JPS62220897A - Nuclear-reactor container cooling device - 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 [Field of Industrial Application] The present invention relates to a boiling water reactor containment cooling system, and particularly to a reactor containment cooling system for nuclear power facilities such as nuclear power plants.

[Prior art]

Conventionally, a reactor containment vessel cooling system has generally had the structure shown in FIG. That is, a reactor containment vessel (hereinafter referred to as dry well) 1 is provided with an upper cooler 2 and a lower cooler 3, and the cooling coil 4 installed in these coolers 2.3 cools the inside of the dry well 1. The atmosphere is cooled, and the cooled air is blown out from the air outlet 8 via the rising duct 6 and the ring duct 7e by blowers 5 connected to the coolers 2 and 3, respectively. Also, among the cooling air blown out from the air outlet 8, the air around the upper cooler 2 is directly sucked into the upper cooler 2, and the cooling air at the lower part of the dry well 1 is drawn into the lower part of the dry well 1. The air is blown into the provided air inlet 9 and guided to the lower cooler 3 via the ring duct 10 and the lower down duct 11. Cold water is supplied to the cooling coil 4 from a refrigerator 12 including a compressor 12a, a condenser 12b, and an evaporator 12C provided outside the dry well 1 via a pump 13 and a cold water pipe 14. ing.

In the conventional cooling device having the above-described configuration, the dry well 1 accommodates components that dissipate a large amount of heat, such as high-temperature equipment and piping, so a cooler with a large cooling capacity is required. As a result, cooler 2. 3 and duct 6,
7. 10. 11 will also be larger in size. Furthermore, since each of the coolers 2.3 is equipped with a blower 5, which is a dynamic device, the upper and lower coolers 2.3 are each equipped with a blower 5, which is a dynamic device, as shown in FIG. 50 of the required capacity
Consisting of 3 coolers with % volume filter, lower cooler 2゜3
When these two units are in operation, they can obtain the capacity to handle the heat load. As a result, cooler 2゜31 blower 5
The ducts 6.7 and 10.11 occupy a large proportion of the interior of the dry well 1, and there is a problem in that they interfere with or come close to other equipment or piping, making it difficult to adjust them.

In order to solve this problem, as shown in FIG. 9, the cooler 21! ! I-Cooling coil 4. The air inside the dry well 1 that is installed together with the blower 5 outside the dry well 1 and sucked in through the isolation valves 19 and 20 and the return duct 16? The cooling coil 4 cools the air, and this cooling air is sent to the air supply duct 1.
5 and isolation valves 17 and 18 into the dry well 1.

However, with such a structure, when considering the number and size of the coolers 2, it is not easy to secure a space for installing them outside the dry well 1. In addition, the diameter of the through-holes through which the air supply duct 15 and the return duct 16 pass through the dry well 1 must be approximately 1.5 m to 2 m, making it difficult to adjust the arrangement with the through-holes of other piping. It is. Furthermore, inside and outside where the air supply duct 15 and the return duct 16 pass through the dry well 1'kjY,
Isolation valve with accumulator that closes with air pressure in an emergency 1
Since it is necessary to provide 7 to 20, there is a problem that this space must be secured.

As disclosed in Japanese Patent Application Laid-Open No. 51-35888, this type of cooling device has a structure in which cooling air is passed through using a space between a pressure vessel and a gamma ray shield. However, according to this proposal, it would be necessary to install a blower inside the dry well, as well as a stand-up air supply duct and an air supply ring duct, which would require a very large amount of space within the dry well to install the cooling system. There was a problem. Another problem was that it was unnatural to transfer high-temperature gas from top to bottom between the pressure vessel and the gamma ray shield.

Furthermore, as disclosed in Japanese Patent Application Laid-Open No. 57-136191, a blower is provided outside the gamma ray shield at the lower part of the reactor containment vessel, and a space is formed between the lower part of the shield and the pressure vessel. There is a proposal for a structure that connects the two. In this proposal, as in the case of the previous proposal, the blower is installed in the dry well, so the installation space for the cooling device is large, and the high-temperature gas is transferred from top to bottom between the pressure vessel and the gamma ray shield. Furthermore, there were problems such as low temperature cooling gas stagnating at the bottom, making it impossible to cool uniformly without a stand-up duct.

[Problem that the invention seeks to solve]

The present invention solves the problem of the conventional cooling system installed in the reactor containment vessel, in which the coolers, blowers, ducts, etc. occupy a large space inside and outside the dry well. It is an object of the present invention to provide a nuclear reactor storage vessel cooling device that solves problems of interference and proximity, occupies a small area, and improves the reliability of equipment operation.

[Means for solving problems]

In order to achieve the above object, the present invention provides primary air cooling outside a reactor containment vessel cooling system that cools the inside of a dry well housing a reactor pressure vessel. A blower for supplying the air into the dry well is installed outside the dry well, and at least one induction unit is installed inside the dry well that blows out this primary air through a nozzle. A cooling coil that attracts and mixes secondary air in the nearby dry well and cools this secondary air near the nozzle? It was established.

[Effect]

According to the above configuration, the blower, which is a dynamic device, is installed outside the dry well, and the induction unit, which is a static device, is installed inside the dry well. This reduces the number of failures of devices inside the dry well. There is no need to install a 4a machine, and since it is smaller, less space is required for a cooling device. In addition, the primary air sent by the blower is jetted out at high speed from a nozzle installed in the attraction unit, and the secondary air inside the dry well that is attracted by the jet is cooled by a cooling coil, mixed with the primary air, and then inside the dry well. Since the air is blown out to the dry well for cooling, the air volume of the blower is only 25 to 33% of the air volume of the air-fuel mixture, and the blower can be used as a shed to reduce the space occupied by the blower outside the dry well.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a reactor containment vessel cooling system according to the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 to 5.

In this figure, the same or equivalent parts as those of the conventional example shown in FIGS. 7 to 9 are designated by the same reference numerals, and the explanation thereof will be omitted. A turbo blower 21 is installed outside the dry well 1, and six induction units 22 are installed inside the dry well 1, and a primary air supply duct 23 and an isolation valve 17.
18'. This attraction unit 22
As shown in FIGS. 2 and 3, there are three parts: a cabinet 24, a plenum chamber 25 housed in the cabinet 24, and an ejector 27 having a nozzle 26 (i-) connected to the plenum chamber 25. It consists of a cabinet 24 and a plenum chamber 2.
5 through which the primary air supply duct 23 passes,
The primary air 2B is blown out into the plenum chamber 25 through the opening. Nozzle 261j of the ejector 27: A blowing chamber 30 for blowing the secondary air 29 inside the dry well 1 is formed in the surrounding outer periphery,
A cooling coil 31 with a double coil structure is installed in the blowing chamber 30.
is provided. In this cooling coil 31,
Cold water is sent from the refrigerator 12 via the cold water pipe 14.

An air outlet 33 is provided at the upper part of the ejector 27 via a diffuser 32 having a reduced diameter, and a wind direction adjustment element 34 is attached to the air outlet 33. The primary air 28 supplied from the primary air supply duct 23 into the plenum chamber 25 is injected from the nozzle 26 at high speed, and the jet stream attracts the secondary air 29 cooled by the cooling coil 31. The mixed air is mixed with the air and blown out from the air outlet 33 as the attraction unit air 35. Note that 36 is a door pan provided at the bottom of the ejector 27. As shown in FIG. 4, these attraction units 22 are connected to the primary air 2 provided on the outer circumference of a gamma ray shield 38 that surrounds the outer periphery of the reactor pressure vessel 37 with a gap therebetween.
8 ducts 7, six units are arranged at approximately equal intervals. Further, for example, three openings 39 and 40 are formed in the upper and lower parts of the gamma ray shielding body 38, respectively, and are connected to the suction chamber 30 of the opposing attraction unit 22 via a suction duct 41. The ring duct 10 having the suction port 9 provided at the lower part of the dry well 1 is connected to the primary air return duct 42 via the lower drop duct 11 and the isolation valves 19, 2 (l). It is connected to a turbo blower 21.

Next is the effect of one lol example? explain. A jet of primary air 28 injected at high speed from the nozzle 26 of the attraction unit 22 attracts secondary air 29 cooled by the cooling coil 31 and mixes with the primary air 28 .
After stirring and removing heat from the upper part of the induction well 1 and the upper part of the reactor pressure vessel 27 through the air outlet 33 of the induction unit 2,
2, some of it descends to the lower part of the dry well 1 and removes heat by stirring the lower part of the dry well 1, and then enters the suction port 9.
, enters the primary air return duct 42 via the ring duct 10 and the lower down duct 11, and returns to the turbo blower 21.

Here, − sky air flow rate 'kGn, secondary air flow rate? ()s
Then, Gn+Gs/Gn (referred to as l pull ratio) is generally 2 to 3. Therefore, the cooling air diffused to the lower part of the dry well 1 is 1/1/2 of the cooling air diffused to the upper part.
3 to 1/4, but there is no risk that the temperature at the bottom of the tri-well 1 will rise due to this for the following reasons. That is, the amount of heat dissipated from equipment and piping in the lower part of the dry well 1 is smaller than that in the upper part, and most of the heat is transferred to the upper part of the dry well 1 as an upward air current. In other words, heat removal from the atmosphere inside the dry well 1 can achieve most of the objectives by intensively removing heat from the upper part of the dry well 1, which has a large amount of heat radiated from equipment and piping and is affected by rising airflow from the lower part. can be achieved. However, since the air between the pressure vessel 27 and the gamma ray shield 38 has a large calorific value, the heat removal described above is insufficient, so the air at the bottom of the dry well 1 is removed from the bottom opening 40.
Heat is removed through forced circulation.

The cooled blowing air 35 from the attraction unit 22 is blown upward in the circumferential direction and the radial direction at an angle of 45 degrees, so if the number and arrangement of the attraction units 22 are appropriately configured, dry It can be uniformly diffused in the upper part of the well 1, and a ring duct 7 as shown in FIG. 8 is not required. Moreover, since the cooling coil 31 built into the attraction unit 22 has a double coil structure provided on both sides of the ejector 27, the equipment arrangement can be made compact. Furthermore, by using low-temperature water (pline) as a cooling source for the cooling coil 31 and reducing the amount of cooling air, the cooling coil 31 can be made smaller. Further, since the attraction unit 22 is a static device, there is no need to provide a spare device, and space saving of the device is achieved.

FIG. 5 shows an attraction unit 22 according to this embodiment.

The figure shows a comparison of the external shape with that of a conventional upper cooler 2, and the attraction unit 22 according to this embodiment is configured to be extremely small.

Drywell Naien calorific value qt - approx. goo, ooow/h,
Assuming that the temperature inside the dry well is TSft57C and the gas temperature at the outlet of the attraction unit Tt30G, the circulating gas flow t(Q) inside the dry well is determined by the following equation.

Here, r: gas specific gravity (Nt gas specific heat) = 1. IKp
/rn''Cp: gas specific heat=0.241o1/V4・C Next, the performance of the ejector 27 will be explained with reference to FIG. 6. Primary/secondary gas flow rate ratio M, pressure ratio N, and ejector efficiency η
are calculated using the following formulas.

M=Gs/Gn=Qs/Qn-(1)
Here, Gn secondary gas (nozzle) weight flow rate (Kl/h
) = r Q n Gl! : 2&cus ttfi amount (K9/h) = r
QsQn Secondary gas (nozzle) volumetric flow rate (In3//h
) QS: Secondary gas volumetric flow* (m”/h) Here, Pl secondary side (nozzle) total pressure (xAq) h: Ejector efficiency 911 (Suction*>Total pressure (Act) Ps: Ejector outlet side total pressure (xAq) Pressure (mAq) η=M x
N...(3) Here, if η=0.5, then.

(2) Formula? i - When deformed, nozzle pressure (PI F2)
can be expressed by the following equation.

This (Ps P2) is the required pressure for circulating gas within the dry well 1, and is approximately 90 wAq. Therefore, the nozzle pressure CPIP2) is M=2(N=0.2
In case 5), M=3 (N=0.17).

Therefore, the static pressure of the blower is the nozzle pressure plus the pressure loss of about 150 A (1) in the primary duct system, which is about 600 mAq when 1M=2 and about 770 Aq when M=3.

As described above, the blower motor output may be about 100 KW in both cases of M=1 and M=2, which is not particularly large as a blower, and it is easy to secure space. Further, the diameter of the primary air supply duct 23 is 550 to 600W.
However, even if the reactor containment vessel 1 is penetrated, there is no problem because the penetration size is the same as that of other pipes.

Further, since the outlet gas temperature of the cooling coil 31 of the attraction unit 22 is about 12 to 17 C as calculated by the following equation, there is no problem in practical use.

Here, T1: fi pull unit cooling coil output log gas temperature (C) T
2: Induction unit exit gas temperature (3(1) Tn secondary gas nozzle exit temperature (r) TS Nidry well internal gas temperature (57C) ΔT: Blower heat-up (C) Therefore, when M = 2, when M = 3 According to this embodiment, a blower, which is a dynamic device for supplying and circulating cooling air into the dry well 1, which has a high ambient temperature of 65 G at maximum, is installed outside the dry well 1, and Since the attraction unit 22, which is a static device, is provided in the dry well 1 to circulate cooling air, the reliability of the operation of the cooling device is improved.

In addition, the size of the t1 equipment is small and there is no need to provide a spare machine, so the space for equipment and ducts can be reduced to 115 mm or less compared to the conventional method, and the dry well 1
This allows for proper placement of other equipment within the unit, and also facilitates maintenance. Moreover, by blowing primary air from outside into the dry well 1 at high speed by the M pulling unit 22, the turbo blower installed outside can also be made smaller, and the equipment for the cooling device outside the dry well 1 can be reduced. The duct space can also be reduced.

In this embodiment, a case has been described in which there are six attraction units 22, but it goes without saying that this number is not limited to six.

〔Effect of the invention〕

As described above, according to the present invention, an induction unit is provided that blows out primary air introduced from the outside into the cooling device of the nuclear reactor dry well through a nozzle, and the secondary air thus induced is cooled and converted into primary air. Since the interior of the dry well is cooled by mixing with and blowing out, the area occupied by the cooling device can be reduced, and the reliability of equipment operation can be improved.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing one embodiment of the reactor containment cooling system according to the present invention, Figs. The figure is a plan view of the arrangement of the attraction unit. FIGS. 5(a) and 5(b) are a plan view and a side view, respectively, comparing the external shapes of a conventional cooling machine and an attraction unit according to this embodiment, and FIG. 6 is a schematic diagram illustrating the operation of this embodiment.
FIG. 7 is a configuration diagram showing a conventional cooling device, FIG. 8 is a perspective view showing the duct configuration of FIG. 7, and FIG. 9 is a configuration diagram showing another conventional cooling device. 1... Dry well, 4, 31... Cooling coil, 5
゜21...Blower, 6.7. 10. 11.23.
41°42...Duct, 22...Attraction unit,
26... Nozzle, 28... Primary air, 29... Secondary air, 37... Pressure vessel.

Claims (1)

[Scope of Claims] 1. In a reactor containment cooling system comprising a cooling coil, a blower, and a duct for cooling the inside of a reactor containment vessel housing a reactor pressure vessel, the blower is installed outside the reactor containment vessel. The blower supplies external primary air to at least one attraction unit provided in the containment vessel, and blows out the primary air from a nozzle provided in the attraction unit to blow out the primary air into the containment vessel in the vicinity. 1. A reactor containment vessel cooling system characterized by attracting and mixing secondary air within the reactor containment vessel and cooling the secondary air by providing a cooling coil near the nozzle. 2. A reactor containment vessel cooling system according to claim 1, wherein the induction unit is disposed above the reactor containment vessel.