JP3483697B2 - Feed water heater for boiling water reactor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feed water heater for a boiling water reactor, and more particularly, to an application of bleed steam containing non-condensable gas generated in a reactor pressure vessel as a heating medium for feed water. The present invention relates to a feedwater heater for a boiling water reactor, which enables efficient discharge of steam condensation drain.

[0002]

2. Description of the Related Art In a boiling water reactor, steam generated in a reactor pressure vessel is sent to a steam turbine through a main steam system pipe, and steam used for work is condensed in a condenser. After that, the condensed condensate is sent by a condensate pump to a water supply system via a condensate heater, a deaerator, etc., and is circulated as a reactor water supply to the reactor pressure vessel via this water supply system.

The water supply system is provided with a water supply pump for giving a water supply power, and a low pressure water supply pump and a high pressure water supply pump which are arranged upstream and downstream of the water supply pump as a boundary.

All of these water supply pumps are tube heat exchangers, in which a large number of heating pipes are arranged in a cylinder, and turbine bleed air or other steam is circulated in the cylinder, and at the same time, in the heating pipes. The feed water is made to pass through, and the feed water is heated by heat exchange at the peripheral wall of the heating pipe. As a result, the thermal efficiency is improved by preheating the reactor water supply with steam.

37 to 40 exemplify the structure of the feed water heater of such a boiling water reactor. 37 is a cross-sectional view schematically showing the overall configuration of the feed water heater, FIG. 38 is an enlarged cross-sectional view taken along the line AA of FIG. 37, and FIG.
9 is a further enlarged view of the heating pipe portion shown in FIG. 38. Further, FIG. 40 is a perspective view showing the internal structure of the lower left half portion (water chamber portion) shown in FIG.

As shown in FIG. 37, this feed water heater 1
Is a horizontal cylinder 2 with one end open, a tube plate 3 provided at the end of the cylinder 2, and a large number of tubes arranged in the cylinder 2 with their ends supported by the tube plate 3. And a tube group 5 including a U-shaped heating tube 4. A steam inlet 6 is provided in the upper part of the cylinder 2 near the tube plate 3, and steam generated in the reactor pressure vessel is introduced from the steam inlet 6 into the cylinder 2 as extracted steam from the turbine and other parts. It flows in the cylinder 2 as indicated by a. Also, a header 7 is provided on the outside of the tube sheet 3.
The header 7 is partitioned into upper and lower parts, and a water supply inlet 8 is provided in the lower part and a water supply outlet 9 is provided in the upper part. The feed water flows from the feed water inlet 8 into the heating pipe 4 as indicated by an arrow b, is heated by heat exchange with steam while flowing through the heating pipe 4, and is discharged from the feed water outlet 9 after being heated. Cylinder 2
One end side of the inside is vertically divided by a horizontal partition wall 10. Then, as a heat exchange area in the cylinder 2, a desuperheating zone 11 for exchanging heat between the steam immediately after introduction and the feed water on the outlet side of the heating pipe 4, and the steam deheated here is supplied to the middle of the heating pipe. A condensing zone 12 for exchanging heat with the water, and a feed water inlet 8 of the heating pipe 4 for the condensed water of steam cooled by heat exchange in these zones 11, 12.
A drain cooling zone 14 is provided which is discharged to a drain outlet 13 provided on the side and heat-exchanges the condensed water with the feed water on the way.

That is, the heat exchange in the feed water heater 1 uses the sensible heat of the heated steam in the desuperheater zone 1
1. The condensing zone 12 uses a large amount of latent heat when steam condenses, and the drain cooling zone 14 uses a difference between condensed saturated water and feed water inlet temperature.

In each of the zones 11, 12 and 14 described above,
A large number of baffles 15, 16 and 17 are provided to make the steam flow meander up and down for the purpose of efficient heat exchange.

Then, as shown in FIGS. 38 and 39,
In the desuperheating zone 11 and the condensing zone 12, the steam comes into contact with each heating pipe 4 to be cooled and condensed, and the condensed water 18 flows down like a waterfall in the cylinder 2. The condensed water that has flowed down is sucked into the water chamber, that is, the drain cooling zone 14 from the inner bottom portion of the cylinder 2, flows toward the drain outlet 13 side, and is discharged from the drain outlet 13 to the outside of the cylinder 2.

Further, as shown in FIG. 40, the baffle plates 17 of the drain cooling zone 14 are arranged in a zigzag pattern at the top and bottom, and the reuse of the drain temperature is a meandering flow (arrow c).
It has been designed to achieve high heat transfer efficiency.

By the way, in the reactor, the reactor water is exposed to radiation (γ
Line) to generate non-condensable gases such as hydrogen (H ₂ ) and oxygen (O ₂ ). The non-condensable gas is collected in the central part or the lower part in the cylinder 2 while being entrained in the condensed water 18 flowing down like a waterfall. Therefore, in order to discharge the non-condensable gas, the conventional feed water heater 1 is provided with a gas vent pipe 19 at, for example, a central position in the cylinder 2, and the non-condensable gas is supplied through the gas vent pipe 19 to the cylinder 2 It is made to flow out to the outside (arrow e in FIG. 38).

However, this non-condensable gas comes into contact with water and is locally concentrated on the surface of the heating pipe 4 to a high concentration.
That is, the non-condensable gas is absorbed by the water with the saturated solubility of water being the upper limit, and the rest is diffused as gas into the vapor, but the condensed water is droplets from the surface of the heating pipe 4 to the drain chamber below. As it falls, the non-condensable gas that diffuses in the vapor is carried to the drain water surface 20 by the downward flow formed by water droplets falling like rain, and is entrained in the drain as shown by the arrow d in FIG. 38. It is possible that

As described above, the gas vent pipe 19 is installed in the feed water heater 1, and the non-condensable gas diffused in the vapor is discharged, but the non-condensate having the saturated solubility is condensed in the condensed water as the drain. The volatile gas will remain.

In the non-condensable gas generated in the desuperheating zone 11 and the condensing zone 12 in the feed water heater 1, hydrogen gas has a low density and is likely to accumulate in the upper portion. The gas vent pipe 19 for discharging the non-condensable gas is located below the desuperheating zone 11 and the condensing zone 12, and it is considered that the non-condensable gas cannot be discharged sufficiently.

The drain generated by the feed water heater 1 is sent to the condenser via the feed water heater or drain cooler having a lower pressure than that. The non-condensable gas separated by the feed water heater 1 is sent to a deaerator or a condenser via a feed water heater having a lower pressure than that or directly through a vent pipe.

[0016]

As described above, the gas vent pipe 19 is installed in the feed water heater 1 to discharge the non-condensable gas diffused in the steam. A non-condensable gas of saturated solubility will remain in it. Further, in the drain water suction portion 21 at the inlet of the drain cooling zone 14, the degree of subcooling of the drain water is small, so that a non-condensable gas is generated and easily stays. Further, since a plurality of baffle plates 17 are staggered in the vertical direction in the drain cooling zone 14, it is conceivable that the non-condensable gas will stay between the baffle plates 17 and stop the drain discharge.

In the non-condensable gas generated in the desuperheating zone 11 and the condensing zone 12 in the feed water heater 1, hydrogen gas has a low density and is likely to accumulate in the upper portion. However, since the gas vent pipe 19 for discharging the non-condensable gas is located in the center or below the desuperheating zone 11 and the condensing zone 12, the non-condensable gas cannot be sufficiently discharged, and thus the non-condensable gas in the drain is not condensed. It is conceivable that the concentration of the characteristic gas will increase.

The present invention has been made in view of the above circumstances, and it is possible to effectively discharge the noncondensable gas accumulated in the water chamber and the condensation section inside the feedwater heater in the boiling water reactor. The purpose of this is to prevent clogging of the drain, keep the water level inside the feed water heater stable, and to facilitate stable operation of the reactor.

[0019]

In order to achieve the above object, in the invention of claim 1, a cylinder, a tube plate provided at an end of the cylinder, and an end portion of the tube plate are provided. A tube group comprising a large number of heating tubes supported and arranged in the cylinder,
The steam containing non-condensable gases such as hydrogen and oxygen generated in the reactor pressure vessel is introduced into the cylinder as extracted steam from the turbine and other parts, and the water supply to the reactor pressure vessel is circulated in the heating pipe. And a pipe-type feed water heater in a boiling water reactor for preheating feed water by heat exchange between the feed water and the steam, wherein the steam immediately after introduction is heated as a heat exchange region in the cylinder. De-super heating zone to exchange heat with the feed water on the outlet side, a condensing zone to exchange heat with the steam de-heated here with the feed water in the middle of the heating pipe, and the steam cooled by heat exchange in each zone. A drain cooling zone for leading the condensed water to a drain outlet provided on the feed water inlet side of the heating pipe and for exchanging heat of the condensed water with the feed water on the way; The baffle has a plurality of baffles that meander the flow of condensed water toward the drain outlet, and a non-condensable gas is introduced into the vapor condensing section of the desuperheating zone or the condensing zone. In the case where a gas vent pipe for discharging to the outside of the cylinder is provided, a plurality of baffles for drain flow meandering in the drain cooling zone are opposed to each other on the left and right to cause the condensed water to meander on a horizontal plane. A feed water heater for a boiling water reactor characterized by having a staggered arrangement.

According to the second aspect of the present invention, the cylinder, the tube plate provided at the end of the cylinder, and the plurality of heating tubes arranged in the cylinder with the end supported by the tube plate. With a tube group consisting of, hydrogen and steam generated in the reactor pressure vessel containing non-condensable gas such as oxygen is introduced into the cylinder as extraction steam from the turbine and other parts, and to the reactor pressure vessel. A feed water of a tube type in a boiling water reactor for preheating feed water by heat exchange between the feed water and the steam, as a heat exchange area in the cylinder. , Desuperheating zone that heat-exchanges the steam immediately after introduction with the feed water on the outlet side of the heating pipe, and the condensing zone that heat-exchanges the steam that has been deheated here with the feed water in the middle of the heating pipe. Condensation of water vapor cooled by heat exchange The drain outlet provided on the feed water inlet side of the heating pipe is provided with a drain cooling zone for exchanging heat of the condensed water with the feed water on the way, and the drain cooling zone has the drain outlet of the condensed water. A plurality of baffle plates that make the flow toward the inner side a meandering flow are arranged, and a gas vent pipe for discharging the non-condensable gas to the outside of the cylinder is provided in the vapor condensing portion of the desuperheating zone or the condensing zone. Is provided
And the drain cooling zone is surrounded by both side wall portions of the cylinder, a bottom wall portion, and an inner partition wall horizontally arranged in the cylinder, and a plurality of drain flow meanders in the drain cooling zone are provided. The baffles are arranged in a zigzag pattern that vertically opposes to cause a meandering flow in the vertical direction with respect to condensed water, and the upper end of the baffle that is arranged on the upper side and forms the flow path on the lower side. A feed water heater for a boiling water reactor, characterized in that a gap of non-condensable gas is formed between an edge and a lower surface of the internal partition wall.

According to the invention of claim 3, the cylinder, the tube plate provided at the end of the cylinder, and the plurality of heating tubes arranged in the cylinder with the end supported by the tube plate. With a tube group consisting of, hydrogen and steam generated in the reactor pressure vessel containing non-condensable gas such as oxygen is introduced into the cylinder as extraction steam from the turbine and other parts, and to the reactor pressure vessel. A feed water of a tube type in a boiling water reactor for preheating feed water by heat exchange between the feed water and the steam, as a heat exchange area in the cylinder. , Desuperheating zone that heat-exchanges the steam immediately after introduction with the feed water on the outlet side of the heating pipe, and the condensing zone that heat-exchanges the steam that has been deheated here with the feed water in the middle of the heating pipe. Condensation of water vapor cooled by heat exchange The drain outlet provided on the feed water inlet side of the heating pipe is provided with a drain cooling zone for exchanging heat of the condensed water with the feed water on the way, and the drain cooling zone has the drain outlet of the condensed water. A plurality of baffle plates that make the flow toward the inner side a meandering flow are arranged, and a gas vent pipe for discharging the non-condensable gas to the outside of the cylinder is provided in the vapor condensing portion of the desuperheating zone or the condensing zone. Is provided
And the drain cooling zone is surrounded by both side wall portions of the cylinder, a bottom wall portion, and an inner partition wall horizontally arranged in the cylinder, and a plurality of drain flow meanders in the drain cooling zone are provided. The baffles are arranged in a zigzag pattern that vertically opposes to cause a meandering flow in the vertical direction with respect to condensed water, and the upper end of the baffle that is arranged on the upper side and forms the flow path on the lower side. Provided is a feed water heater for a boiling water nuclear reactor, which is characterized in that a through hole or a notch for allowing a non-condensable gas to flow therethrough is formed on an edge side.

According to a fourth aspect of the present invention, in the feed water heater for a boiling water reactor according to the second or third aspect, the drain outlet side portion of the drain cooling zone has a drain surrounding the upper portion and side portions of the drain cooling zone. Provided is an outlet pedestal, and the drain outlet pedestal and the drain outlet are connected by an internal drain outlet pipe to provide a feed water heater for a boiling water reactor.

According to the invention of claim 5, in the feed water heater for a boiling water reactor according to claim 4, the internal drain outlet pipe penetrates the drain outlet pedestal and is inserted into the drain cooling zone, and A feed water heater for a boiling water nuclear reactor, wherein an insertion end portion of an internal drain outlet pipe is opened at an upper position in the drain cooling zone.

According to the invention of claim 6, in the feed water heater for a boiling water reactor according to any one of claims 1 to 5, a plurality of gas vent pipes for discharging the non-condensable gas are provided. A feed water heater for a boiling water reactor is provided.

According to a seventh aspect of the present invention, in the feed water heater for a boiling water reactor according to any one of the first to sixth aspects, the gas vent pipe is provided above the flow passage of the vapor condensing section. A feed water heater for a boiling water reactor is provided.

According to an eighth aspect of the present invention, in the feed water heater for a boiling water reactor according to the seventh aspect, the upper wall surface forming the flow path of the steam condensing portion is formed in a convex shape, and the gas vent pipe is arranged in this portion. A feed water heater for a boiling water reactor is provided.

According to a ninth aspect of the present invention, in the feed water heater for a boiling water reactor according to any one of the first to eighth aspects, an external drain outlet pipe that is led outward from the drain outlet of the cylinder is provided. The external drain outlet pipe is provided with a gas vent opening for removing the non-condensable gas, and an external gas vent pipe connected to the opening for leading the non-condensable gas to the outside. A feed water heater for a boiling water reactor is provided.

According to a tenth aspect of the present invention, in the feed water heater for a boiling water reactor according to the ninth aspect, a valve for opening and closing is provided in the external gas vent pipe, and the drain water level in the cylinder is detected to detect the water level. A feed water heater for a boiling water nuclear reactor is provided with a control device for opening the valve when the temperature rises above a certain level.

According to an eleventh aspect of the invention, in the feed water heater for a boiling water reactor according to the ninth aspect, a valve for opening and closing is provided in the external gas vent pipe, and the drain flow rate or drain flow rate in the cylinder is detected. The present invention provides a feed water heater for a boiling water nuclear reactor, which is provided with a control device for opening the valve when the values of these values exceed a certain value.

According to a twelfth aspect of the present invention, in the feed water heater for a boiling water reactor according to the ninth aspect, a valve for opening and closing is provided in the external gas vent pipe, and the valve is opened according to the output of the reactor. Provided is a feed water heater for a boiling water reactor, which is provided with a control device for controlling the feed water heater.

According to a thirteenth aspect of the present invention, in the feed water heater for a boiling water reactor according to any one of the first to eighth aspects, a valve for opening and closing is provided in the gas vent pipe in the cylinder, and the cylinder is provided. Provided is a feed water heater for a boiling water nuclear reactor, which is provided with a control device for detecting a drain flow rate or a drain flow rate inside the valve and opening the valve when those values exceed a certain value. .

According to a fourteenth aspect of the present invention, in the feed water heater for a boiling water reactor according to any one of the first to eighth aspects, a valve for opening and closing is provided in the gas vent pipe in the cylinder, and the reactor is A feed water heater for a boiling water nuclear reactor is provided with a control device for opening the valve according to the output of the above.

According to the invention of claim 15, from claim 1 to 8
In the boiling water reactor feedwater heater as described in any one of 1 above, the upper part of the drain cooling zone and the gas in the cylinder.
The vent pipe is connected with a communication pipe, an opening / closing valve is provided in the communication pipe, and the valve is opened when the drain water level in the cylinder is detected and the water level rises above a certain level. Provided is a feed water heater for a boiling water reactor, which is characterized by being provided with a control device.

According to a sixteenth aspect of the present invention, in the feed water heater for a boiling water reactor according to any one of the first to eighth aspects, a mesh body is formed below the drain liquid level in the drain cooling zone during normal operation. A feed water heater for a boiling water reactor characterized by being installed horizontally.

In the invention of claim 17, claims 1 to 1
6. The boiling water reactor feedwater heater according to any one of 6 to 6, wherein a desuperheating zone and a condensate are provided.
There is an upper wall that surrounds the upper space of the
A feed water heater for a boiling water nuclear reactor is provided, in which the central portion of the upper wall surface bulges in a convex shape .

According to the eighteenth aspect of the present invention, a cylinder, a tube plate provided at an end of the cylinder, and a plurality of heating tubes arranged in the cylinder with their ends supported by the tube plate. With a tube group consisting of, hydrogen and steam generated in the reactor pressure vessel containing non-condensable gas such as oxygen is introduced into the cylinder as extraction steam from the turbine and other parts, and to the reactor pressure vessel. A feed water of a tube type in a boiling water reactor for preheating feed water by heat exchange between the feed water and the steam, as a heat exchange area in the cylinder. , Desuperheating zone that heat-exchanges the steam immediately after introduction with the feed water on the outlet side of the heating pipe, and the condensing zone that heat-exchanges the steam that has been deheated here with the feed water in the middle of the heating pipe. Of water vapor cooled by heat exchange And a drain cooling zone to feed water heat exchange the condensed water on the way as to derive a drain outlet provided on the feed water inlet side of the heating tube Chijimisui,
In addition, in the drain cooling zone, a plurality of baffles that make the flow of condensate water toward the drain outlet a meandering flow are arranged, and non-condensation occurs in the vapor condensing part of the desuperheating zone or condensing zone. In the one provided with a gas vent pipe for discharging the characteristic gas to the outside of the cylinder, the axis of the cylinder is arranged in the vertical direction, and the drain cooling zone is formed in the side wall portion of the cylinder. In addition, a drain outlet is provided on the upper end side of the cylinder, and an external drain outlet pipe is provided above the drain outlet to remove a non-condensable gas, and to this opening. Provided is a feed water heater for a boiling water reactor, which is provided with an external gas vent pipe that is connected to the non-condensable gas and discharges the non-condensable gas to the outside.

[0037]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a feedwater heater for a boiling water reactor according to the present invention will be described below with reference to FIGS. The overall configuration is substantially the same as that shown in FIG. 37, and therefore this figure is also used in the description of the following embodiments.

First Embodiment (FIG. 1) FIG. 1 is a perspective view showing the drain cooling zone 14 portion of the feed water heater 1 of the present embodiment.

As shown in FIGS. 1 and 37, the feed water heater 1 of the present embodiment has a horizontal cylinder 2, a tube plate 3 provided at an end of the cylinder 2, and a tube plate 3 attached to the tube plate 3. A tube group 5 having a large number of heating tubes 4 supported at the ends and arranged in the cylinder 2. Then, while introducing steam containing non-condensable gas such as hydrogen and oxygen generated in the reactor pressure vessel into the cylinder 2 as extraction steam from the turbine and other parts,
The feed water to the reactor pressure vessel is circulated in the heating pipe 4, and the feed water is preheated by heat exchange between the feed water and steam.

As a heat exchange area in the cylinder 2, a desuperheating zone 11 for exchanging heat between the steam just after introduction and the feed water on the outlet side of the heating pipe 4, and the steam deheated here is heated in the heating pipe. 4, a condensing zone 12 for exchanging heat with the water supply in the middle of 4 and condensed water of steam cooled by heat exchange in each of the zones 11, 12 are led to a drain outlet 13 provided on the water supply inlet 8 side of the heating pipe 4. At the same time, a drain cooling zone 14 for heat exchange of the condensed water with the supply water is provided.

Further, in the drain cooling zone 14,
A plurality of baffles 17 having a meandering flow toward the condensate drain outlet 13 are arranged, and a non-condensable gas is circulated in the vapor condensing part of the desuperheating zone 11 or the condensing zone 12. A gas vent pipe is provided for discharging the gas to the outside.

In this case, in the feed water heater 1 of this embodiment, as shown in FIG. 1, a plurality of baffle plates 17 for meandering the drain flow in the drain cooling zone 14 are provided.
The condensate 18 is arranged in a zigzag pattern in which the condensed water 18 is made to meander on a horizontal plane and is opposed to each other on the left and right.

With such a configuration, the condensed water 18 becomes a meandering flow in the left-right direction along the horizontal plane, as shown by the arrow f in FIG. 1, and flows in the drain cooling zone 14. Therefore, a certain amount of drain flows along the bottom side in the drain cooling zone 14 by its own weight, so that a space is formed above the drain in the drain cooling zone 14.

Therefore, according to this embodiment, the non-condensable gas can easily flow to the downstream side through the space above the drain cooling zone 14 and can be easily discharged to the outside from the drain outlet 13. become.

Second Embodiment (FIGS. 2 and 3) FIG. 2 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of the present embodiment, and FIG.
It is a B line sectional view.

In the present embodiment, the drain cooling zone 14 is surrounded by the side wall portions 26, the bottom wall portion 27, and the inner partition wall 28 as an upper wall horizontally arranged in the cylinder. Then, the plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are provided with the condensed water 18
The upper and lower parts are arranged in a zigzag pattern so that they meander vertically. An upper edge of one of the baffle plates 17 arranged on the upper side to form the flow path on the lower side,
A gap 30 through which the non-condensable gas can flow is formed between the inner partition wall 28 and the lower surface thereof.

According to the present embodiment having such a configuration, the condensed water 18 flowing into the drain cooling zone 14 from the suction portion 29 has a baffle plate 17 as shown by an arrow g in FIG.
As a result, it becomes a meandering flow in the vertical direction and flows toward the drain outlet 13 side. At this time, the non-condensable gas can be easily discharged to the downstream side through the gaps 30 formed in the upper portions of the baffle plates 17.

Third Embodiment (FIGS. 4 and 5) FIG. 4 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of the present embodiment, and FIG.
It is a C line sectional view.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the second embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A circular through hole 31 through which the non-condensable gas flows is formed on the upper edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Even with the feed water heater 1 of the present embodiment, the condensed water 18 that has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by the arrow h in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the circular through holes 31 of each baffle plate 17.

Fourth Embodiment (FIGS. 6 and 7) FIG. 6 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment, and FIG.
It is a D line sectional view.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the third embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A triangular through hole 32 through which the non-condensable gas flows is formed on the upper edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Even with the feed water heater 1 of the present embodiment, the condensed water 18 that has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by the arrow i in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the triangular through holes 32 of each baffle plate 17.

Fifth Embodiment (FIGS. 8 and 9) FIG. 8 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of the present embodiment, and FIG.
It is an E line sectional view.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the fourth embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A square through hole 33 for allowing the non-condensable gas to flow is formed on the upper edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Also in the feed water heater 1 of the present embodiment as described above, the condensed water 18 that has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by the arrow j in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the rectangular through holes 33 of each baffle plate 17.

Sixth Embodiment (FIGS. 10 and 11) FIG. 10 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment, and FIG.
6 is a cross-sectional view taken along line FF of FIG.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the fifth embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A trapezoidal through hole 34 for allowing the non-condensable gas to flow is formed at the upper end edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Also in the feed water heater 1 of this embodiment as described above, the condensed water 18 which has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by an arrow k in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the trapezoidal through holes 34 of each baffle plate 17.

Seventh Embodiment (FIGS. 12 and 13) FIG. 12 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of the present embodiment, and FIG.
FIG. 9 is a sectional view taken along line GG of FIG.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the sixth embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A triangular notch 35 for allowing the non-condensable gas to flow is formed on the upper edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Also in the feed water heater 1 of the present embodiment as described above, the condensed water 18 which has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by an arrow l in FIG. When flowing, the non-condensable gas can be easily discharged downstream through the triangular notches 35 in each baffle plate 17.

Eighth Embodiment (FIGS. 14 and 15) FIG. 14 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment, and FIG.
3 is a cross-sectional view taken along line HH of FIG.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the seventh embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A rectangular notch 36 for allowing the non-condensable gas to flow is formed on the upper edge of the baffle plate 17 which is disposed on the upper side and forms the flow path on the lower side.

Also in the feed water heater 1 of this embodiment as described above, the condensed water 18 that has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by the arrow m in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the rectangular notches 36 of each baffle plate 17.

Ninth Embodiment (FIGS. 16 and 17) FIG. 16 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment, and FIG.
2 is a cross-sectional view taken along line I-I of FIG.

In this embodiment, the drain cooling zone 14 has the side wall portions 26 and the bottom wall portion 2 as in the eighth embodiment.
7 and an inner partition wall 28 as an upper wall arranged horizontally in the cylinder 2. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction.
A trapezoidal notch 37 for allowing the non-condensable gas to flow is formed on the upper edge of the baffle plate 17 which is arranged on the upper side and forms the flow path on the lower side.

Also in the feed water heater 1 of this embodiment as described above, the condensed water 18 which has become the drain meanders vertically by the baffle plate 17 toward the drain outlet 13 side as shown by the arrow n in FIG. When flowing, the non-condensable gas can be easily discharged to the downstream side through the trapezoidal notch 37 of each baffle plate 17.

Tenth Embodiment (FIG. 18) FIG. 18 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

In this embodiment, the drain cooling zone 14 is surrounded by the side wall portions 26, the bottom wall portion 27, and the inner partition wall 28 that is horizontally arranged in the cylinder 2 as an upper wall. Then, the plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are provided with the condensed water 1
8 are arranged in a zigzag pattern so as to face each other in the vertical direction in order to perform meandering in the vertical direction. In this structure, a drain outlet pedestal 38 that surrounds the upper portion and the side portion of the drain cooling zone 14 is provided at the drain outlet 13 side portion of the drain cooling zone 14, and the drain pedestal 38 and the drain outlet 13 are L-shaped bends. It is connected by an inner drain outlet pipe 39, which is a pipe, and is further connected to an outer drain outlet pipe 40.

According to the feed water heater 1 of the present embodiment as described above, the drain cooling zone 14 is separated from the other portion of the cylinder 2 by the drain pedestal 38. The function of discharging the condensed water 18 is surely performed. Therefore, the non-condensable gas is also discharged at the same time by the reliable discharge action of the condensed water 18, so that the retention of the non-condensable gas in the drain cooling zone 14 is reduced, and the non-condensable gas is quickly discharged. You can

Eleventh Embodiment (FIG. 19) FIG. 19 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

In the present embodiment, the drain cooling zone 14 is surrounded by the side wall portions 26, the bottom wall portion 27, and the inner partition wall 28 as the upper wall horizontally arranged in the cylinder 2. Then, the plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are provided with the condensed water 1
8 are arranged in a zigzag pattern so as to face each other in the vertical direction in order to perform meandering in the vertical direction. In this structure, a drain outlet pedestal 38 that surrounds the upper portion and the side portion of the drain cooling zone 14 is provided at the drain outlet 13 side portion of the drain cooling zone 14, and the drain pedestal 38 and the drain outlet 13 are L-shaped bends. It is connected by an inner drain outlet pipe 39, which is a pipe, and is further connected to an outer drain outlet pipe 40. The upstream end 41 of the internal drain outlet pipe 39 is inserted into the drain cooling zone 14 and stands upright, and the upright upper end is open upward in the upper part of the drain cooling zone 14.

Also in the feed water heater 1 of the present embodiment, the drain cooling zone 14 is separated from the other parts in the cylinder 2 by the drain pedestal 38, as in the tenth embodiment. Therefore, the function of discharging the condensed water 18 from the inside of the drain cooling zone 14 is reliably performed, and the non-condensable gas is also discharged at the same time by the reliable function of discharging the condensed water 18. The retention in 14 is reduced, and the non-condensable gas can be quickly discharged. Moreover, in the present embodiment, the upstream end portion 41 of the internal drain outlet pipe 39 is inserted into the drain cooling zone 14 and stands vertically.
The erected upper end portion is open upward in the upper portion of the drain cooling zone 14, so that the non-condensable gas that easily accumulates in the upper portion of the drain cooling zone 14 is efficiently discharged from the opening portion of the internal drain outlet pipe 39. It can be flowed in and discharged.

Twelfth Embodiment (FIGS. 20 and 21) FIG. 20 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment, and FIG.
It is sectional drawing which expands and shows the heating pipe 4 part shown in FIG.

In the present embodiment, as shown in these figures, the gas vent pipes 42, 43 are provided above and below, for example, the desuperheating zone 11 and the condensing zone 12 which are the condensation parts of the non-condensable gas in the cylinder 2. There are a plurality of arrangements. The lower gas vent pipe 43 is arranged below the desuperheating zone 11 and the condensing zone 12 in the same manner as in the conventional example, but the upper gas vent pipe 42 is disposed in the desuperheating zone 11 and the condensing zone. It is arranged above 12.

According to the feed water heater 1 of the present embodiment as described above, by providing the plurality of gas vent pipes 42 and 43 in the cylinder 2, the conventional feed water heater having the single gas vent pipe is provided. In comparison with the above, the non-condensable gas in the desuperheating zone 11 and the condensing zone 12 can be discharged more.

In addition, the desuperheating zone 11
Further, in the condensing zone 12, the non-condensable gas separated from the vapor tends to gather upward due to the difference in density with the vapor. Therefore, by disposing the upper gas vent pipe 42 above the desuperheating zone 11 and the condensing zone 12 as in the present embodiment, the noncondensable gas collected above can be efficiently discharged.

Thirteenth Embodiment (FIG. 22) FIG. 22 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

In this embodiment, as shown in FIG. 22, the desuperheating zone 1 in the cylinder 2 is
1 and an upper wall surface 44 surrounding the upper space of the condensing zone 12 are provided, and the upper wall surface 44 has a central portion having a roof shape having a triangular cross section and bulging in a convex shape. A plurality of gas vent pipes 42, 43 are provided vertically in a range surrounded by the upper wall surface 44.
Then, of the plurality of gas vent pipes 42 and 43, the one 42 located on the upper side is arranged at a position bulging in a convex shape at the center of the upper wall surface 44.

Also in the feed water heater 1 of the present embodiment as described above, as in the thirteenth embodiment, by providing the plurality of gas vent pipes 42 and 43, the desuperheating zone 11 and the condensing zone 12 are provided. Of the non-condensable gas in the upper part of the desuperheating zone 11 and the condensing zone 12 can be efficiently discharged. Can be discharged well.

In addition, in the present embodiment, the upper wall surface 44 defines the upper space of the desuperheating zone 11 and the condensing zone 12, and the upper wall surface 44 is located in the central portion of the upper wall surface 44 in a convexly bulged position. Since the gas vent pipe 42 is arranged, the non-condensable gas gathered upward is further gathered in the convex bulge portion, and the non-condensable gas is discharged in that portion, so that the discharge efficiency is further improved. You will be able to plan.

Fourteenth Embodiment (FIG. 23) FIG. 22 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

The feed water heater 1 of this embodiment is a modification of the feed water heater 1 of the thirteenth embodiment shown in FIG. That is, in the present embodiment, the upper portion of the upper wall surface 45 that surrounds the upper space of the desuperheating zone 11 and the condensing zone 12 in the cylinder 2,
It is configured to have a roof shape with a circular cross section and bulge in a convex shape. Other configurations are similar to those of the thirteenth embodiment.

Also in this embodiment, as in the thirteenth embodiment, the non-condensable gas gathered upward is efficiently discharged at the convexly bulged portion.

Fifteenth Embodiment (FIGS. 24 to 26) FIG. 24 is a side sectional view showing the drain cooling zone 14 portion and the external drain outlet pipe 40 portion of the feed water heater 1 of the present embodiment. FIG. 25 is a system diagram showing the entire external drain outlet pipe 26. FIG. 26 is a graph showing the pressure change in the external drain outlet pipe 26 in relation to the position in the flow direction.

In this embodiment, as shown in FIG. 24, the drain cooling zone 14 is horizontally arranged in the side wall portions 26, the bottom wall portion 27 and the cylinder 2 as in the tenth embodiment. It is surrounded by an internal partition wall 28 as an upper wall. The plurality of baffle plates 17 for the drain flow meandering in the drain cooling zone 14 are arranged in a staggered arrangement facing each other in the vertical direction so as to cause the condensed water 18 to meander in the vertical direction. In this, at the drain outlet 13 side portion of the drain cooling zone 14,
A drain outlet pedestal 38 that surrounds the top and sides of the drain cooling zone 14 is provided.
And the drain outlet 13 are connected by a substantially straight horizontal inner drain outlet pipe 39, and further connected to an outer drain outlet pipe 40.

In this case, as shown in FIG.
A gas venting opening 46 for venting the non-condensable gas is provided in the upper wall portion of the external drain outlet pipe 40.
An external gas vent pipe 47 for leading out the non-condensed gas to the outside is connected to the external gas vent pipe 47.
Is provided with a valve 48 for opening and closing.

According to the feed water heater 1 of this embodiment as described above, since the external gas vent pipe 47 is connected to the upper wall portion of the external drain outlet pipe 40 in a communicating state, the drain flowing as a drain in the external drain outlet pipe 40 is used. The non-condensable gas caught in the condensed water 26 can be easily removed through the external gas vent pipe 47. Therefore, the non-condensable gas can be prevented from accumulating in the external drain outlet pipe 40, the non-condensable gas can be discharged satisfactorily, and the drain flow can be prevented from being hindered by the gas pressure. Can be

By the way, the external drain outlet pipe 40 is shown in FIG.
As shown in FIG. 5, the length is appropriately bent according to the plant and is guided to the drain tank 49. In FIG. 25, the length up to the drain tank 49 with respect to the external drain outlet pipe 40 is divided by a predetermined distance. 1-No. 24
The symbol is attached.

In the graph of FIG. 26, the horizontal axis represents the position in the drain flow direction corresponding to each position (No. 1 to No. 24 in FIG. 25) of the external drain outlet pipe 40, and the vertical axis represents the drain pressure and the atom. It represents the void ratio when the furnace output is low. As is clear from FIG. 26, the drain pressure (solid curve) and the void fraction (dashed curve) change in a correlated manner. Therefore, if the external gas vent pipe 47 is connected in communication with the external drain outlet pipe 40 at or before a point where the drain pressure becomes high (for example, the position of No. 13 and the position of No. 22), the gas can be effectively discharged. Can be pulled out.

Sixteenth Embodiment (FIG. 27) FIG. 27 is a diagram showing a control system for the drain cooling zone 14 portion, the external drain outlet pipe 40 portion, the external gas vent pipe 47, etc. of the feed water heater 1 of this embodiment.

In this embodiment, a valve 48 for opening and closing is provided in the external gas vent pipe 47, and the valve 4 is operated when the drain water level in the cylinder 2 is detected and the water level rises above a certain level.
A control device 50 for opening 8 is provided.

That is, the control device 50 includes a water level measuring device 51 for detecting the drain water level in the cylinder 2, and a controller 52 for inputting the water level detection signal 101 from the water level measuring device 51 to set the valve opening degree. It is composed by. The control signal 102 is output from the controller 52 to the valve 48,
The opening degree of the external gas vent pipe 47 is set by this.
The gas flow rate inside is determined.

According to the feed water heater 1 of the present embodiment as described above, by controlling the opening degree of the valve 48 according to the control signal 102 from the water level controller 52 based on the drain water level in the feed water heater 1. It is possible to prevent the drain water level from rising abnormally, thereby preventing noncondensable gas from accumulating in the horizontal portion of the external drain outlet pipe 26 and obstructing the flow of the drain water.

Seventeenth Embodiment (FIG. 28) FIG. 28 is a diagram showing a control system for the drain cooling zone 14 portion, the external drain outlet pipe 40 portion, the external gas vent pipe 47, etc. of the feed water heater 1 of this embodiment.

In this embodiment, a valve 48 for opening and closing is provided in the external gas vent pipe 47, and the valve 48 is opened when the drain flow rate or the drain flow velocity in the cylinder 2 is detected and these values are above a certain level. A control device 53 for opening operation is provided. The control device 53 includes a flow rate or flow velocity measuring device 54 for detecting the drain flow rate or flow velocity in the cylinder 2,
It is configured with a controller 55 that inputs the detection signal 103 from the measuring device 54 and sets the valve opening degree. The control signal 104 is output from the controller 55 to the valve 48 to set the opening degree of the valve 48, and thereby the gas flow rate in the external gas vent pipe 47 is determined.

According to the feed water heater 1 of the present embodiment, the opening degree of the valve 48 is controlled according to the control signal 104 when the drain flow rate or the flow velocity in the feed water heater 1 becomes abnormally high. This can prevent the non-condensable gas from accumulating in the external drain outlet pipe 26 and obstructing the flow of the drain water.

18th Embodiment (FIG. 29) FIG. 29 is a diagram showing a control system for the drain cooling zone 14 portion, the external drain outlet pipe 40 portion, the external gas vent pipe 47, and the like of the feed water heater 1 of this embodiment.

In this embodiment, the external gas vent pipe 47 is provided with a valve 48 for opening and closing and a control device 56 for opening the valve 48 according to the output of the nuclear reactor. The control device 53 includes a reactor output detector (not shown) and a controller 57 that inputs a detection signal 105 from the detector to set the valve opening degree. The control signal 106 is output from the controller 57 to the valve 48, and the valve 4
The opening degree of 8 is set, whereby the external gas vent pipe 4 is set.
The gas flow rate in 7 is defined.

According to the feed water heater 1 of the present embodiment as described above, by controlling the opening degree of the valve 48 according to the control signal 106 when the reactor output becomes high, the non-condensable gas is discharged to the outside. It is possible to prevent the drain outlet pipe 26 from being stagnant and obstructing the flow of the drain water.

19th Embodiment (FIG. 30) FIG. 30 is a diagram showing a control system for the drain cooling zone 14 part, the external drain outlet pipe 40 part, and the gas vent pipes 42, 43 of the feed water heater 1 of this embodiment. .

In this embodiment, the gas vent pipe 4 inside the cylinder is used.
2 and 43 are provided with valves 57 for opening and closing, and the cylinder 22
A control device 58 is provided for detecting the drain flow rate or drain flow rate inside the valve and opening the valve 57 when these values exceed a certain value. The control device 53 is composed of a flow rate or flow velocity measuring device 59 for detecting the drain flow rate or flow velocity in the cylinder 2, and a controller 60 for inputting a detection signal 107 from the measuring device 59 to set the valve opening degree. ing. A control signal 108 is output from the controller 60 to the valve 57 to set the opening of the valve 57, which determines the gas flow rate in the gas vent pipes 42 and 43.

According to the feed water heater 1 of this embodiment as described above, the opening degree of the valve 57 is controlled according to the control signal 108 when the drain flow rate or flow velocity in the feed water heater 1 becomes abnormally high. As a result, the gas vent pipe 42 in the cylinder 2
Control such as increasing the gas flow rate in 43 is possible. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

Twentieth Embodiment (FIG. 31) FIG. 31 is a diagram showing the drain cooling zone 14 portion, the external drain outlet pipe 26 portion, the gas vent pipes 42, 43 control system, etc. of the feed water heater 1 of this embodiment. .

In this embodiment, the gas vent pipe 4 inside the cylinder is used.
2 and 43 are provided with valves 57 for opening and closing, and a controller 61 for opening the valve 57 according to the output of the nuclear reactor. The control device 61 includes a reactor output detector (not shown) and a controller 62 that inputs a detection signal 109 from the detector to set the valve opening degree. A control signal 110 is output from the controller 62 to the valve 57 to set the opening degree of the valve 57, which determines the gas flow rates in the gas vent pipes 42 and 43 in the cylinder 2.

According to the feed water heater 1 of the present embodiment as described above, by controlling the opening degree of the valve 57 according to the control signal 110 when the reactor output becomes high, the inside of the gas vent pipes 42, 43 can be controlled. It is possible to control such as increasing the gas flow rate. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

Twenty-first Embodiment (FIG. 32) FIG. 32 is a view showing the drain cooling zone 14 portion, the external drain outlet pipe 40 portion, the control system of the gas vent pipes 42, 43, etc. of the feed water heater 1 of this embodiment. .

In the present embodiment, the upper portion of the drain cooling zone 14 and the casvent pipes 42, 43 are connected to each other by the communication pipe 43a in the cylinder 2, and the communication pipe 43a is provided with the valve 63 for opening and closing. A control device 64 is provided which detects the drain water level in the body 2 and opens the valve 63 when the water level rises above a certain level. Control device 6
4 is a water level measuring device 6 for detecting the drain water level in the cylinder 2.
5 and a controller 66 which inputs the water level detection signal 111 from the water level measuring device 65 and sets the valve opening degree. The control signal 112 is sent from the controller 66 to the valve 63.
Is output to set the opening of the valve 63, which determines the gas flow rate in the gas vent pipes 42, 43.

According to the feed water heater 1 of this embodiment, the control signal 11 is generated when the water level in the cylinder 2 becomes high.
By controlling the opening degree of the valve 63 according to 2, it is possible to perform control such as increasing the gas flow rate in the gas vent pipes 42 and 43. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

Twenty-second Embodiment (FIGS. 33 and 34) FIG. 33 is a side sectional view showing the feed water heater 1 of the present embodiment, and FIG. 34 is an enlarged sectional view showing the heating pipe 4 portion of FIG. 33. is there.

In the present embodiment, as shown in these figures, the mesh body 66 is horizontally installed below the drain liquid level in the drain cooling zone 14 during normal operation.

According to the feed water heater 1 of the present embodiment as described above, when the condensed water 18 drops from the heating pipe 4 side to the drain liquid surface portion, the horizontal net-like body 66 can prevent the rippling. . Therefore, it is possible to effectively prevent the bubbles of the non-condensable gas from being caught in the condensed water 18, and it is possible to reduce the inflow amount of the non-condensable gas to the drain cooling zone 14.

Twenty-third Embodiment (FIG. 35) FIG. 35 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

In this embodiment, the height of the inner partition wall 28 as the upper wall forming the drain cooling zone 14 is gradually increased toward the drain outlet 13 side.

According to the feed water heater 1 of the present embodiment as described above, the drain cooling zone 1 by the internal partition wall 28 is formed.
Since the upper wall surface of No. 4 is inclined so as to gradually increase toward the drain outlet 13 side, the upper space of the drain cooling zone 14 gradually expands, so that non-condensable gas retention can be effectively prevented. The drain can be easily discharged to the external drain outlet pipe 40 side.

Twenty-fourth Embodiment (FIG. 36) FIG. 36 is a side sectional view showing a portion of the drain cooling zone 14 of the feed water heater 1 of this embodiment.

In the feed water heater 1 of this embodiment, the axis of the cylinder 2 is oriented in the vertical direction, the drain cooling zone 14 is formed in the side wall of the cylinder 2, and the drain outlet 13 is provided. Provided on the upper end side of the cylinder 2, from the drain outlet 13 to the external drain outlet pipe 40 provided above,
A gas venting opening 46 for venting the non-condensable gas and an external gas vent pipe 47 connected to the opening 46 for leading the non-condensable gas to the outside are provided, and the external gas vent pipe 47 is opened and closed. The valve 48 is attached. The drive of the valve 48 can be performed by the same control device as in each of the above embodiments.

According to the feed water heater 1 of this embodiment, the drain cooling zone 14 is of a vertical type, and the drain outlet 13
Is arranged above, the non-condensable gas is collected above the drain cooling zone 14,
The non-condensable gas can be effectively discharged through the external drain outlet pipe 40.

[0120]

As described in detail in the above embodiments, according to the first aspect of the invention, a plurality of baffles for meandering the drain flow in the drain cooling zone are made to meander in a horizontal plane with respect to condensed water. Due to the staggered arrangement in which the left and right sides are made to face each other, the condensed water becomes a meandering flow in the left-right direction along the horizontal plane and flows in the drain cooling zone. Therefore, since a certain amount of drain flows by its own weight along the bottom side in the drain cooling zone, a space is formed above the drain in the drain cooling zone. Therefore, the non-condensable gas can easily flow to the downstream side through the space above the drain cooling zone,
The drain outlet can be easily discharged to the outside.

According to the invention of claim 2, a plurality of baffles for meandering the drain flow in the drain cooling zone are provided.
The zigzag arrangement is arranged so that it vertically opposes the condensed water in order to make a meandering flow in the vertical direction, and the upper edge of the baffle plate that is arranged on the upper side and forms the flow path on the lower side and the internal partition By forming a gap of non-condensable gas with the lower surface of the wall, when the condensed water that has become the drain meanders in the vertical direction by the baffle and flows to the drain outlet side, It can be easily discharged downstream through the baffle gap.

According to the invention of claim 3, a plurality of baffles for meandering the drain flow in the drain cooling zone are provided.
The zigzag arrangement is arranged so that it vertically opposes the condensed water in order to make a meandering flow in the vertical direction. By forming a through hole or cutout for the non-condensable gas, when the condensed water that has become the drain meanders vertically through the baffle and flows to the drain outlet side, the non-condensable gas will not pass through the hole or the baffle in each baffle. It can be easily discharged to the downstream side through the notch.

According to the fourth aspect of the present invention, the drain outlet pedestal is provided at the drain outlet side portion of the drain cooling zone, the drain outlet pedestal surrounding the upper portion and the side portion of the drain cooling zone.
By connecting the drain outlet pedestal and the drain outlet with the internal drain outlet pipe, the drain cooling zone is separated from the other parts of the cylinder by the drain pedestal, so that the condensation from the drain cooling zone occurs. The water is drained reliably. Therefore, since the non-condensable gas is also discharged at the same time by the reliable discharging action of the condensed water, the retention of the non-condensable gas in the drain cooling zone is reduced, and the non-condensable gas can be quickly discharged. .

According to the invention of claim 5, the internal drain outlet pipe penetrates the drain outlet pedestal and is inserted into the drain cooling zone, and the insertion end of the internal drain outlet pipe is inserted into the drain cooling zone. Since the drain cooling zone is separated from the other parts of the cylinder by the drain pedestal by opening the drain cooling zone in the upper part of the inside, the drainage of condensed water from the inside of the drain cooling zone is surely performed. Since the non-condensable gas is simultaneously discharged by the reliable discharging action of the condensed water, the retention of the non-condensable gas in the drain cooling zone is reduced, and the non-condensable gas can be quickly discharged. Moreover, since the upstream end of the internal drain outlet pipe is inserted into the drain cooling zone and stands upright, and the upper end that stands up is opened upward at the upper part of the drain cooling zone. The non-condensable gas that tends to collect in the upper part of the pipe can be efficiently introduced and discharged from the opening of the internal drain outlet pipe.

According to the sixth aspect of the present invention, by providing a plurality of gas vent pipes for discharging the non-condensable gas,
More non-condensable gas can be discharged in the desuperheating zone and the condensing zone as compared with the conventional feed water heater provided with a single gas vent pipe.

According to the invention of claim 7, since the gas vent pipe is provided above the flow path of the vapor condensing section, the non-condensable gas gathered above the superheating zone and the condensing zone is efficiently discharged. be able to.

According to the eighth aspect of the present invention, the upper wall surface forming the flow path of the vapor condensing portion is formed in a convex shape, and the gas vent pipe is arranged in this portion, so that the desuperheating zone and the condensing are formed by the upper wall surface. Since the upper space of the zone is defined, and the upper gas vent pipe 42 is arranged at the position where the upper wall surface of the zone bulges in the central part of the upper wall, the non-condensable gas gathering upward is further collected in the convex bulge. In this state, the non-condensable gas is discharged in that portion, so that the discharge efficiency can be further improved.

According to the ninth aspect of the present invention, an external drain outlet pipe is provided which is led outward from the drain outlet of the cylinder, and a vent opening for removing the non-condensable gas is provided in the external drain outlet pipe. And an external gas vent pipe connected to this opening for leading out the non-condensable gas to the outside, and the external gas vent pipe was connected to the upper wall part of the external drain outlet pipe in a communicating state, so that in the external drain outlet pipe The non-condensable gas entrained in the condensed water as the flowing drain can be easily removed through the external gas vent pipe. Therefore, the non-condensable gas can be prevented from staying in the external drain outlet pipe, the non-condensable gas can be satisfactorily discharged, and the drain flow can be prevented from being hindered by the gas pressure. can do.

According to the tenth aspect of the present invention, the external gas vent pipe is provided with a valve for opening and closing, and the drain water level in the cylinder is detected and the valve is opened when the water level rises above a certain level. By installing a device, by controlling the opening of the valve according to the control signal from the water level controller based on the drain water level in the feed water heater, it is possible to prevent the drain water level from rising further, thereby preventing non-condensation. It is possible to prevent the volatile gas from accumulating in the horizontal portion of the external drain outlet pipe and obstructing the flow of the drain water.

According to the eleventh aspect of the present invention, a valve for opening and closing is provided in the gas vent pipe, and the valve is opened when the drain flow rate or drain flow rate in the cylinder is detected and the value becomes a certain value or more. By providing a control device to operate the non-condensable gas, the non-condensable gas is controlled by controlling the opening of the valve according to the control signal when the drain flow rate or flow velocity in the water heater becomes higher than the above. It is possible to prevent the water from remaining in the pipe and obstructing the flow of the drain water.

According to the twelfth aspect of the present invention, the external gas vent pipe is provided with a valve for opening and closing, and a control device for opening the valve according to the output of the reactor is provided. In this case, by controlling the opening degree of the valve according to the control signal, it is possible to prevent the non-condensable gas from accumulating in the external drain outlet pipe and obstructing the flow of drain water.

According to the thirteenth aspect of the present invention, when a valve for opening and closing is provided in the gas vent pipe in the cylinder, and the drain flow rate or drain flow rate in the cylinder is detected and the values are above a certain value. By providing a control device for opening the valve to the inside, by controlling the opening degree of the valve according to the control signal when the drain flow rate or flow velocity in the feed water heater becomes higher than that, It is possible to control such as increasing the gas flow rate in the gas vent pipe. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

According to the invention of claim 14, the valve for opening and closing is provided in the gas vent pipe in the cylinder, and the control device for opening the valve according to the output of the reactor is provided. When the value becomes high, by controlling the opening degree of the valve according to the control signal, it becomes possible to perform control such as increasing the gas flow rate in the gas vent pipe. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

According to the invention of claim 15, the upper part of the drain cooling zone and the gas vent pipe are connected by a communication pipe in the cylinder, and the communication pipe is provided with an opening / closing valve.
Moreover, by providing the control device that detects the drain water level in the cylinder and opens the valve when the water level rises above a certain level, the control signal 2 is generated when the water level in the cylinder rises.
By controlling the opening degree of the valve in accordance with the above, it becomes possible to perform control such as increasing the gas flow rate in the gas vent pipe. As a result, the amount of the non-condensable gas trapped in the drain can be reduced and the flow of the drain water due to the retention of the non-condensable gas can be prevented.

According to the sixteenth aspect of the present invention, since the mesh body is horizontally installed below the drain liquid level in the drain cooling zone during normal operation, the condensed water drops from the heating pipe side to the drain liquid level portion. Occasionally, the horizontal mesh prevents undulations. Therefore, it is possible to effectively prevent the bubbles of the non-condensable gas from being caught in the condensed water, and reduce the amount of the non-condensable gas flowing into the drain cooling zone.

According to the invention of claim 17, in the feed water heater for a boiling water reactor according to any one of claims 1 to 16, a desuperheating zone and a co- heating unit are provided.
There is an upper wall that surrounds the upper space of the
The upper wall surface is designed to bulge in a convex shape at the center.
Therefore, in the state where the non-condensable gas gathering upward is further gathered at the convexly bulged portion, the non-condensable gas is discharged at that portion, and the discharge efficiency can be further improved.

According to the eighteenth aspect of the present invention, the cylinder is arranged such that its axial center is oriented in the vertical direction, the drain cooling zone is formed in the side wall portion of the cylinder, and the drain outlet is formed in the cylinder. An external drain outlet pipe, which is provided on the upper end side and is provided above the drain outlet, is provided with a gas vent opening for removing the non-condensable gas and the non-condensable gas is connected to this opening to the outside. By providing an external gas vent pipe to lead out, the drain cooling zone becomes vertical and the drain outlet is arranged above, and the non-condensable gas is collected above the drain cooling zone and passed through the external drain outlet pipe. As a result, the non-condensable gas can be effectively discharged.

[Brief description of drawings]

FIG. 1 is a perspective view showing a drain cooling zone portion of a feed water heater according to a first embodiment of the present invention.

FIG. 2 shows a second embodiment of the present invention and is a side sectional view showing a drain cooling zone portion of a feed water heater.

3 is a sectional view taken along line BB of FIG.

FIG. 4 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a third embodiment of the present invention.

5 is a sectional view taken along line CC of FIG.

FIG. 6 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a fourth embodiment of the present invention.

7 is a cross-sectional view taken along line DD of FIG.

FIG. 8 shows a fifth embodiment of the present invention and is a side sectional view showing a drain cooling zone portion of a feed water heater.

9 is a sectional view taken along line EE of FIG.

FIG. 10 shows a sixth embodiment of the present invention and is a side sectional view showing a drain cooling zone portion of a feed water heater.

11 is a sectional view taken along line FF of FIG.

FIG. 12 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a seventh embodiment of the present invention.

13 is a sectional view taken along line GG of FIG.

FIG. 14 is a side sectional view showing a drain cooling zone portion of a feed water heater according to an eighth embodiment of the present invention.

FIG. 15 is a sectional view taken along line HH of FIG.

FIG. 16 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a ninth embodiment of the present invention.

17 is a cross-sectional view taken along the line I-I of FIG.

FIG. 18 is a side sectional view showing a drain cooling zone portion of the feed water heater according to the tenth embodiment of the present invention.

FIG. 19 shows an eleventh embodiment of the present invention and is a side sectional view showing a drain cooling zone portion of a feed water heater.

FIG. 20 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a twelfth embodiment of the present invention.

FIG. 21 is an enlarged sectional view showing a heating pipe portion shown in FIG. 20.

FIG. 22 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a thirteenth embodiment of the present invention.

FIG. 23 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a fourteenth embodiment of the present invention.

FIG. 24 is a side sectional view showing a drain cooling zone portion and an external drain outlet pipe portion of a feed water heater according to a fifteenth embodiment of the present invention.

25 is a system diagram showing the entire external drain outlet pipe in FIG.

FIG. 26 is a graph showing the pressure change in the external drain outlet pipe in the fifteenth embodiment in relation to the position in the flow direction.

FIG. 27 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, an external gas vent pipe control system, and the like of a feed water heater according to a sixteenth embodiment of the present invention.

FIG. 28 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, an external gas vent pipe control system, and the like of a feed water heater according to a seventeenth embodiment of the present invention.

FIG. 29 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, an external gas vent pipe control system, and the like of a feed water heater according to an eighteenth embodiment of the present invention.

FIG. 30 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, a gas vent pipe control system, and the like of a feed water heater according to a nineteenth embodiment of the present invention.

FIG. 31 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, a gas vent pipe control system, and the like of a feed water heater according to a twentieth embodiment of the present invention.

FIG. 32 is a view showing a drain cooling zone portion, an external drain outlet pipe portion, a gas vent pipe control system, and the like of a feed water heater according to a twenty-first embodiment of the present invention.

FIG. 33 is a sectional view showing a feed water heater according to a twenty-second embodiment of the present invention.

FIG. 34 is an enlarged view of the heating pipe portion shown in FIG. 33.

FIG. 35 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a twenty-third embodiment of the present invention.

FIG. 36 is a side sectional view showing a drain cooling zone portion of a feed water heater according to a twenty-fourth embodiment of the present invention.

FIG. 37 is a cross-sectional view showing the overall configuration of a feedwater heater for a boiling water reactor.

38 shows a conventional feed water heater,
-A line expanded sectional view.

39 is an enlarged sectional view of the heating tube shown in FIG. 38.

FIG. 40 is a perspective view showing a conventional example and showing a drain cooling zone portion of a feed water heater.

[Explanation of symbols]

1 Water Heater 2 Cylinder 3 Tube Plate 4 Heating Tube 5 Tube Group 6 Steam Inlet 7 Header 8 Water Inlet 9 Water Inlet 10 Partition Wall 11 Desuper Heating Zone 12 Condensing Zone 13 Drain Outlet 14 Drain Cooling Zone 15, 16 , 17 Baffle plate 18 Condensed water 19 Gas vent pipe 20 Drain water surface 21 Drain water suction part at the drain cooling zone inlet part 26 Both side wall parts 27 Bottom wall part 28 Internal partition wall 29 Suction part 30 Gap 31 Through hole 32 Through hole 33 Through hole 34 through hole 35 notch 36 notch 37 notch 38 drain pedestal 39 internal drain outlet pipe 40 external drain outlet pipe 41 upstream end portions 42, 43 gas vent pipe 44 upper wall surface 45 upper wall surface 46 degassing opening 47 external gas vent pipe 48 valve 50 controller 51 water level measuring device 53 controller 54 flow velocity measuring device 55 controller 56 control device 57 control device 58 control device 59 flow velocity measuring device 60 control device 61 control device 62 control device 43a communicating pipe 63 valve 64 control device 65 water level measuring device 66 reticulated body 101 to 112 signal for valve control

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroshi Miyano 1 Komukai Toshiba Town, Komukai Toshiba Town, Kawasaki City, Kanagawa Prefecture, Toshiba Research & Development Center Co., Ltd. (56) Reference JP-A-2-166301 (JP, A) Kaihei 7-110103 (JP, A) JP 57-207702 (JP, A) JP 59-13808 (JP, A) Actual 62-81805 (JP, U) Actual 63-104807 ( (58) Fields surveyed (Int.Cl. ⁷ , DB name) G21D 1/02 F22D 1/32

Claims (18)

(57) [Claims] 1. A tube group comprising a cylinder, a tube plate provided at an end of the cylinder, and a large number of heating tubes arranged in the cylinder with an end supported by the tube plate. A steam containing hydrogen, oxygen and other non-condensable gas generated in the reactor pressure vessel is introduced into the cylinder as extraction steam from the turbine and other parts, and the water supply to the reactor pressure vessel is heated. A pipe-type feed water heater in a boiling water reactor that preheats the feed water by heat exchange between this feed water and the steam, as a heat exchange area in the cylinder, and steam immediately after introduction. Desuperheating zone for heat exchange with the feed water on the outlet side of the heating pipe, a condensing zone for exchanging heat of the steam deheated here with the feed water in the middle of the heating pipe, and cooling by heat exchange in each zone. Supply condensed water of steam to the heating pipe A drain cooling zone is provided for draining the condensed water to the drain outlet provided on the water inlet side and for exchanging heat with the feed water on the way, and the drain cooling zone has a meandering flow of the condensed water toward the drain outlet. While arranging a plurality of baffles to be, in the vapor condensing portion of the desuperheating zone or the condensing zone, in the one provided with a gas vent pipe for discharging the non-condensable gas to the outside of the cylinder, A plurality of baffles for drain flow meandering in the drain cooling zone are arranged in a zigzag pattern in which the condensate water is meandered on a horizontal plane and facing each other in a zigzag pattern. Heater. 2. A tube group comprising a cylinder, a tube plate provided at an end of the cylinder, and a plurality of heating tubes arranged in the cylinder with an end supported by the tube plate. A steam containing hydrogen, oxygen and other non-condensable gas generated in the reactor pressure vessel is introduced into the cylinder as extraction steam from the turbine and other parts, and the water supply to the reactor pressure vessel is heated. A pipe-type feed water heater in a boiling water reactor that preheats the feed water by heat exchange between this feed water and the steam, as a heat exchange area in the cylinder, and steam immediately after introduction. Desuperheating zone for heat exchange with the feed water on the outlet side of the heating pipe, a condensing zone for exchanging heat of the steam deheated here with the feed water in the middle of the heating pipe, and cooling by heat exchange in each zone. Supply condensed water of steam to the heating pipe A drain cooling zone is provided for draining the condensed water to the drain outlet provided on the water inlet side and for exchanging heat with the feed water on the way, and the drain cooling zone has a meandering flow of the condensed water toward the drain outlet. And a plurality of baffles are provided, and in the vapor condensing portion of the desuperheating zone or the condensing zone, a gas vent pipe for discharging the non-condensable gas to the outside of the cylinder is provided, and the drain. The cooling zone is surrounded by both side wall portions of the cylinder, a bottom wall portion, and an inner partition wall horizontally arranged in the cylinder, and the plurality of baffles for drain flow meandering in the drain cooling zone are , The staggered arrangement facing each other in the vertical direction in order to cause the condensed water to meander in the vertical direction. A feed water for a boiling water reactor characterized in that a gap of non-condensable gas is formed between an upper edge of one that is arranged on the upper side and forms a flow path on the lower side and a lower surface of the internal partition wall. Heater. 3. A tube group comprising a cylinder, a tube plate provided at an end of the cylinder, and a large number of heating tubes arranged in the cylinder with the end supported by the tube plate. A steam containing hydrogen, oxygen and other non-condensable gas generated in the reactor pressure vessel is introduced into the cylinder as extraction steam from the turbine and other parts, and the water supply to the reactor pressure vessel is heated. A pipe-type feed water heater in a boiling water reactor that preheats the feed water by heat exchange between this feed water and the steam, as a heat exchange area in the cylinder, and steam immediately after introduction. Desuperheating zone for heat exchange with the feed water on the outlet side of the heating pipe, a condensing zone for exchanging heat of the steam deheated here with the feed water in the middle of the heating pipe, and cooling by heat exchange in each zone. Supply condensed water of steam to the heating pipe A drain cooling zone is provided for draining the condensed water to the drain outlet provided on the water inlet side and for exchanging heat with the feed water on the way, and the drain cooling zone has a meandering flow of the condensed water toward the drain outlet. And a plurality of baffles are provided, and in the vapor condensing portion of the desuperheating zone or the condensing zone, a gas vent pipe for discharging the non-condensable gas to the outside of the cylinder is provided, and the drain. The cooling zone is surrounded by both side wall portions of the cylinder, a bottom wall portion, and an inner partition wall horizontally arranged in the cylinder, and the plurality of baffles for drain flow meandering in the drain cooling zone are , The staggered arrangement facing each other in the vertical direction in order to cause the condensed water to meander in the vertical direction. The upper end edge of which is arranged on the upper side to form a flow path on the lower side, the feed water heater of the boiling water nuclear reactor, characterized in that the formation of the holes or notches circulating incondensable gases. 4. The feedwater heater for a boiling water reactor according to claim 2 or 3, wherein a drain outlet pedestal that surrounds an upper portion and a side portion of the drain cooling zone is provided at a drain outlet side portion of the drain cooling zone, A feed water heater for a boiling water reactor characterized in that the drain outlet pedestal and the drain outlet are connected by an internal drain outlet pipe. 5. The feed water heater for a boiling water reactor according to claim 4, wherein the inner drain outlet pipe penetrates the drain outlet pedestal and is inserted into the drain cooling zone, and the internal drain outlet pipe A feed water heater for a boiling water reactor characterized in that the insertion end is opened at an upper position in the drain cooling zone. 6. The boiling water reactor feed water heater according to any one of claims 1 to 5, wherein a plurality of gas vent pipes for discharging the non-condensable gas are provided. Type reactor feed water heater. 7. A boiling water reactor according to any one of claims 1 to 6, wherein a gas vent pipe is provided in an upper portion of the flow path of the steam condensing section. Water heater for furnace. 8. The feed water heater for a boiling water reactor according to claim 7, wherein the upper wall surface forming the flow path of the steam condensing section has a convex shape, and the gas vent pipe is arranged in this portion. Feed water heater for boiling water reactors. 9. The feed water heater for a boiling water reactor according to any one of claims 1 to 8, wherein an external drain outlet pipe that is led outward from a drain outlet of the cylinder is provided, and the external drain is provided. A boiling water atom characterized in that the outlet pipe is provided with a degassing opening for removing the non-condensable gas, and an external gas vent pipe connected to the opening for leading out the non-condensable gas to the outside. Water heater for furnace. 10. The boiling water reactor feed water heater according to claim 9, wherein a valve for opening and closing is provided in the external gas vent pipe, and the drain water level in the cylinder is detected to raise the water level above a certain level. A feed water heater for a boiling water reactor, comprising a control device for opening the valve in the case of the above. 11. The boiling water reactor feed water heater according to claim 9, wherein a valve for opening and closing is provided in the external gas vent pipe, and the drain flow rate or drain flow rate in the cylinder is detected to determine the values thereof. A feed water heater for a boiling water nuclear reactor, comprising a control device for opening the valve when the temperature exceeds a certain level. 12. The feedwater heater for a boiling water reactor according to claim 9, wherein an external gas vent pipe is provided with a valve for opening and closing, and a control device for opening the valve according to the output of the reactor is provided. A feed water heater for a boiling water reactor characterized by the above. 13. The feed water heater for a boiling water reactor according to any one of claims 1 to 8, wherein a valve for opening and closing is provided in a gas vent pipe in the cylinder, and a drain flow rate in the cylinder or A feed water heater for a boiling water nuclear reactor, comprising a control device for detecting the drain flow velocity and opening the valve when these values are above a certain value. 14. The feedwater heater for a boiling water reactor according to any one of claims 1 to 8, wherein a valve for opening and closing is provided on a gas vent pipe in the cylinder, and the reactor is provided with an opening / closing valve according to the output of the reactor. A feed water heater for a boiling water nuclear reactor, comprising a control device for opening the valve. 15. The feed water heater for a boiling water reactor according to any one of claims 1 to 8, wherein the upper portion of the drain cooling zone and the gas vent pipe are connected by a communication pipe in the cylinder. Boiling water characterized in that a valve for opening and closing is provided in the communication pipe, and a control device for detecting the drain water level in the cylinder and opening the valve when the water level rises above a certain level is provided. Type reactor feed water heater. 16. The boiling water reactor feed water heater according to any one of claims 1 to 8, wherein a reticulate body is horizontally installed below the drain liquid level in the drain cooling zone during normal operation. A feed water heater for a boiling water reactor characterized by: 17. A feed water heater for a boiling water reactor according to any one of claims 1 to 16, wherein
Sky above the lighting and condensing zones
There is an upper wall that surrounds the space, and the upper wall has a central part
A feed water heater for a boiling water reactor, which is configured to bulge in a convex shape . 18. A tube group comprising a cylinder, a tube plate provided at an end of the cylinder, and a plurality of heating tubes arranged in the cylinder with an end supported by the tube plate. Equipped with, leading the steam containing non-condensable gas such as hydrogen and oxygen generated in the reactor pressure vessel as extraction steam from the turbine and other parts into the cylinder, and heating the water supply to the reactor pressure vessel A pipe-type feed water heater in a boiling water reactor that preheats the feed water by heat exchange between this feed water and the steam, as a heat exchange area in the cylinder, and steam immediately after introduction. A de-superheating zone for exchanging heat with the feed water on the outlet side of the heating pipe, and a condensing zone for exchanging heat of the steam deheated here with the feed water in the middle of the heating pipe,
A drain cooling zone is provided for discharging condensed water of steam cooled by heat exchange in each of the zones to a drain outlet provided on the feed water inlet side of the heating pipe and for exchanging heat of the condensed water with the feed water on the way. In addition, in the drain cooling zone, a plurality of baffles that make the flow of condensate water toward the drain outlet a meandering flow are arranged, and non-condensation occurs in the vapor condensing part of the desuperheating zone or condensing zone. In the one provided with a gas vent pipe for discharging the characteristic gas to the outside of the cylinder, with the axial center of the cylinder being arranged in the vertical direction,
The drain cooling zone is formed in the side wall portion of the cylinder, the drain outlet is provided on the upper end side of the cylinder, and the non-condensable gas is discharged from the drain outlet to an external drain outlet pipe provided above. A feed water heater for a boiling water reactor, comprising: a degassing opening for discharging the gas and an external gas vent pipe connected to the opening for leading out the non-condensable gas to the outside.