JPH03597B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an auxiliary cooling device for nuclear power generation equipment. Nuclear power generation equipment is equipped with various auxiliary machines such as a residual heat removal system and a pump seal cooling system, and these auxiliary machines are cooled by an auxiliary machine cooling device. From the perspective of these auxiliary machines, that is, the auxiliary machine cooling system, the load is divided into a regular load that is constantly operated and an emergency load. Emergency loads are designed to have higher reliability, such as seismic grade, than regular loads. A plurality of emergency loads and regular loads of the same type are provided, for example, two systems such as A system and B system. By the way, if the auxiliary cooling device is provided for each load system, this auxiliary cooling device system would become extremely complicated, so conventionally it was constructed as shown in FIG. 1. That is, 1 is a regular load, and this regular load 1 is not divided into A system, B system, etc., but is treated as one system. In addition, the emergency load is divided into two systems: A-system emergency load 2a and B-system emergency load 2b, and each system has an A-system coolant pump 8a and a B-system coolant pump 8.
b, A-system auxiliary cooling system 17a, B-system auxiliary cooling system 17 consisting of A-system heat exchanger 7a, B-system heat exchanger 7b, A-system head tank 9a, B-system head tank 9b, etc.
The coolant is supplied to the A-system heat exchanger 7a, the B-system heat exchanger 7b, the A-system emergency inlet piping 11a, and the B-system emergency system inlet piping 11b, A system emergency exit piping 13a, B system emergency exit piping 13
b, and cools the A-system emergency load 2a and the B-system emergency load 2b. In addition, the circulating coolant is transferred to the A system by the A system heat exchanger 7a and the B system heat exchanger 7b.
Heat is exchanged with an external coolant, such as seawater, sent via the system external coolant pump 10a and the B-system external coolant pump 10b. Note that the A-system auxiliary cooling system 17a,
The B system auxiliary cooling system 17b is connected to the A system emergency load 2a, the B system
It is designed to have a high seismic grade, etc. so as to satisfy the requirements as an emergency auxiliary cooling system for the system emergency load 2b. And the above A system emergency inlet piping 11
The A and B system emergency inlet pipes 11b, the A system emergency exit pipe 13a, and the B system emergency exit pipe 13b are connected to each other by connecting pipes 15 and 16. A regular inlet pipe 12 and a regular outlet pipe 14 are provided branching off from the connecting pipes 15 and 16.
It is connected to the. And isolation valves 3a, 3b, 4a, 4b are provided in the middle of the connecting pipes 15, 16, respectively.
Further, isolation valves 5 and 6 are provided in the middle of the regular inlet pipe 12 and the regular outlet pipe 14, respectively. Under normal conditions, the A-system auxiliary cooling system 17
The regular load 1 is cooled by operating the A or B auxiliary cooling system 17b. In addition, in an emergency, the A-system auxiliary cooling system 17a is used to cool the regular load 1 and the B-system emergency load 2a, or the B-system auxiliary cooling system 17b is used to cool the regular load 1 and the B-system emergency load 2a.
operating the regular load 1 and B system emergency load 2b.
Further, the A-system auxiliary cooling system 17a and the B-system auxiliary cooling system 17b are operated to cool the regular load 1, the A-system emergency load 2a, and the B-system emergency load 2b.
By the way, the above regular load 1 is the A-system emergency load 2a,
Since it is designed to have a lower seismic grade than the B-system emergency load 2b, in the event of a large-scale earthquake, the regular load 1 and its piping may break and the coolant may flow out. In this case, a drop in the liquid level in the A system head tank 9a and B system head tank 9b due to the outflow of coolant is detected and the isolation valves 3a, 3b, 4
Close valves a, 4b, 5, 6, etc., and close A system auxiliary cooling system 1.
7a and B system auxiliary equipment cooling system 17b, and prevents the A system emergency load 2a and the B system emergency load 2.
Ensure cooling of b. However, this kind of system is
b are connected by connecting pipes 15 and 16, so in the unlikely event that both the A-system auxiliary cooling system 17a and the B-system auxiliary cooling system 17b may lose their functions, it is conceivable. In addition, in the conventional type, the isolation valves 3a, 3b, 4a, 4b, 5, and 6 are closed after the liquid levels in the A-system head tank 9a and the B-system head tank 9b have decreased, so the closing time of these valves is delayed. In order to prevent loss of coolant, the capacities of the A-system head tank 9a and the B-system head tank 9b had to be increased. The present invention has been made based on the above circumstances, and its purpose is to improve reliability by eliminating the possibility that all of the multiple auxiliary equipment cooling systems will lose their functions even in the event of regular load or breakage of their piping. An object of the present invention is to obtain an auxiliary equipment cooling system which has extremely high cooling capacity and can reduce the capacity of a head tank. The present invention will be described below with reference to an embodiment shown in FIG. In the figure, 100a is the A-system auxiliary cooling system, 1
00b is a B-system auxiliary equipment cooling system, and these systems constitute mutually independent systems. By this A-system auxiliary cooling system 100a, the A-system regular load 101a,
The system emergency load 102a is cooled, and the B system regular load 101b is cooled by the B system auxiliary equipment cooling system 100b.
The B-system emergency load 102b is configured to be cooled. And A-system auxiliary cooling system 100a, B
The system auxiliary cooling system 100b is provided with an A-system coolant pump 103a, a B-system coolant pump 103b, an A-system heat exchanger 104a, and a B-system heat exchanger 104b, respectively. And the coolant is A system coolant pump 1
03a, by the B system coolant pump 103b,
system heat exchanger 104a, B system heat exchanger 104b, A
The system is circulated through the system emergency inlet piping 105a, the B system emergency inlet piping 105b, the A system emergency outlet piping 106a, and the B system emergency outlet piping 106b, and supplies the A system emergency load 102a and the B system emergency load 102b. configured to cool. Further, the A system regular load 101a and the B system regular load 101b are connected in parallel with the A system emergency load 102a and the B system emergency load 102b, and the coolant is supplied to the A system coolant pump 103.
a, A system heat exchanger 104a, B system heat exchanger 104b, A system regular inlet piping 119a, B system regular inlet piping 119b,
A-system regular outlet piping 120a, B-system regular outlet piping 1
20b, the A system regular load 101a,
The B-system regular load 101b is cooled. In addition, the A-system heat exchanger 104a and the B-system heat exchanger 104b are
External coolant, such as seawater, is sent by the system external coolant pump 107a and the B system external coolant pump 107b, and exchanges heat with the coolant circulating in the A system auxiliary cooling system 100a and the B system auxiliary cooling system 100b. . Furthermore, the A-system auxiliary cooling system 100a and the B-system auxiliary cooling system 10
A-system head tanks 108a and B-system head tanks 108a and B are respectively installed in 0b.
A system head tank 108b is provided, and these A system head tank 108a and B system head tank 108
A predetermined amount of coolant is stored in the chamber b to ensure the suction head of the A-system coolant pump 103a and the B-system coolant pump 103b, and to replenish the coolant when the coolant flows out due to pipe breakage or the like. And the above-mentioned A system regular inlet piping 119a and B system regular inlet piping 1
19b includes isolation valves 109a, 110a, and 109 whose opening and closing are controlled by a control circuit 118, which will be described later.
b, 110b are provided in parallel, and the A system regular outlet piping 120a and the B system regular outlet piping 120b
are check valve type isolation valves (hereinafter simply referred to as check valves) 112a, 113a and 112b, 113.
b are provided in parallel. In addition, the above isolation valve 1
09a, 110a, 109b, 110b and check valves 112a, 113a, 112b, 113b
is for 50% rated flow rate, and is set so that two units will have 100% rated flow rate. In addition, the A system regular inlet piping 119a and the B system regular inlet piping 119
Flow rate detectors 111a and 111b are provided in the middle of the pipe b, and detect the flow rate of the coolant flowing through the A-system regular inlet pipe 119a and the B-system regular inlet pipe 119b. And these flow rate detectors 111a, 11
The signals from 1b are each sent to a control circuit 118. This control circuit 118 is connected to the flow rate detector 1.
When the flow rate signals from 11a and 111b become larger than the maximum flow rate of the A-system regular load 101a and the B-system regular load 101b, for example, when they reach 150% of the maximum flow rate, the A-system regular load 101a and the B-system regular load 1
It was determined that there was a leakage of coolant due to the rupture of 01b,
Isolation valve 109a, 110a or 109b, 11
It is configured to send a valve closing signal to 0b to close these valves. Also, isolation valves 109a, 110
a, 109b, 110b and A system regular load 101
a, A system regular inlet piping 119a between B system regular load 101b, B system regular inlet piping 119b and A system regular load 101a, B system regular load 101b and check valves 112a, 113a, 112b, 113b.
Connecting pipes 114 and 115 are provided branching off from the A-system regular outlet piping 120a and the B-system regular outlet piping 120b between these connecting piping 11.
4,115, A system regular inlet piping 119a,
B-system regular inlet piping 119b, A-system regular outlet piping 1
20a and B system common outlet piping are connected to each other. On-off valves 116 and 117 are provided in the middle of these connecting pipes 114 and 115. An embodiment of the present invention configured as described above has a constant A system auxiliary cooling system 100a and a B system auxiliary cooling system 100a.
b is operated and supplies coolant to the A-system regular load 101a and the B-system regular load 101b. In case of an emergency, the A-system regular load 102a and the B-system regular load 102
By opening the valves (not shown) etc. provided in the A-system emergency load 102a and the B-system emergency load 102b, the coolant is also supplied. If a large-scale earthquake or the like occurs, there is a possibility that the A-system regular load 101a or the B-system regular load 101b, which have a low earthquake resistance grade, will be damaged. In such a case, the flow rate detectors 111a and 111b detect the leakage of coolant due to the damage, and the A-system regular load 101a and the B-system regular load 1 are detected by the flow rate detectors 111a and 111b.
Isolation valves 109a, 110a of the system to which 01b belongs,
109b and 110b are closed, and A system regular load 10
1a or B system regular load 101b is isolated to prevent loss of coolant. Furthermore, even if the isolation of the A-system regular load 101a or the B-system regular load 101b is not properly performed, only one of the A-system auxiliary cooling system 100a and the B-system auxiliary cooling system 100b is activated. The other side will continue to operate and at least the A system emergency load 102a will be lost.
Alternatively, the supply of coolant to either one of the B-system emergency loads 102b can be ensured. Furthermore, since the A-system auxiliary cooling system 100a and the B-system auxiliary cooling system 100b are constantly operated, there is no possibility of them being unable to start up in an emergency, and their reliability as an auxiliary cooling system is extremely high. Also, this is the A system regular inlet pipe 11.
9a, by increasing the flow rate of the coolant flowing through the B system regular inlet piping 119b, coolant leakage due to damage to the A system regular load 101a and the B system regular load 101b is detected, and the isolation valves 109a, 110a, 109b, 110 are activated.
Since valve b is closed, these valves close earlier,
The capacity of the A-system head tank 108a and the B-system head tank 108b can be reduced accordingly. Furthermore, this one has isolation valves 109a and 109 with a capacity of 50%.
b, 110a, 110b and check valve 112a,
Since the two valves 113a, 112b, and 113b are provided in parallel, they are small in size, their valve closing operation time is shortened, and their valve closing timing is earlier. Also, during operation, these isolation valves 109a, 110a, 109
b, 110b, 112a, 113a, 112b,
113b can be functionally tested one by one. Also, one of the A-system auxiliary cooling system 100a and the B-system auxiliary cooling system 100b, for example, the A-system auxiliary cooling system 10
When the operation of 0a is stopped for maintenance inspection, etc., the on-off valves 116 and 1 of the connecting pipes 114 and 115 are
17, the coolant can be supplied from the B-system auxiliary cooling system 100b to both the A-system regular load 101a and the B-system regular load 101b. Note that the present invention is not limited to the above embodiment. For example, it is not necessary to provide two isolation valves in parallel. Further, in this embodiment, the auxiliary cooling system is an AB2 system, but three or more systems may be used. As described above, the present invention divides the regular load and emergency load into multiple systems, connects the regular load and emergency load systems in parallel, and connects each system with a coolant pump and coolant in each system. A heat exchanger for exchanging heat with an external coolant is provided, an isolation valve that can be opened and closed is provided in the inlet pipe of the normal load, a check valve is provided in the outlet pipe of the normal load, and an isolation valve is provided in the inlet pipe of the normal load. Connecting piping is provided to connect the inlet piping and outlet piping to each other, which are branched from the portions of the piping and outlet piping between the isolation valves and check valves and the regular load. An on-off valve that is sometimes closed is provided, and a flow rate detector is installed in the inlet piping of each of the above systems, and when signals from these flow rate detectors are received and the flow rate becomes higher than the normal flow rate, the above-mentioned isolation of that system is performed. A control circuit is provided to close the valve. Therefore, even if a break occurs in the service load and its isolation is not performed normally, at least one system will be removed unless the service load in all systems breaks and the isolation of the service loads in all systems fails. can supply coolant to emergency loads. Moreover, since each system is constantly operating, there is little possibility of problems such as inability to start, and reliability is extremely high. Further, since the isolation of the regular load is achieved by increasing the flow rate of the inlet piping, the response is quick and the reliability is even higher, and the capacity of the head tank can be reduced, which has great effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic system diagram of a conventional example, and FIG. 2 is a schematic system diagram of an embodiment of the present invention. 100a ...A auxiliary cooling system, 100b ...B
System auxiliary cooling system, 101a...A system regular load, 10
1b...B system regular load, 102a...A system emergency load, 102b...B system emergency load, 103a...
...A system coolant pump, 103b...B system coolant pump, 104a...A system heat exchanger, 104b...
B-system heat exchanger, 108a...A-system head tank,
108b...B system head tank, 111a...Flow rate detector, 111b...Flow rate detector, 114...
Connection pipe, 115... Connection pipe, 116... Opening/closing valve, 117... Opening/closing valve, 118... Control circuit, 1
19a...A system regular inlet piping, 119b...B system regular inlet piping.

Claims (1)

[Scope of Claims] 1. The regular load and the emergency load are each divided into multiple systems, and each of the regular load and emergency load systems is connected in parallel, and a coolant pump and a cooling system within each system are provided for each system. A heat exchanger is provided for exchanging heat between the refrigerant and the external coolant, an isolation valve that can be opened and closed is provided on the inlet piping for the regular loads, a check valve is provided on the outlet piping for the regular loads, and the inlet piping for the regular loads is provided with a check valve. Connecting piping is provided to connect the inlet piping and outlet piping to each other, which are branched from the portions of the piping and outlet piping between the isolation valves and check valves and the regular load. An on-off valve that is sometimes closed is provided,
In addition, a flow rate detector is installed in the inlet piping of each of the above systems, and when signals from these flow rate detectors are received and the flow rate becomes higher than the normal flow rate, control is performed to open and close the isolation valve of that system. An auxiliary cooling device for nuclear power generation equipment characterized by being equipped with a circuit. 2. The auxiliary cooling device for nuclear power generation equipment according to claim 1, wherein a plurality of isolation valves are connected in parallel.