A double-acting plunger pump and control method

Abstract

The present invention provides a bidirectional piston pump and a control method, belonging to the technical field of booster pumps, comprising at least one piston pump unit, the piston pump unit comprising a cylinder, a piston, and a transmission device for driving the piston movement; the piston comprises a piston head, a piston body, and a connector; the cylinder comprises a first compression chamber that matches the size of the piston head, and a second compression chamber that matches the size of the piston body; using such a bidirectional piston pump and a control method, the piston performs work in both directions, and compared with a conventional booster pump, the pump speed can be reduced under the conditions of the same output pressure and flow rate to extend the life of the piston pump; in addition, the piston pump can 100% utilize the incoming water pressure to drive the plunger to perform boosting on the basis of the incoming water pressure to reach the target water pressure, thereby also having an energy-saving effect. The control method can preset a target delivery capacity and adjust the inverter operating parameters based on the target delivery capacity to maximize efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydraulic pumps, and more particularly relates to a double-acting plunger pump and a control method thereof. Background Art

[0002] A plunger pump uses reciprocating motion within a cylinder to deliver liquids. It's typically used in applications involving high pressure, high viscosity, or where precise flow control is required. Plunger pumps offer high flow rates, high pressures, excellent stability, and high precision, making them widely used in engineering machinery, metallurgy, petrochemicals, shipbuilding, agricultural machinery, and other fields.

[0003] A booster pump, also known as a pressure intensifier or booster pump station, is used to increase fluid pressure. It mechanically transfers fluid from a high-pressure area to a higher-pressure area, thereby increasing the fluid's pressure. Traditional booster pumps only operate in one direction and can result in pressure loss, wasting resources. Summary of the Invention

[0004] Based on this, one object of the present invention is to provide a double-acting plunger pump for increasing liquid pressure, the double-acting plunger pump comprising at least one plunger pump unit, the plunger pump unit comprising a cylinder, a plunger, and a transmission device for driving the plunger movement; the plunger comprises a plunger head, a plunger body, and a connector; the cylinder comprises a first compression chamber matching the size of the plunger head, and a second compression chamber matching the size of the plunger body; the first compression chamber is provided with a first input port and a first output port, the second compression chamber is provided with a second input port and a second output port, and the first input port, the first output port, the second input port, and the second output port are respectively provided with a one-way valve; the connector passes through the end of the cylinder and is connected to the transmission device;

[0005] The transmission device can drive the plunger to reciprocate. When the plunger moves in the first direction, the plunger head moves in the first compression chamber to generate negative pressure, and the liquid input into the cylinder body flows into the first compression chamber from the first input port, while using the energy of the incoming water to do work; the plunger body moves in the second compression chamber to generate positive pressure, and the liquid in the second compression chamber flows out of the cylinder body from the second output port.

[0006] When the plunger moves in the second direction, the plunger head moves in the first compression chamber to generate positive pressure, and the liquid in the first compression chamber flows out of the cylinder body from the first output port; the plunger body moves in the second compression chamber to generate negative pressure, and the liquid input into the cylinder body flows into the second compression chamber from the second input port, while using the energy of the incoming water to do work.

[0007] Preferably, the plunger surface areas on the plunger head and the plunger body for pushing the liquid to flow under pressure are equal.

[0008] Preferably, the inner wall of the cylinder body in contact with the plunger head is provided with a first sealing component, the inner wall of the cylinder body in contact with the plunger body is provided with a second sealing component, and the inner wall of the cylinder body in contact with the connecting head is provided with a third sealing component;

[0009] The first sealing assembly, the second sealing assembly and the third sealing assembly are used to prevent the liquid inside the cylinder from leaking.

[0010] Preferably, the first sealing assembly and / or the second sealing assembly and / or the third sealing assembly includes a sealing ring groove arranged on the inner wall of the cylinder body and a Y-shaped sealing ring arranged in the sealing ring groove, and the Y-shaped sealing ring has a wear compensation function.

[0011] Preferably, the cylinder body further comprises a first lubricating cavity having a size matching that of the plunger body; a first lubricating oil tank is provided outside the cylinder body, and a first lubricating channel is provided between the first lubricating oil tank and the inside of the cylinder body, and the first lubricating channel is used to transport lubricating oil to the first lubricating cavity;

[0012] When the plunger moves in the first direction, the plunger body moves in the first lubrication cavity to generate negative pressure, and the lubricating oil in the first lubricating oil tank flows into the first lubricating cavity through the first lubricating passage; when the plunger moves in the second direction, the plunger body moves in the first lubricating cavity to generate positive pressure, and the lubricating oil in the first lubricating cavity flows into the first lubricating oil tank through the first lubricating passage;

[0013] The lubricating oil in the first lubrication cavity can adhere to the outer surface of the plunger head, the outer surface of the plunger body and the inner surface of the cylinder body; when the plunger moves back and forth, the lubricating oil can delay the wear of the first sealing assembly and the second sealing assembly to extend the service life of the first sealing assembly and the second sealing assembly.

[0014] Preferably, the contact portion between the cylinder body and the connector further includes an annular extension portion, through which the connector passes; a third sealing groove is provided on the inner wall of the extension portion, and the third sealing assembly is provided in the third sealing groove;

[0015] A second lubrication cavity is provided in the radial direction inside the extension portion, and the second lubrication cavity is connected to the third sealing groove; the second lubrication cavity can be filled with lubricating oil, and the lubricating oil in the second lubrication cavity can delay the wear of the third sealing assembly to extend the life of the third sealing assembly.

[0016] Preferably, the plunger surface has a PEEK self-lubricating material layer.

[0017] Preferably, the double-acting plunger pump includes multiple plunger pump units; the transmission device includes a crankshaft and a connecting rod connecting the crankshaft and the plunger; the number of connecting rods is consistent with the number of plunger pump units, and the multiple connecting rods are respectively connected to the connecting heads of the multiple plunger pump units, and the angles of the multiple connecting rods are evenly distributed in the circumferential direction of the crankshaft.

[0018] Preferably, the double-acting plunger pump includes three plunger pump units; the transmission device includes three connecting rods, one end of the three connecting rods is respectively connected to the crankshaft, and the other end is connected to the connecting head of the three plunger pump units respectively; the angles of the three connecting rods are evenly distributed in the circumferential direction of the crankshaft.

[0019] Preferably, the cylinder bodies of the three plunger pump units form a cylinder assembly, and the cylinder assembly is provided with a total input channel and a total output channel; the total input channel is connected to the first input port and the second input port of the three plunger pump units; the total output channel is connected to the first output port and the second output port of the three plunger pump units.

[0020] Preferably, the bidirectional piston pump also includes an input pressure sensor connected to the total input channel, an output pressure sensor connected to the total output channel, a flow sensor connected to the total input channel or the total output channel, a motor for driving the crankshaft rotation, a frequency converter for controlling the motor, and a controller; the controller is connected to the input pressure sensor, the flow sensor, the output pressure sensor, and the frequency converter, and the controller is used to obtain signals from the input pressure sensor, the flow sensor, and the output pressure sensor and to adjust the operating parameters of the frequency converter.

[0021] The present invention also provides a control method for a double-acting plunger pump, comprising:

[0022] Obtain the target delivery capacity, which refers to the total volume of liquid delivered by the double-acting plunger pump during working hours;

[0023] Calculate the target output flow rate based on the target delivery capacity. The target output flow rate refers to the output liquid flow rate that the double-acting plunger pump needs to achieve.

[0024] Obtain the inlet pressure of the total input channel of the double-acting plunger pump, the outlet pressure of the total output channel of the double-acting plunger pump, and the actual output flow of the double-acting plunger pump;

[0025] Adjust the inverter operating parameters according to the target output flow, actual output flow, inlet pressure and outlet pressure.

[0026] Beneficial Effects: According to embodiments of the present invention, a bidirectional plunger pump and control method are provided. The plunger performs bidirectional work, which, compared to conventional booster pumps, reduces pump speed while maintaining the same output pressure and flow rate, thereby extending the life of the plunger pump. Furthermore, the plunger pump utilizes 100% of the incoming water pressure to drive the plunger to boost the pressure to a target water pressure based on the incoming water pressure, thereby achieving energy savings. The control method can preset a target delivery capacity and, based on this, adjust the inverter operating parameters to maximize efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present disclosure includes accompanying drawings, which should be considered as included in and constitute a part of the specification and, together with the specification, illustrate various exemplary embodiments, features, and aspects of the present disclosure and are used to explain the principles of the present disclosure. The present disclosure will be more fully understood through the following detailed description in conjunction with the accompanying drawings. Among them:

[0028] Figure 1 This is a schematic diagram of a double-acting plunger pump in use according to an embodiment of the present invention;

[0029] Figure 2 is a top view of a double-acting plunger pump according to an embodiment of the present invention;

[0030] Figure 3 yes Figure 2 Cross-sectional view of AA;

[0031] Figure 4 yes Figure 3 A partial enlarged view of point D in the middle;

[0032] Figure 5 yes Figure 3 A partial enlarged view of point E in the middle;

[0033] Figure 6 yes Figure 3 A partial enlarged view of point F in the middle;

[0034] Figure 7 yes Figure 2 Cross-sectional view of the middle BB;

[0035] Figure 8 yes Figure 2 Cross-sectional view of CC;

[0036] Figure 9 is a schematic diagram of the internal structure of a plunger pump unit according to an embodiment of the present invention;

[0037] Figure 10 yes Figure 9 A partial enlarged view of point G in the middle;

[0038] Figure 11 yes Figure 9 A partial enlarged view of the H in the middle;

[0039] Figure 12 2 is a schematic diagram of the internal structure of the first input port, the second input port, the main input channel, and the main output channel according to an embodiment of the present invention;

[0040] Figure 13 is a schematic diagram of the internal structure of the first lubrication channel and the first lubrication cavity according to an embodiment of the present invention;

[0041] Figure 14is a schematic diagram of the internal structure of the second input port and the second output port according to an embodiment of the present invention;

[0042] Figure 15 is a schematic structural diagram of an extension portion according to an embodiment of the present invention;

[0043] Among them: cylinder body 10, plunger head 11, plunger body 12, connector 13, first compression chamber 14, second compression chamber 15, first input port 16, first output port 17, second input port 18, second output port 19, first step 21, first lubrication chamber 22, annular channel 23, elastic member 24, ball 25, second lubrication chamber 26, first sealing assembly 31, second sealing assembly 32, third sealing assembly 33, first lubricating oil tank 34, crankshaft 35, connecting rod 36, cylinder assembly 40, total input channel 41, total output channel 42, plug body 43, first lubrication hole 44, stud pipe 45, input collecting channel 46, output collecting channel 47, flow sensor 52, sealing ring 55, driver 61, reducer 62, extension part 63, second lubricating oil tank 64, third sealing groove 65, radial lubrication channel 661, axial lubrication channel 662, positioning ring 67. DETAILED DESCRIPTION

[0044] The technical solutions of the present invention are further described in detail below through examples and in conjunction with the accompanying drawings, but the present invention is not limited to the following examples.

[0045] A plunger pump is a pump that uses a plunger to make reciprocating motion inside a cylinder 10 to achieve liquid transportation. It is usually used in situations with high pressure, high viscosity, or where precise flow control is required. Plunger pumps have the characteristics of large delivery flow, high pressure, good stability, and high precision. They are widely used in engineering machinery, metallurgy, petrochemical industry, shipbuilding, agricultural machinery and other fields. A booster pump is a pump used to increase the pressure of a fluid, also known as a booster or booster pump station. A booster pump transports fluid from a low-pressure area to a high-pressure area through mechanical action, thereby increasing the pressure of the fluid. Traditional booster pumps can only work in one direction, and the incoming water pressure is lost, resulting in a waste of resources.

[0046] In order to solve the above problems, the object of the present invention is to provide a double-acting plunger pump for increasing liquid pressure, the double-acting plunger pump includes at least one plunger pump unit, the plunger pump unit includes a cylinder 10, a plunger, and a transmission device for driving the plunger movement; the plunger includes a plunger head 11, a plunger body 12, and a connector 13; the cylinder 10 includes a first compression chamber 14 that matches the size of the plunger head 11 and a second compression chamber 15 that matches the size of the plunger body 12; the first compression chamber 14 is provided with a first input port 16 and a first output port 17, the second compression chamber 15 is provided with a second input port 18 and a second output port 19, and the first input port 16, the first output port 17, the second input port 18, and the second output port 19 are respectively provided with a one-way valve; the connector 13 passes through the end of the cylinder 10 and is connected to the transmission device;

[0047] The transmission device can drive the plunger to reciprocate. When the plunger moves in the first direction, the plunger head 11 moves in the first compression chamber 14 to generate negative pressure, and the liquid input into the cylinder body 10 flows into the first compression chamber 14 from the first input port 16, while using the energy of the incoming water to perform work; the plunger body 12 moves in the second compression chamber 15 to generate positive pressure, and the liquid in the second compression chamber 15 flows out of the cylinder body 10 from the second output port 19.

[0048] When the plunger moves in the second direction, the plunger head 11 moves in the first compression chamber 14 to generate positive pressure, and the liquid in the first compression chamber 14 flows out of the cylinder body 10 from the first output port 17; the plunger body 12 moves in the second compression chamber 15 to generate negative pressure, and the liquid input into the cylinder body 10 flows into the second compression chamber 15 from the second input port 18, while using the energy of the incoming water to do work.

[0049] In this embodiment, Figure 3 、 Figure 9 As shown, there is space inside the cylinder body 10 for the plunger to move. The plunger includes three parts, namely the plunger head 11, the plunger body 12, and the connector 13, which are arranged in sequence. The plunger head 11, the plunger body 12, and the connector 13 are a whole. The plunger head 11 and the plunger body 12 are kept inside the cylinder body 10, and the connector 13 extends through one end of the cylinder body 10 to the outside of the cylinder body 10. The connector 13 is connected to a transmission device outside the cylinder body 10. The transmission device can be a crankshaft 35, a transmission shaft, etc. The transmission device can be connected to a driver 61 to realize external force driving the plunger to move. The driver 61 can be a motor that drives the crankshaft 35 to rotate.

[0050] In some embodiments, a reducer 62 is further provided between the driver 61 and the crankshaft 35 , and the reducer is used to increase the torque.

[0051] In some embodiments, the diameter of the plunger head 11 is smaller than the diameter of the plunger body 12, and the diameter of the connector 13 is smaller than the diameter of the plunger body 12. A first step 21 is provided inside the cylinder body 10. The first step 21 divides the space inside the cylinder body 10 into a large diameter area and a small diameter area. The outer diameter of the plunger head 11 matches the inner diameter of the small diameter area, and the plunger head 11 moves within the small diameter area; the outer diameter of the plunger body 12 matches the inner diameter of the large diameter area, and the plunger body 12 moves within the large diameter area.

[0052] The plunger body 12 divides the large diameter area into two cavities. The cavity near the small diameter area is the first lubrication cavity 22, and the area near the connecting head 13 is the second compression cavity 15. The area at the end of the plunger head 11 is the first compression cavity 14. The first compression cavity 14 is provided with a first input port 16 and a first output port 17, and the second compression cavity 15 is provided with a second input port 18 and a second output port 19. One end of the first input port 16 and the first output port 17 is connected to the interior of the first compression cavity 14, and the other end of the first input port 16 and the first output port 17 is connected to the outside of the first compression cavity 14. One end of the second input port 18 and the second output port 19 is connected to the interior of the second compression cavity 15, and the other end of the second input port 18 and the second output port 19 is connected to the outside of the second compression cavity 15.

[0053] In some embodiments, the first input port 16 and the second input port 18 are connected to a channel for inputting liquid into the plunger pump, and the first output port 17 and the second output port 19 are connected to a channel for outputting liquid from the plunger pump. Specifically, the liquid input into the plunger pump is connected to the first input port 16 and the second input port 18 via a three-way connector, and the liquid output from the plunger pump is also connected to the first output port 17 and the second output port 19 via a three-way connector.

[0054] In some embodiments, one-way valves are provided at the first input port 16, the first output port 17, the second input port 18, and the second output port 19. The one-way valve at the first input port 16 is configured to allow liquid to be input only into the first compression chamber 14; the one-way valve at the first output port 17 is configured to allow liquid to be output only from the first compression chamber 14. The one-way valve at the second input port 18 is configured to allow liquid to be input only into the second compression chamber 15; the one-way valve at the second output port 19 is configured to allow liquid to be output only from the second compression chamber 15.

[0055] One-way valve Figure 4 、 Figure 5As shown, the one-way valve includes an annular channel 23, a ball 25 that can fit on the inclined surface, and an elastic member 24 that pushes the ball 25 to fit the inclined surface. The annular channel 23 of some one-way valves has an inclined surface, while the inclined surface of other one-way valves is set on the cylinder body 10, with the end with the larger inclined surface opening facing the direction of one-way flow of liquid. When the liquid pressure at the end with the smaller inclined surface opening is greater than the liquid pressure at the end with the larger inclined surface opening, the liquid pressure at the end with the smaller inclined surface opening can push the ball 25 away from the ball 25, and the channel at the center of the annular channel 23 opens, allowing the liquid on the side with higher liquid pressure to flow toward the side with lower liquid pressure. When the liquid pressure at the end with the smaller inclined surface opening is less than the liquid pressure at the end with the larger inclined surface opening, the liquid pressure at the end with the larger inclined surface opening pushes the ball 25 to fit tightly against the inclined surface, preventing liquid flow.

[0056] When the liquid pressure inside the first compression chamber 14 is lower than the liquid pressure outside the first input port 16, the liquid outside the first input port 16 can flow into the first compression chamber 14 through the first input port 16; when the liquid pressure inside the first compression chamber 14 is higher than the liquid pressure outside the first output port 17, the liquid in the first compression chamber 14 can flow out through the first output port 17.

[0057] Similarly, when the liquid pressure inside the second compression chamber 15 is lower than the liquid pressure outside the second input port 18, the liquid outside the second input port 18 can flow into the second compression chamber 15 through the second input port 18; when the liquid pressure inside the second compression chamber 15 is higher than the liquid pressure outside the second output port 19, the liquid in the second compression chamber 15 can flow out through the second output port 19.

[0058] The transmission device drives the plunger to reciprocate. When the plunger moves in a first direction (the first direction of movement refers to the direction in which the plunger moves away from the cylinder body 10), the internal volume of the first compression chamber 14 increases and the pressure decreases. The plunger head 11 moves within the first compression chamber 14, generating negative pressure. The liquid input into the cylinder body 10 flows into the first compression chamber 14 through the first input port 16. The internal volume of the second compression chamber 15 decreases and the pressure increases. The plunger body 12 moves within the second compression chamber 15, generating positive pressure. The liquid in the second compression chamber 15 flows out of the cylinder body 10 through the second output port 19.

[0059] Conversely, when the plunger moves in the second direction (the second direction of movement refers to the direction in which the plunger moves toward insertion into the cylinder body 10), the internal volume of the first compression chamber 14 is smaller and the pressure increases. The plunger head 11 moves within the first compression chamber 14 to generate positive pressure, and the liquid in the first compression chamber 14 flows out of the cylinder body 10 through the first output port 17. The internal volume of the second compression chamber 15 increases and the pressure decreases. The plunger body 12 moves within the second compression chamber 15 to generate negative pressure, and the liquid input into the cylinder body 10 flows into the second compression chamber 15 through the second input port 18.

[0060] Each reciprocating movement of the plunger generates work in both directions, completing two outward output processes. Simultaneously, the incoming water pressure also contributes to the work of driving the plunger. In some embodiments, for example, if the incoming water pressure is 20 MPa and a 5 MPa boost is required, the driver 61 only needs to push the plunger to generate a 5 MPa pressure to boost the output water pressure to 25 MPa.

[0061] For a traditional booster pump with a compensation tube (taking plunger diameter: large plunger Φ36mm, small plunger Φ24mm as an example):

[0062] Assuming the incoming water pressure is 20 MPa, the equipment needs to boost the pressure by 5 MPa, and the final output pressure is 25 MPa.

[0063] S1 piston area: S1=1.8*1.8*3.14=10.1736cm 2

[0064] S2 piston area: S2 = 1.8 * 1.8 * 3.14 – 1.2 * 1.2 * 3.14 = 5.652 cm 2

[0065] The thrust required to output 25 MPa is: F=25*10.1736*10=2543.4kg

[0066] S2 auxiliary compensation thrust: Fcompensation = 20*5.652*10=1130.4kg

[0067] The plunger needs to do work thrust: F plunger = FF fill = 2543.4-1130.4 = 1413kg

[0068] The S1 piston is the piston that contacts the incoming water and the output water, and the S2 piston is the piston that is connected to one end of the driver 61.

[0069] For the plunger pump unit of this embodiment:

[0070] The area of ​​S1 is equal to S2, S1=S2=1.8*1.8*3.14=10.1736cm 2

[0071] The thrust required to output 25 MPa is: F=25*10.1736*10=2543.4kg

[0072] S2 auxiliary compensation thrust: Fcompensation = 20*10.1736*10=2034.72kg

[0073] The plunger needs to do work thrust: F plunger = FF complement = 2543.4-2034.72=508.68kg

[0074] Here, S1 is the plunger surface area of ​​the plunger head 11 used to promote liquid flow, and S2 is the plunger surface area of ​​the plunger body 12 used to promote liquid flow. Although the diameter of the plunger body 12 is larger than that of the plunger head 11, the actual plunger surface area of ​​the plunger body 12 used to promote liquid flow is the plunger body 12 diameter minus the diameter of the connector 13. In some embodiments, the diameter of the connector 13 is equal to the diameter of the plunger head 11. The plunger surface areas of the plunger head 11 and the plunger body 12 used to promote liquid flow are equal.

[0075] Therefore, the incoming water pressure in this embodiment can fully participate in the compensation of the boost pressure.

[0076] In terms of energy consumption: if the daily water injection is 50 cubic meters, the traditional booster pump will waste 22 cubic meters of 20 MPa high-pressure water.

[0077] Hydraulic pump power (kW) = head (m) × flow rate (m³ / s) × fluid density (water is 1000kg / m³) ÷ 10² (power conversion factor) ÷ pump efficiency (about 69%)

[0078] W=2000*(15.28L / min / 60)*1000 / (102*0.69)= 7.2369KW

[0079] Daily power consumption: 7.2369KW ╳ 24h = 173.69 Kw.h

[0080] For high-pressure water booster pumps, this design fully utilizes the incoming water energy and compensates 100% of the incoming water pressure, achieving high efficiency and energy saving.

[0081] The plunger reciprocates in both directions to perform work. Under the condition of the same displacement and area plunger, the pump speed is reduced by half and the service life is extended by more than 2 times.

[0082] Furthermore, the inner wall of the cylinder body 10 in contact with the plunger head 11 is provided with a first sealing component 31, the inner wall of the cylinder body 10 in contact with the plunger body 12 is provided with a second sealing component 32, and the inner wall of the cylinder body 10 in contact with the connector 13 is provided with a third sealing component 33;

[0083] The first sealing assembly 31 , the second sealing assembly 32 , and the third sealing assembly 33 are used to prevent liquid leakage inside the cylinder 10 .

[0084] In this embodiment, Figure 3 、 Figure 5 、 Figure 6 、 Figure 9 、 Figure 10 、 Figure 14As shown, the first sealing assembly 31, the second sealing assembly 32, and the third sealing assembly 33 are sealing rings 55. The inner wall of the small diameter region of the cylinder body 10 is provided with a first sealing groove. The first sealing assembly 31 is sleeved on the outer surface of the plunger head 11 and is located in the first sealing groove. The first sealing assembly 31 is used to seal the gap between the plunger head 11 and the inner wall of the small diameter region of the cylinder body 10 to prevent liquid leakage in the first compression chamber 14.

[0085] The second sealing assembly 32 is sleeved on the outer surface of the plunger body 12. A second sealing groove is provided on the inner wall of the large diameter area of ​​the cylinder body 10, and the second sealing assembly 32 is located in the second sealing groove. The third sealing assembly 33 is sleeved on the outer surface of the connector 13. A third sealing groove 65 is provided on the portion of the connector 13 that passes through the cylinder body 10, and the third sealing assembly 33 is located in the third sealing groove 65. The second and third sealing assemblies 32, 33 are used to seal the gap between the plunger body 12 and the large diameter area of ​​the cylinder body 10, as well as the gap between the connector 13 and the portion of the cylinder body 10 that passes through, to prevent liquid leakage from the second compression chamber 15.

[0086] Furthermore, the first sealing assembly 31 and / or the second sealing assembly 32 and / or the third sealing assembly 33 include a sealing ring groove provided on the inner wall of the cylinder body 10 and a Y-shaped sealing ring 55 provided in the sealing ring groove. The Y-shaped sealing ring 55 has a wear compensation function.

[0087] In this embodiment, Figure 6 As shown, the Y-shaped sealing ring 55 is a sealing ring 55 of a special shape, and its cross-section is Y-shaped. The Y-shaped sealing ring 55 is usually used for dynamic sealing or high-pressure sealing applications, and has good sealing performance and wear resistance. The Y-shaped sealing ring 55 is usually made of rubber, silicone, fluororubber and other materials, and has good elasticity and corrosion resistance. The direction of the Y-shaped opening is toward the direction of high pressure, and the high-pressure liquid can push the Y-shaped opening to open, so that the Y-shaped sealing ring 55 maintains contact with the cylinder body 10 and the plunger. The Y-shaped sealing ring 55 has a wear compensation function. After the Y-shaped sealing ring 55 is worn, the high pressure pressure tends to open the Y-shaped opening to a larger angle, maintaining contact with the cylinder body 10 and the plunger.

[0088] Furthermore, the cylinder body 10 further includes a first lubrication cavity 22 having a size matching that of the plunger body 12; a first lubrication oil tank 34 is provided outside the cylinder body 10, and a first lubrication channel is provided between the first lubrication oil tank 34 and the interior of the cylinder body 10, and the first lubrication channel is used to transport lubrication oil to the first lubrication cavity 22;

[0089] When the plunger moves in the first direction, the plunger body 12 moves in the first lubrication cavity 22 to generate negative pressure, and the lubricating oil in the first lubricating oil tank 34 flows into the first lubricating cavity 22 through the first lubricating passage; when the plunger moves in the second direction, the plunger body 12 moves in the first lubricating cavity 22 to generate positive pressure, and the lubricating oil in the first lubricating cavity 22 flows into the first lubricating oil tank 34 through the first lubricating passage;

[0090] The lubricating oil in the first lubrication cavity 22 can adhere to the outer surface of the plunger head 11, the outer surface of the plunger body 12 and the inner surface of the cylinder body 10; when the plunger moves back and forth, the lubricating oil can delay the wear of the first sealing assembly 31 and the second sealing assembly 32 to extend the service life of the first sealing assembly 31 and the second sealing assembly 32.

[0091] In this embodiment, Figure 3 、 Figure 7 、 Figure 9 As shown, the plunger body 12 divides the large diameter region into two cavities. The cavity adjacent to the small diameter region is the first lubrication cavity 22. The first lubrication passage can be a circular hole drilled in the cylinder body 10, connecting the first lubrication cavity 22 and the first lubricating oil tank 34. The first lubricating oil tank 34 can be a sealable space. When the plunger moves in the first direction, the volume of the first lubrication cavity 22 increases and the pressure decreases. Lubricating oil flows from the first lubricating oil tank 34 into the first lubricating cavity 22, while the lubricating oil adheres to the outer surface of the plunger head 11 and the surface of the first lubricating cavity 22. The pressure in the first lubricating oil tank 34 decreases. When the plunger moves in the second direction, the volume of the first lubricating cavity 22 decreases and the pressure increases. The lubricating oil in the first lubricating cavity 22 flows into the first lubricating oil tank 34, and the lubricating oil on the outer surface of the plunger head 11 and the surface of the first lubricating cavity 22 adheres to the first and second compression cavities 14, 15, and the surface of the plunger body 12. Therefore, when the plunger reciprocates, the lubricating oil can delay the wear of the first sealing assembly 31 and the second sealing assembly 32 to extend the service life of the first sealing assembly 31 and the second sealing assembly 32.

[0092] In some embodiments, two first sealing assemblies 31 are sleeved on the plunger head 11, and two second sealing assemblies 32 are sleeved on the plunger body 12. Multiple first sealing assemblies 31 and multiple second sealing assemblies 32 are distributed along the axial direction of the plunger. Correspondingly, two first sealing grooves are axially provided in the small diameter region of the cylinder body 10, and two second sealing grooves are axially provided in the large diameter region of the cylinder body 10. Multiple first sealing assemblies 31 and multiple second sealing assemblies 32 enhance sealing performance and prevent leakage of liquid within the cylinder body 10.

[0093] Furthermore, the contact portion between the cylinder body 10 and the connector 13 further includes an annular extension portion 63, through which the connector 13 passes; a third sealing groove 65 is provided on the inner wall of the extension portion 63, and the third sealing assembly 33 is provided in the third sealing groove 65;

[0094] A second lubrication cavity 26 is provided in the radial direction inside the extension portion 63, and the second lubrication cavity 26 is connected to the third sealing groove 65; the second lubrication cavity 26 can be filled with lubricating oil, and the lubricating oil in the second lubrication cavity 26 can delay the wear of the third sealing assembly 33 to extend the life of the third sealing assembly 33.

[0095] In this embodiment, Figure 3 、 Figure 4 、 Figure 5 、 Figure 9 、 Figure 10 、 Figure 11 As shown, the extension portion 63 is annular. To facilitate replacement of the third sealing assembly 33 , the extension portion 63 is detachably mounted to the through portion of the connecting head 13 passing through the cylinder body 10 by bolts or other fasteners.

[0096] A third sealing groove 65 is provided on the inner wall of the extension portion 63, and the third sealing groove 65 is provided in the circumferential direction. The second lubricating cavity 26 is provided along the radial direction of the extension portion 63. In order to facilitate the processing of the second lubricating oil cavity, the second lubricating oil cavity of this embodiment is drilled from the outside of the extension portion 63 to the inside, and the end of the hole outside the extension portion 63 is provided with an internal thread. The internal thread can be screwed into the matching plug body 43 with an external thread. A sealing ring 55 is provided on the plug body 43. When filling the second lubricating oil cavity with lubricating oil, the plug body 43 can be removed and the lubricating oil can be directly added to the second lubricating oil cavity 26. After filling, the plug body 43 is put back.

[0097] In some implementations, a sealing ring 55 is provided between the extension portion 63 and the main portion of the cylinder body 10 , and the fastener can compress the sealing ring 55 to prevent leakage between the extension portion 63 and the main portion of the cylinder body 10 .

[0098] In some embodiments, as Figure 13 As shown, a second lubricating oil tank 64 is further provided outside the extension portion 63 , and the second lubricating oil tank 64 is connected to the second lubricating oil tank 64 . The second lubricating oil tank 64 is used to store a certain amount of lubricating oil, and the lubricating oil in the second lubricating oil tank 64 can flow into the second lubricating oil tank 26 .

[0099] In some embodiments, three third sealing grooves 65 are axially defined on the inner wall of the extension portion 63. Three third sealing assemblies 33 are sleeved on the connector 13, each seated within the three third sealing grooves 65. When the transmission device comprises a crankshaft 35 and a crank connecting rod 36, the connector 13 tends to swing within the extension portion 63, which can easily cause wear on the third sealing assemblies 33. Therefore, the three-layer sealing groove ensures sealing performance and prevents leakage.

[0100] In some embodiments, as Figure 15 As shown, the second lubrication cavity 26 includes three radial lubrication channels 661, each connected to the three third sealing grooves 65, and an axial lubrication channel 662 connecting the three radial lubrication channels 661. At least one of the three radial lubrication channels 661 is connected to the second lubricating oil tank 64. In this embodiment, the top end of the radial lubrication channel 661 located in the middle of the three radial lubrication channels 661 is connected to the second lubricating oil tank 64.

[0101] The lubricating oil in the second lubricating oil tank 64 can flow into the three third sealing grooves 65 through the radial lubricating passage 661 and the axial lubricating passage 662 respectively.

[0102] In practice, the three radial lubrication channels 661 are holes drilled radially along the extension 63. They correspond to the three third sealing grooves 65. The top of the central radial lubrication channel 661 is connected to the second lubricating oil tank 64, and plugs 43 are installed at the tops of the radial lubrication channels 661 on either side to seal their ends. The axial lubrication channel 662 connects the three radial lubrication channels 661 and acts as a flow diversion. The axial lubrication channel 662 is a blind hole drilled axially along the extension 63, with plugs 43 installed at its ends for sealing.

[0103] In some embodiments, a positioning ring 67 is provided on one side of the extension portion 63 close to the main portion of the cylinder body 10. The positioning ring 67 can be inserted into the main portion of the cylinder body 10 for connecting to the opening of the extension portion. The positioning ring 67 matches the size of the opening and can ensure the coaxiality of the connection with the opening.

[0104] Furthermore, the plunger surface has a PEEK self-lubricating material layer.

[0105] In this embodiment, PEEK is polyetheretherketone, a high-performance engineering plastic. PEEK has excellent high-temperature resistance, chemical stability, mechanical strength, and wear resistance, and is widely used in various fields, including aerospace, automobiles, medical devices, electronics, and chemicals.

[0106] PEEK is an excellent self-lubricating material. The arrangement structure between PEEK molecular chains makes it self-lubricating, which can reduce friction and wear without the need for additional lubricants.

[0107] Furthermore, the double-acting plunger pump includes multiple plunger pump units; the transmission device includes a crankshaft 35 and a connecting rod 36 connecting the crankshaft 35 and the plunger; the number of connecting rods 36 is the same as the number of plunger pump units, and the multiple connecting rods 36 are respectively connected to the connectors 13 of the multiple plunger pump units. The multiple connecting rods 36 are evenly distributed in the circumferential direction of the crankshaft 35. The connecting rods 36 are hinged to the connector 13.

[0108] In this embodiment, the double-acting plunger pump includes multiple plunger pump units, and a transmission device simultaneously connects the multiple plunger pump units. The transmission device can be a crankshaft 35 crank-connecting rod 36 mechanism. The crankshaft 35 is provided with multiple crank-connecting rods 36. The number of connecting rods 36 is the same as the number of plunger pump units. The multiple connecting rods 36 are respectively connected to the connectors 13 of the multiple plunger pump units. The angles of the multiple connecting rods 36 are evenly distributed in the circumferential direction of the crankshaft 35. Therefore, the multiple plunger pump units can evenly complete the water intake and discharge process, and the outlet water pressure can be kept stable with small fluctuations.

[0109] In this embodiment, the double-acting plunger pump includes three plunger pump units; the transmission device includes three connecting rods 36, one end of the three connecting rods 36 is respectively connected to the crankshaft 35, and the other end is connected to the connecting head 13 respectively connected to the three plunger pump units; the angles of the three connecting rods 36 are evenly distributed in the circumferential direction of the crankshaft 35.

[0110] Furthermore, the cylinder bodies 10 of the three plunger pump units form a cylinder assembly 40, and the cylinder assembly 40 is provided with a total input channel 41 and a total output channel 42; the total input channel 41 is connected to the first input port 16 and the second input port 18 of the three plunger pump units; the total output channel 42 is connected to the first output port 17 and the second output port 19 of the three plunger pump units.

[0111] In this embodiment, Figure 1 、 Figure 2 As shown, the cylinder assembly 40 has a cubic shape, the axis of the plunger is parallel to the length direction of the cylinder assembly 40, the total input channel 41 and the total output channel 42 are arranged along the width direction of the cylinder assembly 40, and the first lubricating oil tank 34 is arranged at the top of the cylinder assembly 40.

[0112] In some embodiments, to facilitate processing, a hole is drilled along the height direction through the cylinder assembly 40 at a corresponding position of the first compression chamber 14 of the cylinder assembly 40. Above the plunger head 11 is the first output port 17, and below the plunger head 11 is the first input port 16. Another hole is drilled along the height direction through the cylinder assembly 40 at a corresponding position of the second compression chamber 15 of the cylinder assembly 40. Above the connector 13 is the second output port 19, and below the connector 13 is the second input port 18. Two plugs 43 are provided at each end of the hole. The plugs 43 can be connected to the cylinder assembly 40 via threads, and a sealing ring 55 can be provided at the connection portion to seal both ends of the hole, which serves as an internal passage of the cylinder assembly 40.

[0113] Then drill two holes along the length of the cylinder assembly 40, such as Figure 12 As shown, the two holes form an input manifold 46 and an output manifold 47, respectively. The input manifold 46 runs through the first input port 16 and the second input port 18, while the output manifold 47 runs through the first output port 17 and the second output port 19. Two plugs 43 are provided at each end of the two holes along the length of the cylinder assembly 40. The plugs 43 can be connected to the cylinder assembly 40 via threads, and a sealing ring 55 can be provided at the connection to seal the ends of the hole, which serves as the internal passage of the cylinder assembly 40.

[0114] Next, two blind holes are drilled along the width of the cylinder assembly 40. These two blind holes extend through the input manifold 46 and output manifold 47 of each plunger pump unit, respectively. The main input channel 41 extends through the input manifold 46, and the main output channel 42 extends through the output manifold 47. Both the main input channel 41 and the main output channel 42 include connectors for connecting to external pipes.

[0115] In some embodiments, to facilitate the installation of the one-way valve, as Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 、 Figure 14 As shown, for the second input port 18 and the second output port 19: as described above, first drill a hole in the height direction at the corresponding position of the second compression chamber 15 of the cylinder assembly 40, and then drill two holes along the length direction of the cylinder assembly 40 to form the input collecting channel 46 and the output collecting channel 47. Then, enlarge the hole to form a second step on the second output port 19. The elastic member 24 of the one-way valve is a spring, and one end of the spring is placed on the second step. Then, an internal thread is machined at the intersection of the second input port 18 and the input collecting channel 46. The annular channel 23 is provided with a matching external thread. The ball 25 is installed to contact the spring and then screwed into the annular channel 23 to complete the installation of the one-way valve. Finally, an internal thread is machined at the end of the second input port 18 on the outside of the cylinder assembly 40 and the plug body 43 is installed.

[0116] For the second output port 19, a chamfered surface matching the ball 25 is machined at the intersection of the second output port 19 and the second compression chamber 15. An internal thread is then machined at the intersection of the second output port 19 and the output manifold 47. The annular channel 23 is provided with a matching external thread. The ball 25 and elastic member 24 are then inserted and screwed into the annular channel 23, completing the installation of the one-way valve. Finally, an internal thread is machined at the end of the second output port 19 outside the cylinder assembly 40, and the plug 43 is installed. The installation of the first output port 17, the second input port 18, and their corresponding one-way valves follows the same process as described above.

[0117] In some embodiments, a chamfer is provided in the direction of the larger opening of the inclined surface matching the ball 25 , and the chamfer can increase the liquid flow after the ball 25 leaves the inclined surface.

[0118] In some embodiments, the first lubrication channel includes a first lubrication hole 44 on the cylinder assembly 40 and a stud pipe 45 arranged on the first lubrication hole 44. The first lubrication hole 44 passes through the upper surface of the cylinder assembly 40 and the first lubrication cavity 22. The first lubrication hole 44 is provided with an internal thread at the end of the upper surface of the cylinder assembly 40. The stud pipe 45 has a matching external thread and both ends of the stud channel are connected.

[0119] The first lubricating oil tank 34 is located at the top of the cylinder assembly 40. The stud passages of the multiple plunger pump units extend from the bottom of the first lubricating oil tank 34 into the first lubricating oil tank 34. Two nuts, a first nut and a second nut, are installed on the stud passage 45. The first nut is located between the first lubricating oil tank 34 and the cylinder assembly 40 and is used to fix the stud passage in place. A sealing ring 55 is provided between the first nut and the cylinder assembly 40.

[0120] The second nut is used to fix the relative position of the stud pipe 45 and the first lubricating oil tank 34 . A sealing ring 55 is provided between the second nut and the first lubricating oil tank 34 .

[0121] In some embodiments, as Figure 7 、 Figure 13 As shown, multiple first lubrication cavities 22 are connected to the first lubricating oil tank 34 via a stud pipe 45. A longitudinal pipe 68 and a transverse pipe 69 are also provided inside the cylinder body 10. Each lubrication cavity is connected to a longitudinal pipe 68 respectively, and the transverse pipe 69 connects multiple longitudinal pipes 68. The stud pipe 45 is connected to the transverse pipe 69. The lubricating oil in the first lubricating oil tank 34 can flow into each first lubrication cavity 22 through the stud pipe 45, the transverse pipe 69, and the longitudinal pipe 68.

[0122] To facilitate the machining of the longitudinal and transverse pipes 68 and 69, the longitudinal pipe 68 is drilled from the outside to the inside of the cylinder body 10. A plug 43 is provided at one end of the longitudinal pipe 68 outside the cylinder body 10 to seal the end of the longitudinal pipe 68 on the surface of the cylinder body 10. The transverse pipe 69 runs through the cylinder body 10, and plugs 43 are provided at both ends of the transverse pipe 69 for sealing.

[0123] In this embodiment, the first lubrication channels of multiple plunger pump units are connected to the same first lubricating oil tank 34. Because the first lubricating oil tank 34 is sealable and airtight, when the plunger of one plunger pump unit moves in the second direction, the pressure in the first lubricating cavity 22 increases. This pressure assists in pumping lubricating oil into the first lubricating cavity 22 of another plunger pump unit whose plunger is also moving in the first direction. As the plungers of the multiple plunger pump units reciprocate, the plunger bodies 12 provide each other with power to assist in the flow of lubricating oil.

[0124] Furthermore, the bidirectional piston pump also includes an input pressure sensor connected to the total input channel 41, an output pressure sensor connected to the total output channel 42, a flow sensor 52 connected to the total input channel 41 or the total output channel 42, a motor for driving the crankshaft 35 to rotate, a frequency converter and a controller for controlling the motor; the controller is connected to the input pressure sensor, the flow sensor, the output pressure sensor and the frequency converter, and the controller is used to obtain signals from the input pressure sensor, the flow sensor 52 and the output pressure sensor and to adjust the operating parameters of the frequency converter.

[0125] In this embodiment, the frequency converter controls the speed and torque of the motor by adjusting the output frequency and voltage. The frequency converter can adjust the operating speed of the motor as needed, thereby achieving precise control of the motor. By changing the parameter settings of the frequency converter, different operating modes and control methods can be achieved to meet different application requirements. The frequency converter can also realize functions such as starting, stopping, accelerating, and decelerating to improve the operating efficiency and energy-saving performance of the motor. The motor is controlled by the frequency converter, which can control the output flow of the pump. A double-acting plunger pump in this embodiment can be connected to an information system, and the operating condition of the pump can be monitored in real time and remotely turned on and off through a cloud platform.

[0126] In some embodiments, a double-acting plunger pump further includes a PLC, which is a programmable logic controller (PLC), a dedicated digital computer used in industrial control systems. PLCs are primarily used to control various motion, logic, and process controls in production lines, machinery, and industrial automation systems. PLCs can control input and output devices according to pre-written programs, achieving automated control and monitoring functions. The PLC is connected to data acquisition modules such as an input pressure sensor, a flow sensor 52, and an output pressure sensor via a 485 bus to collect various operating parameters of the plunger pump, pre-process the data, and transmit it remotely to a data center. The PLC is connected to an Internet of Things communication module and connected to a cloud platform server via a wireless network to achieve remote control of the double-acting plunger pump. The PLC is connected to a frequency converter via a 485 bus to collect frequency converter operating data, pre-process the data, and transmit it remotely to a data center. It transmits various control instructions from the data center to the frequency converter, controlling the motor operating status and ensuring the plunger pump is in the optimal operating state. The PLC can also be connected to a touch screen to enable on-site human-computer interaction.

[0127] The present invention also provides a control method for a double-acting plunger pump, comprising:

[0128] Obtain the target delivery capacity, which refers to the total volume of liquid delivered by the double-acting plunger pump during working hours;

[0129] Calculate the target output flow rate based on the target delivery capacity. The target output flow rate refers to the output liquid flow rate that the double-acting plunger pump needs to achieve.

[0130] Obtaining the inlet pressure of the total input channel 41 of the double-acting plunger pump, the outlet pressure of the total output channel 42 of the double-acting plunger pump, and the actual output flow of the double-acting plunger pump;

[0131] Adjust the inverter operating parameters according to the target output flow, actual output flow, inlet pressure and outlet pressure.

[0132] The control method of this embodiment is suitable for a double-acting plunger pump to output high-pressure liquid for water well injection. The target delivery capacity can be, for example, 50m3 per day. 3 The output water pressure is 27 MPa, and the target output flow rate is calculated according to the target delivery capacity. The target output flow rate of this embodiment can be 35 L per minute.

[0133] During operation, the bidirectional piston pump continuously collects data from the input pressure sensor, flow sensor 52, and output pressure sensor, analyzes whether the output pressure and output flow meet the requirements, and can dynamically generate the inverter working parameters based on the output flow and input pressure to achieve energy consumption reduction while completing the water injection task.

[0134] In some embodiments, working time refers to a specific working time period, which may be one day, one week, one month, or other time periods.

[0135] The various embodiments disclosed in the present invention have been described above. The above description is exemplary and not exhaustive, and the scope of the present invention is not limited to the above embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the spirit and scope of the present invention. That is to say, those skilled in the art can make various changes and improvements to the present invention in form and detail, and these are all considered to fall within the scope of protection of the present invention. The choice of terms used in this article is intended to best explain the principles of the various embodiments, practical applications or improvements to the technology in the market, or to enable those skilled in the art to understand the various embodiments disclosed herein.

Claims

1. A double-acting plunger pump for increasing liquid pressure, characterized in that: The double-acting plunger pump comprises at least one plunger pump unit, which comprises a cylinder (10), a plunger, and a transmission device for driving the plunger to move; the plunger comprises a plunger head (11), a plunger body (12), and a connector (13); the cylinder (10) comprises a first compression chamber (14) whose size matches the plunger head (11), and a second compression chamber (15) whose size matches the plunger body (12); the first compression chamber (14) is provided with a first input port (16) and a first output port (17), the second compression chamber (15) is provided with a second input port (18) and a second output port (19), and the first input port (16), the first output port (17), the second input port (18), and the second output port (19) are respectively provided with a one-way valve; the connector (13) passes through the end of the cylinder (10) and is connected to the transmission device; A first step (21) is provided inside the cylinder body (10), and the first step (21) divides the space inside the cylinder body (10) into a large diameter area and a small diameter area. The outer diameter of the plunger head (11) matches the inner diameter of the small diameter area, and the plunger head (11) moves within the small diameter area; the outer diameter of the plunger body (12) matches the inner diameter of the large diameter area, and the plunger body (12) moves within the large diameter area. The plunger body (12) divides the large diameter area into two cavities, the area close to the connecting head (13) is the second compression cavity (15); the area at the end of the plunger head (11) is the first compression cavity (14); The first input port (16) and the second input port (18) are connected to a channel for inputting liquid into the plunger pump, and the first output port (17) and the second output port (19) are connected to a channel for outputting liquid from the plunger pump; The one-way valve of the first input port (16) is configured to be able to input liquid only into the first compression chamber (14); the one-way valve of the first output port (17) is configured to be able to output liquid only from the first compression chamber (14); the one-way valve of the second input port (18) is configured to be able to input liquid only into the second compression chamber (15); the one-way valve of the second output port (19) is configured to be able to output liquid only from the second compression chamber (15); The cylinder body (10) is provided with an input collecting channel (46) and an output collecting channel (47), the input collecting channel (46) runs through the first input port (16) and the second input port (18), and the output collecting channel (47) runs through the first output port (17) and the second output port (19); The transmission device is capable of driving the plunger to reciprocate. When the plunger moves in a first direction, the plunger head (11) moves in the first compression chamber (14) to generate negative pressure, and the liquid input into the cylinder body (10) flows into the first compression chamber (14) from the first input port (16), while using the energy of the incoming water to perform work; the plunger body (12) moves in the second compression chamber (15) to generate positive pressure, and the liquid in the second compression chamber (15) flows out of the cylinder body (10) from the second output port (19); When the plunger moves in the second direction, the plunger head (11) moves in the first compression chamber (14) to generate positive pressure, and the liquid in the first compression chamber (14) flows out of the cylinder (10) from the first output port (17); the plunger body (12) moves in the second compression chamber (15) to generate negative pressure, and the liquid input into the cylinder (10) flows into the second compression chamber (15) from the second input port (18), while using the energy of the incoming water to perform work; The plunger surface areas on the plunger head (11) and the plunger body (12) for pushing the liquid to flow with increased pressure are equal, so that the incoming water pressure fully participates in the compensation of the increased pressure; The piston performs work in both directions during one reciprocating movement, completing two outward output processes; The inner wall of the cylinder body (10) in contact with the plunger head (11) is provided with a first sealing component (31), the inner wall of the cylinder body (10) in contact with the plunger body (12) is provided with a second sealing component (32), and the inner wall of the cylinder body (10) in contact with the connector (13) is provided with a third sealing component (33); The first sealing assembly (31), the second sealing assembly (32), and the third sealing assembly (33) are used to prevent leakage of liquid inside the cylinder (10); The cylinder body (10) further comprises a first lubricating cavity (22) having a size matching that of the plunger body (12); a first lubricating oil tank (34) is provided outside the cylinder body (10); a first lubricating channel is provided inside the first lubricating oil tank (34) and the cylinder body (10); the first lubricating channel is used to transport lubricating oil to the first lubricating cavity (22); When the plunger moves in a first direction, the plunger body (12) moves in the first lubricating cavity (22) to generate negative pressure, and the lubricating oil in the first lubricating oil tank (34) flows into the first lubricating cavity (22) through the first lubricating passage; when the plunger moves in a second direction, the plunger body (12) moves in the first lubricating cavity (22) to generate positive pressure, and the lubricating oil in the first lubricating cavity (22) flows into the first lubricating oil tank (34) through the first lubricating passage; The lubricating oil in the first lubricating cavity (22) can adhere to the outer surface of the plunger head (11), the outer surface of the plunger body (12), and the inner surface of the cylinder body (10); When the plunger reciprocates, the lubricating oil in the first lubricating cavity (22) can delay the wear of the first sealing component (31) and the second sealing component (32) to extend the service life of the first sealing component (31) and the second sealing component (32).

2. A double-acting plunger pump according to claim 1, characterized in that: The first sealing assembly (31) and / or the second sealing assembly (32) and / or the third sealing assembly (33) comprises a sealing ring groove provided on the inner wall of the cylinder body (10) and a Y-shaped sealing ring provided in the sealing ring groove, wherein the Y-shaped sealing ring has a wear compensation function.

3. A double-acting plunger pump according to claim 1, characterized in that: The contact portion between the cylinder body (10) and the connector (13) further includes an annular extension portion (63), and the connector (13) passes through the extension portion (63); a third sealing groove (65) is provided on the inner wall of the extension portion (63), and the third sealing assembly (33) is provided in the third sealing groove (65); A second lubricating cavity (26) is provided in the radial direction inside the extension portion (63), and the second lubricating cavity (26) is connected to the third sealing groove (65); the second lubricating cavity (26) can be filled with lubricating oil, and the lubricating oil in the second lubricating cavity (26) can delay the wear of the third sealing assembly (33) to extend the service life of the third sealing assembly (33).

4. A double-acting plunger pump according to claim 1, characterized in that: The surface of the plunger is provided with a PEEK self-lubricating material layer.

5. A double-acting plunger pump according to any one of claims 1 to 4, characterized in that: The bidirectional piston pump comprises a plurality of piston pump units; the transmission device comprises a crankshaft (35), and a connecting rod (36) connecting the crankshaft (35) and the piston; the number of the connecting rods (36) is consistent with the number of the piston pump units, the plurality of connecting rods (36) are respectively connected to the connectors (13) of the plurality of piston pump units, and the angles of the plurality of connecting rods (36) are evenly distributed in the circumferential direction of the crankshaft (35).

6. A double-acting plunger pump according to claim 5, characterized in that: The bidirectional piston pump comprises three piston pump units; the transmission device comprises three connecting rods (36), one end of each of the three connecting rods (36) is connected to a crankshaft (35), and the other end is connected to a connector (13) respectively connected to the three piston pump units; the angles of the three connecting rods (36) are evenly distributed in the circumferential direction of the crankshaft (35).

7. A double-acting plunger pump according to claim 6, characterized in that: The cylinder bodies (10) of the three plunger pump units form a cylinder assembly (40), and the cylinder assembly (40) is provided with a total input channel (41) and a total output channel (42); the total input channel (41) is connected to the first input port (16) and the second input port (18) of the three plunger pump units; and the total output channel (42) is connected to the first output port (17) and the second output port (19) of the three plunger pump units.

8. A double-acting plunger pump according to claim 7, characterized in that: The bidirectional piston pump further comprises an input pressure sensor connected to the total input channel (41), an output pressure sensor connected to the total output channel (42), a flow sensor connected to the total input channel (41) or the total output channel (42), a motor for driving the crankshaft (35) to rotate, a frequency converter for controlling the motor, and a controller; the controller is connected to the input pressure sensor, the output pressure sensor, the flow sensor, and the frequency converter, and is used to obtain signals from the input pressure sensor, the flow sensor, and the output pressure sensor and to adjust operating parameters of the frequency converter.

9. A control method for a double-acting plunger pump according to any one of claims 1 to 8, characterized in that: include: Obtain the target delivery capacity, which refers to the total volume of liquid delivered by the double-acting plunger pump during working hours; Calculate the target output flow rate based on the target delivery capacity. The target output flow rate refers to the output liquid flow rate that the double-acting plunger pump needs to achieve. Obtaining the inlet pressure of the total input channel (41) of the bidirectional piston pump, the outlet pressure of the total output channel (42) of the bidirectional piston pump, and the actual output flow rate of the bidirectional piston pump; Adjust the inverter operating parameters according to the target output flow, actual output flow, inlet pressure and outlet pressure.

Images