JPS5851547A - Cooler for electric device - Google Patents

Abstract

PURPOSE:To obtain a cooler having preferable cooling effect and high insulating withstand voltage by boiling a coolant in a heat sink which is contacted with a heating element for cooling and maintaining insulation between elements with evaporated vapor phase coolant. CONSTITUTION:A heater 1A such as a thyristor or the like and a heat sink 3A are integrally associated, thereby forming a stack. Further, a coolant tank 6A and each heat sink 3A are coupled via a pipe 5A. They are contained in a sealed container 20, and a condenser 21 is mounted on the top of the container 20. The coolant condensed by the condenser 21 is led through a pipe 22 to a coolant reservoir 12A, and is returned from the reservoir by a pump 11A to the tank 6A. The coolant is evaporated by the heat which is generated from the heater 1A in the heat sink 3A. In this manner, since the environment of the heater 1 is filled with vapor phase, the heaters 1A are insulated only with the vapor phase, thereby obtaining high withstand voltage characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for electrical equipment used in high voltage.

8F, insulation by pressurized gas such as gas or chlorofluorocarbon gas is (
Due to the good insulation properties of the insulation distance, the insulation distance is significantly reduced.
Since electrical equipment will be IJs type, it will be put into practical use in various equipment.
ing. This method is easier to handle and work with than oil insulation, and has better heat dissipation characteristics than solid insulation. -7jNr
Included in high voltage t1 lister valve used for lft power transmission etc.
Elements that generate a large amount of heat such as semiconductors such as diodes, resistors, etc. do not require cooling with air, oil, or water, or boiling cooling using the latent heat of vaporization of liquids such as fluorocarbons is also performed. C. With boiling cooling, the phase change of the refrigerant removes a large amount of the heat generated by the element, resulting in good cooling efficiency.

The heat sink can be designed to be small, and the electric device can be made small.
Wear.

The conventional fluorocarbon boiling cooled T1 large thyristor valve shown in Figure 1 has a hole. This first solid state.

A monolithic stack of electrical circuit heat sinks or immersed in a fluorocarbon liquid phase. In Fig. 1, 1 is a closed container, 2 is a condenser, 3 is a cooling fan, 4 is a liquid phase fluorocarbon, 5 is a gas phase fluorocarbon, 6 is a bubble of gas phase fluorocarbon mixed in the liquid phase circle, 7
is a thyristor, 8 is a copper heat sink, 9 is a stack incorporating a thyristor and a heat sink, 10 is an insulator that supports the stack, %11 and 12 Hiro terminals, 13tj
14 is a gas phase pipe through which gaseous flora rises, and 14 is a liquid phase pipe through which liquid fluorocarbons descend. From the terminal 11, pass the heat sink 8 of the stack 9 and the builisty tough 1.

At the terminal 12Ktl (if the current flows, heat of about tjlKW will be generated for one element) due to the forward fall of the builistub. This heat is transferred to the heat sink 8 and becomes the latent heat of the fluorocarbon that changes from the 1* phase to the gas phase on the surface. Large fluorocarbons turn into a gas phase and become bubbles that rise through the liquid phase circle and reach the gas phase. This gas phase Freon rises inside the gas phase pipe 13 and reaches the condenser 2, and the outside of the condenser 2 is air-cooled by a cooling fan 3, and the gas phase Freon becomes liquid Freon in the condenser 2. . The liquid phase Freon descends through the liquid phase pipe 14 by gravity and returns to the stack section. When boiling cooling is used in this way, the cooling efficiency is high, and there is a long tube in which the refrigerant circulates through natural circulation.

However, the conventional boiling cooling power method cannot be used for large or ultra-high voltage applications where the gas phase and liquid phase coexist, and the electric field concentrates in the gas phase due to the difference in dielectric constant, leading to partial discharge and dielectric breakdown. Problem: 60 Diagram 2 Company, insulation breakdown of the above Freon jiIiIi
The graph shows that the dielectric strength of gaseous chlorofluorocarbons is 1/3 to 1/3 of the dielectric strength of liquid chlorofluorocarbons! within the range of Figure 3: A larger explanation of the electric field strength of the equal electric field.The thickness is d.
When a voltage Vt is applied to a material using a plane electrode, the electric field strength E is expressed by the following formula "elfX" as is well known.

Figure 4 shows the dielectric constant t□ of the thickness given χ between the thickness d.

Gas phase and 1. This is an explanatory diagram of the electric field strength in the presence of a liquid phase having a thickness of d-re)lie, and the electric field strength E1 of the gas phase portion and the electric field strength E of the liquid phase portion are calculated by the following equation.

In the case of chlorofluorocarbon, the liquid phase permittivity is t, -'l,, 41 for the gas phase dielectric heavy electric □ = 1, but when 2 is very close to zero, the gas phase electric field strength E□ is at its maximum. So, 70 value E1ma
Therefore, when r is the same as in the conventional boiling cooling method, the electric field strength in the gas phase when gaseous and liquid phase fluorocarbons are mixed is 25 times the electric field strength of the same phase fluorocarbons.
Double value and t11! , there is a possibility of discharge in the gas phase part having a low breakdown voltage t'l or 6*O. ft type, the refrigerant tube is boiled in a large heat sink circle that is closely attached to the heating element, and the insulation is maintained by the atmospheric phase refrigerant after vaporization. Cooling of electrical equipment in the shed m1ll. is intended to provide.

An embodiment of the present invention will be described below with reference to Figures 5 to 7.

In Figure 115, 1 person is responsible for electric circuit elements such as semiconductor medium resistors such as thyristors, 2 people are for reinforcing devices, 3 are for heat sinks, 5 are for liquid pipes, 6 are for refrigerant tanks, and 7 are for refrigerant tanks. The overflow part keeps the refrigerant liquid level constant, and the 8th meter is lower than the overflow part.
9A is a pull-pull that is made up of a large stack and a refrigerant tank by assembling an electric single-path element and a heat sink into one, an insulator that supports a 10A block, 11 is a pump that sends the refrigerant, 12A is a liquid pipe that carries a large refrigerant. is a large refrigerant reservoir provided at the bottom of the container, 13 is a connecting conductor, 14A, 14B terminals, 15
20 is a closed container, and 21 is condensation! ls%22#l; is the liquid phase refrigerant return p pipe, 23- is the liquid sending pipe, 30 is the liquid phase refrigerant, and 31 is the gas phase refrigerant. 022A is #! This is used in the second embodiment, and the refrigerant is transferred from the condenser 21 to mI! This is a liquid phase refrigerant return pipe leading to the refrigerant tank 6A.

FIG. 6 is a structural diagram illustrating the structure of the heat sink 3A in the tIR5 diagram.

In Figure 1!46, a is the inlet of the liquid phase refrigerant, b is the heat transfer surface of the heat sink to which the heat of the Fi electric circuit element is transferred and the liquid phase refrigerant boils to become a gas phase, and C is the heat transfer surface of the heat sink where the gas phase refrigerant is released. An opening, d is an eliminator that traps liquid particles scattered by boiling of the refrigerant, 1 is an electric circuit element, 3 is a heat sink, and 3 is a liquid phase refrigerant.
The above liquid phase refrigerant 30 is caught by the heat sink 38, and when the loss generated by one electric circuit element is transmitted to the heat sink 3, the liquid phase refrigerant boils and turns into a vapor phase. The cold 1s is discharged from the opening C into the closed tank.

This invention will be described in detail below. The above electric circuit element IA
A block 9A, which is made up of a large stack and a refrigerant tank 6A, is housed in an airtight container 20 by a support insulator 10A. The airtight container 20 is evacuated and a t1'ft bale of refrigerant is inserted into the airtight container. This refrigerant has a pressure corresponding to the temperature of the closed container 20, and is separated into a liquid phase refrigerant 3◎ and a gas phase refrigerant 31.

The pump 11A sucks up the liquid phase refrigerant 30 from the refrigerant reservoir 12A and pours it into the refrigerant tank 6AK. The liquid phase refrigerant 30 poured into the refrigerant tank 6°A passes through the liquid sending pipe 5At and is introduced into the heat sink 3AK, or the liquid level in the refrigerant tank 6A is maintained at one level by the overflow part 7A, and the liquid level of the heat sink 3mm is maintained. Keep the surface almost the same 7t
tlru.

When a current is applied to the electric circuit element 1A and heat is generated, this heat is transferred to the heat sink 3A, and the liquid phase refrigerant 30 in the heat sink 3A boils, becomes vapor phase, and is transferred to the large refrigerant 31 or the airtight container 20 from the opening of the heat sink. released in a circle. The gas phase refrigerant 31 has a light specific gravity, and is installed at the top of the book-closing machine for large condensation.
21, takes away 1 heat at ζζ, changes again to liquid phase refrigerant 30, passes through the return pipe 22, and falls to the refrigerant reservoir 12AK. In this way, the above-mentioned electric circuit element 1A can be cooled by using the boiling phenomenon, and a large, excellent 11* cooling effect can be obtained, and the heat sink 3A' and the heat sink 3A' can be assembled together in one body. Large block 9A and airtight container 20
A gas phase refrigerant 31 is filled in between, and the voltage applied to the block 9A and the sealed container 20 is maintained by the dielectric strength of the gas phase refrigerant 31.The electric field strength of the gas phase refrigerant is According to the embodiments of the present invention, it is possible to achieve good cooling characteristics due to the boiling phenomenon and good insulation characteristics due to the gas phase refrigerant, which is significantly improved compared to the phase refrigerant mixed P electric field strength. Furthermore, gas phase refrigerants have excellent insulation properties such as sp, etc.
It is also possible to mix t* refrigerant to improve insulation properties.

In the 1142% embodiment of the present invention, the return pipe 22m from the condenser 21 is connected to the refrigerant tank 6m, and 1mm of liquid phase refrigerant falls.
By guiding the refrigerant to the refrigerant tank 6A, the pump 11At can be made smaller.
Since about 00 thyristors are connected in series, even one iris thyristor pulp circle is used in combination with 10 stack Yts each incorporating 10 thyristors and a heat sink. The 78th embodiment is a third embodiment of the present invention which is not used in such a case, and shows a cooling bag M for an electric appliance made up of a plurality of stacks.

A third embodiment of the present invention will be described below with reference to FIG. 7, in which the same parts as those in FIG. 5 are denoted by the same reference numerals. After the airtight container 20 is evacuated rL, a footrest of refrigerant is inserted, and the plurality of blocks 9A are stacked vertically along the support insulator 10AK.

The refrigerant is divided into a liquid refrigerant 30 and a gas phase refrigerant i31, and the pump 11A pumps up the liquid refrigerant 30 from the refrigerant 12A and injects it into the refrigerant tank 6m of the uppermost block 9A. Refrigerant tank 6A
The liquid phase refrigerant 30 injected into the heat sink 3AK passes through the liquid feed pipe 5A and is introduced into the heat sink 3AK, but the liquid level in the refrigerant tank 6A is kept at a constant level by the overflow part 7A, and the liquid level in the heat sink 3 is also almost constant. The large liquid phase refrigerant 30 overflowing from the overflow section 7A of the uppermost block 9A, which is maintained in the direction of The flow part lowers the refrigerant to the lower refrigerant tank and leads to each of the seven heat sinks, or the refrigerant of each stage heat sink.
The I side is also kept the same.

A large amount of heat is generated due to the large current flowing through the electric circuit element IA.
Transferred to heat sink 3A 9, heat sink p 3 AP3
o liquid Q cold al: 1 boiling jlL in 30, zs conversion t, *e medium 3
The gas phase refrigerant 31 released from the opening of the heat sink into the closed container 20 rises and reaches the condenser 21,
The heat is removed and becomes liquid phase refrigerant 30, which passes through the return pipe 22 and falls into the refrigerant reservoir 12A. With the configuration of this embodiment, it is possible to obtain a large cooling effect due to the boiling phenomenon.
The space between the block 9A and the closed container 20 is filled with a gas phase refrigerant 31, and the bond strength of the gas phase refrigerant 310 is the same as above. The non-embodiment utilizes the boiling phenomenon tube and avoids voltage holding 1 due to the two-phase mixed state, which is a disadvantage of the boiling phenomenon.

Above implementation 1 PIIK pipe 1, return pipe 2 from condenser 21
2 to the refrigerant tank 6A of the top plotter.

By guiding 311 ml of liquid phase refrigerant that falls to the uppermost block, the pump 11A can be reduced in size by 74%.

Although the above example describes the case of thyristor pulp, it can also be applied to cooling other electrical equipment used at high voltage, such as transformers and switchgear, with the same effect, without going too far. .

As described above, according to the present invention, since the gas with good cooling properties and high dielectric strength is used by boiling cooling, /
I) An inexpensive and highly safe cooling system for electrical equipment has the effect of

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing a conventional evaporative cooling thyristor valve, Figure 2 is a characteristic diagram showing the insulation properties of fluorocarbons, Figure 3 is an explanatory diagram explaining the electric field strength of a homogeneous electric field, Figure 4 is a ti liquid phase -Explanatory diagram explaining electric field strength when gas phase is mixed, Part 5
6 and 6 are block diagrams showing one embodiment of the present invention, and FIG. 7 is a block diagram showing another embodiment of the present invention. 1... Airtight container, 2... Condenser, 3... Cooling fan,
4...Liquid phase Freon %5...Gas phase Freon, 6...Liquid phase Freon foam, ? - Thyristor, 8- Heat sink, 9 Stack, 10- Insulation, 11.12
・One terminal, 13... Gas phase pipe, 14 +=e liquid phase pipe, IA-Electric circuit element, 2A-Sleeve reinforcement, 3A-Heat sink, 5 A-...Liquid pipe, 6 A--・Refrigerant tank, 7A-Overflow part %8A...Liquid pipe, 9mm--Block, 10 A-...Insulation outer shell, 11mm...Pump, 12
A - Refrigerant reservoir, 13 A - Connection conductor, 14A, 14B
...Terminal, 15A--Futurta, 20--Airtight container, 21-#Ji device, 23--Liquid phase refrigerant return pipe, 22,
22A-liquid phase refrigerant return pipe, 30-liquid phase refrigerant, 31-.vapor phase refrigerant. Note that the same reference numerals in the figures indicate the same or enlarged equivalent parts. Agent Haku Tsutano - → Shokumura Hero pressure no v Kg/Cm2 Figure 3 11'i4 Figure @6

Claims (1)

[Claims] (1) An airtight container for storing electrical circuit elements and large heat sink tubes that are in close contact with each other, a refrigerant tank that supplies refrigerant tubes that can be seen in the heat sink circle, and one part of the airtight container K11ff.
a pump that sends refrigerant from the cooling reservoir to the refrigerant tank;
A condenser that liquefies the vaporized refrigerant is installed in the cooling 1i1K for large electrical equipment, and the heat sink evaporates and releases the large refrigerant pipe into the sealed container. -5, and maintains insulation of an electric circuit. 1. A cooling device f for an electrical appliance according to claim 1, characterized in that the refrigerant (1) is electrically conductive from the condensation to the refrigerant tank through the refrigerant (1) return pipe, and the pump is small in size. C) Stacking several blocks tm consisting of the above electric circuit elements, scissor heat sinks, and scissor coolant tanks in the vertical direction,
The pump supplies refrigerant from the cooling reservoir to the refrigerant tank in the uppermost block, and then the refrigerant tank in the lower block. Keep the refrigerant liquid level on the heat sink of the lock at a constant level.
Cooling of electrical equipment according to claim 1 as a percentage 1
i1i.