JPH02118419A - Residual hydrogen quantity meter - Google Patents

Abstract

PURPOSE:To inexpensively and accurately measure a residual hydrogen quantity by largely fluctuating the detecting liquid of a liquid chamber having the sectional area smaller than the sectional area of a diaphragm by the fluctuation of the diaphragm caused by a change in the volume of a hydrogen occluding alloy. CONSTITUTION:The hydrogen occluding alloy 32 is stored in a hydrogen storage tank 31. A sintered metal filter 14 consisting of a gaseous hydrogen permeating material is provided in this tank 31 and the hydrogen occluding alloy 13 is housed in the filter 14. An inside magnet 17 is movable vertically in a space 11a according to a change in the volume of the hydrogen occluding alloy 13 with a change in the hydrogen occlusion quantity. An outside magnet 18 moves as well as the magnet 17 moves. The diaphragm 19 moves vertically according to this movement. A display body 27 formed internally with a diaphragm chamber 27a and a liquid chamber 27b is provided in the upper part of a holding body 11. The liquid chamber 27b is made into a capillary shape and is formed to the sectional area smaller than the sectional area of the chamber 27a. The non-volatile liquid 20 in the liquid chamber 27b is, therefore, fluctuated largely by the small fluctuation of the diaphragm 19.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a hydrogen remaining amount meter installed in a hydrogen storage tank, and is particularly capable of measuring the remaining amount of hydrogen at low cost and with high accuracy. Regarding hydrogen fuel gauge.

(Prior Art) Conventionally, a method is known in which hydrogen is stored by storing a hydrogen storage alloy in a hydrogen storage tank and causing the hydrogen storage alloy to store hydrogen. In this case, rare earth L a N i 5 or the like is used as the hydrogen storage alloy.

In addition, in order to measure the remaining amount of hydrogen in the hydrogen storage tank,
Various methods of measuring residual hydrogen are used.

As such a hydrogen residual ffi measurement method, (1) For example, the temperature T of the hydrogen storage alloy and the internal pressure P of the hydrogen storage tank are
(Hydrogen equilibrium pressure) is detected by temperature and pressure sensors, and the Van't Hoff diagram shown in Fig. 3 and P shown in Fig. 4 are detected.
A method of determining the remaining amount of hydrogen from the CT curve has been considered.

Here, FIG. 3 shows the relationship between 1nP and 1/T when the hydrogen composition H/M in the hydrogen storage alloy is constant, and FIG. 4 shows the relationship between 1nP and 1/T at each temperature T i and T 2. and H
/M shows the relationship.

Specifically, the temperature T is determined in advance from FIGS. 3 and 4.
A three-dimensional map of 1 pressure P and hydrogen composition H/M is created, and based on this three-dimensional map, the remaining amount of hydrogen is determined from the detected temperature and detected pressure.

Since this method of measuring the amount of remaining hydrogen is generally performed by a microcomputer, the installation cost of the remaining amount of hydrogen meter becomes high.

(2) In addition, in the PCT curve shown in Figure 4, the plateau region (the region where the pressure is flat and is generally used as a fuel) is tilted by making the alloy composition multi-component. A method has been considered in which the remaining amount of hydrogen is determined by linearly changing the pressure and measuring this pressure.

However, with this measurement method, the hydrogen pressure shifts, so
Measurement accuracy is very poor outside of a place where the temperature is stable, and when hydrogen is released or absorbed, the temperature is forcibly raised or lowered, making measurement impossible.

(3) Furthermore, a method has been considered in which a mass flow meter is installed between the hydrogen supply system, the consumption system, and the hydrogen storage tank to measure the flow rate of transferred hydrogen, and then subtracted from the maximum hydrogen storage capacity of the alloy. There is.

However, mass flow meters are very expensive (approximately 800,000 yen or more) and lack simplicity.

(Problems to be Solved by the Invention) In order to measure the amount of hydrogen remaining in the hydrogen storage tank as described above, various methods for measuring the amount of remaining hydrogen have been considered.

However, (1) temperature T1 pressure P and hydrogen composition H
The method of creating a three-dimensional map of /M and calculating the remaining amount of hydrogen from the detected temperature and pressure based on this three-dimensional map has the problem that the installation cost is high because it uses a microcomputer, etc. . (2) Furthermore, in the method of determining the remaining amount of hydrogen by tilting the plateau region of the PCT curve, there is a problem in that the measurement accuracy is very poor outside of a place where the temperature is stable. (3) Furthermore, in the method of providing a mass flow meter and measuring the flow rate of transferred hydrogen and subtracting it from the maximum hydrogen storage capacity of the alloy, the installation cost becomes high.

The present invention has been made in consideration of these points,
It is an object of the present invention to provide a hydrogen remaining amount meter that can accurately measure the remaining amount of hydrogen at low cost.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a storage box made of a hydrogen gas permeable material in a hydrogen storage tank, and stores a hydrogen storage alloy that causes a volume change depending on the amount of hydrogen storage in the storage box. A diaphragm chamber housing a diaphragm that moves in response to changes in the volume of the hydrogen storage alloy is provided outside the storage box, and a capillary liquid chamber having a cross-sectional area smaller than the area of the diaphragm is communicated with one side of the diaphragm chamber. and filling the diaphragm chamber with a detection liquid that reaches the liquid chamber,
The hydrogen remaining amount meter is characterized in that the detection liquid in the liquid chamber is greatly changed by a small change in the diaphragm.

(Function) Depending on the remaining amount of hydrogen in the hydrogen storage tank, the hydrogen storage alloy in the storage box causes a volume change and the diaphragm changes, and due to this diaphragm change, a liquid chamber with a cross-sectional area smaller than the area of the diaphragm is created. The detection liquid can be varied greatly.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

Figures 1 and 2 are diagrams showing an embodiment of the hydrogen fuel gauge according to the present invention. Figure 1 is a side sectional view of the hydrogen fuel gauge, and Figure 2 shows the characteristics of the hydrogen storage alloy. FIG.

In FIG. 1, a hydrogen storage alloy 32 is stored in a hydrogen storage tank 31. As shown in FIG. As the hydrogen storage alloy 32, a particulate alloy whose volume changes depending on the amount of hydrogen storage is used, such as rare earth-based LaNi5, LaNi4.7AI, 3, etc., and the particle size of the hydrogen storage alloy 32 is adjusted in advance.

Next, the configuration of the remaining hydrogen gauge 10 will be explained.

A mounting seat 33 is provided at the upper opening of the hydrogen storage tank 31, and a holder 11 having a cylindrical sintered metal filter 14 underneath is mounted on the mounting seat 33, and is fixed with a set screw 25. . Further, the space between the mounting seat 33 and the holding body 11 is sealed by an O-ring 15.

The sintered metal filter 14 extends into the hydrogen storage tank 31 and contains the hydrogen storage alloy 13 therein.

Hydrogen storage alloy 13 housed in sintered metal filter 14
is the hydrogen storage alloy 3 stored in the hydrogen storage tank 31
An alloy having the same composition as No. 2 is used, but an alloy of compression molding is used to prevent pulverization due to repeated absorption and release of hydrogen.

In addition, the sintered metal filter 14 is made of stainless steel with good heat conductivity and allows hydrogen gas to pass through, but it is necessary to prevent the pulverized alloy from entering the sintered metal filter 14 from the hydrogen storage tank 31 side. It has become. Further, the shape of the sintered metal filter 14 is a cylindrical shape elongated in the vertical direction, and has a diameter to length ratio of 115, for example.

A cylindrical space 11a is formed in the holding body 11, and this space 11a is used for a sintered metal filter 14 attached below.
It communicates with the inside. The diameter inside the space 11a is larger than the diameter inside the sintered metal filter 14, and the sintered metal filter 14 has a stepped portion 1 connected to the holder 11 at the upper end.
4a is formed. Further, in this space 11a, an internal magnet 17 is provided which contacts the upper surface of the hydrogen storage alloy 13 housed in the sintered metal filter 14.

This internal magnet 17 is movable in the vertical direction within the space 11a according to a change in the volume of the hydrogen storage alloy 13 due to a change in the amount of hydrogen storage. Further, the internal magnet 17 is placed between the upper surface of the space 11a and the internal magnet 17, and the hydrogen storage alloy 13 is connected to the internal magnet 17.
A disc spring 16 is interposed that presses toward the upper surface. Further, the internal magnet 17 is formed with a plurality of through holes 17a that vertically penetrate the internal magnet 17. This through hole 17a is formed at a position corresponding to the step portion 14a of the sintered metal filter 14, so that the hydrogen gas in the space 11a in which the disc spring 16 is provided is transmitted through the through hole 1.7a and the step portion 14a. It can communicate with the inside of the hydrogen storage tank 31 via the portion 14a.

In addition, a diaphragm chamber 2 is provided inside the upper part of the holding body 11.
7a and a display body 27 in which a liquid chamber 27b is formed. Inside the diaphragm chamber 27a, a diaphragm 19 having an area approximately equal to the cross-sectional area of the diaphragm chamber 27 is disposed horizontally, and an external magnet 18 is attached to the lower surface of the diaphragm 19. Further, the liquid chamber 27b communicates with the upper part of the diaphragm chamber 27a, and the upper part of the liquid chamber 27b is open.

Furthermore, a diaphragm chamber 2 is provided above the diaphragm 19.
A non-volatile liquid (detection liquid) 20 is stored that reaches from the liquid chamber 7a to the liquid chamber 27b.

Further, the liquid chamber 27b has a thin tube shape, and its cross-sectional area is considerably smaller than the cross-sectional area of the diaphragm chamber 27a.

For example, the cross-sectional area of the liquid chamber 27b is the same as that of the diaphragm chamber 27.
The area ratio is 1/30 to the cross-sectional area of a. Therefore, due to small fluctuations in the diaphragm 19, the liquid chamber 27
The nonvolatile liquid 20 of b varies greatly.

The external magnet 18 attached to the lower surface of the diaphragm 19 is placed at a position facing the internal magnet 17 across the earthen wall of the holder 11, and is always kept at a predetermined distance from the internal magnet 17 due to magnetic repulsion. It is movable. Therefore, as the internal magnet 17 moves in the vertical direction,
The external magnet 18 also moves, thereby causing the diaphragm 19 to move in the vertical direction.

Further, the display body 27 is configured such that the non-volatile liquid 20 stored therein can be confirmed from the outside, and the display body 27 is entirely covered with a glass cover tube 28. The glass covered tube 28 is filled with an inert gas such as argon. This inert gas prevents corrosion due to chemical reaction between the nonvolatile liquid 20 and air.

Note that the rise in the nonvolatile liquid 20 may also cause an increase in the pressure of the inert gas, but since the cross-sectional area of the liquid chamber 27b is very small, this pressure increase can be ignored.

Next, the operation of this embodiment having such a configuration will be explained.

First, FIG. 2 shows a hydrogen storage alloy 13, 32, for example, LaN.
The characteristics of i4.7AI, 3 will be explained.

Figure 2 shows the amount of hydrogen storage (hydrogen composition) on the horizontal axis and the volume change rate on the vertical axis, and the number of hydrogen storage and release times N-5, 10
, 15 shows the volume change rate corresponding to .

This rate of volume change is detected as the amount of movement in the uniaxial direction (opening direction), and is calculated ignoring changes in the side wall direction.

As shown in FIG. 2, the volume change rate of the hydrogen storage alloy, that is, the amount of movement in the opening direction changes linearly in accordance with the change in the amount of hydrogen storage. Therefore, by detecting the volume change rate of the hydrogen storage alloy, the amount of hydrogen storage can be measured.

In the hydrogen fuel gauge 10 shown in FIG. 1, the sintered metal filter 1
4 has gas permeability, so the hydrogen storage amount of the hydrogen storage alloy 13 in the sintered metal filter 14 and the hydrogen storage alloy 32 in the hydrogen storage tank 31 are equal. In this case, if the hydrogen storage amount of the hydrogen storage alloy 32 in the hydrogen storage tank 31 increases, the hydrogen storage amount of the hydrogen storage alloy 13 in the sintered metal filter 14 also increases, and the volume increases linearly. . In this way, the sintered metal filter 14
When the volume of the hydrogen storage alloy 13 in the holding body 11 increases,
The internal magnet 17 in the space 11a is pushed up by the hydrogen storage alloy 13.

On the other hand, when hydrogen is released from the hydrogen storage alloy 32 stored in the hydrogen storage tank 31 and consumed, the volume of the hydrogen storage alloy 13 in the sintered metal filter 14 decreases, and the internal magnet 17 is pressed and moves downward.

When the internal magnet 17 moves vertically within the space 11a in this manner, the external magnet 18 also moves at a predetermined distance from the internal magnet 17 due to the magnetic repulsion force, so that the diaphragm 19 moves vertically.

Note that the through hole 17a is formed in the internal magnet 17, and the hydrogen gas pressure in the space 11a where the disc spring 16 is provided is equal to the hydrogen gas pressure in the hydrogen storage tank 31. The movement of is not affected by hydrogen gas pressure.

Next, as the diaphragm 19 moves in the vertical direction, the nonvolatile liquid 20 stored in the diaphragm chamber 27a and the liquid chamber 27b moves in the vertical direction. The upper surface of the non-volatile liquid 20 can be confirmed from the outside of the glass-covered tube 28, and the upper surface of the non-volatile liquid 20 is detected by comparing it with the two remaining hydrogen amount indicators drawn on the surface of the glass-covered tube 28. This allows the remaining amount of hydrogen to be measured.

According to this embodiment, since the cross-sectional area of the liquid chamber 27b is considerably smaller than the area of the diaphragm 19, even if the diaphragm 19 moves slightly in the vertical direction, the non-volatile liquid 2° in the liquid chamber 27b can be It can be varied greatly. Therefore, even small changes in the amount of hydrogen remaining in the hydrogen storage tank 31 can be accurately measured using the nonvolatile liquid 20.

〔Effect of the invention〕

As explained above, according to the present invention, the cross-sectional area of the liquid chamber is smaller than the cross-sectional area of the diaphragm, so even if the diaphragm changes slightly, the detected liquid in the liquid chamber can be greatly changed. .

Therefore, even small changes in the amount of hydrogen remaining in the hydrogen storage tank can be accurately determined using this detection liquid.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing an embodiment of a hydrogen storage meter according to the present invention, FIG. 2 is a diagram showing the characteristics of a hydrogen storage alloy, and FIG. 3 is a Van't Hoff' diagram of the hydrogen storage alloy. FIG. 4 is a diagram showing a PCT curve of a hydrogen storage alloy. 10...Hydrogen remaining amount meter, 11...Holding body, lla...
・Space, 13... Hydrogen storage alloy, 14... Sintered metal fill, 17... Internal magnet, 18... External magnet,
19...Diaphragm, 20...Nonvolatile liquid, 2
7...Display body, 27a...Diaphragm chamber, 27b
...liquid chamber.

Claims (1)

[Claims] A storage box made of a hydrogen gas permeable material is provided in the hydrogen storage tank, a hydrogen storage alloy whose volume changes depending on the amount of hydrogen absorbed is stored in the storage box, and the volume of the hydrogen storage alloy is changed outside of the storage box. A diaphragm chamber containing a diaphragm that moves in accordance with the change is provided, a capillary liquid chamber having a cross-sectional area smaller than the area of the diaphragm is communicated with one side of the diaphragm chamber, and detection that reaches the liquid chamber into the diaphragm chamber is provided. A residual hydrogen meter, characterized in that it is filled with a liquid and configured so that a small change in the diaphragm causes a large change in the detected liquid in the liquid chamber.