JP3093306B2 - Emergency condenser system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an emergency condenser system used for an emergency core cooling system of a boiling water nuclear power plant, a cooling system for isolating a reactor, and the like.

[0002]

2. Description of the Related Art In a boiling water nuclear power plant, high-temperature, high-pressure steam is usually generated by heat generated in a reactor core, and a turbine generator is rotated. Even if the reactor is isolated for some reason, a cooling system is provided at the time of reactor isolation in order to condense surplus steam and keep the reactor in a high-temperature standby state. As an example of the system configuration, a system using an emergency condenser (hereinafter, referred to as IC) is known.

[0003] In addition, at the time of reactor water loss accident (hereinafter referred to as LO
As heat removal means referred to as CA), a dynamic device since it can be as much as possible not to use systems, attempts to achieve the alternative function of the residual heat removal system for cooling of the reactor containment vessel by using the IC Considerations have been made.

[0004] For this purpose, from the viewpoint of analysis of steam condensation, stability of behavior and handling of non-condensable gas (N ₂ ) sealed in the reactor containment vessel, a vertical type as shown in FIG. 3 is used. I
C is desirable.

A conventional example will be described with reference to FIG. A conventional emergency condenser system is configured as shown in FIG. In the figure, reference numeral 1 denotes a IC, the lower portion of the heat exchanger tube 2 a number the IC 1 'this water reservoir 3, and a steam reservoir chamber 4 is provided in an upper portion, the steam storage chamber 4 at the heat transfer tubes 2 The cooled condensed water 5 accumulates. A drain pipe 7 having a drain valve 6 is connected to a lower portion of the water pool chamber 3, and a steam line 8 is inserted into the steam pool chamber 4.

[0006] The IC 1 is submerged in the cooling water 10 in the pool 9. The reactor steam flows in from the steam line 8, but the steam stays in the steam storage chamber 4 and the steam line 8 because the drain valve 6 is closed during standby. Portion up to the opening height of the heat transfer tubes 2 and steam line 8 is condensed water 5 collected, excess condensate will back flow back from the steam line 8 to the reactor side.

When cooling by the IC 1 becomes necessary, the drain valve 6 is opened and a line for returning the condensed water from the drain pipe 7 to the reactor is formed. And the steam continuously flows from the steam line 8 to I
Flows into C 1, condensed to return to the reactor coolant loop is achieved without the pump. Therefore, IC1 and pool 9
Must be installed at a higher level than the reactor.

[0008]

Problems with the prior art are as follows. (1) Since the steam reservoir chamber 4 is always in contact with the cooling water via the outer wall of the IC 1, heat exchange is performed. Condensed water is generated in the IC 1, and when overflows, the steam is passed through the steam line 8 to the reactor side. The phenomenon of flowing to the main steam line occurs. Although this is not as long as a small amount as usual condensation same odd problems in pipe wall, if desired to increase the IC 1, or the heat transfer from the shape
If the heat transfer portion of the pipe 2 is widened and condensed water is generated, water droplets may be brought into the turbine side, which is not preferable.

(2) On the other hand, since the pool 9 side also removes heat by evaporating the cooling water 10 , the initial pool water temperature and the amount of water are important design parameters. It is desirable to keep water 10 . That is,
If the temperature of the cooling water 10 is kept low, the amount of water and the volume of the body of the pool 9 associated with it can be reduced. For this reason,
A cooling system must be provided to keep the temperature of the cooling water 10 in the pool 9 constant.

[0010] However, in the prior art, after the temperature limit of about 40 ° C. before the cooling water 10 to a temperature of the reactor vapor about 270
° C, and it was necessary to provide cooling system equipment in consideration of the heat input to the cooling water 10 of a considerable amount. For this reason, not only is it uneconomical in terms of the power cost and equipment cost of the cooling system, but also the heat of the nuclear reactor is wasted and the fuel economy is deteriorated or the electric output is lost.

[0011] (3) IC1 is for the are installed by entering deaths maintenance and leakage monitoring in cooling water 10, in each case
It is necessary to drain the pool 9 and it takes time and effort.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an IC is installed in air, which is more advantageous in heat transfer coefficient than water, to reduce heat loss and condensate generated. ,
It is an object of the present invention to provide an emergency condenser system which can be easily inspected, repaired and monitored for leakage.

[0013]

According to the present invention, there is provided a pool, an insulating room partitioned into a cooling water in the pool by a separating wall in the pool, and an emergency condenser installed in the insulating room. The emergency condenser is provided with a heat insulating material that covers a steam reservoir chamber , a cooling water injection valve provided on the separation wall, and a water drain valve provided on the heat insulating chamber.

According to the present invention, an appropriate space is maintained by installing an IC in an insulated room, and the cooling water in the pool can be prevented from being heated. Further, heat generation from the IC is suppressed as much as possible by a heat insulating material or a heat insulating material. On the other hand, when a situation necessary for the IC occurs, the cooling water injection valve is automatically opened.

As described above, since the IC can be installed from the submerged state to the in-air state, no heating occurs in the pool. The heat radiation from the IC is only natural convection of the air, so that the heat loss can be sufficiently reduced, and the cooling equipment of the pool can be greatly reduced. Also,
Since it is rarely used during normal times, it is usually in a dry state, has good maintainability, and can be easily inspected and repaired even in case of leakage.

[0016]

The first embodiment of the emergency condenser system according to the present invention embodiments of the invention will be described with reference to FIG.
In FIG. 1, the same portions as those in FIG. 3 are denoted by the same reference numerals, and the description of the overlapping portions will be omitted.

That is, in FIG. 1, the interior of the pool 9 is divided by a separation wall 12 to form a heat insulating chamber 11, and the IC 1 is installed in the heat insulating chamber 11. Above the inside of the insulation room 11 is the insulation wall 13
Is provided, and an inspection ladder 14 is installed on the side wall surface, and a cooling water injection valve 16 is attached further below,
A drain drain valve 17 is connected through the bottom surface.

A heat insulating material 15 is provided on the upper outer surface of the vapor reservoir 4 of the IC 1. Thus, the IC 1 takes a suitable space in the heat insulating chamber 11 and is surrounded by the separation wall 12 on the entire circumference. During normal operation, since the IC 1 is not required, the drain valve 6 is closed, and condensed water 5 and steam 8 from the nuclear reactor are contained in the IC 1.

Therefore, although the IC 1 is in a high temperature state, the surroundings are air and the heat transfer is only natural convection, so that the separation wall
The heat loss from the IC 1 is greatly reduced by installing the heat insulating material on the IC 12 and the heat insulating material 15 on the IC 1 as compared with the case where the IC 1 is submerged.

Although very rare, I
When the C1 is a situation that is required has occurred, IC 1 by a drain valve 6 at the signal IC 1 'starts simultaneously with the opening, and automatically open the injection valve 16 to the cooling water 10 in pool 9, conventional Similarly, the main body of the IC 1 can be submerged and cooled.

On the other hand, since the IC 1 is not required at all in normal plant start-up, shutdown, and continuous operation, the inside of the separation wall 12 is in a dry state, and the external appearance can be easily viewed by installing the inspection ladder 14 or the like. Also, maintenance and inspection properties are good, for example, leakage is easily detected.

According to the present embodiment, it becomes possible to greatly reduce the heat input to the pool from the IC plant during normal operation. Thus, the capacity of the pool cooling system and reactor auxiliary cooling system IC is reduced. Further, depending on the outside air condition, the pool cooling system of the IC can be deleted.

Furthermore, the reduction of heat loss can reduce the generation of condensed water. On the other hand, at normal times, the surroundings of the IC 1 can be monitored, and by installing in the air, maintenance and inspection can be performed much more easily than submersion. In addition, a thermal reaction or the like due to a vertical temperature difference generated by installation in water is also reduced.

Next, with reference to FIG. 2 illustrating a second embodiment of the present invention. In FIG. 2, a chimney 18 is connected above a separation wall 12 constituting the heat insulating chamber 11, and an upper portion of the chimney 18 penetrates a building outdoor wall 19 and is exposed outside.

[0025] as possible performing a first thermal insulation in the embodiment, and that confine the heat generated from the IC1, inevitable heat generation becomes to heat removal by the air conditioning, heated in the second embodiment The discharged air is discharged directly to the outside to substantially reduce the load on the air conditioning system.

When the IC 1 is used, the cooling water 10 in the pool 9 eventually boils and is discharged outside. The other operation and effects are almost the same as those of the first embodiment, and the description is omitted.

[0027]

According to the present invention, it is possible to reduce heat loss and improve maintainability by using a reactor cooling emergency condenser (IC) at the time of reactor isolation and accident which are important for safety. Can do things.

That is, various problems which have conventionally occurred due to the underwater installation can be handled in the same manner as a normal heat exchanger by installing the apparatus in the air during standby. According to the present invention, it is possible to greatly rationalize ancillary equipment for cooling an IC pool.

By utilizing these effects, the applicable range of the emergency condenser system, which is a promising design capable of reducing the number of dynamic devices such as pumps, which has not been adopted in the conventional large-scale furnace, is expanded.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of an emergency condenser system according to the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the emergency condenser system according to the present invention.

FIG. 3 is a longitudinal sectional view schematically showing a conventional emergency condenser system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Emergency condenser, 2 ... Heat transfer tube, 3 ... Sump chamber, 4 ... Steam chamber, 5 ... Condensed water, 6 ... Train valve, 7 ... Drain pipe,
8 ... Steam line, 9 ... Pool, 10 ... Cooling water, 11 ... Insulated room, 12 ... Separation room, 13 ... Insulated wall, 14 ... Inspection ladder, 15 ...
Insulation material, 16… Cooling water injection valve, 17… Drainage drain valve, 18…
Chimney, 19 ... Outdoor wall.

Claims (1)

(57) [Claims] 1. A pool, an insulated room partitioned into a cooling water in the pool by a separating wall in the pool, an emergency condenser installed in the insulated room, and an emergency condenser installed in the insulated room. a heat insulating material covering the steam reservoir chamber, wherein the cooling water injection valve provided in the separation wall, the emergency condenser system characterized by comprising a drain drain valve provided in the cross heat chamber.