CN113972053A

CN113972053A - Improved cooling structure suitable for environment-friendly GIT

Info

Publication number: CN113972053A
Application number: CN202111237922.0A
Authority: CN
Inventors: 黄之明; 杨贤; 贾磊; 马志钦; 成传晖; 舒想; 卓然; 王伟
Original assignee: CSG Electric Power Research Institute; Electric Power Research Institute of Guangdong Power Grid Co Ltd
Current assignee: CSG Electric Power Research Institute; Electric Power Research Institute of Guangdong Power Grid Co Ltd
Priority date: 2021-10-25
Filing date: 2021-10-25
Publication date: 2022-01-25

Abstract

The invention discloses an improved cooling structure suitable for an environment-friendly GIT (gas insulated switchgear), which comprises a coil, insulating gas and an iron core, wherein the coil, the insulating gas and the iron core are positioned in a tank body, a cooling system comprises a plurality of non-metal pipes, heat exchange devices and condensing devices, the heat exchange devices comprise metal pipes which are arranged in rows, the heat exchange devices are communicated with the condensing devices positioned outside the tank body through pipelines, the lower parts of the non-metal pipes are inserted into the coil, the upper parts of the non-metal pipes are connected with the heat exchange devices, a first evaporated liquid is filled in the non-metal pipes, and a second evaporated liquid is filled in the metal pipes. The improved cooling structure provided by the invention can solve the technical problems of low cooling efficiency, complex cooling system structure and difficult manufacturing of the existing gas-insulated transformer.

Description

Improved cooling structure suitable for environment-friendly GIT

Technical Field

The invention relates to the technical field of gas insulated transformers, in particular to an improved cooling structure suitable for an environment-friendly GIT.

Background

The Gas Insulated Transformer (GIT) has the characteristics of non-combustibility, non-explosiveness, low noise and the like, and is suitable for urban areas or underground substations with concentrated population and high requirements on fire prevention and explosion prevention. Depending on the cooling medium, the gas-insulated transformers can be classified into dry (gas-cooled, mainly air and SF6 gas) and wet (auxiliary cooling using insulating liquid) types according to the cooling method. Air-insulated and cooled dry-type transformers are bulky and, to reduce volume and weight, SF6 gas-insulated transformers are often used instead of air-insulated. But due to SF6 gas greenhouse effect index (GWP) 23500 times that of CO2, the compound is unfavorable for environmental protection and is gradually abandoned by the market. The C4F7N/CO2 mixed gas has excellent environmental protection performance, the GWP value is only 2090, the mixed gas is incombustible, can be compatible with most of electrical equipment materials, and the insulating capability of the mixed gas reaches more than 2 times of SF6, so the mixed gas is gradually noticed and applied to the electrical field.

Therefore, studies on the GIT cooling method and apparatus for the C4F7N/CO2 mixed gas are required to solve the heat dissipation problem of the large-capacity and ultra-high voltage gas-insulated transformer.

Disclosure of Invention

The invention provides an improved cooling structure suitable for an environment-friendly GIT (gas insulated switchgear), which can solve the technical problems of low cooling efficiency, complex cooling system structure and difficulty in manufacturing of the conventional gas insulated transformer.

The invention provides an improved cooling structure suitable for an environment-friendly GIT, which is characterized by comprising an electric power system and a cooling system, wherein the electric power system comprises a coil, insulating gas and an iron core which are positioned in a tank body, the cooling system comprises a plurality of non-metal pipes, a heat exchange device and a condensing device, the heat exchange device comprises metal pipes which are arranged in rows, the heat exchange device is communicated with the condensing device positioned outside the tank body through a pipeline, the lower parts of the non-metal pipes are inserted into the coil, the upper parts of the non-metal pipes are connected with the heat exchange device, a first evaporation liquid is filled in the non-metal pipes, and a second evaporation liquid is filled in the metal pipes.

Further, the lower end of the non-metal pipe is flush with the lower end of the coil, the height of the evaporation liquid in the non-metal pipe is marked as a, the height of the coil is marked as b, and a and b meet the following requirements: a/b is more than or equal to 0.5 and less than or equal to 1.

Furthermore, the non-metal pipe is connected with the heat exchange device through heat conducting glue.

Further, an installation part is arranged on the lower end face of the heat exchange device, and the upper end of the non-metal pipe is fixedly installed in the installation part.

Furthermore, the mounting part is a groove arranged on the lower end face of the heat exchange device, and the upper end of the non-metal pipe abuts against the groove; or the upper end of the non-metal pipe is arranged in the annular wall surface.

Further, the upper end of the non-metal pipe is embedded into the groove in a bending mode; or the upper end of the non-metal pipe directly abuts against the groove.

Further, the heat exchange device is filled with insulating gas.

Furthermore, two ends of the condensing device are connected with communicating pipes, one ends of the communicating pipes are communicated with one ends of the metal pipes, and two ends of the metal pipes are communicated with the condensing device through the communicating pipes.

Furthermore, the heat exchanger also comprises heat radiating fins which are arranged around the periphery of the metal tube, and the upper end part of the heat exchanger is provided with the heat radiating fins.

Further, the heat-conducting glue is made of heat-conducting silicone grease 180.

According to the technical scheme, the invention has the following advantages:

the embodiment of the invention provides an improved cooling structure suitable for an environment-friendly GIT, which comprises a power system and a cooling system, wherein the power system comprises a tank body, a coil and insulating gas filled in the tank body; the cooling system comprises a plurality of non-metal pipes, a heat exchange device and a condensing device, wherein rows of metal pipes are arranged in the heat exchange device, the metal pipes are filled with evaporation liquid B, and the non-metal pipes are filled with evaporation liquid A. The lower part of non-metallic pipe is embedded in the coil, the coil passes through heat-conducting mode with the heat and transmits the first evaporated liquid in the non-metallic pipe, the first evaporated liquid is gasified after being heated and rises to the upper portion of non-metallic pipe along the passageway of non-metallic pipe, give heat transfer to heat transfer device, insulating gas in the heat transfer device is heated the back and gives the second evaporated liquid in the metallic pipe with heat transfer, the second evaporated liquid is gasified in back gets into condensing equipment through the pipeline, and through condensing equipment with the second evaporated liquid cooling after the gasification become liquid, flow back to the metallic pipe inside, realize no pump self-loopa. Because the latent heat of vaporization of the liquid medium is far greater than the specific heat value, the heat exchange coefficient of the evaporation liquid side reaches thousands of W/(m2K), the heat exchange efficiency is improved, and the volume, the weight and the floor area of the heat exchanger are reduced. And the air cooler has no noise pollution caused by a fan, the operation pressure is low, the working air pressure is between-0.02 MPa and +0.10MPa relative pressure and is far less than the working pressure of the water cooler, the requirements on the mechanical strength and the sealing of the cooler are reduced, and the possibility of leakage is also reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive exercise.

FIG. 1 is a schematic view of an improved cooling structure for an environmentally friendly GIT according to one embodiment of the present invention;

FIG. 2 is a partial enlarged view of an improved cooling structure for an environmentally friendly GIT according to one embodiment of the present invention.

1-power system, 2-cooling system, 3-tank, 4-coil, 5-iron core, 6-nonmetal tube, 7-heat exchange device, 8-communicating tube, 9-metal tube, 10-heat dissipation fin, 11-condensing device, 12-first evaporated liquid, 13-groove and 14-heat conducting glue.

Detailed Description

The embodiment of the invention provides an improved cooling structure suitable for an environment-friendly GIT (general information technology), which is used for cooling based on phase-change heat exchange of a liquid evaporative liquid medium and solving the problems of low efficiency and the like of the traditional heat dissipation device.

In order to make the objects, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In an electric power system, the GIT is mainly different from a general oil immersed transformer in insulating cooling media and cooling mechanisms, and the GIT cooling methods can be classified into a self-cooling type, a forced air circulation type and an evaporative cooling type according to the cooling method. The evaporative cooling type is divided into a dip type, an isolated type and a spray type. For self-cooled and forced air circulation type gas-insulated transformers, the capacity cannot be very large, since the heat dissipation coefficient of the winding surface in the gas is an order of magnitude smaller than the heat dissipation coefficient in the transformer oil. The evaporative cooling type cooling device is high in cooling capacity and can be used in the field of ultrahigh pressure and high capacity, and particularly the latent heat of vaporization of a liquid medium is far greater than a specific heat value. However, if water is made to have infinite heat capacity, the water cost required for operation is also high, and scale is easily generated during operation. Most fatal is that if leakage occurs during the operation of the transformer, the leakage of cooling water into the transformer is easy to cause insulation accidents, and the safe operation of the transformer is seriously influenced. Based on this, the inventor sets up a novel transformer gas-evaporated liquid cooling system based on liquid evaporated liquid medium phase transition heat transfer cools off, greatly increased heat exchange efficiency.

As shown in fig. 1-2, the improved cooling structure for an environment-friendly GIT provided by the present invention comprises an improved cooling structure for an environment-friendly GIT, including a power system 1 and a cooling system 2, wherein the power system 1 includes a tank 3, a coil 4 and an iron core 5, and the tank 3 is filled with a C4F7N/CO2 mixed gas as an insulating gas. The cooling system 2 comprises a plurality of metal tubes 9 and nonmetal tubes 6, a heat exchange device 7 and a condensing device 11, wherein the lower ends of the metal tubes 9 and nonmetal tubes 6 are inserted into the coil 4, the upper ends of the metal tubes 9 and the heat exchange device 7 abut against each other, and meanwhile, the heat exchange device 7 is communicated with the condensing device 11 through a pipeline. And be filled with first evaporated liquid 12 in tubular metal resonator 9 non-metallic tube 6, phase change becomes steam after the heat that coil 4 sent is inhaled through the pipe wall of tubular metal resonator 9 non-metallic tube 6, rises to the top of tubular metal resonator 9 non-metallic tube 6, and heat transfer 7 is given heat transfer to heat transfer 7 to tubular metal resonator 9 non-metallic tube 6 looks butt under heat transfer device 7. At the same time, the heat generated by the coil 4 and the iron core 5 is also transferred to the metal tube 9 in the heat exchange device 7 through the insulating gas in the box body. The evaporated liquid B in the metal tube 9 absorbs heat and then undergoes phase change vaporization, and enters a radiator outside the transformer box body through an air outlet pipeline to be cooled by air, so that cooling circulation is completed.

Further, the height of the methyl evaporation liquid 12 in the non-metal pipe 6 of the metal pipe 9 is marked as a, the height of the coil 4 is marked as b, the lower end of the non-metal pipe 6 of the metal pipe 9 is flush with the lower end of the coil 4, and a and b satisfy: a/b is more than or equal to 0.5 and less than or equal to 1. If a/b is less than 0.5, the content of the first evaporated liquid 12 is low, and the heat generated by the coil 4 cannot be absorbed; if a/b is larger than 1, the first evaporated liquid 12 exceeds the height of the coil 4, and the vapor generated by the gasification of the first evaporated liquid 12 increases the air pressure of the non-metal tube 6 of the metal tube 9, so that the non-metal tube 6 of the metal tube 9 is broken in serious cases, and potential safety hazards are caused. Only when a/b is more than or equal to 0.5 and less than or equal to 1, the heat transfer efficiency can be improved to the maximum extent under the condition of ensuring safety.

The upper end of the metal tube 9 nonmetal tube 6 is connected with the heat exchange device 7 through the installation part, specifically in the embodiment, the lower end face of the heat exchange device 7 is provided with the groove 13, the heat conducting glue 14 is paved in the groove 13, and the upper end of the metal tube 9 nonmetal tube 6 is directly inserted into the groove 13 to realize heat transfer. Of course, the upper end of the non-metal tube 6 of the metal tube 9 may be bent to increase the contact area with the heat exchanging device 7. The material of the heat-conducting adhesive 14 is heat-conducting silicone grease 180, which has good heat-conducting effect and stable material.

In this embodiment, the heat exchanger 7 is filled with insulating gas, that is, after the metal tube 9 and the nonmetal tube 6 transfer heat to the heat exchanger 7, the insulating gas is heated to transfer heat to the metal tube 9. Because insulating gas can fill in heat transfer device 7 completely, can be with even metal tube 9 that conveys in heat transfer device 7 of heat, guarantee that the metal tube in a row is heated evenly.

Specifically, both ends of the rows of metal tubes 9 are communicated with the condensing device 11 through communicating tubes, and after the second evaporated liquid in the metal tubes 9 is heated and gasified, the second evaporated liquid enters the condensing device 11 through a passage formed by the communicating tubes, and is cooled to form the second evaporated liquid which flows back to the metal tubes 9, so that self-circulation is completed.

The heat dissipation fins 10 are further arranged on the periphery of the metal tube 9, so that the contact area of the metal tube 9 and the insulating gas can be increased, and the heat exchange efficiency is improved.

Example two:

the difference from the first embodiment is that: the lower terminal surface of heat transfer device 7 is provided with the annular lateral wall of downward salient, forms the installation department, and this annular lateral wall wraps up the upper end of 9 non-metallic pipe of tubular metal resonator 6, realizes 9 non-metallic pipe of tubular metal resonator 6 and heat transfer device 7's firm being connected.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides an improve cooling structure suitable for environment-friendly GIT, a serial communication port, including electric power system and cooling system, electric power system is including coil, insulating gas and the iron core that is located jar internal portion, cooling system includes many non-metallic pipe, heat transfer device and condensing equipment, heat transfer device includes the tubular metal resonator of in bank setting, heat transfer device with be located the condensing equipment of jar external portion passes through the pipeline intercommunication, insert the lower part of non-metallic pipe coil, upper portion with heat transfer device meets, be filled with first evaporant in the non-metallic pipe, the tubular metal resonator is filled with second evaporant.

2. The improved cooling structure for environment-friendly GIT as claimed in claim 1, wherein the lower end of said non-metal tube is flush with the lower end of said coil, the height of the evaporation liquid in said non-metal tube is denoted as a, the height of said coil is denoted as b, and a and b satisfy: a/b is more than or equal to 0.5 and less than or equal to 1.

3. The improved cooling structure for an environmentally friendly GIT as described in claim 1, wherein said non-metallic tube is connected to said heat exchanging means by a thermally conductive adhesive.

4. The improved cooling structure suitable for environment-friendly GIT of claim 3, wherein a mounting portion is formed on the lower end surface of said heat exchanging device, and the upper end of said non-metallic tube is mounted and fixed in said mounting portion.

5. The improved cooling structure for an environmentally friendly GIT as claimed in claim 4, wherein said mounting portion is a groove provided at a lower end surface of said heat exchanging means, and an upper end of said non-metallic tube abuts against said groove; or the lower end surface of the heat exchange device is provided with an annular wall surface protruding downwards, and the upper end of the non-metal pipe is arranged in the annular wall surface.

6. The improved cooling structure for an environmentally friendly GIT according to claim 5, wherein an upper end of said non-metal pipe is fitted into said groove in a bent manner; or the upper end of the non-metal pipe directly abuts against the groove.

7. The improved cooling structure for an environmentally friendly GIT according to claim 1, wherein the inside of the heat exchanging means is filled with an insulating gas.

8. The improved cooling structure for an environment-friendly GIT as recited in claim 1, wherein both ends of said condensing means are connected with communicating pipes, and both ends of said metal pipe are communicated with said condensing means through said communicating pipes.

9. The improved cooling structure for an environmentally friendly GIT of claim 1, further comprising heat fins disposed around the periphery of the metal tube and disposed at the upper end of the heat exchange device.

10. The improved cooling structure for an environment-friendly GIT as claimed in claim 3, wherein said heat conductive glue is made of heat conductive silicone grease 180.