set to the char bed. It is desirable to set the top temperature.

Thus, according to this embodiment, the peak temperature detector is obtained by vertically scanning the radiant energy detector 13 having a sensitivity in the wavelength band that is not easily influenced by the radiation of the gas inside the furnace with respect to the char bed 11. The temperature is detected by the edge sample temperature detector 22, the edge sample temperature detector 23, and the temperature change rate detector 24. Therefore, by selecting the optimum detected temperature among the temperatures detected by these, the char bed top can be easily and accurately measured. The part temperature can be measured.
Further, the temperature of the top of the char bed can be controlled by adjusting the flow rate of the combustion air supplied into the recovery boiler 10 using the temperature signal S of the top of the char bed output from the present device, This enables stable and highly efficient operation of the recovery boiler.

The present invention is not limited to the above embodiment.
For example, in the above-described embodiment, one of the temperatures detected by the peak temperature detector 22, the edge sample temperature detector 23, and the temperature change rate detector 24 is checked by the operator looking at the temperature data displayed on the display unit 19. Although the case where one is selected and output as the top temperature of the char bed is shown, a predetermined temperature data pattern is stored in the memory in advance, and this temperature data pattern and the temperature data stored in the storage unit 18 are stored. The output of any one of the detectors 22 to 24 may be determined by comparison and the selected output of the selection unit 25 may be automatically switched. Further, in the above-mentioned embodiment, the case where any one of the detection outputs of the peak temperature detector 22, the edge sample temperature detector 23, and the temperature change rate detector 24 is selected as the char bed top temperature detecting means is shown. These detectors 22
The temperature may be detected by at least one of the detectors -24, and this temperature may be output as the temperature of the top of the char bed. Further, in the temperature change rate detector 24, the case where the temperature change rate is sequentially calculated according to the scanning direction of the viewpoint of the temperature energy detector 13 is shown, but the temperature change rate is sequentially calculated from the opposite direction to the scanning direction. However, the higher temperature when the positive rate of temperature change becomes maximum may be output as the temperature of the top of the char bed. Further, in the above embodiment, the case where the top temperature is measured based on the angle data of the radiation thermometer 12 has been described, but in this case, not only the angle data but also data indicating the position of the radiation thermometer 12 may be used. Of course, various modifications can be made without departing from the scope of the present invention.

〔The invention's effect〕

As described above in detail, the present invention provides a radiation thermometer having a sensitivity in a wavelength band that is not easily influenced by the radiation of the gas body in the recovery boiler on the furnace wall of the recovery boiler, and the viewpoint of the radiation thermometer is determined by the scanning mechanism. The char bed is scanned in the vertical direction, and the top temperature measuring means measures the top temperature of the char bed based on the radiant energy intensity distribution along the scan line of the radiation thermometer scanned by this scanning mechanism. It was done.

Therefore, according to the present invention, the char bed surface temperature along the scanning line of the radiation thermometer is accurately detected, and the char bed top temperature is measured based on this char bed surface temperature. It is possible to provide a char bed top temperature measuring device for a recovery boiler, which can measure the temperature of the recovery boiler easily and with high accuracy, and can stabilize the operation of the recovery boiler and improve efficiency.

[Brief description of drawings]

1 to 5 are views showing an embodiment of the present invention,
FIG. 1 is a system diagram showing the configuration, FIG. 2 is a diagram showing the relationship between the measurement wavelength and the radiant energy intensity in the furnace gas body and the char bed, and FIG. 3 is the configuration of the char bed top temperature detection unit. Block diagrams, FIGS. 4 and 5 are diagrams showing examples of temperature data stored in the storage unit. 10 ... Recovery boiler, 11 ... Charbed, 12 ...
Radiation thermometer, 13 ... Radiant energy detector, 15 ...
Scanning mechanism, 17 ... Data processing unit, 18 ... Storage unit, 1
9 ... Display unit, 20 ... Char bed top temperature measuring unit, 22 ... Peak temperature detector, 23 ... Edge sample temperature detector, 24 ... Temperature change rate detector.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yohei Shioshikoshi, 1-1, Jujo-cho, Yatsushiro-shi, Kumamoto Prefecture, Joujo Paper Co., Ltd. Yatsushiro Mill (72) Inventor, Takashi Tanihara 4-chome, Shimaya, Osaka, Osaka No. 35 Kawasaki Heavy Industries, Ltd. Osaka Plant (72) Inventor Yasumitsu Kurosaki 1-1, Kawasaki-cho, Akashi City, Hyogo Prefecture Kawasaki Heavy Industries Ltd., Akashi Plant (72) Inventor Toshiyuki Ibed 1-1 Kawasaki-cho, Akashi-shi, Hyogo Prefecture Issue Kawasaki Heavy Industries, Ltd. Akashi Plant (72) Inventor Shiro Nakabayashi 1-1 Kawasaki-cho, Akashi-shi, Hyogo Prefecture Kawasaki Heavy Industries Ltd. Akashi Plant (72) Inventor Kazuyuki Iizuka 1-1-1, Shibaura, Minato-ku, Tokyo No. TOSHIBA Head Office Office (72) Inventor Ryuichi Kuwata No. 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Factory (72) Inventor A. Kumaki No. 1 in Toshiba Fuchu factory, Fuchu, Tokyo (72) Inventor, Hideo Chikisa No. 1 in Toshiba Fuchu city, Tokyo, Fuchu, Tokyo (56) References JP-A-62-29803 (JP) , A) JP-A-62-29829 (JP, A) JP-A-61-49903 (JP, A) Actually developed JP-A-60-148851 (JP, U)

Claims (5)

[Claims] 1. A recovery boiler for combusting black liquor discharged from a chip digesting step to generate steam and recovering a raw material for chemicals for chip digestion, in a boiler gas body provided on a furnace wall of the recovery boiler. A radiation thermometer sensitive to the wavelength band that is not easily affected by radiation, a scanning mechanism that scans the viewpoint of this radiation thermometer in the vertical direction with respect to the char bed, and a scanning line of the radiation thermometer that is scanned by this scanning mechanism. A top temperature measuring means for measuring the top temperature of the char bed based on the radiant energy intensity distribution along the top of the char bed. 2. The apex temperature measuring means detects a peak temperature of the char bed based on the radiant energy intensity distribution, and measures the peak temperature as a char bed apex temperature. A char bed top temperature measuring device for a recovery boiler according to claim (1). 3. The apex temperature measuring means detects a peak temperature of the char bed based on the radiant energy intensity distribution and multiplies the peak temperature by a preset ratio to obtain a slice level temperature. The temperature at a position lower than the measurement position of the radiation thermometer corresponding to the slice level temperature by a predetermined position is measured as the temperature of the top of the char bed, and the temperature is measured as the apex temperature of the char bed. Charging bed top temperature measuring device for the recovery boiler described. 4. The apex temperature measuring means detects the temperature change rate of the char bed based on the radiant energy intensity distribution, and measures the radiation thermometer corresponding to the temperature at which the temperature change rate becomes maximum. The temperature at a position lower by a predetermined position than the position is measured as the temperature of the top of the char bed, and the temperature measuring device for the top of the char bed of the recovery boiler according to claim (1). 5. The radiation thermometer has a wavelength band of 3.8 μm which is not easily affected by radiation of the gas inside the boiler.
A char bed top temperature measuring device for a recovery boiler according to claim (1), characterized in that a wavelength band in the vicinity is used.