JP2003329793A - Steam-water separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a supply water level in a steam generator from rising by minimizing the quantity of steam accompanying separated hot water flow without installing a tangential nozzle. <P>SOLUTION: A swirl vane 3 is provided with a plurality of blades 8, and the blades 8 are disposed in a state of being overlapped with each other. At least one slit-like opening 10 is formed between a downcomer barrel 4 and a deck plate 9. An intermediate deck plate 11 having an outer diameter approximately equal to a diameter of the downcomer barrel 4 is installed on a riser 1 in an outlet of a downcomer space constituted of the barrel 4 and the riser 1. <P>COPYRIGHT: (C)2004,JPO

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 for a steam generator used in a pressurized water reactor (PWR), and in particular, a separated hot water flow is accompanied without providing a tangential nozzle. The present invention relates to a steam-water separator in which the amount of steam components to be minimized can be minimized to prevent an increase in the liquid level of feed water in a steam generator.

[0002]

2. Description of the Related Art A vertical steam generator generally used in a pressurized water nuclear reactor generates saturated steam for driving a turbine as shown in a sectional view of FIG. In addition, it is equipped with a steam separator and a moisture separator.

Of these, the steam-water separator is for separating steam and hot water from a gas-liquid two-phase flow which is a mixed liquid of steam and hot water introduced from a steam generator.

3 and 4 are a partial perspective view and a partial cross-sectional view showing a structural example of a conventionally used steam separator of this type.

In FIGS. 3 and 4, a riser 1 which is located near the liquid level in the steam generator and extends upward has a swirl vane 3 therein, and steam and heat rising from below are generated. Gas-liquid two-phase flow 2 (gray arrow), which is a mixture with water
Is separated into steam and water with a swirl vane 3.

The gas-liquid two-phase flow (black solid arrow) separated by the swirl vanes 3 is relatively hot, and is pressed against the inner surface of the riser 1 to rise while swirling. Also,
The gas-liquid two-phase flow (white arrow), which is almost vapor and is separated by the swirl vane 3, rises in the central portion. A horizontal deck plate 9 is installed above the riser 1, goes up through an orifice 14 opened in the center of the riser 1, and goes to the next moisture separator.

Reference numeral 13 is a drain pipe for returning the hot water accumulated on the deck plate 9 to the lower heating and boiling area.

On the other hand, the gas-liquid two-phase flow rising along the inner surface of the riser 1 collides with the lower surface of the deck plate 9 around the orifice 14, and then, the downcomer space constituted by the downcomer barrel 4 and the riser 1 is formed. Inflow, most of the hot water therein falls by gravity in the downcomer space and returns to the heating / boiling region in the steam generator.

Since the gas-liquid two-phase flow flowing out from the outlet of the riser 1 is subjected to the swirling force, the separated hot water 5 is separated into the gas-liquid two-phase into the space formed by the downcomer barrel 4 and the riser 1. Since it is caught in the flow 6 and flows in, it flows out as a gas-liquid two-phase jet 7 from the lower outlet of the downcomer barrel 4. For this reason, the gas phase is also likely to be carried under downward.

Further, the gas-liquid two-phase flow flowing out from the outlet of the riser 1 is passed through the tangential nozzle 15 provided between the downcomer barrel 4 and the deck plate 9,
It flows out as a gas-liquid mixed flow.

Most of this gas-liquid two-phase flow is steam, and the steam flow passes through the vent guide 12 on the deck plate 9 toward the upper moisture separator.

[0012]

By the way, in the steam-water separator having the above-mentioned structure, the separation action of the swirl vane 3 and the tangential nozzle 15 causes the steam which is a gas to be hot water which is a liquid. The hot water descends in the downcomer space, but since the swirling flow is used for the separation action, the shearing force at the interface between the gas phase and the liquid phase causes the hot water to fall. Steam (gas phase)
Is caught (carry under) and returns below the liquid level in the steam generator.

For this reason, steam bubbles enter into the hot water at the upper end of the heating / boiling region in the steam generator to raise the liquid level.

When such a rise in liquid level occurs abruptly, the rising flow velocity of vapor containing droplets increases, and the vapor is blown up from the vent guide 12 to above the deck plate 9.
As a result, the air-water separation function may be deteriorated.

Further, in order to improve the air-water separation performance, the tangential nozzle 15 is provided between the downcomer barrel 4 and the deck plate 9, but the structure is complicated and processing man-hours are required.

Accordingly, an object of the present invention is to prevent the rise of the liquid level of the feed water in the steam generator by minimizing the amount of the steam component accompanied by the separated hot water flow without providing the tangential nozzle. It is to provide a steam separator capable of

[0017]

In order to achieve the above object, in the invention corresponding to claim 1, a gas-liquid two which is a mixed liquid of steam and hot water introduced into a cylindrical riser. The phase flow is separated into steam and water with a swirl vane, and the separated hot water is separated from the lower surface of the deck plate arranged above the riser and the upper end of the riser through the outer peripheral surface of the riser. The steam is discharged into the downcomer space formed annularly between the inner surface of the downcomer barrel coaxially arranged on the outer circumference of the riser and the separated riser, and the separated steam is formed on the deck plate as a steam outlet. In a steam separator that discharges to the outside through an orifice, a swirl vane has a plurality of blades, and the blades are arranged so as to overlap each other, and between the downcomer barrel and the deck plate. To pickpocket Provided at least one place bets shaped opening, the outlet of the downcomer space composed of the downcomer barrel and the riser, and installing a middle deck plate of approximately the same outer diameter as the outer diameter of the downcomer barrel to the riser.

Therefore, in the steam separator of the invention according to claim 1, the plurality of blades of the swirl vane are arranged so that the blades overlap each other, whereby the blades 8 and 8 are separated from each other. It is possible to make it difficult for the separated water to escape from the space. Also, by providing a slit-shaped opening between the downcomer barrel and the deck plate,
The effect of separating water and water can be increased, and processing becomes easy. Furthermore, by installing an intermediate deck plate with the same outer diameter as the outer diameter of the downcomer barrel on the riser at the exit of the downcomer space consisting of the downcomer barrel and the riser, a high-speed jet flows directly from the downcomer barrel to the lower part. Can be suppressed. Furthermore, since the outer diameter is the same as the outer diameter of the downcomer barrel, there is no resistance to the downward flow flowing outside the downcomer barrel.

Further, in the invention according to claim 2, in the steam-water separator of the invention according to claim 1, the distance from the swirl vane to the outlet of the riser is 1.7 times to 2 times the inner diameter of the riser. It is set to .5 times.

Therefore, in the steam separator of the invention according to claim 2, the swirl is controlled by setting the distance from the swirl vane to the outlet of the riser to 1.7 times to 2.5 times the inner diameter of the riser. When the hot water separated by the centrifugal force of the vanes flows as a liquid film on the inner wall surface of the riser, a swirling flow develops, the liquid film becomes thin, and the separated water is effectively discharged from the riser outlet. can do.

Furthermore, in the invention corresponding to claim 3, in the steam-water separator of the invention corresponding to claim 1 or 2, the opening of the riser outlet is made uneven or wavy. I have to.

Therefore, in the steam-water separator of the invention according to claim 3, by making the opening of the riser outlet a wavy opening, the hot water separated by the centrifugal force of the swirl vanes is When flowing as a liquid film on the inner wall surface of the, the separated hot water is sequentially discharged, and it is not affected by the swirling flow at the outlet of the riser, and the gas phase is not entrained. Only the separation effect can be improved.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a diagram showing a structural example of a steam separator according to the present embodiment.
1A is a vertical cross-sectional view of the same, and FIG. 1B is AA of FIG.
A vertical cross-sectional view (cross-sectional view of the swirl vane) and FIG. 1C show a schematic view of the swirl vane.

In FIG. 1, the same parts as those in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof will be omitted. Here, only different parts will be described.

In FIG. 1, the steam generator to riser 1
A gas-liquid two-phase flow 2, which is a mixed liquid of steam and hot water, introduced through the separator is separated by a swirl vane 3 into a gas phase and a liquid phase.

Here, a plurality of swirl vanes 3 (six in this example: the number of blades 8 is not limited to six,
1 and the number of blades 8 is set as necessary.
As shown in (b) and FIG. 1 (c), the trailing edge portion 16 is elongated so that the blades 8 are arranged so as to overlap each other so that the separated water does not escape from between the blades 8. ing.

At the outlet 17 of the riser 1, water flows into the downcomer space composed of the downcomer barrel 4 and the riser 1.

At this time, as described in the conventional example, steam also mixes and flows in.

Further, between the downcomer barrel 4 and the deck plate 9, the conventional tangential nozzle 15 described above is omitted, and a simple slit-shaped opening 10 is provided.

In FIG. 1, the slit-shaped opening 10 is formed.
Are provided at two locations, but are not particularly limited and may be provided at at least one location.

From this slit-shaped opening 10, the mixed flow of separated water and steam is also made to flow out.

At the lower end of the downcomer barrel 4, that is, at the outlet of the downcomer space formed by the downcomer barrel 4 and the riser 1, an intermediate deck plate 11 having an outer diameter substantially the same as the outer diameter of the downcomer barrel 4 is provided. It is installed at No. 1 and suppresses the direct flow of the high speed jet from the downcomer barrel 4 to the lower part.

On the other hand, the steam below the deck plate 9 is
Water above the deck plate 9 flows through the vent guide 12 and down through the drain pipe 13.

Next, the operation of the steam / water separator according to the present embodiment configured as described above will be described.

The description of the operation of the same parts as those in FIGS. 3 and 4 will be omitted, and only the operation of the different parts will be described here.

In FIG. 1, a steam generator is connected to a riser 1
A gas-liquid two-phase flow 2, which is a mixed liquid of steam and hot water, flowing in through is separated by a swirl vane 3 into a gas phase and a liquid phase.

As shown in FIGS. 1 (b) and 1 (c), the swirl vane 3 has six blades 8 and the blades 8 are arranged so as to overlap each other. ,
It is possible to make it difficult for the separated water to escape from between the blades 8.

At the outlet 17 of the riser 1, water flows into the downcomer space constituted by the downcomer barrel 4 and the riser 1. At this time, steam also mixes in.

Further, the mixed flow of separated water and steam also flows out from the slit-shaped opening 10 between the downcomer barrel 4 and the deck plate 9.

In this case, the larger the area of the slit-shaped opening 10, the greater the effect of separating water and water.

Further, the slit-shaped opening 10 is the simplest and easy to process in terms of processing.

On the other hand, at the lower end of the downcomer space formed by the downcomer barrel 4 and the riser 1, an intermediate deck plate 1 having an outer diameter substantially the same as the outer diameter of the downcomer barrel 4.
By installing 1 in the riser 1, it is possible to suppress the high-speed jet flow from the downcomer barrel 4 directly to the lower part.

Since the outer diameter is the same as the outer diameter of the downcomer barrel 4, there is no resistance to the downward flow flowing outside the downcomer barrel 4.

Therefore, the steam at the bottom of the deck plate 9 passes through the vent guide 12 and moves upwards.
The water above the water easily flows downward through the drain pipe 13,
A small amount of water vapor can rise up through the orifice 14.

As described above, in the steam-water separator according to the present embodiment, the amount of vapor component accompanied by the separated hot water flow is minimized without providing the tangential nozzle 15 as in the conventional case. It is possible to prevent the rise of the liquid level of the feed water in the steam generator.

(Second Embodiment) The steam-water separator according to the present embodiment is similar to the steam-water separator according to the first embodiment described above, except that the swirl vane 3 to the outlet 17 of the riser 1 are used.
The distance to is increased by 1.7 to 2.5 times the inner diameter of the riser 1.

Next, the operation of the steam / water separator according to the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 1 is omitted, and only the operation of the different parts will be described here.

A gas-liquid two-phase flow 2, which is a mixed liquid of steam and hot water, flowing from a steam generator through a riser 1,
A swirl vane 3 separates into a gas phase and a liquid phase.

In this case, the hot water separated by the centrifugal force of the swirl vanes 3 flows as a liquid film on the inner wall surface of the riser 1, but the swirl is required to sufficiently develop the swirling liquid film flow. Experiments have shown that the distance from the trailing edge 16 of the vane 3 to the outlet 17 of the riser 1 needs to be 1.7 times or more the inner diameter of the riser 1.

Further, the rear edge portion 1 of this swirl vane 3
As for the distance from 6 to the outlet 17 of the riser 1, up to 2.5 times the inner diameter of the riser 1, the swirl flow develops due to the swirl force of the swirl vanes 3, and the liquid film becomes thin, and the outlet 17 of the riser 1 The separated liquid can be effectively discharged from.

The rear edge portion 16 of the swirl vane 3
At a position where the distance from the riser 1 to the outlet 17 is 1.7 times to 2.5 times the inner diameter of the riser 1 or more, the flow velocity of the liquid film decreases due to the frictional force of the inner wall surface of the riser 1. hand,
The thickness of the liquid film becomes thicker again, so that the discharged hot water becomes worse, and the whole structure becomes large, which is not preferable in terms of cost.

As described above, in the steam separator according to the present embodiment, in addition to being able to obtain the effects of the first embodiment described above, separation is performed by the centrifugal force of the swirl vane 3. When hot water flows as a liquid film on the inner wall surface of the riser 1, a swirling flow develops, the liquid film becomes thin, and the separated water can be effectively discharged from the outlet 17 of the riser 1. Becomes

(Third Embodiment) FIG. 2 is a partial perspective view showing a structural example of the steam separator according to the present embodiment.
The same parts as those in FIGS. 1A to 1C are designated by the same reference numerals and the description thereof will be omitted. Only different parts will be described here.

That is, as shown in FIG. 2, the steam-water separator according to the present embodiment is different from the steam-water separator according to the first or second embodiment described above in that the opening of the outlet 17 of the riser 1 is , The corrugated opening 18, as shown in FIG.
Alternatively, as shown in FIG. 2B, the opening 18 is formed in a concavo-convex shape.

Next, the operation of the steam / water separator according to the present embodiment configured as described above will be described.

The description of the operation of the same parts as in FIG. 1 will be omitted, and only the operation of the different parts will be described here.

A gas-liquid two-phase flow 2, which is a mixed liquid of steam and hot water, flowing from a steam generator through a riser 1,
A swirl vane 3 separates into a gas phase and a liquid phase.

In this case, the hot water separated by the centrifugal force of the swirl vanes 3 flows as a liquid film on the inner wall surface of the riser 1 and flows out from the outlet 17 of the riser 1, but the structure of the outlet 17 of the riser 1 The uneven or wavy opening 1
By setting it as 8, the hot water will flow out earlier than the valley portion 19.

For this reason, the separated hot water is not discharged all at once but sequentially, and is not affected by the swirling flow at the outlet 17 of the riser 1, and steam is entrained. Therefore, the separation effect can be improved by this amount.

As described above, in the steam separator according to the present embodiment, in addition to the effect of the first or second embodiment described above, the centrifugal force of the swirl vane 3 can be obtained. When the hot water separated by is flowing as a liquid film on the inner wall surface of the riser 1, the separated hot water is sequentially discharged, and is not affected by the swirling flow at the outlet 17 of the riser 1. Therefore, the separation effect can be improved because the steam is not involved.

(Other Embodiments) The present invention is not limited to the above-described embodiments, and can be variously modified and implemented at the stage of implementation without departing from the scope of the invention. Is. In addition, the respective embodiments may be implemented in combination as appropriate as possible, and in that case, combined operation effects can be obtained. Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent features. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem (at least one) described in the section of the problem to be solved by the invention can be solved, and When the effect (at least one) described in the section can be obtained, a structure in which this constituent element is deleted can be extracted as an invention.

[0064]

As described above, according to the steam separator of the present invention, the swirl vane has a plurality of blades, and the blades are arranged so as to overlap each other, and the downcomer barrel and the deck are arranged. At least one slit-shaped opening is provided between the plate and the exit of the downcomer space composed of the downcomer barrel and the riser, and the intermediate deck plate with an outer diameter approximately the same as the outer diameter of the downcomer barrel is used as the riser. Since it is installed, it is possible to prevent the rise of the liquid level of the feed water in the steam generator by minimizing the amount of the steam component accompanying the separated hot water flow without providing a tangential nozzle. Become.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of a steam separator according to the present invention.

FIG. 2 is a partial perspective view showing a third embodiment of a steam separator according to the present invention.

FIG. 3 is a partial perspective view showing a configuration example of a steam separator used conventionally.

FIG. 4 is a partial cross-sectional view showing a configuration example of a conventionally used steam separator.

FIG. 5 is a cross-sectional view showing a configuration example of a vertical steam generator generally used in a pressurized water reactor.

[Explanation of symbols]

1 ... riser 2 ... Gas-liquid two-phase flow 3 ... Swirl vane 4. Downcomer barrel 5 ... Hot water 6 ... Gas-liquid two-phase flow 7 ... Gas-liquid two-phase jet 8 ... Tsubasa 9 ... Deck plate 10 ... Slit-shaped opening 11 ... Intermediate deck plate 12 ... Vent guide 13 ... Drain pipe 14 ... Orifice 15 ... tangential nozzle 16 ... rear edge 17 ... Exit of riser 1 18 ... Uneven or wavy opening 19 ... Valley.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshiyuki Mizutani             1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo             No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Kaoru Sakata             2-1-1 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Jiro Kasahara             2-1-1 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Hiro Hirano             1-1 1-1 Wadasaki-cho, Hyogo-ku, Kobe-shi, Hyogo             No. Mitsubishi Heavy Industries, Ltd.Kobe Shipyard (72) Inventor Hiroshi Arikawa             2-5-3 Marunouchi, Chiyoda-ku, Tokyo             Hishi Heavy Industries Ltd. F term (reference) 4D076 AA15 AA22 CA11 CA12 CA14                       CA16 CB03 CB06 CD27 HA13

Claims (3)

[Claims] 1. A gas-liquid two-phase flow, which is a mixed liquid of steam and hot water introduced into a tubular riser, is separated into water and water by a swirl vane, and the separated hot water is The inner circumference of the downcomer barrel coaxially arranged on the outer peripheral surface of the riser and the outer circumference of the riser through the gap provided between the lower surface of the deck plate arranged above the riser and the upper end of the riser. Air-water separation is performed by discharging the separated steam into an annular downcomer space formed between the surface and the surface, and discharging the separated steam to the outside of the vessel through an orifice formed as a steam outlet in the deck plate. In the vessel, the swirl vane has a plurality of blades, and the blades are arranged so as to overlap each other, between the downcomer barrel and the deck plate,
At least one slit-shaped opening is provided, and an intermediate deck plate having an outer diameter substantially the same as the outer diameter of the downcomer barrel is installed on the riser at the outlet of the downcomer space formed by the downcomer barrel and the riser. A steam-water separator characterized in that 2. The steam separator according to claim 1, wherein the distance from the swirl vane to the outlet of the riser is 1.7 to 2.5 times the inner diameter of the riser. A steam-water separator characterized in that. 3. The steam separator according to claim 1 or 2, wherein the opening at the outlet of the riser is an uneven or wavy opening. vessel.