JP2001194488A - Condensor cooler of power plant and its operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the flow of thermal discharge and increase the electric power of a power plant. SOLUTION: Seawater, taken in from an intake 20, is introduced into a sea water pit 22 and sent into heat conduction pipes of a condenser by driving a seawater pump 47. The steam discharged from a low-pressure turbine 6 is cooled by the seawater supplied to the heat conduction pipes and condensed. The heated seawater, discharged from of the heat conduction pipes is introduced into a temporary seawater reservoir 33 through an exhaust path 24. Ten percent of seawater introduced to the temporary seawater reservoir 33 is introduced by a cooler canal 25 to a cooler 26. The rest 90% is discharged through a drainage canal 34 to the sea. The seawater, cooled by the cooler 26 and lowered in temperature, is returned to the seawater pit 22 by the cooler canal 25 and supplied to the heat conduction pipes of the condenser 7, together with the seawater flowing into the intake 20 and is reused for condensing steam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condenser cooling device for a power plant and an operation method thereof, and more particularly to a condenser cooling device for a power plant suitable for application to a thermal power plant and a nuclear power plant. And its operation method.

[0002]

2. Description of the Related Art In a power plant, such as a thermal power plant or a nuclear power plant, which generates steam by driving a turbine, steam discharged from a low-pressure turbine is condensed by a condenser in order to improve the efficiency of the turbine. And reduce the back pressure. In order to condense the steam, seawater, which is cooling water taken from the ocean, is guided into the heat transfer tubes of the condenser. If the power plant is installed near a river, cooling water taken from the river (called river water)
Is supplied into the heat transfer tube of the condenser. Seawater (or river water) used to condense steam discharged from the heat transfer tubes
Rises in temperature. In some power plants, river water (or seawater) is cooled by cooling towers, cooled down, and then returned to the original river (or ocean). In many cases, warmed river water (or seawater) is released directly into rivers (or oceans). In the case of a nuclear power plant, the thermal efficiency is about 33%, 6% of the total heat generated by the reactor.
7% is released as waste heat.

In Europe, river water is often used as condenser cooling water. Since the rise in water temperature of the river is severely restricted downstream of the power plant, the river water discharged from the condenser is generally cooled before being discharged into the river. In this case, a large cooling tower is used to cool a large amount of river water. The river water is brought into contact with air in the cooling tower, and the heat of the river water is transferred to the air side and released to the atmosphere.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a condenser cooling device for a power plant which can reduce the amount of hot waste water discharged and increase the electric output of the power plant.

[0005]

SUMMARY OF THE INVENTION A feature of the present invention to achieve the above-mentioned object is to connect a drain passage connected to a heat transfer tube and opening to a river or an ocean, and a heat transfer tube provided in a condenser. A return passage communicating with the intake passage
That is, a cooling device is provided in the return passage.

By providing a return passage provided with a cooling device, a part of the cooling water flowing in the drain passage is cooled and then supplied to a condenser to be used for condensation of steam. Therefore, it is possible to reduce the amount of hot wastewater discharged into a river or ocean through the drainage passage. Further, by cooling the cooling water with the cooling device, the difference in temperature of the cooling water supplied to the condenser between summer and winter can be reduced. For this reason, it is possible to reduce the difference in the condensation capacity of steam in the condenser between summer and winter,
The power output of the power plant can be increased.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A condenser cooling device for a power plant according to a preferred embodiment of the present invention applied to a boiling water nuclear power plant (hereinafter, referred to as a BWR plant) will be described with reference to FIGS. Will be explained.

An outline of a BWR plant to which this embodiment is applied will be described with reference to FIG. In the nuclear reactor 1, the cooling water is heated by the heat generated by the fission of the nuclear fuel material loaded in the core, and steam is generated. This steam is guided to the high-pressure turbine 3 through the main steam pipe 2. The steam discharged from the high-pressure turbine 3 is sent to the low-pressure turbine 5 after the moisture is removed by the moisture separator 4. The high-pressure turbine 3, the low-pressure turbine 5, and the generator 6 are connected, and the generator 6 is rotated by driving these turbines with steam. The steam discharged from the low-pressure turbine 5 is condensed in the condenser 7. By condensing this steam, the back pressure of the low-pressure turbine 5 is reduced,
The efficiency of the turbine is improved. The condensed water generated by the condensation in the condenser 7 is sequentially pressurized by the low-pressure condensate pump 8, the high-pressure condensate pump 9, and the water supply pump 10, and supplied to the reactor as water through a water supply pipe 15. Is done. During that time, the feedwater is purified by the pre-filter 11 and the desalinator 12, and is heated by the low-pressure feedwater heater 13 and the high-pressure feedwater heater 14 to increase the temperature. The condenser 7 is a low-pressure turbine 5
Thousands of heat transfer tubes are provided inside to condense the steam exhausted from. Reference numeral 17 denotes a recirculation pipe in which a recirculation pump 16 is installed, and 19 denotes a reactor purification pipe in which a desalter 18 is installed.

The condenser cooling device of this embodiment comprises an intake canal 21, a seawater pit 22, an intake line 23, a drain line 24,
Cooling device canal 25, cooling device 26, seawater temporary storage tank 3
3 and a discharge path 34. This condenser cooling device will be described in detail with reference to FIGS. The BWR plant
Located near the ocean. The water intake canal 21 is connected to a water intake 20 that opens to the ocean, and is connected to a seawater pit 22. The intake pipe 23 is composed of the seawater pit 22 and the condenser 7.
A seawater pump 47 is provided to communicate with the inlet side of the heat transfer tube inside. The drainage pipe 24 connects the outlet side of the heat transfer pipe in the condenser 7 with the temporary seawater storage tank 33. The drainage channel 34 connected to the temporary seawater storage tank 33 is connected to the ocean via a discharge port (not shown). The cooling device canal 25 is connected to the drain pipe 2
4 and the seawater pit 22, specifically, the seawater temporary storage tank 33 and the seawater pit 22. The weir 3 is provided at the discharge part of the seawater temporary storage tank 33 on the cooling device canal 25 (entrance canal 28) side.
5 are provided. A weir 36 is also provided at the discharge portion of the temporary seawater storage tank 33 on the drainage channel 34 side. Weir 35 and weir 36
Can be moved up and down. The cooling device 26 is arranged in the cooling device canal 25. The cooling device 26 includes 20 cooling towers 26A,..., 26T, and 20 water storage tanks 2.
7A,..., 27T. One cooling tower and one water storage tank are provided as a pair to form a cooling tower unit.
In each cooling tower unit, a cooling tower covers the water storage tank. That is, as shown in FIG. 3, the cooling tower 26A is located above the water storage tank 27A, and the cooling tower 26A is
A is covered. The cooling tower 26T is also located above the water storage tank 27T, and the cooling tower 26T covers the water storage tank 27T. Other cooling towers 26B, 26C, 26D, 26E, 26F, 2
6G, 26H, 26I, 26J,.
27H, 27I, 27J,... These cooling towers and water storage tanks are arranged adjacent to each other in the horizontal direction as shown in FIG. In FIG. 3, the cooling towers 26F-
26T and the water storage tanks 27F to 27T are omitted, and in FIGS. 4 and 5, the cooling towers 26K to 26T and the water storage tanks 27K to 27T are omitted.

The cooling device canal 25 has an inlet canal 28 and an outlet canal 29. The entrance canal 28 has a plurality of branched canals 28A,..., 28T. The branch canals 28A,.
7A,..., 27T. Exit Canal 29
, 27T are connected to the water storage tanks 27A,. The installation state of the floodgate is shown in FIG. Each of the branch canals 28A, ..., 28J has its own gate 31A, ...
, 31J are provided. Water tank 27 at exit canal 29
A,..., Sluice gate 32A,.
32J are provided. Although not shown, a water gate is also provided in each of the branch canals 28K (not shown),..., 28T, and is connected to each of the water tanks 27K (not shown),. Each has a lock.

The structure of each cooling tower unit is the same as that of the cooling tower 26A.
And a cooling tower unit including the water storage tank 27A. The cooling tower 26A incorporates a packed bed 37 in order to increase the gas-liquid contact efficiency between seawater and air. Seawater supply pipe 40
Connects the water storage tank 27A and the cooling tower 26A. The seawater supply pipe 40 opens to the cooling tower 26 </ b> A above the packed bed 37. A pump 41 and a valve 42 are provided on the seawater supply pipe 40. A pipe 43 having a valve 44 is connected to a pump 41.
And a valve 42 connected to the seawater supply pipe 40. An air supply pipe 45 provided with a blower 46 is connected to the cooling tower 26A.

Each cooling tower of this embodiment cools 1000 tons / hour of seawater at 40 ° C. to 30 ° C. Atmospheric temperature 2
When the temperature is 5 ° C. and the humidity is 70%, the specifications of the cooling tower unit are as follows. The inside diameter of the bottom of the cooling tower is 10 m, the inside diameter of the top of the cooling tower is 9 m, the capacity of the water storage tank is 1200 m ³ , the total height of the cooling tower is 27 m, and the number of stages of the packed bed 37 is 140.

In the case of a BWR plant with an electric power output of 1.1 million kWe, the total heating value of the reactor is 3.3 million kWt (2.9 ×
10 ¹² cal / h). Since the thermal efficiency of the steam turbine generator is 33%, 1.9
A calorie of × 10 ¹² cal / h is released to seawater. If the temperature rise of seawater is 10 ° C., the total amount of seawater used for cooling is 1.9 × 10 ⁵ tons / hour. All of the above calories,
In order to perform cooling using the above cooling tower, 190 cooling towers are required. However, if 190 cooling towers are lined up, it becomes difficult to secure the site area, and the inspection and maintenance work for them becomes enormous. In order to solve such a problem, in this embodiment, a part of the seawater discharged from the condenser is cooled by the cooling tower and then supplied to the condenser again,
The rest of the seawater discharged from the condenser is discharged directly to the ocean. For example, assuming that the amount of seawater guided to the cooling tower by the inlet canal 28 and cooled by the cooling tower is F ₁ , and the amount of seawater discharged directly to the ocean by the drain 34 is F ₂ , F ₁ : F ₂ Is 10:90. In the case of a BWR plant with an electrical output of 1.1 million kWe, the amount of heat dissipated in the cooling tower is 1.9 × 10 ¹¹ cal / h, and the total amount of seawater cooled by the cooling tower is 1.9 × 10 ⁴ tons / h. Therefore, 19 cooling towers of the above specifications are sufficient. Equipped with 20 cooling towers, one of which is always reserved.
By using this spare cooling tower, another 19 cooling towers can be used.
Maintenance and inspection of the original cooling tower becomes easier. In addition, since only 20 cooling towers are required, the required site area can be significantly reduced.

In cooling using river water, when the entire amount of river water discharged from the condenser is cooled by the cooling tower,
Two very large cooling towers with an inner diameter of 60 m at the bottom and a height of 70 m are used.

The cooling using the condenser cooling device of this embodiment will be described. Seawater taken into the water intake canal 22 from the water intake 20 is guided into the seawater pit 22. By driving the seawater pump 47, the seawater is sent from the seawater pit 22 into the heat transfer pipe of the condenser 7. The steam discharged from the low-pressure turbine 6 is cooled and condensed by the seawater supplied into the heat transfer tubes. The temperature discharged from the heat transfer tube is about 10 ° C
The raised seawater is guided to the seawater temporary storage tank 33 by the drainage pipe 24. 10% of the seawater guided to the seawater temporary storage tank 33 is guided to the cooling device 26 by the inlet canal 28. Specifically, 10% of the seawater is stored in each water tank 2
7A, 27B, 27C, 27D, 27E, 27F, 27
G, 27H, 27I, 27J,... 27T.
The remaining 90% is discharged from the outlet through the drain 34 to the ocean. The seawater cooled to a temperature of about 30 ° C. by the cooling device 26 is supplied to the seawater pit 22 by an outlet canal 29.
And is supplied into the heat transfer tube of the condenser 7 together with the seawater guided by the water intake canal 21 to be used again for condensation of steam.

The flow rate of seawater supplied from the temporary seawater storage tank 33 to the inlet canal 28 and the drainage channel 34 is adjusted by adjusting the heights of the weirs 35 and 36. When the flow rate of seawater to the entrance canal 28 side is increased, the weir 35 is lowered, and when the amount of seawater is reduced, the weir 35 is raised. When the seawater flow rate to the inlet canal 28 side is set to zero, the weir 35 is moved sufficiently upward without changing the height of the weir 36. When the amount of seawater discharged to the drainage channel 34 is reduced, the weir 36 is lowered, and when the amount of seawater is reduced, the weir 36 is raised. In order to reduce the amount of seawater to the drainage channel 34 to zero, the weir 36 may be moved sufficiently upward. The movement of the weirs 35 and 36 is easily performed by driving a motor (not shown). The height of the weirs 35 and 36 is adjusted so that the flow rate of seawater toward the inlet canal 28 is 10%, and the flow rate of seawater toward the drain 34 is 90%. In the present embodiment, the flow rate of hot wastewater discharged to the ocean and the amount of heat discharged can be realized by very simple control such as movement of the weirs 35 and 36.

The cooling of seawater in each cooling water unit is as follows:
Description will be made using a cooling tower unit having a cooling tower 26A and a water storage tank 27A. Seawater supplied to the water storage tank 27A is:
The water is supplied into the cooling tower 26A above the packed bed 37 through the seawater supply pipe 40 by the drive of the pump 41. Valve 4
2 is open and valve 44 is closed. By driving the blower 46, air is supplied through the air supply pipe 46 into the cooling tower 26A below the packed bed 37. The air flow 39 rises in the packed bed 37, and the supplied seawater falls as a seawater droplet 38 in the packed bed 37. Seawater droplet 38 and air stream 39
Are brought into countercurrent contact with the packed layer 37, so that the amount of heat held by the seawater droplet 38 is transmitted to the airflow 39. The air stream 39 moistened until the temperature rises and reaches the saturated vapor pressure,
It is discharged outside from the top of the cooling tower 26A. The seawater droplet 38 whose temperature has dropped falls into the water storage tank 27A. The cooled seawater is sent to the seawater pit 22 through the outlet canal 29.

In the present embodiment, the amount of seawater discharged from the condenser 7 and returned to the ocean is reduced by the amount of seawater returned to the seawater pit 22 by the cooling device canal 25. For this reason, the amount of hot waste water is reduced as compared with the conventional case. The important point in this embodiment is to return the seawater cooled by the cooling tower to the upstream side of the seawater pump 47 (for example, the seawater pit 22). In particular, the seawater cooled by the cooling tower is preferably returned to the upstream side of the seawater pump 47 downstream of the water intake 20. With the seawater itself discharged from the cooling tower, the condenser 7
Since the head for supplying the seawater is insufficient, it is indispensable to pressurize the seawater by the seawater pump 47. In addition, when seawater discharged from the cooling tower is returned to the ocean from the water inlet 20, the power generation efficiency of the BWR plant is reduced.

In the present embodiment, a part of the seawater discharged from the condenser is cooled by the cooling tower, so that the size of the cooling tower can be reduced. Further, in the present embodiment, since a plurality of cooling towers are provided and a spare cooling tower is provided, the operation of the entire condenser cooling device is stopped due to failure of the cooling tower and incidental equipment such as a pump. Maintenance inspection can be performed without the need.
In the present embodiment, since 10% of the amount of seawater discharged from the condenser 7 is cooled by the cooling tower and used for steam condensation in the condenser 7, the amount of hot wastewater discharged to the ocean is reduced. it can.

When considering the arrangement of the cooling towers 26A to 26T, the cooling tower and its auxiliary equipment group are efficiently arranged within a limited site, and at the same time, the space for inspection and repair of the cooling tower and its auxiliary equipment is increased. It is important to be prepared. The diameter of the bottom of the cooling tower for cooling the seawater of 1000 tons / hour described above is 10 m, and a site area of 15 m square is required for each tower including the auxiliary equipment space and the inspection space. In order to install 20 cooling towers, it is necessary to secure a site area of 4500 m ^{2 on} the plant site. It is often difficult to secure such a site area on land. On the other hand, in the cooling tower, it is necessary to install a water storage tank for storing seawater to be cooled in order to maintain the operation stability of each tower, and particularly to avoid cavitation of the circulation pump. In this embodiment, as shown in FIG. 3, since the cooling tower is arranged so as to cover the water storage tank, it is possible to effectively use the sea space, and at the same time, direct sunlight to seawater in the water storage tank. Can be avoided. One water tank is 15 m in length and width and 5.3 m in effective depth, so it can store about 1200 m ³ of seawater.

In this embodiment, since the seawater is cooled by the cooling tower, salt and minerals in the seawater can be concentrated in the cooling tower, and seaweed, algae or shellfish can be propagated in the filling tank 37 in the cooling tower. There is. Concentration of salts and minerals may increase the flow resistance of the cooling tower or the heat transfer tubes of the condenser, and eventually lead to blockage of the flow path. However, in this embodiment, part of the seawater discharged from the condenser (specifically,
%) Is cooled in the cooling towers, so that the concentration of salt and minerals in the seawater due to the evaporation of the seawater in each cooling tower is slight. Moreover, the concentrated salt and mineral components are diluted by a large amount of seawater taken in from the water intake 20 in the seawater pit 22. Therefore, the flow resistance of the cooling tower or the heat transfer tube of the condenser does not increase, and the flow passage is not blocked.

If seagrass, algae or shellfish grow in the packed bed 37 of the cooling tower, the heat transfer performance of the cooling tower may be greatly impaired, and the cooling tower may be unusable. In particular, in the packed bed 37, since seawater is sufficiently in contact with the atmosphere and oxygen is sufficiently supplied, biological conditions such as seaweeds and shellfish are good, and there is a high possibility of causing thermal efficiency inhibition. In addition, if the cooling tower is dried when the BWR plant is shut down, these organisms will die. However, these dead bodies will be released into seawater at one time, so the quality of seawater deteriorates, that is, the BOD (biological oxygen concentration) decreases. It can cause secondary adverse effects on the BWR plant as well as the environment, such as growth and the generation of odors.

The most effective means of preventing the growth of such marine life and preventing the packed bed 37 from becoming a hotbed of marine life is to raise the temperature of seawater in the cooling tower.
Marine organisms that thrive around 30 ° C. cannot breed at temperatures above 50 ° C. above 40 ° C., and most die. The use of liquids to kill marine organisms is very dangerous when considering the impact on the environment, so it is preferable to avoid them, and it is possible to kill them simply by increasing the temperature of the cooling water. preferable. Moreover, it is fundamental to kill as much as possible using seawater.

In the present embodiment, seawater is cooled by operating one spare cooling tower, and cooling of seawater by one of the 19 cooling towers in operation is stopped. Spray seawater heated to ℃. When spraying the seawater, the valve 44 is opened and the valve 42 is closed. Pump 41 remains driven. Seawater heated to 50 ° C. by a heater (not shown) is supplied above the packed bed 37 of the cooling tower through the pipeline 43 and the seawater supply pipe 40. The seawater at 50 ° C. flows down in the filling tank 37. For this reason, marine creatures are killed in the early stage of growth and released together with seawater.
The cooling of seawater by the 19 cooling towers was sequentially stopped, and 50 ° C
To kill the marine life in each cooling tower such as in the filling tank 37. In this embodiment, the packed layer 3 which is the most concerned
7, and the propagation of marine life to other parts of the cooling tower,
It can be prevented by a very simple means of spraying warm water of 50 ° C. or higher.

If the cycle of this operation is made slow, the growth of marine organisms between the cycles cannot be ignored.
The cooling towers are disconnected at a rate of two per day, with one cycle as day 0, and heated seawater is sprayed into the cooling towers to kill marine life and inspect the cooling towers, including auxiliary equipment. .
However, the inspection itself does not require the frequency of spraying heated seawater, so the process of disconnecting the cooling tower and spraying hot water can be performed by automatic operation.

By mixing steam from a house boiler or the like in a BWR plant with seawater instead of a heater, the salt concentration of seawater is reduced to about 50 without greatly diluting other components.
℃ seawater. Further, in the BWR plant, the cooling target by seawater is not only the condenser, but also the auxiliary equipment cooling system for cooling the non-regenerative heat exchanger of the reactor water purification system and the other auxiliary equipment cooling systems. Since the source of seawater at about 50 ° C required here is diverse, high-temperature seawater discharged from the auxiliary cooling system is supplied to the cooling tower by a valve switching operation, and the seawater in the cooling tower is supplied to the cooling tower. Can be used to kill organisms.

At the time of the above-mentioned marine life killing operation and maintenance inspection operation, the cooling tower units are disconnected and arranged in parallel at the floodgates 31A, 31B,... Floodgates 32A, 32B, ...
The operation is performed by operating each lock such as. 1 hour
To switch the flow of seawater of 2,000 tons with a valve,
A large valve is required, and it may be difficult to secure the reliability of the valve used in seawater. In this embodiment, since a floodgate is used, such a problem does not occur. For example, when the cooling tower 26A is disconnected, the sluice 31
A and 32A are closed simultaneously. When disconnecting the cooling tower 26B with the cooling tower 26A, the locks 31A and 32A are simultaneously opened, and then the locks 31B and 32B are simultaneously closed. By sequentially performing such an operation on the corresponding sluice gate (FIG. 5), all the cooling towers can be sequentially disconnected and arranged in parallel. These gates can be easily operated by driving a motor (not shown) to move the gate up and down.

The condenser cooling device according to the present embodiment comprises a cooling recirculation system for cooling a part of seawater discharged from the condenser by a cooling tower and reusing it for cooling steam in the condenser. Has the function of both direct discharge of seawater directly to the ocean, so that the BWR plant can be operated to increase the heat output of the BWR plant without increasing the amount of seawater exhaust heat. In addition, the condensation capacity of steam in the condenser changes according to the change in the temperature of the seawater due to the change of the season. The change in the power generation efficiency of the BWR plant due to the change in the condensing capacity can be adjusted by adjusting the ratio of the amount of seawater circulated in the cooling recirculation or the cooling effect of the cooling device 26.

In this embodiment, the heat output of the BWR plant can be increased to the ratio of the flow rate of seawater cooled by the cooling tower to the total flow rate of seawater supplied to the condenser 7 (10% in this embodiment). . Increased heat output in BWR plants leads to increased electrical output.

In general, it is difficult to measure the amount of hot wastewater discharged to the ocean because the amount of hot wastewater discharged is large. For this reason, conventionally, the amount of heat released to the environment as hot wastewater is calculated using the amount of seawater taken in at the water intake 20 and the seawater temperature at the inlet and outlet of the condenser. In the present embodiment, the calculation is basically similar. Even if the total calorific value is determined in the same manner as before, the calorie released from the cooling tower to the outside atmosphere (air calorific value) using the seawater flow rate at the cooling tower and the seawater temperature difference at the entrance and exit of the cooling tower It is easy to calculate, and the total amount of released seawater (the amount of hot wastewater released to the ocean) and the total amount of released heat (the amount of heat released to the ocean by the hot wastewater) can be calculated based on the amount of circulating seawater (through the cooling tower, through the condenser). The amount of seawater released to the ocean and the amount of heat released are calculated by subtracting the amount of heat released to the atmosphere (for cooling the steam) and the atmosphere. It is easy to control these values to be always equal to or less than the target value.

As is well known, in winter, the temperature of seawater decreases, and the efficiency of vacuuming the condenser increases. On the other hand, in summer, the evacuation efficiency of the condenser decreases due to the rise in seawater temperature. For this reason, the power generation efficiency of the BWR plant is improved in winter rather than in summer. However, in this embodiment, the seawater temperature at the condenser inlet in summer and winter is leveled in summer and winter.

A preferred measure to keep the vacuum efficiency of the condenser in summer and winter constant without changing the flow rate of seawater discharged into the ocean is to change the cooling efficiency of the cooling tower between summer and winter. In the summer, all the cooling towers are operated at a rated rate, and air for cooling is blown into the cooling tower in a rated amount. In winter, the cooling efficiency in the cooling tower is reduced by partially shutting off the cooling air supplied into the cooling tower. By performing such an operation, in winter when the seawater temperature is originally low, even if the cooling efficiency of the seawater by the cooling tower is reduced, the vacuuming efficiency of the condenser is maintained at a high state. In summer, when the seawater temperature is high, the amount of air supplied to the cooling tower is increased to increase the efficiency of cooling the seawater by the cooling tower. Therefore, the seawater temperature at the condenser inlet in summer can be reduced so as to approach the seawater temperature in winter. As a result, it is possible to reduce the difference between the vacuuming efficiency of the condenser in summer and the winter, and to improve the power generation efficiency of the BWR plant.

Another embodiment of the cooling tower unit will be described with reference to FIGS. 8 and 9 by using a cooling tower 26A and a water storage tank 27 shown in FIG.
The difference from the cooling tower unit provided with A will be described. FIG.
The same reference numerals have the same configuration. The cooling tower unit of this embodiment includes a cooling tower 26A1 and a water storage tank 27A. 7 have the same configuration. The cooling tower 26A1 is
An auxiliary water tank 48 is provided at the bottom. One side wall of the auxiliary water tank 48 becomes a weir 50, and a seawater downflow channel 51 is formed between the auxiliary water tank 48 and the water storage tank 27A. On the opposite side, a vertically movable water gate 52 is arranged (FIG. 9). Exit canal 29 is water tank 2
7A has not been contacted.

The state in which the cooling tower units of this embodiment are arranged in parallel will be described with reference to FIG. Although not shown, sluice 5
2 is open, and the discharge port 49 of the auxiliary water tank 48 is open to the outlet canal 29. The seawater flowing into the water storage tank 27A from the inlet canal 28 is sprayed into the cooling tower 26A1 through the seawater supply pipe 40 by the drive of the pump 41.
The seawater is cooled while flowing in countercurrent contact with the air flow 39, flows down in the filling tank 37, and falls into the auxiliary water tank 48. Seawater in the auxiliary water tank 48 is discharged from the discharge port 49 to the outlet canal 29.
Run down. The seawater is guided to the seawater pit 22 by the outlet canal 29 and is supplied into the heat transfer tube of the condenser 7 together with the seawater taken in from the water intake 20.

The state of the cooling tower unit according to the present embodiment during disconnection will be described with reference to FIG. In FIG. 9, the air supply pipe 4
5, the blower 46 is omitted. The sluice 52 is closed and the discharge port 49 is closed. The level at the upper end of the floodgate 52 is higher than the level at the upper end of the weir 50. For this reason, the seawater that has dropped from the packed bed 37 accumulates in the auxiliary water tank 48, but falls into the water storage tank 26 </ b> A through the seawater flow passage 51 over the weir 50. In this way, during disconnection,
A circulating operation of the seawater circulating through the water storage tank 27A, the seawater supply pipe 40, the filling tank 37, the auxiliary water tank 48, the seawater flowing down flow path 51, and the water storage tank 27A is performed. Since the sluice 52 is closed,
The seawater in the auxiliary water tank 48 does not flow out to the outlet canal 29.

[0036]

According to the present invention, the amount of hot waste water discharged can be reduced and the electric output of the power plant can be increased.

[Brief description of the drawings]

FIG. 1 is a schematic system diagram of a condenser cooling device according to a preferred embodiment of the present invention applied to a BWR plant.

FIG. 2 is a detailed configuration diagram of a cooling device 26 of FIG.

FIG. 3 is a configuration diagram of a cooling tower unit including a cooling tower and a water storage tank in the cooling device of FIG. 2;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a diagram showing a connection state between each cooling tower unit and an inlet canal and an outlet canal.

FIG. 6 is a diagram showing a connection state between a temporary seawater storage tank, an inlet canal, and a drainage channel.

FIG. 7 is a detailed configuration diagram of a cooling tower unit.

FIG. 8 is a view showing a configuration of another embodiment of the cooling tower unit and showing a state in which the cooling tower units are being inserted.

9 is a diagram showing a state of the cooling tower unit in FIG. 8 during disconnection.

[Explanation of symbols]

5 low-pressure turbine, 7 condenser, 20 intake, 22 ...
Seawater pit, 23 ... intake line, 24 ... drainage line, 25 ...
Cooling device canal, 26 ... cooling device, 26A, 26B, 2
6C, 26D, 26E, 26F, 26G, 26H, 26
I, 26J, 26T: cooling tower, 27A, 26B, 26
C, 26D, 26E, 26F, 26G, 26H, 26
I, 26J, 27T ... water tank, 28 ... entrance canal, 28
A, 28B, 28C, 28D, 28E, 28F, 28
G, 28H, 28I, 28J, 28T ... branch canal, 2
9: outlet canal, 33: seawater temporary storage tank, 37: filling tank, 40: seawater supply pipe, 45: air supply pipe.

Claims (12)

[Claims] 1. An intake passage having an intake opening to a river or ocean and connected to a heat transfer pipe provided in a condenser to which steam discharged from a turbine is supplied, and an intake passage installed in the intake passage. A pump that supplies cooling water taken from the intake port to the heat transfer tube through the intake passage, is connected to the heat transfer tube, is connected to a drain passage that opens to a river or ocean, and is connected to the drain passage. And a return passage connected between the intake port and the pump to the intake passage, and a cooling device provided in the return passage. 2. A flow rate adjusting means for adjusting a flow rate of cooling water supplied from said water intake passage to said return passage.
Condenser for power plant in Thailand. 3. The condenser cooling device for a power plant according to claim 1, wherein said cooling device has a plurality of cooling towers for cooling cooling water by air. 4. The condenser cooling device for a power plant according to claim 3, wherein a water storage tank is provided for each of said cooling towers, and said cooling tower covers said water storage tank. 5. The condenser of a power plant according to claim 3, further comprising a high-temperature water supply device for supplying water having a higher temperature than the cooling water supplied to the cooling tower into the cooling tower. Cooling system. 6. A condenser cooling device for a power plant according to claim 5, wherein said high-temperature water supply device is a device for supplying water of 50 ° C. or higher. 7. The condenser cooling device for a power plant according to claim 1, wherein a water gate is provided in each of the return passages on an upstream side and a downstream side of the cooling device. 8. The condenser cooling device for a power plant according to claim 1, wherein one of said plurality of cooling towers is a standby unit. 9. A water intake passage having a water intake opening to a river or the sea, and connected to a heat transfer tube provided in a condenser to which steam discharged from a turbine is supplied, and a water intake passage installed in the water intake passage. A pump that supplies cooling water taken from the intake port to the heat transfer tube through the intake passage, is connected to the heat transfer tube, is connected to a drain passage that opens to a river or ocean, and is connected to the drain passage. A method for operating a condenser cooling device of a power plant including a return passage connected to the intake passage between the intake port and the pump, and a cooling device provided in the return passage, A method for operating a condenser cooling device for a power plant, wherein the cooling capacity of the cooling device is increased in summer compared with winter. 10. The cooling device has a plurality of cooling towers for cooling the cooling water, and is provided by closing water gates provided in the return passage on the upstream and downstream sides of the cooling device. The method for operating a condenser cooling device for a power plant according to claim 9, wherein the cooling tower is disconnected. 11. A condenser cooling device for a power plant according to claim 10, wherein water having a higher temperature than said cooling water supplied to said cooling tower is supplied to said cooling tower which has been disconnected. Driving method. 12. The cooling device includes a water storage tank to which the cooling water is supplied by the return passage, and a cooling tower that covers the water storage tank and cools the cooling water supplied from the water storage tank. The cooling water flowing down in the cooling tower is stored in an auxiliary water tank provided at the bottom of the cooling tower above the water storage tank, and the auxiliary water tank provided at one end of the auxiliary water storage tank is opened. The cooling water in the water storage tank is discharged into the return passage, guided to the water intake passage, and closed by the water gate, whereby the cooling water in the auxiliary water tank is provided at the other end of the auxiliary water tank. The method for operating a condenser cooling device of a power plant according to claim 9, wherein the weir overflows and falls into the water storage tank.