A method for automatic waste discharge of a water purifier based on a shutdown stagnation state

Abstract

The application discloses a kind of based on the automatic waste discharge method of water purifier of shutdown stagnation state, by microcontroller execution, this method enters standby state when reverse osmosis water purifier, based on the running state initialization concentration evolution parameter of last water production cycle;According to preset sampling period, obtain current sampling temperature parameter, and input shutdown evolution mapping model to determine concentration evolution rate;Concentration evolution parameter is updated based on concentration evolution rate and sampling period accumulation;When concentration evolution parameter reaches waste discharge trigger threshold, control booster pump to open and control waste water discharge valve to alternate conduction and cut-off, to form pulse waste water flow and discharge stagnation waste water, and zero concentration evolution parameter after waste discharge is completed.The application can dynamically determine the opportunity of waste discharge, reduce short-time shutdown invalid waste discharge, and reduce the risk of membrane fouling and first cup water TDS increase caused by long-time shutdown.

Description

Technical Field

[0001] This application relates to the field of water purification equipment control, and in particular to an automatic waste discharge method for a water purifier based on a shutdown and stagnation state. Background Technology

[0002] When existing reverse osmosis water purifiers stop producing water and enter standby mode, residual wastewater usually remains on the concentrate side for a long time inside the reverse osmosis membrane module and concentrate flow path. In existing technologies, the wastewater retained on the concentrate side is mostly treated by static control logic that discharges wastewater at fixed intervals (e.g., automatically opening valves every set number of hours) or by uniformly discharging wastewater before starting the machine.

[0003] However, the reverse osmosis membrane module is not in a static and stable state during shutdown. Driven by the physical difference in osmotic pressure across the membrane and coupled with the influence of external ambient temperature, the retained wastewater on the concentrate side will continuously undergo concentration evolution. This concentration evolution process exhibits nonlinear characteristics in objective physics: in the initial stage of shutdown, the reverse diffusion of ions and wastewater concentration are relatively slow; as the shutdown duration increases and the ambient temperature varies, the rate of change of the concentration of the retained wastewater on the concentrate side will increase sharply at certain stages.

[0004] Because the existing single fixed-time wastewater discharge logic lacks adaptation to the above dynamic evolution law, it cannot comprehensively assess the true concentration state of the wastewater retained on the concentrate side based on real-time temperature parameters and shutdown duration, resulting in the same technical defect: at low temperatures or during short shutdowns, the wastewater is ineffectively discharged before it has been significantly concentrated, wasting water resources; at high temperatures or during long shutdowns, the wastewater concentration has already increased sharply, but it cannot be discharged in time because the fixed wastewater discharge cycle has not been reached, causing scaling of the reverse osmosis membrane module and abnormally high TDS of the first cup water.

[0005] Therefore, the technical problem that urgently needs to be solved in this field is to provide a control method that can dynamically assess the evolution of the concentrated wastewater on the concentrate side based on real-time temperature parameters and downtime, and trigger waste discharge in a timely manner. Summary of the Invention

[0006] This addresses the technical problems of existing water purifiers being unable to dynamically assess the concentration evolution of stagnant wastewater on the concentrate side based on real-time temperature parameters and downtime, resulting in ineffective wastewater discharge and water waste during low temperatures or short-term shutdowns, and untimely wastewater discharge during high temperatures or long-term shutdowns, leading to membrane scaling and abnormally high TDS in the first cup of water.

[0007] This application provides an automatic waste discharge method for a water purifier based on a shutdown and stagnation state. The method is applied to a reverse osmosis water purifier comprising a reverse osmosis membrane module, a temperature sensor, a booster pump, a wastewater discharge valve, a storage unit, and a microcontroller. The method is executed by the microcontroller and includes: S1. When the reverse osmosis water purifier enters the standby state, a preset initial value is determined based on the water production time of the previous water production cycle, and the concentration evolution parameters are initialized with the preset initial value; S2. According to the preset sampling period, monitor whether the reverse osmosis water purifier maintains the standby state: if it maintains the standby state, obtain the current sampling temperature parameter through the temperature sensor and proceed to S3; if it exits the standby state, transfer the current concentration evolution parameter as a historical parameter to the storage unit and end the current sampling period. S3. Input the current sampling temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate; S4. Based on the condensation evolution rate and the sampling period, calculate the condensation evolution increment for the current sampling period, and update the condensation evolution parameters by accumulating the condensation evolution increment; S5. Determine whether the updated concentration evolution parameters have reached the waste discharge trigger threshold: If the waste discharge trigger threshold is reached, control the booster pump to start and control the wastewater discharge valve to alternately perform the on and off actions to form a pressure pulse wastewater flow on the concentrate side of the reverse osmosis membrane module, thereby discharging the stagnant wastewater, and clear the concentration evolution parameters after the waste discharge is completed; if the waste discharge trigger threshold is not reached, return to S2 to enter the next sampling cycle.

[0008] Through the above technical solutions, combined with the previous water production cycle status and historical parameter transfer mechanism, continuous tracking of the concentrated state of retained wastewater throughout its entire life cycle is achieved. At the same time, by combining the shutdown evolution mapping model, the ion diffusion process affected by ambient temperature is transformed into a dynamic digital quantitative index, which adapts to the actual waste discharge critical point under different environments. This avoids premature and ineffective waste discharge under low-temperature short-term conditions and prevents the risk of scaling under high-temperature long-term conditions. When waste discharge is triggered, water hammer pulse jets are further induced by controlling the alternating action of the wastewater discharge valve. The intermittent physical shear force is used to improve the stripping efficiency of locally highly concentrated wastewater, achieving deep descaling and long-term water saving while compressing the water volume.

[0009] Optionally, determining the preset initial value based on the water production duration of the previous water production cycle includes: When the water production duration of the previous water production cycle is greater than or equal to the preset duration threshold, the preset initial value is determined to be zero. When the water production duration of the previous water production cycle is less than the preset duration threshold, the preset initial value is determined to be the historical parameter transferred in the storage unit.

[0010] Optionally, the shutdown evolution mapping model is a two-dimensional data lookup table embedded in the microcontroller; The step of inputting the current sampled temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate includes: Get the current cumulative downtime; The current sampling temperature parameter and the current cumulative downtime are used as two-dimensional addressing indexes and input into the two-dimensional data lookup table. The corresponding values ​​are matched and extracted, and the values ​​are used as the concentration evolution rate. The two-dimensional data lookup table pre-stores numerical mapping relationships between discrete temperature ranges, discrete downtime ranges, and concentration evolution rates.

[0011] Optionally, the shutdown evolution mapping model is an exponential function mapping model; The step of inputting the current sampled temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate includes: Convert the current sampled temperature parameter into an absolute temperature; Based on the preset membrane material constant, ion permeation activation energy constant, ideal gas constant, and absolute temperature, the concentration evolution rate is calculated using an exponential function mapping model with the natural constant as the base. Wherein, the exponential term of the exponential function mapping model is negative, and the absolute value of the exponential term is the ratio of the ion permeation activation energy constant to the product term, wherein the product term is the product of the ideal gas constant and the absolute temperature.

[0012] Optionally, controlling the wastewater discharge valve to alternately perform opening and closing actions includes: Obtain the preset pulse on-time, pulse off-time, and target waste discharge cycle; The wastewater discharge valve is controlled to open according to the pulse opening duration and close according to the pulse closing duration; The switching on and off actions are performed repeatedly until the cumulative time of the alternating actions reaches the target waste discharge cycle; Wherein, the pulse on-time is less than the pulse off-time.

[0013] Optionally, the pulse on-time is 0.5 to 3 seconds, the pulse off-time is 2 to 8 seconds, and the target waste discharge cycle is 10 to 30 seconds.

[0014] Optionally, before controlling the wastewater discharge valve to alternately perform the on and off actions according to the pulse on duration and the pulse off duration, the method further includes: Calculate the excess difference between the updated enrichment evolution parameters and the waste discharge trigger threshold; Based on the aforementioned excess difference and the preset cleaning time mapping relationship, the current target waste discharge cycle is determined; The larger the difference in the excess value, the longer the target waste discharge cycle is determined.

[0015] Optionally, S4 includes: Obtain the cumulative water production time of the reverse osmosis membrane module; The corresponding attenuation compensation coefficient is determined based on the cumulative water production time. The attenuation compensation coefficient is used to characterize the membrane performance status of the reverse osmosis membrane module as the usage time changes. The concentration evolution rate is corrected according to the attenuation compensation coefficient to obtain the corrected concentration evolution rate; Based on the corrected condensation evolution rate and the sampling period, calculate the condensation evolution increment for the current sampling period; The enriched evolution parameters from the previous sampling period are added to the enriched evolution increment to obtain the updated enriched evolution parameters.

[0016] Optionally, the preset sampling period is 30 seconds to 5 minutes.

[0017] Optionally, the reverse osmosis water purifier further includes a communication module; After waste discharge is completed and the concentration evolution parameters are reset to zero, the method further includes: Generate a waste removal execution record that includes the trigger time, the target waste removal cycle, and the waste removal execution status; The communication module is controlled to send the waste discharge execution record to a preset user terminal.

[0018] In summary, this application includes at least one of the following beneficial technical effects: 1. In standby mode, a preset initial value based on historical operating conditions is introduced, and the current sampling temperature parameter is obtained according to a preset sampling period. Combined with the shutdown evolution mapping model, the concentration evolution increment is discretely accumulated, thereby transforming the complex nonlinear ion diffusion process, which is coupled with shutdown time and ambient temperature, into a continuous and quantitative digital evaluation index (concentration evolution parameter). This scheme effectively overcomes the technical bottleneck of existing fixed-time waste discharge logic being unable to adapt to dynamic concentration changes, and can dynamically lock the real waste discharge critical point based on the real-time thermodynamic environment and actual shutdown conditions. This avoids the ineffective waste of water resources caused by premature cleaning under low temperature or short-term shutdown conditions, and reduces the risk of reverse osmosis membrane module scaling and abnormally high total dissolved solids (TDS) in the first cup water due to delayed waste discharge under high temperature or long-term shutdown conditions.

[0019] 2. This invention controls the wastewater discharge valve to alternately perform opening and closing actions within the target wastewater discharge cycle. Utilizing the pressure buildup and release processes created by the periodic opening and closing of the valve body, transient water hammer pulse jets are induced within the concentrated wastewater discharge path. The high-frequency fluid physical shear force generated by this pulse jet can create intermittent, powerful disturbances and impacts on the high-concentration enrichment area on the membrane surface. Compared to the traditional continuous open direct discharge method, this invention significantly improves the stripping and discharge efficiency of locally highly concentrated retained wastewater while significantly reducing the physical water volume required for a single cleaning cycle, achieving a technical unity of deep descaling and high-efficiency water saving. Attached Figure Description

[0020] Figure 1 A flowchart illustrating an automatic waste discharge method for a water purifier based on a shutdown and stagnation state, provided by an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the cumulative changes in the condensation evolution parameters provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the membrane performance degradation compensation coefficient provided in an embodiment of the present invention; Figure 4 The timing diagram for pulse control of the wastewater discharge valve is provided for an embodiment of the present invention. Detailed Implementation

[0021] The following is combined with Figures 1 to 4 This application will be described in further detail below. It should be understood that the following embodiments are used to illustrate the technical solution of this application and are not intended to limit the scope of protection of this application.

[0022] This embodiment provides an automatic waste discharge method for a water purifier based on a shutdown and stagnation state. This method is applied to a reverse osmosis water purifier. The reverse osmosis water purifier includes a reverse osmosis membrane module, a temperature sensor, a booster pump, a wastewater discharge valve, a storage unit, a microcontroller, and a communication module.

[0023] The reverse osmosis membrane module is used to filter raw water through reverse osmosis, forming a purified water side and a concentrated water side; a temperature sensor is used to obtain the current sampling temperature parameters of the environment or water path near the reverse osmosis water purifier; a booster pump is used to provide fluid pressure for the reverse osmosis membrane module and the concentrated water discharge path; a wastewater discharge valve is set on the concentrated water discharge path to control the discharge of wastewater retained on the concentrated water side; a storage unit is used to store the shutdown evolution mapping model, wastewater discharge trigger threshold, historical parameters, and operation records; a microcontroller is used to execute the automatic wastewater discharge control logic of this embodiment; and a communication module is used to send the wastewater discharge execution records to the user terminal.

[0024] Combination Figures 1 to 4 As shown, the automatic waste discharge method in this embodiment includes the following steps: S1. When the reverse osmosis water purifier enters standby mode, the microcontroller determines the preset initial value based on the water production duration of the previous water production cycle, and initializes the concentration evolution parameters with the preset initial value.

[0025] Specifically, when the microcontroller detects that the reverse osmosis water purifier has stopped producing water and the booster pump has stopped running, it determines that the reverse osmosis water purifier has entered standby mode. At this time, the microcontroller reads the water production duration of the previous water production cycle and determines the preset initial values ​​of the concentration evolution parameters based on the water production duration.

[0026] In one implementation, when the water production time of the previous water production cycle is greater than or equal to a preset time threshold, it indicates that the raw water has flushed the concentrate side of the reverse osmosis membrane module and the concentrate discharge path for a certain period of time, and the degree of replacement of the retained wastewater on the concentrate side is relatively high. The microcontroller sets the preset initial value to zero and initializes the concentration evolution parameters with zero.

[0027] In another implementation, if the water production duration of the previous water production cycle is less than a preset duration threshold, it indicates that the previous water production cycle was short, the raw water did not have enough time to flush the concentrate side, and there may still be a high concentration of stagnant wastewater remaining on the concentrate side. At this time, the microcontroller reads the historical parameters transferred from the previous monitoring cycle from the storage unit and uses these historical parameters as preset initial values ​​to initialize the concentration evolution parameters.

[0028] For example, the preset duration threshold can be 30 seconds. When the user stops using water after only 10 seconds, the microcontroller uses the historical parameters stored in the memory unit as the new preset initial value; when the user stops using water after more than 30 seconds, the microcontroller sets the preset initial value to zero.

[0029] In this way, the concentration evolution parameters will not be directly reset to zero due to short-term water intake, and the retention status of the concentrate side can be continuously tracked.

[0030] S2. According to the preset sampling cycle, monitor whether the reverse osmosis water purifier maintains standby mode: if it maintains standby mode, obtain the current sampling temperature parameter through the temperature sensor and proceed to S3; if it exits standby mode, transfer the current concentration evolution parameter as historical parameter to the storage unit and end the current sampling cycle.

[0031] The microcontroller monitors whether the reverse osmosis water purifier remains in standby mode according to a preset sampling period. The preset sampling period can be from 30 seconds to 5 minutes. In this embodiment, the sampling period can be set to 60 seconds.

[0032] If the reverse osmosis water purifier remains in standby mode, the microcontroller obtains the current sampled temperature parameter through the temperature sensor and proceeds to step S3.

[0033] If the reverse osmosis water purifier exits standby mode, for example, when the user starts drawing water, the booster pump restarts, or the system enters water production mode, the microcontroller will transfer the current concentration evolution parameters as historical parameters to the storage unit and end the current sampling cycle.

[0034] The purpose of this approach is to address the issue that when users take a small amount of water for a short period, the concentrate side of the reverse osmosis membrane module may not be adequately flushed. If the concentration evolution parameters are directly reset to zero, the concentration status during the next standby period may be underestimated. By storing the current concentration evolution parameters as historical parameters, the microcontroller can determine whether to inherit these historical parameters when entering standby mode next time, based on the water production duration of the previous water production cycle.

[0035] S3. Input the current sampling temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate.

[0036] The microcontroller determines the corresponding concentration evolution rate based on the current sampled temperature parameters through a shutdown evolution mapping model.

[0037] In one implementation, the shutdown evolution mapping model is a two-dimensional data lookup table embedded within the microcontroller. The microcontroller acquires the current sampled temperature parameter and the current cumulative shutdown duration, and uses the current sampled temperature parameter and the current cumulative shutdown duration as two-dimensional addressing indices to input into the two-dimensional data lookup table. It then matches and extracts the corresponding values, using these values ​​as the condensed evolution rate.

[0038] The two-dimensional data lookup table pre-stores the numerical mapping relationships between discrete temperature ranges, discrete downtime ranges, and concentration evolution rates.

[0039] Table 1. Two-dimensional data lookup table pre-stored inside the microcontroller

[0040] Among them, v11 to v44 represent the concentration evolution rates pre-calibrated through shutdown concentration tests of the same type of reverse osmosis membrane modules under different ambient temperatures and shutdown durations. The current sampling temperature parameter is used to characterize the effect of temperature on ion diffusion rate, and the current cumulative shutdown duration is used to characterize the staged concentration changes of retained wastewater as the shutdown time increases. By simultaneously using the temperature dimension and the shutdown duration dimension for addressing, the matching degree between the concentration evolution rate and the actual shutdown retention state can be improved.

[0041] In another implementation, the shutdown evolution mapping model is an exponential function mapping model. The microcontroller converts the current sampled temperature parameter into an absolute temperature and calculates the concentration evolution rate based on the preset membrane material constant, ion permeation activation energy constant, ideal gas constant, and absolute temperature, using an exponential function mapping model with the natural constant as the base.

[0042] The exponential function mapping model can be expressed as: v = A·exp[-Ea / (R·TK)]; In the formula, v is the concentration evolution rate; A is a preset membrane material constant; Ea is a preset ion permeation activation energy constant; R is the ideal gas constant; TK is the absolute temperature obtained by converting the current sampling temperature parameter, and TK = T + 273.15. The exponential term of the exponential function mapping model is negative, and the absolute value of the exponential term is the ratio of the ion permeation activation energy constant to the product term, which is the product of the ideal gas constant and the absolute temperature.

[0043] In practical applications, the membrane material constant A and the ion permeation activation energy constant Ea can be obtained by fitting the concentration test data of the same type of reverse osmosis membrane module under different temperature conditions during shutdown. When using a two-dimensional data lookup table, the computational load of the microcontroller is low, making it suitable for low-cost controllers; when using an exponential function mapping model, the concentration evolution rate can be calculated through a continuous function, making it suitable for controllers with floating-point arithmetic capabilities.

[0044] S4. Based on the condensation evolution rate and sampling period, calculate the condensation evolution increment for the current sampling period, and update the condensation evolution parameters by accumulating the condensation evolution increment.

[0045] The microcontroller calculates the condensation evolution increment for the current sampling period based on the condensation evolution rate and the sampling period, and updates the condensation evolution parameters by accumulating the condensation evolution increment.

[0046] In one implementation, the enrichment evolution increment for the current sampling period can be calculated as follows: ΔC = v·Ts; In the formula, ΔC is the enrichment evolution increment of the current sampling period; v is the enrichment evolution rate; and Ts is the sampling period.

[0047] Subsequently, the microcontroller updates the condensation evolution parameters as follows: Cnew = Cold + ΔC; In the formula, Cnew is the updated condensed evolution parameter; Cold is the condensed evolution parameter of the previous sampling period.

[0048] In another implementation, the microcontroller can also adjust the concentration evolution rate based on the cumulative water production time of the reverse osmosis membrane module. Specifically, the storage unit records the cumulative water production time of the reverse osmosis membrane module, the microcontroller obtains the current cumulative water production time of the reverse osmosis membrane module, and determines the corresponding attenuation compensation coefficient based on the cumulative water production time. The attenuation compensation coefficient is used to characterize the membrane performance state of the reverse osmosis membrane module as it changes over time.

[0049] Combination Figure 3As shown, the attenuation compensation coefficient k can change with the increase of cumulative water production time. The microcontroller can determine the corresponding attenuation compensation coefficient k by looking up a table based on the cumulative water production time. For example, different attenuation compensation coefficients correspond to different cumulative water production time intervals.

[0050] In one specific implementation, the microcontroller corrects the concentration evolution rate based on the attenuation compensation coefficient to obtain the corrected concentration evolution rate: v'=v / k; In the formula, v' is the corrected condensation evolution rate; v is the condensation evolution rate determined by the shutdown evolution mapping model; k is the decay compensation coefficient, and k is a value greater than zero.

[0051] Subsequently, the microcontroller calculates the condensation evolution increment for the current sampling period based on the corrected condensation evolution rate v' and the sampling period Ts: ΔC = v'·Ts; Then, the condensation evolution parameter Cold from the previous sampling period is added to the condensation evolution increment ΔC to obtain the updated condensation evolution parameter Cnew.

[0052] In this way, the concentration evolution parameters can be continuously accumulated over the downtime and can be affected by the current sampling temperature parameters, the current cumulative downtime, the sampling cycle, and the membrane module usage status.

[0053] S5. Determine whether the updated concentration evolution parameters have reached the waste discharge trigger threshold: If the waste discharge trigger threshold is reached, control the booster pump to start and control the wastewater discharge valve to alternately perform the on and off actions to form a pressure pulse wastewater flow on the concentrate side of the reverse osmosis membrane module, thereby discharging the stagnant wastewater, and clear the concentration evolution parameters after the waste discharge is completed; if the waste discharge trigger threshold is not reached, return to S2 to enter the next sampling cycle.

[0054] Specifically, the microcontroller determines whether the updated enrichment evolution parameters have reached the waste discharge trigger threshold.

[0055] If the updated concentration evolution parameters do not reach the waste discharge trigger threshold, the microcontroller returns to step S2 and continues to monitor whether the reverse osmosis water purifier remains in standby mode according to the preset sampling cycle, and continues to update the concentration evolution parameters in the next sampling cycle.

[0056] If the updated concentration evolution parameters reach the wastewater discharge trigger threshold, the microcontroller controls the booster pump to start and controls the wastewater discharge valve to alternately perform opening and closing actions, thereby creating a pressure pulse wastewater flow on the concentrate side of the reverse osmosis membrane module to discharge the retained wastewater. After the wastewater discharge is completed, the microcontroller resets the concentration evolution parameters and re-enters standby monitoring mode.

[0057] In one implementation, the microcontroller acquires a preset pulse on-time, a pulse off-time, and a target waste discharge cycle. Combined with... Figure 4 As shown, the pulse conduction duration is denoted as... The pulse cutoff duration is denoted as The target waste discharge cycle is denoted as .

[0058] The microcontroller controls the wastewater discharge valve according to the pulse conduction duration. Turn on, and according to the pulse cutoff duration The above-mentioned on / off actions are repeated until the cumulative time of the alternating actions reaches the target waste discharge cycle. Among them, the pulse conduction duration Less than pulse cutoff duration .

[0059] In one specific implementation, the pulse on-time is 0.5 to 3 seconds, the pulse off-time is 2 to 8 seconds, and the target waste discharge cycle is 10 to 30 seconds. For example, the pulse on-time can be 1 second, the pulse off-time can be 4 seconds, and the target waste discharge cycle can be 20 seconds. The microcontroller controls the wastewater discharge valve to be on for 1 second and off for 4 seconds, and repeats this action cyclically until the cumulative alternating action time reaches 20 seconds.

[0060] During the period when the wastewater discharge valve is closed, the booster pump operates to re-establish the pressure in the concentrate side flow path; when the wastewater discharge valve is open, the pressure in the concentrate side flow path is released, forming a pressure pulse wastewater discharge flow. This pressure pulse wastewater discharge flow can disturb the retained wastewater on the concentrate side, which is beneficial to improving the discharge effect of retained wastewater.

[0061] In another implementation, the target waste discharge cycle is a dynamically generated time variable. Before the wastewater discharge valve alternates between on and off actions according to the pulse on duration and pulse off duration, the microcontroller calculates the over-limit difference between the updated concentration evolution parameters and the waste discharge trigger threshold.

[0062] The excess difference can be calculated as follows: D = Cnew - Cth; In the formula, D is the excess difference; Cnew is the updated enrichment evolution parameter; and Cth is the waste discharge trigger threshold.

[0063] The microcontroller determines the current target waste removal cycle based on the out-of-limit difference and a preset cleaning time mapping relationship. The cleaning time mapping relationship can be a data table pre-stored in the storage unit or a preset function relationship. The larger the out-of-limit difference, the longer the target waste removal cycle is determined; the smaller the out-of-limit difference, the shorter the target waste removal cycle is determined.

[0064] For example, when the excess value is in the first difference range, the target waste discharge cycle is set to 10 seconds; when the excess value is in the second difference range, the target waste discharge cycle is set to 20 seconds; and when the excess value is in the third difference range, the target waste discharge cycle is set to 30 seconds. In this way, the waste discharge duration can be matched with the current concentration state.

[0065] Combination Figure 2 As shown, the horizontal axis represents the downtime t, the vertical axis represents the enrichment evolution parameter C, the horizontally extending dashed line represents the waste discharge trigger threshold Cth, and the vertically extending dashed lines are used to mark the time positions corresponding to t1, t2, t3, and t4, respectively.

[0066] During the period from 0 to t1, the concentration evolution parameter C gradually increases with the increase of downtime, but has not yet reached the waste discharge trigger threshold Cth. The microcontroller continues to perform standby state monitoring, temperature sampling, and concentration evolution parameter updates according to the sampling cycle.

[0067] Near time t1, the concentration evolution parameter C reaches the waste discharge trigger threshold Cth. Since the microcontroller performs the judgment according to the discrete sampling period, the system can identify that the concentration evolution parameter C has reached or exceeded the waste discharge trigger threshold Cth at the next sampling judgment node.

[0068] At time t2, the microcontroller triggers the waste discharge control, controls the booster pump to start, and controls the wastewater discharge valve to alternately perform the opening and closing actions.

[0069] At time t3, the waste discharge action is completed, the microcontroller resets the concentration evolution parameter C, and then enters the next standby accumulation process.

[0070] At time t4, the concentration evolution parameter C during the next standby accumulation process reaches the waste discharge trigger threshold Cth again, and the microcontroller can trigger the waste discharge control again.

[0071] Through the above process, the microcontroller can continuously track the state of the wastewater retained on the concentrate side during shutdown based on the concentration evolution parameter C, instead of simply performing waste discharge based on fixed time intervals.

[0072] In one embodiment, the reverse osmosis water purifier also includes a communication module. After waste discharge is completed and the concentration evolution parameters are cleared, the microcontroller generates a waste discharge execution record that includes the trigger time, the target waste discharge cycle, and the waste discharge execution status.

[0073] The trigger time records the start time of this waste removal action; the target waste removal cycle records the duration of this waste removal action; and the waste removal execution status records whether this waste removal action has been completed. Furthermore, the waste removal execution record may also include pulse on-time, pulse off-time, concentration evolution parameters before waste removal, and the waste removal trigger threshold.

[0074] The microcontroller controls the communication module to send the waste discharge execution record to a preset user terminal. The user terminal can be a mobile phone, tablet, smart home terminal, or cloud management platform. Users or management platforms can use the waste discharge execution record to know the automatic waste discharge status of the reverse osmosis water purifier during standby.

[0075] This embodiment uses concentration evolution parameters to quantitatively track the state of the retained wastewater on the concentrate side during the shutdown of a reverse osmosis water purifier. The concentration evolution parameters are not limited to directly measured TDS values, but are used to characterize the concentration trend of the retained wastewater on the concentrate side as temperature and time change during the shutdown period.

[0076] When a reverse osmosis water purifier is in a low-temperature or short-term shutdown state, the concentration evolution parameters increase more slowly, and the system is less likely to trigger waste discharge prematurely, thus reducing ineffective waste discharge. When a reverse osmosis water purifier is in a high-temperature or long-term shutdown state, the concentration evolution parameters increase more rapidly, and the system can trigger waste discharge more promptly, thereby reducing the risk of membrane scaling and increased TDS in the first cup of water caused by long-term retention of wastewater on the concentrate side.

[0077] Furthermore, this embodiment utilizes the coordinated control of a booster pump and a wastewater discharge valve to generate a pressure pulse wastewater flow. Compared to simply continuously opening the wastewater discharge valve, this pressure pulse wastewater flow improves the disturbance and discharge effect of locally retained wastewater on the concentrate side and reduces the problem of excessive water volume in a single wastewater discharge.

[0078] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit the scope of protection of this application. Any adjustments made by those skilled in the art to specific parameters, sampling periods, threshold settings, mapping model forms, or valve-pump control timings without departing from the concept of this application shall fall within the scope of protection of this application.

Claims

1. A method for automatic waste discharge of a water purifier based on a stopped and idle state, characterized in that, The method is applied to a reverse osmosis water purifier comprising a reverse osmosis membrane module, a temperature sensor, a booster pump, a wastewater discharge valve, a storage unit, and a microcontroller. The method is executed by the microcontroller and includes: S1. When the reverse osmosis water purifier enters the standby state, a preset initial value is determined based on the water production time of the previous water production cycle, and the concentration evolution parameters are initialized with the preset initial value; S2. According to the preset sampling period, monitor whether the reverse osmosis water purifier maintains the standby state: if it maintains the standby state, obtain the current sampling temperature parameter through the temperature sensor and proceed to S3; if it exits the standby state, transfer the current concentration evolution parameter as a historical parameter to the storage unit and end the current sampling period. S3. Input the current sampling temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate; S4. Based on the condensation evolution rate and the sampling period, calculate the condensation evolution increment for the current sampling period, and update the condensation evolution parameters by accumulating the condensation evolution increment; S5. Determine whether the updated concentration evolution parameters have reached the waste discharge trigger threshold: If the waste discharge trigger threshold is reached, control the booster pump to start and control the wastewater discharge valve to alternately perform the on and off actions to form a pressure pulse wastewater flow on the concentrate side of the reverse osmosis membrane module, thereby discharging the stagnant wastewater, and clear the concentration evolution parameters after the waste discharge is completed; if the waste discharge trigger threshold is not reached, return to S2 to enter the next sampling cycle.

2. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, The determination of the preset initial value based on the water production duration of the previous water production cycle includes: When the water production duration of the previous water production cycle is greater than or equal to the preset duration threshold, the preset initial value is determined to be zero. When the water production duration of the previous water production cycle is less than the preset duration threshold, the preset initial value is determined to be the historical parameter transferred in the storage unit.

3. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, The shutdown evolution mapping model is a two-dimensional data lookup table embedded inside the microcontroller; The step of inputting the current sampled temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate includes: Get the current cumulative downtime; The current sampling temperature parameter and the current cumulative downtime are used as two-dimensional addressing indexes and input into the two-dimensional data lookup table. The corresponding values ​​are matched and extracted, and the values ​​are used as the concentration evolution rate. The two-dimensional data lookup table pre-stores numerical mapping relationships between discrete temperature ranges, discrete downtime ranges, and concentration evolution rates.

4. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, The shutdown evolution mapping model is an exponential function mapping model; The step of inputting the current sampled temperature parameter into the shutdown evolution mapping model to determine the corresponding concentration evolution rate includes: Convert the current sampled temperature parameter into an absolute temperature; Based on the preset membrane material constant, ion permeation activation energy constant, ideal gas constant, and absolute temperature, the concentration evolution rate is calculated using an exponential function mapping model with the natural constant as the base. Wherein, the exponential term of the exponential function mapping model is negative, and the absolute value of the exponential term is the ratio of the ion permeation activation energy constant to the product term, wherein the product term is the product of the ideal gas constant and the absolute temperature.

5. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, Controlling the wastewater discharge valve to alternately perform opening and closing actions includes: Obtain the preset pulse on-time, pulse off-time, and target waste discharge cycle; The wastewater discharge valve is controlled to open according to the pulse opening duration and close according to the pulse closing duration; The switching on and off actions are performed repeatedly until the cumulative time of the alternating actions reaches the target waste discharge cycle; Wherein, the pulse on-time is less than the pulse off-time.

6. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 5, characterized in that, The pulse on-time is 0.5 to 3 seconds, the pulse off-time is 2 to 8 seconds, and the target waste discharge cycle is 10 to 30 seconds.

7. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 5, characterized in that, Before controlling the wastewater discharge valve to alternately perform on / off actions according to the pulse on duration and the pulse off duration, the method further includes: Calculate the excess difference between the updated enrichment evolution parameters and the waste discharge trigger threshold; Based on the aforementioned excess difference and the preset cleaning time mapping relationship, the current target waste discharge cycle is determined; The larger the difference in the excess value, the longer the target waste discharge cycle is determined.

8. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, S4 includes: Obtain the cumulative water production time of the reverse osmosis membrane module; The corresponding attenuation compensation coefficient is determined based on the cumulative water production time. The attenuation compensation coefficient is used to characterize the membrane performance status of the reverse osmosis membrane module as the usage time changes. The concentration evolution rate is corrected according to the attenuation compensation coefficient to obtain the corrected concentration evolution rate; Based on the corrected condensation evolution rate and the sampling period, calculate the condensation evolution increment for the current sampling period; The enriched evolution parameters from the previous sampling period are added to the enriched evolution increment to obtain the updated enriched evolution parameters.

9. The automatic waste discharge method for a water purifier based on a stopped and idle state according to claim 1, characterized in that, The preset sampling period is 30 seconds to 5 minutes.

10. The automatic waste discharge method for a water purifier based on a shutdown and stagnant state according to claim 5, characterized in that, The reverse osmosis water purifier also includes a communication module; After waste discharge is completed and the concentration evolution parameters are reset to zero, the method further includes: Generate a waste removal execution record that includes the trigger time, the target waste removal cycle, and the waste removal execution status; The communication module is controlled to send the waste discharge execution record to a preset user terminal.

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