An online repair method for castable of circulating fluidized bed boiler

Abstract

This application relates to the field of circulating fluidized bed boiler maintenance technology, and in particular to an online repair method for castable refractory in circulating fluidized bed boilers. The method includes first adjusting the boiler parameters to a stable operating condition suitable for online repair; then, opening an inspection hole at the center of the red-hot area on the outer wall of the insulation component; and enlarging the inspection hole to an operable size after confirming stable negative pressure. If cracks appear inside the insulation component, refractory insulation material is directly filled into the cracks; if areas of castable refractory detachment appear inside, a support member connected to a steerable tie rod is inserted into the detached area through the inspection hole, and the tie rod is pulled to rotate the support member laterally and fix it against the inner wall, forming a filling space, which is then filled with refractory insulation material. After all repairs are completed, the inspection holes are welded and sealed. As can be seen, the online repair method for castable refractory provided in this application can repair the red-hot areas on the outer wall online without stopping the machine, ensuring safe and stable operation of the equipment and preventing the internal refractory layer from detaching and causing uneven material feeding in the return device, thus laying a solid foundation for long-term stable operation of the equipment.

Description

Technical Field

[0001] This application relates to the field of circulating fluidized bed boiler maintenance technology, and in particular to an online repair method for circulating fluidized bed boilers using castable refractory. Background Technology

[0002] Circulating fluidized bed (CFB) boilers have become a major type of boiler widely used in power plants and industrial heating due to their advantages such as wide fuel adaptability, high combustion efficiency, and low desulfurization cost. To reduce heat loss and ensure efficient operation, the separator, return feeder, and horizontal flue of CFB boilers all employ insulated structures. This structure involves welding high-temperature resistant nails to the inner side of the metal cylinder wall, followed by the sequential pouring of insulating and refractory castables to form a composite insulation layer; under ideal operating conditions, the outer wall temperature of these components can be maintained below 100℃. However, in long-term actual operation, these components frequently experience localized overheating on their outer walls, sometimes even glowing red-hot, with temperatures reaching over 500℃. The root cause is the cracking or partial detachment of the internal castable, allowing high-temperature flue gas and circulating materials to directly scour and radiate the metal cylinder wall, causing a rapid increase in the outer wall temperature.

[0003] In related technologies, physical cooling and external sealing box methods are commonly used to address the problem of overheating and red-hot exterior walls of CFB boiler components. Physical cooling involves using compressed air to forcibly purge the red-hot area, which can temporarily lower the wall temperature and delay damage to the pins and cylinder wall. However, it cannot repair the damaged refractory layer; the source of the high temperature is not eliminated, and the wall temperature will quickly rise again after purging stops, causing the refractory detachment area to continue to expand. The external sealing box method involves welding a sealing box to the cylinder wall of the red-hot area and pouring refractory, only sealing the red-hot area from the outside without addressing the cracks and detachment of the internal refractory. The internal wall and pins remain in a high-temperature environment, accelerating carbonization and fracture, ultimately leading to large-scale refractory collapse. This method only lasts for 2-3 months, and the unit still requires a thorough shutdown and overhaul. Summary of the Invention

[0004] This application is made in view of the above-mentioned issues.

[0005] According to one aspect of this application, an online repair method for castable refractory in a circulating fluidized bed boiler is provided, comprising: Adjust the boiler parameters to a steady-state operating condition suitable for online repair; An inspection hole is opened in the center of the superheated red-hot area on the outer wall of the boiler's insulation component. After confirming that the negative pressure is stable, the size of the inspection hole is enlarged to an operable size. If cracks appear inside the insulation component, fire-resistant insulation material is filled into the cracks. If a refractory material falls off inside the insulation component, the support member connected to the steerable tie rod is inserted into the refractory material fall-off area through the probe hole, and the tie rod is pulled to make the support member rotate laterally and fit and fix against the inner wall to form a filling space. Then, fire-resistant and heat-insulating material is filled into the filling space. After the repair is completed, the probe hole will be welded and sealed.

[0006] Compared with existing technologies, the online repair method for castable refractory in circulating fluidized bed boilers provided in this application includes first adjusting the boiler parameters to a steady-state operating condition suitable for online repair. This creates safe operating conditions for online construction, avoids fluctuations in unit operation affecting the repair work, and ensures normal boiler operation during construction. Next, an inspection hole is opened at the center of the overheated area on the outer wall of the boiler's insulation components. After confirming stable negative pressure, the size of the inspection hole is enlarged to an operable size. This allows for direct observation of the damage to the internal castable refractory and confirmation that the negative pressure is within a stable range. When cracks appear inside the insulation components, refractory insulation material is directly filled to quickly seal the damaged area. This not only prevents high temperature transmission outwards and alleviates the problem of overheating and red-hot outer wall, but also prevents further crack expansion. When areas of castable refractory detachment appear inside the insulation components, a support with a steerable tie rod is inserted into the interior and fixed against the inner wall, which securely seals the detached area and forms a regular filling space. Subsequently, insulation and refractory materials are filled in to prevent the leakage of high-temperature heat and flue gas from the source, avoid damage to internal anchoring nails due to high temperatures, prevent the castable refractory from falling off further, and avoid abnormal boiler backflow caused by castable refractory falling off. After the repair is completed, the inspection hole can be welded and sealed.

[0007] Based on this, the online repair method for castables provided in this application can repair the red-hot areas on the outer wall online without stopping the machine. This not only keeps the equipment in a safe and stable operating state, but also avoids the internal refractory layer falling off, which would cause the material feeding device to be unsmooth, thus laying a solid foundation for the long-term stable operation of the equipment.

[0008] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0009] The above and other objects, features, and advantages of this application will become more apparent from the more detailed description of the embodiments of this application in conjunction with the accompanying drawings. The accompanying drawings are used to provide a further understanding of the embodiments of this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof. In the accompanying drawings, the same reference numerals generally represent the same components or steps.

[0010] Figure 1A flowchart illustrating an online repair method for castable refractory in a circulating fluidized bed boiler according to an embodiment of this application is shown; Figure 2 A schematic diagram of the support member and the steerable tie rod according to an embodiment of this application is shown. Detailed Implementation

[0011] To make the objectives, technical solutions, and advantages of this application more apparent, exemplary embodiments according to this application will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments of this application. It should be understood that this application is not limited to the exemplary embodiments described herein.

[0012] Circulating fluidized bed (CFB) boilers have become a major type of boiler widely used in power plants and industrial heating due to their advantages such as wide fuel adaptability, high combustion efficiency, and low desulfurization cost. To reduce heat loss and ensure efficient operation, the separator, return feeder, and horizontal flue of CFB boilers all employ insulated structures. This structure involves welding high-temperature resistant nails to the inner side of the metal cylinder wall, followed by the sequential pouring of insulating and refractory castables to form a composite insulation layer; under ideal operating conditions, the outer wall temperature of these components can be maintained below 100℃. However, in long-term actual operation, these components frequently experience localized overheating on their outer walls, sometimes even glowing red-hot, with temperatures reaching over 500℃. The root cause is the cracking or partial detachment of the internal castable, allowing high-temperature flue gas and circulating materials to directly scour and radiate the metal cylinder wall, causing a rapid increase in the outer wall temperature.

[0013] In related technologies, physical cooling and external sealing box methods are commonly used to address the problem of overheating and red-hot exterior walls of CFB boiler components. Physical cooling involves using compressed air to forcibly purge the red-hot area, which can temporarily lower the wall temperature and delay damage to the pins and cylinder wall. However, it cannot repair the damaged refractory layer; the source of the high temperature is not eliminated, and the wall temperature will quickly rise again after purging stops, causing the refractory detachment area to continue to expand. The external sealing box method involves welding a sealing box to the cylinder wall of the red-hot area and pouring refractory, only sealing the red-hot area from the outside without addressing the cracks and detachment of the internal refractory. The internal wall and pins remain in a high-temperature environment, accelerating carbonization and fracture, ultimately leading to large-scale refractory collapse. This method only lasts for 2-3 months, and the unit still requires a thorough shutdown and overhaul.

[0014] To address the aforementioned issues, this application provides an online repair method for castable refractory in a circulating fluidized bed boiler. This method can repair the red-hot areas on the outer wall online without shutting down the machine, ensuring the equipment maintains a safe and stable operating state and preventing the internal refractory layer from detaching and causing uneven material feeding in the return device, thus laying a solid foundation for the long-term stable operation of the equipment. Figure 1 A flowchart illustrating an online repair method for castable refractory in a circulating fluidized bed boiler, according to an embodiment of this application, is shown. Figure 1 As shown, the method includes the following steps: S101: Adjust the boiler parameters to a steady-state operating condition suitable for online repair.

[0015] For example, the insulation components in this application embodiment include a separator, a horizontal flue, or a return feeder.

[0016] For example, if the insulation component is a separator or horizontal flue, the boiler load needs to be adjusted to below 50% and kept stable, while maintaining the furnace negative pressure between -200Pa and -600Pa. Stabilizing the boiler load reduces the internal boiler temperature and flue gas flow intensity, minimizing the interference of high temperatures on separator and horizontal flue repair work, and creating a safe and stable online construction environment. Maintaining the furnace negative pressure within the above parameter range prevents high-temperature flue gas from escaping from the furnace, ensuring the safety of construction personnel. It also allows repair steps such as hole exploration and material filling to be carried out smoothly, providing reliable operating conditions for the online repair of the separator and horizontal flue, ensuring the smooth implementation of the repair work.

[0017] For example, if the insulation component is a return feeder, the boiler load needs to be adjusted to below 50% and kept stable, and the furnace negative pressure needs to be adjusted to -300Pa. Additionally, the airflow in the return air chamber and loosening duct needs to be adjusted to the lowest stable value. Reducing the boiler load to below 50% and keeping it stable reduces the overall operating intensity of the boiler, minimizing the impact of high-temperature and circulating materials on the return feeder, providing a stable foundation for online repair. Adjusting the furnace negative pressure to -300Pa stabilizes the furnace pressure, preventing high-temperature flue gas or materials from spraying out from the openings, ensuring safety during construction. Simultaneously, adjusting the return air and loosening air to the lowest stable value ensures normal material feeding and basic operation of the return feeder, while minimizing airflow interference and preventing material movement from affecting the repair operation, allowing the opening and filling steps to be completed smoothly and accurately.

[0018] It is worth noting that the minimum stable value refers to the minimum airflow in the return air chamber and loose duct, provided that the material in the return feeder can maintain a minimum fluidization state, without blockage or material interruption, and the return system can operate continuously and stably. The criterion for determining this is that a person skilled in the art can determine it by observing whether the pressure measurement points of the return feeder are stable and whether the material in the sight glass is in a micro-fluidized state without accumulation or material interruption. Essentially, this airflow is the minimum safe operating airflow slightly higher than the critical fluidization airflow of the material in the return feeder.

[0019] Furthermore, if the insulation component is a return feeder, the boiler load needs to be adjusted to 30% and kept stable. At this point, the operating intensity is significantly reduced, and the disturbance of flue gas and materials is smaller, making it suitable for repairing medium-area damage to the return feeder.

[0020] Furthermore, if the insulation component is a return feeder, the boiler load needs to be adjusted to 20% and kept stable. At this time, only the minimum normal operation of the boiler and the return feeder are maintained, and the working conditions are the most stable, which is suitable for emergency repairs of large areas of the return feeder being red-hot.

[0021] S102: Open an inspection hole in the center of the superheated red-hot area on the outer wall of the boiler's insulation component. After confirming that the negative pressure is stable, enlarge the size of the inspection hole to an operable size.

[0022] For example, if the insulation component is a separator or a horizontal flue, the length and width of the inspection hole are both 30mm. This small hole size will not damage the overall structure of the component's outer wall, nor will it cause significant fluctuations in the furnace negative pressure, thus maintaining the boiler's current operating conditions stably. Simultaneously, this hole diameter is sufficient for construction personnel to observe whether the internal negative pressure is stable and to check for actual damage such as cracks and spalling of the castable refractory, providing a reliable basis for subsequent hole enlargement operations and precise repairs. Furthermore, the small opening area effectively reduces the risk of high-temperature flue gas overflow, ensuring the safety of personnel and equipment during online repair operations.

[0023] During the enlargement operation, the operable length is 200mm and the operable width is 100mm. This size allows construction personnel to fill the internal insulation material, refractory castable, and install support components, ensuring smooth repair operations. It also prevents damage to the outer wall structure of components due to excessively large openings, avoiding drastic fluctuations in furnace negative pressure and maintaining stable boiler operation. Simultaneously, this size allows construction personnel to clearly inspect the damage to the internal castable, enabling precise completion of the repair work.

[0024] For example, if the insulation component is a return feeder, the length and width of the probe hole are both 30 mm, and the length and width of the operable dimension are both less than or equal to 70 mm.

[0025] Understandably, the return feeder continuously circulates high-temperature material, and its operating conditions fluctuate more significantly due to disturbances from return air and loosening airflow. An excessively large opening would directly disrupt the stable negative pressure in the furnace, causing high-temperature flue gas and material to spray outwards from the opening, posing a safety hazard. Furthermore, a minimum stable airflow must be maintained during return feeder repairs. A 70mm orifice diameter is sufficient for basic repair operations such as filling with castable refractory and installing support components with steerable tie rods. Exceeding this size would excessively weaken the external wall structure and further increase the risk of airflow and material leakage.

[0026] S103: If cracks appear inside the insulation component, fill the cracks with fire-resistant insulation material.

[0027] For example, the width of the crack is less than or equal to 50 mm. Furthermore, the refractory and heat-insulating material in this application includes at least one of heat-insulating material and refractory castable, wherein the heat-insulating material is a material commonly used in the art, such as aluminum silicate insulation cotton or asbestos-free microporous calcium silicate board. The refractory castable is also a material commonly used in the art, such as silicon carbide castable. The specific selection and usage of the above-mentioned heat-insulating material and refractory castable can be adjusted according to actual conditions and are not limited here.

[0028] S104: If a refractory material falls off inside the insulation component, the support member connected to the steerable tie rod is inserted into the refractory material fall-off area through the inspection hole, and the tie rod is pulled to make the support member rotate laterally and fit and fix against the inner wall to form a filling space. Then, fire-resistant insulation material is filled into the filling space.

[0029] For example, the support member in the embodiments of this application includes stainless steel flat bar or flexible metal support mesh.

[0030] The principle behind the lateral rotation of the support component is understandable: the steerable tie rod and the support component are rotatably connected at the middle via a hinge axis (e.g., a bolt or pin) that runs through them. The position of this hinge axis is the fixed point of the steering axis, which both constrains the relative position of the tie rod and the support component and allows the support component to rotate freely relative to the tie rod about this hinge axis. Before insertion, the support component and tie rod are roughly aligned parallel to each other, i.e., in a folded state, so that the overall contour fits the size of the probe hole, allowing it to be smoothly inserted into the detachment area through the small hole. After reaching the target position, the tie rod is pulled away from the hole from the outside of the component. Under the action of the pulling force, the support component rotates laterally about the hinge axis by an angle of approximately 90°, changing from an initial posture parallel to the tie rod to a posture laterally to the tie rod, until the edge of the support component overlaps the intact inner wall around the detachment area and is tightly fitted and fixed with continued pulling. For rigid support components (e.g., stainless steel flat bars), they do not deform themselves and rotate as a whole about the hinge axis. For flexible metal support mesh, it is hinged to the tie rod through a rigid frame or connecting piece. The flexible mesh unfolds and adheres to the inner wall as the frame rotates laterally, thus forming a stable support surface in the irregular detachment area.

[0031] For example, the method further includes: The tie rod is temporarily welded to the outer cylinder wall at the edge of the inspection hole. Specifically, before the refractory material cures, welding the tie rod to the outer cylinder wall keeps the baffle in continuous contact with the inner wall, forming a stable filling space. After the refractory material has completely cured, the exposed part of the tie rod can be cut off and welded to the outer cylinder wall to restore the seal.

[0032] Figure 2 A schematic diagram of the support member and steerable tie rod according to an embodiment of this application is shown. Figure 2As shown, the steerable tie rod 201 is vertically connected to the middle of the support member 202. A bolt a passes through the overlapping point of the steerable tie rod 201 and the support member 202 to achieve a hinged connection. The installation position of this bolt a is the steering shaft fixing point, which not only firmly constrains the relative position of the support member 202 and the steerable tie rod 201, but also allows the support member 202 to rotate laterally relative to the steerable tie rod 201 about this bolt a as an axis. It should be understood that... Figure 2 This diagram only shows the structure when the support is made of stainless steel flat bar. For cases where the support is a flexible metal mesh, those skilled in the art can directly derive the corresponding structural diagram based on the above structure, so it will not be elaborated upon here. Furthermore, flexible metal mesh is also existing technology, and its parameters can be selected according to actual conditions. For example, the material can be 310S stainless steel, the wire diameter can be 1mm~5.0mm, and the mesh size can be 5mm~150mm to ensure sufficient flexibility and support strength, allowing it to be rolled up and pass through small holes, and unfolded to fit the inner wall after the pull rod is pulled.

[0033] During construction, first, keep the steerable tie rod and the support vertically aligned, ensuring the overall dimensions match the diameter of the inspection hole, and smoothly insert it into the area where the castable refractory has detached inside the insulation component. Once the target position is reached, pull the steerable tie rod away from the orifice from the outside of the component. Since the two are hinged by a central bolt, the support will rotate laterally around this bolt (i.e., the fixing point of the steering shaft), gradually unfolding and fitting against the inner wall of the component until the edge of the support overlaps with the intact inner wall of the castable refractory around the detached area, forming a stable support surface. Then, fix the position of the tie rod to prevent the support from returning to its original position, and fill the space enclosed by the support surface and the inner wall with insulation material and refractory castable. After the material has solidified, release the tie rod and pull out the component. Finally, seal the inspection hole to complete the online repair operation.

[0034] S105: After the repair is completed, the inspection hole will be welded and sealed.

[0035] Understandably, if the insulation component is a return feeder and there are areas where the castable refractory has fallen off, the above method also includes: If the area of ​​the detached region is larger than the preset value, anchor nails are welded to the inner wall of the detached region; after the repair is completed, the outer protective plate of the return feeder is welded back.

[0036] When the refractory detachment from the return feeder occurs over a large area, welding anchoring nails to the inner wall of the detached area effectively improves the bonding strength between the subsequently filled refractory castable and the inner wall of the equipment. This prevents the castable from loosening or detaching under high temperatures, material erosion, and airflow, thus enhancing the stability and durability of the repaired area. After the repair work is completed, welding the outer protective plate of the return feeder restores the operating holes created during the repair process, restoring the complete structure and sealing of the outer wall of the return feeder. This prevents the leakage of high-temperature flue gas and heat, while ensuring the structural strength of the outer wall and ensuring that the outer wall temperature meets the requirements for safe operation, thus guaranteeing the long-term stable operation of the return feeder.

[0037] It should be understood that a large detachment area refers to a deep detachment depth and a continuous, contiguous damaged area. For example, a detachment area with a diameter greater than 100mm is considered to have reached the preset value. Operators can quickly determine this by directly observing and measuring through the inspection hole on-site.

[0038] Example 1 This embodiment discloses a specific implementation method for online repair of separator castable, and the steps are as follows: During repairs, the boiler load must be controlled below 50% and maintained at a stable level to avoid significant load fluctuations. Simultaneously, the pressure in the boiler outlet flue should be adjusted to approximately 200 Pa to ensure a slight negative pressure within the furnace. A 30mm x 30mm inspection hole should be drilled at the center of the red-hot section to observe whether the negative pressure at the furnace outlet flue is stable. Stable negative pressure at the furnace outlet flue is defined as a negative pressure value between -200 Pa and -600 Pa, not exceeding -200 Pa. After confirming stable negative pressure, the hole should be enlarged to 200mm x 100mm.

[0039] After drilling, observe the refractory detachment inside the heated area. If the crack width of the refractory detachment is no more than 50mm, use aluminum silicate insulation cotton to seal the crack until it is seamless. Then fill it with the mixed refractory refractory slurry. The cost of each ton of refractory slurry is 5,000 yuan. The cost of refractory slurry required to repair 0.3 square meters is 300 yuan. The refractory slurry filling volume should account for 80% of the repair space. After the repair is completed, weld the outer cylinder wall. Repair the overheated parts in the same way. After the repair is completed, weld the outer cylinder wall to solve the equipment overheating problem.

[0040] It is understood that, in this embodiment, the specific meaning of 80% of the refractory fill volume in the repair space refers to the following: in the scenario of repairing cracks in separators or horizontal flues, the refractory filler accounts for approximately 80% of the total cavity volume formed after the area to be repaired is cleaned, with the remaining approximately 20% of the space filled by thermal insulation materials such as aluminum silicate insulation cotton. Furthermore, the 80% proportion is exemplary data for this embodiment. In actual construction, it can be flexibly adjusted according to the crack width, depth, and site conditions, with the final standard being the dense filling of the refractory filler; it does not need to be strictly limited to 80%.

[0041] Example 2 This embodiment discloses a specific implementation method for online repair of horizontal flue gas duct castable, and the steps are as follows: During repairs, the boiler load must be controlled below 50% and maintained at a stable level to avoid significant load fluctuations. Simultaneously, the pressure in the boiler outlet flue should be adjusted to approximately 200 Pa to ensure a slight negative pressure within the furnace. A 30mm x 30mm inspection hole should be drilled at the center of the red-hot section to observe whether the negative pressure at the furnace outlet flue is stable. Stable negative pressure at the furnace outlet flue is defined as a negative pressure value between -200 Pa and -600 Pa, not exceeding -200 Pa. After confirming stable negative pressure, the hole should be enlarged to 200mm x 100mm.

[0042] After drilling the hole, observe the refractory detachment inside the heated area. When a detached area with a width of approximately 50mm appears, take a stainless steel flat bar longer than the heated area and weld a swivel shaft to the middle of the flat bar, connecting it perpendicularly to the flat bar. This facilitates positioning the flat bar after inserting it into the cylinder wall. Overlap the two sides of the stainless steel flat bar with the detached refractory areas to cover the cracks and detached areas. Fold the stainless steel flat bar and the movable tie rod and insert them into the hole. Pull the tie rod outward to ensure the stainless steel flat bar fits tightly against the inner wall of the equipment. Tighten and fix the position of the stainless steel flat bar, then weld the movable tie rod to the outer cylinder wall, creating an outward-opening operating space in the heated area. Then, use aluminum silicate insulation cotton for initial sealing, followed by filling with the mixed refractory castable. After the repair work is completed, weld the outer cylinder wall to resolve the equipment overheating issue.

[0043] Example 3 This embodiment discloses a specific implementation method for online repair of the red-hot part of the return feeder, and the steps are as follows: During repairs, the unit load must be controlled below 50% or even lower and maintained stable operation to avoid significant load fluctuations. Adjust the pressure in the boiler outlet flue (after the separator) to approximately 300 Pa, and simultaneously adjust the return air and loosening air to their lowest values, ensuring normal fluidization and return under low load conditions. Drill a 30mm x 30mm hole at the center of the heated section to observe the negative pressure in the horizontal flue of the furnace. If the negative pressure remains stable within the range of -200 Pa to -600 Pa, drilling can continue. The drilling location is determined based on the heated section; the size of a single hole should not be too large, with a maximum of 70mm x 70mm. After drilling, take a stainless steel flat bar longer than the heated section and weld a swivel shaft to the middle of the stainless steel flat bar, connecting it perpendicularly to the stainless steel flat bar. This facilitates inserting the stainless steel flat bar into the cylinder wall for positioning.

[0044] If the area of ​​refractory detachment is large, anchoring nails must first be welded to the inner wall of the detached area. The refractory castable should be mixed to a consistency that allows it to be formed into a ball by hand, then formed into a tight ball to completely fill the gaps in the detached area. After the casting operation is completed, the outer protective plate is welded back on, completing the online repair of the castable in the red-hot area of ​​the return feeder.

[0045] The above description is merely a specific embodiment of this application. Obviously, various modifications and combinations can be made without departing from the spirit and scope of this application. Accordingly, this specification and accompanying drawings are merely exemplary descriptions of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, the intent of this application includes these modifications and modifications. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the stated claims. It should also be noted that in the apparatus and method of this application, the components or steps can be disassembled and / or recombined. These disassemblies and / or recombinations should be considered equivalent solutions of this application. The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this application. Therefore, this application is not intended to be limited to the aspects shown herein, but rather to be applied within the widest scope consistent with the principles and novel features disclosed herein. The above description has been given for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of this application to the forms disclosed herein. Although several exemplary aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for online repair of castable refractory in a circulating fluidized bed boiler, characterized in that, include: Adjust the boiler parameters to a steady-state operating condition suitable for online repair; An inspection hole is opened in the center of the superheated red-hot area on the outer wall of the boiler's insulation component. After confirming that the negative pressure is stable, the size of the inspection hole is enlarged to an operable size. If cracks appear inside the insulation component, fire-resistant insulation material is filled into the cracks. If a refractory material falls off inside the insulation component, the support member connected to the steerable tie rod is inserted into the refractory material fall-off area through the probe hole, and the tie rod is pulled to make the support member rotate laterally and fit and fix against the inner wall to form a filling space. Then, fire-resistant and heat-insulating material is filled into the filling space. After the repair is completed, the probe hole will be welded and sealed.

2. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 1, characterized in that, The insulation components include a separator, a horizontal flue, or a return feeder.

3. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 2, characterized in that, The support component includes stainless steel flat steel or flexible metal support mesh, and the steerable tie rod is vertically connected to the middle of the support component.

4. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 3, characterized in that, When the support is fixed to the inner wall, the edge of the support overlaps the inner wall around the area where the castable material has fallen off.

5. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 2, characterized in that, If the insulation component is a separator or a horizontal flue, adjusting the boiler parameters to a steady-state operating condition suitable for online repair includes: Adjust the boiler load to below 50% and keep it stable, and adjust the furnace negative pressure of the boiler to -200Pa to -600Pa.

6. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 5, characterized in that, The length and width of the probe hole are both 30mm, the length of the operable dimension is 200mm, and the width of the operable dimension is 100mm.

7. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 2, characterized in that, If the insulation component is a return feeder, adjusting the boiler parameters to a steady-state operating condition suitable for online repair includes: Adjust the boiler load to below 50% and maintain it stable, and adjust the boiler furnace negative pressure to -300 Pa; and, Adjust the air volume in the boiler's return air chamber and loose air duct to the lowest stable value.

8. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 7, characterized in that, If the insulation component is a return feeder and there is an area where the castable material has fallen off, the method further includes: If the area of ​​the detached region is larger than a preset value, then anchor nails are welded to the inner wall of the detached region; After the repair is completed, the outer protective plate of the return feeder is welded back on.

9. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 7, characterized in that, If the insulation component is a return feeder, the length and width of the probe hole are both 30mm, and the length and width of the operable dimension are both less than or equal to 70mm.

10. The online repair method for castable refractory of a circulating fluidized bed boiler according to claim 1, characterized in that, After the method involves pulling the lever to rotate the support member laterally and fix it to the inner wall, the method further includes: The tie rod is temporarily welded and fixed to the outer cylinder wall at the edge of the probe hole.

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