JPS5853856B2 - Hydrogen detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrogen detection device that can continuously measure the concentration of hydrogen contained in a gas.

A small leak in the steam generator of a sodium metal-cooled fast reactor plant could damage adjacent heat exchanger tubes and cause a large-scale leak accident.

Therefore, it is necessary to quickly detect small water leaks and prevent accidents from occurring.

To detect this water leak, a detection method that is highly sensitive and can be used for a long time is required.

Various methods have been considered for detecting water leaks, but among them, a method that detects hydrogen released into the cover gas covering the sodium surface during the reaction between sodium and water is suitable.

To detect this hydrogen, a hydrogen detection device consisting of a diffusion membrane section, a vacuum gauge, and an exhaust device is used.

This device is constructed as shown in FIG.

That is, a flange 2 is horizontally glued to the test chamber wall 1 of the steam generator or the cover gas section, which partially shows the wall surface of the test tank, and a gas to be measured, such as argon, is attached to the inner surface of the flange 2. A cylindrical body 3 through which a gas mixture with hydrogen flows is fixed.

A stainless steel tubular body 6 is disposed within this cylindrical body 3, and its upper end opening is fixed by penetrating the flange 2.

A sleeve-shaped diffusion membrane section 7 is connected to the tubular body 6 so as to be suspended downward from the central portion.

As the diffusion membrane part I, palladium, iron, nickel, etc., which selectively permeate hydrogen, are used.

A first heat source 8 and a second heat source 9 are provided above and below this diffusion membrane portion 7, that is, in the tubular rest area near the upper end opening 4 of the cylindrical container 3 and inside the lower end opening 5 of the cylindrical container 3. It is provided.

The first and second heating sources 8, 9 are adjusted to a predetermined temperature by thermocouples 10, 11 and temperature control devices 12, 13.

A sensor 14 is connected above the flange 2 via a pipe 15 communicating with the tubular body 6.

The sensor 14 is controlled by a hydrogen detector controller 16.

For this device, when the gas to be measured flows in due to natural convection caused by the temperature difference between the temperature of the gas to be measured flowing in from the lower end opening 5 of the cylindrical container 3 and the gas to be measured in the flow path 18, hydrogen gas diffuses. The hydrogen passes through the membrane section 7 and is detected by the hydrogen detection section 17, which has 14 sensors.

The hydrogen detection section 17 includes a detection section that measures ion current and degree of vacuum, and a controller 16 such as an ion pump controller and a vacuum gauge controller.

In this conventional hydrogen detection device, especially when the temperature difference between the temperature of the gas to be measured flowing in from the lower end opening 5 and the temperature of the gas to be measured in the flow path 18 is small, the gas flowing out from the upper opening 4 flows into the vicinity of the upper opening 4. Due to the stagnation, the gas in the flow path 18 becomes difficult to flow, and the flow rate necessary for temperature control cannot be obtained.

Therefore, there was a drawback that temperature control of the diffusion film portion 7 was impossible, and accurate measurement of hydrogen concentration was impossible.

On the other hand, even when the temperature difference is large, too much gas flows, making it difficult to control the temperature of the diffusion membrane section 7 due to capacity problems of the first and second heating sources 8 and 9.

An object of the present invention is to provide a hydrogen detection device in which it is possible to control the flow rate of a convecting gas to be measured and to change the flow, thereby making it easy to control the temperature of the diffusion membrane part. be.

Hereinafter, this invention will be explained in detail with reference to an embodiment shown in FIG.

Note that in FIG. 2, the same parts as in FIG. 1 are indicated by the same reference numerals, and explanations of overlapping parts are omitted.

That is, the present invention provides a flow path 18 that allows the gas to be measured to flow in the cylindrical container 3 from the lower end opening 5 to the upper end opening 4.
and a tubular body 6 having a diffusion membrane section 7 disposed in the flow path 18 that allows hydrogen contained in the gas to be measured to permeate therethrough, and a tubular body 6 disposed in the flow path 18 and having a diffusion membrane section 7 that allows hydrogen contained in the gas to be measured to pass therethrough, and a tubular body 6 disposed in the flow path 18 in the flow direction of the gas to be measured and before and after the diffusion membrane section, respectively. By changing the temperature of the first heating source 8 and second heating source 9 provided, the temperature control device 12.13 connected to each of these heating sources 8 and 9, and the temperature of the gas flowing out from the upper end opening 4. A flow control wall 19 interposed between the test chamber wall 1 and the flange 2 for controlling the flow rate, and temperature control fins consisting of fins 20 and a fan 21 for increasing the cooling efficiency of the flow control wall 19. This is a hydrogen detection device characterized by comprising:

Note that 11.10 in FIG. 2 is a temperature sensing element, such as a thermocouple, and the cylindrical container 3 is a body that is easily heated.

In addition, if the gas flows too much due to the large temperature difference, a heating source can be attached to the flow control wall 19 to heat it.A heating source can be attached to the flow control wall 19 and the flow rate can be controlled by heating it. is possible.

Here, according to the present invention, the gas to be measured flows into the cylindrical container 3 from the lower end opening 5, is heated by the second heating source 9 and maintained at a predetermined temperature, passes through the diffusion membrane part 7, After being released from the upper end opening 4 to the outside of the device, the released gas passes through the flow control wall 19.
A temperature change occurs and the flow rate is controlled.

Therefore, according to the present invention, since the flow rate of the inflowing sample fluid is controlled by the flow control wall 19, the influence of changes in the flow rate on the diffusion membrane section 7 is reduced, making it possible to measure the hydrogen concentration with good reproducibility. .

For example, if the cylindrical container 3 has a diameter of 5 m and a length of 50 z, the control temperature of the diffusion membrane section 7 is 500° C., the capacity of the second heat source is 200 W, and the capacity of the first heat source is 100 W, the conventional method as shown in FIG. In this device, the difference between the temperature of the gas to be measured flowing in from the lower end opening 5 and the control temperature of the diffusion membrane section 7 is 50t? t
The temperature of the gas to be measured reached 450°C, which was the temperature controllable limit.

On the other hand, in the device according to the present invention, by cooling the flow control wall 19, the temperature of the gas to be measured can be controlled by increasing the temperature of the gas to be measured by 490° C., with a temperature difference of 10° C.

Note that when the temperature of the gas to be measured becomes 200°C or lower, the temperature of the diffusion film section 7 cannot be raised by 500°C with the capacity of the heater described above in the conventional apparatus shown in FIG. There wasn't.

As described above, according to the present invention, the gas to be measured also flows into the lower end opening 5, and when it is discharged from the upper end opening 4, it comes into contact with the flow regulating wall 19, thereby controlling the flow rate and changing the flow. be able to.

Therefore, the temperature of the inflowing gas to be measured can be varied over a wide range, the temperature of the diffusion membrane section 7 can be easily controlled, the heater capacity can be reduced, and reliability is improved.

[Brief explanation of the drawing]

FIG. 1 is a device layout diagram showing an example of a conventional hydrogen detection device in a partial vertical cross-sectional view, and FIG. 2 is a vertical cross-sectional view showing a portion of the hydrogen detection device according to the present invention. DESCRIPTION OF SYMBOLS 1... Test chamber wall body, 2... Flange, 3... Cylindrical body, 4... Upper end opening, 5... Lower end opening, 6...
- Tubular body, 7... Diffusion membrane part, 8... First heating source, 9
...Second heating source, 10.11...Temperature sensing element, 1
2.13...Temperature control device, 14...Sensor, 15
...pipe, 16...hydrogen detector controller,
17...Hydrogen detection unit, 18...Flow path, 19...Flow control wall, 20...Fin, 21...Fan.

Claims (1)

[Claims] 1. A cylindrical body disposed within the wall of the test chamber, a flow path through which the gas to be measured flows from the lower end to the upper end within the cylindrical body, and a wall of the test chamber surrounding the outlet of the gas to be measured. The mounting that penetrates and fixes the body and the above-mentioned previous state includes a flow control wall interposed between the flange, a temperature adjustment fin provided on the outer circumferential surface of the flow control wall, and a temperature control fin disposed within the cylindrical body. a tubular body whose lower end is sealed and has a diffusion membrane portion that allows hydrogen contained in the gas to be measured to permeate; a first button and a second heat source provided in the flow direction of the gas to be measured and before and after the diffusion membrane section;
A hydrogen detection device characterized by comprising: a temperature control device connected to each heating source.