Bent pipe structure and bent pipe assembly for conveying boiler steam

Abstract

The utility model discloses a bend pipe structure and a bend pipe assembly for conveying boiler steam, and relates to the technical field of boiler pipelines, the bend pipe structure comprises an air inlet straight pipe, a bend pipe and an air outlet straight pipe, a first port of the bend pipe is welded with the air inlet straight pipe, a second port of the bend pipe is welded with the air outlet straight pipe, and the first port of the bend pipe is welded with the air outlet straight pipe. The elbow comprises an inner layer, a supporting layer and an outer layer, the supporting layer is arranged between the inner layer and the outer layer, the inner layer is a corrosion-resistant alloy layer, a supporting framework is arranged in the supporting layer, one side of the supporting framework is connected with the inner layer, and the other side of the supporting framework is connected with the outer layer; the outer layer is a reinforcing layer, a supporting framework is arranged on the supporting layer, one side of the supporting framework is connected with the inner layer, the other side of the supporting framework is connected with the outer layer, and the overall rigidity and stability of the bent pipe are enhanced. When steam pressure acts on the bent pipe, the supporting framework can evenly disperse the pressure, and deformation is effectively resisted.

Description

TECHNICAL FIELD

[0001] The utility model relates to a boiler pipeline technical field, especially a bend structure and boiler steam delivery bend assembly. BACKGROUND

[0002] In the boiler steam delivery system, the bend assembly is a crucial component, and its performance directly affects the operation efficiency and safety of the whole system. However, the existing bend structure exposes many problems in the actual application process, which is difficult to meet the increasingly stringent use requirements.

[0003] The traditional bend structure is often designed as a single layer, or although it has multiple layers, but lacks effective connection and support structure between layers. When facing the high temperature and high pressure environment in the boiler steam delivery process, the defects of such structure become more and more obvious. The structure lacking support is prone to deformation under the action of steam pressure, especially at the welding position of the bend and the straight pipe, the deformation is more prominent. The deformation of the welding position not only changes the inner diameter and shape of the pipe, leading to increased steam flow resistance and reduced delivery efficiency, but also may cause stress concentration, further aggravating the risk of structure damage. SUMMARY

[0004] To solve the problem of lack of support in the multi-layer bend structure in the prior art, the utility model provides a bend structure and a boiler steam delivery bend assembly.

[0005] The technical scheme adopted by the utility model is:

[0006] The first aspect of the application provides a bend structure, which comprises an inlet straight pipe, a bend and an outlet straight pipe, the first port of the bend is welded with the inlet straight pipe, the second port of the bend is welded with the outlet straight pipe, the bend comprises an inner layer, a support layer and an outer layer, the support layer is arranged between the inner layer and the outer layer, the inner layer is a corrosion-resistant alloy layer, the support layer is provided with a support framework, one side of the support framework is connected with the inner layer, the other side of the support framework is connected with the outer layer; the outer layer is a reinforcing layer.

[0007] Preferably, the inner diameter of the first port of the bend is larger than the port inner diameter of the inlet straight pipe, and the inner diameter of the second port of the bend is smaller than the port inner diameter of the outlet straight pipe.

[0008] Preferably, a stress groove is formed on the outer surface of the bend, and the stress grooves are arranged at intervals along the circumferential direction of the bend.

[0009] Preferably, the stress groove is filled with a high-temperature-resistant elastic material.

[0010] Preferably, the support framework comprises a plurality of support bars, the support bars are staggered, one end of the support bars is connected with the outer layer, and one end of the support bars is connected with the inner layer.

[0011] Preferably, the material of the support bars is boron fiber.

[0012] Preferably, the material of the inner layer is chromium molybdenum alloy, and the material of the outer layer is carbon steel or low alloy steel.

[0013] The second aspect of the present application provides a bend pipe assembly for boiler steam delivery, comprising the bend pipe structure in the first aspect.

[0014] The bend pipe of the present application is provided with a support framework in the support layer, and one side of the support framework is connected with the inner layer and the other side is connected with the outer layer, thereby enhancing the rigidity and stability of the whole bend pipe. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a whole structure perspective view of the embodiment one of the present application.

[0016] Figure 2 It is a bend pipe side view perspective view of the embodiment one of the present application.

[0017] Figure 3 It is a bend pipe side view of the embodiment one of the present application.

[0018] Figure 4 It is a structure schematic view of the embodiment two of the present application.

[0019] Signs: 1, inlet straight pipe; 2, bend pipe; 21, inner layer; 22, support layer; 23, outer layer; 24, support framework; 25, stress groove; 3, outlet straight pipe. DETAILED DESCRIPTION

[0020] In order to make the purpose, scheme and advantages of the present application more clear and apparent, the present application is further described in detail below with examples and drawings, the schematic implementation mode and the description thereof are only used for explaining the present application, and do not serve as the limitation of the present application.

[0021] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be practiced without these specific details. In other embodiments, well-known structures, circuits, materials or methods are not specifically described in order to avoid obscuring the present application.

[0022] Reference throughout this specification to "one embodiment", "an embodiment", "one design", or "a design" means that a particular feature, structure, or characteristic described in connection with the embodiment or design is included in at least one embodiment of the application. The appearances of the phrases "in one embodiment", "in an embodiment", "in one design", or "in a design" in various places in the specification are not necessarily all referring to the same embodiment or design. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments or designs. Additionally, a person of ordinary skill in the art will understand that the drawings provided herein are for illustrative purposes and that the drawings are not necessarily drawn to scale. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] In the description of the present application, the terms "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "high", "low", "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the scope of protection of the present application.

[0024] Embodiment one provides a bent pipe structure, as shown in Figure 1 As shown in Figure 2 , comprising a gas inlet straight pipe 1, a bent pipe 2 and a gas outlet straight pipe 3, the first port of the bent pipe 2 is welded with the gas inlet straight pipe 1, the second port of the bent pipe 2 is welded with the gas outlet straight pipe 3, the bent pipe 2 comprises an inner layer 21, a support layer 22 and an outer layer 23, the support layer 22 is arranged between the inner layer 21 and the outer layer 23, the inner layer 21 is a corrosion-resistant alloy layer, the support layer 22 is provided with a support framework 24, one side of the support framework 24 is connected with the inner layer 21, the other side of the support framework 24 is connected with the outer layer 23; the outer layer 23 is a reinforcing layer.

[0025] For reference, the material of the inner layer 21 is chromium molybdenum alloy, wherein the chromium molybdenum alloy has high temperature resistance and corrosion resistance, and can effectively resist the corrosion of high temperature steam.

[0026] For reference, the outer layer 23 is made of carbon steel or low-alloy steel, such as Q345 low-alloy steel. Q345 low-alloy steel can provide reliable structural support for the bend 2. At the same time, its cost is relatively low, effectively controlling manufacturing costs while ensuring the overall performance of the bend 2. Furthermore, Q345 steel also has a certain degree of resistance to atmospheric corrosion and can operate stably in general industrial environments. Another example is Q390 low-alloy steel, which is suitable for bends 2 with more stringent structural strength requirements. In some large steam transmission systems, when the bend 2 needs to withstand greater pressure and external forces, Q390 low-alloy steel can be selected as the material for the outer layer 23.

[0027] Argon arc welding can be used to tightly weld the support frame 24 to the inner layer 21 and the outer layer 23. Argon arc welding provides high welding quality, ensuring a strong interlayer connection and achieving coordinated stress distribution. The first end of the bend 2 is welded to the inlet straight pipe 1 using argon arc welding, and the second end is welded to the outlet straight pipe 3 using the same method. This welding method ensures high weld quality, a strong connection, effectively reduces the risk of steam leakage, and ensures the stability and safety of steam transportation.

[0028] In one possible implementation, such as Figure 2 As shown, the support frame 24 includes multiple support bars arranged in an alternating pattern. One end of each support bar is connected to the outer layer 23, and the other end is connected to the inner layer 21. The dimensions of the support bars are designed based on the inner diameter of the bend 2 and the required support strength. For example, for bends 2 with larger inner diameters and higher steam pressures, the width and thickness of the support bars are appropriately increased, and the spacing between the support bars is reduced to improve the support capacity of the support frame 24.

[0029] For reference, the support strip is made of boron fiber. Boron fiber has high strength and elastic modulus, and its density is lower than that of most metals. The reinforced composite material made of boron fiber has excellent rigidity, providing strong structural support for the bend 2. Even at high temperatures, the boron fiber reinforced composite material maintains good performance, which effectively resists the thermal shock and thermal stress caused by high-temperature steam for the boiler steam conveying bend 2, ensuring long-term stable operation of the bend 2 under harsh conditions.

[0030] In one possible implementation, the inner diameter of the first port of the bend 2 is larger than the inner diameter of the port of the intake straight pipe 1, and the inner diameter of the second port of the bend 2 is smaller than the inner diameter of the port of the exhaust straight pipe 3.

[0031] For reference, the first port inner diameter of the elbow pipe 2 is slightly larger than that of the inlet straight pipe 1, for example, the first port inner diameter of the elbow pipe 2 is 45 mm while the inlet straight pipe 1 is 50 mm. A smooth transition chamfer is arranged at the connecting position of the two pipes, so that when the steam flows from the inlet straight pipe 1 into the elbow pipe 2, the flow rate is reduced and the pressure is increased, forming a certain buffer area, reducing the impact of the steam on the inner wall of the elbow pipe 2, reducing the wear, and at the same time helping to stabilize the flow state of the steam and reducing the generation of vortex.

[0032] The second port inner diameter of the elbow pipe 2 is slightly smaller than that of the outlet straight pipe 3, for example, the second port inner diameter of the elbow pipe 2 is 55 mm while the outlet straight pipe 3 is 50 mm. A smooth transition chamfer is arranged at the connecting position of the two pipes, so that when the steam flows from the elbow pipe 2 into the outlet straight pipe 3, the flow rate and the pressure will change accordingly, and the flow rate and the pressure of the steam can be adjusted according to the actual requirements to meet the requirements of the subsequent equipment or process for the steam parameters.

[0033] In a possible implementation, as shown in Figure 3 The outer surface of the elbow pipe 2 is provided with stress grooves 25, which are arranged along the circumferential direction of the elbow pipe 2. In a possible implementation, the stress grooves 25 are filled with high-temperature elastic materials.

[0034] It should be noted that the stress grooves 25 are arranged on the outer surface of the elbow pipe 2 along the circumferential direction, as shown in Figure 3 The stress grooves 25 are arc-shaped, and the high-temperature elastic material is filled in the stress grooves 25. In this embodiment, high-temperature silicone rubber is selected. The high-temperature silicone rubber has good elasticity and temperature resistance, and can effectively buffer stress. The high-temperature silicone rubber is uniformly filled into the stress grooves 25 by injection molding process, so as to ensure that the high-temperature silicone rubber is tightly filled and tightly adheres to the inner wall of the stress grooves 25, thereby ensuring the sealing performance and stress buffering effect of the elbow pipe 2.

[0035] In summary, the staggered support strips made of boron fibers in the support layer 22 are connected to the inner layer 21 at one end and to the outer layer 23 at the other end, forming a stable structure. For the elbow pipe 2 with large inner diameter and high steam pressure, the overall rigidity is enhanced by adjusting the size of the support strips. For example, in a large steam conveying system, the deformation of the elbow pipe 2 can be effectively inhibited, the pressure can be dispersed, the weld load capacity can be improved, and the stable operation of the elbow pipe 2 under complex working conditions can be ensured.

[0036] The composite structure composed of the inner layer 21 of chromium-molybdenum alloy, the support layer 22 and the outer layer 23 of Q345 or Q390 low alloy steel plays its own characteristics and resists external force together. For example, in a high-temperature and high-pressure environment, the support layer 22 reduces the heat transfer from the inner layer 21 to the outer layer 23, reduces the thermal load of the outer layer 23, at the same time enhances the overall strength, and prolongs the service life of the elbow pipe 2.

[0037] The inner diameter of the first port of the elbow pipe 2 is larger than the inlet straight pipe 1, the inner diameter of the second port is smaller than the outlet straight pipe 3, and a transition chamfer is arranged at the connecting position. When the steam flows in, the flow rate is reduced and the pressure is increased, forming a buffer area, reducing the impact and wear on the inner wall of the elbow pipe 2, stabilizing the steam flow, and reducing the vortex; when the steam flows out, the steam flow rate and pressure can be adjusted to meet the requirements of the subsequent equipment or process for steam parameters, improve the steam conveying efficiency and adaptability.

[0038] The support framework 24 and the inner and outer layers 23, and the elbow pipe 2 and the inlet and outlet straight pipes 3 are welded by argon arc welding process. The argon arc welding has high welding quality and firm connection, effectively reduces the risk of steam leakage, ensures the stability and safety of steam conveying, and reduces energy waste and safety hazards.

[0039] The chromium molybdenum alloy selected for the inner layer 21 has high temperature resistance and corrosion resistance, which can effectively resist the corrosion of high temperature steam, and can protect the inner wall of the elbow pipe 2 even in a steam environment containing corrosive substances, prevent the pipe from thinning and perforating, ensure the reliability of steam conveying, and prolong the service life of the elbow pipe 2 in harsh environments.

[0040] Arc-shaped stress grooves 25 are arranged on the outer surface of the elbow pipe 2 in the circumferential direction at intervals, and are filled with high temperature silicone rubber. When the elbow pipe 2 bears welding stress, steam pressure and the like, the material at the stress groove 25 deforms preferentially, and the high temperature silicone rubber further buffers the stress by virtue of its good elasticity and temperature resistance, while ensuring the sealing of the elbow pipe 2, avoiding steam leakage, and ensuring the normal operation of the elbow pipe 2 under various working conditions.

[0041] Embodiment two provides a kind of elbow pipe assembly for boiler steam conveying, as Figure 4 As shown, including the elbow pipe structure described in embodiment one.

[0042] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A bent pipe structure, characterized by, The elbow pipe (2) is provided with a stress groove (25) on the outer surface, and the stress groove (25) is arranged at intervals along the circumferential direction of the elbow pipe (2).

2. A pipe bend according to claim 1, characterised in that The inner diameter of the first port of the elbow pipe (2) is greater than the inner diameter of the port of the air inlet straight pipe (1), and the inner diameter of the second port of the elbow pipe (2) is less than the inner diameter of the port of the air outlet straight pipe (3).

3. A pipe bend according to claim 1, wherein The elbow pipe (2) is provided with a stress groove (25) on the outer surface, and the stress groove (25) is arranged at intervals along the circumferential direction of the elbow pipe (2).

4. A pipe bend according to claim 3, wherein The stress groove (25) is filled with a high-temperature-resistant elastic material.

5. A pipe bend according to claim 1, wherein The support skeleton (24) comprises a plurality of support strips, the support strips are arranged in a staggered manner, one end of the support strip is connected with the outer layer (23), and the other end of the support strip is connected with the inner layer (21).

6. A bend structure according to claim 5, wherein The material of the support strip is boron fiber.

7. A pipe bend according to claim 1, wherein The material of the inner layer (21) is chromium molybdenum alloy, and the material of the outer layer (23) is carbon steel or low alloy steel.

8. A bend assembly for boiler steam transmission, characterized in that, The elbow pipe structure of any one of claims 1-7 is included.

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