JPH03113255A - Evaporation cooling type electric equipment - Google Patents

Abstract

PURPOSE:To obtain a evaporation cooling type electrical equipment capable of reduction of the lowering of a fluid level in a container upon excess load by providing return tubes communicating with the bottoms of the opposite ends of a coupling tube and the lower part of the fluid level of a cooling medium fluid in the container. CONSTITUTION:In case of an electrical railway rectifier, returned fluid receivers 31 are provided at bottoms of coupling tubes 3 on opposite sides of the same where an evaporator 2 holds therebetween a location of the coupling tube 3 opening to the central bottom part, and return tubes 21 connect the bottoms and the lower position of cooling medium fluid 5 lower than the fluid level in a container 1. The cooling medium cooled and liquefied in a condenser 4 once falls into the return fluid receiver 31 and moves along the bottom and further enters the return tube 21 as return fluid 52. Thereupon, since the bottom position of the return fluid receiver 31 is deeper than that of the coupling tube 3, the entering cooling medium fluid does not return to the container 1 from the evaporator 2. Further, since an opening part of the return tube 21 toward the container 1 is located below the fluid level of the cooling medium fluid 5, any vapor stream by boiling does not enter the container, and the return fluid can smoothly enter the return tube, the amount of the fluid staying in the coupling tube is very small. Thus, there can be reduced the lowering of the fluid level of the cooling medium fluid in the container upon excess load.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention uses a cooling medium made of carbon dioxide to cool a heat generating part, and performs highly efficient cooling by utilizing the heat of evaporation of this cooling medium. The present invention relates to boiling-cooled electrical appliances, particularly boiling-cooled electrical appliances with a large overload capacity, such as rectifiers for electric railways.

[Conventional technology]

It is well known that DC power supplies for electric railways have the characteristic that the load increases each time a train passes near a substation. Therefore, rectifier transformers and rectifiers for electric railways are manufactured to sufficiently withstand overloads. In addition, with the aim of saving space and maintenance-free substations,
A boiling cooling type with high cooling efficiency is used for rectifiers for electric railways.

FIG. 2 is a sectional view mainly illustrating the cooling structure of a rectifier for electric railways. In this figure, the rectifier stack 1 which is the heat generating part
00 is housed in a container IO and immersed in a cooling medium liquid 5 made of carbon dioxide. In the cooling section, a plurality of flat plate-shaped condensers 4 are arranged with gaps large enough to allow sufficient circulation of air for cooling the condensers 4 from the outside. They are connected to each other by a connecting pipe 30 disposed in the two parts, and are put together into one body. The connecting pipes 30 are arranged at the upper part of the container IO, and the central bottom of these connecting pipes 30 and the upper part of the container 10 are connected by the evaporation pipe 2.

The heat generated by the rectifier stack 100 is transferred to the cooling medium liquid 5, but once the cooling medium liquid 5 reaches its boiling temperature, the temperature does not rise any further, and all of the generated heat becomes heat of vaporization and a large amount of heat is generated. Generates steam.

A vapor flow 61 is generated by boiling and passes through the evaporation tube 2.
2 enters the connecting pipe 30, is divided into the condenser 4, and further rises as a vapor stream 63.

Since the outer surface of the condenser 4 is cooled by air, the cooling medium in a gaseous state is cooled and liquefied, and adheres to the inner wall of the condenser 4. The liquefied cooling medium passes along the inner wall of the condenser 4, enters the connecting pipe 30, passes along the bottom thereof, passes along the inner wall of the evaporation pipe 2, and returns to the container 10.

In this way, the cooling medium cools the rectifying stack 100 with high efficiency while circulating from a liquid state to a heated gas and then cooled to a liquid again.

When the railway rectifier is overloaded, use the rectifier stack 10.
The heat generated by the cooling medium 5 increases in proportion to the square of the load current, but the temperature of the cooling medium 5 does not rise above the boiling temperature and absorbs the increased heat generated by the heat of evaporation due to rapid boiling. This is the reason why the boiling cooling type has high cooling efficiency.

The cooling medium that has vaporized due to overload liquefies and returns to container 1.
There is a time lag before the temperature returns to zero, and during this time the level of the coolant liquid 5 decreases.

In order to prevent a part of the rectifying stack 100 from being exposed from the surface of the cooling medium liquid 5 and causing local heating even if such a drop in the liquid level occurs, the cooling medium is adjusted in anticipation of this drop in the liquid level. Add a large amount of liquid 5 (if necessary).

[Problem to be solved by the invention]

Due to overload, the cooling medium liquid 5 boils and a rapid vapor flow 6 occurs.
1.62 occurs, when the cooled and liquefied coolant liquid 51 is about to return to the container 10 through the evaporator tube 2, the coolant liquid 51 is agitated by the upward wind pressure of the vapor flow 62, A phenomenon occurs in which the liquid cannot descend along the inner wall of the connecting pipe 30 and temporarily remains at the bottom of the connecting pipe 30. Therefore, the liquid level of the cooling medium liquid 5 in the container 10 described above will further decrease, which will cause an increase in the amount of cooling medium itself used to store a large amount of the cooling medium liquid 5, and There are two problems, including the need to increase the volume of the rectifier for electric railways, which causes an increase in the price of rectifiers for electric railways.

SUMMARY OF THE INVENTION An object of the present invention is to provide a boiling-cooled electric appliance that can reduce the accumulation of coolant liquid in a connecting pipe during overload, thereby reducing the drop in the liquid level in a container.

[Means to solve the problem]

In order to solve the above problems, according to the present invention, there is provided a container for storing a heat generating part and a cooling medium liquid for cooling the heat generating part;
A plurality of flat condensers arranged horizontally at predetermined intervals, a connecting pipe arranged horizontally and connecting the condensers, and an evaporator connecting the central bottom of the connecting pipe and the upper part of the container. In the boiling-cooled electric appliance equipped with a pipe, return pipes are provided to communicate the bottoms of both ends of the connecting pipe and a portion below the surface of the cooling medium liquid in the container.

[Effect]

In the structure of this invention, by providing a return pipe that communicates between the bottom of both ends of the connecting pipe and the part below the liquid level of the cooling medium liquid of the container that houses the heat generating part, the cooling medium liquid is cooled in the condenser and liquefied, and the connection is made. The coolant liquid that has reached the bottom of the tube passes along the bottom of the connecting tube and returns to the container again through the return tubes on both sides. Since the return pipe opens below the liquid level in the container, the return liquid can enter the return pipe smoothly without being stirred by the steam flow caused by boiling, so that the cooling medium liquid can enter the connecting pipe. The amount that remains will be small.

〔Example〕

The present invention will be explained below based on examples. FIG. 1 is a sectional view mainly illustrating a cooling structure for a rectifier for electric railways showing an embodiment of the present invention, and the same members as those in FIG. In this figure, return liquid receivers 31 are provided at the bottoms on both sides of the position where the evaporation pipe 2 opens at the center bottom of the connecting pipe 3,
A return pipe 21 connects the bottom of the container 1 to a position below the liquid level of the coolant liquid 5 in the container 1 .

In this configuration, the cooling medium that has been cooled and liquefied in the condenser 4 once falls into the return liquid receiver 31, travels along the bottom thereof, becomes a return liquid 52, and enters the return pipe 21. Since the return pipe 21 is connected to the cooling medium liquid 5 in the container 1, one round of circulation of the liquefied cooling medium is completed when it enters the return pipe 21.

Since the bottom of the return liquid receiver 21 is deeper than the bottom of the connecting pipe 3, the coolant liquid that has entered the return liquid receiver 31 flows into the evaporation pipe 2.
Moreover, since the opening of the return pipe 21 into the container 1 is below the liquid level of the cooling medium liquid 5, it is necessarily located on the side of the container 1. The rapid boiling caused by the load and the resulting large amount of coolant vapor that is generated rises toward the upper liquid level, so that almost no coolant vapor enters the return pipe 21. Therefore,
There is nothing to obstruct the return liquid 52 from entering the return pipe 21 (it can enter the return pipe 21 smoothly. Therefore, a large amount of the return liquid 52 does not stay in the return liquid receiver 31, and it simply flows into the return pipe 21. This is about the amount that flows at the bottom until it flows into 21.

In this way, the cooling medium liquefied in the condenser 4 can return to the container 1 without any hindrance, and the amount that remains on the way is very small, so even if there is sudden boiling due to overload, the cooling inside the container 1 can be maintained. The drop in the liquid level of the medium liquid 5 is reduced, and the problems of the prior art described above can be solved.

In Fig. 1, a return liquid receiver 31 is provided in the connecting pipe 3, and the bottom of this part is deepened to block the path for the return liquid to return to the container l through the evaporation pipe 2, but the same purpose can be achieved. Therefore, instead of providing the return liquid receiver 31, the opening of the evaporation tube 2 to the connecting pipe 3 may be slightly protruded and the return liquid may be blocked by this protrusion. When the vapor flow 62 has a significant momentum, the vapor flow 62 returns to the evaporation tube 2 and prevents the liquid from entering. The effects of the present invention can be obtained even if the structure is the same as that shown in FIG. 2 without providing the protrusion of the tip of the opening of the tube 2 into the connecting tube 3. Therefore, the provision of the return liquid receiver 31 shown in FIG. This invention can be applied to electrical appliances that are operated before overload in railway electric appliances, and is not necessarily limited to being used for electric railways or rectifiers, but it is an invention that meets the above two requirements. It can be applied to any compatible electrical appliance to increase the effect.

[Effects of the Invention] As described above, the present invention provides a return system that communicates the bottoms of both ends of the connecting pipe with the portion below the liquid level of the coolant liquid of a container that houses a heat generating part such as a rectifying stack of a rectifier. We decided to install a pipe. As a result, the return liquid of the cooling medium, which has been cooled and liquefied in the condenser and has reached the bottom of the connecting pipe, travels along the bottom of the connecting pipe, passes through the return pipes on both sides, and returns to the container again. Since the return pipe opens below the liquid level in the container, vapor flow due to boiling will not enter, so the return liquid can smoothly enter the return pipe without being agitated by the vapor flow. As a result, the amount of cooling medium liquid that remains in the connecting pipe is very small. As a result, even if the coolant liquid suddenly boils due to an overload and a large amount of steam is generated, the level of the coolant liquid in the container will only drop by a small amount, and this drop in level is anticipated. There is no need to enclose a large amount of coolant liquid or increase the volume of the container, so the amount of coolant used can be reduced, and the container can be made smaller. can be effective in reducing prices.

[Brief explanation of drawings]

FIG. 1 is a sectional view mainly illustrating a cooling structure for a rectifier for electric railways according to an embodiment of the present invention, and FIG. 2 is a sectional view mainly illustrating a cooling structure for a conventional rectifier for electric railways. 1. 1O... Container, 2... Evaporation pipe, 21... Return pipe, 3.30... Connecting pipe, 4... Condenser, 5...
Coolant liquid.

Claims (1)

[Claims] 1) A container for storing a heat generating part and a cooling medium liquid for cooling the heat generating part, a plurality of flat condensers arranged horizontally at predetermined intervals, and a plurality of flat condensers arranged horizontally. In a boiling-cooled electric appliance comprising a connecting pipe that communicates with the condenser, and an evaporator pipe that communicates between the central bottom of the connecting pipe and the upper part of the container, the cooling medium is connected to the bottom of both ends of the connecting pipe and the container. A boiling cooling type electric appliance characterized by each having a return pipe communicating with a portion below the liquid level.