A hydraulic end assembly for a high-pressure plunger pump

Abstract

This invention pertains to the field of high-pressure reciprocating plunger pump technology. To address the technical problem of increased noise and aggravated pump wear caused by the significant water hammer phenomenon in existing high-pressure plunger pump hydraulic end assemblies, this invention discloses a high-pressure plunger pump hydraulic end assembly. An elastic partition structure is provided within the annular inlet chamber to divide the internal space of the annular inlet chamber into a closed gas chamber and a fluid flow chamber for fluid passage. The volume of the gas chamber changes with the pressure within the fluid flow chamber. This invention uses the elastic partition structure to separate the annular inlet chamber into a closed gas chamber, utilizing the compressibility of gas to absorb and release the impact of sudden changes in liquid flow and pressure, thereby mitigating the water hammer phenomenon caused by these changes and reducing noise and pump wear.

Description

Technical Field

[0001] This utility model relates to a hydraulic end assembly of a high-pressure plunger pump, belonging to the technical field of high-pressure reciprocating plunger pumps. Background Technology

[0002] A high-pressure reciprocating piston pump, also known as a piston pump, consists of a power end and a hydraulic end. The power end includes the pump body and crankshaft, while the hydraulic end includes the pump body and pistons. The crankshaft on the power end is connected to a crosshead via a connecting rod, which in turn connects to a connecting rod that connects to the piston on the hydraulic end. The piston pump is an important component of a hydraulic system. It relies on the reciprocating motion of the piston within the cylinder to change the volume of the sealed working chamber, thereby drawing in and compressing the medium to increase its pressure. It offers advantages such as high rated pressure, economical and environmentally friendly operation, and convenient flow regulation. It is widely used in high-pressure, high-flow-rate applications where flow regulation is required, such as liquid transportation, hydraulic power operations, and in mining, petrochemical, and environmental protection fields.

[0003] The booster pump in an oilfield has a hydraulically balanced structure, using primary and secondary plungers to achieve equilibrium. Most booster pumps are high-inlet, high-outlet systems (inlet pressure is generally 10-18 MPa, outlet pressure is generally 28-35 MPa), equipped with primary and secondary sealing packing. The space between the two seals serves as a hydraulic balance source, connected to the high-pressure side by a sealing gland. This creates hydraulic balance between the sealing gland and the pump outlet to balance the pressure difference. During operation, the large pressure difference between the plunger pump's inlet and outlet generates an axial thrust from the outlet (high-pressure side) towards the inlet (low-pressure side). This axial thrust causes the plunger to move axially from the outlet side towards the inlet side. Under the design pressure difference, the plunger's axial displacement is stable, the balance is good, and the pump efficiency is relatively ideal. However, as the formation's water absorption capacity changes, the pump outlet pressure also changes. When it exceeds the original design pressure difference, the plunger experiences axial displacement, and the radial displacement also increases. This weakens the balance of axial thrust, increases the elastic deformation generated by the plunger's reciprocating linear motion, and increases friction in the plunger pump. Furthermore, the plunger's movement is a crank-connecting rod motion, which causes instantaneous changes in plunger acceleration and fluid flow rate. These instantaneous changes in displacement result in instantaneous pressure changes between the discharge and suction systems, inevitably causing instantaneous pressure fluctuations in the system. In other words, the pump's internal components and inlet / outlet pipelines are constantly subjected to instantaneous fluid impacts and vibrations. These conditions lead to instantaneous changes in fluid flow and pressure, inevitably causing "water hammer" phenomena. This exacerbates the perforation of the plunger pump's inlet / outlet pipelines and buffer balls, and also increases noise. The significant difference between the designed pressure difference and the actual operating pressure difference makes it difficult for the plunger force to achieve complete balance, resulting in hydraulic imbalance at the hydraulic end. This leads to intermittent abnormal noises, overheating at the power end, high noise levels, and significant vibration in the booster pump.

[0004] For example, Chinese utility model patent CN28444500Y discloses a pump head assembly for a high-pressure water injection multi-chamber reciprocating pump. Each straight-through combined valve in the pump head assembly has a radial annular groove on its valve body surface, connected to the inlet of the valve body's water inlet channel. The pump head assembly housing corresponding to each combined valve body has a water inlet channel connected to its respective annular groove. The outer port of each water inlet channel is connected to a water inlet pipe fixed to the surface of the pump head assembly. The water inlet channel connecting each combined valve in the pump head assembly is composed of a water inlet pipe fixed to the surface of the pump head housing and the water inlet channels of each combined valve. Combined with the connecting channels inside the pump head assembly housing that sequentially connect to the drainage chambers of each combined valve, the structure of this pump head assembly is very compact, resulting in a small size. It also facilitates processing and saves materials, thus reducing manufacturing costs. However, when the pump head assembly disclosed in this utility model is in use, the volume of the annular inlet chamber formed by the annular groove remains unchanged. Due to the incompressibility of the liquid, the transient water pressure will act directly on the entire valve body without being buffered or reduced, resulting in problems such as easy generation of "water hammer", high noise, and increased wear of the plunger pump. Utility Model Content

[0005] The purpose of this utility model is to provide a hydraulic end assembly for a high-pressure plunger pump, so as to solve the technical problems of existing high-pressure plunger pump hydraulic end assemblies being prone to "water hammer" phenomenon, high noise, and accelerated plunger pump wear.

[0006] To achieve the above objectives, this utility model provides a high-pressure plunger pump hydraulic end assembly, including a pump body, a plunger channel and a plunger movably disposed within the plunger channel, a one-way inlet channel and a one-way outlet channel communicating with the plunger channel, the one-way inlet channel including an annular inlet chamber connected to an external inlet channel and an inlet pipe communicating with the plunger channel, and an elastic partition structure for dividing the internal space of the annular inlet chamber into a closed gas chamber and a liquid flow chamber for fluid passage.

[0007] Furthermore, the elastic spacer structure is an annular sealing ring assembled in the annular liquid inlet cavity. The annular sealing ring is fitted to the cavity wall of the annular liquid inlet cavity to divide the annular liquid inlet cavity into the gas cavity and the liquid flow cavity.

[0008] Furthermore, the annular liquid inlet cavity is an annular groove structure, which is formed by a first groove on the surface of the valve body and a second groove on the valve box on the outer side of the valve body corresponding to the first groove. The annular sealing ring is located in the second groove. The groove width of the second groove located on the radial outer side of the annular sealing ring gradually decreases from the inside to the outside in the radial direction, so as to form the gas cavity between the bottom of the second groove and the annular sealing ring.

[0009] Furthermore, the annular liquid inlet cavity is an annular groove structure, which is formed by a first groove on the surface of the valve body and a second groove on the valve box on the outer side of the valve body corresponding to the first groove. The annular sealing ring is located in the first groove. The groove width of the first groove located on the radial inner side of the annular sealing ring gradually increases from the inside to the outside in the radial direction, so as to form the gas cavity between the bottom of the first groove and the annular sealing ring.

[0010] Furthermore, the elastic spacer structure is an air-barrier membrane assembled on the wall of the annular liquid inlet cavity, and a closed gas cavity is formed between the air-barrier membrane and the wall of the annular liquid inlet cavity.

[0011] Furthermore, the gas barrier membrane is an annular gas barrier membrane, so that the gas cavity is an annular cavity.

[0012] Furthermore, the annular sealing ring is an annular rubber airbag, and the annular rubber airbag is filled with gas.

[0013] Furthermore, the annular sealing ring is an annular rubber ring.

[0014] Furthermore, the cross-section of the annular sealing ring is circular.

[0015] Furthermore, the air-barrier membrane is a rubber membrane.

[0016] Beneficial effects: This utility model is an improved invention. An elastic partition structure is provided in the annular liquid inlet cavity. The elastic partition structure divides the internal space of the annular liquid inlet cavity into a closed gas cavity and a liquid flow cavity for fluid to pass through. By utilizing the compressibility of gas, the volume of the gas cavity changes with the pressure change in the liquid flow cavity. In addition, during the process of water pressure transient change, the volume of the liquid flow cavity in the annular liquid inlet cavity can change, thereby absorbing and releasing the impact of liquid flow and pressure transient change, thus mitigating the "water hammer" phenomenon caused by liquid flow and pressure transient change, thereby reducing noise and wear on the plunger pump. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a high-pressure plunger pump hydraulic end assembly according to the present invention;

[0018] Figure 2 This is a partially enlarged view of the hydraulic end assembly of a high-pressure plunger pump according to this utility model.

[0019] The components are as follows: 1. Plunger; 2. Pressure cap; 201. Copper pressure sleeve; 3. Secondary seal; 4. Body; 5. Main casing; 6. Balance pipe; 7. Main seal; 8. Secondary casing; 9. Valve assembly; 10. Valve pressure sleeve; 11. Side flange; 12. Valve seat; 13. Annular inlet chamber; 14. External balance pipe; 15. Oil collar; 16. Lower flange; 17. Valve box; 18. Inlet valve plate; 19. Outlet valve plate; 20. Plunger chamber; 21. Side flange fixing bolt; 22. Lower flange fixing bolt; 23. Plug; 24. Annular sealing ring; 25. Gas chamber; 26. Inlet. Detailed Implementation

[0020] To address the problems in the background technology, the core inventive concept of this utility model is: to separate a closed gas chamber within the annular liquid inlet chamber through an elastic interval structure, and to utilize the compressibility of the gas to absorb and release the impact of sudden changes in liquid flow and pressure, thereby alleviating the "water hammer" phenomenon caused by sudden changes in liquid flow and pressure, and thus reducing noise and wear on the plunger pump.

[0021] The present invention will be further described in detail below with reference to an embodiment of a high-pressure plunger pump hydraulic end assembly.

[0022] like Figure 1 and Figure 2 As shown, the core difference between the hydraulic end assembly of the high-pressure plunger pump of this invention and the existing hydraulic end assembly of the plunger pump lies in the fact that the annular groove structure of the annular inlet chamber 13 is formed by the first groove on the valve assembly 9 and the second groove located on the valve box 17 on the outer side of the valve body, corresponding to the first groove. The annular sealing ring 24 is located in the second groove and is fitted to the groove wall of the second groove, so as to form a closed gas cavity between the bottom of the second groove and the annular sealing ring 24. A liquid flow cavity for fluid to pass through is formed between the bottom of the first groove and the annular sealing ring 24. The inlet port 26 communicates with the liquid flow cavity, and the liquid flow cavity communicates with the plunger channel through the inlet pipe. The groove width of the second groove located radially outside the annular sealing ring 24 gradually decreases radially from the inside to the outside. Under the action of high-pressure water, the annular sealing ring 24 is further pressed against the groove wall of the second groove by radial clamping force. The annular sealing ring 24 is a solid annular rubber ring, and the cross-section of the annular sealing ring 24 is circular.

[0023] The noise levels before and after applying the annular sealing ring 24 were measured and compared using a noise meter. The test data are as follows: 96.3 dB before application and 80.2 dB after application, indicating that the application of the annular sealing ring 24 has a noise reduction effect.

[0024] The following is a brief introduction to the structure of this utility model, which is similar to the hydraulic end assembly of the existing high-pressure plunger pump. The following structures can all adopt common structural settings in the prior art, such as the corresponding structural settings in CN103375397A, CN204663846U, CN205605386U and CN2844500Y.

[0025] The hydraulic end assembly of the high-pressure plunger pump of this utility model includes a plunger 1, a pressure cap 2, a copper pressure sleeve 201, a secondary seal 3, a body 4, a main casing 5, a balance pipe 6, a main seal 7, a secondary casing 8, a valve group 9, a valve pressure sleeve 10, a side flange 11, a valve seat 12, an inlet chamber 13, an outer balance pipe 14, a grease fitting 15, a lower flange 16, a valve box 17, an inlet valve plate 18, an outlet valve plate 19, and a plunger chamber 20.

[0026] The plunger cavity 20 is a hollow cavity structure, mainly comprising three parts: one inside the valve box 17, one inside the main chamber 5, and one inside the pressure cap 2. The plunger cavity portion inside the valve box 17 is equipped with a valve pressure sleeve 10, while the plunger cavity portion inside the main chamber 5 is equipped with a main seal 7 and a secondary seal 3. The valve box 17 also contains a secondary chamber 8 and a valve pressure sleeve 10, with the valve pressure sleeve 10 connected to one side of the valve box 17.

[0027] The external balance pipe 14 is connected to the threaded plug of the internal balance pipe at the bottom of the main body 5 and the valve box 17 via a grease fitting 15 and a lower flange 16, using a sealing gasket. This creates a hydraulic balance between the main sealing packing 7 and the secondary sealing packing 3, thereby achieving external balance and improving the reflux method. When debris or other impurities enter the balance pipe 14 and cause blockage, it is easy to disassemble and clean, ensuring sufficient supply and discharge of balance fluid by the plunger pump.

[0028] When maintenance is required on the auxiliary valve body 8 and valve assembly 9, the side flange 11 can be removed, and the valve sleeve 10, valve assembly 9, and auxiliary valve body 8 can be taken out for maintenance.

[0029] In the above embodiments, the annular sealing ring 24 is located in the second groove, and the width of the second groove located on the radially outer side of the annular sealing ring 24 gradually decreases from the inside to the outside in the radial direction, so as to form a gas cavity between the bottom of the second groove and the annular sealing ring 24. In other embodiments, the annular sealing ring 24 is located in the first groove, and the width of the first groove located on the radially inner side of the annular sealing ring 24 gradually increases from the inside to the outside in the radial direction, so as to form a gas cavity between the bottom of the first groove and the annular sealing ring 24.

[0030] In the above embodiments, the elastic spacer structure is an annular sealing ring 24 assembled in the annular liquid inlet cavity 13. In other embodiments, the elastic spacer structure is an air-barrier membrane assembled on the cavity wall of the annular liquid inlet cavity 13, and a closed gas cavity is formed between the air-barrier membrane and the cavity wall of the annular liquid inlet cavity 13. Further, the air-barrier membrane is an annular air-barrier membrane so that the gas cavity is an annular cavity. Further, the air-barrier membrane can be made of rubber, silicone or polyurethane, etc.

[0031] In the above embodiments, the annular sealing ring 24 is a solid annular rubber ring, while in other embodiments, the annular sealing ring 24 is an annular rubber airbag filled with gas.

[0032] In the above embodiments, the annular sealing ring 24 is made of rubber, while in other embodiments, the annular sealing ring 24 may also be made of polyurethane or polytetrafluoroethylene, etc.

[0033] In the above embodiments, the cross-section of the annular sealing ring 24 is circular, while in other embodiments, the cross-section of the annular sealing ring 24 is elliptical or other shapes with curved surfaces, as long as it can form a good sealing surface with the cavity wall of the annular liquid inlet cavity 13.

[0034] Finally, it should be noted that the above are merely preferred embodiments of this utility model and are not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some technical features, or organically combine different types of specific implementation methods to create the specific implementation methods shown in the accompanying drawings. Of course, those skilled in the art can also create other specific implementation methods not shown in the accompanying drawings. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A hydraulic end assembly of a high-pressure plunger pump, comprising a pump body, a plunger channel and a plunger movably disposed within the plunger channel, the pump body having a one-way inlet channel and a one-way outlet channel communicating with the plunger channel, the one-way inlet channel including an annular inlet chamber connected to an external inlet channel and an inlet pipe communicating with the plunger channel, characterized in that: The annular liquid inlet chamber is provided with an elastic partition structure that divides the internal space of the annular liquid inlet chamber into a closed gas chamber and a liquid flow chamber for fluid to pass through.

2. The hydraulic end assembly of a high-pressure plunger pump according to claim 1, characterized in that: The elastic spacer structure is an annular sealing ring assembled inside the annular liquid inlet cavity. The annular sealing ring is fitted to the cavity wall of the annular liquid inlet cavity to divide the annular liquid inlet cavity into the gas cavity and the liquid flow cavity.

3. A high pressure piston pump fluid end assembly as claimed in claim 2, characterized in that: The annular liquid inlet chamber is an annular groove structure, which is formed by a first groove on the surface of the valve body and a second groove on the valve box on the outer side of the valve body corresponding to the first groove. The annular sealing ring is located in the second groove. The groove width of the second groove located on the radial outer side of the annular sealing ring gradually decreases from the inside to the outside in the radial direction, so as to form the gas cavity between the bottom of the second groove and the annular sealing ring.

4. A high pressure piston pump fluid end assembly as claimed in claim 2, characterized in that: The annular liquid inlet chamber is an annular groove structure, which is formed by a first groove on the surface of the valve body and a second groove on the valve box on the outer side of the valve body corresponding to the first groove. The annular sealing ring is located in the first groove. The groove width of the first groove located on the radial inner side of the annular sealing ring gradually increases from the inside to the outside in the radial direction, so as to form the gas cavity between the bottom of the first groove and the annular sealing ring.

5. A high pressure piston pump fluid end assembly as claimed in claim 1, wherein: The elastic spacer structure is an air-barrier membrane assembled on the wall of the annular liquid inlet chamber, forming a closed gas cavity between the air-barrier membrane and the wall of the annular liquid inlet chamber.

6. A high pressure piston pump fluid end assembly as claimed in claim 5, characterized in that: The gas barrier membrane is an annular gas barrier membrane, so that the gas cavity is an annular cavity.

7. A high pressure piston pump fluid end assembly as in any of claims 2-4, wherein: The annular sealing ring is an annular rubber airbag, which is filled with gas.

8. A high pressure piston pump fluid end assembly as in any of claims 2-4, wherein: The annular sealing ring is an annular rubber ring.

9. A high pressure piston pump fluid end assembly as in any of claims 2-4, wherein: The cross-section of the annular sealing ring is circular.

10. A high pressure piston pump fluid end assembly as in claims 5 or 6, wherein: The air-barrier membrane is a rubber membrane.

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