A flow path reconfigurable membrane filtration system

Abstract

This application provides a reconfigurable flow path membrane filtration system, comprising a first main pipe, a second main pipe, a third main pipe, multiple membrane filtration modules, and a pipeline switching module. Each membrane filtration module includes a membrane assembly and first, second, and third branch pipes, and the membrane assembly can operate between a first filtration direction and a second filtration direction. The pipeline switching module includes a first switching module and a second switching module. The first switching module is located between the first main pipe and each of the first and second branch pipes, and the second switching module is located between the second main pipe and each of the first and second branch pipes. Each of the third branch pipes is connected to the third main pipe. By controlling the on / off state of the corresponding flow paths through the first and second switching modules, a single membrane filtration module can switch between two filtration directions, and multiple membrane filtration modules can be reconfigured between parallel, series, or hybrid modes. This application eliminates the rigid binding relationship between the membrane assembly and the main pipe in existing devices.

Description

Technical Field

[0001] This application relates to the field of membrane separation technology, and more specifically to a membrane filtration system with reconfigurable flow paths. Background Technology

[0002] Membrane filtration technology is widely used in water treatment, chemical separation, food processing, and other fields. In existing membrane filtration systems, the internal piping connections and the fluid inlet and outlet directions of each membrane module are fixed at the factory. Specifically, the feed end and concentrate outlet of each membrane module are permanently bound to the corresponding main pipe and cannot be changed during operation. This structural irreversibility fundamentally locks the system into a pre-set single operating mode.

[0003] Therefore, once deployed, existing systems struggle to dynamically adjust to real-time water quality fluctuations, changes in permeate demand, or the health status of the membrane module. Furthermore, the fixed flow direction of unidirectional filtration not only leads to long-term accumulation of pollutants at one end of the membrane but also further accelerates the directional degradation of membrane performance. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this application provides a membrane filtration system with reconfigurable flow path, comprising:

[0005] First Chief Steward, Second Chief Steward, and Third Chief Steward; Multiple membrane filtration modules are provided, each of which includes a membrane assembly, a first branch pipe, a second branch pipe, and a third branch pipe. The membrane assembly is configured to operate in a first filtration direction or a second filtration direction. In the first filtration direction, the liquid to be filtered enters through the first branch pipe and the concentrate is discharged through the second branch pipe. In the second filtration direction, the liquid to be filtered enters through the second branch pipe and the concentrate is discharged through the first branch pipe. The permeate is discharged through the third branch pipe. The pipeline switching module includes a first switching module and a second switching module. The first switching module is disposed between the first main pipe and the first branch pipe and the second branch pipe of each membrane filtration module. The second switching module is disposed between the second main pipe and the first branch pipe and the second branch pipe of each membrane filtration module. The third branch pipe of each membrane filtration module is connected to the third main pipe. The first switching module is configured to control the flow path connection and disconnection between the first main pipe and each of the first branch pipes and each of the second branch pipes, and the second switching module is configured to control the flow path connection and disconnection between the second main pipe and each of the first branch pipes and each of the second branch pipes, so that at least one of the membrane filtration modules can switch between the first filtration direction and the second filtration direction, and that multiple membrane filtration modules can operate in parallel mode, series mode, or a hybrid mode consisting of the parallel mode and the series mode.

[0006] In one embodiment, the first switching module includes a plurality of first branch switches and a plurality of second branch switches. Each first branch of the membrane filtration module is provided with a first branch switch between its first branch and the first main pipe, and each second branch of the membrane filtration module is provided with a second branch switch between its second branch and the first main pipe. The second switching module includes multiple third branch switches and multiple fourth branch switches. Each membrane filtration module has a third branch switch between its first branch and the second main pipe, and each membrane filtration module has a fourth branch switch between its second branch and the second main pipe. The pipeline switching module is configured to switch the membrane filtration module between the first filtration direction and the second filtration direction by switching the on / off state of the first branch switch, the fourth branch switch and the second branch switch and the third branch switch corresponding to the same membrane filtration module.

[0007] In one embodiment, a first main pipe switch is provided between the first main pipe and the common flow path of all the first branch pipe switches, and a second main pipe switch is provided between the first main pipe and the common flow path of all the second branch pipe switches. A third main pipe switch is provided between the second main pipe and the common flow path of all the third branch pipe switches, and a fourth main pipe switch is provided between the second main pipe and the common flow path of all the fourth branch pipe switches.

[0008] In one embodiment, the system further includes a control unit, which is communicatively connected to the first switching module and the second switching module, and the control unit is configured to: Identify the current water usage scenario; When a low-demand scenario is identified, the first switching module and the second switching module are controlled to enable the multiple membrane filtration modules to operate in parallel mode and the system to operate at a first recovery rate. When a high-demand scenario is identified, the first switching module and the second switching module are controlled to make the multiple membrane filtration modules operate in series or in a hybrid mode, and the system operates at a second recovery rate, wherein the second recovery rate is greater than the first recovery rate.

[0009] In one embodiment, the system further includes a sensor module configured to acquire system-level operating parameters and / or membrane module-level health status parameters to monitor the overall filtration effect of the membrane filtration system and / or the health of each membrane filtration module. The control unit is communicatively connected to the sensor module, and the control unit is also configured to adjust the operating mode and / or flushing strategy of each membrane filtration module based on the overall filtration effect of the system and the health of the membrane filtration module.

[0010] In one embodiment, the sensor module includes a system monitoring unit and a membrane module monitoring unit; at least one of the first main pipe, the second main pipe and the third main pipe is equipped with the system monitoring unit, and each membrane filtration module is equipped with the membrane module monitoring unit; The control unit is configured to: receive system-level operating parameters acquired by the system monitoring unit, calculate the system recovery rate based on the system-level operating parameters, and compare it with a benchmark threshold to evaluate the overall filtration effect of the system; the control unit is also configured to: receive membrane-level operating parameters acquired by each membrane module monitoring unit, and evaluate the health of each membrane filtration module based on the membrane-level operating parameters.

[0011] In one embodiment, the system monitoring unit includes a main pipe flow sensor and a main pipe pressure sensor; the membrane module-level monitoring unit includes a membrane module pressure sensor for detecting transmembrane pressure difference and / or a permeate flow sensor disposed in the third branch pipe.

[0012] In one embodiment, the control unit is configured to: When the system is running in parallel mode, the real-time health status of each membrane filtration module is obtained, and the membrane filtration modules required for the current parallel connection are selected in descending order of health status to participate in filtration. When the system is running in series mode, the real-time health status of each membrane filtration module is obtained, and the membrane filtration modules required for the current series connection are selected in descending order of health status. The modules are then configured sequentially from the first stage to the last stage in the series connection, so that the health status of each membrane module decreases along the direction of the feed liquid flow.

[0013] In one embodiment, the control unit is configured to: When the health of a membrane filtration module is lower than a first preset threshold but higher than a second preset threshold, the first switching module and the second switching module are controlled to switch the filtration direction of the membrane filtration module. When the health of a certain membrane filtration module is lower than the second preset threshold, the membrane filtration module is identified as a module to be flushed, and the remaining membrane filtration modules are identified as modules that do not need to be flushed. The first switching module and the second switching module are controlled to shut off the flow path of the modules that do not need to be flushed, so that the flushing liquid flows through the first main pipe or the second main pipe to the module to be flushed; the second preset threshold is lower than the first preset threshold.

[0014] In one embodiment, when there are multiple modules to be rinsed, the control unit is configured to selectively perform the following operations: The first switching module and the second switching module are controlled to simultaneously open the flow paths of multiple modules to be rinsed and close the flow paths of modules that do not need to be rinsed, so as to synchronously rinse multiple modules to be rinsed. Alternatively, the first switching module and the second switching module can be controlled to sequentially turn on the flow paths of each module to be rinsed and turn off the flow paths of modules that do not need to be rinsed, so that the rinsing of the current module to be rinsed is completed before switching to the next module to be rinsed, and rinsing is performed sequentially.

[0015] This application has at least the following beneficial effects: Once existing membrane filtration devices leave the factory, their internal pipeline connection methods and fluid inlet and outlet directions for each membrane module are fixed. The feed end and concentrate outlet of each membrane module are permanently bound to the corresponding main pipe. As a result, the system is locked in a single operating mode and cannot be dynamically adjusted according to water quality fluctuations, changes in water production demand, or the actual state of the membrane module. Furthermore, the directional enrichment of pollutants caused by unidirectional filtration will accelerate the degradation of membrane performance.

[0016] The reconfigurable membrane filtration system provided in this application, by setting a first switching module to connect a first main pipe to the first and second branch pipes of each membrane filtration module, and setting a second switching module to connect a second main pipe to the first and second branch pipes of each membrane filtration module, decouples the rigid binding relationship between the membrane module and the main pipe. At the level of a single membrane filtration module, the dual switching modules can be used to switch between the first and second filtration directions; at the level of multiple membrane filtration modules, the dual switching modules can be used to reconfigure between parallel mode, series mode, and a hybrid mode consisting of both.

[0017] This application breaks through the inherent limitation of irreversible flow between the feed end and concentrate discharge end in traditional systems, enabling the same device to dynamically adjust its internal flow path topology based on real-time water quality fluctuations, changes in permeate demand, or membrane health status. When the system operates in parallel mode, it achieves high-flux, low-energy filtration, obtaining stable, high-quality permeate. When operating in series mode (facing water quality fluctuations or peak water demand), it significantly improves the overall system recovery rate, ensuring water yield and permeate volume. The hybrid mode balances parallel processing capacity with high recovery rate requirements, enhancing the system's adaptability to complex and variable operating conditions. Simultaneously, by purposefully switching the filtration direction of individual membrane filtration modules, the fluid inlet and outlet areas within the membrane module can be periodically rotated, effectively preventing long-term directional accumulation of pollutants at one end of the membrane, resulting in a more balanced membrane load, delaying directional degradation of membrane performance, thereby extending the effective service life of the membrane module and reducing maintenance costs. In summary, this invention achieves real-time, on-demand reconfiguration of the flow path within the same device through the coordinated operation of a modular structure and dual switching modules, thus optimizing water quality, water yield, and energy consumption under different demand scenarios. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of a flow path reconfigurable membrane filtration system provided in this embodiment; Figure 2 This is a schematic diagram of a flow path reconfigurable membrane filtration system provided in this embodiment; Figure 3 This is a schematic diagram of a flow path reconfigurable membrane filtration system operating in parallel mode, as provided in this embodiment. Figure 4 This is a schematic diagram of a flow path reconfigurable membrane filtration system operating in series mode, as provided in this embodiment. Figure 5 This is a schematic diagram of a flow path reconfigurable membrane filtration system operating in a hybrid mode, as provided in this embodiment.

[0020] Figure label: 10-Membrane filtration module; 11-Membrane module; 20-Pipeline switching module; 21-First switching module; 22-Second switching module; 30-Sensor module; 31-System monitoring unit; 32-Membrane module monitoring unit; 40-Control unit; A - First branch pipe; B - Second branch pipe; C - Third branch pipe; L1 - First main pipe; L2 - Second main pipe; L3 - Third main pipe; L4 - First common flow path; L5 - Second common flow path; L6 - Third common flow path; L7 - Fourth common flow path; S1 - First branch switch; S2 - Second branch switch; S3 - Third branch switch; S4 - Fourth branch switch; G1 - First main switch; G2 - Second main switch; G3 - Third main switch; G4 - Fourth main switch; M1 - First membrane filtration module; M2 - Second membrane filtration module; M3 - Third membrane filtration module. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] In the description of this application, it should be noted that the terms "vertical", "up", "down", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] like Figure 1 and Figure 2 As shown, this application provides a membrane filtration system with reconfigurable flow path, including a first main pipe L1, a second main pipe L2, a third main pipe L3, multiple membrane filtration modules 10, a pipeline switching module 20, and a control unit 40.

[0025] Each membrane filtration module 10 includes a membrane assembly 11, and a first branch pipe A, a second branch pipe B, and a third branch pipe C connected to the membrane assembly 11. The membrane assembly 11 internally encapsulates a membrane element, which can be an ultrafiltration membrane, a nanofiltration membrane, or a reverse osmosis membrane, etc. The membrane assembly 11 is configured to operate in two filtration directions.

[0026] When operating in the first filtration direction, the liquid to be filtered enters the membrane module 11 through the first branch pipe A. Under pressure, a portion of the liquid permeates through the membrane element, becoming the permeate, and is discharged through the third branch pipe C; the remaining portion is retained and concentrated, and discharged as the concentrate through the second branch pipe B. When operating in the second filtration direction, the liquid to be filtered enters the membrane module 11 through the second branch pipe B, the concentrate is discharged through the first branch pipe A, and the permeate is still discharged through the third branch pipe C. In both filtration directions, the flow direction of the fluid within the membrane module is opposite, enabling alternating flushing of contaminants in different areas of the membrane surface.

[0027] See Figure 2 The pipeline switching module 20 includes a first switching module 21 and a second switching module 22. The control unit 40 is communicatively connected to the first switching module 21 and the second switching module 22. The first switching module 21 is located between the first main pipe L1 and the first branch pipe A and the second branch pipe B of each membrane filter module 10. The second switching module 22 is located between the second main pipe L2 and the first branch pipe A and the second branch pipe B of each membrane filter module 10. The third branch pipe C of each membrane filter module 10 is directly connected to the third main pipe L3 or connected via a valve.

[0028] Once existing membrane filtration devices leave the factory, their internal pipeline connection methods and fluid inlet and outlet directions for each membrane module are fixed. The feed end and concentrate outlet of each membrane module are permanently bound to the corresponding main pipe. As a result, the system is locked in a single operating mode and cannot be dynamically adjusted according to water quality fluctuations, changes in water production demand, or the actual state of the membrane module. Furthermore, the directional enrichment of pollutants caused by unidirectional filtration will accelerate the degradation of membrane performance.

[0029] The flow path reconfigurable membrane filtration system provided in this embodiment, by setting a first switching module to connect the first main pipe to the first and second branch pipes of each membrane filtration module, and setting a second switching module to connect the second main pipe to the first and second branch pipes of each membrane filtration module, decouples the rigid binding relationship between the membrane module and the main pipe. At the level of a single membrane filtration module, the dual switching modules can be used to switch between the first filtration direction and the second filtration direction; at the level of multiple membrane filtration modules, the dual switching modules can be used to reconfigure between parallel mode, series mode, and a hybrid mode composed of both.

[0030] This embodiment breaks through the inherent limitation of irreversible flow between the feed end and concentrate discharge end in traditional systems, enabling the same device to dynamically adjust its internal flow path topology based on real-time water quality fluctuations, changes in permeate demand, or membrane health status. When the system operates in parallel mode, it achieves high-flux, low-energy filtration, obtaining stable, high-quality permeate. When operating in series mode (facing water quality fluctuations or peak water demand), it significantly improves the overall system recovery rate, ensuring water yield and permeate volume. The hybrid mode balances parallel processing capacity with high recovery rate requirements, enhancing the system's adaptability to complex and variable operating conditions. Simultaneously, by purposefully switching the filtration direction of individual membrane filtration modules, the fluid inlet and outlet areas within the membrane module can be periodically rotated, effectively preventing long-term directional accumulation of pollutants at one end of the membrane, resulting in a more balanced membrane load, delaying directional degradation of membrane performance, thereby extending the effective service life of the membrane module and reducing maintenance costs. In summary, this invention achieves real-time, on-demand reconfiguration of the flow path within the same device through the coordinated operation of a modular structure and dual switching modules, thus optimizing water quality, water yield, and energy consumption under different demand scenarios.

[0031] See Figure 1 and Figure 2 In one embodiment, the first switching module 21 includes a plurality of first branch switches S1 and a plurality of second branch switches S2. Each membrane filter module 10 has a first branch switch S1 between its first branch A and its first main pipe L1; and each membrane filter module 10 has a second branch switch S2 between its second branch B and its first main pipe L1.

[0032] The second switching module 22 includes multiple third branch switches S3 and multiple fourth branch switches S4. Each membrane filtration module 10 has a third branch switch S3 between its first branch A and its second main pipe L2; and each membrane filtration module 10 has a fourth branch switch S4 between its second branch B and its second main pipe L2.

[0033] During operation, the control unit 40 can control the pipeline switching module 20 (i.e., control the first switching module 21 and the second switching module 22) to switch at least one membrane filtration module 10 between the first filtration direction and the second filtration direction. The specific switching method is as follows: taking a certain membrane filtration module 10 as an example, when it is in the first filtration direction, its corresponding first branch switch S1 and fourth branch switch S4 are in the on state, and the second branch switch S2 and third branch switch S3 are in the off state. At this time, the liquid to be filtered enters the membrane group 11 from the first main pipe L1 through the first branch switch S1 and the first branch A, the concentrate is discharged from the second branch B through the fourth branch switch S4 into the second main pipe L2, and the permeate is discharged from the third branch C. When it is necessary to switch the membrane filtration module 10 from the first filtration direction to the second filtration direction, the corresponding first branch switch S1 and fourth branch switch S4 are turned off, and the corresponding second branch switch S2 and third branch switch S3 are turned on. At this time, the liquid to be filtered enters the second branch B of the membrane filtration module 10 from the first main pipe L1 through the second branch switch S2, the concentrate is discharged from the first branch pipe A through the third branch switch S3 into the second main pipe L2, and the permeate is still discharged from the third branch pipe C, thus completing the flow direction switch. Conversely, when it is necessary to switch back from the second filtration direction to the first filtration direction, the second branch switch S2 and third branch switch S3 are turned off, and the first branch switch S1 and fourth branch switch S4 are turned on.

[0034] See Figure 1 and Figure 2 In one embodiment, the first main pipe L1 is connected to the first branch pipe A of each membrane filtration module through a first common flow path L4. The first common flow path L4 is provided with a first main pipe switch G1 to control the on / off state of the first common flow path L4 and the first main pipe L1. The first main pipe L1 is connected to the second branch pipe B of each membrane filtration module through a second common flow path L5. The second common flow path L5 is provided with a second main pipe switch G2 to control the on / off state of the second common flow path L5 and the first main pipe L1.

[0035] The second main pipe L2 is connected to the first branch pipe A of each membrane filtration module through a third common flow path L6. The third common flow path L6 is equipped with a third main pipe switch G3, which is used to control the on / off state of the third common flow path L6 and the second main pipe L2. The second main pipe L2 is connected to the second branch pipe B of each membrane filtration module through a fourth common flow path L7. The fourth common flow path L7 is equipped with a fourth main pipe switch G4, which is used to control the on / off state of the fourth common flow path L7 and the second main pipe L2.

[0036] The aforementioned first main pipe switch G1, second main pipe switch G2, third main pipe switch G3, and fourth main pipe switch G4 provide main pipe-level isolation capabilities on the basis of normal system feeding and discharging. By selectively shutting off the corresponding main pipe switch, the first main pipe L1 or the second main pipe L2 can be isolated from a specific common flow path, allowing the relevant pipe sections to be used as normal feeding or discharging channels in parallel mode, and converted into interstage closed connection channels in series mode, realizing the directional transfer of the concentrate from the previous stage to the feed end of the next stage, thereby providing a more thorough main pipe-level isolation and control node for flow path reconfiguration.

[0037] Specifically, each of the above switches can be an electrically controlled valve or a pneumatic valve, and is uniformly controlled by the control unit 40.

[0038] Based on the structure of the pipeline switching module 20 described above, the control unit 40 can control the on / off state of each switch in the first switching module 21 and the second switching module 22 to enable multiple membrane filtration modules 10 to operate in parallel mode, series mode, or mixed mode, as follows: See Figure 3 Taking two membrane filtration modules 10 as an example, parallel operation is implemented. However, in practical applications, the appropriate number of membrane filtration modules 10 can be selected for parallel operation according to the filtration requirements of the current water usage scenario, and is not limited to this. These two membrane filtration modules 10 are denoted as the first membrane filtration module M1 and the second membrane filtration module M2. The first main pipe switch G1 and the fourth main pipe switch G4 are turned on, and the second main pipe switch G2 and the third main pipe switch G3 are turned off. The first branch pipe switch S1 and the fourth branch pipe switch S4 of the first membrane filtration module M1 are turned on, and the second branch pipe switch S2 and the third branch pipe switch S3 are turned off; the first branch pipe switch S1 and the fourth branch pipe switch S4 of the second membrane filtration module M2 are turned on, and the second branch pipe switch S2 and the third branch pipe switch S3 are turned off. At this time, the first membrane filtration module M1 and the second membrane filtration module M2 are both operating in parallel in the first filtration direction: the liquid to be filtered enters the first branch pipe A of each membrane filtration module through the first main pipe L1, the first main pipe switch G1, the first common flow path L4 between the first main pipe switch G1 and each first branch pipe switch S1, and each first branch pipe switch S1; the concentrate enters the second main pipe L2 through each second branch pipe B, the fourth common flow path L7 between each fourth branch pipe switch S4 and the fourth main pipe switch G4, and the fourth main pipe switch G4; and the permeate is sent into the third main pipe L3 through each third branch pipe C.

[0039] When the system provided in this application is in parallel mode, the liquid to be filtered is simultaneously distributed to each membrane filtration module 10 for independent processing. The processing load of each module is relatively balanced, the system has high water flux and low operating energy consumption, and can stably produce high-quality permeate at a low operating cost. It is suitable for nighttime or low demand periods.

[0040] See Figure 4 Taking the first membrane filtration module M1 and the second membrane filtration module M2 as an example, the series operation is implemented. However, in actual applications, the appropriate number of membrane filtration modules 10 can be selected for series operation according to the filtration requirements of the current water use scenario, and it is not limited to this. The first main pipe switch G1 and the third main pipe switch G3 are turned on, and the second main pipe switch G2 and the fourth main pipe switch G4 are turned off.

[0041] The switching states of the first membrane filter module M1 are as follows: the first branch switch S1 is on, and the third branch switch S3 is off; of the second branch switch S2 and the fourth branch switch S4, one is on and the other is off. The switching states of the second membrane filter module M2 are as follows: the first branch switch S1 is off, and the third branch switch S3 is on; the on / off state of the second branch switch S2 of the second membrane filter module M2 is the same as that of the second branch switch S2 of the first membrane filter module M1; the on / off state of the fourth branch switch S4 of the second membrane filter module M2 is the same as that of the fourth branch switch S4 of the first membrane filter module M1.

[0042] The following describes the interstage flow paths under two different on / off combinations: Combination 1: See Figure 4 The second branch switch S2 of the first membrane filtration module M1 is turned on, and the fourth branch switch S4 is turned off. Correspondingly, the second branch switch S2 of the second membrane filtration module M2 is turned on, and the fourth branch switch S4 is turned off. The liquid to be filtered enters the first branch A of the first membrane filtration module M1 via the first main pipe L1, the first main pipe switch G1, the first common flow path L4 between the first main pipe switch G1 and each of the first branch switches S1, and the first branch switch S1 of the first membrane filtration module M1. The first membrane filtration module M1 operates in the first filtration direction. The permeate is sent from the third branch C into the third main pipe L3, and the concentrate is output from the second branch B via the second branch switch S2. Because the second main pipe switch G2 is turned off, the concentrate does not enter the first main pipe L1, but instead flows along the second common flow path L5 between the second main pipe switch G2 and each of the second branch switches S2, and enters the second branch B of the second membrane filtration module M2 via the second branch switch S2. The second membrane filtration module M2 operates in the second filtration direction. The secondary permeate is sent from the third branch pipe C into the third main pipe L3. The secondary concentrate is discharged from the first branch pipe A through the third branch pipe switch S3, the third common flow path L6 between each third branch pipe switch S3 and the second main pipe switch G2, and the third main pipe switch G3 into the second main pipe L2.

[0043] Combination 2: The fourth branch switch S4 of the first membrane filter module M1 is turned on, and the second branch switch S2 is turned off. Correspondingly, the fourth branch switch S4 of the second membrane filter module M2 is turned on, and the second branch switch S2 is turned off.

[0044] The liquid to be filtered enters the first branch pipe A of the first membrane filtration module M1 via the first main pipe L1, the first main pipe switch G1, the first common flow path L4 between the first main pipe switch G1 and each of the first branch pipe switches S1, and the first branch pipe switch S1. The first membrane filtration module M1 operates in the first filtration direction. The permeate is sent from the third branch pipe C into the third main pipe L3, and the concentrate is output from the second branch pipe B via the fourth branch pipe switch S4. Because the fourth main pipe switch G4 is closed, the concentrate cannot enter the second main pipe L2, but instead enters the second branch pipe B of the second membrane filtration module M2 via the fourth common flow path L7 between the fourth main pipe switch G4 and each of the fourth branch pipe switches S4, and the fourth branch pipe switch S4. The second membrane filtration module M2 operates in the second filtration direction. The secondary permeate is sent from the third branch pipe C into the third main pipe L3. The secondary concentrate is discharged from the first branch pipe A through the third branch pipe switch S3, the third common flow path L6 between each third branch pipe switch S3 and the second main pipe switch G2, and the third main pipe switch G3 into the second main pipe L2.

[0045] In both of the above combinations, the interstage concentrate is output through the branch switch of the pre-stage membrane filtration module, and then introduced into the second branch B of the post-stage membrane filtration module through the closed channel formed by the corresponding closed main switch, thus completing two-stage series filtration.

[0046] When the system operates in series mode, the concentrate from the upstream membrane filtration module is used as the feed for the downstream membrane filtration module for secondary filtration, which allows for more complete extraction of recyclable components in the filtrate. The overall recovery rate of the system can be significantly increased from about 50% in parallel mode to 70%-80%. It can effectively ensure the water yield and production of the system during periods of fluctuating influent water quality or peak water usage during the day.

[0047] See Figure 5 Taking three membrane filtration modules 10 as an example, a mixed-mode operation is achieved. However, in practical applications, the appropriate number of membrane filtration modules 10 can be selected for mixed operation according to the filtration requirements of the current water usage scenario, and is not limited to this. These three membrane filtration modules 10 are denoted as the first membrane filtration module M1, the second membrane filtration module M2, and the third membrane filtration module M3. The first membrane filtration module M1 and the second membrane filtration module M2 are connected in parallel to form the first-stage filtration unit, and the third membrane filtration module M3 serves as the second-stage filtration unit. The two stages are connected in series to form a mixed-mode operation.

[0048] Specifically, the first main pipe switch G1 and the third main pipe switch G3 are on, while the second main pipe switch G2 and the fourth main pipe switch G4 are off. In the first-stage filtration unit, the first membrane filtration module M1 and the second membrane filtration module M2 operate in parallel in the first filtration direction. Their switching states are as follows: the first branch pipe switch S1 and the second branch pipe switch S2 of the first membrane filtration module M1 are on, while the third branch pipe switch S3 and the fourth branch pipe switch S4 are off; the first branch pipe switch S1 and the second branch pipe switch S2 of the second membrane filtration module M2 are on, while the third branch pipe switch S3 and the fourth branch pipe switch S4 are off. The liquid to be filtered enters the first branch pipe A of the first membrane filtration module M1 and the second membrane filtration module M2 from the first main pipe L1 through the first main pipe switch G1 and the first common flow path L4 between the first main pipe switch G1 and each first branch pipe switch S1. After filtration by the membrane module, the permeate is sent into the third main pipe L3 from each third branch pipe C. The concentrates from the first membrane filtration module M1 and the second membrane filtration module M2 are discharged from their respective second branch pipes B, and then converge through their respective second branch pipe switches S2 into the second common flow path L5 between the second main pipe switch G2 and each of the second branch pipe switches S2. Because the second main pipe switch G2 is closed, the converged concentrate does not enter the first main pipe L1, but is located in the second common flow path L5, serving as the feed for the second-stage filtration unit.

[0049] The second-stage filtration unit operates independently of the third membrane filtration module M3 in the second filtration direction. Its switching state is as follows: the first branch switch S1 and the fourth branch switch S4 of the third membrane filtration module M3 are closed, while the second branch switch S2 and the third branch switch S3 are open. The concentrated liquid after the first stage filtration flows along the second common flow path L5 between the second main switch G2 and each second branch switch S2, and enters the second branch B of the third membrane filtration module M3 through the second branch switch S2. It undergoes a second filtration within the membrane module. The secondary concentrated liquid flows from the first branch A of the third membrane filtration module M3 through the third branch switch S3, the third common flow path L6 between each third branch switch S3 and the second main switch G2, and the third main switch G3 into the second main pipe L2. The permeate is sent from the third branch C of the third membrane filtration module M3 into the third main pipe L3.

[0050] In another embodiment, the hybrid mode may also be a first stage consisting of two or more membrane filtration modules connected in parallel, a second stage consisting of multiple membrane filtration modules connected in parallel, or a series-parallel combination of more than one stage. Its switching control logic is similar to the above example and will not be repeated here.

[0051] This system operates in a hybrid mode, organically combining parallel and series connections. This allows for the efficient processing of large volumes of filtrate using the high throughput and low energy consumption advantages of parallel mode, while leveraging the advantages of multiple filtrations in series mode to improve the overall system recovery rate. By balancing parallel processing capabilities with high recovery rate requirements, the system can more flexibly balance the relationship between product water quality, yield, and energy consumption when facing conditions with large fluctuations in water quality and complex changes in product water demand, thus enhancing its adaptability to complex and variable operating conditions.

[0052] In one embodiment, the system further includes a sensor module 30, which is configured to acquire system-level operating parameters and / or membrane module-level health status parameters to monitor the overall filtration effect of the membrane filtration system and / or the health of each membrane filtration module 10. A control unit 40 is communicatively connected to the sensor module 30 and is configured to adjust the operating mode and / or flushing strategy of each membrane filtration module 10 based on the overall filtration effect and the health of each membrane filtration module 10.

[0053] In one embodiment, the sensor module 30 includes a system monitoring unit 31 and a membrane module monitoring unit 32. The first main pipe L1, the second main pipe L2, and the third main pipe L3 are all equipped with a system monitoring unit 31. Each system monitoring unit 31 includes at least a main pipe flow sensor and a main pipe pressure sensor, and may optionally be equipped with a turbidimeter, conductivity meter, or other water quality sensors. Specifically, the first main pipe L1 is equipped with a first main pipe flow sensor and a first main pipe pressure sensor to acquire the feed flow rate and feed pressure of the first main pipe L1, respectively; the second main pipe L2 is equipped with a second main pipe flow sensor and a second main pipe pressure sensor to acquire the concentrate flow rate and concentrate pressure of the second main pipe L2, respectively; and the third main pipe L3 is equipped with a third main pipe flow sensor and a third main pipe pressure sensor to acquire the permeate flow rate and permeate pressure of the third main pipe L3, respectively.

[0054] Each membrane filtration module 10 is equipped with a membrane module monitoring unit 32. The membrane module monitoring unit 32 includes at least a pressure sensor group for detecting the transmembrane pressure difference and / or a permeate flow sensor located on the third branch C. Specifically, each membrane filtration module 10 has a feed-side pressure sensor on the first branch A or the second branch B, and a permeate-side pressure sensor and / or a permeate branch flow sensor on the third branch C. The transmembrane pressure difference of the membrane filtration module 10 is obtained by the difference between the feed-side pressure and the permeate-side pressure.

[0055] Based on the sensor module 30 described above, the membrane filtration system of this embodiment performs the following monitoring and control methods.

[0056] During system operation, the control unit 40 receives system-level operating parameters acquired by the system monitoring unit 31, including the feed flow rate of the first main pipe L1 acquired by the first flow sensor, the concentrate flow rate of the second main pipe L2 acquired by the second flow sensor, the permeate flow rate of the third main pipe L3 acquired by the third flow sensor, and the pressure data of each main pipe acquired by the first, second, and third pressure sensors, respectively. The control unit 40 calculates the system recovery rate and transmembrane pressure difference based on these parameters. The system recovery rate is the permeate flow rate divided by the feed flow rate multiplied by 100%, and the transmembrane pressure difference is the average of the feed-side pressure and the concentrate-side pressure minus the permeate-side pressure. The control unit 40 compares the calculated system recovery rate and transmembrane pressure difference with benchmark thresholds to assess whether the overall filtration effect of the system meets expectations. When the system recovery rate deviates from the preset range or the transmembrane pressure difference abnormally increases, the control unit 40 adjusts the operating mode or triggers an alarm accordingly. For example, when the system recovery rate is consistently below the lower limit of the benchmark, it indicates that there may be fouling or sealing leakage in the membrane module. The control unit 40 can switch the current parallel mode to the series mode to improve the recovery rate, or trigger the flushing operation of the relevant membrane filtration module. When the transmembrane pressure difference rises to the upper limit of the benchmark, it indicates that the membrane fouling is aggravated. The control unit 40 can trigger the cleaning procedure of the module to be flushed.

[0057] Simultaneously, the control unit 40 receives membrane-level operating parameters acquired by each membrane module monitoring unit 32, and evaluates the membrane health of each membrane filtration module 10 based on these parameters. In one embodiment, the membrane-level operating parameters include the transmembrane pressure difference measured by the feed-side pressure sensor and the permeate-side pressure sensor of each membrane filtration module 10, and the permeate flow rate measured by the permeate branch flow sensor. The assessment of membrane health is based on standardized permeate, which is defined as the ratio of the permeate flux to the transmembrane pressure difference at a standard temperature. Specifically, the assessment method is as follows: the standardized permeate measured under standard operating conditions at the initial stage of production or after the most recent cleaning of each membrane filtration module 10 is obtained as the initial standardized permeate of that membrane filtration module 10; during system operation, the current standardized permeate of that membrane filtration module 10 is acquired in real time or periodically; and the ratio of the current standardized permeate to the initial standardized permeate is calculated as the membrane health of that membrane filtration module 10.

[0058] This embodiment establishes a two-tiered monitoring system—"system-level—membrane-level"—by deploying monitoring units at both the system mains level and the individual membrane filtration module level. The mains flow and pressure data acquired by the system monitoring unit 31 can be used to calculate the overall system recovery rate and transmembrane pressure difference in real time, providing a macroscopic assessment of whether the system's filtration effect meets expectations and offering a basis for switching operating modes. The transmembrane pressure difference and permeate flow data acquired by the membrane module monitoring unit 32 can be used to calculate the standardized permeate rate and membrane health of each module, accurately locating membrane filtration modules with performance degradation at the microscopic level, providing data support for subsequent flow direction switching, flushing operations, and dynamic adjustments to the module usage sequence. This two-tiered monitoring system works in tandem, enabling the system to simultaneously grasp the overall operating status and the differences in the health of each membrane module, thereby achieving more precise and efficient operational control.

[0059] In one embodiment, the control unit 40 dynamically adjusts the usage order of each membrane filtration module 10 in parallel, series, and hybrid modes based on the membrane health of each module, so as to ensure that the performance of each membrane filtration module 10 decays evenly and extends the overall service life of the system. The specific adjustment strategy is as follows: When the system operates in parallel mode, the control unit 40 acquires the real-time membrane health status of each membrane filtration module 10 and sorts them in descending order of value, prioritizing the use of membrane filtration modules 10 with higher membrane health status for filtration. When there is redundancy in the number of membrane filtration modules 10 participating in parallel operation, membrane filtration modules 10 with membrane health status below a first preset threshold (e.g., below 40%) are deactivated and await subsequent operations, while the remaining membrane filtration modules 10 with the required health status take over the filtration load.

[0060] When the system operates in series, the control unit 40 acquires the real-time membrane health status of each membrane filtration module 10 and sorts them in descending order of value. The membrane filtration module 10 with the highest membrane health status is placed in the first stage of the series, the membrane filtration module 10 with the second highest membrane health status is placed in the second stage, and so on, so that the membrane health status of each filtration unit decreases along the feed flow direction, ensuring that the upstream membrane filtration module 10 has a high anti-fouling capability and that the downstream membrane filtration module 10 operates under relatively mild operating conditions. Membrane filtration modules 10 with a membrane health status below a first preset threshold (e.g., below 40%) are not involved in the series operation, are deactivated, and await subsequent operations.

[0061] When the system operates in hybrid mode, based on the above, the hybrid mode consists of K filter units connected in series to form a multi-stage filtration system, where K ≥ 2. At least one filter unit is formed by multiple membrane filter modules 10 connected in parallel, and the remaining filter units are formed by a single membrane filter module 10 or by multiple membrane filter modules 10 connected in parallel.

[0062] In this mode, the control unit 40 acquires the real-time membrane health status of each membrane filtration module 10 and sorts them in descending order of numerical value. The membrane filtration modules 10 with the highest membrane health status are configured in the first-stage filtration unit, the next highest in the second-stage filtration unit, and so on, ensuring that the average membrane health status of the membrane filtration modules 10 configured in each filtration unit decreases along the feed flow direction. Membrane filtration modules 10 with a membrane health status below a first preset threshold (e.g., membrane health status below 40%) are not used in the mixing mode and are deactivated, awaiting subsequent operations.

[0063] During hybrid mode operation or after the end of an operating cycle, the control unit 40 re-acquires the real-time membrane health status of each membrane filtration module 10, re-sorts them in descending order, and redistributes each membrane filtration module 10 to each level of filtration unit according to the above strategy. Since the allocation of membrane filtration modules 10 to each level of filtration unit is always based on the latest real-time membrane health status ranking result, the membrane health status of the upstream membrane filtration module 10 in the allocation result is always no lower than that of the downstream membrane filtration module 10, thereby making the cumulative pollution load borne by each membrane filtration module 10 tend to be balanced throughout its entire life cycle.

[0064] This embodiment uses dynamic sorting and allocation based on real-time membrane module health, ensuring that the operating order of each membrane filtration module 10 always matches its current real-time health status. Modules with higher health are configured in the upstream stage with higher pollution loads, while modules with lower health are configured in the downstream stage with relatively mild operating conditions or are deactivated. This avoids the problem in traditional fixed rotation methods where modules with lower health are moved to the upstream stage, leading to a decrease in overall filtration efficiency. Through real-time sorting and dynamic allocation, the cumulative pollution load borne by each module throughout its entire life cycle is dynamically matched with its own health status, promoting a more uniform decline in the performance of each module. This prevents individual modules from failing prematurely due to long-term overload operation, thereby extending the overall service life of the system and reducing maintenance frequency and replacement costs.

[0065] In one embodiment, for a membrane filtration module 10 that is shut down due to its membrane health being lower than a preset threshold, the control unit 40 adjusts the flushing strategy of each membrane filtration module according to the degree of health decay and historical operation records, specifically by performing a water flow direction switching operation or a flushing operation as appropriate.

[0066] In one embodiment, when the control unit 40 determines that the membrane module health is below a first preset threshold (e.g., membrane module health is below 40%) but above a second preset threshold (e.g., membrane module health is below 30%), it performs a water flow direction switching operation. The second preset threshold is lower than the first preset threshold. The specific switching method is as described above and will not be repeated here. After the switching is completed, the membrane filtration module 10 restarts operation in the opposite filtration direction. The fluid inlet and outlet areas inside the membrane module are switched, and the original concentrate outlet becomes the feed outlet. This causes the contaminants accumulated at the original end to be flushed in reverse, thereby delaying the degradation of membrane performance without interrupting system operation.

[0067] When the membrane module health level further declines below the second preset threshold, or when the health level fails to recover to above the first preset threshold after a preset number of water flow direction switching operations, the control unit 40 determines that a flushing operation needs to be performed on the membrane filtration module 10. Membrane filtration modules 10 with a membrane module health level below the second preset threshold are identified as modules to be flushed, while the remaining membrane filtration modules 10 are identified as modules that do not require flushing.

[0068] After the current filtration task is completed, the rinsing liquid is introduced through the first main pipe L1 or the second main pipe L2. The rinsing liquid is clean water or chemical cleaning liquid. The control unit 40 controls the first switching module 21 and the second switching module 22 to turn off the branch pipe switch corresponding to the module that does not need to be rinsed, so that the rinsing liquid flows through one or several modules to be rinsed in a concentrated manner, and the waste liquid is discharged through the second main pipe L2 or the third main pipe L3.

[0069] Depending on the location of contamination in the module to be rinsed, either forward or reverse rinsing paths can be selected. For example, rinsing fluid can be introduced into the module to be rinsed in a second filtration direction, so that the force on the membrane surface is opposite to that during the original filtration, thereby improving the removal effect of contaminants.

[0070] When there is only one module to be rinsed, the control unit 40 controls the first switching module 21 and the second switching module 22 to shut off the feed paths of the remaining modules that do not need rinsing, allowing the rinsing fluid to flow through that module alone for centralized cleaning of a single membrane filtration module 10. When there are multiple modules to be rinsed, the control unit 40 can select one of the following methods according to the system configuration: If the rinsing fluid supply is sufficient and the system pipeline allows, the flow paths of multiple modules to be rinsed can be opened simultaneously, and the first switching module 21 and the second switching module 22 can be controlled to shut off the flow paths of the remaining modules that do not need rinsing, so that multiple modules to be rinsed can be cleaned synchronously and centrally; if the rinsing fluid supply is limited or the rinsing pressure needs to be guaranteed, a sequential cleaning method can be adopted, controlling the first switching module 21 and the second switching module 22 to sequentially open the flow path of one module to be rinsed and shut off the flow paths of all other modules, completing the cleaning of one module before switching to the next module to be rinsed, until all modules to be rinsed are cleaned.

[0071] After rinsing is completed, the control unit 40 re-acquires the real-time membrane health status of the membrane filtration module 10. If the health status recovers to above the first preset threshold, it is reinstated into the sequence of available membrane filtration modules 10 and assigned to the corresponding position for operation according to the descending order of real-time membrane health status; if the health status still has not recovered, it is deactivated and the rinsing operation is performed again or a maintenance prompt is issued.

[0072] This embodiment achieves a graded maintenance response strategy by setting graded thresholds for membrane module health. When membrane module health slightly deteriorates, the water flow direction is switched first. Without interrupting normal system operation, reverse flushing loosens and removes contaminants accumulated on the membrane surface, delaying membrane performance degradation. When health deteriorates further, a targeted flushing operation is triggered. By selectively shutting off the main and branch pipe switches, the flushing fluid is concentrated and flows through the modules to be flushed, resulting in stronger and more focused flushing force, avoiding the reduced cleaning effect caused by flushing fluid diversion in traditional whole-system flushing. Simultaneously, synchronous or sequential cleaning methods can be flexibly selected based on the number of modules to be flushed, ensuring both flushing effectiveness and efficiency.

[0073] In one embodiment, the membrane filtration method further includes identifying the current water usage scenario and switching the operating mode based on the identification result. The identification of the water usage scenario can be achieved through at least one of the following methods: Firstly, identification is based on time presets: the control unit 40 has a built-in time period division table, dividing each day into low-demand and high-demand periods. For example, 22:00 to 6:00 the next day is set as a low-demand period, and 6:00 to 22:00 is set as a high-demand period. The control unit 40 obtains the current time through its built-in clock and determines whether it is currently in a low-demand or high-demand period.

[0074] Secondly, identification is based on flow monitoring: the control unit 40 receives the feed flow data of the first main pipe L1 in the system monitoring unit 31 in real time. When the feed flow is continuously lower than the first flow threshold, it is identified as a low demand scenario; when the feed flow is continuously higher than the second flow threshold, it is identified as a high demand scenario.

[0075] Third, identification is based on human instructions: the control unit 40 receives scene switching instructions from external input and identifies the current water use scenario according to the instructions.

[0076] When a low-demand scenario is identified, the control unit 40 controls the first switching module 21 and the second switching module 22 to enable multiple membrane filtration modules 10 to operate in parallel mode, allowing the system to operate at a first recovery rate (for example, the first recovery rate is approximately 50%). At this time, each membrane filtration module 10 operates in the first filtration direction, resulting in high water flux, low energy consumption, and the maintenance of high-quality water production.

[0077] When a high-demand scenario is identified, the control unit 40 controls the first switching module 21 and the second switching module 22 to operate the multiple membrane filtration modules 10 in series or in a hybrid mode, enabling the system to operate at a second recovery rate (exemplarily, the second recovery rate is approximately 70%-80%), which is greater than the first recovery rate. The series or hybrid mode can significantly improve the system's water yield and production capacity, meeting peak water demand.

[0078] The system provided in this embodiment can automatically identify the current water demand intensity based on time, flow rate, or manual commands, and autonomously switch operating modes accordingly. In low-demand scenarios, it adopts a parallel mode to maintain high-quality water production with lower energy consumption, avoiding over-concentration and energy waste. In high-demand scenarios, it switches to a series or hybrid mode, significantly improving the system's recovery rate and water yield to meet peak water production demands. Through adaptive scenario switching, the system achieves a dynamic balance between water quality, water yield, and energy consumption without manual intervention.

[0079] In one embodiment, the first switching module 21 and the second switching module 22 are periodically controlled to switch the flow direction of the membrane filtration module 10. Specifically, the control unit 40 has a built-in timer that triggers the flow direction switching operation periodically according to a preset switching cycle. The preset switching cycle can be set according to the water quality and membrane module characteristics, for example, once every 30 minutes, every 2 hours, or every 8 hours. When the switching cycle is reached, the control unit 40 controls at least one membrane filtration module 10 to switch between the first filtration direction and the second filtration direction. During the switching, the flow direction switching can be performed synchronously on all membrane filtration modules 10, or the switching can be performed sequentially in batches and at different times to avoid large fluctuations in the system's water production during the switching process.

[0080] For example, taking a system containing three membrane filtration modules 10 as an example, the control unit 40 can be set to synchronously perform a flow direction switch for all membrane filtration modules 10 every 2 hours: the current on / off state of each membrane filtration module 10 is reversed, that is, the membrane filtration module 10 originally in the first filtration direction is switched to the second filtration direction, and the membrane filtration module 10 originally in the second filtration direction is switched to the first filtration direction. Alternatively, the control unit 40 can be set to perform a flow direction switch for one of the membrane filtration modules 10 every 40 minutes, and the three modules complete a rotation once every 2 hours to ensure that the system can still maintain a relatively stable water production during the switching period.

[0081] This embodiment periodically rotates the fluid inlet and outlet areas within each membrane filtration module 10, allowing different regions of the membrane surface to alternately experience feed scouring and concentration. This effectively avoids the severe localized contamination and accelerated performance degradation caused by the long-term directional accumulation of pollutants at one end of the membrane in traditional unidirectional filtration modes. The membrane surface load tends to be more balanced, and the performance degradation rate of each membrane filtration module 10 is more consistent, thereby extending the effective service life of the membrane assembly and reducing maintenance frequency and replacement costs. Simultaneously, the batch and time-sharing switching method ensures that the system maintains relatively stable water production during switching periods, avoiding disruption to normal water supply.

[0082] Those skilled in the art will understand that the modules or steps described above in this application can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computing device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0083] Note that the above description is merely a preferred embodiment and the technical principles employed in this application. Those skilled in the art will understand that this application is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of this application. Therefore, although this application has been described in detail through the above embodiments, this application is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of this application, and the scope of this application is determined by the scope of the appended claims.

[0084] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A membrane filtration system with reconfigurable flow path, characterized in that, include: First Chief Steward, Second Chief Steward, and Third Chief Steward; Multiple membrane filtration modules are provided, each of which includes a membrane assembly, a first branch pipe, a second branch pipe, and a third branch pipe. The membrane assembly is configured to operate in a first filtration direction or a second filtration direction. In the first filtration direction, the liquid to be filtered enters through the first branch pipe and the concentrate is discharged through the second branch pipe. In the second filtration direction, the liquid to be filtered enters through the second branch pipe and the concentrate is discharged through the first branch pipe. The permeate is discharged through the third branch pipe. The pipeline switching module includes a first switching module and a second switching module. The first switching module is disposed between the first main pipe and the first branch pipe and the second branch pipe of each membrane filtration module. The second switching module is disposed between the second main pipe and the first branch pipe and the second branch pipe of each membrane filtration module. The third branch pipe of each membrane filtration module is connected to the third main pipe. The first switching module is configured to control the flow path connection and disconnection between the first main pipe and each of the first branch pipes and each of the second branch pipes, and the second switching module is configured to control the flow path connection and disconnection between the second main pipe and each of the first branch pipes and each of the second branch pipes, so that at least one of the membrane filtration modules can switch between the first filtration direction and the second filtration direction, and that multiple membrane filtration modules can operate in parallel mode, series mode, or a hybrid mode consisting of the parallel mode and the series mode.

2. The flow path reconfigurable membrane filtration system according to claim 1, characterized in that, The first switching module includes multiple first branch switches and multiple second branch switches. Each membrane filtration module has a first branch switch between its first branch and the first main pipe, and each membrane filtration module has a second branch switch between its second branch and the first main pipe. The second switching module includes multiple third branch switches and multiple fourth branch switches. Each membrane filtration module has a third branch switch between its first branch and the second main pipe, and each membrane filtration module has a fourth branch switch between its second branch and the second main pipe. The pipeline switching module is configured to switch the membrane filtration module between the first filtration direction and the second filtration direction by switching the on / off state of the first branch switch, the fourth branch switch and the second branch switch and the third branch switch corresponding to the same membrane filtration module.

3. The flow path reconfigurable membrane filtration system according to claim 2, characterized in that, A first main pipe switch is provided between the first main pipe and the common flow path of all the first branch pipe switches, and a second main pipe switch is provided between the first main pipe and the common flow path of all the second branch pipe switches. A third main pipe switch is provided between the second main pipe and the common flow path of all the third branch pipe switches, and a fourth main pipe switch is provided between the second main pipe and the common flow path of all the fourth branch pipe switches.

4. The flow path reconfigurable membrane filtration system according to claim 1, characterized in that, The system further includes a control unit, which is communicatively connected to the first switching module and the second switching module, and the control unit is configured to: Identify the current water usage scenario; When a low-demand scenario is identified, the first switching module and the second switching module are controlled to enable the multiple membrane filtration modules to operate in parallel mode and the system to operate at a first recovery rate. When a high-demand scenario is identified, the first switching module and the second switching module are controlled to make the multiple membrane filtration modules operate in series or in a hybrid mode, and the system operates at a second recovery rate, wherein the second recovery rate is greater than the first recovery rate.

5. A flow path reconfigurable membrane filtration system according to claim 4, characterized in that, The system also includes a sensor module, which is configured to acquire system-level operating parameters and / or membrane module-level health status parameters to monitor the overall filtration effect of the membrane filtration system and / or the health of each membrane filtration module. The control unit is communicatively connected to the sensor module, and the control unit is also configured to adjust the operating mode and / or flushing strategy of each membrane filtration module based on the overall filtration effect of the system and the health of the membrane filtration module.

6. The flow path reconfigurable membrane filtration system according to claim 5, characterized in that, The sensor module includes a system monitoring unit and a membrane module monitoring unit; at least one of the first main pipe, the second main pipe and the third main pipe is equipped with the system monitoring unit, and each membrane filtration module is equipped with the membrane module monitoring unit; The control unit is configured to: receive system-level operating parameters acquired by the system monitoring unit, calculate the system recovery rate based on the system-level operating parameters, and compare it with a benchmark threshold to evaluate the overall filtration effect of the system; the control unit is also configured to: receive membrane-level operating parameters acquired by each membrane module monitoring unit, and evaluate the health of each membrane filtration module based on the membrane-level operating parameters.

7. A flow path reconfigurable membrane filtration system according to claim 6, characterized in that, The system monitoring unit includes a main pipe flow sensor and a main pipe pressure sensor; the membrane module level monitoring unit includes a membrane module pressure sensor for detecting transmembrane pressure difference and / or a permeate flow sensor installed in the third branch pipe.

8. A flow path reconfigurable membrane filtration system according to claim 6, characterized in that, The control unit is configured to: When the system is running in parallel mode, the real-time health status of each membrane filtration module is obtained, and the membrane filtration modules required for the current parallel connection are selected in descending order of health status to participate in filtration. When the system is running in series mode, the real-time health status of each membrane filtration module is obtained, and the membrane filtration modules required for the current series connection are selected in descending order of health status. The modules are then configured sequentially from the first stage to the last stage in the series connection, so that the health status of each membrane module decreases along the direction of the feed liquid flow.

9. A flow path reconfigurable membrane filtration system according to claim 5, characterized in that, The control unit is configured to: When the health of a membrane filtration module is lower than a first preset threshold but higher than a second preset threshold, the first switching module and the second switching module are controlled to switch the filtration direction of the membrane filtration module. When the health of a certain membrane filtration module is lower than the second preset threshold, the membrane filtration module is identified as a module to be flushed, and the remaining membrane filtration modules are identified as modules that do not need to be flushed. The first switching module and the second switching module are controlled to shut off the flow path of the modules that do not need to be flushed, so that the flushing liquid flows through the first main pipe or the second main pipe to the module to be flushed; the second preset threshold is lower than the first preset threshold.

10. A flow path reconfigurable membrane filtration system according to claim 9, characterized in that, When there are multiple modules to be rinsed, the control unit is configured to selectively perform the following operations: The first switching module and the second switching module are controlled to simultaneously open the flow paths of multiple modules to be rinsed and close the flow paths of modules that do not need to be rinsed, so as to synchronously rinse multiple modules to be rinsed. Alternatively, the first switching module and the second switching module can be controlled to sequentially turn on the flow paths of each module to be rinsed and turn off the flow paths of modules that do not need to be rinsed, so that the rinsing of the current module to be rinsed is completed before switching to the next module to be rinsed, and rinsing is performed sequentially.

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