Self-cleaning and anti-coking boiler furnace temperature detection system

Abstract

The embodiment of the invention provides a self-cleaning and anti-coking boiler furnace temperature detection system. Comprising a temperature measuring system, a decoking system, a cooling purging anti-coking system and a signal processing control system, the temperature measuring system comprises an infrared temperature measuring optical probe and a transmission optical fiber, the infrared temperature measuring optical probe is connected with the signal processing control system through the transmission optical fiber, and the signal processing control system comprises a signal processing module and a control box. The signal processing module is connected with the control box through a signal transmission line, and the decoking system and the cooling purging anti-coking system are respectively connected with the signal processing control system through an air inlet pipeline, an air outlet pipeline and a cooling purging pipeline. The system has the advantages of simple and reasonable structural design, and can effectively solve the problems of ash deposition, blockage and the like of a measurement light path in hearth temperature measurement.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of coal-fired power generation, and in particular to a self-cleaning and anti-coking boiler furnace temperature detection system. Background Art

[0002] my country's energy structure is characterized by rich coal, poor oil and little gas, which determines that coal will remain the dominant energy utilization for a long time in the future. However, with the vigorous mining of coal, coal resources have been relatively tight in recent years. Compared with other energy generation methods, thermal power generation has the advantages of safety and stability. Thermal power units, especially coal-fired units, can be used to undertake the task of deep peak regulation of the power grid. For coal-fired boilers, furnace temperature is an important parameter to characterize the stability of the coal powder combustion process, and it is also an important basis for controlling and optimizing the boiler coal powder combustion process. The boiler combustion layer temperature can be used as a real-time and accurate response indicator of the furnace combustion situation. By adjusting the combustion layer temperature, the boiler operation stability and unit efficiency can be effectively improved. The measurement of the boiler combustion layer temperature can intuitively characterize the furnace combustion situation and expand the space for the development of the unit control strategy. Apart from coking, thermal deviation and other problems, the amount of nitrogen oxides NOx generated is also closely related to the combustion temperature, especially the thermal NOx is closely related to the furnace temperature. Accurately measuring and controlling the furnace temperature can effectively reduce the generation of NOx, realize the judgment, prediction and diagnosis of the boiler combustion state, and control the reasonable and sufficient combustion of fuel in the furnace. However, the existing detection methods lack monitoring of the combustion process itself. Operators often make combustion adjustments based on indirect and long-delay parameters such as water-cooled wall measurement point temperature and steam temperature, or based on previous operating experience, which seriously affects the safe and efficient operation of the boiler. Realizing real-time and accurate measurement of the furnace temperature is important for the safe and stable operation of thermal power units.

[0003] Usually, the furnace of the boiler is measured by thermocouple and infrared temperature measurement, but these measures have certain disadvantages: on the one hand, due to its contact characteristics, the original temperature field is easily destroyed by the thermocouple, and its life cannot be guaranteed in a high-temperature and harsh working environment. On the other hand, although infrared spectrum temperature measurement is a non-contact temperature measurement method, due to the complex combustion environment of the boiler, the high-temperature flue gas in the furnace is mixed with a large amount of carbon ash and dust. When the furnace is under slight positive pressure, the high-temperature flue gas has the risk of overflowing through the temperature measurement hole. At the same time, impurities such as fly ash in the flue gas are very easy to adhere to the measurement hole of the infrared temperature detection system, which will lead to unsatisfactory temperature measurement results. Summary of the invention

[0004] The embodiment of the present invention aims to solve at least one of the technical problems existing in the prior art, and provides a self-cleaning and anti-coking boiler furnace temperature detection system.

[0005] The embodiment of the present invention provides a self-cleaning and anti-coking boiler furnace temperature detection system, including a temperature measurement system, a coke removal system, a cooling and purge anti-coking system and a signal processing control system;

[0006] The temperature measurement system comprises an infrared temperature measurement optical probe and a transmission optical fiber, and the infrared temperature measurement optical probe is connected to the signal processing control system through the transmission optical fiber;

[0007] The signal processing control system comprises a signal processing module, a control box and a signal transmission line, wherein the signal processing module is connected to the control box via the signal transmission line;

[0008] The decoking system and the cooling and blowing anti-coking system are connected to the signal processing control system through an air intake pipeline, an air exhaust pipeline and a cooling and blowing pipeline respectively.

[0009] In some possible embodiments, the temperature measuring system is located in the middle and rear section of the temperature measuring tube sleeve. According to the distance from the furnace, the temperature measuring tube sleeve is provided with a first insulation disc and a second insulation disc in sequence from near to far along the axial direction.

[0010] In some possible embodiments, a quartz glass sheet is mounted on the first heat-insulating disc, and the quartz glass sheet is arranged concentrically with the first heat-insulating disc;

[0011] An infrared temperature measuring optical probe and a visible light camera are installed on the second heat-insulating disc. The infrared temperature measuring optical probe is arranged concentrically with the second heat-insulating disc, and the visible light camera is arranged at a lower center of the second heat-insulating disc.

[0012] In some possible embodiments, the decoking system includes a pneumatic device, a pneumatic connecting rod and a decoking hammer. The pneumatic device is installed on the outer wall of the furnace and is connected to the decoking hammer through the pneumatic connecting rod.

[0013] In some possible embodiments, the decoking hammer is generally a round tube, is concentrically sleeved on the outside of the temperature measuring tube sleeve, and is installed together with the temperature measuring tube sleeve in the opening of the furnace;

[0014] The temperature measuring tube sleeve is installed and positioned by a temperature measuring tube sleeve bracket fixed on the outer wall surface of the furnace.

[0015] In some possible embodiments, a compressed air main pipe is also provided on the top of the control box;

[0016] The compressed air main pipe comes from an air compressor, and the air inlet pipeline and the air outlet pipeline of the pneumatic device are connected to the compressed air main pipe in the control box.

[0017] In some possible embodiments, the temperature measuring tube sleeve has four holes respectively formed on the upper side, the lower side, the left side and the right side on the outer surface in front of the first insulation disk, and the cooling and purge pipeline is connected to the holes on the temperature measuring tube sleeve.

[0018] In some possible embodiments, a spent gas main pipe is provided on the top of the control box;

[0019] The exhaust gas main pipe comes from the flue gas purified after combustion in the boiler, and the exhaust gas main pipe is respectively connected to the cooling and purge pipelines after being distributed in the control box.

[0020] In some possible embodiments, the front end of the decoking hammer is aligned with the inner wall of the furnace, the front end is set at an oblique angle, and extends a distance straight inward toward the axis of the temperature measuring tube sleeve to wrap the temperature measuring tube sleeve therein.

[0021] In some possible embodiments, the cooling and purge pipeline is connected to the holes on the upper side, lower side, left side and right side of the outer surface of the temperature measuring tube sleeve at a certain inclination angle, and is twisted along the circumference of the temperature measuring tube sleeve to form spiral air intake in four directions.

[0022] The self-cleaning and anti-coking boiler furnace temperature detection system of the embodiment of the present invention has a simple and reasonable system structure design, can effectively solve the problems of dust accumulation and blockage of the temperature measurement optical path in the boiler furnace temperature measurement, improve the accuracy and reliability of temperature measurement, and can prevent coking near the temperature measuring hole to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 The self-cleaning and anti-coking boiler furnace temperature detection system of the present invention;

[0025] Figure 2 It is a structural diagram of the decoking hammer of the present invention;

[0026] Figure 3 This is a cooling and purge pipeline layout diagram of the present invention.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1. Pneumatic device; 2. Temperature measuring tube sleeve; 3. Temperature measuring tube sleeve bracket; 4. Decoking hammer;

[0029] 5. Pneumatic connecting rod; 6. First heat-insulating disc; 7. Quartz glass sheet; 8. Second heat-insulating disc; 9. Visible light camera; 10. Air intake pipeline; 11. Air exhaust pipeline; 12. Cooling and purge pipeline; 13. Infrared temperature measurement optical probe; 14. Control box; 15. Signal processing module; 16. Transmission optical fiber; 17. Signal transmission line; 18. Exhaust gas main pipe; 19. Compressed air main pipe. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. "Including" or "comprising" used in the embodiments of the present invention neither limit the shapes, numbers, steps, actions, operations, components, originals and / or their groups mentioned, nor exclude the appearance or addition of one or more other different shapes, numbers, steps, actions, operations, components, originals and / or their groups, or the addition of these. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number and order of the indicated technical features. Thus, the features defined as "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0032] Unless otherwise specifically stated, the relative arrangement of the components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship, and the techniques, methods and devices known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and devices shown should be considered as part of the authorized specification. In all examples shown and discussed here, any specific other examples may have different values. It should be noted that similar symbols and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0033] In the description of the embodiments of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the embodiments of the present invention, the schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in the embodiments of the present invention and the features of the different embodiments or examples, without contradiction.

[0034] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described here.

[0035] like Figures 1 to 3 As shown, the self-cleaning and anti-coking boiler furnace temperature measurement system of the embodiment of the present invention includes a temperature measurement system, a cooling and purging anti-coking system, a coking removal system and a signal processing control system. The infrared temperature measurement optical probe 13 is fixed on the axis of the temperature measurement tube sleeve 2 through the second insulation disc 8. In front of the second insulation disc 8, the quartz glass sheet 7 is fixed on the axis of the temperature measurement tube sleeve through the first insulation disc 6, and together with the first insulation disc 6, it protects the infrared temperature measurement optical probe 13 and the electronic equipment behind it. The temperature measurement tube sleeve extends into the furnace through the measurement hole reserved on the wall of the boiler furnace. Starting from the second insulation disc 8, the side close to the furnace is the measurement optical path. The length of the measurement optical path is sufficient to pass through the boiler furnace and extend into the furnace. The front end of the measurement optical path is open, which is used to radiate the radiation light in the furnace to the infrared temperature measurement optical probe 13.

[0036] As a preferred embodiment, in addition to the infrared temperature measuring optical probe 13, a visible light camera 9 is arranged on the second heat insulation plate 8, and its axis is parallel to the axis of the temperature measuring tube sleeve 2, and is installed below the infrared temperature measuring optical probe 13. The infrared temperature measuring optical probe 13 is used to receive the radiation amount signal from the furnace, and transmit the radiation amount signal to the signal processing module 15 arranged at the rear of the temperature measuring tube sleeve 2 through the transmission optical fiber 16, and the visible light camera 9 is used to collect the image of the measurement light path, and transmit the obtained image signal to the signal processing module 15 through the transmission optical fiber 16.

[0037] In the above-mentioned embodiment, at the front end of the first heat-insulating disc 6, four holes are respectively opened on the outside of the temperature measuring tube sleeve 2, which are located at the top, bottom, left and right, and are connected to the cooling and purge pipeline 12. The purified boiler tail flue gas is introduced from the exhaust gas main pipe 18, and the four cooling and purge pipelines 12 are respectively at a certain angle with the temperature measuring tube sleeve 2. Then, the flue gas is blown into the furnace after being twisted at a certain angle along the circumference of the temperature measuring tube sleeve 2, so as to realize the cooling of the measuring optical path and the entire system and purge the fly ash in the optical path, thereby ensuring the light transmittance of the measuring optical path. In addition, the purified flue gas from the exhaust gas main pipe 18 can be further cooled according to the requirements of the cooling effect before being sprayed into the inside of the temperature measuring tube sleeve 2, or the wind speed can be increased or decreased through the control box 14 according to the requirements of cleaning, and then sprayed into the temperature measuring tube sleeve. At the same time, due to the special air intake angles of the four cooling and purge pipelines 12, the injected flue gas forms a spiral forward airflow state in the measuring optical path under their mutual cooperation, which further enhances the cleaning performance.

[0038] As a preferred embodiment, the rear section of the temperature measuring tube sleeve uses an insulating shell to protect the signal processing module 15, which further improves the reliability and service life of the internal electronic components. The signal processing module 15 receives the signals from the infrared temperature measuring optical probe 13 and the visible light camera 9 and processes the signals. When the temperature measuring system works normally and measures the furnace temperature, the infrared temperature measuring optical probe processes the radiated light and sends it to the signal processing module 15 through the transmission optical fiber 16. The signal processing module 15 converts the received light signal into an electrical signal. The signal amplifier amplifies the electrical signal and converts the signal into a standard signal. The processed standard signal is sent to the DCS system of the power plant for output and display.

[0039] In the above embodiments, the RGB image of the measurement hole in the measurement optical path is collected by the visible light camera 9, and in the signal processing module 15, the collected RGB image is converted into a grayscale single-channel numerical image according to Gray = R×299 + G×587 + B×114+(500) / 100 to obtain the converted single-channel numerical image. In the foregoing formula: R, G, and B respectively represent the three primary colors; Gray is the converted grayscale value. Then, the processing module 15 selects a threshold for the converted image through an adaptive mean threshold algorithm. By using the template filtering method, a template with a radius larger than the radius of the fire viewing hole is selected to generate a mean filtering mask of the same size as the original image, and the pixel values of the image after binarization are determined by comparing the grayscale of the original image and the mask. After comparing the grayscale values of the original image and the mask, the image is binarized. The pixel points higher than the threshold are identified as bright points, and the pixel points lower than the threshold are set as dark points. Then, the connected component labeling extraction algorithm is used to identify the measurement hole image, and the interference of false bright points caused by the reflection of the flame on the pipe wall to the identification of the blockage state of the measurement hole is excluded. Finally, the signal processing module 15 makes a blockage determination. When the measurement hole is blocked, the number of bright points of the measurement hole obtained after the connected component extraction algorithm is A, and the number of bright points in the image detected at the current moment is B. When the maximum number of bright points B in the detected image is < A, it is determined that the measurement hole has been blocked, and the signal is sent to the control box 14 via the signal transmission line 17. The control box 14 drives the defocusing system to perform defocusing actions according to the blockage signal.

[0040] As a preferred embodiment, after the signal processing module 15 determines the blockage and issues a defocusing instruction, a stream of compressed air is connected to the pneumatic device 1 through the air inlet pipeline 10. The pneumatic device 1 drives the pneumatic connecting rod 5 to drive the defocusing hammer 4 to move forward. The special bevel in front of the defocusing hammer 4 and the wrapping design of the temperature measuring tube sleeve 2 take the coking block away from the temperature measuring hole and effectively remove it. While the defocusing hammer 4 is moving forward, the exhaust pipeline 11 is connected to drive the reset of the defocusing hammer 4, and this process is repeated until the entire defocusing process is completed.

[0041] In the above embodiment, after the decoking is completed, the purified and cooled flue gas is passed into the cooling and purging pipeline 12 and enters the temperature measuring tube sleeve 2, and is purged forward in a spiral to cool the front section of the temperature measuring system, and the particles dropped into the measuring optical path during the decoking stage are removed by the flow of airflow. At the same time, the cleanliness of the decoking hammer 4 is maintained to a certain extent, so that it is not easy to be contaminated by coking particles, and secondary pollution to the measuring hole is avoided. In addition, when the signal processing module 15 does not determine that coking occurs, the control box 14 can activate the cooling and purging pipeline 14, and periodically spray the purified flue gas to suppress the reducing atmosphere at the temperature measuring hole of the furnace. For boilers, the reducing gas distribution at the wall of the furnace is relatively large. This periodic injection of flue gas can not only purge the fly ash in the temperature measuring tube sleeve, but also suppress the occurrence of coking in terms of preventing the ash melting point from decreasing.

[0042] As a preferred embodiment, in addition to the coke hammer 4 being arranged in the temperature measuring tube sleeve 2, sealing measures are taken between the contact surfaces of the two to prevent the smoke in the furnace from overflowing. This design avoids the obstruction of the light path of the visible light camera 9 and the infrared temperature measuring optical probe 13 caused by the built-in coke cleaning device, thereby realizing real-time monitoring of the measuring hole of the temperature measuring device.

[0043] The technical effects of the embodiments of the present invention are summarized as follows:

[0044] (1) Aiming at the problem of clogging and dust accumulation in the temperature measurement optical path of the ordinary infrared temperature measurement system, a new infrared temperature measurement system structure and corresponding system are designed to reduce the problems of opening blockage and dust accumulation in the pipeline during the infrared temperature measurement process.

[0045] (2) A method of using purified tail flue gas to purge the temperature measurement system is proposed. Since the treated flue gas itself is exhausted gas, it can suppress the generation of reducing atmosphere at the opening, and its energy is lower than the heat radiated from the furnace. Therefore, using purified flue gas to replace other gases can better ensure the smoothness of the optical path of the temperature measurement system and the normal temperature level, suppress the occurrence of coking near the temperature measurement holes, and thus ensure the efficient and safe operation of the infrared temperature measurement system and even the unit.

[0046] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A self-cleaning and anti-coking boiler furnace temperature detection system, characterized in that: It includes temperature measurement system, coke cleaning system, cooling and purge anti-coking system and signal processing control system; The temperature measurement system comprises an infrared temperature measurement optical probe and a transmission optical fiber, and the infrared temperature measurement optical probe is connected to the signal processing control system through the transmission optical fiber; The signal processing control system comprises a signal processing module, a control box and a signal transmission line, wherein the signal processing module is connected to the control box via the signal transmission line; The decoking system and the cooling and blowing anti-coking system are connected to the signal processing control system through an air intake pipeline, an air exhaust pipeline and a cooling and blowing pipeline respectively.

2. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 1, characterized in that: The temperature measuring system is located in the middle and rear section of the temperature measuring tube sleeve. According to the distance from the furnace, the temperature measuring tube sleeve is provided with a first heat insulating disc and a second heat insulating disc in sequence from near to far along the axial direction.

3. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 2, characterized in that: A quartz glass sheet is mounted on the first heat-insulating disc, and the quartz glass sheet is arranged concentrically with the first heat-insulating disc; An infrared temperature measuring optical probe and a visible light camera are installed on the second heat-insulating disc. The infrared temperature measuring optical probe is arranged concentrically with the second heat-insulating disc, and the visible light camera is arranged at a lower center of the second heat-insulating disc.

4. A self-cleaning and anti-coking boiler furnace temperature detection system according to any one of claims 1 to 3, characterized in that: The decoking system comprises a pneumatic device, a pneumatic connecting rod and a decoking hammer. The pneumatic device is mounted on the outer wall of the furnace and is connected to the decoking hammer through the pneumatic connecting rod.

5. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 4, characterized in that: The decoking hammer is generally in the shape of a round tube, and is concentrically sleeved on the outside of the temperature measuring tube sleeve, and is installed together with the temperature measuring tube sleeve in the opening of the furnace; The temperature measuring tube sleeve is installed and positioned by a temperature measuring tube sleeve bracket fixed on the outer wall surface of the furnace.

6. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 4, characterized in that: A compressed air main pipe is also provided on the top of the control box; The compressed air main pipe comes from an air compressor, and the air inlet pipeline and the air outlet pipeline of the pneumatic device are connected to the compressed air main pipe in the control box.

7. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 2, characterized in that: The temperature measuring tube sleeve is provided with four holes on the outer surface in front of the first heat-insulating disc, namely, the upper side, the lower side, the left side and the right side. The cooling and purge pipeline is connected with the holes on the temperature measuring tube sleeve.

8. A self-cleaning and anti-coking boiler furnace temperature detection system according to any one of claims 1 to 3, characterized in that: An exhausted gas main pipe is arranged on the top of the control box; The exhaust gas main pipe comes from the flue gas purified after combustion in the boiler, and the exhaust gas main pipe is respectively connected to the cooling and purge pipelines after being distributed in the control box.

9. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 5, characterized in that: The front end of the decoking hammer is aligned with the inner wall of the furnace, the front end is set at an oblique angle, and extends a distance straight inward toward the axis of the temperature measuring tube sleeve, wrapping the temperature measuring tube sleeve therein.

10. A self-cleaning and anti-coking boiler furnace temperature detection system according to claim 6, characterized in that: The cooling and purge pipeline is connected to the holes on the upper side, lower side, left side and right side of the outer surface of the temperature measuring tube sleeve at a certain inclination angle, and is twisted along the circumference of the temperature measuring tube sleeve to form spiral air intake in four directions.

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