JP2013224779A - Heat transporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly-efficient heat transporting device which is automatically operable without any external power and also has a high heat transporting ability.SOLUTION: A heat transporting device includes: a riser 1 for receiving heat from the outside; a downcomer 2 for radiating heat to the outside; an upper part communicating pipe 3 for connecting the riser with an upper part of the downcomer; a lower part communicating pipe 4 for connecting the riser with a lower part of the downcomer; and a working fluid 22 circulating through each pipe. At least one heat exchanging part 5 is provided around the upper part communicating pipe 3 so as to allow the working fluid 22 in the lower part communicating pipe 4 to circulate through the heat exchanging part 5.

Description

  The present invention relates to a heat transport device for cooling a nuclear power plant having an exothermic part and industrial and consumer equipment, and more particularly to a passive heat transport device that does not use external power.

  For example, many nuclear power plants and industrial and consumer equipment have equipment that generates heat during normal use, but they can be used for cooling in severe accidents where coolant is lost, or for energy saving equipment. In order to reduce the size and weight, there is a growing demand for cooling devices that do not use external power.

  In the nuclear power plant, even if all three functions (all AC power supply, seawater cooling function, and spent fuel storage pool cooling function) are lost due to the tsunami, the core will be increased in order to further improve the reliability and safety of the reactor equipment. There is a need for a heat transport device that can prevent damage and damage to spent fuel, and maintain a cooling function while suppressing the release of radioactive materials. Among these, regarding the cooling of the spent fuel storage pool, assuming the loss of the existing cooling system, an apparatus capable of cooling the pool water is required even in a situation where external power is not available. Means using a heat pipe as such a heat transport device has been proposed (Patent Document 1).

  In the field of electronic / electrical equipment, the miniaturization, weight reduction, and increase in capacity of equipment have progressed, and an increase in heat generation density has become a problem. As a typical device having a high heat generation density, there is a power converter such as a converter or an inverter that is a power source of an electric motor. A semiconductor element is used in these devices, and the semiconductor element generates heat rapidly in a short time during operation. For this heat removal, a cooling device using a heat pipe that does not require external power has been proposed.

  Typical heat pipes include a wick type and a thermosyphon type based on the circulation force. In the wick type, an object (wick) having a capillary structure is enclosed in a sealed container and used as a source of circulation force. On the other hand, the thermosyphon type uses gravity to circulate the working fluid with a density difference between a liquid phase and a gas phase generated by boiling the liquid phase.

JP-A-2-223896

However, in the above-described conventional heat transport device, the heat exchange efficiency and the heat transport capability may be lowered depending on the location of the target heat generating device and the length of the heat transport distance. In particular, the wick-type heat pipe has a problem that an increase in the pressure loss of the flow path due to the extension of the heat transport distance is caused because the liquid phase flows through the void portion of the object having a capillary structure. Furthermore, since it is necessary to avoid the loss of the liquid phase in this gap, it is difficult to improve the cooling capacity.
Moreover, since the thermosiphon type heat pipe needs to install the cooling unit vertically upward, there is a problem that the transport direction of heat and refrigerant is limited.

  The present invention has been made to solve the above problems, and an object thereof is to provide a highly efficient heat transport device that operates automatically without external power and has high heat exchange efficiency and heat transport capability.

  In order to solve the above problems, a heat transport device according to the present embodiment connects a riser pipe that receives heat from the outside, a downcomer pipe that radiates heat to the outside, and an upper part of the riser pipe and the downcomer pipe. In a heat transport device having an upper communication pipe, a lower communication pipe that connects the lower part of the riser pipe and the lower pipe, and a working fluid that circulates in each pipe, at least one heat exchange section around the upper communication pipe And the working fluid in the lower communication pipe is circulated through the heat exchange section.

  According to this embodiment, it is possible to provide a highly efficient heat transport device that operates automatically without external power and has high heat exchange efficiency and heat transport capability.

The cross-sectional block diagram of the heat transport apparatus which concerns on 1st Embodiment. The cross-sectional block diagram of the heat transport apparatus which concerns on 2nd Embodiment. The cross-sectional block diagram of the riser pipe of the heat transport apparatus which concerns on 3rd Embodiment. The cross-sectional block diagram of the heat transport apparatus which concerns on 4th Embodiment. The cross-sectional block diagram of the heat transport apparatus which concerns on 5th Embodiment. Sectional block diagram of the heat transport apparatus which concerns on 6th Embodiment. The cross-sectional block diagram of the heat transport apparatus which concerns on 7th Embodiment. The cross-sectional block diagram of the heat transport apparatus which concerns on 8th Embodiment.

Hereinafter, an embodiment of a heat transport device according to the present invention will be described with reference to the drawings.
[First Embodiment]
The heat transport apparatus according to the first embodiment will be described with reference to FIG.

(Constitution)
FIG. 1 is a heat transport device according to the first embodiment, a bubble pump type heat pipe, a rising pipe 1 that receives heat 11 from the outside, a down pipe 2 that radiates the received heat 12, a rising pipe 1 and a down pipe 2, an upper communication pipe 3 that connects the upper part of the lower pipe 2, a lower communication pipe 4 that connects the lower part of the ascending pipe 1 and the lower pipe 2, and a heat exchanging unit 5 that is disposed around the upper communication pipe 3. As shown in FIG. 1, the lower communication pipe 4 has a bent structure, and the internal working fluid 22 can circulate through the heat exchange unit 5. Further, a communication part 6 that can communicate with each other is provided between the upper communication pipe 3 and the heat exchange part 5.

  In this embodiment, water is used as the working fluid 22 and the saturated vapor pressure is adjusted to a desired pressure before the apparatus is operated. Water is easily available, and even if the piping is damaged, the influence on the surroundings is small. Further, by adjusting the saturated vapor pressure before the operation of the apparatus, it is possible to change the operation start temperature of the apparatus and optimally adjust the heat transport efficiency. Of course, a medium other than water can be used as the heat transport medium.

(Function)
In the heat transport apparatus configured as described above, the working fluid 22 sealed in the pipe receives the heat 11 from the outside by the rising pipe 1 and boils, and each driving force generated by the rising of the bubbles 23 generated by the boiling causes each of the working fluids 22. Circulate in the pipe. The working fluid 22 that has reached a high temperature dissipates heat 12 while circulating through the downcomer 2 and the lower communication pipe 4.

  Furthermore, the working fluid 22 in the lower communication pipe 4 whose temperature has decreased due to heat radiation is circulated in the heat exchange section 5 to promote condensation of the gas phase 21 in the upper connection pipe 3. In addition, the upper connecting pipe 3 and the heat exchanging unit 5 are communicated with each other by the communicating unit 6, so that the space to be condensed is expanded and the condensing capacity is improved.

(effect)
According to the present embodiment, the working fluid is circulated without using external power by the driving force due to the bubbles, and the working fluid is circulated through the heat exchanging portion provided around the upper communication pipe, whereby heat exchange efficiency and heat transport are achieved. Ability can be improved.
Moreover, by providing the communication part in the upper communication pipe and the heat exchange part, the heat exchange efficiency can be further improved by expanding the condensation space and increasing the condensation capacity.

[Second Embodiment]
A heat transport device according to a second embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  As shown in FIG. 2, the heat transport device of the present embodiment is provided with an enlarged diameter portion 7 in the middle of the rising pipe 1, and the inner diameter above the enlarged diameter portion 7 is larger than the lower side. As shown in FIG. 3, a plurality of the enlarged diameter portions 7 may be provided, or the diameter of the rising pipe 1 may be gradually increased from the lower side to the upper side.

  In the heat transport device configured as described above, when the working fluid 22 enclosed in the riser pipe 1 receives heat 11 from the outside, the working fluid 22 boils and bubbles 23 are generated. It circulates in each pipe with the generated driving force. At that time, the increase in diameter due to the growth and bonding of the bubbles 23 is suppressed by the expanded diameter portion 7, and the bubbles 23 can be raised in the ascending pipe 1 while having a fine structure.

That is, when the diameter of the bubbles increases, the total surface area of the bubbles decreases, so that the driving force of the working fluid 22 decreases. In this embodiment, the diameter of the bubbles is increased by providing the enlarged diameter portion 7 in the riser 1. Therefore, the working fluid 22 can be circulated with a large driving force.
Thereby, the heat exchange efficiency and heat transport capability of the heat transport device can be further improved.

[Third Embodiment]
A heat transport device according to a third embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

The heat transport device of this embodiment is characterized in that the ascending pipe 1, the upper communicating pipe 3, the descending pipe 2 and / or the lower communicating pipe 4 are constituted by a plurality of pipes.
FIG. 3 shows an example in which the ascending pipe 1 is constituted by a plurality of pipes, and the upper and lower parts of the plurality of ascending pipes 1 are connected by the ascending pipe upper connecting pipe 30 and the ascending pipe lower connecting pipe 31, respectively. When the downcomer 2 is composed of a plurality of pipes, the plurality of downcomers 2 are connected to the downcomer upper connection pipe and the downcomer lower connection pipe (not shown).

In addition, a plurality of upper communication pipes and lower communication pipes may be provided as appropriate. In that case, the upper connection pipe 30 and the lower connection pipe 31 are connected to the upper connection pipe 30 and the lower connection pipe 31 respectively. Connect (not shown).
In the example of FIG. 3, the diameter of the riser tube is changed according to the amount of heat received from the external heating element and the heat receiving distribution.
A plurality of enlarged diameter portions 7 are provided to improve the driving force of the working fluid 22.

According to the present embodiment, the number of pipes, the pipe diameters, and the arrangement of the riser pipe 1 and the downfall pipe 2 are appropriately adjusted according to the amount of heat received from the external heating element, the heat reception distribution, the amount of heat radiation to the outside, and the heat radiation distribution. This makes it possible to obtain optimum heat exchange efficiency.
Thereby, the heat exchange efficiency and heat transport capability of the heat transport device can be further improved.

[Fourth Embodiment]
A heat transport device according to a fourth embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  As shown in FIG. 4, the heat transport device of the present embodiment is configured such that the upper communication tube 3 is inclined so that the connection portion between the upper communication tube 3 and the riser tube 1 is higher than the connection portion with the downcomer tube 2. The arrangement is arranged.

  As a result, the working fluid 22 sent from the ascending pipe 1 to the upper communicating pipe 3 can smoothly flow in the upper communicating pipe 3 toward the descending pipe 2 by the action of the driving force by the bubbles 23 and gravity. The transportation capacity can be further improved. In addition, you may comprise the inclined surface of an upper communicating pipe in step shape.

[Fifth Embodiment]
A heat transport device according to a fifth embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  The heat transport device according to the present embodiment has a configuration in which a swirling flow generator 8 is provided at the inlet portion and / or the enlarged diameter portion 7 of the riser 1. The swirl flow is generated by installing swirl vanes or torsion tape, or by processing an inclined groove or a spiral groove on the wall surface (not shown), but is not limited to this, and other swirl flow generating means may be used. .

  The swirling flow generator 8 generates a swirling flow in the working fluid 22 rising in the ascending pipe 1. Since this swirl flow can increase heat transfer on the tube wall as compared with a flow without swirl flow, the heat transport capability can be further improved.

The swirl flow also has the effect of uniformly dispersing the bubbles 23 in the ascending pipe 1 and the effect of miniaturizing the bubbles 23, whereby the driving force by the bubbles 23 can be further increased.
According to the present embodiment, since the swirling flow generator is provided in the ascending pipe, the driving force of the bubbles can be increased, so that the heat transport capability can be further improved.

[Sixth Embodiment]
A heat transport device according to a sixth embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  The heat transport device of the present embodiment has a configuration in which a plurality of partition plates 9 are installed on the liquid surface in the upper communication pipe 3. As shown in FIG. 6, the partition plate 9 is provided with a partition plate 9 having a predetermined height on the liquid surface of the working fluid 22 so as not to hinder the flow of the working fluid 22 in the upper communication pipe 3.

  As a result, the bubbles 23 having a predetermined size or more existing in the working fluid 22 going downstream in the upper communication pipe 3 are dammed and eliminated by the partition plate 9, and the driving force of the working fluid may be reduced. Absent.

Note that a mesh member having a predetermined diameter or less may be used as the partition plate 9, whereby bubbles having a predetermined size or more can be damped and eliminated.
According to this embodiment, since the partition plate is provided in the upper communication pipe, the driving force due to the bubbles can be increased, so that the heat transport capability can be further improved.

[Seventh Embodiment]
A heat transport device according to a seventh embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

  The heat transport device according to the present embodiment has a configuration in which a plurality of heat exchange units 5 are provided in the upper communication pipe 3. When the distance between the riser pipe 1 (heat receiving part) and the downcomer pipe 2 (heat radiating part) is increased, and thus the length of the upper communication pipe 3 is increased, a plurality of heat exchange parts 5 are connected to the upper communication pipe 3. It is installed, the lower communication pipe 4 is bent, and the working fluid 22 is circulated through the plurality of heat exchange parts 5.

As described above, even when the upper communication pipe 3 becomes longer, the heat exchange efficiency and the heat transport capability can be optimally maintained by providing the plurality of heat exchange portions 5.
In addition, in FIG. 7, although the example which provided the two heat exchange parts 5 is shown in figure, it is not limited to this, The number can be increased / decreased suitably according to the length of the upper communication pipe 3. FIG.

[Eighth Embodiment]
A heat transport device according to an eighth embodiment will be described with reference to FIG.
In addition, the same code | symbol is attached | subjected to the same or similar structure as the said embodiment, and duplication description is abbreviate | omitted.

The heat transport device of this embodiment is configured such that a communication pipe 32 is installed between the upper part of the heat exchanging unit 5 and the upper part of the ascending pipe 2 and / or the upper part of the descending pipe 3.
Thereby, since the space to condense in the upper communication pipe 3 can further be expanded and a condensation capability can be improved, a heat exchange efficiency and a heat transport capability can further be improved.

  As shown in FIG. 7, even when a plurality of heat exchanging units 5 are installed in the upper communication pipe 3, each heat exchanging part 5 and the upper end part of the rising pipe 2 or the upper end part of the descending pipe 3 are respectively connected to the communicating pipe. 32 may be connected. Further, the communication pipe 32 may be connected to the ascending pipe upper connecting pipe 30 (see FIG. 3).

[Ninth Embodiment]
The heat transport device according to the ninth embodiment has a configuration in which a large number of insoluble microcapsules (not shown) enclosing a heat storage material having a boiling point or lower of the working fluid are mixed in the working fluid 22. For example, when the working fluid is water, a paraffinic phase change material having a melting point of 30 to 70 ° C. is used as the heat storage material of the microcapsules.

  Thereby, the liquid phase 22 heated by the heat receiving 11 causes a phase change of the heat storage material in the microcapsule before the bubbles 23 are generated, so that the latent heat can be used for heat transport. Thereby, a heat transport capability can be improved significantly.

[Tenth embodiment]
The heat transport device according to the tenth embodiment has a configuration in which an adsorbent adsorbed on the bubble surface is added to the working fluid 22 (not shown). Since the adsorbent is adsorbed on the surface of the bubble 23, thereby suppressing the growth of the bubble and the expansion of the bond between the bubbles, the driving force of the working fluid can be kept high.

  The adsorbent is preferably a material that does not cause a chemical reaction due to working fluid, heat, or piping material. For example, fine particles or a surfactant made of titanium oxide, alumina, silica, or the like is used.

Further, when the heat transport device of the above-described embodiment is applied for cooling the spent fuel storage pool or the containment vessel of the nuclear power plant, the generated heat in the spent fuel pool or the containment vessel is not used by using external power. Can be automatically transported to the cooling section. For example, when the heat transport device of the above-described embodiment is used for cooling the containment vessel, the riser 1 may be arranged in the reactor containment vessel, and the downcomer 2 may be arranged outside the reactor containment vessel. At that time, a plurality of heat transport devices may be used according to the heat generation state in the reactor containment vessel.
Thereby, since the temperature rise in a spent fuel pool or a containment vessel can be automatically suppressed for a long time, the safety and reliability of the nuclear power plan can be improved.

  As mentioned above, although some embodiment of this invention was described, embodiment mentioned above is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, combinations, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... Rising pipe, 2 ... Down pipe, 3 ... Upper communication pipe, 4 ... Lower communication pipe, 5 ... Heat exchange part, 6 ... Communication part, 7 ... Diameter expansion part, 8 ... Swirling flow generator, 9 ... Partition plate 21 ... gas phase, 22 ... working fluid, 23 ... bubbles, 30 ... rising pipe upper connecting pipe, 31 ... rising pipe lower connecting pipe, 32 ... communication pipe.

Claims (12)

A riser pipe that receives heat from the outside, a downcomer pipe that dissipates heat to the outside, an upper communication pipe that connects the upper part of the riser pipe and the downcomer pipe, and a lower communication that connects the lower part of the riser pipe and the downcomer pipe In a heat transport device having a pipe and a working fluid circulating in each pipe,
At least one heat exchange part is provided around the upper communication pipe, and the working fluid in the lower communication pipe is circulated through the heat exchange part.   The heat transport device according to claim 1, wherein at least one communication portion is provided between the heat exchange portion and the upper communication pipe.   The heat transport device according to claim 1 or 2, further comprising a communication pipe that communicates the heat exchange part and the upper part of the riser pipe and / or the heat exchange part and the upper part of the lower riser pipe.   The heat transport device according to any one of claims 1 to 3, wherein a plurality of the rising pipes and / or down pipes are provided.   The heat according to any one of claims 1 to 4, wherein the upper communication pipe is inclined so that a connection portion between the upper communication pipe and the rising pipe is higher than a connection portion between the lower communication pipe and the downflow pipe. Transport equipment.   The heat transport device according to any one of claims 1 to 5, wherein at least one enlarged-diameter portion is provided in the middle of the rising pipe.   The heat transport device according to any one of claims 1 to 5, wherein the diameter of the riser pipe is expanded from below to above.   The heat transport device according to any one of claims 1 to 7, wherein at least one partition plate is provided on a liquid surface of the upper communication pipe.   9. The heat transport device according to claim 1, wherein a number of insoluble microcapsules containing a heat storage material having a melting point lower than that of the working fluid is contained in the working fluid.   The heat transport device according to any one of claims 1 to 9, wherein the working fluid contains fine particles adsorbed on a bubble surface.   The heat transport device according to any one of claims 1 to 10, wherein the working fluid is water, and a saturated vapor pressure is adjusted to a desired pressure before the heat transport device is operated.   The heat transport device according to any one of claims 1 to 11, wherein the riser pipe is disposed in a reactor containment vessel, and the downcomer pipe is disposed outside the reactor containment vessel.

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