JP2009175051A - System and method for receiving heat of high heat-flux beam, and energy recovery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To a system for receiving heat of a high heat-flux beam/energy recovery which enables not only reception of heat of high heat flux of a beam and a plasma flow concentrating on a narrow range, but also the high-efficiency recovery of energy, and prevents vacuum degradation due to metal vapor in a chamber where it appears through the interposing of liquid metals. <P>SOLUTION: The system for receiving the heat of the high heat-flux beam/energy recovery includes a differential pumping chamber 20 controlled in a vacuum atmosphere and an evaporation chamber 10. A cooling component 50 for condensing liquid metal evaporating by receiving the heat of the high heat-flux and evaporated metal is placed in the evaporation chamber 10, and the cooling component 50 is equipped with a coolant circulation system 60 for recovering thermal energy through the circulation of the coolant. When the liquid metal collides with the high heat flux, it evaporates and deprives latent heat, and the metal vapor condenses in the cooling component 50, to lower the vapor pressure in the evaporation chamber 10. The metal vapor leaking from the evaporation chamber 10 is removed in the differential pumping chamber 20, to prevent the rise in the degree of vacuum in a beam generation chamber 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high heat flux beam heat receiving / energy recovery system, and in particular, it can cut off high heat fluxes such as plasma, particle beam, electron beam, laser, etc. in vacuum and receive heat to recover energy. The present invention relates to a high heat flux beam heat receiving / energy recovery system and a high heat flux beam heat receiving / energy recovery method.

  Conventionally, as shown in FIG. 3, the fusion apparatus is provided with a diverter 200, and a large number of neutral particles from the plasma are converted into solid heat-resistant material 220 (also referred to as a countering material) in the diverter chamber 210 along the divertor magnetic field lines. Flow into. At this time, impurities are knocked out from the solid heat-resistant material 220, but if the impurities are neutral gas, they are hardly discharged from the narrow slit 230 of the diverter chamber 210 and are exhausted from the diverter chamber 210 by a vacuum exhaust pump. If the impurity is an ion, the ion returns to the solid heat-resistant material 220 along the divertor magnetic field lines and is neutralized. As a result, impurities are prevented from entering the plasma.

  The solid heat-resistant material 220 is made of molybdenum, tungsten, carbon material, etc., and is often cooled with cooling water. The divertor magnetic field lines form a thin bundle and are called a divertor leg. Since the diverter leg is very thin, a very large heat flux flows into the opposing material. In general, when receiving a high heat flux in a pulsed manner, that is, intermittently, cooling is not necessary if the heat capacity of the solid heat-resistant material to be accepted can be accommodated. However, in the case of continuous operation in which the generation of high heat flux is continuously performed, the heat capacity of the solid heat-resistant material that is received cannot be accommodated, and cooling means capable of high-efficiency heat exchange are provided, or particles that can receive heat (beam ) Heat flux needs to be reduced.

Further, when cooling with the cooling water, it is difficult to recover the heat energy because the high heat flux cannot be cooled unless the cooling temperature is lowered.
As an example, in DT fusion, about 1/4 of the neutron output is α heating. For example, in a power output million kW generator, the neutron output is about 3 GW, and the α heating is 750 MW. In steady state, this plasma heating input is equal to the plasma loss. The plasma loss is radiation loss or particle loss, and most of the particle loss flows to the divertor leg. Assuming that a quarter of α-heating comes to one diverter leg, if the main radius is 6 m, the circumference is 38 m, so 5 MW per meter is input to the surface of the diverter leg. The thickness of the diverter leg is 1-5 cm.

Therefore, the heat flux input to the surface of the opposing material of the divertor leg is 100 to 500 MW / m ² , which cannot be handled by a solid opposing material.
In view of this, it has been considered that a high heat flux that cannot be received by a solid opposing material is received by a liquid metal when continuously operated (Non-patent Document 1). However, creating a high-speed flow of liquid metal in a magnetic field has a new problem of countering strong magnetohydrodynamic forces. In this case, the high-speed flow is controlled within a range of 10 to 20 m / s, for example, and is about 15 m / s on average. The high-speed flow is performed at a high speed so as not to evaporate the liquid metal.

Here, the reason why a powerful pump that opposes a strong magnetohydrodynamic force is required when a liquid metal is used as a high-speed flow will be described.
According to Non-Patent Document 5, the pressure loss due to the electromagnetic force generally received by the liquid metal at the velocity V in the magnetic field B is given by the general formula (1).

ここで、Ｃは壁コンダクタンス比

Where C is the wall conductance ratio

ただし、σ_wは壁の電気伝導度、σ_ｆは流体の電気伝導度、ｔは磁場方向の壁厚、ａは管の半径である。Ｈ_ａはハルトマン数

Where σ _w is the electrical conductivity of the wall, σ _f is the electrical conductivity of the fluid, t is the wall thickness in the magnetic field direction, and a is the radius of the tube. H _a is the Hartmann number

である。ただし、μ_ｆは流体の粘性係数である。ｋ_１とｋ_２は管の形状の関数であり、１程度の大きさを持つ。計算例として、Ｂ＝１０Ｔでの液体金属流としてリチウム流を考えると、概ねσ_ｆ＝３×１０^６Ｓ／ｍ、Ｈａ＝１０^４、Ｃ＝０．０１であるから、流速Ｖ＝１ｍ／ｓでも、圧力損失は３MPaという大きな電磁力による圧力損失となる。従って、この圧力損失分を上回る圧力を発生可能な強力なポンプが必要となる。

It is. However, the mu _f is the viscosity coefficient of the fluid. k ₁ and k ₂ are functions of the tube shape and have a size of about one. As a calculation example, when a lithium flow is considered as a liquid metal flow at B = 10T, since σ _f = 3 × 10 ⁶ S / m, Ha = 10 ⁴ , and C = 0.01, the flow velocity V = 1 m / Even in s, the pressure loss is a pressure loss due to a large electromagnetic force of 3 MPa. Therefore, a powerful pump capable of generating a pressure exceeding the pressure loss is required.

In Non-Patent Documents 2 to 4, it is natural that the liquid metal rather evaporates under a high heat flux, and when the liquid evaporates, a large latent heat is taken away, so that a cooling effect can be expected.
A Y Ying, MA Abdou, N. Morley, T. Skechley, R. Woolley, Jay Barris (J. Burris), R. Kaita, P., Forgarty, H. Huang, X. Lao, M. Narula ), S. Smolentsev, M. Ulrickson, "Exploratory Studies of Floating Liquid Metal Dibeta Options for Fusion-Relivant Magnetic Fields in the M.O. Al Facility (Exploratory studies of flowing liquid metal divertor options for fusion-relevant magnetic fields in the MTOR facility) ", Fusion Engineering and Design Vol.72, pp.35-62 (2004) R. Kaita, R. Majeski, M. Boaz, P. Efthimion, et al., “Spherical Torus Plasma Interactions with Large "Spherical torus plasma interactions with large-area liquid lithium surfaces in CDX-U", Fusion Engineering and Design, Vol.61-62, pp.217-222 (2002) R. Majeski, S. Jardin, R. Kaita, T. Gray, P. Marfuta and others (et al. ), "Recent liquid lithium limiter experiments in CDX-U", Nuclear Fusion, Vol. 45, pp. 519-523 (2005) VA Evtikhin, IE Lyublinsky, AV Vertkov, SV Mirnov, VB Lazarev, etc. (Et al.), "Lithium divertor concept and results of supporting experiments", Plasma Physics and Controlled Fusion, Vol.44, pp955-977 (2002) Satoshi Inoue, “4. Cooling system of fusion reactor and its problems 4.2 Liquid metal cooling”, Journal of Plasma and Fusion Research, Vol.69, pp.1469 (1993)

However, when a high heat flux is received by evaporative cooling using liquid metal, the problem is that a large amount of evaporated metal flows back to the beam source side.
The object of the present invention is not only to receive a high heat flux of a beam or plasma flow concentrated in a narrow range by interposing a liquid metal, but also to perform highly efficient energy recovery, An object of the present invention is to provide a high heat flux beam heat receiving / energy recovery system capable of preventing vacuum deterioration due to generated metal vapor in a room.

  Another object of the present invention is not only to receive a high heat flux of a beam or plasma flow concentrated in a narrow range by interposing a liquid metal, but also to perform highly efficient energy recovery. Another object of the present invention is to provide a high heat flux beam heat receiving / energy recovery method capable of preventing vacuum deterioration due to metal vapor in a room where metal vapor is generated.

  In order to achieve the above object, the invention of claim 1 is characterized in that a high heat flux is introduced and the inside of the differential exhaust chamber is controlled in a vacuum atmosphere, and the differential exhaust chamber is provided adjacent to the differential exhaust chamber. The evaporating chamber is provided with an evaporating chamber that introduces the high heat flux that has passed through the dynamic exhaust chamber and is controlled in a vacuum atmosphere. The evaporating chamber receives the heat of the high heat flux applied to the high heat flux. Liquid metal that evaporates is disposed, the evaporation chamber is provided with a cooling unit that condenses the evaporated metal, and the cooling unit is provided with a cooling medium circulation system that circulates the cooling medium and collects heat energy. The gist of the present invention is a high heat flux beam heat receiving / energy recovery system.

  According to the first aspect of the present invention, the liquid metal evaporates and takes away large latent heat when hit with a high heat flux. The evaporated metal (that is, metal vapor) condenses in the cooling unit, and the vapor pressure in the evaporation chamber decreases as the metal vapor condenses. The heat of condensation of the metal vapor is received by the cooling medium through the cooling unit, and the heat energy is recovered by the cooling medium circulation system. In addition, since the evaporation chamber and the differential exhaust chamber provided adjacent to the evaporation chamber are controlled in a vacuum atmosphere, the metal vapor generated in the evaporation chamber flows back to the outside through the differential exhaust chamber. It is suppressed.

  According to a second aspect of the present invention, in the first aspect of the present invention, the evaporation chamber is provided with a reservoir for storing condensed liquid metal. According to the invention of claim 2, the liquid metal condensed in the cooling part is stored and collected in the storage part.

  The invention of claim 3 is the liquid metal circulation system according to claim 2, wherein the reservoir is included in a liquid metal circulation system that circulates the liquid metal, and the amount of the liquid metal in the region where the high heat flux is hit by the liquid metal circulation system. It is characterized by being kept constant.

  According to the invention of claim 3, the liquid metal accumulated in the reservoir is circulated by the liquid metal circulation system, and the amount of the liquid metal in the region where the high heat flux hits can be kept constant.

  According to a fourth aspect of the present invention, in the liquid metal circulation system according to the third aspect, the liquid metal circulation system is provided with a leaching portion from which the circulating liquid metal oozes, and the liquid leached from the leaching portion. The metal is disposed so as to hit the high heat flux.

  According to the invention of claim 4, since the liquid metal leached from the leaching portion of the liquid metal circulation system has a large surface tension, the liquid metal leached from the leaching portion is It is possible to hold, ie, support against gravity and electromagnetic force.

  Here, since the liquid metal absorbs a beam of ions, neutral particles, or the like, it is necessary to reduce the thickness, but it is very difficult to create a high-speed flow with the liquid metal being thin. For example, a uniform thickness cannot be achieved due to waves. However, if the liquid metal is leached at the leaching part, the liquid metal can be supported by the leaching part because the surface tension of the liquid metal itself is large. If a liquid metal is allowed to flow along the protruding portion, no wave is generated, so that an even thickness can be formed.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the cooling portion is provided with a cooling area expanding member that condenses evaporated metal.
According to the invention of claim 5, by increasing the area for cooling the evaporated metal by means of the cooling area expanding member provided in the cooling section, more metal than in the case where there is no cooling area expanding member. Vapor condenses.

  According to a sixth aspect of the present invention, a high heat flux is introduced into an evaporation chamber whose interior is controlled in a vacuum atmosphere via a differential exhaust chamber whose interior is controlled in a vacuum atmosphere. Is applied to the liquid metal to evaporate the liquid metal, and is provided in the evaporation chamber and is condensed by the cooling medium circulation system in the cooling section where the cooling medium passes through the inside. The gist of the present invention is a high heat flux beam heat receiving / energy recovery method, which recovers heat energy received by a cooling medium.

  According to the sixth aspect of the present invention, the liquid metal evaporates and takes away large latent heat when hit with a high heat flux. The evaporated metal (ie, metal vapor) condenses in the cooling section, thereby lowering the vapor pressure in the evaporation chamber. The heat of condensation of the metal vapor is received by the cooling medium through the cooling unit, and the heat energy is recovered by the cooling medium circulation system. In addition, since the evaporation chamber and the differential exhaust chamber provided adjacent to the evaporation chamber are controlled in a vacuum atmosphere, the metal vapor generated in the evaporation chamber flows back to the outside through the differential exhaust chamber. To suppress that.

  A seventh aspect of the invention is characterized in that, in the sixth aspect, the evaporation chamber is provided with a reservoir for storing condensed liquid metal. According to the invention of claim 7, the liquid metal condensed in the cooling part is stored and recovered in the storage part.

  The invention of claim 8 is the liquid metal circulation system according to claim 7, wherein the reservoir is included in a liquid metal circulation system that circulates the liquid metal, and the amount of liquid metal in the region where the high heat flux hits is reduced by the liquid metal circulation system. It is characterized by being kept constant.

  According to the eighth aspect of the present invention, the liquid metal accumulated in the reservoir is circulated by the liquid metal circulation system, and the amount of the liquid metal in the region where the high heat flux hits can be kept constant.

  The invention of claim 9 is the liquid metal circulation system according to claim 8, wherein the liquid metal circulation system is provided with a leaching part through which the circulating liquid metal oozes, and the liquid leached out from the leaching part. The metal is disposed so as to hit the high heat flux.

  According to the ninth aspect of the present invention, since the liquid metal leached from the leaching portion of the liquid metal circulation system has a large surface tension, the liquid metal leached from the leaching portion is Can be held, that is, supported. Here, since the liquid metal absorbs a beam of neutrons or the like, it is necessary to reduce the thickness, but it is very difficult to create a high-speed flow with the liquid metal being thin. For example, a uniform thickness cannot be achieved due to waves. However, if the liquid metal is leached at the leaching part, the liquid metal can be supported by the leaching part because the surface tension of the liquid metal itself is large. Even if the liquid metal is flowed at a low speed along the protruding portion, no wave is generated, so that an even thickness can be formed.

  According to the invention of claim 1, the high heat flux of the beam or plasma flow concentrated in a narrow range can be not only received heat by interposing the liquid metal, but also highly efficient energy recovery can be performed, Vacuum deterioration due to the metal vapor in the room where the metal vapor is generated can be prevented.

According to the invention of claim 2, the liquid metal condensed in the cooling part is stored in the storage part and can be recovered.
According to the invention of claim 3, the liquid metal accumulated in the reservoir is circulated by the liquid metal circulation system, and the amount of the liquid metal in the region where the high heat flux hits can be kept constant.

  According to the invention of claim 4, if the liquid metal is leached at the leaching portion, the liquid metal has a large surface tension, so that the leaching portion is subjected to gravity and electromagnetic force. Since it can be supported in opposition, a high-speed flow is not necessary, and if a liquid metal is allowed to flow along the leaching portion, no wave is generated, so that an equal thickness can be formed.

  According to the invention of claim 5, by increasing the area for cooling the evaporated metal by means of the cooling area expanding member provided in the cooling section, more metal than in the case where there is no cooling area expanding member. Steam can condense.

  According to the invention of claim 6, the high heat flux of the beam or plasma flow concentrated in a narrow range is not only received heat by interposing the liquid metal, but also highly efficient energy recovery can be performed, It is possible to provide a high heat flux beam heat receiving / energy recovery method capable of preventing vacuum deterioration due to metal vapor in a room where metal vapor is generated.

According to the invention of claim 7, the liquid metal condensed in the cooling part is stored and recovered in the storage part.
According to the eighth aspect of the present invention, the liquid metal accumulated in the reservoir is circulated by the liquid metal circulation system, and the amount of the liquid metal in the region where the high heat flux hits can be kept constant.

  According to the ninth aspect of the present invention, if the liquid metal is leached at the leaching portion, the liquid metal can be supported by the leaching portion because the surface tension of the liquid metal itself is large. The flow is no longer necessary, and if the liquid metal is flowed along the leaching portion at a low speed, no wave is generated, so that a uniform thickness can be created.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a high heat flux beam heat receiving and energy recovery system in which a high-speed beam of a strong neutron source is used as a high heat flux and liquid metal is used as a high-speed beam opposing material in the high heat flux. Will be described with reference to FIG.

Here, the fast beam of the strong neutron source is assumed to be a 40 MeV, 125 mA (5 MW) deuterium nuclear beam, for example, for 14 MeV neutron irradiation of a fusion reactor material, and this beam is, for example, 20 cm × 5 cm. By irradiating the lithium target with (0.01 m ² ), 14 MeV neutrons are generated. In this case, the heat flux incident on the lithium target is 500 MW / m ² and cannot be handled by a solid. In the case of generating 14 MeV neutrons as described above, for example, there is a project called IFMIF (International Fusion Materials Irradiation Facility). However, in IFMIF, the flow rate of lithium as a liquid metal, which will be described later, is to be handled by a high-speed flow (10-20 m / s).

  In this case, lithium has to be thinned in order to absorb 14 MeV neutrons, but it is very difficult to make a thin high-speed flow, and there is a problem that uniform thickness cannot be achieved due to waves.

This embodiment eliminates these difficulties.
FIG. 1 is a schematic diagram of a high heat flux beam heat receiving / energy recovery system (hereinafter simply referred to as an energy recovery system).

  The energy recovery system includes an evaporation chamber 10 and a differential exhaust chamber 20 provided adjacent to the evaporation chamber 10, and a beam chamber 30 is provided in the differential exhaust chamber 20. A first slit 22 is provided as an opening on the wall between the beam chamber 30 and the differential exhaust chamber 20. A second slit 24 is provided in the wall between the differential exhaust chamber 20 and the evaporation chamber 10. In the first slit 22 and the second slit 24, a high heat flux (not shown) in the beam chamber 30 is introduced into the differential exhaust chamber 20 and the evaporation chamber 10, respectively.

  A liquid metal circulation system 40 is attached to the evaporation chamber 10. In the evaporation chamber 10, the liquid metal circulation system 40 circulates between a wick 42 provided on the wall surface facing the second slit 24 and a liquid metal reservoir 46 provided outside the evaporation chamber 10. The liquid metal circulates in the pipeline 44 by driving a circulation pump 48 provided in the pipeline 44. The liquid metal is lithium having a melting point of 453.7 K (180 ° C.), and is heated in a temperature range not lower than the melting point and lower than the boiling point (1615 K) by a heating source (not shown) provided in the conduit 44.

  The wick 42 is made of a heat-resistant net, a heat-resistant cloth, or a heat-resistant porous material, and the liquid metal circulated in the pipe 44 is made constant on the surface of the wick 42 by the internal pressure applied by the circulation pump 48. It is possible to ooze so as to cover with a thickness of. Since the liquid metal has good wettability, the eyes of the wick 42 that oozes out may be rough. The flow rate of the liquid metal flowing through the pipe 44 by the circulation pump 48 does not need to be a high speed (10 to 20 m / s described in the background art) so as not to evaporate, and is a low speed range lower than the high speed range. Is enough. The wick 42 corresponds to a leaching portion.

  A collection reservoir 56 serving as a reservoir is provided on the bottom surface of the evaporation chamber 10. The collection reservoir 56 stores the liquid metal condensed by the cooling unit 50 described later. The liquid metal in the collection reservoir 56 is moved to the liquid metal reservoir 46 via the conduit 44a by the circulation pump 48. As described above, the collection reservoir 56 is included in the liquid metal circulation system 40.

  A cooling unit 50 is provided on the evaporation chamber 10 and the differential exhaust chamber 20 and the inner wall surfaces thereof. The cooling unit 50 includes a cooling plate. The cooling plate of the evaporation chamber 10 is provided with a plurality of fins 52 in order to increase the cooling area. It is preferable that the interval between the fins 52 adjacent to each other is set so that the liquid metal condensed in the cooling unit 50 is not clogged even if it is solidified. In addition, although the fin 52 is not provided in the cooling part 50 of the differential exhaust chamber 20, you may provide the fin 52 similarly to the cooling part 50 of the evaporation chamber 10. FIG.

  Between the wall surfaces of the cooling unit 50 and the evaporation chamber 10, a pipe line 54 of the cooling medium circulation system 60 is disposed. The pipe 54 of the cooling medium circulation system 60 is filled with a cooling medium, and the cooling medium is circulated through the heat exchanger 62 and the pump 64 as shown in FIG. In this embodiment, the cooling medium is lithium lead (melting point: 235 ° C.). However, the cooling medium is not limited to lithium lead as long as the boiling point is higher than the melting point of the liquid metal.

  As described above, if the cooling medium has a boiling point higher than the melting point of the liquid metal, the metal vapor does not solidify even if it condenses in the cooling unit 50, and therefore the clearance between the cooling plates (for example, the space between the fins 52). ) Will not clog with condensed liquid metal.

  Although not shown, the heat exchanger 62 is provided with a secondary circulation system, and is configured to exchange heat with a heat exchange medium circulating in the secondary circulation system. The heat exchange medium in the secondary circulation system is vaporized by heat exchange, and a steam turbine (not shown) is rotationally driven to rotate a generator (not shown).

  The evaporation chamber 10 is provided with an exhaust port 12 having a baffle plate (that is, a baffle plate) 14. The evaporation chamber 10 is managed to be in a vacuum atmosphere by exhausting the impurity gas in the chamber by a vacuum pump (not shown) connected to the exhaust port 12. The baffle plate 14 prevents metal vapor from entering the vacuum pump (not shown).

  In addition, a jet mechanism 26 is provided in the second slit 24 to reduce the backflow of the metal vapor from the evaporation chamber 10 into the differential exhaust chamber 20. The differential exhaust chamber 20 is provided with an exhaust port 58 having a baffle plate (that is, a baffle plate) 28. The differential exhaust chamber 20 is managed so as to be in a vacuum atmosphere by exhausting the impurity gas in the chamber by a vacuum pump (not shown) connected to the exhaust port 58. A baffle plate 28 prevents metal vapor from entering the vacuum pump (not shown).

The vapor of metal or the like leaking from the evaporation chamber 10 to the differential exhaust chamber 20 through the second slit 24 is exhausted at the exhaust port 12 to suppress the backflow of the vapor of metal or the like to the beam chamber 30. .
(Function)
The operation of the energy recovery system in this embodiment will be described.

  In the liquid metal circulation system 40, the liquid metal is circulated by the circulation pump 48, and the liquid metal is leached so as to cover the wick 42 with a certain thickness. In this state, a high heat flux of a beam (not shown) in the beam chamber 30 is introduced into the differential exhaust chamber 20 and the evaporation chamber 10, the high heat flux hits the surface of the wick 42, and the liquid metal on the surface of the wick 42. When heated above its boiling point, it becomes metal vapor and takes large latent heat from the high heat flux.

  The metal vapor is condensed in the cooling unit 50 to lower the vapor pressure in the evaporation chamber 10. The heat of condensation of the metal vapor is received by the cooling medium via the cooling unit 50, and the heat energy is recovered by the cooling medium circulation system 60. Using the heat of the cooling medium of the cooling medium circulation system 60, a heat exchange medium such as water is generated as steam by a secondary heat exchanger, and electric power is generated by a known power generation system using the steam. Further, since the evaporation chamber 10 and the differential exhaust chamber 20 provided adjacent to the evaporation chamber are managed in a vacuum atmosphere, the metal vapor generated in the evaporation chamber 10 is externally transmitted through the differential exhaust chamber 20. Backflow to a certain beam chamber 30 is suppressed.

Here, the cooling amount by evaporation of lithium as the liquid metal in the present embodiment will be described.
Liquid metal temperature and vapor pressure are almost determined by heat input. Evaporation amount J [atoms / m ² sec] per unit area of vapor pressure p [Pa] and temperature T [K] is

となる。従って、蒸発による冷却量ｑ_ｖは

It becomes. Accordingly, the cooling amount _{q v} by evaporation

となる。ここで、ｍ_Liはリチウムの原子量、γ_vは蒸発潜熱である。

It becomes. Here, m _Li is the atomic weight of lithium, and γ _v is the latent heat of evaporation.

Condensation when this metal vapor is cooled by the cooling plate which is the cooling unit 50 will be described.
The area of the cooling plate can be increased by using a cooling area expanding member that expands the cooling area such as the fins 52. For example, if the area of the cooling plate per unit length is 5 m ² , the cooling amount on the cooling plate is 1 MW / m ² . This is a value that can be sufficiently cooled by the cooling medium. Since the heat flux at the cooling plate is not directly applied, it is not large, and the flow rate and temperature of the cooling medium are flexible, and a value with good power generation efficiency can be selected.

A part of the generated steam flows back to the beam chamber 30, and this amount is calculated.
Mass M _v of lithium evaporation per unit area,

である。

It is.

For example, heat flux Q _in = 500 MW / m ² can be received by metallic lithium (m _Li = 1.15 × 10 ⁻²⁶ [/ kg]), γv = 2.273 × 10 ⁷ [J / kg] It becomes. There is no solid that can receive such a strong heat flux. In this case, the mass of the metal evaporated per unit area is M _v = 22 [kg / m ² -sec].

If this all flows into the beam chamber 30, there is a problem. In this embodiment, the differential exhaust chamber 20 is provided adjacently.
The effects exhibited by this embodiment will be described below.

  (1) The energy recovery system of this embodiment includes a differential exhaust chamber 20 in which a high heat flux is introduced and the inside is managed in a vacuum atmosphere, and a differential exhaust chamber provided adjacent to the differential exhaust chamber 20. And an evaporating chamber 10 in which a high heat flux that has passed through 20 is introduced and the inside is managed in a vacuum atmosphere. The evaporation chamber 10 is provided with lithium (liquid metal) that is applied to the high heat flux and receives the heat of the high heat flux to evaporate, and the evaporation chamber 10 has a cooling unit 50 that condenses the evaporated metal. The cooling unit 50 includes a cooling medium circulation system 60 that circulates the cooling medium and collects heat energy. In this embodiment, lithium (liquid metal) evaporates and takes away large latent heat when hit with a high heat flux, and the metal vapor condenses in the cooling unit 50 to lower the vapor pressure of the evaporation chamber 10. The heat of condensation of the metal vapor is received by the cooling medium via the cooling unit 50, and the heat energy is recovered by the cooling medium circulation system 60. Further, since the evaporation chamber 10 and the differential exhaust chamber 20 are controlled in a vacuum atmosphere, the metal vapor generated in the evaporation chamber 10 flows back to the beam chamber, which is outside, through the differential exhaust chamber 20. Can be suppressed. As a result, the high heat flux of the beam concentrated in a narrow range is not only received heat by interposing lithium, which is a liquid metal, but also highly efficient energy recovery can be performed, and the room where metal vapor is generated It is possible to prevent vacuum degradation due to metal vapor.

  (2) In the energy recovery system of this embodiment, the evaporation chamber 10 is provided with a recovery reservoir 56 (reservoir) that stores condensed liquid metal. For this reason, in this embodiment, lithium (liquid metal) condensed in the cooling unit 50 can be stored and recovered in the recovery reservoir 56.

  (3) In the energy recovery system of the present embodiment, the recovery reservoir 56 is included in the liquid metal circulation system 40 that circulates lithium (liquid metal), and is in a region where high liquid flux is applied by the liquid metal circulation system 40. The amount of lithium (liquid metal) is kept constant. For this reason, in this embodiment, the liquid metal circulation system 40 circulates the lithium (liquid metal) accumulated in the collection reservoir 56 and the amount of lithium (liquid metal) in the region where the high heat flux hits is constant. Can be kept in.

  (4) In the energy recovery system of this embodiment, the liquid metal circulation system 40 is provided with a wick 42 (leaching portion) through which circulated lithium oozes, and the lithium leached out of the wick 42 It is arranged to hit the high heat flux. For this reason, since the lithium leached from the wick 42 of the liquid metal circulation system 40 has a large surface tension, the lithium leached from the wick 42 can be supported by the wick 42. For this reason, since the wick 42 can support lithium against gravity and electromagnetic force, a high-speed flow is not necessary, and if lithium is flowed along the wick 42, no wave is generated, so that an equal thickness can be formed.

  (5) In the energy recovery system of the present embodiment, the cooling unit 50 is provided with the fins 52 (cooling area expanding member) for condensing the evaporated metal, thereby increasing the area for cooling the evaporated metal. Therefore, more metal vapor can be condensed as compared with the case where there is no cooling area expansion member.

  (6) The high heat flux beam heat receiving / energy recovery method of the present embodiment has a high heat flux in the evaporation chamber 10 whose interior is managed in a vacuum atmosphere via the differential exhaust chamber 20 whose interior is managed in a vacuum atmosphere. In the evaporation chamber 10, the high heat flux is applied to lithium which is a liquid metal to evaporate lithium. In the recovery method, the evaporated lithium is condensed in the cooling unit 50 of the cooling medium circulation system 60 provided in the evaporation chamber 10. Then, the cooling medium circulation system 60 collects the thermal energy received by the cooling medium.

  As a result, lithium as a liquid metal evaporates and takes away large latent heat when it is exposed to a high heat flux. Further, the metal vapor is condensed in the cooling unit 50 to lower the vapor pressure in the evaporation chamber 10. The heat of condensation of the metal vapor is received by the cooling medium via the cooling unit 50, and the heat energy is recovered by the cooling medium circulation system 60. Further, since the evaporation chamber 10 and the differential exhaust chamber 20 provided adjacent to the evaporation chamber 10 are managed in a vacuum atmosphere, the metal vapor generated in the evaporation chamber 10 passes through the differential exhaust chamber 20. Backflow to the beam chamber that is outside can be suppressed.

  (7) In the high heat flux beam heat receiving / energy recovery method of this embodiment, the evaporation chamber 10 is provided with a recovery reservoir 56 (reservoir) for storing lithium as condensed liquid metal. As a result, in the present embodiment, the liquid metal condensed in the cooling unit 50 can be stored and collected in the collection reservoir 56 (storage unit).

  (8) In the high heat flux beam heat receiving / energy recovery method of the present embodiment, the recovery reservoir 56 (reservoir) is included in the liquid metal circulation system 40 that circulates lithium as the liquid metal. The amount of liquid metal in the region where the high heat flux hits is kept constant. As a result, the liquid metal circulation system 40 circulates the lithium accumulated in the collection reservoir 56 (reservoir) and keeps the amount of lithium leaching out to the area where the high heat flux hits, that is, the surface of the wick 42, constant. Can be kept in.

  (9) In the high heat flux beam heat receiving / energy recovery method of the present embodiment, the liquid metal circulation system 40 is provided with a wick 42 (leaching portion) through which lithium as the circulating liquid metal oozes. The lithium leached out of the wick 42 is arranged so that the high heat flux hits it. According to the recovery method of the present embodiment, the lithium leached from the wick 42 of the liquid metal circulation system 40 has a large surface tension, so that the liquid lithium leached from the wick 42 can be supported by the wick 42. It becomes possible. Since lithium is supported by the wick 42 in this way, high-speed flow is not necessary, and if lithium is flowed along the wick 42, no wave is generated, so that an even thickness can be formed.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIG.
The second embodiment is embodied in a fusion reactor diverter countermeasure material system. As shown in FIG. 2, the diverter chamber 100 of the diverter countermeasure material system is divided into an evaporation chamber 110 and a differential exhaust chamber 120. A first slit 122 and a second slit 112 for introducing a diverter leg are formed in the differential exhaust chamber 120 and the evaporation chamber 110, respectively.

  For convenience of explanation, the fusion reactor diverter countermeasure material system shown in FIG. 2 shows a configuration in which the left half and the right half are different in the circulation system of lithium, which is a liquid metal, respectively. Then, the lithium circulation system shown by A in FIG. 2, that is, the natural circulation system is adopted. Therefore, in the second embodiment, it is to be understood that the configuration of the right half of the fusion reactor diverter countermeasure material system is substantially symmetrical with the configuration of the left half of FIG.

  In A of FIG. 2, a storage portion 114 for storing lithium Li as a liquid metal is provided in the evaporation chamber 110 of the diverter chamber 100 in the lower portion of the evaporation chamber 110. Lithium Li is used as a countermeasure material. A cooling plate as a cooling unit 150 is provided on the inner wall surface of the evaporation chamber 110, and a cooling medium circulation system pipe 154 is provided between the cooling plate and the inner wall surface. Since the cooling medium circulation system has the same configuration as the cooling medium circulation system 60 of the first embodiment, it is not shown in the present embodiment.

  The evaporation chamber 110 is provided with an exhaust port 118 provided with a baffle plate 116. The evaporation chamber 110 is managed to be in a vacuum atmosphere by exhausting the impurity gas in the chamber by a vacuum pump (not shown) connected to the exhaust port 118. Further, the baffle plate 116 prevents metal vapor from entering the vacuum pump (not shown).

  The differential exhaust chamber 120 is provided with an exhaust port 130 having a baffle plate 128. The differential exhaust chamber 120 is managed so as to be in a vacuum atmosphere by exhausting the impurity gas in the chamber by a vacuum pump (not shown) connected to the exhaust port 130. The baffle plate 128 prevents metal vapor from entering the vacuum pump (not shown).

The vapor of metal or the like leaking from the evaporation chamber 110 to the differential exhaust chamber 120 through the second slit 112 is exhausted through the exhaust port 130 to suppress the backflow of the vapor of metal or the like to the beam chamber 30. .
In the diverter countermeasure material system configured as described above, as shown in FIG. 2A, a large number of neutrons emitted from the plasma are converted into high heat fluxes along the divertor magnetic field lines and the differential of the diverter chamber 100. They are introduced into the exhaust chamber 120 and the evaporation chamber 110 through the first slit 122 and the second slit 112, respectively. A high heat flux hits the surface of lithium Li as a liquid-to-metal stored in the storage section 114, and when the lithium on the surface is heated to the boiling point or more, it becomes a metal vapor and takes a large latent heat from the high heat flux.

  The metal vapor is condensed in the cooling unit 150 to lower the vapor pressure in the evaporation chamber 110. Lithium Li, which is a condensed liquid metal, drops into the reservoir 114 and circulates naturally. On the other hand, the condensation heat of the metal vapor is received by the cooling medium via the cooling unit 150, and the thermal energy is recovered by a cooling medium circulation system (not shown). Note that the cooling medium circulation system has the same configuration as the cooling medium circulation system of the first embodiment, and thus the description thereof is omitted. In addition, since the evaporation chamber 110 and the differential exhaust chamber 120 are controlled in a vacuum atmosphere, the metal vapor generated in the evaporation chamber 110 passes through the differential exhaust chamber 120 to the plasma outside the diverter chamber 100. Backflow is suppressed.

As explained in the background art, in DT fusion, about 1/4 of the neutron output is α-heating. For example, in a power output million kW power generator, the neutron output is about 3 GW. 750 MW. In steady state, this plasma heating input is equal to the plasma loss. The plasma loss is radiation loss or particle loss, and most of the particle loss flows to the divertor leg. Assuming that a quarter of α heating comes to one diverter leg, if the main radius is 6 m, the circumference is 38 m, so 5 MW per 1 m ² is input to the surface of the diverter leg. If the thickness of the diverter leg is the width of the scrape-off layer, it is about 1 cm.

Then, the heat flux input to the diverter leg counter material surface is 500 MW / m ² , which cannot be handled by a solid counter material.
However, in the present embodiment, not only can this heat flux be withstood, but α heating that finally comes to the diverter can also be used for power generation. That is, a high-temperature heat medium (for example, helium or carbon dioxide gas) can be used, and high-efficiency power generation is possible.

  Unlike the beam of the first embodiment, the plasma flows along a bent diverter magnetic field line (see A in FIG. 2), and therefore a plasma chamber in which a metal vapor plasma leaking from the evaporation chamber 110 is formed. It is easy to reduce the amount of inflow.

As a modification of the second embodiment, as shown by B in FIG. 2, the liquid metal may be circulated by a forced circulation method.
For convenience of explanation, in the modified example, as shown in FIG. 2B, only the configuration of the right half of the fusion reactor divertor countermeasure material system is shown, but the configuration of the left half of FIG. It should be understood that half of the configuration is provided substantially symmetrically. In addition, the same or corresponding components as those described in the second embodiment are denoted by the same reference numerals and description thereof is omitted.

  In this modification, the evaporation chamber 110 is adjacent to the first reservoir 160 for storing the liquid metal and receiving the diverter leg to evaporate the stored liquid metal. A second storage unit 170 that is provided and collects the liquid metal condensed in the cooling unit 150 is provided.

  A pipeline 190 is connected between the first reservoir 160 and the second reservoir 170 so that the liquid metal is forcedly circulated by driving the circulation pump 180. And the area | region where a high heat flux strikes the liquid metal collect | recovered with the 2nd storage part 170, ie, 1st storage part, so that the liquid metal of the 1st storage part 160 may not reduce by receiving and diverting a diverter leg. The amount of liquid metal in the first reservoir 160 is kept constant by replenishing 160 with liquid metal.

The conduit 190 is provided with a heating means (not shown) for heating the liquid metal to the melting point or higher and lower than the boiling point.
A liquid metal circulation system 195 is configured by the pipe line 190, the circulation pump 180, the first storage unit 160, and the second storage unit 170.

  As described above, even if liquid metal is circulated in the fusion reactor diverter counter material system by the forced circulation method, it is not only possible to withstand high heat flux as in the second embodiment, but also finally. In addition, α heating that comes to the divertor can also be used for power generation.

In addition, the said embodiment can also be changed and comprised as follows.
In each of the above embodiments, the liquid metal is lithium. However, the liquid metal is not limited to lithium, and may be, for example, sodium metal. It only needs to be heated to be in a liquid state.

  In the first embodiment, the cooling medium is lithium lead (melting point: 235 ° C.), but helium gas, carbon dioxide gas, or nitrogen gas may be used instead of lithium lead.

1 is a schematic diagram of a high heat flux beam heat receiving and energy recovery system according to an embodiment of the present invention. Schematic of the high heat flux beam heat receiving and energy recovery system of other embodiment. Schematic of a conventional diverter.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Evaporation chamber, 20 ... Differential exhaust chamber, 22 ... 1st slit, 24 ... 2nd slit,
40 ... Liquid metal circulation system, 42 ... Wick (leaching part), 50 ... Cooling part,
52 ... Fin, 54 ... Pipe, 56 ... Recovery reservoir (reservoir), 58 ... Exhaust port,
60 ... Cooling medium circulation system,
110 ... evaporation chamber, 112 ... second slit, 120 ... differential exhaust chamber,
122 ... 1st slit, 150 ... Cooling part,
154 ... Pipe line of the coolant circulation system, 160 ... First reservoir,
170 ... 2nd storage part, 195 ... Liquid metal circulation system.

Claims (9)

A differential exhaust chamber in which a high heat flux is introduced and the inside is controlled in a vacuum atmosphere;
An evaporation chamber that is provided adjacent to the differential exhaust chamber and introduces the high heat flux that has passed through the differential exhaust chamber and whose interior is managed in a vacuum atmosphere;
A liquid metal that is applied to the high heat flux and receives the heat of the high heat flux to evaporate is disposed in the evaporation chamber,
The evaporation chamber is provided with a cooling unit for condensing evaporated metal,
A high heat flux beam heat receiving / energy recovery system, wherein the cooling unit includes a cooling medium circulation system in which a cooling medium circulates to recover thermal energy.   The high heat flux beam heat receiving / energy recovery system according to claim 1, wherein the evaporation chamber is provided with a reservoir for storing condensed liquid metal.   The storage part is included in a liquid metal circulation system that circulates liquid metal, and the amount of liquid metal in a region where the high heat flux hits is kept constant by the liquid metal circulation system. Item 3. The high heat flux beam heat receiving / energy recovery system according to Item 2.   The liquid metal circulation system is provided with a leaching part through which the circulating liquid metal oozes, and the liquid metal leached from the leaching part is arranged so as to hit the high heat flux. The high heat flux beam heat receiving / energy recovery system according to claim 3.   5. The high heat flux beam heat receiving and energy recovery according to claim 1, wherein the cooling unit is provided with a cooling area expanding member that condenses evaporated metal. system. A high heat flux is introduced into the evaporation chamber whose interior is controlled in a vacuum atmosphere through a differential exhaust chamber whose interior is controlled in a vacuum atmosphere, and the high heat flux is applied to the liquid metal in the evaporation chamber. Evaporating the liquid metal, condensing the liquid metal evaporated in the cooling section provided in the evaporation chamber and passing through the cooling medium by the cooling medium circulation system;
A high heat flux beam heat receiving / energy recovery method, wherein the heat energy received by the cooling medium in the cooling medium circulation system is recovered.   The high heat flux beam heat receiving / energy recovery method according to claim 6, wherein the evaporation chamber is provided with a reservoir for storing condensed liquid metal.   The storage part is included in a liquid metal circulation system that circulates liquid metal, and the amount of liquid metal in a region where the high heat flux hits is kept constant by the liquid metal circulation system. Item 8. The high heat flux beam heat receiving / energy recovery method according to Item 7.   The liquid metal circulation system is provided with a leaching part through which the circulating liquid metal oozes, and the liquid metal leached from the leaching part is arranged so that the high heat flux hits it. The high heat flux beam heat receiving / energy recovery method according to claim 8.

Images