JPS6329829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improving the cooling characteristics of a boiling cooling device that cools a heat generating element such as a power semiconductor element by applying boiling heat transfer.

FIG. 1 is a sectional view of an example of a conventional evaporative cooling device. In FIG. 1, 100 is a conventional evaporative cooling device, 1 is a heating element assembly consisting of a plurality of heating elements, 2 is a refrigerant liquid, and 3 is a cylindrical container containing the heating element assembly 1 and the refrigerant liquid 2. , 4 is an air bubble of refrigerant generated from the surface (heat transfer surface) of the heating element assembly 1 in contact with the refrigerant liquid 2, 5 is a gas phase space, and 2A is an air bubble 4 that rises in the refrigerant liquid 2. The vapor of the refrigerant that has reached the gas phase space 5 rises in the gas phase space 5 as shown by the solid arrow, and condenses on the inner wall surface of the container 3 to form a refrigerant liquid.

As shown in FIG. 1, refrigerant vapor is generated on the heat transfer surface of the heating element assembly 1 in contact with the refrigerant liquid 2, rises as bubbles 4, and reaches the gas phase space 5. In the process of rising and becoming refrigerant liquid 2A on the inner wall surface of the container 3, the heat generated in the heating element assembly 1 is radiated to the outside of the container 3 as latent heat of condensation. At this time,
The condensed and liquefied refrigerant liquid 2A descends under the action of gravity along the inner wall surface of the container 3 and flows back into the refrigerant liquid 2.
At this time, the refrigerant liquid 2 is disturbed by the rising gas bubble 4. Therefore, a part of the heat generated in the heating element assembly 1 is transferred to the portion of the inner wall surface of the container 3 that is in contact with the refrigerant liquid 2 by convection heat transfer of the refrigerant liquid 2, and the wall of the container 3 is transferred. It is diffused to the outside of the container 3 through the air.

However, in the conventional boiling cooling device 100, the disturbance of the refrigerant liquid 2 by the rising air bubble 4 was incoherent, so the convective heat transfer coefficient was extremely low, and the rate of heat dissipation by convective heat transfer was extremely small. There was a drawback.

The present invention has been made in view of the above circumstances, and the first invention is to make the height of the duct of the heating element assembly higher than the height of the heating element assembly so that the vapor of the refrigerant passes through the duct. The purpose of the present invention is to promote circulation of the refrigerant liquid by spouting the refrigerant liquid upward from the surface of the refrigerant liquid, thereby improving cooling performance.

Moreover, the second invention improves cooling performance by configuring the heating element assembly to have a duct, and
The purpose of this invention is to fill the space between the heating element assembly and the rectifying plate with a filler to save refrigerant liquid and reduce costs.

FIG. 2 is a sectional view showing the boiling cooling device according to the first embodiment of the present invention. In FIG. 2, the same reference numerals as in FIG. 1 represent the same components as shown in FIG. 130 is the evaporative cooling device of the first embodiment; 6 is a duct formed inside the heating element assembly 1 to form a flow path for the refrigerant liquid 2; A rectifying plate 8 provided along which the water flows is a flow path formed by the inner wall surface of the container 3 and the rectifying plate 7. The duct 6 extends above the heating element assembly 1 and close to the surface of the refrigerant liquid 2.

When the heating element assembly 1 generates heat, as the air bubble 4 generated in the duct 6 rises, a frictional force based on viscosity acts between the air bubble 4 and the refrigerant liquid 2 to scrape up the refrigerant liquid 2 in the duct 6. A so-called air pump effect works. In addition, when the heat generated from the heating element assembly 1 is small and no air bubbles 4 are generated within the duct 6, the refrigerant liquid 2 within the duct 6 is heated, its density is reduced, and buoyancy is generated. Therefore, in any case, when the heating element assembly 1 generates heat, an upward flow occurs within the duct 6. The driving force for raising the refrigerant liquid 2 is the difference between the average density of the gas [air bubble 4] and liquid in the duct 6 and the average density of the refrigerant liquid 2 outside the duct 6, and the vertical height of the duct 6. It is known that the larger the size, the larger the size.

Therefore, if the baffle plate 7 and the duct 6 are arranged in the boiling cooling device 130 as shown in FIG. 2, the refrigerant liquid 2 will circulate as shown by the solid arrows. That is, due to the increased driving force in the tall duct 6 in the heating element assembly 1, the refrigerant liquid 2 flows into the duct 6 from the lower part of the duct 6,
The liquid rises from the upper part of the duct 6 to the upper part of the liquid level and collides with the inner wall surface of the container 3, and part of it flows along the inner wall surface, and the other part flows from the center of the container 3 toward the periphery.
A flow path 8 formed between the inner wall surface of the container 3 and the rectifying plate 7
It circulates within the duct 6 and flows into the lower part of the duct 6. Therefore, the flow of the refrigerant liquid 2 induced and increased in the duct 6 is blown upward into the gas phase space 5 and comes into contact with the gas phase space 5 and the inner wall surface of the container 3 over a wide area, thereby promoting cooling. The refrigerant liquid 2 flows in the flow path 8 in an orderly manner and improves the convective heat transfer characteristics between the refrigerant liquid 2 in the flow path 8 and the inner wall surface of the container 3.

FIG. 3 is a sectional view of a boiling cooling device according to a second embodiment of the present invention. Most of the heat generated in the heating element assembly 1 is transferred to the heating element assembly 1 facing the duct 6.
When dissipating from the surface of
As in the boiling cooling device 140 of the embodiment, the rectifier plate 7
By inserting the filler 10 between the container 3 and the heating element assembly 1, the amount of expensive refrigerant liquid 2 filled into the container 3 can be reduced.

In each of the above embodiments, the case where the container 3 has a cylindrical shape is illustrated, but the shape is not limited to a cylindrical shape, and may be, for example, a rectangular cylinder shape.

As explained above, both the first and second inventions not only increase the surface area of the heating element assembly, but also make it possible to flow the refrigerant liquid to a position close to the heat generation center of the heating element assembly. Efficient cooling can be achieved by the temperature difference and the rapid circulation of the refrigerant liquid. In addition, the first invention is such that the flow of refrigerant liquid induced by the heat generated from the heating element and increased in the high duct passes through channels formed inside and outside the heating element assembly, so that the refrigerant can be connected to the container. It has the effect of improving heat transfer characteristics between liquids, improving performance and reducing size.

Furthermore, the second invention has the effect of filling the space between the heating element assembly and the rectifying plate to remove the refrigerant liquid from this area, reducing the amount of refrigerant required in the container and reducing costs. has.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of an example of a conventional evaporative cooling device.
Figures 2 and 3 are the first and second figures of this invention, respectively.
FIG. In the figure, 1 is a heating element assembly, 2 is a refrigerant liquid,
3 is a container, 4 is an air chamber, 6 is a duct, 7 is a rectifying plate, 8 is a channel, 10 is a filling material, 130, 140
is a boiling cooler. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A device comprising a refrigerant liquid, a heating element assembly immersed in the refrigerant liquid, and a container containing the refrigerant liquid and the heating element assembly, wherein the circulating flow of the refrigerant liquid is A rectifier plate is provided in the container to form a flow path in contact with the inner wall surface of the container, and a duct is provided in the heating element assembly for allowing the refrigerant to flow in from the lower part of the heating element assembly and to flow out to the upper part of the heating element assembly. is characterized in that the height of the duct is higher than the height of the heating element assembly so that the air formed by the vapor of the refrigerant and the refrigerant liquid passing through the duct are blown upward from the liquid level. Boiling cooler. 2. A device comprising a refrigerant liquid, a heating element assembly immersed in the refrigerant liquid, and a container containing the refrigerant liquid and the heating element assembly, wherein the circulating flow of the refrigerant liquid is in contact with an inner wall surface of the container. A rectifying plate is provided in the container to form a flow path for causing the refrigerant to flow, and the heating element assembly has a duct for allowing the refrigerant liquid to flow in from the lower part of the heating element assembly and to flow out to the upper part. A boiling cooling device characterized in that a filler is filled between the body assembly and the rectifying plate.