A cylinder structure for preventing liquid hammer in a reciprocating piston compressor and a working method thereof

Abstract

The present invention discloses a cylinder structure and a working method for preventing liquid hammer in a reciprocating piston compressor. The cylinder structure mainly includes a piston, a cylinder body, a fixed stopper, and a partition. A partition that can slide along the cylinder body is provided in the cavity between the fixed stopper and the cylinder head. The partition is sealed from the inner wall of the cylinder body. An elastic structure is provided in the cavity surrounded by the partition, the cylinder body, and the cylinder head. The elastic structure applies a thrust toward the piston to the partition, causing the partition to cling to the fixed stopper. The force applied by the elastic structure to the partition is greater than the force acting on the partition in the normal exhaust state of the cylinder structure. When the pressure in the cylinder rises sharply at the end of exhaust due to liquid accumulation, the high pressure in the cylinder will push the partition to overcome the spring force and move toward the cylinder head, forming a buffer space, thereby reducing the pressure in the cylinder and preventing the sudden increase in high pressure from damaging valuable components such as the intake and exhaust valves, piston, and connecting rod. Therefore, the present invention can solve the problem of liquid hammer in the cylinder from the root.

Description

Technical Field

[0001] The invention belongs to the field of reciprocating piston compressors and relates to a cylinder structure and a working method thereof for preventing liquid hammer from occurring in a reciprocating piston compressor. Background Art

[0002] Liquid hammer is a common problem in reciprocating piston compressors. Due to factors such as overlubrication, rapid addition of liquid, and rapid opening of the intake valve, a certain amount of liquid may remain in the compressor cylinder. When the piston reaches top dead center, the incompressible nature of the remaining liquid causes a sudden increase in pressure within the cylinder, damaging load-bearing components such as the exhaust valve, piston, and connecting rod. Prolonged liquid hammer can cause significant deformation or damage to the compressor, leading to its destruction. Therefore, preventing liquid hammer in reciprocating piston compressors can help reduce maintenance costs.

[0003] The invention with application number 201410789768.1 provides an alarm structure for when liquid hammer occurs in a compressor. An arched cavity with a pressure relief hole and an air intake hole at both ends is provided inside the cylinder head, and the pressure relief hole and the air intake hole are connected to the pressure relief sealing sleeve and the air intake sleeve respectively. A spring push rod passes through the arched space, with one end inserted into the air intake sleeve and the other end supporting the pressure relief sealing sleeve. A positioning pin is inserted into the air hole of the air intake sleeve to block the outside of the spring push rod. If liquid hammer occurs in the cylinder, the sudden increase in pressure pushes the spring push rod to break the positioning pin and connect the arched cavity with the cylinder, causing the internal pressure to change sharply, and eventually triggering the pressure transmitter to sound an alarm. In this invention, although the designed structure can alarm when liquid hammer occurs in the cylinder, it cannot prevent the problem of liquid hammer in the cylinder. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a cylinder structure and a working method thereof for preventing liquid hammer in a reciprocating piston compressor. The present invention can solve the problem of liquid hammer in the cylinder from the root.

[0005] The technical solution adopted in the present invention is as follows:

[0006] A cylinder structure for preventing liquid hammer in a reciprocating piston compressor includes a piston and a cylinder body, the piston is arranged in the inner cavity of the cylinder body, a cylinder head is installed on the cylinder body at one end of the piston top dead center, a fixed limiter is provided on the inner wall of the cylinder body at a position between the top dead center of the piston and the cylinder head, an exhaust valve and an intake valve are provided on the cylinder body between the top dead center of the piston and the fixed limiter, the inner cavity of the cylinder body is provided with a partition that can slide along the inner cavity of the cylinder body in the cavity between the fixed limiter and the cylinder head, the partition is sealed from the inner wall surface of the cylinder body, an elastic structure is provided in the cavity surrounded by the partition, the elastic structure can apply a thrust toward the piston to the partition so that the partition is tightly attached to the fixed limiter, and the force applied by the elastic structure to the partition is greater than the force of the gas acting on the partition in the normal exhaust state of the cylinder structure.

[0007] Preferably, the elastic structure adopts a compression spring, and the compression spring is arranged between the partition and the cylinder cover.

[0008] Preferably, the partition plate and the cylinder cover are both provided with fixing grooves for fixing the compression spring at the locations in contact with the compression spring.

[0009] Preferably, the elastic structure includes a plurality of elastic mechanisms, the plurality of elastic mechanisms are arranged on the circumferential inner wall of the cylinder body, the plurality of elastic mechanisms are evenly distributed along the circumference of the cylinder body, the elastic mechanism includes a groove formed on the cylinder body and an elastic limiter arranged in the groove, the elastic limiter includes a wedge-shaped body and a limiter spring, one end of the wedge-shaped body is inserted into the groove, and the other end extends into the inner cavity of the cylinder body, the limiter spring is arranged in the groove and is located between the wedge-shaped body and the bottom of the groove;

[0010] One end of the wedge-shaped body extending into the cylinder cavity is provided with an inclined surface, which faces the partition and abuts against the partition. The limiter spring is in a compressed state, and the inclined surface can apply a thrust toward the piston to the partition.

[0011] Preferably, the longitudinal height of the wedge-shaped body is greater than the depth of the groove, and a distance for the partition to buffer is left between the partition and the cylinder cover, so that the volume in the cylinder body has a buffer space.

[0012] Preferably, a buffer pad is provided between the fixed limiter and the partition.

[0013] Preferably, the fixed limiter is a boss structure raised on the inner wall of the cylinder body, the partition and the cylinder body are clearance-fitted, a piston ring is provided on the outer edge of the partition, and the partition and the cylinder body are sealed by the piston ring.

[0014] The working method of the cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to the present invention includes the following steps:

[0015] The piston reciprocates in the cylinder, and the elastic structure applies a thrust to the partition toward the piston, causing the partition to fit tightly against the fixed stopper;

[0016] During the process of the piston compressing the gas, if there is liquid accumulated inside the cylinder, the force exerted on the partition by one side of the cylinder is greater than the gas force exerted on the partition under normal exhaust state. The partition overcomes the thrust of the elastic structure and moves toward the direction of the cylinder head. At this time, the volume of the cavity surrounded by the partition, cylinder and piston increases, which reduces the pressure of the gas in the cavity. As the cylinder is exhausted, part of the liquid accumulated inside the cylinder is discharged from the cylinder. When the pressure of the gas in the cavity surrounded by the partition, cylinder and piston drops to less than the thrust of the elastic structure, the partition moves toward the fixed limiter under the action of the thrust of the elastic structure until the force exerted on the partition by the elastic structure is greater than the force on one side of the cylinder, and at this time the partition is tightly attached to the fixed limiter.

[0017] Preferably, the elastic structure adopts a compression spring, which is arranged between the partition plate and the cylinder cover;

[0018] During the process of the piston compressing the gas, if there is liquid accumulated inside the cylinder, the force exerted on the partition by one side of the cylinder is greater than the gas force exerted on the partition in the normal exhaust state. The partition overcomes the thrust of the compression spring and moves toward the cylinder head and compresses the compression spring. At this time, the volume of the cavity surrounded by the partition, cylinder and piston increases, which reduces the pressure of the gas in the cavity. As the cylinder is exhausted, part of the liquid accumulated inside the cylinder is discharged from the cylinder. When the pressure of the gas in the cavity surrounded by the partition, cylinder and piston drops to less than the thrust of the compression spring, the partition moves toward the fixed limiter under the action of the compression spring thrust until the force exerted on the partition by the compression spring is greater than the force on one side of the cylinder, and the partition is close to the fixed limiter.

[0019] Preferably, the elastic structure includes a plurality of elastic mechanisms, the plurality of elastic mechanisms are arranged in the inner cavity of the cylinder body, the plurality of elastic mechanisms are evenly distributed along the circumference of the cylinder body, the elastic mechanism includes a groove formed on the cylinder body and an elastic limiter arranged in the groove, the elastic limiter includes a wedge-shaped body and a limiter spring, one end of the wedge-shaped body is inserted into the groove, and the other end extends into the inner cavity of the cylinder body, the limiter spring is arranged in the groove and is located between the wedge-shaped body and the bottom of the groove;

[0020] An inclined surface is provided on one end of the wedge-shaped body extending into the inner cavity of the cylinder, the inclined surface facing the partition and abutting against the partition. The limiter spring is in a compressed state, and the inclined surface can apply a thrust to the partition toward the piston.

[0021] When the piston compresses the gas, if there is liquid accumulated inside the cylinder, the force acting on the partition on one side of the cylinder is greater than the gas force exerted on the partition in the normal exhaust state. The partition overcomes the thrust of the limiter spring and moves toward the cylinder head. At this time, the volume of the cavity surrounded by the partition, cylinder and piston increases, which reduces the pressure of the gas in the cavity. The partition pushes the wedge-shaped body to move into the groove and further compresses the limiter spring. As the cylinder is exhausted, some of the accumulated liquid inside the cylinder is discharged from the cylinder. When the pressure of the gas in the cavity surrounded by the partition, cylinder and piston drops to less than the thrust of the limiter spring, the limiter spring pushes the wedge-shaped body to move out of the groove, and the partition moves toward the fixed limiter under the thrust of the inclined surfaces of all wedge bodies until the combined force of the thrust applied toward the piston by the inclined surfaces of all wedge bodies to the partition is greater than the force on one side of the cylinder, and at this time the partition is tightly attached to the fixed limiter.

[0022] The present invention has the following beneficial effects:

[0023] The advantage of this invention is that when the compressor is operating normally, the partition abuts the stopper and does not move, ensuring normal operation. When liquid is present in the cylinder, the pressure within it increases dramatically, causing the partition to overcome the thrust of the elastic structure and move toward the cylinder head. This expands the volume of the cavity enclosed by the cylinder and piston, thereby reducing the pressure within the cavity. Ultimately, this prevents liquid hammer and protects valuable components such as the intake and exhaust valves, connecting rod, and piston. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a main cross-sectional view of a cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to embodiment 1 of the present invention.

[0025] Figure 2 This is a detailed diagram showing the partition, buffer pad and limiter in Example 1 of the present invention.

[0026] Figure 3 This is a main cross-sectional view of a cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to embodiment 2 of the present invention.

[0027] Figure 4 This is a detailed diagram showing the partition, buffer pad and limiter in Example 2 of the present invention.

[0028] In the figure: 1-piston rod, 2-piston, 3-cylinder body, 4-exhaust valve, 5-intake valve, 6-compression spring, 7-cylinder head, 8-fixed limiter, 9-buffer pad, 10-piston ring, 11-partition, 12-elastic limiter, 12-1-limiter spring, 12-2-wedge-shaped body, 12-2-1-inclined surface, 13-groove. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] See also Figures 1-4 The present invention is a cylinder structure for preventing liquid hammer from occurring in a reciprocating piston compressor, comprising a piston 2 and a cylinder body 3, wherein the piston 2 is arranged in the inner cavity of the cylinder body 3, and a cylinder head 7 is installed on the cylinder body 3 at one end of the top dead center of the piston 2. A fixed limiter 8 is provided on the inner wall of the cylinder body 3 between the top dead center of the piston 2 and the cylinder head 7, and an exhaust valve 4 and an intake valve 5 are provided on the cylinder body 3 between the top dead center of the piston 2 and the fixed limiter 8. A partition 11 capable of sliding along the inner cavity of the cylinder body 3 is provided in the cavity between the fixed limiter 8 and the cylinder head 7. The partition 11 is sealed from the inner wall surface of the cylinder body 3, and an elastic structure is provided in the cavity surrounded by the partition 11, the cylinder body 3 and the cylinder head 7, wherein the elastic structure can apply a thrust to the partition 11 toward the piston 2 so that the partition 11 is tightly attached to the fixed limiter 8, and the force applied by the elastic structure to the partition 11 is greater than the force applied by the gas on the partition 11 in the normal exhaust state of the cylinder structure.

[0031] The working method of the cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to the present invention includes the following steps:

[0032] The piston 2 reciprocates in the cylinder 3, and the elastic structure applies a thrust to the partition 11 toward the piston 2, so that the partition 11 is closely attached to the fixed stopper 8;

[0033] Under normal operating conditions, the piston 2 reciprocates between the inner and outer dead points, periodically changing the pressure in the cylinder 3. However, the gas force acting on the partition 11 is always smaller than the reverse thrust exerted by the elastic structure, so the partition 11 does not move at all, and the compressor can operate normally.

[0034] When there is liquid accumulated inside the cylinder 3, due to the incompressibility of the liquid, the pressure in the cylinder 3 suddenly increases during the process of the piston 2 compressing the gas, which will cause the force acting on the partition 11 on one side of the cylinder 3 to be greater than the gas force exerted on the partition 11 in the normal exhaust state. At this time, the partition 11 overcomes the thrust of the elastic structure and moves toward the cylinder head 7. The volume of the cavity surrounded by the partition 11, the cylinder 3 and the piston 2 increases, which indirectly reduces the pressure of the gas in the cavity. As the cylinder 3 is exhausted, part of the accumulated liquid in the cylinder 3 is discharged from the cylinder 3. When the pressure of the gas in the cavity surrounded by the partition 11, the cylinder 3 and the piston 2 drops to less than the thrust of the elastic structure, the partition 11 moves toward the fixed limiter 8 under the action of the thrust of the elastic structure until the force exerted by the elastic structure on the partition 11 is greater than the force on one side of the cylinder 3. At this time, the partition 11 is tightly attached to the fixed limiter 8.

[0035] From the working method of the cylinder structure for preventing liquid hammer in a reciprocating piston compressor of the present invention, it can be seen that the present invention can effectively avoid the occurrence of liquid hammer in a reciprocating piston compressor and can also discharge the accumulated liquid in the cylinder body 3.

[0036] As a preferred embodiment of the present invention, a buffer pad 9 may be provided between the fixed stopper 8 and the partition 11. The buffer pad 9, on the one hand, helps prevent the fixed stopper 8 and the partition 11 from colliding with each other, thereby ensuring the structural integrity of the fixed stopper 8 and the partition 11, thereby ensuring the service life of the cylinder structure of the present invention and reducing the noise caused by the collision between the fixed stopper 8 and the partition 11; on the other hand, the buffer pad 9 can seal the contact surface between the fixed stopper 8 and the partition 11, thereby ensuring the working pressure in the cylinder body 3.

[0037] As a preferred embodiment of the present invention, the fixed limiter 8 of the present invention can be set as a boss structure protruding from the inner wall of the cylinder body 3. The fixed limiter 8 of this structure can be an integrated structure with the cylinder body 3, thereby ensuring the strength and stability of the fixed limiter 8 structure, and further improving the service life of the cylinder structure of the present invention. There is a clearance fit between the partition 11 and the cylinder body 3, and a piston ring 10 is provided on the outer edge of the partition 11. The partition 11 and the cylinder body 3 are sealed by the piston ring 10. The partition 11 of this structure is similar to a piston, which ensures the movement of the partition 11 in the cylinder body 3, and at the same time ensures that the compressed gas does not leak and ensures the working pressure in the cylinder body 3.

[0038] In the cylinder structure of the present invention, piston rings 10 are also used to dynamically seal the piston 2 against the cylinder body 3, preventing leakage of compressed gas. The intake valve 5 and exhaust valve 4 are radially mounted on the cylinder body 3. A groove is provided on the edge of the cylinder head 7 to accommodate an O-ring, which, together with the bolt preload, provides a seal between the cylinder body 3 and the cylinder head 7.

[0039] The significance of this invention lies in the fact that under normal operating conditions, the partition remains stationary, ensuring the normal operation of the compressor. However, when incompressible liquid is present in the cylinder, the sudden increase in pressure pushes the partition into motion, directly expanding the cylinder volume and indirectly reducing the cylinder pressure, fundamentally preventing liquid hammer. This helps reduce compressor maintenance costs and improve economic efficiency.

[0040] Example 1

[0041] Based on the above structure, see Figure 1 and Figure 2 In this embodiment, the elastic structure adopts a compression spring 6, which is arranged between the partition 11 and the cylinder cover 7.

[0042] When the cylinder structure of this embodiment is working:

[0043] Under normal operating conditions, the piston 2 reciprocates between the inner and outer dead points, periodically changing the pressure in the cylinder 3. However, the gas force acting on the diaphragm 11 is always smaller than the reverse thrust exerted by the compression spring 6. Therefore, the compression spring 6 will not be further compressed, the diaphragm 11 will not move, and the compressor can operate normally.

[0044] When there is liquid accumulated inside the cylinder 3, due to the incompressibility of the liquid, the pressure in the cylinder 3 suddenly increases during the process of the piston 2 compressing the gas, which will make the force acting on the partition 11 on one side of the cylinder 3 greater than the gas force exerted on the partition 11 in the normal exhaust state. The partition 11 overcomes the thrust of the compression spring and moves toward the cylinder head 7 and compresses the compression spring 6. At this time, the volume of the cavity surrounded by the partition 11, cylinder 3 and piston 2 increases, which reduces the pressure of the gas in the cavity. As the cylinder 3 is exhausted, part of the accumulated liquid in the cylinder 3 is discharged from the cylinder 3. When the pressure of the gas in the cavity surrounded by the partition 11, cylinder 3 and piston 2 drops to less than the thrust of the compression spring, the compression spring 6 extends, and the partition 11 moves toward the fixed limiter 8 under the thrust of the compression spring 6 until the force exerted by the compression spring 6 on the partition 11 is greater than the force on one side of the cylinder 3. At this time, the partition 11 is tightly against the fixed limiter 8.

[0045] The elastic structure of this structure is relatively simple and reliable, wherein one or more compression springs 6 can be provided. When one compression spring 6 is provided, the compression spring 6 is provided coaxially with the cylinder body 3, and a spring 6 with a diameter as large as possible is selected to ensure the coaxiality of the partition 11 and the cylinder body 3 during relative motion. When multiple compression springs 6 are used, the multiple compression springs 6 are evenly distributed between the partition 11 and the cylinder head 7. This purpose is also to ensure the coaxiality of the partition 11 and the cylinder body 3 during relative motion, and to prevent the partition 11 from getting stuck due to uneven force when moving in the cylinder body 3. The selection of the spring stiffness in the present invention should be based on actual conditions, so that when the gas pressure in the cylinder body compresses the compression spring 6 to the shortest, the pressure in the cylinder body 3 is still less than the damage strength of other important components of the cylinder structure.

[0046] To ensure the reliability of the installation position of the compression spring 6, the partition 11 and the cylinder head 7 are provided with fixing grooves for fixing the compression spring 6 at the contact points with the compression spring 6. Both ends of the compression spring 6 are embedded in the limiting grooves, which can ensure the reliability of the installation position of the compression spring 6. Alternatively, the two ends of the compression spring 6 are connected to the partition 11 and the cylinder head 7 respectively to ensure the reliability of the installation position of the compression spring 6.

[0047] In this embodiment, during assembly, the cushion 9 is first placed against the surface of the rigid stopper 8, the partition 11 is then inserted, and finally the cylinder head 7 is installed. At this point, the axial distance between the cushion 9 and the inner side of the cylinder head 7 is less than the initial length of the compression spring 6. Therefore, the compression spring 6 is compressed, generating a spring force directed toward the rigid stopper 8 (greater than the gas force acting on the partition 11 under normal exhaust conditions), which balances the support force of the cushion 9 on the partition 11.

[0048] Example 2

[0049] Based on the above structure, see Figure 2 and Figure 3 In this embodiment, the elastic structure includes a plurality of elastic mechanisms, which are arranged on the circumferential inner wall of the cylinder body 3 and are evenly distributed along the circumference of the cylinder body 3. The elastic mechanism includes a groove 13 opened on the cylinder body 3 and an elastic limiter 12 arranged in the groove 13. The elastic limiter 12 includes a wedge-shaped body 12-2 and a limiter spring 12-1. One end of the wedge-shaped body 12-2 is inserted into the groove 13, and the other end of the wedge-shaped body 12-2 extends into the inner cavity of the cylinder body 3. The limiter spring 12-1 is arranged in the groove 13 and is located between the wedge-shaped body 12-2 and the bottom of the groove 13.

[0050] One end of the wedge-shaped body 12-2 extending into the inner cavity of the cylinder body 3 is provided with a slope 12-2-1, which faces the partition 11 and abuts against the partition 11. The limiter spring 12-1 is in a compressed state, and the slope 12-2-1 can apply a thrust to the partition 11 toward the piston 2.

[0051] The groove 13 may be a square groove, and the wedge-shaped body 12 - 2 as a whole may adopt a columnar structure adapted to the square groove, so that the wedge-shaped body 12 - 2 can only move axially in the square groove and cannot rotate relative to it.

[0052] When the cylinder structure of this embodiment is working:

[0053] Under normal operating conditions, the piston 2 reciprocates between the inner and outer dead points, periodically changing the pressure in the cylinder 3. However, the gas force acting on the partition 11 is always smaller than the total thrust exerted by the inclined surfaces 12-2-1 of all the wedge-shaped bodies 12-2. Therefore, all the wedge-shaped bodies 12-2 and the limiter spring 12-1 remain stationary, the partition 11 remains stationary, and the compressor operates normally.

[0054] When there is liquid accumulation inside the cylinder 3, due to the incompressibility of the liquid, the pressure in the cylinder 3 increases suddenly during the process of the piston 2 compressing the gas, which will make the force acting on the partition 11 on one side of the cylinder 3 greater than the gas force on the partition 11 in the normal exhaust state. The partition 11 overcomes the thrust of the limiter spring 12-1 and moves toward the cylinder head 7. At this time, the volume of the cavity surrounded by the partition 11, the cylinder 3 and the piston 2 increases, which reduces the pressure of the gas in the cavity. The partition 11 pushes the wedge-shaped body 12-2 to move into the groove 13 and further compresses the limiter spring 12-1. As the cylinder 3 Exhaust, part of the accumulated liquid inside the cylinder 3 is discharged from the cylinder 3, and when the pressure of the gas in the cavity surrounded by the partition 11, the cylinder 3 and the piston 2 drops to less than the thrust of the limiter spring 12-1, the limiter spring 12-1 pushes the wedge-shaped body 12-2 to move out of the groove 13, and the partition 11 moves toward the fixed limiter 8 under the thrust of the inclined surfaces 12-2-1 of all the wedge-shaped bodies 12-2, until the combined force of the thrust applied by the inclined surfaces 12-2-1 of all the wedge-shaped bodies 12-2 toward the piston 2 for the partition 11 is greater than the force on one side of the cylinder 3, and at this time the partition 11 is tightly against the fixed limiter 8.

[0055] In the elastic structure of this structure, more than three elastic mechanisms are provided to ensure the coaxiality of the partition 11 and the cylinder body 3 during relative movement, and to prevent the partition 11 from getting stuck due to uneven force when moving in the cylinder body 3 .

[0056] In order to prevent the partition 11 from moving too much toward the cylinder head 7 under normal exhaust pressure fluctuations in the cylinder, thereby preventing the partition 11 from returning normally (i.e., the partition 11 is again tightly attached to the fixed limiter 8), the longitudinal height of the wedge-shaped body 12-2 (the length of the wedge-shaped body 12-2 in the radial direction of the cylinder body 3) is set to be greater than the depth of the groove 13, so that the wedge-shaped body 12-2 will not be completely sunk into the groove 13, and the partition 11 will stop after moving a limited distance, so that the outer edge of the partition 11 will always be in contact with the inclined surface 12-2-1 of the wedge-shaped body 12-2, so that the inclined surface 12-2-1 of the wedge-shaped body 12-2 will always apply a thrust toward the piston 2 to the partition 11, ensuring that the partition 11 can return normally. There is a buffer distance between the partition 11 and the cylinder head 7 for the partition 11. The purpose of setting the buffer distance is that if liquid hammer occurs during the compression of gas by the piston 2, the pressure in the cylinder body 3 will increase rapidly. At this time, the thrust of the partition 11 causes the wedge-shaped body 12-2 to deform, and the partition 11 can break through the limit of the wedge-shaped body 12-2 and move further toward the cylinder head 7. At this time, the volume of the cavity surrounded by the partition 11, cylinder body 3 and piston 2 is further increased, and the pressure of the gas in the cavity is further reduced to ensure that other important components of the cylinder structure are not damaged. After that, the partition 11 and the wedge-shaped body 12-2 can be replaced. The force strength of the wedge-shaped body 12-2 when it is deformed is less than the damage strength of other important components of the cylinder structure, such as the air valve, piston rod and crank connecting rod.

[0057] In summary, it can be seen that the technical solution of the present invention can fundamentally avoid the occurrence of liquid hammer, and solve the technical problem of damage to valuable components such as intake and exhaust valves, connecting rods, and pistons caused by the sudden increase in pressure caused by retained liquid during compression.

Claims

1. A cylinder structure for preventing liquid hammer in a reciprocating piston compressor, characterized in that: The invention comprises a piston (2) and a cylinder body (3), wherein the piston (2) is arranged in the inner cavity of the cylinder body (3), a cylinder head (7) is installed on the cylinder body (3) at one end of the piston (2) at the top dead center, a fixed stopper (8) is provided on the inner wall of the cylinder body (3) at a position between the top dead center of the piston (2) and the cylinder head (7), an exhaust valve (4) and an intake valve (5) are provided on the cylinder body (3) at a position between the top dead center of the piston (2) and the fixed stopper (8), and the inner cavity of the cylinder body (3) is between the fixed stopper (8) and the cylinder head (7). A partition (11) capable of sliding along the inner cavity of the cylinder body (3) is provided in the cavity, the partition (11) and the inner wall surface of the cylinder body (3) are sealed, and an elastic structure is provided in the cavity surrounded by the partition (11), the cylinder body (3) and the cylinder cover (7), the elastic structure being capable of applying a thrust toward the piston (2) to the partition (11), so that the partition (11) is closely attached to the fixed limiter (8), and the force applied by the elastic structure to the partition (11) is greater than the force applied by the gas on the partition (11) in the normal exhaust state of the cylinder structure; A buffer pad (9) is provided between the fixed stopper (8) and the partition (11).

2. A cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 1, characterized in that: The elastic structure adopts a compression spring (6), and the compression spring (6) is arranged between the partition plate (11) and the cylinder cover (7).

3. A cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 2, characterized in that: The partition plate (11) and the cylinder cover (7) are both provided with fixing grooves for fixing the compression spring (6) at locations in contact with the compression spring (6).

4. The cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 1, characterized in that: The elastic structure includes a plurality of elastic mechanisms, the plurality of elastic mechanisms are arranged on the circumferential inner wall of the cylinder body (3), the plurality of elastic mechanisms are evenly distributed along the circumference of the cylinder body (3), the elastic mechanism includes a groove (13) opened on the cylinder body (3) and an elastic limiter (12) arranged in the groove (13), the elastic limiter (12) includes a wedge-shaped body (12-2) and a limiter spring (12-1), one end of the wedge-shaped body (12-2) is inserted into the groove (13), and the other end of the wedge-shaped body (12-2) extends into the inner cavity of the cylinder body (3), and the limiter spring (12-1) is arranged in the groove (13) and is located between the wedge-shaped body (12-2) and the bottom of the groove (13); An inclined surface (12-2-1) is provided at one end of the wedge-shaped body (12-2) extending into the inner cavity of the cylinder body (3). The inclined surface (12-2-1) faces the partition (11) and abuts against the partition (11). When the limiter spring (12-1) is in a compressed state, the inclined surface (12-2-1) can apply a thrust to the partition (11) toward the piston (2).

5. The cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 4, characterized in that: The longitudinal height of the wedge-shaped body (12-2) is greater than the depth of the groove (13), and a buffering distance for the partition (11) is left between the partition (11) and the cylinder cover (7), so that the volume in the cylinder body (3) has a buffer space.

6. The cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 1, characterized in that: The fixed stopper (8) is a boss structure protruding from the inner wall of the cylinder body (3), and a clearance fit is formed between the partition plate (11) and the cylinder body (3). A piston ring (10) is provided on the outer edge of the partition plate (11), and the partition plate (11) and the cylinder body (3) are sealed by the piston ring (10).

7. The method for operating a cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 1, characterized in that: The process includes the following: The piston (2) reciprocates in the cylinder (3), and the elastic structure applies a thrust toward the piston (2) to the partition (11), so that the partition (11) is closely attached to the fixed stopper (8); During the process of gas compression by the piston (2), if there is accumulated liquid inside the cylinder (3), the force exerted by one side of the cylinder (3) on the partition (11) is greater than the gas force exerted on the partition (11) in the normal exhaust state, and the partition (11) overcomes the thrust of the elastic structure and moves toward the cylinder head (7). At this time, the volume of the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) increases, so that the pressure of the gas in the cavity decreases. As the cylinder (3) is exhausted, part of the accumulated liquid inside the cylinder (3) is discharged from the cylinder (3). When the pressure of the gas in the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) decreases to less than the thrust of the elastic structure, the partition (11) moves toward the fixed stopper (8) under the action of the thrust of the elastic structure until the force exerted by the elastic structure on the partition (11) is greater than the force exerted on one side of the cylinder (3). At this time, the partition (11) is close to the fixed stopper (8).

8. The method for operating a cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 7, characterized in that: The elastic structure adopts a compression spring (6), and the compression spring (6) is arranged between the partition (11) and the cylinder cover (7); During the process of gas compression by the piston (2), if there is accumulated liquid inside the cylinder (3), the force exerted by one side of the cylinder (3) on the partition (11) is greater than the gas force exerted on the partition (11) in the normal exhaust state. The partition (11) overcomes the thrust of the compression spring and moves toward the cylinder head (7) and compresses the compression spring (6). At this time, the volume of the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) increases, so that the pressure of the gas in the cavity decreases. As the cylinder (3) is exhausted, part of the accumulated liquid inside the cylinder (3) is discharged from the cylinder (3). When the pressure of the gas in the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) decreases to less than the thrust of the compression spring, the partition (11) moves toward the fixed limiter (8) under the thrust of the compression spring (6) until the force exerted by the compression spring (6) on the partition (11) is greater than the force exerted on one side of the cylinder (3). At this time, the partition (11) is close to the fixed limiter (8).

9. The method for operating a cylinder structure for preventing liquid hammer in a reciprocating piston compressor according to claim 7, characterized in that: The elastic structure includes a plurality of elastic mechanisms, the plurality of elastic mechanisms are arranged in the inner cavity of the cylinder (3), the plurality of elastic mechanisms are evenly distributed along the circumference of the cylinder (3), the elastic mechanism includes a groove (13) opened on the cylinder (3) and an elastic limiter (12) arranged in the groove (13), the elastic limiter (12) includes a wedge-shaped body (12-2) and a limiter spring (12-1), one end of the wedge-shaped body (12-2) is inserted into the groove (13), and the other end of the wedge-shaped body (12-2) extends into the inner cavity of the cylinder (3), and the limiter spring (12-1) is arranged in the groove (13) and is located between the wedge-shaped body (12-2) and the bottom of the groove (13); An inclined surface (12-2-1) is provided at one end of the wedge-shaped body (12-2) extending into the inner cavity of the cylinder body (3), the inclined surface (12-2-1) facing the partition (11) and abutting against the partition (11), the limiter spring (12-1) being in a compressed state, and the inclined surface (12-2-1) can apply a thrust to the partition (11) toward the piston (2); During the process of the piston (2) compressing the gas, if there is liquid accumulation inside the cylinder (3), the force exerted by one side of the cylinder (3) on the partition (11) is greater than the gas force exerted on the partition (11) in the normal exhaust state, and the partition (11) overcomes the thrust of the limiter spring (12-1) and moves toward the cylinder head (7). At this time, the volume of the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) increases, so that the pressure of the gas in the cavity decreases. The partition (11) pushes the wedge-shaped body (12-2) to move into the groove (13) and further compresses the limiter spring (12-1). As the cylinder (3) is exhausted, part of the liquid accumulation inside the cylinder (3) is released. The cylinder (3) is discharged. When the pressure of the gas in the cavity surrounded by the partition (11), the cylinder (3) and the piston (2) decreases to less than the thrust of the limiter spring (12-1), the limiter spring (12-1) pushes the wedge-shaped body (12-2) to move out of the groove (13), and the partition (11) moves toward the fixed limiter (8) under the thrust of the inclined surfaces (12-2-1) of all the wedge-shaped bodies (12-2) until the resultant force of the thrust applied by the inclined surfaces (12-2-1) of all the wedge-shaped bodies (12-2) toward the piston (2) by the partition (11) is greater than the force on one side of the cylinder (3), and at this time, the partition (11) is in close contact with the fixed limiter (8).

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