Arrangement of a high-pressure stage balance chamber of a piston compressor

Abstract

A kind of piston compressor high pressure stage balance chamber arrangement structure, including being arranged in the balance chamber and compression chamber of both ends of cylinder body, the balance chamber is arranged in the cover side of cylinder, and compression chamber is arranged in the shaft side of cylinder, the wall surface of cylinder body where balance chamber and compression chamber are located is all in pairs and is opened, and balance chamber and compression chamber are communicated by the hole opened on cylinder, realize that balance chamber is connected in series with compression chamber on inlet gas flow process, inlet gas enters compression chamber after passing through balance chamber, and is discharged from compression chamber after being compressed by compression chamber.The balance chamber arrangement structure of the present application can ensure the existence of reverse angle and make it not less than 15 ° by reasonably designing single-stage pressure ratio, the ratio of cross-sectional area of piston and piston rod, and inlet gas pressure loss ratio, to prevent high temperature burnout phenomenon of crosshead pin, connecting rod head bush and bearing bush due to insufficient oil supply;By designing inlet and outlet gas flow process of balance chamber, the gas temperature in balance chamber and working chamber is reduced, the working environment of piston ring and packing gland is improved, and the service life is improved.

Description

Technical Field

[0001] This invention belongs to the field of reciprocating compressors, and specifically relates to a high-pressure stage balance chamber arrangement structure for a reciprocating compressor. Background Technology

[0002] Large reciprocating compressors are critical equipment in the petroleum, chemical, and natural gas industries, and their reliability and safety directly impact the operation of the entire production line. Currently, due to the high-temperature and high-pressure operating conditions, the sealing components of the high-pressure stage of reciprocating compressors—piston rings and stuffing boxes—age rapidly and require frequent replacement. Furthermore, when the high-pressure stage is arranged in a single-acting configuration, there is no reversal angle during compressor operation. The reversal angle is the crank angle corresponding to the piston rod load reversing during one compressor working cycle. The absence of a reversal angle means there is no load reversal process, causing the crosshead pin to be constantly pressed against one side of the connecting rod small end bushing, while the other side remains unlubricated and uncooled. Figure 4 As shown. This can cause the crosshead pin and connecting rod small end bushing to burn out due to high temperatures during compressor operation, seriously affecting the reliability and safety of the reciprocating compressor.

[0003] Currently, double-acting, stepped cylinders, or traditional balance chamber arrangements are commonly used to address the issue of piston rod load not reversing. However, arranging the high-pressure stage as a double-acting or stepped cylinder is detrimental to the miniaturization and high-temperature resistance of the high-pressure stage cylinder, and the extensive use of high-pressure resistant materials drastically increases manufacturing costs. When using a traditional balance chamber, a balance chamber is typically located on the cylinder shaft side, drawing a portion of the exhaust gas from that stage after cooling as the balance gas within the chamber. However, since the traditional balance chamber is essentially a breathing chamber, gas enters and exits only through a single through-hole. Figure 5 As shown, due to the heating effect of the cylinder wall, the temperature of this part of the gas will continue to rise and remain at a high level, which is detrimental to the long-term use of piston rings and stuffing boxes. None of these measures can solve the reliability and safety problems of the high-pressure stage of a reciprocating compressor. Summary of the Invention

[0004] The purpose of this invention is to address the problems in the prior art by providing a balance chamber arrangement structure for the high-pressure stage of a reciprocating compressor. This structure increases the reversing angle to improve the lubrication conditions of the crosshead pin and the small end bushing of the connecting rod, while also reducing the working fluid temperature of the high-pressure stage of the reciprocating compressor, thus ensuring the reliability and safety of the high-pressure stage operation.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The embodiment provides a high-pressure stage balance chamber arrangement structure for a piston compressor, including a balance chamber and a compression chamber disposed at both ends of the cylinder body. The balance chamber is disposed on the cover side of the cylinder, and the compression chamber is disposed on the shaft side of the cylinder. The walls of the cylinder body where the balance chamber and the compression chamber are located are all formed with paired openings. The balance chamber and the compression chamber are connected through the openings on the cylinder body, so that the balance chamber and the compression chamber are connected in series in the intake process. The intake air passes through the balance chamber and then enters the compression chamber, is compressed by the compression chamber, and is discharged from the compression chamber.

[0007] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the piston compressor of the present invention, the hole opened on the cylinder is a through hole, and the air outlet of the balance chamber and the air inlet of the compression chamber are connected by a pipe provided outside the cylinder.

[0008] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the piston compressor of the present invention, an intake cooler is connected to the intake port of the balance chamber.

[0009] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the piston compressor of the present invention, the air inlet is a through hole and the exhaust hole is a blind hole in the hole corresponding to the balance chamber on the wall of the cylinder; the air inlet is a blind hole and the exhaust hole is a through hole in the hole corresponding to the compression chamber on the wall of the cylinder; the air outlet of the balance chamber and the air inlet of the compression chamber are connected by an air passage opened on the wall of the cylinder.

[0010] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the piston compressor of the present invention, a piston is arranged inside the cylinder, and the piston rod passes through the compression chamber and is connected to the piston.

[0011] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention, when the compression chamber is in the intake process, the piston rod is subjected to a force F. in = (P1-ΔP)(A1-A2)-P1A1; When the compression chamber is in the exhaust process, the piston rod is subjected to a force F. out =P2(A1-A2)-P1A1; In the above formula, P1 is the pressure of the balance chamber. Due to resistance loss, the intake pressure of the compression chamber is P1-ΔP; the exhaust pressure is P2; the area of ​​the piston is A1; and the area of ​​the piston rod is A2.

[0012] As a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention, the piston force direction when the piston rod is under tension is positive, and the piston rod is under compression during the suction process, i.e., F in <0, during the exhaust process, the piston rod is under tension, i.e., F out If the pressure ratio P2 / P1 and the ratio of the cross-sectional areas of the piston and piston rod A1 / A2 satisfy:

[0013]

[0014] Furthermore, as a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention, the ratio of the absolute values ​​of the maximum positive load and the maximum reverse load on the piston rod satisfies: Make the reverse angle not less than 15°.

[0015] Furthermore, as a preferred embodiment of the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention, the pressure ratio P2 / P1, the ratio of the cross-sectional areas of the piston and piston rod A1 / A2, and the intake pressure loss ratio ΔP / P1 satisfy the following:

[0016]

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] The balance chamber and compression chamber of this reciprocating compressor's high-pressure stage balance chamber arrangement have paired openings on the cylinder wall, connecting them via these openings. This ensures the balance chamber and compression chamber are connected in series during the intake flow. Cooled intake air enters the balance chamber, then the compression chamber, is compressed, and finally exits. This reciprocating compressor's high-pressure stage balance chamber arrangement, through its designed intake and exhaust flow, reduces the gas temperature within the balance chamber and working chamber, improving the working environment of the piston rings and stuffing box, and extending their service life. Addressing the problems of severe wear on the crosshead pin and connecting rod small end bushing due to the lack of a reverse angle or an excessively small reverse angle in the high-pressure stage of existing reciprocating compressors, as well as the rapid aging of piston rings and stuffing box due to excessively high cylinder gas temperature, this invention's high-pressure stage balance chamber arrangement, while increasing the reverse angle to improve lubrication conditions for the crosshead pin and connecting rod small end bushing, also reduces the working fluid temperature in the high-pressure stage, ensuring the reliability and safety of the high-pressure stage operation.

[0019] Furthermore, the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention, through reasonable design of the single-stage pressure ratio, the ratio of the cross-sectional area of ​​the piston and the piston rod, and the intake pressure loss ratio, ensures the existence of the reversing angle and makes it not less than 15°, effectively preventing the crosshead pin, connecting rod head bushing and bearing from high-temperature burn-out due to insufficient oil supply. Attached Figure Description

[0020] Figure 1 A schematic diagram of the forces acting on the piston rod when the piston in the high-pressure stage balance chamber of the reciprocating compressor of the present invention is at the top and bottom dead centers.

[0021] Figure 2 A schematic diagram of the present invention showing the connection between the balance chamber and the compression chamber via an external pipe in the cylinder block;

[0022] Figure 3 A schematic diagram of the structure of this invention, which connects the balance chamber and the compression chamber through an air passage on the cylinder wall;

[0023] Figure 4 A schematic diagram showing the effect of the reverse angle on the lubrication of the crosshead pin and the small end bushing of the connecting rod;

[0024] Figure 5 A schematic diagram of the structure and air intake process of a traditional balance chamber.

[0025] In the attached diagram: 1-piston, 2-cylinder, 3-stuffing gland, 4-piston rod, 5-crosshead, 6-connecting rod, 7-exhaust cooler, 8-balance chamber, 9-compression chamber, 10-crosshead pin. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0027] Existing reciprocating compressors have a high-pressure stage section with no reverse angle or an excessively small reverse angle, such as... Figure 4 As shown, this causes the crosshead pin 10 to be constantly pressed against one side of the small end bushing of the connecting rod 6, while the other side never receives lubrication or cooling, resulting in severe wear of the crosshead pin 10 and the small end bushing of the connecting rod 6. On the other hand, a balance chamber 8 is typically provided on the cylinder shaft side, drawing a portion of the exhaust gas cooled by the cooler as balance gas within the balance chamber 8. However, in traditional structures, the balance chamber 8 is a breather chamber, with gas entering and exiting only through a single through-hole. Figure 5 As shown, due to the heating of the cylinder wall, the temperature of this part of the gas will continue to rise and remain at a high level. Eventually, the piston rings and stuffing box 3 will age rapidly due to the excessively high temperature of the gas inside the cylinder.

[0028] This invention proposes a balanced chamber arrangement structure for the high-pressure stage of a reciprocating compressor. While increasing the reversing angle to improve the lubrication conditions of the crosshead pin and connecting rod small end bushing, it also reduces the working fluid temperature of the high-pressure stage, ensuring the reliability and safety of the high-pressure stage operation. Figure 2 as well as Figure 3 As shown, the present invention includes a balance chamber 8 and a compression chamber 9 disposed at both ends of a cylinder body 2. The balance chamber 8 is arranged on the cover side of the cylinder, and the compression chamber 9 is arranged on the shaft side of the cylinder. The walls of the cylinder body 2 containing the balance chamber 8 and the compression chamber 9 are both formed with paired openings. The balance chamber 8 and the compression chamber 9 are connected through the openings in the cylinder body 2, thereby realizing that the balance chamber 8 and the compression chamber 9 are connected in series in the intake process. The intake air passes through the balance chamber 8 and then enters the compression chamber 9, is compressed by the compression chamber 9, and is then discharged from the compression chamber 9. In one possible embodiment, the openings in the cylinder body 2 are through holes, and the air outlet of the balance chamber 8 and the air inlet of the compression chamber 9 are connected by a pipe disposed outside the cylinder body 2, such as... Figure 2As shown. In one possible implementation, the intake port of the cylinder 2 is a through hole and the exhaust port is a blind hole in the hole corresponding to the balance chamber 8 on the wall of the cylinder 2; the intake port of the cylinder 2 is a blind hole and the exhaust port is a through hole in the hole corresponding to the compression chamber 9 on the wall of the cylinder 2; and the exhaust port of the balance chamber 8 and the intake port of the compression chamber 9 are connected by an air passage opened on the wall of the cylinder 2.

[0029] Furthermore, when the air outlet of the balance chamber 8 and the air inlet of the compression chamber 9 are connected through a pipe provided outside the cylinder body 2, an intake air cooler can be connected to the air inlet of the balance chamber 8.

[0030] like Figure 1 As shown, a piston 1 is disposed inside the cylinder body 2 of the present invention, and a piston rod 4 passes through the compression chamber 9 and is connected to the piston 1.

[0031] When the compression chamber 9 is in the intake process, the piston rod 4 is subjected to a force F. in = (P1-ΔP)(A1-A2)-P1A1;

[0032] When the compression chamber 9 is in the process of exhausting, the piston rod 4 is subjected to a force F. out =P2(A1-A2)-P1A1;

[0033] In the above formula, P1 is the pressure of the balance chamber 8. Due to resistance loss, the intake pressure of the compression chamber 9 is P1-ΔP; the exhaust pressure is P2; the area of ​​the piston 1 is A1; and the area of ​​the piston rod 4 is A2.

[0034] To ensure a certain reversing angle, the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of this invention can be configured as follows:

[0035] The piston force is defined as positive when piston rod 4 is under tension, and positive when piston rod 4 is under compression during the intake process, i.e., F in <0, during the exhaust process, piston rod 4 is under tension, i.e., F out If the pressure ratio P2 / P1 and the cross-sectional area ratio A1 / A2 of piston 1 and piston rod 4 are greater than 0, then the following conditions must be met:

[0036]

[0037] Furthermore, the high-pressure stage balance chamber arrangement structure of the reciprocating compressor of the present invention can ensure that the reversing angle is not less than 15°, requiring that the ratio of the absolute values ​​of the maximum forward load and the maximum reverse load on the piston rod 4 satisfy the following:

[0038]

[0039] Therefore, the pressure ratio P2 / P1, the ratio of the cross-sectional areas of piston 1 and piston rod 4 A1 / A2, and the intake pressure loss ratio ΔP / P1 satisfy the following:

[0040]

[0041] The high-pressure stage balance chamber arrangement structure of the reciprocating compressor of this invention ensures the existence of a reversing angle and keeps it not less than 15° by rationally designing the single-stage pressure ratio, the ratio of the cross-sectional area of ​​the piston and piston rod, and the intake pressure loss ratio. This prevents the crosshead pin, connecting rod head bushing, and bearing from burning out due to insufficient oil supply at high temperatures. By designing the gas inlet and outlet flow of the balance chamber, the gas temperature in the balance chamber and working chamber is reduced, improving the working environment of the piston rings and stuffing box and increasing their service life.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A high-pressure stage balance chamber arrangement structure for a reciprocating compressor, characterized in that: It includes a balance chamber (8) and a compression chamber (9) located at both ends of the cylinder body (2). The balance chamber (8) is located on the cover side of the cylinder, and the compression chamber (9) is located on the shaft side of the cylinder. The walls of the cylinder body (2) where the balance chamber (8) and the compression chamber (9) are located are connected by holes. The balance chamber (8) and the compression chamber (9) are connected through the holes on the cylinder body (2) so that the balance chamber (8) and the compression chamber (9) are connected in series in the air intake process. The air intake passes through the balance chamber (8) and then enters the compression chamber (9). After being compressed by the compression chamber (9), the air is discharged from the compression chamber (9). The hole on the cylinder (2) is a through hole, and the air outlet of the balance chamber (8) and the air inlet of the compression chamber (9) are connected by a pipe set outside the cylinder (2). The air inlet of the cylinder (2) is a through hole and the exhaust hole is a blind hole in the hole corresponding to the balance chamber (8) on the wall of the cylinder (2); the air inlet of the cylinder (2) is a blind hole and the exhaust hole is a through hole in the hole corresponding to the compression chamber (9) on the wall of the cylinder (2); the air outlet of the balance chamber (8) and the air inlet of the compression chamber (9) are connected by an air passage opened on the wall of the cylinder (2); A piston (1) is installed inside the cylinder (2), and a piston rod (4) passes through the compression chamber (9) and is connected to the piston (1); When the compression chamber (9) is in the intake process, the piston rod (4) is subjected to force. When the compression chamber (9) is in the process of exhausting, the piston rod (4) is subjected to force. ; In the above formula, P1 is the pressure of the balance chamber (8). Due to the resistance loss, the intake pressure of the compression chamber (9) is P1-ΔP; the exhaust pressure is P2; the area of ​​the piston (1) is A1; and the area of ​​the piston rod (4) is A2. The pressure ratio P2 / P1, the ratio of the cross-sectional areas of piston (1) and piston rod (4) A1 / A2, and the intake pressure loss ratio ΔP / P1 satisfy the following: 。 2. The reciprocating compressor high-pressure stage balance chamber arrangement structure according to claim 1, characterized in that: An air intake cooler is connected to the air intake port of the balance chamber (8).

3. The reciprocating compressor high-pressure stage balance chamber arrangement structure according to claim 1, characterized in that: The piston rod (4) is under tension when the piston force is positive, and under compression during the intake process, i.e., F in <0, during the exhaust process, the piston rod (4) is under tension, i.e., F out If the pressure ratio P2 / P1 and the ratio of the cross-sectional areas of piston (1) and piston rod (4) A1 / A2 satisfy: 。 4. The reciprocating compressor high-pressure stage balance chamber arrangement structure according to claim 3, characterized in that: The ratio of the absolute values ​​of the maximum positive load and the maximum negative load on the piston rod (4) satisfies: The reverse angle should be no less than 15°.

Images