JPH0794238B2 - Spray cooling type heat remover - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray cooling type heat remover, and more particularly to a spray cooling type heat remover used in a low pressure environment close to a vacuum such as in space orbit.

[0002]

2. Description of the Related Art The heat generated in space orbital devices such as satellites, space stations, platforms, etc. and in space shuttles must be exhausted to outer space. Conventionally, a heat radiating plate is often used as the heat exhausting means, but in some cases, the heat radiating plate cannot be used, or the amount of heat radiated by the heat radiating plate may be less than the required amount of heat exhausted.

In such a situation, a heat discharging means other than the heat radiating plate is required, and as one of the powerful heat discharging means,
There is an evaporative heat exchanger that uses the latent heat of vaporization of the cooling medium, and among these evaporative heat exchangers, the spray cooling heat remover 1 shown in FIG.
Is used. This spray cooling type heat remover 1 is provided with a cooling medium flow passage 4 between a circular inner cylinder 2 and a circular outer cylinder 3 each having an inner surface 2 a having a tooth profile in cross section, and an inlet header 5 at a lower end portion of the flow passage 4. The outlet header 6 is provided at the upper end of the circular inner cylinder 2
A cooling medium spray nozzle 7 is provided near the center of the inner end. Then, the cooling medium A is sprayed from the spray nozzle 7 into the circular inner cylinder 2, and takes heat from the cooled medium B via the circular inner cylinder 2 to be evaporated. The cooling medium A that has evaporated to a gas phase is discharged from the vapor outlet 8 below the circular inner cylinder 2 to the outlet pipe. On the other hand, the medium to be cooled B is supplied from the inlet header 5 to the flow path 4 and exchanges heat with the cooling medium A via the circular inner cylinder 2 in the process of flowing in the flow path 4 in a direction parallel to the central axis of the cylinder. Cooled and sprayed from the outlet header 6
Taken out of.

By the way, this conventional spray cooling type heat remover 1
In order to improve the heat transfer performance on the cooled medium B side, fins are incorporated in the flow path 4, but the manufacturability of the fins, the circular inner cylinder 2, the fins, and the circular outer cylinder 3 can be brazed. The clearance between the circular inner cylinder 2 and the circular outer cylinder 3 is 2 in terms of assembling workability.
The limit is about mm, and it is difficult to make the width smaller than this. For this reason, since the flow passage cross-sectional area of the cooled medium B is wide and the flow velocity becomes slow, the heat transfer performance on the cooled medium B side is poor,
The heat removal efficiency as a heat exchanger (heat remover) is poor.

Further, since the pressure loss in the flow path 4 is extremely small, the pressure loss in the inlet header 5 cannot be ignored, and the flow distribution of the cooled medium B in the circumferential direction tends to be non-uniform.
When uneven flow distribution occurs, in the part where the flow rate is low,
Since the temperature of the cooled medium B decreases and the difference from the temperature of the cooling medium A (saturation temperature of evaporation) decreases, the amount of heat removed decreases. Therefore, the heat removal efficiency of the heat exchanger is reduced.

Further, a circular inner cylinder 2 which is a spray cooling heat transfer surface.
The temperature of is likely to be locally reduced (cold spot) in a portion where the flow rate of the cooling medium is small, and the sprayed cooling medium may be frozen. When freezing occurs, that portion does not contribute to heat removal, and the heat removal efficiency further decreases.

Further, in the spray cooling type heat remover 1, the diameter D and the length L (same as the length of the flow path 4) are such that the spread angles θ ₁ , θ ₂ of the spray of the cooling medium A from the spray nozzle 7 are large. However, when the diameter D is increased, the flow passage cross-sectional area of the cooled medium B increases, the flow velocity of the cooled medium B decreases, heat transfer performance decreases, and pressure loss Cause a decrease. Further, when the length L is shortened, the pressure loss is further reduced. For this reason, the diameter D and the length L cannot be selected as optimal values.

On the other hand, recently, in the spray cooling type heat remover as described above, the heat exchange section between the cooling medium and the cooled medium is the first
It is divided into a heat exchanging part and a second heat exchanging part, the second heat exchanging part is formed in a tubular shape, and a plurality of flow paths through which the cooling medium flows and the cooled medium flow through the first heat exchanging part. It is proposed that the first heat exchange section is formed from a flow path and a partition wall between the flow paths, and the first heat exchange section is installed in a substantially spiral shape along the outer circumference of the second heat exchange section. (As a prior art document, Japanese Patent Laid-Open No.
-258500 is available. )

This spray cooling type heat remover has a completely different purpose and shape from the type shown in FIG. 5, and allows the cooling medium (water, ammonia) to evaporate in a spiral manner as a two-phase flow while evaporating. Thus, the two-phase flow is separated by centrifugal force, the liquid is pushed to the outside (partition wall with the medium to be cooled) to promote the evaporation of the cooling medium, and the heat exchange efficiency is improved.

However, such a spray cooling type heat remover is the first
Since the cooling medium of the heat exchange section is guided to the nozzle (two-phase flow nozzle) of the second heat exchange section, the pressure of the cooling medium (two-phase) of the first heat exchange section is increased when the valve is engaged during the intermittent spraying. As a result, the saturation temperature rises and the heat exchange efficiency decreases. Also,
In order to perform load control, in the embodiment in which the cooling medium of the first heat exchange section and the cooling medium of the second heat exchange section are separated, the cooling medium of the first heat exchange section must be flow rate controlled (continuous flow) at the inlet. ,
The pressure loss changes depending on the flow rate, and the saturation temperature changes.
Attempting to control the flow rate with the control valve at the outlet is unstable because of the two-phase flow. Further, unstable flow peculiar to the cooling medium of the first heat exchange section may occur. That is, since each flow path from the inlet header to the outlet header of the first heat exchange section is a two-phase flow parallel channel, the flow rate may vibrate in a sinusoidal manner and may even reach a reverse flow. Therefore, it is not practical.

[0011]

Therefore, the present invention solves the drawbacks of the conventional spray cooling type heat removal device shown in FIG. 5, significantly improves the heat removal efficiency, and evenly distributes the flow rate of the medium to be cooled. In addition, the heat transfer surface freezing due to cold spots can be eliminated, and the diameter and length can be selected to be optimal considering the spread angle of the spray of the cooling medium. An object of the present invention is to provide a spray cooling type heat remover capable of achieving reduction.

[0012]

One of the spray cooling type heat removers of the present invention for solving the above-mentioned problems is to provide a cooling medium flow passage between an inner cylinder and an outer cylinder, In a spray cooling type heat remover in which headers are provided on both ends of the inner cylinder, and a cooling medium spray nozzle is provided near the center of the inner end of the inner cylinder, the cooled medium flow path is evenly divided in the circumferential direction. In addition, each of the divided flow paths is formed in a meandering shape in the vertical direction. Another one of the spray cooling type heat removal devices of the present invention is characterized in that fins are arranged along the flow path direction in each of the meandering flow paths of the spray cooling type heat removal device. It is a thing.

[0013]

As described above, in one of the spray cooling type heat removers of the present invention, the flow path of the medium to be cooled is evenly divided in the circumferential direction, and each flow path is formed in a meandering shape in the vertical direction. Therefore, the cross-sectional area of the flow path is narrow, the flow velocity of the cooled medium is increased, the heat transfer performance on the cooled medium side is improved, and the heat removal efficiency is significantly improved.
In addition, since the flow path length increases and the flow path length increases, the pressure loss on the cooled medium side increases, and an appropriate pressure loss can be secured in the flow path section, and the cooled medium from the inlet header is uniform in each flow path. Will be distributed to. Therefore, the temperature distribution in the circumferential direction of the inner cylinder, which is the medium to be cooled and the spray cooling heat transfer surface, becomes uniform, the heat removal efficiency is improved, and there is no concern about freezing of the heat transfer surface due to cold spots.

Particularly, in another one of the spray cooling type heat remover of the present invention in which fins are arranged in each of the meandering flow passages, the heat transfer area of the medium to be cooled is remarkably increased and the heat transfer performance is improved. It will be further improved and the heat removal efficiency will be even higher. In addition, since the pressure loss on the cooled medium side is increased in the flow passage, an optimal pressure loss can be set in the flow passage, uniform distribution of the cooled medium can be established, and the temperature distribution in the circumferential direction can be ensured. Can be uniform. Furthermore, since the fins function as a reinforcing member for the inner cylinder and the outer cylinder against the pressure of the medium to be cooled, the structural strength and durability of the heat remover are improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the spray cooling type heat remover of the present invention will be described with reference to the drawing. In FIG. 1, 2 is a circular inner cylinder having an inner surface 2a having a tooth profile, and 3 is a circular outer cylinder. A flow path 4 for a medium to be cooled (CFC in this example) is provided between the flow path 2 and the outer cylinder 3, and an inlet header 5 is provided at the lower end of the flow path 4.
An outlet header 6 is provided at the upper end, and a pulse actuated valve 7 for a cooling medium (water in this example) is provided in the inner cylinder 2 near the center of the upper end.
A spray nozzle 7 with a is provided. The cooling medium flow path 4 is divided into a plurality of, in this example, eight flow paths 4a to 4h by a vertical partition plate 9 in the circumferential direction, and each of the divided flow paths 4a is divided.
4 h are formed in a meandering shape with the horizontal partition plates 10 having a constant interval in the up-down direction and a plurality of stages, in this example, seven stages with the gaps 11 alternately provided on the left and right.

In the spray cooling type heat remover 1'of the embodiment for exchanging heat between the spray water and the freon as described above, the freon passages are evenly divided in the circumferential direction, and the respective passages 4a to 4h are vertically arranged. Since it is formed in a meandering shape in the direction, the cross-sectional area of the flow path is narrow, the flow velocity of freon is increased, the heat transfer performance on the freon side is improved more than that on the spray water side, and the heat removal efficiency is significantly improved. Further, as the flow velocity increases, the lengths of the flow paths 4a to 4h become longer,
The pressure loss on the CFC side increases, and an appropriate pressure loss can be secured in the flow path section. In this case, the inlet header 5 is
Since the pressure loss at 1 is negligible, the CFCs are uniformly distributed from the inlet header 5 to the flow paths 4a to 4h in the circumferential direction. Therefore, the temperature distribution in the circumferential direction of the freon and the circular inner cylinder 2 as the spray cooling heat transfer surface becomes uniform, the heat removal efficiency is improved, and there is no fear of the heat transfer surface freezing due to cold spots.

Next, another embodiment of the spray cooling type heat remover of the present invention will be described with reference to FIG. 2. In this embodiment, fins are provided in the respective flow paths 4a to 4h of the above embodiment, and in this embodiment, FIG. A part 17a shown in FIG. 4 in which the offset fin 17 shown in FIG. 4 is cut and formed so that CFCs flow along the direction of the meandering flow path.
.About.17e are arranged, and the other structure is the same as that of the above embodiment. According to this embodiment, the heat transfer area of the CFCs in the channels 4a to 4h is significantly increased, the heat transfer performance is further improved, and the heat removal efficiency is further increased. Further, since the pressure loss on the chlorofluorocarbon side is further increased in the flow passage, it is possible to set the optimum pressure loss in the flow passage, to establish uniform distribution of chlorofluorocarbon, and to ensure the temperature distribution in the circumferential direction. Can be uniform. Further, since the offset fins 17 in the flow paths 4a to 4h serve as a reinforcing member for the inner cylinder 2 and the outer cylinder 3 against the pressure of CFC, the structural strength and durability of the heat remover are improved. .

In the spray cooling type heat remover 1'of the present invention, the diameter D of the cylinder and the length L of the cylinder (height of flow passage) shown in FIG. It can be selected to be optimal considering the spread angle of. This is because, if the number of divisions of the flow passage in the circumferential direction and the number of meandering steps in each flow passage are appropriately selected, the flow velocity and pressure loss of the medium to be cooled are transmitted for a given cylinder diameter D and cylinder length L. This is because it can be made appropriate in terms of thermal performance and flow rate distribution.

In the spray cooling type heat remover of each of the above-mentioned embodiments, the body (the inner cylinder 2 and the outer cylinder 3) is cylindrical, but the invention is not limited to this, and each flow path of the medium to be cooled is flat. It is also possible to make it into a square tubular body by combining it with 6 or 8 sheets. In addition, the inlet header 5 includes the flow paths 4a to 4
The outlet header 6 is provided at the lower end of h and at the upper ends of the flow paths 4a to 4h, but the reverse is also possible. Further, although the cooling medium spray nozzle 7 is provided near the center of the upper end portion on the outlet header 6 side, it may be provided so as to spray in the reverse direction near the center of the lower end portion on the inlet header 5 side.

Further, the fins arranged in each of the flow paths 4a to 4h of the spray cooling type heat remover of the embodiment shown in FIG. 2 are offset fins, but the fins are not limited to these, and are louver fins and pin fins. , Wavyfin, etc. are also acceptable.

[0021]

As described above, the spray cooling type heat remover of the present invention has a narrow flow passage cross-sectional area of the medium to be cooled and a high flow velocity of the medium to be cooled, so that the heat transfer performance of the medium to be cooled is improved, The heat removal efficiency is significantly improved. Further, since the flow velocity of the medium to be cooled is high and the length of the flow channel is long, the pressure loss on the side of the medium to be cooled is increased moderately, an appropriate pressure loss can be secured in the flow channel portion, and the flow rate from the inlet header to each flow channel is increased. The medium to be cooled can be evenly distributed. Therefore, the temperature distribution in the circumferential direction of the inner cylinder, which is the medium to be cooled and the spray cooling surface, becomes uniform, the heat removal efficiency is improved, and there is no fear of the heat transfer surface freezing due to the cold pot. In particular, in a spray cooling type heat remover in which fins are arranged in a meandering flow path, the heat transfer area of the medium to be cooled is significantly increased, the heat transfer performance is further improved, and the heat removal efficiency is further improved. Get higher Also,
Since the pressure loss of the cooled medium is further increased in the flow passage, the pressure loss can be set optimally in the flow passage, uniform distribution of the cooled medium can be established, and the temperature distribution in the circumferential direction can be surely made uniform. . Furthermore, since the fins function as a reinforcing member for the inner cylinder and the outer cylinder against the pressure of the medium to be cooled, the structural strength and durability of the heat remover are improved. Further, the spray cooling type heat remover of the present invention has a given body diameter and body length by appropriately selecting the number of divisions of the flow passage in the circumferential direction and the number of meandering steps in each flow passage. On the other hand, the flow velocity and pressure loss of the medium to be cooled can be made appropriate in terms of heat transfer performance and flow distribution. Furthermore, in the spray cooling type heat remover of the present invention, the flow path is divided in the circumferential direction, so if each flow path is manufactured and then assembled in the body, the manufacturing work can be rationalized and the cost can be reduced. Can be planned.

[Brief description of drawings]

FIG. 1 is a partially cutaway schematic perspective view of an embodiment of a spray cooling type heat remover of the present invention.

FIG. 2 is a partially cutaway development view showing divided cooling medium flow paths in another embodiment of the spray cooling type heat removal device of the present invention.

FIG. 3 is a perspective view of an offset fin.

FIG. 4 is a perspective view showing a baht in which an offset fin is cut and formed.

FIG. 5 is a schematic sectional view of a conventional spray cooling type heat remover.

[Explanation of symbols]

 1'Spray cooling type heat remover 2 Circular inner cylinder 3 Circular outer cylinder 4 Coolant flow path 4a-4h Divided flow path 5 Inlet header 6 Outlet header 7 Coolant spray nozzle 9 Vertical partition plate 10 Horizontal partition plate

Front page continuation (72) Inventor Tatsuzaburo Nakamura 1 Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries, Ltd. Gifu factory (72) Inventor Tadashi Takemura 1-1, Kawasaki-cho, Akashi-shi, Hyogo Akashi factory, Kawasaki Heavy Industries, Ltd. (72) Inventor Akio Yoshizaki 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Akashi factory (72) Inventor Kanzo Takasaki, Kawasaki-cho, Kakamigahara-shi, Gifu Kawasaki Heavy Industries, Ltd. Gifu factory (56) ) Reference JP-A-2-258500 (JP, A)

Claims (2)

[Claims] 1. A cooling medium flow passage is provided between an inner cylinder and an outer cylinder, headers are provided at both ends of the flow passage, and a cooling medium spray nozzle is provided near the center of the inner end of the inner cylinder. In the spray-cooling type heat remover, the spray-cooling type heat removing device is characterized in that the flow path of the medium to be cooled is evenly divided in the circumferential direction, and each of the divided flow paths is formed in a meandering shape in the vertical direction. Heater. 2. A spray cooling type heat remover in which fins are arranged along the flow path direction in each of the meandering flow paths of the spray cooling type heat remover according to claim 1.