An ultra-low temperature bellows stop valve for liquid hydrogen piping

Abstract

The utility model discloses a kind of ultra-low temperature bellows stop valve for liquid hydrogen pipeline, it is related to stop valve technical field.The utility model includes cut-off communication body, first connecting pipe, second connecting pipe, sealing stop cover and spline transmission assembly.Sealing stop body is arranged inside, and top is realized opening and closing control by spline thread shaft pipe and spline shaft rod linkage.It is equipped with inner side sealing bellows and outer side sealing bellows, forms inside and outside double-layer sealing structure, can completely isolate transmission mechanism and liquid hydrogen medium.

Description

Technical Field

[0001] This utility model relates to the field of shut-off valve technology, specifically to an ultra-low temperature bellows shut-off valve for liquid hydrogen pipelines. Background Technology

[0002] Liquid hydrogen requires multiple pipeline systems and flow control during transportation and storage, but the valve structures used to control its flow have long been limited. Traditional cryogenic valves often employ a rigid stem push-type structure, with the stem and body sealed by packing or O-rings. However, in the liquid hydrogen environment, temperatures typically drop to -253°C, causing significant thermal expansion and contraction of metals. Ordinary packing materials tend to harden and fail at these temperatures, leading to minor leaks at the sealing surface. Summary of the Invention

[0003] To overcome the shortcomings of the prior art, this utility model provides the following technical solution: a cryogenic bellows shut-off valve for liquid hydrogen pipelines, comprising a shut-off connecting body, a sealing shut-off body fixedly disposed at the bottom of the inner wall of the shut-off connecting body, the sealing shut-off body forming a stepped surface inside the shut-off connecting body, and a sealing shut-off cover sealingly contacting the top of the sealing shut-off body; a first connecting pipe and a second connecting pipe are also fixedly installed on the shut-off connecting body, the first connecting pipe and the second connecting pipe communicating with the inside of the shut-off connecting body, wherein the second connecting pipe is aligned and communicating with the sealing shut-off body, and the sealing shut-off cover is used to cut off the flow path between the first connecting pipe and the second connecting pipe.

[0004] Preferably, a top sealing cover is fixedly installed on the top of the shut-off connector, a splined threaded shaft tube is threaded into the center of the top sealing cover, an inner sealing bellows is sleeved on the outside of the splined threaded shaft tube, and the two ends of the inner sealing bellows are fixedly and sealingly connected to the top sealing cover and the sealing shut-off cover.

[0005] Preferably, the bottom end of the splined threaded shaft tube is rotatably fitted with the sealing stop cover, the axial position of the splined threaded shaft tube is slidably inserted with a spline in a spline manner, and a sealing cylindrical shaft is fixedly installed at the top end of the splined shaft.

[0006] Preferably, an outer sealing cylinder is fixedly installed on the top sealing cover, and the top end of the outer sealing cylinder is rotatably sealed with the sealing cylindrical shaft.

[0007] Preferably, an outer sealing bellows is sleeved on the outer side of the spline shaft, and the two ends of the outer sealing bellows are fixedly sealed with the outer sealing cylinder and the top sealing cover. The outer sealing bellows and the outer sealing cylinder are used to form a double seal at the connection between the top sealing cover and the spline threaded shaft tube.

[0008] Preferably, a dial wheel is rotatably mounted on the top of the outer sealing cylinder, and the dial wheel is fixed coaxially with the sealing cylindrical shaft.

[0009] Preferably, both the second connecting pipe and the first connecting pipe are fixedly equipped with flanges at the ends away from the cut-off communication body.

[0010] Compared with the prior art, the present invention has the following advantages: (1) The present invention sets up two sealing units, an inner sealing bellows and an outer sealing bellows, to form a double isolation between the cut-off connecting body and the top sealing cover and the external connection part of the spline threaded shaft tube, respectively, which completely eliminates the risk of liquid hydrogen medium leaking outward, and significantly improves the sealing durability and safety level of the valve under low temperature conditions; (2) The inner sealing bellows of the present invention always isolates the inside of the cut-off connecting body from the drive structure during the valve operation process, avoids the gas inside the valve cavity from contacting the outside, fundamentally blocks the hydrogen leakage path, and significantly improves the system safety. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0012] Figure 2 This is a schematic diagram of the internal structure of the cut-off connector of this utility model.

[0013] Figure 3 This is a cross-sectional view of the overall structure of this utility model.

[0014] In the diagram: 001 - Cut-off connector; 002 - First connecting pipe; 003 - Second connecting pipe; 004 - Flange; 005 - Top sealing cover; 006 - Outer sealing cylinder; 007 - Dial wheel; 008 - Outer sealing bellows; 009 - Sealing cylindrical shaft; 010 - Splined shaft; 011 - Splined threaded shaft tube; 012 - Inner sealing bellows; 013 - Sealing stop cover; 014 - Sealing stop body. Detailed Implementation

[0015] The following is in conjunction with the appendix Figures 1-3 The technical solution of this utility model will be further illustrated through specific implementation methods.

[0016] This utility model provides a cryogenic bellows shut-off valve for liquid hydrogen pipelines, including a shut-off connecting body 001. A sealing shut-off body 014 is fixedly mounted on the bottom of the inner wall of the shut-off connecting body 001. The sealing shut-off body 014 is used to form a stepped surface inside the shut-off connecting body 001. A sealing shut-off cover 013 is sealed to the top of the sealing shut-off body 014. A first connecting pipe 002 and a second connecting pipe 003 are also fixedly installed on the shut-off connecting body 001. The first connecting pipe 002 and the second connecting pipe 003 communicate with the inside of the shut-off connecting body 001. The second connecting pipe 003 is aligned and communicates with the sealing shut-off body 014. The sealing shut-off cover 013 is used to cut off the flow path between the first connecting pipe 002 and the second connecting pipe 003. A top sealing cover 005 is fixedly and sealed at the top of the shut-off connector 001. A spline-threaded shaft tube 011 is threadedly inserted into the center of the top sealing cover 005. An inner sealing bellows 012 is sleeved on the outside of the spline-threaded shaft tube 011. Both ends of the inner sealing bellows 012 are fixedly and sealingly connected to the top sealing cover 005 and the sealing shut-off cover 013. The bottom end of the spline-threaded shaft tube 011 is rotatably engaged with the sealing shut-off cover 013. A spline shaft 010 is slidably inserted into the axial center of the spline-threaded shaft tube 011 using a spline configuration. A sealing cylindrical shaft 009 is fixedly installed at the top end of the spline shaft 010. An outer sealing cylinder 006 is fixedly installed on the top sealing cover 005. The top end of the outer sealing cylinder 006 is rotatably and sealingly engaged with the sealing cylindrical shaft 009. An outer sealing bellows 008 is fitted around the outside of the splined shaft 010. Both ends of the outer sealing bellows 008 are fixedly sealed to the outer sealing cylinder 006 and the top sealing cover 005. The outer sealing bellows 008 and the outer sealing cylinder 006 form a double seal at the connection between the top sealing cover 005 and the splined threaded shaft tube 011. A dial wheel 007 is rotatably mounted on the top of the outer sealing cylinder 006, and the dial wheel 007 is coaxially fixed to the sealing cylindrical shaft 009. Flanges 004 are fixedly mounted at the ends of the second connecting pipe 003 and the first connecting pipe 002 away from the cut-off communication body 001.

[0017] The working principle of the cryogenic bellows shut-off valve for liquid hydrogen pipeline disclosed in this utility model is as follows: The first connecting pipe 002 and the second connecting pipe 003 are connected in series in the pipeline through the flange 004. When connection is required, the dial 007 is rotated, which drives the sealing cylindrical shaft 009 and the spline shaft 010 to rotate. The spline shaft 010 drives the spline threaded shaft tube 011 to rotate. The rotation of the spline threaded shaft tube 011 causes it to move axially linearly on the top sealing cover 005. At this time, the sealing shut-off cover 013 is separated from the sealing shut-off body 014, so that the first connecting pipe 002 and the second connecting pipe 003 are connected. During this process, the inner sealing bellows 012 completely isolates the inside of the shut-off connecting body 001 from the spline threaded shaft tube 011, thereby improving the sealing performance at the connection between the spline threaded shaft tube 011 and the top sealing cover 005. Conversely, if it is necessary to cut off the connection, simply rotate the dial 007 in the opposite direction to make the sealing stop cover 013 contact the sealing stop body 014 to seal, thus cutting off the connection path between the first connecting pipe 002 and the second connecting pipe 003.

Claims

1. A cryogenic bellows shut-off valve for liquid hydrogen pipelines, characterized in that: The device includes a stop-connector (001), and a sealing stop (014) is fixedly provided at the bottom of the inner wall of the stop-connector (001). The sealing stop (014) is used to form a stepped surface inside the stop-connector (001), and the top of the sealing stop (014) is in sealing contact with a sealing stop cover (013). The stop connector (001) is also fixedly installed with a first connecting pipe (002) and a second connecting pipe (003). The first connecting pipe (002) and the second connecting pipe (003) are connected to the inside of the stop connector (001). The second connecting pipe (003) is aligned and connected with the sealing stop body (014). The sealing stop cover (013) is used to cut off the flow path between the first connecting pipe (002) and the second connecting pipe (003).

2. The cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 1, characterized in that: The top of the stop connector (001) is fixedly sealed with a top sealing cover (005). A spline threaded shaft tube (011) is threaded into the center of the top sealing cover (005). An inner sealing bellows (012) is sleeved on the outside of the spline threaded shaft tube (011). The two ends of the inner sealing bellows (012) are fixedly sealed to the top sealing cover (005) and the sealing stop cover (013).

3. The cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 2, characterized in that: The bottom end of the spline threaded shaft tube (011) is rotatably fitted with the sealing stop cover (013). The spline threaded shaft tube (011) is slidably inserted with a spline shaft (010) at the axial center position. A sealing cylindrical shaft (009) is fixedly installed at the top end of the spline shaft (010).

4. A cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 3, characterized in that: An outer sealing cylinder (006) is fixedly installed on the top sealing cover (005), and the top end of the outer sealing cylinder (006) is rotatably sealed with the sealing cylindrical shaft (009).

5. A cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 4, characterized in that: An outer sealing bellows (008) is sleeved on the outside of the spline shaft (010). The two ends of the outer sealing bellows (008) are fixedly sealed with the outer sealing cylinder (006) and the top sealing cover (005). The outer sealing bellows (008) and the outer sealing cylinder (006) are used to form a double seal at the connection between the top sealing cover (005) and the spline threaded shaft tube (011).

6. A cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 5, characterized in that: The top of the outer sealing cylinder (006) is equipped with a dial wheel (007), which is fixed coaxially with the sealing cylindrical shaft (009).

7. A cryogenic bellows shut-off valve for liquid hydrogen pipelines according to claim 6, characterized in that: Both the second connecting pipe (003) and the first connecting pipe (002) are fixedly equipped with flanges (004) at the ends away from the cut-off communication body (001).

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