JPH1183712A - Method and device for testing non-water bath type pressure-proof expansion for high-pressure gas vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for non-water bath type pressure- proof expansion test for a high-pressure gas vessel with high precision by eliminating unstability in water pressure caused by pulsation of a pressurizing pump used for a normal pressure-proof expansion test. SOLUTION: An inspection head 32 is engaged with, for fixing to, a high- pressure gas vessel 31 which is to be inspected, then water is supplied from an air release/water supply hole 20 and water is discharged from an air release/ water discharge opening, the pressure within the high-pressure gas vessel 31 is raised to a constant value using a plunger pump provided with a servo motor 46 for reading a position of the servo motor 46, the inside of the high-pressure gas vessel 31 is depressed after a specified time period is maintained, the position of the servo motor 46 when a water pressure falls to a constant value by depressure is read, and based on position of each servo motor 46, a permanent increase ratio is obtained based on an equation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous tank type pressure expansion test method and apparatus for a high pressure gas container, and more particularly to a novel method and apparatus for performing an accurate and efficient pressure expansion test. .

[0002]

2. Description of the Related Art A high-pressure gas container generally used for liquefied petroleum gas or the like must be subjected to a pressure expansion test at the time of manufacture and every time a predetermined period elapses in order to inspect the safety in a pressurized state. This pressure expansion test is determined based on the permanent increase rate determined by the following equation (1). If the permanent increase rate is equal to or less than a certain value specified by law, the test is judged as passing. This is because a container having a smaller permanent increase rate has a larger restoring force and is more excellent in pressure resistance. Permanent increase rate (%) = {Permanent increase amount (Δv) ÷ Total increase amount (ΔV)} × 100 (1)

Here, the total increase (ΔV) is defined as V ₂ −, where V _{1 is} the capacity of the gas container before pressurization and V ₂ is the capacity after pressurization.
The volume increase due to the expansion of the gas container represented by V ₁ , and the permanent increase (Δv) is V ₃ − when the volume of the gas container when the pressurization of the gas container is released is V _3.
This is the increase in capacity due to incomplete restoration of the gas container, represented by V ₁ .

A water tank type and a non-water tank type are known as test devices for measuring the total increase (ΔV) and the permanent increase (Δv), of which the water tank type pressure-resistant expansion test device is to be inspected. The high-pressure gas container is placed in the water of a closed water tank, and high-pressure water or the like is externally pressed into the high-pressure gas container to a predetermined high pressure, and water discharged from the water tank due to expansion of the high-pressure gas container generated at this time. Is measured by detecting the water level in a burette provided in communication with the water tank.

However, in such a water tank type pressure expansion test apparatus, the amount of water discharged due to expansion generated in the high-pressure gas container is considerably smaller than the amount of water to be filled in the water tank in principle. Therefore, there is a disadvantage that the ratio of the signal to the whole is small and the measurement accuracy is low. Further, in the water tank type pressure expansion test apparatus, since the amount of water used is large, the amount of fluctuation due to expansion and contraction of water caused by the environmental temperature is large. The amount of the variation is an error with respect to the amount of water discharged due to the expansion of the high-pressure gas container to be detected. This disadvantage is remarkable especially when the water tank is large.

[0006] Under the circumstances described above, a non-aqueous tank type pressure-resistant expansion test apparatus is generally used for large-sized high-pressure gas containers. However, the conventional non-aqueous tank-type pressure-resistant expansion test device changes the water volume every moment due to the difference between the environmental temperature and the water temperature, and the fluctuation rate of the volume is large. The drawback is that it is difficult to do.

Japanese Patent Publication No. Sho 63-52692 proposes a non-aqueous tank type pressure expansion test apparatus shown in FIG. This device has a fixed quantity water tank 8 for storing a predetermined amount of water 7 therein.
And a pressurizing line for supplying the pressurized water 7 in the fixed water tank 8 to the gas container 2 by connecting the fixed water tank 8 and the gas container 2 to be inspected via the pressurizing pump 3. Lp
Other than the pressurizing line Lp which is formed in the pressurizing line Lp and bypasses the pressurizing pump 3 and short-circuits.
A return line LR connecting the fixed water tank 8 and the gas container 2 and an electronic balance 9 for mounting the fixed water tank 8 and measuring the weight of the water 7 in the fixed water tank 8 are mainly used. Components.

The fixed water tank 8 is provided with a thermometer 5 for measuring the temperature of the water 7 stored therein and an overflow pipe 11 for maintaining a constant water level.
Further the water supply line Ls ₁ is disposed.

In the gas container 2 to be inspected, a spindle 23 is fixed to a fixture 22 screwed to the base 21, and a pressurizing line Lp (return line LR), an air vent line LA, and a water supply line are provided via the fixture 22. and it is connected to the Ls _2. 4 pressure gauge, VR returns provided in the bypass 6 valves, Vp is the water supply valve valve, Vs is provided to the water supply line Ls ₂ provided in the pressure line (return line LR), VA is the vent line LA It is an air vent valve provided.

The electronic balance 9 includes a microcomputer 91
Is a digital display-type balance in which is embedded, and is connected to the computer 92. The connection position between the pressurizing line Lp (return line LR) and the attachment 22 attached to the gas container 2 is slightly lower than the connection position between the pressurizing line Lp (return line LR) and the fixed water tank 8. Have been.

According to the pressure-resistant expansion test apparatus, when the water supply to the pressurizing line Lp, the bypass 6, and the pressurizing pump 3 is completed, the valve Vp is closed, the air vent valve VA and the water supply valve Vs are opened, and the water supply line Ls ₂ Since the air in the gas container 2 is discharged from the air vent line LA by injecting more water into the gas container 2, if the water supply valve Vs and the air vent valve VA are closed here, a predetermined amount of water 7 Is stored. Next, the valve Vp of the pressurizing line Lp is opened and the return valve VR is closed, and then the pressurizing pump 3 is operated to press water into the gas container 2, and the gas container 2 is expanded by this pressure, and the gas container 2 keeps the pressure P for a predetermined time stipulated by law in a state of complete inflation. At this time, the weight ΔM ₁ of the reduced amount of water 7 in the fixed amount water tank 8 corresponding to the amount of the injection water is weighed by the electronic balance 9, and the result is input to the computer 92 and is calculated based on a predetermined arithmetic expression. The amount of increase (ΔV) and the amount of permanent increase (Δv) can be determined.

Next, the operation of the pressurizing pump 3 is stopped to release the pressurized state, and the return valve VR is opened. Then, with the release of the pressure, the gas container 2 is restored, and the injected water flows back into the fixed water tank 8 through the return line LR. At this time, the weight ΔM ₂ of the increased amount of water 7 in the fixed amount water tank 8 is weighed by the electronic balance 9, and the result is transmitted to the computer 92.
Then, by inputting a calculation program and necessary data, the permanent increase rate can be automatically obtained.

[0013]

According to such a non-aqueous tank type pressure-resistant expansion test method, relatively high-precision measurement can be performed in a short time without being influenced by the volume change of water due to thermal expansion. However, there is a problem that a pulsation may be generated in the gas container when the pressurizing pump is operated, the water pressure becomes unstable, and a measurement error easily occurs. Furthermore, the pressurized state is not stable due to the air remaining in the various pipes, and the accuracy of the pressure switch for detecting the pressing force is not always good, and the operation accuracy of the electromagnetic switching valve for opening and closing the various valves. Insufficient values also cause measurement errors.

Therefore, the present invention solves the problems of the conventional non-aqueous tank type pressure-resistant expansion test method and apparatus, prevents an unstable state of water pressure due to pulsation, and provides an objective and high objective. It is an object of the present invention to provide a non-aqueous tank type pressure-resistant expansion test method and apparatus for a high-pressure gas container that can quickly and accurately perform measurement with high accuracy.

[0015]

According to the present invention, in order to achieve the above object, a high-pressure gas container to be tested is fixed at a fixed position, and then a test head is fitted and fixed, and provided at the other end of the test head. After performing water injection and air release and drainage from the air vent injection hole, the pressure in the high-pressure gas container is increased to a constant value using a plunger pump driven by the servo motor, and the position of the servo motor is read. After maintaining the time, the pressure in the high-pressure gas container is reduced, and the position of the servomotor when the water pressure in the high-pressure gas container drops to a constant value is read. A non-aqueous tank pressure-resistant expansion test method and apparatus for a high-pressure gas container, wherein the amount and the permanent increase amount are obtained, and the permanent increase rate of the high-pressure gas container is calculated based on an arithmetic expression.

According to the non-aqueous tank type pressure-resistant expansion test method and apparatus, after the test head is fitted and fixed to the high-pressure gas container to be tested, water is injected from the air vent water injection hole provided at the other end of the test head. After the air is drained and drained, the pressure in the high-pressure gas container is increased to a certain value by the plunger pump, and the position of the servomotor is read.
After the predetermined time is maintained, the pressure in the high-pressure gas container is reduced, and the position of the servomotor when the water pressure drops to a constant value is read. And a permanent increase amount, and a permanent increase rate of the high-pressure gas container can be calculated based on an arithmetic expression.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a non-aqueous tank type pressure expansion test method and apparatus for a high-pressure gas container according to the present invention. FIG. 1 is a schematic view showing an apparatus configuration of the present embodiment. In the figure, reference numeral 31 denotes a high-pressure gas container used for a pressure-resistant expansion test, and 32 denotes an inspection head, and a tube on one side led out from the inspection head 32. road 33 is a air vent drain pipe, valve V ₁ is being deployed.

The conduit 41 of the other side derived from the test head 32 are pressure pipe pressure and is connected to the air vent water injection holes 20 through the pressure sensor 42 and the water supply valve V ₂ and the check valve 43.

The inspection head 32 and the plunger pump 44 driven by the servo motor 46 to the pressure tube 41 located between the valve V ₂ is equipped. The plunger pump 44 has a function of increasing the pressure of water injected into the pressurizing pipe 41 to a predetermined pressure and reducing the pressure. The structure of the plunger pump 44 is shown in FIGS. )
This will be described with reference to FIG.

In FIGS. 2A and 2B, reference numeral 45 denotes a box-shaped housing, and a servomotor 46 is provided on one outer side of the housing 45. An output shaft 46a of the servomotor 46 is connected and fixed to a ball screw 48 by a connecting portion 47. Reference numeral 49 denotes a bearing for pivotally supporting the end of the ball screw 48, and reference numeral 50 denotes a bearing nut. A known oil seal, a bearing presser, and a bearing collar are provided inside the bearing nut 50.
The ball screw 48 is rotatably supported by the bearing 49 and the bearing nut 50.

Reference numeral 51 denotes a slide base screwed to the ball screw 48. The slide base 51 is movable along the longitudinal direction of the ball screw 48 in response to the rotation of the ball screw 48. Reference numerals 52, 52 denote a pair of guide shafts arranged in the housing 45 in parallel with the ball screw 48, and a slider 53 is slidably fitted to the guide shafts 52, 52. The slider 53 is connected to the slide base 51, so that when the slide base 51 moves, the slider 53 also slides along the guide shafts 52,52.

Reference numeral 54 denotes a piston constituting the plunger pump, and 55 denotes the same cylinder. One end of the piston 54 is fixed to the slider 53, and the other end of the piston 54 enters the cylinder 55. Reference numeral 56 denotes a nut for retaining the piston 54. On the inner wall portion of the cylinder 55 into which the piston 54 enters, there is disposed a seal portion 57 composed of a well-known bush, packing, a ring for locking them, and a dust cover. Based on the sealing action, the cylinder 55 is
It can be freely pulled in. The tip 55a of the cylinder 55 is connected to the pressure pipe 41 of FIG. 1, and a pressure relief valve 58 is attached to the tip 55a of the cylinder 55.

Further, the position of the servo motor 46 is transmitted to the microcomputer 80, and the permanent increase rate (%) of the high-pressure gas container 31 is calculated based on a calculation formula described later. 81 is a control panel of the microcomputer 80.

The basic operation of this embodiment will be described below. First, the high-pressure gas container 31 to be subjected to the test is collected using a transport vehicle as a previous step, and after the cylinder check and the residual gas collection are performed, the main valve of the container is removed, and then the pressure expansion test according to the present embodiment is started. .

The high-pressure gas container 31 is fixed at a fixed position by using a centering mechanism (not shown), and the inspection head 32 is driven downward from above to fit into the high-pressure gas container 31 for firm chucking.

Next, after closing the valve V ₂ , the pipe 3
By opening the valve V ₁ of _No. 3, air and excess moisture are released from the pipe line 33. Then exit the air vent water injection for high-pressure gas container 31 and a valve V ₁ and valve V ₂ to the "closed". Then, the pressure release valve 58 is opened to eliminate the air release water pressure remaining in the circuit.
Is “closed”. At this time, the head pressure remains in the circuit. This head pressure is read by the microcomputer 80 as data of the pressure sensor 42. The process proceeds to the pressurizing step using the plunger pump 44 in the next stage.

The procedure of the pressurizing step using the plunger pump 44 will be described. First, FIG.
When the PO point of the servo motor 46 shown in FIG.
The torque of 6a is transmitted from the connecting portion 47 to the ball screw 48, and the ball screw 48 starts rotating. Then, the slide base 51 screwed to the ball screw 48 moves to the left in FIG. 2 along the longitudinal direction of the ball screw 48 in response to the rotation of the ball screw 48, and accordingly, the ball screw 48
Sliders 53 fitted to a pair of guide shafts 52, 52 arranged in parallel with each other slide in the same direction.

Therefore, the piston 54 having one end fixed to the slider 53 enters the cylinder 55 and
Water pressure rises. As the water pressure rises, the water pressure is applied from the pressurizing pipe 41 to the high-pressure gas container 31, and when the pressure in the high-pressure gas container 31 reaches a certain value, the pressure sensor 42 operates to stop the operation of the servomotor 46. FIG. 3 conceptually illustrates the mode of the above operation, and the high-pressure gas container 31 expands from a broken line A to a solid line B.

In this embodiment, the water pressure is 31 (kgf / c
m ² ), the operation of the servomotor 46 is stopped. Then, the inside of the high-pressure gas container 31 is maintained for a predetermined time, for example, about 30 seconds while maintaining the above-mentioned water pressure. In this example, the water pressure maintenance time is set to 30 seconds, which is legally determined, by setting a timer.

Here, the position P1 of the servomotor 46 is read. After the elapse of the water pressure maintaining time, the high pressure gas container 31
Start pressure reduction. This pressure reduction is performed by rotating the servomotor 46 in the reverse direction. As a result, the water pressure in the high-pressure gas container 31 decreases due to the operation of the plunger pump 44, and when the water pressure reaches a predetermined value, the pressure sensor 42 operates to stop the operation of the servomotor 46 and the pressure reduction ends. Then, the position P2 of the servomotor 46 is read, and the high-pressure gas container 31 is read based on the measurement principle described below.
Calculate the permanent increase rate (%) of.

First, the total increase (ΔV) of the high-pressure gas container 31
A method for determining the permanent increase (Δv) will be described below. That is, the water pressure P is maintained at 31 (kgf / cm ² ) for a predetermined time while the high-pressure gas container 31 is completely expanded. Then, the PO point of the servomotor 46 at the end of the air bleeding and injection is read, and then the position P1 of the servomotor 46 when the inside of the high-pressure gas container 31 is maintained at a water pressure of 31 (kgf / cm ² ) for 30 seconds. Is read, and the difference in the number of rotations of the servo motor 46, that is, “P1-P
“0” (= water amount difference) is input to the microcomputer 80.

High-pressure gas corresponding to the amount of water injected at this time
Weight ΔM of reduced water in container 31 ₁Then the total increase
The volume A of the injection water in equation (1), which leads to the quantity (ΔV), is
Assuming that the density of water at the test temperature is ρ,
Is required. A = ΔM₁÷ ρ ... (2)

The permanent increase (Δv) is obtained by the following equation (3), where ρ is the density of water at the test temperature. Δv = (ΔM ₁ −ΔM ₂ ) ÷ ρ (3)

Then, by inputting the calculation programs of the equations (1) to (3) and the data necessary for them into the microcomputer 80, the permanent increase rate can be automatically obtained.

FIGS. 4 (A) and 4 (B) show an overall view of a pressure tester 70 according to the present embodiment.
1, the water injection process D, the inspection process E, the drainage process F, and the steam drying process G automatically proceed in this order. Reference numeral 71 denotes an electric control panel.

After the test, the inspection head 32 is removed from the high-pressure gas container 31, and the process proceeds to the next step. Subsequent steps include container paint removal, mass inspection and marking, container painting and drying, installation of a new main valve and evacuation inspection.

[0037]

As described above in detail, according to the non-aqueous tank type pressure-resistant expansion test method and apparatus for a high-pressure gas container according to the present invention, the test head is fixed after the high-pressure gas container to be tested is fixed at a fixed position. After the fitting and fixing, the water is drained from the air drainage hole provided at the other end of the inspection head and the air is drained and drained, the pressure in the high-pressure gas container is kept constant using a plunger pump driven by a servomotor. Value and read the position of the servomotor, and after maintaining the predetermined time, reduce the pressure in the high-pressure gas container to read the position of the servomotor when the water pressure in the high-pressure gas container drops to a certain value. The total increase amount and the permanent increase amount of the high-pressure gas container are obtained from the reading position of each servomotor, and the permanent increase rate of the high-pressure gas container can be calculated based on an arithmetic expression.

Therefore, pulsation does not occur in the pipeline and the high-pressure gas container when the plunger pump is operated, the water pressure is stabilized, and the instability of the pressurized state due to the air remaining in the pipeline is eliminated. Moreover, since the accuracy of the pressure sensor for detecting the pressing force is good, the measurement error can be minimized.

In particular, in this embodiment, the weight of the reduced or increased amount of water in the high-pressure gas container, which is instantaneously obtained from the value read by the servomotor, the density at the water temperature at this time, and the volume of water Since the calculation is performed, a highly accurate measurement can be quickly performed in a short time without being affected by the influence of the environmental temperature or a change in the volume of water due to thermal expansion occurring with the passage of time. Moreover, it is possible to obtain an objective test result without causing visual misreading or individual differences due to different measurers, and to obtain a high-precision measurement in a short time and quickly. An aquarium type pressure expansion test method and apparatus are provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an entire embodiment of a non-aqueous tank pressure-resistant expansion test apparatus for a high-pressure gas container according to the present invention.

FIG. 2A is a front view showing the structure of a plunger pump employed in this embodiment, and FIG. 2B is a side view thereof.

FIG. 3 is a schematic diagram conceptually illustrating an operation mode of the embodiment.

FIG. 4A is a plan view showing the whole of a pressure resistance tester according to the present embodiment, and FIG. 4B is a side view of the same.

FIG. 5 is a schematic diagram showing an example of a conventional non-aqueous tank pressure-resistant expansion test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 31 ... High-pressure gas container 32 ... Inspection head 42 ... Pressure sensor 43 ... Check valve 44 ... Plunger pump 45 ... Housing 46 ... Servo motor 47 ... Connection part 48 ... Ball screw 49 ... Bearing 50 ... Bearing nut part 51 ... Slide base 52 ... Guide shaft 53 ... Slider 54 ... Piston 55 ... Cylinder 57 ... Seal part 58 ... Pressure release valve 80 ... Microcomputer 81 ... Control panel serial number P2831

Claims (3)

[Claims] An inspection head was fitted and fixed after fixing a high-pressure gas container to be used for a test in a fixed position, and water was injected from an air vent hole provided at the other end of the inspection head and air was drained and drained. Then, using a plunger pump driven by a servomotor, the pressure in the high-pressure gas container is increased to a constant value, the position of the servomotor is read, and after maintaining for a predetermined time, the pressure in the high-pressure gas container is reduced to perform high pressure. The position of the servomotor when the water pressure in the gas container falls to a certain value is read, the total increase and the permanent increase of the high-pressure gas container are obtained from the read positions of the servomotors, and the high A non-aqueous tank type pressure-resistant expansion test method for a high-pressure gas container, comprising calculating a permanent increase rate of the gas container. 2. An air vent injection hole whose operation state is controlled by opening and closing a valve is provided in one of the pipelines led from an inspection head fitted and fixed to a high-pressure gas container to be subjected to a test. A non-aqueous tank type high-pressure gas container, which is equipped with a plunger pump, which is driven by a servomotor and has a function of increasing and decreasing the pressure of water injected into the pipeline to a predetermined pressure. Pressure expansion test equipment. 3. A reading position of said servomotor is inputted to a microcomputer, and a permanent increase rate is calculated based on an arithmetic expression from a total increase amount and a permanent increase amount of a high-pressure gas container for performing a pressure expansion test. The non-aqueous tank type pressure-resistant expansion test apparatus for a high-pressure gas container according to claim 2.