Helium protection structure of safety valve

Abstract

The utility model provides a safety valve helium protection structure, and particularly relates to the technical field of low-temperature equipment, the safety valve helium protection structure is connected with a first positive pressure connecting pipe through a micro-positive pressure helium system, and then the first positive pressure connecting pipe is sequentially connected with an inlet flange, a safety valve, an outlet flange, a negative pressure connecting pipe and a negative pressure pipeline. When the negative pressure pipeline leaks, micro-positive pressure helium enters the negative pressure pipeline, it is ensured that air outside the system cannot enter the system, and stable operation can be achieved in a 2K superfluid helium temperature area.

Description

Technical Field

[0001] The utility model relates to the technical field of cryogenic equipment, in particular to a helium protection structure for a safety valve. Background Art

[0002] Currently, the ultra-low temperature cold box mainly reaches the 4.2K liquid helium temperature range. The safety valve connection structure set on its pipeline is mainly a threaded interface, and a tetrafluoro gasket or thread sealant is used for sealing. The pipeline in this temperature range is in a positive pressure environment. When the internal pressure of the system is greater than the external pressure, external air is not easily introduced into the internal system.

[0003] Since the operating temperature range of the ultra-low temperature cold box in the prior art is 4.2K, the pressure of the system pipeline is positive, and the internal pressure of the environment is greater than the external pressure, so external air is not easily introduced into the internal system. However, when in the 2K temperature range, the pressure of the system is negative, and the inlet and outlet of the safety valve are exposed to the air. If the system stops or the safety valve leaks, external air is easily introduced into the low-temperature system, causing pollution to the entire system. Therefore, the safety valve structure in the 4.2K cold box cannot be directly used in the 2K temperature range.

[0004] In view of this, the utility model provides a helium protection structure for a safety valve that can be applied in the 2K temperature range and a negative pressure system. Content of the Utility Model

[0005] In order to solve the problem that external air is easily introduced into the system when leakage occurs in a low-temperature negative pressure helium system, the utility model proposes a helium protection structure for a safety valve.

[0006] The utility model is realized through the following technical solutions:

[0007] The utility model proposes that the helium protection structure for a safety valve includes a negative pressure connection pipeline, a safety valve, and a first slightly positive pressure connection pipeline, wherein:

[0008] An outlet flange is arranged on one side of the negative pressure connection pipe, an inlet flange is arranged on one side of the first slightly positive pressure connection pipe, the safety valve is provided with an air inlet and an exhaust port, the air inlet and exhaust port of the safety valve are respectively and hermetically connected to the negative pressure connection pipe and the first slightly positive pressure connection pipe through the inlet flange and the outlet flange, and the negative pressure connection pipe and the first slightly positive pressure connection pipe are respectively connected to a negative pressure pipeline and a slightly positive pressure helium system.

[0009] Furthermore, it further includes a flow control valve, and the flow control valve is respectively arranged on two branches at one end of the second slightly positive pressure connection pipe.

[0010] Further, the outlet flange and the inlet flange have the same structure, and an inner sealing groove and an outer sealing groove are respectively arranged from the inside to the outside on one side connecting the safety valve. A sealing ring is arranged in each of the inner sealing groove and the outer sealing groove.

[0011] Further, a vent hole is arranged between the two sealing rings of the inner sealing groove and the outer sealing groove. A second slightly positive pressure connecting pipe is further arranged on one side of the safety valve. Two branches at one end of the second slightly positive pressure connecting pipe are respectively connected to the vent holes of the outlet flange and the inlet flange, and the other end is connected to the slightly positive pressure helium system.

[0012] Further, the inner diameter of the first slightly positive pressure connecting pipe is larger than the inner diameter of the second slightly positive pressure connecting pipe.

[0013] Advantages of the present utility model:

[0014] (1) For the helium protection structure of the safety valve proposed by the present utility model, the slightly positive pressure helium system is connected to the first positive pressure connecting pipe, and the first slightly positive pressure connecting pipe is then sequentially connected to the inlet flange, the safety valve, the outlet flange, the negative pressure connecting pipe and the negative pressure pipeline. When there is a leak in the negative pressure pipeline, in the slightly positive pressure pipeline, the slightly positive pressure helium will enter the negative pressure pipeline to ensure that the air outside the system cannot enter the system interior, and it can operate stably in the 2K superfluid helium temperature range.

[0015] (2) For the helium protection structure of the safety valve proposed by the present utility model, the inner and outer double sealing grooves are used in cooperation with the sealing rings for sealing, which can ensure the sealing performance of the connection between the inlet and outlet of the safety valve. Finally, it is connected to the second slightly positive pressure connecting pipe through the vent hole and then connected to the slightly positive pressure system. When there is a leak between the sealing rings, the slightly positive pressure helium of the slightly positive pressure system will flow into the inlet and outlet of the safety valve to prevent external gas from entering the system interior. Description of the drawings

[0016] Figure 1 is the overall structure diagram of the helium protection structure of the safety valve of the present utility model;

[0017] Figure 2 is the structure diagram of the inlet and outlet flanges of the helium protection structure of the safety valve of the present utility model;

[0018] In the figure: safety valve 1, exhaust port 11, inlet port 12, first slightly positive pressure connecting pipe 2, negative pressure connecting pipe 3, second slightly positive pressure connecting pipe 4, outlet flange 5, inlet flange 6, outer sealing groove 61, inner sealing groove 62, sealing ring 63, vent hole 64;

[0019] The realization, functional characteristics and advantages of the present utility model will be further described with reference to the embodiments and the drawings. Specific embodiments

[0020] To more clearly and completely illustrate the technical solution of the present utility model, the present utility model will be further described below with reference to the accompanying drawings.

[0021] Please refer to Figure 1 - Figure 2 , the present utility model provides a helium protection structure for a safety valve 1 applied to a superfluid helium negative pressure pipeline, which includes a negative pressure connecting pipe 3, a safety valve 1, and a first slightly positive pressure connecting pipe 2, where:

[0022] An outlet flange 5 is provided on one side of the negative pressure connecting pipe 3, an inlet flange 6 is provided on one side of the first slightly positive pressure connecting pipe 2, the safety valve 1 is provided with an air inlet 12 and an exhaust port 11, the air inlet 12 and the exhaust port 11 of the safety valve 1 are respectively and hermetically connected to the negative pressure connecting pipe 3 and the first slightly positive pressure connecting pipe 2 through the inlet flange 6 and the outlet flange 5, and the negative pressure connecting pipe 3 and the first slightly positive pressure connecting pipe 2 are respectively connected to a negative pressure pipeline and a slightly positive pressure helium system.

[0023] In this embodiment:

[0024] The safety valve 1 is used to discharge gas;

[0025] In a specific embodiment, both ends of the safety valve 1 are respectively attached to the inlet flange 6 and the outlet flange 5, and the safety valve 1 and the inlet flange 6 and the outlet flange 5 are hermetically sealed inside and outside through a sealing ring 63. The other ends of the inlet flange 6 and the outlet flange 5 are respectively and hermetically connected to the first slightly positive pressure connecting pipe 2 and the second slightly positive pressure connecting pipe 4. The air inlet 12 of the safety valve 1 is connected to the negative pressure pipeline through the negative pressure connecting pipe 3, and the air outlet of the safety valve 1 is connected to the slightly positive pressure helium system through the first slightly positive pressure connecting pipe 2. If the safety valve 1 leaks, the slightly positive pressure helium will enter the negative pressure connecting pipe 3 and the connected negative pressure pipeline through the first slightly positive pressure connecting pipe 2 and the safety valve 1, so that the gas leaking into the negative pressure pipeline is also slightly positive pressure helium, so as to prevent air from the external system from entering the pipeline interior. By connecting the slightly positive pressure helium system to the safety valve 1 and the negative pressure pipeline through the first slightly positive pressure pipeline, the present utility model can prevent air from the external system from entering the pipeline and polluting the internal system.

[0026] Furthermore, the outlet flange 5 and the inlet flange 6 have the same structure, and an inner sealing groove 62 and an outer sealing groove 61 are respectively arranged from the inside to the outside on the side connecting the safety valve 1. A sealing ring 63 is arranged in each of the inner sealing groove 62 and the outer sealing groove 61;

[0027] A vent hole 64 is also arranged between the two sealing rings 63 of the inner sealing groove 62 and the outer sealing groove 61. A second slightly positive pressure connecting pipe 4 is also arranged on one side of the safety valve 1. Two branches at one end of the second slightly positive pressure connecting pipe 4 are respectively connected to the vent holes 64 of the outlet flange 5 and the inlet flange 6, and the other end is connected to the slightly positive pressure helium system.

[0028] In this embodiment:

[0029] The sealing groove is used to place the sealing ring 63;

[0030] The sealing ring 63 is used to improve the sealing performance between the inlet flange 6 and the outlet flange 5;

[0031] In a specific embodiment, both the inlet flange 6 and the outlet flange 5 are circular. Inner sealing grooves 62 and outer sealing grooves 61 are provided on the sides of the inlet flange 6 and the outlet flange 5 that are in contact with the safety valve 1, and the inner and outer sides of the inlet flange 6 and the outlet flange 5 are sealed. There is a vent hole 64 between the two sealing grooves. The vent hole 64 is connected to the second slightly positive pressure connecting pipe 4 through the flow channels on the inlet flange 6 and the outlet flange 5, and the second slightly positive pressure connecting pipe 4 is further connected to the slightly positive pressure helium system;

[0032] By cooperating with the sealing ring 63 through the inner and outer sealing grooves, the sealing performance can be improved. At the same time, a closed space is formed between the two inner and outer sealing grooves 61. When leakage occurs between the two sides of the safety valve 1 and the inlet flange 6 and the outlet flange 5, part of the slightly positive pressure helium will enter between the inlet flange 6 and the outlet flange 5 through the second slightly positive pressure connecting pipe 4, and prevent external gas from entering the safety valve 1 or the negative pressure pipeline through the gap between the inlet flange 6, the outlet flange 5 and the safety valve 1. At the same time, normal operation in the 2K superfluid helium temperature range and the 4.2K superfluid helium temperature range can be achieved.

[0033] Furthermore, it further includes flow control valves, and the flow control valves are respectively arranged on two branches at one end of the second slightly positive pressure connecting pipe 4.

[0034] In this embodiment:

[0035] The flow control valves are used to control the flow rates of the two branches of the second slightly positive pressure connecting pipe 4;

[0036] In a specific embodiment, the flow control valves control the flow rates of the two branches of the second slightly positive pressure connecting pipe 4 to ensure that the appropriate slightly positive pressure helium acts on the sealing structure and does not affect the sealing of the sealing ring 63.

[0037] Furthermore, the inner diameter of the first slightly positive pressure connecting pipe 2 is larger than the inner diameter of the second slightly positive pressure connecting pipe 4.

[0038] Of course, the present utility model can also have many other embodiments. Based on this embodiment, other embodiments obtained by those of ordinary skill in the art without any creative work belong to the scope protected by the present utility model.

Claims

1. A helium protection structure for a safety valve, characterized in that, It includes a negative pressure connection pipeline, a safety valve and a first slightly positive pressure connection pipeline, wherein: An outlet flange is provided on one side of the negative pressure connection pipe, an inlet flange is provided on one side of the first slightly positive pressure connection pipe, the safety valve is provided with an air inlet and an air outlet, the air inlet and the air outlet of the safety valve are respectively hermetically connected to the negative pressure connection pipe and the first slightly positive pressure connection pipe through the inlet flange and the outlet flange, and the negative pressure connection pipe and the first slightly positive pressure connection pipe are respectively connected to a negative pressure pipeline and a slightly positive pressure helium system.

2. The helium protection structure of the safety valve according to claim 1, characterized in that The outlet flange and the inlet flange have the same structure, and an inner sealing groove and an outer sealing groove are respectively arranged from the inside to the outside on the side connecting the safety valve, and a sealing ring is arranged in each of the inner sealing groove and the outer sealing groove.

3. The helium protection structure of the safety valve according to claim 2, wherein A vent hole is further arranged between the two sealing rings of the inner sealing groove and the outer sealing groove, a second slightly positive pressure connection pipe is further arranged on one side of the safety valve, and two branches at one end of the second slightly positive pressure connection pipe are respectively connected to the vent holes of the outlet flange and the inlet flange, and the other end is connected to the slightly positive pressure helium system.

4. The helium protection structure of the safety valve according to claim 3, wherein The inner diameter of the first slightly positive pressure connection pipe is larger than the inner diameter of the second slightly positive pressure connection pipe.

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