JP2923122B2 - Drain recovery equipment for nuclear power plants - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisture separation heater in a nuclear power plant, and a drain of the moisture separator together with a drain of a feed water heater, which is sent to a drain pump and pressurized by a drain pump to a condensate pipe. The present invention relates to a drain recovery device of a nuclear power plant that is configured to recover the drain.

[0002]

2. Description of the Related Art Generally, in a boiling water or pressurized water nuclear power plant, steam generated in a nuclear reactor is wet steam having a lower pressure than steam generated in a boiler in a thermal power plant. In the process where the wet steam expands in the turbine and is converted into mechanical energy, the moisture in the steam rapidly increases. Install a moisture separator heater between the high-pressure turbine and the low-pressure turbine, because introducing high-humidity steam directly into the subsequent low-pressure turbine will promote erosion inside the turbine and reduce the performance of the turbine. Then, moisture in the steam is removed and reheated.
In the moisture separator housed in the moisture separator heater, the moisture in the high-pressure turbine exhaust steam is removed and discharged as a moisture separator drain. Similarly, in the heater housed in the moisture separator heater, the steam extracted from the moisture separator is heated (reheated) using the turbine bleed air and the main steam, and the turbine bleed air and the heat that have been subjected to the heat exchange are removed. The main steam condenses and is discharged as a heater drain. These moisture separator drain and heater drain are configured to be sent to a feedwater heater in a turbine cycle for further heat recovery.

Further, as described above, in a nuclear power plant, since steam flowing into a turbine is wet steam having a low pressure, a large amount of turbine extraction steam is required for heating a feed water heater. The turbine bleed steam condenses after performing condensate or heat exchange with the feedwater in each feedwater heater and generates a large amount of drain. Recently, in order to make maximum use of the heat of the feed water heater drain, a system that raises the pressure of the feed water heater drain together with the above-mentioned moisture separator drain and heater drain by a drain pump and collects it in a condensate pipe, Pump-up systems are used in many nuclear power plants. As a result, the efficiency of the power plant is increased by about 2.3% in combination with the use of the above-mentioned moisture separation heater.
To some extent.

[0004] Fig. 9 shows an example of a drain recovery device that has already been proposed in a nuclear power plant employing the above-mentioned moisture separation heater and drain pump-up system.

The steam generated by the steam generator 1 is supplied to a main steam pipe 2
Through the high-pressure turbine 3 and expands in the high-pressure turbine 3 to perform work. The exhaust steam of the high-pressure turbine 3 is guided to a moisture separation heater 5 through a low-temperature reheat steam pipe 4.
As shown in FIG. 9, the moisture separator / heater 5 contains a moisture separator 6 and heaters 7 and 8. In the moisture separator 5, the moisture in the steam is removed and discharged by the moisture separating element. In the heater 7, the outlet steam of the moisture separator 6 is heated by the turbine bleed from the middle stage of the high-pressure turbine 3 guided by the bleed pipe 9, and the turbine bleed air after the heat exchange is condensed and discharged as a heater drain. Is done. Further, in the heater 8, the outlet steam of the heater 7 is heated by the main steam branched from the main steam pipe 2, and the main steam after the heat exchange is condensed and discharged similarly as a heater drain.

[0006] The steam leaving the moisture separation heater 5 is sent to a low pressure turbine 11 through a high temperature reheat steam pipe 10, and after further work, is condensed in a condenser 12 to be condensed. This condensed water is pressurized by the condensate pump 13 and then the low pressure turbine 1
Low pressure feed water heater 1 using turbine bleed air from 1 as heating source
Heated by 4 and 15 and sent to the steam generator feed pump 17 through the condenser pipe 16. The condensed water is further pressurized by a steam generator water supply pump 17 to become water supply, and after being further heated by a two-stage high pressure water heater, that is, a next-stage water heater 18 and a maximum pressure water heater 19, the water supply pipe 2 is heated.
0 to the steam generator 1. Here, the next-stage feed water heater 18 is heated by the exhaust steam of the high-pressure turbine 3 passing through the bleed pipe 21 branched from the low-temperature reheat steam pipe 4. Further, turbine bleed air is sent to the highest pressure feed water heater 19 from the middle stage of the high pressure turbine 3 downstream of the bleed stage to the heater 7 through the bleed pipe 22 to perform heating.

On the other hand, the drain generated in the moisture separator 6 is temporarily stored in the moisture separator drain tank 23 and then sent to the next-stage feed water heater 18 through the moisture separator drain tank water level control valve 24. . The drain generated in the heaters 7 and 8 is temporarily stored in the heater drain tanks 25 and 26 and then sent to the maximum pressure water heater 19 through the heater drain tank water level control valves 27 and 28. I have. In the highest pressure feedwater heater 19, the feedwater is heated by the turbine bleed from the extraction pipe 22 and the heater drain, and the drain from the highest pressure feedwater heater 19 is cascaded by the pressure difference and sent to the next stage feedwater heater 18. Can be Next stage feed water heater 18
In this example, the feedwater is heated by the exhaust steam of the high-pressure turbine 3 passing through the extraction pipe 21, the moisture separator drain, and the highest-pressure feedwater heater drain. Further, the drain from the next stage feed water heater 18 is pressurized by the drain pump 29 and
And mixed with condensate to measure heat recovery. The drain of the low-pressure feed water heater 15 is cascaded and sent to the low-pressure feed water heater 14, and is finally collected in the condenser 12.

As described above, in the above-described drain recovery apparatus, the heater of the moisture separation heater and the drain of the moisture separator are sent to the condensate pipe by the drain pump together with the drain of the feed water heater to recover heat, and the efficiency of the power plant is improved. We are improving.

[0009]

However, the above-mentioned drain recovery apparatus has a drawback that the drain is flushed and the drain cannot be smoothly transferred as described below.

That is, in FIG. 9, the moisture separator 6 and the next-stage feed water heater 18 are communicated with each other by the bleeding pipe 21 and have substantially the same pressure. Here, when the saturated drain generated in the moisture separator 6 is sent to the next-stage feed water heater 18, a drain flush occurs in the moisture separator drain tank water level control valve 24 due to insufficient pressure difference, and the drain is drained. In some cases, the drainage of the moisture separator drain tank 23 cannot be controlled.

Further, since the drain from the next-stage feed water heater 18 is also generally a saturated drain, the drain is easily flushed in a pipe for sending the saturated drain to the drain pump 29. In particular, when the drain flashes and bubbles are generated when the load of the power plant fluctuates and the pressure in the next-stage feedwater heater 18 changes, the bubbles may flow into the drain pump 29 and damage the drain pump 29. There was.

As described above, in the conventional drain recovery apparatus, since no effective countermeasures have been taken against the above-mentioned drain flushing, malfunction of the drain water level control and damage to the drain pump often occur, resulting in the safety of the power plant. It often hindered driving.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a highly reliable drain recovery device that prevents harmful drain flush.

[0014]

According to a first aspect of the present invention, there is provided a drain recovery apparatus for a nuclear power plant, comprising a maximum pressure water supply below a building floor on which a moisture separation heater is installed. A heater and a next-stage feedwater heater are installed, and a drain cooler for cooling the drain from the next-stage feedwater heater is installed below the installation position of the next-stage feedwater heater. A drain recovery tank for storing drain from a drain cooler is provided below the drain cooler.

Then, the drain from the heater of the moisture separation heater is supplied to the highest-pressure feedwater heater, and the drain from the highest-pressure feedwater heater is supplied to the next-stage feedwater heater. The drain from the moisture separator is supplied to a drain recovery tank.

Further, the drain from the heater of the moisture separation heater is supplied to the highest pressure feedwater heater, and the drain from the highest pressure feedwater heater is supplied to the next stage feedwater heater. The drain from the moisture separator is supplied to the drain cooler.

On the other hand, in the drain recovery apparatus for a nuclear power plant according to the present invention, the maximum pressure water supply is provided on a floor lower than a building floor on which a moisture separation heater is installed. The heater and the next-stage feedwater heater are installed, and the drain from the next-stage feedwater heater and the humidity of the moisture separation heater are placed on the floor below the installation position of the highest-pressure feedwater heater and the next-stage feedwater heater. A drain recovery tank for storing drain from the separator is installed, and a drain cooler for cooling the drain from the drain recovery tank is installed on a floor lower than the installation position of the drain recovery tank. And

Then, the drain from the heater of the moisture separation heater is supplied to the highest-pressure feedwater heater, and the drain from the highest-pressure feedwater heater is supplied to the next-stage feedwater heater.

Further, the drain from the heater of the moisture separation heater is supplied to the highest pressure feed water heater, and the drain from the highest pressure feed water heater is supplied to the drain recovery tank.

[0020]

In the drain recovery apparatus according to the present invention, the highest pressure feed water heater and the next-stage feed water heater are installed below the floor of the building where the moisture separation heater is installed. Further, a drain cooler that uses water supplied downstream of the steam generator water supply pump as a cooling medium is installed further below to cool (subcool) the drain from the next-stage water supply heater. For this reason, since the drain at the drain cooler outlet side is always in a supercooled state, the drain in the pipe line sent to the drain pump does not flush. In addition, a drain collection tank is installed below the installation position of the next-stage feed water heater, and the drain from the moisture separator drain tank is sent to this drain collection tank together with the drain from the drain cooler. The container drain is collected smoothly with a sufficient positional difference, and no drain flush occurs.

On the other hand, in the drain recovery system for a nuclear power plant according to the present invention, the maximum pressure water supply is provided on a floor lower than the building floor on which the moisture separating heater is installed. A heater and the next-stage feedwater heater are installed, and a drain recovery tank is further installed on the floor on the lower floor.The moisture separator drain from the moisture separation drain tank has a sufficient positional difference, and the drain recovery tank Is collected smoothly. In addition, a drain cooler is installed on the floor below the drain collection tank to cool (subcool) the drain from the drain collection tank and supply it to the drain pump. Flash can be prevented.

[0022]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 9, the same components as those in the above-described specific example will be described with the same reference numerals.

FIG. 1 is a configuration diagram showing one embodiment of the drain recovery apparatus of the present invention. 9 is different from that of FIG. 9 in that a drain cooler 30 that uses water as a cooling medium is installed in a water supply line downstream of the steam generator water supply pump 17, and the drain from the next-stage water supply heater 18 is The water is sent to the drain cooler 30 and is cooled (subcooled) by performing heat exchange with water supplied downstream of the steam generator water supply pump 17. In addition, a drain recovery tank 31 is provided in a drain pipe from the drain cooler 30, and the drain from the drain cooler 30 and the moisture separator drain from the moisture separation drain tank 23 are sent to the drain recovery tank 31. ing.

FIG. 2 is a diagram showing the installation position of each device and the drain line in the embodiment of FIG. The moisture separation heater 5 and the high-pressure feedwater heaters 18 and 19 are generally installed on both sides of the turbine shaft, that is, in two lines, but only one side (one line) is shown in FIG. In general, the moisture separator / heater 5 is provided on the building floor where the high-pressure turbine 3 and the low-pressure turbine 11 are provided, that is, on the turbine operating floor, and on the floor one floor below the turbine operating floor. However, in this drawing, the example in which the moisture separation heater 5 is provided on the floor one floor below the turbine operation floor is shown.

As shown in FIG. 2, the highest-pressure feedwater heater 19 and the next-stage feedwater heater 18 are installed on a floor below the floor on which the moisture separation heater 5 is installed. Drains generated in the heaters 7 and 8 of the moisture separation heater 5 are temporarily stored in heater drain tanks 25 and 26 on the floor where the moisture separation heater 5 is installed, and then are respectively stored in the heater drain tank water level control valves 27. ,
All are sent to the highest pressure feed water heater 19 through 28. The next-stage feedwater heater 18 collects the drain from the highest-pressure feedwater heater 19. A drain cooler 30 that is cooled by feed water downstream of the steam generator feed pump 17 is provided further below the installation position of the next-stage feed water heater 18. Drain from the next-stage feed water heater 18 is sent to the drain cooler 30. It is configured to be cooled. Also, a drain recovery tank 31 is provided below the installation position of the next-stage feedwater heater 18. Moisture separator 6 of moisture separator heater 5
Is temporarily stored in the moisture separator drain tank 23 on the floor where the moisture separator heater 5 is installed, and then passes through the moisture separator drain tank water level control valve 24 arranged on the floor where the drain recovery tank 31 is installed. Then, it is sent to the drain recovery tank 31 together with the drain from the drain cooler 30. In the drain recovery tank 31, the drain from the moisture separator drain and the drain from the drain cooler 30 are combined and stored once, and then the drain is sent to the drain pump 29. In addition, drain cooler 3
In order to fill 0 with drain, the drain recovery tank 31 is arranged such that the drain water level in the tank is slightly higher than the top of the drain cooler 30.

In this embodiment, the heater drain of the moisture separator heater, the moisture separator drain, the highest pressure feed water heater drain and the next stage feed water heater drain are smoothly transferred as follows, and the drain flush is performed. The drain can be supplied to the drain pump without generating water.

Since the turbine bleed air to the heater 7 is bleed from the upstream stage of the high pressure turbine 3 more than the turbine bleed air to the highest pressure feed water heater 19, the pressure of the drain of the heater 7 which is the condensed drain is the lowest. The pressure of the high-pressure feed water heater 19 is higher than that of the high-pressure feed water heater 19, and the drain of the heater 8 is the main steam drain. Therefore, the drains of the heater drain tanks 25 and 26 are sent to the maximum pressure feed water heater 19 using this pressure difference. Similarly, the drain from the highest pressure feed water heater 19 can be transferred to the next-stage feed water heater 18 without any problem due to the pressure difference.

One of the features of this embodiment is that the drain from the next-stage feed water heater 18 is sent to a drain cooler 30 installed on the floor further below by a positional difference to cool the drain (subcool). Drain cooler 3
At 0, the drain at the outlet of the drain cooler 30 is a supercooled drain because the drain is cooled by the water supply downstream of the steam generator water supply pump 17. This supercooled drain is further merged with the moisture separator drain in the drain recovery tank 31 and is temporarily stored. Since the condensed moisture separator drain is a saturated drain, the temperature of the supercooled drain from the drain cooler 30 slightly increases in the drain recovery tank 31, but the drain amount at the outlet of the drain cooler 30, that is, the outlet of the next-stage feed water heater 18 is generally Since the drain amount is overwhelmingly large, the drain from the drain recovery tank 31 is still a supercooled drain, and this drain is stably sent to the drain pump 29.

Further, a feature of this embodiment is that the drain of the moisture separator drain tank 23 is guided to the drain recovery tank 31. As described above, the pressure of the moisture separator drain is substantially the same as the pressure of the next-stage feedwater heater 18, that is, the pressure of the drain recovery tank 31. However, in this embodiment, as shown in FIG. 2, between the moisture separation drain tank 23 and the drain recovery tank 31, a next-stage feed water heater 18 is provided.
There is a sufficient positional difference beyond the installation floor. Generally, in a building of a nuclear power plant, the distance between floors is about 8 m. Therefore, in this embodiment, there is about 12 m between the drain water level of the moisture separator drain tank 23 and the drain water level of the drain recovery tank 31. Position difference can be secured. Therefore, the moisture separator drain tank 23 to the drain recovery tank 31
Separator drain tank water level control valve 2
4 can provide a sufficient hydrostatic head so that no drain flush occurs. Further, the water level of the moisture separator drain tank 23 can be controlled without any trouble by the moisture separator drain tank water level control valve 24.

As described above, according to this embodiment, the drain generated in the moisture separator 6 can be smoothly transferred without the drain being flushed by the moisture separator drain tank water level control valve 24. The water level of the moisture separator drain tank 23 can be controlled well. Further, the drain from the next-stage feed water heater 18 is cooled by the drain cooler 30,
Since the drain at the outlet of the drain cooler 30 is sent to the drain pump 29 as a supercooled drain, the drain does not flush in the drain pipe line to the drain pump 29,
The next-stage feed water heater 18 depends on the load fluctuation of the power plant.
Even when the internal pressure changes, the drain pump 29 is not damaged by the incorporation of air bubbles unlike the prior art.

In the above-mentioned embodiment, the drain from the moisture separator drain tank 23 is configured to be collected in the drain recovery tank 31. However, as shown in FIGS. The container drain may be led to the drain cooler 30. In the case of this embodiment, the moisture separator drain tank water level control valve 24 can be disposed lower,
Since it can give a larger hydrostatic head, it is more effective in preventing drain flush. Further, in the drain cooler 30, the drain generated in the moisture separator together with the drain from the next-stage feed water heater 18 is also cooled, so that the drain pump 29 can be supplied with a lower-temperature supercooled drain.

FIG. 5 shows another embodiment. The difference from the embodiment shown in FIG. 9 is that a drain recovery tank 30 is first installed in a drain pipe from the next-stage feed water heater 18 and a moisture separation drain tank is provided. The point is that the drain from the moisture separator 23 is sent to the drain recovery tank 31 together with the drain from the feed water heater 18 in the next stage. A drain cooler 30 using water as a cooling medium is provided in a water supply line downstream of the steam generator water supply pump 17.
The drain from the drain recovery tank 31 is sent to the drain cooler 30, and the steam generator feed pump 1
It is configured to supply heat to the drain pump 29 after being cooled (sub-cooled) by performing heat exchange with the supply water at the 7 downstream.

FIG. 6 is a diagram showing the installation position of each device and the drain line in the embodiment of FIG. In general, the moisture separation heater and the high-pressure feed water heater are installed on both sides of the turbine shaft, that is, two lines, but in FIG.
Only). As shown in FIG. 6, the moisture separation heater 5 is installed on the floor of the building where the high-pressure turbine 3 and the low-pressure turbine 11 are provided, that is, on the turbine operation floor, and the highest-pressure feedwater heater 19 and the next-stage feedwater heating are provided. The vessel 18 is installed on the floor below the installation floor of the moisture separation heater 5. The drain generated in the heaters 7 and 8 of the moisture separation heater 5 is supplied to the heater drain tank 25 and the heater drain tank 25 below the turbine operation floor.
After being temporarily stored at 26, both are sent to the maximum pressure feed water heater 19 through the heater drain tank water level control valves 27 and 28, respectively. The next-stage feedwater heater 18 collects the drain from the highest-pressure feedwater heater 19, and the drain from the next-stage feedwater heater 18 is sent to a drain collection tank 31 provided on the floor further below. Drain generated in the moisture separator 6 of the moisture separation heater 5 is temporarily stored in the moisture separator drain tank 23 below the turbine operation floor, and then stored on the installation floor of the drain recovery tank 31. The water is sent to the drain recovery tank 31 in the same manner as the next-stage feed water heater drain through the separator water tank water level control valve 24. Further, a drain cooler 30 that is cooled by water supply downstream of the steam generator water supply pump 17 is provided below the installation position of the drain recovery tank 31, and the drain from the drain recovery tank 31 is sufficiently cooled (subcooled). It is configured to be supplied to the drain pump 29.

In this embodiment, the heater drain of the moisture separator heater, the moisture separator drain, the highest pressure feed water heater drain and the next stage feed water heater drain are smoothly transferred as follows, and the drain is flushed. The drain can be supplied to the drain pump without generating water.

The turbine bleed air to the heater 7 is bleed from the upstream stage of the high-pressure turbine 3 more than the turbine bleed air to the maximum pressure feed water heater 19, so that the pressure of the condensate drain of the heater 7 is minimized. Since the drain of the heater 8 is higher than the pressure of the high pressure feed water heater 19 and the drain of the heater 8 is the main steam drain, the pressure is naturally higher than the pressure of the highest pressure feed water heater 19. Therefore, the drains of the heater drain tanks 25 and 26 are sent to the maximum pressure feed water heater 19 using this pressure difference. Similarly, the drain from the highest-pressure feedwater heater 19 can be transferred to the next-stage feedwater heater 18 without any problem due to the pressure difference. The drain from the next-stage feed water heater 18 flows into a drain recovery tank 31 installed on the floor further down and is temporarily stored due to the positional difference.

One of the features of this embodiment is that the drain of the moisture separator drain tank 23 is guided to the drain recovery tank 31. As described above, the pressure of the moisture separator drain is substantially the same as the pressure of the next-stage feed water heater 18, that is, the pressure of the drain recovery tank 31. However, in this embodiment, as shown in FIG. 6, the moisture separator drain tank 23 and the drain recovery tank
1, a sufficient positional difference is provided beyond the installation floor of the next-stage feed water heater 18.

In general, since the floor-to-floor distance is about 8 m in a building of a nuclear power plant, in this embodiment, the drain water level of the moisture separator drain tank 23 and the drain water level of the drain recovery tank 31 are approximately equal. A position difference of 13 m can be secured. For this reason, the moisture separation drain tank water level control valve 2 provided in the drain pipe at the inlet of the drain recovery tank 30
4 can have a sufficient hydrostatic head so that no drain flush occurs. Also, the water level of the moisture separator drain tank 23 can be controlled without any trouble by the moisture separator drain tank water level control valve 24.

Further, as a feature of this embodiment, the drain from the drain recovery tank 31 is cooled (subcooled) by a drain cooler 30 provided on the floor further below. For this reason, the drain that has exited the drain cooler 30 can always be kept in a supercooled state where the temperature is lower than the saturation temperature, so that it is stably transferred to the drain pump 29.

As described above, according to this embodiment, the drain generated in the moisture separator 6 can be smoothly transferred without the drain being flushed by the moisture separator drain tank water level control valve 24. The water level of the moisture separator drain tank 23 can be controlled well. Further, since the drain from the drain recovery tank 31 is cooled by the drain cooler 30 to form a supercooled drain, the drain does not flush in the drain pipe to the drain pump 29, and the next stage is caused by fluctuations in the load of the power generation plant. Even when the pressure in the feed water heater 18 changes, the drain pump 29 will not be damaged by air bubbles.

In the above-described embodiment, the drain from the highest pressure feed water heater 19 is supplied to the next stage feed water heater 1 by the pressure difference.
8 and is collected in the drain recovery tank 31. However, as in the embodiment shown in FIGS. 7 and 8, the drain from the highest-pressure feed water heater 19 and the next-stage feed water heater are generated. The drain and the drain generated in the moisture separator 6 may be sent to the drain recovery tank 31. Also in this embodiment, the drain from the maximum pressure feed water heater 19 can be collected in the drain collection tank 30 by a pressure difference. Further, in this embodiment, since the next-stage feedwater heater 18 does not need to receive the drain from the highest-pressure feedwater heater 19, the drain treatment amount in the next-stage feedwater heater 18 is reduced, and the next-stage feedwater heater is reduced. There is also an effect that 18 can be downsized.

[0041]

As described above, according to the present invention, the drain generated by the heater of the moisture separation heater, the drain generated by the moisture separator, and the drain from the feed water heater are flushed with the drain. The drain pump can be smoothly transferred to the drain pump without causing the drainage, and the drain pump can be safely operated, and a highly reliable drain recovery device can be provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory view of a device installation position of the embodiment shown in FIG.

FIG. 3 is a configuration diagram showing a second embodiment of the present invention.

FIG. 4 is an explanatory view of a device installation position of the embodiment shown in FIG. 3;

FIG. 5 is a configuration diagram showing a third embodiment of the present invention.

FIG. 6 is an explanatory view of a device installation position of the embodiment shown in FIG.

FIG. 7 is a configuration diagram showing a fourth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a device installation position of the embodiment shown in FIG. 7;

FIG. 9 is a configuration diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam generator 2 Main steam pipe 3 High pressure turbine 4 Low temperature reheat steam pipe 5 Moisture separation heater 6 Moisture separator 7 Heater 8 Heater 9 Bleed pipe 10 High temperature reheat steam pipe 11 Low pressure turbine 12 Condenser 13 Condenser pump 14 Low pressure feed water heater 15 Low pressure feed water heater 16 Condenser pipe 17 Steam generator feed pump 18 Next stage feed water heater 19 Maximum pressure feed water heater 20 Water feed pipe 21 Bleed pipe 22 Bleed pipe 23 Moisture separator drain Tank 24 Moisture separator drain tank water level control valve 25 Heater drain tank 26 Heater drain tank 27 Heater drain tank water level control valve 28 Heater drain tank water level control valve 29 Drain pump 30 Drain cooler 31 Drain recovery tank

Claims (6)

(57) [Claims] 1. A drain generated by a moisture separator heater installed in a nuclear power plant is sent to a maximum pressure feed water heater or a next-stage feed water heater, and the drain of the maximum pressure feed water heater or the next-stage feed water heater is discharged. In a nuclear power plant in which the pressure is increased by a drain pump and collected in a condensate pipe, the highest pressure feed water heater and the next heater are disposed below the floor of the building where the moisture separation heater is installed. Install a stage feed water heater, install a drain cooler for cooling the drain from the next stage feed water heater below the installation position of the next stage feed water heater, from the installation position of the next stage feed water heater A drain recovery tank for storing the drain from the drain cooler below the drain cooler. 2. A drain from a heater of the moisture separation heater is supplied to the highest pressure feedwater heater, and a drain from the highest pressure feedwater heater is supplied to the next stage feedwater heater. 2. The drain recovery device for a nuclear power plant according to claim 1, wherein the drain from the moisture separator of the separation heater is supplied to the drain recovery tank. 3. A drain from the heater of the moisture separation heater is supplied to the highest pressure feedwater heater, and a drain from the highest pressure feedwater heater is supplied to the next stage feedwater heater. 2. The drain cooler according to claim 1, wherein the drain from the moisture separator of the separation heater is supplied to the drain cooler.
A drain recovery device for a nuclear power plant as described in the above. 4. A drain generated by a moisture separation heater installed in a nuclear power plant is sent to a maximum pressure feed water heater or a next-stage feed water heater, and the drain of the maximum pressure feed water heater or the next-stage feed water heater is discharged. Is recovered by a drain pump by raising the pressure in a drain pump, the highest pressure feed water heater on a floor lower than the building floor where the moisture separation heater is installed. And installing the next-stage feedwater heater, and draining the moisture and the moisture separation heater from the next-stage feedwater heater on a floor lower than the installation position of the highest-pressure feedwater heater and the next-stage feedwater heater. A drain recovery tank for storing the drain from the moisture separator of the present invention, and a drain for cooling the drain from the drain recovery tank on a floor lower than the installation position of the drain recovery tank. A drain recovery device for a nuclear power plant, comprising a ren cooler. 5. The drain from the heater of the moisture separation heater is supplied to the highest pressure feedwater heater, and the drain from the highest pressure feedwater heater is supplied to the next stage feedwater heater. The drain recovery apparatus for a nuclear power plant according to claim 4, wherein: 6. The method according to claim 6, wherein the drain from the heater of the moisture separation heater is supplied to the highest-pressure feedwater heater, and the drain from the highest-pressure feedwater heater is supplied to the drain recovery tank. 5. The drain recovery device for a nuclear power plant according to claim 4, wherein: