CN104316276A - Method for quantitatively positioning and detecting SF6 gas leakage of sleeve - Google Patents

Abstract

The invention provides a method for quantitatively positioning and detecting SF6 gas leakage of a sleeve. The method includes the following steps of S1, powering off an ultrahigh voltage converter station transformer, and well taking safety measures for grounding and the like; S2, inflating the sleeve with helium to ensure that the total pressure reaches the rated value under the original SF6 pressure condition of the sleeve through an SF6 gas supplementation opening of the sleeve and a valve; S3, positioning and separating the leakage of the sleeve; S4, quantitatively testing the leakage of the sleeve; S5, calculating and detecting the total annual leakage amount and the annual leakage rate of the sleeve; S6, comparing the annual leakage rate with the leakage standard of the sleeve to determine whether the sleeve needs to be overhauled and replaced or not. The method has the technical advantages that the SF6 gas leakage of the sleeve can be quantitatively positioned and detected, the leakage caused by cracks of a sleeve body, the reducing manufacturing defects of the sleeve and the like can be positioned and quantitatively evaluated in time, and the leakage sleeve can be conveniently replaced or maintained, the pollution caused by SF6 gas leakage can be avoided, and the safety performance of an electric system can be improved.

Description

A kind of quantitative and detection and localization sleeve pipe SF 6the method of Leakage Gas

Technical field

The present invention relates to one and be applied to electric system ultra-high voltage converter station valve chamber sleeve pipe SF ₆the method of Leakage Gas, specifically quantitatively a kind of and detection and localization sleeve pipe SF ₆the method of Leakage Gas.

Background technology

What past detection thimble SF6 Leakage Gas adopted is infrared scanner, whether infrared scanner can only have leakage by qualitative discovery sleeve pipe, before not adopting the present invention, after sleeve pipe SF6 slip has to pass through and runs certain hour, be as the criterion with the online tensimeter change of sleeve pipe and calculate.The evaluation of sleeve pipe pipe fitting valve and the installation quality such as casing cushion, gland nut can not be carried out in time, also cannot position and quantitative evaluation the leakage that the problems such as sleeve body crackle, casing diameter variable manufacturing process defect produce in time.

Summary of the invention

The present invention provides quantitatively a kind of and detection and localization sleeve pipe SF according to the deficiencies in the prior art ₆the method of Leakage Gas, can carry out quantitatively and detection and localization.

Technical scheme of the present invention: quantitatively a kind of and detection and localization sleeve pipe SF ₆the method of Leakage Gas, is characterized in that comprising the following steps:

S1: ultra-high voltage converter station transformer has a power failure, and carries out the safety practices such as ground connection;

S2: by sleeve pipe SF ₆gas supplementing opening and valve, at sleeve pipe SF ₆under former pressure condition, after being filled with helium, ensure that general pressure reaches ratings;

S3: casing leak is tab-delimited, uses plastic sheeting to be wound around sleeve pipe, the small-sized confined space between each cluster parachute of forming sleeves;

S4: casing leak quantitative test, uses the leak rate data of the small-sized confined space between each cluster parachute of helium mass analyzer detection thimble;

S5: the year calculating detection thimble leaks total amount and leakage rate per year;

S6: leakage rate per year and casing leak standard comparing, determines that this sleeve pipe is the need of carrying out examine and replace.

In described step S3, plastic sheeting to be wrapped on sleeve pipe the top of the cluster parachute of equidistantly distribution, and two adjacent cluster parachutes are closed into confined space by plastic sheeting.

In described step S4, will be inserted in confined space by the detection probe that connecting line is connected with helium mass analyzer, detect the leak rate data Q in confined space.

It is M that the described step S5 middle age leaks total amount, and leakage rate per year is K,

The computing formula of leaking total amount M is: M=Q × 24 × 60 × 60 × 365,

The computing formula of leakage rate per year K is: $K=\frac{M^E/H_e}{1000\mathrm{EV}}$

In formula: the leak rate of Q for detecting in step S4, E is filling SF in step S2 middle sleeve ₆gaseous tension ratings, H _efor step S2 middle sleeve filling helium pressure force value, V is casing volume.

Technique effect of the present invention: can quantitatively and detection and localization sleeve pipe SF ₆leakage Gas, positions and quantitative evaluation the leakage that the problems such as sleeve body crackle, casing diameter variable manufacturing process defect produce in time, is convenient for changing or keeps in repair leakage sleeve pipe, avoid SF ₆leakage Gas pollutes, and improves power system security energy.

Accompanying drawing explanation

Fig. 1 is principle of work schematic diagram of the present invention.

Number in the figure represents respectively: 1-sleeve pipe, 2-gas supplementing opening, 3-cluster parachute, 4-plastic sheeting, 5-confined space, 6-detection probe, 7-connecting line, 8-helium mass analyzer.

Embodiment

Below by concrete case study on implementation, the present invention is further described by reference to the accompanying drawings:

For the high-end valve chamber Casing Detection in two imperial current conversion station poles II, Sichuan:

S1: ultra-high voltage converter station transformer has a power failure, and carries out the safety practices such as ground connection;

S2: by sleeve pipe SF ₆gas supplementing opening and valve, at sleeve pipe SF ₆ensure after being filled with about 5kPa helium under former pressure condition that general pressure reaches ratings 300kPa, sleeve pipe inflation cumulative volume is about 0.4m ³;

S3: as shown in Figure 1, plastic sheeting 4 to be wrapped on sleeve pipe 1 top of the cluster parachute 3 of equidistantly distribution, and two adjacent cluster parachutes 3 are closed into confined space 5 by plastic sheeting 4;

S4: casing leak quantitative test, as shown in Figure 1, will be inserted in confined space 5 by the detection probe 6 that connecting line 7 is connected with helium mass analyzer 8, uses the leak rate data Q of the small-sized confined space 5 between each cluster parachute of helium mass analyzer 8 detection thimble;

Two imperial current conversion station poles II, Sichuan high-end valve chamber Casing Detection data see the following form

Two imperial current conversion station poles II, Sichuan high-end valve chamber Casing Detection tables of data

S5: the year calculating detection thimble leaks total amount and leakage rate per year;

For Y/Y--A phase b sleeve pipe and Y/ Δ---B phase a sleeve pipe (see thickened portion data in table), Y/Y--A phase b sleeve pipe is calculated as follows:

Year reveals total amount M:

M=Q × 24 × 60 × 60 × 365=2.0 × 10 ^-7pam ³/ s × 24 × 60 × 60 × 365=6.3Pam ³/ year

Year leakage rate K:

This sleeve pipe SF ₆former pressure 295kPa, after being filled with 5kPa helium, general pressure ratings is 300kPa, and sleeve pipe inflation cumulative volume is 0.4m ³, calculating year leakage rate is as follows accordingly:

M in above-mentioned formula---year leaks total amount (Pam ³/ year)

Q---leak rate (Pam ³/ s)

K---year leakage rate (%/year)

E---cover casing pack SF ₆gaseous tension ratings (kPa)

H _e---sleeve pipe filling helium pressure force value (kPa)

V---casing volume m ³

According to above-mentioned formulae discovery: Y/ Δ--B phase a sleeve pipe maximum possible leakage rate per year is 42.12%/year.

S6: with comparing of 1%/year of casing leak standard, determines that this sleeve pipe is the need of carrying out examine and replace.

Must not more than the standard in 1%/year according to casing leak, in upper example, Y/Y--A phase b sleeve pipe can not be changed, Y/ Δ---and B phase a sleeve pipe should be changed.

One of the present invention quantitatively and detection and localization sleeve pipe SF ₆the method of Leakage Gas, is applied to electric system, can quantitatively and detection and localization ultra-high voltage converter station valve chamber sleeve pipe SF ₆leakage Gas, positions and quantitative evaluation the leakage that the problems such as sleeve body crackle, casing diameter variable manufacturing process defect produce in time, is convenient for changing or keeps in repair leakage sleeve pipe, avoid SF ₆leakage Gas pollutes, and improves power system security energy.

One of the present invention quantitatively and detection and localization ultra-high voltage converter station valve chamber sleeve pipe SF ₆the method of Leakage Gas has been successfully applied to the detection experiment of the two high-end valve chamber of imperial current conversion station pole I 12 sleeve pipes in Sichuan, the high-end valve chamber in pole II 12 sleeve pipes, 600 changes for subsequent use, 2 sleeve pipes, 800 changes for subsequent use, 2 sleeve pipes, accurate quantitative analysis detects that 4 casing leaks are because casing diameter variable section problem of manufacturing qualities causes, belong to producer's warranty coverage, factory must be returned changed by ABB AB of Sweden, avoid the loss of the expense of heavily purchasing of 3,600 ten thousand yuan.In addition, judge that other 24 casing leak rates are in standard tolerance band, do not need outaged equipment to change.The wet season is completely sent out on the occasion of Hydropower Unit in the Sichuan in July, and correct and quick judgement is leaked the order of severity and determined that sleeve pipe is without the need to exiting maintenance, and avoid Hydropower Unit and abandon water loss, indirect benefit is huge.

Claims (4)

1. a quantitative and detection and localization sleeve pipe SF ₆the method of Leakage Gas, is characterized in that comprising the following steps:

S1: ultra-high voltage converter station transformer has a power failure, and carries out the safety practices such as ground connection;

S2: by sleeve pipe SF ₆gas supplementing opening and valve, at sleeve pipe SF ₆under former pressure condition, after being filled with helium, ensure that general pressure reaches ratings;

S3: casing leak is tab-delimited, uses plastic sheeting to be wound around sleeve pipe, the small-sized confined space between each cluster parachute of forming sleeves;

S4: casing leak quantitative test, uses the leak rate data of the small-sized confined space between each cluster parachute of helium mass analyzer detection thimble;

S5: the year calculating detection thimble leaks total amount and leakage rate per year;

S6: leakage rate per year and casing leak standard comparing, determines that this sleeve pipe is the need of carrying out examine and replace.

2. one according to claim 1 quantitatively and detection and localization sleeve pipe SF ₆the method of Leakage Gas, it is characterized in that: in described step S3, plastic sheeting (4) is wrapped in the top of the upper equidistantly cluster parachute (3) of distribution of sleeve pipe (1), and two adjacent cluster parachutes (3) are closed into confined space (5) by plastic sheeting (4).

3. one according to claim 2 quantitatively and detection and localization sleeve pipe SF ₆the method of Leakage Gas, it is characterized in that: in described step S4, to be inserted in confined space (5) by the detection probe (6) that connecting line (7) is connected with helium mass analyzer (8), detect the leak rate data Q in confined space (5).

4. one according to claim 3 quantitatively and detection and localization sleeve pipe SF ₆the method of Leakage Gas, is characterized in that: it is M that the described step S5 middle age leaks total amount, and leakage rate per year is K,

The computing formula of leaking total amount M is: M=Q × 24 × 60 × 60 × 365,

The computing formula of leakage rate per year K is:

In formula: the leak rate of Q for detecting in step S4, E is filling SF in step S2 middle sleeve ₆gaseous tension ratings, H _efor step S2 middle sleeve filling helium pressure force value, V is casing volume.