JPH0354098A - Cooling plate device - Google Patents

Abstract

PURPOSE:To effectively suppress the increase of the temperature of a cooling plate body even when the coefficient of utilization of the latent heat of a refrigerant is improved by providing a heat pipe comprising a closed container the cooling plate body of which forms a part of a constituting wall or which is embedded in the cooling plate body and working fluid with which the closed container is filled. CONSTITUTION:A refrigerant A is heated during the flow of it through a refrigerant pipe 18, a part thereof is vaporized to produce a two-phase flow. When the state at an outlet 20 of the refrigerant A produces a steal single phase or two-phase flow, thermal conductivity between the refrigerant A and the pipe 18 is reduced in the vicinity of the outlet 20, and the temperature of a place in the vicinity thereof is about to be increased. A part of a liquid heat transport medium in the vicinity of the outlet 20 is vaporized in a heat pipe, heat in the vicinity of the outlet 20 is derived, and generated steam is condensed at a part located away from the outlet 20 and where temperature is not increased. Namely, heat in the vicinity of the outlet 20 is transported to a part which is located away from the outlet 20 and where temperature is not increased, an amount of heat transmitted from the pipe 18 to the refrigerant A is reduced in the vicinity of the outlet 20, and the increase of the temperature of the pipe 18 is suppressed. This constitution locally suppresses the increase of the temperature of a cooling plate body 11 even when the coefficient of utilization of the latent heat of a refrigerant is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a cooling plate device suitable for cooling equipment used in space orbit.

(Prior Art) Many devices used in space orbit devices such as artificial satellites and space bases generate heat. Therefore, in order to operate such equipment stably over a long period of time, it is necessary to discharge the generated heat to space by some means to maintain the temperature of the equipment at a predetermined level.

Heat is normally discharged into space by radiation from a heat sink. Therefore, it is necessary to transport the heat generated by the equipment to the heat sink. In large space orbit devices,
Since the amount of heat generated is large and the transportation distance is long, a loop heat transfer system that can transport a large amount of heat is used. In loop heat transport systems, heat generating equipment is typically mounted on a cooling plate arrangement. A coolant flow path is formed in the cooling plate device.

The heat generated by the equipment is transferred to the refrigerant in the refrigerant flow path as sensible heat or latent heat. Then, the refrigerant is guided through the piping and reaches the heat sink, where it exchanges heat with the heat sink. In the loop heat transport system, the heat generated by the equipment is transported to the heat sink using the above-mentioned path.

Loop heat transport systems include two-phase fluid loop heat transport systems that utilize the latent heat of a refrigerant, and single-phase fluid loop heat transport systems that utilize the sensible heat of a refrigerant. The former is
Compared to the latter, it has the feature of being able to transport a large amount of heat with a small amount of refrigerant.

For space orbit devices with strict size and weight restrictions, it is desirable to adopt a two-phase fluid loop heat transport system. In this two-phase fluid loop heat transport system, all or part of the refrigerant is phase-changed (evaporated) from a liquid phase to a gas phase within a refrigerant flow path of a cooling plate device. Therefore, in order to operate in orbit where the influence of gravity is small, it is necessary to select a coolant flow method that can be used under microgravity. Examples of this method include the r-strong 11 convection method, which minimizes the influence of gravity by increasing the inertial force, and the wick surface evaporation method, which uses capillary force as a substitute for gravity.

By the way, a conventional cooling plate device employing the "forced convection method" is constructed as shown in FIG. 5 or FIG. 6. In the cooling plate shown in FIG. 5, refrigerant pipes 2 constituting a refrigerant flow path are embedded in a meandering manner in a cooling plate main body 1 on which a heat generating device is mounted. Refrigerant A is refrigerant pipe 2
It is sent in a liquid phase or a gas-liquid two-phase state from the inlet 3 of the . Heat generated by the equipment is transferred to the refrigerant A through the cooling plate body 1 and the refrigerant vibrator 2. The refrigerant A is heated by the transferred heat, and all or part of it evaporates into a gas phase or a gas-liquid two-phase state, and is discharged from the outlet 4 of the refrigerant vibe 2. This discharged refrigerant A is guided to a heat sink (not shown).

However, the cooling plate device configured as shown in FIG. 5 has the following problems.

That is, in the loop heat transport system, it is desirable to reduce the amount of refrigerant A circulated as much as possible.

Now, let us consider a case where a two-phase fluid loop type heat transport system is constructed using this cooling plate device. In order to reduce the amount of refrigerant circulated in a two-phase fluid loop thermal spread system, it is necessary to make maximum use of the latent heat of refrigerant A. For this purpose, the state of the refrigerant A at the outlet 4 must be a vapor single-phase flow or a gas-liquid two-phase flow whose quality (vapor phase flow rate/total flow rate) is close to 1. However, when the quality approaches 1, fine droplets become a spray stream flowing through the vapor stream.
The heat transfer coefficient between the refrigerant A and the inner wall surface of the refrigerant vibe 2 rapidly decreases. As a result, in the cooling plate device having the configuration shown in FIG. 5, the temperature of the cooling plate body 1, particularly in the vicinity of the outlet 4, increases, and the cooling plate device loses its function as a machine cooling device. Therefore, in order to ensure the function for cooling equipment, it is necessary to increase the refrigerant circulation amount and operate the state at outlet 4 in a gas-liquid two-phase flow, thereby making maximum use of the latent heat of the refrigerant. There was a problem that essentially made it impossible.

Furthermore, in the cooling plate device shown in FIG.
A refrigerant pipe 2 forming a refrigerant flow path is spirally provided between the refrigerant pipes. In this cooling plate device, centrifugal force acting on the refrigerant 8 is used to bring droplets into contact with the inner wall surface of the refrigerant vibe 2, thereby suppressing a decrease in heat transfer coefficient.

However, even in the cooling plate device configured in this way, when the refrigerant A becomes a vapor single-phase flow, the heat transfer coefficient between the refrigerant A and the inner wall surface of the refrigerant pipe 2 is reduced. It cannot be prevented. Therefore, in order to ensure the function of this cooling plate device for equipment cooling, it is necessary to increase the amount of refrigerant circulation and operate the state at outlet 4 as a gas-liquid two-phase flow. It is not possible to make maximum use of the latent heat of

On the other hand, even when the "wick surface evaporation method" is adopted as the refrigerant flow method, if you want to reduce the amount of refrigerant circulation and create a vapor single-phase flow or a gas-liquid two-phase flow with a quality close to 1 at the outlet, , liquid is lost on a part of the evaporation surface. Therefore, there is a problem in that the heat transfer coefficient in the above-mentioned portion decreases rapidly, and as a result, the temperature of the cooling plate body locally increases.

(Problems to be Solved by the Invention) As described above, in the conventional cooling plate device that is considered to be effective in a microgravity environment, when trying to increase the latent heat utilization rate of the refrigerant, a part of the refrigerant flow path is The heat transfer coefficient suddenly decreases, resulting in a localized temperature rise in the cooling plate itself, and there is a risk that it will lose its ability to cool equipment.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cooling plate device that can effectively suppress the temperature rise of the cooling plate body even if the latent heat utilization rate of the refrigerant is increased.

[Structure of the invention 6. ] (Means for Solving the Problems) In order to achieve the above object, a cooling plate device according to the present invention includes a cooling plate main body, a cooling plate device provided along the cooling plate main body, and a cooling plate device that directly connects the cooling plate main body. Alternatively, a refrigerant channel for guiding a refrigerant for indirect cooling, a closed container in which the cooling plate body is a part of the constituent wall, or a closed container embedded in the cooling plate main body, and A working fluid is sealed therein to cause the closed container to perform a heat pipe action.

(Function) According to the above configuration, the temperature distribution of the cooling plate body is made uniform by the heat transport action of the heat pipe consisting of the closed container and the working fluid, and the heat transfer coefficient is reduced in a part of the refrigerant flow path. Even if the temperature increases, local temperature rises in the vicinity are suppressed. Therefore, it is possible to make maximum use of the latent heat of the refrigerant.

(Embodiment) FIG. 1 shows a temporary cooling device according to an embodiment of the present invention.

In the figure, reference numeral 11 indicates a cooling plate main body on which a heat generating device (not shown) is mounted. The cooling plate main body 11 is made of copper, aluminum, aluminum nitride, etc., which have high thermal conductivity. On the lower surface of the cooling temporary wooden body 11 in the figure, a box body 12 made of a material with high thermal conductivity and having vertical and horizontal dimensions almost equal to those of the cooling plate body 11 and having a shallow depth is formed by the cooling plate body 11. The box body 12 and the cooling plate body 11 form a hermetically sealed container 13, which is attached in close contact with the lid.

Inside the airtight container 13, a plurality of struts 16 are provided which thermally connect the bottom wall inner surface 14 of the box 12 and the back surface 15 of the cooling plate main body 11 and mechanically reinforce the cooling plate main body 11. Further, a working fluid (not shown) is sealed in the closed container 13 as a heat transport medium that transports heat by evaporation and condensation.
A wick material (not shown), such as wire mesh or sintered metal, that moves the heat transport medium by capillary force is attached to the back surface 15.

On the lower surface of the bottom wall of the box body 12, as shown in FIG.
A plurality of parallel protrusions 17 are formed integrally with 2. A refrigerant pipe 18 for guiding refrigerant is embedded in these protrusions 17 in a meandering manner. Note that the refrigerant pipe 18 is made of a material with high thermal conductivity.

In the cooling plate device constructed in this way, the refrigerant pipe 18
Refrigerant A is fed from the inlet 19 of the refrigerant pipe 18, and the refrigerant A exiting from the outlet 20 of the refrigerant pipe 18 is guided to a heat sink (not shown). The refrigerant A is forced to circulate through the above-mentioned path, and through this circulation, the heat generated by the equipment mounted on the cooling plate main body 11 is transferred to the heat sink. Therefore, the equipment mounted on the cooling plate main body 11 is maintained at a predetermined temperature.

This cooling effect will be explained in more detail as follows. When the refrigerant 8 flows through the refrigerant pipe 18, the bottom wall of the box 12 is cooled. The closed container 13 contains a heat transport medium and a wick material. Therefore, the closed container 13 acts as a planar heat viper. That is, the liquid phase heat transfer medium held in the wick material attached to the back surface 15 of the cooling plate main body 11 is evaporated by the heat transmitted from the equipment mounted on the cooling plate main body 11.

The generated steam condenses on the inner surface 14 of the bottom wall of the box 12. Due to this condensation, heat is transferred from the bottom wall inner surface 14 to the refrigerant pipe 18 and further to the refrigerant A within the refrigerant pipe 18 . On the other hand, the heat transport medium condensed on the inner surface 14 of the bottom wall is carried to the back surface 15 of the cooling plate body 11 by the capillary force of the wick material attached between the columns 16 and the wick material attached to the side surfaces of the columns 16. It will be done. In this way, heat generated by the equipment mounted on the cooling plate body 1 is transferred to the refrigerant A.

By the way, the refrigerant A is heated while flowing in the refrigerant pipe 18, and a part of the refrigerant evaporates to become a two-phase flow.

In order to maximize the latent heat utilization rate of the refrigerant, it is necessary to minimize the refrigerant flow rate, and for this purpose, the state of the refrigerant A at the outlet 20 should be changed to a vapor single-phase flow or a gas-liquid two-phase flow with a quality close to 1. It is necessary to make it a phase flow.

In this way, if the state of the refrigerant A at the outlet 20 is a vapor single-phase flow or a gas-liquid two-phase flow with quality close to 1, the refrigerant A at the outlet 20
The heat transfer coefficient between the refrigerant A and the refrigerant pipe 18 decreases significantly in a portion close to the refrigerant pipe 18, and the temperature of the portion increases accordingly. However, in the case of this embodiment, since there is a heat pipe constituted by the closed container 13 and the working fluid, the liquid phase existing in the portion near the above-mentioned outlet 20 in the heat pipe is A portion of the heat transport medium evaporates, taking away heat from the portion near this outlet 20. The generated steam condenses in a portion away from the outlet 20 where the temperature has not increased. In this way, the heat in the area near the outlet 20 is transported by the heat transport medium in the heat pipe to the area away from the outlet 20 where the temperature has not increased, and in the area near the outlet 20, the heat is transferred from the refrigerant vibe 18 to the refrigerant A. The amount of heat transfer decreases.

Therefore, in the portion near the outlet 20, the temperature rise of the refrigerant vibrator 18 is suppressed despite the decrease in the heat transfer coefficient, and as a result, the local temperature rise of the cooling plate body 11 is also prevented. . Therefore, even if the refrigerant flow rate is set to a condition that allows maximum use of the latent heat of the refrigerant, a local temperature rise in the cooling plate main body 11 can be suppressed.

FIG. 3 shows a cooling plate device according to another embodiment of the invention. In this figure, the same parts as in FIG. 1 are designated by the same reference numerals. Therefore, detailed explanation of the overlapping parts will be omitted.

In this embodiment, a refrigerant pipe 18 is installed inside the closed container 13. That is, the refrigerant pipe 18 is arranged in a meandering manner while airtightly penetrating the opposing side walls of the box body 12a and in contact with the bottom wall surface 14 of the box body 12a.

Supports 21 and 22 are attached to the outer surface of the refrigerant vibrator 18 located inside the airtight container 13 and to the bottom wall inner surface 14 of the box body 12a to connect these and the back surface of the cooling plate main body l1. Also in this embodiment, the wick material and the working fluid as a heat transport medium are housed in the closed container 13 in the same relationship as in the previous embodiment.

With such a configuration, if the refrigerant flow rate is set so that the state of the refrigerant A at the outlet 20 is a vapor single-phase flow or a gas-liquid two-phase flow with quality close to 1, the refrigerant A near the outlet 20 of the refrigerant vibrator 18 The temperature of the area begins to rise. However, in the case of this embodiment as well, heat in a portion of the refrigerant pipe 18 near the outlet 20 is transported to a portion of the refrigerant pipe 18 away from the outlet 20 due to the action of the heat transport medium housed in the closed container 13. Ru. Therefore, the temperature rise in the portion near the outlet 20 of the refrigerant pipe 18 is suppressed, and as a result, even if the refrigerant flow rate is set to a condition that allows maximum use of the latent heat of the refrigerant, as in the previous embodiment, the cooling plate This means that a local temperature rise in the main body 11 can be suppressed.

FIG. 4 shows a cooling plate device according to yet another embodiment of the present invention.

In this embodiment, a plurality of closed containers 23 are constituted by a plurality of cylindrical containers made of a material with high thermal conductivity. A plurality of heat pipes are constituted by accommodating a wick material and a working fluid as a heat transport medium in these closed containers 23. These airtight containers 23 and the meandering refrigerant pipes 18 form a plurality of squares, and the cooling plate main body 11a is arranged substantially orthogonally to the refrigerant vibe 18.
embedded within.

Therefore, in this embodiment as well, the heat transport medium sealed in each airtight container 23 causes the outlet 2 of the refrigerant vibrator 18 to
The heat of the portion close to zero can be transported to a portion remote from the outlet 20 of the refrigerant vibrator 18, and the same functions and effects as in the previous embodiment can be achieved.

Note that the present invention is not limited to the pointed embodiment described above. That is, in the embodiment shown in FIG. 1, the refrigerant pipe 18 is embedded in the protrusion 17 provided on the box body 12, and in the embodiment shown in FIG. 4, the refrigerant pipe 18 is embedded in the cooling plate body 11a. However, a number of cavities may be provided within the protrusion 17 or within the cooling plate main body 11a, and these cavities may be used as coolant flow paths. Further, in the embodiment shown in FIG. 1, the cooling plate main body, the heat pipe, and the refrigerant pipe are arranged in the thickness direction, but the positions of the heat pipe and the refrigerant pipe may be interchanged. Furthermore, the cooling plate device according to the present invention is not limited to use only in space orbit devices, but can of course also be used on the ground without any problems. When used on the ground, the wick material can be omitted depending on the conditions of use.

[Effects of the Invention] As described above, according to the present invention, the cooling plate main body is
A heat vip is provided, which consists of a closed container as part of the cooling plate or a closed container embedded in the cooling plate body, and a working fluid sealed in this closed container, so that the latent heat of evaporation of the refrigerant flowing into the refrigerant flow path can be absorbed. Even when trying to make maximum use of the cooling plate, local temperature increases in the cooling plate body can be suppressed to a minimum, contributing to the realization of an economical two-phase fluid loop type heat transport system.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view of a temporary cooling device according to an embodiment of the present invention, and FIG. 2 is a perspective view of the temporary cooling device taken along the line X-X in FIG. 1 in the direction of the arrow. Figure as seen in Figure 3
FIG. 4 is a perspective view showing a cooling plate device according to another embodiment of the present invention, partially cut away; FIG. 4 is a perspective view showing a cooling plate device according to still another embodiment of the invention; FIG. is a perspective view showing an example of a conventional cooling plate device, FIG. 6(a) is a side view showing another example of the conventional cooling plate device, and FIG. 6(b) is a longitudinal sectional view of the same cooling plate device. Figure 6(C) shows the same cooling plate device as shown in Figure 6(C).
It is a figure cut along the YY line in a) and seen in the direction of the arrow. 11.1la...Cooling plate main body, 12.12a...Box body, 13.23...Airtight container, 14...Bottom wall inner surface,
15... Back side, 16, 21.22... Pillar, 18.
...Refrigerant vibrator, 1...inlet, 20...outlet, A
... Refrigerant.

Claims (5)

[Claims] (1) A cooling plate main body, a refrigerant flow path provided along the cooling plate main body and guiding a refrigerant for directly or indirectly cooling the cooling plate main body, and a wall constituting the cooling plate main body. The cooling plate is characterized by comprising a closed container as a part or a closed container embedded in the cooling plate main body, and a working fluid sealed in the closed container to cause the closed container to perform a heat pipe action. cooling plate device. (2) The cooling plate device according to claim 1, wherein the closed container and the working fluid sealed in the container constitute a planar heat pipe. (3) The refrigerant flow path is provided in a meandering state, and the airtight container is divided into a plurality of parts, and each divided airtight container is arranged in a positional relationship such that it forms a plurality of squares with the refrigerant flow path. The cooling plate device according to claim 1, further comprising a cooling plate device. (4) The cooling plate device according to any one of claims 1, 2, and 3, wherein a wick material is housed in the closed container. (5) The cooling plate device according to claim 1 or 2, wherein the refrigerant flow path is arranged within the closed container.