JP2014219178A - Heat removal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat removal device small in size, capable of being easily additionally installed in existing facilities, and excellent in heat exchange efficiency by fluid natural circulation.SOLUTION: A heat removal device 10 comprises: a plurality of heat exchange sections 16 each including a supply port 12 via which refrigerant 11a is supplied, an exhaust port for discharging the supplied refrigerant 11b, and passing holes 15 penetrating the heat exchange section 16 from an upper surface through a lower surface and passing through a surrounding fluid 14 (14a, 14b); a partition plate 20 provided in a gap between the heat exchange sections 16 arranged vertically for partitioning an area into a fluid area in contact with an upper surface of one heat exchange section 16 and a fluid area in contact with a lower surface of the other heat exchange section 20; and a refrigerant flow path communicating with the supply ports 12 of the respective heat exchange sections 16, also communicating with the exhaust ports of the respective heat exchange sections 16, and moving refrigerant 11 (11a, 11b).

Description

  The present invention relates to a heat removal apparatus using natural circulation of fluid.

  When a heat source having a high heat output density is cooled by electric power, there is a concern about an increase in the amount of exhaust heat accompanying a large consumption of electric power. Thus, a heat removal system that uses the natural circulation of the fluid surrounding the heat source to minimize the use of electric power has been studied (for example, Patent Document 1).

JP 2010-65912 A

  However, the known heat removal system using the natural circulation of the fluid needs a new dedicated space that defines the fluid circulation path with respect to the heat source, which makes it difficult to increase the scale of the device or to apply to existing facilities. There was a problem.

  The present invention has been made in consideration of such circumstances, and an object of the present invention is to provide a heat removal device that is small in size and can be easily added to an existing facility and is excellent in heat exchange efficiency by natural circulation of fluid. .

  In the heat removal apparatus according to the present invention, a heat exchange unit having a supply port to which a refrigerant is supplied, a discharge port for discharging the supplied refrigerant, and a passage hole that passes from the upper surface to the lower surface and allows the surrounding fluid to pass through, A partition plate that partitions the fluid region in contact with the upper surface of the heat exchange unit and the fluid region in contact with the lower surface in a gap between the heat exchange units arranged in a direction, and the supply of the plurality of heat exchange units And a refrigerant flow path that communicates with each of the ports and further communicates with each of the discharge ports to move the refrigerant.

  According to the present invention, there is provided a heat removal apparatus that is small in size and can be easily added to an existing facility and that is excellent in heat exchange efficiency by natural circulation of fluid.

The perspective view which shows 1st Embodiment of the heat removal apparatus which concerns on this invention. (A) The side view of the heat removal apparatus which concerns on 1st Embodiment, (B) The front view. (A) The side view of the heat removal apparatus which shows the 1st modification of the partition plate applied, (B) The side view of the heat removal apparatus which shows the 2nd modification. The side view of the heat removal apparatus which concerns on 2nd Embodiment. (A) The side view of the heat removal apparatus which concerns on 3rd Embodiment, (B) The front view. Sectional drawing of the cooling pool of the used nuclear fuel to which the heat removal apparatus which concerns on each embodiment was applied.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1 and 2, the heat removal apparatus 10 of the first embodiment includes a supply port 12 to which a refrigerant 11a (11) is supplied, and a discharge port 13 (FIG. 2) that discharges the supplied refrigerant 11b (11). (B)), and in the gap between the heat exchanging portion 16 having a passage hole 15 that passes from the upper surface to the lower surface and allows the surrounding fluid 14 (14a, 14b) to pass therethrough, and a plurality of heat exchanging portions 16 arranged in the vertical direction. A partition plate 20 that divides a fluid region 18a in contact with the upper surface 17 of the heat exchange unit and a fluid region 18b in contact with the lower surface 19 thereof, communicates with each of the supply ports 12 of the plurality of heat exchange units 16, and further has a discharge port 13 Refrigerant flow paths 21 (21a, 21b) that move in communication with the refrigerant 11 (11a, 11b) are also provided.

The refrigerant 11 (11a, 11b) passes through the inside of the heat exchanging section 16 in a liquid state and exchanges heat with the fluid 14 (14a, 14b) passing through the passage hole 15.
In addition, the refrigerant 11 may be used in the form of a liquid that is supplied to the supply port 12 in a liquid state and is then discharged from the discharge port 13 after at least a part thereof is vaporized by heat exchange with the fluid 14.

  Both ends of the passage hole 15 are opened on the upper surface and the lower surface of the heat exchanging portion 16 so that the refrigerant 11a and the fluid 14a are heat-exchanged so as not to mix with each other, and the fluid 14b having increased specific gravity is removed downward. Let it pass.

Both ends of the partition plate 20 are connected to one edge of the lower surface 19 of the upper heat exchange unit 16 and the other edge of the upper surface 17 of the lower heat exchange unit 16.
By providing the partition plate 20 in this manner, the fluid region 18 a in contact with the upper surfaces 17 of the plurality of heat exchange units 16 arranged in the vertical direction and the fluid region 18 b in contact with the lower surface 19 are partitioned.
By using a heat insulating material having a small heat conduction coefficient, the partition plate 20 suppresses heat exchange between the fluid 14a before heat removal and the fluid 14b after heat removal across the partition plate 20, thereby improving heat removal efficiency. Prevent decline.

In addition, the partition plate 20 can take various shapes other than the case where a flat plate slope is shown as shown in FIG.
For example, as shown in FIG. 3 (A), the partition plate 20A may have a curved surface structure along the direction in which the fluid 14b is guided, or both ends are bent at right angles as shown in FIG. 3 (B). In some cases, a rectangular structure is shown.
With such a structure, the space between the upper surface 17 and the lower surface 19 of the heat exchange part and the partition plates 20A, 20B is made uniform, and the flow rate of each through hole 15 (FIG. 1) is made uniform. Constant thermal performance is maintained.

  As illustrated in FIG. 2B, the refrigerant flow path 21 a communicates with each of the supply ports 12 of the plurality of heat exchange units and supplies the refrigerant 11 a to the heat exchange unit 16. And the refrigerant | coolant 11b heated up by exchanging heat with the fluid 14 is discharged | emitted outside the heat exchange part 16 by the refrigerant | coolant flow path 21b connected to each of the discharge port 13. FIG.

A closed system is formed from the supply port 12 to which the refrigerant flow path 21 a is connected to the discharge port 13 to which the refrigerant flow path 21 b is connected, so that the refrigerant 11 is prevented from being mixed with the fluid 14.
And the inside of the refrigerant | coolant flow path 21 can maintain the state pressure-reduced rather than atmospheric pressure, By adjusting the internal pressure of this refrigerant | coolant flow path 21, the vaporization temperature of the refrigerant | coolant 11 can be adjusted. .
Thereby, the operation start temperature of the heat removal apparatus 10 can be set by adjusting the internal pressure of the refrigerant flow path 21 with respect to the fluid 14 in the temperature rising process.

With the configuration described above, the fluid 14a in the region 18a in contact with the upper surfaces 17 of the plurality of heat exchanging units 16 arranged in the vertical direction is removed by the partition plate 20 after passing through the passage holes 15 when heat is removed by the refrigerant 11. 19 is guided to a region 18b in contact with 19.
Thus, the fluid 14a before heat removal and the fluid 14b after heat removal are not mixed across the partition plate 20. For this reason, the fluid 14a and the refrigerant 11b before heat removal continue to be supplied to the heat exchange unit 16 while maintaining a large temperature gradient, thereby realizing efficient heat removal.

Then, the fluid 14b after heat removal further descends the region 18b in contact with the lower surface 19 of the heat exchange part and reaches a heat source (not shown).
The fluid 14a reheated by the heat source rises because the specific gravity is reduced, and is again input to the heat exchange unit 16 from the upper surface 17 in the region 18a.
In this way, the natural circulation of the fluids 14 a and 14 b continues, and the fluid 14 that is continuously heated by the heat source is efficiently heat-treated by the heat removal device 10.

(Second Embodiment)
Next, a second embodiment of the present invention will be described based on FIG.
4, parts having the same configuration or function as those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted.

As shown in FIG. 4, the heat removal apparatus 10 according to the second embodiment passes through the passage hole 15 (FIG. 1) at the edge opposite to the side to which the partition plate 20 is connected on the lower surface 19 of the heat exchange unit. A first guide member 23 for guiding the fluid 14b is provided.
Thereby, in each heat exchange part 16, the fluid resistance in the point where the fluid 14b after heat removal joins can be made small.

Furthermore, the 2nd guide member 24 which guides the fluid 14b which passed each heat exchange part 16 is provided in the side of the several heat exchange part 16 arranged in an up-down direction.
This prevents the fluid 14b after heat removal from diffusing and joining the fluid 14a before heat removal, and causes a downward flow to occur inside the second guide member 24, so that the fluid 14b before heat removal The suction force of the heat exchange unit 16 is increased.

  Thus, in the heat removal apparatus 10 according to the second embodiment, the amount of natural circulation can be increased and the heat removal effect of the fluid 14 can be improved.

(Third embodiment)
Next, a third embodiment of the present invention will be described based on FIG.
5 that have the same configuration or function as those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted.
The heat removal apparatus 10 according to the third embodiment is provided with a cooling member 25 that cools the fluid 14 before or after passing through the heat exchange unit 16 in the gap between the plurality of heat exchange units 16 arranged in the vertical direction. ing.

Such a cooling member 25 may be a fin or a heat pipe that is thermally connected to the heat exchange unit 16.
Thereby, the heat transfer area which heat-exchanges with the fluid 14 increases, and the improvement of heat removal efficiency can be aimed at.

FIG. 6 shows a cross-sectional view of a spent nuclear fuel cooling pool 30 to which the heat removal apparatus 10 according to each embodiment is applied.
Spent nuclear fuel discharged from the nuclear reactor is accommodated in a fuel rack 31 in which a plurality of square tubes are arranged in a lattice shape, with a fuel assembly as a unit. And it cools for a fixed period in the cooling pool 30 until a radiation and decay | heat decay | decay heat attenuate | damp.

The heat removal apparatus 10 is provided so as to be immersed in the pool water 32 in the gap between the inner wall of the cooling pool 30 and the rack 31 containing spent fuel.
And the heat removal apparatus 10 and the cooling pool 30 are being fixed by the fixing member 27 in the bottom part.
Thereby, the heat removal apparatus 10 can be additionally installed without extracting spent fuel in an existing nuclear power plant.

Water is used as the refrigerant held inside the heat exchange unit 16.
The heat exchange unit 16 has its internal pressure reduced by the refrigerant circulation control unit 28 via the flow paths 21a and 21b so that the retained refrigerant water is vaporized at a temperature lower than the boiling point temperature of the pool water 32. Yes.
When the refrigerant circulation control unit 28 receives the vaporized refrigerant from the channel 21b, the refrigerant circulation control unit 28 returns the cooled and condensed refrigerant to the heat exchange unit 16 through the channel 21a.

In addition, the refrigerant | coolant hold | maintained inside the heat exchange part 16 is not limited to water, When the pool water 32 is normal setting temperature, it will show liquid state and will vaporize at the temperature exceeding this normal setting temperature. If appropriate.
Moreover, the refrigerant | coolant to be used may be a thing which does not evaporate at the temperature exceeding normal setting temperature, and should just provide the heat removal function of a liquid refrigerant in the refrigerant | coolant circulation control part 28 in this case.

When the function of the fuel pool cooling and purification system (FPC), which is normally operated, is lost due to natural disasters, the pool water 32 evaporates due to decay heat and is used in the fuel rack 31 exposed to the air. There is a risk that the fuel will be further heated and damaged.
Even if such an abnormal situation occurs, the heat removal apparatus 10 according to the present embodiment performs heat removal of the heated pool water 32 with a slight auxiliary power or without using power. be able to.

  According to the heat removal apparatus of at least one embodiment described above, the fluid is separated by partitioning the fluid before heat removal and the fluid after heat removal by the partition plate in the gap between the plurality of heat exchange units arranged in the vertical direction. Naturally circulates and exhibits excellent heat exchange efficiency.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Heat removal apparatus, 11 (11a, 11b) ... Refrigerant, 12 ... Supply port, 13 ... Discharge port, 14 (14a, 14b) ... Fluid, 15 ... Pass-through hole, 16 ... Heat exchange part, 17 ... Heat exchange part 18a: Fluid region in contact with the upper surface of the heat exchange unit, 18b: Fluid region in contact with the lower surface of the heat exchange unit, 19: Lower surface of the heat exchange unit, 20, 20A, 20B ... Partition plates, 21 (21a, 21b) ... refrigerant flow path, 23 ... first guide member, 24 ... second guide member, 25 ... cooling member, 27 ... fixing member, 28 ... refrigerant circulation controller, 30 ... cooling pool, 31 ... fuel rack, 32 ... Pool water.

Claims (8)

A heat exchange section having a supply port through which a refrigerant is supplied, a discharge port through which the supplied refrigerant is discharged, and a passage hole that passes from the upper surface to the lower surface and allows the surrounding fluid to pass through;
A partition plate that partitions the fluid region in contact with the upper surface of the heat exchange unit and the fluid region in contact with the lower surface in a gap between the plurality of heat exchange units arranged in the vertical direction;
A heat removal apparatus comprising: a refrigerant flow path that communicates with each of the supply ports of the plurality of heat exchange units and further communicates with each of the discharge ports to move the refrigerant.   2. The heat removal device according to claim 1, wherein a first guide member that guides the fluid that has passed through the passage hole is provided at an edge opposite to a side to which the partition plate is connected on a lower surface of the heat exchange unit. apparatus.   The heat removal according to claim 1 or 2, wherein a second guide member that guides the fluid that has passed through each of the heat exchange units is provided on a side of the plurality of heat exchange units arranged in the vertical direction. apparatus.   4. The cooling member for cooling the fluid before or after passing through the heat exchange unit is provided in a gap between the plurality of heat exchange units arranged in the vertical direction. 5. The heat removal apparatus described in 1.   The heat removal device according to any one of claims 1 to 4, wherein the refrigerant is discharged in a liquid state after at least a part thereof is vaporized after being supplied to the heat exchange unit.   The heat removal apparatus according to any one of claims 1 to 5, wherein the inside of the refrigerant flow path is depressurized from atmospheric pressure.   The heat removal apparatus according to any one of claims 1 to 6, wherein the partition plate exhibits a curved surface structure or a rectangular structure along a direction in which the fluid is guided.   The heat removal apparatus according to any one of claims 1 to 7, wherein the heat removal apparatus is disposed in a cooling pool for spent nuclear fuel.

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