Power plant boiler heating surface fin overheating crack prevention system

Abstract

This invention discloses a system for preventing overheating and cracking of the heating surface fins in a power plant boiler. The system, used in power plant boilers, includes: heating surface tubes extending along a first direction, multiple heating surface tubes spaced apart along a second direction; fins connecting adjacent heating surface tubes; and rib structures disposed on the wall surface of the fins facing the outer side of the furnace, with the rib structures located in the middle region of the fins along the second direction. According to this invention, by adding rib structures to the wall surface of the fins facing the outer side of the furnace, and with the rib structures located in the middle region of the fins along the second direction, the system can effectively dissipate heat from the middle region of the fins along the second direction without changing the fin width, overcoming the problem of fin cracking caused by fin overheating in the prior art, which leads to cracking and leakage of the heating surface tubes.

Description

Technical Field

[0001] This invention relates to the field of overheating crack prevention technology for heating surface fins of power plant boilers, and in particular to a system for preventing overheating cracking of heating surface fins in power plant boilers. Background Technology

[0002] Currently, leaks in the heated surface tubes caused by fin cracking occur frequently. The causes are generally twofold: expansion mismatch and wide fins. For in-service units, expansion mismatch is relatively easy to resolve, but there is currently no good solution for leaks caused by cracking of wide fins, which seriously affects the normal operation of power plant boilers. Summary of the Invention

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a system for preventing overheating and cracking of the heating surface fins in a power plant boiler. This system can dissipate heat from the fins, preventing cracking and leakage of the heating surface tubes caused by fin cracking, thus ensuring the normal operation of the power plant boiler.

[0004] The overheating crack prevention system for the heating surface fins of a power plant boiler according to an embodiment of the present invention is used in a power plant boiler and includes: a heating surface tube extending along a first direction, wherein there are multiple heating surface tubes, and the multiple heating surface tubes are spaced apart in a second direction; fins, wherein fins are connected between two adjacent heating surface tubes; and a rib structure disposed on the wall surface of the fins facing the outside of the furnace, wherein the rib structure is located in the middle region of the fins along the second direction.

[0005] The overheating crack prevention system for the heating surface fins of a power plant boiler according to an embodiment of the present invention, by adding a rib structure to the wall surface of the fins facing the outer side of the furnace, and the rib structure being located in the middle region of the fins along the second direction, can effectively dissipate heat in the middle region of the fins along the second direction without changing the fin width, preventing the temperature of the middle region of the fins along the second direction from becoming too high, overcoming the problem of fin cracking caused by fin overheating in the prior art, which in turn leads to cracking and leakage of the heating surface tubes, and ensuring the normal operation of the power plant boiler.

[0006] In addition, the power plant boiler heating surface fin overheating crack prevention system according to the present invention may also have the following additional technical features:

[0007] In some embodiments, the length of the rib structure in a third direction is adjustable, and the third direction, the first direction, and the second direction are perpendicular to each other.

[0008] In some embodiments, the rib structure includes a plurality of heat sinks connected in sequence, and two adjacent heat sinks are rotatably connected, and the plurality of heat sinks can be stacked along the third direction.

[0009] In some embodiments, the rib structure further includes a hinge, through which any two adjacent heat sinks are connected.

[0010] In some embodiments, the rib structure further includes a driving component, wherein the driving component is provided between any two adjacent heat sinks for driving one of the two adjacent heat sinks to rotate relative to the other.

[0011] In some embodiments, the power plant boiler heating surface fin overheating crack prevention system further includes: a temperature monitoring device, the temperature monitoring device including a first temperature monitoring device and a second temperature monitoring device, the first temperature monitoring device being disposed on the surface of the heating surface tube facing the inner side of the furnace, the second temperature monitoring device being disposed on the wall surface of the fin facing the inner side of the furnace, and the second temperature monitoring device being located in the middle region of the fin along the second direction, the fin structure being configured to adjust the length of the fin structure in the third direction according to the temperature difference between the first temperature monitoring device and the second temperature monitoring device on adjacent heating surface tubes and fins.

[0012] In some embodiments, the first temperature monitoring device is located on the center surface of the heated surface tube along the second direction.

[0013] In some embodiments, the first temperature monitoring device is welded to the heated surface tube; and / or, the second temperature monitoring device is welded to the fins.

[0014] In some embodiments, the rib structure is rotatably connected to the fin; or, the rib structure is welded to the fin.

[0015] In some embodiments, each fin is provided with a plurality of rib structures, and the plurality of rib structures located on the same fin are arranged in the first direction; and / or, the plurality of rib structures located on the same fin are arranged in the second direction.

[0016] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0018] Figure 1 This is a three-dimensional schematic diagram of a power plant boiler heating surface fin overheating crack prevention system according to an embodiment of the present invention;

[0019] Figure 2 This is a top view schematic diagram of a power plant boiler heating surface fin overheating crack prevention system according to an embodiment of the present invention, wherein hinges and drive components are not shown;

[0020] Figure 3 This is a length curve of the temperature difference-rib structure according to an embodiment of the present invention in the third direction.

[0021] Figure label:

[0022] 100. Overheating and cracking prevention system for heating fins in power plant boilers;

[0023] 1. Heated surface tube;

[0024] 2. Fins;

[0025] 3. Finned structure; 31. Heat sink;

[0026] 4. Temperature monitoring device; 41. First temperature monitoring device; 42. Second temperature monitoring device. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention 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 invention.

[0029] Furthermore, 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] The following description, with reference to the accompanying drawings, describes a power plant boiler overheating fin crack prevention system 100 according to an embodiment of the present invention.

[0032] like Figure 2 As shown, the power plant boiler overheating crack prevention system 100 according to an embodiment of the present invention is used in a power plant boiler and includes a heating surface tube 1, fins 2 and rib structure 3.

[0033] Specifically, see the attached document. Figure 1 As shown, the heated surface tube 1 is along the first direction (e.g. Figure 1 As shown), the heating surface tube 1 extends in multiple directions, and the multiple heating surface tubes 1 extend in the second direction (e.g., Figure 1 As shown, the tubes are spaced apart, and fins 2 are connected between two adjacent heat-receiving tubes 1. The two ends of the fins 2 along the second direction are respectively welded to the two adjacent heat-receiving tubes 1 to form an integral heat-receiving surface, which constitutes a membrane heat exchange element.

[0034] The heating surface tube 1 directly absorbs the high-temperature heat from the furnace and transfers it to the cooling medium (usually water) within it, heating the medium into saturated steam. This not only achieves heat energy conversion but also reduces the furnace wall temperature, protecting it from high-temperature damage. The fins 2, as metal extension structures directly welded to the outside of the heating surface tube 1, optimize the heat transfer process by expanding the heat exchange area of ​​the membrane heat exchange element. This significantly increases the contact area with the high-temperature flue gas in the furnace, allowing more heat to be rapidly transferred to the cooling medium within the heating surface tube 1, improving overall heat transfer efficiency. By enhancing heat exchange capacity, it effectively reduces heat loss to the outside through the heating surface tube 1, thus improving the overall thermal efficiency of the power plant boiler heating surface fin overheating crack prevention system 100.

[0035] Further, see Appendix Figure 2 As shown, the rib structure 3 is disposed on the wall surface of the fin 2 facing the outer side of the furnace, and the rib structure 3 is located in the middle region of the fin 2 along the second direction. According to the principle of heat transfer, the rib structure 3 has the function of enhancing heat transfer. Adding the rib structure 3 can make the surface temperature on the side with the rib structure 3 closer to the temperature of the fluid on the same side. The rib structure 3 is disposed on the wall surface of the fin 2 facing the outer side of the furnace, which can enhance the heat transfer coefficient between the fin 2 and the external environment of the furnace, realize effective heat dissipation in the middle region of the fin 2 along the second direction, prevent the temperature of the middle region of the fin 2 along the second direction from being too high, and ensure the normal operation of the power plant boiler.

[0036] In existing technologies, when receiving heat radiation from combustion within a power plant boiler, the internal temperature of the heat exchange tubes is maintained within a controlled range due to the cooling medium. However, the fins connecting adjacent heat exchange tubes can only maintain their own temperature by transferring the radiant heat they receive to the heat exchange tubes on either side. When the fins are smaller in the second direction, the heat exchange tubes connected to both sides of the fins can effectively cool the middle fins. However, in power plant boiler walls, there are unavoidable special locations such as openings, tube joints, and tube-panel connections. The fins in these special locations are larger in the second direction, which can easily lead to excessively high temperatures in the middle area of ​​the fins along the second direction, creating a temperature difference with the adjacent heat exchange tubes. If the temperature difference between the fins and the heat exchange tubes is large, significant expansion stress will be generated, causing the fins to tear under the pressure of expansion stress. This tearing can then extend to the heat exchange tubes on both sides, leading to leakage and failure of the cooling medium within the heat exchange tubes.

[0037] The present invention adds a rib structure 3 to the wall surface of the fin 2 facing the outer side of the furnace, and the rib structure 3 is located in the middle region of the fin 2 along the second direction. This can effectively dissipate heat in the middle region of the fin 2 along the second direction without changing the width of the fin 2, preventing the temperature of the middle region of the fin 2 along the second direction from being too high. This overcomes the problem of fin cracking caused by fin overheating in the prior art, which leads to cracking and leakage of the heated surface tube, and ensures the normal operation of the power plant boiler.

[0038] For example, the fins 2 with a size greater than 20mm in the second direction are wide fins. A rib structure 3 can be added to the wall surface of the wide fins facing the outside of the furnace to dissipate heat from the wide fins, so as to avoid the temperature difference between the middle area of ​​the wide fins along the second direction and the heating surface tube 1 exceeding 100℃, thereby avoiding cracking of the wide fins and thus avoiding cracking and leakage of the heating surface tube 1.

[0039] The power plant boiler overheating crack prevention system 100 according to an embodiment of the present invention provides a rib structure 3 on the wall surface of the fin 2 facing the outside of the furnace, with the rib structure 3 located in the middle region of the fin 2 along the second direction. This system can effectively dissipate heat in the middle region of the fin 2 along the second direction without changing the width of the fin 2, preventing the temperature of the middle region of the fin 2 along the second direction from becoming too high. This overcomes the problem of fin cracking caused by fin overheating in the prior art, which leads to cracking and leakage of the heating surface tube, and ensures the normal operation of the power plant boiler.

[0040] In some embodiments of the present invention, reference is made to the appendix. Figure 2 As shown, the rib structure 3 in the third direction (see attached diagram) Figure 2 The length of the rib structure 3 in the inner and outer directions is adjustable. The third direction is the inner and outer direction of the furnace. The third direction, the first direction and the second direction are perpendicular to each other. By adjusting the length of the rib structure 3 in the third direction, the heat dissipation area of ​​the rib structure 3 can be changed, and the heat exchange area between the fin 2 and the external medium of the furnace can be changed, thereby adjusting the heat dissipation of the rib structure 3.

[0041] It should be noted that the heat dissipation formula for fin structure 3 is as follows: The physical meanings of each parameter are as follows:

[0042] Φ (Heat dissipation): Represents the amount of heat lost to the surrounding medium through the fin structure 3 per unit time, measured in watts (W). It is a key indicator for measuring the heat dissipation capacity of the fin structure 3 and reflects the amount of energy transferred by the fin structure 3 during the heat transfer process.

[0043] h (convective heat transfer surface heat transfer coefficient): represents the intensity of convective heat transfer between the surface of the finned structure 3 and the surrounding fluid, and is measured in W / (m²). 2 The value of h depends on the properties of the fluid (such as flow velocity, specific heat capacity, thermal conductivity, etc.), the flow state (laminar or turbulent), and the surface condition of the finned structure 3. The larger h is, the more heat can be transferred between the finned structure 3 and the surrounding fluid under the same temperature difference, that is, the stronger the convective heat transfer capacity.

[0044] λ (thermal conductivity of rib structure 3): is a physical quantity that measures the thermal conductivity of rib structure 3, with the unit being W / (m·K). The higher the thermal conductivity, the stronger the material's ability to conduct heat. Inside rib structure 3, heat can be transferred more quickly from the higher temperature part to the lower temperature part, which is conducive to the dissipation of heat from the surface of rib structure 3 into the surrounding medium.

[0045] P (perimeter of fin structure 3): The unit is meters (mm). It determines the boundary length of the contact between fin structure 3 and the surrounding fluid. The larger the perimeter, the larger the contact area between fin structure 3 and the external fluid. In the process of convective heat transfer, there is more area to exchange heat with the fluid, which directly affects the heat dissipation.

[0046] A (Cross-sectional area of ​​rib structure 3 perpendicular to the third direction): The unit is square meters (㎡). It reflects the effective heat transfer area of ​​rib structure 3 perpendicular to the heat flow direction. The larger the cross-sectional area, the more heat can be transferred during the heat conduction process, because more material participates in the heat conduction, providing a larger channel for the heat transfer inside rib structure 3.

[0047] θ = to - t ∞ (Temperature difference between rib structure 3 and the surrounding fluid): to is the rib base temperature, t ∞ The temperature of the surrounding fluid is expressed in degrees Celsius (°C) or Kelvin (K). The temperature difference θ is the driving force for heat transfer. The greater the temperature difference, the stronger the tendency for heat to transfer from the finned structure 3 to the surrounding fluid, according to the basic principles of heat conduction and convection, and the greater the heat dissipation.

[0048] m (parameters related to the geometric parameters, material properties, and convective heat transfer conditions of fin structure 3): m comprehensively considers the influence of factors such as surface heat transfer coefficient, perimeter of fin structure 3, thermal conductivity, and cross-sectional area on the heat dissipation of fin structure 3. The larger the value of m, the stronger the heat dissipation capacity of fin structure 3. It affects the heat dissipation in the formula through the term tanh(mH), reflecting the comprehensive effect of the geometry, material properties, and surrounding convective heat transfer environment of fin structure 3 on the heat dissipation effect.

[0049] H (length of rib structure 3 in the third direction): The unit is meters (mm), which is the length of rib structure 3 in the heat transfer direction. Figure 2 The dimensions shown in the internal and external directions indicate that increasing the length of the fin structure 3 usually increases the heat dissipation area, which is beneficial for heat dissipation. However, it is also constrained by the tanh(mH) function and is not a simple linear relationship. When mH is large, tanh(mH) approaches 1. At this time, the effect of increasing the length of the fin structure 3 on improving heat dissipation will gradually weaken.

[0050] From the heat dissipation formula of fin structure 3, it can be seen that, under the condition that other conditions remain unchanged, increasing the heat transfer direction of fin structure 3 ( Figure 2 The dimensions in the inward and outward directions shown can increase the heat dissipation area of ​​the fin structure 3, thereby increasing the heat dissipation of the fin structure 3.

[0051] In a further embodiment of the invention, reference is made to the appendix. Figure 2As shown, the fin structure 3 includes multiple heat dissipation plates 31, which are connected sequentially and rotatably connected to adjacent heat dissipation plates 31. The multiple heat dissipation plates 31 can be stacked along a third direction. Through the rotatable connection between adjacent heat dissipation plates 31, the fin structure 3 can be unfolded into a larger area, thereby increasing the contact area between the fin structure 3 and the external medium of the furnace and improving the heat dissipation efficiency of the fin structure 3. Furthermore, the rotatably connected heat dissipation plates 31 can be adjusted according to the installation environment and space constraints of the power plant boiler heating surface fin overheating crack prevention system 100 to adapt to different heat dissipation requirements. At the same time, the rotatably connected heat dissipation plates 31 also facilitate the disassembly and assembly of the fin structure 3, making it convenient for users to clean and maintain.

[0052] When the fin structure 3 is in its initial state, the heat sink 31 closest to the fin 2 is in contact with the fin 2, and the remaining heat sinks 31 are stacked sequentially along the third direction. When it is necessary to increase the length of the fin structure 3 in the third direction, the heat sink 31 farthest from the fin 2 is rotated open. At this time, the plane of the heat sink 31 farthest from the fin 2 is perpendicular to the plane of the second farthest heat sink 31. When it is necessary to increase the length of the fin structure 3 in the third direction again, the heat sink 31 second farthest from the fin 2 is rotated open. At this time, the heat sink 31 farthest from the fin 2 and the second farthest heat sink 31 are located in the same plane, and the plane of the second farthest heat sink 31 is perpendicular to the plane of the third farthest heat sink 31. This process continues until all heat sinks 31 are located in the same plane, and the plane of the multiple heat sinks 31 is perpendicular to the first direction.

[0053] It is understandable that there is a first state and a second state between two adjacent heat sinks 31. In the first state, the two adjacent heat sinks 31 are stacked along the third direction. In the second state, the two adjacent heat sinks 31 are in the same plane. When the two adjacent heat sinks 31 change from the first state to the second state, the length of the fin structure 3 in the third direction increases, which can increase the overall heat dissipation area of ​​the fin structure 3 and increase the heat dissipation of the fin structure 3.

[0054] For example, depending on the space outside the furnace of different electric boilers, the number of heat dissipation plates 31 in the fin structure 3 can be two, three, four, five, or six to meet different heat dissipation requirements. In a specific example, refer to the appendix... Figure 2As shown, the rib structure 3 includes two heat dissipation plates 31, which are a first heat dissipation plate 31 and a second heat dissipation plate 31, respectively. The first heat dissipation plate 31 and the second heat dissipation plate 31 are rotatably connected. In the first state, the first heat dissipation plate 31 is attached to the wall surface of the fin 2 facing the outside of the furnace, and the second heat dissipation plate 31 is stacked on the side of the first heat dissipation plate 31 facing away from the fin 2. In the second state, the second heat dissipation plate 31 rotates relative to the first heat dissipation plate 31, so that the second heat dissipation plate 31 extends towards the outside of the furnace.

[0055] Preferably, the heat dissipation plate 31 is a rectangular steel plate, which can meet the heat dissipation required by the rib structure 3 while ensuring the structural strength of the rib structure 3. It has good heat dissipation performance and simple manufacturing process, which facilitates the production and processing of the rib structure 3.

[0056] In a further embodiment of the present invention, the rib structure 3 also includes a hinge, and any two adjacent heat dissipation plates 31 are connected by a hinge. The hinge can ensure the rotational connection between two adjacent heat dissipation plates 31, reduce friction at the hinge connection, make the relative rotation between two adjacent heat dissipation plates 31 smoother, and the hinge has high durability, rust resistance and convenient installation and adjustment, which facilitates the assembly of the rib structure 3 and can ensure the normal operation of the power plant boiler.

[0057] In a further embodiment of the present invention, the rib structure 3 further includes a driving component, and a driving component is provided between any two adjacent heat sinks 31 to drive one of the two adjacent heat sinks 31 to rotate relative to the other, so as to ensure that the rib structure 3 can be unfolded into a larger area, thereby increasing the contact area between the rib structure 3 and the external medium of the furnace and improving the heat dissipation efficiency of the rib structure 3.

[0058] In a further embodiment of the invention, reference is made to the appendix. Figure 1 and attached Figure 2As shown, the power plant boiler heating surface fin overheating crack prevention system 100 also includes a temperature monitoring device 4. The temperature monitoring device 4 includes a first temperature monitoring device 41 and a second temperature monitoring device 42. The first temperature monitoring device 41 is disposed on the surface of the heating surface tube 1 facing the inner side of the furnace, and the second temperature monitoring device 42 is disposed on the wall surface of the fin 2 facing the inner side of the furnace. The second temperature monitoring device 42 is located in the middle region of the fin 2 along the second direction. The fin structure 3 is configured to monitor the first temperature monitoring device 41 and the second temperature monitoring device 42 on adjacent heating surface tubes 1 and fins 2. The temperature difference between the temperature monitoring devices 42 adjusts the length of the fin structure 3 in the third direction. The first temperature monitoring device 41 and the second temperature monitoring device 42 are respectively used to accurately monitor the temperature of the heated surface tube 1 and the fin 2, realizing real-time monitoring of the temperature and stress of the heated surface tube 1 and the fin 2. This allows for timely adjustment of the length of the fin structure 3 in the third direction, keeping the temperature of the fin 2 within a safe range. Positioning the second temperature monitoring device 42 in the middle region along the second direction of the fin 2 allows for more accurate measurement of the maximum temperature of the fin 2. Furthermore, by adding the temperature monitoring device 4, the arrangement position, length, and length of the fin structure 3 in the third direction can be determined to solve the problem of fin 2 overheating.

[0059] When the temperature difference between the first temperature monitoring device 41 and the second temperature monitoring device 42 on adjacent heated surface tubes 1 and fins 2 exceeds a preset temperature difference, at least part of the drive assembly drives relative rotation between the two adjacent heat sinks 31. In a specific example, the actual temperature difference collected between the first temperature monitoring device 41 and the second temperature monitoring device 42 is ΔT. c The preset critical temperature difference is ΔT cm Set the critical temperature difference ΔT cm =100℃ is the over-temperature alarm temperature, when the actual collected temperature difference ΔT c ≥T cm At this time, the drive system drives one of the two adjacent heat sinks 31 to rotate relative to the other, thereby increasing the length of the fin structure 3 in the third direction, until the actual temperature difference ΔT is measured. c <T cm .

[0060] Optionally, the first temperature monitoring device 41 can be a plurality of devices spaced apart in the first direction of the heated surface tube 1 to improve the accuracy of the temperature measured by the first temperature monitoring device 41 at the heated surface tube 1. The second temperature monitoring device 42 can be a plurality of devices spaced apart in the first direction of the fins 2 to improve the accuracy of the temperature measured by the second temperature monitoring device 42 in the middle region of the fins 2, thereby enabling the fin structure 3 to be adjusted to the required length more accurately.

[0061] Specifically, considering the harsh environment of flames, flue gas, and fly ash inside the furnace, the heating surface tube 1 and fins 2 are subjected to high temperature and high stress for extended periods. Both the first temperature monitoring device 41 and the second temperature monitoring device 42 are quartz fiber optic temperature monitoring devices 4. Each quartz fiber optic temperature monitoring device 4 includes a blackbody cavity sensor, a blackbody cavity tube, a quartz fiber optic temperature probe, a detection fiber, and connecting components. The heat collector block, acting as the blackbody cavity sensor, can be fixed inside the furnace via the connecting components, allowing the heat collector block to fully contact the heating surface tube 1 and fins 2, thus reducing the temperature of the heat collector block. The blackbody cavity sensor is then subjected to the temperature changes within the furnace. The heat generated by the heated surface tube 1 and fins 2 produces blackbody radiation, which enters the containment cavity defined by the blackbody cavity tube. The quartz fiber optic temperature sensor extends into the heat collection block, collects the blackbody radiation in the containment cavity, and processes it to form an optical signal. After the detection fiber detects the optical signal, it can be converted into a voltage signal by a photodetector, and then processed by a terminal processor to form a temperature value. This temperature value is the detected temperature value of the heated surface tube 1 and fins 2 in the furnace, which can ensure the accuracy of the temperature at the heated surface tube 1 and fins 2 in the furnace and protect the quartz fiber optic temperature sensor from the influence of harsh environments.

[0062] In a further embodiment of the invention, reference is made to the appendix. Figure 1 and attached Figure 2 As shown, the first temperature monitoring device 41 is located on the center plane of the heated surface tube 1 along the second direction, so as to accurately measure the highest temperature of the heated surface tube 1 and ensure the accuracy of calculating the temperature difference between the first temperature monitoring device 41 and the second temperature monitoring device 42.

[0063] In a further embodiment of the present invention, the first temperature monitoring device 41 is welded to the heated surface tube 1, which can ensure the reliability and stability of the first temperature monitoring device 41, realize real-time monitoring of the temperature of the heated surface tube 1, reduce heat loss and interference in the heat transfer process, and more accurately reflect the actual temperature of the heated surface tube 1.

[0064] Furthermore, the second temperature monitoring device 42 is welded to the fin 2, which can ensure the reliability and stability of the second temperature monitoring device 42, realize real-time monitoring of the temperature of the fin 2, reduce heat loss and interference in the heat transfer process, and more accurately reflect the actual temperature of the fin 2.

[0065] In some embodiments of the present invention, the rib structure 3 is rotatably connected to the fin 2, which can make full use of the structure of the rib structure 3, so that the length of the rib structure 3 in the third direction can be as large as possible, and the contact area between the rib structure 3 and the external medium of the furnace can be increased as much as possible according to the user's needs, thereby improving the heat dissipation efficiency of the rib structure 3.

[0066] Alternatively, the rib structure 3 can be welded to the fin 2, which can ensure the reliability and stability of the connection between the rib structure 3 and the fin 2, ensure the effective heat dissipation of the rib structure 3 to the middle area of ​​the fin 2 along the second direction, prevent the temperature of the middle area of ​​the fin 2 along the second direction from being too high, and ensure the normal operation of the power plant boiler.

[0067] In some embodiments of the present invention, each fin 2 is provided with multiple rib structures 3, and the multiple rib structures 3 located on the same fin 2 are arranged in a first direction, and / or, the multiple rib structures 3 located on the same fin 2 are arranged in a second direction. The arrangement of multiple rib structures 3 can further effectively dissipate heat from the fin 2 without changing the width of the fin 2, prevent the fin 2 from cracking due to excessive temperature, and thus avoid cracking and leakage of the heated surface tube 1, thereby ensuring the normal operation of the power plant boiler.

[0068] It is understood that each fin 2 is provided with multiple rib structures 3, which may be multiple rib structures 3 arranged at intervals along a first direction, or multiple rib structures 3 arranged at intervals along a second direction, or multiple rib structures 3 may include multiple groups of ribs spaced apart along the first direction, with each group of ribs including multiple rib structures 3 spaced apart along the second direction.

[0069] For example, each fin 2 may have six rib structures 3. These six rib structures 3 may be located on the center line of the fin 2 along the second direction, and spaced apart in the first direction; or the six rib structures 3 may be spaced apart in the second direction; or the six rib structures 3 may be arranged in a two-row, three-column matrix, forming two groups of ribs spaced apart in the first direction, each group including three rib structures 3 spaced apart in the second direction; or the six rib structures 3 may be arranged in a three-row, two-column matrix, forming three groups of ribs spaced apart in the first direction, each group including two rib structures 3 spaced apart in the second direction.

[0070] Understandably, the control methods for the power plant boiler fin overheating crack prevention system 100 include:

[0071] A power plant boiler overheating crack prevention system 100 is installed on the actual power plant boiler. The temperature difference between the first temperature monitoring device 41 and the second temperature monitoring device 42 on the adjacent heating surface tube 1 and fin 2 during the actual operation of the power plant boiler is collected. The correspondence between the temperature difference and the length of the required fin structure 3 in the third direction is established, and a reference curve of temperature difference-fin structure 3 in the third direction is plotted.

[0072] The drive assembly is operated based on the temperature difference-fin structure 3 length reference curve in the third direction to achieve real-time control of the fin structure 3 length in the third direction, ensuring the actual temperature difference ΔT between the heated surface tube 1 and the fin 2. c <ΔT cm .

[0073] During the shutdown of the power plant boiler, several rib structures 3 are arranged at the actual overheating location of the widest fin where the high-temperature radiation in the furnace is most severe. A second temperature monitoring device 42 is arranged at the center of the wide fin inside the furnace, and a first temperature monitoring device 41 is arranged at the heat-receiving surface tube 1 adjacent to the wide fin inside the furnace. The temperatures measured by the first temperature monitoring device 41 and the second temperature monitoring device 42 are T1 and T2, respectively, and the temperature difference ΔT measured by the first temperature monitoring device 41 and the second temperature monitoring device 42 is recorded. c =T2-T1 is used as a control parameter.

[0074] During the operation of the power plant boiler, the initial temperature difference ΔT between the centerline of fin 2 along the second direction and the adjacent heated surface tube 1 is collected. c0 .

[0075] Adjust the overheating crack prevention system of the power plant boiler heating surface fins 100 until ΔT c1 =120℃, record the length dH of the rib structure 3 in the third direction at this time.

[0076] Adjust the overheating crack prevention system of the power plant boiler heating surface fins 100 until ΔT c2 =100℃, record the length cH of the rib structure 3 in the third direction at this time.

[0077] Adjust the overheating crack prevention system of the power plant boiler heating surface fins 100 until ΔT c3 =80℃, record the length bH of the rib structure 3 in the third direction at this time.

[0078] Adjust the overheating crack prevention system of the power plant boiler heating surface fins 100 until ΔT c4 =60℃, record the length aH of the rib structure 3 in the third direction at this time.

[0079] like Figure 3 As shown, the temperature difference (ΔT) between the centerline of the inner fin 2 of the furnace along the second direction and the adjacent heated surface tube 1 is... c Using ℃ as the x-axis and the length (H) of rib structure 3 in the third direction as the y-axis, mark ΔT sequentially on the coordinate graph. cThe lengths dH, cH, bH, and aH of the rib structure 3 in the third direction corresponding to 120℃, 100℃, 80℃, and 60℃ are smoothly connected to form the reference curve of temperature difference-length of rib structure 3 in the third direction.

[0080] During power plant boiler shutdown, for all fins 2 with a length exceeding 20mm along the third direction in the high-radiation direction, the plotted temperature difference-fin structure 3 length reference curve in the third direction is input into the power plant boiler heating surface fin overheating crack prevention system 100, and the length of the fin structure 3 in the third direction is adjusted according to this curve. During power plant boiler operation, based on the real-time temperature difference between the centerline of the fin 2 along the second direction and the adjacent heating surface tube 1, the length of the fin structure 3 in the third direction is adjusted to achieve real-time control of the fin length along the third direction, ensuring the actual temperature difference ΔT c <ΔT cm .

[0081] Other components and operations of the power plant boiler overheating crack prevention system 100 according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0082] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0083] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A system for preventing overheating cracking of a finned heating surface of a utility boiler, characterized by, A boiler for a power plant, comprising: heating surface tubes extending in a first direction, the heating surface tubes being a plurality of the heating surface tubes being spaced apart in a second direction; fins connected between two adjacent heating surface tubes; a fin structure provided on a wall surface of the fin facing an outside of a furnace, the fin structure being located in a middle region of the fin in the second direction, the fin structure being adjustable in length in a third direction, the third direction, the first direction and the second direction being perpendicular to each other, the fin structure comprising a plurality of heat dissipation plates connected in sequence, and two adjacent heat dissipation plates being rotatably connected, the plurality of heat dissipation plates being stackable in the third direction; a temperature monitoring device comprising a first temperature monitoring device and a second temperature monitoring device, the first temperature monitoring device being provided on a surface of the heating surface tube facing an inside of the furnace, the second temperature monitoring device being provided on a wall surface of the fin facing the inside of the furnace, and the second temperature monitoring device being located in the middle region of the fin in the second direction, the fin structure being configured to adjust the length of the fin structure in the third direction according to a temperature difference between the first temperature monitoring device and the second temperature monitoring device on the adjacent heating surface tube and the fin.

2. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, The fin structure further comprises: a hinge connecting any two adjacent heat dissipation plates.

3. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, The fin structure further comprises: a driving assembly provided between any two adjacent heat dissipation plates, for driving one of the two adjacent heat dissipation plates to rotate relative to the other.

4. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, The first temperature monitoring device is located on a center surface of the heating surface tube in the second direction.

5. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, The first temperature monitoring device is welded to the heating surface tube. The second temperature monitoring device is welded to the fin.

6. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, The fin structure is rotatably connected to the fin. The fin structure is welded to the fin.

7. The system for preventing and treating superheater cracking of heating surface fin of a utility boiler according to claim 1, characterized by, Each fin is provided with a plurality of fin structures, The plurality of fin structures on the same fin are arranged in the first direction. The plurality of fin structures on the same fin are arranged in the second direction.

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