JPH053725B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a cooling device for an oil-filled transformer.

[Prior art and its problems]

A conventional oil-filled transformer is shown in FIG. 1 is a transformer body consisting of an iron core 2 and a coil 3, and 4 is a tank that houses it. The tank 4 contains approximately eight parts of insulating oil 5, and the space above it is filled with nitrogen gas 6 to prevent deterioration of the insulating oil. The transformer body 1 is immersed in insulating oil 5, and heat generated by copper loss and iron loss is transferred to the heat radiating ribs 7 and the like on the surface of the tank 4 by convection of the insulating oil 5, and is radiated.

In this way, conventional oil-filled transformers are cooled by natural heat radiation from the tank surface, so it is necessary to create space around the tank for heat radiation.For example, in underground transformers, etc. It was difficult to secure that space. Furthermore, since heat is naturally dissipated from the tank surface, there is a problem that the cooling efficiency is poor.

[Means for solving problems and their effects]

The present invention provides a cooling device for an oil-filled transformer that solves the problems of the prior art as described above, and has a structure in which the circumferential wall of the tank of the oil-filled transformer has a double structure, and its inner wall and A refrigerant vaporization chamber is formed between the outer walls, and a vaporization pipe connects the upper part of the vaporization chamber to the vaporized refrigerant inlet of a radiator installed outside the transformer, and the liquefied refrigerant outlet of the radiator and the vaporization chamber are connected by a liquid pipe, and a refrigerant is sealed in a circulation system consisting of the vaporization chamber, the gas pipe, a radiator, and the liquid pipe, and the liquefied refrigerant outlet of the liquid pipe is connected to the vaporization chamber. It is characterized by opening toward the inner wall at the upper part of the chamber, and forming a spiral protrusion or groove from the outer surface of the inner wall downward from the liquefied refrigerant outlet position of the liquid pipe.

This device guides the liquefied refrigerant flowing out from the outlet of the liquid pipe to the entire circumference of the outer surface of the inner wall by a spiral protrusion or groove, and causes the liquefied refrigerant to flow down along the outer surface of the inner wall from the protrusion or groove, The latent heat generated when it evaporates is used to efficiently cool it down. The vaporized refrigerant enters the radiator through the gas line, where it liquefies, and then returns to the vaporization chamber through the liquid line.

〔Example〕

1 and 2 show one embodiment of the invention. In the figure, 11 is an oil-filled transformer, 12 is a transformer body consisting of an iron core and a coil, 13 is a tank,
14 is insulating oil, and 15 is nitrogen gas. tank 1
3 has a double-walled peripheral wall, and a refrigerant vaporization chamber 18 is formed between an inner wall 16 and an outer wall 17. The vaporization chamber 18 is connected to the vaporized refrigerant inlet of a radiator (condenser) 19 installed above the transformer 11 by a gas pipe 20, and the liquefied refrigerant outlet of the radiator 19 is connected to the vaporization chamber 18. are connected by a liquid conduit 21. A heat radiating finned tube 22 is provided in the radiator 19 to communicate the gas pipe 20 and the liquid pipe 21 . As a result, the vaporization chamber 18 - gas pipe line 20 - radiator 19 - liquid pipe line 2
1-A closed circulation system is constituted of a vaporization chamber 18, in which a refrigerant such as Freon or water is sealed.

Further, the liquid pipe line 21 is bent into a U-shape within the vaporization chamber 18, and the liquefied refrigerant outlet thereof opens toward the inner wall 16 at the upper part of the vaporization chamber 18. Further, on the outer surface of the inner wall 16, a protrusion 23 is provided in a spiral shape downward from the liquefied refrigerant outlet position of the liquid pipe line 21. The protrusion 23 is formed, for example, by spirally winding a linear body around the inner wall 16 and welding it.

The refrigerant sealed in the circulation system is cooled and liquefied when it exits the radiator 19, and this liquefied refrigerant is led to the vaporization chamber 18 by the liquid pipe 21,
It flows out from the outlet to the top of the protrusion 23. Since the protrusion 23 spirally descends from that position, the liquefied refrigerant is guided by the protrusion 23 and reaches the inner wall 1.
6 and flows down from there to wet almost the entire circumference of the inner wall 16. The liquefied refrigerant flowing down the outer surface of the inner wall 16 transfers heat from the inner wall 16 and partially vaporizes, and the rest accumulates at the bottom of the vaporization chamber 18, but this is also gradually vaporized by heat from inside. Note that 24 indicates the liquefied refrigerant accumulated at the bottom of the vaporization chamber 18. The vaporized refrigerant enters the radiator 19 from the upper part of the vaporization chamber 18 through the gas pipe 20, where it is condensed and circulated again along the above-mentioned path.

The transformer 11 in the above embodiment is installed, for example, underground, and the radiator 19 is installed above ground.

Since the upper surface of the insulating oil 14 reaches the highest temperature due to convection, it is preferable that the upper end of the protrusion 23 that guides the liquefied refrigerant be above the oil level. Further, the lower end of the protrusion 23 may reach the liquid level of the liquefied refrigerant in the vaporization chamber 18 (the liquid level during cooling operation), and the protrusion 23 does not necessarily have to be provided on the entire inner wall. Also, the gas pipe 20
The lower end (inlet of the vaporized refrigerant) is preferably located above the outlet of the liquid conduit 21, and particularly preferably located at the top of the vaporization chamber 18.

In the above embodiment, the liquid pipe line 21 is connected to the vaporization chamber 18.
The reason why the inner part is bent into a U-shape is to prevent the vaporized refrigerant in the vaporization chamber 18 from entering the liquid pipe line 21 by storing the liquefied refrigerant in the U-shaped part.

FIG. 3 shows another embodiment of the invention. In this device, a groove 25 is spirally formed on the outer surface of the inner wall 16 in place of the protrusion 23 in the above embodiment. The other configurations are the same as those of the above embodiment.

FIG. 4 shows yet another embodiment of the invention. This device has a net 26 wrapped around the outer surface of an inner wall 16 in which grooves 25 (or protrusions may be used) are formed. In this way, the liquefied refrigerant flowing down from the grooves 25 is further spread over the entire surface of the inner wall 16 by the net 26, so that the effect of uniformly cooling the entire circumference is great.

〔Effect of the invention〕

As explained above, according to the present invention, the circumferential wall of the tank has a double structure, a refrigerant vaporization chamber is formed between the inner wall and the outer wall, and the spiral protrusion or groove provided on the outer surface of the inner wall extends along the outer surface of the inner wall. The oil-filled transformer is cooled by guiding the liquefied refrigerant all around the tank and by flowing the liquefied refrigerant down along the outer surface of the inner wall from the protrusions or grooves. There is no need to create a space, and the installation space can be reduced. Additionally, since cooling is performed using latent heat when the refrigerant vaporizes, it also has the advantage of high cooling efficiency.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a cooling device for an oil-filled transformer according to an embodiment of the present invention, and FIG. 2 is a -
A line sectional view, FIGS. 3 and 4 are sectional views of main parts showing other embodiments of the present invention, and FIG. 5 is a partially cutaway perspective view showing a conventional oil-filled transformer. 11 - oil-filled transformer, 13 - tank, 14 - insulating oil, 16 - inner wall, 17 - outer wall, 18 - vaporization chamber,
19 - radiator, 20 - vaporization pipe line, 21 - liquid pipe line, 23 - protrusion, 24 - liquefied refrigerant, 25 - groove, 2
6 ~ Net.

Claims (1)

[Claims] 1. The peripheral wall of the tank of the oil-filled transformer is made into a double structure, and a refrigerant vaporization chamber is formed between the inner wall and the outer wall,
The upper part of the vaporization chamber and the vaporized refrigerant inlet of a radiator installed outside the transformer are connected by a gas pipe, and the liquefied refrigerant outlet of the heat radiator and the vaporization chamber are connected by a liquid pipe. A refrigerant is sealed in a circulation system consisting of the vaporization chamber, a gas pipe, a radiator, and a liquid pipe, and the liquefied refrigerant outlet of the liquid pipe is opened toward the inner wall at the upper part of the vaporization chamber, and the outer surface of the inner wall is sealed. A cooling device for an oil-filled transformer, characterized in that a protrusion or groove is formed in a spiral shape downward from the liquefied refrigerant outlet position of the liquid pipe. 2. The device according to claim 1,
The liquid pipe line is bent into a U-shape inside the vaporization chamber. 3. The device according to claim 1 or 2, in which a net is wound around the outer surface of an inner wall provided with spiral protrusions or grooves.