Piston liquid seal structure and liquid-driven piston compressor for hydrogen energy

Abstract

The present invention provides a piston liquid seal structure and a liquid-driven piston compressor for hydrogen energy, which relates to the technical field of compressors and solves the technical problems of severe wear and poor sealing effect of piston seal structures after long-term use. The piston liquid seal structure includes a piston rod and a piston. A comb tooth structure is provided on the outer peripheral wall of the piston, and a closed space is formed between the comb tooth structure and the inner wall of the cylinder body; a liquid inlet channel and a reflux channel are provided in the piston rod, and the liquid inlet channel and the reflux channel are both connected to the closed space. A high-pressure and high-viscosity liquid flows in the liquid inlet channel, and the comb tooth structure is used to reduce the pressure of the liquid and then flow into the reflux channel. The piston liquid seal structure uses high-viscosity liquid for sealing, and there is no need to consider the wear problem. The running resistance of the piston is further reduced by the lubrication of the oil, and the sealing effect is good; the comb tooth structure is used to maintain the pressure at the front end and reduce the pressure at the rear end, thereby improving the service life of the piston liquid seal structure.

Description

Technical Field

[0001] The invention relates to the technical field of compressors, and in particular to a piston liquid seal structure and a hydrogen energy liquid-driven piston compressor. Background Art

[0002] A liquid-driven piston compressor refers to a compressor that uses a hydraulic cylinder to directly drive the cylinders on both sides. The reciprocating motion of the hydraulic cylinder causes the pistons in the cylinders on both sides to reciprocate to compress the gas. The working pressure of liquid-driven piston compressors for hydrogen energy is generally very high, about 50MPa or more, and can be as high as 300MPa or more.

[0003] After a long period of operation, some leakage will generally occur between the piston and the inner wall of the cylinder of a hydraulic compressor. Traditional piston compressors generally use metal piston rings for piston sealing, but it is difficult to ensure complete sealing of piston rings, especially for ultra-high pressure and slow-moving pistons. The current hydraulic compressor piston seals mainly use multi-pass lip seals or O-ring seals made of rubber or composite materials. The lip seal relies on pressure to deform the sealing ring to fill the gap between the piston and the inner wall of the cylinder to form a seal.

[0004] The applicant has discovered that the prior art has at least the following technical problems: the sealing structures in the prior art are mostly solid filler seals such as lip seals or O-ring seals, which usually require the piston seal to have a large contact pressure or a large contact area on the cylinder wall to effectively seal the high-pressure gas in the cylinder. The above-mentioned structure of the prior art causes serious wear of the sealing structure, affecting the sealing effect; the resistance to the movement of the piston is also large, and the sealing structure needs to be frequently replaced after running for a period of time, resulting in an increase in the operating cost of the compressor. Summary of the invention

[0005] The purpose of the present invention is to provide a piston liquid seal structure and a hydrogen energy liquid-driven piston compressor to solve the technical problems of the piston seal structure in the prior art that the piston seal structure is severely worn after long-term use and has poor sealing effect. The various technical effects that can be produced by the preferred technical solution among the various technical solutions provided by the present invention are described in detail below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The piston liquid seal structure provided by the present invention comprises a piston rod and a piston, wherein:

[0008] A comb tooth structure is provided on the outer peripheral wall of the piston, and a closed space is formed between the comb tooth structure and the inner wall of the cylinder body;

[0009] A liquid inlet channel and a reflux channel are provided in the piston rod, and both the liquid inlet channel and the reflux channel are connected to the closed space. High-pressure and high-viscosity liquid flows in the liquid inlet channel, and the comb tooth structure is used to reduce the pressure of the liquid and allow it to flow into the reflux channel.

[0010] Preferably, the comb tooth structure comprises sealing teeth, which are annular teeth arranged around the piston, and the sealing teeth are arranged at intervals along the axial direction of the piston.

[0011] Preferably, the teeth of the sealing teeth extend in the radial direction of the piston.

[0012] Preferably, a support ring is provided on the piston, and the support ring is located at opposite ends of the comb tooth structure. The support ring is sealed and cooperated with the inner wall of the cylinder body to enclose the closed space.

[0013] Preferably, the liquid inlet channel comprises a total liquid inlet channel and a branch liquid inlet channel, wherein:

[0014] All the liquid inlet channels are connected to the total liquid inlet channel, and the liquid inlet channels extend into the piston and are connected to the fluid inlet of the comb tooth structure. The fluid inlet of the comb tooth structure is located on the side of the piston facing the compression end face.

[0015] Preferably, the liquid inlet channels extend in the radial direction of the piston, and the liquid inlet channels are arranged at intervals around the axial direction of the piston rod; and the total liquid inlet channel extends in the axial direction of the piston rod.

[0016] Preferably, the reflux channel includes a main reflux channel and a branch reflux channel, wherein:

[0017] All the branch return channels are connected to the total return channel, the branch return channels extend into the piston and are connected to the fluid outlet of the comb tooth structure, and the fluid outlet of the comb tooth structure is located on the side of the piston away from the compression end face.

[0018] Preferably, the branch reflux channels extend in the radial direction of the piston, and the branch reflux channels are arranged at intervals around the axial direction of the piston rod; and the total reflux channel extends in the axial direction of the piston rod.

[0019] Preferably, a first sealing ring is extruded and assembled between the piston rod and the piston, and / or a second sealing ring is extruded and assembled between the piston and the inner wall of the cylinder body.

[0020] The present invention also provides a hydrogen energy liquid-driven piston compressor, comprising the above piston liquid seal structure.

[0021] The piston liquid seal structure and hydrogen energy liquid-driven piston compressor provided by the present invention have the following beneficial effects compared with the prior art: high-pressure and high-viscosity liquid flows into the closed space through the liquid inlet channel, which can effectively seal the piston and the inner wall of the cylinder body to prevent gas leakage; after the high-pressure and high-viscosity liquid passes through the sealing and pressure reduction of the comb tooth structure, it flows out of the piston rod from the reflux channel. The comb tooth structure maintains the high pressure on the fluid inlet side, reduces the pressure flowing into the reflux channel, and prevents the piston liquid seal structure from being subjected to a large pressure and reducing the service life of the piston liquid seal structure. The piston liquid seal structure uses high-viscosity liquid for sealing, and there is no need to consider the wear problem. The running resistance of the piston is further reduced by the lubrication of the oil, and the sealing effect is good; the comb tooth structure is used to maintain the pressure at the front end and reduce the pressure at the rear end, which increases the service life of the piston liquid seal structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the external structure of the piston liquid seal structure;

[0024] Figure 2 It is a schematic diagram of the axial section structure of the piston liquid seal structure;

[0025] Figure 3 yes Figure 2 A partial enlarged view of the middle A;

[0026] Figure 4 It is a schematic diagram of the structure of the piston.

[0027] In the figure, 100, closed space; 1, piston; 10, compression end face; 11, comb tooth structure; 111, sealing tooth; 12, support ring; 2, piston rod; 21, slot; 3, liquid inlet channel; 31, total liquid inlet channel; 32, branch liquid inlet channel; 4, reflux channel; 41, total reflux channel; 42, branch reflux channel. DETAILED DESCRIPTION

[0028] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0030] In the prior art, after a long period of operation, some leakage generally occurs between the piston and the inner wall of the cylinder. Traditional piston compressors generally use metal piston rings for piston sealing, but it is difficult to ensure complete sealing of piston rings, especially for ultra-high pressure and slow moving pistons. The current piston seals of liquid-driven compressors mainly use multi-pass lip seals or O-ring seals made of rubber or composite materials. The lip seal relies on pressure to deform the sealing ring to fill the gap between the piston and the inner wall of the cylinder to form a seal.

[0031] The sealing structures in the prior art are mostly solid filler seals such as lip seals or O-ring seals, which usually require the piston seal to have a large contact pressure or a large contact area on the cylinder wall to effectively seal the high-pressure gas in the cylinder. The above structure of the prior art causes serious wear of the sealing structure, affecting the sealing effect; the resistance to the movement of the piston is also large, and the sealing structure needs to be frequently replaced after running for a period of time, resulting in an increase in the operating cost of the compressor.

[0032] The embodiment of the present invention provides a piston liquid seal structure and a liquid-driven piston compressor for hydrogen energy, which utilizes high-viscosity liquid for sealing, has a good sealing effect, utilizes a comb tooth structure 11 to maintain pressure at the front end and reduce pressure at the rear end, thereby increasing the service life of the piston liquid seal structure.

[0033] Combine the following Figure 1-Figure 4 The technical solution provided by the present invention is described in more detail.

[0034] Embodiment 1:

[0035] like Figure 1-Figure 4 As shown, Figure 2 and Figure 3The arrow direction in the figure indicates the flow direction of the liquid. The piston liquid seal structure provided by the present invention comprises a piston rod 2 and a piston 1, wherein: a comb tooth structure 11 is arranged on the outer peripheral wall of the piston 1, and a closed space 100 is formed between the comb tooth structure 11 and the inner wall of the cylinder body; a liquid inlet channel 3 and a reflux channel 4 are arranged in the piston rod 2, and both the liquid inlet channel 3 and the reflux channel 4 are connected to the closed space 100, and a high-pressure and high-viscosity liquid flows in the liquid inlet channel 3, and the comb tooth structure 11 is used to reduce the pressure of the liquid and flow into the reflux channel 4.

[0036] In the piston liquid seal structure of this embodiment, high-pressure and high-viscosity liquid flows into the closed space 100 through the liquid inlet channel 3, which can effectively seal the piston 1 and the inner wall of the cylinder body to prevent gas leakage; after the high-pressure and high-viscosity liquid is sealed and depressurized by the comb tooth structure 11, it flows out of the piston rod 2 from the reflux channel 4. The comb tooth structure 11 maintains the high pressure on its fluid inlet side, reduces the pressure flowing into the reflux channel 4, and prevents the piston liquid seal structure from being subjected to a large pressure and reducing the service life of the piston liquid seal structure.

[0037] The high-pressure and high-viscosity liquid may be glycerin or the like.

[0038] As an alternative embodiment, see Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 The arrow direction in the figure indicates the flow direction of the liquid. A support ring 12 is provided on the piston 1. The support ring 12 is located at opposite ends of the comb tooth structure 11. The support ring 12 is sealed with the inner wall of the cylinder body to enclose a closed space 100.

[0039] The support ring 12 is in direct contact with the inner wall of the cylinder. Figure 2 and Figure 3 The dotted line in the figure indicates the position of the inner wall of the cylinder body. The support ring 12 fits the inner wall of the cylinder body, so that the comb tooth structure 11 is located in the closed space 100, and the high-pressure and high-viscosity liquid circulates in the closed space 100 to prevent the high-pressure and high-viscosity liquid from mixing with the gas at the compression end face 10 of the piston 1.

[0040] In this embodiment, a high-viscosity liquid is used. Even if a small amount of gas leaks, the gas and the high-viscosity liquid are mixed. Due to the high viscosity of the liquid, it can adhere to the gas to a certain extent, preventing the liquid and gas from fully mixing and making it difficult to separate.

[0041] The piston liquid seal structure, on the one hand, utilizes high-viscosity liquid for sealing and uses liquid as a sealing material. The liquid does not need to consider wear issues. At the same time, the contact area and pressure between the piston 1 and the cylinder wall will be significantly reduced. The running resistance of the piston 1 can be further reduced through the lubrication effect of the oil, and the piston 1 can also dissipate heat to a certain extent.

[0042] If the comb tooth structure 11 is not used, and high-pressure liquid is directly used between the piston 1 and the inner wall of the cylinder body for sealing, the high-pressure liquid is directly set to seal for blocking, which will also cause great pressure on the sealing structure and affect the service life of the sealing structure.

[0043] Therefore, the piston liquid seal structure, on the other hand, uses the comb tooth structure 11 to maintain pressure at the front end and reduce pressure at the rear end, that is, the liquid pressure at the liquid inlet side of the comb tooth structure 11 is higher, which ensures the sealing effect, and reduces the pressure of the liquid flowing into the reflux channel 4, preventing the pressure at the reflux channel 4 from being too high, thereby increasing the service life of the piston liquid seal structure. It should be understood that, see Figure 2 and Figure 3 , Figure 2 and Figure 3 The direction of the arrow in the figure indicates the flow direction of the liquid. The reflux channel 4 is not a position that needs to be sealed, so excessive pressure is not required. Excessive pressure can easily reduce the life of the sealing structure, thereby increasing the service life of the piston liquid seal structure.

[0044] As an alternative embodiment, see Figure 1-Figure 3 As shown, the comb tooth structure 11 includes sealing teeth 111 , which are annular teeth arranged around the piston 1 , and the sealing teeth 111 are arranged at intervals along the axial direction of the piston 1 .

[0045] The sealing teeth 111 are annular teeth, which can reduce the pressure of the high-pressure and high-viscosity liquid from a 360° direction, thereby preventing the high-pressure and high-viscosity liquid from directly flowing into the reflux channel 4 at a relatively high pressure.

[0046] The comb tooth structure 11 can reduce the pressure of high-pressure and high-viscosity liquids, which is mainly achieved by: Figure 2 and Figure 3 As shown, Figure 2 and Figure 3 The direction of the arrow in the figure indicates the flow direction of the liquid. When the high-pressure and high-viscosity liquid flows through the sealing teeth 111 in sequence, since the teeth of the sealing teeth 111 extend along the radial direction of the piston 1, the sealing teeth 111 can collide with the high-pressure and high-viscosity liquid, thereby buffering the high-pressure and high-viscosity liquid and consuming part of the kinetic energy of the high-pressure and high-viscosity liquid, thereby reducing the pressure.

[0047] Assuming that the pressure in the cylinder is 100MPa and a 90MPa liquid is introduced, it is calculated that the pressure on the fluid inlet side of the comb structure 11 can reach 89MPa, and the pressure on the fluid outlet side of the comb structure 11 can be less than 1MPa, effectively achieving the effect of pressure-maintaining sealing.

[0048] The liquid inlet channel 3 and the return channel 4 in this embodiment enable high-viscosity liquid to flow between the piston 1 and the piston rod 2 .

[0049] As an alternative embodiment, see Figure 2 and Figure 3 As shown, the liquid inlet channel 3 includes a total liquid inlet channel 31 and a branch liquid inlet channel 32, wherein: all branch liquid inlet channels 32 are connected to the total liquid inlet channel 31, the branch liquid inlet channels 32 extend into the piston 1, and are connected to the fluid inlet of the comb tooth structure 11, and the fluid inlet of the comb tooth structure 11 is located on the side of the piston 1 facing the compression end face 10.

[0050] The “compression end face 10” refers to the end face of the piston 1 used for compressing gas, see Figure 2 and Figure 3 The end face of the piston 1 that is in direct contact with the gas is shown.

[0051] See also Figure 2 As shown, the high-pressure and high-viscosity liquid flows into the closed space 100 from different directions after being divided by the total liquid inlet channel 31 and the multiple liquid inlet channels 32, and flows through the grate structure 11 from the inlet side of the grate structure 11. The above structure can ensure that the high-pressure and high-viscosity liquid flows into the closed space 100 evenly, and prevents uneven liquid inflow into the closed space 100.

[0052] As an alternative embodiment, see Figure 2 and Figure 3 As shown, the liquid inlet channel 32 extends in the radial direction of the piston 1, and the liquid inlet channels 32 are arranged at intervals around the axial direction of the piston rod 2; the total liquid inlet channel 31 extends in the axial direction of the piston rod 2. The high-pressure and high-viscosity liquid flows into the liquid inlet channel 32 along the total liquid inlet channel 31, which can reduce the liquid retention area, ensure that the high-pressure and high-viscosity liquid flows into the closed space 100 evenly, and prevent the liquid from entering the closed space 100 unevenly.

[0053] As an alternative embodiment, see Figure 2-Figure 4 As shown, the reflux channel 4 includes a total reflux channel 41 and a branch reflux channel 42, wherein: all branch reflux channels 42 are connected to the total reflux channel 41, the branch reflux channels 42 extend into the piston 1, and are connected to the fluid outlet of the comb tooth structure 11, and the fluid outlet of the comb tooth structure 11 is located on the side of the piston 1 away from the compression end face 10.

[0054] See also Figure 2 and Figure 3 As shown, after the buffering and pressure reduction of the comb tooth structure 11, the high-viscosity liquid enters the main reflux channel 41 from multiple sub-reflux channels 42, preventing the high-viscosity liquid from being retained in the closed space 100, thereby ensuring smooth reflux of the high-viscosity liquid in the closed space 100.

[0055] As an alternative embodiment, see Figure 3 and Figure 4As shown, the sub-return channel 42 extends in the radial direction of the piston 1, and the sub-return channels 42 are arranged at intervals around the axial direction of the piston rod 2; the total return channel 41 extends in the axial direction of the piston rod 2. The high-pressure and high-viscosity liquid flows into the total return channel 41 along the sub-return channel 42, which can reduce the retention area of ​​the liquid reflux, ensure that the high-pressure and high-viscosity liquid returns to the reflux channel 4 evenly, and prevent uneven liquid return in the closed space 100.

[0056] To further ensure the sealing effect, as an optional implementation, in this embodiment, a first sealing ring is extruded and assembled between the piston rod 2 and the piston 1, and / or a second sealing ring is extruded and assembled between the piston 1 and the inner wall of the cylinder body.

[0057] That is, the first sealing ring can be extruded and assembled only between the piston rod 2 and the piston 1, or the second sealing ring can be extruded and assembled only between the piston 1 and the inner wall of the cylinder body; or the first sealing ring can be extruded and assembled between the piston rod 2 and the piston 1, and the second sealing ring can be extruded and assembled between the piston 1 and the inner wall of the cylinder body.

[0058] Since the above-mentioned liquid inlet channel 3, reflux channel 4 and comb tooth structure 11 are provided, the inner wall of the cylinder body and the piston 1 are sealed by using high-pressure and high-viscosity liquid. Therefore, the assembly pressure between the first sealing ring and the inner wall of the cylinder body and the assembly pressure between the second sealing ring and the inner wall of the cylinder body will not be too high.

[0059] See also Figure 4 As shown, a groove 21 can be provided on the outer wall of the piston rod 2 for assembling the first sealing ring. Similarly, a groove structure can be provided on the piston 1 for assembling the second sealing ring.

[0060] Embodiment 2:

[0061] The present invention provides a hydrogen energy liquid-driven piston compressor, comprising the above-mentioned piston liquid seal structure.

[0062] The hydrogen energy liquid-driven piston compressor of this embodiment has the above-mentioned piston liquid seal structure, so there is no need to consider the wear problem. The running resistance of the piston 1 is further reduced by the lubrication of the oil, and the sealing effect is good. The comb tooth structure 11 is used to maintain the pressure at the front end and reduce the pressure at the rear end, thereby increasing the service life of the piston liquid seal structure.

[0063] In the description of this specification, specific features, structures or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0065] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A piston liquid seal structure, characterized in that: It comprises a piston rod and a piston, wherein: A comb tooth structure is provided on the outer peripheral wall of the piston, and a closed space is formed between the comb tooth structure and the inner wall of the cylinder body; The piston rod is provided with a liquid inlet channel and a reflux channel, both of which are connected to the closed space, a high-pressure and high-viscosity liquid flows in the liquid inlet channel, and the comb tooth structure is used to reduce the pressure of the liquid and flow into the reflux channel; The comb tooth structure includes sealing teeth, which are annular teeth arranged around the piston, and the sealing teeth are arranged at intervals along the axial direction of the piston; The liquid inlet channel comprises a total liquid inlet channel and a branch liquid inlet channel, wherein: All the liquid inlet channels are connected to the total liquid inlet channel, the liquid inlet channels extend into the piston and are connected to the fluid inlet of the comb tooth structure, and the fluid inlet of the comb tooth structure is located on the side of the piston facing the compression end surface; The reflux channel includes a main reflux channel and a branch reflux channel, wherein: All the branch return channels are connected to the total return channel, and the branch return channels extend into the piston and are connected to the fluid outlet of the comb tooth structure. The fluid outlet of the comb tooth structure is located on the side of the piston away from the compression end face.

2. The piston liquid seal structure according to claim 1, characterized in that: The teeth of the sealing teeth extend in a radial direction of the piston.

3. The piston liquid seal structure according to claim 1, characterized in that: The piston is provided with a support ring, and the support ring is located at two opposite ends of the comb tooth structure. The support ring is sealed and matched with the inner wall of the cylinder body, thereby enclosing the closed space.

4. The piston liquid seal structure according to claim 3, characterized in that: The liquid inlet channels extend in the radial direction of the piston, and are arranged at intervals around the axial direction of the piston rod; the total liquid inlet channel extends in the axial direction of the piston rod.

5. The piston liquid seal structure according to claim 1, characterized in that: The branch reflux channels extend in the radial direction of the piston, and are arranged at intervals around the axial direction of the piston rod; the total reflux channel extends in the axial direction of the piston rod.

6. The piston liquid seal structure according to claim 1, characterized in that: A first sealing ring is extruded and assembled between the piston rod and the piston, and / or a second sealing ring is extruded and assembled between the piston and the inner wall of the cylinder body.

7. A hydrogen-powered liquid-driven piston compressor, characterized in that: It comprises the piston liquid sealing structure described in any one of claims 1-6.

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