JP5562908B2 - Steam separator and boiling water reactor equipped with the same - Google Patents

Description

  The present invention relates to a steam / water separator and a boiling water reactor equipped with the steam / water separator, and more particularly to a steam / water separator suitable for an upper part of a core for separating water and steam generated in the core. And a boiling water reactor including the same.

  In general boiling water reactors, a steam separator is installed in the upper part of the core in order to separate water and steam generated in the core. In this steam separator, swirling speed is given to the water-steam gas-liquid two-phase flow by the swirler (swirl blade), and water and steam are separated by utilizing the gas-liquid density difference by centrifugal force.

  The separated water is drained from below the steam separator, returns to the downcomer, and is sent to the core again by the recirculation pump. On the other hand, the separated steam is sent to a turbine after moisture is further removed through a steam dryer. That is, power generation efficiency is improved by removing moisture from the steam generated in the core as much as possible.

  By the way, in order to improve the electric output while suppressing the enlargement of the boiling water reactor, it is effective to increase the steam generation amount by increasing the quality of the core. When the quality of the two-phase flow flowing into the steam separator changes, the steam separation performance also changes. In general, when the quality is increased and the steam flow rate is increased, the swirling speed given to the two-phase flow by the swirler is increased, the centrifugal force is increased, and the steam-water separation performance is improved.

  In the three-stage steam / water separator used in the improved boiling water reactor, the first and second steam-separated water is almost completely mixed with the second and third steam / water separator outer cylinders. Separated water and steam are discharged from the discharge port provided in. When the steam flow rate increases, the steam velocity discharged from the second and third stage outlets increases, and the separated water can be entrained as droplets and directly flowed into the steam dryer with the droplets. There is sex.

  Moreover, the droplet discharged without being separated from the outlet of the steam separator and the droplet accompanying the steam are separated by a steam dryer. The amount of droplets flowing into these steam dryers is defined as a weight ratio (carry over) with steam, and a limit value is provided for carry over according to the specifications of the steam dryer.

  It is described in Patent Document 1 that a droplet capturing ring that covers between the steam-water separators is installed as a means for removing droplets accompanying the vapor discharged from the second-stage and third-stage discharge ports. Has been.

Japanese Patent Laid-Open No. 8-179077

  However, in patent document 1 which employ | adopted said droplet capture ring, since it is necessary to cover between steam-water separators with a droplet capture ring, a quantity increases greatly and cost increases. In addition, when trying to capture a droplet with a small particle size entrained by the vapor rising outside the steam separator, the density of the droplet capture ring may increase and the steam ventilation resistance may increase. Concerned.

  The present invention has been made in view of the above points, and the object of the present invention is to reduce an appropriate amount of liquid entrained by steam outside the steam separator using a simple structure and increase steam ventilation resistance. It is an object of the present invention to provide a steam / water separator and a boiling water reactor equipped with the steam / water separator capable of reducing carryover under high quality conditions while suppressing the above.

In order to achieve the above object, the steam-water separator of the present invention forms a flow path in communication with a stand pipe that guides a gas-liquid two-phase flow from below to above, and an upper end face of the stand pipe, A diffuser that expands the cross-sectional area of the channel upward from the cross-sectional area of the channel on the upper end surface, a first-stage inner cylinder that communicates with the upper end surface of the diffuser to form a channel, A first-stage outer cylinder that concentrically surrounds the cylinder to form an annular flow path, and closes the inner peripheral edge of the upper end surface of the first-stage outer cylinder and has a smaller diameter than the first-stage inner cylinder A first-stage annular plate having a circular hole, and a cylindrical standing from the inner peripheral edge forming the circular hole of the first-stage annular plate downward to the second-stage inner cylinder A first-stage pick-off ring formed as a flow path, and a flow path that is installed on the first-stage annular plate A second-stage inner cylinder, a second-stage outer cylinder that concentrically surrounds the second-stage inner cylinder to form an annular second-stage discharge channel, and an upper end surface of the second-stage outer cylinder. A second-stage annular plate that closes the inner periphery and forms a circular hole having a smaller diameter than the second-stage inner cylinder; a third-stage inner cylinder that is installed on the second-stage annular plate and forms a flow path; A second-stage pick-off ring that rises in a cylindrical shape downward from an inner peripheral edge forming the circular hole of the second-stage annular plate and forms the circular hole as a flow path to the third-stage inner cylinder; A hub that passes through the axial center of the gas-liquid two-phase flow path and a plurality of swirl vanes that are attached radially about the hub, and an inner edge of the swirl vane is fixed to the hub in a radial direction. And an outer edge is fixed to the inner wall of the diffuser or the inner wall of the first stage inner cylinder in the radial direction of the swirl vane. In the steam / water separator provided with the swirler, the second-stage separated water discharge port for discharging water that has flowed into the second-stage discharge channel into the second-stage outer cylinder and the second-stage steam discharge for discharging steam. An outlet is provided, and the second-stage steam discharge port is disposed at a position higher than the second-stage separated water discharge port, and the second-stage discharge flow path along an edge of the second-stage steam discharge date A projection projecting toward the second stage, and the tip of the projection is bent in a direction that does not block the flow path of the second-stage steam discharge port, so that a groove-shaped flow path is formed between the second-stage outer cylinder. A protruding groove is formed .
In order to achieve the above object, the steam / water separator according to the present invention forms a flow path in communication with a stand pipe that guides a gas-liquid two-phase flow from the lower side to the upper side and the upper end surface of the stand vip. A diffuser that expands a channel cross-sectional area upward from a channel cross-sectional area of the upper end surface, a first-stage inner cylinder that communicates with the upper end surface of the diffuser to form a channel, and the first A first-stage outer cylinder that concentrically surrounds the inner-stage cylinder to form an annular flow path, and closes the inner peripheral edge of the upper end surface of the first-stage outer cylinder, and more than the first-stage inner cylinder A first-stage annular plate having a small-diameter circular hole, and a cylindrical shape standing downward from an inner peripheral edge of the first-stage annular plate forming the circular hole so that the circular hole is in the second stage. A first-stage pick-off ring formed as a flow path to the cylinder and a flow path installed on the first-stage annular plate The second-stage inner cylinder, a second-stage outer cylinder that concentrically surrounds the second-stage inner cylinder to form an annular second-stage discharge channel, and an upper side of the second-stage outer cylinder A second-stage annular plate that closes the inner peripheral edge of the end face and has a circular hole having a smaller diameter than the second-stage inner cylinder; and a third-stage inner cylinder that is installed on the second-stage annular plate and forms a flow path. A second-stage pick-off in which the circular hole is formed as a flow path to the third-stage inner cylinder by standing upward in a cylindrical shape from the inner peripheral edge forming the circular hole of the second-stage annular plate A ring, a third-stage outer cylinder that concentrically surrounds the third-stage inner cylinder to form an annular third-stage discharge channel, and an inner peripheral edge of the upper end surface of the third-stage outer cylinder. A third-stage annular plate that is closed and formed with a circular hole having a smaller diameter than the third-stage inner cylinder, and is directed downward from an inner peripheral edge that forms the circular hole of the third-stage annular plate. A third-stage pick-off ring that rises in a cylindrical shape to form the circular hole as a gas-water separator outlet flow path, a hub that passes through the axial center of the flow path of the gas-liquid two-phase flow, and a radial shape about the hub A plurality of swirl vanes attached to the inner edge of the swirl vane, and an inner edge of the swirl vane is fixed to the hub. In the steam / water separator having a swirler to which the water is fixed, a second-stage separation water discharge port for discharging water that has flowed into the second-stage discharge flow path into the second-stage outer cylinder and a second for discharging steam. A second stage steam outlet is provided, and the second stage steam outlet is disposed at a position higher than the second stage separated water outlet, and flows into the third stage outlet passage into the third stage outer cylinder. Third-stage separation water discharge port for discharging discharged water and third-stage steam for discharging steam An air discharge port is provided, the third stage steam discharge port is disposed at a position higher than the third stage separated water discharge port, and at the edge of the second stage steam discharge port and the third stage steam discharge port. Along the second stage discharge channel and the third stage discharge channel, respectively, and the tip of the projection is the flow of the second stage steam discharge port and the third stage steam discharge port. Whether a protruding groove that is a groove-like flow path is formed between the second-stage outer cylinder and the third-stage outer cylinder by being bent in a direction that does not block the path,
Alternatively, the second-stage outer cylinder is provided with a second-stage separated water discharge port for discharging water flowing into the second-stage discharge channel and a second-stage steam discharge port for discharging steam, and the second-stage steam A third stage steam outlet for discharging steam to the third stage outer cylinder is provided at a position higher than the second stage separated water outlet, and a lower end of the third stage steam outlet. Is located above the second stage annular plate, and a communication hole is provided in the second stage annular plate, and the separated water flowing down from the communication hole is disposed below the second stage discharge channel. A communication pipe leading to the second stage discharge channel is provided in the second-stage discharge flow path.

  In order to achieve the above object, the boiling water reactor of the present invention includes a reactor pressure vessel, a core provided in the reactor pressure vessel and loaded with a plurality of fuel assemblies, and the core. And a steam / water separator disposed above the core in the reactor pressure vessel and separating a steam / water mixture flow generated in the reactor core into steam / water. A steam dryer located above the water separator and drying wet steam separated by the steam separator; a main steam pipe for supplying steam dried by the steam dryer to the turbine; and the nuclear reactor A downcomer formed between the pressure vessel and the shroud and through which the water separated by the steam separator circulates, and an internal pump or a jet pump disposed below the downcoma and supplying water in the downcoma to the core Boiling water reactor with Oite, the steam-water separator, characterized in that it is a steam-water separator of the above configuration.

  According to the present invention, an appropriate amount of liquid entrained by steam outside the steam / water separator is reduced using a simple structure, and carryover under high quality conditions is suppressed while suppressing increase in steam ventilation resistance. Therefore, it is possible to increase the output of the boiling water reactor at a low cost by suppressing the deterioration of the steam-water separation performance.

It is a longitudinal cross-sectional view which shows schematic structure of the boiling water reactor to which the steam-water separator of this invention is applied. It is a longitudinal cross-sectional view which shows the conventional steam separator. It is a characteristic view which shows an example of the relationship between the quality and carry over in the conventional steam separator. It is a longitudinal cross-sectional view which shows Example 1 of the steam-water separator of this invention. FIG. 3 is an enlarged cross-sectional view showing the vicinity of the second-stage discharge flow path outlet of the steam / water separator in the first embodiment. It is a front view which shows Example 1 of the steam-water separator of this invention. It is a front view which shows Example 2 of the steam-water separator of this invention. It is a figure which shows the vertical upward speed distribution of the vapor | steam in the 2nd stage steam discharge port in Example 2, and a 3rd stage separated water discharge port. It is a front view which shows Example 3 of the steam-water separator of this invention. It is a front view which shows Example 4 of the steam-water separator of this invention. It is the perspective view which permeate | transmitted the inside of the 2nd stage discharge flow path in Example 4 from the 2nd stage inner cylinder side.

  Hereinafter, a steam separator according to the present invention, particularly a steam separator applied to a boiling water reactor, will be described based on the illustrated embodiments.

  First, before describing the steam-water separator of the present embodiment, the schematic structure of a boiling water reactor to which the steam-water separator is applied will be described with reference to FIG.

  FIG. 1 shows an improved boiling water reactor (hereinafter referred to as ABWR).

  As shown in the figure, the ABWR has a reactor pressure vessel 3, a core shroud 2 is installed inside the reactor pressure vessel 3, and a core 5 loaded with a plurality of fuel assemblies (not shown). Is disposed in the core shroud 2. Also, above the core 5 in the reactor pressure vessel 3, an air / water separator 6 for separating the steam / water mixture flow generated in the core 5 into steam and water is disposed. Above 6, a steam dryer 7 for drying the wet steam separated by the steam separator 6 is disposed. Furthermore, an internal pump 10 (recirculation pump) for supplying water to the core 5 is disposed below the annular downcomer 4 formed between the reactor pressure vessel 3 and the core shroud 2. By operating this internal pump 10, the cooling water in the downcomer 4 is supplied to the core 5.

  On the other hand, in the core 5, the cooling water boils with heat generated by fission, and a two-phase flow state of steam and water is obtained. The gas-liquid two-phase flow generated in the reactor core 5 flows into the steam-water separator 6, and a swirl speed is given by the swirler in the steam-water separator 6, and centrifugal force acts on the two-phase flow by this swirl speed, Water and steam are separated due to the density difference between water and steam. The two-phase flow that has passed through the steam-water separator 6 flows into the steam dryer 7 where moisture is further removed.

  In this way, steam with moisture content reduced to 0.1 weight percent or less is sent to the turbine (not shown) through the main steam pipe 8 to generate electricity.

  The configuration of the steam separator 6 will be described in detail with reference to FIG.

  As shown in FIG. 2, the steam / water separator 6 includes a stand pipe 61 that guides a gas-liquid two-phase flow from below to above and a flow path that communicates with the upper end face of the stand pipe 61, and the upper end face A diffuser 62 that expands the cross-sectional area of the flow path upward from the cross-sectional area of the first flow pipe, a first-stage inner cylinder 64 that communicates with the upper end surface of the diffuser 62 and forms a flow path, Are closed concentrically with a space therebetween to form an annular flow path 50, and the inner peripheral edge of the upper end surface of the first stage outer cylinder 66 is closed, and moreover than the first stage inner cylinder 64. A first-stage annular plate 67 having a small-diameter circular hole, and a cylindrical hole extending downward from the inner peripheral edge forming the circular hole of the first-stage annular plate 67 to form the circular hole in the second stage A first stage pick-off ring 65 formed as a flow path to the cylinder 68 and a first stage annular plate 67 are provided. The second-stage inner cylinder 68 that forms a flow path, and the second-stage outer cylinder 70 that concentrically surrounds the second-stage inner cylinder 68 to form an annular second-stage discharge flow path 51. A second-stage annular plate 71 that closes the inner peripheral edge of the upper end surface of the second-stage outer cylinder 70 and has a circular hole with a smaller diameter than the second-stage inner cylinder 68; and the circular hole of the second-stage annular plate 71 A second-stage pick-off ring 69 that forms a circular hole as a flow path to the third-stage inner cylinder 72 by standing upright in a cylindrical shape from the inner peripheral edge forming the upper surface, and on the second-stage annular plate 71 The third-stage inner cylinder 72 that is installed in the pipe and forms a flow path, and the third-stage outer cylinder that forms the annular third-stage discharge flow path 52 by concentrically surrounding the third-stage inner cylinder 72 with a space therebetween 74 and a third stage in which a circular hole having a smaller diameter than the third stage inner cylinder 72 is formed while closing the inner peripheral edge of the upper end surface of the third stage outer cylinder 74 And a third stage in which the circular hole is formed as a gas-water separator outlet flow path by standing downward in a cylindrical shape from the inner peripheral edge forming the circular hole of the third-stage annular plate 75 A pick-off ring 73, a hub 101 passing through the axial center of the gas-liquid two-phase flow path, and a plurality of swirling blades 102 attached radially about the hub 101, the inner edge of the swirling blade 102 in the radial direction of the hub 101 And a swirler 63 whose outer edge is fixed to the inner wall of the diffuser 62 or the inner wall of the first stage inner cylinder 64 in the radial direction of the swirl vane 102.

  The swirler 63 is provided with a plurality of swirl blades 102 for imparting a swirl speed to a two-phase flow on a cylindrical structure called a hub 101, and the outer edge of the swirl blades 102 is fixed to the diffuser 62. For this reason, the swirler 63 itself does not rotate, but the fluid that has passed through the swirler 63 rotates.

  The swirl vane 102 is parallel to the vertical direction at the entrance of the swirler 63, and increases in angle with respect to the vertical direction toward the exit of the swirler 63. That is, at the entrance of the swirler 63, it is parallel to the vertical direction, but from there, the shape can be turned toward the exit of the swirler 63 while increasing the angle with respect to the vertical direction. In the swirl vane 102, the angle of the swirler outlet with respect to the vertical direction of the swirl vane 102 is referred to as a swirler outlet angle, and the larger the swirler outlet angle, the larger the swirl speed of the fluid can be given.

  The gas-liquid two-phase flow from the core 5 has a quality of about 14%, and the two-phase flow that has flowed into the stand pipe 61 forms a liquid film on the inner wall surface of the stand pipe 61, and steam flows through the center portion. It is an annular spray flow in which droplets are suspended in the vapor. When swirling speed is given to the gas-liquid two-phase flow by the swirler 63, the steam mixed in the liquid film on the wall surface moves to the steam side of the central part due to the difference in centrifugal force due to the gas-liquid density difference, and in the steam The liquid droplet floating on the surface moves to the wall surface and is taken into the liquid film. The liquid film formed on the wall surface of the first stage inner cylinder 64 passes through the first stage discharge channel 50 formed by the first stage inner cylinder 64 and the first stage outer cylinder 66 by the first stage pick-off ring 65. And discharged to the outside of the steam separator 6. The water discharged from the first-stage discharge channel 50 flows into the downcomer 4 again and is sent to the core 5 by the internal pump 10.

  On the other hand, the droplets in the vapor that have not reached the wall surface by the first stage inner cylinder 64 reach the wall surface by the second stage inner cylinder 68 or the third stage inner cylinder 72, and the second stage pick-off ring 69 or the third stage. It is discharged from the stage pick-off ring 73 through the second-stage discharge channel 51 or the third-stage discharge channel 52 to the outside of the steam / water separator 6. The liquid droplets that have not reached the inner cylinder wall surface before passing through the third stage pick-off ring 73 flow out of the steam / water separator outlet 55 together with the steam.

  Carry over is one of the performance indicators of the steam / water separator 6 and is defined as the weight ratio of the liquid contained in the fluid flowing out of the steam / water separator 6.

  When the vapor mass flow rate is Wg (kg / s) and the liquid mass flow rate is Wl (kg / s), the carry-over CO is expressed by the following equation.

CO = Wl / (Wg + Wl) × 100 (%) (1)
In the boiling water reactor, the carry-over of the steam separator 6 is limited in order to guarantee the performance of the steam dryer 7.

  Steam and separated water flow into the second-stage discharge flow path 51 and the third-stage discharge flow path 52, and are discharged from the second-stage discharge flow path outlet 103 and the third-stage discharge flow path outlet 104. When the steam flow rate is small (the quality is small), the steam flow rate outside the steam / water separator 6 is small, so the separated water discharged outside the steam / water separator 6 falls by gravity and is returned to the reactor water 5. . For this reason, most of the carry-over is a droplet that flows out from the separator outlet without being separated.

  When the steam flow rate is high (quality is high), the steam flow rate outside the steam separator 6 increases, the drag between the steam and the droplets overcomes the gravity applied to the droplets, and the droplets accompany the steam. Then, it flows into the steam dryer 7.

  FIG. 3 shows an example of the relationship between quality and carryover. As shown in the figure, it is based on this principle that carryover increases as quality increases.

  And in Example 1 of this invention, as shown in FIG. 4 thru | or 6, a 2nd stage discharge port is divided into the 2nd stage steam discharge port 93 and the 2nd stage separated water discharge port 91, respectively, and this 2nd stage discharge port is divided. The stage steam outlet 93 is disposed above the second stage separated water outlet 91. At this time, the cross-sectional area of the second-stage separated water discharge port 91 is smaller than the cross-sectional area of the second-stage steam discharge port 93.

  Further, the second stage steam discharge port 93 is provided with a projection protruding toward the second stage discharge flow path 51 along the edge of the second stage steam discharge port 93, and the tip of the projection is the second end. A second-stage projection groove 81 having a trumpet shape that is a groove-like flow path is provided between the second-stage outer cylinder 70 and the second-stage outer cylinder 70 that is bent in a direction that does not block the flow path of the stage steam discharge port 93. That is, the second-stage protruding groove 81 causes the second-stage steam exhaust when the liquid film 25 described later flows down vigorously and rolls up to the second-stage outer cylinder 70 side at the bottom of the second-stage discharge channel 51. The liquid film rolled up to the outlet 93 protrudes so as not to flow in, and the liquid film flowing down the second-stage outer cylinder 70 collides with the second-stage protrusion groove 81, and enters the second-stage protrusion groove 81. Any groove that guides the flow along the bottom of the second-stage discharge channel 51 may be used.

  Next, the operation of the first embodiment configured as described above will be described.

  The liquid droplets that have not been separated by the first stage inner cylinder 64 flow into the second stage inner cylinder 68. The liquid droplets that have reached the wall of the second stage inner cylinder 68 by centrifugal force form the liquid film 23 on the wall surface of the second stage inner cylinder 68 and are guided to the second stage discharge channel 51 by the second stage pickoff ring 69. The The induced liquid film 23 becomes the liquid film 25 flowing down the second-stage inner cylinder 68 wall side in the second-stage discharge channel 51 as it is along the second-stage inner cylinder 68 wall. Further, a part of the liquid film 23 leaves the second-stage inner cylinder 68 wall due to inertia, collides with the second-stage annular plate 71, and remains as it is in the second-stage outer cylinder 70 wall in the second-stage drain channel 51. The liquid film 26 flows down the side.

  The liquid film 25 flowing down the wall side of the second stage inner cylinder 68 reaches the bottom of the second stage drainage channel 51 as it is, and the separated water 21 is discharged from the second stage separated water discharge port 91 to the outside of the steam / water separator 6. It is discharged and returned to the reactor water 5. Even when the liquid film 25 flows down vigorously and rolls up toward the second-stage outer cylinder 70 at the bottom of the second-stage drainage flow channel 51, the second-stage projection groove 81 provided in the second-stage steam discharge port 93 Therefore, the liquid film 25 flowing down the wall side of the second stage inner cylinder 68 does not flow out directly from the second stage steam outlet 93.

  The liquid film 26 that has flowed down the second-stage outer cylinder 70 collides with the second-stage projection groove 81 provided in the second-stage steam discharge port 93, flows along the second-stage projection groove 81, and is discharged into the second stage. It reaches the bottom of the flow path 51, is discharged from the second-stage separated water discharge port 91 to the outside of the steam / water separator 6, and is returned to the reactor water 5. For this reason, the liquid film 26 that has flowed down the second-stage outer cylinder 70 does not directly flow out of the second-stage steam discharge port 93.

  Therefore, the steam and water that have flowed into the second-stage discharge channel 51 are separated and flow out from the respective discharge ports, and the second-stage steam discharge port 93 is disposed above the second-stage separated water discharge port 91. Therefore, the separated water 21 discharged from the second-stage separated water discharge port 91 does not come into contact with the steam 31 discharged from the second-stage steam discharge port 93, so that the separated water 21 flows into the flow of the steam 31. It is never captured. Even when the steam flow rate is large, the amount of droplets that are entrained in the steam and carried to the steam dryer 7 can be remarkably reduced, so that carryover can be greatly reduced even under high quality conditions.

  When the liquid flow rate is small, steam also flows out from the second stage separated water discharge port 91. The cross-sectional area of the second-stage separated water discharge port 91 is smaller than the cross-sectional area of the second-stage steam discharge port 93, and further, the flow out area of the liquid is reduced by the liquid outflow area, so It is getting bigger. For this reason, more steam flows through the second stage steam discharge port 93, and the amount of steam flowing out from the second stage separated water discharge port 91 is small.

  Therefore, even if there is steam flowing through the second-stage separated water discharge port 91, the flow rate is small, so that almost no droplets flow to the steam dryer 7 accompanying the steam.

  In the first embodiment, the third-stage discharge flow path 52 has the same structure as the second-stage discharge flow path 51 described above. That is, the third stage outlet is divided into a third stage steam outlet 94 and a third stage separated water outlet 92, and the third stage steam outlet 94 is disposed above the third stage separated water outlet 92. In the third-stage steam outlet 94 side of the third-stage steam outlet 94, along the edge of the third-stage steam outlet 94, the third tubular trumpet having the same configuration as the second-stage projection groove 81 described above. A step protrusion groove 82 is provided, and the cross-sectional area of the third-stage separated water discharge port 92 is smaller than the cross-sectional area of the third-stage steam discharge port 94.

  In this way, the third-stage discharge flow path 52 has the same mechanism as the second-stage discharge flow path 51, so that the steam 32 is discharged from the third-stage steam discharge port 94 and the separated water 22 is discharged from the third-stage separated water discharge. Each can be discharged from the outlet 92.

  In the conventional third-stage outlet 104, steam and separated water are discharged from the same third-stage outlet 104, and the separated water joins the steam 33 discharged from the second stage to the steam 32 discharged from the third stage. Therefore, since it is involved in the flow of the steam 34 having a higher flow velocity, there is a high possibility that the steam will flow to the steam dryer accompanying the steam flow.

  However, in the first embodiment described above, the separated water 22 discharged from the third-stage separated water discharge port 92 is exposed only to the steam 33 discharged from the second-stage steam discharge port 93, and therefore accompanies the steam flow. Separated water is reduced and carryover is reduced.

  As described above, according to the first embodiment, it is possible to reduce an appropriate amount of liquid entrained by steam outside the steam separator using a simple structure, while suppressing an increase in steam ventilation resistance, Since carry-over under high quality conditions can be reduced, it is possible to increase the output of the boiling water reactor at a low cost by suppressing the deterioration of the steam-water separation performance.

  Embodiment 2 of the steam / water separator of the present invention will be described with reference to FIG.

As shown in FIG. 7, the steam separator 6 according to the second embodiment has the second stage separated water so that the openings of the second stage steam outlet 93 and the second stage separated water outlet 92 do not overlap in the vertical direction. divided into two outlet 92 in the circumferential direction, in which the second stage separated water outlet 92a and 92 b arranged so as not to overlap in the vertical direction and the second-stage vapor exhaust outlet 93. Further, the second-stage separated water discharge ports are also divided into two in the circumferential direction, and second-stage separated water discharge ports 91a and 91b are arranged.

  As described above, in the configuration of the first embodiment shown in FIG. 6, the separation water 22 discharged from the third-stage separation water discharge port 92 has the flow velocity of the steam 31 discharged from the second-stage steam discharge port 93. If it is large, it may be accompanied to the steam dryer 7. On the other hand, the steam 31 discharged from the second stage steam discharge port 93 is distributed in the circumferential direction due to the shape of the discharge port when flowing upward.

  That is, as shown in FIG. 8, immediately after the second stage steam outlet 93, the right and left edges of the second stage steam outlet 93 have a speed distribution of 0 and a peak at the center. After exiting the second stage steam outlet 93, the velocity distribution is wider than the width of the second stage steam outlet 93, but also when the steam reaches the height of the third stage separated water outlets 92a, 92b. The distribution remains, and the steam flow velocity is the smallest at a position farthest from the opening of the second stage steam outlet 93 in the circumferential direction.

  Therefore, when the third-stage separated water discharge ports 92a and 92b are arranged at this position in the circumferential direction, the ratio of the separated water 22a and 22b accompanying the steam 31 discharged from the second-stage steam discharge port 93 becomes the smallest. Carryover can be further reduced.

  According to the second embodiment, the same effect as that of the first embodiment described above can be obtained, and the carryover can be further reduced, so that a further effect can be expected.

  Embodiment 3 of the steam / water separator of the present invention will be described with reference to FIG.

  As shown in FIG. 9, the steam separator 6 of the third embodiment has a second-stage discharge flow path above the second-stage steam discharge port 93 and the third-stage steam discharge port 94 in addition to the configuration of the second embodiment described above. 51 and the third-stage discharge flow path 52 side, the second-stage projection groove having a trumpet shape extending obliquely downward (downward) from the center of the second-stage steam discharge port 93 and the third-stage steam discharge port 94 toward the left and right ends. 81 and a third-stage protruding groove 82 are provided.

  Usually, of the water flowing into the second-stage outlet channel 51 and the third-stage outlet channel 52, the water flowing down the second-stage outer cylinder 70 wall and the third-stage outer cylinder 74 side is the second-stage protruding groove. 81 and the third-stage protruding groove 82, so that they are not directly discharged to the outside from the second-stage steam outlet 93 and the third-stage steam outlet 94.

  However, when the water colliding with the second stage projection groove 81 and the third stage projection groove 82 does not flow smoothly to the side of the second stage steam discharge port 93 and the third stage steam discharge port 94, the second stage projection There is a possibility that the water in the groove 81 and the third-stage protruding groove 82 overflows, gets over the protruding groove, and is discharged together with the steam from the second-stage steam outlet 93 and the third-stage steam outlet 94.

  Therefore, in Example 3, the water flowing down the second-stage discharge flow path 51 and the third-stage discharge flow path 52 is smoothly flowed to the side of the second-stage steam discharge port 93 and the third-stage steam discharge port 94. For this purpose, a second-stage projection groove 81 and a third-stage projection groove 82 are provided that extend obliquely downward from the center of the second-stage steam discharge port 93 and the third-stage steam discharge port 94 in the left and right direction.

  According to the configuration of the third embodiment, after the water flowing down the second-stage outer cylinder 70 and the third-stage outer cylinder 74 collides with the second-stage protrusion groove 81 and the third-stage protrusion groove 82, It smoothly flows alongside the second-stage projection groove 81 and the third-stage projection groove 82 to the side of the second-stage steam discharge port 93 and the third-stage steam discharge port 94, and the second-stage discharge channel 51 and the third stage. It reaches the bottom surface of the discharge channel 52 and is discharged to the outside through the second-stage separated water discharge ports 91a and 91b and the third-stage separated water discharge ports 92a and 92b.

  Therefore, in Example 3, since overflow from the second step protrusion groove 81 and the third step protrusion groove 82 is eliminated, carryover can be reliably reduced.

  Therefore, the same effect as that of the first embodiment described above can be obtained, and the carryover can be further reduced, so that a further effect can be expected.

  The upper edges of the second-stage steam discharge port 93 and the third-stage steam discharge port 94 are convex upward, and the second-stage discharge flow path 51 and the third-stage discharge flow path 52 side along the upper edges. The second step protrusion groove 81 and the third step protrusion groove 82 may be provided. Further, when the second-stage outer cylinder 70 and the third-stage outer cylinder 74 are manufactured from the circular pipe, after the second-stage steam discharge port 93 and the third-stage steam discharge port 94 are formed, the edges are formed at the second stage. Since the second-stage projection groove 81 and the third-stage projection groove 82 can be formed by bending the outlet channel 51 and the third-stage discharge channel 52, there is an effect that it is not necessary to newly attach the projection groove by welding or the like. .

  Embodiment 4 of the steam / water separator of the present invention will be described with reference to FIGS. 10 and 11.

  As shown in FIGS. 10 and 11, the steam separator 6 of the fourth embodiment has a third-stage separated water discharge port 92 in addition to the configuration of the third embodiment, and has a communication hole 98 a in the second-stage annular plate 71. 98b is provided, and communication pipes 99a and 99b extending from the communication holes 98a and 98b to the vicinity of the second-stage separated water discharge ports 91a and 91b are provided. At this time, the lower end of the third stage steam outlet 94 is disposed above the second stage annular plate 71.

  According to the configuration of the fourth embodiment, the water flowing down to the bottom in the third-stage discharge flow path 52 passes through the communication holes 99a and 98b and the communication pipes 99a and 99b, and the bottom of the second-stage discharge flow path 51. Led to. The separated water led to the bottom of the second stage discharge channel 51 by the communication pipes 99a and 99b joins with the separated water flowing into the second stage discharge channel 51 from the second stage pick-off ring 65 and is separated into the second stage. The water is discharged from the water discharge ports 91a and 91b to the outside.

  Thus, discharging the separated water flowing into the third-stage discharge flow path 52 from the second-stage separated water discharge ports 91a and 91b has the following merit.

  That is, as in the third embodiment, when the separated water 22 is discharged from the third stage separated water discharge ports 92a and 92b, the separated water 22 is exposed to the rising steam 31 discharged from the second stage steam discharge port 93. When the steam flow rate is high, there is a concern that part of the separated water 22 flows along with the steam 31 to the steam dryer 7.

  On the other hand, in Example 4, since separated water can be discharged | emitted collectively from the 2nd stage separated water discharge port 91a, 91b from which separation water is not exposed to a vapor | steam, it accompanies with a vapor | steam and is to the steam dryer 7. The separated water that flows can be greatly reduced.

  Even with such a configuration as in the fourth embodiment, it is possible to obtain the same effects as in the above-described embodiments.

  The outlets of the communication pipes 99a and 99b are preferably located at a position lower than the lower end of the second stage steam discharge port 93. That is, when the outlets of the communication pipes 99a and 99b are located higher than the lower end of the second stage steam discharge port 93, the separated water flowing out from the outlets of the communication pipes 99a and 99b is accompanied by the steam, and the second stage steam. There is a possibility that it flows out from the discharge port 93 and flows to the steam dryer as it is.

  Therefore, if the outlets of the communication pipes 99a and 99b are positioned lower than the second stage steam discharge port 93, the separated water flowing down in the communication pipes 99a and 99b may be exposed to the steam flow outside the steam separator. Since it falls to the bottom of the second stage discharge channel 51 as it is, the separated water can be reliably discharged from the second stage separated water discharge ports 91a and 91b without being exposed to the steam flow.

  2 ... core shroud, 3 ... reactor pressure vessel, 4 ... downcomer, 5 ... core, 6 ... steam separator, 7 ... steam dryer, 8 ... main steam pipe, 10 ... internal pump, 21 ... second stage Separation water discharged from the separation water discharge port, 22 ... Separation water discharged from the third-stage separation water discharge port, 23 ... Liquid film formed inside the second-stage inner cylinder, 24 ... Inside the third-stage inner cylinder , Liquid film formed on the second-stage inner cylinder discharge flow path side, 26 liquid film formed on the inner side of the second-stage outer cylinder, 27. Liquid film formed 28 ... Liquid film formed inside the third stage outer cylinder, 31 ... Steam discharged from the second stage steam outlet, 32 ... Steam discharged from the third stage steam outlet, 33 ... Steam rising outside the second stage outer cylinder, 34 ... Steam rising outside the third stage outer cylinder, 50 ... First stage discharge flow path, 51 ... Second stage discharge , 52... Third stage discharge channel, 55... Steam outlet, 61. Stand pipe, 62. Diffuser, 63. Swirler, 64 ... First stage inner cylinder, 65 ... First stage pick-off ring, 66. First stage outer cylinder, 67 ... First stage annular plate, 68 ... Second stage inner cylinder, 69 ... Second stage pick-off ring, 70 ... Second stage outer cylinder, 71 ... Second stage annular plate, 72 ... Third Step inner cylinder, 73 ... Third stage pick-off ring, 74 ... Third stage outer cylinder, 75 ... Third stage annular plate, 81 ... Second stage projection groove, 82 ... Third stage projection groove, 91, 91a, 91b ... Second stage separated water discharge port, 92, 92a, 92b ... Third stage separated water discharge port, 93 ... Second stage steam discharge port, 94 ... Third stage steam discharge port, 98a, 98b ... Communication hole, 99a, 99b ... Communication pipe, 101 ... Hub, 102 ... Swirl blade, 103 ... Second stage discharge channel outlet, 104 ... Third stage discharge channel outlet.

Claims (9)

A stand pipe that guides the gas-liquid two-phase flow from below to above, and a flow path that communicates with the upper end surface of the stand pipe to form a flow path. A diffuser that expands the area, a first stage inner cylinder that communicates with the upper end surface of the diffuser to form a flow path, and an annular flow path that surrounds the first stage inner cylinder in a concentric manner to form an annular flow path A first-stage outer cylinder, a first-stage annular plate that closes the inner peripheral edge of the upper end surface of the first-stage outer cylinder, and that has a circular hole with a smaller diameter than the first-stage inner cylinder, and the first-stage annular plate A first-stage pick-off ring that rises in a cylindrical shape downward from an inner peripheral edge forming the circular hole of the plate and forms the circular hole as a flow path to a second-stage inner cylinder; and the first stage The second stage inner cylinder that is installed on the annular plate and forms a flow path, and the second stage inner cylinder are concentrically spaced from each other. A second-stage outer cylinder that surrounds and forms an annular second-stage discharge channel, and closes the inner peripheral edge of the upper end surface of the second-stage outer cylinder and has a circular hole with a smaller diameter than the second-stage inner cylinder A second-stage annular plate, a third-stage inner cylinder that is installed on the second-stage annular plate and forms a flow path, and downward from an inner periphery that forms the circular hole of the second-stage annular plate A second-stage pick-off ring that rises in a cylindrical shape and forms the circular hole as a flow path to the third-stage inner cylinder, and a hub that passes through the axial center of the flow path of the gas-liquid two-phase flow, and A plurality of swirl vanes attached radially about a hub, and an inner edge of the swirl vane is fixed to the hub in a radial direction; In the steam-water separator provided with a swirler whose outer edge is fixed in the radial direction of
The second-stage outer cylinder is provided with a second-stage separated water discharge port for discharging water flowing into the second-stage discharge channel and a second-stage steam discharge port for discharging steam, and the second-stage steam discharge port Is provided at a position higher than the second-stage separated water discharge port , and a protrusion protruding to the second-stage discharge passage along the edge of the second-stage steam discharge date is provided, the protrusion A tip groove is bent in a direction that does not block the flow path of the second-stage steam discharge port, and a protruding groove that is a groove-shaped flow path is formed between the second-stage outer cylinder and the second-stage outer cylinder. To steam separator. A stand pipe that guides the gas-liquid two-phase flow once upward from below, and a flow path that communicates with the upper end surface of the stand vip, forming a flow path, and breaking the flow path upward from the cross-sectional area of the upper end face. A diffuser that expands the area, a first stage inner cylinder that communicates with the upper end surface of the diffuser to form a flow path, and an annular flow path that surrounds the first stage inner cylinder in a concentric manner to form an annular flow path A first-stage outer cylinder, a first-stage annular plate that closes the inner peripheral edge of the upper end surface of the first-stage outer cylinder, and that has a circular hole with a smaller diameter than the first-stage inner cylinder, and the first-stage annular plate A first-stage pick-off ring that rises in a cylindrical shape downward from an inner peripheral edge forming the circular hole of the plate and forms the circular hole as a flow path to a second-stage inner cylinder; and the first stage The second stage inner cylinder that is installed on the annular plate and forms a flow path, and the second stage inner cylinder are concentrically spaced from each other. A second-stage outer cylinder that surrounds and forms an annular second-stage discharge channel, and closes the inner peripheral edge of the upper end surface of the second-stage outer cylinder and has a circular hole with a smaller diameter than the second-stage inner cylinder A second-stage annular plate, a third-stage inner cylinder that is installed on the second-stage annular plate and forms a flow path, and downward from an inner periphery that forms the circular hole of the second-stage annular plate A second-stage pick-off ring that rises in a cylindrical shape and forms the circular hole as a flow path to the third-stage inner cylinder, and an annular first ring surrounding the third-stage inner cylinder at a concentric interval. A third-stage outer cylinder that forms a three-stage discharge channel, and a third-stage annular cylinder that closes the inner peripheral edge of the upper end surface of the third-stage outer cylinder and that has a smaller diameter circular hole than the third-stage inner cylinder Plate, and the circular hole is erected in a cylindrical shape downward from the inner peripheral edge forming the circular hole of the third-stage annular plate, and the circular water hole is connected to the steam / water separator outlet flow path. A third stage pick-off ring, a hub passing through the axial center of the gas-liquid two-phase flow path, and a plurality of swirl vanes attached radially about the hub, the radially inner edge of the swirl vanes In the steam-water separator provided with a swirler, the outer edge of which is fixed to the inner wall of the diffuser or the inner wall of the first stage inner cylinder in the radial direction of the swirl vane.
The second-stage outer cylinder is provided with a second-stage separated water discharge port for discharging water flowing into the second-stage discharge channel and a second-stage steam discharge port for discharging steam, and the second-stage steam discharge port Is disposed at a position higher than the second-stage separated water discharge port, and a third-stage separated water discharge port and a steam for discharging water that has flowed into the third-stage discharge channel into the third-stage outer cylinder. setting a third stage steam discharge port for discharging only the third-stage steam outlet is located at a position higher than the third stage separated water outlet, moreover, the second stage vapor exhaust outlet and the third stage Protrusions that protrude to the second-stage discharge channel and the third-stage discharge channel are provided along edges of the steam discharge ports, respectively, and the tips of the projections are provided at the second-stage steam discharge port and the third-stage discharge channel. A groove-like flow between the second-stage outer cylinder and the third-stage outer cylinder is bent in a direction that does not block the flow path of the stage steam discharge port. Steam separator, wherein a projection grooves are formed at. The steam separator according to claim 2 ,
The third-stage separated water discharge port is divided into a circumferential direction so as not to overlap the opening of the second-stage steam discharge port in the vertical direction. The steam-water separator according to claim 2 or 3 ,
The protrusion groove along the upper edge of the second-stage steam outlet and the third-stage steam outlet is inclined diagonally from the center of the second-stage steam outlet and the third-stage steam outlet to both ends. A steam-water separator, wherein the steam-water separator is disposed with an inclination extending downward. A stand pipe that guides the gas-liquid two-phase flow from below to above and a flow path that communicates with the upper end face of the stand pipe to form a flow path, and the flow path breaks upward from the flow path cross-sectional area of the upper end face. A diffuser that expands the area, a first stage inner cylinder that communicates with the upper end surface of the diffuser to form a flow path, and an annular flow path that surrounds the first stage inner cylinder in a concentric manner to form an annular flow path A first-stage outer cylinder, a first-stage annular plate that closes the inner peripheral edge of the upper end surface of the first-stage outer cylinder, and that has a circular hole with a smaller diameter than the first-stage inner cylinder, and the first-stage annular plate A first-stage pick-off ring that rises in a cylindrical shape downward from an inner peripheral edge forming the circular hole of the plate and forms the circular hole as a flow path to a second-stage inner cylinder; and the first stage The second stage inner cylinder that is installed on the annular plate and forms a flow path, and the second stage inner cylinder are concentrically spaced from each other. A second-stage outer cylinder that surrounds and forms an annular second-stage discharge channel, and closes the inner peripheral edge of the upper end surface of the second-stage outer cylinder and has a circular hole with a smaller diameter than the second-stage inner cylinder A second-stage annular plate, a third-stage inner cylinder that is installed on the second-stage annular plate and forms a flow path, and downward from an inner periphery that forms the circular hole of the second-stage annular plate A second-stage pick-off ring that rises in a cylindrical shape and forms the circular hole as a flow path to the third-stage inner cylinder, and an annular first ring surrounding the third-stage inner cylinder at a concentric interval. A third-stage outer cylinder that forms a three-stage discharge channel, and a third-stage annular cylinder that closes the inner peripheral edge of the upper end surface of the third-stage outer cylinder and that has a smaller diameter circular hole than the third-stage inner cylinder Plate, and the circular hole is erected in a cylindrical shape downward from the inner peripheral edge forming the circular hole of the third-stage annular plate, and the circular water hole is connected to the steam / water separator outlet flow path. A third stage pick-off ring, a hub passing through the axial center of the gas-liquid two-phase flow path, and a plurality of swirl vanes attached radially about the hub, the radially inner edge of the swirl vanes In the steam-water separator provided with a swirler, the outer edge of which is fixed to the inner wall of the diffuser or the inner wall of the first stage inner cylinder in the radial direction of the swirl vane.
The second-stage outer cylinder is provided with a second-stage separated water discharge port for discharging water flowing into the second-stage discharge channel and a second-stage steam discharge port for discharging steam, and the second-stage steam discharge port Is disposed at a position higher than the second-stage separated water discharge port, and a third-stage steam discharge port for discharging steam is provided in the third-stage outer cylinder, and the lower end of the third-stage steam discharge port is The second stage annular plate is located above the second stage annular plate, and a communication hole is provided in the second stage annular plate, and the separated water flowing down from the communication hole is guided below the second stage discharge channel. An air / water separator, wherein a communication pipe is provided in the second-stage discharge flow path. The steam separator according to claim 5 ,
The steam-water separator, wherein a lower end of the communication pipe is disposed below a lower end of the second stage steam discharge date. The steam-water separator according to claim 5 or 6 ,
Protrusions projecting into the second-stage discharge channel and the third-stage discharge channel are provided along edges of the second-stage steam discharge port and the third-stage steam discharge port, respectively, and tips of the projections Is a groove-like flow path between the second stage outer cylinder and the third stage outer cylinder that is bent in a direction that does not block the flow paths of the second stage steam discharge port and the third stage steam discharge port. An air / water separator, characterized in that a protruding groove is formed. The steam-water separator according to any one of claims 5 to 7 ,
The protrusion groove along the upper edge of the second-stage steam outlet and the third-stage steam outlet is inclined diagonally from the center of the second-stage steam outlet and the third-stage steam outlet to both ends. A steam-water separator, wherein the steam-water separator is disposed with an inclination extending downward. A reactor pressure vessel, a core provided in the reactor pressure vessel and loaded with a plurality of fuel assemblies, a shroud in which the core is disposed, and disposed above the core in the reactor pressure vessel A steam / water separator for separating the steam / water mixture flow generated in the core into steam and water, and a wet steam located above the steam / water separator and separated by the steam / water separator A steam dryer for drying the steam, a main steam pipe for supplying steam dried by the steam dryer to the turbine, water formed between the reactor pressure vessel and the shroud, and separated by the steam separator. In a boiling water nuclear reactor comprising a circulating downcomer and an internal pump or a jet pump disposed below the downcoma and supplying water in the downcoma to the core,
The steam-water separator, a boiling water reactor, which is a steam-water separator according to any one of claims 2 to 8.

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