Pipeline thermal conductivity gas sensing detection module

Abstract

A pipeline thermal conductivity gas sensor detection module and a detection method thereof, comprising a module body, wherein a through left threaded hole, a middle mounting hole and a right threaded hole are sequentially provided inside the module body from left to right, an insulation bridge is respectively provided on the left and right sides of the middle mounting hole, a cylindrical measuring gas chamber is provided between the two insulation bridges, two fine perforations are provided on the side of the module body along the radial direction of the middle mounting hole, a tensioned platinum wire is provided in the measuring gas chamber, and the platinum wire is bent at both ends of the insulation bridge and passes through the module body through the fine perforations on the left and right sides. The present invention adopts an online detection method, does not require gas extraction operation, does not affect the safe operation of the equipment, does not cause gas changes in the equipment, and avoids gas extraction detection errors and measurement errors caused by regional inconsistency and temperature inconsistency caused by broken gas paths.

Description

Technical Field

[0001] The invention belongs to the technical field of gas online detection, and in particular relates to a pipeline thermal conductivity gas sensor detection module. Background Art

[0002] Sulfur hexafluoride (SF6) gas is widely used in gas-insulated power equipment due to its insulating properties. Due to various reasons in the manufacture and operation of the equipment, the gas in the equipment may have composition changes, resulting in changes in the purity of SF6, affecting the safe and stable operation of the equipment. The original detection method uses gas to be taken out of the equipment for analysis. On the one hand, it will cause gas loss in the equipment, and on the other hand, the process of taking out the gas will also affect the safe operation of the equipment, and the taken out gas may be contaminated again.

[0003] Sulfur hexafluoride (SF6) gas is widely used in various electrical equipment such as gas insulated circuit breakers, gas insulated switchgear (GIS), transformers, and mutual inductors due to its excellent insulation and arc extinguishing properties. Since various defects may occur in SF6 gas-insulated equipment during manufacturing, installation, or operation, discharge (arc discharge, spark discharge, partial discharge) and overheating failure may occur, causing SF6 gas to decompose. If the discharge phenomenon occurs near the solid insulating medium, decomposition products such as CF4, CO, and CO2 will also be generated. The content, generation rate and other characteristics of these products are closely related to the internal insulation degradation of the equipment, and can be used as a basis for judging the early latent faults of the insulation equipment. Relevant research literature at home and abroad shows that diagnosing the internal insulation defects of the above-mentioned equipment by detecting the decomposition components of SF6 gas has become a hot topic of current research. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides a pipeline thermal conductivity gas sensor detection module which has a simple structure, is easy to install and detect.

[0005] In order to solve the above technical problems, the present invention adopts the following technical scheme: a pipeline thermal conductivity gas sensor detection module, including a module body, wherein a through left threaded hole, a middle mounting hole and a right threaded hole are sequentially opened inside the module body from left to right, an insulating bridge is respectively arranged on the left and right sides of the middle mounting hole, a cylindrical measuring gas chamber is arranged between the two insulating bridges, two fine through holes are opened on the side of the module body along the radial direction of the middle mounting hole, the inner ends of the two fine through holes are connected to the middle mounting hole and are respectively located on the left and right sides of the insulating bridge, a tensioned platinum wire is passed through the measuring gas chamber, the measuring gas chamber, the middle mounting hole and the platinum wire inside the measuring gas chamber are on the same center line, and the platinum wire is bent at both ends of the insulating bridge and passes through the module body through the fine through holes on the left and right sides respectively.

[0006] The measuring air chamber is a cylinder made of nylon or polytetrafluoroethylene material. Insulating covers are respectively provided at both ends of the measuring air chamber. A step hole for assembling the insulating cover is provided at the center of the insulating bridge. A through hole for passing the platinum wire is provided in the center of the insulating cover. The insulating cover is provided with heat dissipation holes evenly arranged around the through hole.

[0007] The outer circumferential surface of the measuring air chamber is provided with a cylindrical heating film, and a temperature resistance wire is arranged inside the heating film.

[0008] The left threaded hole, the middle mounting hole and the right threaded hole have the same center line, the inner diameter of the right threaded hole is equal to the inner diameter of the left threaded hole, and the inner diameter of the middle mounting hole is smaller than the inner diameter of the left threaded hole.

[0009] A detection method for a pipeline thermal conductivity gas sensing detection module comprises the following steps:

[0010] (1) Install the left threaded hole and the right threaded hole of the module body on the sulfur hexafluoride gas pipeline respectively;

[0011] (2) Connect the two ends of the platinum wire that passes through the outside of the module body and the temperature resistance wire to the measuring instrument accordingly;

[0012] (3) Start the measuring instrument and energize the platinum wire;

[0013] (4) The measuring instrument measures the power and resistance of the platinum wire, and then calculates the thermal conductivity of the gas in the gas chamber, and calculates the gas purity through the mixed gas thermal conductivity theory.

[0014] The calculation process of step (4) is as follows: suppose the length of the platinum wire in the measuring air chamber is l, the radius is r1, and the 0 degree resistance is R0; the voltage loaded on the platinum wire is v, and the current is i;

[0015] The output power of the platinum wire is

[0016]

[0017] The resistance of platinum wire is:

[0018]

[0019] The temperature of the platinum wire is:

[0020]

[0021] The radius of the measuring air chamber is r2, and the temperature of the air chamber wall is measured by measuring the temperature resistance wire of the air chamber wall as T0;

[0022] According to Fourier's law, the thermal conductivity of the gas in the air chamber is:

[0023]

[0024] Assume that there are two gases A and B in the measuring chamber, and their thermal conductivities are C A and C B . The concentrations are a% and b% respectively;

[0025] Where a%+b%=100%

[0026] According to the law of thermal conductivity of mixed gases, the thermal conductivity of mixed gases is:

[0027]

[0028] According to the thermal conductivity of the mixed gas in the gas chamber measured earlier, the mixed gas ratio can be obtained by substituting it into the formula:

[0029] .

[0030] By adopting the above technical solution, the present invention has the following beneficial effects:

[0031] 1. The present invention adopts online detection means, does not require gas extraction operation, does not affect the safe operation of the equipment, does not cause changes in the gas in the equipment, and avoids gas extraction detection errors.

[0032] 2. By adopting pipeline detection means, it is only necessary to add equipment to the original maintenance pipeline of the equipment without changing the main structure of the power equipment and having no impact on the original safe operation conditions of the power equipment.

[0033] 3. The heating film and temperature resistance wire are integrated inside the pipeline, directly contacting the gas, without a gas guide tube structure, avoiding measurement errors caused by regional inconsistency and temperature inconsistency caused by broken gas lines.

[0034] 4. The heating film and temperature resistance wire are integrated inside the pipeline, with a small size and no unnecessary external components, making it easy to install and construct. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a three-dimensional structural schematic diagram of the present invention;

[0036] Figure 2 It is a schematic diagram of the left side planar structure of the present invention;

[0037] Figure 3 yes Figure 2 Middle AA section view;

[0038] Figure 4 yes Figure 3 Enlarged view of point B in the middle. DETAILED DESCRIPTION

[0039] like Figure 1-Figure 4As shown, the pipeline thermal conductivity gas sensor detection module of the present invention includes a module body 1, and the module body 1 is provided with a through left threaded hole 2, a middle mounting hole 3 and a right threaded hole 4 from left to right in sequence. A heat insulating bridge 8 is respectively provided on the left and right sides of the middle mounting hole 3, and a cylindrical measuring gas chamber 7 is provided between the two heat insulating bridges 8. Two fine through holes 5 are provided on the side of the module body 1 along the radial direction of the middle mounting hole 3. The inner ends of the two fine through holes 5 are connected to the middle mounting hole 3 and are respectively located on the left and right sides of the heat insulating bridge 8. A tensioned platinum wire 6 is passed through the measuring gas chamber 7. The measuring gas chamber 7, the middle mounting hole 3 and the platinum wire 6 inside the measuring gas chamber 7 are on the same center line. The platinum wire 6 is bent at both ends of the heat insulating bridge 8 and passes through the module body 1 through the fine through holes 5 on the left and right sides respectively.

[0040] The measuring air chamber 7 is a cylinder made of nylon or polytetrafluoroethylene material. Insulating covers 9 are respectively provided at both ends of the measuring air chamber 7. A step hole for assembling the insulating cover 9 is provided at the center of the insulating bridge 8. A through hole for passing the platinum wire 6 is provided at the center of the insulating cover 9. The insulating cover 9 is provided with heat dissipation holes 10 evenly arranged around the through hole.

[0041] A cylindrical heating film 11 is provided on the outer circumferential surface of the measuring gas chamber 7 , and a temperature resistance wire 12 is provided inside the heating film 11 .

[0042] The left threaded hole 2 , the middle mounting hole 3 and the right threaded hole 4 have the same center line, the inner diameter of the right threaded hole 4 is equal to the inner diameter of the left threaded hole 2 , and the inner diameter of the middle mounting hole 3 is smaller than the inner diameter of the left threaded hole 2 .

[0043] A detection method for a pipeline thermal conductivity gas sensing detection module comprises the following steps:

[0044] (1) Install the left threaded hole 2 and the right threaded hole 4 of the module body 1 on the sulfur hexafluoride gas pipeline respectively;

[0045] (2) Connect the two ends of the platinum wire 6 passing through the outside of the module body 1 and the temperature resistance wire 12 to the measuring instrument accordingly;

[0046] (3) Start the measuring instrument and energize the platinum wire 6;

[0047] (4) The measuring instrument measures the power and resistance of the platinum wire 6, and then calculates the thermal conductivity of the gas in the gas chamber, and calculates the gas purity through the mixed gas thermal conductivity theory.

[0048] The calculation process of step (4) is as follows: assuming that the length of the platinum wire 6 in the measuring chamber 7 is l, the radius is r1, and the 0-degree resistance is R0; the voltage loaded on the platinum wire 6 is v, and the current is i;

[0049] Then the output power of the platinum wire 6 is

[0050]

[0051] The resistance of platinum wire 6 is:

[0052]

[0053] The temperature of the platinum wire 6 is:

[0054]

[0055] The radius of the measuring air chamber 7 is r2, and the air chamber wall temperature is measured by the temperature resistance wire 12 of the measuring air chamber 7 wall as T0;

[0056] According to Fourier's law, the thermal conductivity of the gas in the air chamber is:

[0057]

[0058] Assume that there are two gases A and B in the measuring chamber 7, and their thermal conductivities are C A and C B . The concentrations are a% and b% respectively;

[0059] Where a%+b%=100%

[0060] According to the law of thermal conductivity of mixed gases, the thermal conductivity of mixed gases is:

[0061]

[0062] According to the previously measured thermal conductivity of the mixed gas in the measuring chamber 7, the mixed gas ratio can be obtained by substituting it into the formula:

[0063] .

[0064] This embodiment does not impose any formal limitation on the shape, material, structure, etc. of the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. Pipeline thermal conductivity gas sensing detection module, characterized by: The module body comprises a module body, wherein a through left threaded hole, a middle mounting hole and a right threaded hole are sequentially provided inside the module body from left to right, a heat-insulating bridge is respectively provided on the left and right sides of the middle mounting hole, a cylindrical measuring air chamber is provided between the two heat-insulating bridges, two fine through holes are provided on the side of the module body along the radial direction of the middle mounting hole, the inner ends of the two fine through holes are connected to the middle mounting hole and are respectively located on the left and right sides of the heat-insulating bridge, a tensioned platinum wire is passed through the measuring air chamber, the measuring air chamber, the middle mounting hole and the platinum wire inside the measuring air chamber are on the same center line, and the platinum wire is bent at both ends of the heat-insulating bridge and passes through the module body through the fine through holes on the left and right sides respectively; The measuring air chamber is a cylindrical body made of nylon or PTFE material. Both ends of the measuring air chamber are respectively provided with heat insulation covers. A step hole for assembling the heat insulation cover is provided at the center of the heat insulation bridge. A through hole for passing the platinum wire is provided at the center of the heat insulation cover. The heat insulation cover is provided with heat dissipation holes evenly arranged around the through hole. A cylindrical heating film is provided on the outer circumferential surface of the measuring air chamber, and a temperature resistance wire is provided inside the heating film; The left threaded hole, the middle mounting hole and the right threaded hole have the same center line, the inner diameter of the right threaded hole is equal to the inner diameter of the left threaded hole, and the inner diameter of the middle mounting hole is smaller than the inner diameter of the left threaded hole; The detection method of the pipeline thermal conductivity gas sensor detection module includes the following steps: (1) Install the left threaded hole and the right threaded hole of the module body on the sulfur hexafluoride gas pipeline respectively; (2) Connect the two ends of the platinum wire passing through the outside of the module body and the temperature resistance wire to the measuring instrument accordingly; (3) Start the measuring instrument and energize the platinum wire; (4) The measuring instrument measures the power and resistance of the platinum wire, and then calculates the thermal conductivity of the gas in the gas chamber, and calculates the gas purity through the mixed gas thermal conductivity theory; The calculation process of step (4) is as follows: assuming that the length of the platinum wire in the measuring air chamber is l, the radius is r1, and the 0-degree resistance is R0; the voltage loaded on the platinum wire is v, and the current is i; The output power of the platinum wire is W=V*iThe resistance of platinum wire is: R=v / i The temperature of the platinum wire is: The radius of the measuring air chamber is r2, and the temperature of the air chamber wall is measured by measuring the temperature resistance wire of the air chamber wall as T0; According to Fourier's law, the thermal conductivity of the gas in the air chamber is: Assume that there are two gases A and B in the measuring chamber, and their thermal conductivities are C A and C B ; The concentrations are a% and b% respectively; Where a%+b%=100% According to the law of thermal conductivity of mixed gases, the thermal conductivity of mixed gases is: λ=C A *a%+C B *b% According to the thermal conductivity of the mixed gas in the gas chamber measured earlier, the mixed gas ratio can be obtained by substituting it into the formula:

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