Large-diameter corrosion-resistant austenite seamless stainless steel pipe for nuclear power station

Abstract

The utility model discloses a large-caliber corrosion-resistant austenite seamless stainless steel pipe for a nuclear power station, which comprises a main body, the main body consists of an inner pipe, an outer pipe and a graphite sleeve arranged between the inner pipe and the outer pipe, the periphery of the outer pipe is provided with a spiral raised line, each end angle of the raised line is an arc-shaped transition angle, and a limiting rod is inserted among the inner pipe, the outer pipe and the graphite sleeve. The two ends of the inner pipe penetrate out of the two ends of the outer pipe and the two ends of the graphite sleeve respectively, limiting flanges are fixed to the two ends of the inner pipe respectively, the limiting flanges limit the two ends of the outer pipe and the two ends of the graphite sleeve, the two ends of the inner pipe are further provided with connecting ends respectively, and the two main bodies are connected through a connector.

Description

Technical Field

[0001] The utility model relates to a large-caliber corrosion-resistant austenitic seamless stainless steel pipe for nuclear power plants. Background Art

[0002] Austenitic seamless stainless steel pipes have been used in heat transfer pipes of waste heat removal systems in nuclear power plants. Due to the harsh application environment, higher requirements are placed on the corrosion resistance of seamless stainless steel pipes. If seamless stainless steel pipes are directly used as heat transfer pipes in waste heat removal systems, their service life will only meet the standards and it is difficult to achieve a longer service life. Utility Model Content

[0003] The utility model aims to overcome the deficiencies of the prior art and provide a large-diameter corrosion-resistant austenitic seamless stainless steel pipe for a nuclear power plant, which can be used for a longer time and has higher strength and heat transfer capacity.

[0004] The technical solution of the utility model is: a large-caliber corrosion-resistant austenitic seamless stainless steel pipe for nuclear power plants, comprising a main body, the main body consisting of an inner pipe, an outer pipe and a graphite sleeve arranged between the inner pipe and the outer pipe;

[0005] The outer circumference of the outer tube has spiral convex strips, each end angle of the convex strips is an arc transition angle, and the outer surface of the convex strips is polished to a smooth surface;

[0006] The inner tube and the outer tube also have corresponding limiting grooves, and the graphite sleeve has a long groove corresponding to the two limiting grooves, the long groove runs through both ends of the graphite sleeve, and a limiting rod passes through the long groove and is inserted between the two limiting grooves to limit the inner tube, the outer tube and the graphite sleeve in radial direction;

[0007] The two ends of the inner tube pass through the two ends of the outer tube and the graphite sleeve respectively, and the two ends of the inner tube are respectively fixed with limiting flanges, and the limiting flanges limit the two ends of the outer tube and the graphite sleeve. The two ends of the inner tube also have connecting ends respectively, and the two main bodies are connected through a joint.

[0008] Specifically, the inner tube is a large-diameter corrosion-resistant austenitic seamless stainless steel tube, the outer tube is an aluminum tube, and the limiting rod is a stainless steel rod.

[0009] Furthermore, a gasket is provided between the joint and the limiting flange.

[0010] Specifically, the convex strips are densely surrounded on the outer wall of the outer tube.

[0011] Specifically, the convex strip and the outer tube are an integrally formed structure.

[0012] Specifically, the limiting flange is screwed onto the outer pipe.

[0013] Specifically, the joint is a double-headed joint. When the two main bodies are connected, the connecting ends of the two inner tubes are respectively screwed to the two ends of the joint.

[0014] The beneficial effects of the utility model are as follows: in the utility model, the outer tube mainly plays the role of preventing the inner tube from being corroded and improving the strength of the inner tube; the graphite sleeve plays a lubricating role in the main body assembly process on the one hand, and on the other hand, it also plays a role of filling the gap between the inner tube and the outer tube and conducting heat; heat is quickly transferred between the inner tube and the outer tube through the graphite sleeve, and the spiral convex strips on the outer tube increase the surface area of ​​the outer tube, so that the main body has better heat transfer capacity; at the same time, the split structure will not greatly damage the surface of the inner tube, and the aluminum outer tube is easier to process, which can reduce the manufacturing difficulty and manufacturing cost of the main body. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a transverse cross-sectional view of the utility model;

[0016] Figure 2 It is a longitudinal cross-sectional view of the utility model;

[0017] Figure 3 It is a structural schematic diagram of the utility model;

[0018] Figure 4 It is a structural schematic diagram of the connection between two main bodies in the utility model.

[0019] In the figure: main body 1, inner tube 2, outer tube 3, graphite sleeve 4, convex strip 5, limit rod 6, limit flange 7, joint 8, gasket 9. DETAILED DESCRIPTION

[0020] The technical solution of the utility model is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0021] Combination Figure 1-4 As shown, a large-caliber corrosion-resistant austenitic seamless stainless steel pipe for a nuclear power plant comprises a main body 1, wherein the main body 1 is composed of an inner tube 2, an outer tube 3, and a graphite sleeve 4 disposed between the inner tube 2 and the outer tube 3;

[0022] The outer circumference of the outer tube 3 has a spiral convex strip 5, each end angle of the convex strip 5 is an arc transition angle, and the outer surface of the convex strip 5 is polished to a smooth surface to reduce the accumulation of impurities on the surface of the outer tube 3 and improve the corrosion resistance of the surface;

[0023] The inner tube 2 and the outer tube 3 also have corresponding limiting grooves, and the graphite sleeve 4 has a long groove corresponding to the two limiting grooves, the long groove runs through both ends of the graphite sleeve 4, and a limiting rod 6 passes through the long groove and is inserted between the two limiting grooves to radially limit the inner tube 2, the outer tube 3 and the graphite sleeve 4 to avoid relative radial rotation between the inner tube 2, the outer tube 3 and the graphite sleeve 4;

[0024] The two ends of the inner tube 2 pass through the two ends of the outer tube 3 and the graphite sleeve 4 respectively. The two ends of the inner tube 2 are respectively fixed with limiting flanges 7. The limiting flanges 7 limit the two ends of the outer tube 3 and the graphite sleeve 4. The two ends of the inner tube 2 also have connecting ends respectively. The two main bodies 1 are connected by a joint 8.

[0025] Specifically, the inner tube 2 is a large-diameter corrosion-resistant austenitic seamless stainless steel tube, the outer tube 3 is an aluminum tube, and the limiting rod 6 is a stainless steel rod.

[0026] In the above structure, the outer tube 3 mainly plays the role of preventing the inner tube 2 from being corroded and improving the strength of the inner tube 2. The graphite sleeve 4 plays a lubricating role during the assembly process of the main body 1 on the one hand, and on the other hand, it also plays a role of filling the gap between the inner tube 2 and the outer tube 3 and conducting heat. Heat is quickly transferred between the inner tube 2 and the outer tube 3 through the graphite sleeve 4, and the spiral convex strips 5 on the outer tube 3 increase the surface area of ​​the outer tube 3, so that the main body 1 has a better heat transfer ability; at the same time, the split structure will not significantly damage the surface of the inner tube 2, and the aluminum outer tube 3 is easier to process, which can reduce the manufacturing difficulty and manufacturing cost of the main body 1.

[0027] In another embodiment, if Figure 4 As shown, a gasket 9 is further provided between the joint 8 and the limiting flange 7 to ensure that the joint 8 abuts against the limiting flange 7 to prevent the limiting flange 7 from loosening.

[0028] In another embodiment, in combination Figure 1 and Figure 2 As shown, the convex strips 5 are densely surrounded on the outer wall of the outer tube 3.

[0029] In another embodiment, the convex strip 5 and the outer tube 3 are an integrally formed structure.

[0030] In another embodiment, the limiting flange 7 is screwed onto the outer tube 3 .

[0031] In another embodiment, the joint 8 is a double-headed joint, and when the two main bodies 1 are connected, the connecting ends of the two inner tubes 2 are respectively screwed to the two ends of the joint 8 .

Claims

1. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for use in a nuclear power plant, comprising a main body (1), characterized in that: The main body (1) is composed of an inner tube (2), an outer tube (3), and a graphite sleeve (4) arranged between the inner tube (2) and the outer tube (3); The outer circumference of the outer tube (3) is provided with a spiral convex strip (5), each end angle of the convex strip (5) is an arc-shaped transition angle, and the outer surface of the convex strip (5) is polished to a smooth surface; The inner tube (2) and the outer tube (3) also have corresponding limiting grooves, and the graphite sleeve (4) has a long groove corresponding to the two limiting grooves, the long groove passes through both ends of the graphite sleeve (4), and a limiting rod (6) passes through the long groove and is inserted between the two limiting grooves to radially limit the inner tube (2), the outer tube (3) and the graphite sleeve (4); The two ends of the inner tube (2) pass through the two ends of the outer tube (3) and the graphite sleeve (4), respectively. The two ends of the inner tube (2) are respectively fixed with limiting flanges (7), and the limiting flanges (7) limit the two ends of the outer tube (3) and the graphite sleeve (4). The two ends of the inner tube (2) also have connecting ends, respectively. The two main bodies (1) are connected via a joint (8).

2. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for a nuclear power plant as claimed in claim 1, characterized in that: The inner tube (2) is a large-diameter corrosion-resistant austenitic seamless stainless steel tube, the outer tube (3) is an aluminum tube, and the limiting rod (6) is a stainless steel rod.

3. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for nuclear power plants as claimed in claim 2, characterized in that: A gasket (9) is also provided between the joint (8) and the limiting flange (7).

4. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for a nuclear power plant as claimed in claim 3, characterized in that: The convex strips (5) are densely surrounded on the outer wall of the outer tube (3).

5. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for nuclear power plants as claimed in claim 4, characterized in that: The convex strip (5) and the outer tube (3) are an integrally formed structure.

6. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for a nuclear power plant as claimed in claim 5, characterized in that: The limiting flange (7) is screwed onto the outer tube (3).

7. A large-diameter corrosion-resistant austenitic seamless stainless steel pipe for nuclear power plants as claimed in claim 6, characterized in that: The joint (8) is a double-headed joint. When the two main bodies (1) are connected, the connection ends of the two inner tubes (2) are respectively screwed to the two ends of the joint (8).

Images