JP2004012350A - Pressure test apparatus and test method for high pressure gas container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure testing device and a test method of a compressed-gas cylinder capable of performing efficiently a pressure test of the gas cylinder by reducing a load of a person in charge of the test, and discovering early a defect of the gas cylinder. <P>SOLUTION: This pressure testing device of the compressed-gas cylinder is equipped with a pump 22 for pressurizing the inside of the compressed-gas cylinder 21 which is a test object, and a measuring part (buret 23) for measuring by water level fluctuation, a volume change of the compressed-gas cylinder caused by expansion by pressurization and contraction after pressurization finish. In the device, a water level sensor 24 is provided on the buret 23 which is a measuring part as a water level detection means for detecting continuously the water level fluctuation. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pressure test apparatus and a test method for a high-pressure gas container, and more particularly, to a test apparatus and a test method for performing a pressure test specified by law on a high-pressure gas container filled with a high-pressure gas.
[0002]
[Prior art]
According to the container security regulations of the High Pressure Gas Safety Law, high-pressure gas containers are required to conduct a pressure test of each container once every five years for seamless containers and once every three years for general composite containers such as FRP. ing. In the pressure test of the high-pressure gas container, as shown in the system diagram of FIG. 2, a gas container 12 serving as a test body is immersed in a water tank 11 filled with water, and pressurized water is injected into the gas container 12 from a pump 13. At the same time, the change in volume due to the expansion of the gas container 12 due to the pressurization and the contraction of the gas container 12 after the pressurization is read by the change in the water level of the burette 14 connected to the water tank 11, and based on the change in the water level. A method (water tank type) for determining the pressure resistance of the gas container 12 is generally performed.
[0003]
Further, in the case of a gas container which is long and difficult to immerse in the water tank, as shown in the system diagram of FIG. There is also a method (non-aqueous tank type) in which pressurized water is injected into the inside and a change in the amount of water during and after pressurization is read by a burette 18 provided on the primary side of the pump 17.
[0004]
[Problems to be solved by the invention]
In the case of the water tank type, not only does it need to dig a pit for burying the water tank 11 in the ground, but also there is a problem that the size of the specimen is limited. On the other hand, the non-aqueous tank type has the advantages that it is not necessary to dig a pit, the initial cost can be kept low, and the size of the test piece is widely limited.
[0005]
However, in the case of the non-aqueous tank type, when a gas phase such as air (gas) or dissolved air is present in the container, the gas phase is compressed when pressure is applied, and a corresponding amount of pressurized water is injected. Therefore, there is a problem that the change in the amount of water measured by the burette 18 becomes inaccurate. For this reason, in the case of the non-aqueous tank type, the gas phase must be removed from the system including the test object over a long period of time, or the expensive gas pressure reducing mechanism must be used to eliminate the gas phase.
[0006]
Further, in order to efficiently remove the gas phase from the inside of the system, equipment including a pipe from a gas container 15 as a test body to a pump and a burette 18 is arranged in a vertical direction. In this case, there is a problem that the position of the burette becomes high and it takes time to measure the water level. In other words, in charge of checking the zero point at the start of the test, checking the water level at the time of pressurization, and checking the water level when the pressure in the gas container is released after the pressurization is completed, it is up to the burette installation location A person needs to move, and at this time, if the burette is installed at a high position, the user must go up and down stairs each time. Therefore, it is extremely burdensome for a person who tests many gas containers a day.
[0007]
Therefore, the present invention provides a high-pressure gas container pressure test apparatus and test apparatus capable of efficiently performing a pressure test of a gas container by reducing the burden on a tester, and also capable of detecting defects of the gas container at an early stage. It is intended to provide a way.
[0008]
[Means for Solving the Problems]
To achieve the above object, a high-pressure gas container pressure test apparatus of the present invention includes a pump for pressurizing the inside of a high-pressure gas container as a test body, and a high-pressure gas due to expansion by the pressurization and contraction after the pressurization is completed. In a high-pressure gas container withstand pressure test device provided with a measuring unit for measuring a change in volume of the container based on a change in water level, a water level detecting means for continuously detecting the change in water level is provided in the measuring unit. And
[0009]
Further, the piping of the system from the high-pressure gas container to the pump is characterized in that the pump side rises at an angle of 30 degrees or more with respect to the horizontal direction.
[0010]
Further, the pressure test method for a high-pressure gas container of the present invention is a pressure test method for a high-pressure gas container using the pressure test device, wherein the secondary pressure of the pump and the detection value of the water level detection means are continuously measured. By comparing with, the pass / fail of the test body is characterized, furthermore, when the secondary pressure of the pump exceeds a set pressure, or the fluctuation of the detection value of the water level detection means is set in advance When the maximum fluctuation range is exceeded, the operation of the pump is stopped.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a system diagram showing an embodiment of the high-pressure gas container pressure test apparatus of the present invention. This high-pressure gas container pressure test apparatus includes a pump 22 for injecting pressurized water into a high-pressure gas container 21 held by a container holding device (not shown), and a high-pressure gas by expansion and contraction after pressurization. A burette 23 as a measuring unit for measuring a change in volume of the container 21 by a change in water level, a water level sensor 24 as water level detection means for continuously detecting a change in water level in the burette 23, A pressure gauge 25 for detecting the secondary pressure, a pressure relief valve 26 for releasing the pressure in the gas container 21 at the end of pressurization, a water level data output 24 s of the water level sensor 24 and a pressure data output 25 s of the pressure gauge 25 are taken in. And a controller 27 for performing arithmetic processing.
[0012]
An overflow line 28 is provided at the upper end of the burette 23. In addition, a high-pressure plunger pump is usually used as the pump 22. Further, a water tank or a water supply line can be provided in the path 29 between the pump 22 or the decompression valve 26 and the burette 23 as necessary.
[0013]
These devices and piping are arranged so that the high-pressure gas container 21 is located below and the pump 22 and the burette 23 are located above. In particular, by setting the piping vertically, When the water is injected, the gas in the system easily rises, and the gas can be easily removed from the system. The pipe angle is preferably vertical, but may be appropriately set based on the predicted size of the gas (bubbles) and the pipe diameter. If the angle is set to 30 degrees or more, most of the gas can be removed. In addition, it is desirable that the pipes of the entire system be covered by the angle range. However, when there is a restriction in the height direction from the installation location, the system of the part that is affected by gas phase compression when pressurized by the pump 22 is used. May be 30 degrees or more, and other systems may include horizontal pipes.
[0014]
As described above, since the water level sensor 24 is provided in the burette 23 so as to continuously detect water level fluctuations in the burette, the water level data 24 s of the water level sensor 24 can be set at any location. 27, a change in the water level is displayed on a screen or the like, and a pass / fail judgment can be automatically performed based on the pressure data and the water level data. Therefore, it is not necessary for the person in charge of the test to move to the place where the burette 23 is installed, and the burden on the person in charge is greatly reduced, so that the pressure test of the gas container 21 can be performed efficiently. In addition, as the water level sensor 24, it is desirable to use a float type precision water level sensor that can continuously perform precise water level detection.
[0015]
Next, a procedure for performing a pressure test of the high-pressure gas container 21 using the pressure test apparatus will be described. First, after injecting water into the gas container 21 and bleeding air in the same manner as before, the water level of the burette 23 detected by the water level sensor 24 is set to “0 point” before the pump 22 is operated. . Next, the pump 22 is operated to press water (pressurized water) into the gas container at a predetermined pressure increasing rate, and the gas container is pressurized to a predetermined pressure resistance test pressure and left for 90 seconds. At this time, the water level in the burette 23 decreases according to the amount of water corresponding to the change in volume of the high-pressure gas container expanded by pressurization. Therefore, this water level decrease is detected by the water level sensor 24, and based on the detected value, To calculate the total increase in gas container volume.
[0016]
Next, the pressure release valve 26 is slowly opened to release the pressure in the gas container, and the seamless container is left for 30 seconds, and the general composite container is left for 90 seconds. Since the gas container 21 contracts so as to return to the state before pressurization at the end of pressurization, the water level of the burette 23 rises to near the “0 point” position. The rising point is detected by the water level sensor 24, and based on the detected value, the amount of permanent increase in the volume of the gas container is determined. Then, a permanent increase rate (permanent increase amount / total increase amount) is calculated from the calculated total increase amount and the permanent increase amount, and when the obtained permanent increase ratio is within the acceptable range, the gas serving as the test body is obtained. Pass the container.
[0017]
Here, the volume in the container is V [cc], the pressure resistance test pressure is P [MPa], the amount of water injected during pressurization is A [cc], and the amount of water injected into the connecting pipe from the pump to the inlet of the container is B [cc]. ], Assuming that the compression coefficient at the water temperature during the test is β [-], the total increase ΔV [cc] during pressurization is calculated by the following equation.
[0018]
ΔV = (A · B) · Ｂ (AB) + V ＋ Pβ
Then, assuming that a numerical value obtained from the water level after opening the depressurizing valve 26 to release the pressure is a permanent increase amount Δu [cc], the permanent increase rate u ′ [%] is calculated by the following equation.
[0019]
u ′ = Δu / ΔV × 100
When the rate of permanent increase is 10% or less for a seamless container and 5% or less for a general composite container, the high-pressure gas container as a test sample passes.
[0020]
When the pressure test of the high-pressure gas container is performed in this way, the secondary pressure of the pump 22 detected by the pressure gauge 25, that is, the gas container pressurized pressure, and the water level detection value of the burette 23 detected by the water level sensor 24 Is continuously compared to obtain a series of data in the pressure test, for example, the point 0, which was measured by a burette by a person in charge in the past, the injected water amount A [cc] at the time of pressurization, and the pressure after the pressure was released. Since the permanent increase amount Δu [cc] can be automatically obtained by the water level sensor 24, the operations from the start to the end of the test and the determination of pass / fail can be automatically performed. Further, by using a high-precision water level sensor 24, the test accuracy can be improved. Further, since a subtle change in the water level at the time of standing can be detected, the presence / absence of a defect can also be determined.
[0021]
Further, in performing the pressure resistance test as described above, if there is a defect in the gas container, it may be dangerous if pressure is applied. In such a case, the secondary pressure of the pump 22 detected by the pressure gauge 25 is compared with the water level of the burette 23 detected by the water level sensor 24, and, for example, the water level of the water level is compared with the degree of increase of the secondary pressure. When the amount of decrease is large, there is a risk that the high-pressure gas container may be abnormally expanded. In such a case, the pump 27 is output from the controller 27 to stop the operation of the pump 22, thereby causing a dangerous situation. Can be avoided. If a water leak occurs on the secondary side of the pump 22 or a gas phase remains in the system and such a situation occurs, preparation for a retest is immediately made. The retest can be performed without lowering Further, when such a state is caused by a defect generated in the gas container, the defect of the gas container can be found without applying pressure to the pressure test pressure.
[0022]
The present invention can also be used to detect a change in the water level of the burette connected to the aquarium in the above-described aquarium test apparatus, so that the pass / fail judgment is made automatically and with high accuracy. In addition to the above, the defect of the gas container can be found at an early stage.
[0023]
【The invention's effect】
As described above, according to the present invention, the burden on a person who performs a pressure test of a high-pressure gas container can be greatly reduced, and the pass / fail judgment of a test object can be automatically performed with high accuracy. Defects in the gas container can also be found early.
[Brief description of the drawings]
FIG. 1 is a system diagram showing an example of an embodiment of a high-pressure gas container pressure test apparatus of the present invention.
FIG. 2 is a system diagram showing an example of an embodiment of a conventional water tank pressure test apparatus.
FIG. 3 is a system diagram showing one embodiment of a conventional non-aqueous tank pressure test apparatus.
[Explanation of symbols]
21: High-pressure gas container, 22: Pump, 23: Buret, 24: Water level sensor, 25: Pressure gauge, 26: Depressurizing valve, 27: Controller, 28: Overflow line

Claims (4)

A high-pressure gas including a pump for pressurizing the inside of a high-pressure gas container as a test body, and a measuring unit for measuring a volume change of the high-pressure gas container due to expansion due to the pressurization and contraction after the completion of the pressurization based on a change in water level. A pressure-resistant test apparatus for a high-pressure gas container, characterized in that a water level detecting means for continuously detecting the fluctuation of the water level is provided in the measuring section. The pressure test apparatus for a high-pressure gas container according to claim 1, wherein the piping of the system from the high-pressure gas container to the pump has a pump side rising at an angle of 30 degrees or more with respect to a horizontal direction. A pressure test method for a high-pressure gas container using the pressure test apparatus according to claim 1, wherein the pass / fail of the test object is determined by continuously comparing a secondary pressure of the pump with a detection value of the water level detection means. A pressure test method for a high-pressure gas container, characterized in that: When the secondary pressure of the pump exceeds a set pressure, or when the fluctuation of the detection value of the water level detecting means exceeds a preset maximum fluctuation width, the operation of the pump is stopped. The method for testing pressure resistance of a high-pressure gas container according to claim 2.

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