Efficient seawater desalination system

Abstract

The invention discloses an efficient seawater desalination system which comprises a reverse osmosis membrane, a high-pressure water supply pump, a low-pressure water supply pump and a low-pressure-difference boosting filtering module, the reverse osmosis membrane is used for filtering seawater; a water outlet of the high-pressure water supply pump is connected with a seawater inlet of the reverse osmosis membrane; a water inlet of the high-pressure water supply pump is communicated with a water outlet of the low-pressure water supply pump; the low-pressure-difference boosting filtering module comprises an energy transmitter A, a two-position three-way valve A and a reverse osmosis membrane A; the energy transmitter A comprises a shell and a first piston; a seawater inlet / outlet communicated with the first seawater cavity and a brine inlet / outlet communicated with the first brine cavity are formed in the shell; a water inlet of the two-position three-way valve A is communicated with a brine outlet of the reverse osmosis membrane; a seawater inlet of the reverse osmosis membrane A is communicated with a water outlet of the low-pressure water supply pump through a first water inlet pipeline A; when the seawater desalination system is used for seawater desalination, the energy utilization efficiency of the high-pressure pump can be greatly improved, and the operation cost of seawater desalination is reduced.

Description

Technical Field

[0001] This invention relates to a high-efficiency seawater desalination system, belonging to the field of seawater desalination. Background Technology

[0002] Seawater desalination is a key technology for alleviating global freshwater shortages and plays an irreplaceable role in ensuring water security in coastal and island regions. With global population growth and accelerated industrialization, the contradiction between freshwater supply and demand is becoming increasingly prominent. The ocean, covering over 70% of the Earth's surface, offers a potential water source solution for these regions.

[0003] Current traditional seawater desalination processes include multi-stage flash evaporation and reverse osmosis. Multi-stage flash evaporation technology uses multiple pressure-decreasing flash chambers to evaporate and condense seawater to obtain fresh water. Reverse osmosis is a membrane separation technology based on the principle of semi-permeable membrane separation. It selectively retains solutes under high pressure, effectively removing dissolved salts, colloids, organic matter, and microorganisms from water. It relies on a high-pressure pump to maintain the membrane separation process.

[0004] In existing reverse osmosis seawater desalination systems, high-pressure pumps pressurize seawater, and after desalination through reverse osmosis membranes, the resulting brine still has considerable pressure. Currently, this brine is directly discharged, thus its pressure is not fully utilized. This results in low energy efficiency of the high-pressure pumps in seawater desalination and high operating costs. Summary of the Invention

[0005] The purpose of this invention is to provide a high-efficiency seawater desalination system that can significantly improve the energy utilization efficiency of the high-pressure pump and reduce the operating cost of seawater desalination.

[0006] To solve the above problems, the technical solution adopted by the present invention is: a high-efficiency seawater desalination system, including a reverse osmosis membrane, a high-pressure water supply pump, a low-pressure water supply pump, and a low-pressure differential boosting filtration module; the reverse osmosis membrane is used to filter seawater; the outlet of the high-pressure water supply pump is connected to the seawater inlet of the reverse osmosis membrane to provide high-pressure seawater to the reverse osmosis membrane; the inlet of the high-pressure water supply pump is connected to the outlet of the low-pressure water supply pump; the low-pressure differential boosting filtration module includes an energy transfer device A, a two-position three-way valve A, and a reverse osmosis membrane A; the energy transfer device A includes a housing and a first piston, the first piston is disposed inside the housing and can move inside the housing, the first piston divides the housing into... The shell has a first brine chamber and a first seawater chamber, with a seawater inlet / outlet communicating with the first seawater chamber and a brine inlet / outlet communicating with the first brine chamber. The inlet of the two-position three-way valve A is connected to the brine outlet of the reverse osmosis membrane, and one outlet of the two-position three-way valve A is connected to the brine inlet / outlet of the energy transfer device A. The seawater inlet of the reverse osmosis membrane A is connected to the outlet of the low-pressure water supply pump via a first inlet pipe A, and a first check valve A and a second check valve A are installed on the first inlet pipe A. The seawater inlet / outlet of the energy transfer device A is connected to the first inlet pipe A via the first inlet / outlet pipe A between the first check valve A and the second check valve A.

[0007] As a further improvement of the present invention, the low-pressure differential boosting filtration module also includes an energy transferor B and a two-position three-way valve B; the structure of the energy transferor B is the same as that of the energy transferor A; the inlet of the two-position three-way valve B is connected to the brine outlet of the reverse osmosis membrane, and one outlet of the two-position three-way valve B is connected to the brine inlet and outlet of the energy transferor B; when one of the two-position three-way valves A and B is in the open state, the other is in the closed state; the seawater inlet of the reverse osmosis membrane A is also connected to the outlet of the low-pressure water supply pump through a second inlet pipe A, and a third check valve A and a fourth check valve A are installed on the second inlet pipe A; the seawater inlet and outlet of the energy transferor B are connected to the second inlet pipe A through the second inlet and outlet pipe A between the first check valve A and the second check valve A.

[0008] As a further improvement of the invention, it also includes an energy storage device A, which is connected to the brine outlet of the reverse osmosis membrane.

[0009] As a further improvement of the present invention, there are two or more low-pressure differential boosting filter modules. The first water inlet pipe A and the second water inlet pipe A of each low-pressure differential boosting filter module A are connected to the outlet of the low-pressure water supply pump. The inlets of the two-position three-way valve A and the two-position three-way valve B of the latter low-pressure differential boosting filter module are connected to the brine outlet of the reverse osmosis membrane A of the former low-pressure differential boosting filter module.

[0010] As a further improvement of the present invention, it also includes a high pressure differential boosting unit, which includes an energy recovery unit and a two-position three-way valve C. The energy recovery unit includes a housing and a second piston. The housing has seawater inlet and outlet and brine inlet and outlet. The seawater inlet and outlet are connected to the outlet of the low-pressure water supply pump and the seawater inlet of the reverse osmosis membrane via a first pipe and a second pipe, respectively. A first check valve B and a second check valve B are respectively installed on the first pipe and the second pipe. The brine inlet and outlet are connected to one outlet of the two-position three-way valve C. The inlet of the two-position three-way valve C is connected to the brine outlet of the reverse osmosis membrane A via a third pipe. The second piston is located inside the housing and divides the housing into a second seawater chamber and a second brine chamber. The seawater inlet and outlet are connected to the second seawater chamber, and the brine inlet and outlet are connected to the second brine chamber. The brine outlet of the reverse osmosis membrane A is connected to the brine outlet.

[0011] As a further improvement of the present invention, a middle partition is fixed inside the outer shell, which divides the outer shell into two inner cavities. The middle partition has shaft holes that pass through both sides. The second piston includes piston A, piston B and piston connecting shaft. Piston A and piston B are located in the two inner cavities respectively. The piston connecting shaft passes through the shaft holes and its two ends are fixedly connected to piston A and piston B respectively. Piston A divides its inner cavity into a second seawater cavity A and a second brine cavity A. Piston B divides its inner cavity into a second seawater cavity B and a second brine cavity B. There are two seawater inlets and outlets and two brine inlets and outlets. The two seawater inlets and outlets communicate with the second seawater cavity A and the second seawater cavity B respectively. The two brine inlets and outlets communicate with the second brine cavity A and the second brine cavity B respectively.

[0012] As a further improvement of the present invention, the two seawater inlets and outlets are respectively connected to the first pipeline by two connecting pipes A, and a first one-way valve B is provided on each of the two connecting pipes A. The two seawater inlets and outlets are respectively connected to the second pipeline by two connecting pipes B, and a second one-way valve B is provided on each of the two connecting pipes B. The two brine inlets and outlets are both connected to the third pipeline, and a two-position three-way valve C is connected to each of the two brine inlets and outlets.

[0013] As a further improvement of the invention, the energy recovery device also includes an energy storage device B, which is connected to a third pipe.

[0014] As a further improvement of the present invention, the freshwater outlets of the reverse osmosis membrane and all reverse osmosis membranes A are connected to the same freshwater collector via pipes.

[0015] As a further improvement of the present invention, the other outlet of each of the two two-position three-way valves C, all two-position three-way valves A and two-position three-way valves B is connected to the brine collector via a brine pipeline.

[0016] In summary, the beneficial effects of the present invention are as follows: the high-pressure brine produced by the reverse osmosis membrane of the present invention for separating and desalinating seawater is used to provide high-pressure seawater and separate and filter seawater in the low-pressure differential boosting filtration module, so that the pressure of the high-pressure brine is more fully utilized, thereby improving the energy utilization rate of the high-pressure pump and reducing the operating cost of the present invention.

[0017] This invention employs a staged pressurization system using low-pressure and high-pressure water supply pumps, combined with reverse osmosis membrane modules to achieve stable desalination. It also integrates a low-pressure differential booster filtration module and a high-pressure differential booster module. Through pressure cascade utilization and energy recovery, the overall energy efficiency ratio of the high-pressure pump system is improved by 30%-50%. This invention reduces energy loss caused by direct pressurization with high-pressure pumps in existing seawater desalination processes, lowering power consumption and maintenance costs during operation. Simultaneously, it ensures that the reverse osmosis membrane modules operate within their optimal pressure range, improving product water quality and system stability. The invention features a compact overall structure and modular design for easy maintenance and expansion, making it suitable for desalination projects of varying scales. It exhibits significant energy-saving and consumption-reducing effects and has broad application prospects.

[0018] Both the energy transmitter and the energy recovery device in this invention can be used to transfer the pressure of brine to seawater. In the energy transmitter, the brine is located in the brine chamber at the bottom of the piston, and the seawater is located in the seawater chamber at the top of the piston. The seawater and brine are isolated by the piston, and the pressure of the seawater is the same as that of the brine. There is no pressure difference between the brine and the seawater, and it is not easy for brine and seawater to exchange. Therefore, the energy transmitter has lower manufacturing requirements and lower manufacturing and maintenance costs. In the energy recovery device, the brine chamber and the seawater chamber are separated by the piston. The pressure of the brine chamber and the seawater chamber are different. The manufacturing requirements of the energy recovery device shell and the piston are relatively higher than those of the energy transmitter, and the manufacturing and maintenance costs are higher than those of the energy transmitter.

[0019] In the process of seawater desalination, this invention can significantly reduce the amount of brine that the high-pressure differential boosting unit needs to process by setting up multiple low-pressure differential boosting filter modules, thereby greatly reducing the structural size of the energy recovery unit used in this invention and further reducing manufacturing and maintenance costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention.

[0021] Figure 2 This is a schematic diagram of the energy recovery device in this invention.

[0022] Figure 3 This is a schematic diagram of the energy transfer device A in this invention.

[0023] The components include: 1. Reverse osmosis membrane; 2. High-pressure water supply pump; 3. Low-pressure water supply pump; 4. Low-pressure differential booster filtration module; 5. Energy transferor A; 6. Housing; 7. First piston; 8. First brine chamber; 9. First seawater chamber; 10. Seawater inlet / outlet; 11. Brine inlet / outlet; 12. Two-position three-way valve A; 13. Reverse osmosis membrane A; 14. First inlet pipe A; 15. First check valve A; 16. Second check valve A; 17. First inlet / outlet pipe A; 18. Energy transferor B; 19. Two-position three-way valve B; 20. Second inlet pipe A; 21. Third check valve A; 22. Fourth check valve A; 23. Second inlet / outlet pipe A; 24. Accumulator A; 5. High pressure differential booster unit; 26. Energy recovery unit; 27. Two-position three-way valve C; 28. Outer casing; 29. ​​Seawater inlet and outlet; 30. Brine inlet and outlet; 31. First pipeline; 32. Second pipeline; 33. First check valve B; 34. Second check valve B; 35. Third pipeline; 36. Second piston; 37. Second seawater chamber A; 38. Second brine chamber A; 39. Intermediate partition; 40. Piston A; 41. Piston B; 42. Piston connecting shaft; 43. Second seawater chamber B; 44. Second brine chamber B; 45. Connecting pipeline A; 46. Connecting pipeline B; 47. Accumulator B; 48. Freshwater collector; 49. Fourth pipeline; 50. Seawater source. Detailed Implementation

[0024] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0025] like Figure 1 The high-efficiency seawater desalination system shown includes a reverse osmosis membrane 1, a high-pressure water supply pump 2, a low-pressure water supply pump 3, and a low-pressure differential boosting filtration module 4. The reverse osmosis membrane 1 is used to filter seawater. This reverse osmosis membrane 1 is existing technology and will not be described in detail in this invention. The outlet of the high-pressure water supply pump 2 is connected to the seawater inlet of the reverse osmosis membrane 1, and is used to boost the seawater to P1 to supply high-pressure seawater to the reverse osmosis membrane 1. The seawater undergoes primary filtration through the reverse osmosis membrane 1, separating it into freshwater and high-pressure brine. The freshwater is discharged from the freshwater outlet of the reverse osmosis membrane 1 and collected, while the remaining brine is discharged from the brine outlet of the reverse osmosis membrane 1. The pressure of the brine is P. 1卤 .

[0026] like Figure 1 As shown, the inlet of the high-pressure water supply pump 2 and the outlet of the low-pressure water supply pump 3 are connected by a water supply pipeline. The low-pressure water supply pump 3 is connected to the seawater source 50 via a water supply pipeline. The low-pressure differential boosting filtration module 4 includes an energy transfer device A5, a two-position three-way valve A12, and a reverse osmosis membrane A13. Figure 3As shown, the energy transfer device A5 includes a housing 6 and a first piston 7. The housing 6 is a hollow shell structure. The first piston 7 is disposed inside the housing 6 and is in contact with the inner surface of the housing 6. The first piston 7 can move inside the housing 6. The first piston 7 divides the housing 6 into a first brine chamber 8 and a first seawater chamber 9. As the first piston 7 moves inside the housing 6, the volumes of the first brine chamber 8 and the first seawater chamber 9 expand and decrease, or decrease and expand, respectively. The housing 6 has a seawater inlet / outlet 10 communicating with the first seawater chamber 9 and a brine inlet / outlet 11 communicating with the first brine chamber 8. In this invention, the first seawater chamber 9 is located above the first piston 7, while the first brine chamber 8 is located below the first piston 7. The first piston 7 moves up and down inside the housing 6. The seawater inlet / outlet 10 is located at the top of the housing 6, while the brine inlet / outlet 11 is located at the bottom of the housing 6. In this invention, the movement space of the first piston 7 is limited to between the seawater inlet / outlet 10 and the brine inlet / outlet 11.

[0027] like Figure 1 As shown, the inlet of the two-position three-way valve A12 is connected to the brine outlet of the reverse osmosis membrane 1, and one of the outlets of the two-position three-way valve A12 is connected to the brine inlet / outlet 11 of the energy transfer device A5. When the two-position three-way valve A12 is open, the brine discharged from the reverse osmosis membrane 1 is introduced into the first brine chamber 8 of the energy transfer device A5 through the two-position three-way valve A12, pushing the first piston 7 to move upward in the housing 6, pressurizing the seawater in the first seawater chamber 9. The pressure of the pressurized seawater is P. 1卤 Seawater is squeezed out from the seawater inlet / outlet 10. With the two-position three-way valve A12 closed, the brine in the first brine chamber 8 is discharged through the other outlet of the two-position three-way valve A12. The first piston 7 moves downward, and seawater enters the first seawater chamber 9 from the seawater inlet / outlet 10.

[0028] like Figure 1As shown, the seawater inlet of the reverse osmosis membrane A13 is connected to the outlet of the low-pressure water supply pump 3 via a first inlet pipe A14. The invention includes a first one-way valve A15 and a second one-way valve A16 on the first inlet pipe A14, with the second one-way valve A16 located on one side of the reverse osmosis membrane A13. Both the first and second one-way valves ensure that seawater can only flow unidirectionally towards the reverse osmosis membrane A13. The seawater inlet and outlet 10 of the energy transfer device A5 are connected via the first inlet and outlet pipe A17, with the first one-way valve A15 and the second one-way valve A16 located on one side of the reverse osmosis membrane A13. The two one-way valves A16 are connected to the first inlet pipe A14. When the first piston 7 of the energy transmitter A5 moves downward, the low-pressure seawater in the first inlet pipe 14 can enter the first seawater chamber 8 through the first one-way valve A15. When the first piston 7 of the energy transmitter A5 moves upward, the seawater in the first seawater chamber 8 is pushed out with greater pressure and can only enter the reverse osmosis membrane A13 for secondary filtration through the second one-way valve A16. In this invention, the pressure of the high-pressure brine generated after the reverse osmosis membrane A13 filters the seawater is P. 2卤 .

[0029] like Figure 1 As shown, to improve the efficiency of seawater desalination, the low-pressure differential boosting filtration module 4 in this invention is also equipped with an energy transferor B18 and a two-position three-way valve B19. The structure of the energy transferor B18 is the same as that of the energy transferor A5. The inlet of the two-position three-way valve B19 is connected to the brine outlet of the reverse osmosis membrane 1, and one outlet of the two-position three-way valve B19 is connected to the brine inlet / outlet 11 of the energy transferor B18. When one of the two-position three-way valves A12 and B19 is in the open state, the other is in the closed state. Thus, when the energy transferor A5 provides high-pressure seawater to the reverse osmosis membrane A13, the first seawater chamber 8 of the energy transferor B18 draws in low-pressure seawater. When the first seawater chamber 8 of the energy transferor A5 draws in low-pressure seawater, the energy transferor B18 provides high-pressure seawater to the reverse osmosis membrane A13. In this way, high-pressure seawater can be continuously supplied to the reverse osmosis membrane A13, so that the reverse osmosis membrane A13 can continuously filter and desalinate seawater, thereby improving the efficiency of seawater desalination.

[0030] like Figure 1 As shown, in this invention, the seawater inlet of the reverse osmosis membrane A13 is simultaneously connected to the outlet of the low-pressure water supply pump 3 via a second inlet pipe A20. A third one-way valve A21 and a fourth one-way valve A22 are installed on the second inlet pipe A20, wherein the fourth one-way valve A22 is located on the side close to the reverse osmosis membrane A13. The seawater inlet and outlet 10 of the energy transfer device B18 is connected to the second inlet pipe A20 via a second inlet and outlet pipe A23 between the third one-way valve A21 and the fourth one-way valve A22, so that low-pressure seawater can enter the first seawater chamber 8 of the energy transfer device B18 and enter the reverse osmosis membrane A13 unidirectionally for filtration and desalination.

[0031] like Figure 1 As shown, the low differential pressure boosting filtration module 4 in this invention is equipped with an accumulator A24, which is connected to the brine outlet of the reverse osmosis membrane 1. This invention connects the accumulator A24 to the pipeline connecting the reverse osmosis membrane 1 and the two-position three-way valve A12 and the two-position three-way valve B19 to improve the operational stability of this invention.

[0032] like Figure 1 As shown, in this invention, there are two or more low-pressure differential boosting filter modules 4. The first inlet pipe A14 and the second inlet pipe A20 of each low-pressure differential boosting filter module 4A are both connected to the outlet of the low-pressure water supply pump 3. The inlets of the two-position three-way valve A12 and the two-position three-way valve B19 of the subsequent low-pressure differential boosting filter module 4 are both connected to the brine outlet of the reverse osmosis membrane A13 of the preceding low-pressure differential boosting filter module 4. (The appendix of this invention...) Figure 1 The diagram shows a system with two low-pressure differential boosting filtration modules 4. The accumulator A24 of the right-hand low-pressure differential boosting filtration module 4 is connected to a pipe linking the brine outlet of the left-hand reverse osmosis membrane A13 and the two-position three-way valves A12 and B19 of the right-hand low-pressure differential boosting filtration module 4. In this invention, the pressure of the high-pressure brine generated by the reverse osmosis membrane A13 after filtering seawater in the second low-pressure differential boosting filtration module 4 is P. 3卤 .

[0033] like Figure 1 As shown, the present invention includes a high-pressure differential booster assembly 25, which comprises an energy recovery unit 26 and a two-position three-way valve C27, as shown. Figure 2 As shown, the energy recovery unit 26 includes a housing 28 and a second piston 36. The housing 28 has seawater inlet / outlet 29 and brine inlet / outlet 30. The seawater inlet / outlet 10 is connected to the outlet of the low-pressure water pump 3 via a first pipe 31, and simultaneously connected to the seawater inlet of the reverse osmosis membrane 1 via a second pipe 32. A first one-way valve B33 is installed on the first pipe 31, and a second one-way valve B34 is installed on the second pipe 32. The brine inlet / outlet 30 is connected to one outlet of a two-position three-way valve C27. The inlet of the two-position three-way valve C27 is connected to the brine outlet of the reverse osmosis membrane A13 of the rightmost low-pressure differential boosting filter module 4 via a third pipe 35. The second piston 36 is located inside the housing 28, dividing the housing 28 into a second seawater chamber and a second brine chamber. The seawater inlet / outlet 29 communicates with the second seawater chamber, and the brine inlet / outlet 30 communicates with the second brine chamber. The brine outlet of the reverse osmosis membrane A13 is also connected to the brine outlet.

[0034] like Figure 2As shown, the present invention has a middle partition 39 fixed inside the outer shell 28, which divides the outer shell 28 into two inner cavities, left and right. A shaft hole is formed on the middle partition 39, penetrating both sides. The second piston 36 in the present invention includes piston A40, piston B41, and piston connecting shaft 42. Piston A40 and piston B41 are located in the two inner cavities respectively and are in contact with the inner surfaces of the two inner cavities. Piston connecting shaft 42 passes through the shaft hole and its two ends are fixedly connected to piston A40 and piston B41 respectively, allowing piston A40 and piston B41 to move left and right synchronously and in the same direction. Piston A40 divides the left inner cavity into a second seawater cavity A37 and a second brine cavity A38, and piston B41 divides the right inner cavity into a second... The invention includes a seawater cavity B43 and a second brine cavity B44. The second seawater cavity A37 and the second seawater cavity B43 are located on the left and right sides of the intermediate partition 39 and close to the intermediate partition 39, respectively. There are two seawater inlets / outlets 29 and two brine inlets / outlets 30. The two seawater inlets / outlets 29 are connected to the second seawater cavity A37 and the second seawater cavity B43, respectively. The two brine inlets / outlets 30 are connected to the second brine cavity A38 and the second brine cavity B44, respectively. In this invention, the two seawater inlets / outlets 29 are located on both sides of the intermediate partition 39 and close to the intermediate partition 39. The seawater inlets / outlets 29 are opened at the top of the outer shell 28, while the two brine inlets / outlets 30 are located near the two ends of the outer shell 28 and are opened at the bottom of the outer shell 28.

[0035] like Figure 1 As shown, in this invention, the two seawater inlets and outlets 29 are respectively connected to the first pipe 31 via two connecting pipes A45. Each of the two connecting pipes A45 is equipped with a first one-way valve B33, which ensures that seawater can only flow towards the second seawater cavity. The two seawater inlets and outlets 29 are respectively connected to the second pipe 32 via two connecting pipes B46. Each of the two connecting pipes B46 is equipped with a second one-way valve B34, which ensures that seawater in the second seawater cavity can only flow towards the reverse osmosis membrane 1. In this invention, there are two two-position three-way valves C27, and when one of the two two-position three-way valves C27 is in the open state, the other is in the closed state. Each brine inlet and outlet 30 is connected to the third pipe 35 by a fourth pipe 49. Each fourth pipe 49 is connected to one of the outlets of a two-position three-way valve C27, and the inlet of the two-position three-way valve C27 is connected to the third pipe 35. The energy recovery device 26 of this invention is equipped with an energy accumulator B47, which is connected to the third pipe 35.

[0036] When the second piston 36 moves to the left in this invention, low-pressure seawater is introduced into the second seawater chamber A37 through the first pipe 31, while high-pressure seawater is supplied to the reverse osmosis membrane 1 through the second pipe 32 through the second seawater chamber B43. At the same time, brine produced by the reverse osmosis membrane A13 on the right enters the second brine chamber B44, and the brine in the second brine chamber A38 is discharged. When the second piston 36 moves to the right, low-pressure seawater is introduced into the second seawater chamber B43 through the first pipe 31, while high-pressure seawater is supplied to the reverse osmosis membrane 1 through the second pipe 32 through the second seawater chamber A37. At the same time, brine produced by the reverse osmosis membrane A13 on the right enters the second brine chamber A38, and the brine in the second brine chamber B44 is discharged. This continuously supplies high-pressure seawater to the reverse osmosis membrane 1 and utilizes the pressure of brine generated by seawater desalination.

[0037] like Figure 1 As shown, in this invention, the freshwater outlets of reverse osmosis membrane 1 and all reverse osmosis membranes A13 are connected to the same freshwater collector 48 via pipelines to collect the desalinated freshwater. In this invention, the other outlets of the two two-position three-way valves C27, all two-position three-way valves A12, and all two-position three-way valves B19 are connected to a brine collector via brine pipelines to collect the brine produced after seawater desalination.

[0038] The working process of the low-pressure differential boosting filter module 4 on the left side in this invention is as follows: When the two-position three-way valve A12 is energized, the high-pressure brine (brine pressure is P) produced after the reverse osmosis membrane 1 filters seawater is released. 1卤 The brine enters through the two-position three-way valve A12 at the brine inlet / outlet 11 of the energy transmitter A5. The brine pushes the first piston 7 of the energy transmitter A5 upward, and the first piston 7 pushes the seawater in the first seawater chamber 9 at the top of the energy transmitter A5, pressurizing the seawater (the seawater pressure is P). 1卤 The pressurized seawater passes through the second one-way valve A16 and enters the reverse osmosis membrane A13 for secondary filtration. The pressure generated after secondary filtration is P. 2卤 High-pressure brine. At the same time, the two-position three-way valve B19 loses power, and the low-pressure seawater supplied by the low-pressure water supply pump 3 enters the seawater inlet / outlet 10 of the energy transmitter B18 through the third one-way valve A21. The seawater pushes the first piston 7 of the energy transmitter B18 downward, and the first piston 7 pushes the brine in the first brine chamber 8 at the bottom of the energy transmitter B18 out of the energy transmitter B18 and out of the system through the two-position three-way valve B19.

[0039] When the first piston 7 of the energy transmitter A5 reaches its highest position, the two-position three-way valve B19 is energized, and the high-pressure brine (brine pressure P) is released. 1卤The brine enters through the two-position three-way valve B19 and the brine inlet / outlet 11 of the energy transmitter B18. The brine pushes the first piston 7 of the energy transmitter B18 upward, and the first piston 7 pushes the seawater in the first seawater chamber 9 at the top of the energy transmitter B18, pressurizing the seawater (the seawater pressure is P). 1卤 The pressurized seawater passes through the fourth one-way valve A22 and enters the reverse osmosis membrane A13 for secondary filtration. The pressure generated after secondary filtration is P. 2卤 High-pressure brine. At the same time, the two-position three-way valve A12 loses power, and the low-pressure seawater supplied by the low-pressure water supply pump 3 enters the seawater inlet / outlet 10 of the energy transmitter A5 through the first one-way valve A15. The seawater pushes the first piston 7 of the energy transmitter A5 downward, and the first piston 7 pushes the brine in the first brine chamber 8 at the bottom of the energy transmitter A5 out of the energy transmitter A5 and out of the system through the two-position three-way valve A12.

[0040] In this invention, the working process of the low-pressure differential boosting filter module 4 on the right is the same as that of the low-pressure differential boosting filter module 4 on the left. The difference is that the high-pressure brine required by the energy transfer device A5 and energy transfer device B18 of the low-pressure differential boosting filter module 4 on the right is generated by the reverse osmosis membrane A13 of the low-pressure differential boosting filter module 4 on the left after secondary filtration of seawater. The working process of the low-pressure differential boosting filter module 4 on the right will not be described in detail in this invention.

[0041] The working process of the high differential pressure boosting unit 25 in this invention is as follows: When the two-position three-way valve C27 on the right is energized, the high-pressure brine (brine pressure is P) produced by the reverse osmosis membrane A13 of the low-pressure differential boosting filter module 4 on the right is filtered from seawater. 3卤 The brine enters the energy recovery unit 26 through a two-position three-way valve C27 on the right side, via a brine inlet / outlet 30 on the right side. The brine pushes piston B41 to the left, and piston B41 simultaneously pushes piston A40 to the left via piston connecting shaft 42. During this process, high-pressure brine enters the second brine chamber B44, increasing its volume. Seawater in the second seawater chamber B43 is forced out through a seawater inlet / outlet 29 on the right side, and discharged through a second one-way valve B34 on the right side to the outlet of the high-pressure water supply pump 2. The seawater pressure reaches P1 during discharge. The volume of the second seawater chamber A37 increases, and seawater supplied by the low-pressure water supply pump 3 passes through the attached... Figure 1 A first one-way valve B33 in the upper middle section enters the second seawater chamber A37; the volume of the second brine chamber A38 decreases, and at the same time, a two-position three-way valve 27 on the left side is de-energized, and the brine in the second brine chamber A38 is discharged from the system through a two-position three-way valve 27 on the left side.

[0042] At the same time, a two-position three-way valve 27 on the left is energized, and the high-pressure brine (brine pressure is P) is released. 3卤Simultaneously, brine enters the energy recovery unit 26 through a two-position three-way valve 27 on the left side, via a brine inlet / outlet 30 on the left. The brine pushes piston A40 to the right, and piston A40, through piston connecting shaft 42, simultaneously pushes piston B41 to the right. During this process, high-pressure brine enters the second brine chamber A38 (brine pressure is P). 3卤 The volume of the second brine chamber A38 increases, and the seawater in the second seawater chamber A37 is forced out from a seawater inlet / outlet 29 on the left, and discharged through a second one-way valve B34 on the left to the outlet of the high-pressure water supply pump 2. The seawater pressure at the time of discharge reaches P1. The volume of the second seawater chamber B43 increases, and the seawater supplied by the low-pressure water supply pump 3 is discharged through an attached... Figure 1 A first one-way valve B33 in the lower middle section enters the second seawater chamber B43; the volume of the second brine chamber B44 decreases, and at the same time, a two-position three-way valve 27 on the right side is de-energized, and the brine in the second brine chamber B44 is discharged from the system through a two-position three-way valve 27 on the right side.

[0043] Unless otherwise specified in the above description, all parts are prior art, or can be implemented using existing technology. Furthermore, the specific embodiments described in this invention are merely preferred embodiments and are not intended to limit the scope of this invention. That is, all equivalent changes and modifications made within the scope of this invention should be considered within the technical scope of this invention.

Claims

1. A high-efficiency seawater desalination system, comprising: Reverse osmosis membranes are used to filter seawater; A high-pressure water supply pump is connected to the seawater inlet of the reverse osmosis membrane to supply high-pressure seawater to the reverse osmosis membrane. Its features are, It also includes a low-pressure water supply pump and a low-pressure differential boosting filtration module. The inlet of the high-pressure water supply pump is connected to the outlet of the low-pressure water supply pump. The low-pressure differential boosting filtration module includes... Energy transmitter A includes a housing and a first piston. The first piston is disposed inside the housing and can move inside the housing. The first piston divides the housing into a first brine chamber and a first seawater chamber. The housing has a seawater inlet / outlet communicating with the first seawater chamber and a brine inlet / outlet communicating with the first brine chamber. Two-position three-way valve A, whose inlet is connected to the brine outlet of the reverse osmosis membrane, and one outlet of two-position three-way valve A is connected to the brine inlet and outlet of energy transfer device A; The reverse osmosis membrane A has its seawater inlet connected to the outlet of the low-pressure water supply pump via a first inlet pipe A. A first check valve A and a second check valve A are installed on the first inlet pipe A. The seawater inlet and outlet of the energy transfer device A are connected to the first inlet pipe A via the first inlet and outlet pipe A between the first check valve A and the second check valve A.

2. The high-efficiency seawater desalination system according to claim 1, characterized in that, The low differential pressure boosting filter module also includes Energy transferor B has the same structure as energy transferor A; Two-position three-way valve B has its inlet connected to the brine outlet of the reverse osmosis membrane, and one outlet of two-position three-way valve B is connected to the brine inlet and outlet of energy transfer device B. When one of the two-position three-way valves A and B is in the open state, the other is in the closed state. The seawater inlet of the reverse osmosis membrane A is connected to the outlet of the low-pressure water supply pump via the second inlet pipe A. A third check valve A and a fourth check valve A (22) are installed on the second inlet pipe A. The seawater inlet and outlet of the energy transmitter B are connected to the second inlet pipe A via the second inlet and outlet pipe A between the third check valve A and the fourth check valve A (22).

3. The high-efficiency seawater desalination system according to claim 1 or 2, characterized in that, It also includes accumulator A, which is connected to the brine outlet of the reverse osmosis membrane.

4. The high-efficiency seawater desalination system according to claim 1 or 2, characterized in that, There are two or more low-pressure differential boosting filter modules. The first inlet pipe A and the second inlet pipe A of each low-pressure differential boosting filter module A are connected to the outlet of the low-pressure water supply pump. The inlets of the two-position three-way valve A and the two-position three-way valve B of the latter low-pressure differential boosting filter module are connected to the brine outlet of the reverse osmosis membrane A of the former low-pressure differential boosting filter module.

5. The high-efficiency seawater desalination system according to claim 4, characterized in that, It also includes a high-pressure differential booster unit, which comprises an energy recovery unit and a two-position three-way valve C. The energy recovery unit includes... The outer shell has seawater inlet and outlet and brine inlet and outlet. The seawater inlet and outlet are connected to the outlet of the low-pressure water supply pump and the seawater inlet of the reverse osmosis membrane via the first pipe and the second pipe respectively. The first one-way valve B and the second one-way valve B are respectively installed on the first pipe and the second pipe. The brine inlet and outlet are connected to one outlet of the two-position three-way valve C. The inlet of the two-position three-way valve C is connected to the brine outlet of the reverse osmosis membrane A via the third pipe. The second piston is located inside the outer shell and divides the outer shell into a second seawater chamber and a second brine chamber. The seawater inlet and outlet are connected to the second seawater chamber, and the brine inlet and outlet are connected to the second brine chamber. The brine outlet of the reverse osmosis membrane A is also connected to the second brine chamber.

6. The high-efficiency seawater desalination system according to claim 5, characterized in that, A middle partition is fixed inside the outer shell, which divides the outer shell into two inner cavities. A shaft hole is opened on the middle partition to pass through both sides of it. The second piston includes piston A, piston B, and piston connecting shaft. Piston A and piston B are located in two inner cavities respectively. The piston connecting shaft passes through a shaft hole and its two ends are fixedly connected to piston A and piston B respectively. Piston A divides its inner cavity into a second seawater cavity A and a second brine cavity A. Piston B divides its inner cavity into a second seawater cavity B and a second brine cavity B. There are two seawater inlets and two brine ..., respectively.

7. The high-efficiency seawater desalination system according to claim 6, characterized in that, The two seawater inlets and outlets are connected to the first pipeline via two connecting pipes A, and each of the two connecting pipes A is equipped with a first check valve B. The two seawater inlets and outlets are connected to the second pipeline via two connecting pipes B, and each of the two connecting pipes B is equipped with a second check valve B. The two brine inlets and outlets are connected to the third pipeline, and each of the two brine inlets and outlets is connected with a two-position three-way valve C.

8. The high-efficiency seawater desalination system according to claim 6, characterized in that, The energy recovery unit also includes an energy storage unit B, which is connected to a third conduit.

9. The high-efficiency seawater desalination system according to claim 6, characterized in that, The freshwater outlets of the reverse osmosis membrane and all reverse osmosis membranes A are connected to the same freshwater collector via pipes.

10. The high-efficiency seawater desalination system according to claim 9, characterized in that, The other outlet of each of the two two-position three-way valves C, all two-position three-way valves A, and two-position three-way valves B is connected to the brine collector via a brine pipeline.

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