JPS60187893A - Measuring device for concentration of gas - 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 [Technical Field of the Invention] The present invention relates to a gas 11i1 degree measuring device that measures the concentration of gas components to monitor, for example, abnormalities in a nuclear reactor system.

[Technical background of the invention and its problems] When a loss of coolant accident occurs during operation of a nuclear reactor, H2 gas and 02 gas increase in the reactor containment vessel (hereinafter referred to as PCv). come. Therefore, from the standpoint of nuclear reactor safety management, measurement of gas concentration is essential.

By the way, in conventional boiling water reactors (hereinafter referred to as BWRs), diaphragm galvanic cell type detectors are used as a means of measuring gas IIIU, and most of these detectors are PC-based.
It is installed directly inside v. As shown in FIG. 1, in this diaphragm galvanic battery type detector, a presser cover 3 is attached to a concave portion on the front side of a detection base 1 so as to sandwich a gas-permeable resin diaphragm 2. It has a gas introduction port 4 for introducing gas into the diaphragm 2 side, and a detection electrode 5, an electrolyte solution 6, and a counter electrode 7 are arranged inside the detection substrate 1. Note that the resin diaphragm 2 is attached to the detection base 1 via a sealing member such as an O-ring, and has a structure that prevents the electrolyte solution 6 from leaking to the gas inlet 4 side.

When the above-mentioned detector is installed in the atmosphere of the gas to be measured, the components of the gas to be measured pass through the diaphragm 2 in proportion to the partial pressure in the gas atmosphere, and then undergo an oxidation or reduction reaction inside. As a result, a current corresponding to 211 degrees of the component to be measured can be extracted from between the sensing electrode 5 and the counter electrode 7 of the detector.

However, in practice, if a coolant loss accident occurs, the PV
The atmosphere inside C is high temperature (approx. 170°C) and high pressure (approx.
．． 5kg/cm2-gauge pressure), high m (water vapor supersaturation)
It is expected that the situation will be worse, and that radioactivity levels will also increase.

Therefore, if a diaphragm galvanic battery type detector is directly exposed to such an atmosphere inside the PCM, it may shorten its lifespan due to moisture absorption, cause reading errors due to radioactive decomposition of the internal liquid, and delay response speed. .

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and provides a gas concentration measurement method that does not use a diaphragm galvanic cell method, has excellent response speed, and can measure gas component concentrations with high accuracy without being affected by radioactivity. The goal is to provide equipment.

[Summary of the Invention] The present invention extracts the gas present in the PCM to the outside using, for example, a sample pump, cools and dehumidifies the gas with a cooler, and uses the cooled and dehumidified gas to meet the input conditions of an analyzer. The adjusted gas is supplied to the analyzer so that the concentration of gas components can be measured, and the gas after the concentration measurement and the cooled and dehumidified drain are supplied to the analyzer. This gas concentration measuring device aims to achieve the above objective by returning the gas to the PCV.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIG. 2. The calibration gas or the gas to be measured is supplied via electromagnetic valves 11, 12 to the primary filter 13, where coarse particles are removed.

A cooler 14 cools and dehumidifies the gas input through the primary filter 13 with cooling water. Reference numeral 15 denotes a sample pump that sucks the gas to be measured in order to sample it, and a bypass line 7 provided with a solenoid valve 16 is connected between the pumps 15 . This sample pump 1
The output line of No. 5 includes a secondary filter 18 for removing fine dust, a single-pressure valve 19 for adjusting the gas to meet the measurement conditions of the analyzer, which will be described later, and a pressure gauge 20, which functions as an analyzer. An oxygen (02) meter 21 and a hydrogen (H2) meter 22 are arranged in this order. 23 is a flow meter that measures the flow rate of the gas to be measured that has passed through the analyzer; 24 is a pressure regulating valve that adjusts the gas conditions to satisfy the measurement conditions of the analyzer; and 25 is a gas that returns the measured gas to the PCM. return pump, 26
is a stop valve. A drain pot 27 is used to collect moisture in the gas dehumidified by the cooler 14 and return it to the PCM using the discharge pressure of the return pump 25. Solenoid valves 28 and 29 are provided at the inlet and outlet portions of the drain pot 27. 30 is a level meter, 31 is an electromagnetic valve, and 32 to +34 are stop valves.

Next, the operation of the gas concentration measuring device configured as above will be explained. First, the case of collecting the gas to be measured will be described. In this case, after opening the stop valve 34, when the sample pump 15 is operated to suck the sample gas,
The gas to be measured passes through the stop valve 34 and the electromagnetic valve 12 and enters the primary filter 13. After removing dust there, it is cooled and dehumidified by the cooler 14, and further fine dust is removed by the secondary filter 18 before passing through the subsequent filter. Feed it to the line side.

At this time, since the pressure in the line is regulated by the pressure regulating valve 19, the gas that has passed through the secondary filter 18 is sent to the oxygen meter 21 and hydrogen meter 22 at the pressure regulated by the pressure regulating valve 19.
, where 81 degrees of 02 gas and 1''2 gas are measured. In addition, if the source pressure of the gas to be measured is high,
It is introduced into an oxygen meter 21 and a hydrogen meter 22 through a sample pump 15 and a bypass line 17.

Since the gas to be measured has radioactivity, the residue after the concentration measurement is returned to the PCV by the return pump 25 to cover it. At this time, in order to prevent the influence of the suction force of the return pump 25 from being applied to the oxygen side 21 and the water line 22, the pressure regulating valve 24 maintains the gas flowing through the analysis sections 21 and 22 under a constant condition.

On the other hand, moisture in the gas dehumidified by the cold NJ device 14 is collected by the drain bot 27, but this drain is also returned to the PCV. The conditions for this return are that when the drain stone reaches a certain level, a signal is issued from the level it 30, the solenoid valve 31.29 is opened, and at the same time the solenoid valve 28 is closed, and the discharge pressure of the return pump 25 is used. Drenbot 27
The drain inside is sent into the PCV.

Therefore, with the above configuration, the gas to be measured is
Even if the original pressure fluctuates between atmospheric pressure and 5 kg/cm2 (gauge pressure) and the humidity reaches a high humidity state of 100% relative humidity, the cooler 14 cools and dehumidifies, and the pressure regulating valve 19 maintains the specified level. Since the pressure is adjusted, the gas supplied to the analyzer can be maintained at a constant pressure near atmospheric pressure at all times.

Therefore, the life of the analyzer can be extended, and highly accurate measurement of gas concentration can be realized. In addition, since the configuration is such that all of the gas after measurement and condensate generated by dehumidification are returned to the Zamburu source using one return pump 25, it is possible to create a completely closed loop system and avoid the risk of radioactivity. can.

In addition, it is possible to operate the -C sample pump 15 depending on the source pressure, or to stop the sample pump 15 and collect gas via the bypass line 17, which can be put to practical use depending on the system condition. It is.

Next, when calibrating the oxygen meter 21 and hydrogen meter 22, close the solenoid valve 12, then open the solenoid valve 11, and introduce the calibration gas from this line to supply it to the oxygen meter 21 and hydrogen meter 22. , and calibrate these valves 21 and 22. All these operations are automatically performed from a separately installed remote control panel.

The oxygen meter 21 is, for example, a porcelain style type -, -/' (
For example, a thermal conductivity type hydrogen meter 22 is used. Further, in the above embodiment, the oxygen side 21 and the hydrogen 3122 were described, but an analyzer other than the warp type may be used, or a single type of analyzer may be used.

Although only one cooler is described in one embodiment of the present invention, it is also possible to provide a plurality of coolers with cooling II capability and connect them in series or parallel to improve the cooling capacity.
゜Also, in one embodiment of the present invention, the secondary filter 18
, the pressure regulating valve 19 and the pressure gauge are connected via piping in this order, but the arrangement is not limited to this, and even if the arrangement order is changed, J:
stomach. Furthermore, in one embodiment of the present invention, an oxygen meter 21. I wrote it so that it was arranged in the order of hydrogen meter 22), but the hydrogen meter,
They may be arranged in the order of oxygen meters. Furthermore, in one embodiment of the present invention, the gas to be measured is adjusted to a predetermined pressure and flow rate using a flow meter and a pressure regulating valve, but the present invention is not limited to this, and it may also be implemented using a flow controller. good.

Furthermore, in one embodiment of the present invention, the location where the calibration gas is introduced is not limited to the one embodiment, and may be after the pump 15 or just before the analyzer 21.

According to the present invention, even if the atmosphere inside the PCV is high temperature, high pressure, and high humidity when an abnormal condition occurs, the PCV is
The gas within can be supplied to the analyzer. Therefore, the life of the analyzer IT can be extended, and it is not directly exposed to an atmosphere of high-level radioactivity, and the problems of reading errors due to radioactive decomposition of the internal liquid in the analysis port can also be solved. In addition, since the gas concentration inside the PCV can be measured outside the PCV, it can be accessed even for purposes other than regular inspections.Furthermore, since the sample gas is returned to the PCV, the gas concentration can be measured without being affected by radioactivity. It is possible to provide a gas S degree measuring device that can measure S degree.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventionally commonly used gas detector, and FIG. 2 is an overall configuration diagram showing an embodiment of a gas concentration measuring device according to the present invention. 11.12... Solenoid valve, 13... Primary filter, 1
4...Cooler, 15...Sample pump, 17...
・Bypass line, 18...secondary filter, 19...
・Pressure regulating valve, 21...Oxygen meter, 22...Hydrogen meter, 23
...Flow rate cutter, 24...Pressure regulating valve, 25...Return pump, 27...Drain pot. Applicant's agent Patent attorney Takehiko Suzue

Claims (2)

[Claims] (1) An apparatus for measuring the concentration of component gases present in a reactor containment vessel, which requires a dehumidifying means for dehumidifying the gas led outside from the reactor containment vessel, and a dehumidifying means for dehumidifying the gas dehumidified by this means. adjustment means for adjusting to conditions;
An analyzer that measures the component concentration of the gas adjusted by this means, a return pump that returns the gas after temperature measurement by this analyzer 1 to the reactor containment vessel, and a dehumidifying drain obtained by the dehumidifying means. A gas concentration measuring device comprising a dehumidifying drain return means for returning to the reactor containment vessel. (2) The gas concentration measuring device according to claim 1, characterized in that w4 adjustment means are provided before and after the analyzer.