JPS61122600A - Cooling facility for auxiliary machinery of nuclear reactor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to nuclear reactor auxiliary equipment cooling equipment, and particularly to a nuclear reactor auxiliary equipment having a seawater pump for supplying a necessary amount of cooling seawater to a heat exchanger. Regarding cooling equipment.

[Technical background of the invention and its problems]

As shown in FIG. 7, the conventional nuclear reactor auxiliary equipment cooling equipment has a system in which the cooling of the emergency system load 1 and the cooling W of the regular system load 7 are performed independently and separately.

The final cooling source in all of the above systems is seawater, and seawater pumps 4 and 10 are installed to supply cooling water. This seawater pump is a submersible pump with a long pumping pipe, but is equipped with an underwater bearing to support the main shaft. The types of submersible bearings are as follows: a) The sliding surface between the main shaft and the bearing requires constant liquid lubrication during pump operation (main shaft rotation) (hereinafter referred to as initial water injection start-up submersible bearing 12). ) and b) those that do not require lubricating water for a short period of time (hereinafter referred to as non-water injection starting submersible bearings 6).

On the other hand, regarding the durability of underwater bearings (mainly M wear resistance against foreign substances such as sand), type a) has very good properties, and when compared to type b), it has much better characteristics. have.

Furthermore, since bearing wear is strongly affected by foreign substances such as sand contained in the seawater sucked up from the seawater intake source 5, a protection tube 11 is installed on the main shaft to avoid direct contact between the pumped seawater and the bearings. Some devices are designed to ensure that seawater from which sand and the like has been removed can be supplied to the bearing portion within the protection tube 11 as lubricating water, thereby improving durability.

The emergency system seawater pump 4 of the emergency reactor auxiliary equipment cooling equipment is
Since the operation time is very short in terms of system operation, there is no need to require a high degree of durability in a regular system that requires long-term continuous operation compared to a submersible bearing, so the non-water injection starting submersible bearing 6 is used.

The method of operating the emergency seawater pump 4 is to start the pump at the same time that a pump start signal is issued. In other words, when the emergency seawater pump 4 starts up, the submersible bearing 6 is installed above the sea level and is in a dry state. When the emergency system seawater pump 4 is started, seawater is pumped up in the pumping pipe, so even the bearing in a dry state is subject to a slight dry operation. It is then soaked in seawater to ensure lubricating water for the bearings. That is, as described above, the submerged bearing is subjected to a short dry operation only when the pump is initially started. On the other hand, compared to the emergency reactor auxiliary cooling equipment, the regular reactor auxiliary cooling equipment cools the regular system load, so the operating time of the regular system seawater pump 10 is continuous operation for a long period of time. The initial water injection startup submersible bearing 12, which has excellent durability, is used as a bearing.

Further, a protection tube 11 is also provided for the initial water injection start-up submersible bearing 12 in consideration of its durability.

Therefore, due to the relationship between the weir water level and the pumping pipe, at the beginning of startup when it is exposed to the atmosphere and is in a dry state! I) Water injection start-up It is necessary to supply bearing injection water (lubricating water) to the submersible bearing 12 from the outside.

However, the design grade of make-up water for systems other than the reactor auxiliary cooling equipment was lower than that of the reactor auxiliary cooling equipment, making it unsuitable as a stable lubricating water supply source. After operation of the regular seawater pump 10, the pumped seawater is branched from the discharge pipe, and the power water is injected into the bearing portion in the protection tube 11 after removing foreign matter using a strainer or the like. Therefore, when starting the regular system seawater pump 10, it is necessary to receive external water injection from another system, and the regular system τ
The hi water pump 10 requires a self-pressure water circulation system even after starting.

In this way, the cooling system for emergency system load 1 and the regular system load 7
Because the cooling system and cooling system are separated independently, the equipment system becomes complicated, and the supply of lubricating water is not sufficiently reliable.

(Objective of the Invention) The object of the present invention is to eliminate the drawbacks of the above-mentioned prior art, to provide high reliability as an engineering safety facility by stably and reliably supplying lubricating water when necessary, and to ensure long-term continuous operation. An object of the present invention is to provide a nuclear reactor auxiliary cooling equipment that can improve the durability of parts such as bearings.

[Summary of the invention]

The present invention provides two seawater pumps having at least submersible bearings, a heat exchanger to which cooling seawater is supplied from these seawater pumps and exchanges heat with fresh water for cooling reactor auxiliary equipment, and In the reactor auxiliary cooling equipment equipped with a line for supplying lubricating water to the submerged bearing during operation, the reactor auxiliary equipment cooling equipment supplies and stores fresh water from another system outside the reactor auxiliary equipment cooling equipment, and also has water level control means. A lubricating water tank is provided, and a lubricating water supply control valve is provided in the middle of a line that supplies fresh water in the lubricating water tank to each self-pressure water circulation line that is circulated after the seawater pump is started. do.

[Embodiments of the invention]

A first embodiment of the invention is shown in FIG.

An other system supply valve 20 is installed in the middle of one of the other system supply pipes, and the other system supply valve 20 is operated based on a signal from a tank water level control switch 21 provided in a lubricating water tank 22. . Further, the lubricating water tank 22 is installed at a position where a sufficient hydrostatic head can be obtained for injecting water into the bearing portion. The lubricating water tank 22 is branched into two directions via a pressure water line 24, which is provided with lubricating water supply control solenoid valves 23a and 23b in the middle, and has check valves 25a and 25b in the middle. It is connected to piping 26a, 26b. The lubricating water supply pipe 26a has a flow rate switch 27a (l) (gl) (gl) in the middle thereof and is connected to the regular-emergency seawater pump 17a.Similarly, the lubricant water supply pipe 26b has a flow rate switch 27b in the middle thereof. is provided and connected to the regular-emergency system seawater pump 17b.

Self-pressure water line 29 branched from lubricating water supply pipe 26a
A check valve 28a, a cyclone separator 30a, and a strainer 31a are provided in the middle of the self-pressure water line 29b branched from the lubricating water supply pipe 26b, and a check valve 28b, a cyclone separator 30b,
A strainer 31b is provided.

The operating method of the regular-emergency seawater pumps 17a and 17b is that when a start signal is issued, the lubricating water supply control solenoid valve 23a opens, and the fresh water stored in the lubricating water tank 22 is transferred to the other pressure water line 24, Lubricating water supply piping 26a, 26b
After that, the bearing water injection starts. At this time, the check valve 25
a and 25b prevent water injected into the tank from flowing into the discharge pipe side of the regular-emergency seawater pump 1. - When the flow rate of oil injection water reaches the specified flow rate and it is determined that the lubricating water necessary for starting is supplied to the bearing, the style switch 2
7a and 27b provide a regular-emergency system seawater pump 17a,
Avoid starting 17b. Thereafter, seawater is pumped up by the regular/emergency system seawater pumps 17a and 17b. A part of the pumped seawater is transported to the regular-emergency seawater pump 17a,
Self-pressure water lines 29a, 2 branched from the discharge piping section 17b
It flows through 9b. In addition, since the self-pressure water is seawater, as much as possible of sand, etc. contained in the seawater is removed from the strainer 31a.

After removing the cyclone separators 31b and cyclone separators 30a and 30b, lubricating water is supplied to the bearing in the protection tube.

After the above operations, the self-pressure water line 29a.

29b is established and begins to circulate, the lubricating water supply control solenoid valve 23a is closed.

Next, a second embodiment of the present invention is shown in FIG.

2, the difference from the first embodiment shown in FIG. 1 is that the lubricating water supply control N magnetic valves 23a and 23t in FIG.
) and check valves 25a and 25b are omitted, and the other pressure water line 2
A solenoid valve 32a is located near the branching point of the lubricating water supply pipes 25a and 25b branched from 4.

32b was provided. Therefore, in FIG. 2, components that are substantially the same as those in FIG. 1 are designated by the same reference numerals.

The operating method for the regular-emergency seawater pumps 17a and 17b is that when a start signal is issued, the solenoid valves 32a and 32b are activated.
The fresh water stored in the lubricating water tank 22 was
Water injection into the bearing is started via the other pressure water line 24. After the bearing water injection starts, the operation until the self-pressure water lines 29a, 29b are established is the same as in the first embodiment, and when the self-pressure water starts to circulate, the solenoid valves 32a, 32b are closed.

Next, a third embodiment of the present invention is shown in FIG.

3, the difference from the first embodiment shown in FIG. 1 is that the lubricating water supply 1i1J tll solenoid valve 2 in FIG.
Lubricating water supply control air operated valve 33 instead of 3a, 23b
a and 33b, and other components are substantially the same and are designated by the same reference numerals.

The operating method of the regular-emergency seawater pump 17 is that when a start signal is issued, the lubricating water supply AIll III air-operated valves 33a and 33b open, and the fresh water stored in the lubricating water tank 22 is transferred to another pressure. Bearing water injection is started via the water line 24. After starting the bearing water injection, the self-pressure water line 29a
, 29t) are the same as in the first embodiment, and when the self-pressure water begins to circulate, the lubricating water supply control air-operated valves 33a and 33b are closed.

Next, the fourth embodiment 1 of the present invention is shown in FIG.

4, the difference from the second embodiment shown in FIG. 2 is that air-operated valves 34a, 34b are provided instead of the solenoid valves 32a, 32b shown in FIG. Since the parts are substantially the same, they are designated by the same reference numerals.

The operating method of the regular-emergency seawater pump 17 is that when a start signal is issued, the air-operated valves 34a and 34b open, and the fresh water stored in the lubricating water tank 22 is transferred to the bearing water via the ground pressure water line 24. is started. After bearing water injection starts,
Self-pressure water line 29a.

The operation until 29b is established is the same as in the second embodiment, and once the self-pressure water starts circulating, the air-operated valves 34a, 3
4b is closed.

Next, a fifth embodiment of the present invention is shown in FIG.

5, the difference from the fifth embodiment shown in FIG. 1 is that the lubricating water supply control solenoid valves 23a and 23b in FIG.
, the check valves 25a and 25b are omitted, and a lubricating water supply control check valve 35 is provided in the middle of the earth pressure water line 24.

As a method of operating the regular-emergency system seawater pump 17, the pump is started at the same time that the pump start signal 'j)J1;a @ is issued. (In other words, the fresh water stored in the lubricating water tank 22 is always supplied to the ground pressure water line 24, lubricating water supply piping 26a, 26b when all units 17a, 17b are stopped.
Since water is being injected into the bearing portions of the regular-emergency seawater pumps 17a and 17b through the above steps, the supply of lubricating water to the initial water injection starting submersible bearings has also been completed. In this case, since the water level of the lubricating water tank 22 will continuously decrease, the lubricating water tank water level control switch 21 detects the water level, opens the other system fresh water supply source valve 20, and opens the other system fresh water supply pipe 19. Fresh water is supplied to keep the water level of the lubricating water tank 22 constant. ) After the regular use-emergency system seawater bombs 17a and 17b are activated, seawater is pumped up, but some of the pumped seawater is used for regular use.
A self-pressure water line 29a branches from the emergency system seawater pumps 17a and 17b discharge piping.

29b. The seawater flowing through the self-pressure water lines 29a and 29b passes through strainers 31a and 31b provided midway,
The seawater passes through cyclone separators 30a and 30b, and foreign matter such as sand contained in the seawater is removed.

Thereafter, the seawater flowing through the self-pressure water lines 29a and 29b passes through the lubricating water supply pipes 26a and 26b, and begins to be injected into the bearing portions of the normal and emergency seawater bombs 17a and 17b. On the other hand, some of the seawater flowing through the self-pressure water lines 29a and 29b flows back into the earth-pressure water line 24. The pressure associated with the injection of fresh water from the lubricating water tank 22 is only the static head of the lubricating water tank 22, but the discharge pressure of the regular-emergency seawater bombs 17a and 17b remains unchanged for the seawater that has flowed back. Therefore, the pressure on the freshwater side is much smaller. Therefore, the lubricating water supply control check valve 35 is opened by the seawater flowing backward, and the supply of fresh water from the lubricating water tank 22 is stopped.

In addition, if the regular-emergency seawater pump 17a shown in FIG.
, 17b, even if only one of them is activated, the self-pressure water line 29a.

A part of the seawater flowing through 29b is injected into the bearing part of the normal-use/emergency system DLJ water pump 17a, part of which flows backward through the earth pressure water line 24, and a part of the seawater is flowing back into the normal-use water pump 17a which is stopped. Lubricating water supply piping 26b to emergency seawater pump 17b
After that, water is injected into the bearing part of the regular-emergency system seawater pump 1Fb, which is stopped. In other words, two machines are installed for regular use.
If only one of the emergency system seawater pumps 17a and 17b is started, lubricating water will continue to be continuously supplied to the remaining stopped regular-emergency system seawater pump 17b, so this stoppage will occur. Internal regular-emergency seawater pump 17
b is on standby and ready to be activated at any time.

Also, an initial regular use/emergency system seawater pump 17a.

When 17b is started, the lubricating water tank 2
Fresh water from 2 flows continuously, but it is not used regularly for system operation.
The two emergency seawater pumps 17a and 17b stop at the same time during periodic inspections and when power is lost (in this case, approximately 3
Only Q Sec will cause all machines to stop).

Therefore, when considering the capacity of the lubricating water tank 22 in an emergency, and considering the amount that flows out during 30 seconds when the power is lost, there is no functional problem even when there is no fresh water supply from other systems.

〔Effect of the invention〕

As described above, according to the present invention, the emergency system cooling load and the regular system cooling lJl load are installed in the same loop and perform their respective functions, thereby achieving high reliability as an engineering safe IM system. At the same time, it is possible to improve the durability of long-term operation with respect to regular system load cooling.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing a first embodiment of the present invention, Fig. 2 is a system diagram showing a second embodiment of the invention, and Fig. 3 is a system diagram showing a third embodiment of the invention.
A system diagram showing an embodiment, FIG. 4 is a system diagram not showing the fourth embodiment of the present invention, and FIG. 5 is a system diagram showing the fifth embodiment of the present invention.
Fig. 6 is a schematic eastern view of the present invention, Fig. 7 does not show the conventional nuclear reactor prosthetic cooling equipment, iac>''1゜1...Emergency system load, 2...Emergency system fresh water pump,
3...Emergency system seawater heat exchanger, 4...Emergency system seawater pump, 5...Seawater intake source, 6...Non-water injection starting submersible bearing, 7...Normal use, system load, 8 ...Common freshwater pump, 9...Common elm, 1 Commercial seawood exchanger, 10...Common seawater pump, 1k
. 1...Protection tube, 12...Initial water injection start-up submersible bearing, 1
3... Emergency system load, 14... Regular system load, 15.
...Fresh water pump, 16...Seawater heat exchanger, 17.17
a, 17b... Regular-emergency seawater pump, 18...
・Seawater intake source, 19...Other system supply piping 1, 20...
・Other system supply source valve, 21... Tank water level control switch, 22... Lubricating water tank, 24... Other pressure water line,
26a, 26b... Lubricating water supply piping, 27a, 27b
...Flow switch, 28a, 2Bb-...Check valve, 2
9a, 29b...self-pressure water line, 30a, 30b...
- Cyclone separator, 31a, 31b... strainer, 32a. 32b... Solenoid valve, 33a, 33b... Lubricating water supply control air operated valve, 34a, 34b... Air f1'' valve operating.

Claims (1)

[Claims] 1. Two seawater pumps having at least underwater bearings;
A heat exchanger that is supplied with cooling seawater from these seawater pumps and exchanges heat with fresh water for cooling reactor auxiliary equipment, and a line that supplies lubricating water to the underwater bearings at the time of initial startup and during operation of the seawater pumps. In a reactor auxiliary cooling equipment equipped with a reactor auxiliary equipment cooling system, a lubricating water tank is provided which supplies and stores fresh water from other systems outside the reactor auxiliary equipment cooling equipment, and is also equipped with a water level control means. A nuclear reactor auxiliary cooling equipment characterized in that a lubricating water supply control piece is provided in the middle of a line that supplies fresh water to each self-pressure water circulation line that is circulated after the seawater pump is started. 2. The reactor auxiliary equipment cooling equipment according to claim 1, wherein the lubricating water supply control valve is a solenoid valve. 3. The reactor auxiliary equipment cooling equipment according to claim 1, wherein the lubricating water supply control valve is an air-operated valve. 4. The reactor auxiliary equipment cooling equipment according to claim 1, wherein the lubricating water supply control valve is a check valve.