A boiler combustion pressure pulsation control system with triple redundancy function

Abstract

The present invention discloses a boiler combustion pressure pulsation control system with triple redundancy function, which includes an optical fiber pressure pulsation sensor, a boiler, a light source and an optical signal conditioning module, an optical fiber bundle, a data acquisition and analyzer, a combustion pressure pulsation monitoring and processing center, and a feedback control unit; the inlet of the optical fiber pressure pulsation sensor is communicated with the pressure measuring port of the boiler, the output end of the optical fiber pressure pulsation sensor is connected to the input end of the light source and the optical signal conditioning module through the optical fiber bundle, the output end of the light source and the optical signal conditioning module is connected to the input end of the data acquisition and analyzer, the output end of the data acquisition and analyzer is connected to the input end of the combustion pressure pulsation monitoring and processing center, and the output end of the combustion pressure pulsation monitoring and processing center is connected to the control ends of the fuel quantity control valve and the air quantity control valve of the boiler through the feedback control unit. This system can effectively avoid accidents such as accidental shutdown caused by false alarm information triggered when the sensor fails.

Description

Technical Field

[0001] The present invention relates to a boiler combustion pressure pulsation control system, and more particularly to a boiler combustion pressure pulsation control system with triple redundancy function. Background Art

[0002] The combustion system of a power plant boiler is an important link in thermal power production. The combustion state of fuel in the boiler is easily affected by many operating and control conditions such as coal quality characteristics, changes in load conditions, and adjustment of air distribution. When combustion is unstable, thermoacoustic coupling oscillation will occur in the furnace, generating large combustion pressure pulsations, which will seriously affect the safe and stable operation of the boiler when severe. China's energy policy requires power plant boilers to burn inferior or low-grade coal as much as possible, which further increases the possibility and harm of failures in the boiler combustion system.

[0003] To ensure the safe and stable operation of the boiler and reduce the occurrence of failures in the boiler combustion system, it is necessary to monitor and analyze the state parameters of combustion equipment by using advanced combustion monitoring and diagnosis technical means, judge whether the combustion system is in the best combustion state, and provide corresponding countermeasure plans for operators, so as to achieve the purpose of reducing accident shutdown losses, improving combustion efficiency, and reducing pollutant emissions.

[0004] In view of the importance of combustion stability state to the safe and stable operation of the boiler, adopting a combustion monitoring and diagnosis technology with triple redundancy function to monitor and diagnose the combustion state in the boiler furnace in real time is beneficial to improving the operation safety and reliability of the boiler. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned disadvantages of the prior art and provide a boiler combustion pressure pulsation control system with triple redundancy function, which can improve the operation safety of the boiler and reduce the probability of failures in the boiler combustion system.

[0006] To achieve the above purpose, the boiler combustion pressure pulsation control system with triple redundancy function described in the present invention includes an optical fiber pressure pulsation sensor, a boiler, a light source and an optical signal conditioning module, an optical fiber bundle, a data acquisition and analyzer, a combustion pressure pulsation monitoring and processing center, and a feedback control unit;

[0007] The inlet of the optical fiber pressure pulsation sensor is connected to the pressure measuring port of the boiler, the output end of the optical fiber pressure pulsation sensor is connected to the input end of the light source and the optical signal conditioning module through the optical fiber bundle, the output end of the light source and the optical signal conditioning module is connected to the input end of the data acquisition and analyzer, the output end of the data acquisition and analyzer is connected to the input end of the combustion pressure pulsation monitoring and processing center, and the output end of the combustion pressure pulsation monitoring and processing center is connected to the control ends of the fuel quantity control valve and the air quantity control valve of the boiler through the feedback control unit.

[0008] The fiber optic pressure pulsation sensor includes a first fiber optic probe, a second fiber optic probe, a third fiber optic probe, a sensor upper cover, an upper heat insulation layer, a sensor lower cover, a lower heat insulation layer, and a permeable membrane;

[0009] An upper heat insulation layer is provided between the bottom of the sensor upper cover and the top of the sensor lower cover, a lower heat insulation layer is provided at the bottom of the sensor lower cover, and a pressure measurement chamber is provided at the bottom of the sensor lower cover. Among them, a first metal sensing diaphragm, a second metal sensing diaphragm, and a third metal sensing diaphragm are provided in the pressure measurement chamber. Among them, a first vacuum heat insulation chamber is formed between the first metal sensing diaphragm and one side wall of the pressure measurement chamber, a second vacuum heat insulation chamber is formed between the second metal sensing diaphragm and the top of the pressure measurement chamber, and a third vacuum heat insulation chamber is formed between the third metal sensing diaphragm and the other side wall of the pressure measurement chamber. The first fiber optic probe passes through the sensor upper cover and the upper heat insulation layer and then passes through the side wall of the sensor lower cover and is inserted into the first vacuum heat insulation chamber and is directly opposite to the first metal sensing diaphragm. The second fiber optic probe passes through the sensor upper cover and is inserted into the second vacuum heat insulation chamber and is directly opposite to the second metal sensing diaphragm. The third fiber optic probe passes through the sensor upper cover and the upper heat insulation layer and then passes through the side wall of the sensor lower cover and is inserted into the third vacuum heat insulation chamber and is directly opposite to the third metal sensing diaphragm;

[0010] The first fiber optic probe, the second fiber optic probe, and the third fiber optic probe are connected to an optical signal conditioning module through an optical fiber bundle and a light source. A permeable membrane is provided at the bottom opening of the pressure measurement chamber. Among them, a plurality of air guide holes are provided on the permeable membrane, and the pressure measurement chamber is communicated with the pressure measurement port of the boiler through the air guide holes.

[0011] It further includes a mounting nut; the mounting nut is sleeved on the periphery of the sensor upper cover, the upper heat insulation layer, and the sensor lower cover.

[0012] The axes of the sensor upper cover, the upper heat insulation layer, the sensor lower cover, and the lower heat insulation layer coincide.

[0013] The sensor upper cover, the upper heat insulation layer, the sensor lower cover, and the lower heat insulation layer are connected by diffusion welding.

[0014] The outer diameter of the sensor upper cover is 12 mm, the length is 15 mm, the outer diameter of the upper heat insulation layer is 12 mm, the thickness is 2 mm, the side length of the central square hole on the upper heat insulation layer is 2 mm, the outer diameter of the upper heat insulation layer is 12 mm, the length of the pressure measurement chamber is 6 mm, the width is 2 mm, the height is 2 mm, the outer diameter of the lower heat insulation layer is 12 mm, the thickness is 5 mm, and the side length of the central square hole on the lower heat insulation layer is 2 mm; the diameters of the first fiber optic probe, the second fiber optic probe, and the third fiber optic probe are all 1 mm; the side lengths of the first metal sensing diaphragm, the second metal sensing diaphragm, and the third metal sensing diaphragm are all 3 mm, and the thickness is 1 mm; the aperture of the air guide hole is 0.5 mm.

[0015] The present invention has the following beneficial effects:

[0016] When the boiler combustion pressure pulsation control system with triple redundancy function of the present invention is in specific operation, based on the fiber optic pressure pulsation sensor with triple redundancy function, 3 metal sensing diaphragms and 3 fiber optic probes are arranged at the head of the sensor. After the measured working medium enters the pressure measuring cavity, it acts on the 3 metal sensing diaphragms simultaneously, and then the deformations of the metal sensing diaphragms are measured simultaneously by the 3 fiber optic probes, and the pressure of the measured working medium is obtained in real time, realizing that only one pressure measuring installation hole can obtain 3 pressure measurement signals at the same time. The 3 pressure pulsation signals can be mutually verified, improving the reliability and accuracy of the monitoring and diagnosis of the boiler combustion state, thereby enhancing the operation safety of the boiler and reducing the probability of failure of the boiler combustion system. Brief Description of the Drawings

[0017] Figure 1 is a schematic structural diagram of the present invention;

[0018] Figure 2 is a schematic structural diagram of the fiber optic pressure pulsation sensor in the present invention.

[0019] Among them, 1 is the fiber optic pressure pulsation sensor, 2 is the light source and optical signal conditioning module, 3 is the data acquisition and analysis device, 4 is the combustion pressure pulsation monitoring and processing center, 5 is the feedback control unit, 6 is the fiber optic bundle, 7 is the boiler, 8 is the first fiber optic probe, 9 is the second fiber optic probe, 10 is the third fiber optic probe, 11 is the sensor upper cover, 12 is the upper heat insulation layer, 13 is the sensor lower cover, 14 is the lower heat insulation layer, 15 is the third vacuum heat insulation cavity, 16 is the third metal sensing diaphragm, 17 is the first vacuum heat insulation cavity, 18 is the pressure measuring cavity, 19 is the permeable membrane, 20 is the first metal sensing diaphragm, 21 is the second metal sensing diaphragm, 22 is the second vacuum heat insulation cavity, 23 is the mounting nut. Detailed Embodiment

[0020] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments, and are not intended to limit the scope of the present invention disclosure. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts disclosed in the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0021] A schematic structural diagram of an exemplary embodiment of the present invention is shown in the accompanying drawings. These drawings are not drawn to scale, and for the purpose of clear illustration, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary. In practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0022] Referring to Figure 1 , the boiler combustion pressure pulsation control system with triple redundancy function according to the present invention includes an optical fiber pressure pulsation sensor 1, a boiler 7, a light source and optical signal conditioning module 2, an optical fiber bundle 6, a data acquisition and analyzer 3, a combustion pressure pulsation monitoring and processing center 4, and a feedback control unit 5;

[0023] The inlet of the optical fiber pressure pulsation sensor 1 is communicated with the pressure measuring port of the boiler 7. The output end of the optical fiber pressure pulsation sensor 1 is connected to the input end of the light source and optical signal conditioning module 2 through the optical fiber bundle 6. The output end of the light source and optical signal conditioning module 2 is connected to the input end of the data acquisition and analyzer 3. The output end of the data acquisition and analyzer 3 is connected to the input end of the combustion pressure pulsation monitoring and processing center 4. The output end of the combustion pressure pulsation monitoring and processing center 4 is connected to the control ends of the fuel quantity control valve and the air quantity control valve of the boiler 7 through the feedback control unit 5.

[0024] Referring to Figure 2 , the optical fiber pressure pulsation sensor 1 includes a first optical fiber probe 8, a second optical fiber probe 9, a third optical fiber probe 10, a sensor upper cover 11, an upper heat insulation layer 12, a sensor lower cover 13, a lower heat insulation layer 14, a permeable membrane 19, and a mounting nut 23;

[0025] An upper insulation layer 12 is provided between the bottom of the sensor upper cover 11 and the top of the sensor lower cover 13, a lower insulation layer 14 is provided at the bottom of the sensor lower cover 13, and a pressure measuring cavity 18 is provided at the bottom of the sensor lower cover 13, wherein a first metal sensing diaphragm 20, a second metal sensing diaphragm 21 and a third metal sensing diaphragm 16 are provided in the pressure measuring cavity 18, wherein a first vacuum insulation cavity 17 is formed between the first metal sensing diaphragm 20 and a side wall of the pressure measuring cavity 18, a second vacuum insulation cavity 22 is formed between the second metal sensing diaphragm 21 and the top of the pressure measuring cavity 18, and a third metal sensing diaphragm 16 and a first metal sensing diaphragm 20 are provided in the pressure measuring cavity 18. A third vacuum insulation chamber 15 is formed between the other side walls of the pressure measuring chamber 18. The first optical fiber probe 8 passes through the sensor upper cover 11 and the upper insulation layer 12, and then passes through the side wall of the sensor lower cover 13 to be inserted into the first vacuum insulation chamber 17, and faces the first metal sensing diaphragm 20. The second optical fiber probe 9 passes through the sensor upper cover 11 and then is inserted into the second vacuum insulation chamber 22, and faces the second metal sensing diaphragm 21. The third optical fiber probe 10 passes through the sensor upper cover 11 and the upper insulation layer 12, and then passes through the side wall of the sensor lower cover 13 to be inserted into the third vacuum insulation chamber 15, and faces the third metal sensing diaphragm 16.

[0026] The first optical fiber probe 8, the second optical fiber probe 9 and the third optical fiber probe 10 are connected to the optical signal conditioning module 2 via the optical fiber bundle 6 and the light source. A permeable membrane 19 is provided at the bottom opening of the pressure measuring chamber 18, wherein the permeable membrane 19 is provided with a plurality of air ducting holes, and the pressure measuring chamber 18 is connected to the pressure measuring port of the boiler 7 through the air ducting holes.

[0027] The outer diameter of the sensor cover 11 is 12mm and the length is 15mm. The outer diameter of the upper insulation layer 12 is 12mm and the thickness is 2mm. The side length of the central square hole on the upper insulation layer 12 is 2mm. The outer diameter of the upper insulation layer 12 is 12mm. The length of the pressure measuring cavity 18 is 6mm, the width is 2mm, and the height is 2mm. The outer diameter of the lower insulation layer 14 is 12mm and the thickness is 5mm. The side length of the central square hole on the lower insulation layer 14 is 2mm; the diameters of the first optical fiber probe 8, the second optical fiber probe 9 and the third optical fiber probe 10 are all 1mm; the side lengths of the first metal sensing diaphragm 20, the second metal sensing diaphragm 21 and the third metal sensing diaphragm 16 are all 3mm and 1mm thick; the aperture of the air duct is 0.5mm.

[0028] The axes of the sensor upper cover 11, the upper insulation layer 12, the sensor lower cover 13 and the lower insulation layer 14 coincide with each other, and the sensor upper cover 11, the upper insulation layer 12, the sensor lower cover 13 and the lower insulation layer 14 are connected by diffusion welding. The mounting nut 23 is sleeved on the periphery of the sensor upper cover 11, the upper insulation layer 12 and the sensor lower cover 13.

[0029] The working process of the present invention is:

[0030] The high-temperature flue gas in the boiler 7 enters the pressure measurement chamber 18 through the air extraction holes. The first metal sensing diaphragm 20, the second metal sensing diaphragm 21, and the third metal sensing diaphragm 16 deform under the action of the high-temperature flue gas pressure. The light source and the optical signal conditioning module 2 emit a measurement beam, which is respectively transmitted to the first metal sensing diaphragm 20, the second metal sensing diaphragm 21, and the third metal sensing diaphragm 16 through the first optical fiber probe 8, the second optical fiber probe 9, and the third optical fiber probe 10. After being reflected by the first metal sensing diaphragm 20, the second metal sensing diaphragm 21, and the third metal sensing diaphragm 16, it returns to the light source and the optical signal conditioning module 2 through the first optical fiber probe 8, the second optical fiber probe 9, and the third optical fiber probe 10 respectively. The light source and the optical signal conditioning module 2 convert the reflected light in three directions into voltage signals;

[0031] The data acquisition and analyzer 3 real-time collects the voltage signals output by the light source and the optical signal conditioning module 2 according to the sampling frequency set by the combustion pressure pulsation monitoring and processing center 4, and outputs the voltage signals to the combustion pressure pulsation monitoring and processing center 4;

[0032] The combustion pressure pulsation monitoring and processing center 4 converts the voltage signals into real-time pressure. The combustion pressure pulsation monitoring and processing center 4 generates an adjustment instruction for the fuel and air volume of the boiler 7 according to the real-time pressure, and then sends the adjustment instruction for the fuel and air volume of the boiler 7 to the feedback control unit 5. The feedback control unit 5 controls the fuel volume control valve and the air volume control valve of the boiler 7 according to the adjustment instruction for the fuel and air volume of the boiler 7 to adjust the fuel volume and air flow rate entering the boiler 7 in real time, so that the real-time pressure is within the preset range to ensure stable combustion of the boiler 7 and always control the combustion pressure pulsation in the safe and stable area.

[0033] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of the present invention claimed.

Claims

1. A boiler combustion pressure pulsation control system with triple redundancy function, characterized in that, It includes an optical fiber pressure pulsation sensor (1), a boiler (7), a light source and optical signal conditioning module (2), an optical fiber bundle (6), a data acquisition and analyzer (3), a combustion pressure pulsation monitoring and processing center (4), and a feedback control unit (5); The inlet of the optical fiber pressure pulsation sensor (1) is communicated with the pressure measuring port of the boiler (7). The output end of the optical fiber pressure pulsation sensor (1) is connected to the input end of the light source and optical signal conditioning module (2) via the optical fiber bundle (6). The output end of the light source and optical signal conditioning module (2) is connected to the input end of the data acquisition and analyzer (3). The output end of the data acquisition and analyzer (3) is connected to the input end of the combustion pressure pulsation monitoring and processing center (4). The output end of the combustion pressure pulsation monitoring and processing center (4) is connected to the control ends of the fuel quantity control valve and the air quantity control valve of the boiler (7) via the feedback control unit (5); The optical fiber pressure pulsation sensor (1) includes a first optical fiber probe (8), a second optical fiber probe (9), a third optical fiber probe (10), a sensor upper cover (11), an upper heat insulation layer (12), a sensor lower cover (13), a lower heat insulation layer (14), and a permeable membrane (19); An upper heat insulation layer (12) is provided between the bottom of the sensor upper cover (11) and the top of the sensor lower cover (13). A lower heat insulation layer (14) is provided at the bottom of the sensor lower cover (13). A pressure measuring cavity (18) is provided at the bottom of the sensor lower cover (13). Among them, a first metal sensing diaphragm (20), a second metal sensing diaphragm (21), and a third metal sensing diaphragm (16) are arranged in the pressure measuring cavity (18). Among them, a first vacuum heat insulation cavity (17) is formed between the first metal sensing diaphragm (20) and one side wall of the pressure measuring cavity (18). A second vacuum heat insulation cavity (22) is formed between the second metal sensing diaphragm (21) and the top of the pressure measuring cavity (18). A third vacuum heat insulation cavity (15) is formed between the third metal sensing diaphragm (16) and the other side wall of the pressure measuring cavity (18). The first optical fiber probe (8) passes through the sensor upper cover (11) and the upper heat insulation layer (12) and then passes through the side wall of the sensor lower cover (13) and is inserted into the first vacuum heat insulation cavity (17) and faces the first metal sensing diaphragm (20). The second optical fiber probe (9) passes through the sensor upper cover (11) and is inserted into the second vacuum heat insulation cavity (22) and faces the second metal sensing diaphragm (21). The third optical fiber probe (10) passes through the sensor upper cover (11) and the upper heat insulation layer (12) and then passes through the side wall of the sensor lower cover (13) and is inserted into the third vacuum heat insulation cavity (15) and faces the third metal sensing diaphragm (16); The first optical fiber probe (8), the second optical fiber probe (9), and the third optical fiber probe (10) are connected to the light source and optical signal conditioning module (2) via the optical fiber bundle (6). A permeable membrane (19) is provided at the bottom opening of the pressure measuring cavity (18). Among them, a plurality of air guide holes are provided on the permeable membrane (19). The pressure measuring cavity (18) is communicated with the pressure measuring port of the boiler (7) through the air guide holes; The axes of the upper sensor cover (11), the upper heat insulation layer (12), the lower sensor cover (13), and the lower heat insulation layer (14) coincide; It further includes a mounting nut (23); the mounting nut (23) is sleeved on the periphery of the upper sensor cover (11), the upper heat insulation layer (12), and the lower sensor cover (13).

2. The boiler combustion pressure pulsation control system with triple redundancy function according to claim 1, characterized in that, The upper sensor cover (11), the upper heat insulation layer (12), the lower sensor cover (13), and the lower heat insulation layer (14) are connected by diffusion welding.

3. The boiler combustion pressure pulsation control system with triple redundancy function according to claim 1, characterized in that The outer diameter of the upper sensor cover (11) is 12 mm, and the length is 15 mm. The outer diameter of the upper heat insulation layer (12) is 12 mm, and the thickness is 2 mm. The side length of the central square hole on the upper heat insulation layer (12) is 2 mm. The outer diameter of the upper heat insulation layer (12) is 12 mm. The length of the pressure measurement chamber (18) is 6 mm, the width is 2 mm, and the height is 2 mm. The outer diameter of the lower heat insulation layer (14) is 12 mm, and the thickness is 5 mm. The side length of the central square hole on the lower heat insulation layer (14) is 2 mm. The diameters of the first optical fiber probe (8), the second optical fiber probe (9), and the third optical fiber probe (10) are all 1 mm. The side lengths of the first metal sensing diaphragm (20), the second metal sensing diaphragm (21), and the third metal sensing diaphragm (16) are all 3 mm, and the thickness is 1 mm. The pore diameter of the air intake hole is 0.5 mm.

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