JP2012037319A - Steam separator, steam separation method and nuclear reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam separator which has a simple structure and a high steam separation performance.SOLUTION: The present invention relates to a steam separator for separating water in steam generated by heat of a core of a nuclear reactor, including: a first channel 7a in which steam flows in and rises; a second channel 2a which is communicated with the first channel 7a and in which steam passing through the first channel 7a falls; and a third channel 1a which is communicated with the second channel 2a and in which steam passing through the second channel 2a rises. The first channel 7a, the second channel 2a and the third channel 1a are formed sequentially from an outer circumferential side to an inner circumferential side.

Description

  The present invention relates to a steam / water separator, a steam / water separation method, and a nuclear reactor that separates water and steam from a two-phase flow of water and steam.

  In boiling water reactors, steam is generated in the reactor by heat generated in the core of the reactor, and a turbine and a generator are driven to rotate by the steam. On the other hand, a pressurized water reactor is divided into a primary cooling system and a secondary cooling system. In the primary cooling system, high-temperature water is created by the heat generated in the reactor core, and this high-temperature water is sent to the heat exchanger in the steam generator. In this heat exchanger, water in the secondary cooling system boils and becomes steam, and the steam and the generator are driven to rotate by the steam.

  Since the steam sent to the turbine in this way needs to remove moisture, water is removed from the two-phase flow of steam and water generated in the nuclear reactor or steam generator. Therefore, a general nuclear reactor is provided with a plurality of steam separators and dryers.

  FIG. 19 is a vertical sectional view showing the structure of a general boiling water reactor and the flow of water and steam. In FIG. 19 and FIG. 20, the solid arrow indicates the water flow, and the broken arrow indicates the steam flow.

  As shown in FIG. 19, the reactor pressure vessel 15 has a reactor core 16 that houses a large number of fuel assemblies slightly below the center. The upper end opening of the shroud constituting the core 16 is closed by a shroud head 24. The shroud head 24 is provided with a plurality of stand pipes 17 for the steam separator 21. A dryer 22 is disposed above the steam / water separator 21.

  Next, the flow of water and the flow of steam will be described.

  As shown in FIG. 19, the water introduced from the water supply pipe 20 into the reactor pressure vessel 15 is introduced into the reactor core 16 from the lower part of the shroud. Water is boiled by the thermal energy of the core 16, and a two-phase flow of water and steam is generated in the stand pipe 17.

  The steam / water separator 21 includes the stand pipe 17, the swirler 18, and the barrel 25, and has a structure in which water is centrifuged by the swirler 18 and the barrel 25. The centrifugally separated water is introduced below the water surface 4 and mixed with the water flowing in from the water supply pipe 20 and recirculated in the reactor pressure vessel 15. On the other hand, the steam from which most of the water has been removed by the steam separator 21 is further removed from the moisture by the dryer 22 and then guided to the outside of the reactor pressure vessel 15 through the main steam pipe 19. Not sent to the turbine.

  Next, a method for removing the liquid film centrifuged by the swirler 18 will be described with reference to FIG. FIG. 20 is a vertical sectional view showing a conventional steam separator.

  As shown in FIG. 20, when the centrifugal force is received by the swirler 18, water having a large specific gravity forms a liquid film 8 on the inner surface of the barrel 25, while steam mainly flows in the center of the barrel 25. The liquid film 8 is scraped out to a drain pipe 27 formed on the outer periphery of the barrel 25 by a pick-off ring 26 disposed on the inner diameter side of the barrel 25, and descends the drain pipe 27 to the water surface around the steam / water separator 21. 4 is discharged.

  By the way, regarding the structure of the steam separator, as one of means for removing the liquid film formed on the inner surface of the barrel by centrifugal separation with swirl vanes, the technique described in Patent Document 1 has slits in the circumferential direction of the barrel. It is a technique of forming and draining around the barrel. Moreover, the technique described in Patent Document 2 is a technique for reducing carryover by adjusting the diameter of the pick-off ring from the first stage to the third stage in an air-water separator having three stages of pick-off rings. It is. As shown in these figures, the prior art has a structure for removing the liquid film rising on the inner surface of the barrel.

  In the following description, the weight ratio of droplets contained in the steam flowing out from the upper part of the steam separator is referred to as carry-over. The weight ratio of the steam contained in the water separated by the pick-off ring at each stage is called carry-under.

JP 2001-79323 A JP-A-11-326576

  In the conventional steam-water separator including each patent document as described above, the two-phase flow that has flowed into the steam-water separator forms a liquid film on the inner surface of the barrel by the centrifugal separation action by the swirling blades, and the pick-off ring or barrel The liquid film is removed by the provided holes and slits. The liquid film rises until it reaches a removal member such as a pick-off ring, and the liquid film thickness depends on the quality of the two-phase flow and the rising flow velocity. Here, the quality of the two-phase flow is the mass ratio of the vapor in the two-phase flow state. In other words, high quality means more steam and less water.

  Therefore, when there is a large variation in the quality of the two-phase flow that flows into the steam separator, there is a problem that it is difficult to optimize the pickoff ring width and shape. In addition, the liquid film that has not been removed by the pick-off ring may have a high carry-over due to a decrease in centrifugal force or the like.

  The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide a steam / water separator, a steam / water separation method, and a nuclear reactor having a simple structure and high steam / water separation performance.

  In order to achieve the above object, a steam-water separator according to the present invention is a steam-water separator that separates water in steam generated by heat of a reactor core, and the steam flows in and rises. A first channel, a second channel that communicates with the first channel, the vapor that has passed through the first channel descends, a second channel that communicates with the second channel, and the second channel A third flow path in which the vapor that has passed through the flow path rises, and the first flow path, the second flow path, and the third flow path are sequentially from the outer peripheral side to the inner peripheral side. It is formed.

  The steam-water separation method according to the present invention is a steam-water separation method for separating steam generated by the heat of the core of a nuclear reactor, and includes a first flow path and a second flow from the outer peripheral side to the inner peripheral side. A first steam rising step in which a path and a third flow path are sequentially formed, and the steam flows into the first flow path and rises; and after the first steam rising step, the first flow path is A steam lowering step in which the vapor that has passed passes down the second flow path, and a second steam rising step in which the steam that has passed through the second flow path raises the third flow path after the steam lowering step. It is characterized by having.

  Further, the nuclear reactor according to the present invention is a nuclear reactor that separates water in steam generated by the heat of the core by a steam-water separator, and the steam-water separator is a first reactor that rises when the steam flows in. The first flow path, the second flow path through which the vapor that has passed through the first flow path descends, the second flow path, and the second flow path. A third flow path in which the vapor passing through the flow path rises, and the first flow path, the second flow path, and the third flow path are sequentially formed from the outer peripheral side to the inner peripheral side It is characterized by being.

  According to the present invention, high air-water separation performance can be obtained with a simple structure.

(A) is a schematic diagram which shows 1st Embodiment of the steam-water separator which concerns on this invention, (b) is an elevational sectional view. It is a plane sectional view in the II-II line of Drawing 1 (b). It is an elevation sectional view showing a 2nd embodiment of a steam-water separator concerning the present invention. FIG. 4 is a plan sectional view taken along line IV-IV in FIG. 3. It is an elevation sectional view showing a 3rd embodiment of a steam-water separator concerning the present invention. FIG. 6 is a plan sectional view taken along line VI-VI in FIG. 5. It is an elevation sectional view showing a 4th embodiment of a steam-water separator concerning the present invention. It is a plane sectional view in the VIII-VIII line of FIG. It is an elevation sectional view showing a 5th embodiment of a steam-water separator concerning the present invention. It is a plane sectional view in the XX line of FIG. It is an elevation sectional view showing a 6th embodiment of a steam-water separator concerning the present invention. It is a plane sectional view in the XII-XII line of FIG. It is an elevation sectional view showing a 7th embodiment of a steam-water separator concerning the present invention. FIG. 14 is a cross-sectional plan view taken along line XIV-XIV in FIG. 13. It is an elevation sectional view showing an 8th embodiment of a steam-water separator concerning the present invention. It is a plane sectional view in the XVI-XVI line of FIG. It is an elevation sectional view showing a 9th embodiment of a steam-water separator concerning the present invention. It is the plane sectional view in the XVIII-XVIII line of FIG. It is a vertical section lineblock diagram showing the composition of a general boiling water reactor and the flow of water and steam. It is a sectional elevation showing a conventional steam separator.

  Below, each embodiment of the steam-water separator which concerns on this invention is described with reference to drawings.

(First embodiment)
FIG. 1A is a schematic view showing a first embodiment of a steam separator according to the present invention, and FIG. FIG. 2 is a plan sectional view taken along line II-II in FIG. In addition, the water surface and liquid film in the following embodiments will be described using the same reference numerals as those in FIGS. 19 and 20. Moreover, the steam-water separator of this embodiment is similar to the steam-water separator shown in FIG. 19 from the two-phase flow of steam and water generated by the heat of the reactor core installed in the reactor pressure vessel. It separates into water and steam. Further, in FIG. 1A, the thickness of a stand pipe 7 and an upper surface plate 5 to be described later, and a part of the configuration such as the collision plate 3 and the swirl blade 6 are omitted for simplicity.

  As shown in FIGS. 1 (a), 1 (b) and FIG. 2, the steam separator of this embodiment is configured in a triple tube structure in the radial direction. A circular tubular stand pipe 7 is disposed on the outermost periphery of the triple pipe, and the stand pipe 7 is continuously formed via the inner barrel 1 and the upper surface plate 5 which are the innermost circumference of the triple pipe. Has been. That is, the inner barrel 1 is disposed on the inner peripheral side of the stand pipe 7 away from the water surface 4. Further, a separation barrel (first barrel) 2 is disposed between the stand pipe 7 and the inner cylinder barrel (second barrel) 1. The separation barrel (first barrel) 2 is an intermediate portion of a triple pipe whose upper end extends to the vicinity of the upper surface plate 5. Has been. That is, the separation barrel 2 has an outer diameter smaller than the inner diameter of the stand pipe 7.

  Accordingly, an annular first flow path 7 a is formed between the stand pipe 7 and the separation barrel 2, and an annular second flow path 2 a is formed between the separation barrel 2 and the inner cylinder barrel 1. Yes. A folded channel 5a is formed between the first channel 7a and the second channel 2a and between the upper surface plate 5 and the upper end of the separation barrel 2. And the 3rd flow path 1a is formed in the cylindrical shape at the inner peripheral side of the inner cylinder barrel 1. FIG.

  Here, the stand pipe 7 and the separation barrel 2 are erected on the shroud head 24 (shown in FIG. 19), and the first flow path 7a formed between the stand pipe 7 and the separation barrel 2 is the shroud head. 24 is in communication with the inside.

  In the second flow path 2a between the separation barrel 2 and the inner cylinder barrel 1, four swirl vanes 6 are installed at regular intervals in the circumferential direction. In the present embodiment, the surface of the swirl blade 6 is subjected to surface processing using titanium oxide or the like to improve wettability. Between the lower end of the separation barrel 2 and the water surface 4, the collision plate 3 is fixed in the vicinity of the water surface 4 via a plurality of connection members 3 a attached at regular intervals in the circumferential direction. The collision plate 3 is formed in a circular flat plate shape, and the downward flow flowing out from the second flow path 2a collides.

  Furthermore, the steam / water separator of the present embodiment is provided with a communication pipe 28 for the inside to communicate with the surrounding water surface 4. Specifically, the communication pipe 28 shown in FIG. 2 passes through the lower portions of both the separation barrel 2 and the stand pipe 7. As a result, the region below the collision plate 3 in the separation barrel 2 is in communication with the outer periphery of the stand pipe 7, so that the water staying below the collision plate 3 is discharged to the outside through the communication pipe 28. Incidentally, the lower part of the collision plate 3 is closed by the shroud head 24. As shown in FIG. 2, at least one communication pipe 28 may be provided in the circumferential direction so that the inside of the separation barrel 2 and the outside of the stand pipe 7 are in communication with each other.

  Next, the operation of this embodiment will be described.

  As shown in FIGS. 1 and 2, the two-phase flow of steam and water generated by the heat of the reactor core 16 (shown in FIG. 19) is first an annular outermost stand pipe 7 and an intermediate separation barrel 2. Flows into the first flow path 7a formed between the two. The two-phase flow that has risen through the first flow path 7 a is turned back by the turn-back flow path 5 a at the upper end of the stand pipe 7, and then the second flow path formed between the separation barrel 2 and the inner cylinder barrel 1. Move down 2a.

  A swirl vane 6 is installed in the second flow path 2a, and a centrifugal force acts on the two-phase flow that has passed through the swirl vane 6 to form a liquid film 8 on the inner surface of the separation barrel 2. . On the other hand, the vapor descending the second flow path 2a rises in the third flow path 1a in the inner barrel 1 at the center of the steam-water separator after colliding with the collision plate 3 installed in the vicinity of the water surface 4. .

  Therefore, in this embodiment, the liquid film 8 formed on the inner peripheral surface of the separation barrel 2 is gravity-separated by dropping on the water surface 4 as it is, so that the removal for capturing the liquid film 8 as in the past is performed. No structure is required.

  Further, in the present embodiment, the water droplet 9a peeled off from the liquid film 8 by the vapor is formed into a film by colliding with the collision plate 3, so that carry-over can be reduced without accompanying the rising vapor. .

  Furthermore, in this embodiment, since the wettability of the swirl vane 6 is improved, the water droplets 9 that collide with the swirl vane 6 are easily formed into films on the surface of the swirl vane 6 and become coarse water droplets. Thus, the water droplets 9a conveyed can be further reduced.

  As described above, according to the present embodiment, the first flow path 7a in which the steam generated by the heat of the core flows in and rises communicates with the first flow path 7a and passes through the first flow path 7a. A second flow path 2a in which the vapor is lowered, and a third flow path 1a in communication with the second flow path 2a and in which the vapor that has passed through the second flow path 2a rises. Since the flow path 7a, the second flow path 2a, and the third flow path 1a are sequentially formed from the outer peripheral side to the inner peripheral side, a simple structure that does not require a removal structure for capturing the liquid film 8 is required. Thus, the robustness against the variation in the quality of the two-phase flow is high, and a good air-water separation performance can be obtained.

  Further, according to the present embodiment, the dependency on the water level of the water surface 4 is small, and it is not necessary to make the separation structure a multistage structure as in the prior art, so that the air-water separator can be made compact.

(Second Embodiment)
FIG. 3 is an elevational sectional view showing a second embodiment of the steam-water separator according to the present invention. 4 is a plan sectional view taken along line IV-IV in FIG. In addition, the same code | symbol is attached | subjected to the structure same as the said 1st Embodiment, and the overlapping description is abbreviate | omitted. The same applies to other embodiments.

  Although the collision plate 3 of the first embodiment is formed in a circular flat plate shape, in the present embodiment, the collision plate 30 is formed in a curved surface shape protruding upward as shown in FIG. Similar to the first embodiment, the collision plate 30 is fixed to the vicinity of the water surface 4 on the inner peripheral side of the separation barrel 2 via a plurality of connection members 3a. This collision plate 30 also collides with the downward flow flowing out from the second flow path 2a.

  In the present embodiment, the steam descending the second flow path 2a collides with an impact plate 30 having a curved surface shape convex upwardly installed near the water surface 4, and then the inner cylinder barrel at the center of the steam-water separator. The third flow path 1a in 1 is raised.

  Therefore, in the present embodiment, the water droplet 9 a peeled off from the liquid film 8 by the vapor is formed into a film by colliding with the collision plate 30, but the film-shaped water is water surface along the curved surface of the collision plate 30. 4 flows down. Therefore, water does not stay on the surface of the collision plate 30, and the water droplets 9a accompanying the rising steam can be further reduced.

  As described above, according to the present embodiment, the collision plate 30 installed in the vicinity of the water surface 4 is formed in a curved surface shape that is convex upward, thereby further reducing carryover. Can be achieved.

  In this embodiment, surface treatment using titanium oxide or the like is performed on the upper surface of the collision plate 30 to improve wettability, or a plurality of radial grooves are formed radially from the top to the periphery of the collision plate 30. If so, the water removal effect can be enhanced.

(Third embodiment)
FIG. 5 is an elevational sectional view showing a third embodiment of the steam-water separator according to the present invention. 6 is a cross-sectional plan view taken along line VI-VI in FIG.

  In this embodiment, instead of the collision plates of the first and second embodiments, a funnel shape is formed in the vicinity of the water surface 4 on the inner peripheral side of the separation barrel 2 as shown in FIGS. A liquid film guide plate 10 is installed. The liquid film guide plate 10 has an outer peripheral edge fixed to the inner peripheral surface of the separation barrel 2 by welding. In addition, the said funnel shape means that it is formed in the taper shape so that it may reduce diameter gradually toward the downward direction.

  In the present embodiment, the liquid film 8 descending the separation barrel 2 is guided to the water surface 4 along the liquid film guide plate 10. On the other hand, the vapor descending the second flow path 2a collides with the liquid film guide plate 10 and then moves up the third flow path 1a in the inner barrel 1 at the center of the steam-water separator.

  Therefore, in this embodiment, since the liquid film 8 formed on the inner surface of the separation barrel 2 does not flow directly into the water surface 4 but flows along the liquid film guide plate 10, it is possible to suppress entrainment of bubbles below the water surface 4. it can.

  As described above, according to the present embodiment, the liquid film guide plate 10 formed in a funnel shape is disposed in the vicinity of the water surface 4 on the inner peripheral side of the separation barrel 2, in addition to the effects of the first embodiment. Further, it is possible to reduce carry-under under the water surface 4.

  In this embodiment, as in the second embodiment, surface treatment using titanium oxide or the like is performed on the upper surface of the liquid film guide plate 10 to improve wettability, or the upper portion of the liquid film guide plate 10 is If a plurality of flow grooves are formed radially from the bottom to the bottom, the water removal effect can be enhanced.

(Fourth embodiment)
FIG. 7 is an elevational sectional view showing a fourth embodiment of the steam-water separator according to the present invention. 8 is a cross-sectional plan view taken along line VIII-VIII in FIG.

  In the present embodiment, as shown in FIGS. 7 and 8, a funnel-shaped liquid film guide plate 10 is installed in the vicinity of the water surface 4 of the separation barrel 2, and the collision plate 3 covers the opening of the liquid film guide plate 10. Is installed. The collision plate 3 is connected to the liquid film guide plate 10 via connection members 3a attached at, for example, four locations in the circumferential direction. That is, the collision plate 3 is connected to the liquid film guide plate 10 with a predetermined gap in the vertical direction.

  In this embodiment, as shown in FIGS. 7 and 8, a funnel-shaped liquid film guide plate 10 is installed in the vicinity of the water surface 4 of the separation barrel 2, and the liquid film 8 descending the separation barrel 2 is the liquid film guide plate. 10 to the water surface 4. On the other hand, the vapor descending the second flow path 2a collides with the collision plate 3 installed so as to cover the opening of the liquid film guide plate 10, and then the second in the inner barrel 1 in the center of the steam separator. 3 channel 1a is raised.

  Therefore, in this embodiment, the downward flow of the vapor directly collides with the liquid film 8 flowing along the liquid film guide plate 10, so that the water droplet 9 a is rolled up from the liquid film 8, or the vapor is generated in the liquid film 8. Inflow can be suppressed.

  Thus, according to this embodiment, the funnel-shaped liquid film guide plate 10 is installed in the vicinity of the water surface 4 of the separation barrel 2, and the collision plate 3 is installed so as to cover the opening of the liquid film guide plate 10. Thus, in addition to the effect of the first embodiment, it is possible to reduce carry-under under the water surface 4 and to suppress increase in carry-over.

(Fifth embodiment)
FIG. 9 is an elevational sectional view showing a fifth embodiment of the steam / water separator according to the present invention. 10 is a cross-sectional plan view taken along line XX in FIG.

  In this embodiment, as shown in FIGS. 9 and 10, in addition to the configuration of the first embodiment, an enlarged tube 11 formed in a funnel shape is fixed to the lower end of the inner barrel 1 by welding, for example. That is, the expansion pipe 11 is formed so that the diameter of the third flow path 1a gradually increases in the direction in which the vapor rises in the third flow path 1a.

  Therefore, in this embodiment, it is possible to prevent the steam that has passed through the second flow path 2a from directly bypassing the third flow path 1a in the inner cylinder barrel 1 without colliding with the collision plate 3. Moreover, the minute water droplet accompanying the vapor | steam which raises after colliding with the collision board 3 is made to collide with the outer peripheral surface of the expansion tube 11, and it can be made into a film | membrane, and it can become a coarse water droplet easily. The coarse water drops fall on the water surface.

  As described above, according to the present embodiment, by fixing the expansion tube 11 formed in a funnel shape at the lower end of the inner cylinder barrel 1, in addition to the effects of the first embodiment, carryover can be further reduced. Can do.

  In the present embodiment, the expansion tube 11 is formed so as to expand in a linear taper shape in FIG. 9 toward the third flow path 1a, but the expansion tube 11 is not limited to this. Even if it is formed as shown in an arc shape in FIG. 9, the same effect can be obtained.

(Sixth embodiment)
FIG. 11 is an elevational sectional view showing a sixth embodiment of the steam / water separator according to the present invention. 12 is a cross-sectional plan view taken along line XII-XII in FIG.

  In this embodiment, as shown in FIGS. 11 and 12, in addition to the configuration of the first embodiment, a collision net 12 as a porous member is provided inside the inner barrel 1 so as to cross the third flow path 1a. It is attached. The fineness of the mesh of the collision network 12 is selected as appropriate based on the relationship between the pressure loss and the size of the largest amount of minute water droplets that rise accompanying steam.

  Therefore, in the present embodiment, minute water droplets accompanying the vapor rising after colliding with the collision plate 3 can be made to collide with the collision network 12 to be coarsened. Since the water droplets coarsened in this way are easily dropped by gravity, the amount of fine water droplets conveyed upward by steam can be reduced.

  In addition, if the collision net | network 12 of this embodiment is a porous body which allows vapor | steam to pass through, the same effect will be acquired.

  As described above, according to the present embodiment, by attaching the collision net 12 to the lower end of the inner cylinder barrel 1, it is possible to further reduce carryover in addition to the effects of the first embodiment.

(Seventh embodiment)
FIG. 13 is an elevational sectional view showing a seventh embodiment of the steam / water separator according to the present invention. 14 is a cross-sectional plan view taken along line XIV-XIV in FIG.

  In the present embodiment, the swirl vanes 6 are eliminated from the second flow path 2a as shown in FIGS. That is, in the present embodiment, the inner cylinder barrel 1 is attached so as to incline in the outer peripheral direction from the upper side to the lower side so that the second flow path 2a gradually narrows from the upper side to the lower side. Yes.

  In the present embodiment, a liquid film guide plate 10 formed in a funnel shape is installed in the vicinity of the water surface 4 on the inner peripheral side of the separation barrel 2. The liquid film guide plate 10 has an outer peripheral edge fixed to the inner peripheral surface of the separation barrel 2 by welding.

  Therefore, in this embodiment, as shown in FIG. 13, the inner cylinder barrel 1 is attached so as to be inclined in the outer peripheral direction from the upper side to the lower side, and the second flow path 2a has a flow path from the upper side to the lower side. Since it is gradually narrowed, a two-phase flow flows in the outer peripheral direction and is ejected toward the inner peripheral surface of the separation barrel 2. Then, this two-phase flow collides with the inner peripheral surface of the separation barrel 2, so that water droplets 9 are easily collected on the inner peripheral surface of the separation barrel 2. The collected coarse water droplets and liquid film flow along the inner peripheral surface of the separation barrel 2.

  A funnel-shaped liquid film guide plate 10 is installed in the vicinity of the water surface 4 of the separation barrel 2. Coarse water droplets and liquid films descending the separation barrel 2 are placed on the water surface 4 along the liquid film guide plate 10. Led. On the other hand, the vapor descending the second flow path 2a collides with the liquid film guide plate 10 and then moves up the third flow path 1a in the inner barrel 1 at the center of the steam-water separator.

  In the present embodiment, the liquid film formed on the inner peripheral surface of the separation barrel 2 flows along the liquid film guide plate 10 without directly flowing into the water surface 4, thereby suppressing entrainment of bubbles below the water surface 4. Can do.

  Moreover, in this embodiment, since the inner cylinder barrel 1 is attached so as to be inclined in the outer peripheral direction from the upper side to the lower side, water droplets are not formed on the inner peripheral surface of the separation barrel 2 without installing the swirl vanes 6. Since 9 can be collected, the structure can be further simplified.

  As described above, according to the present embodiment, since the inner barrel 1 is attached so as to be inclined in the outer circumferential direction from the upper side to the lower side, in addition to the effects of the first embodiment, the structure is further simplified. Can be planned.

(Eighth embodiment)
FIG. 15 is an elevational sectional view showing an eighth embodiment of the steam-water separator according to the present invention. 16 is a cross-sectional plan view taken along line XVI-XVI in FIG.

  In this embodiment, as shown in FIGS. 15 and 16, in the first embodiment, the communication hole 1b in which the second flow path 2a and the third flow path 1a communicate with each other is constant in the circumferential direction of the inner barrel 1 Several places (four places in this embodiment) are provided at intervals, and drain pipes 13 extending vertically downward are connected to these communication holes 1b.

  Therefore, in the present embodiment, when the two-phase flow rising up the annular stand pipe 7 is turned back at the upper end of the stand pipe 7, water droplets are applied to the inner peripheral side of the return flow path 5 a by the centrifugal force, that is, to the outer peripheral surface of the inner barrel 1. 9 gather. Since many of these water droplets 9 gather on the inner diameter side of the second flow path 2 a, the water is discharged to the vicinity of the collision plate 3 through the communication hole 1 b and the drain pipe 13. That is, the drain pipe 13 guides water to the side away from the third flow path 1a.

  As described above, according to this embodiment, the communication hole 1b that connects the second flow path 2a and the third flow path 1a is formed, and the drain for guiding the water that has flowed into the communication hole 1b to the water surface 4 is formed. Since the tube 13 is installed, in addition to the effect of the first embodiment, the centrifugal separation effect in the folded flow path 5a is added, so that the amount of moisture passing through the swirl vane 6 can be reduced, and the quality is further improved. Robustness can be improved.

  In the present embodiment, four communication holes 1b are provided in the inner barrel 1 and the drain pipe 13 is connected to each of these communication holes 1b. However, the present invention is not limited thereto, and more communication holes 1b are provided. The opening of one drain pipe 13 may be formed wide and connected to a plurality of communication holes 1b. In addition, the water inlet side of each communication hole 1b may be formed wider than the outlet side.

(Ninth embodiment)
FIG. 17 is an elevational sectional view showing a ninth embodiment of the steam / water separator according to the present invention. 18 is a cross-sectional plan view taken along line XVIII-XVIII in FIG.

  In the eighth embodiment, in the eighth embodiment, a drain pocket 14 that is continuous in the circumferential direction is provided at a position in the vertical direction of the communication hole 1 b that communicates with the second flow path 2 a provided in the inner cylinder barrel 1.

  Therefore, in the present embodiment, when the two-phase flow rising up the annular stand pipe 7 is folded at the upper end of the stand pipe, the water droplets 9 are collected on the inner peripheral side of the folded flow path 5a by centrifugal force. 14 can be captured. The water captured in the drain pocket is discharged to the vicinity of the collision plate 3 through the communication hole 1b and the drain pipe 13.

  As described above, according to the present embodiment, the drain pocket 14 for collecting the water in the second flow path 2a and the water collected in the drain pocket 14 are passed through the second flow path 2a and the third flow path 1a. By providing the drain pipe 13 for guiding the water away from the third flow path 1a through the communicating hole 1b, the amount of water passing through the swirl vane 6 can be further reduced. Furthermore, the robustness with respect to quality can be improved.

  In the present embodiment, the drain pocket 14 is formed so as to extend upward in parallel with the inner cylinder barrel 1, but the present invention is not limited thereto, and the drain pocket 14 may be formed so as to expand to the outer peripheral side with respect to the inner cylinder barrel 1. By forming the drain pocket 14 in this way, it becomes possible to enhance the capturing effect of the water droplet 9.

  Furthermore, although each embodiment of this invention was described as mentioned above, these embodiment is shown as an example only and is not intending limiting the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

  For example, the drain pipe 13 may extend through the collision plate 3 and the liquid film guide plate 10 to the lower side thereof, or may be directly discharged to the outside of the stand pipe 7. The inner barrel 1, the separation barrel 2 and the stand pipe 7 have been described as being cylindrical, but are not limited to this and may be formed in a polygon or the like.

  Further, in each of the above-described embodiments, the fifth to ninth embodiments are basic configurations, and the collision plate 3 and the liquid film guide plate 10 of the first to fourth embodiments are included in each of these embodiments. An appropriate combination is also possible.

  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.

1 ... Inner barrel (second barrel)
DESCRIPTION OF SYMBOLS 1a ... 3rd flow path 1b ... Communication hole 2 ... Separation barrel (1st barrel)
2a ... second flow path 3, 30 ... impact plate 4 ... water surface 5 ... upper surface plate 6 ... swivel blade 7 ... stand pipe 7a ... first flow path 8 ... liquid film 9 ... water droplet 9a ... water droplet 10 ... liquid film guide Plate 11 ... Magnifying tube 12 ... Collision network (porous member)
DESCRIPTION OF SYMBOLS 13 ... Drain pipe 14 ... Drain pocket 15 ... Reactor pressure vessel 16 ... Core 21 ... Steam separator 28 ... Communication pipe

Claims (13)

A steam separator for separating water in steam generated by heat of a reactor core,
A first flow path through which the steam flows and rises;
A second channel that communicates with the first channel and in which the vapor that has passed through the first channel descends;
A third channel that communicates with the second channel and in which the vapor that has passed through the second channel rises;
The air-water separator, wherein the first flow path, the second flow path, and the third flow path are sequentially formed from an outer peripheral side to an inner peripheral side. A cylindrical standpipe,
A first barrel disposed on the inner peripheral side of the standpipe;
A second barrel disposed on the inner peripheral side of the first barrel,
The first flow path is formed between the stand pipe and the first barrel,
The second flow path is formed between the first barrel and the second barrel;
The third flow path is formed on the inner peripheral side of the second barrel,
2. The steam / water separator according to claim 1, further comprising an upper surface plate that connects the stand pipe and the second barrel and closes the first flow path and the second flow path. .   The steam / water separator according to claim 2, wherein a collision plate is provided below the second barrel so as to collide with the vapor descending through the second flow path.   The steam / water separator according to claim 3, wherein the collision plate is formed in a curved shape convex upward.   A guide plate for guiding a liquid film formed on the inner peripheral surface of the first barrel through the second flow path on the inner surface of the first barrel to the inner side in the radial direction of the first barrel The steam-water separator according to any one of claims 2 to 4, wherein the steam-water separator is installed.   The steam-water separator according to any one of claims 1 to 5, wherein a swirl blade is installed in the second flow path.   The expansion pipe | tube which a said 3rd flow path diameter-expands gradually is fixed to the lower end of the said 2nd barrel in the direction which the said vapor | steam raises in the said 3rd flow path. The steam separator according to any one of the above.   The steam-water separator according to any one of claims 1 to 7, further comprising a porous member provided inside the second barrel so as to cross the third flow path.   The said 2nd barrel is attached so that it may incline in the outer peripheral direction toward the downward direction from upper direction, The said 2nd flow path was narrowly formed toward the downward direction, The Claim 1 or 2 characterized by the above-mentioned. Steam separator.   A communication hole that communicates the second flow path and the third flow path, and a drain pipe that guides the water that has flowed into the communication hole to the side away from the third flow path. The steam-water separator according to any one of claims 1 to 9, characterized in that   The air-water according to claim 10, further comprising a drain pocket provided on an outer peripheral surface of the first barrel, wherein water trapped in the drain pocket flows into the communication hole. Separator. A steam separation method for separating steam generated by heat of a reactor core,
A first flow path, a second flow path, and a third flow path are sequentially formed from the outer peripheral side to the inner peripheral side,
A first steam rising step in which the steam flows into the first flow path and rises;
A steam lowering step in which the steam that has passed through the first flow path descends the second flow path after the first steam rise step;
A second steam raising step in which the steam that has passed through the second flow path raises the third flow path after the steam lowering step;
A steam-water separation method characterized by comprising: A nuclear reactor that separates water in steam generated by the heat of the core with a steam separator,
The steam separator is
A first flow path through which the steam flows and rises;
A second channel that communicates with the first channel and in which the vapor that has passed through the first channel descends;
A third channel that communicates with the second channel and in which the vapor that has passed through the second channel rises;
The nuclear reactor according to claim 1, wherein the first flow path, the second flow path, and the third flow path are sequentially formed from an outer peripheral side to an inner peripheral side.

Images