阅读说明：本技术 具有能量回收功能的旋转活塞式高压泵 (Rotary piston type high-pressure pump with energy recovery function ) 是由 朱荣辉 于 2019-10-22 设计创作，主要内容包括：本发明涉及一种具有能量回收功能的旋转活塞式高压泵,包括壳体、驱动机构、若干活塞组件、缸体转子组件和配流机构；驱动机构、活塞组件、缸体转子组件和配流机构依次安装在壳体内；活塞组件一端与驱动机构连接,另一端位于缸体转子组件的缸体内,将缸体分为有杆的能量回收腔和无杆的泵腔,随着缸体转子组件的转动,活塞组件在驱动机构的作用下在缸体转子组件中的缸体内往复运动；配流机构包括配流窗口和设置在缸体转子组件和壳体上的加压流体以及能量回收流体的进、出流道,将缸体转子组件上各缸体的泵腔流道与壳体上加压流体的低压进口和高压出口流道交替对接,能量回收腔与相应的能量回收流道接通,提高高压加压与能量回收的效率。(The invention relates to a rotary piston type high-pressure pump with an energy recovery function, which comprises a shell, a driving mechanism, a plurality of piston assemblies, a cylinder rotor assembly and a flow distribution mechanism, wherein the shell is provided with a plurality of piston assemblies; the driving mechanism, the piston assembly, the cylinder rotor assembly and the flow distribution mechanism are sequentially arranged in the shell; one end of the piston assembly is connected with the driving mechanism, the other end of the piston assembly is positioned in the cylinder body of the cylinder body rotor assembly, the cylinder body is divided into an energy recovery cavity with a rod and a pump cavity without a rod, and the piston assembly reciprocates in the cylinder body rotor assembly under the action of the driving mechanism along with the rotation of the cylinder body rotor assembly; the flow distribution mechanism comprises a flow distribution window, and inlet and outlet channels for pressurized fluid and energy recovery fluid which are arranged on the cylinder rotor assembly and the shell, pump cavity channels of each cylinder on the cylinder rotor assembly are alternatively butted with low-pressure inlet and high-pressure outlet channels of the pressurized fluid on the shell, and the energy recovery cavity is communicated with the corresponding energy recovery channels, so that the efficiency of high-pressure pressurization and energy recovery is improved.)

1. A rotary piston high-pressure pump with energy recovery function, its characterized in that: comprises a shell (1), a driving mechanism (2), a plurality of piston assemblies (3), a cylinder body rotor assembly (4) provided with a plurality of cylinder bodies and a flow distribution mechanism (5); the driving mechanism (2), the piston assembly (3), the cylinder rotor assembly (4) and the flow distribution mechanism (5) are sequentially arranged in the shell (1); one end of the piston assembly (3) is connected with the driving mechanism (2), the other end of the piston assembly is positioned in the cylinder body of the cylinder body rotor assembly (4), the cylinder body is divided into an energy recovery cavity (A) with a rod and a pump cavity (B) without a rod, and along with the rotation of the cylinder body rotor assembly (4), the piston assembly (3) reciprocates in the cylinder body rotor assembly (4) under the action of the driving mechanism (2); the flow distribution mechanism (5) comprises a flow distribution window (C) for pressurizing fluid and energy recovery fluid, and inlet and outlet flow channels (D) for pressurizing fluid and energy recovery fluid which are arranged on the cylinder body rotor assembly (4) and the shell (1), wherein the flow distribution window is in running fit with the cylinder body rotor assembly (4), when the cylinder body rotor assembly (4) rotates, flow channels of a pump cavity (B) of each cylinder body on the cylinder body rotor assembly (4) are alternatively butted with a low-pressure inlet and a high-pressure outlet flow channel of the pressurizing fluid on the shell (1), and synchronously, flow channels of an energy recovery cavity (A) of each cylinder body on the cylinder body rotor assembly (4) are alternatively communicated with a low-pressure outlet and a high-pressure inlet flow channel of the fluid which needs energy recovery on the shell.

2. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: the driving mechanism (2) is a first inclined shaft mechanism (21), the first inclined shaft mechanism (21) comprises a driving disc (215), a first main shaft (211) and a first return disc (218), the driving disc (211) is coaxially and fixedly connected with the first main shaft (211), a plurality of ball sockets are distributed at equal intervals along the circumferential direction of the driving disc (215), the first return disc (218) is fixedly connected with the driving disc (215) in a threaded mode, the driving disc (215) and the first return disc (218) are connected with one end of the piston assembly (3) in a spherical hinge mode, a first oblique angle is formed between the axis of the driving disc (215) and the axis of the cylinder body rotor assembly (4), and when the driving disc (215) and the cylinder body rotor synchronously rotate, the piston assembly (3) is driven to reciprocate in the cylinder body of the cylinder body rotor assembly (4).

3. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: the driving mechanism (2) is a swash plate mechanism (22), the swash plate mechanism (22) comprises a second main shaft (221), a swash plate (225) and a second return plate (226), the second return plate (226) and the swash plate (225) jointly limit sliding connection of one end of the piston assembly (3) on the swash plate (225), the second main shaft (221) and the cylinder rotor assembly (4) are fixedly connected in the circumferential direction and synchronously rotate, a second oblique angle is arranged between the axis of the swash plate (225) and the axis of the cylinder rotor assembly (4), the second main shaft (221) drives the cylinder rotor assembly (4) to rotate, one end of the piston assembly (4) is driven to slide on the swash plate (225), and the other end of the piston assembly reciprocates in the cylinder rotor assembly (4).

4. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: the ratio of the cavity sectional area of the energy recovery cavity (A) to the cavity sectional area of the pump cavity (B) is equal to the ratio of the flow rate of the fluid needing energy recovery to the flow rate of the fluid needing pressurization.

5. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: the flow distribution mechanism (5) comprises a central flow distribution shaft (512) which is arranged in the center of the cylinder rotor (43) and is provided with a high-pressure independent energy recovery flow channel (E) and a low-pressure independent energy recovery flow channel (E), and an energy recovery flow distribution window I (F) of the flow distribution mechanism (5) is radially arranged on the central flow distribution shaft (512).

6. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: the flow distribution mechanism (5) comprises an axial energy recovery flow channel (H) arranged on the inner side of each cylinder body of the cylinder body rotor assembly (4) and a crescent energy recovery flow distribution window II (K) correspondingly arranged on the inner side of the pump cavity flow distribution window (J), and the energy recovery flow distribution window II (K) is positioned between the cylinder body rotor assembly (4) and the shell (1).

7. The rotary piston high-pressure pump with energy recovery according to claim 1, characterized in that: and a static pressure balance area (G) is arranged opposite to the high-pressure flow distribution window of the cylinder body rotor assembly (4) and the flow distribution mechanism (5).

8. The rotary piston high-pressure pump with energy recovery according to claim 2 or 3, characterized in that: and a bearing is arranged on the first main shaft (211) or the second main shaft (221), and the bearing is an oil or grease lubricated rolling bearing.

Technical Field

The invention belongs to the field of equipment such as a high-pressure pump and an energy recoverer required in a reverse osmosis technology, and particularly relates to a rotary piston type high-pressure pump with an energy recovery function.

Background

The reverse osmosis technology is a technology for separating a liquid solute from a solvent by pressurizing the liquid and then passing the solvent through a semipermeable membrane or a molecular sieve by using the principle of reverse osmosis by a membrane method. Is widely applied to the fields of liquid concentration, solute separation, sewage treatment, brackish water desalination, seawater desalination and the like.

In this technique, the high pressure pressurization of the liquid requires a lot of energy consumption, and at the same time, the high pressure potential energy in the concentrate is effectively recovered to save the energy consumed in the reverse osmosis process. Therefore, reverse osmosis technology involves two key devices: a high-pressure pump (HP-highpressuerepump) and an energy recovery device (ERD-energy recovery device). In a membrane-method seawater desalination plant adopting the reverse osmosis principle, even if a high-efficiency energy recoverer is adopted, the total energy consumption cost still accounts for more than 50% of the operation cost. How to further improve the efficiency of the two devices and reduce the cost thereof is the development direction of reverse osmosis technology devices.

1. A high-pressure pump:

high pressure pump technology that has become widely used includes both plunger pumps and centrifugal pumps.

The plunger pump is a displacement pump, and the plunger pump applies pressure by volume change caused by the reciprocating motion of the plunger in the cylinder body, and the efficiency can reach more than 90 percent. The plunger pump is divided into valve flow distribution and rotary flow distribution according to different flow distribution modes. The axial plunger pump is divided into a radial plunger pump with the cylinder axis perpendicular to the main shaft axis and an axial plunger pump with the cylinder axis parallel to the main shaft axis according to the position relationship between the cylinder and the main shaft. Because the plunger pump is a reciprocating mechanism, the reciprocating motion inertia force of machinery and fluid inevitably causes vibration and noise, and the fluid PV value is restricted no matter valve distribution or rotary distribution, so that the plunger pump is more suitable for a small-flow high-pressure reverse osmosis device.

The centrifugal pump is pressurized by utilizing centrifugal force generated by high-speed rotation of fluid driven by the rotating blades, and under the condition of high pressure, the centrifugal pump needs to be pressurized by serially connecting a plurality of stages of centrifugal impellers, so that the overall efficiency is low, generally about 80%, and the high-efficiency area is narrow, and the centrifugal pump is suitable for a high-flow medium-high pressure reverse osmosis device with fixed capacity.

2. An energy recoverer:

the early energy recovery device adopts the principle of a water turbine, and the energy recovery efficiency is below 70%. In some small applications, oil hydraulic motor technology is gradually being developed to move to direct fluid regenerators, such as those based on axial piston motors, vane motors and gear motors, to come out. With the progress of the technology, the isobaric exchange technology with the recovery efficiency of more than 90 percent is applied, wherein the energy recovery device with a piston-free rotary flow distribution rotating cylinder structure and the energy recovery device with a valve flow distribution fixed cylinder structure are the most successful. In the piston-free energy recovery device, there is no piston physically divided between the concentrated solution and the stock solution, and a mixing phenomenon inevitably occurs, resulting in a decrease in system efficiency. In a valve-gated regenerator, it is necessary to reduce shock vibration to improve service life and how to reduce system complexity caused by valve control.

In the current large and medium reverse osmosis system, the high pressure pump and the energy recovery device are two independent devices, even in some small applications, in order to simplify the system, the two devices are only coaxially installed, for example, an axial high pressure plunger pump and a vane type motor, or the high pressure pump and the energy recovery device are formed by coupling with another axial plunger type motor, so as to save the installation space and simplify the connection of the devices, but the energy recovery efficiency of the structure is still low. During the last decade, some attempts have been made to incorporate isobaric exchange energy recovery into high-pressure pumps, all of which have failed to enter industrial applications due to structural design deficiencies.

The invention and granted Chinese patent application No. CN201210324608.0 of the inventor of the invention, namely a membrane method seawater desalination high-pressure pump and energy recovery integrated device, provides a basic idea of completing the functions of the high-pressure pump and the energy recovery device on a single structure: a rod cavity and a rodless cavity are formed by a group of piston bodies with single rods and a piston cylinder, the rod cavity is used as an energy recovery cavity, the rodless cavity is used as a high-pressure pump cavity, and the functions of pressurization and energy recovery can be simultaneously finished when the piston moves, namely 'one cylinder has two functions'. The invention replaces centrifugal pressurization with hydraulic pressurization, replaces piston-free isobaric exchange with piston-isolated isobaric exchange, and practice proves that the efficiency of the RO system can be greatly improved by more than 10% compared with the traditional centrifugal pump and rotary water piston energy recoverer mode. The pipeline connection is simple, the occupied space is reduced, the manufacturing difficulty is reduced, and particularly, the pipeline connection device has the characteristic of being capable of efficiently operating in a wide flow and pressure range, so that the pipeline connection device can play a role in the fields of variable salt content, variable flow, variable energy supply and the like. For example, the system is directly coupled and matched with new energy such as unstable solar energy, wind energy and the like, so that the cost of the new energy can be greatly reduced; for example, the device can be automatically matched and adapted when various water sources with different salt contents such as rainwater, brackish water, seawater and reclaimed water are supplied, so that various devices do not need to be matched for coping, the flow of water treatment can be greatly simplified, and the total investment cost is greatly reduced. However, the system adopts hydraulic cylinder driving and valve flow distribution, relates to a hydraulic pump, a hydraulic oil circuit, a control water valve and a corresponding electric control system, is relatively complex in structure, and has a space for improvement and optimization.

In summary, the existing reverse osmosis technology has the problems that how to further improve the energy efficiency, simplify the structure and reduce the investment cost and the operation cost of equipment is the development direction.

Disclosure of Invention

The invention aims to provide a rotary piston type high-pressure pump reverse osmosis device integrating an energy recovery function based on the basic idea of the invention of Chinese patent application No. CN201210324608.0 of the inventor, namely a membrane seawater desalination high-pressure pump and energy recovery integrated device, by replacing a driving mechanism of an axial plunger pump and an innovative mechanism of rotary flow distribution for driving a hydraulic cylinder and controlling valve flow distribution, and the invention realizes the following effects:

1. the efficiency of high-pressure pressurization and energy recovery is further improved;

2. the structure is simpler, the manufacture is easier, and the production cost is lower.

3. The system is more reliable and more convenient to maintain.

The purpose of the invention is realized as follows:

the invention discloses a rotary piston type high-pressure pump with an energy recovery function, which comprises a shell, a driving mechanism, a plurality of piston assemblies, a cylinder rotor assembly and a flow distribution mechanism, wherein the cylinder rotor assembly is provided with a plurality of cylinders; the driving mechanism, the piston assembly, the cylinder body rotor assembly and the flow distribution mechanism are sequentially arranged in the shell; one end of the piston assembly is connected with the driving mechanism, the other end of the piston assembly is positioned in the cylinder body of the cylinder body rotor assembly, the cylinder body is divided into an energy recovery cavity with a rod and a pump cavity without a rod, and the piston assembly reciprocates in the cylinder body rotor assembly under the action of the driving mechanism along with the rotation of the cylinder body rotor assembly; the flow distribution mechanism comprises a flow distribution window for pressurizing fluid and energy recovery fluid, and an inlet flow channel and an outlet flow channel for pressurizing fluid and energy recovery fluid which are arranged on the cylinder body rotor assembly and the shell, wherein the flow distribution window is in running fit with the cylinder body rotor assembly, when the cylinder body rotor assembly rotates, a pump cavity flow channel of each cylinder body on the cylinder body rotor assembly is in butt joint with a low-pressure inlet flow channel and a high-pressure outlet flow channel of the pressurizing fluid on the shell alternately, and synchronously, the energy recovery cavity flow channel of each cylinder body on the cylinder body rotor assembly is in communication with a low-pressure outlet flow channel and a high-pressure inlet flow channel of the fluid which need to be subjected to.

Further, actuating mechanism is the oblique axis mechanism, the oblique axis mechanism includes driving-disc, main shaft one and return stroke dish one, the driving-disc is coaxial fixed connection with main shaft one, and has a plurality of ball sockets along the equidistant distribution of driving-disc circumference, return stroke dish one and driving-disc screw thread fixed connection, the driving-disc constitutes the ball pivot with one end of piston assembly together with return stroke dish one and is connected, there is first oblique angle between the axis of driving-disc and the cylinder body rotor subassembly axial lead, when driving-disc and cylinder body rotor synchronous revolution, the reciprocating motion of drive piston assembly in the cylinder body of cylinder body rotor subassembly.

Furthermore, actuating mechanism is sloping cam plate mechanism, sloping cam plate mechanism includes main shaft two, sloping cam plate and return stroke dish two, return stroke dish two and sloping cam plate prescribe a limit to the sliding connection of piston assembly's one end on the sloping cam plate jointly, main shaft two and cylinder body rotor subassembly circumference fixed connection and synchronous revolution, there is the second oblique angle between the axis of sloping cam plate and cylinder body rotor subassembly axial lead, and main shaft two drive cylinder body rotor subassembly is rotatory, and when the one end of drive piston assembly slided on the sloping cam plate, the other end reciprocating motion in cylinder body rotor subassembly.

Further, the ratio of the cavity sectional area of the energy recovery cavity to the cavity sectional area of the pump cavity is equal to the ratio of the flow rate of the fluid needing energy recovery to the flow rate of the fluid needing pressurization.

Furthermore, the flow distribution mechanism comprises a central flow distribution shaft which is arranged in the center of the cylinder rotor and is provided with a high-pressure independent energy recovery flow channel and a low-pressure independent energy recovery flow channel, and an energy recovery flow distribution window of the flow distribution mechanism is radially arranged on the central flow distribution shaft.

Furthermore, the flow distribution mechanism comprises an axial energy recovery cavity arranged on the inner side of each cylinder of the cylinder rotor assembly and a crescent energy recovery flow distribution window II correspondingly arranged on the inner side of the flow distribution window of the pump cavity, wherein the energy recovery flow distribution window II is positioned between the cylinder rotor assembly and the shell.

Further, a static pressure balance area is arranged opposite to the high-pressure flow distribution window of the flow distribution mechanism and the cylinder body rotor assembly.

Further, a bearing is arranged on the first main shaft or the second main shaft and is an oil or grease lubricated rolling bearing

The invention has the beneficial effects that:

1. the system is simplified, and the efficiency is further improved:

for large and medium seawater desalination systems, the axial piston type high-pressure pump with the energy recovery function simplifies a high-pressure pump, an energy recoverer, a booster pump and pipeline valves connected with the energy recoverer of a traditional reverse osmosis system into one device, improves the system efficiency to more than 85% compared with the traditional device, reduces the energy consumption by 15%, and greatly reduces the water making cost.

2. The manufacture is easier, and the production cost is further reduced:

for manufacturers, the structure of the high-pressure pump is similar to that of the existing hydraulic pump, manufacturers of the existing hydraulic pump can put the high-pressure pump into operation without purchasing new equipment, and the applicable flow pressure interval of each model of the centrifugal pump is narrow. The pump of the invention belongs to a displacement pump, one model can cover a quite wide flow and pressure range downwards, the model spectrum is less, the manufacturing equipment investment is less, and the production cost is reduced.

For the equipment user, the equipment saves the installation space, a large amount of pipeline valves and equipment installation engineering cost, and reduces the initial investment.

3. The operation is simple, the maintenance is convenient, and the operation and maintenance cost is low:

the reverse osmosis equipment disclosed by the invention is started and stopped by one key, and does not need complex start and stop control and overcurrent, overvoltage and flow balance treatment. In addition, the wearing parts of the friction pair are all independent from the main body, and the friction pair is easy to replace and install due to the embedded structure. Thus, the operation and maintenance cost is reduced.

4. Reliability is improved, no failure time and service life are prolonged:

the simplified structure reduces the number of fault points; the reasonable design and material selection are optimized, the embedded design of the quick-wear part avoids the occurrence of faults as much as possible, and meanwhile, the service life of the pump is prolonged.

Drawings

The following is further described with reference to three embodiments and the corresponding drawings. The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1: a front view of a high-pressure oblique axis pump according to embodiment 1 of the present invention;

FIG. 2: the piston body and the piston cylinder of the high-pressure inclined shaft pump in the embodiment 1 of the invention are structurally and crosssectional;

FIG. 3: a front view of a high-pressure swash plate pump according to embodiment 2 of the present invention;

FIG. 4: the sectional structure of the cylinder and piston body of the high-pressure swash plate pump of the embodiments 1 and 2 of the present invention;

FIG. 5: the cross-sectional view of the outlet end of the port shaft of the high-pressure swash plate pump of embodiments 1 and 2 of the present invention;

FIG. 6: the invention embodiment 1 and 2 of the high pressure pump cylinder rotor three-dimensional schematic diagram;

FIG. 7: the three-dimensional schematic diagram of the central port shaft of the high-pressure pump of embodiments 1 and 2 of the invention;

FIG. 8: the invention embodiment 1 and 2 high pressure pump energy recovery cavity distribution cross section view;

FIG. 9: the three-dimensional schematic diagrams of the flow distribution ring and the sliding bearing ring of the energy recovery cavity of the high-pressure pump according to embodiments 1 and 2 of the present invention;

FIG. 10: the schematic diagrams of the cylinder rotor back cover and the pump cavity channel of embodiments 1 and 2 of the present invention;

FIG. 11: schematic diagrams of the port plate and the port window of embodiments 1 and 2 of the present invention;

FIG. 12: the end surface flow distribution oblique axis pump of embodiment 3 of the invention;

FIG. 13: the end surface flow distribution oblique axis pump cylinder body rotor body three-dimensional schematic diagram of embodiment 3 of the invention;

FIG. 14: the three-dimensional schematic diagram of the rear end cover of the end surface flow distribution oblique shaft pump cylinder rotor in embodiment 3 of the invention;

FIG. 15: the three-dimensional schematic diagram of the port plate of the end face flow-distributing oblique axis pump in embodiment 3 of the present invention. Legend: 1. a housing; 11. a front housing; 12. a middle shell; 13. a tail shell; 14. a first drainage hole; 2. a drive mechanism; 21. a first inclined shaft mechanism; 210. a bevel gear assembly; 211. a first main shaft; 212. a first front bearing; 213. a first rear bearing; 214. sealing the end face; 215. a drive disc; 216. a ball socket; 217. radial sealing; 218. a first return disc; 219. pre-pressing a spring; 22. a swash plate mechanism; 221. a second main shaft; 222. rotating the lip seal ring; 223. a front bearing II; an O-ring seal; 225. a swash plate; 226. a second return disc; 227. a return disc spherical hinge prepressing spring; 228. a return disc is in spherical hinge; 23. a second inclined shaft mechanism; 230. a ball hinge assembly; 231. a central shaft; 232. double seal rings; 233. a tail bearing; 3. a piston assembly; 31. a first piston assembly; 311. a push rod big ball; 312. a push rod; 313. a piston rod; 314. a pusher ball; 315. a push rod small ball socket; 316. a piston disc; 317. a small through-flow hole; 32. a piston assembly II; 321. a piston rod ball head; 322. a slipper; 323. a first piston rod; 324. a piston and a seal; 4. a cylinder rotor assembly; 41. a cylinder cover sealing seat; 42. a cylinder rotor front cover; 43. a cylinder rotor; 44. a cylinder body and a cylinder sleeve; 45. a cylinder rotor rear cover; 46. an outer sliding bearing ring; 5. a flow distribution mechanism; 51. shaft flow distribution; 511. a first fluid port plate to be pressurized; 512. a central port shaft; 513. a first low-pressure inlet of a fluid to be pressurized; 514. a first low-pressure outlet for fluid to be energy recovered; 515. a first high-pressure outlet for fluid to be pressurized; 516. a first high-pressure inlet of the fluid to be recovered with energy; 517. a rotor rear sliding bearing ring; 518. the energy recovery cavity flow distribution ring and the sliding bearing ring; 52. end surface flow distribution; 521. a second fluid valve plate to be pressurized; 522. a rotating shaft seal ring; 523. a second low-pressure inlet for fluid to be pressurized; 524. a second fluid low-pressure outlet for energy recovery; 525. a second high-pressure outlet for the fluid to be pressurized; 526. a second high-pressure inlet for fluid to be energy-recovered; 527. a seal ring; 528. a second drainage hole; A. an energy recovery cavity; B. a pump chamber; C. a distribution window for the pressurized fluid and the energy recovery fluid; D. inlet and outlet channels for pressurized fluid and energy recovery fluid; E. a high-pressure independent energy recovery flow channel and a low-pressure independent energy recovery flow channel; F. a first energy recovery flow distribution window; G. a static pressure balancing area; H. an axial energy recovery flow channel; J. a pump cavity flow distribution window; K. and a second energy recovery flow distribution window.

Detailed Description

The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

The embodiments of the present disclosure are described below with specific examples, and other advantages and effects of the present disclosure will be readily apparent to those skilled in the art from the disclosure in the specification. It is to be understood that the described embodiments are merely illustrative of some, and not restrictive, of the embodiments of the disclosure. The disclosure may be embodied or carried out in various other specific embodiments, and various modifications and changes may be made in the details within the description without departing from the spirit of the disclosure. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments disclosed herein without making any creative effort, shall fall within the protection scope of the present disclosure.

A rotary piston type high-pressure pump with an energy recovery function comprises a shell 1, a driving mechanism 2, a plurality of piston assemblies 3, a cylinder rotor assembly 4 provided with a plurality of cylinders and a flow distribution mechanism 5; the driving mechanism 2, the piston assembly 3, the cylinder rotor assembly 4 and the flow distribution mechanism 5 are sequentially arranged in the shell 1; one end of the piston assembly 3 is connected with the driving mechanism 2, the other end of the piston assembly is positioned in the cylinder body of the cylinder body rotor assembly 4, the cylinder body is divided into an energy recovery cavity A with a rod and a pump cavity B without a rod, and the piston assembly 3 reciprocates in the cylinder body rotor assembly 4 under the action of the driving mechanism 2 along with the rotation of the cylinder body rotor assembly 4; the flow distribution mechanism 5 comprises a flow distribution window C for pressurized fluid and energy recovery fluid, and an inlet flow channel D and an outlet flow channel D for the pressurized fluid and the energy recovery fluid which are arranged on the cylinder rotor assembly 4 and the shell 1, wherein the flow distribution window is in running fit with the cylinder rotor assembly 4, when the cylinder rotor assembly 4 rotates, the flow channel of the pump cavity B of each cylinder on the cylinder rotor assembly 4 is in butt joint with the flow channel of the low-pressure inlet and the high-pressure outlet of the pressurized fluid on the shell 1 alternately, and synchronously, the flow channel of the energy recovery cavity A of each cylinder on the cylinder rotor assembly 4 is in communication with the flow channel of the low-pressure outlet and the high-pressure inlet of the fluid which needs to be.