Overheat cracking prevention system for fins on heating surface of power station boiler

Abstract

The invention discloses a power station boiler heating surface fin overheating cracking prevention system which is used for a power station boiler and comprises a plurality of heating surface pipes extending in the first direction and arranged at intervals in the second direction. The fins are connected between every two adjacent heating surface pipes; the fin structures are arranged on the wall faces, facing the outer side of the hearth, of the fins, and the fin structures are located in the middle areas, in the second direction, of the fins. According to the overheating cracking prevention and treatment system for the fins on the heating surface of the power station boiler, the fin structures are additionally arranged on the wall surfaces, facing the outer side of the hearth, of the fins, and the fin structures are located in the middle areas, in the second direction, of the fins, so that on the premise that the widths of the fins are not changed, the fins can be prevented from being cracked; and effective heat dissipation is carried out on the middle area of the fins in the second direction, and the problem that in the prior art, the fins crack due to overheating of the fins, and then the heating surface pipe cracks and leaks is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of preventing and controlling overheating cracking of finned surfaces in utility boilers, and in particular to a system for preventing and controlling overheating cracking of finned surfaces in utility boilers. Background Art

[0002] At present, accidents of heat transfer surface tube leakage caused by fin cracking occur from time to time. Generally, there are two reasons: inconsistent expansion and wide fins. For in-service units, inconsistent expansion is relatively easy to solve, while there is no good solution to the cracking and leakage accidents caused by wide fins at present, which seriously affects the normal operation of utility boilers. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. For this purpose, the present invention provides a system for preventing and controlling overheating cracking of finned surfaces in utility boilers, which can dissipate heat from the fins, avoid the problem of cracking and leakage of heat transfer surface tubes caused by fin cracking, and ensure the normal operation of utility boilers.

[0004] The system for preventing and controlling overheating cracking of finned surfaces in utility boilers according to an embodiment of the present invention is used for a utility boiler and includes: heat transfer surface tubes, the heat transfer surface tubes extend in a first direction, there are a plurality of the heat transfer surface tubes, and the plurality of heat transfer surface tubes are spaced apart in a second direction; fins, the fins are connected between two adjacent heat transfer surface tubes; a fin structure, the fin structure is provided on the wall surface of the fin facing the outside of the furnace, and the fin structure is located in the middle area of the fin in the second direction.

[0005] The system for preventing and controlling overheating cracking of finned surfaces in utility boilers according to an embodiment of the present invention can effectively dissipate heat from the middle area of the fin in the second direction without changing the width of the fin by providing a fin structure on the wall surface of the fin facing the outside of the furnace and the fin structure being located in the middle area of the fin in the second direction, prevent the temperature of the middle area of the fin in the second direction from being too high, overcome the problem of fin cracking caused by fin overheating in the prior art and then lead to cracking and leakage of heat transfer surface tubes, and ensure the normal operation of utility boilers.

[0006] In addition, the system for preventing and controlling overheating cracking of finned surfaces in utility boilers according to the present invention may further have the following additional technical features:

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

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

[0009] In some embodiments, the fin structure further includes: hinges, and any two adjacent heat dissipation plates are connected by the hinges.

[0010] In some embodiments, the fin structure further includes: a driving assembly, and the driving assembly is provided between any two adjacent heat dissipation plates for driving one of the two adjacent heat dissipation plates to rotate relative to the other.

[0011] In some embodiments, the prevention and control system for overheating cracking of the fin of the heating surface of a utility boiler further includes: a temperature monitoring device, the temperature monitoring device includes a first temperature monitoring device and a second temperature monitoring device, the first temperature monitoring device is disposed on the surface of the heating surface tube facing the inner side of the furnace, the second temperature monitoring device is disposed on the wall surface of the fin facing the inner side of the furnace, and the second temperature monitoring device is located in the middle area of the fin in the second direction, and the fin structure is 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 the adjacent heating surface tube and the fin.

[0012] In some embodiments, the first temperature monitoring device is located on the central plane of the heating surface tube in the second direction.

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

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

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

[0016] Additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present invention. Description of the Drawings

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

[0018] Figure 1 is a three-dimensional schematic diagram of a prevention and control system for overheating cracking of finned surfaces of a power station boiler according to an embodiment of the present invention;

[0019] Figure 2 is a top view schematic diagram of a prevention and control system for overheating cracking of finned surfaces of a power station boiler according to an embodiment of the present invention, where the hinge and the driving assembly are not shown;

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

[0021] Reference numerals:

[0022] 100, prevention and control system for overheating cracking of finned surfaces of a power station boiler;

[0023] 1, heating surface tube;

[0024] 2, fin;

[0025] 3, fin structure; 31, heat dissipation plate;

[0026] 4, temperature monitoring device; 41, first temperature monitoring device; 42, second temperature monitoring device. Detailed implementation manners

[0027] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0029] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0030] In the present invention, unless otherwise clearly specified and defined, terms such as "installed", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] The prevention and control system 100 for overheating cracking of finned surfaces of a utility boiler according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0032] As Figure 2 shown, the prevention and control system 100 for overheating cracking of finned surfaces of a utility boiler according to an embodiment of the present invention is used for a utility boiler and includes a heating surface tube 1, fins 2, and a rib structure 3.

[0033] Specifically, as Figure 1 shown, the heating surface tube 1 extends along a first direction (as Figure 1 shown), there are a plurality of heating surface tubes 1, and the plurality of heating surface tubes 1 are spaced apart in a second direction (as Figure 1 shown). Fins 2 are connected between two adjacent heating surface tubes 1, and both ends of the fins 2 in the second direction are respectively welded to the two adjacent heating surface tubes 1 to form an integral heating surface, constituting a membrane type heat exchange element.

[0034] Among them, the heating surface tube 1 can directly absorb the high-temperature heat in the furnace and transfer the heat to the cooling medium (usually water) inside the heating surface tube 1, heating the cooling medium into saturated steam. It can not only achieve the conversion of thermal energy but also reduce the temperature of the furnace wall, protecting the furnace wall from high-temperature damage. The fins 2, as a metal extension structure directly welded and fixed on the outside of the heating surface tube 1, can optimize the heat transfer process by expanding the heat exchange area of the membrane type heat exchange element, greatly increasing the area in contact with the high-temperature flue gas in the furnace, enabling more heat to be quickly transferred to the cooling medium inside the heating surface tube 1, improving the overall heat transfer efficiency, effectively reducing the situation of heat directly dissipating to the outside through the heating surface tube 1 by enhancing the heat exchange capacity, and enhancing the overall thermal efficiency of the prevention and control system 100 for overheating cracking of finned surfaces of a utility boiler.

[0035] Further, referring to the attached Figure 2 As shown, the fin structure 3 is provided on the wall surface of the fin 2 facing the outside of the furnace, and the fin structure 3 is located in the middle area of the fin 2 along the second direction. According to the heat transfer principle, the fin structure 3 has the function of enhancing heat transfer. Installing the fin structure 3 can make the surface temperature on the side where the fin structure 3 is installed closer to the temperature of the fluid on the same side. And setting the fin structure 3 on the wall surface of the fin 2 facing the outside of the furnace can strengthen the heat transfer coefficient between the fin 2 and the external environment of the furnace, realize effective heat dissipation in the middle area of the fin 2 along the second direction, prevent the temperature in the middle area of the fin 2 along the second direction from being too high, and ensure the normal operation of the power station boiler.

[0036] In the prior art, under the same heat radiation brought by the internal combustion of the power station boiler, the inside of the heating surface tube can be kept within a controlled temperature range due to the cooling of the cooling medium. However, the fin connecting two adjacent heating surface tubes can only transfer the radiant heat it receives to the heating surface tubes on both sides to keep its own temperature from overheating. When the size of the fin in the second direction is small, the heating surface tubes connected to both sides of the fin can effectively cool the middle fin. However, there are inevitably special parts such as openings, pipe passing, and tube panel docking in the furnace wall of the power station boiler. The fins in these special parts have a large size in the second direction, which easily causes the temperature in the middle area of the fin along the second direction to be too high, resulting in a temperature difference with the adjacent heating surface tubes. Once the temperature difference between the fin and the heating surface tube is large, a large expansion stress will be generated, causing the fin to crack under the action of the expansion stress, and then spreading to the heating surface tubes on both sides, resulting in the leakage and failure of the cooling medium in the heating surface tubes.

[0037] In the present invention, by providing a fin structure 3 on the wall surface of the fin 2 facing the outside of the furnace, and the fin structure 3 is located in the middle area of the fin 2 along the second direction, it is possible to effectively dissipate heat from the middle area of the fin 2 along the second direction without changing the width of the fin 2, prevent the temperature in the middle area of the fin 2 along the second direction from being too high, overcome the problem of fin cracking caused by fin overheating in the prior art and then resulting in heating surface tube cracking and leakage, and ensure the normal operation of the power station boiler.

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

[0039] The prevention and control system 100 for overheating cracking of fin of heating surface of utility boiler according to an embodiment of the present invention can effectively dissipate heat from the middle area of the fin 2 in the second direction without changing the width of the fin 2 by adding a fin structure 3 on the wall surface of the fin 2 facing the outside of the furnace, and the fin structure 3 is located in the middle area of the fin 2 along the second direction, preventing the temperature of the middle area of the fin 2 along the second direction from being too high, overcoming the problem of fin cracking caused by overheating of the fin in the prior art and further causing cracking and leakage of the heating surface tube, and ensuring the normal operation of the utility boiler.

[0040] In some embodiments of the present invention, referring to the attached Figure 2 As shown, the length of the fin structure 3 in the third direction (the inside-outside direction shown in the attached Figure 2 figure) is adjustable. The third direction is the inside-outside direction of the furnace, and the third direction, the first direction, and the second direction are perpendicular to each other pairwise. By adjusting the length of the fin structure 3 in the third direction, the heat dissipation area of the fin structure 3 can be changed, the heat exchange area between the fin 2 and the external medium of the furnace can be changed, and the heat dissipation amount of the fin structure 3 can be adjusted.

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

[0042] Φ (heat dissipation amount): represents the heat dissipated from the fin structure 3 to the surrounding medium per unit time, with the unit of watt (W). It is a key index to measure the heat dissipation ability 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 fin structure 3 and the surrounding fluid, with the unit of W / (m 2 ·K). Its value depends on the properties of the fluid (such as flow velocity, specific heat capacity, thermal conductivity, etc.), the flow state (laminar flow or turbulent flow), and the surface condition of the fin structure 3, etc. The larger h is, the more heat can be transferred between the fin structure 3 and the surrounding fluid under the same temperature difference, that is, the stronger the convective heat transfer ability.

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

[0045] P (Perimeter of the fin structure 3): in millimeters (mm), which determines the boundary length of the fin structure 3 in contact with the surrounding fluid. The larger the perimeter, the larger the contact area between the fin structure 3 and the external fluid. In the convective heat transfer process, more area can exchange heat with the fluid, thus having a direct impact on the heat dissipation.

[0046] A (Cross-sectional area of the fin structure 3 perpendicular to the third direction): in square meters (㎡), which reflects the effective heat transfer area of the fin structure 3 in the direction perpendicular to the heat flow. The larger the cross-sectional area, the more heat can be transferred during the heat conduction process because more materials are involved in the heat conduction, providing a larger channel for the heat transfer inside the fin structure 3.

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

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

[0049] H (Length of the fin structure 3 in the third direction): in millimeters (mm), which is the dimension of the fin structure 3 in the heat transfer direction ( Figure 2 the inner and outer direction shown). The increase in the length of the fin structure 3 usually increases the heat dissipation area, which is beneficial to heat dissipation. However, it is also restricted by the tanh(mH) function and is not a simple linear relationship. When mH is relatively large, tanh(mH) approaches 1, and at this time, the increase in the length of the fin structure 3 has a gradually weakening effect on the improvement of heat dissipation.

[0050] From the heat dissipation formula of the fin structure 3, it can be seen that under other unchanged conditions, increasing the dimension of the fin structure 3 in the heat transfer direction ( Figure 2 the inner and outer direction shown) can increase the heat dissipation area of the fin structure 3, and thus can increase the heat dissipation of the fin structure 3.

[0051] In a further embodiment of the present invention, referring to the attached Figure 2As shown, the fin structure 3 includes a plurality of heat dissipation plates 31. The plurality of heat dissipation plates 31 are connected in sequence, and two adjacent heat dissipation plates 31 are rotatably connected. The plurality of heat dissipation plates 31 can be stacked along the third direction. Through the rotational connection between two adjacent heat dissipation plates 31, the fin structure 3 can be expanded into a larger area, thereby increasing the contact area between the fin structure 3 and the external medium of the furnace, improving the heat dissipation efficiency of the fin structure 3. Moreover, the rotatably connected heat dissipation plates 31 can be adjusted according to the installation environment and space limitations of the fin overheating cracking prevention and control system 100 of the utility boiler to adapt to different heat dissipation requirements. At the same time, the rotatably connected heat dissipation plates 31 are also beneficial to the disassembly and assembly of the fin structure 3, facilitating the user to clean and maintain it.

[0052] When the fin structure 3 is in the initial state, one of the heat dissipation plates 31 closest to the fin 2 among the plurality of heat dissipation plates 31 is in contact with the fin 2, and the remaining heat dissipation plates 31 are stacked in sequence along the third direction. When it is necessary to increase the length of the fin structure 3 in the third direction, the heat dissipation plate 31 farthest from the fin 2 rotates and opens. At this time, the plane where the heat dissipation plate 31 farthest from the fin 2 is located is perpendicular to the plane where the heat dissipation plate 31 second farthest from the fin 2 is located. When it is necessary to increase the length of the fin structure 3 in the third direction again, the heat dissipation plate 31 second farthest from the fin 2 rotates and opens. At this time, the heat dissipation plate 31 farthest from the fin 2 and the heat dissipation plate 31 second farthest from the fin 2 are in the same plane, and the plane where the heat dissipation plate 31 second farthest from the fin 2 is located is perpendicular to the plane where the heat dissipation plate 31 third farthest from the fin 2 is located. And so on, until all the heat dissipation plates 31 are in the same plane, and the plane where the plurality of heat dissipation plates 31 are located is perpendicular to the first direction.

[0053] It can be understood that there are a first state and a second state between two adjacent heat dissipation plates 31. In the first state, two adjacent heat dissipation plates 31 are stacked along the third direction. In the second state, two adjacent heat dissipation plates 31 are in the same plane. When two adjacent heat dissipation plates 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 realize the increase of the heat dissipation amount of the fin structure 3.

[0054] For example, according to the space outside the furnace of different electric boilers, the number of heat dissipation plates 31 of 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 fin structure 3 includes two heat dissipation plates 31, which are respectively a first heat dissipation plate 31 and a second heat dissipation plate 31. The first heat dissipation plate 31 and the second heat dissipation plate 31 are rotatably connected. In a 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 away from the fin 2; in a 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 toward 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 fin structure 3 while ensuring the structural strength of the fin structure 3 , has good heat dissipation performance, and has a simple manufacturing process, which facilitates the production and processing of the fin structure 3 .

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

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

[0058] In a further embodiment of the present invention, referring to the attached Figure 1 and attached Figure 2As shown, the prevention and control system 100 for overheating cracking of the fin of the heating surface of a power station boiler further 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, and the second temperature monitoring device 42 is located in the middle area of the fin 2 along the second direction. The fin structure 3 is configured to adjust the length of the fin structure 3 in the third direction according to 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. The settings of the first temperature monitoring device 41 and the second temperature monitoring device 42 can be respectively used to accurately monitor the temperatures of the heating surface tube 1 and the fin 2, realize the real-time monitoring of the temperatures and stresses of the heating surface tube 1 and the fin 2, so that the length of the fin structure 3 in the third direction can be adjusted in time, and the temperature of the fin 2 can be controlled within a safe range. And making the second temperature monitoring device 42 located in the middle area of the fin 2 along the second direction can more accurately measure the highest temperature of the fin 2. Moreover, by installing the temperature monitoring device 4, the arrangement position, length of the fin structure 3, and the length of the fin structure 3 in the third direction can be determined to solve the problem of overheating of the fin 2.

[0059] When 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 is greater than the preset temperature difference, at least part of the driving assembly drives the relative rotation between the adjacent two heat dissipation plates 31. In a specific example, the actually collected temperature difference 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 °C as the over-temperature alarm temperature. When the actually collected temperature difference ΔT c ≥ T cm , the driving system drives one of the adjacent two heat dissipation plates 31 to rotate relative to the other, realizing the increase in the length of the fin structure 3 in the third direction until the actually collected temperature difference ΔT c < T cm .

[0060] Optionally, the first temperature monitoring device 41 can be multiple ones spaced apart in the first direction of the heating surface tube 1 to improve the accuracy of the temperature measured by the first temperature monitoring device 41 at the heating surface tube 1. The second temperature monitoring device 42 can be multiple ones spaced apart in the first direction of the fin 2 to improve the accuracy of the temperature measured by the second temperature monitoring device 42 in the middle area of the fin 2, so that the fin structure 3 can be adjusted to the required length more accurately.

[0061] Specifically, in view of the harsh environment of the flame, flue gas and fly ash in the furnace, the heating surface tubes 1 and the fins 2 are in a high-temperature and high-stress environment for a long time. Both the first temperature monitoring device 41 and the second temperature monitoring device 42 are quartz fiber optic temperature monitoring devices 4. The quartz fiber optic temperature monitoring device 4 includes a blackbody cavity sensor, a blackbody cavity tube, a quartz fiber optic temperature sensing probe, a detection optical fiber and a connecting component. The heat collecting block, as the blackbody cavity sensor, can be fixed in the furnace through the connecting component, enabling the heat collecting block to be in full contact with the heating surface tubes 1 and the fins 2, reducing the temperature of the heat collecting block. The blackbody cavity sensor generates blackbody radiation under the action of the heat of the heating surface tubes 1 and the fins 2 in the furnace. The blackbody radiation enters the accommodation cavity defined by the blackbody cavity tube. The quartz fiber optic temperature sensing probe extends into the heat collecting block, collects the blackbody radiation in the accommodation cavity and processes it into an optical signal. After the detection optical fiber detects this optical signal, it can be converted into a voltage signal through a photodetector and then processed by a terminal processor to form a temperature value. This temperature value is the temperature value of the heating surface tubes 1 and the fins 2 detected in the furnace, which can ensure the accuracy of the temperature at the heating surface tubes 1 and the fins 2 in the furnace and protect the quartz fiber optic temperature sensing probe from the influence of the harsh environment.

[0062] In a further embodiment of the present invention, referring to the attached Figure 1 and the attached Figure 2 As shown, the first temperature monitoring device 41 is located on the central plane of the heating surface tube 1 along the second direction, so as to accurately measure the highest temperature of the heating 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 heating surface tube 1, which can ensure the reliability and stability of the fixation of the first temperature monitoring device 41, realize the real-time monitoring of the temperature of the heating surface tube 1, reduce the loss and interference in the heat transfer process, and more accurately reflect the actual temperature of the heating 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 fixation of the second temperature monitoring device 42, realize the real-time monitoring of the temperature of the fin 2, reduce the 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 fin structure 3 is rotatably connected to the fin 2, which can make full use of the structure of the fin structure 3, so that the length of the fin structure 3 in the third direction can be made as large as possible, and the contact area between the fin structure 3 and the external medium of the furnace can be increased as much as possible according to the needs of users, improving the heat dissipation efficiency of the fin structure 3.

[0066] Alternatively, the fin structure 3 is welded to the fin 2, which can ensure the reliability and stability of the connection between the fin structure 3 and the fin 2, ensure the effective heat dissipation of the middle area of the fin 2 in the second direction by the fin structure 3, prevent the temperature of the middle area of the fin 2 in the second direction from being too high, and ensure the normal operation of the utility boiler.

[0067] In some embodiments of the present invention, a plurality of fin structures 3 are provided on each fin 2. The plurality of fin structures 3 located on the same fin 2 are arranged in the first direction, and / or the plurality of fin structures 3 located on the same fin 2 are arranged in the second direction. The setting of the plurality of fin 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 further avoid the cracking and leakage of the heating surface tube 1, thereby ensuring the normal operation of the utility boiler.

[0068] It can be understood that a plurality of fin structures 3 are provided on each fin 2. The plurality of fin structures 3 can be arranged at intervals in the first direction, or can be arranged at intervals in the second direction, or the plurality of fin structures 3 can include multiple groups of fin groups spaced apart in the first direction, and each group of fin groups includes a plurality of fin structures 3 spaced apart in the second direction.

[0069] For example, six fin structures 3 are provided on each fin 2. The six fin structures 3 can be all arranged on the center line of the fin 2 in the second direction, and the six fin structures 3 are spaced apart in the first direction; the six fin structures 3 can be spaced apart in the second direction; or the six fin structures 3 are arranged in a matrix of two rows and three columns, and the six fin structures 3 form two groups of fin groups spaced apart in the first direction, and each group of fin groups includes three fin structures 3 spaced apart in the second direction; or the six fin structures 3 are arranged in a matrix of three rows and two columns, and the six fin structures 3 form three groups of fin groups spaced apart in the first direction, and each group of fin groups includes two fin structures 3 spaced apart in the second direction.

[0070] It can be understood that the control method of the utility boiler heating surface fin overheating cracking prevention system 100 includes:

[0071] Install the utility boiler heating surface fin overheating cracking prevention system 100 on an actual utility boiler, actually collect 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 operation of the actual utility boiler, establish the corresponding relationship between the temperature difference and the length of the required fin structure 3 in the third direction, and draw the temperature difference - fin structure 3 length reference curve in the third direction;

[0072] The driving component is controlled according to the drawn temperature difference-length reference curve of the fin structure 3 in the third direction to achieve real-time control of the length of the fin structure 3 in the third direction, ensuring the actual temperature difference ΔT between the heating surface tube 1 and the fin 2 c <ΔT cm .

[0073] During the shutdown of the power plant boiler, a plurality of fin structures 3 are arranged at the actual over-temperature position of the widest fin where the high temperature radiation of the furnace is most serious, 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 heating 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 calculated. c =T2-T1 as the control parameter.

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

[0075] Adjust the power station boiler heating surface fin overheating cracking prevention system 100 until ΔT c1 =120°C, and record the length dH of the fin structure 3 in the third direction at this time.

[0076] Adjust the power station boiler heating surface fin overheating cracking prevention system 100 until ΔT c2 =100°C, and record the length cH of the fin structure 3 in the third direction at this time.

[0077] Adjust the power station boiler heating surface fin overheating cracking prevention system 100 until ΔT c3 =80°C, and record the length bH of the fin structure 3 in the third direction at this time.

[0078] Adjust the power station boiler heating surface fin overheating cracking prevention system 100 until ΔT c4 =60°C, and record the length aH of the fin structure 3 in the third direction at this time.

[0079] like Figure 3 As shown, the temperature difference (ΔT c , °C) as the horizontal coordinate, and the length (H) of the fin structure 3 in the third direction as the vertical coordinate, and ΔT is marked on the coordinate graph in sequence. cThe lengths dH, cH, bH, and aH of the fin structure 3 in the third direction corresponding to 120 °C, 100 °C, 80 °C, and 60 °C are smoothly connected to these 4 points, and thus the drawing of the reference curve of the temperature difference - the length of the fin structure 3 in the third direction is completed.

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

[0081] The other components and operations of the prevention and control system 100 for overheating cracking of the fins of the utility boiler heating surface according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.

[0082] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above - mentioned terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

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

Claims

1. A system for preventing overheating and cracking of heating surface fins of power station boilers, characterized in that: For use in power station boilers and includes: A heating surface tube, the heating surface tube extending along a first direction, the heating surface tube being in plurality, and the plurality of heating surface tubes being arranged at intervals in a second direction; Fins, wherein the fins are connected between two adjacent heating surface tubes; A fin structure is provided on the wall surface of the fin facing the outside of the furnace, and the fin structure is located in the middle area of ​​the fin along the second direction.

2. The power station boiler heating surface fin overheating cracking prevention system according to claim 1 is characterized in that: The length of the fin structure in the third direction is adjustable, and the third direction, the first direction and the second direction are perpendicular to each other.

3. The power station boiler heating surface fin overheating cracking prevention system according to claim 2 is characterized in that: The fin structure includes a plurality of heat dissipation plates, the plurality of heat dissipation plates are connected in sequence, and two adjacent heat dissipation plates are rotatably connected, and the plurality of heat dissipation plates can be stacked along the third direction.

4. The power station boiler heating surface fin overheating cracking prevention system according to claim 3 is characterized in that: The fin structure further comprises: Hinge, any two adjacent heat sinks are connected via the hinge.

5. The power station boiler heating surface fin overheating cracking prevention system according to claim 3 is characterized in that: The fin structure further comprises: A driving assembly is provided between any two adjacent heat sinks, and is used to drive one of the two adjacent heat sinks to rotate relative to the other.

6. The power station boiler heating surface fin overheating cracking prevention system according to claim 2 is characterized in that: The power station boiler heating surface fin overheating cracking prevention system also includes: A temperature monitoring device, the temperature monitoring device includes a first temperature monitoring device and a second temperature monitoring device, the first temperature monitoring device is arranged on the surface of the heating surface tube facing the inner side of the furnace, the second temperature monitoring device is arranged on the wall surface of the fin facing the inner side of the furnace, and the second temperature monitoring device is located in the middle area of ​​the fin along the second direction, and the fin structure is 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 the adjacent heating surface tube and the fin.

7. The power station boiler heating surface fin overheating cracking prevention system according to claim 6 is characterized in that: The first temperature monitoring device is located on the center plane of the heating surface tube along the second direction.

8. The power station boiler heating surface fin overheating cracking prevention system according to claim 6 is characterized in that: The first temperature monitoring device is welded to the heating surface tube; And / or, the second temperature monitoring device is connected to the fin by welding.

9. The power station boiler heating surface fin overheating cracking prevention system according to claim 1, characterized in that: The rib structure is rotatably connected to the fin; Alternatively, the fin structure is connected to the fin by welding.

10. The power station boiler heating surface fin overheating cracking prevention system according to claim 1, characterized in that: Each of the fins is provided with a plurality of fin structures. A plurality of the fin structures located on the same fin are arranged in the first direction; And / or, a plurality of the fin structures located on the same fin are arranged in the second direction.

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