JPH07120592A - Ventilation equipment for closed rooms and support method in case of power failure - Google Patents

Abstract

(57) [Abstract] [Purpose] This study relates to a ventilation system for closed rooms and a support method for power outages. The soundness of the facility is ensured by suppressing fluctuations in the gas pressure ranking of the suction system and various equipment connected to it. [Structure] As a facility for maintaining a decompressed atmosphere in the room by sucking the internal air of the closed chamber with an exhaust fan and exhausting it to the outside of the room, an exhaust fan and a flywheel that continuously rotates the exhaust fan by inertial force during a power failure , An emergency power generation facility which is connected to the rotary drive source for the exhaust fan, is activated at the time of a power failure, and supplies electric power within the time for supplying the inertial force by the flywheel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ventilation facility for a closed room and a support method for a power failure, and more particularly to maintaining the internal atmosphere of the closed room at a reduced pressure with respect to atmospheric pressure even during a power failure. Is.

[0002]

2. Description of the Related Art In facilities that handle radioactive substances and hazardous chemical substances, such as a spent nuclear fuel reprocessing plant, a closed chamber that is isolated from the surrounding environment must be constructed to exhaust indoor air. The harmful substances are released to the outside of the closed room by suctioning the air to create a pressure-reduced atmosphere relative to the atmospheric pressure, and processing the suctioned air with the exhaust gas processing means and then sending it to the off-gas processing system. I try not to be.

The exhaust fan is rotated by a rotary drive source such as an electric motor which is supplied with power from a commercial power source. However, even if there is a power failure of the commercial power source, it is extremely important that the decompressed atmosphere in the sealed chamber be maintained. It is necessary to prepare a power generation facility for the power plant, start it up in the event of a power failure, and promptly restart the suction and exhaust by the blower.

[0004]

However, the time required to start the power supply from the emergency power generation equipment is set, for example, within a few tens of seconds to a few minutes. When the volume of the chamber is large and various facilities and equipment are involved, the gas pressure order of the suction system etc. collapses due to the stop of the exhaust fan, and various gases flow backward from the exhaust system and mix, etc. However, there are still technical problems to be solved, such as the possibility of occurrence of damage and the possibility that the decompressed atmosphere in a required place may be damaged.

The present invention has been made in view of these problems, and maintains a decompressed atmosphere by suction in a sealed chamber until power supply by an emergency power generation facility is started, and a gas suction system and the same. The purpose is to ensure the soundness of the facility by suppressing fluctuations in the gas pressure ranking of various connected equipment.

[0006]

[Means for Solving the Problems] Several means for solving the above problems are proposed. The first means is equipment for maintaining a decompressed atmosphere in the room by sucking the internal air of the closed chamber with the exhaust fan and exhausting it to the outside of the room, and an exhaust fan operated by a rotary drive source for the exhaust fan, A flywheel connected to the exhaust fan to continuously rotate the exhaust fan due to inertial force during a power outage, and an emergency connection that is connected to the rotation drive source for the exhaust fan to be activated during a power outage and that supplies power within the inertial force supply time of the flywheel. It is equipped with a power generation facility. The second means is the same as the first means,
A starter motor for rotating the flywheel to a steady rotation speed is connected to the flywheel, and a clutch is provided between the flywheel and the exhaust fan to keep the clutch in the connected state at the steady rotation. In the third means, a configuration in which the flywheel is housed in the vacuum chamber is added to the first means or the second means. The fourth means is, as a support method at the time of power failure of the ventilation equipment for a closed room, the exhaust fan is driven to rotate in a steady state by a rotary drive source for the exhaust fan supplied from a commercial power source, and the flywheel is synchronously rotated with the exhaust fan. Then, when the commercial power supply fails, the emergency power generation equipment that supplies power to the blower rotary drive source is started, and until the power is supplied from the emergency power generation equipment, the exhaust fan continues to operate due to inertial force of the flywheel. It employs a configuration that operates.

[0007]

In normal operation, the air in the closed chamber is sucked and discharged to the outside by the operation of the exhaust fan, and the decompressed atmosphere in the closed chamber is maintained. At this time, the flywheel is maintained in a rotating state at a steady rotation speed. During a power failure, the exhaust fan is continuously rotated by the inertial force of the flywheel, the rotary drive source for the exhaust fan, and the inertial force of the exhaust fan, and the decompressed state of the sealed chamber is maintained. After a power outage,
Until the power is supplied from the emergency power generation equipment to the rotary drive source for the exhaust fan of the exhaust fan, suction and exhaust of the exhaust fan by inertial force is continued. When changing the flywheel from a stopped state to a steady rotation state, the flywheel rotation speed is gradually increased by disconnecting the flywheel from the rotation system of the exhaust fan and operating the starter motor. Then the flywheel is connected to the blower. When the flywheel has a vacuum atmosphere in the vacuum chamber, wind loss due to rotation of the flywheel hardly occurs, and energy loss during steady rotation is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the closed room ventilation equipment and the support method for a power failure according to the present invention are applied to a spent nuclear fuel reprocessing plant will be described below with reference to FIGS. 1 and 2. In the figure, reference numeral 1 is a reprocessing factory building, 2 is a closed room (cell room), 3 is a power supply facility (commercial power supply), 4 is a power supply cable, 5 is a rotary drive source for an exhaust fan, 6 is an exhaust fan, and 7 is Blackout detection means, 8 is an emergency power generation facility, 9 is a flywheel, 1
0 is a vacuum chamber, 11 is a connecting shaft, 12 is a speed change gear, 1
3 is a clutch, 14 is a starting motor, and 15 is a connecting gear.

Explaining these details, inside the closed chamber (cell chamber) 2 in the reprocessing plant building 1, a reprocessing facility 21 for reprocessing spent nuclear fuel and a discharge from the reprocessing facility 21. Exhaust gas treatment facility 22 for removing harmful substances in exhaust gas to be discharged and discharging harmless air and water vapor
An air suction port 23 arranged in each place of the closed chamber 2 and an internal ventilation facility 24 connected to the air suction port 23 and collecting suction air are installed. Reference numeral 25 denotes an exhaust tower, which has an off-gas treatment system for treating the exhaust gas discharged from the exhaust gas treatment equipment 22 and discharges detoxified air and water vapor.

The power supply equipment 3 is an ordinary commercial power source, that is, a high voltage power source of 6600 V, 440 V or 220 V, for example.
Is a low-voltage power source, and is connected to each exhaust fan rotary drive source 5 and the like via a power supply cable 4.

The rotary drive source 5 for the air exhausters includes the respective air exhausters 6
Are arranged in a connected state in correspondence with.

The exhaust fan 6 is, for example, a large blower, and is arranged in a connected state between the exhaust tower 25 and the downstream side of the exhaust gas treatment equipment 22 and the internal ventilation equipment 24, and is connected to the exhaust gas treatment equipment 22 and the internal ventilation equipment 24. The inside and the upstream side thereof are set to a reduced pressure atmosphere.

The power failure detection means 7 is connected to the power supply equipment 3 and detects the occurrence of a power failure accident while the power is being supplied to the blower rotary drive source 5 and the recovery after the power failure. The presence or absence of is detected and the emergency power generation equipment 8 is started.

The emergency power generation facility 8 includes a power feeding cable 4
As described above, the time required to start power feeding is, for example, several 1
It is set to be within 0 seconds or several minutes.

The flywheel 9 is connected to the exhaust fan 6 via a connecting shaft 11, a speed change gear 12 and a clutch 13, and airtightly penetrates into a vacuum chamber 10 set to a high degree of vacuum. It is rotatably supported by a bearing or the like that stores large inertial energy.

The clutch 13 is, for example, an electromagnetic clutch that can be remotely controlled, is arranged between the flywheel 9 and the exhaust fan 6, and connects them during steady rotation. .

The starting motor 14 is connected to the flywheel 9 via a connecting gear 15, and the flywheel 9
The rotation speed is increased from the stopped state to the steady rotation speed, and for example, a short-time rated specification is used.

A method for operating the ventilation equipment for a closed room having such a configuration and a support method at the time of power failure will be described below.

During normal operation of the reprocessing facility 21, the exhaust gas treatment facility 22, the internal ventilation facility 24, and the closed room ventilation facility, power is supplied from the power feeding facility 3 to the blower rotary drive source 5 to operate the blower 6. In this state, the exhaust gas from the exhaust gas treatment equipment 22 and the internal ventilation equipment 24 is sucked to make the inside of the suction system and the closed chamber 2 a decompressed atmosphere, and the sucked gas is exhausted outside the closed chamber 2 to the exhaust tower 25. Process by sending to.

The gas pressure in the suction system of the exhaust fan 6 is
The degree of decompression increases as the value becomes closer to, and a gradient of the gas pressure order is given in which the degree of decompression of the internal atmosphere of the closed chamber 2 is the smallest.

When the blower 6 is operating, the clutch 1
When the exhaust fan 6 and the flywheel 9 are connected via 3 the flywheel 9 is maintained in a rotating state at a steady rotation speed. At this time, the flywheel 9 is arranged in a vacuum atmosphere inside the vacuum chamber 10 to suppress the generation of frictional resistance with the internal gas (occurrence of windage loss) and reduce energy loss during steady rotation. can do.

When a power failure occurs in the power supply equipment 3, the power failure detection means 7 detects the power failure state and promptly starts the emergency power generation equipment 8.

Further, when a power failure occurs, the power supply to the blower rotary drive source 5 is stopped, so that the number of rotations decreases corresponding to the load of the blower 6. However, since the flywheel 9 is connected to the blower 6, the inertial force based on the rotational energy of the flywheel 9 functions to maintain the rotation of the blower rotary drive source 5 and the blower 6. While the suction action by the air exhauster 6 is continuously performed and the suction action gradually decreases, while the depressurized state of the closed chamber 2 is maintained for a while, and the suction action of the air exhauster 6 is effective. The soundness of the facility can be secured by suppressing the occurrence of the backflow phenomenon of the gas and the unnecessary mixing phenomenon of the gas suction system and various equipment connected to the gas suction system without changing the gas pressure order.

Exhaust fan 6 due to inertial force of flywheel 9
When the emergency power generation facility 8 is activated and power supply is started while the continuous rotation is performed, the clutch 13 operates to disconnect the exhaust fan 6 and the flywheel 9, and
The blower rotary drive source 5 increases the number of rotations of the blower 6 and returns to the steady rotation state.

When the flywheel 9 is disengaged by the clutch 13 or in the initial state, the flywheel 9 in the stopped state gradually increases the rotational speed of the flywheel 9 by the operation of the starting motor 14 shown in FIG. After the steady rotation state is established, the exhaust fan 6 and the flywheel 9 are returned to the synchronous rotation state by connecting the exhaust fan 6 and the flywheel 9 with the clutch 13.

[Example of Calculation of Inertial Energy in Flywheel] Output of rotary drive source for exhaust fan: 150 kW Target start time of emergency power generation facility: 2 minutes after power failure (from start command to start of power supply) The required stored energy is: stored energy of flywheel = 150 kW × 2 × 60 = 150 × 10 ² × 120 = 1.8 × 10 ⁷ J Gears, bearing energy loss of 20%, the required stored energy = 1 .2 × 1.8 × 10 ⁷ J = 2.16 × 10 ⁷ J ........ (Equation 1) Moment of inertia: I, I = (1/2) Mr ² Kinetic energy: E is represented by E = (1/2) Iω ² . However, M: mass, r: radius, ω: angular velocity. Thus, the kinetic energy: E = (1/2) {( 1/2) Mr 2} ω
² = (1/4) Mr ² ω ² . If the steady rotation speed of the flywheel is set to 360 rpm and fluctuations in the rotation speed are allowed up to 180 rpm (effective use), usable energy becomes three quarters. In this case, the size of the flywheel is calculated. Since 360 rpm = 360 × 2π ÷ 60 = 12π (Rad), E = (1/4) Mr ² (12π) ² × (3/4) = 266.48Mr ² ………… (Equation 2) is derived. Get burned. Furthermore, (Equation 1) because it is necessary that (Equation 2) are ^{equal, 2.16 × 10 7 J = 266.48Mr} 2 Mr 2 = 2.16 × 10 7 ÷ 266.48 = 8.1057 × 10 ⁴ ………… (Equation 3) If r: 1.5 m, then from (Equation 3), M = 8.1057 × 10 ⁴ kg ÷ 1.5 ² = 3.602
5 × 10 ⁴ kg is required. Flywheel has height: h, density: 7
If it is formed of a steel disc of 800 kg / m ³ , from πr ² h × 7800 = 3.6025 × 10 ⁴ , h = 3.6025 × 10 ⁴ ÷ (π1.5 ² × 7800) = 0. 6534 m is required. In other words, weight: 36025kg, diameter 3
m, height: 0.6534 m steel disc at 360 rpm
It may be rotated by and effectively used up to 180 rpm.

It is possible to reduce the size by increasing the number of revolutions of the flywheel, and it is also possible to adopt a shape such as weight distribution to the peripheral portion.

[0028]

EFFECTS OF THE INVENTION According to the ventilating equipment for a closed room and the support method at the time of power failure according to the present invention, the following effects are exhibited. (1) It has an exhaust fan, a flywheel that continuously rotates the exhaust fan by inertial force during a power failure, and an emergency power generation facility that is connected to the rotary drive source for the exhaust fan and that is activated in the event of a power failure. However, the decompressed atmosphere in the closed chamber can be maintained until the indoor air is continuously sucked by the exhaust fan and the power supply by the emergency power generation facility is started. (2) Since the suction force of the exhaust fan gradually decreases, the fluctuation of the pressure order of the internal gas of the gas suction system and various equipment connected to it is suppressed, and the backflow and mixing phenomenon of the gas occur. Can be prevented and the soundness of the facility can be secured. (3) A flywheel is provided with a starter motor for rotating the flywheel to a steady rotational speed, and a clutch is arranged between the flywheel and the exhaust fan to separate the flywheel from the rotation system of the exhaust fan. By gradually increasing the number of revolutions of the flywheel, the flywheel can be restored to a normal rotation state, and it is possible to avoid interference with the rotation system of the exhaust fan.
The connection to the blower can be made at any time. (4) By adding the configuration in which the flywheel is housed in the vacuum chamber, it is possible to prevent wind loss due to rotation of the flywheel and suppress unnecessary energy supply.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment in which a closed room ventilation facility and a support method at the time of a power failure according to the present invention are applied to a spent nuclear fuel reprocessing plant.

FIG. 2 is a block connection diagram showing a connection state of the exhaust fan and the flywheel shown in FIG.

[Explanation of symbols]

 1 Reprocessing plant building 2 Closed room (cell room) 3 Power supply equipment (commercial power supply) 4 Power supply cable 5 Wind blower rotary drive source 6 Wind blower 7 Power failure detection means 8 Emergency power generation equipment 9 Flywheel 10 Vacuum chamber 11 Connecting shaft 12 Speed Change Gear 13 Clutch 14 Starter Motor 15 Connection Gear 21 Reprocessing Facility 22 Exhaust Gas Treatment Facility 23 Air Suction Port 24 Internal Ventilation Facility 25 Exhaust Tower

Claims (4)

[Claims] 1. A facility for maintaining a decompressed atmosphere in a room by sucking the internal air of a closed chamber with a ventilator and exhausting it outside the ventilator, the ventilator being operated by a rotary drive source for the ventilator, A flywheel connected to the exhaust fan to continuously rotate the exhaust fan by inertial force during a power failure,
A ventilation facility for a closed room, comprising: an emergency power generation facility that is connected to a rotary drive source for an exhaust fan and that is activated at the time of a power failure and that supplies power during an inertial force supply time by a flywheel. 2. A flywheel is connected to a starting motor for rotating the flywheel to a steady rotation speed, and a clutch, which is in a connected state at the time of steady rotation, is arranged between the flywheel and the exhaust fan. The ventilation equipment for a closed room according to claim 1. 3. The ventilation equipment for a closed chamber according to claim 1, wherein the flywheel is housed in a vacuum chamber. 4. A rotary drive source for an exhaust fan when the exhaust fan rotary drive source supplied from a commercial power supply brings the exhaust fan into a steady rotation state and a flywheel is in a synchronous rotation state with the exhaust fan, when the commercial power supply fails. Ventilation equipment for closed rooms, characterized by activating an emergency power generation facility for supplying power to a power source and continuously operating an exhaust fan by inertia force of a flywheel until power is supplied from the emergency power generation facility. How to support time.