CN-117180984-B - Fluid switcher, seawater desalination energy recovery tower and array structure thereof

CN117180984BCN 117180984 BCN117180984 BCN 117180984BCN-117180984-B

Abstract

The invention belongs to the technical field of liquid residual pressure energy recycling in process industry, discloses a novel fluid switcher, and develops a novel sea water desalination energy recycling tower and a typical parallel array form on the basis of the novel fluid switcher so as to solve the problems of complex structure, low reliability and the like of an original valve control device. The invention vertically arranges the pressure exchange cylinders, thereby greatly reducing the occupied area, increasing and expanding the capacity of the device, being more flexible and convenient, ensuring that the design of the fluid switcher at the salt water end and the internal cavity of the check valve group at the sea water end is more compact and smooth, ensuring that the design of the inlet and outlet pipe joints of each fluid is more reasonable, ensuring that the fluid flowing in or out directly through the main pipe has better flow state and uniform distribution condition and smaller flow resistance loss, and further improving the energy recovery efficiency and reliability of the device.

Inventors

WANG YUE
WANG JUNQI
XU HONGSHAN
XU SHICHANG
Hou Xinmiao
WU YUDONG

Assignees

天津大学

Dates

Publication Date: 20260505
Application Date: 20230828

Claims (10)

1. The fluid switcher is characterized by comprising a switcher valve body, wherein one end of the switcher valve body is coaxially connected with a pressure release cavity shell, and the other end of the switcher valve body is coaxially connected with a high-pressure cavity connecting pipe; The inside of the switcher valve body is coaxially provided with a switcher axial through cavity, the switcher axial through cavity comprises a switcher middle cavity, and a switcher first concave cavity and a switcher second concave cavity which are arranged at the two ends of the switcher middle cavity, wherein the inner diameters of the switcher first concave cavity and the switcher second concave cavity are larger than the inner diameter of the switcher middle cavity; the switcher valve body is radially provided with a first interface of a pressure exchange cylinder, and the first interface of the pressure exchange cylinder is communicated with the switcher intermediate cavity and is used for connecting the pressure exchange cylinder; A first internal part of the switching valve and a second internal part of the switching valve are arranged in the axial through cavity of the switcher, and the first internal part of the switching valve and the second internal part of the switching valve are of an integrated structure; The first inner piece of the switching valve comprises a first connecting shaft, a first valve plate and a second connecting shaft which are sequentially and coaxially connected, wherein the first valve plate can slide in the middle cavity of the switching valve, a first limiting end is coaxially arranged on one surface of the first valve plate, which faces the first connecting shaft, the diameter of the first limiting end is larger than the inner diameter of the middle cavity of the switching valve, a step surface of the first limiting end is processed into an arc-shaped surface and is used for forming line seal with a conical surface structure at the junction of the middle cavity of the switching valve and a first concave cavity of the switching valve, a plurality of sealing waterlines are arranged on the circumferential surface of the first valve plate and are used for forming circumferential seal with the middle cavity of the switching valve, a first radial circulating part and a first positioning ring are coaxially arranged on one surface of the first valve plate, which faces the second connecting shaft, and the first radial circulating part is positioned between the first valve plate and the first positioning ring, and the first positioning ring is used for ensuring that the first inner piece of the switching valve is not separated from the middle cavity of the switching valve all the time in the switching process; The second inner part of the switching valve is formed by integrally forming a third connecting shaft, a second limiting end, a second valve plate, a second radial circulating part and a second positioning ring, wherein the third connecting shaft is coaxially connected with the second valve plate, the third connecting shaft is in threaded connection with the second connecting shaft, the second valve plate, the second limiting end, the second radial circulating part and the second positioning ring are respectively and symmetrically arranged with the first valve plate, the first limiting end, the first radial circulating part and the first positioning ring in the same structure, the step surface of the second limiting end is processed into a circular arc surface and used for forming line seal with a conical surface structure at the junction of the intermediate cavity of the switching device and the second cavity of the switching device, and the circumferential surface of the second valve plate is provided with a plurality of water lines for forming circumferential seal with the intermediate cavity of the switching device; The pressure relief cavity shell is provided with a pressure relief cavity, a first connecting shaft is connected with the pressure relief cavity shell, a second connecting shaft is connected with the pressure relief cavity shell, a third connecting shaft is connected with the pressure relief cavity shell, the second connecting shaft is connected with the pressure relief cavity shell, the third connecting shaft is connected with the pressure relief cavity shell, the second connecting shaft is connected with the pressure relief cavity shell, and the third connecting shaft is connected with the pressure relief cavity shell; the high-pressure cavity connecting pipe is provided with a high-pressure fluid inlet which is axially communicated with the high-pressure cavity connecting pipe and the valve body of the switcher through a flange, so that the high-pressure fluid inlet is communicated with the second concave cavity of the switcher; The side wall of the switcher valve body and the side wall of the pressure release cavity shell are respectively provided with a flow hole at the same circumference angle, the two flow holes are respectively communicated with the balance cavity and the switcher second concave cavity, the two flow holes are connected by a balance pipe, the balance pipe is provided with a flow regulating valve, the flow regulating valve is used for introducing high-pressure fluid into the balance cavity, and the purpose that the driving shaft is used for applying differential pressure force to the first internal part of the switching valve and the second internal part of the switching valve is achieved, so that the differential pressure force in the opening process of the first internal part of the switching valve and the second internal part of the switching valve is balanced.
2. The fluid switch of claim 1, wherein the first radial flow section comprises a plurality of radial flow windows for fluid flow and a web between the radial flow windows, wherein the web has an outer diameter that is the same as the outer diameter of the first valve plate and the first retaining ring; The second radial circulation part comprises a plurality of radial circulation windows for fluid flow and rib plates between the radial circulation windows, wherein the outer diameter of the rib plates is the same as the outer diameters of the second valve plate and the second positioning ring.
3. A fluid switch according to claim 1, wherein the balance piston is retained on one side by a pillow block on the drive shaft and on the other side by a lock nut mounted on the drive shaft.
4. A fluid switching device according to claim 1, wherein the central bore of the balance piston is provided with a seal for static sealing and the outer circumferential surface is provided with a seal for dynamic sealing.
5. The fluid switching device according to claim 1, wherein the drive shaft, the balance piston, the switching valve first internal member, and the switching valve second internal member are all coaxially disposed.
6. The seawater desalination energy recovery tower is characterized by comprising a vertically arranged pressure exchange cylinder, wherein the upper part of the pressure exchange cylinder is connected with a fluid switcher as set forth in any one of claims 1-5, and the fluid switcher is used as a brine end; the fluid switcher is connected with the pressure exchange cylinder through a first interface of the pressure exchange cylinder, and the check valve group is connected with the pressure exchange cylinder through a second interface of the pressure exchange cylinder.
7. The energy recovery tower for desalinating seawater of claim 6, wherein the check valve assembly includes a check valve body having one end coaxially connected to a plenum housing and the other end coaxially connected to a low pressure chamber nipple; The check valve is characterized in that a check valve axial through cavity is coaxially arranged in the check valve body, and the check valve axial through cavity comprises a check valve middle cavity and check valve first concave cavities and check valve second concave cavities at two ends of the check valve middle cavity; the inner diameters of the first concave cavity of the check valve and the second concave cavity of the check valve are both larger than the inner diameter of the middle cavity of the check valve; The check valve body is provided with a second interface of the pressure exchange cylinder along the radial direction of the check valve body, and the second interface of the pressure exchange cylinder is communicated with the check valve middle cavity; The inside of the pressurizing cavity shell is coaxially provided with a pressurizing cavity, one end of the pressurizing cavity shell is radially communicated with a pressurizing fluid outlet, and the other end of the pressurizing cavity shell is connected with the check valve body through a flange so that the pressurizing cavity is communicated with the first concave cavity of the check valve; The low-pressure cavity connecting pipe is coaxially provided with a low-pressure fluid inlet, and is connected with the check valve body through a flange, so that the low-pressure fluid inlet is communicated with a second concave cavity of the check valve; The junction of the pressurizing cavity shell and the check valve body is fixedly provided with a check valve first shaft sleeve, the junction of the check valve intermediate cavity and the check valve second cavity is fixedly provided with a check valve second shaft sleeve, and the check valve first shaft sleeve and the check valve second shaft sleeve are respectively provided with a check valve first internal part and a check valve second internal part; The structure and the installation direction of the first check valve inner piece and the second check valve inner piece are the same, the first check valve inner piece and the second check valve inner piece comprise a central shaft and a valve plate integrally connected to one end of the central shaft, a spring is sleeved outside the central shaft, the central shaft of the first check valve inner piece penetrates through the first check valve shaft sleeve and can slide relative to the first check valve shaft sleeve, the valve plate of the first check valve inner piece moves in the first check valve cavity and has a diameter larger than the inner diameter of the middle check valve cavity, the spring of the first check valve inner piece is located between the valve plate of the first check valve inner piece and the first check valve shaft sleeve, the central shaft of the second check valve inner piece penetrates through the second check valve shaft sleeve and can slide relative to the second check valve shaft sleeve, the valve plate of the second check valve inner piece moves in the second check valve cavity and has a diameter larger than the inner diameter of the low-pressure fluid inlet, and the spring of the second check valve inner piece is located between the valve plate and the second check valve shaft sleeve.
8. The seawater desalination energy recovery tower of claim 7, wherein the first sleeve of the check valve and the second sleeve of the check valve have the same structure, each of the first sleeve of the check valve and the second sleeve of the check valve comprises a fixed ring and a central ring which are concentrically arranged, the central ring and the fixed rings are connected through connecting parts which are uniformly distributed in the radial direction, the fixed rings are used for fixing the first sleeve of the check valve and the second sleeve of the check valve, and the central rings are used for installing the first internal part of the check valve and the second internal part of the check valve.
9. An array structure of sea water desalination energy recovery towers, which is characterized by comprising one or more sea water desalination energy recovery tower basic units arranged side by side, wherein each sea water desalination energy recovery tower basic unit comprises two sea water desalination energy recovery towers according to any one of claims 6-8, the fluid switches in the two sea water desalination energy recovery towers in each sea water desalination energy recovery tower basic unit are symmetrically arranged, and the check valve groups are symmetrically arranged.
10. A desalination energy recovery tower array structure according to claim 9, wherein the high pressure fluid inlets in the fluid switches of two of the desalination energy recovery towers in each of the desalination energy recovery tower base units are opposite in direction and the low pressure fluid inlets in the check valve sets are opposite in direction; The high-pressure fluid inlets in the fluid switches of the two sea water desalination energy recovery towers are directly connected with the same high-pressure brine main pipe, and the pressure release fluid outlets are respectively and directly connected with the two pressure release brine main pipes; the low-pressure fluid inlets in the check valve groups of the two sea water desalination energy recovery towers are directly connected with the same low-pressure sea water main pipe, and the pressurized fluid outlets are respectively and directly connected with the two pressurized sea water main pipes.

Description

Fluid switcher, seawater desalination energy recovery tower and array structure thereof Technical Field The invention belongs to the technical field of waste pressure energy recycling of process industrial liquid, and particularly relates to a reverse osmosis sea water desalination energy recycling device for pressure energy exchange between a pressurizing liquid and a pressurized liquid. Background Reverse osmosis seawater desalination is an important high-new technology for producing fresh water resources by utilizing seawater, and has been widely popularized and applied in global coastal areas. The technology belongs to a pressure-driven membrane separation process, wherein in the process, feed seawater is firstly boosted to 5.5-8.0MPa by a high-pressure pump and then enters a reverse osmosis membrane assembly to carry out salt/water separation, the desalinated water produced by the reverse osmosis membrane accounts for about 45% of the total feed water, and about 55% of the seawater is trapped and concentrated by the reverse osmosis membrane, the pressure is still higher than 5.0MPa, and if the high-pressure brine is directly discharged, the great waste of system energy can be caused. Therefore, the energy recovery device is adopted to efficiently recycle the pressure energy in the high-pressure brine, and becomes an important way for energy conservation, consumption reduction and green low-carbon development of the reverse osmosis sea water desalination system. The energy recovery device is used as one of key equipment of reverse osmosis sea water desalination technology and is mainly divided into two main categories of centrifugal type and positive displacement type according to the working principle. The centrifugal device is used as an early product, the energy recovery efficiency is 50-80%, and the positive displacement energy recovery device only needs to be converted by one step of pressure energy-pressure energy, and the energy recovery efficiency is up to more than 95%, so that the centrifugal device becomes a main stream product for research, development and market popularization and application at home and abroad. Valve-controlled energy recovery devices are typically representative of positive displacement energy recovery devices that generally consist of a brine-side fluid switch, a pressure exchange cylinder, and a seawater-side check valve block. The alternating operation of the pressurizing process and the pressure releasing process of the single-cylinder device is completed through the reciprocating switching of the fluid switcher and the passive response of the check valve group. The continuous and stable performance of the pressure exchange process of the system can be realized by parallel arrays of single-cylinder devices, such as double cylinders, three cylinders or more than three cylinders. The fluid switcher at the saline end is a core component of the device, and patent 201310005355.5 discloses a reciprocating self-sealing fluid switcher provided with a single pressure exchange cylinder, which mainly reduces the driving power and energy consumption of a valve core assembly by additionally arranging a pre-pressurizing valve plate and a pre-depressurizing valve plate outside a valve plate of a high pressure chamber and a valve plate of a low pressure chamber. The valve plate structure has the advantages that the valve plate structure is combined, the valve plate structure is sequentially linked in the opening or closing process of the valve plate structure, the structure is complex, small elements are easy to damage, the reliability of the reciprocating motion of the switch is reduced, the pressure difference resistance on two sides of the valve plate in the opening and closing process is not fundamentally eliminated although the pre-pressurizing valve plate and the pre-depressurizing valve plate are introduced on the outer side of the valve plate, the driving force is still larger in the switching process, and the cavity-separating structure design of the switch increases the flow state complexity in the fluid flow process, more dead end areas exist, the flow resistance loss is larger, and the energy recovery efficiency is reduced. Disclosure of Invention The invention designs a novel fluid switcher aiming at the technical problems of complex structure, lower valve plate reliability, higher driving power and energy consumption and the like of the fluid switcher in the existing valve-controlled energy recovery device, and develops a novel seawater desalination energy recovery tower and a typical parallel array form on the basis of the novel fluid switcher so as to solve the problems of complex structure, low reliability and the like of the original valve-controlled device. In order to solve the technical problems, the invention is realized by the following technical scheme: According to one aspect of the present invention, there is provided a fluid switch comprising a switch valve