A single-stage residual pressure recovery device and seawater treatment system

Abstract

The present invention provides a single-stage residual pressure recovery device and a seawater treatment system, which belongs to the field of fluid residual pressure energy recovery technology. The device comprises a cylinder, wherein a main chamber and secondary chambers symmetrically arranged on both sides of the main chamber are formed in the cylinder, wherein the main chamber and the secondary chambers are connected, and a double-rod piston is provided in the main chamber, and the piston rods at both ends of the double-rod piston extend to the secondary chambers on both sides respectively; the two sides of the main chamber are used to alternately enter high-pressure fluid, and the secondary chambers on both sides are connected to low-pressure fluid. The high-pressure fluid entering one side of the main chamber pushes the double-rod piston to move to the other side in the main chamber, exchanging the energy of the high-pressure fluid with the low-pressure fluid in the secondary chamber on the other side. Through the movement of the double-rod piston, the high-pressure energy of the high-pressure fluid is consumed, and the energy of the high-pressure fluid is exchanged with the low-pressure fluid. While reducing the pressure of the high-pressure fluid, the high pressure of the high-pressure fluid is used to pressurize the low-pressure fluid, thereby improving the residual pressure recovery efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid residual pressure energy recovery, and in particular to a single-stage residual pressure recovery device and a seawater treatment system. Background Art

[0002] The field of fluid residual pressure energy recovery involves numerous processes involving decompression of high-pressure fluids and pressurization of low-pressure fluids. Pressurization of low-pressure fluids requires specialized external equipment and consumes significant energy. Direct pressure relief during discharge of high-pressure fluids also wastes energy. Therefore, recovering the residual pressure energy of high-pressure fluids is of great significance in practical engineering.

[0003] Currently, residual pressure recovery devices are primarily categorized into two types: externally driven and self-driven. Externally driven devices achieve higher efficiency through precise control, while self-driven devices often have lower efficiency. However, externally driven devices are cost-constrained and are therefore primarily used in large-scale desalination plants. Summary of the Invention

[0004] The object of the present invention is to provide a single-stage excess pressure recovery device and a seawater treatment system, which have high excess pressure recovery efficiency and low cost.

[0005] The embodiment of the present invention is achieved as follows:

[0006] One aspect of an embodiment of the present invention provides a single-stage residual pressure recovery device, which includes a cylinder, a main chamber and sub-chambers symmetrically arranged on both sides of the main chamber are formed in the cylinder, the main chamber and the sub-chambers are connected, a double-rod piston is provided in the main chamber, and the piston rods at both ends of the double-rod piston extend to the sub-chambers on both sides respectively; the two sides of the main chamber are used for alternating entry of high-pressure fluid, and the sub-chambers on both sides are connected to low-pressure fluid, and the high-pressure fluid entering one side of the main chamber pushes the double-rod piston to move to the other side in the main chamber, exchanging the energy of the high-pressure fluid to the low-pressure fluid in the sub-chamber on the other side.

[0007] Optionally, the cylinder includes a main cylinder and secondary cylinders symmetrically connected on both sides of the main cylinder, the main chamber is located in the main cylinder, and the secondary chamber is located in the secondary cylinder; the double-rod piston includes a piston head and two symmetrically arranged piston rods, the piston head is located in the main chamber, and the two piston rods are respectively connected to the piston head and extend into the corresponding secondary chambers.

[0008] Optionally, it further includes two disc-type rotating valves respectively sleeved on the auxiliary cylinder, and the end faces on both sides of the main cylinder are circumferentially distributed with multiple fluid inlets and multiple fluid outlets, the fluid inlets and the fluid outlets are connected to the main cavity, and the fluid inlets and the fluid outlets are circumferentially alternately arranged, and the disc-type rotating valve is provided with a valve port corresponding to the fluid inlet or the fluid outlet, and the fluid inlet and the fluid outlet are alternately opened or closed by rotating the disc-type rotating valve.

[0009] Optionally, the number of the fluid inlet and the number of the fluid outlet are both three, and the angle between adjacent fluid inlet and fluid outlet is 60°.

[0010] Optionally, the disc-type rotary valve is connected to the fluid inlet and the fluid outlet respectively through water pipes.

[0011] Optionally, one end of the sub-chamber is in communication with the outside world, and a pressure-limiting valve is provided at the end of the sub-chamber in communication with the outside world, and the pressure-limiting valve is in communication with the sub-chamber.

[0012] Optionally, a reflux ring is provided on the peripheral wall of the piston rod, and the reflux ring extends to the end of the piston rod away from the piston head. A reflux groove is provided on the secondary cylinder, and the reflux groove extends to the end of the secondary cylinder away from the main cylinder for connecting low-pressure fluid. The reflux groove is connected to the secondary chamber, and the reflux groove and the reflux ring are in a connected state to relieve pressure in the secondary chamber.

[0013] Optionally, it also includes a controller and a power assembly connected to the disc-type rotating valve, and the controller is electrically connected to the power assembly; the end of the sub-chamber connected to the outside world is provided with a flow sensor electrically connected to the controller, which is used to sense the flow of the low-pressure fluid discharged from the sub-chamber and transmit the signal to the controller, and the controller controls the power assembly to drive the disc-type rotating valve to rotate according to the signal.

[0014] Optionally, a piston ring is provided on the outer periphery of the piston head.

[0015] One aspect of an embodiment of the present invention provides a seawater treatment system, comprising a seawater desalination device, a freshwater device, and the above-mentioned single-stage residual pressure recovery device, wherein the water outlet of the seawater desalination device is connected to the main chamber of the single-stage residual pressure recovery device, for providing high-pressure seawater to the single-stage residual pressure recovery device; the freshwater device is connected to the secondary chamber of the single-stage residual pressure recovery device, for providing low-pressure fresh water to the single-stage residual pressure recovery device.

[0016] The beneficial effects of the embodiments of the present invention include:

[0017] The single-stage residual pressure recovery device and seawater treatment system provided by an embodiment of the present invention has a main chamber and secondary chambers symmetrically arranged on either side of the main chamber formed in a cylinder. The main chamber and the secondary chambers are connected, and the two sides of the main chamber are used to alternately enter high-pressure fluid. A double-rod piston is provided in the main chamber, and the two piston rods of the double-rod piston are symmetrically arranged, and the two ends of the double-rod piston extend to the two secondary chambers on either side. When high-pressure fluid enters the left side of the main chamber, the high-pressure fluid pushes the double-rod piston to the right, and the double-rod piston pressurizes the low-pressure fluid in the secondary chamber, exchanging the energy of the high-pressure fluid entering from the left side with the low-pressure fluid in the right secondary chamber, completing the pressure exchange and achieving pressure relief for the high-pressure fluid. At the same time, the high pressure of the high-pressure fluid is used to pressurize the low-pressure fluid, realizing the recovery and utilization of the residual pressure energy of the high-pressure fluid. When high-pressure fluid enters from the right side of the main chamber, it pushes the double-rod piston to the left, pressurizing the low-pressure fluid in the left secondary chamber, and the reciprocating cycle is repeated. Through the movement of the double-rod piston, the high pressure energy of the high-pressure fluid is consumed, and self-driven pressure exchange is achieved through the residual pressure of the high-pressure fluid, exchanging the high-pressure fluid energy to the low-pressure fluid. While reducing the pressure of the high-pressure fluid, the high pressure of the high-pressure fluid is used to pressurize the low-pressure fluid, thereby improving the residual pressure recovery efficiency, and the cost is also lower than that of the external-driven residual pressure recovery device. It is energy-saving and environmentally friendly, has a simple structure, is easy to install, and has low manufacturing and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 This is a schematic diagram of the structure of a single-stage residual pressure recovery device provided by an embodiment of the present invention;

[0020] Figure 2 The second structural diagram of the single-stage residual pressure recovery device provided by an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of the cylinder structure of a single-stage residual pressure recovery device provided in an embodiment of the present invention;

[0022] Figure 4 Schematic diagram of the double-rod piston structure of the single-stage residual pressure recovery device provided in an embodiment of the present invention.

[0023] Icons: 1-pressure limiting valve; 2-reflux groove; 3-auxiliary chamber; 4-fluid inlet; 5-disc rotary valve; 6-piston ring; 7-fluid outlet; 8-reflux ring; 9-piston head; 10-main chamber; 11-piston rod; 12-main cylinder; 13-auxiliary cylinder. DETAILED DESCRIPTION

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0027] Example 1

[0028] Please refer to Figure 1 The present embodiment provides a single-stage residual pressure recovery device, which includes a cylinder, in which a main chamber 10 and sub-chambers 3 are symmetrically arranged on both sides of the main chamber 10. The main chamber 10 and the sub-chambers 3 are connected. A double-rod piston is provided in the main chamber 10. The two piston rods 11 of the double-rod piston are symmetrically arranged, and the two ends of the double-rod piston extend to the sub-chambers 3 on both sides respectively; the two sides of the main chamber 10 are used for alternately entering high-pressure fluid, and the sub-chambers 3 on both sides are connected to low-pressure fluid. The high-pressure fluid entering one side of the main chamber 10 pushes the double-rod piston to move to the other side in the main chamber 10, exchanging the energy of the high-pressure fluid to the low-pressure fluid in the sub-chamber 3 on the other side.

[0029] like Figure 3 As shown, the cylinder includes a main cylinder 12 and auxiliary cylinders 13 symmetrically connected on both sides of the main cylinder 12. A main chamber 10 is formed in the main cylinder 12, and auxiliary chambers 3 are formed in the auxiliary cylinders 13 on both sides. The main chamber 10 and the auxiliary chamber 3 are connected.

[0030] like Figure 4 As shown, a double-rod piston is provided in the main chamber 10, and the two piston rods 11 of the double-rod piston are symmetrically arranged, and the two ends of the double-rod piston extend to the sub-chambers 3 on both sides respectively. The double-rod piston includes a piston head 9 and two piston rods 11, and the two piston rods 11 are respectively connected to the piston head 9. The piston head 9 is located in the main chamber 10, and the two piston rods 11 extend to the corresponding sub-chambers 3 on both sides respectively.

[0031] A groove is provided on the outer periphery of the piston head 9, and a piston ring 6 is provided in the groove to reduce pressure loss when pressure is transmitted.

[0032] High-pressure fluid is alternately introduced into the main chamber 10 on both sides. A fluid inlet 4 and a fluid outlet 7 are located on opposite sides of the master cylinder 12. When high-pressure fluid is introduced to one side's fluid inlet 4, the fluid outlet 7 on that side closes, while the fluid outlet 7 on the other side opens and the fluid inlet 4 on the other side closes. Vice versa, high-pressure fluid enters from one side, pushing the twin-rod piston to generate work, exchanging pressure energy from the high-pressure fluid with the low-pressure fluid on the other side, which is then expelled from the other side.

[0033] Both side sub-chambers 3 are connected to low-pressure fluid. For example, when high-pressure fluid enters the left side of the main chamber 10, the high-pressure fluid pushes the piston head 9 to move rightward within the main chamber 10. When the piston head 9 moves rightward, it pushes the fluid on the right side of the main chamber 10 to be discharged from the main chamber 10 through the right fluid outlet 7 of the main chamber 10. At the same time, the right piston rod 11 moves rightward within the sub-chamber 3, pressurizing the low-pressure fluid in the sub-chamber 3, exchanging the energy of the high-pressure fluid entering from the left with the low-pressure fluid in the right sub-chamber 3, completing the energy exchange and realizing the recovery and utilization of the residual pressure of the high-pressure fluid.

[0034] When the left fluid inlet 4 is closed and the fluid outlet 7 is opened, and the right fluid inlet 4 is opened and the fluid outlet 7 is closed, high-pressure fluid enters the main chamber 10 from the right, pushing the double-rod piston to the left, thereby pressurizing the low-pressure fluid in the left sub-chamber 3, and circulating reciprocatingly.

[0035] The single-stage residual pressure recovery device provided in this embodiment has a main chamber 10 and sub-chambers 3 symmetrically arranged on both sides of the main chamber 10 formed in the cylinder. The main chamber 10 and the sub-chambers 3 are connected, and the two sides of the main chamber 10 are used to alternately enter high-pressure fluid. A double-rod piston is provided in the main chamber 10, and the two ends of the double-rod piston extend to the sub-chambers 3 on both sides. When the high-pressure fluid enters the left side of the main chamber 10, the high-pressure fluid pushes the double-rod piston to move to the right, and the double-rod piston pressurizes the low-pressure fluid in the sub-chamber 3, and exchanges the energy of the high-pressure fluid entering from the left side to the low-pressure fluid in the right sub-chamber 3, completing the pressure exchange, achieving the pressure relief of the high-pressure fluid, and at the same time using the high pressure of the high-pressure fluid to pressurize the low-pressure fluid, realizing the recovery and utilization of the residual pressure energy of the high-pressure fluid; when the high-pressure fluid enters from the right side of the main chamber 10, it pushes the double-rod piston to move to the left, realizing the pressurization of the low-pressure fluid in the left sub-chamber 3, and the reciprocating cycle. Through the movement of the double-rod piston, the high-pressure energy of the high-pressure fluid is consumed, and the residual pressure of the high-pressure fluid is used to achieve self-driven pressure exchange, exchanging the high-pressure fluid energy with the low-pressure fluid. While reducing the pressure of the high-pressure fluid, the high pressure of the high-pressure fluid is used to pressurize the low-pressure fluid, improving the efficiency of residual pressure recovery. The cost is also significantly lower than that of externally driven residual pressure recovery devices, and it has high commercial value in actual engineering applications. This single-stage residual pressure recovery device is energy-saving and environmentally friendly, with a simple structure, easy installation, and low manufacturing and maintenance costs.

[0036] Specifically, the alternating flow of high-pressure fluid into the main chamber 10 is achieved through the disc-type rotary valve 5. A disc-type rotary valve 5 is sleeved on each of the two auxiliary cylinders 13. Multiple fluid inlets 4 and multiple fluid outlets 7 are circumferentially distributed on both end surfaces of the main cylinder 12. These fluid inlets 4 and outlets 7 communicate with the main chamber and are arranged alternately around the circumference. The disc-type rotary valve 5 is provided with valve ports corresponding to the fluid inlets 4 or outlets 7. Rotating the disc-type rotary valve 5 alternately opens and closes the fluid inlets 4 and outlets 7.

[0037] For example, Figure 2As shown, the left end face of the master cylinder 12 has three fluid inlets 4 and three fluid outlets 7, each arranged alternately around the circumference, with the angle between adjacent fluid inlets 4 and fluid outlets 7 being 60°. The disc-shaped rotary valve 5 is provided with three valve ports, each corresponding to a fluid inlet 4 or a fluid outlet 7. When the three valve ports correspond to the fluid inlet 4, the valve ports of the disc-shaped rotary valve 5 communicate with external high-pressure fluid, allowing the high-pressure fluid to enter the main chamber 10 through the valve ports of the disc-shaped rotary valve 5 and the fluid inlet 4. At this point, the three fluid outlets 7 are blocked, preventing fluid from flowing out. At this point, the three valve ports of the disc-shaped rotary valve 5 in the right slave cylinder 13 communicate with the right fluid outlet 7, allowing the fluid remaining on the right side of the main chamber 10 to be discharged through the right fluid outlet 7 by the double-rod piston. After completing the one-way high-pressure exchange, the disc rotary valve 5 is rotated 60° so that the valve port of the left disc rotary valve 5 is connected to the left fluid outlet 7 and the left fluid inlet 4 is closed; the valve port of the right disc rotary valve 5 is connected to the right fluid inlet 4 and the right fluid outlet 7 is closed. At this time, high-pressure fluid enters the main chamber 10 from the right and the fluid remaining on the left side of the main chamber 10 is discharged from the left fluid outlet 7.

[0038] The disc-type rotary valve 5 is connected to the fluid inlet 4 and fluid outlet 7 via fluid pipes. Specifically, the disc-type rotary valve 5 includes two connecting plates: one for communication with the outside world and the other for communication with the main chamber 10. Each connecting plate is provided with six holes. The six holes in one connecting plate are connected to water pipes for receiving high-pressure fluid and discharging fluid. The six holes in the other connecting plate are also connected to the fluid inlet 4 and fluid outlet 7 on one side of the main chamber 10 via water pipes. A rotating disk is located between the two connecting plates, with three valve ports on the disk. The rotating disk rotates while the connecting plates do not rotate. Rotating the rotating disk causes the three valve ports to correspond to the fluid inlet 4 or the fluid outlet 7, respectively, thereby alternately opening and closing the fluid inlet 4 and fluid outlet 7.

[0039] The disc-type rotary valve 5 is rotated by automatic control. Specifically, the single-stage residual pressure recovery device also includes a controller and a power assembly connected to the disc-type rotary valve 5, and the controller is electrically connected to the power assembly; the end of the sub-chamber 3 connected to the outside world is provided with a flow sensor electrically connected to the controller, which is used to sense the flow of the low-pressure fluid discharged from the sub-chamber 3 and transmit the signal to the controller. The controller controls the power assembly to drive the disc-type rotary valve 5 to rotate according to the signal.

[0040] The pressurized low-pressure fluid is discharged from the secondary chamber 3. When the discharged low-pressure fluid reaches a certain flow rate, the cycle is completed and the next cycle can be started. At this time, a signal is sent to the controller, which controls the power assembly to drive the disc rotary valve 5 to rotate, starting the next cycle.

[0041] The signal is provided by the flow sensor, which is located at the end of the sub-chamber 3 connected to the outside world to sense the flow of the fluid discharged from the sub-chamber 3. When the set flow is reached, a signal is sent to the controller.

[0042] One end of the secondary chamber 3 is connected to the outside world. A pressure-limiting valve 1 is provided at this end, communicating with the secondary chamber 3. A reflux groove 2 is also provided on the secondary cylinder 13. This groove extends to the end of the secondary cylinder 13 away from the main cylinder 12 for communicating with low-pressure fluid. This groove is in communication with the secondary chamber 3. A reflux ring 8 is provided on the peripheral wall of the piston rod 11. This ring extends to the end of the piston rod 11 away from the piston head 9. The reflux groove 2 and the ring 8 are in communication, relieving pressure from the secondary chamber 3.

[0043] Specifically, high-pressure fluid enters the main chamber 10 from the left, and the double-rod piston moves to the right. The double-rod piston pressurizes the low-pressure fluid in the right sub-chamber 3. When the pressurized pressure reaches the threshold of the pressure-limiting valve 1 of the right sub-chamber 3, the pressure-limiting valve 1 of the right sub-chamber 3 opens, allowing the pressurized fluid that meets the pressure setting to be sent out of the sub-chamber 3 for use. When the piston rod 11 moves to the right end, the return ring 8 on the right piston rod 11 is connected to the return groove 2 of the right sub-chamber 3, and the pressure state in the right sub-chamber 3 is broken, which has the effect of actively relieving the pressure in the right sub-chamber 3. After the pressure is relieved, the pressure in the right sub-chamber 3 does not reach the threshold of the pressure-limiting valve 1, causing the pressure-limiting valve 1 door to close. At this time, the left sub-chamber 3 allows the low-pressure fluid to enter and fill the left sub-chamber 3 through the left return groove 2, preparing for the next pressurization of the low-pressure fluid in the left sub-chamber 3.

[0044] Then rotate the disc rotary valve 5 to open the three fluid outlets 7 on the left and close the three fluid inlet 4; open the three fluid inlet 4 on the right and close the three fluid outlets 7; the high-pressure fluid enters the main chamber 10 from the right, and the double-rod piston moves to the left to discharge the fluid remaining in the main chamber 10 from the previous cycle. After the high-pressure fluid in the main chamber 10 in the previous cycle pushes the double-rod piston to do work, the high-pressure energy has been exchanged to the low-pressure fluid, and the high-pressure energy of the high-pressure fluid has been consumed. Therefore, the fluid remaining in the main chamber 10 is no longer a high-pressure fluid.

[0045] At the same time, the double-rod piston pressurizes the low-pressure fluid in the left sub-chamber 3 reserved from the previous cycle. When the pressurized pressure reaches the threshold of the pressure-limiting valve 1 of the left sub-chamber 3, the pressure-limiting valve 1 of the left sub-chamber 3 opens, allowing the pressurized fluid that meets the pressure setting to be sent out of the sub-chamber 3 for use. When the piston rod 11 moves to the left end, the return ring 8 on the left piston rod 11 connects with the return groove 2 of the left sub-chamber 3, breaking the pressure state in the left sub-chamber 3, and actively relieving the pressure in the left sub-chamber 3. After the pressure is relieved, the pressure in the left sub-chamber 3 does not reach the threshold of the pressure-limiting valve 1, causing the pressure-limiting valve 1 to close. At this time, the right sub-chamber 3 allows the low-pressure fluid to enter and fill the right sub-chamber 3 through the right return groove 2, preparing for the next pressurization of the low-pressure fluid in the right sub-chamber 3. Reciprocating cycle.

[0046] The pressure limiting valve 1 controls the output pressure of the single-stage residual pressure recovery device. The arrangement of the reflux ring 8 and the reflux groove 2 ensures the pressure of the output fluid is stable and reduces fluctuations.

[0047] In summary, this embodiment utilizes a "pressure-to-pressure" energy transfer method, converting the high-pressure fluid through a "water pressure energy-water pressure energy" step to recover its energy. High-pressure fluid enters from the left side, pushing the double-rod piston to the right. The double-rod piston directly exchanges pressure with the low-pressure fluid on the right side. Once sufficient pressure is reached, the fluid is discharged through pressure-limiting valve 1. After this pressure exchange, high-pressure fluid enters from the right side via the rotating disc valve 5. The above process is repeated, and the high-pressure seawater that performed the previous work is recovered.

[0048] This embodiment utilizes "work exchange," a one-step "fluid pressure energy - fluid pressure energy" energy conversion process, to improve energy recovery efficiency. It is a piston-type, valve-controlled pressure exchanger. This embodiment utilizes a disc-type rotary valve 5, a reflux groove 2, and a pressure-limiting valve 1 to achieve more stable pressure output.

[0049] This embodiment also discloses a seawater treatment system, comprising a seawater desalination device, a freshwater device, and the single-stage residual pressure recovery device described in the above embodiment. The desalination device discharges high-pressure seawater from its outlet, which is connected to the main chamber 10 of the single-stage residual pressure recovery device to provide high-pressure seawater to the single-stage residual pressure recovery device. The freshwater device is connected to the secondary chamber 3 of the single-stage residual pressure recovery device to provide low-pressure fresh water to the single-stage residual pressure recovery device.

[0050] After passing through this single-stage residual pressure recovery device, the high-pressure energy of high-pressure seawater pushes the double-rod piston to work, consuming the high-pressure energy and achieving the purpose of reducing the pressure and releasing the high-pressure seawater. At the same time, the high-pressure seawater pushes the double-rod piston, exchanging the high-pressure energy for low-pressure fresh water, pressurizing the low-pressure fresh water for use, thus achieving the effect of recovering and utilizing the residual pressure energy of the high-pressure fluid.

[0051] The seawater treatment system has the same structure and benefits as the single-stage residual pressure recovery device in the aforementioned embodiment. The structure and benefits of the single-stage residual pressure recovery device have been described in detail in the aforementioned embodiment and will not be repeated here.

[0052] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A single-stage residual pressure recovery device, characterized in that: The invention comprises a cylinder, wherein a main chamber and sub-chambers symmetrically arranged on both sides of the main chamber are formed in the cylinder, the main chamber and the sub-chambers are connected, a double-rod piston is provided in the main chamber, and the piston rods at both ends of the double-rod piston extend to the sub-chambers on both sides respectively; the two sides of the main chamber are used for alternately entering high-pressure fluid, and the sub-chambers on both sides are connected to low-pressure fluid, and the high-pressure fluid entering one side of the main chamber pushes the double-rod piston to move to the other side in the main chamber, thereby exchanging the energy of the high-pressure fluid with the low-pressure fluid in the sub-chamber on the other side; The cylinder includes a main cylinder and auxiliary cylinders symmetrically connected on both sides of the main cylinder, the main chamber is located in the main cylinder, and the auxiliary chamber is located in the auxiliary cylinder; the end faces of both sides of the main cylinder are circumferentially distributed with multiple fluid inlets and multiple fluid outlets, the fluid inlets and the fluid outlets are connected to the main chamber, and the fluid inlets and the fluid outlets are circumferentially alternately arranged; the number of the fluid inlets and the fluid outlets are both three, and the angle between adjacent fluid inlets and fluid outlets is 60°.

2. The single-stage residual pressure recovery device according to claim 1, characterized in that: The double-rod piston includes a piston head and two symmetrically arranged piston rods, the piston head is located in the main chamber, and the two piston rods are respectively connected to the piston head and extend into the corresponding sub-chambers.

3. The single-stage residual pressure recovery device according to claim 2, characterized in that: It also includes two disc-type rotating valves respectively sleeved on the auxiliary cylinder, and the disc-type rotating valves are provided with valve ports corresponding to the fluid inlet or the fluid outlet. The fluid inlet and the fluid outlet are alternately opened or closed by rotating the disc-type rotating valve; the disc-type rotating valve includes two connecting plates, one connecting plate is used to communicate with the outside world, and the other connecting plate is used to communicate with the main chamber. A turntable is provided between the two connecting plates, and three valve ports are provided on the turntable. The turntable is rotatable. By rotating the turntable, the three valve ports correspond to the fluid inlet or the fluid outlet respectively, thereby completing the alternating opening or closing of the fluid inlet and the fluid outlet.

4. The single-stage residual pressure recovery device according to claim 3, characterized in that: The disc-type rotary valve is communicated with the fluid inlet and the fluid outlet respectively through water pipes.

5. The single-stage residual pressure recovery device according to claim 3, characterized in that: One end of the sub-chamber is communicated with the outside world. A pressure-limiting valve is provided at the end of the sub-chamber that is communicated with the outside world. The pressure-limiting valve is communicated with the sub-chamber.

6. The single-stage residual pressure recovery device according to claim 5, characterized in that: A reflux ring is provided on the peripheral wall of the piston rod, and the reflux ring extends to the end of the piston rod away from the piston head. A reflux groove is provided on the secondary cylinder, and the reflux groove extends to the end of the secondary cylinder away from the main cylinder for connecting low-pressure fluid. The reflux groove is connected to the secondary chamber, and the reflux groove and the reflux ring are in a connected state to relieve pressure in the secondary chamber.

7. The single-stage residual pressure recovery device according to claim 5, characterized in that: It also includes a controller and a power assembly connected to the disc-type rotary valve, wherein the controller is electrically connected to the power assembly; The end of the sub-chamber communicating with the outside world is provided with a flow sensor electrically connected to the controller, which is used to sense the flow of the low-pressure fluid discharged from the sub-chamber and transmit the signal to the controller. The controller controls the power component to drive the disc rotary valve to rotate according to the signal.

8. The single-stage residual pressure recovery device according to claim 2, characterized in that: The outer periphery of the piston head is sleeved with a piston ring.

9. A seawater treatment system, characterized in that: It comprises a seawater desalination device, a fresh water device and a single-stage residual pressure recovery device as described in any one of claims 1 to 8, wherein the water outlet of the seawater desalination device is connected to the main chamber of the single-stage residual pressure recovery device, and is used to provide high-pressure seawater to the single-stage residual pressure recovery device; the fresh water device is connected to the secondary chamber of the single-stage residual pressure recovery device, and is used to provide low-pressure fresh water to the single-stage residual pressure recovery device; the high-pressure energy of the high-pressure seawater is consumed by the single-stage residual pressure recovery device to reduce the pressure of the high-pressure seawater and discharge it; at the same time, the single-stage residual pressure recovery device exchanges the high-pressure energy for the low-pressure fresh water, pressurizes the low-pressure fresh water for use, and recovers and utilizes the residual pressure energy of the high-pressure fluid.

Images