JPS61211649A - Ventilating and air-conditioning unit in atomic power plant - Google Patents

Abstract

PURPOSE:To effectively prevent snow infiltrating together with external air from adhering onto filter surfaces by providing movable screens and brushes between an outside air intake port and a filter and a molten snow pit at the lower parts of the movable screens. CONSTITUTION:When the ventilation air conditioning unit is operated during snow falling, snow as well as the outside air enter into a feed air processing device 3 through a louver 2. Since on the upstream side of a bag type filter 4, movable screen devices 21 are disposed, snow infiltrated together with the outside air is caught by warp screens 24a and laterally supported screens 25a so that snow is prevented from adhering to the surfaces of the bag type filter 4. Snow adhering to respective screens 24a and 25a is swept off by brushes 38a, 38b, 39a and 39b and falls down. Fallen snow is collected in a snowmelt pit 23 positioned at the lower part of the movable screen device 21, and is melted by means of a heater 23a and snowmelt water is discharged out of an exhaust water port 23b.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a ventilation air conditioning system that controls moisture, humidity, and maintains cleanliness inside a building in a nuclear power plant. This invention relates to a ventilation air conditioning system in a nuclear power plant I that can prevent adhesion.

[Technical background of the invention]

Ventilation and air conditioning equipment in nuclear power plants maintains the environment necessary for the normal operation of branded equipment, and
The purpose is to provide appropriate environmental conditions (V internal temperature, humidity, cleanliness, ventilation flow, etc.) to operators and workers.

Figures 13 to 15 show this type of conventional ventilation air conditioner, in which a louver 2 is attached to the outside air intake port 1a installed in the IZYA I, and outside air is introduced into the supply air processing device 3. In addition, it prevents rainwater from entering the building 1.

11a Inside the supply air processing device 3, there is a bag-type filter 4 that removes foreign substances such as dust and particulate salt from the outside air.
: Heating coil 5 and cooling coil 6 for controlling the temperature of outside air.
are installed respectively, and the outside air after being processed by the supply air processing device 3 is transferred to the supply air duct 1-7 having a damper 7a.
13 units of 50% capacity FF (one of which is a spare) or 2 units of 100% capacity (one of which is reserved) 1fi
8, air is supplied to each air-conditioned space 9 in a space with a high level of waste radiation (a so-called contaminated area) or a space where radioactive materials are not present (a so-called clean area).

By the way, in the case of air conditioning for contaminated areas, the purpose is to prevent radioactive materials from stagnation in the air conditioned space 9, so as shown in FIG. 13, the air supply duct 7 is
The same volume of air as that supplied to the air conditioned space 9,
Bug type filter 100 and high performance particle filter 1
Exhaust duct 11 equipped with exhaust treatment device 10 to the right of 0b
A one-time system is adopted in which the air is discharged outdoors from the exhaust stack 13 by the IJt 741 aircraft 12. The air processing device 10J3 and the air blower 12 are equipped with a
%0% capacity 3 units, one of which is a spare) or 100% capacity of 2 units (one of which is a spare).

On the other hand, in the case of air conditioning for a clean area, Ni retention of radioactive substances is not a problem, so a part of the air heat exchanged in the air conditioned space 9 is returned to the air supply station WHH3, and the remaining air is A return duct system is used to exhaust the air.

(Problems with Frontal Technology) In the conventional ventilation air conditioning system for nuclear power plants having the above configuration, foreign objects (birds,
To prevent the intrusion of bird feathers, etc., the length of the − side is 10.
It is customary to arrange a wire mesh called a bird screen with a wire diameter of about 1.5 to 2.3φl111.

However, if a nuclear power plant is built in an area with heavy snowfall, snow that has a high moisture content will adhere to the bird screen or the blades of the louver 2 and freeze, narrowing the air flow path. , there is a risk that it will not be possible to take in the required amount of air necessary for building ventilation.

On the other hand, in the case of powder snow with a low moisture content, the snow passes through the bird screen and the louvers 2 and enters the air supply processing device 3 along with the outside air, and is deposited and collected on the bag-type filter 4, especially at the top. If there is a large amount of air, the bug type filter 4 will become clogged in an extremely short period of time, making it impossible to maintain the health of the ventilation air conditioning system.

[Purpose of the invention]

The present invention has been made with these points in mind, and it is an object of the present invention to provide a ventilation air conditioning system for a nuclear power plant that can effectively prevent snow that enters with outside air from an outside air intake port from reaching the filter surface (St M ). With the goal.

[Summary of the invention]

The present invention provides at least one movable screen between an outside air intake port and a filter, which is composed of only warp yarns or only weft yarns and is driven in the direction in which the yarns are stretched, and which attaches snow that has entered together with the outside air. A brush that removes snow that has adhered to the town and a snow melting pit that is located below the Machi VJ screen and melts the snow that has fallen from the movable screen. It is characterized by being able to effectively prevent fJi from forming on the surface.

[Embodiments of the invention]

A first embodiment of the present invention will be described below with reference to FIGS. 1 to 9.

In Figure 1? ``TT No. 1 and 2 are installed in this building 1.
Outside air intake 1a1. : This is the attached louver, and the outside air is supplied through this louver 2! ! ! The sea urchin is guided into the device 3.

Inside the casing 3a of this air supply processing device 3, as shown in FIG. 1, l+! A bag-type filter 4 for removing foreign matter such as dust and particulate salt, and a heating coil 5 and a cooling coil 6 for regulating the temperature of the outside air are installed, and this air supply station II! The outside air that has been treated by the device 3 passes through the air supply duct 7 and is sent by an air blower 118 to each air-conditioned space (not shown) in the contaminated area or the clean area.

Space 20 between the louver 2 and the bag type filter 4
As shown in FIG. 1, a movable screen device 21 is installed on the inner peripheral surface of the casing 3a on the upstream side of this movable screen device 21, as shown in FIGS. 1, 3, and 4. An eaves 22 having a triangular cross section is provided to cover the peripheral edge of the movable screen device 21.

Furthermore, at the upstream and downstream positions of the movable screen device 21 at the bottom of the space 20, there are steam coils, heating wires, etc. for melting snow that has fallen from the movable screen device 21, as shown in FIG. Heater 23 formed
a, and a drain port 23b for discharging snowmelt water to the outside! Snow bits 23 are installed respectively.

The movable screen device 21 includes an upstream screen device 24 having an endless warp screen 24 a and an endless weft screen 2 as shown in FIGS. 2 to 4.
5a, and a drive device 26 for rotationally driving both the screen devices 24.25 in the thread tensioning direction.
5a4. It is constructed by stringing a large number of strong nylon or Kevlar threads with a diameter of 1 oboro at intervals of 211IIR, which prevent snow from adhering to them.This ensures that the snow that enters is removed while maintaining the required static pressure for the ventilation air conditioning system. It is possible to capture it.

The warp screen 24a has radial ball bearings 27a at both ends, as shown in FIGS. 2 to 6.

The weft screen 25a is stretched between an upper shaft 28a and a lower shaft 28b, which are rotatably supported on both sides of the casing 38 via 27b. , FIG. 7, and FIG. 8: A horizontal shaft 30a rotatably supported at both ends of the casing 3a and the lower surface of the casing 3a through thrust ball bearings 29a and 29b, respectively.

30b. and both screens 24
a, 25a, power is transmitted from the drive device 26 via the upper shaft 28a and the horizontal shaft 30a, and each screen 24
a, 25a are rotated in the direction in which they are stretched.

As shown in FIGS. 2 to 4, the drive device 26 includes a motor 31 installed on the casing 3a, a bearing 33 that supports the tip of the output @ 32 of the motor 31, and an output shaft 3.
The pulley 34a is connected to a pulley 34b attached to the upper shaft 28a via a belt 36, and the bevel gear 35a is connected to a pulley 34b attached to the upper shaft 28a. Horizontal axis 30
Bevel 1 taken at the top end of a by ζ1! 35b. The output shaft 32 portion is covered with a cover 37.

Each screen 2 is rotationally driven by the drive device 26.
4a, 25a are provided with a pair of brushes 38a, 38b and 39a, 39b at the upper and lower ends of the warp screen 24a and at both ends of the weft screen 25a, respectively, as shown in FIGS. 2 to 8. ing. and a brush 38a.

398 is arranged upstream of each screen 24a, 25a, and brushes 38b, 39b are arranged upstream of each screen 24a, 25a.
It is arranged downstream of 25a.

Each of these brushes 38a, 38b, 39a.

39b, as shown in FIGS. 5 to 9, there is a stand 40 made of, for example, glass fiber, and a stand 40 made of, for example, hard plastic book, which is inserted between adjacent threads to maintain a constant thread spacing. It is composed of a liner 41 and a brush main body 42 made of Neulon or the like for removing snow that has landed on the threads. It is now possible to remove snow that has adhered to it.

Next, the operation of this embodiment will be explained.

When the motor 31 of the drive device 26 is started, the pulley 34a
, 34b, bevel gears 35a, 35b.

The rotational force of the output shaft 32 is transmitted to the upper shaft 38 a J3 and the horizontal shaft 30 a via the belt 36 and the upper shaft 38 a J3, respectively, and both the screens 24 a and 25 a are rotationally driven in the vertical direction or the horizontal direction.

When the ventilation air conditioner is operated in this state, outside air is guided into the air supply I+P device 3 through the louver 2, and foreign matter in the outside air is removed by the bag type filter 4.
After the temperature is controlled by the heating coil 5 or the cooling fJ coil 6, the air is sent to an air-conditioned space (not shown).

By the way, when the ventilation air conditioner is operated at ll'F MIF, +i, snow enters the air supply processing system 3 through the louver 2 along with the outside air.

However, in this embodiment, since the movable screen device 21 is disposed upstream of the bag-type filter 4, the snow that has entered with the outside air is captured by the warp screen 24a and the weft screen 25a, and is not deposited on the surface of the bag-type filter 4. It can prevent snow from accumulating on your food. At this time, since both screens 248° 25a are used in combination, the threads form a grid pattern and the rate at which snow is blocked by the threads increases.
Even if a large amount of snow invades, please take care of this thoroughly.
can be captured.

Each brush') -> 24a, 25a (= J The snow that has fallen is brushed off by each brush 38a, 38b, 39a, 39b and falls. Is the fallen snow covered by a movable screen? +
The snow melting water is collected in the snow melting pit 23 located below the snow melting pit 21, and is melted by the heater 23a.
23 b.

In this way, the movable screen device i! is installed in the space between the louver 2 and the bug type filter 4! Since 21 is arranged,
This movable screen device prevents snow from entering with the outside air.
! It adheres to i21 and is removed from the outside air. For this reason,
It is possible to effectively prevent a situation in which snow adheres to the surface of the bug type filter 4 and causes clogging, making it impossible to maintain the integrity of the ventilation air conditioning system.

In addition, each screen 2 constituting the movable screen device 21
The snow attached to 4a, 25a is removed by brushes 38a, 38b, 3
9a and 39b, it is possible to maintain constant performance at all times.

Furthermore, the snow that falls from the movable screen 1 haze 21 is automatically melted and drained by the snow melting pit 23 below, making it extremely easy to handle.

10 and 12 show other embodiments of the present invention, the movable screen device 21 in J3 of the above embodiments
The downstream screen device 25 is omitted from this embodiment, and only the upstream screen device 23 is provided, and its structure and operation are completely the same as those of the previous embodiment.

With this configuration, the snow removal efficiency is somewhat lower than in the previous embodiment, but the configuration can be further simplified.

Therefore, it is effective to apply to nuclear power plants 1 to 1 to be constructed in areas where WF snowfall is relatively low.

〔Effect of the invention〕

As explained above, the present invention provides at least one section between the outside air intake [1] and the filter, which is composed of only the warp yarns or only the weft yarns and is driven in the yarn tensioning direction to attach snow that has entered together with the outside air. It is equipped with a movable screen on the stand, a brush that removes snow adhering to the movable screen, and a snow melting pit that is located below the movable screen and melts the snow that has fallen from the movable screen, so that it can be combined with outside air. It is possible to effectively prevent intruding snow from adhering to the filter surface, and maintain the integrity of the ventilation air conditioning system.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Fig. 2 is a sectional view of the movable screen device seen from the upstream side, and Fig. 3 is a sectional view of the movable screen device as seen from the upstream side.
Fig. 4 is a cross-sectional view of Fig. 2 seen from the right side, Fig. 5 is a detailed view of the upstream screen device, Fig. 6 is a cross-sectional view of Fig. 5 viewed from above. 7 is a detailed view of the downstream screen device, FIG. 8 is a sectional view of FIG. 7 viewed from above, FIG. 9 is a perspective view showing the structure of the brush, and FIG. 10 is a detailed view of the downstream screen device. Second solid phase % diagram showing other embodiments of the invention, first
Figure 1 is a similar figure equivalent to Figure 3, and figure ff112 is a similar figure 4.
Fig. 13 is a system diagram showing a conventional ventilation air conditioner, Fig. 14 is a perspective view of a nuclear power plant showing the louver installation position, and Fig. 15 is a diagram showing the xv-xv line of Fig. 14. There is a cross-sectional view. DESCRIPTION OF SYMBOLS 1... Building, 1a... Outside air intake, 3... Supply air processing device, 4... Bag type noirter, 5... Heating coil, 6... Cooling coil, 20... Space, 21...
・Movable screen device, 23...to snow melting point], 23
a...Heater, 23b...1h water outlet, 24...Upstream screen! fj device 1.24a...warp screen, 25...downstream screen device 5.25a...
Weft screen, 26... Drive device, 38a, 38b
, 39a, 39b-... brush, 40... stand, 41...
...Liner, 42...Brush body.

Claims (1)

[Claims] 1. Ventilation air conditioning in a nuclear power plant in which outside air taken in from an outside air intake is guided to a filter to remove foreign matter in the outside air, and the temperature is controlled by a temperature control means and the air is sent to an air-conditioned space. In the apparatus, between the outside air intake port and the filter, there is provided at least one movable screen composed of only warp threads or only weft threads, which is driven in the direction in which the threads are stretched to attach snow that has entered together with the outside air, and to the movable screen. A ventilation air conditioning system for a nuclear power plant, characterized in that it is provided with a brush that removes snow that has adhered to it, and a snow melting pit that is located below a movable screen and that melts and discharges snow that has fallen from the movable screen. 2. The ventilation air conditioning system for a nuclear power plant according to claim 1, characterized in that a movable screen made up of only warp yarns and a movable screen made up of only weft yarns are arranged in combination.