Seawater desalination system and seawater desalination method

Abstract

The invention belongs to the technical field of seawater treatment, and discloses a seawater desalination system and a seawater desalination method.The seawater desalination system comprises a first channel, a second channel, a plunger pump device, a pressure stabilizing device and a reverse osmosis device; the first channel is communicated with the second channel, the plunger pump device is movably arranged in the first channel, the pressure stabilizing device and the reverse osmosis device are both arranged in the second channel, and the pressure stabilizing device comprises a piston piece, a blocking piece and an adjusting mechanism; the piston piece is elastically arranged in the second channel, the blocking piece is arranged in the second channel and located in the movement stroke interval of the piston piece, the adjusting mechanism acts on the piston piece and adjusts the distance between the piston piece and the blocking piece, and the maximum compression stroke is achieved when the piston piece moves to abut against the blocking piece. The seawater desalination system can guarantee that the stable state of the pressure of seawater entering the reverse osmosis device is good, the pressure range is controlled between the pressure capable of being applied by the plunger pump device and the pressure capable of being borne by the reverse osmosis device, and the reverse osmosis device is effectively prevented from being damaged.

Description

Technical Field

[0001] The invention belongs to the technical field of seawater treatment equipment, and in particular relates to a seawater desalination system and a seawater desalination method. Background Art

[0002] With the influence of multiple factors such as population growth and environmental degradation, the freshwater resources that can meet human needs are decreasing. Seawater desalination technology is one of the ways to solve the freshwater crisis. However, high energy consumption, water production costs, and by-product brine treatment seriously restrict the large-scale industrial development of seawater desalination. Although the cost of seawater desalination in my country has shown a downward trend in recent years, the overall cost is still relatively high. Compared with other seawater desalination technologies, the production cost of reverse osmosis is lower, so it is more widely used.

[0003] Reverse osmosis desalination requires the use of high-pressure plunger pumps to pressurize seawater to 6-7MPa to overcome the osmotic pressure of seawater. At present, the more ideal seawater boosting equipment is a plunger-type booster, which is mainly composed of a piston, a piston rod, a pump cylinder, a pump valve, a crank connecting rod, etc. The working principle is that the piston moves back and forth under the action of an external force, thereby changing the volume and pressure in the working chamber, forming a negative pressure in the working chamber, and the liquid in the storage tank enters the working chamber through the suction valve. When the reciprocating movement of the plunger opens and closes the suction and discharge valves, the liquid in the working chamber is squeezed, the pressure increases, and it is discharged from the discharge valve to achieve the purpose of conveying liquid.

[0004] Since the speed of the piston of the plunger-type booster device changes continuously during its movement, the water pressure at the outlet of the plunger-type booster device is pulsating. The pulsation of seawater pressure seriously affects the performance of the reverse osmosis membrane assembly and the stability of the entire seawater desalination system, brings alternating loads to the reverse osmosis membrane assembly, damages the membrane assembly, and reduces the performance and service life of the membrane assembly. Therefore, it is a better choice to stabilize the pressure of the pulsating seawater before entering the membrane assembly.

[0005] In order to avoid damaging the reverse osmosis membrane assembly, the material must be pressure-stabilized before entering the reverse osmosis membrane assembly. The prior art proposes a method and device for integrating seawater desalination and salt production, wherein the seawater extracted from the sea is converted into pulsating high-pressure seawater through a plunger-type booster device, and the pulsating high-pressure seawater and the stable hot air flow realize energy exchange in a pulsating energy exchange device and are converted into stable high-pressure seawater and pulsating hot air flow. The stabilized high-pressure seawater passes through a reverse osmosis membrane assembly to produce fresh water, and the high-pressure concentrated seawater discharged from the reverse osmosis membrane assembly is sprayed into the pulsating hot air flow to evaporate and crystallize to produce salt.

[0006] Another voltage stabilization method is to use an elastic pressure-changing bag structure and a heavy hammer structure, both of which aim to temporarily store the pulsating energy elsewhere to achieve temporary voltage stabilization.

[0007] The above technology absorbs the pulsating energy after it is generated. Although it can recover part of the pulsating energy and improve the energy utilization efficiency, it can also avoid the damage of the pulsating energy to the reverse osmosis membrane components to a certain extent. However, this method absorbs or eliminates the pulsating energy after it is generated, which plays a role in temporary voltage stabilization. However, due to the limited energy exchange efficiency or the limited ability of the elastic pressure-changing bag or the heavy hammer to absorb the pulsating energy, it cannot completely absorb or transfer the generated pulsating energy, which will cause certain potential risks to the stable operation of the system. Summary of the invention

[0008] The object of the present invention is to provide a seawater desalination system which can stabilize the pressure in time when the seawater pressure fluctuates.

[0009] The above-mentioned purpose is achieved by the following technical solutions.

[0010] A first aspect of the present invention provides a seawater desalination system, the seawater desalination system comprising a first channel, a second channel, a plunger pump device, a pressure stabilizing device and a reverse osmosis device;

[0011] The first channel is connected to the second channel, the plunger pump device is movably arranged in the first channel, the pressure stabilizing device and the reverse osmosis device are both arranged in the second channel, the pressure stabilizing device includes a piston member, a stopper and an adjusting mechanism; the piston member is elastically arranged in the second channel, and the stopper is arranged in the second channel and is located in the movement stroke range of the piston member, the adjusting mechanism acts on the piston member and adjusts the distance between the piston member and the stopper, and the maximum compression stroke is when the piston member moves to abut against the stopper, when the pressure of seawater entering the second channel is too large, the piston member is squeezed to form elastic compression, and after the seawater pressure in the second channel drops, the piston member releases the pressure to further pressurize the seawater in the second channel so that the pressure of the seawater in the second channel is in a stable state.

[0012] In some embodiments, the adjusting mechanism includes a fixed plate, an elastic member, a fixed column and an adjusting member; the fixed plate and the piston member are connected via the elastic member, the fixed column is arranged in the second channel, and the fixed plate and the piston member are movably arranged on the fixed column, the adjusting member is arranged on the side of the fixed plate away from the elastic member, and the adjusting member is movably connected to the fixed column, and when the adjusting member moves relative to the fixed column, it can drive the piston member to approach or move away from the blocking member through the fixed plate.

[0013] In some embodiments, a threaded section is provided on the fixing column, and the adjusting member is an adjusting nut, and the adjusting nut is threadedly connected to the threaded section.

[0014] In some embodiments, a plurality of elastic members are provided, and the elastic members cooperate to support the piston member on the fixing plate.

[0015] In some embodiments, two stoppers are provided, and the two stoppers are provided on the side walls of the second channel on opposite sides along the moving direction of the piston member; and / or,

[0016] The second channel is arranged transversely, the pressure stabilizing device and the reverse osmosis device are arranged at opposite ends of the second channel in the transverse direction, the first channel is arranged vertically and intersects and communicates with the middle position of the second channel, and the second channel is located above the first channel.

[0017] In some embodiments, the first channel is provided with an inlet and an outlet, the outlet of the first channel is connected with the second channel, a first flow direction restricting device is provided at the inlet of the first channel, and a second flow direction restricting device is provided at the outlet of the first channel, when the plunger pump device moves in the first channel in a direction away from the outlet, the first flow direction restricting device controls the inlet to open so that external seawater flows into the first channel, and when the plunger pump device moves in the first channel in a direction close to the outlet, the second flow direction restricting device controls the outlet to open so that seawater enters the second channel from the first channel.

[0018] In some embodiments, the first flow restriction device and the second flow restriction device are one-way valves.

[0019] In some embodiments, the outlet is arranged opposite to the plunger pump device, and the inlet is opened on a side of the first channel corresponding to the moving direction of the plunger pump device.

[0020] In some embodiments, the reverse osmosis device is a reverse osmosis membrane device.

[0021] A second aspect of the present invention provides a seawater desalination method, using the seawater desalination system as described above, comprising a pressurization step and a pressure stabilization step:

[0022] The pressurizing step includes: controlling the plunger pump device to move in the first channel so that external seawater flows into the first channel;

[0023] Then, the plunger pump device moves in the first channel in the reverse direction, so that the seawater inside the first channel enters the second channel from the first channel in the form of carrying pulsating energy;

[0024] The pressure stabilization step includes: after the seawater enters the second channel, the pulsating potential energy of the seawater causes the seawater pressure in the second channel to change relative to the initial pressure, pushing the piston member to move in the second channel to pressurize or relieve the seawater in the second channel; when the pressure of the seawater entering the second channel is too high, the piston member is squeezed to form elastic compression to perform a pressure relief operation; after the seawater pressure in the second channel drops, the piston member releases the pressure to pressurize the seawater in the second channel, so that the pressure of the seawater in the second channel is in a stable state.

[0025] The technical solution provided by the present invention has the following advantages and effects:

[0026] The seawater desalination system can push seawater from the first channel into the second channel in the form of carrying pulsating energy under the action of the plunger pump device. After the seawater enters the second channel, the pulsating potential energy of the seawater will cause the seawater pressure in the second channel to change relative to the initial pressure value. When the pressure of the seawater entering the second channel is too large, the piston member is squeezed to form elastic compression, which plays a buffering role. After the high-pressure seawater pressure in the second channel drops, the piston member releases the pressure and further pressurizes the seawater in the second channel to stabilize the pressure of the seawater in the second channel, ensuring that the stable state of the seawater pressure entering the reverse osmosis device is better, effectively avoiding damage to the reverse osmosis device caused by excessive pulsating energy of seawater, thereby improving the service life of the reverse osmosis device, and combining the adjustment mechanism to act on the piston member to adjust the distance between the normally uncompressed piston member and the stopper, so that the maximum compression stroke of the piston member can be adjusted according to the pressure range that the plunger pump device can apply and the pressure range required by the reverse osmosis device, so that the pressure range of the seawater inside the second channel can be controlled, ensuring that the seawater pressure in the second channel is stable within a certain range, not too large or too small, and effectively avoiding affecting the service life of the reverse osmosis device and the quality of fresh water. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of a seawater desalination system according to an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 100. Seawater desalination system;

[0030] 1. First channel; 11. Inlet; 12. Outlet; 2. Second channel; 3. Plunger pump device; 4. Pressure stabilizing device; 41. Piston member; 42. Stop member; 43. Adjusting mechanism; 431. Fixed plate; 432. Elastic member; 433. Fixed column; 434. Adjusting member; 5. Reverse osmosis device; 6. First flow direction limiting device; 7. Second flow direction limiting device. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0032] Unless otherwise specified or defined, the "first, second..." used in this article is merely used to distinguish names and does not represent a specific quantity or order.

[0033] Unless specifically stated or defined otherwise, the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] It should be noted that, in this document, “fixed to” or “connected to” may mean directly fixing or connecting to an element, or indirectly fixing or connecting to an element.

[0035] The embodiment of the present invention provides a seawater desalination system 100, such as Figure 1 As shown, the seawater desalination system 100 includes a first channel 1 , a second channel 2 , a plunger pump device 3 , a pressure stabilizing device 4 and a reverse osmosis device 5 .

[0036] The first channel 1 is connected to the second channel 2, the plunger pump device 3 is movably arranged in the first channel 1, the pressure stabilizing device 4 and the reverse osmosis device 5 are both arranged in the second channel 2, the pressure stabilizing device 4 includes a piston member 41, a stopper 42 and an adjusting mechanism 43; the piston member 41 is elastically arranged in the second channel 2, and the stopper 42 is arranged in the second channel 2 and is located in the movement stroke range of the piston member 41, the adjusting mechanism 43 acts on the piston member 41 and adjusts the distance between the piston member 41 and the stopper 42, and the piston member 41 moves to abut against the stopper 42 to reach the maximum compression stroke. Among them, the adjusting mechanism 43 can act on the piston member 41 to adjust the distance between the normally uncompressed piston member 41 and the baffle 42, or, in other embodiments, the adjusting mechanism 43 can also act on the baffle 42 to adjust the distance between the normally uncompressed piston member 41 and the baffle 42, so that the maximum compression stroke of the adjusting piston member 41 can be adapted according to the pressure range that can be applied by the plunger pump device 3 and the pressure range required by the reverse osmosis device 5. When the pressure of seawater entering the second channel 2 is too large, the piston member 41 is squeezed to form elastic compression. After the seawater pressure in the second channel 2 drops, the piston member 41 releases the pressure to further pressurize the seawater in the second channel 2 so that the pressure of the seawater in the second channel 2 is in a stable state.

[0037] It can be understood that when it is necessary to perform reverse osmosis desalination treatment on seawater, the plunger pump device 3 is controlled to pull backward in the first channel 1 so that the space inside the first channel 1 increases, so that a negative pressure is formed inside the first channel 1 compared to the external seawater environment outside the inlet 11 of the first channel 1. At this time, the external seawater can flow into the first channel 1, and then the plunger pump device 3 is controlled to push in the opposite direction in the first channel 1 so that the space inside the first channel 1 becomes smaller, so that a positive pressure is formed inside the first channel 1 compared to the second channel 2, and the seawater is pushed from the first channel 1 into the second channel 2 in the form of carrying pulsating energy. After the seawater enters the second channel 2, the pulsating potential energy of the seawater will cause the seawater pressure in the second channel 2 to change relative to the initial pressure value, and the piston member 41 is pushed to move in the second channel 2 to pressurize or relieve the seawater in the second channel 2. Among them, when the pressure of seawater entering the second channel 2 is too high, the piston member 41 is squeezed to form elastic compression, which plays a buffering role. After the high-pressure seawater pressure in the second channel 2 drops, the piston member 41 releases the pressure and further pressurizes the seawater in the second channel 2 to stabilize the pressure of the seawater in the second channel 2, thereby ensuring that the seawater pressure entering the reverse osmosis device 5 is in a stable state, effectively avoiding excessive seawater pulsation energy causing damage to the reverse osmosis device 5, thereby improving the service life of the reverse osmosis device 5. Combined with the adjustment mechanism 43 acting on the piston member 41, before the seawater enters the second channel, by adjusting the distance between the normally uncompressed piston member 41 and the stopper 42, the maximum compression stroke of the piston member 41 can be adjusted according to the pressure range that the plunger pump device 3 can apply and the pressure range required by the reverse osmosis device 5, so that the pressure range of the seawater inside the second channel 2 can be controlled, ensuring that the seawater pressure in the second channel 2 is stable within a certain range and will not be too large or too small, effectively avoiding affecting the service life of the reverse osmosis device 5 and the quality of fresh water. The pressure range is usually set between the pressure that the plunger pump device 3 can apply and the pressure that the reverse osmosis device 5 can withstand, so that the seawater pressure in the second channel 2 pulsates within a controllable range.

[0038] In some embodiments, Figure 1As shown, the adjusting mechanism 43 includes a fixed plate 431, an elastic member 432, a fixed column 433 and an adjusting member 434; the fixed plate 431 and the piston member 41 are connected through the elastic member 432, the fixed column 433 is arranged in the second channel 2, and the fixed plate 431 and the piston member 41 are movably arranged on the fixed column 433, the adjusting member 434 is arranged on the side of the fixed plate 431 away from the elastic member 432, and the adjusting member 434 is movably connected to the fixed column 433, and when the adjusting member 434 moves relative to the fixed column 433, it can drive the piston member 41 to approach or move away from the blocking member 42 through the fixed plate 431. It can be understood that, by fixing the stopper 42 at a preset position of the second channel 2, an external force acts on the adjusting member 434, so that when the adjusting member 434 moves relative to the fixing column 433, it can drive the piston member 41 to move close to or away from the stopper 42 under the guidance of the fixing column 433, so as to adjust the distance between the piston member 41 in the uncompressed normal state and the stopper 42. Among them, through holes are provided on the piston member 41 and the fixing plate 431, and the fixing column 433 is movably arranged through the through holes of the piston member 41 and the fixing plate 431 and the two are sealed, and the piston member 41 is slidably arranged in the second channel 2 and is also sealed with the inner wall of the second channel 2, so that seawater will not enter the pressure stabilizing device 4, avoiding affecting the movement of the pressure stabilizing device 4.

[0039] In some embodiments, a limit member may be provided at the end of the fixing column 433 , and the limit member blocks the piston member 41 from sliding out further, thereby preventing the piston member 41 from separating from the fixing column 433 .

[0040] In some embodiments, Figure 1 As shown, the fixing column 433 is provided with a threaded section, and the adjusting member 434 is an adjusting nut, which is threadedly connected with the threaded section. It can be understood that by adjusting the threaded cooperation between the adjusting nut and the threaded section of the fixing column 433, the piston member 41 can be moved along the fixing column 433 to be close to or away from the stopper 42 by rotating the adjusting nut, and after moving into place, it is locked by the threaded cooperation between the adjusting nut and the threaded section, thereby preventing the fixing plate 431 from moving outward relative to the fixing column 433, avoiding the displacement of the fixing plate 431 under the pulsating pressure of seawater, resulting in a change in the distance between the normal piston member 41 and the stopper 42, and having the effects of stable locking and convenient adjustment.

[0041] In some embodiments, Figure 1 As shown, the elastic member 432 is provided with a plurality of elastic members 432, and the elastic members 432 cooperate to support the piston member 41 on the fixing plate 431. The piston member 41 can be uniformly stressed by the plurality of elastic members 432, and its elastic load capacity can be improved.

[0042] In some embodiments, Figure 1 As shown, two stoppers 42 are provided, and the two stoppers 42 are provided on the side walls of the second channel 2 on opposite sides along the moving direction of the piston 41. By providing two stoppers 42 to jointly block the further compression of the piston 41, the resistance of the piston 41 can be dispersed, and the pressure on each stopper 42 can be reduced, thereby improving the overall stability and durability.

[0043] In some embodiments, Figure 1 As shown, the second channel 2 is arranged horizontally, the pressure stabilizing device 4 and the reverse osmosis device 5 are arranged at opposite ends of the second channel 2 in the horizontal direction, the first channel 1 is arranged vertically and intersects and communicates with the middle position of the second channel 2, and the second channel 2 is located above the first channel 1. It can be understood that through the specific structural arrangement of the two channels, seawater entering the second channel 2 from the first channel 1 will not directly impact the reverse osmosis device 5, but will impact the inner wall of the second channel 2, and then the pressure of the seawater in the second channel 2 is stabilized by the pressure stabilizing device 4, and then fresh water is produced through the reverse osmosis device 5, so that the pulsating seawater can be prevented from directly impacting the reverse osmosis device 5 and causing damage.

[0044] In some embodiments, Figure 1As shown, the first channel 1 is provided with an inlet 11 and an outlet 12, the outlet 12 of the first channel 1 is communicated with the second channel 2, a first flow direction restriction device 6 is provided at the inlet 11 of the first channel 1, and a second flow direction restriction device 7 is provided at the outlet 12 of the first channel 1, when the plunger pump device 3 moves in the first channel 1 in a direction away from the outlet 12, the first flow direction restriction device 6 controls the inlet 11 to open so that external seawater flows into the first channel 1, and when the plunger pump device 3 moves in the first channel 1 in a direction close to the outlet 12, the second flow direction restriction device 7 controls the outlet 12 to open so that seawater enters the second channel 2 from the first channel 1. Specifically, the first flow direction limiting device 6 is a directional flow limiting device, which can only allow seawater to flow into the first channel 1 from the outside through the inlet 11, but the seawater inside the first channel 1 cannot flow out through the inlet 11. Similarly, the second flow direction limiting device 7 is also a directional flow limiting device, which can only allow seawater to flow into the second channel 2 through the outlet 12 of the first channel 1, but the seawater inside the second channel 2 cannot flow out to the first channel 1 through the outlet 12. It can be understood that the inlet 11 of the first channel 1 can be connected to an external storage tank storing seawater extracted from the sea. When the plunger pump device 3 is pulled outward until the first channel 1 forms a negative pressure compared to the external seawater environment outside the inlet 11 of the first channel 1, the first flow restriction device 6 controls the inlet 11 to open so that the external seawater flows into the first channel 1. At this time, the second flow restriction device 7 is closed. Then the plunger pump device 3 moves in the first channel 1 in the reverse direction so that the space inside the first channel 1 becomes smaller, so that the inside of the first channel 1 forms a positive pressure compared to the second channel 2. The second flow restriction device 7 controls the outlet 12 to open so that the seawater enters the second channel 2 from the first channel 1. At this time, the first flow restriction device 6 is closed. In addition, it should be noted that the plunger pump device 3 is a conventional structure and is not specifically described here.

[0045] Specifically, the first flow restriction device 6 and the second flow restriction device 7 are one-way valves. The core function of the one-way valve is to allow the fluid to flow freely in one direction while effectively preventing the fluid from flowing in the opposite direction. This feature ensures that the flow direction of seawater in the first channel 1 and the second channel 2 is accurately controlled, avoiding system disorder, equipment damage or safety accidents that may be caused by the backflow of seawater, and can simplify the structural design. It should be noted that the initial pressure of the piston member 41 is less than the maximum pressure that the plunger pump device 3 can provide, so that the seawater in the first channel 1 can smoothly pass through the one-way valve 2 into the second channel 2, and at the same time ensure that when the seawater in the first channel 1 enters the second channel 2, the piston member 41 can play a role in time and stabilize the pressure in time; the function of the stopper 42 is to prevent the piston member 41 from being over-compressed due to inertia during movement, resulting in too low seawater pressure in the first channel 1 affecting the reverse osmosis effect.

[0046] In some embodiments, Figure 1 As shown, the outlet 12 is arranged opposite to the plunger pump device 3, and the inlet 11 is opened on the side of the first channel 1 corresponding to the moving direction of the plunger pump device 3. Among them, by the outlet 12 being arranged opposite to the plunger pump device 3, the plunger pump device 3 can smoothly transport seawater through the outlet 12 to the second channel 2 during the reciprocating movement, ensuring that the seawater can flow out directly and efficiently during the pumping process, reducing the retention and vortex of seawater inside the first channel 1, thereby improving the pumping efficiency.

[0047] In some embodiments, the reverse osmosis device 5 is a reverse osmosis membrane device. The reverse osmosis membrane device is a conventional device. After the seawater is pressurized by the plunger pump device 3, its pressure rises, and then the high-pressure seawater stabilized by the pressure stabilizing device 4 enters the reverse osmosis membrane device, and is separated by the reverse osmosis membrane device. Under the action of pressure, water molecules pass through the membrane to the other side to form fresh water, while salt and other impurities are retained on one side of the membrane and discharged with concentrated water, which has the advantages of high efficiency, stability, energy saving and environmental protection.

[0048] The embodiment of the present invention further provides a seawater desalination method, using the seawater desalination system 100 as described above, including a pressurization step and a pressure stabilization step:

[0049] The pressurizing step includes: controlling the plunger pump device 3 to move in the first channel 1 so that external seawater flows into the first channel 1;

[0050] Then, the plunger pump device 3 moves in the first channel 1 in the reverse direction, so that the seawater in the first channel 1 enters the second channel 2 from the first channel 1 in the form of carrying pulsating energy;

[0051] The pressure stabilization step includes: after the seawater enters the second channel 2, the pulsating potential energy of the seawater causes the seawater pressure in the second channel 2 to change relative to the initial pressure, pushing the piston member 41 to move in the second channel 2 to pressurize or relieve the seawater in the second channel 2. When the pressure of the seawater entering the second channel 2 is too high, the piston member 41 is squeezed to form elastic compression to perform a pressure relief operation. After the seawater pressure in the second channel 2 drops, the piston member 41 releases the pressure to pressurize the seawater in the second channel 2, so that the pressure of the seawater in the second channel 2 is in a stable state.

[0052] In summary, the seawater desalination method can use the seawater desalination system 100 to push the seawater from the first channel 1 into the second channel 2 in the form of carrying pulsating energy under the action of the plunger pump device 3. After the seawater enters the second channel 2, the pulsating potential energy of the seawater will cause the seawater pressure in the second channel 2 to change relative to the initial pressure value. When the pressure of the seawater entering the second channel 2 is too large, the piston member 41 is squeezed to form elastic compression, which plays a buffering role. After the high-pressure seawater pressure in the second channel 2 drops, the piston member 41 releases the pressure and further pressurizes the seawater in the second channel 2, so that the pressure of the seawater in the second channel 2 is stabilized, ensuring that the seawater entering the reverse osmosis device 5 The stable state of seawater pressure is better, which can effectively avoid the damage of reverse osmosis device 5 caused by excessive pulsation energy of seawater, thereby increasing the service life of reverse osmosis device 5. In combination with the adjusting mechanism 43, the piston member 41 is acted on to adjust the distance between the normally uncompressed piston member 41 and the stopper 42, so that the maximum compression stroke of the piston member 41 can be adjusted according to the pressure range that can be applied by the plunger pump device 3 and the pressure range required by the reverse osmosis device 5, so that the pressure range of seawater inside the second channel 2 can be controlled, ensuring that the seawater pressure in the second channel 2 is stable within a certain range and will not be too large or too small, effectively avoiding affecting the service life of the reverse osmosis device 5 and the quality of fresh water.

[0053] The above embodiments are not exhaustive enumerations of the present invention, and there may be multiple other implementations not listed. Any replacement and improvement made without violating the concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A seawater desalination system, characterized in that: The seawater desalination system comprises a first channel, a second channel, a plunger pump device, a pressure stabilizing device and a reverse osmosis device; The first channel is connected to the second channel, the plunger pump device is movably arranged in the first channel, the pressure stabilizing device and the reverse osmosis device are both arranged in the second channel, the pressure stabilizing device includes a piston member, a stopper and an adjusting mechanism; the piston member is elastically arranged in the second channel, and the stopper is arranged in the second channel and is located in the movement stroke range of the piston member, the adjusting mechanism acts on the piston member and adjusts the distance between the piston member and the stopper, and the maximum compression stroke is when the piston member moves to abut against the stopper, when the pressure of seawater entering the second channel is too large, the piston member is squeezed to form elastic compression, and after the seawater pressure in the second channel drops, the piston member releases the pressure to further pressurize the seawater in the second channel so that the pressure of the seawater in the second channel is in a stable state.

2. The seawater desalination system according to claim 1, characterized in that: The adjusting mechanism includes a fixed plate, an elastic member, a fixed column and an adjusting member; the fixed plate and the piston member are connected via the elastic member, the fixed column is arranged in the second channel, and the fixed plate and the piston member are movably arranged through the fixed column, the adjusting member is arranged on a side of the fixed plate away from the elastic member, and the adjusting member is movably connected to the fixed column, and when the adjusting member moves relative to the fixed column, it can drive the piston member to approach or move away from the blocking member via the fixed plate.

3. The seawater desalination system according to claim 2, characterized in that: The fixing column is provided with a threaded section, and the adjusting member is an adjusting nut, which is threadably connected with the threaded section.

4. The seawater desalination system according to claim 3, characterized in that: A plurality of elastic members are provided, and the elastic members cooperate to support the piston member on the fixing plate.

5. The seawater desalination system according to claim 1, characterized in that: There are two stoppers, which are arranged on the side walls of the second channel on opposite sides along the moving direction of the piston; and / or, The second channel is arranged transversely, the pressure stabilizing device and the reverse osmosis device are arranged at opposite ends of the second channel in the transverse direction, the first channel is arranged vertically and intersects and communicates with the middle position of the second channel, and the second channel is located above the first channel.

6. The seawater desalination system according to any one of claims 1 to 5, characterized in that: The first channel is provided with an inlet and an outlet, the outlet of the first channel is communicated with the second channel, a first flow direction restriction device is provided at the inlet of the first channel, and a second flow direction restriction device is provided at the outlet of the first channel, when the plunger pump device moves in the first channel in a direction away from the outlet, the first flow direction restriction device controls the inlet to open so that external seawater flows into the first channel, and when the plunger pump device moves in the first channel in a direction close to the outlet, the second flow direction restriction device controls the outlet to open so that seawater enters the second channel from the first channel.

7. The seawater desalination system according to claim 6, characterized in that: The first flow restriction device and the second flow restriction device are one-way valves.

8. The seawater desalination system according to claim 6, characterized in that: The outlet is arranged opposite to the plunger pump device, and the inlet is opened on a side of the first channel corresponding to the moving direction of the plunger pump device.

9. The seawater desalination system according to any one of claims 1 to 5, characterized in that: The reverse osmosis device is a reverse osmosis membrane device.

10. A method for desalination of seawater, characterized in that: The seawater desalination system according to any one of claims 1 to 9 is characterized in that it comprises a pressurizing step and a pressure stabilizing step: The pressurizing step includes: controlling the plunger pump device to move in the first channel so that external seawater flows into the first channel; Then, the plunger pump device moves in the first channel in the reverse direction, so that the seawater inside the first channel enters the second channel from the first channel in the form of carrying pulsating energy; The pressure stabilization step includes: after the seawater enters the second channel, the pulsating potential energy of the seawater causes the seawater pressure in the second channel to change relative to the initial pressure, pushing the piston member to move in the second channel to pressurize or relieve the seawater in the second channel; when the pressure of the seawater entering the second channel is too high, the piston member is squeezed to form elastic compression to perform a pressure relief operation; after the seawater pressure in the second channel drops, the piston member releases the pressure to pressurize the seawater in the second channel, so that the pressure of the seawater in the second channel is in a stable state.

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