JPH0961090A - Cleaning device of tube body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide boiler equipment enabling improvement of an effect of removing-cleaning ashes and others. SOLUTION: The title device is equipped with at least two oscillating bodies 3A and 3B, a frequency controller 8 regulating an oscillation frequency of at least one of the oscillating bodies 3A and 3B and a sound pressure sensor 7 detecting a sound pressure level of a space wherefrom combustion ashes and the like are to be removed, and the oscillation frequency of the oscillating body 3B is regulated according to an output of the sound pressure sensor 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a boiler, a combustion furnace,
The cleaning equipment for pipes installed in incinerators, independent superheaters, independent economizers, various heat exchangers, various plants or various industrial equipment, especially dust particles that have adhered to and accumulated on the wall surface of the pipes The present invention relates to a pipe body cleaning device that removes dusts from a pipe wall by vibrating a surrounding gas body with sound waves.

[0002]

2. Description of the Related Art FIG. 8 is a diagram showing a schematic configuration of a boiler device. As shown in the figure, a rear heat transfer front wall 102 and a rear heat transfer side wall 1 installed at the rear of the furnace 101.
03, the rear heat transfer partition 104, and the rear heat transfer rear wall 105, the horizontal superheater 106, the horizontal evaporator 107, the economizer 108, etc. are provided at predetermined intervals in the flue. It is installed along the flow direction of combustion gas.

[0003] Each of the horizontal superheater 106 and the horizontal evaporator 10
7. In the economizer 108, a large number of heat transfer tubes 109 extend horizontally at narrow intervals, so that heat exchange between the high-temperature combustion gas G flowing in the flue and the fluid flowing in the heat transfer tubes 109 occurs. Done.

Particularly in a pulverized coal burning boiler, the combustion gas G contains a large amount of combustion ash and the like, which adheres to and accumulates on the wall surface of the heat transfer tube 109. When the combustion ash adheres to and accumulates on the wall surface of the heat transfer tube in this manner, the heat transfer performance of the heat transfer tube 109 deteriorates. Therefore, a soot blower (not shown) is activated periodically or as necessary to transfer the combustion ash to the heat transfer tube 10.
The method of removing from the wall surface of 9 is taken.

However, as shown in the figure, the steam S ejected from the soot blower flows along the rows of the heat transfer tubes 109 from the top to the bottom or from the bottom to the top like the flow of the combustion gas. A portion of the combustion ash 110 that is not removed remains between the lower heat transfer tubes 109.

FIG. 9 shows this state, in which the combustion gas G
When a passage between the heat transfer tubes 109 is generated, a Karman vortex 111 is generated in the wake of the heat transfer tube 109, and the flow velocity decreases,
A bridge of combustion ash 110 remains between the heat transfer tubes 109. Since the combustion ash having a relatively large particle size flows together with the combustion gas G, the adhesion and deposition on the heat transfer tube 109 is small, but recently, the combustion ash having a small particle size 1 is used for denitration combustion.
10 increases, and accordingly adheres to the heat transfer tube 109,
The amount of deposition is increasing.

Conventionally, in order to remove dust in the heat exchanger,
For example, a method as disclosed in Japanese Patent Publication No. 62-27375 is proposed. FIG. 10 is a view for explaining this dust removal method, in which a heat transfer tube group 122 is horizontally arranged in a casing 121, and a sound generator (siren) 123 is installed at the same height as the heat transfer tube group 122. The granular material 12 is installed on the upstream side of the casing 121.
A charging chute 125 for charging 4 is provided.

When the acoustic generator (siren) 123 generates acoustic vibration to remove the combustion ash adhering to and depositing on the heat transfer tube group 122, it has a particle size considerably larger than that of the combustion ash. Granular material 12 such as sand
4 from the chute 125 to add to the cleaning surface,
This is a method of promoting the falling of the combustion ash from the heat transfer tube 122 by substantially increasing the area subjected to vibration.

In addition to this, a sonic cleaning method as disclosed in Japanese Patent Publication No. 55-500355 is also known. This method arranges at least two sound wave generators at a predetermined distance and controls a phase difference of a pressure wave emitted from another sound wave generator in relation to a pressure wave emitted from one sound wave generator. This is a method of generating an amplified pressure wave and concentrating the pressure wave on the surface to be cleaned.

[0010]

The method of removing dust in the heat exchanger shown in FIG. 10 requires a mechanism for separating used particulate matter from the dust and collecting it, and the charged particulate matter is heat-exchanged. Since it may be accumulated in the recesses or gaps inside the container, it is necessary to remove it, which makes the device larger, complicates the work after dust removal, and raises the cost.

On the other hand, in the latter sonic cleaning method, it is possible to concentrate the amplified pressure wave on the surface to be cleaned and perform local cleaning, but for example, a large number in a wide space such as the flue of a boiler device. If heat ash is installed and combustion ash is accumulated on the heat transfer tube group of each heat exchanger, scan the surface to be cleaned by changing the direction of the amplified pressure wave. Therefore, the scanning time is long and the work efficiency is low.

Further, the scanning of the pressure wave is performed by controlling the phase difference between two or more pressure waves. However, since the distance between the sound wave generator and the surface to be cleaned is sequentially changed depending on the scanning position, the position of the pressure wave is changed. It has problems such as very difficult phase difference control.

An object of the present invention is to effectively solve the above-mentioned drawbacks of the prior art, and to provide a pipe cleaning device having good cleaning efficiency without making the device too large.

[0014]

To achieve the above object, the present invention provides at least two sound wave generators, a frequency controller for adjusting the sound wave frequency of at least one of the sound wave generators, and a tubular body (for example, The sound wave of the sound wave generator is provided with a removal detection unit such as a sound pressure sensor that detects a removal state of dust (eg, combustion ash) attached to and accumulated on the heat transfer tube. It is characterized in that the frequency is finely adjusted.

[0015]

When sound waves (pressure waves) of different frequencies f1 and f2 are transmitted from the two sound wave generators (oscillators) to the space, the sound pressure level generally fluctuates at the difference frequency of | f1-f2 |. . In particular, when the difference between f1 and f2 is small (for example, within 10% of f1 or f2), the fluctuation of the sound pressure level at the difference frequency becomes remarkable.

Therefore, for example, if the generated sound wave frequency f1 of one of the two sound wave generators is fixed and the generated sound wave frequency f2 of the other sound wave generator is changed in the vicinity of f1, the difference frequency can be easily obtained. It is possible to generate fluctuations in the sound pressure level at. In particular, in a box-type substantially closed space such as a boiler device, the sound pressure level at the difference frequency is more likely to change than in an open space.
Due to this change in the sound pressure level, it is possible to effectively remove the dust that has adhered to and accumulated on the pipe body in a short time.

Further, the conventionally proposed granular material charging chute, the circulation system for reusing the granular material, the mechanism for separating the granular material from the dust that has fallen, etc. are not required, so that the apparatus becomes large in size, High costs are eliminated.

Further, since the frequency is only finely adjusted, the control is simpler than the conventional method of giving directivity to the sound wave by the phase control to locally remove the dusts, and moreover, the overall control is possible. Since dusts are removed in this way, the efficiency is high.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an ash removing device of a boiler device according to a first embodiment of the present invention.

The ash removing device is an electric oscillator (a speaker is used in the present embodiment, which is installed near the wall surface of the rear heat transfer tube portion 1 (heat transfer tube groups 2A and 2B), but has an oscillation of another configuration. Body can also be used.) 3A, 3B and oscillator 3
Frequency-variable oscillators 5A and 5B that send signals to A and 3B
, Power amplifiers 4A and 4B with variable amplification factors for power-amplifying the signals of the transmitters 5A and 5B, and near the wall surface (heat transfer tube group 2
Basically, it is composed of a sound pressure sensor 7 installed in C) and a frequency controller 8 that outputs a control signal for finely adjusting the frequency of the oscillator 5B based on the output signal of the sound pressure sensor 7. There is.

In the present embodiment, the oscillator 3, the power amplifier 4 and the oscillator 5 constitute an electric sound wave generator.

Sound wave frequencies f1 and f from the oscillators 3A and 3B
The sound wave 2 is transmitted to the space portion of the rear heat transfer tube portion 1. At this time, the sound pressure level of the rear heat transfer tube portion 1 is detected by the sound pressure sensor 7, and the ratio m (of the maximum sound pressure level (Imax) and the minimum sound pressure level (Imin) of the difference frequency component of | f1-f2 | m
= Imax / Imin), and then the sound wave frequency f2 of the oscillator 3B is transmitted via the frequency controller 8 to the oscillator 5B.
Change to the sound wave frequency f3 by the sound pressure sensor 7
The sound pressure level is detected by and the ratio m'of the maximum sound pressure level and the minimum sound pressure level of the difference frequency component is calculated.

By repeating such an operation, the sound wave of the oscillator 3B is increased so that the ratio between the maximum sound pressure level and the minimum sound pressure level increases, that is, the value of m is 2 or more, preferably 10 or more. Always control the frequency. In addition,
If the value of m is less than 2, the effect of removing dusts from the pipe due to the change in sound pressure is not sufficient, so the value of m should be kept at 2 or more. Further, it has been experimentally confirmed that the signal waveforms of the oscillators 5A and 5B are more likely to generate a difference frequency component when a sine wave is used than when a rectangular wave or a triangular wave is used.

FIG. 2 shows an example in which the sound wave frequency is controlled by the above method to increase the ratio m between the maximum sound pressure level and the minimum sound pressure level of the difference frequency component. In the case of this example, the frequencies f1 and f2 are deviated by 2 Hz, the ratio m between the maximum sound pressure level (Imax) and the minimum sound pressure level (Imin) of the difference frequency component is about 7, which is periodic in the space. Swelling of sound waves is occurring.

Usually, in the rear heat transfer tube section 1 of a boiler device using pulverized coal as a fuel, combustion ash often adheres to and accumulates in the gaps between the heat transfer tubes vertically adjacent to each other, and the removal of these combustion ash by sound waves proceeds. Since the ratio of the maximum sound pressure level and the minimum sound pressure level changes with the above, in order to always maintain a high combustion ash removal effect, pay attention to the sound pressure level of the difference frequency component as described above, and A frequency control method for tracking is particularly effective.

In this embodiment, an electric sound wave generator is used,
Since all fine adjustments of the sound wave frequency can be performed electrically, the device is simplified and the difference frequency component is easily generated. Also, because it is an electric type, the waveform distortion of the sound wave generated by the oscillator can be made smaller than other methods (in other words, it is close to a single frequency sound wave), and similarly a difference frequency component is generated. There is an effect peculiar to the embodiment that it can be easily performed.

In the above description, only the fine adjustment of the frequency is described, but at the same time, by finely adjusting the amplification factor α of the power amplifiers 4A and 4B (either one) based on the detection signal of the sound pressure sensor 7, It is possible to further increase the ratio between the maximum sound pressure level and the minimum sound pressure level of the difference frequency component.

FIG. 3 is a schematic configuration diagram of an ash removing device of a boiler device according to a second embodiment of the present invention. The difference from the first embodiment is that a laser light source 9 is used instead of the sound pressure sensor 7.
And an optical sensor 10 for measuring the transmitted light intensity of the laser light.
Is the point that is installed. In addition, the portion showing the arrangement state of the laser light source 9 and the optical sensor 10 in the same figure shows the aa cross section of the rear heat transfer tube portion 1 shown above it.

The rear heat transfer tube portion 1 is constituted by the oscillators 3A and 3B.
The sound waves of frequencies f1 and f2 are transmitted to. Combustion ash is scattered in the space due to the ash removal (scattering) effect of this sound wave,
In this embodiment, the scattered state (scattered concentration) of the combustion ash is detected by the transmitted light intensity of the laser light. The laser light source 9 is driven so as to have a constant output, and when the scattered concentration of combustion ash is small (that is, the effect of removing combustion ash is small), the laser light is hardly scattered by the combustion ash and the laser light source 9 And reaches the optical sensor 10 installed at a position opposite to, and the output of the optical sensor 10 is large.

On the other hand, when the scattered concentration of the combustion ash is high (that is, the effect of removing the combustion ash is great), the laser light is scattered by the combustion ash, so that the laser light hardly reaches the optical sensor 10 and the light is emitted. The output of the sensor 10 is drastically reduced.

FIG. 4 shows the relationship between the transmitted light intensity (optical sensor output) of the laser light and the sound wave frequency relating to the scattered concentration of combustion ash in two cases. Both cases are 100 ~
The transmitted light intensity (optical sensor output) of the laser light is reduced at around 110 Hz, which is in good agreement with the frequency at which the ash removal effect is large observed by the CCD camera which is another combustion ash removal detection means.

As described above, since the output of the optical sensor 10 is related to the effect of removing combustion ash, the output is guided to the frequency controller 8 as shown in FIG. Then, the frequency of the oscillator 5B is finely adjusted to change the sound wave frequency from the oscillator 3B.

Depending on the arrangement positions of the laser light source 9 and the optical sensor 10, a change in sound pressure level of the difference frequency component and a time delay until ash scattering due to removal of combustion ash are expected,
It is necessary to consider that the output of the frequency controller 8 has a certain delay time with respect to the input from the optical sensor 10.

FIG. 5 shows the sound wave frequency of one of the electric sound wave generators while detecting the transmitted light intensity of the laser light centering on the frequency of 100 to 110 Hz which is an example of the frequency where the ash removal effect is large. It is a figure which shows the time change of the optical sensor output at the time of fine adjustment.

As is clear from this figure, it is understood that the decrease in the output of the optical sensor (that is, the large effect of scattering ash) occurs relatively continuously. When the sound wave frequency is not finely adjusted, a continuous decrease in the optical sensor output is not seen, as shown in FIG.

If a sheet-shaped beam generator such as a rod lens is installed at the outlet of the light source as the laser light source, the amount of ash scattered on the surface can be detected, and a more accurate combustion ash removal effect can be obtained. Can be grasped and the sound wave frequency can be adjusted more effectively.

In this embodiment, since the sound wave frequency of the sound wave generator is controlled by using the signal directly related to the effect of removing the combustion ash, a more reliable removing effect can be obtained.

Further, in this embodiment, since the laser light is used as the light source, the dust removal state is maintained even if the dust removal target space is large (for example, height 30 m, width 20 m, depth 10 m). Can be reliably detected.

FIG. 6 is a diagram for explaining the third embodiment of the present invention. In the case of this embodiment, the detection signals of both the sound pressure sensor 7 installed inside the furnace and the optical sensor 10 installed outside the furnace are input to the frequency controller 8.

FIG. 7 is a diagram for explaining the fourth embodiment of the present invention. In the case of this embodiment, the inspection plate 12 is arranged in the furnace so as to face the CCD camera 11, and the CCD camera 1
1 can be scanned in the width direction of the inspection plate 12. The output signal of the CCD camera 11 is input to the image processing device 13, the monitor television 14 is connected to the image processing device 13, and the output signal of the image processing device 13 is input to the frequency controller 8 based on it. The oscillators 9a and 9b are drive-controlled.

Line charts such as bar codes, characters, symbols, patterns, etc. are drawn on the inspection plate 12 in a stepwise manner such that the number, thickness, and shading are changed. It is intended to optically detect the falling state of combustion ash by utilizing the fact that the visible range such as a diagram is inversely proportional, and the relationship between the area where the diagram can be detected and the amount of combustion ash fall has been obtained in advance. There is.

During cleaning, the CCD camera 11 monitors the range (area) in which the diagram of the inspection plate 12 can be detected through the space where the combustion ash is falling, and the signal is monitored by the image processing device 12.
The processed image data is input to the television 13 to monitor the falling state of the combustion ash.

The frequency controller 8 stores in advance the relationship between the amount of combustion ash dropped and the output of the image processing device 13, and the maximum amount of combustion ash dropped based on the output from the image processing device 13. As described above, the oscillation frequencies of the oscillators 5A and 5B are sequentially and automatically changed.

The sound wave generators may be opposed to each other in the width direction of the furnace or may be opposed to each other in the depth direction of the furnace orthogonal thereto.

In the above embodiment, the case where the sound wave generator is installed inside the furnace has been described, but the sound wave generator can be installed outside the furnace. Thus a sound wave generator,
By installing a combustion ash dropout detection device (for example, a monitoring camera), a laser light source, an optical sensor, etc. outside the furnace, dust is removed during operation of the device or equipment to be cleaned (boiler device in this embodiment). Therefore, it is not necessary to stop the operation of the device or equipment for cleaning. Further, by starting the cleaning device during operation, it is possible to prevent dust from adhering to the pipe body.

When the pipe cleaning device of the present invention is applied to a boiler device, the set frequency of the sound wave generator is 30 to 150H.
The range of z is appropriate, and the | f1-f2 | difference frequency is appropriately within 10% of the above-mentioned frequency f1 or f2.

As shown in the above embodiment, the difference frequency component of the sound wave is effectively generated when the oscillator is installed in the space formed between the tube groups.

In the above embodiment, the removal of the combustion ash that adheres to and deposits on the heat transfer tubes of the boiler device has been described, but the present invention is not limited to this, and is installed in various plants or various industrial equipment, for example. It is also applicable to cleaning existing pipes.

[0049]

When sound waves (pressure waves) having different frequencies f1 and f2 are transmitted from the two sound wave generators (oscillators) to the space, the sound pressure level generally fluctuates at the difference frequency of | f1-f2 |. appear. Especially when the difference between f1 and f2 is small (for example, within 10% of the above-mentioned frequency f1 or f2),
The fluctuation of the sound pressure level at the difference frequency becomes remarkable.

Therefore, for example, if the sound wave frequency f1 generated by one sound wave generator of the two sound wave generators is fixed and the sound wave frequency f2 generated by the other sound wave generator is changed in the vicinity of f1, the difference frequency can be easily obtained. It is possible to generate fluctuations in the sound pressure level at. In particular, in a box-type substantially closed space such as a boiler device, the sound pressure level at the difference frequency is more likely to change than in an open space.
Due to this change in the sound pressure level, it is possible to effectively remove the dust that has adhered to and accumulated on the pipe body in a short time.

Further, the conventionally proposed granular material charging chute, the circulation system for reusing the granular material, the mechanism for separating the granular material from the dust that has fallen, etc. are not required, and therefore the apparatus is increased in size, High costs are eliminated.

Further, since the frequency is only finely adjusted, the control is simpler than the method conventionally proposed in which the directivity is imparted to the sound wave by the phase control to locally remove the dusts, and the overall control is performed. It has features such as high efficiency because dust is removed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an ash removing device of a boiler device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a difference frequency component and an output of a sound pressure sensor in the ash removing device.

FIG. 3 is a schematic configuration diagram of an ash removing apparatus according to a second embodiment of the present invention.

FIG. 4 is a characteristic diagram showing the relationship between the frequency of the ash removing device and the output of the optical sensor.

FIG. 5 is a characteristic diagram showing an example of detection of the amount of ash scattered by an optical sensor.

FIG. 6 is a schematic configuration diagram of an ash removing apparatus according to a third embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of an ash removing apparatus according to a third embodiment of the present invention.

FIG. 8 is a schematic configuration diagram of a boiler device.

FIG. 9 is an explanatory diagram showing a state in which combustion ash adheres to and accumulates on a heat transfer tube in the boiler device.

FIG. 10 is a schematic configuration diagram of a conventionally proposed cleaning device.

[Explanation of symbols]

 1 Rear heat transfer tube section 2A, 2B, 2C Heat transfer tube group 3A, 3B Sound wave generator 4A, 4B Power amplifier 5A, 5B Oscillator 7 Sound pressure sensor 8 Frequency controller 9 Laser light source 10 Optical sensor 11 CCD camera 12 Inspection plate 13 Image Processor 14 Monitor TV

Claims (10)

[Claims] 1. At least two sound wave generators, a frequency controller that adjusts the sound wave frequency of at least one of the sound wave generators, and a removal detection unit that detects the state of removal of dusts adhering to and accumulating on the pipe body. And a structure for adjusting the sound wave frequency of the sound wave generator based on the output of the removal detecting means. 2. The pipe body cleaning apparatus according to claim 1, wherein the removal detecting unit is a sound pressure sensor that detects a sound pressure in a space surrounding the pipe body. 3. The pipe body cleaning device according to claim 1, wherein the removal detecting unit is a scattering state detection sensor that detects a scattering state of the dusts. 4. The pipe cleaning apparatus according to claim 3, wherein the scattered state detection sensor is composed of a laser light source and an optical sensor for detecting the amount of light from the laser light source. 5. The pipe cleaning device according to claim 1, wherein the sound wave generator is an electric sound wave generator having an oscillator. 6. The pipe cleaning apparatus according to claim 5, wherein the signal waveform output from the oscillator is a sine wave. 7. The tubular body cleaning device according to claim 5, wherein the electric sound wave generator includes a power amplifier having an adjustable amplification factor. 8. The maximum sound pressure level (Imax) of the difference frequency component | f1-f2 | between the sound wave frequency f1 of the first sound wave generator and the sound wave frequency f2 of the second sound wave generator according to claim 1. And the minimum sound pressure level (Imin) ratio m
A pipe cleaning apparatus, wherein (m = Imax / Imin) is set to 2 or more. 9. The pipe body cleaning device according to claim 1, wherein the pipe body is installed in a substantially sealed space. 10. The pipe cleaning apparatus according to claim 9, wherein the pipe is a heat transfer pipe and the dust is combustion ash.