Self-pressurizing energy recovery high-pressure pump

Abstract

The present invention relates to a self-boosting energy recovery high-pressure pump, which comprises: a first cylinder block, on which a low-pressure raw water inlet and a high-pressure raw water outlet are provided; a second cylinder block, on which a low-pressure raw water inlet and a high-pressure raw water outlet are provided; a piston assembly, including a piston and a piston rod, with 2 pistons provided and respectively located in the first cylinder block and the second cylinder block, both ends of the piston rod being fixedly connected to the 2 pistons respectively, a reversing channel along the axial direction of the piston rod being provided inside the piston rod, both ends of the reversing channel being communicated with the rodless cavities of the first cylinder block and the second cylinder block respectively, and a first liquid flow hole for communicating the reversing channel with the outside of the piston rod being provided on the side wall of the piston rod; a reversing valve, which is controlled to reverse by the flowing water in the first liquid flow hole so as to make the piston rod reciprocate. The present invention has small energy loss, optimizes the design process of the reverse osmosis system, solves the problem of high energy consumption of small reverse osmosis seawater desalination systems, and the effective energy conversion efficiency of the utilization of the concentrated water residual pressure can reach more than 91%.

Description

Technical Field

[0001] The present invention relates to the technical field of seawater reverse osmosis energy recovery pumps, and particularly to a self-boosting energy recovery high-pressure pump. Background Art

[0002] Reverse osmosis desalination technology uses a high-pressure pump to pressurize raw seawater so that its pressure reaches the operating pressure required for reverse osmosis. The pressurized raw water flows into the reverse osmosis membrane pressure vessel. The fresh water formed by the raw water permeating through the reverse osmosis membrane becomes the product water, while the concentrated brine that does not permeate through the reverse osmosis membrane is discharged with high pressure.

[0003] An important goal in the development of reverse osmosis desalination technology is to reduce the operating cost. Among the components of the operating cost, the energy consumption accounts for the largest proportion. Therefore, reducing energy consumption is the most effective means to reduce the cost of reverse osmosis desalination. Generally speaking, for medium and large-scale reverse osmosis seawater desalination plants, the energy consumption per ton of water has been reduced to 3.8 - 4.5 kWh, while the energy consumption per ton of water for small-scale seawater desalination plants is as high as 9 - 12 kWh. The main reasons are as follows: First, the efficiency of large high-pressure pumps used in reverse osmosis seawater desalination systems is higher than that of small high-pressure pumps; second, there is no energy recovery equipment suitable for small-scale reverse osmosis seawater desalination plants. If the energy recovery equipment type of a larger reverse osmosis seawater desalination plant is adopted, it is either difficult to select a model or the investment is very uneconomical. Therefore, improving the efficiency of high-pressure pumps and recycling the residual pressure of concentrated brine are the two most important directions for reducing the operating cost.

[0004] Energy recovery technology is a technology that recovers and utilizes the residual pressure energy of concentrated brine in a reverse osmosis system. Using energy recovery technology can utilize the energy carried by concentrated brine and save more than half of the energy consumption. In a typical reverse osmosis seawater desalination system, two sets of equipment, namely a high-pressure pump and a booster pump, are required to pressurize seawater: the high-pressure pump is used to directly pressurize the feed water before reverse osmosis to the operating pressure required by the reverse osmosis system; the booster pump is used to pressurize the raw seawater to the pressure required for the pretreatment process section; the reverse osmosis concentrated water is returned to the front of the high-pressure pump to better utilize the energy of the concentrated water and reduce the system energy consumption. The above two parts of raw seawater are combined and then enter the reverse osmosis membrane for desalination. Since two sets of pressurization equipment are required, the system process is complex, the investment is high, and the operation and maintenance are difficult, which is not suitable for small-scale reverse osmosis seawater desalination systems.

[0005] Chinese Patent CN102588240A discloses a self - pressurizing energy recovery high - pressure pump for reverse osmosis seawater desalination, which includes: a central block with multiple internal flow channels formed therein; a reversing control valve located above the central block, communicating with the internal flow channels of the central block, and provided with a high - pressure brine hole, a first discharge hole and a second discharge hole symmetrically located on both sides of the high - pressure brine hole; a guiding control valve located below the central block, communicating with the internal flow channels of the central block, and provided with a raw seawater inlet hole, a third discharge hole and a fourth discharge hole symmetrically arranged on both sides of the raw seawater inlet hole; a first hydraulic cylinder located on the left side of the central block, communicating with the internal flow channels of the central block, and symmetrically provided with a first liquid flow hole and a second liquid flow hole; a second hydraulic cylinder located on the right side of the central block, communicating with the internal flow channels of the central block, and symmetrically provided with a third liquid flow hole and a fourth liquid flow hole. This invention is applicable to small - scale reverse osmosis seawater desalination systems, but when in use, the high - pressure brine needs to push two reversing valves and one piston rod, resulting in relatively large energy losses. Summary of the Invention

[0006] The present invention provides a self - pressurizing energy recovery high - pressure pump to solve the technical problems such as existing energy recovery devices not supporting small - scale devices, high energy consumption of small - scale reverse osmosis seawater desalination systems, and large energy losses of existing energy recovery devices.

[0007] To solve the above - mentioned technical problems, the technical solution provided by the present invention is as follows:

[0008] The present invention relates to a self - pressurizing energy recovery high - pressure pump, which includes:

[0009] A first cylinder block, on which a low - pressure raw water inlet and a high - pressure raw water outlet are provided;

[0010] A second cylinder block, on which a low - pressure raw water inlet and a high - pressure raw water outlet are provided;

[0011] A piston assembly, including a piston and a piston rod. There are 2 pistons respectively located in the first cylinder block and the second cylinder block. Both ends of the piston rod are fixedly connected to the 2 pistons. A reversing channel along the axial direction of the piston rod is provided inside the piston rod. Both ends of the reversing channel are connected to the rod - less chambers of the first cylinder block and the second cylinder block respectively. A first liquid flow hole communicating the reversing channel with the outside of the piston rod is provided on the side wall of the piston rod;

[0012] A reversing valve, on which a high - pressure concentrated water inlet and a low - pressure concentrated water outlet are provided. The first cylinder block is sealed and installed at one end of the reversing valve, the second cylinder block is sealed and installed at the other end of the reversing valve. The piston rod passes through the reversing valve. The first liquid flow hole is located inside the reversing valve. The reversing valve is controlled to reverse by the water flowing in the first liquid flow hole, so as to make the piston rod reciprocate.

[0013] Preferably, the reversing valve includes a valve housing and a concentrated water diversion ring. The high-pressure concentrated water inlet and the low-pressure concentrated water outlet are arranged on the outer wall of the valve housing. A rod sleeve is arranged inside the valve housing. The rod sleeve is sleeved on the piston rod and is in sliding fit with the piston rod. Second liquid flow holes are respectively arranged on the side walls at both ends of the rod sleeve. The second liquid flow holes connect the inside and outside of the rod sleeve. The second liquid flow holes correspond to the positions of the first liquid flow holes. The concentrated water diversion ring is sleeved on the rod sleeve and is in sliding fit with the rod sleeve. The concentrated water diversion ring includes a first ring member and a second ring member located inside the first ring member. The middle parts of the first ring member and the second ring member are fixedly connected through an annular partition plate. The annular partition plate passes through the second ring member. The inner side of the annular partition plate is slidably sleeved on the rod sleeve. A high-pressure concentrated water chamber is formed between the first ring member and the valve housing. The high-pressure concentrated water chamber is connected to the high-pressure concentrated water inlet. Third liquid flow holes are respectively arranged at both ends of the first ring member. A reversing chamber is formed between the second ring member and the rod sleeve. The reversing chamber is communicated with the second liquid flow holes. End covers are arranged at both ends of the valve housing. Fourth liquid flow holes are arranged on the end covers. The fourth liquid flow holes connect the rodless chambers of the first cylinder or the second cylinder. When the concentrated water diversion ring is in the right extreme position, the right third liquid flow hole on the first ring member is connected to the right fourth liquid flow hole. When the concentrated water diversion ring is in the left extreme position, the left third liquid flow hole on the second ring member is connected to the left fourth liquid flow hole.

[0014] Preferably, there are 2 low-pressure concentrated water outlets on the valve housing. The high-pressure concentrated water inlet is located between the 2 low-pressure concentrated water outlets. Annular flow-stop parts are arranged at both ends of the first ring member. When the concentrated water diversion ring is in the right extreme position, the right flow-stop part on the first ring member blocks the right low-pressure concentrated water outlet, and the left low-pressure concentrated water outlet is connected to the left fourth liquid flow hole. When the concentrated water diversion ring is in the left extreme position, the left flow-stop part on the first ring member blocks the left low-pressure concentrated water outlet, and the right low-pressure concentrated water outlet is connected to the right fourth liquid flow hole.

[0015] Preferably, the rod sleeve is further provided with a fifth liquid flow hole. The fifth liquid flow hole is located outside the second liquid flow hole. A low-pressure raw water outlet is arranged on the valve housing. The fifth liquid flow hole connects the inside of the rod sleeve and the low-pressure raw water outlet. When the first liquid flow hole on the piston rod is connected to the second liquid flow hole, the first diversion groove on the other side of the piston rod simultaneously connects the second liquid flow hole and the fifth liquid flow hole on the same side, so that the water flow in the reversing chamber on this side sequentially passes through the second liquid flow hole and the fifth liquid flow hole and is discharged to the outside, reducing the reversing resistance of the concentrated water diversion ring and reducing the energy loss.

[0016] Preferably, one-way valves that only allow liquid to flow into the reversing channel are arranged at both ends of the reversing channel. The concentrated water diversion ring is driven to reverse by the raw water in the first cylinder or the second cylinder. One-way valves that only allow liquid to flow into are arranged on the low-pressure raw water inlets of the first cylinder and the second cylinder. One-way valves that only allow liquid to flow out are arranged on the high-pressure raw water outlets of the first cylinder and the second cylinder.

[0017] Preferably, an annular second flow guiding groove is provided on the outer wall of the piston rod, and the first liquid flow hole is located in the second flow guiding groove, which is used to improve the error tolerance rate of the connection between the first liquid flow hole and the second liquid flow hole, so that the two are easy to connect without deliberately aligning the first liquid flow hole and the second liquid flow hole, facilitating use.

[0018] Preferably, the area between the first ring member and the second ring member is divided into two left and right first cavities by an annular partition plate. The two first cavities communicate with each other through through holes on the annular partition plate. An annular retaining ring extends from the end cover towards the inner side of the valve housing. The outer side of the annular retaining ring is slidably matched with the first ring member, and the inner side of the annular retaining ring is slidably matched with the second ring member. When the concentrated water guiding ring is in the right extreme position, the right annular retaining ring is located on the left side of the right third liquid flow hole, and the left annular retaining ring is located on the left side of the left third liquid flow hole. When the concentrated water guiding ring is in the left extreme position, the left annular retaining ring is located on the right side of the left third liquid flow hole, and the right annular retaining ring is located on the right side of the right third liquid flow hole.

[0019] Preferably, a first flow guiding ring and a second flow guiding ring are provided on the inner side of the end cover. One end of the first flow guiding ring contacts the end cover. The other end of the first flow guiding ring is provided with a folded portion that folds outwards. The outer side of the folded portion contacts the connecting portion between the annular retaining ring and the end cover. A second cavity is formed between the folded portion and the end cover, and the second cavity communicates with the fifth liquid flow hole. A flow blocking ring is provided on the inner side of the first flow guiding ring. The flow blocking ring is located between the second liquid flow hole and the fifth liquid flow hole to separate the second liquid flow hole from the fifth liquid flow hole; One end of the second flow guiding ring contacts the end cover. The outer side wall of the second flow guiding ring fits with the valve housing. The inner side wall of the second flow guiding ring fits with the connecting portion between the annular retaining ring and the end cover. An annular third flow guiding groove is provided on the outer side wall of the second flow guiding ring. The third flow guiding groove communicates with the second cavity, and the third flow guiding groove communicates with the low-pressure raw water outlet.

[0020] Preferably, a flow guiding port is opened at one end of the first flow guiding ring that contacts the end cover. The flow guiding port communicates with the fifth liquid flow hole and the second cavity; A radial sixth liquid flow hole is provided on the second flow guiding ring. The sixth liquid flow hole is located in the third flow guiding groove, and the sixth liquid flow hole communicates with the second cavity and the third flow guiding groove.

[0021] Preferably, an axially arranged first flow channel is provided on the second flow guiding ring. The fourth liquid flow hole communicates with the low-pressure concentrated water outlet or the high-pressure concentrated water inlet through the first flow channel. A seventh liquid flow hole is provided on the connecting portion on the inner side of the end cover. The sixth liquid flow hole communicates with the seventh liquid flow hole. The fifth liquid flow hole communicates with the second cavity through the flow guiding port. The second cavity communicates with the third flow guiding groove through the sixth liquid flow hole and the seventh liquid flow hole. The third flow guiding groove communicates with the low-pressure raw water outlet and the low-pressure raw water outlet.

[0022] Adopting the technical solution provided by the present invention, compared with the prior art, it has the following beneficial effects:

[0023] 1. The self - pressurizing energy - recovery high - pressure pump involved in the present invention uses the high - pressure concentrated water discharged from the reverse osmosis device, and the raw water in the first cylinder and the second cylinder together as the drive for the piston rod to produce high - pressure raw water; uses the raw water in the first cylinder and the second cylinder as the drive for the reversal of the concentrated - water diversion ring; the concentrated - water diversion ring is equivalent to a reversing spool valve, and its automatic reversal is realized through the ingenious liquid - flow channel structure in the present invention. When reversing, the energy of the high - pressure concentrated water is not used, reducing the energy consumption of the high - pressure concentrated water and having a more efficient energy - conversion efficiency.

[0024] 2. In the self - pressurizing energy - recovery high - pressure pump involved in the present invention, a first diversion groove is provided on the piston rod. When the first liquid - flow hole on the piston rod is connected to the second liquid - flow hole, the first diversion groove on the other side of the piston rod simultaneously connects the second liquid - flow hole and the fifth liquid - flow hole on the same side, so that the water flow in the reversing chamber on that side is discharged to the outside successively through the second liquid - flow hole and the fifth liquid - flow hole, relieving the pressure in the reversing chamber, reducing the reversing resistance of the concentrated - water diversion ring, and further reducing energy loss.

[0025] 3. When in use, the self - pressurizing energy - recovery high - pressure pump involved in the present invention only needs a pre - installed low - pressure raw - seawater supply pump, which can directly increase the pressure of the raw water to the operating pressure required by the reverse osmosis system without the need to install additional high - pressure pumps or booster pumps. This makes the design process of the reverse osmosis system simpler, reduces the volume and weight of small - scale reverse osmosis desalination devices, reduces equipment investment and system energy consumption. The effective energy - conversion efficiency of the utilization of the residual pressure of the high - pressure concentrated water in the present invention can reach more than 91%.

[0026] 4. For a small - scale reverse osmosis seawater desalination system using the self - pressurizing energy - recovery high - pressure pump involved in the present invention, the energy consumption per ton of water is about half lower than that of other small - scale seawater desalination devices. Through actual measurement and comparison, the energy consumption of small - scale seawater desalination devices on the market is mostly between 9 - 12 kWh, while the energy consumption per ton of water of a small - scale reverse osmosis seawater desalination device using the self - pressurizing energy - recovery high - pressure pump involved in the present invention is between 4 - 5 kWh, and the energy - saving rate can be as high as 67%. It can be used in reverse osmosis desalination devices with a scale of less than 50 tons of fresh water per day, and can be used at least for a reverse osmosis desalination device of 0.5 tons per day, which is conducive to popularization and use in medium - sized and small - scale reverse osmosis seawater desalination systems.

[0027] 5. The self - pressurizing energy - recovery high - pressure pump involved in the present invention controls the water production rate of the reverse osmosis system to which the present invention applies, that is, the ratio of the amount of fresh water produced to the input raw water, between 8% and 25% by changing the ratio of the piston - rod area to the piston area and changing the provided pressure, and is designed as a fixed value to meet the water - production pressure requirements of reverse osmosis systems of different specifications.

[0028] 6. Since the self-boosting energy recovery high-pressure pump involved in the present invention is in a self-boosting mode, the requirements for the high-pressure pump are reduced, but it can still boost to the operating pressure of the reverse osmosis system. Therefore, the entire system is more easily combined with new energy sources such as solar energy and wind energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a perspective view of the self-boosting energy recovery high-pressure pump involved in the present invention;

[0030] Figure 2 is a front view of the self-boosting energy recovery high-pressure pump involved in the present invention;

[0031] Figure 3 is a cross-sectional view of the self-boosting energy recovery high-pressure pump involved in the present invention;

[0032] Figure 4 is a perspective view of the concentrated water diversion ring in the present invention;

[0033] Figure 5 is a perspective view of the end cap in the present invention;

[0034] Figure 6 is a perspective view of the second diversion ring in the present invention;

[0035] Figure 7 is a perspective view of the first diversion ring in the present invention;

[0036] Figure 8 is a perspective view of the piston rod in the present invention;

[0037] Figure 9 is a schematic diagram of the working process of the present invention.

[0038] In the figure: 1. First cylinder block, 11. Low-pressure raw water inlet, 12. High-pressure raw water outlet, 13. Rodless cavity, 14. Rod cavity, 2. Second cylinder block, 21. Low-pressure raw water inlet, 22. High-pressure raw water outlet, 23. Rodless cavity, 24. Rod cavity, 3. Directional control valve, 31. High-pressure concentrated water inlet, 32. Low-pressure concentrated water outlet, 33. Low-pressure concentrated water outlet, 34. Low-pressure raw water outlet, 35. Low-pressure raw water outlet, 36. High-pressure concentrated water cavity, 4. Concentrated water guide ring, 41. First ring part, 42. Second ring part, 43. Third liquid flow hole, 44. Flow-stop part, 45. First cavity, 46. Direction-changing cavity, 47. Annular partition plate, 48. Through hole, 5. End cover, 51. Fourth liquid flow hole, 52. Seventh liquid flow hole, 53. Annular retaining ring, 54. Connecting part, 6. Second guide ring, 61. Third guide groove, 62. Sixth liquid flow hole, 63. First flow channel, 7. First guide ring, 71. Folded part, 72. Guide port, 73. Flow-blocking ring, 74. Second cavity, 8. Piston, 81. Composite seal, 9. Rod sleeve, 91. Second liquid flow hole, 92. Fifth liquid flow hole, 10. Piston rod, 101. First guide groove, 102. First liquid flow hole, 103. Direction-changing hole channel, 104. Second guide groove, 20. Check valve. Detailed implementation mode

[0039] To further understand the content of the present invention, the present invention will be described in detail in combination with embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention.

[0040] To solve the above technical problems, the technical solution provided by the present invention is as follows:

[0041] Please refer to Figures 1 to 9 , the present invention relates to a self-boosting energy recovery high-pressure pump, which includes:

[0042] A first cylinder block 1, on which a low-pressure raw water inlet 11 and a high-pressure raw water outlet 12 are provided;

[0043] A second cylinder block 2, on which a low-pressure raw water inlet 21 and a high-pressure raw water outlet 22 are provided;

[0044] A piston assembly, including a piston 8 and a piston rod 10. There are 2 pistons 8 which are respectively located in the first cylinder block 1 and the second cylinder block 2. Both ends of the piston rod 10 are fixedly connected to the 2 pistons 8. Inside the piston rod 10, there is a direction-changing hole channel 103 along the axial direction of the piston rod 10. Both ends of the direction-changing hole channel 103 are connected to the rodless cavities 13 and 23 of the first cylinder block 1 and the second cylinder block 2 respectively. On the side wall of the piston rod 10, there is a first liquid flow hole 102 connecting the direction-changing hole channel 103 and the outside of the piston rod; A conventional composite seal 81 is sleeved on the piston 8.

[0045] A reversing valve is provided with a high-pressure concentrated water inlet 31 and a low-pressure concentrated water outlet. The first cylinder block 1 is hermetically installed at one end of the reversing valve, and the second cylinder block 2 is hermetically installed at the other end of the reversing valve. The piston rod 10 passes through the reversing valve. The first liquid flow hole 102 is located inside the reversing valve. The reversing valve is controlled to reverse by the flowing water in the first liquid flow hole 102, so that the piston rod 10 reciprocates. The reversing valve includes a valve housing 3 and a concentrated water guide ring 4. The high-pressure concentrated water inlet 31 and the low-pressure concentrated water outlet are arranged on the outer wall of the valve housing 3. A rod sleeve 9 is arranged inside the valve housing 3. The rod sleeve 9 is sleeved on the piston rod 10 and is in sliding fit with the piston rod 10. Second liquid flow holes 91 are respectively arranged on the side walls at both ends of the rod sleeve 9. The second liquid flow holes 91 connect the inside and outside of the rod sleeve 9. The second liquid flow holes 91 and the first liquid flow hole 102 are in corresponding positions. The concentrated water guide ring 4 is sleeved on the rod sleeve 9 and is in sliding fit with the rod sleeve. The concentrated water guide ring 4 includes a first ring member 41 and a second ring member 42 located inside the first ring member. The middle parts of the first ring member 41 and the second ring member 42 are fixedly connected by an annular partition plate 47. The annular partition plate 47 passes through the second ring member 42. The inner side of the annular partition plate 47 is slidably sleeved on the rod sleeve 9. A high-pressure concentrated water chamber 36 is formed between the first ring member 41 and the valve housing 3. The high-pressure concentrated water chamber 36 is connected to the high-pressure concentrated water inlet 31. Third liquid flow holes 43 are respectively arranged at both ends of the first ring member 41. A reversing chamber 46 is formed between the second ring member 42 and the rod sleeve 9. The reversing chamber 46 is communicated with the second liquid flow holes 91. End covers 5 are arranged at both ends of the valve housing 3. Fourth liquid flow holes 51 are arranged on the end covers 5. The fourth liquid flow holes 51 connect to the rodless chambers of the first cylinder block 1 or the second cylinder block 2. When the concentrated water guide ring 4 is in the right extreme position, the right third liquid flow hole 43 on the first ring member 41 is connected to the right fourth liquid flow hole 51. When the concentrated water guide ring 4 is in the left extreme position, the left third liquid flow hole 43 on the second ring member is connected to the left fourth liquid flow hole 51.

[0046] Please refer to Figures 1 to 3 As shown in FIGS. 5 and 9, there are 2 low-pressure concentrated water outlets provided on the valve housing 3. This embodiment includes a low-pressure concentrated water outlet 32 and a low-pressure concentrated water outlet 33. The high-pressure concentrated water inlet 31 is located between the 2 low-pressure concentrated water outlets. Annular flow-stop portions 44 are provided at both ends of the first ring member 41. Please refer to Figure 9 FIG. 7. When the concentrated water guide ring 4 is in the right extreme position, the right flow-stop portion 44 on the first ring member 41 blocks the right low-pressure concentrated water outlet 32, and the left low-pressure concentrated water outlet 33 is connected to the left fourth liquid flow hole 51. Correspondingly, when the concentrated water guide ring 4 is in the left extreme position, the left flow-stop portion 44 on the first ring member 41 blocks the left low-pressure concentrated water outlet 33, and the right low-pressure concentrated water outlet 32 is connected to the right fourth liquid flow hole 51.

[0047] Please refer to Figures 1 to 3, 9. The rod sleeve is further provided with a fifth liquid flow hole 92, which is located outside the second liquid flow hole 91. In this embodiment, the valve housing 3 is provided with a low-pressure raw water outlet 34 and a low-pressure raw water outlet 35. The fifth liquid flow holes 92 on both sides of the rod sleeve connect the inside of the rod sleeve 9 to the low-pressure raw water outlet 34 and the low-pressure raw water outlet 35. Please refer to Figure 8 , 9 , annular first flow guiding grooves 101 are provided on the outer walls of the left and right sides of the piston rod 10. When the first liquid flow hole 102 on the piston rod 10 is connected to the second liquid flow hole 91, the first flow guiding groove 101 on the other side of the piston rod 10 is simultaneously connected to the second liquid flow hole 91 and the fifth liquid flow hole 92 on the same side, so that the water flow in the commutation cavity 46 on that side is discharged to the outside in sequence through the second liquid flow hole 91 and the fifth liquid flow hole 92, reducing the commutation resistance of the concentrated water guiding ring 4 and reducing energy loss. Check valves 20 that only allow liquid to flow into the commutation hole 103 are provided at both ends of the commutation hole 103, and the concentrated water guiding ring is driven to commutate by the raw water in the first cylinder or the second cylinder; check valves 20 that only allow liquid to flow into are provided on the low-pressure raw water inlets 11 and 12 of the first cylinder 1 and the second cylinder 2, and check valves 20 that only allow liquid to flow out are provided on the high-pressure raw water outlet 12 and the low-pressure raw water inlet 22 of the first cylinder 1 and the second cylinder 2. The check valve structure in this embodiment includes a spherical valve core and a spring. The spring presses the valve core to block the water inlet of the check valve, and the check valve is connected when the pressure generated by the water pressure is greater than the set pressure of the spring. Please refer to Figure 8 , 9 , an annular second flow guiding groove 104 is provided on the outer wall of the piston rod 10, and the first liquid flow hole 102 is located in the second flow guiding groove 104, which is used to improve the error tolerance rate of the connection between the first liquid flow hole 102 and the second liquid flow hole 91, so that it is convenient for the two to be connected without deliberately aligning the first liquid flow hole and the second liquid flow hole, which is convenient for use.

[0048] Please refer to Figures 3 to 4 、8, 9. The area between the first ring member 41 and the second ring member 42 is divided into two left and right first cavities 45 by an annular partition plate 47. The two first cavities 45 communicate with each other through through holes 48 on the annular partition plate 47. An annular retaining ring 53 extends from the end cover 5 towards the inside of the valve housing 3. The outer side of the annular retaining ring 53 is slidably matched with the first ring member 41, and the inner side of the annular retaining ring 53 is slidably matched with the second ring member 42. When the concentrated water guiding ring 4 is in the right extreme position, the right annular retaining ring 53 is located on the left side of the right third liquid flow hole 43, and the left annular retaining ring 53 is located on the left side of the left third liquid flow hole 43. Correspondingly, when the concentrated water guiding ring 4 is in the left extreme position, the left annular retaining ring 53 is located on the right side of the left third liquid flow hole 43, and the right annular retaining ring is located on the right side of the right third liquid flow hole.

[0049] Please refer to Figure 3 , 6~8, 9. Inside the end cap 5, there are a first flow guiding ring 7 and a second flow guiding ring 6. One end of the first flow guiding ring 7 is in contact with the end cap 5. The other end of the first flow guiding ring 7 is provided with a folded part 71 that folds outward. The outer side of the folded part 71 is in contact with the connecting part 54 between the annular retaining ring 53 and the end cap 5. A second cavity 74 is formed between the folded part 71 and the end cap 5. The second cavity 74 is connected to the fifth liquid flow hole 92. Inside the first flow guiding ring 7, there is a flow blocking ring 73. The flow blocking ring 73 is located between the second liquid flow hole 91 and the fifth liquid flow hole 92 to separate the second liquid flow hole from the fifth liquid flow hole. One end of the second flow guiding ring 6 is in contact with the end cap 5. The outer side wall of the second flow guiding ring 6 fits with the valve housing 3. The inner side wall of the second flow guiding ring 6 fits with the connecting part 54 between the annular retaining ring and the end cap. On the outer side wall of the second flow guiding ring 6, there is an annular third flow guiding groove 61. The third flow guiding groove 61 is connected to the second cavity 74. The third flow guiding grooves 61 on both sides are respectively connected to the low-pressure raw water outlet 34 and the low-pressure raw water outlet 35. On the end of the first flow guiding ring 7 in contact with the end cap 5, there is a flow guiding port 72. The flow guiding port 72 connects the fifth liquid flow hole 92 and the second cavity 74. The second flow guiding ring 6 is provided with a radial sixth liquid flow hole 62. The sixth liquid flow hole 62 is located in the third flow guiding groove 61. The sixth liquid flow hole 62 connects the second cavity 74 and the third flow guiding groove 61. In this embodiment, the second flow guiding ring 6 is provided with an axially arranged first flow channel 63. The fourth liquid flow hole 51 is connected to the low-pressure concentrated water outlet or the high-pressure concentrated water inlet 31 through the first flow channel 63. On the connecting part 54 inside the end cap 5, there is a seventh liquid flow hole 52. The sixth liquid flow hole 62 is connected to the seventh liquid flow hole 52. The fifth liquid flow hole 92 is connected to the second cavity 74 through the flow guiding port 72. The second cavity 74 is connected to the third flow guiding groove 61 through the sixth liquid flow hole 62 and the seventh liquid flow hole 52. The third flow guiding groove 61 is connected to the low-pressure raw water outlet 34 and the low-pressure raw water outlet 35.

[0050] The working steps and principles of the self-boosting energy recovery high-pressure pump involved in the present invention are as follows:

[0051] 1) Connect the low-pressure raw water inlets 11 and 21 of the first cylinder block 1 and the second cylinder block 2 to the low-pressure raw water supply pump in the front for water supply; connect the high-pressure raw water outlets 12 and 22 of the first cylinder block 1 and the second cylinder block 2 to the water inlet of the reverse osmosis device; connect the high-pressure concentrated water inlet 31 to the high-pressure concentrated water outlet of the reverse osmosis device to complete the installation of the system;

[0052] 2) Start the system, refer to Figure 3, the raw water first enters the rodless cavity 23 of the second cylinder block 2 from the low-pressure raw water inlet 21, pushing the piston 8 to move leftward. At the same time, the high-pressure raw water outlet 22 conveys high-pressure raw water to the reverse osmosis device; when the piston rod moves leftward to the left extreme position, the first liquid flow hole 102 is connected to the second liquid flow hole 91 on the left side. At this time, the raw water in the rodless cavity 23 of the second cylinder block 2 passes through the one-way valve and enters the left-side reversing cavity 46 successively through the reversing hole channel 103, the first liquid flow hole 102, and the second liquid flow hole 91 on the left side, pushing the concentrated water guiding ring 4 to move rightward to the right extreme position, reaching Figure 9 the state shown in the figure. At this time, the high-pressure concentrated water cavity 36 is connected to the rodless cavity 24 of the second rod body through the third liquid flow hole 43 on the right side, the first flow channel 63 on the right side, and the fourth liquid flow hole 51 on the right side. At the same time, the right-side flow stop portion 44 blocks the right-side low-pressure concentrated water outlet 32. The high-pressure concentrated water in the high-pressure concentrated water cavity 36 pushes the right-side piston 8 to move rightward, and the left-side low-pressure concentrated water outlet 33 is connected to the rodless cavity 14 of the first cylinder block. The low-pressure concentrated water in the rodless cavity 14 is discharged through the low-pressure concentrated water outlet 33;

[0053] 3) After the piston rod reaches the right extreme position under the push of the high-pressure concentrated water, the first liquid flow hole 102 is connected to the second liquid flow hole 91 on the right side. At this time, the raw water in the rodless cavity 13 of the first cylinder block 1 enters the right-side reversing cavity 46 successively through the reversing hole channel 103, the first liquid flow hole 102 on the right side, and the second liquid flow hole 91 on the right side, pushing the concentrated water guiding ring 4 to move leftward. After the concentrated water guiding ring 4 moves leftward to the left extreme position, the high-pressure concentrated water cavity 36 is connected to the rodless cavity 14 of the first rod body through the third liquid flow hole 43 on the left side, the first flow channel 63 on the left side, and the fourth liquid flow hole 51 on the left side. At the same time, the left-side flow stop portion 44 blocks the left-side low-pressure concentrated water outlet 33. The high-pressure concentrated water in the high-pressure concentrated water cavity 36 pushes the left-side piston 8 to move leftward, and the right-side low-pressure concentrated water outlet 32 is connected to the rodless cavity 24 of the second cylinder block. The low-pressure concentrated water in the rodless cavity 24 is discharged through the low-pressure concentrated water outlet 32, and the concentrated water guiding ring completes a cycle of reciprocating motion. The concentrated water guiding ring and the piston assembly perform this reciprocating motion to recycle the pressure of the high-pressure concentrated water generated by the reverse osmosis device.

[0054] When the piston rod 10 moves to the left extreme position, the first left liquid flow hole 102 is connected to the second left liquid flow hole 91. At the same time, the second right liquid flow hole 91 is connected to the fifth right liquid flow hole 92 through the first right diversion groove 101. The raw water in the right commutation cavity 46 sequentially passes through the second right liquid flow hole 91, the fifth right liquid flow hole 92, the diversion port 72, the second cavity 74, the seventh liquid flow hole 52, the sixth liquid flow hole 62 and the third guiding groove 61, and then is discharged through the low-pressure raw water outlet 34 on the right side. In this way, the concentrated water diversion ring 4 will not be affected by the resistance of the raw water in the right commutation cavity 46 when moving to the right. The same is true when the piston rod 10 moves to the right extreme position. When the piston rod 10 moves to the left or right, in addition to being pushed by the high-pressure concentrated water, it will also be pushed by the raw water in the rodless cavity on the side away from the piston rod, further saving energy.

[0055] The present invention has been described in detail in combination with the embodiments, but the above content is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A self-pressurizing energy recovery high-pressure pump, characterized in that it comprises: a first cylinder block, on which a low-pressure raw water inlet and a high-pressure raw water outlet are provided; a second cylinder block, on which a low-pressure raw water inlet and a high-pressure raw water outlet are provided; a piston assembly, including a piston and a piston rod, with 2 pistons provided and respectively located in the first cylinder block and the second cylinder block, both ends of the piston rod are fixedly connected to the 2 pistons respectively, a reversing channel along the axial direction of the piston rod is arranged inside the piston rod, both ends of the reversing channel are respectively communicated with the rodless cavities of the first cylinder block and the second cylinder block, and a first liquid flow hole for communicating the reversing channel with the outside of the piston rod is arranged on the side wall of the piston rod; a reversing valve, on which a high-pressure concentrated water inlet and a low-pressure concentrated water outlet are provided, the first cylinder block is hermetically installed at one end of the reversing valve, the second cylinder block is hermetically installed at the other end of the reversing valve, the piston rod passes through the reversing valve, the first liquid flow hole is located inside the reversing valve, and the reversing valve is controlled to reverse by the flowing water in the first liquid flow hole so as to make the piston rod reciprocate; the said reversing valve includes a valve housing and a concentrated water diversion ring, the high-pressure concentrated water inlet and the low-pressure concentrated water outlet are arranged on the outer wall of the valve housing, a rod sleeve is arranged inside the valve housing, the rod sleeve is sleeved on the piston rod and is in sliding fit with the piston rod, second liquid flow holes are respectively arranged on the side walls at both ends of the rod sleeve, the second liquid flow holes communicate the inside and the outside of the rod sleeve, the second liquid flow holes and the first liquid flow holes are in corresponding positions, the concentrated water diversion ring is sleeved on the rod sleeve and is in sliding fit with the rod sleeve, the concentrated water diversion ring includes a first ring part and a second ring part located inside the first ring part, the middle parts of the first ring part and the second ring part are fixedly connected by an annular partition plate, the annular partition plate passes through the second ring part, the inner side of the annular partition plate is slidably sleeved on the rod sleeve, a high-pressure concentrated water cavity is formed between the first ring part and the valve housing, the high-pressure concentrated water cavity is communicated with the high-pressure concentrated water inlet, third liquid flow holes are respectively arranged at both ends of the first ring part, a reversing cavity is formed between the second ring part and the rod sleeve, the reversing cavity is communicated with the second liquid flow holes, end covers are arranged at both ends of the valve housing, and fourth liquid flow holes are arranged on the end covers, the fourth liquid flow holes communicate with the rod cavities of the first cylinder block or the second cylinder block, when the concentrated water diversion ring is at the right extreme position, the right third liquid flow hole on the first ring part is communicated with the right fourth liquid flow hole; when the concentrated water diversion ring is at the left extreme position, the left third liquid flow hole on the second ring part is communicated with the left fourth liquid flow hole.

2. A self-pressurizing energy recovery high-pressure pump according to claim 1, characterized in that: 2 low-pressure concentrated water outlets are arranged on the valve housing, the high-pressure concentrated water inlet is located between the 2 low-pressure concentrated water outlets, annular flow-stop parts are arranged at both ends of the first ring part, when the concentrated water diversion ring is at the right extreme position, the right flow-stop part on the first ring part blocks the right low-pressure concentrated water outlet, and the left low-pressure concentrated water outlet is communicated with the left fourth liquid flow hole; when the concentrated water diversion ring is at the left extreme position, the left flow-stop part on the first ring part blocks the left low-pressure concentrated water outlet, and the right low-pressure concentrated water outlet is communicated with the right fourth liquid flow hole.

3. A self-pressurizing energy recovery high-pressure pump according to claim 1, characterized in that: The rod sleeve is further provided with a fifth liquid flow hole which is located outside the second liquid flow hole. The valve housing is provided with a low-pressure raw water outlet. The fifth liquid flow hole connects the inside of the rod sleeve and the low-pressure raw water outlet. Annular first flow guiding grooves are provided on the outer walls on both the left and right sides of the piston rod. When the first liquid flow hole on the piston rod is connected to the second liquid flow hole, the first flow guiding groove on the other side of the piston rod is simultaneously connected to the second liquid flow hole and the fifth liquid flow hole on the same side.

4. A self-boosting energy recovery high-pressure pump according to claim 1, characterized in that: One-way valves that only allow liquid to flow into the commutation hole are provided at both ends of the commutation hole; one-way valves that only allow liquid to flow into are provided at the low-pressure raw water inlets on the first cylinder block and the second cylinder block, and one-way valves that only allow liquid to flow out are provided at the high-pressure raw water outlets on the first cylinder block and the second cylinder block.

5. A self-boosting energy recovery high-pressure pump according to claim 1, characterized in that: An annular second flow guiding groove is provided on the outer wall of the piston rod, and the first liquid flow hole is located in the second flow guiding groove.

6. A self-boosting energy recovery high-pressure pump according to claim 3, characterized in that: The area between the first ring member and the second ring member is divided into two left and right first cavities by an annular partition. The two first cavities communicate with each other through through holes in the annular partition. An annular retaining ring extends from the end cover towards the inside of the valve housing. The outer side of the annular retaining ring is slidably matched with the first ring member, and the inner side of the annular retaining ring is slidably matched with the second ring member. When the concentrated water diversion ring is in the right extreme position, the right annular retaining ring is located on the left side of the right third liquid flow hole, and the left annular retaining ring is located on the left side of the left third liquid flow hole. When the concentrated water diversion ring is in the left extreme position, the left annular retaining ring is located on the right side of the left third liquid flow hole, and the right annular retaining ring is located on the right side of the right third liquid flow hole.

7. A self-boosting energy recovery high-pressure pump according to claim 6, characterized in that: A first flow guiding ring and a second flow guiding ring are provided on the inner side of the end cover. One end of the first flow guiding ring contacts the end cover. The other end of the first flow guiding ring is provided with a folded portion that turns outwards. The outer side of the folded portion contacts the connecting portion between the annular retaining ring and the end cover. A second cavity is formed between the folded portion and the end cover. The second cavity is connected to the fifth liquid flow hole. A flow blocking ring is provided on the inner side of the first flow guiding ring. The flow blocking ring is located between the second liquid flow hole and the fifth liquid flow hole and separates the second liquid flow hole from the fifth liquid flow hole; One end of the second flow guiding ring contacts the end cover. The outer side wall of the second flow guiding ring fits with the valve housing. The inner side wall of the second flow guiding ring fits with the connecting portion between the annular retaining ring and the end cover. An annular third flow guiding groove is provided on the outer side wall of the second flow guiding ring. The third flow guiding groove is connected to the second cavity, and the third flow guiding groove is connected to the low-pressure raw water outlet.

8. A self-boosting energy recovery high-pressure pump according to claim 7, characterized in that: A diversion port is opened at one end of the first flow guiding ring that contacts the end cover. The diversion port connects the fifth liquid flow hole and the second cavity; A radial sixth liquid flow hole is provided on the second flow guiding ring. The sixth liquid flow hole is located in the third flow guiding groove, and the sixth liquid flow hole connects the second cavity and the third flow guiding groove.

9. A self-boosting energy recovery high-pressure pump according to claim 8, characterized in that: The second diversion ring is provided with a first flow channel arranged axially, and the fourth liquid flow hole is connected to the low-pressure concentrated water outlet or the high-pressure concentrated water inlet through the first flow channel; a seventh liquid flow hole is provided on the connecting part inside the end cover, and the sixth liquid flow hole is connected to the seventh liquid flow hole.

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