A distributed temperature measurement optical cable material level monitoring system for an electric dust hopper of a thermal power plant
By using distributed temperature-measuring optical cables and nuclear level gauge systems, the distribution of flue dust in the ash hopper is monitored in real time and early warnings are issued, which solves the problem of accuracy in monitoring the ash hopper level and flue dust distribution, and improves the safety and economic efficiency of thermal power plants.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUANENG LINYI POWER GENERATION CO LTD
- Filing Date
- 2023-07-14
- Publication Date
- 2026-07-21
AI Technical Summary
Existing technologies cannot accurately monitor the material level and ash distribution in the ash hopper of electrostatic precipitators in thermal power plants, leading to frequent ash hopper collapse accidents, which pose safety hazards and economic losses.
It employs distributed temperature-measuring optical cables, temperature-measuring elements, passive nuclear level gauges, PLC control systems, display systems, alarm systems, and indication processing systems to monitor the distribution of flue dust in the ash hopper in real time and issue early warning information by measuring the temperature and level values at multiple measuring points.
It enables accurate monitoring of the distribution of soot inside the ash hopper, allowing for early detection of ash accumulation anomalies, improving safety and reducing economic losses.
Smart Images
Figure CN117146932B_ABST
Abstract
Description
Technical Field
[0001] This invention patent relates to the field of material level measurement technology in the ash hopper of electrostatic precipitators in thermal power plants, specifically to a distributed temperature-measuring optical cable material level monitoring system for the ash hopper of electrostatic precipitators in thermal power plants. Background Technology
[0002] The purpose of the ash hopper in an electrostatic precipitator in a thermal power plant is to collect the soot produced by coal combustion. The soot collected in the ash hopper is then transported to other locations by an ash conveying device. Because the ash hopper of an electrostatic precipitator is large in size but has an upper limit to its load-bearing capacity, if the material level in the ash hopper is not monitored in time, the overall material level may be too high or there may be excessive ash caking on one side, which may cause the load to be exceeded and structural damage to occur. In the end, the ash hopper may collapse. In recent years, there have been many accidents of ash hopper collapse.
[0003] Currently, power plants generally use level switches or nuclear level gauges to monitor ash levels. Level switches trigger an alarm only when the ash level reaches a certain point, but their operation is susceptible to failure due to installation location limitations, and they cannot pinpoint the exact internal ash level, nor can they eliminate the risk of unilateral caking. Nuclear level gauges only reflect the quantity of ash in a specific area within the ash hopper, but not its distribution. Furthermore, high ash levels in the ash hopper require timely manual intervention to assist with ash conveying. Prolonged high ash levels can force the thermal power unit to shut down, resulting in significant economic losses. Manual intervention involves tapping or damaging the ash hopper wall to manually release ash. However, both of these methods fail to reveal the actual distribution of ash within the ash hopper, posing safety hazards and hindering the identification of ash accumulation locations, thus impeding effective problem-solving.
[0004] Therefore, how to accurately monitor the material level in the ash hopper and the distribution of flue ash on the inner wall of the ash hopper, and detect abnormal ash accumulation in advance, is a technical problem that needs to be solved. Summary of the Invention
[0005] This invention provides a distributed temperature-measuring optical cable material level monitoring system for electrostatic precipitator ash hoppers in thermal power plants, to solve the technical problems in existing technologies that cannot accurately monitor the material level and the distribution of soot inside the ash hopper, and cannot detect abnormal ash accumulation in advance. The system includes:
[0006] A temperature detection system, comprising a distributed temperature-measuring optical cable, a temperature-measuring optical cable host, and a temperature-measuring element. The distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall, and is evenly distributed to divide the ash hopper surface into multiple measuring points in the horizontal and vertical directions for measuring the temperature at the multiple measuring points. The temperature-measuring element is inserted in the center of the ash hopper for measuring the temperature T00 in the middle of the ash hopper.
[0007] A material level detection system, comprising a passive nuclear level gauge, wherein the passive nuclear level gauge is used to measure the material level value of flue ash in the ash hopper;
[0008] The PLC control system is connected to the temperature measuring optical cable host, the temperature measuring element and the passive nuclear level gauge respectively. The PLC control system is used to acquire the measurement data of the distributed temperature measuring optical cable, the temperature measuring element and the passive nuclear level gauge and to perform calculation and processing on the measurement data.
[0009] The display system is used to display the measurement data acquired by the PLC control system and the calculation and processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper.
[0010] The alarm system is used to issue a warning message of the corresponding level when the amount of ash accumulated at the measuring point in the ash hopper reaches the preset ash accumulation threshold or the material level in the ash hopper reaches the preset material level threshold.
[0011] The instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper.
[0012] In some embodiments of this application, the distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall, evenly distributed, dividing the ash hopper surface into multiple measuring points in horizontal and vertical directions, used to measure the temperature at the multiple measuring points, including:
[0013] After the distributed temperature measurement optical cable is wound along the side wall of the ash hopper, the temperature measurement positions on the surface of the side wall of the ash hopper are evenly divided into three layers, A, B and C, in the vertical direction, and each layer is divided into 12 measurement points in the horizontal direction.
[0014] When there is no ash accumulation on the side wall of the ash hopper, the temperatures of the measuring points at different points in each layer are similar. The initial temperatures of each layer are set as TA, TB, and TC, and TA > TB > TC. The temperatures corresponding to the 12 measuring points in each layer are set as TA1~TA12, TB1~TB12, and TC1~TC12, where the temperatures of TA1~TA12 are similar and approximately equal to TA, the temperatures of TB1~TB12 are similar and approximately equal to TB, and the temperatures of TC1~TC12 are similar and approximately equal to TC.
[0015] When there is ash accumulation on the side wall of the ash hopper, the temperature of the measuring points at different points in each layer decreases and the decrease range is different. Specifically, the temperatures of TA1 to TA12 are different, the temperatures of TB1 to TB12 are different, and the temperatures of TC1 to TC12 are different.
[0016] In some embodiments of this application, the PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to perform calculations and processing on the measurement data, including:
[0017] The PLC control system obtains the intermediate temperature TOO of the ash hopper through the temperature measuring element. The intermediate temperature TOO of the ash hopper is the temperature value in the middle of the ash hopper after ash is fed into the ash hopper and there is no ash accumulation on the side wall of the ash hopper.
[0018] The PLC control system obtains the temperature of multiple measuring points through the temperature measuring optical cable host, and calculates the temperature drop of the multiple measuring points and the dust accumulation thickness corresponding to the temperature drop.
[0019] The temperature drop at the measuring point is the difference between the initial temperature of the corresponding layer and the temperature at the measuring point. Different temperature drops at the measuring point correspond to different dust accumulation thicknesses.
[0020] If dust accumulates at measuring point A1, let the thickness of the dust accumulation at measuring point A1 be H, and the temperature drop per unit measuring point be T', where T' corresponds to a unit dust accumulation thickness of H'.
[0021]
[0022] In some embodiments of this application, the PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to perform calculations on the measurement data, further comprising:
[0023] The PLC control system obtains the material level value through the passive nuclear level gauge, and calculates the increase in the material level value and the total amount of ash accumulation corresponding to the increase in the material level value.
[0024] When there is no ash accumulation on the side wall of the ash hopper, the material level value measured by the passive nuclear level gauge is the initial material level value, and the initial material level value is set to S;
[0025] When there is ash accumulation on the side wall of the ash hopper, the ash level in the ash hopper rises, and the rise in the ash level is the difference between the ash level in the ash hopper and the initial ash level. Different rises in the ash level correspond to different total ash accumulations. The total ash accumulation is the total amount of ash accumulated in different directions and at different levels on the side wall of the ash hopper.
[0026] The material level is set to S', and the total ash accumulation is set to L.
[0027] L = S' - S ;
[0029] The PLC control system calculates the ratio of dust accumulation thickness between each measuring point based on the dust accumulation thickness at each measuring point, and calculates the dust accumulation amount at each measuring point based on the ratio of dust accumulation thickness at each measuring point and the total dust accumulation amount.
[0030] In some embodiments of this application, the system further includes:
[0031] The initial temperatures TA, TB, and TC of each layer are calculated based on the distance relationship between the temperature measuring positions of the three temperature measuring optical cables (A, B, and C) and the center position of the ash hopper. Specifically, this includes:
[0032] The temperature measuring position of layer B is located in the middle of the ash hopper, TB = TOO. The distances of layers A and C from the middle of the ash hopper are equal. Let E be the vertical distance between layer A or layer C and the middle of the ash hopper. After ash enters the ash hopper, let the temperature difference corresponding to the vertical distance E be TO. Then, the initial temperature of layer A TA = TOO + TO, and the initial temperature of layer C TC = TOO - TO.
[0033] In some embodiments of this application, the display system is used to display the measurement data acquired by the PLC control system and the processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper, including:
[0034] The measurement data includes: the intermediate temperature of the ash hopper (T0O), the temperature of the multiple measuring points, and the material level value;
[0035] The calculation and processing results of the measurement data include: the ash accumulation thickness at each measuring point, the total ash accumulation on the side wall of the ash hopper, and the ash accumulation at each measuring point;
[0036] The display system shows the dynamic distribution of soot inside the ash hopper. Specifically, the display system generates a dynamic soot distribution map inside the ash hopper based on the constantly changing amount of soot at each measuring point. The dynamic soot distribution map inside the ash hopper shows the distribution location of soot inside the ash hopper and the amount of soot at different distribution locations.
[0037] In some embodiments of this application, the alarm system is used to issue a warning message of a corresponding level when the amount of ash accumulated at a measuring point in the ash hopper reaches a preset ash accumulation threshold or the material level value in the ash hopper reaches a preset material level value threshold, including:
[0038] The system presets a first threshold and a second threshold for the amount of ash accumulated at a measuring point. When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper reaches the first threshold, the alarm system is triggered and issues a first-level warning. When the display system shows that the amount of ash accumulated at a certain measuring point in the ash hopper reaches the second threshold, the alarm system issues a second-level warning. When the display system shows that the amount of ash accumulated at multiple measuring points in the ash hopper reaches the second threshold, the alarm system issues a third-level warning.
[0039] The system presets a first material level threshold and a second total material level threshold. When the display system shows that the material level in the ash hopper reaches the first total material level threshold, the alarm system first issues a first-level warning message, and then issues a second-level warning message after an interval of T. When the display system shows that the material level in the ash hopper reaches the second total material level threshold, the alarm system first issues a first-level warning message, and then issues a third-level warning message after an interval of T.
[0040] When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper and the material level value simultaneously reach a preset threshold, the alarm system directly issues a level three warning message.
[0041] In some embodiments of this application, the instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper, including:
[0042] The corresponding actions for the first-level early warning information are: to close the feed valve, inspect and process the ash hopper, and prepare for ash conveying.
[0043] The processing items corresponding to the secondary early warning information are: according to the processing direction indicated by the indicator system, carry out ash conveying processing on the measuring point with abnormal ash accumulation in the ash hopper or the bottom of the ash hopper;
[0044] The corresponding actions for the Level 3 early warning information are: to carry out emergency ash conveying treatment for the entire ash hopper, and to inspect and repair the entire electrostatic precipitator ash hopper distributed temperature measurement optical cable material level monitoring system.
[0045] Compared with the prior art, the embodiments of this application bring the following beneficial effects:
[0046] This invention provides a distributed temperature-measuring optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant. The system includes: a temperature detection system comprising a distributed temperature-measuring optical cable, a main unit for the optical cable, and temperature-measuring elements, used to measure the temperature at multiple measuring points and the intermediate temperature T00 of the ash hopper; a material level detection system for measuring the material level of the ash inside the ash hopper; a PLC control system for acquiring and processing the measurement data from the temperature and material level detection systems; a display system for displaying the measurement data acquired by the PLC control system, the processing results of the measurement data, and the dynamic distribution of the ash inside the ash hopper; an alarm system for issuing warning information of corresponding levels; and an instruction processing system for indicating the corresponding processing items and directions for different levels of warning information. This invention can accurately monitor the distribution of ash inside the ash hopper and detect abnormal ash accumulation in advance, enabling timely ash removal and improving safety. Attached Figure Description
[0047] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0048] Figure 1 This invention presents a schematic diagram of a distributed temperature-measuring optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant.
[0049] Figure 2 This invention presents a schematic diagram of the overall structure of a distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant, as proposed in an embodiment of the present invention.
[0050] In the figure: T00 is the temperature sensing element and the corresponding measured temperature in the ash hopper; TA1~TA12, TB1~TB12, TC1~TC12 are the temperature measurement positions formed by the same temperature sensing optical cable after it is wrapped around the ash hopper wall and the corresponding measured temperatures. Detailed Implementation
[0051] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.
[0052] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.
[0053] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0054] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.
[0055] Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0056] This application provides a distributed temperature-measuring optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant, such as... Figure 1-2 As shown, the system includes:
[0057] A temperature detection system, comprising a distributed temperature-measuring optical cable, a temperature-measuring optical cable host, and a temperature-measuring element. The distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall, and is evenly distributed to divide the ash hopper surface into multiple measuring points in the horizontal and vertical directions for measuring the temperature at the multiple measuring points. The temperature-measuring element is inserted in the center of the ash hopper for measuring the temperature T00 in the middle of the ash hopper.
[0058] A material level detection system, comprising a passive nuclear level gauge, wherein the passive nuclear level gauge is used to measure the material level value of flue ash in the ash hopper;
[0059] The PLC control system is connected to the temperature measuring optical cable host, the temperature measuring element and the passive nuclear level gauge respectively. The PLC control system is used to acquire the measurement data of the distributed temperature measuring optical cable, the temperature measuring element and the passive nuclear level gauge and to perform calculation and processing on the measurement data.
[0060] The display system is used to display the measurement data acquired by the PLC control system and the calculation and processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper.
[0061] The alarm system is used to issue a warning message of the corresponding level when the amount of ash accumulated at the measuring point in the ash hopper reaches the preset ash accumulation threshold or the material level in the ash hopper reaches the preset material level threshold.
[0062] The instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper.
[0063] In some embodiments of this application, the distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall, evenly distributed, dividing the ash hopper surface into multiple measuring points in horizontal and vertical directions, used to measure the temperature at the multiple measuring points, including:
[0064] After the distributed temperature measurement optical cable is wound along the side wall of the ash hopper, the temperature measurement positions on the surface of the side wall of the ash hopper are evenly divided into three layers, A, B and C, in the vertical direction, and each layer is divided into 12 measurement points in the horizontal direction.
[0065] When there is no ash accumulation on the side wall of the ash hopper, the temperatures of the measuring points at different points in each layer are similar. The initial temperatures of each layer are set as TA, TB, and TC, and TA > TB > TC. The temperatures corresponding to the 12 measuring points in each layer are set as TA1~TA12, TB1~TB12, and TC1~TC12, where the temperatures of TA1~TA12 are similar and approximately equal to TA, the temperatures of TB1~TB12 are similar and approximately equal to TB, and the temperatures of TC1~TC12 are similar and approximately equal to TC.
[0066] When there is ash accumulation on the side wall of the ash hopper, the temperature of the measuring points at different points in each layer decreases and the decrease range is different. Specifically, the temperatures of TA1 to TA12 are different, the temperatures of TB1 to TB12 are different, and the temperatures of TC1 to TC12 are different.
[0067] In this embodiment, when the distributed temperature-measuring optical cable is wound along the ash hopper, the side wall of the ash hopper is evenly divided into multiple measuring points according to the shape of the electrostatic precipitator ash hopper, so as to detect the temperature and temperature change at different positions in the ash hopper. When ash enters the ash hopper, if there is no ash accumulation on the side wall of the ash hopper, the temperature of the four walls of the ash hopper is similar to the temperature of the ash entering from the top. After the flue ash enters the ash hopper, the lower the temperature of the flue ash, the longer the cooling time of the flue ash is. Therefore, the temperature of the side wall of the ash hopper decreases from top to bottom. If there is ash accumulation on the side wall of the ash hopper, the temperature display value of the side wall of the ash hopper decreases due to the obstruction of heat transfer. The thicker the ash accumulation, the greater the temperature drop. During the ash entry process, different measuring points in the ash hopper will have different degrees of ash accumulation. Therefore, the temperature drop of different measuring points is different. In fact, the temperature of the three layers TA, TB, and TC also decreases at different rates during the ash drop process.
[0068] It should be noted that when the temperature measuring optical cable is wrapped around the side wall of the ash hopper, the division position of the side wall and the number of measuring points can be designed and adjusted according to the actual situation.
[0069] In some embodiments of this application, the PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to perform calculations and processing on the measurement data, including:
[0070] The PLC control system obtains the intermediate temperature TOO of the ash hopper through the temperature measuring element. The intermediate temperature TOO of the ash hopper is the temperature value in the middle of the ash hopper after ash is fed into the ash hopper and there is no ash accumulation on the side wall of the ash hopper.
[0071] The PLC control system obtains the temperature of multiple measuring points through the temperature measuring optical cable host, and calculates the temperature drop of the multiple measuring points and the dust accumulation thickness corresponding to the temperature drop.
[0072] The temperature drop at the measuring point is the difference between the initial temperature of the corresponding layer and the temperature at the measuring point. Different temperature drops at the measuring point correspond to different dust accumulation thicknesses.
[0073] If dust accumulates at measuring point A1, let the thickness of the dust accumulation at measuring point A1 be H, and the temperature drop per unit measuring point be T', where T' corresponds to a unit dust accumulation thickness of H'.
[0074]
[0075] In this embodiment, when there is ash accumulation on the side wall of the ash hopper, the temperature value of different measuring points starts to decrease from the initial temperature value of the corresponding level. When the PLC control system calculates the temperature decrease of different measuring points, it is calculated relative to the initial temperature value of each measuring point. The greater the temperature decrease of the measuring point, the thicker the ash accumulation at the measuring point. The ash accumulation thickness is the total ash accumulation thickness of the measuring point compared to when there is no ash accumulation.
[0076] In this embodiment, for every decrease of T' in the temperature value of the measuring point, the corresponding increase in ash thickness at the measuring point is H. TA-TA1 is the total decrease in the initial temperature TA of measuring point A1 at temperature TA1 compared to the initial temperature TA before ash accumulation. For example, if for every 2°C decrease in the temperature value of the measuring point, the corresponding increase in ash thickness at the measuring point is 10 cm, and the temperature value of the measuring point is 32°C at this time, and the initial temperature value of the measuring point is 58°C, then the ash thickness at the measuring point at this time is (58-32)÷2×10=130 cm.
[0077] It should be noted that the numerical relationship between the temperature drop per unit measuring point T' and the corresponding unit ash accumulation thickness H' in this embodiment can be designed and adjusted according to actual conditions.
[0078] In some embodiments of this application, the PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to perform calculations on the measurement data, further comprising:
[0079] The PLC control system obtains the material level value through the passive nuclear level gauge, and calculates the increase in the material level value and the total amount of ash accumulation corresponding to the increase in the material level value.
[0080] When there is no ash accumulation on the side wall of the ash hopper, the material level value measured by the passive nuclear level gauge is the initial material level value, and the initial material level value is set to S;
[0081] When there is ash accumulation on the side wall of the ash hopper, the ash level in the ash hopper rises, and the rise in the ash level is the difference between the ash level in the ash hopper and the initial ash level. Different rises in the ash level correspond to different total ash accumulations. The total ash accumulation is the total amount of ash accumulated in different directions and at different levels on the side wall of the ash hopper.
[0082] The material level is set to S', and the total ash accumulation is set to L.
[0083] L = S' - S;
[0084] The PLC control system calculates the ratio of dust accumulation thickness between each measuring point based on the dust accumulation thickness at each measuring point, and calculates the dust accumulation amount at each measuring point based on the ratio of dust accumulation thickness at each measuring point and the total dust accumulation amount.
[0085] In this embodiment, when there is ash accumulation on the sidewall of the ash hopper, the material level inside the ash hopper will be higher than the initial material level when there is no ash accumulation. The total increase in material level is the total amount of ash accumulated on the four walls of the ash hopper at this time. By measuring the temperature at different locations on the sidewall of the ash hopper using distributed temperature measuring optical cables, the temperature change values at different measuring points can be obtained, and the corresponding ash thickness can be calculated. That is, the distribution position of the soot on the inner sidewall of the ash hopper and the corresponding ash thickness at different locations can be obtained. The ash accumulation ratio at each measuring point can be calculated from the ash accumulation thickness at each measuring point. Then, the ash accumulation at each measuring point can be obtained based on the total amount of ash accumulated on the inner wall of the ash hopper and the ash accumulation ratio at each measuring point. For example, if the total amount of ash accumulated is 60 kg, the sidewall of the ash hopper is divided into 5 measuring points, and the ash accumulation thickness ratio of the 5 measuring points is 3:2:5:15:5, then the ash accumulation at these 5 measuring points is as follows: 6 kg, 4 kg, 10 kg, 30 kg, and 10 kg.
[0086] In some embodiments of this application, the system further includes:
[0087] The initial temperatures TA, TB, and TC of each layer are calculated based on the distance relationship between the temperature measuring positions of the three temperature measuring optical cables (A, B, and C) and the center position of the ash hopper. Specifically, this includes:
[0088] The temperature measuring position of layer B is located in the middle of the ash hopper, TB = TOO. The distances of layers A and C from the middle of the ash hopper are equal. Let E be the vertical distance between layer A or layer C and the middle of the ash hopper. After ash enters the ash hopper, let the temperature difference corresponding to the vertical distance E be TO. Then, the initial temperature of layer A TA = TOO + TO, and the initial temperature of layer C TC = TOO - TO.
[0089] In this embodiment, since the temperature sensing element can measure the temperature T00 at the middle position of the ash hopper, the starting temperature of the three layers A, B, and C can be calculated with the middle position of the ash hopper as the reference standard. The position of layer B coincides with the middle position of the ash hopper in the horizontal direction. The vertical distance E between layer A or layer C and the middle position of the ash hopper and the temperature difference T0 can be obtained by actual measurement and calculation, and can be appropriately adjusted later.
[0090] In some embodiments of this application, the display system is used to display the measurement data acquired by the PLC control system and the processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper, including:
[0091] The measurement data includes: the intermediate temperature of the ash hopper (T0O), the temperature of the multiple measuring points, and the material level value;
[0092] The calculation and processing results of the measurement data include: the ash accumulation thickness at each measuring point, the total ash accumulation on the side wall of the ash hopper, and the ash accumulation at each measuring point;
[0093] The display system shows the dynamic distribution of soot inside the ash hopper. Specifically, the display system generates a dynamic soot distribution map inside the ash hopper based on the constantly changing amount of soot at each measuring point. The dynamic soot distribution map inside the ash hopper shows the distribution location of soot inside the ash hopper and the amount of soot at different distribution locations.
[0094] In this embodiment, as ash is continuously fed into the ash hopper, the amount of ash accumulated at different locations on the side wall of the ash hopper will continuously change. In actual practice, in order to detect abnormal material levels in the ash hopper and abnormal ash accumulation at a certain location in the ash hopper in advance, it is necessary to monitor the distribution of flue ash in the ash hopper and the amount of flue ash at different locations in real time. Therefore, it is necessary to form a dynamic flue ash distribution map inside the ash hopper based on the measurement data and data calculation results, so as to accurately locate the ash and transport it in advance, thereby improving safety.
[0095] In some embodiments of this application, the alarm system is used to issue a warning message of a corresponding level when the amount of ash accumulated at a measuring point in the ash hopper reaches a preset ash accumulation threshold or the material level value in the ash hopper reaches a preset material level value threshold, including:
[0096] The system presets a first threshold and a second threshold for the amount of ash accumulated at a measuring point. When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper reaches the first threshold, the alarm system is triggered and issues a first-level warning. When the display system shows that the amount of ash accumulated at a certain measuring point in the ash hopper reaches the second threshold, the alarm system issues a second-level warning. When the display system shows that the amount of ash accumulated at multiple measuring points in the ash hopper reaches the second threshold, the alarm system issues a third-level warning.
[0097] The system presets a first material level threshold and a second total material level threshold. When the display system shows that the material level in the ash hopper reaches the first total material level threshold, the alarm system first issues a first-level warning message, and then issues a second-level warning message after an interval of T. When the display system shows that the material level in the ash hopper reaches the second total material level threshold, the alarm system first issues a first-level warning message, and then issues a third-level warning message after an interval of T.
[0098] When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper and the material level value simultaneously reach a preset threshold, the alarm system directly issues a level three warning message.
[0099] In this embodiment, the warning information level is set according to the severity of ash accumulation in the ash hopper and the material level. The first-level warning information indicates that the ash accumulation in the ash hopper is the least severe, and ash conveying is not required but the amount of ash that needs to be conveyed is about to be reached, so ash conveying preparation work needs to be done. The third-level warning information indicates that the ash accumulation in the ash hopper is the most severe. After the ash conveying preparation work is completed, an appropriate time interval T is set according to the actual situation so as to remind the staff to carry out the corresponding ash conveying work in a timely manner.
[0100] It should be noted that the ash accumulation threshold, material level threshold, number of thresholds, warning information level, and correspondence between the ash accumulation in the ash hopper and the warning information in this embodiment can all be designed and adjusted according to the actual situation.
[0101] In some embodiments of this application, the instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper, including:
[0102] The corresponding actions for the first-level early warning information are: to close the feed valve, inspect and process the ash hopper, and prepare for ash conveying.
[0103] The processing items corresponding to the secondary early warning information are: according to the processing direction indicated by the indicator system, carry out ash conveying processing on the measuring point with abnormal ash accumulation in the ash hopper or the bottom of the ash hopper;
[0104] The corresponding actions for the Level 3 early warning information are: to carry out emergency ash conveying treatment for the entire ash hopper, and to inspect and repair the entire electrostatic precipitator ash hopper distributed temperature measurement optical cable material level monitoring system.
[0105] In this embodiment, the processing procedures are designed based on a comprehensive analysis of the correspondence between the material level and ash accumulation in the ash hopper and the early warning information. After a first-level early warning is issued, only preparations for ash conveying are required. When a second-level early warning is issued, it indicates that ash needs to be conveyed at a certain measuring point on the side wall of the ash hopper, or that the material level has reached the level requiring ash conveying. The system indicates the direction of the measuring point that needs ash conveying based on the dynamic ash distribution map inside the ash hopper displayed by the display system, so that the staff can accurately handle the ash accumulation anomaly. When a third-level early warning is issued, it indicates that the ash accumulation in the ash hopper is serious, or that the material level has reached a dangerous value, requiring emergency ash conveying. After the ash conveying work is completed, the entire system equipment also needs to be inspected and repaired to avoid subsequent safety accidents caused by system failure.
[0106] Compared with the prior art, the embodiments of this application bring the following beneficial effects:
[0107] This invention provides a distributed temperature-measuring optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant. The system includes: a temperature detection system comprising a distributed temperature-measuring optical cable, a main unit for the optical cable, and temperature-measuring elements, used to measure the temperature at multiple measuring points and the intermediate temperature T00 of the ash hopper; a material level detection system for measuring the material level of the ash inside the ash hopper; a PLC control system for acquiring and processing the measurement data from the temperature and material level detection systems; a display system for displaying the measurement data acquired by the PLC control system, the processing results of the measurement data, and the dynamic distribution of the ash inside the ash hopper; an alarm system for issuing warning information of corresponding levels; and an instruction processing system for indicating the corresponding processing items and directions for different levels of warning information. This invention can accurately monitor the distribution of ash inside the ash hopper and detect abnormal ash accumulation in advance, enabling timely ash removal and improving safety.
[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented in hardware or by means of software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of the present invention can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.
[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A distributed temperature-measuring optical cable material level monitoring system for ash hoppers in thermal power plants, characterized in that, The system includes: A temperature detection system, comprising a distributed temperature-measuring optical cable, a temperature-measuring optical cable main unit, and a temperature-measuring element, wherein the distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall and is evenly distributed, dividing the ash hopper surface into multiple measuring points in the horizontal and vertical directions for measuring the temperature at the multiple measuring points; and the temperature-measuring element is inserted in the center of the ash hopper for measuring the temperature TOO in the middle of the ash hopper. A material level detection system, comprising a passive nuclear level gauge, wherein the passive nuclear level gauge is used to measure the material level value of flue ash in the ash hopper; The PLC control system is connected to the temperature measuring optical cable host, the temperature measuring element and the passive nuclear level gauge respectively. The PLC control system is used to acquire the measurement data of the distributed temperature measuring optical cable, the temperature measuring element and the passive nuclear level gauge and to perform calculation and processing on the measurement data. The display system is used to display the measurement data acquired by the PLC control system and the calculation and processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper. The alarm system is used to issue a warning message of the corresponding level when the amount of ash accumulated at the measuring point in the ash hopper reaches the preset ash accumulation threshold or the material level in the ash hopper reaches the preset material level threshold. The instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper; The distributed temperature-measuring optical cable is wound and fixed around the perimeter of the ash hopper wall, evenly distributed, dividing the ash hopper surface into multiple measuring points in the horizontal and vertical directions, used to measure the temperature at these multiple measuring points, including: After the distributed temperature-measuring optical cable is wound along the side wall of the ash hopper, the temperature measurement positions on the surface of the ash hopper side wall are evenly divided into three layers, A, B, and C, in the vertical direction, and each layer is divided into 12 measurement points in the horizontal direction; When there is no ash accumulation on the sidewall of the ash hopper, the temperatures at different measuring points in each layer are similar. The initial temperatures of each layer are set as TA, TB, and TC, with TA > TB > TC. The temperatures corresponding to the 12 measuring points in each layer are set as TA1~TA12, TB1~TB12, and TC1~TC12, where the temperatures of TA1~TA12 are similar and approximately equal to TA, the temperatures of TB1~TB12 are similar and approximately equal to TB, and the temperatures of TC1~TC12 are similar and approximately equal to TC. When there is ash accumulation on the side wall of the ash hopper, the temperature of the measuring points at different measuring points in each layer decreases and the decrease is different. Specifically, the temperatures of TA1~TA12, TB1~TB12, and TC1~TC12 are different. The PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to process the measurement data, including: The PLC control system obtains the intermediate temperature TOO of the ash hopper through the temperature measuring element. The intermediate temperature TOO of the ash hopper is the temperature value in the middle of the ash hopper after ash is fed into the ash hopper and there is no ash accumulation on the side wall of the ash hopper. The PLC control system obtains the temperature of multiple measuring points through the temperature measuring optical cable host, and calculates the temperature drop of the multiple measuring points and the dust accumulation thickness corresponding to the temperature drop. The temperature drop at the measuring point is the difference between the initial temperature of the corresponding layer and the temperature at the measuring point. Different temperature drops at the measuring point correspond to different dust accumulation thicknesses. If dust accumulates at measuring point A1, let the thickness of the dust accumulation at measuring point A1 be H, and the temperature drop per unit measuring point be T', where T' corresponds to a unit dust accumulation thickness of H'. 。 2. The distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant according to claim 1, characterized in that, The PLC control system is used to acquire measurement data from the distributed temperature-measuring optical cable, the temperature-measuring element, and the passive nuclear level gauge, and to process the measurement data. It also includes: The PLC control system obtains the material level value through the passive nuclear level gauge, and calculates the increase in the material level value and the total amount of ash accumulation corresponding to the increase in the material level value; When there is no ash accumulation on the side wall of the ash hopper, the level value measured by the passive nuclear level gauge is the initial level value, and the initial level value is set to S; When there is ash accumulation on the side wall of the ash hopper, the ash level in the ash hopper rises, and the rise in the ash level is the difference between the ash level in the ash hopper and the initial ash level. Different rises in the ash level correspond to different total ash accumulations. The total ash accumulation is the total amount of ash accumulated in different directions and at different levels on the side wall of the ash hopper. The material level is set to S', and the total ash accumulation is set to L. ; The PLC control system calculates the ratio of dust accumulation thickness between each measuring point based on the dust accumulation thickness at each measuring point, and calculates the dust accumulation amount at each measuring point based on the ratio of dust accumulation thickness at each measuring point and the total dust accumulation amount.
3. The distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant according to claim 1, characterized in that, The system also includes: The initial temperatures TA, TB, and TC of each layer are calculated based on the distance relationship between the temperature measuring positions of the three temperature measuring optical cables (A, B, and C) and the center position of the ash hopper. Specifically, this includes: The temperature measuring position of layer B is located in the middle of the ash hopper, TB=TOO. The distances of layers A and C from the middle of the ash hopper are equal. Let E be the vertical distance between layer A or layer C and the middle of the ash hopper. When ash enters the ash hopper, let the temperature difference corresponding to the vertical distance E be TO. Then, the initial temperature of layer A TA=TOO+TO, and the initial temperature of layer C TC=TOO-TO.
4. The distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant according to claim 2, characterized in that, The display system is used to display the measurement data acquired by the PLC control system and the processing results of the measurement data, and to display the dynamic distribution of soot inside the ash hopper, including: The measurement data includes: the intermediate temperature of the ash hopper (T0O), the temperature of the multiple measuring points, and the material level value; The calculation and processing results of the measurement data include: the ash accumulation thickness at each measuring point, the total ash accumulation on the side wall of the ash hopper, and the ash accumulation at each measuring point; The display system shows the dynamic distribution of soot inside the ash hopper. Specifically, the display system generates a dynamic soot distribution map inside the ash hopper based on the constantly changing amount of soot at each measuring point. The dynamic soot distribution map inside the ash hopper shows the distribution location of soot inside the ash hopper and the amount of soot at different distribution locations.
5. The distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant according to claim 1, characterized in that, The alarm system is used to issue a warning message of a corresponding level when the amount of ash accumulated at the measuring point in the ash hopper reaches a preset ash accumulation threshold or the material level value in the ash hopper reaches a preset material level threshold, including: The system presets a first threshold and a second threshold for the amount of ash accumulated at a measuring point. When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper reaches the first threshold, the alarm system is triggered and issues a first-level warning. When the display system shows that the amount of ash accumulated at a certain measuring point in the ash hopper reaches the second threshold, the alarm system issues a second-level warning. When the display system shows that the amount of ash accumulated at multiple measuring points in the ash hopper reaches the second threshold, the alarm system issues a third-level warning. The system presets a first material level threshold and a second total material level threshold. When the display system shows that the material level in the ash hopper reaches the first total material level threshold, the alarm system first issues a first-level warning message, followed by a second-level warning message after an interval T. When the display system shows that the material level in the ash hopper reaches the second total material level threshold, the alarm system first issues a first-level warning message, followed by a third-level warning message after an interval T. When the display system shows that the amount of ash accumulated at one or more measuring points in the ash hopper and the material level value simultaneously reach a preset threshold, the alarm system directly issues a level three warning message.
6. The distributed temperature measurement optical cable material level monitoring system for the ash hopper of an electrostatic precipitator in a thermal power plant according to claim 5, characterized in that, The instruction processing system is used to prompt the processing matters corresponding to different levels of warning information based on the warning information, and to indicate the corresponding processing direction based on the dynamic distribution of soot inside the ash hopper, including: The corresponding actions for the first-level early warning information are: to close the feed valve, inspect and process the ash hopper, and prepare for ash conveying. The processing items corresponding to the secondary early warning information are: according to the processing direction indicated by the indicator system, carry out ash conveying processing on the measuring point with abnormal ash accumulation in the ash hopper or the bottom of the ash hopper; The corresponding actions for the Level 3 early warning information are: to carry out emergency ash conveying treatment for the entire ash hopper, and to inspect and repair the entire electrostatic precipitator ash hopper distributed temperature measurement optical cable material level monitoring system.