JPH051436B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to cooling of a nuclear power plant equipped with a freshwater cooling system and a seawater cooling system, which are divided into two systems corresponding to the divisions of the core cooling system. Regarding equipment.

[Technical background of the invention and its problems] In a nuclear power plant, for example, as shown in Fig. 1, two independent cooling systems A and B are installed in order to improve the reliability of the cooling system. ing. That is, to explain one cooling system A, a heat exchanger 2a is connected to the core cooling system 1a, and a heat exchanger 4a is also connected to each incidental equipment and peripheral equipment 3a of the core cooling system 1a. ing.
A heat exchanger 8a, a pump 5a, and a supply pipe 6 are used to supply a freshwater cooling system to the heat exchangers 2a and 4a.
A, a freshwater cooling system consisting of heat exchangers 2a and 4a, a return pipe 7a, and a heat exchanger 8a is provided. The heat exchanger 8a also includes a seawater intake tank 9a, a seawater pump 10a, and a seawater pump 10a for supplying seawater cooling water.
Seawater supply pipe 11a, heat exchanger 8a, water discharge pipe 12
A seawater cooling system consisting of a and a discharge channel 13a is provided. The other cooling system B also has the same configuration as the cooling system A. That is, a heat exchanger 2b is connected to the core cooling system 1b, and a heat exchanger 4b is also connected to each incidental equipment and peripheral equipment 3b of the core cooling system 1b. A heat exchanger 8 is used to supply fresh water cooling water to the heat exchangers 2b and 4b.
b, a freshwater cooling system consisting of a pump 5b, a supply pipe 6b, heat exchangers 2b and 4b, a return pipe 7b, and a heat exchanger 8b. The heat exchanger 8b also includes a seawater intake tank 9b, a seawater pump 10b, and a seawater supply pipe 11 to supply seawater cooling water.
b, heat exchanger 8b, water discharge pipe 12b, water discharge channel 13b
A seawater cooling system consisting of:

The cooling systems A and B are configured as described above. For example, to explain the function of the cooling system A, the heat exchanger 2a connected to the core cooling system 1a and the heat exchanger 2a connected to the auxiliary equipment/peripheral equipment 3a Heat is removed from the exchanger 4a by a freshwater cooling system, and heat is removed from the freshwater cooling system heat exchanger 8a by a seawater cooling system. It is clear that the cooling system B has the same effect as the cooling system A, so a description thereof will be omitted.

By the way, the seawater intake tanks 9a and 9 mentioned above
b, seawater pumps 10a and 10b, heat exchanger 8a
8b, pumps 5a and 5b, etc., need to be maintained and inspected, and during this maintenance and inspection, there is a possibility that the conventional cooling system configuration will not be able to supply freshwater cooling water to equipment that requires freshwater cooling water. This can lead to problems such as longer inspection times.

[Object of the invention] The present invention has been made in view of the above circumstances, and
The purpose is to develop a cooling system for a nuclear power plant that allows easy maintenance and inspection of various equipment that needs to be inspected while supplying cooling water to the core cooling system and its ancillary equipment and peripheral equipment. It is on offer.

[Summary of the Invention] In order to achieve the above object, the present invention provides a fresh water cooling system having a pump for supplying fresh water for cooling a core cooling system and ancillary equipment and peripheral equipment of this core cooling system, and a fresh water cooling system for this fresh water cooling system. In a cooling system for a nuclear power plant that is equipped with two lines of seawater cooling systems each having a pump that supplies seawater to cool the installed heat exchanger, the seawater cooling system is installed between the two lines of freshwater cooling system or between the two lines of seawater cooling system. A connecting pipe is connected between at least one cooling system between the systems and downstream of the pump, and a gate valve is provided in the middle of this connecting pipe, and the connecting pipe is connected to the connecting pipe. A gate valve or check valve is installed on the upstream side of the section.

[Embodiments of the invention] Embodiments of the present invention will be described with reference to the drawings.

FIG. 2 is a schematic diagram of a cooling system according to the first embodiment of the present invention, and the same parts as in FIG. 1 are given the same reference numerals and explained. That is, the cooling device of the present invention has two
It is composed of cooling systems A and B in series, and to explain one cooling system A, a heat exchanger 2a is connected to the core cooling system 1a, and each incidental equipment of the core cooling system 1a and the surrounding A heat exchanger 4a is also connected to the device 3a. A heat exchanger 8 is used to supply fresh water cooling water to the heat exchangers 2a and 4a.
A freshwater cooling system is provided, which includes a pump 5a, a supply pipe 6a, heat exchangers 2a and 4a, a return pipe 7a, and a heat exchanger 8a. The heat exchanger 8a also includes a seawater intake tank 9a, a seawater pump 10a, and a seawater supply pipe 11 for supplying seawater cooling water.
a, heat exchanger 8a, water discharge pipe 12a, water discharge channel 13a
A seawater cooling system consisting of: The other cooling system B also has the same configuration as the cooling system A. That is, a heat exchanger 2b is connected to the core cooling system 1b, and a heat exchanger 4b is also connected to each incidental equipment and peripheral equipment 3b of the core cooling system 1b. In order to supply a fresh water cooling system to the heat exchangers 2b and 4b, a heat exchanger 8b, a pump 5b, a supply pipe 6b, a heat exchanger 2b and 4b, a return pipe 7b,
A freshwater cooling system consisting of a heat exchanger 8b is provided. The heat exchanger 8b also includes a seawater intake tank 9b and a seawater pump 1 to supply seawater cooling water.
0b, a seawater cooling system consisting of a seawater supply pipe 11b, a heat exchanger 8b, a water discharge pipe 12b, and a water discharge channel 13b. Further, the supply pipes 6a and 6b for supplying freshwater cooling water are connected by a communication pipe 14, and a gate valve 15 is provided in the middle of this communication pipe. Further, the return pipes 7a and 7b of the fresh water cooling water are connected by a communication pipe 17, and a gate valve 18 is provided in the middle of the communication pipe 17. And supply piping 6a and 6
Gate valves 16a and 16b are provided in the supply pipes 6a and 6b upstream from the connection point of the communication pipe 14 of b,
Further, gate valves 19a and 19b are provided in the return pipes 7a and 7b, respectively, on the downstream side of the connection point of the communication pipe 17 between the return pipes 7a and 7b.

The cooling equipment according to the present invention is configured as described above, and during normal operation, the gate valves 15 and 18 provided in the middle of the communication pipes 14 and 17 are closed and the supply pipe 6 is closed.
Since the gate valves 16a and 16b provided in a and 6b and the gate valves 19a and 19b provided in return pipes 7a and 7b are open, the system operates as two independent cooling systems A and B, similar to conventional cooling equipment. can do.

Next, during regular maintenance inspections, etc., for example, cooling system A
pump 5a, heat exchanger 8a, seawater pump 10
a. When performing maintenance and inspection of equipment in the water intake tank 9a, use the gate valve 16 installed in the supply pipe 6a of the cooling system A.
a and the return pipe 7a to close the gate valve 19a, and the gate valve 15 of each of the communication pipes 14 and 17 is closed.
and open 18. Then, heat exchangers 2a and 4a of cooling system A also have heat exchanger 8b of cooling system B.
Cooling water is supplied from That is, the fresh water cooling water is supplied through a heat exchanger 8b, a pump 5b, a supply pipe 6b,
In addition to the routes consisting of the heat exchangers 2b and 4b, the return pipe 7b, and the heat exchanger 8b, the heat exchanger 8b and the supply pipe 6
b, pump 5b, communication pipe 14, supply pipe 6a, heat exchangers 2a and 4a, return pipe 7a, communication pipe 1
7, return pipe 7b, and heat exchanger 8b. Therefore, maintenance and inspection of the pump 5a, heat exchanger 8a, seawater pump 10a, and water intake tank 9a can be performed while cooling water is supplied to the heat exchangers 2a and 4a of the cooling system A. Also,
When performing maintenance inspection of the pump 5b, heat exchanger 8b, seawater pump 10b, and water intake tank 9b of the cooling system B, close the gate valves 16b and 19b of the cooling system B,
Gate valves 15 and 18 of communication pipes 14 and 17 are opened. Then, with the cooling water from the heat exchanger 8a of the cooling system A being supplied to the heat exchangers 2b and 4b of the cooling system B, the pump 5b of the cooling system B, the heat exchanger 8b,
Maintenance and inspection of the seawater pump 10b and water intake tank 9b can be performed.

FIG. 3 is a schematic diagram of a cooling system according to a second embodiment of the present invention. The difference from FIG. and connect it with gate valve 2 in the middle.
1, and a seawater supply pipe 11 upstream of the connection point of the communication pipe 20 of the seawater supply pipes 11a and 11b.
The other points are that gate valves 22a and 22b are provided at ports a and 11b, respectively, and that the communication pipes 14 and 17 and gate valves 16a and 16b; 19a and 19b in FIG. Therefore, the same parts as in FIG. 2 will be given the same reference numerals and their explanation will be omitted.

In FIG. 3, during normal operation, the gate valve 21 of the communication pipe 20 is closed, and the seawater supply pipe 11a,
When the gate valves 22a and 22b provided in 11b are opened,
As in the past, it can be operated as two independent cooling systems A and B. Next, for example, cooling system A
When performing maintenance and inspection of the seawater pump 10a and water intake tank 9a, the gate valve 21 of the communication pipe 20 is opened, and the gate valve 22a provided in the seawater supply pipe 11a of the cooling system A is closed. Then, the seawater pump 10b of the cooling system B can supply seawater not only to the heat exchanger 8b but also to the heat exchanger 8a through the communication pipe 20. Therefore, while supplying seawater to the heat exchanger 8a, the seawater pump 10a and the water intake tank 9a
Maintenance and inspection can be carried out. Furthermore, when performing maintenance and inspection of the seawater pump 10b and water intake tank 9b of the cooling system B, the gate valve 21 of the communication pipe 20 is opened, and the gate valve 22b provided in the seawater supply pipe 11b of the cooling system B is closed. Then, the seawater pump 10a of the cooling system A can supply seawater not only to the heat exchanger 8a but also to the heat exchanger 8b as described above. Therefore, maintenance and inspection of the seawater pump 10b and water intake tank 9b can be performed while supplying seawater to the heat exchanger 8b.

FIG. 4 is a schematic diagram of the cooling system of the embodiment of the present invention shown in FIG. That is, the seawater supply pipes 11a of the two cooling systems A and B,
A connecting pipe 20 is connected between 11b, and the connecting pipe 20
A gate valve 21 is provided in the middle of the connecting pipe 20.
A gate valve 22 is installed in the seawater supply pipes 11a, 11b upstream from the connection point of the seawater supply pipes 11a, 11b.
a, 22b are arranged, and the same parts as in FIGS. 2 and 3 are given the same reference numerals, so the explanation thereof will be omitted.
Also in this case, the first and second
By opening and closing the gate valves according to the equipment to be maintained and inspected in exactly the same way as explained in the example above, it is possible to perform maintenance and inspection of the equipment while supplying cooling water to the specified heat exchanger. Of course.

In addition, in each of the above embodiments, the fresh water supply pipe 6
Although gate valves 16a, 16b; 22a, 22b are provided in the seawater supply pipes 11a, 11b and the seawater supply pipes 11a, 11b, check valves may be used instead of the gate valves.

[Effects of the Invention] According to the present invention, two independent cooling systems arranged in a nuclear power plant are skillfully connected by connecting pipes and gate valves or check valves. Since cooling water can be supplied to the heat exchanger while equipment to be maintained and inspected can be maintained and inspected, the inspection period can be significantly shortened compared to the conventional method.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a cooling system of a conventional nuclear power plant, and FIGS. 2 to 4 are schematic diagrams of cooling systems of different embodiments of the present invention. 1a, 1b... Core cooling system, 2a, 2b,; 4
a, 4b; 8a, 8b...heat exchanger, 3a, 3b
...Core cooling system auxiliary equipment/peripheral equipment, 5a, 5
b... Pump, 6a, 6b... Supply piping, 7a,
7b... Return piping, 9a, 9b... Seawater intake tank,
10a, 10b...Seawater pump, 11a, 11b
... Seawater supply pipe, 12a, 12b ... Water discharge pipe,
13a, 13b...Discharge channel, 14, 17, 20...
...Communication pipe, 15, 18, 21...Gate valve, 16
a, 16b, 19a, 19b, 22a, 22b...
...Gate valve.

Claims (1)

[Scope of Claims] 1. A fresh water cooling system having a pump that supplies fresh water to cool a core cooling system and ancillary equipment/peripheral equipment of the core cooling system, and a heat exchanger disposed in the fresh water cooling system. In a cooling system for a nuclear power plant that is equipped with two lines of seawater cooling systems each having a pump for supplying seawater, between the two lines of freshwater cooling systems or between at least one cooling system between the two lines of seawater cooling systems. and a connecting pipe is connected to the downstream side of the pump, and a gate valve is provided in the middle of the connecting pipe, and a gate valve or a checker is installed on the upstream side of the connection part with the connecting pipe of the piping to which the connecting pipe is connected. A cooling device for a nuclear power plant characterized by being equipped with a valve. 2. The cooling system for a nuclear power plant according to claim 1, wherein the communication pipes connected between the two freshwater cooling systems are connected to the supply pipes and the return pipes of the freshwater cooling systems. 3. The cooling device for a nuclear power plant according to claim 1, wherein the communication pipes connected between the two series of seawater cooling systems are connected to the supply pipes of the seawater cooling systems.