JP2619454B2 - Air conditioner for PCV - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for a containment vessel of a boiling water nuclear power plant, and more particularly to an air conditioner suitable for equalizing the temperature distribution of the atmosphere in the containment vessel. .

[Conventional technology]

FIG. 10 shows a conventional example. FIG. 10 shows an air conditioner in a containment vessel of a boiling water nuclear power plant. 1 is a containment vessel, 2
Is a reactor pressure vessel, 5 is a duct, 6 is an annular outlet duct,
7 is an annular suction duct, 8 is a blower, and 9 is a cooler.
In the containment vessel 1, since there are heating elements such as the reactor pressure vessel 2, the main steam pipe 11, the recirculation pipe, and the water supply pipe, an air conditioner is provided to make the atmospheric temperature uniform. FIG. 10 shows only the main steam pipe 11 of these pipes for simplification. As shown in FIG. 10, three blowers 8 and coolers 9 are provided in the lower part of the containment vessel 1 and three in the upper part, respectively. In normal operation, two blowers 8 and two coolers 9 are provided. use. An annular outlet duct 6 is provided in the containment vessel 1.
And an annular suction duct 7, which are arranged concentrically outside the gamma ray shield 3. There are two cases of the air flow in the air conditioner. The air that has obtained heat from the reactor pressure vessel 2 and the main steam pipe 11 that generates heat becomes an upward flow, is sucked from the annular suction duct 7u on the upper part of the containment vessel 1, passes through the duct 5, and is cooled by the cooler 9l and the blower 8l. Then, the air is further blown out from the lower annular blow-out duct 6l of the containment vessel 1 to the lower part of the containment vessel 1 to the control rod drive area 4 and the gamma ray shield area 10. Another flow is as follows. The air sucked from the outlet of the cooler 9u on the upper part of the storage container 1 is cooled and then blown out from the annular blow-out duct 6u via the blower 8u. As described above, the heating elements such as the reactor pressure vessel 2 and the main steam pipe 11 are cooled by the cool air blown from the annular blowing ducts 6u and 61, the control rod driving area 4 and the gamma ray shielding area 10. In the conventional method, the low-temperature air region tends to stay at the lower part of the containment vessel 1 and the high-temperature air area tends to stay at the upper part of the containment vessel 1. The upper limit on the high temperature side of the operating temperature of the containment vessel is provided to maintain the reliability of electrical components such as cables and instrumentation, and the lower limit on the low temperature side is provided to prevent dew condensation on piping. Condensation in the pipes made it easier for chlorides and the like to adhere to the pipes, possibly leading to corrosion of the pipes. In order to prevent dew condensation on the piping, it is necessary to control the temperature of the atmosphere and at the same time to make the temperature equal to or higher than the lower limit on the lower temperature side. It must be maintained within the control temperature.

It should be noted that related devices of this type include, for example, JP-A-54-71291, JP-A-54-121390, JP-A-57-136191, and JP-A-62-64988.

[Problems to be solved by the invention]

In the above prior art, sufficient consideration has not been given to the point of uniforming the temperature distribution of the atmosphere of the containment vessel, and there has been a problem that a low-temperature air area tends to be generated at the lower part of the containment vessel and a high-temperature air area tends to be generated at the upper part of the containment vessel. Also, sufficient consideration has not been given to the rationalization of equipment.

An object of the first aspect of the present invention is to change the temperature of the air outlet of the air conditioner for each air outlet when the temperature distribution of the atmosphere in the containment vessel is made uniform to provide a streamlined air conditioner. It is to make the temperature distribution even more uniform.

A second object of the present invention, in addition to the first object of the present invention, is to obtain a temperature distribution in the best case by adjusting the outlet temperature by adjusting the flow rate.

A third object of the present invention is to change the duct cross-sectional area on the suction port side and each of the outlet ports in addition to the object of the first claim, so that the temperature distribution becomes the best.

[Means for solving the problem]

A first means for achieving the object of claim 1 is an air conditioner for a reactor containment vessel having a series of air passages composed of a cooler, a blower, and an air passage, wherein the reactor pressure vessel and the shield The gap and the control rod drive area at the lower part of the pressure vessel are connected by a wind path via a blower, a first outlet of the air path is provided at an upper position of the containment vessel, and the blower flows downward from the outlet. A second air outlet of the wind to be blown, a first air inlet of the air path provided below the second air outlet, and a blower from the first air inlet to the first air outlet. In the air conditioner of the containment vessel, the cooler is connected in the order of the air path, the blower outlet and the second outlet are connected by the air path, and the cooler outlet and the second outlet are connected by the air path. is there.

The second means for achieving the object of the second aspect is the second aspect.
An air conditioner for a reactor containment vessel in which an air flow regulating valve is provided between a cooler outlet and a second outlet in addition to the means of the twelfth aspect.

A third means for achieving the object of claim 3 is to maximize the cross-sectional area of the air path connecting the first suction port and the first air outlet in addition to the first means. The cooler outlet and the second
The cross-sectional area of the air path connecting the air outlets of the air passages is made smaller than the cross-sectional area of the air path between the first air inlet and the second air outlet. The cross-sectional area of the air path before connecting the air path to the connecting air path between the
This is an air conditioner for a containment vessel that is smaller than the cross-sectional area of two airways.

[Action]

In the first means, the gap between the reactor pressure vessel and the shield and the control rod drive area are connected by an air path and a blower, and by driving the blower, the ascending flow accompanying the heat generation of the reactor pressure vessel is reduced. Accelerate. The high-temperature air that has reached the upper part of the containment vessel is cooled by the cooling air blown out from the first outlet through the cooler by the blower, thereby forming a circulating flow. Furthermore, by having a structure that blows out from the second outlet at the intermediate height position of the containment vessel to the heat generation pipe group, the secondary flow accompanying the flow descending along the shield outer wall is promoted, and the intermediate height is increased. The temperature distribution in the height direction can be made uniform by forming a secondary circulation flow surrounding the equipment and the piping group existing in the above. Furthermore, the cooled air and the uncooled air from the cooler are mixed with each other to reach an appropriate temperature and blow out from the second outlet, so that the temperature can be made more uniform.

In the second means, in addition to the function of the first means, the air flow rate adjusting valve adjusts the mixing ratio of the cooled air and the uncooled air to achieve more accurate temperature uniformity.

According to the third means, in addition to the operation of the first means, the cross-sectional ratio of the air passage to each location is changed to change the air flow ratio from each outlet, thereby maintaining the blow-out air volume relationship that facilitates temperature uniformity. The point has a characteristic action.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9.

In FIG. 1, a reactor pressure vessel 2 is surrounded by a gamma ray shield 3 in a containment vessel 1. 6u is an annular outlet duct, and 7l is an annular suction duct leading to it. 8 is a blower, 9 is a cooler, and 14 is an air volume control valve. However, three blowers 8 and nine coolers 9 are installed, and two are used for operation. The duct 5 connects the gamma ray shield area 10 around the reactor pressure vessel 2 and the control rod drive area 4
The control rod drive area is used as a suction port, and a blower 8c is provided in the middle of this duct. An upper annular outlet duct 6u is provided at an upper position of the storage container 1, an intermediate annular outlet duct 6m is provided at an intermediate position, and a lower annular suction duct 71 is provided at a lower position. Duct 5 connects lower annular suction duct 7l and upper annular outlet duct 6u,
A blower 8 and a cooler 9 are arranged in the middle of the duct as shown in FIG. The outlet of the blower 8 and the middle section annular outlet duct 6m
And the outlet of the cooler 9 and the annular outlet duct in the middle
6 m is connected to the air flow regulating valve 14 via the check valve 13.

FIG. 2 shows an example of the arrangement of the upper annular outlet duct 6u. The duct 6u is arranged so as to surround the gamma ray shield 3 concentrically. The upper annular outlet duct 6u has a plurality of openings 15, and air passing through the annular outlet duct 6nu is blown into the storage container 1 from the opening 15. Similarly, the middle annular discharge duct 6m and the lower annular suction duct 71 also surround the gamma ray shield 3 in a concentric manner,
A plurality of openings 15 are provided on the inner vertical surface or lower surface of each duct.

FIG. 3 shows an example of the arrangement of the connecting duct 5 and the blower 8 between the control rod driving area 4 and the gamma ray shielding area 10. The blower 8c is provided outside the gamma ray shield 3. In the gamma ray shield 3, a plurality of through holes for the duct 5 are provided, and the duct 5 connects the control rod drive area 4 to the blower 8 c and the gamma ray shield 3 to the blower 8 c.

FIG. 4 shows the flow of air in the embodiment of FIG. In FIG. 4, the heat sources are the reactor pressure vessel 2, the main steam pipe 11, and the like, and their surfaces are usually covered with a heat insulating material. In addition to the piping, there is a heating piping group region 16 such as a water supply piping and a recirculation piping, which is simply shown in FIG. The air in the gamma ray shielding area 10 around the reactor pressure vessel 2 becomes an upward flow under the influence of buoyancy caused by heat generation from the reactor pressure vessel 2. This upward flow is further accelerated by air forcedly flowing in from the control rod drive area 4 by the blower 8c. The high-temperature air that has risen to the upper part of the storage container 1 is cooled by the cool air from the upper annular blowing duct 6u of the storage container 1. The cooled air descends near the outer surface of the gamma ray shield 3 having a small heat source, flows into the control rod drive area 4 from the entrance 12 of the control rod drive area 4, and then returns to the gamma ray shield via the blower 8c. It flows into area 3. In this way, an air circulating flow surrounding the gamma ray shield 3 is formed. On the other hand, in the piping group region 16 including the main steam pipe 11, the nearby air rises under the influence of buoyancy caused by heat generation from the piping group. These upward flows are cooled by cold air blown from the upper annular blow duct 6u and the middle annular blow duct 6u of the storage container 1. The air blown out from the upper annular blow-out duct 6u of the containment vessel 1 passes through the cooler 9, whereas the air blown out from the middle annular blow-out duct 6m of the containment vessel 1 flows through the cooler 9 outlet and the blower 8 outlet. It is a mixture of air, and the latter air has a higher temperature and a smaller air volume than the former. The provision of the intermediate annular outlet duct 6m suppresses partial channel flow and forms a gentle upward flow as a whole, and forms a secondary flow as shown in FIG.

By forming two large circulation flows in this way, the temperature distribution in the storage container 1 is to be made uniform.

FIG. 5 shows a part of an air conditioner.
Numeral 14 denotes an air flow regulating valve, and 13 denotes a check valve. Blower 8, Cooler 9
And the upper annular outlet duct 6u has the largest air passage cross-sectional area. The cross-sectional area of the air passage of the duct 5 connecting the cooler 9, the air flow regulating valve 14, the check valve 13 and the middle annular outlet duct 6m is smaller than that of the duct. Further, it is assumed that the duct 5 connecting the blower 8 and the intermediate annular outlet duct 6m has the smallest air passage sectional area. The upper annular outlet duct 6u and the middle annular outlet duct are adjusted by adjusting the opening of the air volume regulating valve 14.
Adjust the air flow to 6m. Upper annular outlet duct 6u and middle annular outlet duct when opening degree of air volume adjusting valve 14 is changed
Fig. 6 shows the air volume characteristics from 6m. Duct 5 ₁ in FIG. 5, 5 _2, by a 5 ₃ that different from one the size of Kazerodan area, upper annular air duct 6u by air flow rate adjusting valve 14
And the air volume to the middle annular discharge duct 6m can be adjusted. At the same time, the cooler 9
6 (b)
Can be changed as follows.

FIG. 7 shows the relationship between the installation method of the outlet and the inlet in the height direction of the containment vessel and the temperature distribution in the height direction near the piping group. (A) shows a conventional example, and (b) shows a case in which an annular outlet duct 6u is provided at an upper portion of a storage container and an annular suction duct 71 is provided at a lower portion. (C) shows the case of (b) in which an intermediate annular outlet duct 6m is provided. In (b), the temperature rises near the middle of the height of the containment vessel due to the influence of the heat generation of the piping group. In (c),
By providing the outlet at the middle part, the temperature distribution in the height direction is made uniform.

FIG. 8 shows the temperature distribution in the height direction near the pipe group when the air volume adjusting valve 14 is operated. 8th
(A) of the figure shows the case where the air flow regulating valve 14 maintains a predetermined opening degree, the temperature of the middle part is higher than the control temperature, and the temperature of the upper part becomes lower, and (b) shows the temperature distribution of (a). Shows a case where the air volume adjustment valve 14 is opened to bring the value into the control range.
In FIG. 6 (b), the air flow regulating valve 14 is opened further, so that the middle portion annular discharge duct is provided in accordance with the characteristics shown in FIGS. 6 (a) and 6 (b).
Increase the blowout volume of 6m and lower the blowout temperature. Further, the air volume of the upper annular outlet duct 6u is reduced, and the temperature distribution as shown in FIG.

Next, FIG. 8 (c) shows the case where the temperature of the upper part of the containment vessel becomes higher than the control range and the temperature of the lower part becomes lower. In this case, by closing the air volume adjusting valve 14, the air volume of the upper annular outlet duct 6u is increased, and the air volume of the middle annular outlet duct 6m is reduced. Thus, the temperature distribution in the height direction of the containment vessel can be made as shown in FIG. In the example shown in FIG. 8, the total amount of heat generated in the storage container is constant. At the time of reactor rated output operation, the total heat generation from the piping group and the reactor pressure vessel may be considered to be constant, and it is sufficient to consider partial temperature fluctuations as in cases (a) and (c).

FIG. 9 is a control block diagram for realizing the temperature control of FIG. When the temperature exceeds the control range, the process amount related to the temperature is changed by operating a valve to control the temperature. This method is general and can be easily realized. An example is shown in FIG. 17 is a temperature detector, 19 is a comparator, 25 is a motor, and 27 is a valve driving device. Temperature detection is performed at three locations: the upper, middle, and lower positions of the containment vessel. The comparator 19 compares the two analog quantities and outputs an output signal "1" only when the difference between the analog quantities is positive. The motor 25 rotates forward and reverse, and the valve driving device 27 performs an opening operation when the motor rotates forward, and performs a closing operation when the motor rotates reversely. AN
The D circuit 21, the inverter 22, and the ANDs 21 ₂ and 21 ₃ are for preventing the above-mentioned normal rotation and reverse rotation from being operated simultaneously.

Whether the output of the upper temperature detector 17u is lower than the value of the lower limit temperature setter 18l, the output of the intermediate temperature detector 17m is larger than the value of the upper limit temperature setter 18u, or the lower temperature detector 17l
Output of the comparator 19ul, 19mu, 19lu becomes "1" when the output of
And one of these three comparators 19ul, mu, lu
If it becomes "1" in the number output of the motor normal rotation control circuit 23 through the OR circuit 20n and AND circuit 21 ₂ becomes "1", the motor 25 is rotated forward rotation, the valve drive device 27 via a reduction gear 26 Works,
The valve opens. On the other hand, the output of the upper temperature detector 17u is larger than the value of the upper temperature setter 18u, the output of the intermediate temperature detector 17m is smaller than the value of the lower temperature setter 18l, or the output of the lower temperature detector 17l is When the temperature is lower than the lower limit temperature detector 18l, the comparators 19uu and 19
ml, the output of 19lu is "1", and these three comparators 19Uu, ml, the output of the motor inversion control circuit 24 through the OR circuit 20r and the AND circuit 21 ₃ when it becomes "1" in one of the lu is "1 ", The motor 25 rotates in the reverse direction, the valve driving device 27 operates via the speed reducer 26, and the valve closes. In FIG. 9, if the outputs of the upper / middle and lower temperature detectors 17u, m, l are both smaller than the value of the lower limit temperature setter 18l or larger than the value of the upper limit temperature setter 18u, Prohibit forward and reverse rotation of 25. In this case, the total calorific value in the containment vessel has changed, and it is necessary to separately adjust the flow rate of the secondary-side cooling water of the cooler 9. Here, the total calorific value in the containment vessel is assumed to be constant. However, the above case is excluded from the target because the target is a partial temperature change.

In FIG. 9, the temperature detector 17 is, for example, a combination of a thermocouple and an amplifier, the upper and lower limit temperature setting units 18u, l are potentiometers, and the comparator 19 is one of analog devices.
The OR circuit 20, the AND circuit 21, and the inverter 22 are general-purpose products as logic elements. Motor forward and reverse control circuit
23 and 24 are general-purpose products in combination with the motor 25, and the reduction gear 26 and the valve driving device 27 (actuator) are also general-purpose products, and the control block diagram of FIG. 9 can be easily realized.

As described above, according to the present embodiment, since the control rod drive area and the gamma ray shield area are connected by the blower and the duct, the rise of high temperature air in the gamma ray shield around the reactor vessel is promoted. The temperature of the upward flow is lowered by the cool air from the annular outlet duct at the top of the containment vessel, the air is lowered along the outer surface of the gamma ray shield, and the cool air from the intermediate annular outlet duct is further blown to lower the downward flow. Promotes and forms a circulating flow surrounding the gamma shield. On the other hand, the upward flow due to the heat generation of the piping group is suppressed by the cool air from the upper annular blow duct and the middle annular blow duct, and the secondary flow is generated along with the above-mentioned circulating flow, thereby reducing the temperature distribution inside the containment vessel. Can be uniform. In addition, the cool air from the middle annular outlet duct uses the mixed air at the cooler outlet and the blower outlet.
The air volume and temperature of the middle annular outlet duct and the air volume of the upper annular outlet duct can be changed, making it easier to control the temperature in the height direction of the containment vessel and preventing partial cold air channel flow. Becomes

FIG. 11 shows still another embodiment. In any one of the above-described embodiments, the following configuration is added. 28 is a laser oscillator, 29 is a cylindrical lens, 31 is a TV camera, and 32 is a monitor. FIG. 11 is for detecting whether the circulating flow of air in the storage container 1 is a constant flow. The laser light from the laser oscillation device 28 is transmitted to the optical fiber 30.
To the cylindrical lens 29 in the storage container 1. The cylindrical lens 29 expands the laser beam into a slit shape, causes dust 33 in the air to emerge, captures the dust 33 on the monitor 32 by the television camera 31, and turns the air circulation into a predetermined circulation flow. Detect if there is. As described above, by installing the air circulation flow detection system, the temperature control can be made more reliable by knowing the degree of uniformity of the temperature distribution in the storage container.

In any of the embodiments of the present invention, the circulating flow surrounding the gamma ray shield is generated, and the secondary circulating flow accompanying this circulating flow is generated in the piping group, so that the air in the containment vessel can be reduced in the stagnation area. Therefore, the temperature distribution of the atmosphere in the containment vessel can be made uniform. Further, since the temperature and air volume of the upper annular outlet of the containment vessel and the intermediate annular outlet can be easily changed, the controllability is improved. Furthermore, the number of coolers and blowers can be reduced, and the amount of ducts can be reduced, and rationalization can be achieved.

〔The invention's effect〕

According to the first aspect of the present invention, the circulating flow surrounding the shield is generated, and the secondary circulating flow accompanying the circulating flow is generated in the group of pipes, so that the area where air stays in the storage container can be reduced. The temperature distribution of the atmosphere inside the containment vessel can be made uniform, and the temperature of the blown air from the intermediate height can be controlled by mixing the cooled and uncooled air. Can be achieved.

According to the second aspect of the present invention, the temperature control obtained in the first aspect can be surely performed by using the air volume adjusting means, so that the temperature can be controlled more finely than the uniform temperature distribution according to the first aspect of the present invention. The distribution can be made uniform.

According to the third aspect of the invention, since the ratio of the air flow rate is adjusted by determining the ratio of the cross-sectional area of the air path of each air path, the finer than the uniform temperature distribution according to the first aspect of the invention. Uniform temperature distribution can be achieved.

[Brief description of the drawings]

1 is a longitudinal sectional view of a containment vessel according to one embodiment of the present invention, FIG. 2 is a perspective view of an upper annular blow-off duct of FIG. 1, and FIG. 3 is a view of a connecting blower and a duct of FIG. Perspective view, fourth
Fig. 5 is a longitudinal sectional view showing the direction of air flow in a containment vessel according to one embodiment of the present invention. Fig. 5 is a partial duct connection diagram of an air conditioner. Figs. 6 (a) and 6 (b) show a control valve. FIGS. 7 (a), (b), (c) and FIGS. 8 (a), (b), (c), (d) showing the air volume and temperature characteristics are shown in the height direction of the containment vessel. FIG. 9 is a temperature distribution diagram, FIG.
FIG. 10 is a longitudinal sectional view of a conventional containment vessel, and FIG. 11 is a view showing a circulating air flow detection system. 1 ... containment vessel, 2 ... reactor pressure vessel, 3 ... gamma ray shield, 4 ... control rod drive area, 5 ... duct, 6u
…… Upper annular outlet duct, 6m …… Middle part annular outlet duct, 6l …… Lower annular outlet duct, 7u …… Upper annular inlet duct, 7l …… Lower annular inlet duct, 8 …… Blower, 9…
... Cooler, 10 ... Gamma ray shielding area, 11 ... Main steam pipe, 12 ... Control rod drive area entrance, 13 ... Check valve, 1
…… Air flow control valve, 16 …… Piping group area, 25 …… Motor, 27
…… Valve drive device, 28 …… Laser oscillation device, 29 …… Cylindrical lens, 31 …… TV camera, 32 …… Monitor.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-67191 (JP, A) JP-A-60-53886 (JP, A) JP-A-61-100694 (JP, A) JP-A-61-1986 76990 (JP, A)

Claims (3)

(57) [Claims] An air conditioner for a containment vessel having a series of air passages comprising a cooler, a blower, and an air passage, wherein a control rod drive at a gap between the reactor pressure vessel and a shield and a lower part of the pressure vessel. The areas are connected by an air path through a blower, a first air outlet of the air path is provided at an upper position of the storage container, a second air outlet is provided below the air outlet, and the second air outlet is provided. A first suction port of the air passage is provided below, and a blower and a cooler are connected in this order from the first suction port to the first blowout port by a blower, and a blower outlet and a second blowout port are provided. Contact by wind
The air conditioner for a containment vessel, wherein the cooler outlet and the second outlet are connected by an air path. 2. An air conditioner for a containment vessel according to claim 1, wherein an air flow regulating valve is provided between the cooler outlet and the second outlet. Harmony equipment. 3. The air conditioner for a containment vessel according to claim 1, wherein an air path cross-sectional area of an air path connecting the first suction port and the first air outlet is maximized, and the cooler outlet is provided. The cross-sectional area of the air passage connecting the first air inlet and the second air outlet is made smaller than the cross-sectional area of the air passage connected between the first air inlet and the second air outlet. The air passage in the reactor containment vessel, wherein an air passage cross-sectional area of the air passage from the cooler outlet to the connecting air passage between the second air outlet is smaller than the air passage cross-sectional area of the two air passages. Harmony equipment.