JP2518275B2 - Cold plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a cold plate provided for radiating heat generated from a battery, a power transistor and the like to outer space in space equipment such as spacecrafts and artificial satellites. It is about.

[Prior Art] In space, since it is vacuum and weightless, heat transfer due to the convection phenomenon of air on the earth cannot be expected. Furthermore, the place where heat is dissipated is outer space, and ultimately it must rely on heat radiation.

Therefore, it is necessary to have a means for transferring heat from a heat source such as a battery to a radiator provided by exposing the space equipment to the outside, and it is a kind of heat exchanger as a part of this heat transfer means. A cold plate is provided.

At present, a plate fin heat exchanger shown in FIG. 10 and FIG. 11 is considered, and a pipe b for letting in a refrigerant such as water or freon is connected to one end of a hollow flat plate-shaped heat receiving body a. The outflow pipe c is connected to the other end. Further, inside the heat receiving body a, a fin d also serves as a flow path formation.
Is provided in parallel with the line connecting the pipes b and c. The coolant is circulated between the radiator and the cold plate by a pump (not shown).

The heat from the heat source e such as a battery or a power transistor is transferred to the heat receiving body a, the heat of the heat receiving body a is transferred to the refrigerant flowing inside, and the heat of the refrigerant is a radiator exposed to the outside of the space equipment. It is designed to be released to outer space by heat radiation.

[Problems to be Solved by the Invention] However, in the cold plate described above, the pressure is constant in the direction (width direction) perpendicular to the direction of the flow path in principle, and there is no movement of the refrigerant in the width direction. A boundary layer develops along and the heat transfer between the heat receiver and the refrigerant decreases as it goes downstream.

Moreover, in the cold plate described above, with the refrigerant flowing in the central portion of the heat receiver and the refrigerant flowing in both sides, the phenomenon that the flow velocity of the central portion is fast and the flow velocity of both sides is slow occurs, and the heat receiving body should be cooled uniformly. It causes a problem that you cannot do it.

In view of the above situation, the present invention aims to provide a cold plate that uniformly improves heat transfer between the heat receiving body and the refrigerant over the entire heat receiving body.

[Means for Solving Problems] In the present invention, a supply nozzle and a discharge nozzle connectable to a refrigerant circulation system are attached to an apex portion of a hollow flat plate-shaped heat receiving body, and a plurality of branch passages are provided in the heat receiving body. The straight fins and the offset fins are arranged such that there is a space between the straight fins and the offset fins so that the flow direction of the refrigerant flowing in each fin intersects the line connecting the supply nozzle and the discharge nozzle. It is characterized by that.

[Operation] Since the supply nozzle and the discharge nozzle are on a substantially diagonal line, and the flow direction of the flow passage intersects with the diagonal line instead of being parallel to each other, the refrigerant entering the flow passage from the supply nozzle is in the flow direction of the flow passage. Since it enters from a diagonal direction, the generation of the boundary layer in the flow path is repeatedly interrupted, and the effect of promoting transmission is increased.

Further, the heat transfer efficiency between the heat receiving body and the refrigerant is improved over the entire heat receiving body by the offset fin, and a space is provided between each of the straight fin and the offset fin arranged in the heat receiving body. Therefore, even in this space, the refrigerant flowing out of the straight fins and the refrigerant flowing out of the offset fins can be further agitated and mixed, and the unevenness of the temperature in the refrigerant can be eliminated by this diffusion and mixing. Therefore, the heat transfer efficiency between the heat receiving body and the refrigerant can be further improved.

[Examples] Examples of the present invention will be described below with reference to the drawings.

1 to 7 show an embodiment of the present invention, in which a frame 3 is inserted and fixed between the heat-receiving surface plates 1 and 2 to form a rectangular space 4.
And a supply nozzle 5 and a discharge nozzle 6 are provided on the surface plate 2 so that they can communicate with the opposite tops of the space 4, respectively.
The nozzles 5 and 6 are connected to a refrigerant circulation system (not shown).

Straight fins 10 having straight flow paths 9 shown in FIG.
Place it avoiding the 6th opening. The direction of the straight flow path 9 of the straight fin 10 is substantially parallel to the inner walls 7 and 8, and the straight fins 10 and 10 'are notched so as to taper from the nozzles 5 and 6 side to the tip end. The cross sections of the straight flow paths 9 are opened on the opposite side surfaces of the straight fins 10 and 10 ', respectively.

Further, in the remaining space of the space 4 excluding the openings of the nozzles 5 and 6 (portion indicated by a broken line in FIG. 1 in a substantially parallelogram shape), a flow path 11 as shown in FIG. The offset fins 12 are divided into two parts, and the other divided flow paths are joined together so that the main flow direction of the flow paths 11 is perpendicular to the inner walls 7 and 8. The offset fin 12 and each straight fin 1
The space between the nozzles 5 and 6 is defined as a supply header 13 and a discharge header 14 with a slight distance from 0 and 10 '.

In the figure, 15 is a bolt for fastening and fixing the surface plates 1 and 2 and a heat source such as a power transistor, 16 is a bolt hole, 17 is a washer, and 18 is a flange.

Since it is configured as described above, the control circuit board 21 which is a heat source is attached to the cold plate 20 as shown in FIG.
When the refrigerant is supplied to the supply header 13 from the supply nozzle 5 of the cold plate 20, a part of the refrigerant is directly supplied to the offset fin.
12, the wall that is the main flow direction of the offset fin 12
It flows in a direction parallel to 19, is repeatedly divided and merged at regular intervals, and is diffused and heat-exchanged as it reaches the downstream side of the offset fin 12.

The remaining refrigerant enters each straight flow path 9 of the straight fin 10 and flows in parallel with the wall 7, is discharged from the openings formed on the side surfaces of the straight fin 10, and then flows into the flow path 11 of the adjacent offset fin 12. Each of them flows in, and the divided flow is repeated and diffused as described above.

Here, by using the offset fin 12,
It is possible to prevent a decrease in heat transfer rate that generally occurs on the downstream side of the flat plate laminar flow. Further, the bolt hole 16 can flow around the washer 17 portion, and the flow passage 11 is not blocked by the washer 17.

In this way, the cooling plate 20 is uniformly diffused to cool the control circuit board 21, and the heat-exchanged refrigerant flows out from the downstream side of the offset fin 12, and a part is directly discharged from the discharge header 14. The flow flows to the nozzle 6, and the rest enters the straight flow passages 9 from the side surface openings of the straight fins 10 ′ and is discharged from the discharge nozzle 6 via the discharge header 14.

Here, since the line connecting the supply nozzle 5 and the discharge nozzle 6 intersects with the main flow direction of the offset fin 12,
As shown in FIG. 9, the convective heat transfer coefficient is improved by about 3 times as compared with the case where the nozzles are provided at the central portions of both ends and the line connecting the nozzles and the main flow direction of the offset fin are made parallel. , Can approach the theoretical limit considerably.

The cold plate of the present invention is not limited to the above-mentioned embodiment, and various modifications may be made within the range not departing from the gist of the present invention.

[Effects of the Invention] As described above, according to the cold plate of the present invention, the supply nozzle and the discharge nozzle are provided in the diagonal direction, and the flow path having a large number of branch passages is arranged so that the diagonal direction and the flow direction intersect. Therefore, the refrigerant is repeatedly divided and merged by the branch passages so that there is no unevenness in cooling, the cooling efficiency can be increased to three times or more of that of the conventional one, damage due to insufficient cooling of the object to be cooled can be prevented, and the heat can be distributed in the heat receiver In the space between each of the straight fins and the offset fins provided, the refrigerant flowing out of the straight fins and the refrigerant flowing out of the offset fins are agitated and mixed, and the unevenness of the temperature in the refrigerant is eliminated by this diffusion and mixing.
It exhibits various excellent effects such as improving the heat transfer efficiency between the heat receiving body and the refrigerant.

[Brief description of drawings]

FIG. 1 is an explanatory view of an embodiment of the cold plate of the present invention, FIG. 2 is a partially cut arrow view in the II-II direction of FIG. 1, and FIG.
FIG. 4 is a detailed view of the straight fins in FIG. 1, FIG. 4 is a detailed view of the offset fins in FIG. 1, FIG. 5 is a detailed view of V portion in FIG. 1, and FIG. 6 is a detailed view of VI in FIG. , 7th
FIG. 7 is a view taken along the line VII-VII in FIG. 1, FIG. 8 is an explanatory view showing an example of use of the cold plate of the present invention, and FIG. 9 is a graph showing Reynolds number and convective heat transfer coefficient by the cold plate of the present invention. FIG. 10 is a comparative view showing the relationship, FIG. 10 is an explanatory view of a conventional cold plate, and FIG. 11 is a view taken in the direction of arrows XI-XI in FIG. Reference numerals 1 and 2 are surface plates, 5 is a supply nozzle, 6 is a discharge nozzle, 9 is a straight flow path, 10 and 10 'are straight fins, and 12 is an offset fin.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Seiichi Uchida 1-6-2 Marunouchi, Chiyoda-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Head Office Annex (72) Inventor Kaoru Torii 2231-47 Kamigocho, Sakae-ku, Yokohama ( 56) References JP 62-69098 (JP, A)

Claims (1)

(57) [Claims] 1. A supply nozzle and a discharge nozzle connectable to a refrigerant circulation system are attached to the top of a hollow flat plate heat receiving body, and a plurality of straight fins and offset fins having a large number of branch passages are provided in the heat receiving body. A cold plate, characterized in that a space is provided between the straight fins and the offset fins so that the flow direction of the refrigerant flowing in each of the fins intersects a line connecting the supply nozzle and the discharge nozzle.