Sealing structure of plunger type ultrahigh-pressure hydrogen compressor

Abstract

The invention provides a plunger type ultrahigh-pressure hydrogen compressor sealing structure and aims to solve the problem that in the prior art, a piston ring is arranged for sealing, abrasion is prone to occurring, and then sealing failure is caused. The sealing device mainly comprises a cylinder body, a plunger and a plurality of sealing units. According to the sealing main body, a sealing unit is formed by the universal seal lip-shaped sealing rings and the spacer rings, each spacer ring is provided with the pressure release valve and the throttling hole, when the pressure difference of the two sides of the sealing rings is larger than a set value, the pressure release valves are opened, and the follow-up sealing rings jointly bear sealing pressure. When all the pressure release valves are opened, gas flow is established, the throttling holes with different hole diameters in the spacer ring generate a pressure division effect, and the throttling holes are matched with the pressure release valves to complete gas pressure division together. According to the scheme of the sealing structure, the front-back pressure difference of the single-stage sealing ring is limited, the stress condition of the sealing ring is improved, the abrasion speed of the sealing ring can be effectively reduced, and therefore the service life of the sealing ring is prolonged.

Description

Technical Field

[0001] This invention relates to the field of hydrogen compressor sealing technology, and in particular to a plunger-type ultra-high pressure hydrogen compressor sealing structure. Background Technology

[0002] Ultra-high pressure hydrogen compressors typically employ piston seals, relying primarily on piston rings mounted on the outer cylindrical surface of the piston body to seal the high-pressure gas. While this sealing structure is simple, it has a significant drawback: the piston rings are prone to wear, leading to seal failure and requiring timely replacement. This problem not only results in frequent, difficult, and costly maintenance but also makes it difficult to ensure long-term, continuous, and stable operation of the equipment.

[0003] Therefore, there is an urgent need for a sealing structure that addresses the pain points of this technology. Summary of the Invention

[0004] This application addresses the shortcomings of the prior art by providing a plunger-type ultra-high pressure hydrogen compressor sealing structure. Through multi-stage sealing units connected in series, combined with the synergistic effect of a pressure relief valve and a throttling orifice, the pressure difference of a single-stage sealing ring is effectively limited, significantly reducing wear rate, extending seal life, and decreasing maintenance frequency. Simultaneously, the sealing rings are positioned on the cylinder block for easy heat dissipation, further improving sealing reliability and service life.

[0005] The technical solution adopted in this invention is as follows: A piston-type ultra-high pressure hydrogen compressor sealing structure includes a cylinder body and a piston that is slidably disposed inside the cylinder body. The inner cavity of the cylinder body is divided into a front sealing shaft section and a rear sliding inner cavity section. The diameter of the sealing shaft section is larger than that of the sliding inner cavity, and a sealing assembly is provided inside the sealing shaft section; The sealing assembly includes a plurality of sealing units arranged sequentially along the axial direction of the plunger; Each of the sealing units includes: a spacer ring and a sealing ring disposed between adjacent spacer rings; the spacer ring is provided with a pressure relief valve and a throttling orifice; The pressure relief valve on each sealing unit is configured to open when the pressure difference across the sealing ring exceeds a preset value, allowing gas to flow from the high-pressure side to the low-pressure side; the throttling orifice is configured to generate a pressure drop during gas flow. The sealing units are connected in series, and through the linkage of the pressure relief valve and the throttling orifice, a stepped pressure distribution is formed between adjacent sealing units, so that the pressure difference borne by each lip sealing ring is limited to a preset range.

[0006] Furthermore, the spacer ring has an L-shaped cross-section, and a first sealing cavity is formed at the end of the spacer ring near the outer wall of the plunger, while a second sealing cavity is formed at the end of the spacer ring near the inner wall of the cylinder. The sealing ring is provided in the first sealing cavity, and the O-ring is provided in the second sealing cavity; An airflow channel is formed on the spacer ring along its end near the plunger, from the inside of its body to the next spacer ring and the current sealing ring.

[0007] Furthermore, each of the pressure relief valves includes a pre-compressed spring and a sealing ball abutting against one end of the spring, and the pressure relief valve adjusts the opening pressure of its body by adjusting the spring stiffness and the amount of pre-compression.

[0008] Furthermore, the number of sealing units is set to three.

[0009] Furthermore, the orifices on the three sealing units have different diameters, with the orifice diameters configured from large to small from the front to the rear of the plunger.

[0010] Furthermore, the sealing ring is a Pan-Sai seal lip ring.

[0011] Furthermore, the plunger is a polished smooth ceramic plunger or a metal plunger.

[0012] The advantages of this invention over the prior art are as follows: The sealing body of this invention adopts a lip seal based on the Pan-Syss seal. The plunger is a polished smooth ceramic or metal plunger. The Pan-Syss seal lip seal and the spacer ring form a sealing unit, which contacts the smooth plunger surface to form a seal. Each spacer ring is equipped with a pressure relief valve and a throttling orifice. When the pressure difference across the sealing ring exceeds a set value, the pressure relief valve opens, and the subsequent sealing rings share the sealing pressure. When all pressure relief valves are open, gas flow is established, and the throttling orifices of different diameters on the spacer rings create a pressure-dividing effect, working in conjunction with the pressure relief valves to complete the gas pressure division. Simultaneously, the Pan-Syss seal's placement on the cylinder block facilitates heat dissipation measures, reducing the operating temperature of the sealing ring. The sealing structure provided by this invention limits the pressure difference across a single-stage sealing ring, improving the stress and heat dissipation conditions of the sealing ring. Therefore, it effectively reduces the wear rate of the sealing ring, thereby extending the seal's service life and reducing maintenance frequency. By connecting multiple sealing units in series, higher gas sealing pressure can be provided. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the internal structure of the present invention based on a three-stage sealing unit; Figure 2 This is a partially enlarged view of the sealing unit in this invention.

[0014] The components are: 1. Cylinder block; 2. Piston; 3. Sealing unit; 31. Spacer ring; 32. Sealing ring; 33. Pressure relief valve; 331. Spring; 332. Sealing ball; 34. Throttling orifice; 35. First sealing cavity; 36. Second sealing cavity; 37. O-ring seal; 38. Airflow channel. Detailed Implementation

[0015] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0016] This invention provides a sealing structure for a plunger-type ultra-high pressure hydrogen compressor, aiming to solve the problem that the existing technology, which uses piston rings for sealing, is prone to wear and thus leads to seal failure.

[0017] like Figure 1 and Figure 2 As shown, in a preferred embodiment, the main structure of the present invention includes a cylinder body 1 and a plunger 2 slidably disposed within the cylinder body 1. The inner cavity of the cylinder body 1 is divided into a front sealing shaft diameter section and a rear sliding inner cavity section. The diameter of the sealing shaft diameter section is larger than that of the sliding inner cavity section, and a sealing assembly is provided therein. The sealing assembly includes a plurality of sealing units 3 arranged sequentially along the axial direction of the plunger 2.

[0018] In one embodiment of the present invention, each sealing unit 3 includes a spacer ring 31 and a sealing ring 32. The spacer ring 31 is provided with a pressure relief valve 33 and a throttling orifice 34. The pressure relief valve 33 opens when the pressure difference across the sealing ring 32 exceeds a set value, allowing gas to flow from the high-pressure side to the low-pressure side; the throttling orifice 34 generates a pressure drop during gas flow. Multiple sealing units 3 are arranged in series, and through the linkage of the pressure relief valve 33 and the throttling orifice 34, a stepped pressure distribution is formed between each stage of the sealing unit 3, thereby controlling the pressure difference borne by a single sealing ring 32 within a preset range.

[0019] In one embodiment of the present invention, the spacer ring 31 has an L-shaped cross-section, with a first sealing cavity 35 at the end near the plunger 2 for installing a sealing ring 32, and a second sealing cavity 36 at the end near the inner wall of the cylinder 1 for installing an O-ring seal 37. Simultaneously, the spacer ring 31 has an airflow channel 38 inside for guiding gas flow between the spacer rings 31.

[0020] In one embodiment of the present invention, the pressure relief valve 33 includes a pre-compressed spring 331 and a sealing ball 332, and its opening pressure can be set by adjusting the stiffness of the spring 331 and the amount of pre-compression.

[0021] Preferably, there are three sealing units 3, and the diameter of their throttling orifices 34 decreases sequentially from the front to the rear of the plunger 2 to create a step-by-step pressure reduction effect.

[0022] In one embodiment of the present invention, the sealing ring 32 is preferably a Pan-Sai seal lip ring, and the plunger 2 is a polished smooth ceramic plunger or a metal plunger.

[0023] Working principle of the invention: During the gas compression process, as the plunger 2 compresses the gas in the cavity, the gas pressure increases. First, the first pressure relief valve 33 opens, increasing the pressure in the cavity between the first and second sealing rings 32. This, in turn, opens subsequent pressure relief valves 33, creating a stepped pressure between the sealing rings 32. Secondly, as gas flow is established, a flow pressure difference is generated through the designed throttling orifices 34 of different diameters. This, in conjunction with the pressure relief valves 33, again creates a stepped pressure, allowing a single sealing ring 32 to withstand a limited pressure difference. Furthermore, the superposition of multiple seals can seal higher gas pressures. This invention, by employing the above technical solution, limits the pressure difference across the sealing ring 32, improving the stress and heat dissipation conditions of the sealing ring 32. Therefore, it effectively reduces the wear rate of the sealing ring 32, thereby extending the seal's service life and reducing maintenance frequency. By connecting multiple sealing units 3 in series, even higher gas sealing pressures can be provided.

[0024] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A sealing structure for a plunger-type ultra-high pressure hydrogen compressor, characterized in that: Includes a cylinder body (1) and a plunger (2) that is slidably disposed inside the cylinder body (1). The inner cavity of the cylinder body (1) is divided into a front sealing shaft section and a rear sliding inner cavity section. The diameter of the sealing shaft section is larger than that of the sliding inner cavity, and a sealing assembly is provided inside the sealing shaft section; The sealing assembly includes a plurality of sealing units (3) arranged sequentially along the axial direction of the plunger (2); Each of the sealing units (3) includes: a spacer ring (31) and a sealing ring (32) disposed between adjacent spacer rings (31); the spacer ring (31) is provided with a pressure relief valve (33) and a throttle orifice (34). The pressure relief valve (33) on each sealing unit (3) is configured to open when the pressure difference across the sealing ring (32) exceeds a preset value, allowing gas to flow from the high-pressure side to the low-pressure side; the throttle orifice (34) is configured to generate a pressure drop when the gas flows. Among them, multiple sealing units (3) are connected in series. Through the linkage of the pressure relief valve (33) and the throttle orifice (34), a stepped pressure distribution is formed between adjacent sealing units (3), so that the pressure difference borne by each sealing ring (32) is limited to a preset range.

2. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 1, characterized in that: The spacer ring (31) has an L-shaped cross section. A first sealing cavity (35) is formed at one end of the spacer ring (31) near the outer wall of the plunger (2), and a second sealing cavity (36) is formed at one end of the spacer ring (31) near the inner wall of the cylinder (1). The sealing ring (32) is provided in the first sealing cavity (35), and the O-ring (37) is provided in the second sealing cavity (36). An airflow channel (38) is formed on the spacer ring (31) along its end near the plunger (2) from the inside of its body to the next spacer ring (31) and the current sealing ring (32).

3. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 1, characterized in that: Each of the pressure relief valves (33) includes a pre-compressed spring (331) and a sealing ball (332) abutting against one end of the spring (331). The pressure relief valve (33) adjusts the opening pressure of its body by adjusting the stiffness of the spring (331) and the amount of pre-compression.

4. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 1, characterized in that: The number of sealing units (3) is set to three.

5. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 4, characterized in that: The orifices (34) on the three sealing units (3) have different diameters, and the orifices (34) from the front to the rear of the plunger (2) are configured to decrease in diameter.

6. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 1, characterized in that: The sealing ring (32) is a Pan-Sai seal lip ring.

7. The sealing structure of a plunger-type ultra-high pressure hydrogen compressor as described in claim 1, characterized in that: The plunger (2) is a polished smooth ceramic plunger or a metal plunger.

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