Reciprocating compressor capable of automatically discharging liquid

Abstract

The invention discloses a reciprocating compressor capable of automatically discharging liquid, belongs to the technical field of petroleum and natural gas exploitation, and aims to solve the problems that an existing liquid discharging device is more in structure and tedious in maintenance. The compressor comprises a cylinder body, a U-shaped pipe, an L-shaped pipe, a liquid discharging part and a driving part, and a piston rod is in sliding fit with the interior of the cylinder body; the liquid discharging part is installed in the installation pipe and comprises an inner barrel, an outer barrel and a circular-truncated-cone-shaped blocking cover, the inner barrel is arranged in the outer barrel, side holes are correspondingly formed in the inner barrel and the outer barrel, a through hole is formed in the top of the circular-truncated-cone-shaped blocking cover, and an annular groove and a liquid discharging pipe are arranged on an outer ring of the circular-truncated-cone-shaped blocking cover. After gas carrying liquid enters the U-shaped pipe, gas-liquid separation is achieved through impact of gravity and the circular-truncated-cone-shaped blocking cover, the liquid is collected in the inner cylinder and the outer cylinder and can be discharged through the valve, and the compressor is suitable for gas compression and automatic liquid discharging in petroleum and natural gas extraction, convenient to maintain and stable in sealing.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to a reciprocating compressor with automatic liquid drainage. Background Technology

[0002] In the field of oil and gas extraction, especially in the development of shale gas, reciprocating compressors are common equipment for gas extraction and transportation. Shale gas wells usually adopt large-scale hydraulic fracturing operations, which have long fracturing fluid flowback cycles. As gas well extraction progresses, the reservoir pressure gradually decreases, and the gas well's fluid carrying capacity deteriorates, resulting in the natural gas containing fracturing fluid, formation water, and other free liquids. At the same time, during the compression process, due to the increase in pressure and temperature changes, the saturated water vapor in the natural gas will condense into liquid water. If these liquids remain inside the compressor, they will cause safety hazards and performance loss. The existing liquid drainage technology of reciprocating compressors has shortcomings: some automatic liquid drainage devices have complex structural designs, which require the machine to be stopped and related parts to be disassembled during maintenance, making the operation cumbersome, affecting the continuity of gas well production, and requiring the installation of too much equipment, such as liquid separators and buffers.

[0003] To address the aforementioned issues, an automatic liquid-draining reciprocating compressor was designed that is suitable for oil and gas extraction conditions, has reliable sealing, a simple structure, is easy to retrofit into existing equipment, and is convenient to maintain. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as numerous structures and cumbersome maintenance, by proposing an automatic liquid-draining reciprocating compressor.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An automatic liquid-draining reciprocating compressor includes a cylinder body, a piston rod that is slidably fitted inside the cylinder body, an air inlet at the upper part of the cylinder body and an air outlet at the lower part, and a valve chamber is correspondingly fitted at both the air inlet and the air outlet. U-shaped tubes and L-shaped tubes, wherein the U-shaped tube includes an integrally formed vertical section I, a horizontal section and a vertical section II, the vertical section I is fixedly connected to the air outlet of the cylinder, the vertical section of the L-shaped tube is fixedly connected to the vertical section II, and an installation tube is fixedly connected to the outer wall of the vertical section II, and the installation tube is coaxially arranged with the vertical section II and the vertical section of the L-shaped tube; A draining component, installed inside an installation pipe, includes an outer cylinder, an inner cylinder, and a frustum-shaped baffle. Both the inner and outer cylinders are topless but bottomless structures. The inner cylinder is coaxially disposed inside the outer cylinder, and the outer cylinder is coaxially installed inside the installation pipe. The outer wall of the outer cylinder has a side hole II, which corresponds to the transverse section. The outer wall of the inner cylinder has a side hole I, which corresponds to the side hole II. The frustum-shaped baffle is fixed to the top of the inner cylinder. The top of the frustum-shaped baffle has multiple through holes. An outer ring is fixedly sleeved on the outer wall of the frustum-shaped baffle. The outer ring is disposed at the top of the outer cylinder, and the top of the outer ring has an annular groove. The driving component is used to drive the piston rod to perform reciprocating motion. In this process, the gas carrying the liquid enters the U-shaped tube through the cylinder outlet, and then enters the inner cylinder through the side hole II and side hole I along the vertical section I, the horizontal section, and the vertical section II. Under the obstruction of gravity and the frustum-shaped baffle, the liquid separates from the gas, and the gas is discharged through the through hole into the L-shaped tube, thus achieving automatic liquid discharge.

[0006] In one possible design, the top of the outer cylinder has a groove, the inner wall of the groove is fixed with a positioning rod, the bottom of the outer ring is embedded in the groove, and the bottom of the outer ring has a positioning groove. The positioning groove and the positioning rod are fitted together to achieve positioning of the outer ring and the outer cylinder.

[0007] In one possible design, the draining component further includes a drain pipe, the top end of which is fixed to the bottom of the outer ring and communicates with the ring groove, the bottom end of which penetrates the bottom of the groove and extends into the inner wall of the outer cylinder, and the inner wall of the outer cylinder has a through hole adapted to the drain pipe, so that liquid splashed into the ring groove flows into the outer cylinder through the drain pipe.

[0008] In one possible design, the bottom of the inner cylinder has a connecting hole that connects the inner cylinder to the interior of the outer cylinder. A valve is fixedly installed at the bottom of the outer cylinder, and the liquid collected in the outer and inner cylinders can be discharged by opening the valve, making maintenance convenient.

[0009] In one possible design, the drain component further includes a limiting ring, which is installed between the flange rings of the vertical section II and the vertical section of the L-shaped pipe. The bottom of the limiting ring is provided with a downwardly extending convex ring, and a limiting convex end is fixedly provided on the inner wall of the convex ring. A limiting groove is opened at the top edge of the frustum-shaped baffle, and the end of the limiting convex end is pressed against the limiting groove to prevent the frustum-shaped baffle and the inner cylinder from shifting under gas impact.

[0010] In one possible design, the outer walls of both the inner and outer cylinders are covered with a rubber layer, which is used to achieve sealing performance and damping vibration.

[0011] In one possible design, the draining component further includes a guide plate, the bottom end of which is fixed inside the transverse section, and the top end of which is located inside the transverse section or flush with the edge of the vertical section II. The guide plate is inclined toward the interior of the vertical section II to guide the gas to flow at an upward angle.

[0012] In one possible design, the drive component includes a shaft box, a crankshaft, a connecting rod, and a middle body. The crankshaft is rotatably mounted inside the shaft box via bearings. One end of the connecting rod is hinged to the crankshaft, and the other end is hinged to the piston rod. The middle body is fixed to the side wall of the shaft box. The piston rod is slidably engaged with the middle body. The end of the middle body away from the shaft box is fixedly connected to the cylinder block to provide guiding support for the piston rod.

[0013] In one possible design, multiple intermediate bodies and cylinders can be installed on both sides of the axle box along its length to form a multi-row compression structure.

[0014] In this application, during actual use, when gas is discharged through the cylinder into the U-shaped tube, it will enter the inner cylinder inside the vertical section II along the vertical section I and the horizontal section. Then it will flow and be discharged to the next stage through the L-shaped tube. When there is liquid in the gas, the liquid will fall downwards due to gravity when passing through the vertical section II, and will fall into the lower part of the inner cylinder for storage. The top of the inner cylinder is equipped with a frustum-shaped baffle. The gas will pass through the through hole on its surface normally, while some of the liquid that is flushed upwards along with the liquid will hit the frustum-shaped baffle and fall down together. A very small amount of liquid that may hit the frustum-shaped baffle and splash out through the through hole will also fall into the annular groove due to gravity. Then it will flow into the inner cylinder through the drain pipe, thus automatically achieving the effect of draining liquid in the pipeline. During subsequent operation and maintenance, the staff only needs to open the valve to drain the liquid stored in the outer cylinder and the inner cylinder. When the gas enters the interior of the vertical section II through the transverse section, it will be affected by the guide plate, causing it to flow upward into the interior of the vertical section II. Then it will enter the interior of the inner cylinder through the side hole II and the side hole I, thus ensuring the normal flow of the gas.

[0015] In this invention, the reciprocating compressor with automatic liquid discharge has an inclined design of the guide plate to guide the gas to flow at an upward angle. Combined with the wide air passage layout of the U-shaped tube and the corresponding setting of side hole I and side hole II, it ensures a smooth gas flow path. In this invention, the reciprocating compressor with automatic liquid drainage is easy to maintain, ensures continuous production, and the liquid drainage process does not require manual intervention, achieving automatic collection. During maintenance, only the valve needs to be opened to drain the liquid without disassembling the equipment. The operation is simple and quick, shortens maintenance time, reduces maintenance costs, ensures the continuity of gas well production, meets the high-efficiency requirements of oil and gas field operations, and can be equipped with an electrically controlled valve for further convenient control. In this invention, during use, the gas and liquid are separated by the coordinated structure of the inner cylinder, outer cylinder, and frustum-shaped baffle, utilizing gravity separation and impact separation. The annular groove and drain pipe can collect a very small amount of splashed liquid, preventing liquid from being carried away by the airflow and ensuring thorough drainage, thereby ensuring the safe and stable operation of the unit. It is suitable for the working conditions of liquid entrainment in shale gas extraction, and can be directly installed on the pipeline connected to the compressor, making the structure simple and easy to install. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the main structure of a reciprocating compressor with automatic liquid drainage proposed in this invention; Figure 2 This is an exploded structural diagram of a reciprocating compressor drive component with automatic liquid drainage proposed in this invention. Figure 3 This is a schematic diagram of the exploded front view of the draining component of a reciprocating compressor with automatic draining mechanism proposed in this invention. Figure 4 For the present invention Figure 3 Enlarged view of the structure of section A; Figure 5 For the present invention Figure 3 Enlarged view of the structure of section B; Figure 6 This is an exploded rear view structural diagram of the automatic drainage reciprocating compressor drainage component proposed in this invention; Figure 7 For the present invention Figure 6 Enlarged view of the structure of section C; Figure 8 For the present invention Figure 6 Enlarged view of the structure of section D; Figure 9 This is a cross-sectional schematic diagram of the U-shaped tube of an automatic liquid-draining reciprocating compressor proposed in this invention.

[0017] In the diagram: 1. Axle box; 2. Crankshaft; 3. Middle body; 4. Cylinder block; 5. U-tube; 511. Vertical section I; 512. Transverse section; 513. Vertical section II; 6. L-tube; 7. Connecting rod; 8. Piston rod; 9. Valve chamber; 10. Mounting pipe; 11. Inner cylinder; 12. Outer cylinder; 13. Valve; 14. Side hole I; 15. Side hole II; 16. Frustum-shaped baffle; 17. Through hole; 18. Annular groove; 19. Outer ring; 20. Drain pipe; 21. Limiting groove; 22. Embedded groove; 23. Positioning rod; 24. Positioning groove; 25. Limiting ring; 26. Limiting protrusion; 27. Guide plate. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] In one embodiment: Reference Figure 1-2 An automatic liquid discharge mechanism includes: a cylinder 4, which is a component of a reciprocating compressor, with a sliding cavity axially formed inside; a piston rod 8, which is adapted to slide within the sliding cavity; one end of the piston rod 8 extends to the outside of the cylinder and is connected to a drive component; an air inlet is provided at the upper part of the cylinder, and an air outlet is provided at the lower part; a valve chamber 9 is correspondingly installed at both the air inlet and the air outlet; an air inlet valve and an air outlet valve are installed in the valve chamber 9 to control the unidirectional flow of gas and realize the intake and exhaust cycle.

[0020] The drive unit provides power for the reciprocating motion of the piston rod 8. It includes a bearing box 1, a crankshaft 2, a connecting rod 7, and a middle body 3. The crankshaft 2 is rotatably mounted inside the bearing box 1 via bearings. One end of the connecting rod 7 is hinged to the crankshaft 2 via a crankshaft pin, and the other end is hinged to the end of the piston rod 8 extending to the outside of the cylinder. The middle body 3 is fixedly disposed on the side wall of the bearing box 1. The outer wall of the piston rod 8 slides axially within the middle body 3. The end of the middle body 3 away from the bearing box 1 is fixedly connected to the cylinder, serving to guide and support the piston rod 8. According to actual usage requirements, multiple middle bodies 3 and cylinders can be installed on both sides of the bearing box 1 along its length to form a multi-row compression structure.

[0021] refer to Figure 3-8The U-shaped tube is divided into three sections: vertical section I 511, horizontal section 512, and vertical section II 513. These three sections are integrally formed and have an overall U-shaped layout. The top of vertical section I 511 is fixedly connected to the air outlet of the cylinder, allowing the high-pressure gas discharged from the cylinder to smoothly enter the U-shaped tube. One end of horizontal section 512 is fixedly connected to the bottom end of vertical section I 511, and the other end is fixedly connected to the bottom end of vertical section II 513, forming a gas flow channel. The middle of the outer wall of vertical section II 513 is fixedly connected to the installation pipe 10. The top of vertical section II 513 is fixedly connected to the vertical section of L-shaped tube 6. The axis of the vertical section of L-shaped tube 6 is consistent with the axis of installation pipe 10 and vertical section II 513 to ensure smooth gas flow.

[0022] The drain assembly is a component that enables automatic draining. It is installed inside the mounting pipe 10 and includes an outer cylinder 12, an inner cylinder 11, a frustum-shaped baffle 16, an outer ring 19, a drain pipe 20, a valve 13, a limiting ring 25, and a guide plate 27. The assembly relationship of each component is as follows: Both the outer cylinder 12 and the inner cylinder 11 are cylindrical structures without a top and with a bottom. The inner cylinder 11 is coaxially arranged inside the outer cylinder 12, and the outer cylinder 12 is coaxially installed inside the mounting tube 10. The outer wall of the outer cylinder 12 is tightly fitted with the inner wall of the mounting tube 10. The outer wall of the outer cylinder 12 is provided with a side hole II 15, and the position of the side hole II 15 corresponds to the transverse section 512 of the U-shaped tube. The outer wall of the inner cylinder 11 is provided with a corresponding side hole I 14, which corresponds to the side hole II 15, ensuring that gas can enter the inner cylinder 11 through the side hole II 15 and the side hole I 14.

[0023] A frustum-shaped baffle 16 is fixedly installed at the top of the inner cylinder 11. The large diameter end of the frustum-shaped baffle 16 faces downward and the small diameter end faces upward. Multiple through holes 17 are opened on its top end face. The through holes 17 are evenly distributed around the end face to allow gas to pass through normally. An outer ring 19 is fixedly fitted in the middle of the outer wall of the frustum-shaped baffle 16. The outer ring 19 has an annular structure. The bottom of the outer ring 19 is embedded in the groove 22 opened at the top of the outer cylinder 12. Multiple positioning rods 23 are fixedly installed on the inner wall of the groove 22. Multiple positioning grooves 24 are correspondingly opened at the bottom of the outer ring 19. The positioning rods 23 and the positioning grooves 24 are engaged one-to-one to realize the positioning of the outer ring 19 and the outer cylinder 12.

[0024] The top of the outer ring 19 is provided with an annular groove 18, which is an annular groove for collecting splashed liquid. The top end of the drain pipe 20 is fixedly set at the bottom of the outer ring 19, and the interior of the drain pipe 20 is connected to the annular groove 18. The bottom end of the drain pipe 20 passes through the bottom of the groove 22 and extends to the inside of the outer cylinder 12. The inner wall of the outer cylinder 12 is provided with a through hole 17 that matches the bottom end of the drain pipe 20 to ensure that the drain pipe 20 is connected to the inside of the outer cylinder 12.

[0025] The bottom of the inner cylinder 11 is provided with a connecting hole 17 to enable communication between the inner cylinder 11 and the outer cylinder 12. A valve 13 is fixedly installed at the center of the bottom of the outer cylinder 12 to control the discharge of liquid inside the outer cylinder 12.

[0026] The limiting ring 25 is installed between the flange rings of the vertical section II 513 and the vertical section of the L-shaped tube 6. The bottom of the limiting ring 25 is provided with a downwardly extending convex ring. Multiple limiting protrusions 26 are fixedly provided on the inner wall of the convex ring. The limiting protrusions 26 are evenly distributed along the circumference of the convex ring. The top edge of the frustum-shaped baffle 16 is provided with an annular limiting groove 21. The ends of the limiting protrusions 26 are pressed into the limiting groove 21 to achieve axial limiting of the frustum-shaped baffle 16 and the inner cylinder 11, so as to prevent them from being displaced under gas impact.

[0027] The outer walls of both the inner cylinder 11 and the outer cylinder 12 are covered with a rubber layer. The rubber layer is made of a high-pressure resistant and corrosion-resistant elastic material. On the one hand, it enhances the sealing performance between the inner cylinder 11 and the outer cylinder 12, and between the outer cylinder 12 and the mounting pipe 10, to prevent gas leakage. On the other hand, it can buffer the vibration generated by gas flow and improve the corrosion resistance of the components, making it suitable for working conditions containing acidic gases.

[0028] The bottom end of the guide plate 27 is fixed inside the transverse section 512 of the U-shaped tube, and the top end of the guide plate 27 extends upward.

[0029] When the drive unit is activated, the crankshaft 2 inside the axle box 1 rotates under the drive of external power. This drives the piston rod 8 to reciprocate linearly within the sliding chamber of the cylinder via the connecting rod 7. When the piston rod 8 moves away from the valve chamber 9, a negative pressure is formed inside the cylinder, the intake valve opens, and the natural gas to be compressed enters the cylinder through the intake port. When the piston rod 8 moves towards the valve chamber 9, the gas inside the cylinder is compressed, the intake valve closes, the exhaust valve opens, and the high-pressure gas carrying liquid is discharged from the cylinder through the exhaust port and enters the vertical section I511 of the U-shaped tube.

[0030] High-pressure gas flows along vertical section I 511 to horizontal section 512. In horizontal section 512, it is guided by guide plate 27 and flows into vertical section II 513 at an upward angle. Then, the gas enters the inner cylinder 11 through side hole II 15 of outer cylinder 12 and side hole I 14 of inner cylinder 11. It flows upward along inner cylinder 11, passes through through hole 17 at the top of frustum-shaped baffle 16 and enters L-shaped pipe. Finally, it is transported to the next operation stage through L-shaped pipe.

[0031] During the flow of gas, the entrained liquid, due to its greater density than the gas, separates from the gas under the action of gravity, drips down along the inner wall of the inner cylinder 11, collects at the bottom of the inner cylinder 11, and flows into the inner cylinder 12 for storage through the connecting hole 17 at the bottom of the inner cylinder 11. Some of the liquid moving upward with the airflow loses kinetic energy after hitting the inner wall of the frustum-shaped baffle 16 and drips down along the inner wall of the baffle. It also flows into the outer cylinder 12 through the connecting hole 17. A very small amount of liquid that may splash out through the connecting hole 17 falls into the annular groove 18 at the top of the outer ring 19 under the action of gravity and flows into the interior of the outer cylinder 12 through the drain pipe 20, thus achieving complete collection of the liquid.

[0032] When the liquid in the outer cylinder 12 reaches a certain level, the operator only needs to open the valve 13 at the bottom of the outer cylinder 12 to drain the liquid collected inside the outer cylinder 12 and the inner cylinder 11. After the liquid is drained, the valve 13 is closed, and the equipment can continue to operate normally, achieving convenient maintenance.

[0033] This application can be used in the field of oil and gas extraction, or in other fields applicable to this application.

[0034] In another embodiment: Reference Figure 9 An automatic liquid-draining reciprocating compressor is applied in the field of oil and gas extraction. The structure of this embodiment is basically the same as that of the previous embodiment, except that the top end face of the guide plate 27 is flush with the edge of the vertical section II 513, and the guide plate 27 is inclined with its inclination direction facing the interior of the vertical section II 513. This is used to guide the gas in the transverse section 512 into the vertical section II at an upward angle to ensure smooth gas flow. The accompanying drawings in this application are for illustrative purposes only. The dimensions and shapes of the components shown are not actual limitations but are merely schematic representations. In actual implementation, the components can be reasonably configured and adjusted according to specific needs and actual conditions.

[0035] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A reciprocating compressor with automatic liquid drainage, characterized in that, include: The cylinder (4) has a piston rod (8) that slides inside it. The cylinder (4) has an air inlet at the top and an air outlet at the bottom, and valve chambers (9) are installed at both the air inlet and the air outlet. The U-shaped tube (5) and the L-shaped tube (6) are integrally formed vertical section I (511), horizontal section (512) and vertical section II (513). The vertical section I (511) is fixedly connected to the air outlet of the cylinder (4). The vertical section of the L-shaped tube (6) is fixedly connected to the vertical section II (513). The outer wall of the vertical section II (513) is fixedly connected to the mounting tube (10). The mounting tube (10) is coaxially arranged with the vertical section II (513) and the vertical section of the L-shaped tube (6). A draining device is installed inside the mounting pipe (10). The draining device includes an outer cylinder (12), an inner cylinder (11), and a frustum-shaped baffle (16). Both the inner cylinder (11) and the outer cylinder (12) are topless and bottomless structures. The inner cylinder (11) is coaxially disposed inside the outer cylinder (12), and the outer cylinder (12) is coaxially installed inside the mounting pipe (10). A side hole II (15) is provided on the outer wall of the outer cylinder (12). The side hole II (15) is connected to the transverse section (512). Correspondingly, the outer wall of the inner cylinder (11) is provided with a side hole I (14), the side hole I (14) is opposite to the side hole II (15), the frustum-shaped baffle (16) is fixed to the top of the inner cylinder (11), the top of the frustum-shaped baffle (16) is provided with multiple through holes (17), the outer wall of the frustum-shaped baffle (16) is fixedly fitted with an outer ring (19), the outer ring (19) is provided at the top of the outer cylinder (12), and the top of the outer ring (19) is provided with an annular groove (18). The driving component is used to drive the piston rod (8) to reciprocate. Among them, the gas carrying the liquid enters the U-shaped tube (5) through the gas outlet of the cylinder (4), and enters the inner cylinder (11) through the side hole (15) and the side hole (14) along the vertical section I (511), the horizontal section (512), and the vertical section II (513). The liquid separates from the gas under the obstruction of gravity and the frustum-shaped baffle (16), and the gas enters the L-shaped tube (6) through the through hole (17) and is discharged, realizing automatic liquid discharge.

2. The reciprocating compressor with automatic liquid drainage according to claim 1, characterized in that, The top of the outer cylinder (12) is provided with a groove (22), and a positioning rod (23) is fixedly provided on the inner wall of the groove (22). The bottom of the outer ring (19) is embedded in the groove (22), and a positioning groove (24) is provided at the bottom of the outer ring (19). The positioning groove (24) and the positioning rod (23) are fitted together to realize the positioning of the outer ring (19) and the outer cylinder (12).

3. The reciprocating compressor with automatic liquid drainage according to claim 2, characterized in that, The draining component also includes a drain pipe (20). The top end of the drain pipe (20) is fixed to the bottom of the outer ring (19) and communicates with the ring groove (18). The bottom end of the drain pipe (20) penetrates the bottom of the groove (22) and extends to the inside of the outer cylinder (12). The inner wall of the outer cylinder (12) is provided with a through hole that matches the drain pipe (20). Liquid splashed into the ring groove (18) flows into the outer cylinder (12) through the drain pipe (20).

4. The reciprocating compressor with automatic liquid drainage according to claim 3, characterized in that, The inner cylinder (11) has a connecting hole (17) at the bottom, which connects the inner cylinder (11) with the inner cylinder (12). A valve (13) is fixedly installed at the bottom of the outer cylinder (12). By opening the valve (13), the liquid collected in the outer cylinder (12) and the inner cylinder (11) can be discharged, making maintenance convenient.

5. The reciprocating compressor with automatic liquid drainage according to claim 4, characterized in that, The draining component also includes a limiting ring (25), which is installed between the flange rings of the vertical section II (513) and the vertical section of the L-shaped pipe (6). The bottom of the limiting ring (25) is provided with a downwardly extending convex ring, and the inner wall of the convex ring is fixedly provided with a limiting convex end (26). The top edge of the frustum-shaped baffle (16) is provided with a limiting groove (21), and the end of the limiting convex end (26) is pressed against the limiting groove (21) to prevent the frustum-shaped baffle (16) and the inner cylinder (11) from shifting under gas impact.

6. The reciprocating compressor with automatic liquid drainage according to claim 5, characterized in that, The outer walls of both the inner cylinder (11) and the outer cylinder (12) are covered with a rubber layer, which is used to achieve sealing performance and buffer vibration.

7. The reciprocating compressor with automatic liquid drainage according to claim 6, characterized in that, The drainage component also includes a guide plate (27), the bottom end of which is fixed inside the transverse section (512), and the top end is located inside the transverse section (512) or flush with the edge of the vertical section II (513). The guide plate (27) is inclined towards the interior of the vertical section II (513) to guide the gas to flow at an upward angle.

8. The reciprocating compressor with automatic liquid drainage according to claim 7, characterized in that, The drive unit includes a shaft box (1), a crankshaft (2), a connecting rod (7), and a middle body (3). The crankshaft (2) is rotatably mounted inside the shaft box (1) via bearings. One end of the connecting rod (7) is hinged to the crankshaft (2), and the other end is hinged to the piston rod (8). The middle body (3) is fixed to the side wall of the shaft box (1). The piston rod (8) is slidably fitted with the middle body (3). The end of the middle body (3) away from the shaft box (1) is fixedly connected to the cylinder block (4) to provide guide support for the piston rod (8).

9. The reciprocating compressor with automatic liquid drainage according to claim 8, characterized in that, Multiple intermediate bodies (3) and cylinder bodies (4) can be installed on both sides of the axle box (1) along its length direction to form a multi-row compression structure.

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