A pumpless lubrication sealing system and method for a reciprocating compressor

Abstract

The present application relates to a pumpless lubrication seal and system for a reciprocating compressor, which includes a cylinder, a sliding compression block is sealed and slidably connected inside the cylinder, a driving rod is fixedly connected to the sliding compression block, the driving rod extends out of the cylinder, and a stuffing box for guiding the movement of the driving rod is sleeved on the outside of the driving rod; both ends of the cylinder are fixed with an air inlet valve and an exhaust valve, the cylinder is fixed with a lubrication port for feeding lubricating oil into its inner cavity, the inner cavity of the stuffing box is provided with a pressure oil cavity, and the stuffing box is connected with a lubricating oil tank for feeding lubricating oil into the pressure oil cavity; a lubricating oil main pipe is provided between the lubricating oil tank and the lubricating port to connect them, and the lubricating oil main pipe can only transport lubricating oil to the lubricating port in one direction; the lubricating oil tank is connected with the exhaust valve, and the exhaust valve feeds high-pressure gas into the lubricating oil vent pipe. The present application has the effect of reducing the failure rate of the whole machine.

Description

Technical Field

[0001] The present application relates to the field of reciprocating compressors, and in particular to a pumpless lubrication sealing system and method for a reciprocating compressor. Background Art

[0002] Currently, a reciprocating compressor includes a cylinder having a cavity arranged therein and a device capable of reciprocating motion, the device including a piston and a piston rod, and a drive member configured to move the device in a reciprocating manner.

[0003] Reciprocating compressors rely on an oil pump, usually a plunger pump, to pump lubricating oil to the cylinder and stuffing for lubrication and auxiliary sealing. The reciprocating compressor is provided with a stuffing box sleeved on the outside of the piston rod, and a lubricating oil tank is provided on the seasoning box. The lubricant in the existing lubricating oil tank enters between the piston rod and the stuffing box to lubricate the piston rod.

[0004] With regard to the above-mentioned related technologies, the inventor believes that the existence of a plunger pump unit requires a certain cost, and the plunger pump is provided with a motor for driving the plunger pump. The plunger pump unit as a whole has a certain failure rate, which increases the defect of the failure rate of the compressor as a whole; on the other hand, when the existing compressor is used, if the inner cavity of the cylinder is under negative pressure, the pressure in the inner cavity of the cylinder is less than the external atmospheric pressure, and a small amount of air will enter the inner cavity of the cylinder through the seasoning box. If the gas compressed by the compressor is a flammable gas, air enters the inner cavity of the compressor, which will cause a safety hazard. In order to prevent air from entering the inner cavity of the compressor, a high-pressure nitrogen filling device is installed, which will significantly increase the cost. Summary of the invention

[0005] In order to reduce the failure rate of the entire machine, the present application provides a pumpless lubrication sealing system and method for a reciprocating compressor.

[0006] In a first aspect, the present application provides a pumpless lubrication and sealing system for a reciprocating compressor, which adopts the following technical solution:

[0007] A pumpless lubrication sealing system for a reciprocating compressor comprises a cylinder, wherein a sliding compression block is sealingly and slidingly connected in the cylinder, a driving rod is fixedly connected to the sliding compression block, the driving rod extends out of the cylinder, and can maintain a relative closure between the cylinder cavity and the atmosphere when the driving rod slides, a stuffing box is sleeved on the outer side of the driving rod for guiding the movement of the driving rod, the stuffing box is fixedly connected to the cylinder, a hole on the stuffing box for accommodating the driving rod to pass through is a guide hole, the guide hole is communicated with the cylinder cavity, and the stuffing box and the cylinder are relatively stable; both ends of the cylinder are fixedly provided with an intake valve communicated with its inner cavity, both ends of the cylinder are fixedly provided with an exhaust valve communicated with its inner cavity, a lubrication port for feeding lubricating oil into its inner cavity is fixedly provided on the cylinder, and the lubricating oil sprayed from the lubrication port can enter both ends of the moving direction of the sliding compression block, the inner cavity of the stuffing box is provided with an isolation chamber and a pressure oil chamber communicated with the guide hole, the isolation chamber is located between the pressure oil chamber and the cylinder; the isolation chamber is communicated with the intake pipeline where the intake valve is located;

[0008] After the driving rod is connected to the stuffing box, the isolation chamber and the pressure oil chamber are relatively closed to the outside atmosphere, and the stuffing box is connected to a lubricating oil tank for feeding lubricating oil into the pressure oil chamber;

[0009] A lubricating oil main pipe is provided between the pressure oil chamber and the lubricating port to connect them, and the lubricating oil main pipe can only transport lubricating oil to the lubricating port in one direction;

[0010] The lubricating oil tank is connected with a lubricating oil high-pressure air inlet pipe, and the lubricating oil high-pressure air inlet pipe is connected with an air outlet pipeline where an exhaust valve is located.

[0011] By adopting the above technical solution, when the exhaust valve outputs high-pressure gas, the high-pressure gas enters the lubricating oil tank, and the lubricating oil in the lubricating oil tank is pressed into the pressure oil chamber. The lubricating oil filled in the pressure oil chamber can lubricate the sliding between the driving rod and the stuffing box. The high-pressure gas discharged by the exhaust valve is used as the high-pressure gas source of the lubricating oil tank, and the lubricating oil in the lubricating oil tank is pressed into the pressure oil chamber, avoiding the use of an external pressure gas source or a plunger pump, reducing the overall failure rate of the equipment, realizing pump-free lubrication, and reducing the failure points for the equipment.

[0012] At the same time, since the pressure in the pressure oil chamber of the stuffing box is always greater than the external atmospheric pressure, an isolation chamber is provided between the cylinder and the pressure oil chamber of the stuffing box. The isolation chamber is connected to the air intake, and the pressure inside the isolation chamber is always lower than the pressure in the pressure oil chamber. When the cylinder is under negative pressure, air will not leak into the cylinder.

[0013] At the same time, it ensures that when the pressure in the cylinder cavity is too high, the high-temperature and high-pressure process gas enters the isolation cavity, and no high-temperature and high-pressure process gas leaks from the cylinder into the packing pressure oil cavity to cause oxidation and foaming of the lubricating oil therein; the isolation and sealing of the negative pressure in the cylinder is achieved, and the adaptability of the compressor to different working conditions is expanded; this solution is particularly suitable for the use of low-speed compressors.

[0014] Preferably, a throttle valve and a one-way valve are provided on the lubricating oil main pipe.

[0015] By adopting the above technical solution, the flow rate of lubricating oil entering the cylinder is limited by the throttle valve; the one-way valve ensures the unidirectional movement of the fluid in the lubricating oil main pipe, preventing the gas in the cylinder from entering the lubricating oil main pipe and causing air blockage.

[0016] Preferably, an oil storage groove is provided on the side wall of the sliding compression block, and two sealing rings are fixedly provided on the side wall of the sliding compression block. The two sealing rings are located at both ends of the oil storage groove along the sliding direction of the sliding compression block.

[0017] By adopting the above technical solution, when the lubrication port does not supply lubricating oil to the cylinder cavity and there is relative movement between the sliding compression block and the cylinder, that is, when the compressor starts, the lubricating oil accumulated in the oil storage tank can lubricate the moving sliding compression block.

[0018] Preferably, the lubricating oil tank is provided with an oil replenishing system, the oil replenishing system comprises a high-position oil tank, an oil replenishing pipe is provided between the high-position oil tank and the lubricating oil tank, and the high-position oil tank delivers lubricating oil into the lubricating oil tank through the oil replenishing pipe.

[0019] By adopting the above technical solution, oil is added to the lubricating oil tank through the high-position oil tank, ensuring that there is always lubricating oil in the inner cavity of the lubricating oil tank, which is convenient for long-term use of the compressor.

[0020] Preferably, the high-position oil tank is connected to the atmosphere, and a one-way valve is provided on the oil replenishment pipe;

[0021] The lubricating oil tank is connected to a lubricating oil vent pipe, and the lubricating oil vent pipe is connected to a three-way valve, one valve port of the three-way valve is connected to the atmosphere, and the other valve port of the three-way valve is connected to a lubricating oil high-pressure intake pipe.

[0022] By adopting the above technical scheme, the lubricating oil vent pipe can be connected with the atmosphere through the three-way valve, and the lubricating oil vent pipe and the lubricating oil high-pressure air inlet pipe are closed and isolated; the three-way valve can realize the connection between the lubricating oil vent pipe and the lubricating oil high-pressure air inlet pipe, and the lubricating oil vent pipe and the atmosphere are closed and isolated. When the lubricating oil vent pipe is connected with the atmosphere, the high-pressure oil can be added to the inner cavity of the lubricating oil tank.

[0023] Preferably, a cooling and separation device is provided on the lubricating oil high-pressure intake pipe.

[0024] By adopting the above technical solution, the purity of the gas output to the next process is further improved, the content of water molecules in the gas is reduced, and the gas temperature is lowered, thereby preventing the emulsification and oxidation of the lubricating oil in the lubricating oil tank.

[0025] Preferably, a support ring is fixedly disposed on the outer side of the sliding compression block, and the support ring is provided with two support rings spaced apart along the sliding direction thereof;

[0026] A sealing ring is fixedly arranged on the outer side of the sliding compression block;

[0027] Two sealing rings are fixedly arranged inside the stuffing box and located at both ends of the pressure oil chamber along the sliding direction of the driving rod;

[0028] The stuffing box is connected with a dustproof ring.

[0029] By adopting the above technical solution, the support ring reduces the wear between the sliding compression block and the inner wall of the cylinder, facilitating the sliding of the sliding compression block; the sealing ring ensures a good sealing effect of the pressure oil chamber; and the dustproof ring prevents foreign particles from entering the gap between the stuffing box and the drive rod.

[0030] In a second aspect, the present application provides a pumpless lubrication sealing method for a reciprocating compressor, which adopts the following technical solution:

[0031] A reciprocating compressor lubrication method, comprising a cylinder, wherein a sliding compression block is sealingly and slidingly connected in the cylinder, a driving rod is fixedly connected to the sliding compression block, the driving rod extends out of the cylinder, and when the driving rod slides, it can keep the cylinder cavity and the atmosphere relatively closed; both ends of the cylinder are fixedly provided with an intake valve connected to the inner cavity, both ends of the cylinder are fixedly provided with an exhaust valve connected to the inner cavity, a lubrication port for feeding lubricating oil into the inner cavity is fixedly provided on the cylinder, and the lubrication port is located in the middle area of ​​the length direction of the cylinder;

[0032] The minimum intake pressure Ps of the cylinder is less than the atmospheric pressure P0, taking into account the pressure losses of pipelines and valves at various locations; the pressure Pl of the lubricating oil at the cylinder injection point is less than the exhaust pressure Pd, but greater than the atmospheric pressure P0; e is the midpoint of the cylinder, a and c are the rodless side dead point and the rod side dead point of the sliding compression block movement, respectively. At this time, when the sliding compression block moves to a and c, the movement direction changes; Pl is the lubricating oil pressure at the injection point; the injection point is the point where the lubrication port is located; the sliding compression block of the cylinder cavity along the axial direction of the two sides of the sliding compression block compressing the gas is the compression side, and the side of the cylinder inhaling the gas is the suction side;

[0033] 1. When the compression ratio is relatively large, when the sliding compression block moves from a to e, the pressure on the compression side is less than the exhaust pressure and less than the lubricating oil pressure at the injection point;

[0034] When the sliding compression block moves from a to e, pressure is applied to the lubricating oil in the lubrication port, so that the pressure at the injection point is greater than the pressure on the compression side of the cylinder cavity; when the sliding compression block moves from e to c, pressure is applied to the lubricating oil in the lubrication port, so that the pressure at the injection point is greater than the pressure on the suction side of the cylinder cavity, and the lubricating oil can be sprayed out at the injection point;

[0035] 2. When the compression ratio is small, when the sliding compression block moves from a to e, the pressure on the compression side is less than the exhaust pressure and gradually changes to equal to or greater than the lubricating oil pressure at the injection point. At this time, there is point b, which is the cylinder position corresponding to the intersection of Pl and the air pressure on the compression side.

[0036] From a to point b, the lubricating oil is sprayed on the compression side; from b to e, since the injection point is still on the compression side and the pressure in the cylinder is higher than the oil pressure Pl at the injection point, the system does not spray oil; from e to c, the injection point enters the suction side and starts to spray oil until the sliding compression block runs to the dead point c on the rod side.

[0037] By adopting the above technical scheme, at the initial stage of cylinder startup, the compression ratio is relatively small. This scheme realizes a small compression ratio and provides a small amount of lubricating oil to the cylinder cavity. When the cylinder is running stably and the compression ratio is relatively large, an appropriate amount of lubricating oil is provided to the cylinder cavity.

[0038] Preferably, the outlet pressure of the exhaust valve provides pressure for the lubricating oil in the inner cavity of the lubrication port.

[0039] By adopting the above technical solution, it is possible to avoid using external equipment to provide lubricating oil pressure and reduce the overall failure rate of the equipment.

[0040] Preferably, an oil storage groove is provided on the side wall of the sliding compression block, the oil storage groove is communicated with the inner cavity of the cylinder, and is located at two ends of the sliding compression block and is relatively closed.

[0041] By adopting the above technical solution, when the compressor is turned on and the compression ratio of the compressor is reduced, the lubricating oil in the inner cavity of the oil storage tank provides lubrication effect for the sliding of the sliding compression block.

[0042] In summary, the present application includes at least one of the following beneficial technical effects:

[0043] 1. When the exhaust valve outputs high-pressure gas, the high-pressure gas enters the lubricating oil tank, and the lubricating oil in the lubricating oil tank is pressed into the pressure oil chamber. The lubricating oil filled in the pressure oil chamber can lubricate the sliding between the driving rod and the stuffing box. The high-pressure gas discharged by the exhaust valve is used as the high-pressure gas source of the lubricating oil tank, and the lubricating oil tank in the lubricating oil tank is pressed into the pressure oil chamber, avoiding the use of external pressure gas source or plunger pump, reducing the overall failure rate of the equipment, realizing pump-free lubrication, and reducing the failure points for the equipment;

[0044] At the same time, since the pressure in the pressure oil chamber in the stuffing box is always greater than the external atmospheric pressure, an isolation chamber is provided between the cylinder and the pressure oil chamber of the stuffing box. The isolation chamber is connected to the air intake, and the pressure inside it is always lower than the pressure in the pressure oil chamber. When the cylinder is under negative pressure, air will not leak into the cylinder. At the same time, it is ensured that when the pressure in the cylinder cavity is too high, high-temperature and high-pressure process gas enters the isolation chamber, and no high-temperature and high-pressure process gas leaks from the cylinder into the packing pressure oil chamber to cause oxidation and foaming of the lubricating oil therein. The isolation and sealing of the negative pressure in the cylinder is realized, and the adaptability of the compressor to different working conditions is expanded.

[0045] 2. By connecting different valve ports of the three-way valve, the high-level oil tank can replenish the lubricating oil in the inner cavity of the lubricating oil tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic diagram of the overall structural system of the embodiment;

[0047] Figure 2 : is a schematic diagram of the structure of the cylinder pressure and volume in the high pressure ratio working condition in the embodiment;

[0048] Figure 3 It is a structural principle diagram of cylinder pressure and volume in a low pressure ratio working condition in an embodiment.

[0049] Explanation of the reference numerals in the accompanying drawings: 1. Cylinder; 11. Intake valve; 12. Exhaust valve; 121. High-pressure gas output pipe; 13. Lubrication port; 2. Sliding compression block; 21. Oil storage tank; 22. Support ring; 3. Drive rod; 4. Stuffing box; 41. Guide hole; 42. Pressure oil chamber; 43. Isolation chamber; 44. Lubricating oil main pipe; 45. Throttle valve; 5. Lubricating oil tank; 51. Lubricating oil high-pressure intake pipe; 52. Lubricating oil vent pipe; 53. Three-way valve; 54. Cooling and separation equipment; 55. Lubricating oil supply pipe; 6. High-level oil tank; 61. Oil replenishing pipe; 7. Sealing ring; 8. Dustproof ring. DETAILED DESCRIPTION

[0050] The following is combined with Figure 1-3 This application is described in further detail.

[0051] The present application discloses a pumpless lubrication sealing system and method for a reciprocating compressor. Figure 1A pumpless lubrication sealing system for a reciprocating compressor includes a cylinder 1, which is a cylindrical tube body with both ends closed. A sliding compression block 2 is sealingly and slidingly connected inside the cylinder 1. The sliding compression block 2 is a piston in this embodiment, and a plunger in another embodiment. The outer side of the sliding compression block 2 is provided with four annular inner grooves spaced apart along its axial direction, two of which are provided with support rings 22, and the other two are provided with sealing rings 7. The two support rings 22 are located outside the two sealing rings 7. The sealing ring 7 is a dynamic sealing ring, which realizes the sealing between the sliding compression block 2 and the cylinder 1 when the sliding compression block 2 slides in the inner cavity of the cylinder 1. The support ring 22 is a ring body that is matched with the inner side of the cylinder 1 with high precision. The two support rings 22 can improve the stability of the sliding compression block 2 when it slides, and reduce the sliding resistance between the sliding compression block 2 and the cylinder 1. The support ring 22 can reduce the difficulty of processing the sliding compression block 2 and facilitate the processing of the sliding compression block 2.

[0052] The cylinder 1 is divided into two relatively independent and closed chambers by the sliding compression block 2. The two chambers are an inner chamber and an outer chamber respectively. The sealing ring 7 keeps the inner and outer chambers relatively closed.

[0053] The outer sides of both ends of the cylinder 1 are fixedly provided with an intake valve 11 connected to the inner cavity thereof. The pipeline through which the intake valve 11 guides the gas into the cylinder 1 is the intake pipeline. The gas connected to the intake pipeline of the intake valve 11 in this embodiment is natural gas, and the gas connected in other embodiments is air. The intake valve 11 can be controlled to open or close. In this embodiment, the intake valve 11 is a one-way intake valve. When the pressure difference at both ends of the intake valve 11 meets the opening pressure difference, the intake valve 11 opens, and the gas to be compressed can enter the cylinder 1. When the intake valve 11 is opened, the chamber of the cylinder 1 is connected to the outside atmosphere.

[0054] Both ends of the cylinder 1 are fixedly provided with exhaust valves 12 connected to the inner cavity thereof, and the exhaust valves 12 can be controlled to open or close. In the present embodiment, the exhaust valve 12 is a one-way air intake valve. When the pressure difference at both ends of the exhaust valve 12 satisfies the opening pressure difference, the exhaust valve 12 is opened, and the high-pressure gas in the cylinder 1 is output to the next process. The exhaust valve 12 is connected with a high-pressure gas output pipe 121, and the high-pressure gas output pipe 121 is used to transport the high-pressure gas discharged from the exhaust valve 12 to the next process. In another embodiment, the intake valve 11 and the exhaust valve 12 are electromagnetic switch valves that can be individually controlled to open or close.

[0055] A driving rod 3 is fixedly connected to the sliding compression block 2. The driving rod 3 is a round rod coaxial with the sliding compression block 2. One end of the driving rod 3 along the sliding direction of the sliding compression block 2 extends out of the cylinder 1. The cylinder 1 is provided with a round hole for accommodating the extension of the driving rod 3. A stuffing box 4 is sleeved on the outside of the driving rod 3 to guide the movement of the driving rod 3. The stuffing box 4 is stably connected to the cylinder 1, that is, no relative movement occurs during use. In this embodiment, one end of the stuffing box 4 is fixedly connected to the cylinder 1, and the stuffing box 4 and the cylinder 1 are sealed by a flange. In another embodiment, the stuffing box 4 and the cylinder 1 are integrally formed. In another embodiment, there is a gap between the stuffing box 4 and the cylinder 1. The stuffing box 4 and the cylinder 1 are fixedly arranged to maintain stability. The stuffing box 4 is a round tube in this embodiment. The hole on the stuffing box 4 that accommodates the driving rod 3 passing through is a guide hole 41. The guide hole 41 and the driving rod 3 are matched with high precision. The stuffing box 4 supports and guides the driving rod 3 to slide. The external driving structure drives the driving rod 3 to move back and forth along the axis direction of the sliding compression block 2 to provide power for the operation of the compressor.

[0056] The inner cavity of the stuffing box 4 is provided with a pressure oil cavity 42 . The pressure oil cavity 42 is an annular cavity. The pressure oil cavity 42 is communicated with the guide hole 41 . The pressure oil cavity 42 is always filled with lubricating oil.

[0057] Preferably, the inner cavity of the stuffing box 4 is provided with an isolation cavity 43, which is an annular cavity. The isolation cavity 43 is connected with the guide hole 41, and the isolation cavity 43 is located between the pressure oil cavity 42 and the cylinder 1. The isolation cavity 43 is connected with the intake pipeline where the intake valve 11 is located.

[0058] Reference Figure 1 The inner cavity of the stuffing box 4 is provided with an annular outer groove, which is an annular cavity, connected with the guide hole 41, and three annular outer grooves are arranged at intervals along the axial direction of the stuffing box 4. The isolation cavity 43 and the pressure oil cavity 42 are respectively located between the two annular outer grooves, and an annular outer groove is arranged between the isolation cavity 43 and the pressure oil cavity 42. A sealing ring 7 is embedded in the annular outer groove, and the sealing ring 7 realizes the relative closure between the inner cavity of the cylinder 1 and the isolation cavity 43, and the relative closure between the isolation cavity 43 and the pressure oil cavity 42. After the driving rod 3 is connected and assembled with the stuffing box 4, the pressure oil cavity 42 and the inner cavity of the cylinder 1 are relatively closed from the outside atmosphere.

[0059] Preferably, an annular groove is provided in the inner cavity of the stuffing box 4, and the annular groove is located at the end of the annular outer groove away from the cylinder 1. A dust ring 8 is arranged in the annular groove. When the driving rod 3 moves toward the sliding compression block 2, the dust ring 8 can remove impurities on the surface of the part where the driving rod 3 slides into the inner cavity of the stuffing box 4, thereby reducing the wear on the sealing ring 7.

[0060] The lubrication method for the compressor is as follows, refer to Figure 1The cylinder 1 is provided with a lubrication port 13 for feeding lubricating oil into its inner cavity. The lubricating oil sprayed from the lubrication port 13 can enter both ends of the moving direction of the sliding compression block 2. In another embodiment, no valve is provided, and only a joint is provided to allow the lubricating oil to enter the inner cavity of the cylinder 1. In another embodiment, a plurality of lubrication ports 13 are provided, and the plurality of lubrication ports 13 are evenly spaced along the circumference of the cylinder 1.

[0061] The stuffing box 4 is connected to a lubricating oil main pipe 44 which is in communication with the pressure oil chamber 42. The pressure oil chamber 42 is filled with lubricating oil. The lubricating oil main pipe 44 is in communication with the lubricating port 13 and lubricating oil is fed into the lubricating port 13. A one-way valve is provided on the lubricating oil main pipe 44 so that lubricating oil can only be fed into the lubricating port 13 from the pressure oil chamber 42. Preferably, a throttle valve 45 is provided on the lubricating oil main pipe 44 for adjusting the flow rate of lubricating oil fed from the pressure oil chamber 42 to the lubricating port 13.

[0062] The stuffing box 4 is connected to a lubricating oil tank 5 for feeding lubricating oil into the pressure oil chamber 42. The lubricating oil tank 5 is connected to a lubricating oil supply pipe 55 for feeding lubricating oil into the pressure oil chamber 42. The lubricating oil supply pipe 55 is provided with a solenoid valve, which controls the connection or closing of the lubricating oil supply pipe 55. In another embodiment, a one-way valve is provided on the lubricating oil supply pipe 55, so that the lubricating oil can only be fed from the lubricating oil tank 5 into the pressure oil chamber 42.

[0063] The lubricating oil tank 5 is connected with a lubricating oil vent pipe 52, and the lubricating oil vent pipe 52 is connected with a three-way valve 53. The three-way valve 53 is a pneumatic three-way valve. One of the valve ports of the three-way valve 53 is connected with the atmosphere, and the other valve port of the three-way valve 53 is connected with the lubricating oil high-pressure air intake pipe 51. The three-way valve 53 can realize the connection between the lubricating oil vent pipe 52 and the atmosphere, and at this time, the lubricating oil vent pipe 52 and the lubricating oil high-pressure air intake pipe 51 are closed and isolated; the three-way valve 53 can realize the connection between the lubricating oil vent pipe 52 and the lubricating oil high-pressure air intake pipe 51, and at this time, the lubricating oil vent pipe 52 and the atmosphere are closed and isolated. The lubricating oil high-pressure air intake pipe 51 is connected with the exhaust valve 12, and the exhaust valve 12 can deliver high-pressure air to the lubricating oil. The lubricating oil high-pressure air intake pipe 51 is connected with the high-pressure air output pipe 121, and a small amount of high-pressure air in the high-pressure air output pipe 121 can enter the lubricating oil high-pressure air intake pipe 51. A one-way valve is provided on the lubricating oil high-pressure intake pipe 51 , and the fluid can only enter the lubricating oil ventilation pipe 52 from the lubricating oil high-pressure intake pipe 51 through the three-way valve 53 .

[0064] Preferably, a cooling and separating device 54 is provided on the high-pressure gas output pipe 121, and the cooling and separating device 54 is located in the area between the connection between the high-pressure gas output pipe 121 and the lubricating oil high-pressure air inlet pipe 51 and the connection between the high-pressure gas output pipe 121 and the exhaust valve 12. The cooling and separating device 54 is used to cool the output high-pressure gas. On the one hand, it can prevent the oxygen in the high-temperature gas from entering the lubricating oil tank 5 through the lubricating oil high-pressure air inlet pipe 51 to accelerate the oxidation of the lubricating oil. On the other hand, when there is water vapor in the high-pressure gas, the cooling and separating device 54 liquefies the water vapor and discharges it, thereby reducing the liquid or gaseous water from entering the lubricating oil tank 5 to emulsify the lubricating oil.

[0065] In another embodiment, a cooling and separation device 54 is provided on the lubricating oil high-pressure intake pipe 51 .

[0066] Reference Figure 1 A pressure pipeline is provided on the three-way valve 53, and a liquid level switch is provided in the lubricating oil tank 5. The liquid level switch is a float switch. The liquid level switch is used to control the opening and closing of the pressure pipeline. The pressure pipeline applies pressure to the three-way valve 53 to control the connection between different valve ports of the three-way valve 53.

[0067] In another embodiment, a liquid level gauge is provided in the lubricating oil tank 5 , and a controller is electrically connected to the liquid level gauge. The controller is electrically connected to the three-way valve 53 and controls the opening and closing of different valve ports of the three-way valve 53 .

[0068] When the liquid level gauge detects that the liquid level in the lubricating oil tank 5 is lower than the set liquid level, the controller controls the corresponding valve port of the three-way valve 53 to connect the atmosphere with the lubricating oil vent pipe 52, and the lubricating oil high-pressure air inlet pipe 51 and the lubricating oil vent pipe 52 are isolated. At this time, the lubricating oil tank 5 can be replenished with lubricating oil.

[0069] When the liquid level in the lubricating oil tank 5 is higher than the set liquid level, the controller controls the corresponding valve port of the three-way valve 53 to isolate the atmosphere from the lubricating oil vent pipe 52, and the lubricating oil high-pressure air inlet pipe 51 is connected to the lubricating oil vent pipe 52. At this time, the high-pressure gas delivered by the exhaust valve 12 can be delivered to the lubricating oil tank 5, and the lubricating oil in the lubricating oil tank 5 is pressed into the pressure oil chamber 42, so as to keep the pressure oil chamber 42 filled with pressurized lubricating oil.

[0070] The lubricating oil tank 5 is connected with an oil replenishing pipe 61, and the oil replenishing pipe 61 is connected with a high-position oil tank 6 located above the lubricating oil tank 5. A one-way valve is provided on the oil replenishing pipe 61 to prevent the lubricating oil in the lubricating oil tank 5 from entering the high-position oil tank 6 in reverse. When the lubricating oil tank 5 is connected to the atmosphere, the lubricating oil in the high-position oil tank 6 is directly sent to the lubricating oil tank 5. The height of the high-position oil tank 6 is higher than the height of the pressure oil chamber 42. In another embodiment, the lubricating oil pressure in the high-position oil tank is greater than the atmospheric pressure. When the lubricating oil tank 5 is connected to the atmosphere, the lubricating oil in the high-position oil tank can still enter the lubricating oil tank 5.

[0071] Preferably, an oil storage tank 21 is provided on the side wall of the sliding compression block 2, and the oil storage tank 21 is located between the two sealing rings 7. The oil storage tank 21 is connected to the inner cavity of the cylinder 1, and the two ends of the sliding compression block 2 are relatively closed. When the oil storage tank 21 passes through the oil injection port 13 on the cylinder 1, the lubricating oil is sprayed into the oil storage tank 21. When the lubrication port 13 does not supply the lubricating oil into the inner cavity of the cylinder 1, the lubricating oil accumulated in the oil storage tank 21 can lubricate the moving sliding compression block 2.

[0072] The implementation principle of the pumpless lubrication and sealing system for a reciprocating compressor in the present application is as follows:

[0073] When the exhaust valve 12 outputs high-pressure gas, the high-pressure gas enters the lubricating oil tank 5, and the lubricating oil in the lubricating oil tank 5 is pressed into the pressure oil chamber 42. The full lubricating oil in the pressure oil chamber 42 can lubricate the sliding between the driving rod 3 and the stuffing box 4. The high-pressure gas discharged from the exhaust valve 12 is used as the high-pressure gas source of the lubricating oil tank 5, and the lubricating oil in the lubricating oil tank 5 is pressed into the pressure oil chamber 42, avoiding the use of an external pressure gas source or a plunger pump, reducing the overall failure rate of the equipment, realizing pump-free lubrication, and reducing failure points for the equipment;

[0074] At the same time, since the pressure in the pressure oil chamber 42 in the stuffing box 4 is always greater than the external atmospheric pressure, an isolation chamber 43 is provided between the cylinder 1 and the pressure oil chamber 42 of the stuffing box 4. The isolation chamber 43 is communicated with the air intake, and the pressure in the isolation chamber 43 is always lower than the pressure in the pressure oil chamber 42. When the cylinder 1 is under negative pressure, air will not leak into the cylinder 1. At the same time, it is ensured that when the pressure in the inner chamber of the cylinder 1 is too high, the high-temperature and high-pressure process gas enters the isolation chamber 43, and no high-temperature and high-pressure process gas leaks from the cylinder 1 into the stuffing pressure oil chamber 42 to cause oxidation and foaming of the lubricating oil therein. The isolation and sealing of the negative pressure in the cylinder 1 is achieved, and the adaptability of the compressor to different working conditions is expanded.

[0075] When the oil pressure in the pressure oil chamber 42 is lower than the pressure in the inner chamber of the cylinder 1 where the lubrication port 13 is located, the lubrication port 13 stops supplying high-pressure oil to the inner chamber of the cylinder 1;

[0076] At the initial start-up of the compressor or when the lubricating oil tank 5 is replenished with oil, the lubricating oil accumulated in the pressure oil chamber 42 can lubricate the driving rod 3 passing through the stuffing box 4, and the lubricating oil accumulated in the oil storage tank 21 can lubricate the moving sliding compression block 2.

[0077] The present application also discloses a pumpless lubrication and sealing method for a reciprocating compressor. Figure 1Under normal working conditions, the atmospheric port of the three-way valve 53 is closed and the other two ports are open. The exhaust pressure of the cylinder 1 acts on the lubricating oil level in the lubricating oil tank 5 through the one-way valve and the three-way valve 53. The lubricating oil flows into the pressure oil chamber 42 of the stuffing box 4 along the pipeline through the one-way valve, and then is sprayed into the cylinder 1 through the one-way valve after the flow rate is adjusted according to needs by the throttle valve 45. Its power source is the intake and exhaust pressure difference of the cylinder 1.

[0078] The fuel injection process is as follows: Figure 2 and Figure 3 , double-acting cylinder compression PV diagram. The designed minimum intake pressure Ps is less than the atmospheric pressure P0, taking into account valve losses and pipe losses at various locations. The pressure Pl of the lubricating oil at the injection point of cylinder 1 is less than the exhaust pressure Pd, but greater than the atmospheric pressure P0. e is the midpoint of cylinder 1, a and c are the rodless side dead center and rod side dead center of the sliding compression block 2, respectively. At this time, when the sliding compression block 2 moves to a and c, the movement direction changes. Pl is the lubricating oil pressure at the injection point; the injection point is the point where the lubrication port 13 is located.

[0079] The side of the sliding compression block 2 in the inner cavity of the cylinder 1 along the axial direction thereof where the sliding compression block 2 compresses the gas is the compression side, and the side where the cylinder 1 inhales the gas is the suction side. The intake valve 11 on the compression side is closed, and the exhaust valve 12 is opened, while the intake valve 11 on the suction side is opened, and the exhaust valve 12 is closed.

[0080] Reference Figure 2 In the high pressure ratio working condition, lubricating oil will be sprayed in during the whole process of the sliding compression block 2's reciprocating motion: a→e sprays on the compression side, and e→c sprays on the suction side. When moving from a→e, the lubricating port 13 is located on the compression side, and the pressure in the lubricating oil tank 5 is greater than the pressure in the compression side, so the lubricating port 13 can spray out the lubricating oil; when moving from e→c, the lubricating port 13 is located on the suction side, and the pressure in the lubricating oil tank 5 is greater than the pressure in the suction side, so the lubricating port 13 can spray out the lubricating oil.

[0081] Reference Figure 3 , under low pressure ratio conditions, a→b point, b point is the position of cylinder 1 corresponding to the intersection of Pl and the compression side air pressure, and the lubricating oil is sprayed on the compression side; b→e, since the injection point is still on the compression side and the pressure in the cylinder is higher than the injection point oil pressure Pl, the system does not spray oil; e→c, the injection point enters the suction side and starts to spray oil until the sliding compression block 2 runs to the rod side dead point c.

[0082] The return stroke of the sliding compression block 2 is similar to the return stroke, c→d point, d point is the position of cylinder 1 corresponding to the intersection of Pl and the air pressure on the compression side during the return stroke, and the lubricating oil is sprayed on the compression side; d→e, because the injection point is still on the compression side, and the pressure in the cylinder is higher than the oil pressure Pl at the injection point, the system does not spray oil; e→a, the injection point enters the suction side and starts to spray oil until the sliding compression block 2 runs to the rodless side dead point a. The one-way valve on the lubricating oil main pipe 44 prevents the process gas from entering the lubrication pipeline during the period when the system does not spray oil.

[0083] The smaller the working pressure ratio of the compressor, the smaller the pressure difference, the shorter the system injection time, the smaller the pressure difference, and the smaller the injection flow; the injection amount is equal to the product of the injection time and the injection flow, so the smaller the injection amount. At the beginning of the compressor startup, the pressure ratio is close to 1, and the system does not inject oil during the entire operation of the sliding compression block 2. At this time, the lubricating oil accumulated in the pressure oil chamber 42 and the oil storage tank 21 provides lubrication for the local parts until the pressure difference is established.

[0084] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A pumpless lubrication sealing system for a reciprocating compressor, comprising a cylinder, a sliding compression block is sealingly and slidingly connected in the cylinder, a driving rod is fixedly connected to the sliding compression block, the driving rod extends out of the cylinder, and can maintain a relative closure between the cylinder cavity and the atmosphere when the driving rod slides, a stuffing box is sleeved on the outer side of the driving rod for guiding the movement of the driving rod, the stuffing box is fixedly connected to the cylinder, the hole on the stuffing box for accommodating the driving rod to pass through is a guide hole, the guide hole is connected to the cylinder cavity, and the stuffing box and the cylinder are relatively stable; both ends of the cylinder are fixedly provided with an intake valve connected to its inner cavity, both ends of the cylinder are fixedly provided with an exhaust valve connected to its inner cavity, the cylinder is fixedly provided with a lubrication port for feeding lubricating oil into its inner cavity, and the lubricating oil sprayed from the lubrication port can enter both ends of the moving direction of the sliding compression block, characterized in that: The inner cavity of the stuffing box is provided with an isolation cavity and a pressure oil cavity which are communicated with the guide hole, and the isolation cavity is located between the pressure oil cavity and the cylinder; the isolation cavity is communicated with the intake pipeline where the intake valve is located; After the driving rod is connected to the stuffing box, the isolation chamber and the pressure oil chamber are relatively closed to the outside atmosphere, and the stuffing box is connected to a lubricating oil tank for feeding lubricating oil into the pressure oil chamber; A lubricating oil main pipe is provided between the pressure oil chamber and the lubricating port to connect them, and the lubricating oil main pipe can only transport lubricating oil to the lubricating port in one direction; The lubricating oil tank is connected with a lubricating oil high-pressure air inlet pipe, and the lubricating oil high-pressure air inlet pipe is connected with an air outlet pipeline where an exhaust valve is located; The lubricating oil tank is provided with an oil replenishing system, the oil replenishing system comprises a high-position oil tank, an oil replenishing pipe is provided between the high-position oil tank and the lubricating oil tank, and the high-position oil tank supplies lubricating oil into the lubricating oil tank through the oil replenishing pipe; The high-position oil tank is connected to the atmosphere, and a one-way valve is provided on the oil replenishment pipe; The lubricating oil tank is connected to a lubricating oil vent pipe, and the lubricating oil vent pipe is connected to a three-way valve, one valve port of the three-way valve is connected to the atmosphere, and the other valve port of the three-way valve is connected to a lubricating oil high-pressure intake pipe; The lubricating oil high-pressure air intake pipe is connected to a cooling and separation device; A support ring is fixedly arranged on the outer side of the sliding compression block, and two support rings are arranged at intervals along the sliding direction thereof; A sealing ring is fixedly arranged on the outer side of the sliding compression block; Two sealing rings are fixedly arranged inside the stuffing box and located at two ends of the pressure oil chamber along the sliding direction of the driving rod; and a dustproof ring is connected to the stuffing box.

2. A reciprocating compressor pumpless lubrication sealing system according to claim 1, characterized in that: The lubricating oil main pipe is provided with a throttle valve and a one-way valve.

3. A pumpless lubrication and sealing system for a reciprocating compressor according to claim 1, characterized in that: An oil storage groove is provided on the side wall of the sliding compression block. Two sealing rings are fixedly provided on the side wall of the sliding compression block. The two sealing rings are located at two ends of the oil storage groove along the sliding direction of the sliding compression block.

4. The sealing method of a pumpless lubrication sealing system for a reciprocating compressor according to claim 1, characterized in that: It comprises a cylinder, wherein a sliding compression block is sealingly and slidingly connected in the cylinder, a driving rod is fixedly connected to the sliding compression block, the driving rod extends out of the cylinder, and when the driving rod slides, it can keep the cylinder cavity and the atmosphere relatively closed; both ends of the cylinder are fixedly provided with an intake valve connected to the inner cavity, and both ends of the cylinder are fixedly provided with an exhaust valve connected to the inner cavity, and a lubrication port for feeding lubricating oil into the inner cavity is fixedly provided on the cylinder, and the lubrication port is located in the middle area of ​​the length direction of the cylinder; The minimum intake pressure Ps of the cylinder is less than the atmospheric pressure P0, taking into account the pressure losses of pipelines and valves at various locations; the pressure Pl of the lubricating oil at the cylinder injection point is less than the exhaust pressure Pd, but greater than the atmospheric pressure P0; e is the midpoint of the cylinder, a and c are the rodless side dead point and the rod side dead point of the sliding compression block movement respectively, and at this time, when the sliding compression block moves to a and c, the movement direction changes; Pl is the lubricating oil pressure at the injection point; the injection point is the point where the lubrication port is located; the sliding compression block of the cylinder cavity along the axial direction of the two sides of the sliding compression block compressing the gas is the compression side, and the side of the cylinder inhaling the gas is the suction side; 1. When the compression ratio is relatively large, when the sliding compression block moves from a to e, the pressure on the compression side is less than the exhaust pressure and less than the lubricating oil pressure at the injection point; When the sliding compression block moves from a to e, pressure is applied to the lubricating oil in the lubrication port, so that the pressure at the injection point is greater than the pressure on the compression side of the cylinder cavity; when the sliding compression block moves from e to c, pressure is applied to the lubricating oil in the lubrication port, so that the pressure at the injection point is greater than the pressure on the suction side of the cylinder cavity, and the lubricating oil can be sprayed out at the injection point; 2. When the compression ratio is small, when the sliding compression block moves from a to e, the pressure on the compression side is less than the exhaust pressure and gradually changes to equal to or greater than the lubricating oil pressure at the injection point. At this time, there is point b, which is the cylinder position corresponding to the intersection of Pl and the air pressure on the compression side. From a to point b, the lubricating oil is sprayed on the compression side; from b to e, since the injection point is still on the compression side and the pressure in the cylinder is higher than the oil pressure Pl at the injection point, the system does not spray oil; from e to c, the injection point enters the suction side and starts to spray oil until the sliding compression block runs to the dead point c on the rod side.

5. The sealing method according to claim 4, characterized in that: The outlet pressure of the exhaust valve provides pressure for the lubricating oil in the inner cavity of the lubrication port.

6. The sealing method according to claim 4, characterized in that: The side wall of the sliding compression block is provided with an oil storage groove, which is communicated with the inner cavity of the cylinder and is relatively closed at both ends of the sliding compression block.

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