System for preventing reciprocating compressor cylinder from carrying liquid

Abstract

The utility model discloses a system for preventing an air cylinder of a reciprocating compressor from carrying liquid, and relates to the technical field of reciprocating compressors. According to the technical scheme, a hydrogen inlet pipeline is connected with a first liquid drainage transformation pipeline, and a first-stage gas inlet buffer tank, a second-stage gas inlet buffer tank, a third-stage gas inlet buffer tank and a fourth-stage gas inlet buffer tank are sequentially connected with a second liquid drainage transformation pipeline, a third liquid drainage transformation pipeline, a fourth liquid drainage transformation pipeline and a fifth liquid drainage transformation pipeline. The liquid drainage transformation pipeline I and the liquid drainage transformation pipeline II are respectively connected with the hydrogen buffer tank, and the liquid drainage transformation pipeline III, the liquid drainage transformation pipeline IV and the liquid drainage transformation pipeline V are respectively connected with the dehydrogenation product buffer tank. According to the utility model, each stage of gas inlet buffer tank can be connected back to the previous stage of condensate tank, the condensate of the hydrogen inlet pipeline can be discharged to the hydrogen buffer pipe, and basically no condensate is found in each stage of gas inlet buffer tank, so that the problem of liquid carrying of the reciprocating compressor is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of reciprocating compressors, in particular to a system for preventing a reciprocating compressor cylinder from being entrained with liquid. Background Art

[0002] Isobutyl alcohol enters the dehydrogenation reactor to undergo a chemical reaction, and the reaction products MEK, SBA, H2 and a small amount of water enter the dehydrogenation product buffer tank. The liquid mixture at the bottom of the dehydrogenation product buffer tank enters the MEK refining unit for purification to obtain the product MEK; the by-product hydrogen enters the reciprocating compressor after "salt cooling, sedimentation and adsorption" from the upper part of the dehydrogenation product buffer tank, and is sent to the boundary area after compression, condensation, sedimentation and adsorption.

[0003] Reciprocating compressor cylinders can be subject to liquid carryover. The main causes include process gas carryover, excessively high inlet buffer tank levels, and changes in the pumping medium's composition. These factors can cause the liquid in the cylinder to be pushed by the piston, violently impacting the cylinder head, potentially shattering it. The reaction force can also bend the piston rod, leading to complete compressor damage and threatening both the equipment and personnel safety.

[0004] At present, when reciprocating compressors are running with liquid, the following problems will occur: 1) Due to the introduction of condensate such as MEK into the cylinder, long-term compression and high temperature will cause different degrees of carbon deposition on the exhaust valves of each stage of the reciprocating compressor, especially the third-stage exhaust valve, which is seriously carbonized and cannot be cleaned. It can only be replaced directly. Basically, the exhaust valve needs to be cleaned or replaced after running for about 2000 hours; 2) Mild carbon deposition on the exhaust valve causes internal leakage. When inhaling, the H2 leaked from the exhaust valve is sucked into the cylinder, causing the high-temperature and high-pressure H2 compressed in the next stage to be injected into the previous stage, so that the exhaust valve will leak from the exhaust valve to the upper stage. The pressure in the three-stage exhaust buffer tank is high, exceeding the normal range to varying degrees; 3) If most of the exhaust valves in a single stage are leaking internally, resulting in a decrease in the compression ratio of this stage, the amount of compressed H2 in each subsequent stage will decrease, and at the same time the exhaust pressure will drop, the current of the reciprocating compressor will decrease, and the inlet pressure of the reciprocating compressor and the hydrogen buffer tank will increase, causing the safety valve of the hydrogen buffer tank to trip, resulting in a drop in volume or other safety accidents; 4) The liquid level of the three-stage condensate tank and the four-stage condensate tank rises too quickly. If it is not adjusted in time, the condensate will be injected into the four-stage air inlet buffer tank and subsequent processes.

[0005] Therefore, a solution should be provided to prevent the reciprocating compressor from being entrained with liquid, so as to solve the above problems. Utility Model Content

[0006] The technical problem to be solved by the utility model is: to overcome the deficiencies of the prior art and provide a system for preventing liquid from being carried over the cylinder of a reciprocating compressor, so that the air intake buffer tanks at each level can be connected back to the condensate tank at the previous level, and the condensate of the hydrogen intake pipeline can be discharged to the hydrogen buffer pipe. Basically, no condensate is found in the air intake buffer tanks at each level, thereby solving the problem of liquid being carried over the reciprocating compressor.

[0007] The technical solution of the utility model is:

[0008] A system for preventing liquid from entering the cylinder of a reciprocating compressor. The reciprocating compressor includes a first-stage cylinder, a second-stage cylinder, a third-stage cylinder and a fourth-stage cylinder. The first-stage cylinder is connected to a first-stage air intake buffer tank and a first-stage exhaust buffer tank. The first-stage exhaust buffer tank is connected to a first-stage interstage cooler. The first-stage interstage cooler is connected to a first-stage condensate tank. The second-stage cylinder is connected to a second-stage air intake buffer tank and a second-stage exhaust buffer tank. The second-stage exhaust buffer tank is connected to a second-stage interstage cooler. The second-stage interstage cooler is connected to a second-stage condensate tank. The third-stage cylinder is connected to a third-stage air intake buffer tank and a third-stage exhaust buffer tank. The third-stage exhaust buffer tank is connected to a third-stage interstage cooler. The third-stage interstage cooler is connected to a third-stage condensate tank. The fourth-stage cylinder is connected to a fourth-stage air intake buffer tank and a fourth-stage exhaust buffer tank. The fourth-stage exhaust buffer tank is connected to a fourth-stage interstage cooler. The fourth-stage interstage cooler is connected to a fourth-stage condensate tank. The first-stage air intake buffer tank is connected to the first-stage exhaust buffer tank. The tank is connected to a hydrogen inlet pipeline, the hydrogen inlet pipeline is connected to the hydrogen buffer tank, the first-level condensate tank is connected to the second-level inlet buffer tank, the second-level condensate tank is connected to the third-level inlet buffer tank, the third-level condensate tank is connected to the fourth-level inlet buffer tank, and the fourth-level condensate tank is connected to a hydrogen exhaust pipeline; the first-level condensate tank, the second-level condensate tank, the third-level condensate tank and the fourth-level condensate tank are respectively connected to the dehydrogenation product buffer tank through a drainage pipeline; the hydrogen inlet pipeline is connected to a drainage modification pipeline one, the first-level inlet buffer tank, the second-level inlet buffer tank, the third-level inlet buffer tank and the fourth-level inlet buffer tank are connected in sequence with a drainage modification pipeline two, a drainage modification pipeline three, a drainage modification pipeline four and a drainage modification pipeline five, the drainage modification pipeline one and the drainage modification pipeline two are respectively connected to the hydrogen buffer tank, and the drainage modification pipeline three, the drainage modification pipeline four and the drainage modification pipeline five are respectively connected to the dehydrogenation product buffer tank.

[0009] Preferably, the third drainage modification pipeline, the fourth drainage modification pipeline and the fifth drainage modification pipeline are sequentially connected to the first-stage condensate tank, the second-stage condensate tank and the third-stage condensate tank.

[0010] Preferably, the first interstage cooler, the second interstage cooler, the third interstage cooler and the fourth interstage cooler are connected in sequence with the drainage transformation pipeline six, the drainage transformation pipeline seven, the drainage transformation pipeline eight and the drainage transformation pipeline nine, and the drainage transformation pipeline six, the drainage transformation pipeline seven, the drainage transformation pipeline eight and the drainage transformation pipeline nine are respectively connected to the dehydrogenation product buffer tank.

[0011] Preferably, the drainage modification pipeline six, the drainage modification pipeline seven, the drainage modification pipeline eight and the drainage modification pipeline nine are connected to the first-stage condensate tank, the second-stage condensate tank, the third-stage condensate tank and the fourth-stage condensate tank in sequence.

[0012] Preferably, the third-stage condensate tank and the fourth-stage condensate tank are respectively provided with liquid level gauges, and the discharge pipelines of the third-stage condensate tank and the fourth-stage condensate tank are respectively provided with electric regulating valves, and the liquid level gauges and the electric regulating valves are electrically connected to the control system.

[0013] Preferably, the sealing rings of the first-stage cylinder, the second-stage cylinder, the third-stage cylinder and the fourth-stage cylinder are connected to a nitrogen purge pipeline and an oil drain pipeline, and the oil drain pipeline is connected to a mid-body oil recovery tank.

[0014] Preferably, the bottoms of the first-level exhaust buffer tank, the second-level exhaust buffer tank, the third-level exhaust buffer tank and the fourth-level exhaust buffer tank are connected with backwash line one, backwash line two, backwash line three and backwash line four in sequence, and sampling valves are respectively provided on backwash line one, backwash line two, backwash line three and backwash line four.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The system of the present invention for preventing liquid from being carried in the cylinder of a reciprocating compressor can allow the air intake buffer tanks at each level to be connected back to the condensate tank at the previous level, so that basically no condensate is found in the air intake buffer tanks at each level; at the same time, the condensate in the hydrogen intake pipeline of the reciprocating compressor can be discharged to the hydrogen buffer pipe, so that the first-level air intake buffer tank is basically free of condensate.

[0017] 2. The utility model improves the heat exchange efficiency by discharging the condensate at the bottom of each interstage cooler into the corresponding condensate tank, thereby reducing the temperature of the compressed H2, reducing the liquid entrainment of the H2 after each stage of compression, and basically reducing the temperature of the air intake buffer tank at each stage by 2-3°C.

[0018] 3. The utility model monitors the liquid levels of the third-stage condensate tank and the fourth-stage condensate tank in real time through the control system, so that they are basically stable at 20% and 30% respectively, to avoid excessive liquid level leading to an increase in the amount of liquid entrained in H2 and thus entering the various levels of air intake buffer tanks.

[0019] 4. Through the system of the utility model, the service life of the exhaust valve of the cylinder can be basically increased from 2000H to 4500H, and the service life of the exhaust valve of the three-stage cylinder can be basically increased from 1400H to 3300H; and the exhaust pressure of the first-stage cylinder, the second-stage cylinder, and the third-stage cylinder are within the normal range, and there is no high pressure; within one year, there is no low exhaust pressure of the compressor caused by internal leakage of the exhaust valve of the first-stage cylinder, which affects the work performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of the present utility model.

[0021] In the figure, 101, first-stage cylinder; 102, first-stage air intake buffer tank; 103, first-stage exhaust buffer tank; 104, first-stage interstage cooler; 105, first-stage condensate tank; 201, second-stage cylinder; 202, second-stage air intake buffer tank; 203, second-stage exhaust buffer tank; 204, second-stage interstage cooler; 205, second-stage condensate tank; 301, third-stage cylinder; 302, third-stage air intake buffer tank; 303, third-stage exhaust buffer tank; 304, third-stage interstage cooler; 305, third-stage condensate tank; 401, fourth-stage cylinder; 402, fourth-stage air intake buffer tank; 403, fourth-stage Exhaust buffer tank; 404, four-stage interstage cooler; 405, four-stage condensate tank; 5, hydrogen inlet pipeline; 6, hydrogen exhaust pipeline; 7, drain pipeline; 8, drain modification pipeline one; 9, drain modification pipeline two; 10, drain modification pipeline three; 11, drain modification pipeline four; 12, drain modification pipeline five; 13, drain modification pipeline six; 14, drain modification pipeline seven; 15, drain modification pipeline eight; 16, drain modification pipeline nine; 17, electric control valve; 18, nitrogen purge pipeline; 19, oil drain pipeline; 20, mid-body oil recovery tank; 21, sampling valve. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0023] Example 1

[0024] like Figure 1 As shown, the reciprocating compressor of this embodiment is a reciprocating piston type, with a power of 450kW and a displacement of 41m 3 / min, four cylinders, the specific structure is as follows: including a first-stage cylinder 101, a second-stage cylinder 201, a third-stage cylinder 301 and a fourth-stage cylinder 401, the first-stage cylinder 101 is connected to a first-stage air intake buffer tank 102, a first-stage exhaust buffer tank 103, the first-stage exhaust buffer tank 103 is connected to a first-stage interstage cooler 104, the first-stage interstage cooler 104 is connected to a first-stage condensate tank 105; the second-stage cylinder 201 is connected to a second-stage air intake buffer tank 202, a second-stage exhaust buffer tank 203, the second-stage exhaust buffer tank 203 is connected to a second-stage interstage cooler 204, the second-stage interstage cooler 204 is connected to a second-stage condensate tank 205; the third-stage cylinder 301 is connected to a third-stage air intake buffer tank 302, a third-stage exhaust buffer tank 303, the third-stage exhaust buffer tank 303 is connected to a third-stage interstage cooler 304, the third-stage interstage cooler 3 04 is connected to a third-stage condensate tank 305; the fourth-stage cylinder 401 is connected to a fourth-stage air intake buffer tank 402 and a fourth-stage exhaust buffer tank 403, the fourth-stage exhaust buffer tank 403 is connected to a fourth-stage interstage cooler 404, and the fourth-stage interstage cooler 404 is connected to a fourth-stage condensate tank 405; the first-stage air intake buffer tank 102 is connected to a hydrogen intake pipeline 5, the hydrogen intake pipeline 5 is connected to the hydrogen buffer tank, the first-stage condensate tank 105 is connected to the second-stage air intake buffer tank 202, the second-stage condensate tank 205 is connected to the third-stage air intake buffer tank 302, the third-stage condensate tank 305 is connected to the fourth-stage air intake buffer tank 402, and the fourth-stage condensate tank 405 is connected to a hydrogen exhaust pipeline 6; the first-stage condensate tank 105, the second-stage condensate tank 205, the third-stage condensate tank 305 and the fourth-stage condensate tank 405 are respectively connected to the dehydrogenation product buffer tank through a drainage pipeline 7.

[0025] Among them, the first-stage air intake buffer tank 102 has a size of DN1000×6×4306, a material of 16MnR, a design pressure of 0.03MPa, a design temperature of 100℃, and a volume of 3m 3 The first-stage exhaust buffer tank 103 has the dimensions of DN900×6×4615, is made of 16MnR, has a design pressure of 0.3MPa, a design temperature of 150°C, and a volume of 2.7m 3 The first-stage condensate tank 105 has the dimensions of DN800×6×2655, is made of 16MnR, has a design pressure of 0.3MPa, a design temperature of 100℃, and a volume of 1m 3 Secondary air inlet buffer tank 202 size DN900×6×2575, material 16MnR, design pressure 0.3MPa, design temperature 100℃, volume 1.4m 3 Secondary exhaust buffer tank 203 size DN850×6×2600, material 16MnR, design pressure 0.6MPa, design temperature 150℃, volume 1.3m 3 Secondary condensate tank 205 size DN700×6×2506, material 16MnR, design pressure 0.6MPa, design temperature 100℃, volume 0.7m 3The third-stage air inlet buffer tank 302 has the dimensions of DN650×6×2087, is made of 16MnR, has a design pressure of 0.6MPa, a design temperature of 100°C, and a volume of 0.65m 3 The three-stage exhaust buffer tank 303 has the dimensions of DN650×6×2120, is made of 16MnR, has a design pressure of 1.3MPa, a design temperature of 150°C, and a volume of 0.6m 3 The third-stage condensate tank 305 has the dimensions of DN600×6×2411, is made of 16MnR, has a design pressure of 1.3MPa, a design temperature of 100℃, and a volume of 0.54m 3 The fourth-stage air inlet buffer tank 402 has the dimensions of DN500×6×1835, is made of 16MnR, has a design pressure of 1.3MPa, a design temperature of 100°C, and a volume of 0.3m 3 The fourth-stage exhaust buffer tank 403 has the dimensions of DN500×8×1639, is made of 16MnR, has a design pressure of 2.8MPa, a design temperature of 150°C, and a volume of 0.3m 3 The fourth-stage condensate tank 405 has the dimensions of DN500×8×2368, is made of 16MnR, has a design pressure of 2.8MPa, a design temperature of 100°C, and a volume of 0.335m 3 .

[0026] The size of the first-stage intercooler is DN350×8×2945, the tube diameter is Ф25×2.5×6000, U-tube type, and the heat exchange area is 18.5m 3 , design pressure tube side 0.5MPa, shell side 0.3MPa, design temperature tube side 60℃, shell side 150℃, two tube sides, tube side material 20#, shell side material 16MnR, tube side circulating water, shell side H2; secondary interstage cooler size DN350×8×2136, tube diameter Ф25×2.5×3900, U-tube type, heat exchange area 12m 3 , design pressure tube side 0.5MPa, shell side 0.6MPa, design temperature tube side 60℃, shell side 150℃, two tube sides, tube side material 20#, shell side material 16MnR, tube side circulating water, shell side H2; three-stage interstage cooler size DN350×8×2136, tube diameter Ф25×2.5×3900, U-tube type, heat exchange area 12m 3 , design pressure tube side 0.5MPa, shell side 1.3MPa, design temperature tube side 60℃, shell side 150℃, two tube sides, tube side material 20#, shell side material 16MnR, tube side circulating water, shell side H2; four-stage interstage cooler size DN350×8×1950, tube diameter Ф25×2.5×3500, U-tube type, heat exchange area 11.2m 3, design pressure tube side 0.5MPa, shell side 2.5MPa, design temperature tube side 60℃, shell side 150℃, two tube sides, tube side material 20#, shell side material 16MnR, tube side circulating water, shell side H2.

[0027] The H2 produced as a by-product of the dehydrogenation reaction of isobutyl alcohol is extracted from the upper part of the dehydrogenation product buffer tank, and after adsorption, condensation, adsorption and sedimentation, it enters the reciprocating compressor for compression. The compressed H2 is sent to the boundary area after compression, condensation, sedimentation and adsorption.

[0028] Hydrogen enters the first-stage air intake buffer tank 102 through the hydrogen inlet pipeline 5 of the reciprocating compressor, and then enters the first-stage cylinder 101. The piston of the first-stage cylinder 101 compresses H2 to 0.12-0.17 MPa under the drive of the crankshaft, crosshead, connecting rod and piston rod. The first-stage cylinder 101 is cooled by jacket circulating water. The H2 after the first-stage compression enters the first-stage exhaust buffer tank 103, and then enters the first-stage condensate tank 105 after cooling through the first-stage interstage cooler 104. The condensate in the first-stage condensate tank 105 is discharged into the dehydrogenation product buffer tank. The H2 in the first-stage condensate tank 105 enters the second-stage air intake buffer tank 202 and then enters the second-stage cylinder 201. Driven by the crankshaft, crosshead, connecting rod and piston rod, the piston of the second-stage cylinder 201 compresses the H2 to 0.4-0.45 MPa. The second-stage cylinder 201 is cooled by jacket circulating water. The H2 after the second-stage compression enters the second-stage exhaust buffer tank 203 and then enters the second-stage condensate tank 205 after being cooled by the second-stage interstage cooler 204. The condensate in the second-stage condensate tank 205 is discharged into the dehydrogenation product buffer tank. The H2 in the secondary condensate tank 205 enters the tertiary air intake buffer tank 302 and then enters the tertiary cylinder 301. Driven by the crankshaft, crosshead, connecting rod and piston rod, the piston of the tertiary cylinder 301 compresses the H2 to 0.9-1.05 MPa. The tertiary cylinder 301 is cooled by jacket circulating water. The H2 after the tertiary compression enters the tertiary exhaust buffer tank 303 and then enters the tertiary condensate tank 305 after being cooled by the tertiary interstage cooler 304. The condensate in the tertiary condensate tank 305 is discharged into the dehydrogenation product buffer tank. The H2 in the tertiary condensate tank 305 enters the tertiary air inlet buffer tank 402 and then enters the tertiary cylinder 401. Driven by the crankshaft, crosshead, connecting rod and piston rod, the piston of the tertiary cylinder 401 compresses the H2 to 2±0.5 MPa. The tertiary cylinder 401 is cooled by jacket circulating water. The H2 after the tertiary compression enters the tertiary exhaust buffer tank 403 and then enters the tertiary condensate tank 405 after being cooled by the tertiary interstage cooler 404. The condensate in the tertiary condensate tank 405 is discharged into the dehydrogenation product buffer tank. The H2 in the tertiary condensate tank 405 is sent to the boundary area after compression, condensation, sedimentation and adsorption.

[0029] In order to solve the problem of liquid in the cylinder of the reciprocating compressor during operation, this embodiment provides a system for preventing liquid in the cylinder of the reciprocating compressor, and improves the reciprocating compressor, specifically: Figure 1 As shown, the hydrogen inlet pipeline 5 is connected to the drainage modification pipeline 1 8, the first-level air inlet buffer tank 102, the second-level air inlet buffer tank 202, the third-level air inlet buffer tank 302 and the fourth-level air inlet buffer tank 402 are connected to the drainage modification pipeline 2 9, the drainage modification pipeline 3 10, the drainage modification pipeline 4 11 and the drainage modification pipeline 5 12 in sequence, the drainage modification pipeline 1 8 and the drainage modification pipeline 2 9 are respectively connected to the hydrogen buffer tank, and the drainage modification pipeline 3 10, the drainage modification pipeline 4 11 and the drainage modification pipeline 5 12 are connected to the first-level condensate tank 105, the second-level condensate tank 205 and the third-level condensate tank 305 in sequence.

[0030] Through the above system, condensate carried by H2 in hydrogen inlet line 5 is recovered through drainage modification line 1 (8) and then settled into the hydrogen buffer tank, preventing the condensate from entering the reciprocating compressor. Subsequently, condensate carried by H2 entering the first-stage inlet buffer tank 102 is recovered into the hydrogen buffer pipe via drainage modification line 2 (9), preventing it from entering the first-stage cylinder 101. Similarly, condensate in the second-stage inlet buffer tank 202, the third-stage inlet buffer tank 302, and the fourth-stage inlet buffer tank 402 is discharged into the dehydrogenation product buffer tank via drainage modification line 3 (10), drainage modification line 4 (11), and drainage modification line 5 (12), respectively, preventing the condensate from entering the second-stage cylinder 201, the third-stage cylinder 301, and the fourth-stage cylinder 401.

[0031] At the same time, if Figure 1 As shown, in this embodiment, the first interstage cooler 104, the second interstage cooler 204, the third interstage cooler 304 and the fourth interstage cooler 404 are connected in sequence with the drain modification pipeline six 13, the drain modification pipeline seven 14, the drain modification pipeline eight 15 and the drain modification pipeline nine 16, and the drain modification pipeline six 13, the drain modification pipeline seven 14, the drain modification pipeline eight 15 and the drain modification pipeline nine 16 are connected in sequence with the first condensate tank 105, the second condensate tank 205, the third condensate tank 305 and the fourth condensate tank 405.

[0032] During operation, condensate at the bottom of the first-stage interstage cooler 104 is discharged through the sixth drainage modification pipeline 13 to the first-stage condensate tank 105, and ultimately to the dehydrogenation product buffer tank, thereby ensuring the cooling effect of the first-stage interstage cooler 104 and condensing as much condensate as possible in the H2. Similarly, condensate at the bottom of the second-stage interstage cooler 204, the third-stage interstage cooler 304, and the fourth-stage interstage cooler 404 is discharged through the seventh drainage modification pipeline 14, the eighth drainage modification pipeline 15, and the ninth drainage modification pipeline 16 to the second-stage condensate tank 205, the third-stage condensate tank 305, and the fourth-stage condensate tank 405, and ultimately to the dehydrogenation product buffer tank, thereby ensuring their cooling effect.

[0033] The system of this embodiment allows each level of intake buffer tank to be connected back to the previous-stage condensate tank 105, resulting in virtually no condensate being found in each level of intake buffer tank. Furthermore, by draining condensate from the bottom of each interstage cooler into the corresponding condensate tank, the heat exchange efficiency is improved, reducing the temperature of compressed H2 and the amount of liquid entrained H2 after each stage of compression, resulting in a 2-3°C drop in the temperature of each level of intake buffer tank. Furthermore, condensate from the reciprocating compressor's hydrogen intake line 5 can be drained into the hydrogen buffer pipe, leaving the first-stage intake buffer tank 102 essentially condensate-free.

[0034] Example 2

[0035] On the basis of Example 1, Figure 1 As shown, the tertiary condensate tank 305 and the quaternary condensate tank 405 are respectively provided with liquid level gauges, and the discharge lines 7 of the tertiary condensate tank 305 and the quaternary condensate tank 405 are respectively provided with electric regulating valves 17, and the liquid level gauges and the electric regulating valves 17 are electrically connected to the control system.

[0036] Since the liquid levels of the tertiary condensate tank 305 and the fourth-stage condensate tank 405 rise rapidly, this embodiment uses a control system to monitor the liquid levels of the tertiary condensate tank 305 and the fourth-stage condensate tank 405 in real time, so that they are basically stable at 20% and 30%, respectively, to avoid excessively high liquid levels that lead to an increase in the amount of liquid entrained in H2 and thus enter the various levels of air intake buffer tanks.

[0037] Example 3

[0038] On the basis of Example 1, Figure 1 As shown, the sealing rings of the first-stage cylinder 101 , the second-stage cylinder 201 , the third-stage cylinder 301 and the fourth-stage cylinder 401 are connected to a nitrogen purge pipeline 18 and an oil drain pipeline 19 , and the oil drain pipeline 19 is connected to a mid-body oil recovery tank 20 .

[0039] This embodiment adds a nitrogen seal near the cylinder side. During operation, nitrogen is introduced into the cylinder and the nitrogen pressure is maintained at 20KPa. The nitrogen is used to blow the material leaking from the cylinder side and the lubricating oil in the middle body into the middle body oil recovery tank 20 to prevent the lubricating oil from entering the cylinder and blowing the material out at the same time.

[0040] Example 4

[0041] On the basis of Example 1, Figure 1 As shown, the bottoms of the first-level exhaust buffer tank 103, the second-level exhaust buffer tank 203, the third-level exhaust buffer tank 303 and the fourth-level exhaust buffer tank 403 are connected in sequence with the backwash line 1, the backwash line 2, the backwash line 3 and the backwash line 4, and the backwash line 1, the backwash line 2, the backwash line 3 and the backwash line 4 are respectively provided with sampling valves 21.

[0042] By opening sampling valve 21, the liquid in the first-stage exhaust buffer tank 103, the second-stage exhaust buffer tank 203, the third-stage exhaust buffer tank 303, and the fourth-stage exhaust buffer tank 403 can be regularly sampled and tested. Since the liquid's main components are 61.5% MEK and 37.5% sec-butyl alcohol (SBA), with a water content of less than 1000 ppm and a conductivity of less than 10 µs / cm, while the conductivity of the cylinder jacket circulating water is 4000 µs / cm, leakage of the cylinder jacket circulating water will cause the water content and conductivity of the liquid in each exhaust buffer tank to increase. A large amount of jacket circulating water leakage will cause the liquid level in the subsequent condensate tank to rise too quickly, ultimately causing liquid to enter the cylinder from the next-stage intake buffer tank. In this case, a backup reciprocating compressor will need to be switched and the original reciprocating compressor will need to be repaired. Therefore, this embodiment ensures the normal operation of the reciprocating compressor by regularly sampling and testing the liquid in each exhaust buffer tank.

Claims

1. A system for preventing liquid from being carried in a reciprocating compressor cylinder, wherein the reciprocating compressor comprises a first-stage cylinder (101), a second-stage cylinder (201), a third-stage cylinder (301) and a fourth-stage cylinder (401), wherein the first-stage cylinder (101) is connected to a first-stage air intake buffer tank (102) and a first-stage exhaust buffer tank (103), wherein the first-stage exhaust buffer tank (103) is connected to a first-stage inter-stage cooler (104), and wherein the first-stage inter-stage cooler (104) is connected to a first-stage condensate tank (105); (201) is connected to a secondary air intake buffer tank (202) and a secondary exhaust buffer tank (203), the secondary exhaust buffer tank (203) is connected to a secondary interstage cooler (204), the secondary interstage cooler (204) is connected to a secondary condensate tank (205); the third-stage cylinder (301) is connected to a third-stage air intake buffer tank (302) and a third-stage exhaust buffer tank (303), the third-stage exhaust buffer tank (303) is connected to a third-stage interstage cooler (304), the third-stage interstage cooler ( 304) is connected to a third-stage condensate tank (305); the fourth-stage cylinder (401) is connected to a fourth-stage air intake buffer tank (402), a fourth-stage exhaust buffer tank (403), the fourth-stage exhaust buffer tank (403) is connected to a fourth-stage interstage cooler (404), the fourth-stage interstage cooler (404) is connected to a fourth-stage condensate tank (405); the first-stage air intake buffer tank (102) is connected to a hydrogen intake pipeline (5), the hydrogen intake pipeline (5) is connected to the hydrogen buffer tank, the first-stage condensate tank (105 ) is connected to the secondary air inlet buffer tank (202), the secondary condensate tank (205) is connected to the tertiary air inlet buffer tank (302), the tertiary condensate tank (305) is connected to the quaternary air inlet buffer tank (402), and the quaternary condensate tank (405) is connected to a hydrogen exhaust pipeline (6); the primary condensate tank (105), the secondary condensate tank (205), the tertiary condensate tank (305) and the quaternary condensate tank (405) are respectively connected to the dehydrogenation product buffer tank via a drainage pipeline (7); characterized in that, The hydrogen inlet pipeline (5) is connected to the drainage modification pipeline 1 (8); the first-stage inlet buffer tank (102), the second-stage inlet buffer tank (202), the third-stage inlet buffer tank (302) and the fourth-stage inlet buffer tank (402) are connected to the drainage modification pipeline 2 (9), the drainage modification pipeline 3 (10), the drainage modification pipeline 4 (11) and the drainage modification pipeline 5 (12) in sequence; the drainage modification pipeline 1 (8) and the drainage modification pipeline 2 (9) are respectively connected to the hydrogen buffer tank; the drainage modification pipeline 3 (10), the drainage modification pipeline 4 (11) and the drainage modification pipeline 5 (12) are respectively connected to the dehydrogenation product buffer tank.

2. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 1, wherein: The drainage reforming pipeline three (10), drainage reforming pipeline four (11) and drainage reforming pipeline five (12) are connected to the first-stage condensate tank (105), the second-stage condensate tank (205) and the third-stage condensate tank (305) in sequence.

3. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 1, wherein: The first interstage cooler (104), the second interstage cooler (204), the third interstage cooler (304) and the fourth interstage cooler (404) are connected in sequence to the drainage reforming pipeline six (13), the drainage reforming pipeline seven (14), the drainage reforming pipeline eight (15) and the drainage reforming pipeline nine (16), and the drainage reforming pipeline six (13), the drainage reforming pipeline seven (14), the drainage reforming pipeline eight (15) and the drainage reforming pipeline nine (16) are respectively connected to the dehydrogenation product buffer tank.

4. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 3, wherein: The drainage reforming pipeline six (13), drainage reforming pipeline seven (14), drainage reforming pipeline eight (15) and drainage reforming pipeline nine (16) are connected to the first-stage condensate tank (105), the second-stage condensate tank (205), the third-stage condensate tank (305) and the fourth-stage condensate tank (405) in sequence.

5. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 1, wherein: The third-stage condensate tank (305) and the fourth-stage condensate tank (405) are respectively provided with a liquid level gauge, and the discharge pipelines (7) of the third-stage condensate tank (305) and the fourth-stage condensate tank (405) are respectively provided with an electric regulating valve (17), and the liquid level gauge and the electric regulating valve (17) are electrically connected to the control system.

6. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 1, wherein: The sealing rings of the first-stage cylinder (101), the second-stage cylinder (201), the third-stage cylinder (301) and the fourth-stage cylinder (401) are connected to a nitrogen purge pipeline (18) and an oil discharge pipeline (19), and the oil discharge pipeline (19) is connected to a mid-body oil recovery tank (20).

7. The system for preventing liquid from entering the cylinder of a reciprocating compressor according to claim 1, wherein: The bottoms of the first-stage exhaust buffer tank (103), the second-stage exhaust buffer tank (203), the third-stage exhaust buffer tank (303) and the fourth-stage exhaust buffer tank (403) are sequentially connected with a backwash pipeline 1, a backwash pipeline 2, a backwash pipeline 3 and a backwash pipeline 4, and a sampling valve (21) is respectively provided on the backwash pipeline 1, the backwash pipeline 2, the backwash pipeline 3 and the backwash pipeline 4.

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