JP7455779B2 - Buck-boost system and buck-boost method - Google Patents

Description

The present invention relates to a voltage raising/lowering system and a voltage raising/lowering method.

Conventionally, pressurized containers, hydrogen containers, etc. are filled with fluids, gases, etc. and pressurized to increase the pressure, thereby verifying the effectiveness of pressurization treatment using fluids and gases under high pressure, and the effectiveness of pressurized containers, hydrogen containers, etc. Pressure tests were being conducted.

However, when increasing the pressure by filling it with fluid, gas, etc., or decreasing the pressure by discharging fluid, gas, etc., if the pressure is suddenly increased or decreased, it may damage the pressurized container, hydrogen container, etc., and even the surrounding systems. It may cause a malfunction.

For example, in order to eliminate such causes of failure, a piping system has been disclosed in which an expansion tank is installed at a position lower than the highest part of the piping and is connected to the discharge side of a circulation pump (for example, Japanese Patent No. 5708992 (hereinafter referred to as "Patent Document 1"). This makes it possible to operate the pipes in a vacuum (negative pressure below atmospheric pressure), preventing water leaks in the unlikely event of a water leak, and providing the high level of reliability required for facilities where water leaks cannot be tolerated. and ensure sufficient safety.

In Patent Document 1, the pressure inside the piping can be maintained in a vacuum state by raising and lowering the expansion tank. However, if the expansion tank is large, it is necessary to expand the range of pressure within the piping, resulting in a large-scale system including a lifting mechanism.

Moreover, in Patent Document 1, it is assumed to be used for air conditioning equipment in a clean room, a chemical liquid transport route in a chemical factory, and the like. When pressurizing or pressure testing a pressurized container, hydrogen container, etc., it is necessary to temporarily retain the pressurized fluid in the surrounding system, such as the pressurized container or hydrogen container. Therefore, improvements are required to efficiently switch between the high pressure state and the non-high pressure state.

Furthermore, the external environment of the pressurized container, hydrogen container, etc. may affect the pressure increase or decrease. For example, the external pressure applied to a pressurized container, hydrogen container, etc. is significantly different depending on whether the water is 1 meter deep or 100 meters deep. Therefore, when verifying the effectiveness of pressurized containers, hydrogen containers, etc., there has been a need to develop a system that takes internal and external pressure into account.

The present invention provides a pressure-up/down system that optimizes the internal and external pressure of a pressurized container, hydrogen container, etc., and adjusts the pressure increase/decrease in stages when performing pressure treatment or pressure resistance testing on a pressurized container, hydrogen container, etc. The purpose is to provide a step-up and step-down method.

The first aspect of the present invention is
a high-pressure pump that increases or decreases the pressure of pressurized liquid in a pressurized object;
a discharge section that is connected to the pressurized object and discharges the pressurized liquid;
a control device that controls the rotation speed of the high-pressure pump during pressure increase or pressure decrease, and the discharge amount of the pressurized liquid by the discharge section;
It is a step-up/down system with

The second aspect of the present invention is
A pressure raising/lowering method for raising or lowering the pressure of a pressurized liquid in a pressurized object,
Filling the pressurized liquid into the pressurized object while operating a high-pressure pump at a first rotation speed,
After the pressurized liquid is filled up to the volume of the pressurized object, the high-pressure pump is operated at a second rotation speed that is higher than the first rotation speed;
This is a step-up/down method.

According to the pressure raising/lowering system and the pressure raising/lowering method of the present invention, when a pressurized container, a hydrogen container, etc. is subjected to pressure treatment or a pressure resistance test, the internal pressure and external pressure of the pressurized container, hydrogen container, etc. are optimized, and the pressure is raised/lowered. can be adjusted in stages.

System diagram of an embodiment of a voltage elevating and lowering system when the pressurized object is above System diagram of an embodiment of a voltage elevating and lowering system when the pressurized object is below System diagram showing details of the workpiece detection unit of the step-up/down system of the embodiment

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
The pressure elevating and lowering system 1 of this embodiment performs pressurization processing and pressure resistance tests by filling a pressurized object W with liquid (for example, water) and increasing the pressure to 10 to 500 MPa. Here, the pressurized object W is, for example, a pressurized container or a hydrogen container. In pressure processing, liquid is used under high pressure. Verify the effectiveness of pressurized containers, hydrogen containers, etc. in pressure tests.
If the pressurized object W is a hydrogen container, the inside (surface) of the container may be made of a material that is resistant to corrosion and hydrogen embrittlement, or may be coated with a coating. It is desirable to consider this and verify effectiveness.
The pressure raising/lowering system 1 includes a high pressure pump P, a discharge section 2, a detection section 3, and a control device 6. The detection section 3 includes a workpiece detection section 4 and a discharge detection section 5. Note that each component of the pressure raising/lowering system 1 is connected by a flow path L. A pressurized liquid Q passes through the flow path L.

The flow path L includes a water supply flow path L1, a pressurized liquid supply flow path L2, a pressurized liquid discharge flow path L3, and a circulation flow path L4. The fluid in the tank T is supplied to the high-pressure pump P through the water supply channel L1. The pressurized liquid Q pressurized by the high-pressure pump P is supplied to the pressurized object W through the pressurized liquid supply channel L2. A valve (not shown) is provided between the pressurized liquid supply channel L2 and the pressurized object W. Note that the pressurized liquid Q in the pressurized object W is discharged to the discharge section 2 through the pressurized liquid discharge channel L3. The pressurized liquid Q discharged from the discharge section 2 returns to the tank T through the circulation channel L4.

The high-pressure pump P increases or decreases the pressure of the pressurized liquid Q within the pressurized object W. The pressure Q1 of the pressurized liquid is 10 to 500 MPa. The high pressure pump P raises or lowers the pressure of the liquid to a high pressure state. The high-pressure pump P is, for example, a piston pump, a plunger pump, or a hydraulic pump.

The discharge part 2 and the pressurized object W are connected by a pressurized liquid discharge channel L3. The discharge part 2 discharges the pressurized liquid Q. Note that the pressurized liquid Q is in a non-pressurized state by being discharged from the discharge section 2.
For the discharge section 2, a manual, electric, air-driven, etc. valve or discharge valve can be appropriately selected.

In addition to discharging the pressurized liquid Q, the discharge section 2 also discharges air bubbles within the pressurized liquid Q. When operating the pressure raising/lowering system 1, the presence of air bubbles in the flow path L, the high pressure pump P, and the pressurized object W may cause a malfunction. Therefore, by creating a structure in which air bubbles do not accumulate in each element, the product life of the pressure raising/lowering system 1 is extended as a result.

Further, the discharge section 2 has a plurality of discharge sections (a first discharge section 2a, a second discharge section 2b, and a third discharge section 2c). The discharge amount Q3 of pressurized liquid from the plurality of discharge portions 2a to 2c may be the same or different.
For example, by making the shape (diameter) of each discharge hole of the first to third discharge parts 2a to 2c the same, the discharge amount Q3 of the pressurized liquid of each discharge part 2a to 2c becomes the same. At this time, by adjusting the order and combination of the first to third discharge portions 2a to 2c and discharging the pressurized liquid Q, the discharge amount Q3 of the pressurized liquid can be adjusted in stages.
Further, by making the diameters of the respective discharge holes of the first to third discharge parts 2a to 2c different, the discharge amount Q3 of the pressurized liquid from each of the discharge parts 2a to 2c is different. At this time, the discharge amount Q3 of the pressurized liquid can be finely adjusted by combining the magnitudes of the respective discharge amounts of the first to third discharge portions 2a to 2c.
In addition, the discharge amount Q3 of the pressurized liquid can be adjusted more finely by adjusting the ON or OFF state of the discharge section 2 manually or automatically using the control device 6.

Moreover, the discharge part 2 is arranged at a position higher than the height H of the pressurized object W. The pressurized object W is subjected to an internal pressure of 10 to 500 MPa due to pressure increase by the pressurized liquid Q. If the liquid is discharged all at once from the discharge section 2 in this state, the pressurized object W will rapidly return to its original state, and the surface of the pressurized object W will be deformed. By adjusting the discharge amount Q3 of the pressurized liquid discharged from the discharge section 2, deformation of the surface of the pressurized object W can be prevented. Furthermore, the liquid filled in the pressurized object W flows from top to bottom due to gravity. Therefore, by arranging the discharge part 2 at a position higher than the height H of the pressurized object W, rapid discharge of the pressurized liquid Q can be further prevented.

The bubbles dissolved in the pressurized liquid Q move upward in the flow path L. Therefore, by arranging the discharge section 2 at a position higher than the height H of the pressurized object W, the bubbles move upward and the accumulated bubbles are also discharged at once.
The pressurized liquid Q1 is a liquid pressurized to 10 to 500 MP. Therefore, the dissolved air bubbles are also in a compressed state, and the influence of the air bubbles is greater than that of a liquid that is not pressurized.
Therefore, even if the amount of bubbles present in the flow path L is small, the energy given to the flow path L, the discharge section 2, etc. is large. By creating a structure that eliminates air bubbles from the entire system, longevity and maintainability can be improved.

More preferably, the discharge part 2 is arranged at a position higher than the height H of the pressurized object W, and the high-pressure pump P is arranged at a position lower than the height H of the pressurized object W. .
As a result, bubbles dissolved in the pressurized liquid Q generated by the high-pressure pump P rise and accumulate in the pressurized object W and the discharge section 2 in order, and can be discharged or degassed from the discharge section 2 at once.

The detection unit 3 detects the pressure and flow rate of the pressurized object W and the liquid flowing in the flow path L.
The workpiece detection unit 4 detects the pressure Q1, the supply amount Q2, the discharge amount Q3 of the pressurized liquid Q, the vibration and position of the pressurized object W, and the like. The workpiece detection unit 4 is a pressure sensor, a flow rate sensor, a vibration sensor, a position sensor, or the like.

For example, as shown in FIG. 3, the workpiece detection section 4 includes a pressure detection section 4a, a flow rate detection section 4b, a vibration detection section 4c, and a position detection section 4d. The pressure detection unit 4a detects the pressure Q1 of the pressurized liquid Q. The flow rate detection unit 4b detects the supply amount Q2 of the pressurized liquid Q to the pressurized object W and the discharge amount Q3 from the pressurized object W. The vibration detection unit 4c detects vibrations of the pressurized object W. The position detection unit 4d detects the shape of the pressurizing object W. The position detection unit 4d detects whether or not the shape of the pressurized object W is deformed due to internal pressure.
It not only detects the pressure Q1, supply amount Q2, and discharge amount Q3 of the pressurized liquid Q, but also detects the position and vibration of the pressurized object W, and then adjusts the rotation speed of the high-pressure pump P and the discharge part 2. This allows the voltage raising and lowering system 1 to operate stably.

The discharge detection section 5 is arranged near the discharge section 2. The discharge detection section 5 detects the pressure Q1 or the discharge amount Q3 of the pressurized liquid Q. When detecting the pressure Q1 of the pressurized liquid Q, the discharge detection section 5 is preferably arranged at a position before the pressurized liquid Q is discharged. When detecting the discharge amount Q3 of the pressurized liquid Q, the discharge detection section 5 is preferably arranged at a position after the pressurized liquid Q has been discharged.
The discharge detection section 5 is a pressure sensor, a flow rate sensor, a vibration sensor, a position sensor, or the like. The discharge detection section 5 includes a plurality of discharge detection sections (a first discharge detection section 5a, a second discharge detection section 5b, and a third discharge detection section 5c). The first to third discharge detectors 5a to 5c are arranged at positions after the pressurized liquid Q is discharged from the first to third discharge parts 2a to 2c, respectively.

The control device 6 controls the pressure increase and decrease of the pressure of the high-pressure pump P, and the pressure Q1, supply amount Q2, and discharge amount Q3 of the pressurized liquid Q in the discharge section 2. The control device 6 includes a receiving section 6a, a calculation section 6b, a storage section 6c, and a feedback section 6d.

The receiving section 6a receives detection information from the workpiece detection section 4 and the discharge detection section 5. The receiving section 6a may be directly connected to the work detecting section 4 and the discharging detecting section 5 by wiring, or may remotely receive detection information from the work detecting section 4 and the discharging detecting section 5 using a sensor or the like. It's okay.

The calculation unit 6b calculates the detection information. The calculation unit 6b is, for example, a CPU (central processing unit). The calculation unit 6b calculates whether the detection information has reached a specified abnormal value. In addition, the calculation unit 6b calculates the rotational speed of the high-pressure pump P, the pressure Q1 of the pressurized liquid Q in the pressurized object W, the flow path L, the discharge part 2, etc., the supply amount Q2, the discharge amount Q3, etc. Calculate the value. The operating value may be set in advance when increasing or decreasing the pressure of the pressurized object W, or may be set (changed) in real time.

The storage unit 6c stores detection information, calculation information, information on the pressurized object W, and the like. The storage unit 6c is a nonvolatile memory, volatile memory, or the like.
The feedback section 6d feeds back the calculation information to the high pressure pump P. Thereby, the voltage raising/lowering system 1 can be adjusted to operate normally.

Further, the control device 6 adjusts the rotation speed of the high-pressure pump P and the discharge amount Q3 of the pressurized liquid Q from the discharge section 2 in stages. Thereby, the pressure of the pressurized object W can be stably raised and lowered.
By increasing the rotation speed of the high-pressure pump P in stages, the pressure Q1 of the pressurized liquid Q in the pressurized object W is increased in stages. Therefore, the internal pressure is not suddenly applied to the pressurized object W, and it is possible to prevent the entire pressure raising/lowering system 1 from malfunctioning or from stopping.

A degassing section 7 may be arranged between the tank T and the high pressure pump P. By degassing the gas in the degassing section 7, the amount of bubbles mixed in is reduced at the stage when the high pressure pump P generates the pressurized liquid Q. Therefore, the mixture of air bubbles into the flow path L can be suppressed. The degassing section 7 can prevent air bubbles contained in the pressurized liquid Q from adversely affecting the pressurized object W and the flow path L when the pressurized liquid Q reaches 300 to 500 MPa.

Further, as shown in FIG. 3, a bubble suction unit 7a may be arranged near the pressurized object W. The bubble suction unit 7a deaerates bubbles within the pressurized object W. Thereby, when supplying the pressurized liquid Q into the pressurized object W, even if it is difficult to remove a small amount of air bubbles from the pressurized object W, the bubble suction section 7a Air bubbles inside can be evacuated.

Further, the pressurized object W is placed on the external pressure adjustment section 8 in the water tank A. As shown in FIGS. 1 and 2, the inside of the water tank A is filled with water, pure water, seawater, etc., and the pressurized object W is immersed therein to perform pressurization treatment and a pressure resistance test.
By switching the processing when the depth of the water tank A is shallow or deep, the external pressure adjustment unit 8 adjusts the pressure based on the external environment (external pressure), assuming that the pressurized object W is used underwater. Perform pressure treatment and pressure resistance tests. The external pressure adjustment section 8 includes an elevating section 8a, a mounting table 8b, and an elevating motor M.

The elevating part 8a is a frame (base) placed in the water tank A. The elevating part 8a is fixed in the water tank A even if there is the weight of the pressurized object W or various liquids in the water tank A.
The pressurizing object W is placed on the placement table 8b. The mounting table 8b is connected to the elevating section 8a. The mounting table 8b can be moved up and down as driven by a lifting motor M such as an air motor. In addition, from the viewpoint of operation within the water tank A, the lifting motor M may be not only an air motor but also a power source such as an air cylinder.

While the external environment of the pressurized object W is changed using the external pressure adjustment section 8, the pressure of the pressurized object W is raised or lowered from inside the pressurized object W using the high-pressure pump P. Thereby, various tests can be performed in consideration of the internal pressure and external pressure on the pressurized object W.
Specifically, more effective pressurization can be achieved by adjusting the discharge amount Q3 of the pressurized liquid Q so that the external pressure and internal pressure of the pressurized object W are equal (for example, within ±5 to 10%). Pressure treatment and pressure tests can be performed.

Next, a method of operating the voltage elevating and lowering system of this embodiment will be explained.
First, preparations are made to fix the pressurized object W. A pressurized object W is fixed to a mounting table 8b of an external pressure adjustment section 8 arranged in a water tank A. The lifting motor M is driven to move the mounting table 8b downward along the lifting section 8a, and the pressurized object W is immersed in the liquid in the water tank A.

Next, the pressure Q1 of the pressurized liquid Q in the pressurized object W, the supply amount Q2 of the pressurized liquid Q, the discharge amount Q3 of the pressurized liquid Q in the discharge part 2, and the operating time are set.
In addition, when the discharge part 2 has the first to third discharge parts 2a to 2c, the discharge amount Q3 of the pressurized liquid Q can be set the same or individually for each of the first to third discharge parts 2a to 2c. At the same time, set the timing of discharge.

Next, the liquid supply source (not shown) and the high-pressure pump P are started to supply the pressurized liquid Q into the flow path L and the pressurized object W. In order to prevent breakdowns of the pressure raising/lowering system 1 and the pressurized object W, the control device 6 is used to increase the rotation speed of the high pressure pump P in stages to reduce the pressure of the pressurized liquid Q in the pressurized object W. The pressure Q1 is increased stepwise.

Hereinafter, a method of increasing the pressure of the pressurized object W by increasing the rotational speed of the high-pressure pump P in stages will be described.
First, in the filling process, the pressurized object W is filled with the pressurized liquid Q. At this time, the high pressure pump P is operated at the first rotation speed R1.

When the pressurized liquid Q is filled up to the volume of the pressurized object W, the process proceeds to the pressurization step. In the pressure increasing step, the high pressure pump P is operated at the second rotation speed R2. Here, the second rotation speed R2 is larger than the first rotation speed R1. In the pressure increasing step, it is preferable to gradually increase the second rotation speed R2 of the high pressure pump P. As a result, the pressure of the pressurized liquid Q in the pressurized liquid supply channel L2 and the pressurized object W gradually increases to, for example, 50 MPa, 100 MPa, 150 MPa, and 200 MPa. In this way, the pressure of the pressurized object W is increased stepwise to the target pressure.

After the pressurized liquid Q is filled up to the volume of the pressurized object W and before the pressurization step, a part of the pressurized liquid Q is discharged from the discharge part 2, so that the inside of the flow path L and the pressurized container are It may also include a preparation step (primary degassing step) in which air bubbles accumulated from inside the W are also degassed.
Before and after the pressurization process, degassing process (secondary degassing process) is always performed from the degassing unit 7 placed between the tank T and the high-pressure pump P and the bubble suction unit 7a placed near the pressurized object W. You can also do that.

Furthermore, an adjustment step may be provided before the pressure increase step or simultaneously with the pressure increase step. After the filling process, the position of the pressurized object W is lowered in a immersed state. For example, the pressurized object W is immersed in water at depths of 1 m, 10 m, 50 m, and 100 m in stages. As a result, the external pressure that the pressurized object W receives increases in stages. In the adjustment step, the second rotation speed R2 of the high-pressure pump P is temporarily maintained constant until the balance between the internal pressure and the external pressure with respect to the volume of the pressurized object W can be adjusted. For example, the pressurization or pressure resistance test is performed while maintaining the second rotational speed R2 of the high-pressure pump P constant for at least a predetermined period of time, such as 5 to 10 minutes. This allows more effective pressure treatment and pressure tests to be performed.

Next, a description will be given of a step of lowering the pressure of the pressurized object W by discharging the pressurized liquid Q from the discharge section 2 in stages. Note that the high pressure pump P is stopped before the pressure lowering step. After a predetermined period of time has elapsed after the pressurization process, the pressurized fluid Q inside the pressurized object W is discharged in order to verify the state of the pressurized object W.
In the pressure lowering step, the discharge amount Q3 of the pressurized liquid Q discharged from the discharge section 2 is adjusted. For example, the discharge amount Q3 of the pressurized liquid Q discharged from the discharge section 2 is discharged in stages within the range of 5 to 20% of the volume inside the pressurized object W, or the discharge amount that can be discharged from the discharge section 2 Pressurized liquid Q is continuously discharged by limiting Q3 to a constant value. The discharge amount in each of the plurality of discharge parts 2 (first to third discharge parts 2a to 2c) may be adjusted according to the same or a combination of large, medium and small.

The discharged pressurized fluid Q is stored in the tank T via the flow path L (pressurized liquid discharge flow path L3, circulation flow path L4).
In this way, by repeating the pressure treatment and the pressure test multiple times, it is possible to verify the longevity of the pressurized object W.

Further, by changing the external pressure depending on the position (depth) of the pressurized object W in the water tank A and repeating the pressurization treatment and the pressure test, the effects of internal pressure and external pressure on the pressurized object W can be verified.

As mentioned above, it goes without saying that the present invention is not limited to the embodiments described above, and that the present invention can be modified as appropriate without departing from the spirit thereof.

1 Pressure raising/lowering system 2 Discharge section 2a First discharge section 2b Second discharge section 2c Third discharge section 3 Detection section 4 Workpiece detection section 4a Pressure detection section 4b Flow rate detection section 4c Vibration detection section 4d Position detection section 5 Discharge detection unit 5a first detection unit for discharge 5b second detection unit for discharge 5c third detection unit for discharge 6 control device 6a reception unit 6b calculation unit 6c storage unit 6d feedback unit 7 degassing unit 7a bubble suction unit 8 External pressure adjustment section 8a Lifting section 8b Mounting table M Lifting motor P High pressure pump T Tank A Water tank W Pressurized container L Flow path Q Pressurized liquid Q1 Pressure of pressurized liquid Q2 Supply amount of pressurized liquid Q3 Supply amount of pressurized liquid Emission amount H Height

Claims (13)

a high-pressure pump that increases or decreases the pressure of pressurized liquid in a pressurized object;
a discharge section that is connected to the pressurized object and discharges the pressurized liquid;
a control device that controls the rotation speed of the high-pressure pump during pressure increase or pressure decrease, and the discharge amount of the pressurized liquid by the discharge section;
has
The discharge part is arranged at a position higher than the height of the pressurized object .
Buck-boost system. The high-pressure pump is arranged at a position lower than the height of the pressurized object,
The step-up/down system according to claim 1. a high-pressure pump that increases or decreases the pressure of pressurized liquid in a pressurized object;
a discharge section that is connected to the pressurized object and discharges the pressurized liquid;
a control device that controls the rotation speed of the high-pressure pump during pressure increase or pressure decrease, and the discharge amount of the pressurized liquid by the discharge section;
a workpiece detection unit that is disposed near the pressurized object and detects the pressure or the discharge amount of the pressurized liquid and also detects the position of the pressurized object;
A step-up and step-down system. further comprising a discharge detection section disposed near the discharge section and configured to detect the pressure of the pressurized liquid or the discharge amount;
The step-up/down system according to claim 3 . having a plurality of the discharge parts;
The step-up/down system according to any one of claims 1 to 4 . The control device includes:
a receiving unit that receives detection information from the workpiece detection unit and the discharge detection unit;
a calculation unit that calculates calculation information based on the detection information;
a storage unit that stores the detection information and the calculation information;
a feedback unit that feeds back the calculation information to the high pressure pump;
The step-up/down system according to claim 4 . The control device increases the rotation speed of the high-pressure pump in stages, and increases the pressure of the pressurized liquid in the pressurized object in stages.
The step-up/down system according to any one of claims 1 to 6 . The control device gradually increases the amount of the pressurized liquid discharged by the discharge unit, and lowers the pressure of the pressurized liquid in the pressurized object.
The step-up/down system according to any one of claims 1 to 7 . a high-pressure pump that increases or decreases the pressure of pressurized liquid in a pressurized object;
a discharge section that is connected to the pressurized object and discharges the pressurized liquid;
a control device that controls the rotation speed of the high-pressure pump during pressure increase or pressure decrease, and the discharge amount of the pressurized liquid by the discharge section;
a degassing unit that deaerates the pressurized object and the flow path ;
A step-up and step-down system. a high-pressure pump that increases or decreases the pressure of pressurized liquid in a pressurized object;
a discharge section that is connected to the pressurized object and discharges the pressurized liquid;
a control device that controls the rotation speed of the high-pressure pump during pressure increase or pressure decrease, and the discharge amount of the pressurized liquid by the discharge section;
An external pressure adjustment unit that adjusts the external pressure applied to the pressurized object,
A lifting section;
a mounting table that fixes the pressurized object, is connected to the elevating section, and moves up and down along the elevating section ;
an external pressure adjustment section having;
A step-up and step-down system. A pressure raising/lowering method for raising or lowering the pressure of a pressurized liquid in a pressurized object,
Filling the pressurized liquid into the pressurized object while operating a high-pressure pump at a first rotation speed,
After the pressurized liquid is filled up to the volume of the pressurized object, the high-pressure pump is operated at a second rotation speed that is higher than the first rotation speed ,
ejecting the pressurized liquid in the pressurized object in stages from a discharge part disposed at a position higher than the height of the pressurized object;
Step-up/down method. adjusting the second rotation speed of the high-pressure pump based on the external pressure that the pressurized object receives;
The voltage raising and lowering method according to claim 11 . The pressurized liquid has a pressure of 100 to 150 MPa.
The voltage raising and lowering method according to claim 11 or 12 .

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