JP2002143619A - Steam separator group, steam generator, and steam separating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the efficiency of steam separation. SOLUTION: Plural entrained streams 7 are formed respectively in plural cylinders 11, vapor stream contents in the entrained streams 7 are introduced respectively to plural orifices 12 which are disposed on the downstream side of the entrained streams 7 and water stream contents in the entrained streams 7 are introduced respectively to plural annular gaps 15 which are formed between the plural cylinders 11 and the plural orifices 12. The ratio of the quantity of vapor stream contents to the quantity of water stream contents corresponds to the width and narrowness of cross-sectional area of the annular gaps 15. One cross-sectional area corresponding to a larger value of the ratio of the quantity of the water stream contents to the quantity of the vapor stream contents is wider than another cross-sectional area corresponding to a smaller value of the ratio of the quantity of the water stream contents to the quantity of the vapor stream contents. In a cold leg region 4, the cross-sectional area is wider and, in a hot leg region 3, the cross-sectional area is narrower. In accordance with the quantity of liquid contents, the liquid contents are properly guided to the annular gap 15, the inflow of liquid contents to the orifice is properly suppressed and the excessive inflow of vapor stream to the annular gap is properly suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam / water separator group and a steam / water separation method, and more particularly, to an improved steam / water separation efficiency of a steam / water separator of equipment using steam, such as a turbine generator. The present invention relates to a steam-water separator group and a steam-water separation method.

[0002]

2. Description of the Related Art A steam generator, which constitutes a power generation facility for generating power using steam, such as a turbine generator, includes a steam separator for preventing erosion and preventing a reduction in energy transfer efficiency. FIG. 4 shows a steam generator used in a nuclear power plant.
1, a steam-water separator group 111, and a moisture separator group 112. The U-shaped tube group 101 is arranged over a cold leg region 101A and a hot leg region 101B. FIG. 5 shows a set of a large number of steam-water separator elements 102 arranged in an upper region of the arrangement region of the U-tube group 101, which is an aggregate of a large number of U-tubes. U-tube group 101
High-temperature pressurized water generated in a steam generator, such as the reactor core of a nuclear reactor or a combustion furnace for thermal power generation, flows into one of the pipe ends,
It flows out from the other end of each tube. The water 103 which is secondarily introduced into the arrangement region of the U-shaped tube group 101 is heated and evaporated on the outer surface of the U-shaped tube group 101 as shown in FIGS.
Part of the water is stirred by the steam that evaporates intensely as described above and accompanies the steam to form water droplets having various particle diameters, and together with the steam, the water-water separator element 102 of the steam-water separator group 111 has two droplets.
It flows in as a phase flow. It is important to separate the liquid portion from such a two-phase stream and send the steam to the turbine section. FIG.
As shown in (1), the primary cooling water (heat exchange medium) is introduced from a lower portion 113 of the hot leg region 101b, turned around at an upper U-shaped portion, and drawn out from a lower portion 114 of the cold leg region 101A. The steam 114 from which moisture has been removed by the steam-water separator group 111 is supplied to the top 1 of the steam generator.
15 The secondary cooling medium 116 is located between the U-shaped tubes and exchanges heat with the primary cooling medium.

The high-temperature pressurized water passing through the tubes of the U-shaped tube group 101 naturally has different temperatures in the first half and the second half of the U-shaped tube group, and the right half divided by the center plane S of the U-shaped tube group 101. The amount of heat applied outside the tube differs between the region and the left half region. A region where the water flow rate is small and the steam flow rate is large outside the tube is called a hot leg region, and a region where the water flow rate is large and the steam flow amount is small is called a cold leg region. In the hot leg region and the cold leg region, the ratio of water and steam in each two-phase flow is different.

[0004] Steam separator elements 102 differ in their steam separation performance in relation to the steam / water ratio. The design of the steam-water separator element 102 is such that the liquid removed by separation is steam /
It is hoped that it is appropriate for the ratio of water. In the future, high-performance steam-water separators that are required to have higher performance will be designed to be divided into a hot-leg region and a cold-leg region, and the separation performance will be individually optimized in both regions to further improve gas-liquid separation efficiency. Is desired.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a steam-water separator group and a steam-water separation method in which the gas-liquid separation efficiency is further improved. Another object of the present invention is to provide a steam-water separator group and a steam-water separation method in which the separation performance is individually optimized based on the steam / water ratio and the gas-liquid separation efficiency is further improved. Is to do.

[0006]

Means for solving the problem are described as follows. The technical items appearing in the expression are appended with numbers, symbols, and the like in parentheses (). The numbers, symbols, and the like are technical items that constitute at least one embodiment or a plurality of the embodiments of the present invention, in particular, the embodiments or the examples. Corresponds to the reference numerals, reference symbols, and the like assigned to the technical matters expressed in the drawings corresponding to the above. Such reference numbers and reference symbols clarify the correspondence and bridging between the technical matters described in the claims and the technical matters of the embodiments or examples. Such correspondence / bridge does not mean that the technical matters described in the claims are interpreted as being limited to the technical matters of the embodiments or the examples.

[0007] The steam-water separators according to the present invention include a first steam-water separator group corresponding to a cold leg region (4) having a relatively high water flow rate and a relatively low steam flow rate,
A second steam-water separator group arranged corresponding to the hot drain region (3) in which the water flow rate is comparatively low and the steam flow rate is comparatively high. The first steam / water separator group has a plurality of first steam / water separator units (8c) as elements. The first steam-water separator unit (8c) includes a tubular first riser (11),
A first orifice (12) having a first open end positioned on a first outlet side of the first riser (11); and a first riser (1).
1) and a first downcomer barrel (9) surrounding the first open end. The first liquid (16) flowing on the inner peripheral surface of the first riser (11) passes through the first downstream edge of the first riser (11), and the outer peripheral surface of the first riser (11). And the inner peripheral surface of the first downcomer barrel (9), and a first gap width (A-D) is formed between the open end of the first orifice (12) and the open end of the first riser (11). Has been given. The second steam / water separator group has a plurality of second steam / water separator units (8h) as elements. The second steam-water separator unit (8h) includes a cylindrical second riser (11) and a second orifice (1) having a second opening end positioned on the second outlet side of the second riser (11).
2), a second riser (11) and a second downcomer barrel (9) surrounding the second opening end, and a second liquid component (16) flowing on the inner peripheral surface of the second riser (11) is: Second riser (1
The second riser (11) passes through the second downstream edge of (1).
Flows between the outer peripheral surface of the second orifice and the inner peripheral surface of the second downcomer barrel (9), and the second gap width (A−) is formed between the open end of the second orifice (12) and the open end of the second riser (11). D) and at least one of the plurality of first steam separator units is provided.
One first gap width (AD) is larger than at least one second gap width (AD) of the plurality of second steam separator units. In the cold leg region (4), the ratio of the water flow to the steam flow is larger in comparison with the hot leg region. The water flow having such a large flow rate appropriately flows into the first down cam barrel (9) through the annular gap having the larger (larger) first gap width, and the water flow does not stagnate in the region of the annular gap. The amount of water entering the first orifice (12) is effectively limited to a small amount.

A first swirl vane is added to the first riser (11) for imparting a component orthogonal to the axial direction to the accompanying two-phase flow introduced in the axial direction and rotating the two-phase flow. Is preferred. Similarly, a second swirl vane for swirling the two-phase flow by giving a component orthogonal to the axial direction to the accompanying two-phase flow introduced into the second riser (11) in the axial direction is also added. First
The first liquid component (16) flowing on the inner peripheral surface of the riser (11) is opposite to the second liquid component flowing on the outer peripheral surface of the first riser (11) or the inner peripheral surface of the first downcomer barrel (9). The second liquid component flows in the direction, in particular, flows vertically downward, and flows on the inner peripheral surface of the second riser (11) and the outer peripheral surface of the second riser or the inner peripheral surface of the second downcomer barrel. The second liquid component flows in the opposite direction, and in particular, flows vertically downward. Such vertical downward flow is promoted by the steam flow properly flowing into the first and second downcomer barrels (9).

Any one of the first gap widths (A-D) of the plurality of first steam / water separator units is equal to any one of the second gap widths (AD) of the plurality of second steam / water separator units. ) Greater than. A large gap width (A-D) includes a large sectional area. Alternatively, the first gap width of the first steam / water separator unit farther from the hot leg region of the plurality of first steam / water separator units is closer to the hot leg region of the plurality of first steam / water separator units. It is larger than the first gap width of the steam separator. Further, the second gap width of the second steam / water separator unit farther from the cold leg region of the plurality of second steam / water separator units is closer to the cold leg region of the plurality of second steam / water separator units. It is smaller than the second gap width of one steam-water separator unit. Further, the first gap width of the first steam / water separator unit farther from the hot leg region of the plurality of first steam / water separator units is closer to the hot leg region of the plurality of first steam / water separator units. The second gap width of the second steam separator unit larger than the first gap width of one steam separator unit and farther from the cold leg region among the plurality of second steam separator units is a plurality of second gap separator units. It is smaller than the second gap width of the first steam / water separator unit closer to the cold leg region of the two steam / water separator units.

A first flow restricting structure for providing resistance to the flow of the first liquid flowing between the outer peripheral surface of the first riser (11) and the inner peripheral surface of the first downcomer barrel (9); and a second riser. A second liquid-phase resistance for the flow of the second liquid flowing between the outer peripheral surface of (11) and the inner peripheral surface of the second downcomer barrel (9).
A flow restriction structure is further added. The resistance of at least one first flow restriction structure of the plurality of first steam separator units is greater than the resistance of at least one second flow restriction structure of the plurality of second steam separator units. The greater the resistance, the more water will flow properly and properly suppress the steam flow in the annular space (14). The low resistance includes that no special flow limiting structure is provided.

The plurality of first gap widths (AD) of the plurality of first steam separators are equal to each other, and the plurality of second gap widths (AD) of the plurality of second steam separator units are equal to each other. It is not denied that they are equal to each other. It cannot be denied that the adjustment of the gap width is equally performed in each of the hot leg region and the cold leg region. The steam generator is assembled using the above-described set of steam-water separators.

The steam / water separation method according to the present invention provides a plurality of first cylinders (1) arranged corresponding to the cold leg area (4).
1) forming a first entrainment flow (7) generated in the cold leg region (4) in each of the first entrainment flow (7) and a steam flow of the first entrainment flow (7); Introducing the water flow of the first entrainment flow (7) between the plurality of first cylinders (11) and the plurality of first orifices (12). The plurality of first cylinder gaps (15) formed therein are respectively introduced into the plurality of second cylinders (1) arranged corresponding to the hot leg region (3).
1) forming a second entrainment stream (7) generated in the hot leg region (3) in the hot leg area (3), and transferring a steam flow of the second entrainment stream (7) downstream of the second entrainment stream (7). Introducing into the plurality of second orifices (12) arranged, the plurality of water streams of the second entrainment flow (7) formed between the second cylinder (11) and the second orifice (12), respectively. Second annular gap (15)
Introducing to. One of the cross-sectional areas of the plurality of first annular gaps (15) is larger than the largest cross-sectional area of the plurality of cross-sectional areas of the second annular gaps (15). The plurality of first annular gaps (15) have a plurality of sectional areas equal to each other and the plurality of second annular gaps (1).
It is not denied that the plurality of cross-sectional areas in 5) are equal to each other.

According to the steam / water separation method of the present invention, a plurality of entrained streams (7) are formed in a plurality of cylinders (11), respectively, and a steam flow of the entrained stream (7) is entrained. To each of the orifices (12) arranged on the downstream side of the pipe, and the water flow of the entrainment flow (7) is introduced into a plurality of cylinders (1).
1) and a plurality of orifices (12) are respectively introduced into a plurality of annular gaps (15) formed respectively, and the ratio of the amount of steam flow to the amount of water flow is: It corresponds to the width of the cross-sectional area of the annular gap (15). One cross-sectional area corresponding to a larger value of the ratio (the amount of the water stream) / (the amount of the steam stream) is (the amount of the water stream)
It is wider than one cross-sectional area corresponding to a smaller value of / (the amount of the steam flow).

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Corresponding to the drawings, in the embodiment of the steam-water separator group according to the present invention, a heat transfer tube group is provided in a steam generator vessel together with the steam-water separator group. The heat transfer tube group 1 and the steam-water separator group 2 are, as shown in FIG.
It is located in the vessel wall of a steam generator, not shown. The steam separator group 2 is disposed vertically above the heat transfer tube group 1. The heat transfer tube group 1 is a U-shaped tube aggregate composed of a large number of U-shaped tubes. In each U-tube, a medium for heat exchange before heat exchange is introduced from one end of the tube, and the medium after heat exchange is led out from the other end of the tube. The heat exchange medium circulates in a circulation path composed of a U-tube and a steam generation source such as a boiler or a core.

A secondary heat exchange medium is introduced into the arrangement area where the heat transfer tube group 1 is arranged from outside the vessel wall of the steam generator described above. Water is usually used as the secondary heat exchange medium. The secondary heat exchange medium flows almost entirely in the steam generator from a region below the region where the heat transfer tube group 1 is arranged to a region above the region. The secondary heat exchange medium contacts the pipe wall surface of each pipe of the heat transfer pipe group 1 and is vaporized. The vaporized vapor rises toward the steam-water separator group 2 arranged on the outlet side by its own vapor pressure. The vapor contains a liquid component in the form of droplets having variously different particle diameters, and the liquid component accompanies the vapor and rises with the vapor.

A hot leg region 3 and a cold leg region 4 are provided on both sides of a vertical center plane S which divides the arrangement region of the heat transfer tube group 1 into two.
Are located separately. Since the temperature of the heat exchange medium in the heat transfer tube group 1 on the side of the hot leg region 3 is higher than the temperature of the heat exchange medium in the heat transfer tube group 1 on the side of the cold leg region 4, the temperature of the secondary The heat exchange medium has a higher vapor fraction than the secondary heat exchange medium on the side of the cold leg area 4. The water flow rate (flow rate of liquid water) 5 is comparatively small on the side of the hot leg area 3 and large on the side of the cold leg area 4. The steam flow 6 is relatively high on the side of the hot leg region 3 and low on the side of the cold leg region 4 for comparison.

The entrained two-phase flow 7 of the gas-water mixture flows into the unit steam separator 8 of the steam separator group 2. The unit steam separator 8 includes a plurality of high-temperature unit steam separators 8h arranged in the hot leg region 3 and a plurality of low-temperature unit steam separators 8c arranged in the cold leg region 4. . As shown in FIG. 2, the unit steam separator 8 includes a downcomer barrel 9 constituting a cylindrical main body tube, a riser 11 disposed coaxially with the downcomer barrel 9 in the downcomer barrel 9, and an orifice 12. , Turning blade 13. The swirl vanes 13 are stationary vanes fixed to the inner peripheral surface of the riser 11, and apply a rotational force around the central axis of the riser 11 to the entrained two-phase flow 7 introduced from the lower end opening of the riser 11. The two-phase flow that has passed through the swirl vanes 13 rises in the riser 11 while swirling.

The height position of the lower opening edge of the orifice 12 matches or substantially matches the height position of the upper opening edge of the riser 11. In the drawing, the outer diameter of the orifice 12, particularly, the outer diameter of the orifice at the lower end opening edge is represented by D. The inner diameter of the riser 11, in particular, the inner diameter of the upper opening edge is represented by A. An annular space 14 between the downcomer barrel 9 and the riser 11 is connected to a space inside the riser 11 via an annular gap 15 between the orifice 12 or its lower opening edge and the downcomer barrel 9 or its upper opening edge. Communicating.

FIG. 1 shows the outer diameter D of each orifice of each unit steam separator 8. Low-temperature unit steam separator 8c
Orifice outside diameters Dc1 to Dc3 are different from each other or the same. In the following description, the orifice outer diameters Dc1 to Dc3 of the low temperature side unit steam separator 8c are the same,
c. The orifice outer diameters Dh1 to Dh3 of the high temperature side unit steam separator 8h are different from each other or the same. In the following description, the orifice outer diameters Dh1 to Dh3 of the high temperature side unit steam separator 8h are the same, and are represented by Dh. If the inner diameters A of the risers 11 of all the unit steam separators 8 are common, the following relationship is set. Dc <Dh However, the following relationship and the like are not denied. Dc3 <Dc2 <Dc1 <Dh3 <Dh <Dh1

The above equation is equivalent to the following equation when the inner diameter A is common. A-Dc> A-Dh Generally, the flow rate per unit time flowing through the annular gap 15 between the riser 11 and the orifice 12 per unit time is small on the side of the hot leg area 3 and is large on the side of the cold leg area 4. An outer diameter D and an inner diameter A are defined.

The entrained two-phase flow 7 enters the riser 11, is given a rotational force by the swirling blades 13, and rises while swirling. As a result, water (liquid) flows to the inner peripheral surface of the riser 11 due to centrifugal force. The water 16 which is pressed and adsorbed on the surface and thus adsorbed on the inner peripheral surface of the riser 11 rises on the inner peripheral surface by receiving accompanying force from the steam flow. Steam riser 11
Most of the liquid component 16 is distributed on the inner surface of the riser 11. The flow of the moisture 16 which is adsorbed and rises as described above forms a laminar flow or the liquid film 16. When the thickness of the upper end of the liquid film 16 is larger (wider) than the radial width of the annular gap 15, part of the liquid film does not flow into the annular space 14 but enters the inside of the orifice 12. To avoid such a case, the width of the annular gap 15 is set to be appropriately large (wide). If the thickness of the upper end of the liquid film 16 is excessively smaller than the radial width of the annular gap 15, a part of the vapor does not flow into the orifice 12 but enters the annular space 14. To avoid such a case, the width of the annular gap 15 is set appropriately small.

The liquid component 16 entering the annular space 14 is adsorbed on the inner peripheral surface of the downcomer barrel 9 and the outer peripheral surface of the riser 11 and flows downward. The liquid 16 flowing down in this way is returned to the lower region of the heat transfer tube group 1 through a circulation path (not shown).

The thickness of the liquid film 16 adsorbed on the inner peripheral surface of the riser 11 depends on the ratio between the flow rate of water flowing into the unit steam separator 8 and the flow rate of steam flowing into the unit steam separator 8. When the ratio of the water flow rate is larger than the ratio of the steam flow rate, the thickness of the liquid film 16 is larger. When the ratio of the water flow rate is smaller than the ratio of the steam flow rate, the thickness of the liquid film 16 is smaller. Therefore, the thickness of the liquid film 16 is comparatively thinner on the side of the hot leg region 3 and thicker on the side of the cold leg region 4. For comparison, the width of the annular gap 15 is thinner (narrower) on the side of the hot leg area 3 and thicker (wider) on the side of the cold leg area 4, so that the inner peripheral surface of the upper end of the liquid film 16 and the lower end of the orifice 12 are compared. Between the hot leg region 3 and the cold leg region 4 is appropriately defined, and the increase in the liquid flowing into the orifice 12 on the hot leg region 3 side is appropriately suppressed. In addition, the amount of steam flowing into the annular space 14 on the side of the cold leg region 4 is increased, so that a large amount of steam carried from the downcomer barrel 9 is appropriately suppressed. As described above, the outflow of the unseparated water from the orifice 12 and the carrier of the steam to the downcomer barrel 9 are effectively suppressed and reduced, and the steam-water separation performance is improved. Reduction of the descending water carrier can effectively maintain a smooth flow of the descending water.

FIG. 3 shows an additional embodiment of the steam-water separators according to the invention. In this embodiment, a flow rate limiting structure 21 is further added to the above-described embodiment. An annular flow restricting structure is disposed between the downcomer barrel 9 and the riser 11. The flow of the liquid flowing down in the annular space 14 is subjected to resistance by the flow restricting structure 21, and the flow of the liquid is appropriately maintained. The resistance of the flow restricting structure 21 is comparatively smaller on the side of the hot leg area 3 and higher on the side of the cold leg area 4.

Since such a resistance value differs between the side of the hot leg region 3 and the side of the cold leg region 4, the annular space 1
4 prevents the liquid from overflowing from the downcomer barrel 9 and entering the orifice 12, and further suppresses an excessively large amount of vapor (carrier vapor) accompanying the annular space 14. You.

The appropriate amount of liquid flowing into the annular space 14 with the width of the annular gap 15 properly defined is determined by the flow restricting structure 2.
1, the flow of the separated liquid is appropriately controlled, the amount of the liquid flowing into the orifice 12 is properly restricted, and the separated vapor in the annular space 14 is Thus, the amount of Carunda vapor that flows down is appropriately restricted.

[0027]

According to the steam-water separator group and the steam-water separation method according to the present invention, the gap for introducing the liquid component is properly adjusted in different regions, and the gas-liquid separation efficiency is higher. The flow restricting structure further increases the gas-liquid separation efficiency.

Further, the steam generator having such a steam-water separator group can generate and supply steam having a lower moisture content, which is effective for preventing erosion in the turbine section of the turbine generator. Becomes

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a steam-water separator group according to the present invention.

FIG. 2 is a sectional view showing a unit of the gas-liquid separator.

FIG. 3 is a sectional view showing another unit of the gas-liquid separator.

FIG. 4 is a sectional view showing an example of a steam generator generally used in a nuclear power plant.

FIG. 5 is a sectional view showing a known gas-liquid separator.

[Explanation of symbols]

 4: Cold leg area 3: Hot leg area 8c: First steam / water separator unit 8h: Second steam / water separator unit 11: First riser (second riser) 12: First orifice (second orifice) 14: Annular space 15: first annular gap (second annular gap) 16: first liquid component (second liquid component)

Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) // G21C 15/16 G21D 1/00 GDPS (72) Inventor Yasuhiko Hirao 2-1-1 Shinhama, Araimachi, Takasago-shi, Hyogo Prefecture In the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Toshiyuki Mizutani 1-1-1, Wadazakicho, Hyogo-ku, Kobe-shi, Hyogo Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Hiroshi Hirano, Hyogo-ku, Kobe-shi, Hyogo 1-1-1 Tazakicho Mitsubishi Heavy Industries, Ltd. Kobe Shipyard F-term (reference) 4D031 AC05 BA07 DA02 EA01

Claims (14)

[Claims] 1. A first arrangement corresponding to a cold leg region in which a water flow rate is comparatively high and a steam flow rate is comparatively low.
A steam-water separator group, and a second steam-water separator group arranged corresponding to a hot drain region having a relatively low water flow rate and a relatively high steam flow rate, and The group includes a plurality of first steam-water separator units as elements, the first steam-water separator unit includes a cylindrical first riser, and a first open end positioned at a first outlet side of the first riser. A first orifice, the first riser and a first downcomer barrel surrounding the first opening end, wherein a first liquid flowing on an inner peripheral surface of the first riser is a first liquid of the first riser. Via the wake-side edge, the outer peripheral surface of the first riser and the inner peripheral surface of the first downcomer barrel flow, and the open end of the first orifice and the open end of the first riser A first gap width is provided between the first and second steam / water separators, and the second steam / water separator group requires a plurality of second steam / water separator units. The second steam-water separator unit includes a cylindrical second riser, a second orifice having a second opening end positioned at a second outlet side of the second riser, the second riser and the second riser. A second downcomer barrel surrounding the open end, wherein the second liquid flowing on the inner peripheral surface of the second riser passes through the second downstream edge of the second riser, and the second riser And a second gap width is provided between the opening end of the second orifice and the opening end of the second riser. A steam-water separator group in which at least one first gap width of one steam-water separator unit is larger than at least one second gap width of a plurality of second steam-water separator units. 2. A first swirl vane for imparting a component orthogonal to the axial direction to an entrained two-layer flow introduced into the first riser in the axial direction and rotating the two-layer flow, 2. The air turbine according to claim 1, further comprising a second swirler for swirling the two-layer flow by giving a component orthogonal to the axial direction to the accompanying two-layer flow introduced into the second riser in the axial direction. 3. Water separator group. 3. A direction in which the first liquid flowing on the inner peripheral surface of the first riser is opposite to the first liquid flowing on the outer peripheral surface of the first riser or the inner peripheral surface of the first downcomer barrel. And the second liquid component flowing on the inner peripheral surface of the second riser and the second liquid component flowing on the outer peripheral surface of the second riser or the inner peripheral surface of the second downcomer barrel are in opposite directions. Claim 1 which flows
Or 2 steam-water separators. 4. An arbitrary one of a plurality of said first steam separators.
3. The steam / water separator group according to claim 1, wherein one of the first gap widths is larger than any one of the second gap widths of the plurality of second steam / water separator units. 4. 5. The first gap width of the first steam / water separator unit, which is farther from the hot leg region among the plurality of first steam / water separator units, is equal to that of the plurality of first steam / water separator units. 3. The steam / water separator group according to claim 1, wherein the first gap width of the first steam / water separator unit closer to the hot leg region is larger than the first gap width. 6. The second gap width of the second steam / water separator unit, which is farther from the cold leg region among the plurality of second steam / water separator units, is equal to that of the plurality of second steam / water separator units. 3. The steam / water separator group according to claim 1, wherein the second gap width of the first steam / water separator unit closer to the hot leg region is smaller than the second gap width. 4. 7. The first gap width of the first steam separator unit, which is farther from the hot leg region among the plurality of first steam separator units, is equal to that of the plurality of first steam separator units. The second gap separator, which is larger than the first gap width of the first steam separator unit closer to the hot leg zone, and farther to the cold leg zone of the plurality of second steam separator units. The second gap width of the unit is smaller than the second gap width of the first steam separator unit closer to the hot leg region among the plurality of second steam separator units. Steam-water separators. 8. A first flow restricting structure for providing resistance to the flow of the first liquid flowing between an outer peripheral surface of the first riser and an inner peripheral surface of the first downcomer barrel, and the second riser. Further comprising a second flow restriction structure for providing resistance to the flow of the second liquid flowing between the outer peripheral surface of the second downcomer barrel and the inner peripheral surface of the second downcomer barrel. The resistance of at least one of the first flow restricting structures is greater than the resistance of at least one of the second flow restricting structures of a plurality of second steam separator units. 1
A steam-water separator group according to the claims. 9. The plurality of first gap widths of the plurality of first steam separator units are equal to each other, and the plurality of second gap widths of the plurality of second steam separator units are equal to each other. 1
Steam-water separators. 10. A group of steam-water separators selected from claim 1 to 9, a group of inverted U-shaped tubes using cooling water from a primary system of a nuclear reactor as a heating medium, a moisture separator. And including a steam generator. 11. A first entrainment flow generated in the cold leg region is formed in each of a plurality of first cylinders arranged corresponding to the cold leg region, and a steam flow of the first entrainment flow is formed. Introducing the water flow of the first entrainment flow between the plurality of first cylinders and the plurality of first orifices, respectively; Forming a second entrainment flow generated in the hot leg region in a plurality of second cylinders arranged corresponding to the hot leg region; (2) introducing a steam flow of the entrained flow into a plurality of second orifices arranged on the downstream side of the second entrained flow; and distributing a water flow of the second entrained flow to the second cylinder and the second orifice. A plurality of second rings formed between each Wherein the cross-sectional area of one of the plurality of cross-sectional areas of the plurality of first annular gaps is greater than the largest cross-sectional area of the plurality of cross-sectional areas of the plurality of second annular gaps. Even a big water-water separation method. 12. The method according to claim 11, wherein a plurality of cross-sectional areas of the plurality of first annular gaps are equal to each other, and a plurality of cross-sectional areas of the plurality of second annular gaps are equal to each other. 13. A plurality of entrained flows are respectively formed in a plurality of cylinders, and a steam flow of the entrained flows is respectively introduced into a plurality of orifices arranged downstream of the entrained flows. Introducing the water flow of the entrainment flow into each of a plurality of annular gaps formed between the plurality of cylinders and the plurality of orifices, respectively, the amount of the steam flow and the flow of the water flow The steam-water separation method, wherein the ratio to the amount corresponds to the width of the cross-sectional area of the annular gap. 14. One cross-sectional area corresponding to a larger value of (the amount of the water stream) / (the amount of the steam stream) is (the amount of the water stream) / (the amount of the steam stream). 14. The method according to claim 13, wherein the cross section is wider than one cross-sectional area corresponding to a smaller value of.