Regulating valve flange sealing ring structure of residual heat removal system of nuclear power station

Abstract

The utility model discloses a nuclear power station residual heat removal system regulating valve flange sealing ring structure, which relates to the technical field of regulating valve sealing rings, comprises a flange upper cover, a flange seat and a connecting plate which are sequentially connected from bottom to top, and is characterized by further comprising two sealing rings which are of Y-shaped structures, and the two sealing rings are arranged in the flange upper cover. And the sealing ring is connected between the flange upper cover and the flange seat. The Y-shaped sealing ring structure has large compensation performance and excellent self-excitation sealing capacity, stress analysis and tests prove that the Y-shaped sealing ring can achieve a reliable sealing effect, after compression and in a high-temperature environment, the Y-shaped sealing ring is mainly stressed towards the axial direction and the position of a lip opening of the Y-shaped sealing ring, the sealing ring is stressed evenly, and the sealing effect is good. The sealing ring on the inner side (in the extrusion direction) is small in stress, the stress of the whole structure does not have the local stress concentration phenomenon, and the risks of local damage and high-temperature extrusion do not exist.

Description

Technical Field

[0001] The utility model relates to the technical field of regulating valve sealing rings, in particular to a flange sealing ring structure of a regulating valve of a waste heat discharge system of a nuclear power plant. Background Art

[0002] The traditional nuclear power plant waste heat removal system regulating valve flange uses an "L" type sealing ring structure. However, after analyzing the original "L" type sealing ring, it was found that the original L type sealing ring needs to be under a large compression deformation (compression rate is 28.3%) to form a sealing performance. During the compression process, the root of the sealing ring (the junction of the vertical and horizontal planes) is subjected to a large stress concentration, and is in a state of deformation and aging for a long time, which is more prone to cracking. Under high temperature or alternating temperature conditions, when the local strength of the sealing ring is low, extrusion will occur simultaneously. Its force is as follows: Figure 4 , Figure 5 , Figure 6 shown.

[0003] Therefore, a sealing ring with greater compensation performance, better self-excited sealing ability, and more stable and reliable sealing performance is needed to solve the current problems. Utility Model Content

[0004] In view of the above-mentioned problems, the utility model provides a flange sealing ring structure of a regulating valve of a waste heat discharge system of a nuclear power plant, which has greater compensation performance and excellent self-excited sealing ability. It has been proved through force analysis and experiments that the "Y"-shaped sealing ring can achieve a reliable sealing effect. After compression and in a high-temperature environment, the main force is axially directed to the lip of the "Y"-shaped sealing ring and the base. The force on the sealing ring is relatively uniform, and the force on the inner side (extrusion direction) of the sealing ring is smaller. There is no local stress concentration phenomenon when the overall structure is subjected to force, and there is no risk of local damage and high-temperature extrusion.

[0005] The technical solution adopted to solve the above technical problems is: a flange sealing ring structure of a regulating valve of a waste heat removal system of a nuclear power plant, including a flange cover, a flange seat and a connecting plate, wherein the connecting plate, the flange seat and the flange cover are connected in sequence from bottom to top, and also include: two sealing rings, both of which are "Y"-shaped structures, and the sealing rings are connected between the flange cover and the flange seat.

[0006] Furthermore, a circle of wire sealing structure is provided on both the upper and lower sides of the sealing ring.

[0007] The beneficial effects of the utility model are:

[0008] (1) The "Y"-shaped sealing ring structure provided in the utility model has a large compensation performance and excellent self-excited sealing ability. Through force analysis and experiments, it is proved that the "Y"-shaped sealing ring can achieve a reliable sealing effect. After compression and in a high temperature environment, the main force is axially directed to the lip of the "Y"-shaped sealing ring and the base. The sealing ring is subjected to a relatively uniform force, and the inner side (extrusion direction) of the sealing ring is subjected to a smaller force. In addition, there is no local stress concentration phenomenon when the overall structure is subjected to force, and there is no risk of local damage and high-temperature extrusion.

[0009] (2) The utility model adds a line sealing structure on the basis of the "Y"-shaped sealing ring, so that the sealing reliability is more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0011] Figure 2 for Figure 1 Enlarged view of point A in the middle.

[0012] Figure 3 This is a schematic diagram of the "Y" sealing ring structure of the utility model.

[0013] Figure 4 This is a diagram of the "L" type sealing ring before it is subjected to force.

[0014] Figure 5 This is the stress state diagram of the "L" type sealing ring after the bolts are tightened.

[0015] Figure 6 This is a diagram of the stress state of the "L" type sealing ring after heating and pressure increase.

[0016] Figure 7 This is a diagram of the "Y" type sealing ring before it is subjected to force.

[0017] Figure 8 This is the stress state diagram of the "Y" type sealing ring after the bolts are tightened.

[0018] Fig. 9 This is a diagram of the stress state of the "Y" type sealing ring after heating and pressure increase.

[0019] Fig.10 This is the hot test curve of "Y" type sealing ring.

[0020] Figure numerals: 1. flange cover; 2. flange seat; 3. connecting plate; 4. sealing ring; 5. wire sealing structure; 6. gate; 7. flange. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model and are not used to limit the utility model.

[0022] like Figure 1 , Figure 2 , Figure 3 As shown, the present embodiment provides a flange sealing ring structure of a regulating valve of a waste heat removal system of a nuclear power plant, comprising a flange cover 1, a flange seat 2 and a connecting plate 3, wherein the connecting plate 3, the flange seat 2 and the flange cover 1 are sequentially connected from bottom to top, and further comprising: two sealing rings 4, each of which is a "Y"-shaped structure, and the sealing ring 4 is connected between the flange cover 1 and the flange seat 2.

[0023] like Figure 7 , Figure 8 , Fig. 9 As shown, the "Y"-shaped sealing ring 4 structure arranged in the utility model has greater compensation performance and excellent self-excited sealing ability. After force analysis and experiments, it is proved that the "Y"-shaped sealing ring 4 can achieve a reliable sealing effect. After compression and in a high-temperature environment, the main force is axially and at the base of the "Y"-shaped sealing ring lip. The sealing ring 4 is subjected to a relatively uniform force, and the inner side (extrusion direction) of the sealing ring 4 is subjected to less force. There is no local stress concentration phenomenon when the overall structure is subjected to force, and there is no risk of local damage and high-temperature extrusion.

[0024] Specifically, Figure 2 , Figure 3 As shown, a circle of wire sealing structure 5 is provided on both the upper and lower sides of the sealing ring 4.

[0025] The utility model adds a line sealing structure 5 on the basis of the "Y"-shaped sealing ring, so that the sealing reliability is more reliable.

[0026] Specifically, Figure 7 , Figure 8 , Fig. 9 As shown, the changes of the structure of the "Y"-shaped sealing ring 4 under different forces. From the compressed state, it can be seen that there is still space inside the "Y"-shaped sealing ring 4 after compression, and a large clamping force is not required to make the sealing surface fit completely, and it has no effect on the tightening torque of the bolt.

[0027] Specifically, accelerated thermal aging tests were conducted. The material thermal aging test conditions simulated the use of the material for 9 years at a temperature of 50°C in a boric water medium (2400±100PPm). The accelerated thermal aging formula t2=t1expEa / KB[1 / T2-1 / T1] was used to calculate the accelerated thermal aging conditions in the water medium: 150°C×88.74h. The actual thermal aging conditions were 150°C×89h. After aging, the hardness of the material only increased by 1ShoreA, the tensile properties were all above 90%, and the compression permanent deformation was 15%. The specific changes are shown in Table 1.

[0028] Table 1

[0029] Specifically, Fig.10 As shown in the figure, the working condition test of the prototype is to conduct a superimposed hot working condition sealing test on the prototype after heat aging + 700KGy irradiation, that is, 150℃×88.74h+700KGy+180℃×46.5bar×(144+96×110%)h, that is, assuming that the sealing ring is used normally for 9 years (including 100KGy), and is irradiated with 600KGy under accident working conditions, and at the end of its life, it undergoes 12 high / low temperature switches of 180℃→60℃*46.5bar*12h and still has excellent sealing performance.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A flange sealing ring structure of a regulating valve of a waste heat removal system of a nuclear power plant, comprising a flange upper cover (1), a flange seat (2) and a connecting plate (3), wherein the connecting plate (3), the flange seat (2) and the flange upper cover (1) are connected in sequence from bottom to top, and characterized in that: Also includes: Two sealing rings (4), each of which is a "Y"-shaped structure, are connected between the flange upper cover (1) and the flange seat (2).

2. A flange sealing ring structure for a regulating valve of a waste heat removal system of a nuclear power plant according to claim 1, characterized in that: A circle of wire sealing structure (5) is provided on both the upper and lower sides of the sealing ring (4).

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