GB2605500A

GB2605500A - Liquid piston compressor with oil-supplementing slippage pump and high-speed switch valve

Info

Publication number: GB2605500A
Application number: GB2201573.9A
Authority: GB
Inventors: Zhao Shengdun; Zhou Hao; Jiang Hong; Zhu Shumiao; Feng Zhiyan
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2021-02-09
Filing date: 2022-02-08
Publication date: 2022-10-05
Anticipated expiration: 2042-02-08
Also published as: GB2605500B; CN112983780A; CN112983780B; GB2605500A8

Abstract

A liquid piston compressor with an oil-supplementing slippage pump 42 and a high-speed switch valve 36, comprising a drive plunger pump 2, a compression unit 1 and a controller. The compression unit comprises, a booster cylinder 5 with a piston assembly 11 and a compression cavity 12 and a hydraulic cavity 13, wherein a displacement sensor 18 is arranged in the compression cavity. An oil port of the hydraulic cavity is divided into one path connected with the drive plunger pump through a second one-way valve 38, and another path sequentially connected with the high-speed switch valve and an oil tank 43. The drive plunger pump is further connected with the oil tank through a third one-way valve 39 and the slippage pump. The controller determined whether the piston assembly is in the upper limit position or a descending state using the sensor, and if yes, the high-speed switch valve is opened. The hydraulic cavity may be divided into two cavities 30, 31 by a buffer groove disc (fig.2, 27) that may comprise a through hole 29 that matches with a buffer shaft 19 of the booster cylinder.

Description

LIQUID PISTON COMPRESSOR WITH OIL-SUPPLEMENTING SLIPPAGE

PUMP AND HIGH-SPEED SWITCH VALVE

TECHNICAL FIELD

100011 The present disclosure relates to the technical field of gas compressors, in particular to a liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve

BACKGROUND ART

100021 At present, most commonly-used compressors are of mechanical structures, and due to the fact that the mechanical compressor is complex in overall structure and large in transmission system, the service life of the mechanical compressor in the high-pressure environment is short, and the transmission efficiency is low. In addition, in the working process, due to the action of reciprocating motion and high alternation of the transmission structure, the noise of the mechanical compressor is large. Therefore, in recent years, hydraulic compression systems have been commonly applied at higher pressures. However, existing hydraulic compression systems suffer from several problems in the following aspects: 100031 Firstly, due to the fact that the position and the speed of a piston of the compressor cannot be controlled in real time, the compression process of the compressor is easy to be uncontrolled. Specifically, in some situations, the compressor may not reach the same upper and lower limit positions each time due to oil leakage, so that the compression efficiency is reduced, the energy utilization rate of the compressor is greatly reduced, and large gas output pulsation and large vibration of the compressor are caused; and in other situations, it may occur that the piston hits the upper and lower limit positions at a greater speed, so that significant vibrations are caused, and the service life of the components of the compressor is greatly shortened.

100041 Secondly, an existing liquid piston compressor can cause the problem that the compressed gas is polluted by the hydraulic oil without using ionic liquid to isolate hydraulic oil and compressed gas, and currently used ionic liquid generally has the defects of high corrosivity, high environmental pollution and the like.

SUMMARY

100051 According to a liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve provided by the embodiment of the present disclosure, the displacement and the speed of a piston assembly can be accurately controlled, oil is supplemented to the compressor in time through a slippage pump, it is guaranteed that the piston assembly can reach the upper limit position and the lower limit position every time, and high-speed collision is avoided.

100061 In order to achieve the purpose, the embodiment of the present disclosure provides a liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve, comprising a drive plunger pump, a compression unit and a controller, wherein the compression unit comprises a booster cylinder, the booster cylinder comprises a sealed cavity, the sealed cavity is internally provided with a piston assembly, and the sealed cavity is divided into a compression cavity and a hydraulic cavity located on the lower portion of the compression cavity by the piston assembly; a displacement sensor is arranged at the end, located in the compression cavity, of the piston assembly; an oil port of the hydraulic cavity is divided into two paths, one path is connected with the drive plunger pump through a second one-way valve, and the other path is sequentially connected with a high-speed switch valve and an oil tank; the drive plunger pump is further connected with the oil tank through a third one-way valve and the slippage pump; an inlet of the second one-way valve faces the drive plunger pump, and an inlet of the third one-way valve faces the slippage pump; the drive plunger pump can drive the piston assembly to move in the direction close to the compression cavity, and liquid discharged from the hydraulic cavity is sucked into a plunger cavity when the piston assembly moves downwards; the displacement volume of the drive plunger pump is larger than the volume of the hydraulic cavity; and the controller can receive displacement signals transmitted by the displacement sensor and judge whether the piston assembly is in the upper limit position or a descending state, and if yes, the high-speed switch valve is opened.

100071 Further, the liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve further comprises an energy accumulator at the inlet of the third one-way valve.

100081 Further, the liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve further comprises a discharge valve connected with the high-speed switch valve in parallel.

100091 Further, a plurality of compression units are arranged in series, a gas inlet of the compression unit located at the head end is used for being connected with a gas source, and a gas outlet of the compression unit located at the tail end is connected with a gas storage bottle 100101 Further, the drive plunger pump is a multi-cylinder radial plunger pump, the cylinder number of the drive plunger pump is equal to the number of the compression units, and plungers of the drive plunger pump correspond to the compression units one to one.

100111 Further, a buffer shaft is arranged at the end, close to the hydraulic cavity, of the piston assembly, the hydraulic cavity is internally provided with a buffer groove disc, a through hole matched with the buffer shaft is formed in the buffer groove disc, the hydraulic cavity is divided into a main hydraulic cavity and a buffer hydraulic cavity by the buffer groove disc, an oil suction port of the slippage pump is connected with the oil tank, an oil discharge port of the slippage pump is connected with the inlet of the third one-way valve, and an outlet of the third one-way valve is connected with an oil port of the drive plunger pump; an inlet of the high-speed switch valve is connected with an oil port of the main hydraulic cavity, and an outlet of the high-speed switch valve is connected with the oil tank; an oil port of the buffer hydraulic cavity is connected with an inlet of an adjustable throttle valve, and an outlet of the adjustable throttle valve is connected with the inlet of the high-speed switch valve; the inlet of the second one-way valve is connected with the oil port of the drive plunger pump, an outlet of the second one-way valve is connected with an inlet of a fourth one-way valve, and an outlet of the fourth one-way valve is connected with the oil port of the buffer hydraulic cavity.

100121 Further, the piston assembly is an I-shaped piston assembly.

100131 Further, the compression unit comprises a first cylinder barrel, the piston assembly comprises a first piston, the first piston can move in the first cylinder barrel, a water jacket is arranged on the outer side of the first cylinder barrel, and a cooling liquid sealed cavity is formed between the first cylinder barrel and the water jacket.

100141 Further, an upper end cover is arranged at an opening of the first cylinder barrel, a limiting shaft is arranged on the bottom surface of the upper end cover, and the limiting shaft and the piston assembly are coaxially arranged and located above the piston assembly.

100151 Further, the piston assembly further comprises a first connecting shaft and a second piston, the first connecting shaft is arranged between the second piston and the first piston, and the second piston and the first connecting shaft are connected through a screw; and the compression unit further comprises a second cylinder barrel, the second piston can move in the second cylinder barrel, the second cylinder barrel and the first cylinder barrel are connected through a connecting flange, and the first connecting shaft can move in an inner hole of the connecting flange.

100161 Compared with the prior art, the liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve has the following beneficial effects: 100171 Firstly, the position of the piston assembly is detected in real time through the displacement sensor, hydraulic oil is supplemented to the drive plunger pump in time through the slippage pump and the oil tank, and on the premise that the displacement and the speed of the piston assembly are accurately controlled in real time, it is guaranteed that the piston assembly can reach the upper limit position and the lower limit position every time and high-speed collision of the piston assembly is avoided 100181 Secondly, hydraulic oil discharged in the gas inlet process is circulated after entering the oil tank, and the cooling effect of the compressor is better due to the fact that the heat dissipation area of the oil tank is larger.

100191 Thirdly, the discharge valve is arranged in parallel with the high-speed switch valve, and the energy accumulator is arranged at the inlet of the third one-way valve, so that the safety and the pressure stabilizing effect of the compressor are further improved.

100201 Fourthly, through the compression ratio of compression stages matched with the number of drive plungers, multi-stage compression is achieved, and the compression ratio of the compression stages distributed to each stage is low, so that the compression process is closer to isothermal compression, and the compression efficiency and the energy utilization rate are improved 100211 Fifthly, the flow is controlled through the high-speed switch valve, and then the displacement-time relation of upward movement of the piston assembly is controlled, so that the compression efficiency of the compressor is improved.

100221 Sixthly, by adopting a one-way buffer structure, the buffer function of the gas inlet of the compressor is achieved under the condition that energy of the gas compression is not consumed, it is guaranteed that the compressor cannot collide with the bottom of the second cylinder barrel due to high gas inlet pressure, and safe and low-vibration work of the compressor is achieved.

100231 Seventhly, the I-shaped piston is adopted to isolate the hydraulic oil from the compression cavity, so that compressed gas is prevented from being polluted by the hydraulic oil, and corrosion to the compressor and pollution to the environment caused by using ionic liquid are avoided.

100241 Eighthly, the water jacket is arranged on the outer side of the first cylinder barrel, so that the cooling liquid sealed cavity for cooling the compression cavity is formed between the first cylinder barrel and the water jacket, and the heat dissipation effect of the compression cavity is better.

BRIEF DESCRIPTION OF THE DRAWINGS

100251 In order to illustrate the technical solutions in the embodiment of the present disclosure or in the prior art more clearly, the attached figures needing to be used in the embodiment or in the description in the prior art are simply described. Apparently, the embodiments in the following description are merely a part rather than all of the embodiments of the present disclosure. For those of ordinary skill in the art, under the premise of without contributing creative labor, other attached figures further can be obtained according to these attached figures.

100261 FIG. 1 is a schematic diagram of a compressor in an embodiment of the present disclosure; 100271 FIG. 2 is a structural schematic diagram of a booster pump in a single compression unit of a compressor in an embodiment of the present disclosure; and 100281 FIG. 3 is a schematic diagram of a hydraulic system in a single compression unit of a compressor in an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

100291 The following clearly and completely describes the technical solutions in the embodiments of the present disclosure with reference to the attached figures in the embodiments of the present disclosure. Apparently, the described embodiments are only a part rather than all of the embodiments of the present disclosure. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present disclosure without creative efforts shall fall within the protection scope of the present disclosure.

100301 In the description of the present disclosure, it needs to be illustrated that the indicative direction or position relations of the terms such as "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are direction or position relations illustrated based on the attached figures, just for facilitating the description of the present disclosure and simplifying the description, but not for indicating or hinting that the indicated device or element must be in a specific direction and is constructed and operated in the specific direction, the terms cannot be understood as the restriction of the present disclosure.

100311 In the description of the present disclosure, it needs to be illustrated that, except as otherwise noted, the terms such as "install", "link" and "connect" should be generally understood, for example, the components can be fixedly connected, and also can be detachably connected or integrally connected; and for those skilled in the art, the specific meanings of the terms in the present disclosure can be understood according to specific conditions.

100321 The terms "first" and "second" are merely intended for a purpose of description, and shall not be understood as an indication or implication of relative importance or implicit indication of the number of indicated technical features. Therefore, a feature limited by "first" or "second" may include one or more features explicitly or implicitly. In the descriptions of the embodiments of the present disclosure, "plurality" means at least two, unless otherwise specified.

100331 Referring to FIG. 1 to FIG. 3, the embodiment of the present disclosure provides a liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve, and the compressor comprises a drive plunger pump 2, a compression unit 1 and a controller (unshown in the figures). One or a plurality of compression units 1 can be arranged, and when a plurality of compression units 1 are arranged, the drive plunger pump 2 is a multi-cylinder radial plunger pump, the cylinder number of the drive plunger pump 2 is equal to the number of the compression units 1, and plungers of the drive plunger pump 2 correspond to the compression units 1 one to one. Five compression units 1 are described below as an example.

100341 Referring to FIG. 1, the compression is a five-stage compression type ultrahigh pressure compressor, the number of the compression units 1 is five, the five compression units 1 are arranged in series, a gas inlet of the compression unit 1 located at the head end is connected with a gas source (unshown in the figures), and a gas outlet of the compression unit 1 located at the tail end is connected with a gas storage bottle 4. The gas inlet and the gas outlet of each compression unit 1 are respectively provided with a first one-way valve 3. The first one-way valve 3 is used for achieving the gas inlet and compression processes of the compressor. The compressed gas of each stage is guided into the next stage to be compressed continuously, and finally ultrahigh pressure Gas obtained through compression is fed into the gas storage bottle 4 to be stored.

100351 Referring to FIG. 1 and FIG. 2, each compression unit 1 comprises a booster cylinder 5, the booster cylinder 5 comprises a first cylinder barrel 6 and a second cylinder barrel 7 arranged on the lower portion of the first cylinder barrel 6, a flange 8 is arranged between the first cylinder barrel 6 and the second cylinder barrel 7, the first cylinder barrel 6 and the flange 8 are connected through a first threaded disc 9, and the second cylinder barrel 7 and the flange 8 are connected through a second threaded disc 10. The first cylinder barrel 6 and the second cylinder barrel 7 jointly form a sealed cavity, the sealed cavity is internally provided with a piston assembly 11, the piston assembly 11 is in an I shape, and the sealed cavity is divided into a compression cavity 12 and a hydraulic cavity 13 by the piston assembly 11. Wherein, the compression cavity 12 is located in the first cylinder barrel 6, and the hydraulic cavity 13 is located in the second cylinder barrel 7. The piston assembly 11 comprises a first piston 14 and a second piston 15, the first piston 14 can move in the first cylinder barrel 6, the second piston 15 can move in the second cylinder barrel 7, a first connecting shaft 16 is arranged between the first piston 14 and the second piston 15, and the second piston 15 and the first connecting shaft 16 are connected through a screw 17. The first connecting shaft 16 can move in an inner hole of the connecting flange 8. A third sealing ring 32 and two first sealing rings 33 are arranged between the first piston 14 and the first cylinder barrel 6. A fourth sealing ring 34 and two second sealing rings 35 are arranged between the second piston 15 and the second cylinder barrel 7. A displacement sensor 18 is arranged on the first piston 14. A buffer shaft 19 is arranged on the second piston 15. The drive plunger pump 2 can drive the piston assembly 11 to move upwards and suck liquid discharged from the hydraulic cavity 13 into the plunger cavity when the piston assembly 11 moves downwards.

100361 An upper end cover 20 is arranged at an opening of the compression cavity 12, a limiter 21 is arranged on the bottom surface of the upper end cover 20, specifically, the limiter 21 is a limiting shaft, and the limiting shaft and the piston assembly 11 are coaxially arranged and located above the piston assembly 11. The limiting shaft and the first cylinder barrel 6 are sealed through a first sealing element 22.

100371 A water jacket 23 is arranged on the outer side of the first cylinder barrel 6, the first cylinder barrel 6 and the water jacket 23 are sealed through two second sealing elements 24, and a cooling liquid sealed cavity is formed between the first cylinder barrel 6 and the water jacket 23.

100381 The bottom of the second cylinder barrel 7 is sequentially connected with a connecting disc 25, an oil inlet disc 26, a buffer groove disc 27 and a base 28 from top to bottom. A through hole 29 matched with the buffer shaft 19 is formed in the buffer groove disc 27, the hydraulic cavity 13 is divided into a main hydraulic cavity 30 and a buffer hydraulic cavity 31 by the buffer groove disc 27.

100391 Referring to FIG. 3, an oil suction port of an slippage pump 42 is connected with an oil tank 43, an oil discharge port of the slippage pump 42 and an oil port of an energy accumulator 40 are both connected with an inlet of a third one-way valve 39, and an outlet of the third one-way valve 39 is connected with an oil port of the drive plunger pump 2.

100401 An inlet of a high-speed switch valve 36 and an inlet of a discharge valve 44 are both connected with an oil port of the main hydraulic cavity 30, and an outlet of the high-speed switch valve 36 and an outlet of the discharge valve 44 are both connected with the oil tank 43.

100411 An oil port of the buffer hydraulic cavity 31 is connected with an inlet of an adjustable throttle valve 37, and an outlet of the adjustable throttle valve 37 is connected with the inlet of the high-speed switch valve 36 and the inlet of the discharge valve 44 respectively.

100421 An inlet of a second one-way valve 38 is connected with the oil port of the drive plunger pump 2, an outlet of the second one-way valve 38 is connected with an inlet of a fourth one-way valve 41, and an outlet of the fourth one-way valve 41 is connected with the oil port of the buffer hydraulic cavity 31.

100431 The displacement volume of a single plunger of the drive plunger pump 2 is larger than the volume of the hydraulic cavity 13, the controller can receive displacement signals transmitted by the displacement sensor 18 and judge whether the piston assembly 11 is in the upper limit position or the lower limit position, and if yes, the high-speed switch valve 36 is opened.

100441 According to the embodiment of the present discourse, the hydraulic cavity 13 and the compression cavity 12 are separated through the piston assembly 11, so that the pollution of hydraulic oil to compressed gas is prevented, the displacement volume of the hydraulic oil in the plunger cavity is slightly larger than the maximum volume of the hydraulic oil in the hydraulic cavity 13 in consideration of possible leakage in a hydraulic oil way and the compressor, and the displacement sensor 18 is further arranged to control the high-speed switch valve 36 to be switched on and off, so that the effects of optimizing the compression stroke of the compressor, returning oil in the gas inlet and supplementing oil to the whole hydraulic system are achieved.

100451 Referring to FIG. 1 to FIG. 3, the working principle of the liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve in the embodiment of the present disclosure is as follows: 100461 In the gas inlet process, the high-speed switch valve 36 and the slippage pump 42 are both in an open state, and the slippage pump 42 is continuously opened. After pressurized gas in an external gas source opens the first one-way valve 3 at a gas inlet of a booster pump, the piston assembly 11 is pushed to move downwards, the displacement sensor 18 collects displacement signals of the piston assembly 11 in real time and sends the displacement signals to the controller, and hydraulic oil in the hydraulic cavity 13 of the booster pump flows out of the oil port of the main hydraulic cavity 30 and then enters the oil tank 43 through the high-speed switch valve 36. When the piston assembly 11 reaches the lower limit position, the controller controls the high-speed switch valve 36 to be closed, and the hydraulic oil in the oil tank 43 enters the drive plunger pump 2 to supplement the hydraulic oil in the drive plunger pump 2.

100471 In the gas inlet process, before the buffer shaft 19 enters the through hole 29 in the buffer groove disc 27, the hydraulic oil flows out through the oil port of the main hydraulic cavity 30, and a buffer effect is not achieved. After the buffer shaft 19 enters the through hole 29 in the buffer groove disc 27, the hydraulic oil in the main hydraulic cavity 30 continues to flow out of the oil port of the main hydraulic cavity 30, and the hydraulic oil in the buffer hydraulic cavity 31 enters the oil tank 43 through the high-speed switch valve 36 after being throttled by the adjustable throttle valve 37, so that instantaneous high pressure is formed, and a buffer effect is achieved.

100481 In the gas compression process, the high-speed switch valve 36 is closed, the hydraulic oil in the drive plunger pump 2 enters the hydraulic cavity 13 through the oil port of the main hydraulic cavity 30 after passing through the second one-way valve 38, or the hydraulic oil enters the hydraulic cavity 13 through the oil port of the buffer hydraulic cavity 31 after passing through the second one-way valve 38 and the fourth one-way valve 41 to drive the piston assembly 11 to move upwards until the piston assembly 11 moves upwards to the upper limit position, the controller controls the high-speed switch valve 36 to be opened, the main hydraulic cavity 30 starts to discharge oil, the piston assembly 11 descends, and the gas inlet process continues to be repeated. The compressed gas of each stage is guided into the next stage to be compressed continuously, and finally ultrahigh pressure gas obtained through compression is fed into the gas storage bottle 4 to be stored.

100491 In the whole gas inlet and compression process, the energy accumulator 40 and the discharge valve 43 can guarantee that the pressure of the whole hydraulic system is stable, and the use safety of the compressor is improved.

100501 The foregoing descriptions are merely specific implementations of this application, but are not intended to limit the protection scope of this application. Any variation or replacement within the technical scope disclosed in this application shall fall within the protection scope of this application. Therefore, the protection scope of this application shall be subject to the protection scope of the claims.

Claims

WHAT IS CLAIMED IS: 1. A liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve, comprising a drive plunger pump, a compression unit and a controller, wherein the compression unit comprises a booster cylinder, the booster cylinder comprises a sealed cavity, the sealed cavity is internally provided with a piston assembly, and the sealed cavity is divided into a compression cavity and a hydraulic cavity located on the lower portion of the compression cavity by the piston assembly; a displacement sensor is arranged at the end, located in the compression cavity, of the piston assembly; an oil port of the hydraulic cavity is divided into two paths, one path is connected with the drive plunger pump through a second one-way valve, and the other path is sequentially connected with a high-speed switch valve and an oil tank, the drive plunger pump is further connected with the oil tank through a third one-way valve and the slippage pump; an inlet of the second one-way valve faces the drive plunger pump, and an inlet of the third one-way valve faces the slippage pump; the drive plunger pump can drive the piston assembly to move in the direction close to the compression cavity, and liquid discharged from the hydraulic cavity is sucked into a plunger cavity when the piston assembly moves downwards; the displacement volume of the drive plunger pump is larger than the volume of the hydraulic cavity; and the controller can receive displacement signals transmitted by the displacement sensor and judge whether the piston assembly is in the upper limit position or a descending state, and if yes, the high-speed switch valve is opened.
2. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 1, further comprising an energy accumulator at the inlet of the third one-way valve.
3. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 1, further comprising a discharge valve connected with the high-speed switch valve in parallel
4. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to any one of claims 1 to 3, wherein a plurality of compression units are arranged in series, a gas inlet of the compression unit located at the head end is used for being connected with a gas source, and a gas outlet of the compression unit located at the tail end is connected with a gas storage bottle
5. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 4, wherein the drive plunger pump is a multi-cylinder radial plunger pump, the cylinder number of the drive plunger pump is equal to the number of the compression units, and plungers of the drive plunger pump correspond to the compression units one to one
6. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 1, wherein a buffer shaft is arranged at the end, close to the hydraulic cavity, of the piston assembly, the hydraulic cavity is internally provided with a buffer groove disc, a through hole matched with the buffer shaft is formed in the buffer groove disc, the hydraulic cavity is divided into a main hydraulic cavity and a buffer hydraulic cavity by the buffer groove disc, an oil suction port of the slippage pump is connected with the oil tank, an oil discharge port of the slippage pump is connected with the inlet of the third one-way valve, and an outlet of the third one-way valve is connected with an oil port of the drive plunger pump; an inlet of the high-speed switch valve is connected with an oil port of the main hydraulic cavity, and an outlet of the high-speed switch valve is connected with the oil tank; an oil port of the buffer hydraulic cavity is connected with an inlet of an adjustable throttle valve, and an outlet of the adjustable throttle valve is connected with the inlet of the high-speed switch valve; the inlet of the second one-way valve is connected with the oil port of the drive plunger pump, an outlet of the second one-way valve is connected with an inlet of a fourth one-way valve, and an outlet of the fourth one-way valve is connected with the oil port of the buffer hydraulic cavity.
7. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 1, wherein the piston assembly is an I-shaped piston assembly.
8. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 1, wherein the compression unit comprises a first cylinder barrel, the piston assembly comprises a first piston, the first piston can move in the first cylinder barrel, a water jacket is arranged on the outer side of the first cylinder barrel, and a cooling liquid sealed cavity is formed between the first cylinder barrel and the water jacket.
9. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 8, wherein an upper end cover is arranged at an opening of the first cylinder barrel, a limiting shaft is arranged on the bottom surface of the upper end cover, and the limiting shaft and the piston assembly are coaxially arranged and located above the piston assembly.
10. The liquid piston compressor with an oil-supplementing slippage pump and a high-speed switch valve according to claim 9, wherein the piston assembly further comprises a first connecting shaft and a second piston, the first connecting shaft is arranged between the second piston and the first piston, and the second piston and the first connecting shaft are connected through a screw; and the compression unit further comprises a second cylinder barrel, the second piston can move in the second cylinder barrel, the second cylinder barrel and the first cylinder barrel are connected through a connecting flange, and the first connecting shaft can move in an inner hole of the connecting flange.