Ultrafiltration reverse osmosis direct connection system and operation method

Abstract

The invention provides an ultrafiltration reverse osmosis direct connection system and an operation method. The ultrafiltration reverse osmosis direct connection system comprises: an ultrafiltration component, which comprises at least one set of ultrafiltration device; the steady flow tank is provided with a second inlet, a second water replenishing port and a second outlet, and the second inlet is connected with the first outlet of the ultrafiltration device through a first pipeline; the water supplementing tank is provided with a third inlet and a third outlet, and the first outlet is connected with the second water supplementing opening of the flow stabilizing tank; an inlet of the pressure supply device is connected with the second outlet of the steady flow tank through a third pipeline, and an outlet of the pressure supply device is connected with the drainage pipeline; an inlet of the backwashing pipeline is connected with the drainage pipeline, and an outlet of the backwashing pipeline is connected with the first backwashing inlet. Therefore, according to the ultrafiltration reverse osmosis direct connection system disclosed by the invention, the occupied area and the cost can be reduced, the energy consumption is saved, and the service life can be prolonged.

Description

Technical Field

[0001] This invention relates to the field of membrane separation water treatment technology, specifically to an ultrafiltration reverse osmosis direct connection system and its operation method. Background Technology

[0002] In reverse osmosis membrane water treatment systems, ultrafiltration systems typically serve as crucial pretreatment units to remove suspended solids, colloids, microorganisms, and macromolecular organic matter from the raw water to meet the feed water requirements of the reverse osmosis system (e.g., sludge density index SDI < 3). The "ultrafiltration-reverse osmosis" dual-membrane water treatment process in related technologies usually employs the following configuration: the permeate from the ultrafiltration system first enters an intermediate buffer tank at atmospheric or low pressure. However, this results in a lengthy process and redundant equipment. Setting up a large intermediate tank not only increases the system's footprint and infrastructure investment but also increases the risk of secondary water pollution (e.g., contact with air, microbial growth). The independent booster pump set and its associated piping, valves, and control equipment increase system complexity and initial investment costs. Furthermore, energy consumption is high. After the ultrafiltration permeate enters the intermediate tank, its residual pressure (typically 0.05-0.2 MPa) is completely released. The booster pump needs to repressurize the water from near atmospheric pressure to 0.3-0.5 MPa, resulting in secondary energy consumption and reducing the overall energy efficiency of the system. Ultrafiltration systems require periodic backwashing to restore membrane flux during operation. In traditional processes, backwashing is typically performed by a separate backwash pump drawing water from an intermediate tank or an external water source. At the moment of backwash initiation, the backwash pump draws a large amount of water from the intermediate tank, causing a rapid drop in the tank level. This disrupts the normal and stable operation of the downstream booster pump, resulting in fluctuations in the flow and pressure supplied to the reverse osmosis high-pressure pump. These fluctuations can range from affecting the quality of the reverse osmosis permeate to potentially causing cavitation in the high-pressure pump, damaging the equipment. The system needs to coordinate the control of the intermediate tank level, the start / stop and frequency conversion of the booster pump, the start / stop of the backwash pump, and the switching between the ultrafiltration system's operating and backwashing states. The coordinated control of multiple variables and multiple devices increases the difficulty of the system's automation design and the likelihood of failure. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose an ultrafiltration reverse osmosis direct connection system and its operation method.

[0004] The ultrafiltration reverse osmosis direct connection system of this invention includes: An ultrafiltration component, the ultrafiltration component comprising at least one ultrafiltration device, each of the ultrafiltration devices having a first inlet, a first outlet and a first backwash inlet; A flow stabilizing tank, the volume of which is less than or equal to a first preset volume value, the flow stabilizing tank having a second inlet, a second water supply port and a second outlet, the second inlet being connected to the first outlet of the ultrafiltration device through a first pipeline; The water supply tank has a third inlet and a third outlet. The third inlet is connected to the first outlet of the ultrafiltration device through a second pipeline, and the first outlet is connected to the second water supply port of the flow stabilizing tank. A pressure supply device, the inlet of which is connected to the second outlet of the flow stabilizing tank via a third pipeline, the pressure supply device being used to regulate the drainage water pressure, and the outlet of which is connected to the drainage pipeline; The backwashing pipeline has its inlet connected to the drain pipeline and its outlet connected to the first backwashing inlet.

[0005] Therefore, the ultrafiltration reverse osmosis direct connection system according to embodiments of the present invention can reduce floor space and cost, save energy and improve service life.

[0006] In some embodiments, the volume V of the water replenishment tank satisfies the following formula: ...First formula; Wherein, Q1 is the backwash water flow rate required for backwashing each set of the ultrafiltration device, Q2 is the average drainage flow rate at the outlet of the drainage pipeline during the backwashing duration, and T is the duration of a single backwashing operation.

[0007] In some embodiments, the ultrafiltration reverse osmosis direct connection system further includes a reverse osmosis treatment device, the inlet of which is connected to the outlet of the drainage pipe, and the reverse osmosis treatment device includes a high-pressure pump and a concentrated brine reverse osmosis membrane module. In the first formula, Q2 is the average water flow rate required by the reverse osmosis treatment unit during the backwashing duration.

[0008] In some embodiments, the second pipeline is provided with a first regulating valve, which is used to regulate the water flow rate of the second pipeline; The backwash pipeline is equipped with a backwash return valve; The pressure supply device includes a water supply pump set and a pressure stabilizing tank. The inlet of the water supply pump set is connected to the second outlet through the third pipeline, and the outlet of the water supply pump set and the pressure stabilizing tank are connected to the drainage pipeline.

[0009] In some embodiments, the water replenishment tank is a sealed water tank; The flow stabilizing tank is equipped with a level gauge, which is interlocked with the first regulating valve. When the level gauge detects that the water level in the flow stabilizing tank is lower than a preset lower limit, the first regulating valve is opened or its opening degree is increased. The water supply pump set includes multiple first pump bodies arranged in parallel, at least one of which is a variable frequency pipeline pump. The adjustment range of the variable frequency pipeline pump is 30% to 120% of the water production flow rate of the ultrafiltration component.

[0010] The ultrafiltration reverse osmosis direct connection system of this invention also includes A first pressure sensor is installed in the third pipeline and is used to monitor the water pressure in the third pipeline. A second pressure sensor is installed in the drainage pipe and is used to monitor the water pressure in the drainage pipe. A water quality monitoring device, wherein the water quality monitoring device is located at at least one of the second inlet and the second outlet of the flow stabilizing tank; The controller is electrically connected to the water quality monitoring device, the backwash return valve, the first regulating water valve, the first pressure sensor, the second pressure sensor, and the water supply pump set.

[0011] In some embodiments, the controller is configured to execute the following control logic: When the pressure value detected by the first pressure sensor is lower than the first preset threshold, the first regulating water gate is controlled to adjust to the first opening degree. When the backwash return valve is opened, the first regulating water gate is simultaneously controlled to increase to a second opening degree, the second opening degree being greater than the first opening degree; When the pressure value detected by the second pressure sensor exceeds the second preset threshold, the operating frequency of the water supply pump group is reduced to adjust the water flow rate into the drainage pipe.

[0012] In some embodiments, the ultrafiltration component includes multiple sets of the ultrafiltration devices, which are arranged in parallel, and each set of the ultrafiltration devices is provided with valves at the first outlet and the first backwash inlet; The first inlet of each ultrafiltration device is connected to the water inlet pipe, the inlet of the water inlet pipe is connected to the water supply of the ultrafiltration system, and the outlet of the water inlet pipe is connected to the drain trough.

[0013] The present invention also proposes an operation method for the ultrafiltration reverse osmosis direct connection system according to the above, comprising the following steps; In the water production mode, the water produced by the ultrafiltration device enters the pressure supply device after passing through the flow stabilizing tank. After being pressurized by the water supply pump group of the pressure supply device and stabilized by the pressure stabilizing tank, the water is introduced into the drain pipeline. The backwash return valve and the first regulating water valve are closed. When the supply pressure at the inlet of the pressure supply device is insufficient, the first regulating water valve is opened, and the water replenishment tank replenishes water into the flow stabilizing tank to maintain a stable water supply pressure. When the ultrafiltration device needs to be backwashed, the backwash return valve and the first regulating water valve are opened, and a portion of the water in the drain pipe is introduced into the first backwash inlet of the ultrafiltration device through the backwash pipe for backwashing. At the same time, the water supply tank replenishes water into the flow stabilizing tank to ensure the water flow at the outlet of the drain pipe.

[0014] In some embodiments, the ultrafiltration component includes multiple sets of ultrafiltration devices, which are arranged in parallel. Each set of ultrafiltration devices is provided with a valve at its first outlet and first backwash inlet. When backwashing of the ultrafiltration devices is required, the multiple sets of ultrafiltration devices are backwashed alternately in sequence. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an ultrafiltration reverse osmosis direct connection system according to an embodiment of the present invention.

[0016] Figure label: 1. Ultrafiltration unit; 11. First inlet; 12. First outlet; 13. First backwash inlet; 14. Inlet water pipeline; 2. Flow stabilizer tank; 21. Second inlet; 22. Second water supply port; 23. Second outlet; 24. First pipeline; 25. Third pipeline; 26. Second regulating valve. 3. Water supply tank; 31. Third inlet; 32. Third outlet; 33. Second pipeline; 34. First regulating valve; 4. Water supply pump set; 41. First pump body; 42. Pressure stabilizing tank; 5. Drainage pipes; 51. High-pressure pump; 6. Backwash pipeline, 61. Backwash return valve. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0018] The ultrafiltration reverse osmosis direct connection system according to an embodiment of the present invention is described below with reference to the accompanying drawings. Figure 1As shown, the ultrafiltration-reverse osmosis direct connection system according to an embodiment of the present invention includes an ultrafiltration component, a flow stabilizing tank 2, a water replenishment tank 3, a pressure supply device, a backwashing pipeline 6, and a reverse osmosis treatment device.

[0019] The ultrafiltration system includes at least one ultrafiltration unit 1, each ultrafiltration unit 1 having a first inlet 11, a first outlet 12, and a first backwash inlet 13. Specifically, the ultrafiltration unit 1 can filter water entering it through the first inlet 11 to pretreat the raw water. For example, as... Figure 1 As shown, there is one ultrafiltration device 1, which includes multiple membrane elements.

[0020] In some embodiments, the ultrafiltration system includes multiple ultrafiltration units 1 connected in parallel. Each ultrafiltration unit 1 has valves at its first outlet 12 and first backwash inlet 13. In product water mode, the valve at the first backwash inlet 13 is closed. In backwashing mode, the valve at the first outlet 12 is closed. The multiple ultrafiltration units 1 are backwashed alternately to avoid affecting system operation. Each ultrafiltration unit 1 has an electrically operated butterfly valve at its first outlet 12 and first backwash inlet 13.

[0021] The first inlet 11 of each ultrafiltration unit 1 is connected to the inlet water pipe 14, the inlet of the inlet water pipe 14 is connected to the water supply of the ultrafiltration system, and the outlet of the inlet water pipe 14 is connected to the drain tank. During backwashing, the backwash water can be discharged from the outlet of the inlet water pipe 14 into the drain tank.

[0022] The volume of the flow stabilizing tank 2 is less than or equal to a first preset volume value, thereby facilitating installation and reducing floor space and production costs. The flow stabilizing tank 2 has a second inlet 21, a second water supply port 22, and a second outlet 23. The second inlet 21 is connected to the first outlet 12 of the ultrafiltration device 1 via a first pipe 24. Specifically, this allows the drainage from the first outlet 12 of the ultrafiltration device 1 to be introduced into the flow stabilizing tank 2 through the first pipe 24, and the flow stabilizing tank 2 is used to stabilize the drainage from the first outlet 12 of the ultrafiltration device 1. The flow stabilizing tank 2 receives and temporarily stores the ultrafiltration permeate discharged from the ultrafiltration device 1, providing initial buffering against potential instantaneous flow fluctuations in the ultrafiltration permeate. For example, the drainage from multiple ultrafiltration devices 1 can all be introduced into the flow stabilizing tank 2 through the first pipe 24.

[0023] The water supply tank 3 has a third inlet 31 and a third outlet 32. The third inlet 31 is connected to the first outlet 12 of the ultrafiltration device 1 via a second pipe 33, and the first outlet 12 is connected to the second water supply port 22 of the flow stabilizing tank 2. Specifically, the water supply tank 3 is a closed water tank, and at least a portion of the water supply tank 3 is located above the flow stabilizing tank 2. A first regulating valve 34 is provided on the second pipe 33 to regulate the water flow rate of the second pipe 33. For example, the drainage from multiple ultrafiltration devices 1 can be introduced into the water supply tank 3 through the second pipe 33.

[0024] For example, the first regulating valve 34 is a controllable inlet valve. The first regulating valve 34 can be closed to prevent water from flowing through the second pipeline 33. The flow rate of the second pipeline 33 can be adjusted by changing the opening degree of the first regulating valve 34. Another example is that the first regulating valve 34 is an electric or pneumatic regulating valve.

[0025] like Figure 1 As shown, the inlet of the pressure supply device is connected to the second outlet 23 of the flow stabilizing tank 2 via the third pipe 25. The pressure supply device is used to regulate the water pressure during drainage, and its outlet is connected to the drainage pipe 5. Specifically, the third pipe 25 is equipped with a second regulating valve 26, which is used to regulate the water flow rate of the third pipe 25. The opening degree of the second regulating valve 26 is adjusted to regulate the water flow rate entering the pressure supply device. For example, during backwashing, the opening degree of the second regulating valve 26 is increased to increase the water flow rate of the third pipe 25.

[0026] The inlet of the reverse osmosis treatment device is connected to the outlet of the drainage pipe 5. The reverse osmosis treatment device includes a high-pressure pump 51 and a concentrated brine reverse osmosis membrane module. The outlet of the drainage pipe 5, the high-pressure pump 51 and the concentrated brine reverse osmosis membrane module are connected in sequence. After being pressurized by the high-pressure pump 51, the water pressure entering the concentrated brine reverse osmosis membrane module meets the operating requirements. The concentrated brine reverse osmosis membrane module is used for desalination.

[0027] The inlet of backwash line 6 is connected to the drain line 5, and the outlet of backwash line 6 is connected to the first backwash inlet 13. Specifically, a backwash return valve 61 is provided on the backwash line 6. Thus, when backwashing of the ultrafiltration unit 1 is required, the backwash return valve 61 is opened to backwash the corresponding ultrafiltration unit 1. For example, the outlet of backwash line 6 is connected to the first backwash inlet 13 of each ultrafiltration unit 1. When the corresponding ultrafiltration unit 1 needs backwashing, the valve at the first backwash inlet 13 of the ultrafiltration unit 1 is opened, the valve at the first outlet 12 of the ultrafiltration unit 1 is opened, and the backwash return valve 61 is opened to backwash the ultrafiltration unit 1.

[0028] In some embodiments, the volume V of the water replenishment tank 3 satisfies the following formula: ...First formula; Where Q1 is the backwash water flow rate required for backwashing each ultrafiltration unit 1, Q2 is the average drainage flow rate at the outlet of the drain pipe 5 during the backwashing duration, and T is the duration of a single backwashing operation. Specifically, in the first formula, Q2 is the average water flow rate required by the reverse osmosis treatment unit during the backwashing duration. That is to say, the makeup water tank 3 is a makeup water device for the backwashing of ultrafiltration unit 1. When an ultrafiltration unit 1 is backwashed, the first outlet 12 stops discharging water. During the backwashing duration T, the volume V (water volume) in the makeup water tank 3 needs to meet the water volume required for backwashing of ultrafiltration unit 1, and at the same time, it needs to meet the drainage volume (water volume required by the reverse osmosis treatment unit) of the drain pipe 5, so that the system can operate continuously.

[0029] like Figure 1 As shown, in some embodiments, the pressure supply device includes a water supply pump group 4 and a pressure stabilizing tank 42. The inlet of the water supply pump group 4 is connected to the second outlet 23 via a third pipeline 25, and the outlet of the water supply pump group 4 and the pressure stabilizing tank 42 are connected to the drainage pipeline 5. Specifically, the water supply pump group 4 and the pressure stabilizing tank 42 are arranged in parallel, and the outlet of the water supply pump group 4 is connected to the inlet of the reverse osmosis high-pressure pump 51 via the pressure stabilizing tank 42. The function of the water supply pump group 42 is to replace the booster pump in the traditional process. The water supply pump group 42 directly draws water from the flow stabilizing tank 2 and pressurizes it to the inlet pressure required by the reverse osmosis high-pressure pump 51, which can effectively prevent cavitation (e.g., 0.4-0.6 MPa). The pressure stabilizing tank 42 is used to further smooth out the small pulsations in the output pressure of the water supply pump group 4, providing extremely stable water inlet conditions for the reverse osmosis high-pressure pump 51. The water supply pump group 4 provides power, and the pressure stabilizing tank 42 ensures smooth drainage. The cooperation between the water supply pump group 4 and the pressure stabilizing tank 42 makes the system drainage stable.

[0030] In some embodiments, the inlet of the backwash pipeline 6 is located downstream of the water supply pump set 4 and the pressure stabilizing tank 42, so as to utilize the excess pressure head (relative to the pressure required for backwashing) of the water supply pump set 4 and the pressure stabilizing tank 42 as the power source for backwashing. When backwashing is required, the backwash return valve 61 is opened, and a portion of the high-pressure water output from the water supply pump set 4 can be diverted to the ultrafiltration device 1 for efficient backwashing, eliminating the need for a separate backwash water pump and achieving cascaded utilization of energy.

[0031] In some embodiments, the water supply pump group 4 includes a plurality of first pump bodies 41 arranged in parallel, at least one of which is a variable frequency pipeline pump. The adjustment range of the variable frequency pipeline pump is 30% to 120% of the water flow rate of the ultrafiltration component. For example, the variable frequency pipeline pump is a rotary drum plunger pump. The rotary drum plunger pump has the characteristics of stable output pressure, small pulsation, relatively relaxed requirements on inlet pressure, and high efficiency, making it particularly suitable as the "core power pump" in this system. Preferably, the rotary drum plunger pump adopts a multi-plunger parallel structure, and its rated flow rate can be continuously adjusted within the range of 30%-120% of the maximum water supply flow rate of the system to adapt to the operating requirements of the system under different loads.

[0032] In some embodiments, the flow stabilizing tank 2 is equipped with a level gauge, which is interlocked with the first regulating valve 34. When the level gauge detects that the water level in the flow stabilizing tank 2 is lower than a preset lower limit, the first regulating valve 34 is opened or its opening degree is increased. Specifically, the inlet flow rate of the first pipeline 24 is stable. When the water level in the flow stabilizing tank 2 is lower than the set safety lower limit, the first regulating valve 34 is forcibly opened to replenish water, regardless of the pressure signal. By opening or increasing the opening degree of the first regulating valve 34, the amount of water flowing into the replenishment tank 3 is increased, thereby using the replenishment tank 3 to replenish water to the flow stabilizing tank 2, increasing system safety.

[0033] In some embodiments, the ultrafiltration reverse osmosis direct connection system further includes a first pressure sensor, a second pressure sensor, a water quality monitoring device, and a controller.

[0034] The first pressure sensor is installed in the third pipe 25 and is used to monitor the water pressure in the third pipe 25. The second pressure sensor is installed in the drain pipe 5 and is used to monitor the water pressure in the drain pipe 5.

[0035] A water quality monitoring device is installed at at least one of the second inlet 21 and the second outlet 23 of the flow stabilization tank 2. The water quality monitoring device is used to monitor key water quality parameters such as turbidity and SDI value (sludge density index of water treatment) of the produced water online, providing data support for system operation status assessment and membrane cleaning decisions.

[0036] The controller is electrically connected to the water quality monitoring device, backwash return valve 61, first regulating valve 34, first pressure sensor, second pressure sensor, and water supply pump set 4. The controller can receive detection data from the water quality monitoring device, first pressure sensor, and second pressure sensor, and control the opening and closing of the backwash return valve 61, the opening degree of the first regulating valve 34, and the operating frequency of the water supply pump set 4. The controller is configured to execute the following control logic: When the pressure value detected by the first pressure sensor is lower than the first preset threshold, indicating insufficient ultrafiltration water production pressure or excessive suction by the water supply pump group 4, the first regulating valve 34 is adjusted to the first opening degree. Specifically, when the first regulating valve 34 is closed or has a small opening degree, the ultrafiltration component will experience pressure buildup, reducing the water production. Adjusting the first regulating valve 34 to the first opening degree allows water to enter the water supply tank 3, enabling the water supply tank 3 to replenish water into the flow stabilizing tank 2. This increases the water flow into the flow stabilizing tank 2, thereby increasing the water production of the ultrafiltration component and increasing the water intake of the water supply tank 3. This facilitates water replenishment to the flow stabilizing tank 2, increasing the drainage of the flow stabilizing tank 2 and thus increasing the drainage water pressure of the flow stabilizing tank 2, which in turn increases the water pressure in the third pipeline 25 (the inlet water pressure of the water supply pump group 4).

[0037] When the backwash return valve 61 is opened, the first regulating valve 34 is simultaneously increased to a second opening degree, which is greater than the first opening degree. This increases the water inlet to the makeup water tank 3, thereby increasing the makeup water supply to the stabilizing tank 2. This, in turn, increases the water flow into the water supply pump group 4 and the drainage pipe 5, thus meeting the backwash water volume and drainage volume requirements of the drainage pipe 5. Specifically, when backwashing is not performed, the opening degree of the first regulating valve 34 is small, and the water supply flow of the stabilizing tank 2 is only the drainage volume of the drainage pipe 5 (the water volume required for reverse osmosis). At this time, the ultrafiltration component will experience pressure buildup, reducing the water production. When one of the ultrafiltration devices 1 in the ultrafiltration component is backwashed, the opening degree of the first regulating valve 34 can be increased, and the drainage volume of the stabilizing tank 2 increases (for example, by increasing the opening degree of the second regulating valve 26). This allows the ultrafiltration component to increase water production, thereby increasing the water inlet to the makeup water tank 3, facilitating the makeup water supply to the stabilizing tank 2, and meeting the backwash water volume and drainage volume requirements of the drainage pipe 5 (the water volume required for reverse osmosis).

[0038] When the pressure value detected by the second pressure sensor exceeds the second preset threshold, the controller reduces the operating frequency of the water supply pump group 4. Specifically, when the second pressure sensor detects that the reverse osmosis feed water pressure exceeds the second preset threshold (possibly due to excessive output of the water supply pump group 4 or changes in reverse osmosis side resistance), the controller can take protective measures, such as reducing the operating frequency of the water supply pump group 4, to prevent system overpressure.

[0039] The present invention also proposes an operation method for an ultrafiltration reverse osmosis direct connection system according to an embodiment of the present invention, the operation method of the ultrafiltration reverse osmosis direct connection system according to an embodiment of the present invention includes the following steps; In the water production mode, the permeate from the ultrafiltration unit 1 enters the pressure supply device after passing through the stabilizing tank 2. After being pressurized by the water supply pump set 4 and stabilized by the pressure stabilizing tank 42, the water flows into the drain pipe 5. The backwash return valve 61 and the first regulating water valve 34 are closed. Specifically, in the normal water production mode, the ultrafiltration unit 1 produces water normally, and the permeate enters the stabilizing tank 2. The water supply pump set 4 draws water from the stabilizing tank 2, pressurizes it, and then delivers it to the reverse osmosis high-pressure pump 51 via the pressure stabilizing tank 42. The backwash return valve 61 and the first regulating water valve 34 are both closed. The system operates stably with minimal energy consumption.

[0040] When the supply pressure at the inlet of the pressure supply device (third pipeline 25) is insufficient, the first regulating valve 34 is opened, and the water supply tank 3 replenishes water into the flow stabilizing tank 2 to maintain a stable water supply pressure. Specifically, in the water replenishment and pressure stabilization mode, i.e., when water is produced, the water flow in the flow stabilizing tank 2 is insufficient. When insufficient supply pressure is detected at the inlet of the water supply pump set 4 (third pipeline 25) (for example, due to ultrafiltration membrane fouling causing a drop in water production pressure, or a decrease in the frequency of the raw water pump), the control system (controller) automatically opens the first regulating valve 34. The stored water in the water supply tank 3 flows into the flow stabilizing tank 2 under the action of pressure difference or small potential energy, quickly replenishing the water volume and helping to maintain a stable outlet water pressure in the flow stabilizing tank 2, thereby ensuring that the inlet conditions of the water supply pump set 4 do not deteriorate and the feed water of the downstream reverse osmosis system is not affected.

[0041] When backwashing of the ultrafiltration unit 1 is required, the backwash return valve 61 and the first regulating water valve 34 are opened, allowing a portion of the water flow in the drain pipe 5 to be introduced into the first backwash inlet 13 of the ultrafiltration unit 1 through the backwash pipe 6 for backwashing. Simultaneously, the water supply tank 3 replenishes water into the stabilizing tank 2 to ensure the water flow rate at the outlet of the drain pipe 5. Specifically, when the ultrafiltration unit 1 needs backwashing (triggered by parameters such as operating time and transmembrane pressure difference), the control system performs the following coordinated operations: the backwash return valve 61 is opened, and the first regulating water valve 34 is simultaneously opened to a preset maximum opening. The water supply pump group 4 maintains operation or adjusts its frequency as needed. The high-pressure water flow output by the water supply pump group 4 is divided into two paths: the main part continues to flow through the pressure stabilizing tank 42 to supply the reverse osmosis high-pressure pump 51; the other part is diverted through the backwash pipe 6 to the ultrafiltration unit 1 as a backwash water source. At the same time, the water supply tank 3 replenishes water into the stabilizing tank 2 at a higher flow rate. The added water precisely compensates for the water volume that should have been supplied to the reverse osmosis system due to the diversion backwash, as well as the temporarily reduced water production volume that might have been caused by the ultrafiltration unit 1 being disconnected from the backwash. Through this dynamic balance, the backwashing of the ultrafiltration unit 1 can be completed without shutting down the system or interrupting the reverse osmosis water supply.

[0042] When multiple ultrafiltration units 1 need backwashing, they are backwashed sequentially and alternately. For configurations with multiple ultrafiltration units 1 connected in parallel, an alternating backwashing method is used. The control system plans the backwashing sequence to ensure that when one ultrafiltration unit 1 is backwashed, at least one or a certain number of other ultrafiltration units 1 are still producing water normally, thus guaranteeing that the total influent flow rate to the flow stabilization tank is never lower than a preset minimum value. This further enhances the stability and maintainability of the system in large-scale applications.

[0043] The ultrafiltration-reverse osmosis direct connection system according to embodiments of the present invention eliminates the intermediate buffer tank and independent booster pump (including pumps, motors, frequency converters, inlet and outlet valves, etc.), greatly simplifying the system process. The number of devices is reduced by approximately 20%-30%, and the floor space is correspondingly reduced by 25%-40%, making it particularly suitable for space-constrained applications (such as ships, offshore platforms, and renovations of existing factories). This results in a significant reduction in investment and land occupation.

[0044] The ultrafiltration reverse osmosis direct connection system according to embodiments of the present invention uses a flow stabilizing tank as the hydraulic buffer and distribution center, a high-pressure water supply pump set as the sole power source, and a makeup water tank as a strategic water reserve. It is an integrated architecture that dynamically balances the needs of all parties through an intelligent control system (controller). The water supply pump set directly utilizes the residual pressure of the ultrafiltration permeate (typically still 0.05MPa-0.15MPa) as the inlet pressure, only needing to be pressurized to the target pressure. Compared to the booster pumps in related technologies that start pressurizing from near atmospheric pressure (0MPa), this can save approximately 30%-50% of energy consumption in this stage. Simultaneously, the high-pressure surplus energy at the outlet of the water supply pump set is used for backwashing, completely eliminating the energy consumption of a separate backwash pump. The backwash pressure is higher (typically reaching 0.2MPa-0.4MPa), the backwashing effect is better, and energy savings can reach 100% (relative to the operating energy consumption of a separate backwash pump). Through a three-stage stabilization mechanism—physical buffering with a flow stabilizing tank, real-time feedback from a pressure sensor, and precise adjustment by a controller—the pressure fluctuation of the feed water to the reverse osmosis high-pressure pump can be controlled within an extremely narrow range of ±0.02 MPa, far exceeding the ±0.15 MPa fluctuation level of traditional systems. This fundamentally eliminates the risk of high-pressure pump cavitation and extends the service life of the pump and membrane elements. The makeup water tank solves the water shortage problem of the reverse osmosis system during ultrafiltration backwashing. Furthermore, the makeup water tank is a closed-loop tank. The system remains in a closed, pressurized state from ultrafiltration permeate to reverse osmosis feed water, avoiding contact with air and effectively preventing pH changes caused by carbon dioxide dissolution, oxidation risks caused by oxygen dissolution, and the intrusion of external pollutants and microorganisms, providing higher-quality feed water for the reverse osmosis membrane. While reducing initial investment and operating energy consumption, the improved system reliability reduces unplanned downtime and maintenance costs, and the extended membrane life reduces replacement costs. The overall life cycle cost is significantly reduced. Energy saving also means emission reduction, which has positive environmental significance.

[0045] Therefore, the ultrafiltration reverse osmosis direct connection system according to embodiments of the present invention can reduce floor space and cost, save energy and improve service life.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to 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 invention.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "beneath" of the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0050] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0051] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An ultrafiltration reverse osmosis direct connection system, characterized in that, The system comprises: an ultrafiltration component comprising at least one set of ultrafiltration device, each set of the ultrafiltration device having a first inlet, a first outlet and a first backwash inlet; a surge tank having a volume equal to or less than a first preset volume value, the surge tank having a second inlet, a second water supplement outlet and a second outlet, the second inlet being connected to the first outlet of the ultrafiltration device through a first pipeline; a water supplement tank having a third inlet and a third outlet, the third inlet being connected to the first outlet of the ultrafiltration device through a second pipeline, the first outlet being connected to the second water supplement outlet of the surge tank; a pressure supply device, an inlet of the pressure supply device being connected to the second outlet of the surge tank through a third pipeline, the pressure supply device being used for adjusting the water pressure of the drainage, an outlet of the pressure supply device being connected to a drainage pipeline; a backwash pipeline, an inlet of the backwash pipeline being connected to the drainage pipeline, an outlet of the backwash pipeline being connected to the first backwash inlet.

2. The ultrafiltration reverse osmosis direct connection system according to claim 1, characterized in that, The volume V of the water supplement tank satisfies the following formula: … first equation; wherein Q1 is the backwash water flow required for backwashing each set of the ultrafiltration device, Q2 is the average drainage flow of the outlet of the drainage pipeline within the backwashing duration, and T is the duration of a single backwashing operation.

3. The ultrafiltration reverse osmosis direct connection system according to claim 2, further comprising a reverse osmosis treatment device, an inlet of the reverse osmosis treatment device being connected to the outlet of the drainage pipeline, the reverse osmosis treatment device comprising a high-pressure pump and a concentrated brine reverse osmosis membrane group. In the first formula, Q2 is the average water flow required for the reverse osmosis treatment device within the backwashing duration.

4. The ultrafiltration reverse osmosis direct connection system according to any one of claims 1-3, wherein a first adjustable water gate is arranged on the second pipeline, the first adjustable water gate being used for adjusting the water flow of the second pipeline; a backwash backflow valve is arranged on the backwash pipeline; the pressure supply device comprises a water supply pump group and a pressure stabilizing tank, an inlet of the water supply pump group being connected to the second outlet through the third pipeline, an outlet of the water supply pump group and the pressure stabilizing tank being connected to the drainage pipeline.

5. The ultrafiltration reverse osmosis direct connection system according to claim 4, wherein the water supplement tank is a closed water tank; a liquid level meter is arranged in the surge tank, the liquid level meter being interlocked with the first adjustable water gate, when the liquid level meter detects that the water level in the surge tank is lower than a preset lower limit value, the first adjustable water gate is opened or the opening degree of the first adjustable water gate is increased; the water supply pump group comprises a plurality of first pump bodies arranged in parallel, at least one of the plurality of first pump bodies being a variable frequency pipeline pump, the adjustment range of the variable frequency pipeline pump being 30% to 120% of the water production flow of the ultrafiltration component. Further comprising a first pressure sensor arranged on the third pipeline and used for monitoring the water pressure in the third pipeline; a second pressure sensor arranged on the drainage pipeline and used for monitoring the water pressure in the drainage pipeline. ​ ​ ​ ​ 6. The ultrafiltration reverse osmosis direct connecting system according to claim 5, characterized in that, ​ ​ ​ A water quality monitoring device is arranged at at least one of the second inlet and the second outlet of the flow stabilizing tank; A controller is electrically connected with the water quality monitoring device, the backwashing backflow valve, the first regulating water gate, the first pressure sensor, the second pressure sensor, and the water supply pump set.

7. The ultrafiltration reverse osmosis direct connection system according to claim 6, wherein the controller is configured to execute the following control logic: when the pressure value detected by the first pressure sensor is lower than a first preset threshold value, the first regulating water gate is controlled to be adjusted to a first opening degree; when the backwashing backflow valve is opened, the first regulating water gate is synchronously controlled to be increased to a second opening degree, the second opening degree being greater than the first opening degree; when the pressure value detected by the second pressure sensor exceeds a second preset threshold value, the operating frequency of the water supply pump set is controlled to be reduced so as to adjust the water flow into the drain pipeline.

8. The ultrafiltration reverse osmosis direct connection system according to claim 4, wherein the ultrafiltration component comprises a plurality of sets of the ultrafiltration device, the plurality of sets of the ultrafiltration device being arranged in parallel, and a valve is arranged at the first outlet and the first backwashing inlet of each set of the ultrafiltration device; the first inlet of each set of the ultrafiltration device is connected with a water inlet pipeline, an inlet of the water inlet pipeline is connected with water inlet of an ultrafiltration system, and an outlet of the water inlet pipeline is connected with a drain tank. The method comprises the following steps: in a water production mode, water produced by the ultrafiltration device enters the pressure supply device through the flow stabilizing tank, the water is pressurized by the water supply pump set of the pressure supply device and is stabilized by the pressure stabilizing tank, and then the water enters the drain pipeline, the backwashing backflow valve and the first regulating water gate being closed; 9. A method for operating a direct connection system of ultrafiltration and reverse osmosis according to any one of claims 4-8, characterized in that, when the supply pressure at the inlet of the pressure supply device is insufficient, the first regulating water gate is opened, and the water supplement tank supplements water into the flow stabilizing tank to maintain stable water supply pressure; when backwashing of the ultrafiltration device is required, the backwashing backflow valve and the first regulating water gate are opened, a part of water flow in the drain pipeline enters the first backwashing inlet of the ultrafiltration device through the backwashing pipeline for backwashing, and at the same time, the water supplement tank supplements water into the flow stabilizing tank to ensure the water flow at the outlet of the drain pipeline. the ultrafiltration component comprises a plurality of sets of the ultrafiltration device, the plurality of sets of the ultrafiltration device being arranged in parallel, a valve being arranged at the first outlet and the first backwashing inlet of each set of the ultrafiltration device, and when backwashing of the ultrafiltration device is required, the plurality of sets of the ultrafiltration device are sequentially and alternately backwashed. ​ 10. The method of claim 9, wherein the ultrafiltration reverse osmosis direct connection system is operated in a manner that, ​

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