An oil mist isolation structure for a liquid-driven compressor

Abstract

The present invention relates to the technical field of clean energy equipment, and specifically to an oil mist isolation structure of a liquid-driven compressor, comprising an oil cylinder and an air cylinder, wherein the oil cylinder and the air cylinder are connected, a piston is arranged in the oil cylinder, the cylinder inhales / exhales air through the movement of the piston, an isolating member is arranged between the oil cylinder and the cylinder, a piston rod is connected to the piston, the other end of the piston rod is located in the air cylinder, and the isolating member blocks the oil film on the piston rod from entering the air cylinder. The purpose is to add an isolating member between the oil cylinder and the cylinder so that the oil film attached to the piston shaft is isolated in the isolating member and cannot directly enter the air cylinder, thereby preventing the oil film on the piston rod from volatilizing due to the high temperature in the air cylinder and causing pollution to the gas in the air cylinder.

Description

Technical Field

[0001] The invention belongs to the technical field of clean energy equipment, and in particular relates to an oil mist isolation structure for a liquid-driven compressor. Background Art

[0002] In the new energy industry, the core equipment of hydrogen refueling stations is the boosting system. At present, many stations still use traditional diaphragm compressors. The emerging hydraulic drive compressors will mature and replace the traditional ones. At present, hydraulic drive compressors basically rely on foreign imports, such as Maximator from Germany; Haskel and Hydro-Pac from the United States, etc. Domestic boosting equipment is still in the research and development exploration stage. It is necessary to absorb and learn from foreign advanced technologies and improve and innovate itself. In addition to ensuring the quality and cleanliness of hydrogen in terms of material application, this problem should also be thoroughly solved in terms of structure.

[0003] As for the technical problem of ensuring the quality and cleanliness of hydrogen, the focus is now generally on the application of materials, but the structural considerations are very lacking. Some equipment is also equipped with a very short oil-gas separator and a nitrogen purge port, which can indeed separate the leaked gas or liquid oil and discharge them separately, but the oil film attached to the piston rod always exists. When the oil-attached piston rod extends into the cylinder, the high temperature of the cylinder will cause the oil film to evaporate and generate oil mist, which will then cause the compressed hydrogen to be more or less contaminated. Summary of the invention

[0004] In order to solve the problem that the oil film attached to the piston rod may pollute the hydrogen, the present invention provides an oil mist isolation structure for a liquid-driven compressor. The oil mist isolation structure adds an isolation piece between the oil cylinder and the air cylinder so that the oil film attached to the piston shaft is isolated in the isolation piece and cannot directly enter the cylinder, thereby preventing the oil film on the piston rod from volatilizing due to the high temperature in the cylinder and polluting the gas in the cylinder.

[0005] The technical solution adopted by the present invention is: an oil mist isolation structure of a liquid-driven compressor, including an oil cylinder and an air cylinder, the oil cylinder and the air cylinder are connected, a piston is arranged in the oil cylinder, the cylinder inhales / exhales air through the movement of the piston, an isolation piece is arranged between the oil cylinder and the cylinder, a piston rod is connected to the piston, the other end of the piston rod is located in the cylinder, and the isolation piece blocks the oil film on the piston rod from entering the cylinder.

[0006] Preferably, the piston rod passes through an isolating member, and a sealing ring 1 and a sealing ring 2 are respectively provided at both ends of the isolating member, and the distance between the sealing ring 1 and the sealing ring 2 is greater than the maximum stroke of the piston.

[0007] Preferably, one end of the cylinder is connected to a circulating gas pipeline, and the connecting port between the circulating gas pipeline and the cylinder is arranged at an end close to the oil cylinder; the circulating gas pipeline is filled with inert positive pressure gas, and the inert positive pressure gas makes the end of the cylinder close to the oil cylinder have a positive pressure; the other end of the cylinder is provided with an air inlet and an air outlet.

[0008] Preferably, the number of the cylinders is two, the two cylinders are symmetrically arranged on both sides of the oil cylinder, and the two cylinders are connected via a circulating gas pipeline; the inert positive pressure gas is nitrogen, and the pressure of the inert positive pressure gas is 0.1-1.0 MPa.

[0009] Preferably, the circulating gas pipeline is connected to the isolation element, a gas circuit is arranged on the isolation element, and the circulating gas pipeline is connected to the cylinder through the gas circuit; the isolation element is an isolation cylinder, the sealing ring 1 is arranged on the isolation element or the cylinder, and the sealing ring 2 is arranged on the isolation element or the oil cylinder.

[0010] Preferably, a gas leakage detector and an oil discharge port are provided on the isolation member, the detection end of the gas leakage detector is arranged inside the isolation member, and the oil discharge port is arranged on the path through which the oil flows.

[0011] Preferably, a piston assembly is arranged on one end of the piston rod arranged in the cylinder, and the piston assembly is arranged separately from the piston rod. The piston assembly includes a piston head, a piston body and a piston tail cover. The piston body and the piston tail cover are provided with guide rings, and the guide rings protrude from the circumferential surface of the piston assembly; a sealing ring is provided on the piston assembly.

[0012] Preferably, a groove is provided on the piston tail cover, and the groove is matched with the end of the piston rod; and the diameter of one end of the piston head is smaller than the diameter of the piston body.

[0013] Preferably, a buffer chamber is provided at the end of the oil cylinder, and the buffer chamber is adapted to the piston; the buffer chamber is connected to the inside of the oil cylinder through an oil circuit.

[0014] Preferably, the position where the oil circuit is connected to the buffer chamber is arranged on a side away from the piston, and a throttle valve group is arranged on the oil circuit; a proximity switch assembly is arranged on the oil cylinder, and the sensing end on the proximity switch assembly is arranged in the buffer chamber.

[0015] The present invention is beneficial in that:

[0016] 1) The present invention provides seals at both ends of the isolation member to block the hydraulic oil and the compressed hydrogen leaking from the cylinder. The distance between the seals at both ends is greater than the distance of the piston stroke in the cylinder. This ensures that the oil film on the piston rod can be completely isolated in the isolation cavity in the isolation member and will not enter the cylinder to pollute the gas in the cylinder, thereby achieving physical isolation.

[0017] 2) The present invention combines physical isolation with gas phase isolation, and fills a positive pressure inert gas on the side of the cylinder close to the oil cylinder, so that a positive pressure is generated at the position where the piston rod contacts the cylinder, thereby preventing hydraulic oil mist from entering the cylinder and completely isolating the hydraulic oil and oil mist from entering the cylinder to contaminate the compressed hydrogen;

[0018] 3) The present invention provides a circulating gas pipeline so that when the device is reciprocating, the positive pressure inert gas can be filled in the two cylinders through the circulating gas pipeline and the pressure is always kept constant, thereby preventing a small amount of volatile oil mist in the isolation chambers at both ends from entering the cylinders;

[0019] 4) The piston assembly of the present invention is supported by the guide ring and is coaxial with the cylinder. The piston assembly and the piston rod are separately arranged, which can solve the problem of the piston rod and the piston assembly not being coaxial when processing a long piston rod. Separating the piston assembly from the piston rod also facilitates the replacement and maintenance of the piston assembly without the need for overall replacement, thereby reducing costs.

[0020] 5) The present invention sets a buffer chamber in the oil cylinder to match with the piston. When the piston moves, the squeezed hydraulic oil can only pass through the gap of the annular oil chamber after matching, which increases the oil discharge resistance and achieves the purpose of buffering; an oil circuit is opened in the buffer chamber so that the oil circuit is connected with the inside of the oil cylinder. By controlling the throttle valve group on the oil circuit, the flow area of ​​the hydraulic oil can be better controlled and the flow rate can be adjusted, thereby better assisting in adjusting the piston buffer speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention;

[0022] Figure 2 It is a partial enlarged view of the cylinder end;

[0023] Figure 3 This is a partial enlarged view of the cylinder piston.

[0024] In the figure: 1-oil cylinder; 2-piston rod; 3-isolator; 4-cylinder; 5-circulating gas pipeline; 6-gas circuit; 7-flange; 8-cylinder flange; 9-end flange; 10-gas outlet; 11-gas inlet; 12-piston assembly; 13-piston; 14-proximity switch assembly; 15-sensing end; 16-buffer chamber; 17-throttle valve group; 18-oil circuit; 19-buffer section; 20-sealing ring 1; 21-sealing ring 2; 22-contact section; 24-gas leak detector; 25-oil unloading port; 26-piston head; 27-piston body; 28-piston tail cover; 29-guide ring; 30-sealing ring; 31-groove. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] The present invention takes hydrogen filling as an example, and the structure of the present invention is suitable for use in a hydrogen filling machine for filling high-pressure hydrogen.

[0027] Embodiment 1

[0028] like Figure 1 As shown, a liquid-driven compressor oil mist isolation structure includes an oil cylinder 1 and a cylinder 4, wherein the oil cylinder 1 and the cylinder 4 are connected, a piston 13 is arranged in the oil cylinder 1, and the cylinder 4 inhales / exhales air through the movement of the piston 13. The two ends of the oil cylinder 1 are respectively connected to an oil inlet and an oil outlet, and the piston 13 is pushed to move left and right in the oil cylinder 1 by hydraulic oil, so that the cylinder inhales air and then exhausts air, and is filled with high-pressure hydrogen.

[0029] An isolating member 3 is arranged between the oil cylinder 1 and the air cylinder 4, and a piston rod 2 is connected to the piston 13. The isolating member 3 can block the oil film on the piston rod 2 connected to the piston 13 in the oil cylinder to prevent the oil film from entering the air cylinder 4 and volatilizing to pollute the gas in the air cylinder. The piston rod 2 passes through the isolating member 3, and the piston assembly 12 on the other end of the piston rod 2 is located in the air cylinder 4; a sealing ring 20 and a sealing ring 21 are respectively arranged at both ends of the isolating member 3, and a distance between the sealing ring 1 20 and the sealing ring 21 is greater than the maximum stroke of the piston 13, thereby ensuring that the portion of the piston rod 2 located in the oil cylinder 1 cannot enter the air cylinder 4, but enters the isolating member 3 to achieve isolation, thereby achieving the purpose of physical isolation.

[0030] The isolating member 3 is an isolating cylinder, the sealing ring 1 20 is arranged on the isolating member 3 or the cylinder 4, and the sealing ring 21 is arranged on the isolating member 3 or the oil cylinder 1. In the present invention, the isolating member 3 is connected to the oil cylinder 1 through the flange 7, and the flange 7 can also be arranged integrally with the oil cylinder 1 or the cylinder 4, and the sealing ring 1 20 and the sealing ring 2 21 ensure the sealing of the two ends of the isolating member 3.

[0031] The specific working mode of this embodiment is that the piston 13 in the oil cylinder 1 reciprocates left and right, thereby driving the piston assembly 12 in the cylinder 4 to reciprocate left and right, and realizing the process of inhaling and then exhausting high-pressure hydrogen. Figure 2 As shown, an air inlet 11 and an air outlet 10 are provided on the cylinder flange 8 at the end of the cylinder 4. When the piston 13 moves to the right, the cylinder 4 inhales high-pressure hydrogen through the air inlet 11. When the piston 13 moves to the left, the cylinder 4 discharges the high-pressure hydrogen through the air outlet 10. Check valves are provided at the air inlet 11 and the air outlet 10 to ensure air intake and exhaust.

[0032] Embodiment 2

[0033] The difference from the above embodiment is that in this embodiment, a circulating gas pipeline 5 is connected to one end of the cylinder 4, and the connecting port between the circulating gas pipeline 5 and the cylinder 4 is set at the end close to the oil cylinder 1. Since the piston assembly 12 is in close contact with the inner wall of the cylinder 4, the piston assembly 12 divides the inside of the cylinder 4 into two left and right cavities; the circulating gas pipeline 5 is filled with inert positive pressure gas, and the inert positive pressure gas makes the end of the cylinder 4 close to the oil cylinder 1 have positive pressure; the cavity close to the oil cylinder 1 is filled with positive pressure gas, which can prevent the oil mist in the isolation member 3 from entering the cylinder 4, forming gas phase isolation. The inert positive pressure gas is filled in through the circulating gas pipeline 5, that is, the circulating gas pipeline 5 is provided with a charging port connected to the outside, so as to ensure the charging of the inert gas.

[0034] In this embodiment, the inert positive pressure gas is preferably nitrogen, and the pressure of the inert positive pressure gas is 0.1-1.0 MPa.

[0035] like Figure 1 As shown, the circulating gas pipeline 5 is connected to the isolation member 3 , a gas circuit 6 is arranged on the isolation member 3 , and the circulating gas pipeline 5 is connected to the cylinder 4 through the gas circuit 6 .

[0036] Embodiment 3

[0037] The difference from the above embodiment is that the number of cylinders 4 is two, the two cylinders 4 are symmetrically arranged on both sides of the oil cylinder 1 , and the two cylinders 4 are connected via a circulating gas pipeline 5 .

[0038] When working, the left and right cylinders 4 (corresponding to Figure 1 The air outlets 10 of the left and right cylinders 4 are connected to the same air outlet pipe, thereby ensuring that the air can be continuously discharged from the air outlet pipe when the piston 13 moves. Figure 1 As shown, the specific working method is that when the piston 13 moves to the left, nitrogen is filled into the left cylinder 4, so that a positive pressure is generated in the left cylinder. At this time, the left cylinder 4 discharges air and the right cylinder 4 inhales air; when the piston 13 moves to the right, nitrogen is filled into the right cylinder 4, so that a positive pressure is generated in the right cylinder. At this time, the right cylinder 4 discharges air and the left cylinder 4 inhales air, and this is repeated to form a cycle, thereby preventing oil and oil mist from entering the cylinder 4.

[0039] An inflation port is provided on the circulating gas pipeline 5, through which inert gas can be filled into the cylinder 4. A pressure sensor or pressure gauge can also be provided at the position of the inflation port. When the pressure increases, it indicates that the piston seal in the cylinder 4 may fail, resulting in leakage of high-pressure hydrogen; when the pressure decreases, it indicates that the seal between the cylinder 4 and the isolation member 3 fails, resulting in leakage of nitrogen.

[0040] Embodiment 4

[0041] The difference from the above embodiment is that a gas leakage detector 24 and an oil discharge port 25 are provided on the isolation member 3, the detection end of the gas leakage detector 24 is provided inside the isolation member 3, and the oil discharge port 25 is provided on the path through which the oil flows.

[0042] In this embodiment, the gas leakage detector 24 is preferably arranged above the isolation member 3. If the front seal (cylinder 4 side) fails, the gas leaking in the isolation chamber will be monitored in real time through sensor communication. The oil discharge port 25 is arranged below the isolation member 3. If the rear seal (cylinder 1 side) fails, the hydraulic oil will leak through the oil discharge port and be observed by the user. The arrangement of the gas leakage detector 24 and the oil discharge port 25 can help the user to find problems in time and quickly repair them.

[0043] Embodiment 5

[0044] This embodiment may include the above-mentioned embodiments 1 to 4, and an implementation method better than the above-mentioned embodiments 1 to 4 is as follows: Figure 2 As shown, the piston assembly 12 is separately arranged from the piston rod 2, and the piston assembly 12 includes a piston head 26, a piston body 27 and a piston tail cover 28. The piston body 27 and the piston tail cover 28 are provided with guide rings 29, and two guide rings 29 are provided to provide support for the piston assembly 12 and remain coaxial with the cylinder 4. The guide rings 29 protrude from the circumferential surface of the piston assembly 12; the piston assembly 12 is provided with a sealing ring 30.

[0045] An end flange 9 is provided at the end of the cylinder 4, and the end flange 9 is connected to the cylinder flange 8. When the piston assembly 12 is installed, the end flange is opened and the assembly and disassembly can be performed directly.

[0046] The piston tail cover 28 is provided with a groove 31, which is adapted to the end of the piston rod 2 to provide a guide for the movement of the piston rod 2; the diameter of one end of the piston head 26 is smaller than the diameter of the piston body 27, so that the piston head 26 will not hinder the movement of the piston assembly 12.

[0047] When the one-way valve at the air inlet 11 is opened, pressurized hydrogen is sucked into the front end of the cylinder 4. At this time, the piston assembly 12 is subjected to an axial thrust in the cylinder 4, forcing it to fit closely to the end of the piston rod 2 and then move backward synchronously. When moving in the opposite direction, the one-way valve at the air inlet 11 is closed, and the one-way valve at the air outlet 10 is opened. The piston rod 2 applies a reverse axial thrust, pushing the piston assembly 12 to discharge the compressed hydrogen in the gas compression chamber, thereby realizing a reciprocating stroke motion.

[0048] In this embodiment, it is preferred that the pressure at the air inlet 11 is greater than 1.5 MPa, so as to force it to closely adhere to the end of the piston rod 2 and move backward synchronously, thereby ensuring that no noise will occur when the piston rod 2 impacts the piston assembly during operation.

[0049] Embodiment Six

[0050] This embodiment may include the above-mentioned Embodiments One to Five. The preferred implementation mode compared with the above-mentioned Embodiments One to Five is as follows. Figure 3 As shown, a buffer cavity 16 is provided at the end inside the oil cylinder 1, that is, a buffer cavity 16 is provided on the flange 7 connected to the oil cylinder 1. The buffer cavity 16 is adapted to the piston 13. The piston 13 is arranged in a structure with a larger middle part and smaller ends, that is, the diameter at the middle of the piston 13 is equivalent to the inner diameter of the oil cylinder 1, and the diameters at both ends of the piston 13 are smaller than the diameter at the middle of the piston 13. A buffer section 19 is formed at the two sections with smaller diameters at both ends of the piston 13, and the buffer section 19 is adapted to the buffer cavity 16; when the distance between the buffer section 19 and the buffer cavity 16 gets closer and closer, the buffer section 19 enters the buffer cavity 16. At this time, the hydraulic oil is squeezed, and the squeezed hydraulic oil can only pass through the clearance after fitting (the clearance between the buffer section 19 and the buffer cavity 16), thereby increasing the oil discharge resistance and achieving the purpose of buffering.

[0051] A further technical solution is that the buffer cavity 16 is communicated with the inside of the oil cylinder 1 through an oil passage 18. The position where the oil passage 18 is communicated with the buffer cavity 16 is arranged on the side far from the piston 13, and a throttle valve group 17 is arranged on the oil passage 18; the throttle valve group 17 is convenient for controlling the flow area of the hydraulic oil, thereby adjusting the flow rate and better assisting in adjusting the buffering speed of the piston 13.

[0052] A further technical solution is that a proximity switch assembly 14 is arranged on the oil cylinder 1, and the sensing end 15 on the proximity switch assembly 14 is arranged in the buffer cavity 16. Adjust the position of the sensing area of the proximity switch assembly 14 to facilitate the commutation action after the stroke of the oil cylinder piston 13 reaches the position.

[0053] When the right cavity of the oil cylinder 1 starts to be filled with oil and pushes the oil cylinder piston 13 to move leftward at a speed V, the hydraulic oil in the left cavity of the oil cylinder 1 is discharged into the oil cylinder 1 through the oil passage 18 on the flange 7. When the cylindrical buffer section 19 is inserted into the buffer cavity 16, the flow area of the hydraulic oil passing through the annular oil cavity clearance decreases, the resistance increases, and the speed of the oil cylinder piston 13 decreases to V1. At this time, V1 < V, realizing buffering.

[0054] After throttling, the cylinder piston 13 continues to move leftward at a low speed. When the piston 13 approaches the head sensing area of ​​the proximity switch assembly 14, that is, the contact section 22 on the piston approaches the proximity switch assembly 14, a signal is given, and a reversing signal is given. At this time, the distance between the piston 13 and the flange 7 is 3 to 4 mm; the diameter of the contact section 22 is smaller than the diameter of the buffer section 19, but due to inertia, the cylinder piston 13 will inevitably continue to decelerate and move forward for a distance. Therefore, when the proximity switch assembly 14 sends a signal, an inertial buffer distance of about 100% is left between the piston 13 and the flange 7, which can ensure the action of the piston 13 and also ensure that the flange 7 will not be damaged due to long-term work.

[0055] The buffering effect can be observed and judged, and the throttle valve group 17 can be manually controlled to adjust the throttling area to match the optimal opening and closing degree, so as to achieve the purpose of stable buffering.

[0056] The above embodiments are preferred embodiments. It should be noted that the above preferred embodiments should not be regarded as limiting the invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An oil mist isolation structure for a liquid-driven compressor, comprising an oil cylinder (1) and an air cylinder (4), wherein the oil cylinder (1) and the air cylinder (4) are connected, a piston (13) is arranged in the oil cylinder (1), and the air cylinder (4) inhales / exhales air through the movement of the piston (13), characterized in that: An isolating member (3) is arranged between the oil cylinder (1) and the air cylinder (4); the piston (13) is connected to a piston rod (2); the other end of the piston rod (2) is located in the air cylinder (4); and the isolating member (3) blocks the oil film on the piston rod (2) from entering the air cylinder (4); The piston rod (2) passes through the isolation member (3), and a sealing ring 1 (20) and a sealing ring 2 (21) are respectively provided at two ends of the isolation member (3), and the distance between the sealing ring 1 (20) and the sealing ring 2 (21) is greater than the maximum stroke of the piston (13); One end of the cylinder (4) is connected to a circulating gas pipeline (5), and a communication port between the circulating gas pipeline (5) and the cylinder (4) is arranged at an end close to the oil cylinder (1); the circulating gas pipeline (5) is filled with an inert positive pressure gas, and the inert positive pressure gas causes a positive pressure to be present in the cylinder (4) at the end close to the oil cylinder (1); an air inlet (11) and an air outlet (10) are arranged at the other end of the cylinder (4); The cylinders (4) are provided in two numbers, the two cylinders (4) are symmetrically arranged on both sides of the oil cylinder (1), and the two cylinders (4) are connected via a circulating gas pipeline (5); the inert positive pressure gas is nitrogen, and the pressure of the inert positive pressure gas is 0.1 to 1.0 MPa; A piston assembly (12) is arranged on one end of the piston rod (2) arranged in the cylinder (4); the piston assembly (12) is arranged separately from the piston rod (2); the piston assembly (12) comprises a piston head (26), a piston body (27) and a piston tail cover (28); the piston body (27) and the piston tail cover (28) are provided with a guide ring (29), and the guide ring (29) protrudes from the circumferential surface of the piston assembly (12); and a sealing ring (30) is provided on the piston assembly (12); The piston tail cover (28) is provided with a groove (31), and the groove (31) is adapted to fit the end of the piston rod (2); the diameter of one end of the piston head (26) is smaller than the diameter of the piston body (27); A buffer chamber (16) is provided at the end of the oil cylinder (1), and the buffer chamber (16) is adapted to the piston (13); the buffer chamber (16) is connected to the interior of the oil cylinder (1) via an oil passage (18).

2. The oil mist isolation structure of a liquid-driven compressor according to claim 1, characterized in that: The circulating gas pipeline (5) is connected to the isolation member (3), a gas path (6) is arranged on the isolation member (3), and the circulating gas pipeline (5) is connected to the cylinder (4) through the gas path (6); the isolation member (3) is an isolation cylinder, the sealing ring 1 (20) is arranged on the isolation member (3) or the cylinder (4), and the sealing ring 2 (21) is arranged on the isolation member (3) or the oil cylinder (1).

3. The oil mist isolation structure of a liquid-driven compressor according to claim 2, characterized in that: A gas leakage detector (24) and an oil discharge port (25) are arranged on the isolation member (3); a detection end of the gas leakage detector (24) is arranged inside the isolation member (3); and the oil discharge port (25) is arranged on a path through which oil flows.

4. The oil mist isolation structure of a liquid-driven compressor according to claim 1, characterized in that: The position where the oil circuit (18) communicates with the buffer chamber (16) is arranged on a side away from the piston (13), and a throttle valve group (17) is arranged on the oil circuit (18); a proximity switch assembly (14) is arranged on the oil cylinder (1), and a sensing end (15) on the proximity switch assembly (14) is arranged in the buffer chamber (16).

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