Arrangement method and on-line monitoring method for expansion measuring point positions of water-cooled wall header of peak-shaving boiler

Abstract

The invention discloses an arrangement method and an online monitoring method for expansion measuring point positions of a peak-shaving boiler water-cooled wall header, and relates to the technical field of boiler water-cooled wall engineering, in particular to the field of design of expansion measuring points of the boiler water-cooled wall header. The arrangement method comprises the steps that S1, the actual expansion center of the boiler water-cooled wall header is determined, and expansion displacement data of the boiler water-cooled wall header are obtained; s2, according to the expansion displacement data in the S1, measuring point positions on the integral header and the tube rows on the two sides of the integral header are designed; and S3, according to the expansion displacement data in the S1, measuring point positions on the sectional header and the middle tube row are designed. By reasonably arranging the positions of the measuring points, the problem of stress fatigue cracking of fillet welds of a water-cooled wall tube socket and fins of the water-cooled wall caused by insufficient expansion monitoring is effectively avoided, the risk of equipment damage or operation shutdown caused by leakage of the water-cooled wall is reduced from the source, and meanwhile, the safety and reliability of boiler operation are improved. The method is suitable for a deep peak regulation coal-fired thermal power generating unit with the capacity of 300 MW or above

Description

Technical Field

[0001] The invention relates to the technical field of boiler water-cooled wall engineering, and in particular to the design field of expansion measuring points of a boiler water-cooled wall header. Background Art

[0002] At present, the units of thermal power plants are in a deep peak-shaving state all year round. Due to the frequent fluctuations in peak-shaving loads, the temperature of the boiler water-cooled wall header and tube row changes significantly. This temperature change leads to complex expansion behavior of the header and tube row, especially in deep peak-shaving coal-fired thermal power units with a capacity of 300MW and above. The expansion changes caused by temperature fluctuations can easily cause stress concentration at the connection between the header and the tube row, and ultimately lead to frequent stress fatigue cracking of the water-cooled wall tube seat corner welds or fins, thus posing a serious threat to the safety of the unit equipment.

[0003] In this case, how to reasonably select the expansion measurement point location and accurately reflect the expansion state of the header and pipe row under different working conditions is the key to improving equipment safety and operational reliability. Reasonable measurement point arrangement can capture the expansion characteristics of the header and pipe row in three-dimensional space, helping operation and maintenance personnel to timely grasp the deviation trend of the expansion center and the relative expansion of the header and pipe row, thereby providing a scientific basis for formulating targeted operation and maintenance strategies.

[0004] However, the expansion measurement point settings of deep peak-shaving coal-fired power plants are generally missing or unreasonable. For example, the measurement points at some key locations are not covered, resulting in the inability to fully capture the expansion behavior of the boiler water-cooled wall header; the layout of some measurement points does not fully consider the dynamic change law of the expansion center, resulting in limitations in the monitoring data. These problems directly affect the accurate analysis of the expansion behavior of the boiler water-cooled wall header, making it difficult to detect potential structural stress concentration in a timely manner. Once a water-cooled wall leakage accident occurs, it will not only cause equipment damage and a significant increase in maintenance costs, but may also threaten the lives of on-site workers.

[0005] The lack and unreasonable location of the expansion measuring points on the water-cooled wall of the peak-shaving boiler has led to a significant increase in the risk factors of deep peak-shaving coal-fired power plants. This is a problem that technical personnel in this field have always been eager to solve, but no effective technical means have been found. Summary of the invention

[0006] In order to fill the detection gap caused by insufficient expansion measurement points of the peak boiler water wall header and accurately monitor the expansion data of the peak boiler water wall header, this application proposes the following solutions:

[0007] A method for arranging expansion measurement points of a peak-shaving boiler water-cooled wall header, wherein the boiler water-cooled wall header includes an integral header and tube banks on both sides, a segmented header and a tube bank in the middle, and the method includes the following steps:

[0008] S1. Determine the actual expansion center of the boiler water wall header and obtain the expansion displacement data of the boiler water wall header;

[0009] S2. Design the measurement point positions on the integral header and the tube banks on both sides thereof according to the expansion displacement data of S1;

[0010] S3. Based on the expansion displacement data of S1, design the measurement point locations on the segmented header and the pipe row in the middle.

[0011] Furthermore, the S1 is:

[0012] 8 measuring points are set on the boiler water-cooled wall header, and the 8 measuring points are respectively located at the left, right, front and rear expansion centers of the boiler water-cooled wall header, as well as the lower left corner measuring point, the lower right corner measuring point, the upper right corner measuring point and the upper left corner measuring point when viewed from the top. The lower left corner, the lower right corner, the upper right corner and the upper left corner when viewed from the top form a plane rectangle, and the initial expansion center C is set to be located at a rearward position of the center in the plane rectangle. The distances of the initial expansion center C from the left, right, rear and front of the plane rectangle are L1, L2, L3 and L4 respectively;

[0013] The expansion amount of the lower left corner measuring point to the left is ΔL 左 , the rightward expansion of the lower right corner measuring point is ΔL 右 ,

[0014] If ΔL 左 >ΔL 右 ,

[0015] The expansion center is offset to the left by ΔL 左 -ΔL 右 ,

[0016] If ΔL 左 <ΔL 右 ,

[0017] The expansion center is offset to the right by ΔL 右 -ΔL 左 ,

[0018] The method for locating the actual expansion center position of the front and rear sides is:

[0019] Assume that the expansion amount of the upper left measuring point toward the back of the furnace is Assume that the expansion amount of the lower left measuring point toward the furnace is The actual expansion amount of the upper left corner measuring point toward the back of the furnace is The actual expansion amount of the lower left corner measuring point toward the furnace is

[0020] At full load, if and

[0021] The expansion centers of the front and rear sides remain in their original positions.

[0022] At full load, if and

[0023] If the expansion center of the front and rear sides changes, further judgment is made:

[0024] like and

[0025] The forward displacement of the expansion center is

[0026] like and

[0027] The expansion center is offset backwards by

[0028] Among them, α is the expansion coefficient and ΔT is the temperature change.

[0029] Furthermore, S2 is: arranging measuring points at the connecting corners of the tube rows adjacent to the four corners of the top of the integral header, combining S1 to obtain the expansion displacement data of the boiler water-cooled wall header, obtaining the expansion offset of the integral header and the tube rows on both sides thereof, and adjusting the positions of the measuring points according to the expansion offset.

[0030] Furthermore, S3 is: arranging measuring points at the connecting corners of the tube rows adjacent to the top four corners of the middle section of the segmented header, combining S1 to obtain the expansion displacement data of the boiler water-cooled wall header, obtaining the offset of the segmented header and the tube row in the middle thereof, and adjusting the position of the measuring points according to the expansion offset.

[0031] Furthermore, the boiler water-cooled wall header includes an upper water-cooled wall header, an intermediate water-cooled wall mixing header and a lower water-cooled wall header, and the upper water-cooled wall header, the intermediate water-cooled wall mixing header and the lower water-cooled wall header are arranged with measuring points in the same way.

[0032] Furthermore, the initial expansion center C becomes a changed expansion center C' after expansion of the boiler water wall header, and the distances of the changed expansion center C' from the left, right, back and front of the plane rectangle are L1', L2', L3' and L4' respectively.

[0033] Further, after the boiler water-cooled wall header is deflected, the lower left corner measuring point, the lower right corner measuring point, the upper right corner measuring point, and the upper left corner measuring point become the lower left corner measuring point after deflection, the lower right corner measuring point after deflection, the upper right corner measuring point after deflection, and the upper left corner measuring point after deflection; after the boiler water-cooled wall header is deflected, the lower left corner measuring point, the lower right corner measuring point, the upper right corner measuring point, and the upper left corner measuring point become the lower left corner measuring point after twisting, the lower right corner measuring point after twisting, the upper right corner measuring point after twisting, and the upper left corner measuring point after twisting.

[0034] An online monitoring method for the expansion of a water-cooled wall header of a peak-shaving boiler, wherein the online monitoring method is implemented based on data feedback from all measuring points in the measuring point positions obtained based on the arrangement method of the present invention, and the online monitoring method comprises:

[0035] F1. Fixed position measurement of all measuring points obtained by any one of the arrangement methods of claims 1 to 7;

[0036] F2, collect the data fed back from all measuring points in real time as expansion data;

[0037] F3. Obtaining expansion data of each measuring point according to the expansion data;

[0038] F4. Obtain expansion abnormality data based on all expansion data;

[0039] F5. Generate and output alarm information according to the abnormal expansion data, wherein the alarm information includes: abnormal expansion state and corresponding measuring point position;

[0040] F6, store all expansion data;

[0041] F7. Draw a boiler water wall header expansion trend analysis chart based on all stored expansion data.

[0042] Furthermore, based on the data feedback from the measuring points of the connection angle positions of the tube rows adjacent to the four corners on the top of the integral header, the three-dimensional expansion amount of the integral header and the tube rows on both sides of it is obtained, the synchronization of the relative expansion of the integral header and the tube rows on both sides of it is judged, and the expansion displacement data of the integral header and the tube rows on both sides of it are obtained based on the synchronization.

[0043] Furthermore, based on the feedback data of the measuring points of the connection angle positions of the adjacent tube rows at the top four corners of the middle section of the segmented header, the three-dimensional expansion amount of the segmented header and its intermediate tube row is obtained, the synchronization of the relative expansion of the segmented header and its intermediate tube row is judged, and the expansion displacement data of the segmented header and its intermediate tube row is obtained based on the synchronization.

[0044] Beneficial effects:

[0045] (1) The method for arranging the expansion measurement point positions of the water-cooled wall header of a peak-shaving boiler described in the present invention effectively avoids the problem of stress fatigue cracking of the water-cooled wall tube seat corner welds and water-cooled wall fins caused by insufficient expansion monitoring by reasonably arranging the measurement point positions, thereby reducing the risk of equipment damage or operation shutdown caused by water-cooled wall leakage from the source, while improving the safety and reliability of boiler operation.

[0046] (2) The method for arranging the positions of expansion measuring points of the water-cooled wall header of a peak-shaving boiler described in the present invention arranges expansion measuring points at key positions of the integral header and the segmented header to ensure that all important areas where dynamic changes in expansion may occur during the operation of the boiler are covered. The expansion behavior of the boiler water-cooled wall header can be fully captured, especially for the frequently fluctuating operating characteristics of deep peak-shaving coal-fired power generating units, and the expansion state of the header and pipe row under different operating conditions can be accurately captured.

[0047] (3) The method for arranging the expansion measurement points of the peak-shaving boiler water-wall header described in the present invention obtains the expansion data of the boiler water-wall header by setting 8 measurement points on the boiler water-wall header in advance, and then determines the position of the expansion center, which fully reflects the expansion behavior characteristics of the boiler water-wall header and the pipe row under the deep peak-shaving load, and comprehensively considers the position distribution of the expansion center, the dynamic changes of the three-dimensional expansion characteristics and the load characteristics of different working conditions, ensuring that the monitoring data can truly and accurately reflect the actual expansion state of the equipment during operation. Compared with the monitoring blind spots caused by unreasonable distribution of measurement points in traditional solutions, this method effectively solves the problem of missing expansion behavior information of key parts.

[0048] (4) The method for arranging the expansion measurement points of the water-cooled wall header of a peak-shaving boiler described in the present invention can accurately identify the stress concentration area at the connection between the water-cooled wall header and the tube row of the peak-shaving boiler by selecting the locations with large temperature changes and significant expansion fluctuations in the water-cooled wall header and the tube row of the peak-shaving boiler to provide reliable data support to avoid fatigue cracking of the equipment structure caused by expansion. In view of the complex expansion behavior under deep peak-shaving load, the expansion dynamics and temperature change laws of the header and the tube row are comprehensively considered, and the distribution of measurement points is reasonably designed to make the monitoring of stress concentration areas more accurate and comprehensive.

[0049] (5) The method for online monitoring the expansion of the water-cooled wall header of a peak-shaving boiler described in the present invention is based on the design method of locating the expansion center of the boiler water-cooled wall header and adjusting the measurement point position by the expansion offset. The real-time data collection of 52 measurement points installed in the upper header, middle mixing header, and lower header of the peak-shaving boiler water-cooled wall significantly improves the monitoring accuracy. Through the monitoring of the three-dimensional expansion amount, the relative expansion synchronization of the integral and segmented headers and the tube row is judged in real time, providing a strong technical guarantee for the accuracy of the monitoring data.

[0050] This method is applicable to deep peak-shaving coal-fired power units with a capacity of 300MW and above. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the initial expansion center position and the expansion center position after the change in the top view of the water-cooled wall header of the peak-shaving boiler described in the second embodiment of the present application. Figure symbols: lower left corner measuring point 1, lower right corner measuring point 2, upper right corner measuring point 3, upper left corner measuring point 4, initial expansion center C, the distances of the initial expansion center to the left, right, back and front of the plane rectangle are L1, L2, L3, L4 respectively, and the expansion center C' after the change, the distances of the expansion center to the left, right, back and front of the plane rectangle after the change are L1', L2', L3', L4' respectively.

[0052] Figure 2 It is the appearance of the peak-shaving boiler water-cooled wall header in the top view of the third embodiment of the present application, after the overall expansion posture of the header is deflected. Figure symbols: lower left corner measuring point X1 after deflection, lower right corner measuring point X2 after deflection, upper right corner measuring point X3 after deflection, upper left corner measuring point X4 after deflection.

[0053] Figure 3 It is the shape of the peak-shaving boiler water-cooled wall header in the top view of the third embodiment of the present application, after the overall expansion posture of the header is twisted. Figure symbols: lower left corner measurement point Y1 after twisting, lower right corner measurement point Y2 after twisting, upper right corner measurement point Y3 after twisting, upper left corner measurement point Y4 after twisting.

[0054] Figure 4 This is the arrangement of the relative expansion measurement points of the integral header as described in the fourth embodiment of the present application. The two gray dots in the figure represent the positions of the measurement points, and the arrows in the figure point to the connection angles of the integral header and the pipe rows on both sides thereof.

[0055] Figure 5 This is the arrangement method of measuring points for the relative expansion of the middle position of the segmented header and its pipe row as described in Embodiment 5 of the present application. The four gray dots in the figure represent the positions of the measuring points, and the arrows in the figure point to the connection angles of the segmented header and the pipe row in the middle.

[0056] Figure 6 This is a distribution diagram of measuring points of the water-cooled wall intermediate mixing header described in Embodiment 6 of the present application, in which the red dots are the locations of the measuring points.

[0057] Figure 7 This is a distribution diagram of measuring points of the lower header of the water-cooled wall according to the sixth embodiment of the present application, in which the red dots are the locations of the measuring points. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] Implementation Method 1

[0060] A method for arranging expansion measurement points of a peak-shaving boiler water-cooled wall header, wherein the boiler water-cooled wall header includes an integral header and tube banks on both sides, a segmented header and a tube bank in the middle, and the method includes the following steps:

[0061] S1. Determine the actual expansion center of the boiler water wall header and obtain the expansion displacement data of the boiler water wall header;

[0062] S2. Design the measurement point positions on the integral header and the tube banks on both sides thereof according to the expansion displacement data of S1;

[0063] S3. Based on the expansion displacement data of S1, design the measurement point locations on the segmented header and the pipe row in the middle.

[0064] By targeting the characteristics of the integral header, segmented header and their corresponding pipe rows, combined with the actual expansion center and expansion displacement data of the boiler water wall header, the location of the measuring point is scientifically designed. Step S1 accurately obtains the expansion displacement data, providing a reliable basis for the subsequent measurement point design; steps S2 and S3 arrange the measuring points according to the structural characteristics of different headers, respectively, to achieve the expansion state monitoring optimization of the integral and segmented headers. This method improves the rationality of the measurement point arrangement and the monitoring accuracy, and provides efficient and accurate technical support for the dynamic structural monitoring and safety assessment during boiler operation, with wide applicability and engineering value.

[0065] Furthermore, the boiler water-cooled wall header includes an upper water-cooled wall header, an intermediate water-cooled wall mixing header and a lower water-cooled wall header, and the upper water-cooled wall header, the intermediate water-cooled wall mixing header and the lower water-cooled wall header are arranged with measuring points in the same way.

[0066] Implementation Method 2

[0067] This embodiment is a further example of the first embodiment. Figure 1-3 This embodiment is described. In this embodiment, the actual expansion center of the boiler water wall header is determined to obtain the expansion data of the boiler water wall header, which is specifically as follows:

[0068] 8 measuring points are set on the boiler water-cooled wall header, and the 8 measuring points are respectively located at the left, right, front and rear expansion centers of the boiler water-cooled wall header, as well as the lower left corner measuring point 1, the lower right corner measuring point 2, the upper right corner measuring point 3 and the upper left corner measuring point 4 when viewed from the top. The lower left corner, the lower right corner, the upper right corner and the upper left corner when viewed from the top form a plane rectangle, and the initial expansion center is set at a rearward position of the center in the plane rectangle. The distances of the initial expansion center from the left, right, rear and front of the plane rectangle are L1, L2, L3 and L4 respectively;

[0069] The expansion amount of the lower left corner measuring point 1 to the left is ΔL 左 , the rightward expansion of the lower right corner measuring point 2 is ΔL 右 ,

[0070] If ΔL 左 >ΔL 右 ,

[0071] The expansion center is offset to the left by ΔL 左 -ΔL 右 ,

[0072] If ΔL 左 <ΔL 右 ,

[0073] The expansion center is offset to the right by ΔL 右 -ΔL 左 ,

[0074] In the front and rear wall directions of the water-cooled wall header, since the initial expansion center is located at the rear of the center in the plane rectangle, the actual expansion center position positioning calculation method of the front and rear sides is as follows:

[0075] Assume that the expansion amount of the upper left measuring point 4 to the rear of the furnace is Assume that the expansion amount of the lower left corner measuring point 1 toward the furnace is The actual expansion amount of the upper left corner measuring point in the 4-direction furnace rear is The actual expansion amount of the lower left corner measuring point 1 toward the furnace is

[0076] At full load, if and

[0077] The expansion centers of the front and rear sides remain in their original positions.

[0078] At full load, if and

[0079] If the expansion center of the front and rear sides changes, further judgment is made:

[0080] like and or and

[0081] The forward displacement of the expansion center is

[0082] like and or and

[0083] The expansion center is offset backwards by

[0084] Among them, α is the expansion coefficient and ΔT is the temperature change.

[0085] In addition, according to different combinations of measuring points,

[0086] ΔL 设 Can be

[0087] ΔL 实 Can be

[0088] The results derived from the above-mentioned combinations of measuring points should all be included in the protection scope of the present invention.

[0089] By setting measuring points at different positions of the boiler water wall header, the expansion data of the water wall header in all directions can be fully captured. In particular, the rectangular area formed by the four corner measuring points looking down from the top can effectively detect the all-round expansion changes of the header.

[0090] Furthermore, the initial expansion center C becomes a changed expansion center C' after expansion of the boiler water wall header, and the distances of the changed expansion center C' from the left, right, back and front of the plane rectangle are L1', L2', L3' and L4' respectively.

[0091] Further, after the boiler water-cooled wall header is deflected, the lower left corner measuring point 1, the lower right corner measuring point 2, the upper right corner measuring point 3, and the upper left corner measuring point 4 become the lower left corner measuring point X1 after deflection, the lower right corner measuring point X2 after deflection, the upper right corner measuring point X3 after deflection, and the upper left corner measuring point X4 after deflection; after the boiler water-cooled wall header is deflected, the lower left corner measuring point 1, the lower right corner measuring point 2, the upper right corner measuring point 3, and the upper left corner measuring point 4 become the lower left corner measuring point Y1 after twisting, the lower right corner measuring point Y2 after twisting, the upper right corner measuring point Y3 after twisting, and the upper left corner measuring point Y4 after twisting.

[0092] Implementation Method 3

[0093] This embodiment is a further example of the first embodiment. Figure 4To explain this embodiment, in this embodiment, further, step S2: designing the measurement point positions on the integral header and the tube banks on both sides thereof according to the expansion displacement data of S1, specifically:

[0094] Measuring points are arranged at the connecting corners of the tube rows adjacent to the four corners of the top of the integral header. The expansion displacement data of the boiler water-cooled wall header is obtained in combination with S1, and the expansion offset of the integral header and the tube rows on both sides thereof are obtained. The positions of the measuring points are adjusted according to the expansion offset.

[0095] By arranging measuring points at the connecting corners of the tube rows adjacent to the four corners of the top of the integral header, and combining the expansion displacement data of the boiler water-cooled wall header, the expansion offset of the integral header and the tube rows on both sides thereof can be accurately obtained. Adjusting the position of the measuring points based on the expansion offset can effectively improve the rationality of the measuring point arrangement and the accuracy of the data measurement, thereby more comprehensively and in real time reflecting the expansion characteristics of the water-cooled wall header during the operation of the boiler. This method of the present invention simplifies the complexity of the design and arrangement of the measuring points.

[0096] Implementation Method 4

[0097] This embodiment is a further example of the first embodiment. Figure 5 To explain this embodiment, in this embodiment, further, the S3: designing the measurement point positions on the segmented header and the pipe row in the middle thereof according to the expansion displacement data of S1, specifically:

[0098] Measuring points are arranged at the connecting corners of the tube rows adjacent to the top four corners of the middle section of the segmented header. The expansion displacement data of the boiler water-cooled wall header is obtained in combination with S1, and the offset of the segmented header and the tube row in the middle is obtained. The position of the measuring point is adjusted according to the expansion offset.

[0099] By arranging measuring points at the connecting corners of the tube rows adjacent to the four corners of the top of the middle section of the segmented header, combined with the expansion displacement data, the expansion offset of the segmented header and its middle tube row can be accurately obtained. Adjusting the measuring point position based on the offset can effectively improve the rationality of the measuring point arrangement and the accuracy of the data measurement, thereby more comprehensively and in real time reflecting the expansion characteristics of the water-cooled wall header during boiler operation. This method of the present invention simplifies the complexity of measuring point design and arrangement.

[0100] Implementation Method 5

[0101] An online monitoring method for the expansion of a water-cooled wall header of a peak-shaving boiler, wherein the online monitoring method is implemented based on data feedback from all measuring points in the measuring point positions obtained based on the arrangement method of the present invention, and the online monitoring method comprises:

[0102] F1. Fixed position measurement of all measuring points obtained by any one of the arrangement methods of claims 1 to 7;

[0103] F2, collect the data fed back from all measuring points in real time as expansion data;

[0104] F3. Obtaining expansion data of each measuring point according to the expansion data;

[0105] F4. Obtain expansion abnormality data based on all expansion data;

[0106] F5. Generate and output alarm information according to the abnormal expansion data, wherein the alarm information includes: abnormal expansion state and corresponding measuring point position;

[0107] F6, store all expansion data;

[0108] F7. Draw a boiler water wall header expansion trend analysis chart based on all stored expansion data.

[0109] Furthermore, based on the data feedback from the measuring points of the connection angle positions of the tube rows adjacent to the four corners on the top of the integral header, the three-dimensional expansion amount of the integral header and the tube rows on both sides of it is obtained, the synchronization of the relative expansion of the integral header and the tube rows on both sides of it is judged, and the expansion displacement data of the integral header and the tube rows on both sides of it are obtained based on the synchronization.

[0110] Furthermore, based on the feedback data of the measuring points of the connection angle positions of the adjacent tube rows at the top four corners of the middle section of the segmented header, the three-dimensional expansion amount of the segmented header and its intermediate tube row is obtained, the synchronization of the relative expansion of the segmented header and its intermediate tube row is judged, and the expansion displacement data of the segmented header and its intermediate tube row is obtained based on the synchronization.

[0111] Based on the precisely designed measuring point positions in the layout method, comprehensive monitoring of the expansion state of the boiler water wall header is achieved. Through the measuring points at the connecting corners of the adjacent tube rows at the four corners of the top of the integral header, the three-dimensional expansion of the integral header and the tube rows on both sides can be monitored, the synchronization of their relative expansion can be determined, and the expansion displacement data can be obtained; while the measuring points at the top of the middle section of the segmented header monitor the three-dimensional expansion of the segmented header and its middle tube row, and the expansion coordination of the two can be simultaneously evaluated. Through comprehensive and accurate online monitoring, this method can timely capture the expansion state and deviation of key components in boiler operation, providing reliable data support and technical guarantee for operation optimization, structural safety analysis, and long-term stable operation of the boiler.

[0112] Implementation Method 6

[0113] This embodiment provides an example, which is used to explain the above-mentioned embodiments 1 to 5. The specific example is as follows:

[0114] A method for arranging expansion measurement point positions of a peak-shaving boiler water-cooled wall header and an online monitoring method, wherein the boiler water-cooled wall header comprises an integral header and tube banks on both sides, a segmented header and a tube bank in the middle, and the method comprises the following steps:

[0115] (1) Design of water wall header expansion measurement point layout

[0116] The boiler water wall header is usually divided into the upper water wall header, the middle water wall mixing header and the lower water wall header. The three headers are connected by water wall tubes to form the spatial structure of the entire boiler. Under deep peak load conditions, the failure modes of water wall headers at different locations are different. The expansion measurement points of the headers are arranged according to different failure modes.

[0117] 1) Water-cooled wall header

[0118] Under deep peak regulation, the temperature of the upper header and water-cooled wall tubes of the unit fluctuates greatly. On the one hand, due to the great difference in the thickness of the header and the water-cooled wall tube, the different heat conduction capabilities of the two cause the expansion of the header and the connecting pipe seat to be asynchronous. On the other hand, due to the long-term temperature fluctuation, the corner weld of the header pipe seat suffers from long-term thermal fatigue. The combination of these two factors can easily lead to fatigue stress cracking of the corner weld of the upper header pipe seat. The principles for determining the arrangement of measurement points for these problems are as follows:

[0119] Step 1: First determine the actual expansion center of the boiler water wall header, which is the basis for analyzing whether the overall expansion posture of the water wall header is skewed or twisted. According to the following calculation method, it is necessary to set one expansion center monitoring point on the left and right sides of the furnace, one on the front and rear, and one on each of the four corners, so as to obtain the actual expansion center position. The calculation method is as follows:

[0120] The water-cooled wall upper header forms a closed rectangle around it. The initial design expansion center position is as follows: Figure 1 However, the boiler may deflect during actual operation, causing the actual expansion center of the water-cooled wall header to deviate from the initial design expansion center.

[0121] In the left and right directions, since the initial design expansion center is located in the middle of the left and right sides, theoretically the header expands and elongates in equal proportions on the left and right sides. Assume that the expansion amount of measuring point 1 to the left is ΔL 左 , the expansion amount of measuring point 2 to the right is ΔL 右 , if ΔL 左 >ΔL 右 , then the displacement of the expansion center to the left in the left and right directions is ΔL 左 -ΔL 右 Similarly, if ΔL 左 <ΔL 右 , then the rightward displacement of the expansion center in the left and right directions is ΔL 右 -ΔL 左 .

[0122] In the front and rear directions, since the initial design expansion center is located at the rear of the furnace, the actual expansion center position of the front and rear sides is calculated as follows. Assuming that the expansion amount of the initial design position in the 4-direction rear of the furnace is The expansion amount of position 1 toward the furnace is The actual position 4 expansion amount behind the furnace is The expansion amount of position 1 toward the furnace is α is the expansion coefficient and ΔT is the temperature change.

[0123] At full load, if and The expansion centers of the front and rear sides remain unchanged at their original positions.

[0124] At full load, if and The expansion center of the front and rear sides changes.

[0125] when and When the expansion center is offset to the front of the furnace,

[0126] when and When the expansion center is offset to the rear of the furnace,

[0127] Step 2: To determine whether the overall expansion posture of the water wall header occurs as follows Figure 2 , 3 The deflection and torsion shown are based on the actual position of the expansion center of the boiler water-cooled wall upper header determined in step 1, and then based on the expansion amount of the expansion measuring points at the four corners, the spatial position of the upper header around is calculated to determine whether deflection and torsion occur.

[0128] Step 3: Combined with the frequent cracking and failure of the fillet welds connecting the two sides of the header and the pipe row on site, the measurement point layout design is carried out, such as Figure 4 As shown. By monitoring the three-dimensional expansion of the pipe row and the header respectively, it is possible to determine whether the two are expanding asynchronously relative to each other. The expansion measurement points arranged in step 1 above cover the four corners of the front, rear, left and right walls, so expansion monitoring points are arranged at the adjacent pipe row positions at the four corners to determine the relative expansion of the pipe row and the header.

[0129] Step 4: Combined with the frequent cracking of the fillet welds at the middle position of the segmented header and the pipe bank connection, the measurement point layout design is carried out, such as Figure 5 By monitoring the three-dimensional expansion of the tube bank and the header respectively, it can be determined whether the two are expanding asynchronously relative to each other.

[0130] The measuring points of the following water-cooled wall intermediate mixing header and water-cooled wall lower header are arranged in the same way as the water-cooled wall upper header.

[0131] 2) Water-cooled wall intermediate mixing header

[0132] Under deep peak regulation, the wide fins of the water-cooled wall intermediate header and the four-corner fins of the spiral section are prone to fin cracking. At the same time, the rigid hanger of the water-cooled wall intermediate header has a large area of ​​unloading and emptying, and the header deviates from the design position abnormally, resulting in abnormal stress on the corner weld of the header pipe seat and abnormal stress cracking of the fin. Figure 6 As shown in the figure, the principles for determining the arrangement of measuring points for these problems are as follows:

[0133] Step 1: Determine the actual expansion reference point of the boiler water wall mixing header. Set up 4 expansion center monitoring points on the left and right sides and front and back of the boiler;

[0134] Step 2: Determine the overall expansion posture of the water-cooled wall intermediate header, and monitor whether the overall expansion of the intermediate header is deflected or twisted. Set 8 monitoring points for the overall expansion posture of the front, rear, left, and right wall headers;

[0135] Step 3: Determine the vulnerable parts of the four corners of the vertical water-cooled wall and the relative expansion of the tube row and the header. Set up 4 monitoring points;

[0136] Step 4: Determine the expansion of the four corners of the spiral water wall where the fins are prone to cracking and the relative expansion of the tube row and the header. Monitoring point 4.

[0137] 3) Water-cooled wall lower header

[0138] The header under the water-cooled wall is generally long, and the length varies according to the capacity of different units. For example, the header of a million-unit unit is more than 30 meters long. The expansion displacement on both sides of the header is the largest under the heat state, so the expansion of the header and the pipe seat is often asynchronous, causing the corner weld of the pipe seat to frequently crack due to abnormal stress. Figure 7 As shown in the figure, the principles for determining the arrangement of measuring points for these problems are as follows:

[0139] Step 1: Determine the actual expansion reference point of the boiler water wall lower header. Set up two expansion center monitoring points on the left and right sides of the boiler (headers);

[0140] Step 2: Determine the overall expansion posture of the water-cooled wall lower header, and monitor whether the overall expansion of the lower header is deflected or twisted. There are 4 monitoring points for the overall expansion posture of the front and rear wall headers;

[0141] Step 3: Determine the relative expansion of the pipe row and the header, and monitor whether there is any relative expansion anomaly. There are 4 monitoring points for the relative expansion of the front and rear wall headers and the pipe row.

[0142] (3) Communication method

[0143] Solution 1: Power plant self-organizing network solution and 4G network composite networking solution.

[0144] This solution combines the advantages of LoRa (LongRange) wireless communication technology and 4G LTE mobile communication network to achieve wide coverage and low power consumption data transmission. This solution is suitable for environments that require real-time monitoring and data collection through remote devices and cloud systems. Its core structure is to use LoRa for local transmission and send data to the cloud or remote server through the 4G network.

[0145] LoRa Data Gateway: LoRa technology is used to achieve long-distance wireless data transmission, which can effectively cover the key nodes of a wide-area power plant. LoRa nodes are arranged at different monitoring points to collect key data such as expansion monitoring data, temperature, pressure, etc. of the equipment.

[0146] 4GLTE communication: The LoRa data gateway is connected to the 4GLTE network, and the gateway is responsible for transmitting the collected data to the remote server through the 4GLTE network. 4G communication can ensure the reliability of remote communication when the signal is strong, which is convenient for cloud management or remote monitoring.

[0147] Backend server: The core of this solution is to store all collected data on a cloud server, which can be accessed by remote device managers at any time via the Internet or mobile devices.

[0148] Provide efficient data analysis and decision support to facilitate predictive maintenance and real-time alarm of equipment.

[0149] Solution 2: Power plant self-organizing network solution.

[0150] The solution completely relies on LoRa self-organizing network technology, realizing independent data transmission and monitoring without relying on external networks (such as 4G). Each monitoring point is connected through LoRa relay to form a complete self-organizing network, which transmits the monitoring data to the server inside the power plant for internal monitoring and analysis.

[0151] LoRa self-organizing network: LoRa technology serves as the only means of data transmission in this solution, and the monitoring points transmit data through LoRa relays. Each LoRa relay node transfers data to areas with poor signals, ensuring that data can be transmitted stably even in complex power plant environments and weak signals.

[0152] Internal data gateway: All data transmitted through the LoRa network is finally collected in the LoRa data gateway inside the power plant. The gateway is responsible for collecting and integrating data from all monitoring points.

[0153] Internal server of power plant: Different from solution 1, the data of this solution is concentrated on the server inside the power plant, without relying on external cloud system. This enhances the security and independence of data.

[0154] The internal server is responsible for data storage, processing and analysis, and provides local monitoring through the intranet.

[0155] (4) Data display functions and modules

[0156] The seven functional modules of the online monitoring method for header expansion work closely together to achieve comprehensive monitoring and efficient management of boiler equipment. The design and implementation of these modules are aimed at improving the safety, stability and efficiency of equipment operation, especially in operating environments with high load fluctuations and complex working conditions.

[0157] 1. Equipment management module: This module not only supports the daily management of monitoring equipment, but also includes the function of remote control of equipment. Operators can adjust key parameters such as equipment start and stop, calibration, and data collection frequency in real time according to the working status of the equipment. Equipment fault detection and automated maintenance reminder functions can effectively reduce human operating errors and maintenance cycles, and improve the working reliability of equipment. By monitoring the operating status of the equipment in real time, the system can detect and diagnose potential equipment failures in the first place, so as to provide early warning and handle problems before they become serious.

[0158] 2. Threshold management module: The core function of this module is to flexibly set the safety threshold of the monitoring point according to the different working conditions of the boiler. By setting the thresholds under different load conditions, especially the strict standards under peak load conditions, the system can adapt to the real-time changes in boiler conditions and ensure the data accuracy and alarm reliability of each monitoring point. The dynamic adjustment capability of the threshold enables the system to maintain the most efficient monitoring at different operating stages of the boiler, effectively avoiding excessive warnings or missed reports.

[0159] 3. Monitoring status module: By monitoring the expansion data in real time and displaying the data in a visual form, the operator can intuitively see the operating status of the equipment and determine whether abnormal expansion or distortion occurs. The system uses charts to display the expansion trend and supports dynamic data updates to ensure that the status of all monitoring points is reflected in real time, helping operators to detect potential problems in a timely manner. In addition, the monitoring status module also supports real-time alarms. Once the data exceeds the set threshold, the system will automatically trigger an alarm and prompt the operator to take emergency measures.

[0160] 4. Historical data module: The historical data module not only provides long-term recording and storage of expansion data, but also has powerful data query and analysis functions. Users can select different time periods for data backtracking and analyze the long-term change trend of expansion displacement. Through trend analysis, the system can help operators identify the long-term operation mode and potential hidden dangers of equipment, and discover signs of equipment aging or damage in advance, thereby avoiding sudden failures. The data export function allows data to be used for further external analysis, report generation or technical research.

[0161] 5. Alarm management module: The alarm management module performs intelligent analysis based on the real-time data collected by the system. When the monitored data exceeds the set safety threshold, the system will automatically issue an alarm. There are multiple levels of alarms, ranging from general warnings to emergency alarms, to ensure that operators take appropriate countermeasures according to different alarm levels. Alarm notification methods include SMS, email, message push, etc., to ensure that information can be conveyed to relevant personnel in a timely manner and minimize the risks caused by equipment failure. The alarm management module can also provide historical records of alarms for subsequent analysis and tracking.

[0162] 6. Intranet data module: This module is responsible for the transmission management of boiler monitoring data in the internal network of the power plant, ensuring that data transmission is not affected by network failures or interference. Through real-time monitoring of network status, the system can promptly detect network anomalies and ensure the security and stability of data transmission. The intranet data module also supports synchronous data backup to ensure the integrity and security of monitoring data. When necessary, the system can interact with the external network for remote monitoring, data sharing or cross-platform analysis.

[0163] 7. Measurement point log module: In order to further enhance the reliability and traceability of the monitoring system, the measurement point log module records the operation history of each monitoring point, including key operations such as equipment start and stop, calibration, and alarm triggering. These logs can provide an important basis for equipment maintenance, troubleshooting, and data analysis. Through classified query and analysis of logs, operators can easily understand the historical status, alarm status, and changes in the operation of each measurement point, and promptly identify potential problems and take measures.

[0164] Through the close cooperation of these functional modules, the online monitoring method of header expansion realizes comprehensive monitoring of boiler equipment and ensures the safety and reliability of equipment under complex operating conditions. The system can not only alarm in time when the equipment is abnormal, but also help operators foresee potential problems through trend analysis and historical data backtracking, so as to prevent them before they happen. Finally, the online monitoring system of header expansion effectively reduces equipment failures, improves the working efficiency of boilers, and provides strong guarantee for the safe operation of power plants through intelligent management and operation.

[0165] The technical solution provided by the present invention is further described in detail through the above specific implementation modes in order to highlight the advantages and benefits of the technical solution provided by the present invention. However, the above specific implementation modes are not intended to limit the present invention. Any reasonable modification and improvement of the present invention, combination of implementation modes and equivalent substitution within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0166] Those skilled in the art will appreciate that the above are only preferred embodiments of the present invention, and the various embodiments of the present disclosure and / or the features described in the claims may be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or perform equivalent substitutions on some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0167] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for arranging the expansion measurement point positions of a peak-shaving boiler water-cooled wall header, wherein the boiler water-cooled wall header comprises an integral header and tube banks on both sides, a segmented header and a tube bank in the middle, characterized in that: The method comprises the following steps: S1. Determine the actual expansion center of the boiler water wall header and obtain the expansion displacement data of the boiler water wall header; S2. Design the measurement point positions on the integral header and the tube banks on both sides thereof according to the expansion displacement data of S1; S3. Based on the expansion displacement data of S1, design the measurement point locations on the segmented header and the pipe row in the middle.

2. The arrangement method according to claim 1, characterized in that: The S1 is: 8 measuring points are set on the boiler water-cooled wall header, and the 8 measuring points are respectively located at the left, right, front and rear expansion centers of the boiler water-cooled wall header, as well as the lower left corner measuring point (1), the lower right corner measuring point (2), the upper right corner measuring point (3) and the upper left corner measuring point (4) when viewed from the top. The lower left corner, the lower right corner, the upper right corner and the upper left corner when viewed from the top form a plane rectangle, and the initial expansion center C is set at a rearward position of the center in the plane rectangle. The distances of the initial expansion center C from the left, right, rear and front of the plane rectangle are L1, L2, L3 and L4 respectively; The amount of expansion to the left of the lower left corner measuring point (1) is ΔL 左 , the rightward expansion of the lower right corner measuring point (2) is ΔL 右 , If ΔL 左 > ΔL 右 , The expansion center is offset to the left by ΔL 左 -ΔL 右 , If ΔL 左 <ΔL 右 , The expansion center is offset to the right by ΔL 右 -ΔL 左 , The method for locating the actual expansion center position of the front and rear sides is: Assume that the expansion amount of the upper left measuring point (4) toward the back of the furnace is Assume that the expansion amount of the lower left measuring point (1) toward the furnace is The actual expansion amount of the upper left corner measuring point (4) toward the back of the furnace is The actual expansion amount of the lower left corner measuring point (1) toward the furnace is At full load, if and The expansion centers of the front and rear sides remain in their original positions. At full load, if and If the expansion center of the front and rear sides changes, further judgment is made: like and The forward displacement of the expansion center is like and The expansion center is offset backwards by Among them, α is the expansion coefficient and ΔT is the temperature change.

3. The arrangement method according to claim 1, characterized in that: The S2 is: arranging measuring points at the connecting corners of the tube rows adjacent to the four corners of the top of the integral header, combining S1 to obtain the expansion displacement data of the boiler water-cooled wall header, obtaining the expansion offset of the integral header and the tube rows on both sides thereof, and adjusting the positions of the measuring points according to the expansion offset.

4. The arrangement method according to claim 1, characterized in that: The S3 is: arranging measuring points at the connecting corners of the tube rows adjacent to the top four corners of the middle section of the segmented header, combining S1 to obtain the expansion displacement data of the boiler water-cooled wall header, obtaining the offset of the segmented header and the tube row in the middle, and adjusting the position of the measuring points according to the expansion offset.

5. The arrangement method according to claim 1, characterized in that: The boiler water-cooled wall header includes an upper water-cooled wall header, an intermediate water-cooled wall mixing header and a lower water-cooled wall header. The upper water-cooled wall header, the intermediate water-cooled wall mixing header and the lower water-cooled wall header are arranged with measuring points in the same way.

6. The arrangement method according to claim 2, characterized in that: The initial expansion center C becomes a changed expansion center C' after expansion in the boiler water wall header. The distances of the changed expansion center C' from the left, right, back and front of the plane rectangle are L1', L2', L3' and L4' respectively.

7. The arrangement method according to claim 2, characterized in that: After the boiler water-cooled wall header is deflected, the lower left corner measuring point (1), the lower right corner measuring point (2), the upper right corner measuring point (3), and the upper left corner measuring point (4) become the lower left corner measuring point (X1) after deflection, the lower right corner measuring point (X2) after deflection, the upper right corner measuring point (X3) after deflection, and the upper left corner measuring point (X4) after deflection; after the boiler water-cooled wall header is deflected, the lower left corner measuring point (1), the lower right corner measuring point (2), the upper right corner measuring point (3), and the upper left corner measuring point (4) become the lower left corner measuring point (Y1) after twisting, the lower right corner measuring point (Y2) after twisting, the upper right corner measuring point (Y3) after twisting, and the upper left corner measuring point (Y4) after twisting.

8. An online monitoring method for the expansion of a water-cooled wall header of a peak-shaving boiler, characterized in that: The online monitoring method is: F1. Fixed position measurement of all measuring points obtained by any one of the arrangement methods of claims 1 to 7; F2, collect the data fed back from all measuring points in real time as expansion data; F3. Obtaining expansion data of each measuring point according to the expansion data; F4. Obtain expansion abnormality data based on all expansion data; F5. Generate and output alarm information according to the abnormal expansion data, wherein the alarm information includes: abnormal expansion state and corresponding measuring point position; F6, store all expansion data; F7. Draw a boiler water wall header expansion trend analysis chart based on all stored expansion data.

9. The online monitoring method according to claim 8, characterized in that: Based on the data feedback from the measuring points of the connection angle positions of the adjacent tube rows at the four corners of the top of the integral header, the three-dimensional expansion of the integral header and the tube rows on both sides of it is obtained, and the synchronization of the relative expansion of the integral header and the tube rows on both sides of it is judged. Based on the synchronization, the expansion displacement data of the integral header and the tube rows on both sides of it are obtained.

10. The online monitoring method according to claim 8, characterized in that: Based on the feedback data of the measuring points of the connection angle positions of the adjacent tube rows at the top four corners of the middle section of the segmented header, the three-dimensional expansion amount of the segmented header and its intermediate tube row is obtained, the synchronization of the relative expansion of the segmented header and its intermediate tube row is judged, and the expansion displacement data of the segmented header and its intermediate tube row is obtained based on the synchronization.

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