CN206498131U - Ring main unit filled with halogenated hydrocarbon insulating gas - Google Patents

Abstract

The utility model discloses a kind of ring main unit filled with halogenated hydrocarbons insulating gas.Disconnecting switch is lower isolation three-station in ring main unit, is made up of isolation blade, isolation main shaft, grounding contact, isolation dynamic sealing；Isolation blade is made up of the copper tool piece of the electroplate of two 6mm thickness, and disk spring is installed between two isolation blades；Disk spring outer surface is provided with metal cap.Gas in the air chamber of ring main unit includes halogenated hydrocarbon gas and auxiliary gas；Wherein, the volume fraction of halogenated hydrocarbon gas is 15%~75%, and remaining is auxiliary gas.The alternative sulfur hexafluoride gas of halogenated hydrocarbons insulating gas of the present utility model, dielectric strength is suitable with the dielectric strength of sulfur hexafluoride, even higher than sulfur hexafluoride gas, and with certain arc extinguishing ability, wherein CF₃The GWP of I CF3Is is less than 5, and almost suitable with carbon dioxide, there is life cycle in air is 0.005 year.

Description

Ring main unit filled with halogenated hydrocarbon insulating gas

technical field

The utility model relates to the technical field of ring network cabinets, in particular to a ring network cabinet filled with halogenated hydrocarbon insulating gas.

Background technique

Sulfur hexafluoride gas has a history of one hundred years. It is an artificial inert gas synthesized by two French chemists, Moissan and Lebeau, in 1900. Around 1940, the US military used it for the Manhattan Project (nuclear military), and it was provided in 1947. commercial. Sulfur hexafluoride gas is mainly used in the power industry. Sulfur hexafluoride gas is used in 4 types of electrical equipment as insulation and/or arc extinguishing; SF6 circuit breakers and GIS (here refers to SF6 closed Type combination electrical appliances, known internationally as "gas insulated switchgear"), sulfur hexafluoride load switchgear, sulfur hexafluoride insulated transmission pipelines, sulfur hexafluoride transformers and sulfur hexafluoride insulated substations, 80% of which are used for High and medium voltage power equipment.

At present, the fully enclosed gas-insulated ring network cabinets in the medium-voltage field on the market are mainly filled with sulfur hexafluoride gas. The GWP value (global warming potential value) of sulfur hexafluoride gas is 23900, which is listed in the Kyoto Protocol. One of the greenhouse gases whose use is restricted. Moreover, with the rapid development of sulfur hexafluoride electrical equipment, more and more people are exposed to sulfur hexafluoride gas and sulfur hexafluoride decomposition products after arc action.

The toxicity of sulfur hexafluoride gas mainly comes from five aspects:

1. Certain toxic products produced by sulfur hexafluoride gas in electrical equipment when high-temperature arcs occur.

2. The sulfur hexafluoride product is impure, and contains highly toxic subsulfur fluoride, hydrogen fluoride and other toxic gases when it leaves the factory.

3. Sulfur hexafluoride gas and decomposition products in electrical equipment react with electrodes (Cu-W alloy) and metal materials (Al, Cu) to generate some toxic products.

4. The decomposition product of sulfur hexafluoride gas in electrical equipment reacts with the moisture in it to produce some toxic products.

5. Sulfur hexafluoride gas and decomposition products in electrical equipment react with insulating materials to produce some toxic products. Such as insulating parts such as epoxy phenolic glass cloth boards (rods, tubes) containing silicon components; or epoxy resin castings, molded parts, porcelain bottles, silicone rubber, silicone grease, etc. filled with quartz sand and glass. , generating SiF ₄ , Si(CH ₃ ) ₂ F ₂ and other products.

The disadvantages of inflatable ring network cabinets currently on the market are as follows:

First, most of the inflatable ring network cabinets in the medium voltage field use sulfur hexafluoride gas as the filling gas. Sulfur hexafluoride is a gas with a high greenhouse effect, with a GWP value of 23900, which is extremely unfriendly to the atmospheric environment. .

Second, pure sulfur hexafluoride is sensitive to the surface roughness of the electrode and conductive particles, which has certain requirements for the electrode processing technology and the ring network cabinet assembly process. Compared with the halogenated hydrocarbon mixed gas ring network cabinet, the process requirements more stringent.

Third, there is also a ring network cabinet filled with dry air or nitrogen on the market, but the insulation strength of air and nitrogen is small, which means that the size of the ring network cabinet is relatively large and its reliability is not high.

Therefore, it is imperative to seek a ring main unit filled with other insulating gases.

Utility model content

The purpose of this utility model is to provide a ring network cabinet filled with halogenated hydrocarbon insulating gas.

A ring network cabinet filled with halogenated hydrocarbon insulating gas, wherein the isolation switch in the ring network cabinet is a lower isolation three-position switch, which is composed of an isolation blade, an isolation spindle, a ground contact, and an isolation dynamic seal; the isolation blade consists of two A silver-plated copper blade with a thickness of 6mm is formed, and a disc spring is worn between the two isolation blades; the outer surface of the disc spring (16) is provided with a metal cap (17).

In the ring main unit filled with halogenated hydrocarbon insulating gas according to the present invention, the isolating switch has three states of closing, opening and grounding; the disc spring (16) is compressed after assembly, providing 150 -200N of pressure is given to the isolation blade, so that the isolation blade can closely contact the main contact and the ground contact when the switch is closed and grounded;

The ring main unit filled with halogenated hydrocarbon insulating gas according to the present invention is characterized in that: the material of the isolation main shaft is epoxy glass rod, and the isolation dynamic seal adopts magnetic fluid dynamic seal.

Compared with the prior art, the ring main unit filled with halogenated hydrocarbon insulating gas of the utility model has outstanding effects in that:

(1) The halogenated hydrocarbon insulating gas of this utility model can replace sulfur hexafluoride gas, and its dielectric strength is equivalent to that of sulfur hexafluoride gas, even higher than that of sulfur hexafluoride gas, and has a certain arc extinguishing ability, Among them, the GWP of CF ₃ I trifluoroiodomethane is less than 5, which is almost equivalent to that of carbon dioxide, and its lifetime in the atmosphere is 0.005 years.

(2) The boiling point of halogenated hydrocarbon gas is relatively high, among which the boiling point of CF ₃ I is -22.5°C, and the boiling point of cC ₄ F ₈ octafluorocyclobutane is -8°C, which cannot be used in cold regions of China. The proportion of weakly electronegative gas or neutral gas with low boiling point makes its boiling point drop below minus 30 degrees, which can be applied in severe cold regions.

(3) The critical field strength of CF ₃ I measured by Thomson pulse method (PT) is 440X10 ^-17 V/cm ² , the critical field strength of SF ₆ is 360X10 ^-17 V/cm ² , and the critical field strength of CF ₃ I Far greater than the critical field strength of SF ₆ , it means that the insulation performance of CF ₃ I is better than that of SF ₆ , and the insulation strength of a mixed gas with a mixing ratio of CF ₃ I and N ₂ of 70% is comparable to that of pure SF ₆ .

(4) In order to improve the insulation performance of the halogenated hydrocarbon mixed gas, the utility model optimizes and improves the isolation blade, and adds four cylindrical metal caps on the outer surface of the disc spring, which can improve the electric field distribution of the isolation blade disc spring, Optimize the extremely uneven distribution electric field to a more uniform electric field.

(5) Among them, CF ₃ I mixed gas is a kind of green and environment-friendly gas, which has almost no greenhouse effect, and will not cause damage to the ozone layer. It has good insulation performance and certain arc extinguishing ability, which can completely replace the current medium-voltage inflatable gas The sulfur hexafluoride gas in the ring network cabinet has broad application prospects, and the GWP value of several other halogenated hydrocarbon gases is much smaller than that of sulfur hexafluoride, and the survival life is also short, which has a certain promotion prospect.

(6) The halogenated hydrocarbon mixed gas has a positive synergistic effect, which can reduce the sensitivity to the electrode surface roughness and conductive particles, and improve the reliability of the ring network cabinet.

(7) Since a certain proportion of other gases are mixed, the cost of the mixed gas is reduced. Has better economy.

(8) Due to the high breakdown field strength of halogenated hydrocarbon mixed gas, this means that the size of the ring network cabinet itself is smaller than that of the air-insulated ring network cabinet.

The halogenated hydrocarbon insulating gas of the present invention and its application will be further described below in conjunction with the description of the drawings and specific examples.

Description of drawings

Figure 1 is a left view of the structure of a single-loop ring network cabinet;

Fig. 2 is a left view of the four-circuit ring network cabinet;

Fig. 3 is the front view of the four-circuit ring network cabinet;

Fig. 4 is an axial sectional view of the four-circuit ring network cabinet;

Fig. 5 is the schematic diagram of isolating switch in the ring main unit of comparative example 10;

Fig. 6 is a schematic diagram of the isolating switch in the ring main unit of embodiment 31.

Among them, 1-circuit breaker, 2-circuit breaker mechanism, 3-circuit breaker isolation interlock, 4-isolation mechanism, 5-cabinet door interlock, 6-outlet bushing, 7-cable room, 8-grounding bar, 9-isolation Switch, 10-main contact, 11-air chamber, 12-mechanism chamber, 13-explosion-proof plate, 14-panel, 15-cabinet door, 16-isolating disc spring, 17-metal cap.

detailed description

As shown in Figure 1-6, the ring main unit filled with halogenated hydrocarbon insulating gas, the circuit breaker body 1 is composed of vacuum interrupter, circuit breaker tie rod, circuit breaker main shaft, circuit breaker dynamic seal, main contact and so on. The vacuum interrupter adopts Baoguang brand model TD31-12/630-20D, which plays the role of breaking short-circuit current and working current. The pull rod of the circuit breaker is equipped with a spring with a rectangular cross section, and the spring provides the contact pressure of about 1800N for the circuit breaker. The pull rod of the circuit breaker is connected with the crank arm of the main shaft of the circuit breaker through the link pin, the main shaft of the circuit breaker is made of epoxy glass rod, and the main shaft of the circuit breaker is connected with the circuit breaker mechanism 2 through the magnetic fluid dynamic seal. The magnetic fluid dynamic seal plays the role of sealing and transmitting motion.

The isolating switch 9 is a lower isolating three-position switch, which is composed of an isolating blade, an isolating main shaft, a grounding contact, and an isolating dynamic seal. The isolating switch 9 has three states of closing, opening, and grounding, and can carry current, provide a safe visible fracture, and be grounded. The isolation blade is composed of two silver-plated copper blades with a thickness of 6mm. A set of disc springs 16 of national standard a6 are passed between the two isolation blades. The disc springs 16 are compressed after assembly to provide a pressure of 150-200 N Give the isolation blade so that the isolation blade can closely contact the main contact and the ground contact in the closed and grounded state. The material of the isolation spindle is epoxy glass rod, and the isolation dynamic seal adopts magnetic fluid dynamic seal.

The disc spring 16 is covered with four cylindrical metal caps 17, which can improve the electric field distribution of the isolation blade disc spring 16, optimize the extremely uneven electric field distribution to a relatively uniform electric field, and reduce the partial discharge capacity from 20PC to about 5PC.

The gas chamber 11 is welded by 304 stainless steel plates with a thickness of 3 mm, and plays a role of supporting the switch body and the mechanism box and sealing. The lower end of the air chamber 11 has an explosion-proof plate 8, and the explosion-proof plate 8 mainly plays an explosion-proof effect.

In the mechanism room 12, there are circuit breaker mechanism 2, isolating switch 9 and related chains, which are used for closing and opening of circuit breaker 1 and closing and grounding of isolating switch 9 and other actions. The circuit breaker mechanism 2 is composed of an energy storage spring, a closing spring, a cam shaft, a connecting rod, a tripping shaft, a closing and opening coil, and the like. The isolating switch 9 is a single spring mechanism, which can realize the operations of three states of closing, opening and grounding. The interlocking includes the circuit breaker isolating interlocking 3 between the circuit breaker mechanism 2 and the isolating switch 9, the cabinet door interlocking 5, etc., and is used to meet the five defense functions. Mechanism chamber 12 outermost is panel 14, but observation window is housed on panel 14, can observe what state isolating switch 9 is in.

Outlet bushing 6 is arranged in cable chamber 7, is used for connecting external cable.

The air chamber 11 is filled with a halogenated hydrocarbon mixed gas with a relative pressure of 0.04MPa, which includes halogenated hydrocarbon gas and auxiliary gas; wherein, the volume fraction of halogenated hydrocarbon gas is 15% to 75%, and the rest is auxiliary gas. Wherein, the halogenated hydrocarbon gas is at least one of CF ₃ I, cC ₄ F ₈ , C ₄ F ₆ and C ₃ F ₆ . The auxiliary gas is a gas with a low boiling point, which is at least one of N ₂ , CO ₂ and dry air.

Halogenated hydrocarbon gas is a kind of strong electronegativity gas, which has a strong ability to absorb electrons, and its relative molecular weight is relatively large, so the halogenated hydrocarbon gas has a high electric strength and can be used in medium and high voltage fields. A certain proportion of other low-boiling-point weakly electronegative gases and neutral gases are added to the halogenated hydrocarbon gas, and the positive synergistic effect between the gases can improve the electric strength and reduce the boiling point of the mixed gas to below minus 30 degrees. This allows the ring main unit to be used in any low temperature area.

When the ring network cabinet is working, the current flows through the vacuum interrupter through the incoming conductor, through the soft connection and contact, the isolation blade, the outgoing busbar and the outgoing bushing 6 into the cable chamber 7 and flows into the outgoing cable, where the vacuum interrupter The circuit breaker composed of chamber, circuit breaker pull rod and mechanism plays the role of breaking the arc extinguishing current. The halogenated hydrocarbon gas plays the role of insulation and arc extinguishing, and the gas box plays the role of supporting and shielding external interference. The isolating switch 9 composed of the isolating main shaft and the isolating mechanism 4 plays the role of a safety fracture and provides a visible fracture.

In order to highlight the beneficial effects of the utility model, the following comparative examples were also tested.

Comparative example:

As shown in Figures 1-5, the ring network cabinet filled with halogenated hydrocarbon insulating gas, compared with the embodiment, there is no cylindrical metal cap outside the disc spring 16.

For embodiment and comparative example, measure the partial discharge capacity of the dish spring of ring main unit, test data is as follows table:

serial number Partial discharge Example 5PC comparative example 20pcs

The above-mentioned embodiments are only described to the preferred implementation of the utility model, and are not limited to the scope of the utility model. Various modifications and improvements made should fall within the scope of protection determined by the claims of the utility model.

Claims (3)

1. A ring main unit filled with halogenated hydrocarbon insulating gas, characterized in that: the isolating switch in the ring main unit is a lower isolating three-position switch, which is composed of an isolating blade, an isolating main shaft, a grounding contact, and an isolating dynamic seal; The isolation blade is made up of two silver-plated copper blades with a thickness of 6 mm, and a disc spring is worn between the two isolation blades; the outer surface of the disc spring (16) is provided with a metal cap (17). 2. The ring main unit filled with halogenated hydrocarbon insulating gas according to claim 1, characterized in that: the isolating switch has three states of closing, opening and grounding; the disc spring (16) is assembled After being compressed, a pressure of 150-200 N is provided to the isolation blade, so that the isolation blade can closely contact the main contact and the ground contact when the switch is closed and grounded. 3. The ring main unit filled with halogenated hydrocarbon insulating gas according to claim 2, characterized in that: the material of the isolation main shaft is epoxy glass rod, and the isolation dynamic seal adopts magnetic fluid dynamic seal.