JPS63229399A - Gas processor - 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 the operation of exhaust gas system equipment used in BWR plants, and in particular utilizes conventional equipment without installing a dedicated extraction device in the tank vent treatment equipment. The present invention relates to a gas processing device characterized by a simplified system.

[Conventional technology]

Conventional equipment for thermal and nuclear power generation fi December 1978 102
As shown in Figure 8 of BWR gaseous waste treatment system on page 8, the exhaust gas from each equipment vent is installed with a dedicated filter and discharged into the exhaust stack independently, while a vacuum pump is used to exhaust air from the condenser at startup. There were two separate lines that discharged to the exhaust stack. FIG. 2 shows a prior art tank venting system. The tank 1 inside the nuclear power plant, which contains radioactivity, is connected by a collecting pipe 9 and released because there is a problem in which the radioactivity inside the tank is released due to the breathing phenomenon of air in the atmosphere due to the rise and fall of the water level, contaminating nearby stations with radioactivity. After moisture is removed from the vent in a steam/water separator 2, it is led to a filter 3, where radioactivity in the vent is removed. The vent is continuously discharged by the exhaust fan 5, and the amount of discharge is controlled by the inlet vane 4 on the exhaust side of the exhaust fan 5. Since the discharge amount is generally small, in order to prevent burnout due to the zero discharge amount in the exhaust fan 5, a recirculation pipe 14 for discharging more than a specified flow rate is connected to the filter outlet pipe 11, and a recirculation valve 7 is provided in the middle, which is interlocked with the flow meter 6. let

The clean air is discharged into the atmosphere from the exhaust stack 8 via the exhaust pipe 12.

[Problem that the invention seeks to solve]

Many tanks 1 have a nearly closed structure, and the amount of emissions from the atmosphere is zero unless there are glue-fins.

In this case, the recirculation pipe 14 prevents burnout of the exhaust fan 5.
Although recirculation operation is performed, the temperature gradually rises due to the temperature rise in the exhaust fan 5, making continuous operation impossible. In order to avoid this problem, air leaks in from the tank 1 to prevent burnout of the exhaust fan 5, but the presence of the leak-in section means that radioactive gas is continuously released from the exhaust stack 8 and released into the atmosphere. There is a problem in reducing radioactivity.

There is also the problem of increased auxiliary power due to continuous operation of the exhaust fan 5.

The present invention suppresses emitted radioactivity as much as possible, reduces auxiliary power,
The purpose is also to reduce equipment costs.

[Means for Solving the Problems] The above object is achieved by using an extraction device that is idle equipment that is used only when starting up the plant.

[Effect]

Since the amount of leakage from the tank during normal operation is small, a pressure regulating tank was installed to stop continuous exhaust operation using the exhaust fan, and the exhaust fan was operated intermittently depending on the vacuum level inside the pressure regulating tank. In addition, this method increases the capacity of the exhaust fan, so
Remove the exhaust fan and use the existing extraction equipment.

〔Example〕

FIG. 1 shows a system diagram of the present invention.

The air inside the condenser 21 is extracted from the condenser 21 by the vacuum pump 26 via the pump inlet pipe 29, and then the air inside the condenser 21 is extracted from the condenser 21 via the pump inlet pipe 29.
The moisture contained in the air is removed, and the air is discharged into the atmosphere from the exhaust pipe 8 via the exhaust pipe 31. When the degree of vacuum inside the condenser 21 rises to a specified value, the driving steam is then transferred to the steam supply pipe 32 to the air extractor first stage nozzle 22,23.
The vacuum level inside the condenser 21 is maintained.

After that, the pump inlet valve 28 is fully opened, the vacuum pump 26 is stopped, and the vacuum level inside the condenser 21 is maintained using the first stage nozzle 22. Second
The exhaust gas is discharged into the atmosphere from the exhaust stack 8 after removing radioactivity in the exhaust gas treatment device 25. After that, after operating the vacuum pump 26 again, the filter outlet valve 16
Open and shift to tank vent system operation. When the tank 1 is not operated and the amount of air leakage is small, the degree of vacuum in the pressure regulating tank 43 increases. The vacuum switch 44 detects the specified degree of vacuum, and the vacuum pump 26 is stopped by that signal.

A regulating valve 42 is installed upstream of the pressure regulating tank, and is opened and closed by a signal from a pressure controller 41 installed in front of the regulating valve 42 to maintain the pressure in front of the regulating valve at a specified degree of vacuum. Therefore, when the tank 1 is not in use, its state is held, and when it starts to be used, the vacuum level of the pressure in front of the regulating valve decreases due to air leak-in, the regulating valve 42 is opened, the vacuum level is maintained, and the pressure is regulated accordingly. As air enters the tank, the pressure regulating tank 43
The degree of vacuum inside is gradually getting worse. When the degree of vacuum decreases to the specified degree of vacuum, the vacuum switch 44 is activated again, the vacuum pump 26 is activated, and the degree of vacuum in the pressure regulating tank 43 is increased.
The vacuum pump 26 is stopped at the specified vacuum level. By repeating the above operating procedure, the tank vent system is maintained, and according to this example, vent processing is possible without installing a dedicated extractor, reducing equipment costs and reducing the amount of air leak-in. If the amount is low, the vacuum pump 26 is continuously stopped, unnecessary power consumption is eliminated, and operating costs can be reduced.

〔Effect of the invention〕

According to the present invention, there is no need to install a dedicated extractor for the tank vent system, which reduces equipment costs and simplifies the system configuration.Also, since the vacuum pump is used once a year, a surveillance test is required once a month. However, this is no longer necessary, and it is also effective in terms of operational benefits and effective use of equipment.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention, and FIG. 2 is a system diagram of the prior art. 1...tank, 2...steam water separator, 3...filter, 4...inlet vane, 5...exhaust fan, 6...
・Flow meter, 7... Recirculation valve, 8... Exhaust pipe, 9...
Collecting pipe, 21... condenser, 22... first stage nozzle,
23... Second stage nozzle, 25... Exhaust gas treatment device, 2
6... Vacuum pump, 27... Separator, 41...
・Pressure controller.

Claims (1)

[Claims] 1. Steam and water separators used in nuclear power plants to prevent radioactive contamination by communicating with the atmosphere in equipment that contains radioactive gas;
A waste treatment system consisting of a filter and an extraction device is equipped with a regulating valve and a pressure regulating tank to enable intermittent operation of the extraction device, and a condenser vacuum pump is used in the extraction device, which is used only when starting up the plant. A gas processing device characterized by: