A rotor channel rotation positive displacement type liquid pressure energy recovery device

Abstract

The application discloses a rotor channel rotary positive displacement type liquid pressure energy recovery device, which comprises a sleeve with a cylindrical hollow cavity, a central shaft, a rotor, a flow guide end cover and a sealing end cover arranged in the sleeve, locking pieces are arranged at the length ends of the central shaft, the locking pieces limit the spacing between the two sealing end covers, so that a gap d is formed between the flow guide end cover and the rotor, and rotor channels are arranged on the rotor and take the specific spiral as a reference. Through the structural optimization, the application overcomes the high-precision machining limitation of the existing rotary energy recovery device, reduces the liquid leakage between the end face and the rotor, optimizes the rotor channel structure, improves the stability of the fluid flow in the rotor channel, reduces the rotor vibration, the fastener is a fastening nut, the adjustment of the gap between the rotor and the flow guide end cover can be realized, and the adaptability of different flow / pressure and higher energy recovery efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of liquid pressure energy recovery technology in areas such as seawater desalination and petrochemicals. Specifically, it relates to a rotor-channel rotary positive displacement liquid pressure energy recovery device. Background Technology

[0002] In processes such as reverse osmosis seawater desalination, petrochemicals, and industrial reverse osmosis water treatment systems, high-pressure waste liquids are often directly discharged or subjected to throttling treatment. Because the discharged liquids still contain significant pressure energy, this results in substantial energy waste and increases the overall energy consumption of the process. By using pressure energy recovery devices to recover and utilize the pressure energy carried by the high-pressure waste liquids, the overall energy consumption of the system can be reduced.

[0003] Current energy recovery devices are mainly divided into centrifugal and positive displacement types. Positive displacement energy recovery devices outperform centrifugal devices in all aspects, making them the most widely used pressure energy recovery technology in practical engineering projects both domestically and internationally. Positive displacement energy recovery devices can be further divided into rotary and piston-valve-controlled types. Compared to piston-valve-controlled types, rotary pressure energy recovery devices are simpler to operate, run more smoothly, and are more efficient. Rotary energy recovery devices utilize the incompressibility of liquids, allowing the liquid to directly contact within the rotating rotor's channels, thus transferring pressure energy from high-pressure fluid to low-pressure fluid. Because the high and low-pressure fluids directly contact within the rotor channels, an energy conversion in the form of "pressure energy - pressure energy" is achieved. Compared to the previous "pressure energy - mechanical energy - pressure energy" energy conversion methods of centrifugal and piston types, this method has a higher energy recovery efficiency.

[0004] Energy Recovery Inc. (ERI) is the largest manufacturer of energy recovery devices abroad. Its PX series devices are currently the most widely used positive displacement pressure energy recovery devices. It is a ceramic rotor with multiple axial through holes. The rotor rotates in a ceramic sleeve with precise clearance dimensions. In order to reduce the leakage between the end face and the rotor, its components need to be machined with ultra-high precision to form a precise fit; however, this places high demands on the processing equipment and processing technology, making it difficult to reduce the cost of the device. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a rotor channel rotation positive displacement liquid pressure energy recovery device that overcomes the limitations of ultra-high precision machining of existing rotary energy recovery devices through structural optimization.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A rotor-channel rotary positive displacement liquid pressure energy recovery device includes a sleeve with an internal cylindrical hollow cavity, a central shaft, a rotor, a flow guide end cap, and a sealing end cap disposed within the sleeve. The rotor is rotatably mounted on the middle of the central shaft. The flow guide end cap is mounted on the central shaft and located at both ends of the rotor's length. The sealing end cap is mounted on the central shaft and closely adheres to the end of the flow guide end cap furthest from the rotor. The flow guide end cap and the sealing end cap can only slide axially relative to the central shaft. Locking elements are installed at both ends of the central shaft's length, limiting the distance between the two sealing end caps, thus creating a gap d between the flow guide end cap and the rotor. The gap d can be adjusted by adjusting the distance between the two locking elements, improving the adaptability to different flow rates / pressures and higher energy recovery efficiency, thereby achieving high-efficiency energy recovery under different operating conditions.

[0008] The rotor has rotor channels with a reference along a specific spiral. The rotor channels are inclined relative to the rotor central axis. Each of the flow guide end caps has a liquid collection groove corresponding to the rotor channel. During the rotation of the rotor, the liquid collection groove communicates with only a part of the rotor channel each time. The sealing end cap has end cap inlets and outlets that communicate with the liquid collection grooves one by one.

[0009] Furthermore, the width of the gap d is 0.02 to 0.05 mm.

[0010] Furthermore, the gap d is filled with working fluid to prevent hard contact and damaging friction between the rotor and the guide end cover during rotation.

[0011] Furthermore, the central shaft includes a column located in the middle, fastening portions connected to both ends of the column length, and a connecting portion connected to the end of the fastening portion away from the column; the center of the flow guide end cap is provided with a second mounting hole for mounting on the central shaft, the cross-section of the second mounting hole and the fastening portion are both non-circular, and the flow guide end cap is at least partially mounted on the fastening portion.

[0012] Furthermore, the connecting part is threaded, and the locking element is a fastening nut, which is threaded onto the connecting part.

[0013] Furthermore, the centerline of the rotor channel passes through the plane containing multiple rotor axes, and the inclination angle of the rotor channel relative to the rotor center axis ranges from 5 to 30°.

[0014] Furthermore, the cross-section of the rotor channel is a rounded trapezoid, the number of rotor channels is an even number of not less than 6, and the rotor channels are arranged in a single-layer or double-layer circular array around the central axis.

[0015] Furthermore, the diameter of the liquid collection trough changes along the axial direction of the end cover; the end of the liquid collection trough near the rotor is the large diameter end, and the end of the liquid collection trough near the sealing end cover is the small diameter end, and the outer end face of the large diameter end of the liquid collection trough covers two to less than half the total number of rotor channels.

[0016] The technical solution of the present invention achieves the following beneficial technical effects:

[0017] This invention, through structural optimization, changes the conventional practice of setting the rotor channel parallel to the rotor axis. Instead, it sets the rotor channel with a unique helical shape, altering the fluid inlet angle of the high-pressure fluid entering the rotor channel. This reduces the impact force of the high-pressure fluid on the gap between the rotor and the guide end face, improves the smoothness of fluid flow inside the rotor channel, and reduces rotor vibration. This innovative design overcomes the stringent requirements for the gap size between the rotor and the guide end face, reduces liquid leakage between the end face and the rotor, overcomes the ultra-high precision machining limitations of existing rotary energy recovery devices, reduces the processing equipment requirements and assembly difficulty of the device, and helps to reduce production costs.

[0018] The gap d between the guide end face and the rotor can maintain the sealing performance under high pressure conditions, while also maintaining the dynamic seal between the end cover and the rotor, ensuring that the working fluid fills the gap to form a lubricating film, and avoiding hard contact and damaging friction between the rotor and the guide end cover during rotation;

[0019] By using fixed components such as the central shaft, sealing end cap, and locking parts, the gap d between the rotor and the guide end cap can be controlled and adjusted, thereby improving the adaptability to different flow rates / pressures and higher energy recovery efficiency, so as to achieve higher energy recovery efficiency of this device under different operating conditions. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention;

[0021] Figure 2 This is a perspective structural diagram of an embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional structural diagram of an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the rotor channel outline according to an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of the central shaft in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the flow guide end cap located at the bottom according to an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram showing the tangency between the rotor channel and the liquid collection tank of the guide end cap in an embodiment of the present invention;

[0027] Figure 8 This is a diagram showing the rotor rotation driving force torque analysis in an embodiment of the present invention.

[0028] The reference numerals in the figure are as follows: 10-rotor, 11-rotor channel, 12-first mounting hole; 20-guide end cap, 21-high pressure liquid inlet, 22-low pressure liquid outlet, 23-high pressure liquid outlet, 24-low pressure liquid inlet, 25-second mounting hole; 31-sealing end cap; 41-column, 42-fastening part, 43-connecting part, 44-fastening nut; 51-sleeve; 100-gap d. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0030] like Figures 1 to 8 As shown, a rotor-channel rotary positive displacement liquid pressure energy recovery device includes a sleeve 51 with an internal cylindrical hollow cavity, a central shaft, and a rotor 10, a flow guide end cap 20, and a sealing end cap 31 disposed within the sleeve 51. The sleeve 51 is used to support the components and provide space for the energy exchange of the working liquid.

[0031] The rotor 10 is rotatably sleeved in the middle of the central shaft. The flow guide end cap 20 is sleeved on the central shaft and located at both ends of the rotor 10. The sealing end cap 31 is sleeved on the central shaft and closely attached to the end of the flow guide end cap 20 away from the rotor 10. The flow guide end cap 20 and the sealing end cap 31 can only slide axially relative to the central shaft. Locking elements are installed at both ends of the central shaft. The locking elements limit the distance between the two sealing end caps 31, so that a gap d100 is formed between the flow guide end cap 20 and the rotor 10. The width of the gap d100 is 0.02 to 0.05 mm. During operation, the working fluid will fill the gap d100.

[0032] The rotor 10 has rotor channels 11 with a specific spiral as a reference. The center line of the rotor channels 11 passes through the plane containing the axes of multiple rotors 10. Each guide end cover 20 has a liquid collection groove corresponding to the rotor channel 11. The liquid collection groove vertically penetrates the guide end cover 20. During the rotation of the rotor 10, the liquid collection groove communicates with only a portion of the rotor channels 11 each time. The sealing end cover 31 has end cover inlets and outlets that communicate with the liquid collection grooves one by one.

[0033] The liquid collection trough changes diameter along the axial direction of the end cover; the end of the liquid collection trough near the rotor 10 is the large diameter end, and the end of the liquid collection trough near the sealing end cover 31 is the small diameter end. The outer end face of the large diameter end of the liquid collection trough covers two to less than half the total number of rotor channels 11.

[0034] The rotor channel 11 has a certain inclination angle relative to the end face of the rotor 10. The range of the inclination angle will change according to the change of the helix parameters. The inclination angle of the rotor channel 11 relative to the central axis of the rotor 10 ranges from 5-30°. The rotor channel 11 has a trapezoidal cross-section and has appropriate rounded corners, so that the flow of fluid in the rotor channel 11 is more in line with the fluid dynamics characteristics. The number of rotor channels 11 is 6, 8, 10, 12, 14, 16, 18, 20, 22, 24... an even number. The rotor channels 11 are arranged in a single-layer or double-layer circular array around the central axis. This invention uses rotor channels 11 that are inclined relative to the axis. The inclined channels of the rotor 10 and the vertical channels of the guide end cover 20 are the basic structures for forming the rotational driving force of the rotor 10. Figure 7 As shown, when the high-pressure fluid flows out from the channel of the guide end cap 20, it impacts the inclined channel of the rotor 10, thereby generating a driving force μ for the rotation of the rotor 10. By optimizing the flow channel structure of the rotor 10, the smoothness of the fluid flow inside the rotor channel 11 is improved, and the vibration of the rotor 10 is reduced. This invention designs the vertical channel, which is usually parallel to the central axis, as a channel with a unique helical shape, and designs the channel of the guide end cap 20, which is usually at a certain angle, as a vertical channel. This changes the fluid inlet angle of the high-pressure fluid entering the rotor channel 11, reducing the impact force of the high-pressure fluid on the gap between the rotor 10 and the guide end face. Compared with the traditional vertical channel rotor 10, this invention allows for a larger gap between the rotor 10 and the guide end face, i.e., gap d100, which can overcome the stringent requirements for the gap d100 dimension between the rotor 10 and the guide end face, thereby reducing the difficulty of processing, manufacturing, and assembling the device.

[0035] Based on the energy exchange process of the working fluid, the collection tanks of the two guide end caps 20 are distinguished, such as... Figure 2 , Figure 3 , Figure 5 , Figure 7As shown, the liquid collection tank of the upper guide end cover 20 is designated as the high-pressure liquid inlet 21 and the low-pressure liquid outlet 22, and the liquid collection tank of the lower guide end cover 20 is designated as the high-pressure liquid outlet 23 and the low-pressure liquid inlet 24. The high-pressure liquid inlet 21 is used to guide the high-pressure liquid entering the energy recovery device into the rotor channel 11. The low-pressure liquid outlet 22 is used to collect and discharge the waste liquid in the rotor channel 11 after the energy exchange is completed. The high-pressure liquid outlet 23 collects and discharges the fresh high-pressure liquid that has exchanged pressure energy and achieved pressure increase in the rotor channel 11. The low-pressure liquid inlet 24 is used to guide the fresh low-pressure liquid into the rotor channel 11 to squeeze out the liquid that has exchanged pressure energy. When the energy recovery device is working, the rotor 10 is the only moving part in the device. High-pressure waste liquid enters the rotor 10 through the high-pressure liquid inlet 21. Simultaneously, fresh low-pressure liquid supplied by the water pump enters the rotor 10 through the low-pressure liquid inlet 24 of the energy recovery device. The rotor 10 rotates due to the impact force of the high-pressure waste liquid. During rotation, the rotor channel 11 intermittently aligns with different collection tanks. The fresh low-pressure liquid entering the rotor channel A gradually aligns with the high-pressure liquid inlet 21 after the rotor 10 rotates. The high-pressure liquid inlet 21 is connected to the high-pressure liquid outlet 23 through the rotor channel A. The high-pressure waste liquid pressurizes the fresh low-pressure liquid in the rotor channel A. The two are in direct contact within the rotor channel 11 of the energy recovery device, where the pressure energy of the high-pressure waste liquid is directly transferred to the fresh low-pressure liquid. When the fresh liquid in rotor channel A is completely expelled, rotor channel A is filled with the energy-exchanged waste liquid and continues to rotate until the low-pressure liquid inlet 24 connects with the low-pressure liquid outlet 22. The newly entering low-pressure waste liquid then expels the waste liquid from rotor channel A. The pressurized fresh liquid, with a pressure and flow rate close to that of the waste liquid, enters the system through the high-pressure liquid outlet 23 of the energy recovery device for continued use. The high-pressure waste liquid, having completed pressure energy exchange, becomes low-pressure waste liquid and is discharged through the low-pressure liquid outlet 22 of the energy recovery device. Through the interaction between the guide end face and the inclined rotor channel 11, the energy recovery device achieves self-drive of the rotor 10 under the impact of the high-pressure fluid, as well as adaptation to different flow rates and pressures. Furthermore, when high-pressure waste liquid is injected, the waste liquid enters the gap d100 between the guide end face and the rotor 10, forming a lubricating film in the gap d100. Under high pressure conditions, it maintains the sealing while also maintaining the dynamic seal between the end cover and the rotor 10. That is, it keeps the liquid filling the gap d100 to form a lubricating film, avoiding hard contact and damaging friction between the rotor 10 and the end cover during rotation and reducing rotational resistance.

[0036] like Figures 1 to 8As shown, the central shaft includes a column portion 41 located in the middle, fastening portions 42 connected to both ends of the column portion 41, and a connecting portion 43 connected to the end of the fastening portion 42 away from the column portion 41. The column portion 41 is used to install a rotatable rotor 10, the fastening portion 42 is used to install a flow guide end cap 20 and a fastening end cap, and the connecting portion 43 is used to install a locking element. The flow guide end cap 20 has a second mounting hole 25 at its center for mounting on the central shaft. The cross-section of the second mounting hole 25 and the fastening portion 42 are both non-circular. The flow guide end cap 20 is at least partially mounted on the fastening portion 42, so that the flow guide end cap 20 cannot rotate relative to the central shaft. Specifically, the cross-section of the fastening part 42 can be rectangular or regular hexagonal, etc. The shape of the second mounting hole 25 is consistent with the outer contour of the fastening part 42. The cross-section of the column part 41 is circular, regular hexagonal, or other regular polygonal. The center of the rotor 10 is provided with a circular first mounting hole 12 with a size slightly larger than the outer contour of the column part 41, so that the rotor 10 can be fitted onto the column part 41 and rotate stably. The connecting part 43 is threaded, and the locking member is a fastening nut 44, which is threaded onto the connecting part 43. After the fastening nut 44 is threaded onto the connecting part 43, the inner side of the fastening nut 44 presses against the sealing end cap 31. The inner side of the sealing end cap 31 is in close contact with the flow guide end cap 20. The sealing end cap 31 and the flow guide end cap 20 are in hard surface-to-surface contact. The sealing end cap 31 and the flow guide end cap 20 are mainly fixed in the sleeve 51 by the fastening nut 44. The liquid exists only between the flow guide end cap 20 and the rotor 10, thereby adjusting the gap d100 between the flow guide end cap 20 and the rotor 10 to achieve higher recovery efficiency of the energy recovery device under different operating conditions. In addition, the sealing end cap 31 can disperse and evenly distribute the compressive stress of the fastening nut 44, preventing the flow guide end cap 20 from being damaged or deformed when squeezed by the fastening nut 44.

[0037] Specifically, a reference torque is applied to the fastening nut 44 during assembly. This torque is set to a uniform initial value during assembly, considered as the gap d100 between the guide end cover 20 and the rotor 10 to achieve a suitable distance. During operation, the recovery efficiency can be calculated by measuring the inlet and outlet pressures and flow parameters. Based on the calculation results, the torque of the fastening nut is adjusted accordingly to ensure the device maintains a consistently high recovery efficiency.

[0038] The cylindrical sleeve 51 encloses all components within the cavity, providing support, fixation, and partial fluid sealing. The sleeve 51 has threaded holes on its sides corresponding to at least one sealing end cap 31 and guide end cap 20. During assembly, the rotor 10 is first placed on the central shaft and then into the sleeve 51. Next, the guide end cap 20 and sealing end cap 31, aligned with the liquid collection tank and end cap inlet / outlet, are fitted onto the central shaft from both sides. Then, the sealing end cap 31 at one end is sealed and fixed to the inner wall of the sleeve 51. The fasteners at both ends of the central shaft are tightened to the appropriate positions (anti-loosening measures can also be added to the fasteners). Then, a fastening screw is screwed into the threaded hole of the guide end cap 20, so that the inner end of the fastening screw presses against the guide end cap 20 to fix it. Finally, the sealing end cap 31 on that side is positioned using the same method with the fastening screw.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A rotor-channel rotary positive displacement type liquid pressure energy recovery device, characterized in that, The device includes a sleeve (51) with an internal cylindrical hollow cavity, a central shaft, and a rotor (10), a flow guide end cap (20), and a sealing end cap (31) disposed within the sleeve (51). The rotor (10) is rotatably mounted on the middle part of the central shaft. The flow guide end cap (20) is mounted on the central shaft and located at both ends of the length of the rotor (10). The sealing end cap (31) is mounted on the central shaft and closely attached to the end of the flow guide end cap (20) away from the rotor (10). The flow guide end cap (20) and the sealing end cap (31) slide only axially relative to the central shaft. Locking elements are installed at both ends of the length of the central shaft. The locking elements limit the distance between the two sealing end caps (31), so that a gap d (100) is formed between the flow guide end cap (20) and the rotor (10). The rotor (10) is provided with rotor channels (11) based on the spiral. The rotor channels (11) are inclined relative to the central axis of the rotor (10). Each of the flow guide end caps (20) is provided with a liquid collection groove corresponding to the rotor channel (11). During the rotation of the rotor (10), the liquid collection groove is only connected to a part of the rotor channel (11) each time. The sealing end cap (31) is provided with end cap inlets and outlets that are connected to the liquid collection grooves one by one. The central shaft includes a column (41) located in the middle, fastening parts (42) connected to both ends of the column (41) and a connecting part (43) connected to the end of the fastening part (42) away from the column (41); the flow guide end cap (20) is provided with a second mounting hole (25) for mounting on the central shaft at its center. The cross-section of the second mounting hole (25) and the fastening part (42) are both non-circular. The flow guide end cap (20) is at least partially mounted on the fastening part (42). The connecting part (43) is threaded, and the locking part is a fastening nut (44). The fastening nut (44) is threaded onto the connecting part (43). The inner side of the fastening nut (44) presses against the sealing end cap (31), and the inner side of the sealing end cap (31) is in close contact with the flow guide end cap (20). The sealing end cap (31) and the flow guide end cap (20) are fixed in the sleeve (51) by the fastening nut (44). The liquid exists between the flow guide end cap (20) and the rotor (10), thereby realizing the adjustment of the gap d (100) between the flow guide end cap (20) and the rotor (10).

2. The rotor-channel rotary positive displacement liquid pressure energy recovery device according to claim 1, characterized in that, The width of the gap d (100) is 0.02 to 0.05 mm.

3. The rotor-channel rotary positive displacement liquid pressure energy recovery device according to claim 1, characterized in that, The gap d (100) is filled with working fluid.

4. The rotor-channel rotary positive displacement liquid pressure energy recovery device according to claim 1, characterized in that, The centerline of the rotor channel (11) passes through the plane containing the axes of multiple rotors (10), and the inclination angle of the rotor channel (11) relative to the central axis of the rotor (10) ranges from 5 to 30°.

5. The rotor-channel rotary positive displacement liquid pressure energy recovery device according to claim 1, characterized in that, The cross-section of the rotor channel (11) is a rounded trapezoid, and the number of rotor channels (11) is an even number of not less than 6. The rotor channels (11) are arranged in a single-layer or double-layer circular array around the central axis.

6. The rotor-channel rotary positive displacement liquid pressure energy recovery device according to claim 1, characterized in that, The diameter of the liquid collection trough changes along the axial direction of the end cover; the end of the liquid collection trough near the rotor (10) is the large diameter end, and the end of the liquid collection trough near the sealing end cover (31) is the small diameter end. The outer end face of the large diameter end of the liquid collection trough is covered with 2 to less than half the total number of rotor channels (11).

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