SF6 gas leakage rate detection device and detection method for O-shaped sealing ring for GIS

Abstract

The invention relates to the technical field of sealing ring tests, in particular to an SF6 gas leakage rate detection device and detection method for an O-shaped sealing ring for a GIS, and the detection device comprises a sealing assembly part, a gas source distributor, a constant temperature box and an SF6 gas chamber. Wherein the plurality of sealing assembly parts are arranged in the constant-temperature box; the SF6 gas chamber is connected with a sealing assembly part in the constant-temperature box through a gas source distributor; a to-be-checked sealing ring is arranged in the sealing assembly part in a sealing manner; the gas source distributor comprises a main connector, a gas source distributor gas chamber and a plurality of branch connectors, the main connector is used for being connected with the SF6 gas chamber through a main gas pipe, and the branch connectors are used for being connected with the sealing assembly parts through gas distribution pipes; the gas source distributor gas chamber is used for temporarily storing gas from the SF6 gas chamber and is connected with at least one sealing assembly part at the same time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sealing ring test, in particular to a SF6 (sulfur hexafluoride) gas leakage rate detection device and method for O-shaped sealing ring of GIS. BACKGROUND

[0002] Detecting SF6 gas leakage rate is a direct method for evaluating the sealing effect of sealing ring. The leakage rate measured by the existing method can represent the sealing effect of the sealing ring and the flange as a whole. When exploring the leakage characteristics of the sealing ring alone, the control variable method is used to exclude the influence of the flange. The leakage rate detection method given by the technical standard is generally used to judge whether the factory assembly is qualified, but its accuracy and detection efficiency cannot meet the needs of scientific research. Although there are devices for detecting the leakage rate of sealing ring, the leakage characteristics of each sealing medium are different, and the needs of various equipment for sealing performance are also different. Therefore, the existing sealing ring leakage rate detection device cannot meet the actual needs. In summary, there is a lack of SF6 leakage rate detection device and method for GIS sealing ring in the prior art. SUMMARY

[0003] The purpose of the present application is to overcome the shortcomings and deficiencies of the prior art, and to provide a SF6 gas leakage rate detection device and method for O-shaped sealing ring of GIS.

[0004] In one aspect, the embodiments of the present application propose a SF6 gas leakage rate detection device for O-shaped sealing ring of GIS, comprising sealing assembly parts, a gas source distributor, a constant temperature box and an SF6 gas chamber; wherein the sealing assembly parts are provided in plurality and arranged in the constant temperature box; the SF6 gas chamber is connected with the sealing assembly parts in the constant temperature box through the gas source distributor. The sealing ring to be examined is arranged in the sealing assembly part in a sealing manner. The gas source distributor comprises a main joint, a gas source distributor gas chamber and a plurality of branch joints; the main joint is used to connect with the SF6 gas chamber through a main gas pipe; the branch joint is used to connect with the sealing assembly part through a branch gas pipe; the gas source distributor gas chamber is used to temporarily store the gas from the SF6 gas chamber and simultaneously connect with at least one sealing assembly part.

[0005] Preferably, the sealing assembly part comprises a base, a flange group, a top cover, a sealing ring to be examined, a qualified sealing ring and a branch gas pipe; the upper and lower ends of the flange group are both provided with the qualified sealing ring; the sealing ring to be examined is installed in the flange group and located between the two qualified sealing rings; the sealing assembly part is stacked in sequence from bottom to top according to the order of the base, the qualified sealing ring, the flange group, the qualified sealing ring and the top cover.

[0006] Preferably, the plurality of sealing assembly parts are arranged in layers in the constant temperature box.

[0007] In another aspect, the embodiments of the present application also provide a SF6 gas leakage rate detection method for an O-ring seal for GIS, which is realized based on the gas leakage rate detection device, and comprises the following steps: S1, assembling the seal ring to be tested in a sealing assembly, and connecting the sealing assembly after assembly to a gas source distributor through a gas distribution pipe; S2, filling the gas from the SF6 gas chamber into the gas source distributor gas chamber through the main gas pipe by the main joint, and filling the gas from the SF6 gas chamber temporarily stored in the gas source distributor gas chamber into the sealing assembly through the gas distribution pipe by the branch joint, so that the gas pressures of the SF6 gas chamber and the gas chambers of the plurality of sealing assemblies are consistent under the condition that the filling and discharging of gas is stopped and the sealing is good; S3, monitoring the SF6 gas in the SF6 gas chamber, when the gas pressure of the SF6 gas chamber decreases, it is judged that at least one of the plurality of sealing assemblies connected with the gas source distributor has occurred leakage; if the gas pressure of the SF6 gas chamber is maintained stable, it is judged that all the sealing assemblies connected with the gas source distributor are sealed perfectly.

[0008] Compared with the prior art, the present application has the following advantages and effects: The SF6 gas leakage rate detection device and detection method provided by the present application are suitable for GIS seal rings, and a complete detection device can carry out parallel detection on a plurality of sealing assemblies; at the same time, the design that a plurality of sealing assemblies share one gas chamber makes the detection device smaller in size, shortens the time of SF6 gas filling / recovery, greatly improves the time and space efficiency, helps to build a temperature and humidity controlled test environment, and supports the research on SF6 gas leakage path, condition and conversion mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a structural schematic diagram of the SF6 gas leakage rate detection device in the embodiments of the present application; Figure 2 is a structural schematic diagram of the sealing assembly in the embodiments of the present application; Figure 3 is a top view of the gas source distributor; Figure 4 is a sectional view of the base of the sealing assembly; Figure 5 is a schematic diagram of the gas pipe and its joint; In the figure, 1 is a thermostat, 2 is a gas source distributor, 21 is a gas source distributor gas chamber, 22 is a main joint, 23 is a branch joint, 24 is a sealing cover, 241 is a sealing ring, 25 is a main gas pipe, 3 is an SF6 gas chamber, 31 is a gas filling valve, 4 is a base, 41 is a gas inlet joint, 42 is a sealing groove, 43 is a through hole, 5 is a flange group, 6 is a top cover, 7 is a qualified sealing ring, 8 is a sealing ring to be tested, 9 is a gas distribution pipe, 91 is a gas pipe joint, and 911 is a sealing ring. Detailed Implementation

[0010] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Example

[0011] See Figure 1 This embodiment provides an SF6 gas leakage rate detection device for O-rings used in GIS, including sealing components, a constant temperature chamber 1, and an SF6 gas chamber 3; wherein multiple sealing components are provided and are disposed inside the constant temperature chamber; the SF6 gas chamber is connected to the sealing components inside the constant temperature chamber through a gas source distributor 2. Preferably, the multiple sealing components are arranged in layers inside the constant temperature chamber.

[0012] like Figure 2 As shown, the sealing assembly includes a base 4, a flange assembly 5, a top cover 6, a sealing ring 8 to be tested, a qualified sealing ring 7, and a gas distribution pipe 9. Qualified sealing rings are provided at both the upper and lower ends of the flange assembly 5. The sealing ring 8 to be tested is installed in the flange assembly 5, positioned between two qualified sealing rings. The sealing assembly is assembled by stacking the base, qualified sealing ring, flange assembly, qualified sealing ring, and top cover sequentially from bottom to top. After assembly, the sealing assembly is connected to the gas distributor via the gas distribution pipe 9 located on the base.

[0013] like Figure 3 The gas distributor 2 mainly includes the following three parts: main connector 22, gas distributor chamber 21 and multiple branch connectors 23, wherein the main connector and each branch connector are equipped with a corresponding sealing cover 24. The main connector connects to the SF6 chamber 3 via the main gas pipe 25, allowing gas from the SF6 chamber to be supplied to the gas source distributor chamber or recycled, and maintaining equal gas pressure between the gas source distributor chamber and the SF6 chamber when gas supply stops. The tap connects to the sealing fittings via the distribution pipe 9, allowing gas from the SF6 chamber to be supplied to the sealing fittings or recycled, and maintaining equal gas pressure between the gas source distributor chamber and the sealing fitting chamber when gas supply stops. The gas source distributor chamber temporarily stores gas from the SF6 chamber, and due to its multiple taps, it can connect to at least one (i.e., multiple) sealing fittings simultaneously, ensuring consistent gas pressure between the connected SF6 chamber and the multiple sealing fitting chambers when gas supply stops and the seal is intact. The sealing cap seals unused taps, controlling the number of connected sealing fittings. The sealing cap contains a sealing ring 241; when the sealing cap is tightened, the internal sealing ring compresses and deforms to fill the gaps between the threads, thus achieving a seal. Similarly, the main air pipe and branch air pipe joints used when connecting the main connector and branch connector also have sealing rings.

[0014] In the embodiment, the gas source distributor can be provided with a plurality of gas distribution pipes, each of which is connected to a plurality of sealed assemblies; the gas source distributor is connected to the SF6 gas chamber through a main gas pipe 25, so that all the sealed assemblies connected to the gas source distributor share the same SF6 gas chamber and have the same gas pressure. The main joint is connected to the SF6 gas chamber through the main gas pipe, and the branch joint is connected to the sealed assembly through the gas distribution pipe, so that the SF6 gas can be filled from the SF6 gas chamber to the gas source distributor, and then from the gas source distributor to the sealed assembly. When filling the gas, the SF6 gas is only needed to be filled into the whole device from the gas filling valve at the top of the SF6 gas chamber. When recovering, the gas is only needed to be extracted from the gas filling valve.

[0015] The SF6 gas chamber is filled and discharged through the gas filling valve 31 at the top, and a gas pressure gauge can also be installed on the gas filling valve to monitor the SF6 gas in the gas chamber. When the gas pressure of the SF6 gas chamber decreases, it is determined that at least one of the plurality of sealed assemblies connected to the gas source distributor has leaked. If the gas pressure of the SF6 gas chamber can be maintained stable, it is determined that all the sealed assemblies connected to the gas source distributor are sealed perfectly.

[0016] That is, in the embodiment, a gas pressure gauge is installed at the gas filling valve at the top of the SF6 gas chamber. When the gas filling and discharging is stopped, under the premise that all parts of the whole device except the sealed ring to be tested are sealed well, the sealing performance of the sealed ring to be tested can be judged by observing the change of the gas pressure gauge. If the sealing performance of the sealed ring to be tested is good, the gas pressure in the device should remain stable. If there is a leak in the sealed ring to be tested, the SF6 gas in the whole device will leak from there. Since all the gas chambers of the whole device are connected through the gas source distributor, the gas in the SF6 gas chamber will flow to the gas chamber with lower gas pressure, and the gas pressure of the SF6 gas chamber will decrease, resulting in a decrease in the reading of the gas pressure gauge. In the prior art, each sealed assembly needs a set of leak detection device. The embodiment of the present application realizes that a plurality of sealed assemblies can be detected for leakage by using only one complete detection device, reduces the floor area occupied by the detection device, and greatly shortens the filling / recovery time of SF6 gas. Moreover, the structural design of the embodiment enables the sealed assembly to be separated out through a gas distribution pipe, so that it can be put into a thermostat for detecting the leakage rate. The detection that can only be carried out at room temperature can be carried out at different temperatures by adjusting the thermostat.

[0017] As shown in Figure 4 , the base 4 of the sealed assembly is provided with a groove, i.e. a sealing groove 43, which can be used to install a sealing ring. The flange group 5 includes upper and lower flanges, both of which are also provided with grooves for installing qualified sealing rings. Figure 5 As shown in , the gas distribution pipe 9 is also provided with a gas pipe joint 91, and the gas pipe joint is provided with a sealing ring 911.

[0018] The sealing assembly is also provided with a plurality of through holes which communicate the base 4, the flange group 5 and the top cover 6, and are used for mounting the threaded rods and nuts. The assembly of the sealing assembly comprises the following steps: (1) A nut is screwed on one end of a threaded rod which is longer than the sealing assembly by about 10 cm, and 1-2 cm of the threaded rod is exposed, and the operation is repeated to obtain a plurality of threaded rods with nuts at one end; (2) The threaded rod is passed through the through hole on the base, the nut on the threaded rod is abutted against the bottom of the base, the sealing ring is installed in the groove on the base, and then the through hole on the lower flange of the flange group is passed through the threaded rod and horizontally placed on the sealing ring; (3) The sealing ring is installed in the groove on the lower flange, and then the through hole on the upper flange of the flange group is passed through the threaded rod and horizontally placed on the sealing ring; (4) The sealing ring is installed in the groove on the upper flange, and then the through hole on the top cover is passed through the threaded rod and horizontally placed on the sealing ring; (5) The nuts are respectively screwed on the exposed sections of the threaded rod on the top cover, the sealing rings in the flange group are compressed to realize sealing, and the assembly of the sealing assembly is completed.

[0019] The sealing ring between the lower flange and the upper flange is the sealing ring to be examined, and the two sealing rings arranged on the lower flange and the upper flange are qualified sealing rings and are only used for sealing.

[0020] Based on the same inventive concept, the embodiment also provides a SF6 gas leakage rate detection method for an O-shaped sealing ring for GIS, which is specifically implemented by using the gas leakage rate detection device. The detection method comprises the following steps: S1, the sealing ring to be examined is assembled in the sealing assembly, and the sealing assembly after assembly is connected to the gas source distributor through the gas distribution pipe; S2, the main joint fills the gas from the SF6 gas chamber into the gas chamber of the gas source distributor through the main gas pipe, and the branch joint fills the gas from the SF6 gas chamber temporarily stored in the gas chamber of the gas source distributor into the sealing assembly through the gas distribution pipe, so that the gas pressures of the SF6 gas chamber and the gas chambers of the plurality of sealing assemblies are consistent under the condition that the filling and discharging is stopped and the sealing is good; S3, the SF6 gas in the SF6 gas chamber is monitored, when the gas pressure of the SF6 gas chamber decreases, it is judged that at least one of the plurality of sealing assemblies connected with the gas source distributor has occurred leakage; if the gas pressure of the SF6 gas chamber is maintained stable, it is judged that all the sealing assemblies connected with the gas source distributor are sealed perfectly.

[0021] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A device for detecting the SF6 gas leakage rate of an O-ring seal for a GIS, characterized by, The SF6 gas chamber is connected with the sealing assembly in the thermostat through the gas source distributor. The sealing assembly to be tested is arranged in the sealing assembly. The gas source distributor comprises a main joint, a gas source distributor gas chamber and a plurality of branch joints.

2. The gas leak rate detection apparatus according to claim 1, characterized by, The sealing assembly comprises a base, a flange group, a top cover, a sealing ring to be tested, a qualified sealing ring and a gas distribution pipe.

3. The gas leak rate detection apparatus according to claim 2, characterized by, The base of the sealing assembly is provided with a groove for mounting the sealing ring.

4. The gas leak rate detection apparatus according to claim 2, characterized by The flange group comprises an upper flange and a lower flange, and the upper flange and the lower flange are both provided with a groove for mounting the qualified sealing ring.

5. The gas leak rate detection apparatus according to claim 2, characterized by The sealing assembly is further provided with a plurality of through holes communicating the base, the flange group and the top cover.

6. The gas leak rate detection apparatus according to claim 1, wherein The top of the SF6 gas chamber is provided with a gas filling valve.

7. The gas leak rate detection apparatus according to claim 6, wherein A gas pressure gauge is mounted on the gas filling valve for monitoring the SF6 gas in the SF6 gas chamber.

8. The gas leak rate detection apparatus according to claim 1, characterized by The plurality of sealing assemblies are arranged in layers in the thermostat.

9. The gas leak rate detection apparatus according to claim 1, wherein The main joint and each branch joint of the gas source distributor are each provided with a sealing cover, and the sealing cover is internally provided with a sealing ring.

10. A method for detecting SF6 gas leakage rate of an O-ring seal for GIS, based on the gas leakage rate detection device of any one of claims 1-9, characterized in that, The detection method comprises the following steps: S1, assembling the sealing ring to be tested in the sealing assembly, and connecting the sealing assembly after assembly with the gas source distributor through the gas distribution pipe; S2, filling the gas from the SF6 gas chamber into the gas source distributor gas chamber through the main gas pipe, and filling the gas temporarily stored in the gas source distributor gas chamber from the SF6 gas chamber into the sealing assembly through the gas distribution pipe, so that the gas pressures of the SF6 gas chamber and the plurality of sealing assembly gas chambers are consistent under the condition of stopping filling and discharging and good sealing; S3, monitoring the SF6 gas in the SF6 gas chamber, when the gas pressure of the SF6 gas chamber decreases, it is judged that at least one of the plurality of sealing assemblies connected with the gas source distributor has leaked; if the gas pressure of the SF6 gas chamber remains stable, it is judged that all the sealing assemblies connected with the gas source distributor are sealed perfectly.

Images