KR102503493B1 - Compressor Structure Using Ionic Liquid - Google Patents

Abstract

In the compressor structure using the ionic liquid according to the present invention, the cylinder; a piston and a piston rod disposed within the cylinder; the piston rod extends in the longitudinal direction and is connected to the piston; the piston is capable of reciprocating longitudinally within the cylinder; The piston is formed as a labyrinth piston and has an accommodating portion capable of accommodating the ionic liquid therein, and a plurality of accommodating holes formed by connecting the accommodating portion and an upper end of the piston, wherein the ionic liquid We propose a compressor structure using an ionic liquid, characterized in that a plurality of receiving holes are formed at the upper end of the piston to the extent of being submerged at a certain height.

Description

Compressor Structure Using Ionic Liquid

The present invention relates to a compressor structure using an ionic liquid, and more particularly, to compressing a specified specific gas composed of one or more compressor cylinders and a piston structure, and in particular, ionic liquids and a piston as a tool for compression. It is about the structure of the structure. As for the designated specific gas, hydrogen is most commonly used, and it is possible to compress the designated gas according to the characteristics of other ionic liquids such as carbon dioxide or natural gas. These gases do not dissolve in the ionic liquid and are separated from the gases without residue, and the compressed gases can maintain a very high purity.

The technology of compressing a specific gas by applying an ionic liquid to a compressor does not use the same concept as a conventional piston, but uses an ionic liquid as a concept of a piston to compress gas with a liquid piston concept, or The ionic liquid is filled at the top of the piston and the piston is pushed up so that the ionic liquid directly contacts the gas and compresses the gas.

This method is used where high-pressure filling gas up to hundreds of bars is required, such as hydrogen vehicles, where demand has recently started to increase, and has begun to be applied to industrial sites where various special gases must be compressed.

This is possible because the ionic liquid used has almost no vapor pressure and has little reactivity and solubility with gas, allowing separation without dissolution.

For example, imidazolium based ionic liquids are used for hydrogen compression and have suitable viscosity, density, melting point, corrosiveness, low hydrogen solubility, low compressibility, chemical stability, thermal stability, heat capacity, high It is known to satisfy thermal conductivity and suitable lubricating properties.

Compressors using these ionic liquids have an inherently low coefficient of friction, so they have a long lifespan (except for the case of filling on a normal piston), and the cooling effect according to the use of liquid is excellent, so the external cooling device is relatively simple, and the operation It has the advantage of reducing energy and obtaining a high-purity gas compression medium. In practice, conventional compressors have a lifespan of 2 to 3 years, while ionic liquid compressors have been reported to have a long lifespan of 7 years or more.

However, compared to the long history of the existing reciprocating piston compressor or diaphragm, the current technology has not been fully developed, so the improvement continues. is forming

In addition, there is still a large amount of expensive ionic liquid used in the entire system, so there is an advantage in cooling effect, but due to the concept of a liquid piston, it should not affect the metal piston during compression, and high-pressure gas flows to the bottom of the piston should not leak, so a sufficient amount of ionic liquid must exist at the top of the piston, and the ionic liquid discharged along with the gas through the exhaust valve must be collected through the collector and then circulated back into the cylinder, so There was a problem that an ionic liquid was also required.

In addition, there is a large number of ionic liquids passing through the above-mentioned exhaust valve, and since it is possible to separate from gas, there is little effect on gas concentration, but there is a problem in that compression efficiency is lowered.

In addition, since the maximum acceleration force of the ionic liquid at the top of the piston is limited by the gravitational acceleration, the operating speed cannot be raised beyond a certain level. Accordingly, the multi-stage (5 or more stages, of course, the need for multi-stage compression to obtain high pressure) cylinders exists. The system is essential, and there is a problem that there is an energy efficiency problem and a factor for increasing the price of the system.

In addition, it is very difficult to control the movement of the liquid according to the vertical movement of the liquid, so when the ionic liquid is loaded on the piston by the conventional ring-shaped sealing, heat generation and durability reduction due to friction between the conventional piston and the cylinder cannot be avoided. There was a problem with no.

Related prior literature is Patent Document 1 (Korean Patent Publication No. 10-2009-0059156 (2009.06.10.)) and Patent Document 2 (Korean Patent Publication No. 10-2012-0017068 (2012.02.27.)) And Patent Document 3 (Republic of Korea Patent Publication No. 10-2020-0045469 (2020.05.04.)) has been published.

Republic of Korea Patent Publication No. 10-2009-0059156 (2009.06.10.) Republic of Korea Patent Publication No. 10-2012-0017068 (2012.02.27.) Republic of Korea Patent Publication No. 10-2020-0045469 (2020.05.04.)

The purpose of the present invention is to minimize the amount of ionic liquid distributed at the top of the piston, and to enable operation with little friction by using a labyrinth type piston, thereby minimizing heat generation and durability reduction due to friction At the same time, it is to provide a piston compressor structure using an ionic liquid that can increase the reciprocating speed and reduce the amount that escapes to the exhaust valve.

In the compressor structure using the ionic liquid according to the present invention, in the compressor structure,

cylinder; a piston and a piston rod disposed within the cylinder; the piston rod extends in the longitudinal direction and is connected to the piston; the piston is capable of reciprocating longitudinally within the cylinder; The piston is formed as a labyrinth piston and has an accommodating portion capable of accommodating the ionic liquid therein, and a plurality of accommodating holes formed by connecting the accommodating portion and an upper end of the piston, wherein the ionic liquid It is characterized in that a plurality of accommodating holes are formed at the upper end of the piston so as to be locked at a certain height.

Preferably, a discharge hole capable of discharging the ionic liquid contained in the piston is formed at the lower middle end of the piston; The pressure transmitted by the gas at the top of the piston through the discharge hole is transmitted to the cylinder wall through the ionic liquid, so that the compressed gas does not leak and can be sealed.

Also preferably, it is characterized in that the dynamic characteristics can be adjusted by placing an internal metal part inside the piston to adjust the amount of the ionic liquid and the weight of the piston.

Also preferably, the accommodation hole formed at the top of the piston is characterized in that it has a size that minimizes the difference between the force due to inertia and the force due to viscosity during the reciprocating motion of the piston.

Also preferably, the ionic liquid is characterized in that it covers the top of the piston to prevent gas contact during reciprocating motion.

The present invention minimizes the amount of ionic liquid distributed on the top of the piston, and uses a labyrinth type piston to enable operation with little friction, thereby minimizing heat generation and reduction in durability due to friction. It has the effect of increasing the reciprocating speed of the piston and reducing the amount of ionic liquid exiting the cylinder.

1 and 2 are conceptual views of a piston cylinder structure.
3 is a view showing a labyrinth piston structure according to an embodiment of the present invention.
4 is a diagram showing the structure of a compressor using an ionic liquid according to the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

The advantages and features of the present invention, and how to achieve them, will become clear with reference to the detailed description of the following embodiments in conjunction with the accompanying drawings.

However, the present invention is not limited by the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention pertains. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims.

In addition, when it is determined that related known technologies may obscure the gist of the present invention in describing the present invention, a detailed description thereof will be omitted.

1 and 2 are conceptual diagrams of a piston cylinder structure method, FIG. 3 is a diagram showing a labyrinth piston structure according to an embodiment of the present invention, and FIG. 4 is a diagram showing an ionic liquid according to the present invention. It is a diagram showing the compressor structure.

Referring to FIGS. 1 and 2, FIG. 1 (a) shows a ring-type piston structure, and FIG. 1 (b) shows a labyrinth-type piston structure.

1 (a) shows that a piston with a labyrinth type sealing is used instead of a piston with a conventional ring type sealing.

Figure 2 (a) shows a ring-shaped piston, Figure 2 (b) shows a labyrinth-shaped piston. As shown in FIG. 2(b), the labyrinth type piston is characterized in that the piston protrusion 1 does not contact the cylinder wall 2.

This is a piston used in a state where a certain amount of leakage is allowed by forming a vortex through the piston protrusion 1.

Although the leakage is larger than that of the ring-type piston, it can be used by increasing the length of the labyrinth-type piston within the allowable range to adjust the allowable leakage. This arrangement is known to be suitable for clean gas service.

More specifically, the compressor structure using the ionic liquid according to the present invention is a labyrinth-type compressor structure, and at least the walls of the piston and cylinder are formed by labyrinth sealing.

Labyrinth sealing is a non-contact sealing. The effect of sealing is based on the extension of the flow path through the sealed gap, which significantly increases the flow resistance. The extension of the movement is achieved by the surface structure of the piston and, if necessary, the cylinder wall.

Preferably, the surface of the piston has a plurality of circumferential projections spaced from each other in the longitudinal direction of the piston. Absolute secrecy is not possible with this contactless design.

A labyrinth piston with a labyrinth seal for this purpose has the advantage that the labyrinth seal is non-contact because the piston and the cylinder wall do not come into contact with each other and thus no lubrication is required between the piston and the cylinder wall.

Therefore, it is characterized in that it is possible to solve the disadvantages of heat generation and reduced durability due to friction by enabling operation in a state with almost no friction using a labyrinth-shaped piston. This type of piston has not been used because it is essentially inapplicable to high-pressure gas compression, but the piston structure according to the present invention is modified and applied so that it can be used for high-pressure gas compression by the method described below.

Referring to Figure 3, looking at the labyrinth piston structure according to the present invention, as shown in Figure 3 (a), the labyrinth piston (1) is not in contact with the wall of the cylinder (2) have a structure

It occupies a long installation space in the axial direction, and there is no limit to the range of use where slight leakage is allowed.

It is characterized in that the gradual pressure is reduced by repeating the throttling process in which the cross-sectional area is suddenly reduced through a small gap through the labyrinth piston structure and the pressure drops due to the generation of the vortex (3).

When a labyrinth piston structure is used between the piston 1 and the cylinder 2 with an ionic liquid rather than a gas, there is not much pressure difference in the longitudinal direction of the piston as shown in the pressure distribution shown in FIG. 3 (b), It makes a very subtle difference. Therefore, when this structure is used for high-pressure gas compression, there is an advantage in terms of friction, but the amount of leakage increases.

If the labyrinth-type piston structure is used for high-pressure gas compression using such a minute difference, gas leakage may occur, and a structure to prevent gas leakage is required.

In addition, since the reciprocating motion of the ionic liquid at the top of the piston is limited by the acceleration of gravity, when the ionic liquid is held inside the piston and reciprocating, most of the ionic liquid is trapped in the solid piston and moves, so the power of the liquid The difficulty of geometrical control is mostly alleviated, and the acceleration ability of the upper part can be improved.

The top of the piston is characterized in that it reciprocates with the ionic liquid inside the piston, leaving only a small amount to protect the metal from a permeable gas such as hydrogen.

Referring to FIG. 4, looking at the structure of a compressor using an ionic liquid according to the present invention, FIG. 4 (a) shows a front cross-sectional view of the compressor structure, and FIGS. 4 (b) and 4 (c) show plan views and conceptual views. .

A labyrinth compressor, comprising a cylinder 190, a piston 100 disposed in the cylinder 190, and a piston rod 101, wherein the piston rod 101 extends in the longitudinal direction and the piston ( 100), the piston 100 can reciprocate in the longitudinal direction inside the cylinder 190, and the piston 100 forms a plurality of small holes to accommodate the receiving hole 111 capable of accommodating the ionic liquid. ) is formed, and the ionic liquid inside the piston 100 and the ionic liquid at the top of the piston exchange with each other.

In addition, the piston 100 is basically a labyrinth type with protrusions that do not contact the cylinder 190, and contains an ionic liquid 200 inside, and the ionic liquid 200 on the top of the piston is attacked by metal. It is set to the minimum height (h1) within the limit of not receiving, so that the influence of inertia is minimized during movement. This height h1 is sufficient even when the piston 100 reciprocates when the surface of the piston 100 is not directly exposed to gas, so it is preferable to set it within several mm.

Essentially, since the piston 100 carries the ionic liquid 200 inside and reciprocates, there is room for limiting the operating speed for acceleration. In particular, when the piston 100 moves downward, the size of the receiving hole 111 By making the inertial force of the ionic liquid 200 and the viscous force similar to each other, it is possible to produce an effect similar to that of a solid piston. The size of the receiving hole 111 is preferably 3 mm or less in diameter.

In addition, the ionic liquid 200 at the top of the piston 100 is positioned so as to be spaced apart from one end of the cylinder 190 at a predetermined interval (h2) even at maximum compression, so that the influence during movement is minimized.

In addition, it is preferable to use an ionic liquid of imidazolium based ionic liquids as the ionic liquid in the present invention, but is not limited thereto. It can be selected by considering solubility with a specific gas and lubricity with metal. The amount of ionic liquid contained inside the piston 100 can be controlled by the inner metal part 150 of the piston 100, and this inner metal part 150 controls the dynamic mass of the piston 100. is also used to

That is, it is possible to reduce the amount of the ionic liquid included in the piston and set the weight of the piston through the inner metal part 150 .

As shown in FIG. 4(b), a plurality of small holes are formed in the piston 100 to form an accommodating hole 111 capable of accommodating the ionic liquid, and the accommodating hole 111 is It is preferable to have a size of 0.1 to 3 mm in diameter so that the difference between the force due to inertia and the force due to viscosity during reciprocating motion is minimized.

In addition, as shown in FIG. 4(c), it shows that the ionic liquid is provided in a state in which the piston 100 including the accommodating hole 111 is submerged to a certain height h1.

The ionic liquid covering the top of the piston preferably has a thickness of 0.1 to 5 mm to prevent gas contact during reciprocating motion.

In addition, in the labyrinth piston of the present invention, as the gas compression chamber is compressed, the high-pressure gas to the side may leak finely and come down in some sections.

At this time, according to the labyrinth principle, a pressure drop distribution appears due to a slight vortex, and a discharge hole 120 through which the ionic liquid contained inside the piston can pass is formed at the middle and lower end of the piston, so that the gas at the top passes The pressure may be transferred to the wall of the cylinder 190 as it is through the ionic liquid. The discharge hole 120 is preferably formed in a slit shape.

Therefore, the airtight state can be maintained without leakage during the rising time of the piston 100 due to the minute pressure reduction by the labyrinth and the action of the high pressure applied to the cylinder wall of the ionic liquid.

In addition, the possibility of gas leakage can be blocked by using the equilibrium according to the pressure distribution, but a part of the ionic liquid discharged through the discharge hole (slit) is essentially present in a small amount continuously descending to the bottom.

Therefore, as in the prior art, it is necessary to continuously separate and resupply the ionic liquid.

However, the amount is very small, and there is an advantage that it can be used with small additional equipment.

For example, an ionic liquid suction part (not shown) may be provided at the upper end of the cylinder head, and the ionic liquid sucked from the suction part may join the ionic liquid accommodating part accommodated inside the piston. This has a structure similar to the known conventional method, and the suction pipe is branched to the suction valve pipe side at the top of the cylinder to supply the ionic liquid or a separate head part is provided with a supply unit to supply the ionic liquid during the suction stroke. In this case, the installation direction of the cylinder must be in the direction of gravity.

Therefore, since the piston has an ionic liquid inside and moves like a solid case, it is possible to operate at a relatively high speed and the control is very advantageous, unlike the existing method in which the reciprocating motion of only the liquid must be controlled and bound to the acceleration of gravity. .

This has the effect of reducing frictional heat, increasing durability, and reducing the relative amount of ionic liquid used.

So far, specific embodiments of the compressor structure using the ionic liquid according to the present invention have been described, but it is obvious that various modifications are possible within the limits that do not depart from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments and should not be conveyed, and should be defined by not only the claims to be described later, but also those equivalent to these claims.

That is, it should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention is indicated by the claims to be described later rather than the detailed description, and the meaning and scope of the claims and All changes or modified forms derived from the equivalent concept should be construed as being included in the scope of the present invention.

100: labyrinth piston
101: piston rod
110: receiving part
111: receiving hole
120: discharge hole
150: inner metal part
190: cylinder
200: ionic liquid

Claims (5)

In the compressor structure,
cylinder;
a piston and a piston rod disposed within the cylinder;
the piston rod extends in the longitudinal direction and is connected to the piston;
the piston is capable of reciprocating longitudinally within the cylinder;
The piston is formed as a labyrinth piston and has an accommodating portion capable of accommodating the ionic liquid therein, and a plurality of accommodating holes formed by connecting the accommodating portion and an upper end of the piston, wherein the ionic liquid Compressor structure using an ionic liquid, characterized in that a plurality of receiving holes are formed at the upper end of the piston so as to be submerged at a certain height.
The method of claim 1,
A discharge hole through which the ionic liquid contained in the piston can be discharged is formed at the lower middle end of the piston;
Compressor structure using an ionic liquid, characterized in that the pressure transmitted by the gas at the top of the piston through the discharge hole is transmitted to the cylinder wall through the ionic liquid so that the compressed gas can be sealed without leaking.
The method of claim 1,
Compressor structure using an ionic liquid, characterized in that the dynamic characteristics can be adjusted by adjusting the amount of the ionic liquid and the weight of the piston by placing an inner metal part inside the piston.
The method of claim 1,
The receiving hole formed at the top of the piston is a compressor structure using an ionic liquid, characterized in that it has a size such that the difference between the force due to inertia and the force due to viscosity is minimized during the reciprocating motion of the piston.
The method of claim 2,
Compressor structure using an ionic liquid, characterized in that the ionic liquid covers the top of the piston to prevent gas contact during reciprocating motion.

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