Countertop reverse osmosis water purifier and its control method

Abstract

This invention discloses a countertop reverse osmosis water purifier and its control method, relating to the field of water purifiers. The key technical points are: it includes a reverse osmosis membrane assembly, a booster pump containing a motor housing, an integrated water circuit board, a temperature control switching assembly including a temperature-controlled reversing valve and a direct bypass pipe, and a heat exchange assembly; the temperature-controlled reversing valve, based on the raw water temperature in the first flow channel, drives a temperature-sensing actuator to switch between opening the first outlet of the heat exchange pipe and the second outlet of the direct bypass pipe. The technical effects are: by utilizing the raw water to absorb the waste heat of the booster pump motor, the raw water temperature is passively increased to compensate for the low-temperature water permeate flux loss of the reverse osmosis membrane without introducing external heating energy consumption; simultaneously, it provides liquid cooling for the booster pump, alleviating heat accumulation and delaying component aging; the temperature control switching avoids the risk of membrane damage caused by excessive heating of the raw water during high-temperature seasons, and the integrated flow channel design reduces the leakage failure rate.

Description

Technical Field

[0001] This invention relates to the field of water purifiers, and in particular to a countertop reverse osmosis water purifier and its control method. Background Technology

[0002] Countertop reverse osmosis water purifiers have become the mainstream choice for modern drinking water purification due to their extremely high filtration accuracy. However, existing countertop reverse osmosis water purifiers still face the following technical problems that urgently need to be solved in practical applications: The permeate flux of a reverse osmosis membrane is extremely sensitive to the feed water temperature. The physical properties of the reverse osmosis membrane determine that the resistance of water molecules to passing through the membrane is inversely proportional to the water temperature. In winter or under low water temperature conditions, such as when the water temperature is below 10℃, the viscosity of the raw water increases significantly, resulting in a substantial decrease in the permeate flow rate of the countertop reverse osmosis water purifier and an excessively long water production time. Summary of the Invention

[0003] The purpose of this invention is to provide a countertop reverse osmosis water purifier, which has the advantages of low-temperature water production flux adaptive compensation, active heat dissipation of power components, protection against stagnant water replacement, and high reliability of water system operation.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A countertop reverse osmosis water purifier includes a reverse osmosis membrane assembly, a booster pump, an integrated water circuit board, a temperature control switching assembly, and a heat exchange assembly; it also includes an inlet water interface, a pure water interface, and a concentrated water interface; The integrated water circuit board is provided with a first flow channel, a second flow channel, a third flow channel and a fourth flow channel that are isolated from each other; The temperature control switching component includes a temperature control reversing valve and a straight-through bypass pipe; the heat exchange component includes a heat exchange pipe that is attached to the periphery of the booster pump motor housing. The first flow channel is connected at both ends to the water inlet and the inlet of the temperature control reversing valve, respectively. The first outlet of the temperature-controlled reversing valve is connected to the input end of the heat exchange pipeline, and the second outlet is connected to the input end of the straight-through bypass pipeline. The heat exchange pipeline and the output end of the straight-through bypass pipeline converge and are connected to the suction port of the booster pump via the second flow channel; The pressure port of the booster pump is connected to the inlet of the reverse osmosis membrane module via the third and fourth flow channels in sequence; The pure water output end of the reverse osmosis membrane module is connected to the pure water interface, and the wastewater output end is connected to the concentrated water interface. The temperature-controlled reversing valve is equipped with a temperature-sensing actuator, which is configured to: in response to the raw water temperature in the first flow channel being lower than a preset temperature threshold, drive the temperature-controlled reversing valve to open the first outlet and close the second outlet; in response to the raw water temperature being greater than or equal to the preset temperature threshold, drive the temperature-controlled reversing valve to open the second outlet and close the first outlet.

[0005] Further configuration: The heat exchange pipeline is a metal heat-conducting pipe spirally wound on the surface of the motor housing, and a heat-conducting medium is filled between the heat exchange pipeline and the motor housing.

[0006] Further settings: also includes: Wastewater balancing valve, flushing solenoid valve, and micro-orifice pressure relief valve; The wastewater balancing valve is connected between the wastewater output end of the reverse osmosis membrane module and the concentrate interface. The flushing solenoid valve is connected in parallel across the two ends of the wastewater balance valve. The flushing solenoid valve is configured to perform a high-frequency on / off action in response to a flushing command, so as to generate hydraulic oscillations inside the reverse osmosis membrane module to remove deposits from the membrane surface. One end of the microporous pressure relief valve is connected to the fourth flow channel, and the other end of the microporous pressure relief valve is connected to the concentrate interface. The microporous pressure relief valve is configured to release the high-pressure fluid remaining at the inlet of the reverse osmosis membrane module to the concentrate interface during the shutdown of the booster pump.

[0007] Further settings: also includes: Gas-liquid buffer blind cavity; The gas-liquid buffer blind cavity is integrally formed inside the integrated water circuit board and is connected to the third or fourth flow channel to absorb the hydraulic shock generated when the flushing solenoid valve is switched on and off at high frequency and when the booster pump is started and stopped.

[0008] Further features include a pure water reflux assembly, which includes a water storage container, a reflux pipeline, and a reflux control valve. The inlet of the water storage container is connected to a pure water interface or the pure water output of the reverse osmosis membrane module to collect pure water; One end of the return pipe is connected to the outlet of the water storage container, and the other end of the return pipe is connected to the second flow channel; The reflux control valve is located on the reflux pipeline and is configured to: open the reflux pipeline in response to a replacement command triggered by the shutdown of the booster pump, so as to guide the pure water in the water storage container to the second flow channel, and pump it into the inlet of the reverse osmosis membrane module via the booster pump, so as to replace the resident concentrate on the raw water side of the reverse osmosis membrane module.

[0009] Further configuration: The pure water reflux assembly also includes: First check valve and second check valve; The first one-way valve is located between the output end of the heat exchange pipeline and the second flow channel to prevent the pure water released from the water storage container from flowing back into the heat exchange pipeline. The second one-way valve is installed on the return pipeline to prevent the raw water in the second flow channel from entering the water storage container.

[0010] Further settings: also includes: Concentrate discharge pipeline and drain solenoid valve; One end of the concentrate discharge pipeline is connected to the wastewater output end of the reverse osmosis membrane module, and the other end of the concentrate discharge pipeline is connected to the concentrate interface. The drain solenoid valve is installed on the concentrate discharge pipeline. The drain solenoid valve is configured to open when the reverse osmosis membrane module performs desalination or flushing treatment, and to close when the system is in standby and static state to cut off the physical connection with the external drain end.

[0011] Another object of the present invention is to provide a control method for a countertop reverse osmosis water purifier, comprising: S1. Obtain the temperature of the raw water flowing through the inlet interface; S2. In response to the raw water temperature being lower than the preset temperature threshold, the temperature control switching component is controlled to direct the raw water to the heat exchange pipeline so as to utilize the raw water to absorb the waste heat of the booster pump, and the heated raw water is pumped into the reverse osmosis membrane module via the booster pump to perform desalination treatment. S3. In response to the raw water temperature being greater than or equal to a preset temperature threshold, the temperature control switching component is controlled to direct the raw water to the direct bypass pipe and pump the raw water into the reverse osmosis membrane module via a booster pump to perform desalination treatment. S4. In response to the shutdown and replacement command for the booster pump, control the pure water return component to open, guide the pre-stored pure water to the suction port of the booster pump, and pump the pure water into the inlet of the reverse osmosis membrane module through the booster pump, so as to replace the resident concentrate in the raw water side of the reverse osmosis membrane module with pure water.

[0012] Further settings: S4 includes the following sub-steps: S41. In response to the shutdown replacement command, open the return flow control valve and control the drain solenoid valve to open synchronously; S42. Drive the booster pump to run, draw pure water from the water storage container into the reverse osmosis membrane module, and discharge the displaced concentrate into the concentrate interface through the drain solenoid valve. S43. In response to the pure water replacement process reaching a preset time threshold, stop the booster pump and close the reflux control valve and drain solenoid valve to keep the reverse osmosis membrane module in a physically isolated pure water immersion state.

[0013] Further settings: This also includes the following steps: S5. In response to the high-frequency flushing command, control the flushing solenoid valve connected in parallel to the wastewater output end of the reverse osmosis membrane module to open and close periodically at a preset frequency, generating hydraulic oscillations inside the reverse osmosis membrane module to remove deposits from the membrane surface. S6. In response to the booster pump being in a stationary state where it is stopped and no replacement command has been executed, the microporous pressure relief valve is opened to release the high-pressure fluid at the inlet of the reverse osmosis membrane module to the concentrate interface.

[0014] In summary, the present invention has the following beneficial effects: First, this invention uses a temperature-controlled switching component to automatically determine the flow path based on the raw water temperature. At low temperatures, the raw water flows through a heat exchange pipe attached to the motor housing, absorbing waste heat from the motor. The water is then pressurized by a booster pump and sent to the reverse osmosis membrane module. Through the coordination of the temperature-controlled reversing valve and the heat exchange pipe, the transfer and reuse of heat within the system are achieved. When the inlet water temperature is low, the raw water absorbs waste heat from the booster pump motor housing, increasing the permeate flux of the reverse osmosis membrane and providing liquid cooling for the booster pump, thus delaying the aging of motor components. When the inlet water temperature is high, the raw water flows through a direct bypass pipe, preventing damage to the reverse osmosis membrane due to excessively high inlet water temperatures. The structure of this invention eliminates the need for an external heating module, improving performance while avoiding increased overall energy consumption and preventing low efficiency and pump heat buildup at low temperatures.

[0015] Secondly, to ensure that the raw water fully absorbs the heat dissipated by the motor as it flows through the heat exchange components, it is necessary to reduce the thermal resistance of the heat transfer interface. This is achieved by using a spirally wound metal heat-conducting pipe on the surface of the motor housing, with a heat-conducting medium filling the gap between the pipe and the housing. This fills the tiny gap between the pipe and the housing, increasing the effective contact area and improving the overall thermal conductivity. The combination of the metal heat-conducting pipe and the heat-conducting medium reduces the contact thermal resistance between the heat exchange pipes and the motor housing. This allows the waste heat generated by the booster pump to be transferred more quickly and fully to the internally flowing raw water, improving heat exchange efficiency and thus ensuring the temperature compensation effect on the permeate flux of the reverse osmosis membrane under low-temperature conditions.

[0016] Third, conventional reverse osmosis equipment uses constant water flow flushing, which has limited effectiveness in removing stubborn deposits from the membrane surface; moreover, the system maintains high pressure after shutdown, and prolonged pressure buildup can easily damage water circuit components. This solution uses flushing solenoid valves connected in parallel across the wastewater balancing valve to create hydraulic oscillations by causing rapid changes in water pressure within the pipeline through their high-frequency on / off switching. Simultaneously, a micro-perforated pressure relief valve connects the fourth flow channel to the concentrate interface, providing a discharge channel for high-pressure fluid during shutdown. The high-frequency on / off action of the flushing solenoid valves generates pulsed hydraulic oscillations within the reverse osmosis membrane module, effectively removing fouling from the membrane surface using the reciprocating impact force of the water flow, thus improving the self-cleaning effect of the reverse osmosis membrane. Furthermore, the micro-perforated pressure relief valve slowly releases the high-pressure fluid from the upstream end to the depressurized concentrate interface during booster pump shutdown, eliminating static pressure buildup within the pipeline, reducing the risk of component fatigue cracking, and extending the service life of the water circuit system.

[0017] Fourth, the high-frequency on / off switching of the flushing solenoid valve and the frequent start-stop operation of the booster pump will generate hydraulic impact within the enclosed integrated water circuit board, which can damage the solid walls of the flow channel. The gas-liquid buffer blind cavity utilizes the compressibility of the internal gas to provide a physical buffer space when local pressure changes occur in the water channel. The gas-liquid buffer blind cavity, integrally formed within the integrated water circuit board, can absorb the water hammer energy generated by the high-frequency flushing action and the pump's start-stop operation. This smooths out instantaneous pressure fluctuations within the flow channel, protects the integrated water circuit board from fatigue damage caused by hydraulic impact, and improves the structural stability of the entire system under complex hydraulic conditions.

[0018] Fifth, when reverse osmosis equipment is idle for extended periods, high concentrations of ions on the raw water side can permeate to the pure water side, causing a decline in the quality of the first cup of water upon restarting. This solution utilizes a storage container to pre-collect pure water. When the booster pump stops and triggers a replacement command, pure water is introduced into the second flow channel via a reflux control valve and reflux pipeline. The booster pump is then reused to pressurize the pure water into the reverse osmosis membrane module, replacing the concentrated water on the raw water side. By using the pure water reflux component to replace the water quality after system shutdown, the raw water side of the reverse osmosis membrane module is filled with pure water, reducing the osmotic pressure difference across the membrane and preventing stagnation caused by ion permeation during shutdown. This ensures the quality of the water dispensed when the user draws water again. This process reuses the existing booster pump as a power source, eliminating the need for an additional drive pump and simplifying the system's internal hardware structure.

[0019] Sixth, since both the return pipeline and the heat exchange pipeline are connected to the second flow channel, during the pure water return replacement period, there is a possibility that pure water may flow back into the heat exchange pipeline; during normal water production, pressurized raw water may also flow back into the storage container. The first and second one-way valves respectively impose strict one-way flow constraints on these two converging paths. The first one-way valve prevents the pure water used for replacement from flowing back into the heat exchange pipeline, avoiding the loss of pure water volume and ineffective mixing of hot and cold fluids; the second one-way valve prevents raw water from entering the storage container under normal water production conditions, avoiding contamination of the collected pure water. The one-way valves clearly define the water flow boundaries under different operating conditions, ensuring the independent operation of the pure water return function and the temperature-controlled heat exchange function.

[0020] Seventh, after the equipment is in standby mode and pure water replacement is complete, the reverse osmosis membrane module needs to be kept immersed in pure water. If the wastewater output is always connected to the outside, the pure water inside may gradually leak out to the concentrate interface due to gravity or siphon effect. The drain solenoid valve is closed when the system is stationary, cutting off the physical connection to the outside. The drain solenoid valve is closed when the system is in standby mode, cutting off the physical connection between the reverse osmosis membrane module and the external drain end, forming a closed internal circulation space. This allows the replaced pure water to remain inside the reverse osmosis membrane module for a long time, preventing pure water loss and maintaining the long-term effect of preventing osmotic pressure decline. Attached Figure Description

[0021] Figure 1 This is a structural diagram of the countertop reverse osmosis water purifier casing; Figure 2 This is a schematic diagram of the internal structure of a countertop reverse osmosis water purifier; Figure 3 This is a system topology diagram of a countertop reverse osmosis water purifier; Figure 4 This is a flowchart of the control method for a countertop reverse osmosis water purifier.

[0022] In the diagram, 100 is the water inlet; 101 is the pure water inlet; and 102 is the concentrated water inlet. 1. Chassis; 10. Integrated water circuit board; 11. First flow channel; 12. Second flow channel; 13. Third flow channel; 14. Fourth flow channel; 15. Gas-liquid buffer blind cavity; 20. Temperature-controlled directional valve; 30. Heat exchange piping; 31. Straight-through bypass pipe; 32. First check valve; 40. Booster pump; 50. Water storage container; 51. Reflux control valve; 52. Second check valve; 60. Reverse osmosis membrane module; 70. Wastewater balance valve; 71. Flushing solenoid valve; 72. Microporous pressure relief valve; 73. Drain solenoid valve. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings.

[0024] 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 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 invention.

[0025] This invention provides a countertop reverse osmosis water purifier and its control method. Through the basic flow channel of the integrated water circuit board 10, combined with a temperature control switching component and a heat exchange component, low-temperature heat compensation and high-temperature bypass protection are achieved. During shutdown, it works in conjunction with the pure water return component, the flushing solenoid valve 71, and the microporous pressure relief valve 72 to complete zero-stagnant water replacement, high-frequency descaling, and static pressure release of the reverse osmosis membrane. The steps and equipment operation logic are described in detail below.

[0026] Before detailing the embodiments of the present invention, some core technical terms and application scenarios will be explained first. The integrated water circuit board 10 is the central support for the internal fluids of the countertop reverse osmosis water purifier. It can be manufactured through integrated injection molding of polymer materials or by using a double-layer hot-melt welding process, thereby forming physically isolated first flow channels 11 to fourth flow channels 14 within a single entity, avoiding the risk of leakage caused by traditional hose splicing. The reverse osmosis membrane module 60 is the core component for desalination and purification. Its physical characteristics determine that the resistance of water molecules to permeate the membrane is inversely proportional to the water temperature. Under standard operating conditions of 25°C, the water production flux is typically 100%. When the water temperature drops to 5°C, the water production flux often decreases significantly to about 50% of the normal level. To intuitively demonstrate the control logic of the present invention, the following embodiments will construct a specific scenario of extremely cold winter conditions, setting the current ambient raw water inlet temperature to 5°C and the system's preset temperature threshold to 15°C.

[0027] S1. Obtain the temperature of the raw water flowing through the inlet 100. Specifically, the water temperature can be collected in real time by a temperature sensor located inside the inlet 100 or at the front end of the temperature control switching component. In the winter scenario described above, the temperature sensor detects that the current temperature of the raw water flowing into the inlet 100 is 5°C and transmits the temperature signal to the control system or directly to the temperature control element.

[0028] After obtaining the raw water temperature, S2. In response to the raw water temperature being lower than the preset temperature threshold, the temperature control switching component is controlled to direct the raw water to the heat exchange pipeline 30, so as to utilize the raw water to absorb the waste heat of the booster pump 40, and then pump the heated raw water into the reverse osmosis membrane module 60 for desalination treatment via the booster pump 40. The current raw water temperature is 5℃, which is lower than the preset temperature threshold of 15℃. The temperature-sensitive actuator such as the thermosensitive paraffin valve core or the electric drive motor in the temperature control reversing valve 20 is activated, opening the first outlet to the heat exchange pipeline 30. At this time, the raw water flows from the inlet port 100 into the first flow channel 11 of the integrated water circuit board 10, and is then guided by the temperature control reversing valve 20 into the heat exchange pipeline 30 coiled around the booster pump 40. Taking the booster pump 40 with an operating power of 24W as an example, part of the energy generated by its motor operation will be converted into motor waste heat. Cold raw water at 5°C flows through heat exchange pipe 30, absorbing some of the waste heat, resulting in a preheating increase in the temperature of the raw water exiting heat exchange pipe 30 compared to the inlet water temperature. The warmed raw water then flows into the second channel 12, is drawn into the booster pump 40 for pressurization, and is finally pumped into the reverse osmosis membrane module 60 via the third channel 13 and the fourth channel 14. This process achieves the transfer and reuse of heat within the system. On one hand, the increased temperature of the raw water after absorbing waste heat increases the activity of water molecules, thus passively compensating for the loss of permeate flux caused by the low temperature of the reverse osmosis membrane without consuming additional electrical energy for preheating. On the other hand, the flowing cold raw water provides an excellent liquid-cooled heat dissipation environment for the booster pump 40 motor, alleviating the problem of heat accumulation in the enclosed casing and delaying the thermal aging and degradation of the motor windings and rubber diaphragm.

[0029] To ensure that the raw water can fully absorb the heat dissipated by the motor as it flows through the heat exchange pipe 30, in some embodiments, the heat exchange pipe 30 is a spirally coiled metal heat-conducting pipe wound around the surface of the motor housing, with a heat-conducting medium filling the space between the heat exchange pipe 30 and the motor housing. The metal heat-conducting pipe can be made of copper, and the spiral coiling greatly increases the residence time and heat exchange area of ​​the raw water on the surface of the motor housing. The heat-conducting medium can be thermally conductive silicone grease or liquid thermally conductive adhesive, which fills the microscopic air gap between the metal heat-conducting pipe and the motor housing, significantly reducing the contact thermal resistance and ensuring that the waste heat generated by the booster pump 40 can be transferred to the internally flowing raw water more quickly and with low loss.

[0030] The above describes one embodiment of the heat exchange assembly, namely a spiral metal tube combined with a heat-conducting medium. In other embodiments, the heat exchange assembly may include a liquid-cooled jacket integrally die-cast onto the surface of the motor housing. The liquid-cooled jacket has reciprocating microchannels machined inside, which serve as heat exchange pipes 30. Unlike a spirally wound independent metal tube, the liquid-cooled jacket is directly part of the motor housing. When the raw water flows through the microchannels of the jacket, it directly exchanges heat with the heated stator outer wall. The liquid-cooled jacket can also achieve the purpose of increasing the heat transfer area and eliminating contact thermal resistance, and therefore also belongs to the embodiment of using raw water to absorb the waste heat of the booster pump 40.

[0031] In addition to the heat compensation mechanism under low-temperature conditions mentioned above, the countertop reverse osmosis water purifier of the present invention also has an adaptive bypass protection function for high-temperature conditions. Specifically, S3. In response to the raw water temperature being greater than or equal to a preset temperature threshold, the temperature control switching component is controlled to guide the raw water to the direct bypass pipe 31, and the raw water is pumped into the reverse osmosis membrane module 60 via the booster pump 40 for desalination treatment. Under summer conditions, the raw water temperature obtained by the temperature sensor reaches 30°C, which is greater than the preset temperature threshold of 15°C. At this time, the valve core in the temperature control reversing valve 20 switches, opening the inlet of the direct bypass pipe 31. Through the switching of fluid routing, the raw water no longer enters the heat exchange pipe 30 attached to the periphery of the booster pump 40 motor housing, but instead flows directly into the second flow channel 12 via the direct bypass pipe 31 and then into the suction port of the booster pump 40. Thermal isolation here refers to the process where, under high-temperature operating conditions, the raw water bypasses the heat exchange pipeline 30, which is the main heat exchange component. This prevents the raw water from lingering along the periphery of the motor casing and continuously absorbing waste heat from the motor before entering the booster pump 40. After entering the booster pump 40, the raw water mainly flows through the pump head water passage. Its residence time in the pump chamber is relatively short, and there is a structural gap between the pump head water passage and the motor casing, preventing the formation of a continuous heat exchange path similar to that of the heat exchange pipeline 30. This reduces the risk of the high-temperature raw water being further heated before entering the reverse osmosis membrane module 60, thereby protecting the membrane life of the reverse osmosis membrane module 60.

[0032] During water production, or at the beginning and end of the water production cycle, the system needs to perform periodic self-cleaning of the reverse osmosis membrane module 60. In some embodiments, the control method includes a high-frequency flushing step: S5. In response to a high-frequency flushing command, the flushing solenoid valve 71 connected in parallel to the wastewater output end of the reverse osmosis membrane module 60 is controlled to periodically open and close at a preset frequency, generating hydraulic oscillations inside the reverse osmosis membrane module 60 to remove deposits from the membrane surface. The flushing solenoid valve 71 performs rapid on-off actions at a specific frequency of 2Hz to 5Hz, and a large flow of raw water is continuously cut off and released in the pipeline. This drastic change in dynamic pressure generates pulsed hydraulic oscillations inside the raw water side of the reverse osmosis membrane module 60, utilizing the reciprocating physical impact force generated by the high-frequency water hammer effect to improve the removal effect of calcium and magnesium ion scale and colloidal deposits, restoring the water permeation flux of the reverse osmosis membrane.

[0033] Because the high-frequency switching of the flushing solenoid valve 71 and the frequent start-stop of the booster pump 40 can generate instantaneous water hammer impacts within the system, in some embodiments, the countertop reverse osmosis water purifier also includes a gas-liquid buffer blind cavity 15. The gas-liquid buffer blind cavity 15 is integrally formed inside the integrated water circuit board 10 and is connected to the third flow channel 13 or the fourth flow channel 14 on the high-pressure side. During the initial water filling of the system, the top of the gas-liquid buffer blind cavity 15 naturally seals in a portion of the air that cannot be expelled, forming an elastic gas-liquid interface. When a transient pressure spike occurs in the pipeline, the air sealed in the blind cavity is hydraulically compressed, passively absorbing and suppressing this portion of the water hammer destructive energy, protecting the solid wall of the integrated water circuit board 10 from fatigue damage. In other embodiments, an externally connected elastic diaphragm accumulator connected to the third flow channel 13 can be used instead, where a pre-charged high-pressure nitrogen-filled rubber diaphragm deforms to absorb hydraulic fluctuations within the pipeline network.

[0034] When water production or flushing is completed and the user stops drawing water, the system enters a static standby state. To this end, the control system executes a static pressure relief step: S6. In response to the booster pump 40 being in a stopped and static state without a replacement command, the microporous pressure relief valve 72 is activated to release the high-pressure fluid at the inlet of the reverse osmosis membrane module 60 to the concentrate interface 102. The microporous pressure relief valve 72 has an extremely small normally open throttling orifice diameter of 0.1 mm. In the static state after the booster pump 40 is stopped and powered off, the high-pressure static water residing in the fourth flow channel 14 can bypass the closed drain solenoid valve 73 through this microporous path, slowly and continuously releasing to the atmospheric pressure concentrate interface 102. This eliminates the high static pressure in the pipeline network during long-term standby, avoiding the risk of creep cracking of the filter membrane housing due to long-term pressure buildup.

[0035] After the system is shut down and enters a long standby state, the high concentration of concentrate remaining on the feed water side of the reverse osmosis membrane, while the low concentration of pure water remains on the pure water side, will slowly diffuse through the reverse osmosis membrane to the pure water side due to the natural osmotic pressure difference. This phenomenon is called TDS creep, forming so-called stagnant water. To eliminate this problem, the control system triggers the pure water reflux replacement logic: S4. In response to the shutdown replacement command for the booster pump 40, the pure water reflux component is activated, guiding the pre-stored pure water to the suction port of the booster pump 40, and the booster pump 40 pumps the pure water into the inlet of the reverse osmosis membrane module 60, so as to replace the stagnant concentrate in the feed water side of the reverse osmosis membrane module 60 with pure water.

[0036] Specifically, S4 includes the following sub-steps: S41. In response to the shutdown replacement command, the reflux control valve 51 is opened, and the drain solenoid valve 73 is opened simultaneously. At this time, the physical channel for reflux and sewage discharge is opened. S42. The booster pump 40 is driven to run, drawing pure water from the water storage container 50 into the reverse osmosis membrane module 60, and displacing the concentrate into the concentrate interface 102 via the drain solenoid valve 73. The booster pump 40 can operate at low frequency, actively drawing pure water from the water storage container 50. The pure water rushes in from the inlet end, pushing the high-concentration resident concentrate on the raw water side forward. S43. In response to the pure water replacement process reaching the preset time threshold, the booster pump 40 is stopped, and the reflux control valve 51 and the drain solenoid valve 73 are closed. The control system calculates the amount of pure water required for complete replacement based on the internal volume of the reverse osmosis membrane housing and sets the preset time threshold to 60 seconds. After 60 seconds, the concentrate has been 100% replaced with pure water, and the valve is simultaneously closed, placing the reverse osmosis membrane module 60 in a physically isolated state of pure water immersion. At this point, the osmotic pressure difference is leveled off, eliminating ion permeation during standby.

[0037] The above describes an implementation method for determining the end point of the replacement process based on a preset time threshold. In other embodiments, a TDS conductivity sensor can be installed near the wastewater output end of the reverse osmosis membrane module 60. During the replacement process, the TDS value of the discharged wastewater is acquired in real time. When the TDS value of the discharged wastewater decreases and stabilizes at an extremely low threshold such as below 10 ppm, it indicates that the concentrate on the raw water side has been completely replaced by pure water, and the system issues a command to stop the replacement and close the valve to maintain pressure. This feedback control method is also an alternative implementation method for the pure water replacement determination step.

[0038] To ensure bidirectional interference prevention of the system, the pure water reflux assembly also includes a first one-way valve 32 and a second one-way valve 52. The first one-way valve 32 is located between the output end of the heat exchange pipeline 30 and the second flow channel 12 to prevent pure water released from the water storage container 50 from flowing back into the heat exchange pipeline 30, thus avoiding waste of pure water resources. The second one-way valve 52 is located on the reflux pipeline to prevent raw water in the second flow channel 12 from entering the water storage container 50. During normal pressurization and water supply, the second one-way valve 52 eliminates the possibility of unpurified raw water entering the water storage container 50 and contaminating the pure water.

[0039] Based on the above control method, this embodiment of the invention provides a physical countertop reverse osmosis water purifier that executes the above logic. The device uses an integrated water circuit board 10, internally formed with mutually isolated first flow channels 11 to fourth flow channels 14, as the central hub of the piping network. It is equipped with a booster pump 40, a reverse osmosis membrane module 60, a temperature-controlled reversing valve 20, a direct bypass pipe 31, and a heat exchange pipe 30 spirally wrapped around the motor housing. One end of the first flow channel 11 is connected to the water inlet 100, and the other end is connected to the inlet of the temperature-controlled reversing valve 20. The first outlet of the temperature-controlled reversing valve 20 is connected to the input end of the heat exchange pipe 30, and the second outlet is connected to the input end of the direct bypass pipe 31. The output end of the heat exchange pipe 30 and the output end of the direct bypass pipe 31 converge and connect to one end of the second flow channel 12. The other end of the second flow channel 12 is connected to the suction port of the booster pump 40. The pressure port of the booster pump 40 is connected to one end of the third flow channel 13, and the other end of the third flow channel 13 is connected to the inlet of the reverse osmosis membrane module 60 through the fourth flow channel 14. All the above control steps are executed in coordination by the water circuit structure and the electronically controlled valves in the countertop reverse osmosis water purifier, ultimately achieving high-efficiency operation of the whole machine.

[0040] The above embodiments are merely explanations of the present invention and are not intended to limit the present invention. After reading this specification, those skilled in the art can make modifications to these embodiments without contributing any inventive step, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A countertop reverse osmosis water purifier, comprising a reverse osmosis membrane assembly (60), a booster pump (40), an integrated water circuit board (10), a temperature control switching assembly, and a heat exchange assembly; further comprising a water inlet (100), a pure water inlet (101), and a concentrated water inlet (102), characterized in that: The integrated water circuit board (10) is provided with a first flow channel (11), a second flow channel (12), a third flow channel (13) and a fourth flow channel (14) that are isolated from each other; The temperature control switching assembly includes a temperature control reversing valve (20) and a direct bypass pipe (31); the heat exchange assembly includes a heat exchange pipe (30) that is attached to the periphery of the motor housing of the booster pump (40); The first flow channel (11) is connected at both ends to the water inlet (100) and the inlet of the temperature control reversing valve (20); The first outlet of the temperature control reversing valve (20) is connected to the input end of the heat exchange pipeline (30), and the second outlet is connected to the input end of the straight bypass pipe (31); The heat exchange pipeline (30) and the output end of the straight bypass pipeline (31) merge and are connected to the suction port of the booster pump (40) via the second flow channel (12); The pressure port of the booster pump (40) is connected to the inlet of the reverse osmosis membrane module (60) via the third flow channel (13) and the fourth flow channel (14) in sequence; The pure water output end of the reverse osmosis membrane module (60) is connected to the pure water interface (101), and the wastewater output end is connected to the concentrated water interface (102). The temperature-controlled reversing valve (20) is provided with a temperature-sensing actuator, which is configured to: in response to the raw water temperature in the first flow channel (11) being lower than a preset temperature threshold, drive the temperature-controlled reversing valve (20) to open the first outlet and close the second outlet; in response to the raw water temperature being greater than or equal to the preset temperature threshold, drive the temperature-controlled reversing valve (20) to open the second outlet and close the first outlet.

2. The countertop reverse osmosis water purifier according to claim 1, characterized in that, The heat exchange pipe (30) is a metal heat-conducting pipe spirally wound on the surface of the motor housing, and a heat-conducting medium is filled between the heat exchange pipe (30) and the motor housing.

3. The countertop reverse osmosis water purifier according to claim 1, characterized in that, Also includes: Wastewater balancing valve (70), flushing solenoid valve (71), and micro-orifice pressure relief valve (72); The wastewater balancing valve (70) is connected between the wastewater output end of the reverse osmosis membrane module (60) and the concentrate interface (102); The flushing solenoid valve (71) is connected in parallel to both ends of the wastewater balance valve (70). The flushing solenoid valve (71) is configured to perform a high-frequency on / off action in response to a flushing command, so as to generate hydraulic oscillations inside the reverse osmosis membrane module (60) to remove the deposits on the membrane surface. One end of the microporous pressure relief valve (72) is connected to the fourth flow channel (14), and the other end of the microporous pressure relief valve (72) is connected to the concentrate interface (102). The microporous pressure relief valve (72) is configured to release the resident high-pressure fluid at the inlet of the reverse osmosis membrane module (60) to the concentrate interface (102) during the shutdown of the booster pump (40).

4. The countertop reverse osmosis water purifier according to claim 3, characterized in that, Also includes: Gas-liquid buffer blind cavity (15); The gas-liquid buffer blind cavity (15) is integrally formed inside the integrated water circuit board (10) and connected to the third flow channel (13) or the fourth flow channel (14) to absorb the hydraulic shock generated when the flushing solenoid valve (71) is switched on and off at high frequency and when the booster pump (40) is started and stopped.

5. The countertop reverse osmosis water purifier according to claim 1, characterized in that, It also includes a pure water reflux assembly, which includes a water storage container (50), a reflux pipeline, and a reflux control valve (51); The inlet of the water storage container (50) is connected to the pure water interface (101) or the pure water output of the reverse osmosis membrane module (60) to collect pure water; One end of the return pipe is connected to the outlet of the water storage container (50), and the other end of the return pipe is connected to the second flow channel (12). The reflux control valve (51) is located on the reflux pipeline. The reflux control valve (51) is configured to: open the reflux pipeline in response to the replacement command triggered by the shutdown of the booster pump (40) so as to guide the pure water in the water storage container (50) to the second flow channel (12) and pump it into the inlet of the reverse osmosis membrane module (60) via the booster pump (40) so as to replace the resident concentrate on the raw water side of the reverse osmosis membrane module (60).

6. The countertop reverse osmosis water purifier according to claim 5, characterized in that, The pure water reflux assembly also includes: First check valve (32) and second check valve (52); The first one-way valve (32) is located between the output end of the heat exchange pipeline (30) and the second flow channel (12) to prevent the pure water released from the water storage container (50) from flowing back into the heat exchange pipeline (30); The second one-way valve (52) is installed on the return pipeline to prevent the raw water in the second flow channel (12) from entering the water storage container (50).

7. The countertop reverse osmosis water purifier according to claim 1, characterized in that, Also includes: Concentrate discharge pipeline and drain solenoid valve (73); One end of the concentrate discharge pipeline is connected to the wastewater output end of the reverse osmosis membrane module (60), and the other end of the concentrate discharge pipeline is connected to the concentrate interface (102). The drain solenoid valve (73) is installed on the concentrate discharge pipeline. The drain solenoid valve (73) is configured to open when the reverse osmosis membrane module (60) performs desalination or flushing treatment, and to close when the system is in standby and static state to cut off the physical connection with the external drain end.

8. A control method for a countertop reverse osmosis water purifier as described in any one of claims 1 to 7, characterized in that, include: S1. Obtain the temperature of the raw water flowing through the inlet (100); S2. In response to the raw water temperature being lower than the preset temperature threshold, the temperature control switching component is controlled to direct the raw water to the heat exchange pipeline (30) so as to utilize the raw water to absorb the waste heat of the booster pump (40) and pump the heated raw water into the reverse osmosis membrane module (60) via the booster pump (40) to perform desalination treatment. S3. In response to the raw water temperature being greater than or equal to a preset temperature threshold, the temperature control switching component is controlled to direct the raw water to the direct bypass pipe (31) and pump the raw water into the reverse osmosis membrane module (60) via the booster pump (40) to perform desalination treatment; S4. In response to the shutdown and replacement command for the booster pump (40), the pure water return component is turned on to guide the pre-stored pure water to the suction port of the booster pump (40) and pump the pure water into the inlet of the reverse osmosis membrane module (60) through the booster pump (40) so as to replace the resident concentrate in the raw water side of the reverse osmosis membrane module (60) with pure water.

9. The control method according to claim 8, characterized in that, S4 includes the following sub-steps: S41. In response to the shutdown replacement command, the return flow control valve (51) is opened, and the drain solenoid valve (73) is opened synchronously. S42. Drive the booster pump (40) to run, draw pure water from the water storage container (50) into the reverse osmosis membrane module (60), and discharge the displaced concentrate into the concentrate port (102) through the drain solenoid valve (73); S43. In response to the pure water replacement process reaching a preset time threshold, stop the booster pump (40) and close the reflux control valve (51) and the drain solenoid valve (73) so that the reverse osmosis membrane module (60) is in a physically isolated pure water immersion state.

10. The control method according to claim 8, characterized in that, It also includes the following steps: S5. In response to the high-frequency flushing command, the flushing solenoid valve (71) connected in parallel to the wastewater output end of the reverse osmosis membrane module (60) is controlled to open and close periodically at a preset frequency, generating hydraulic oscillations inside the reverse osmosis membrane module (60) for stripping the membrane surface of the deposits. S6. In response to the booster pump (40) being in a stationary state where it is stopped and no replacement command is executed, the micropore pressure relief valve (72) is opened to release the high-pressure fluid at the inlet of the reverse osmosis membrane module (60) to the concentrate interface (102).

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