Water level detection control method for heat preservation tank of water purifier

Abstract

The embodiment of the invention discloses a water level detection control method for a heat preservation tank of a water purifier, and relates to the technical field of water purifiers, and the method comprises the following steps: under the triggering of a water supplementing signal and / or a water taking signal, collecting a real-time water level height sequence of the heat preservation tank within a preset time, and fitting the real-time water level height sequence to obtain a real-time water level height sequence; determining an incidence relation model of the water level height and the water level change time; and when the heat preservation tank is in the water supplementing process or the water taking process, the operation parameters of the water pump and / or the heating body are / is controlled according to the incidence relation model. The real-time real flow velocity can be dynamically measured through the incidence relation model of the water level height and the water level change time, and control errors caused by flow velocity fluctuation are avoided; under the dynamic operation working condition, the operation parameters of the execution mechanism are adjusted in real time through the incidence relation model, the technical problem that the water taking amount is inaccurate in the water taking process is solved, the water level rising trend can be monitored in real time according to the model during water supplementing, and water level overflow is effectively prevented.

Description

TECHNICAL FIELD

[0001] The present specification relates to the technical field of water purifiers, and in particular to a water level detection and control method for a water tank of a water purifier. BACKGROUND

[0002] In existing water purification products, especially instant water purification products, the detection and control of the water level in the water tank is the key to realizing quantitative water taking, preventing water overflow, and coordinating heating. In current heat storage instant water purification products, a water tank is generally provided for storing pretreated pure water and raising the water temperature to a preset preheating temperature through a built-in heating device. This structure enables users to quickly fill a cup of hot water with a high water flow rate when selecting the hot water function, significantly improving the user experience. Currently, the water tank usually uses mechanical liquid level detection devices, such as mechanical sensors such as float switches. Such mechanical sensors have simple structures, but have the risk of mechanical jamming and can only provide limited point signals (such as high and low water levels), which cannot achieve continuous monitoring of the water level. Common liquid level detection techniques also include capacitive sensors or preset fixed time control. Capacitive sensors are easily affected by water quality changes and have insufficient stability. A more common solution is to use a fixed time control, i.e., the system controls the start and stop of the water pump to perform water replenishment or water taking according to a preset fixed time.

[0003] However, through in-depth analysis of existing technologies, it is found that the flow rate of the water flow in the water tank during actual water replenishment or water taking is not constant. The flow rate is affected by various factors such as water source pressure, water pump performance degradation, waterway blockage, viscosity changes caused by water temperature changes, and membrane element usage time. This uncertainty in flow rate causes significant errors between the control method based on fixed time and the actual water consumption or water replenishment. For example, when taking water, if the actual flow rate is lower than the preset value, the water taken will be insufficient when the fixed time ends; otherwise, it may exceed the user's demand. When replenishing water, it may overflow due to too fast replenishment flow rate, or it may affect the user experience due to too slow replenishment flow rate.

[0004] In the process of water taking by the user, in order to realize the water transfer operation for different water taking modes (such as large water taking and fine water taking), the prior art usually adopts a control strategy of directly switching from a large-flow water pump to a small-flow water pump. Such instantaneous switching will cause a sharp mutation of water flow and produce an instantaneous flow interruption phenomenon. At this moment, the water flow through the instant heating body sharply decreases or even temporarily interrupts, but the power of the heating body cannot be adjusted in time, the large amount of heat accumulated by the heating body cannot be taken away by the water flow in time, the surface of the heating body is overheated instantaneously, a small amount of residual water is rapidly vaporized, and a jet phenomenon is caused, which has a safety hazard. At the same time, the sudden change of water flow from large to small will also make the user feel confused and think that the product is unstable; for the control system, the step change of flow also poses a great challenge to the constant control of the outlet water temperature, and is easy to cause instantaneous fluctuation of water temperature, affecting the user experience.

[0005] Therefore, the prior art solution cannot perform adaptive and accurate control in the dynamic water supplementing or water taking process when facing complex and variable application conditions, has problems of inaccurate water level detection and control lag, and affects the user experience. SUMMARY

[0006] One or more embodiments of the present specification provide a water level detection control method of a water purifier heat preservation tank, which is used to solve the technical problem that the prior art solution cannot perform adaptive and accurate control in the dynamic water supplementing or water taking process when facing complex and variable application conditions, has problems of inaccurate water level detection and control lag, and affects the user experience.

[0007] One or more embodiments of the present specification adopt the following technical solutions: One or more embodiments of the present specification provide a water level detection control method of a water purifier heat preservation tank, the method comprising: under the triggering of a water supplementing signal and / or a water taking signal, collecting a real-time water level height sequence of the heat preservation tank within a preset time, fitting the real-time water level height sequence, and determining a correlation relationship model of water level height and water level change time; in the process of water supplementing or water taking of the heat preservation tank, according to the correlation relationship model, controlling the operation parameters of the water pump and / or the heating body.

[0008] Triggered by water replenishment and / or water intake signals, this technology collects real-time water level sequences, solving the problem of continuous water level monitoring inherent in existing technologies such as float switches. Data acquisition is triggered by specific water replenishment or intake events, ensuring high efficiency and targeted data collection. Collecting real-time water level sequences means acquiring dynamic water level data points over a period of time, rather than isolated, static instantaneous values. This provides a data foundation for subsequent analysis of water level trends, rather than just the current state, overcoming the limitations of point-based detection methods like float switches and achieving stepless, continuous water level detection. By fitting the real-time water level sequences, a correlation model between water level height and water level change time is determined. Mathematical methods extract the objective laws governing water level height changes over time from discrete water level data points, enabling dynamic measurement of real-time flow velocity and avoiding control errors caused by flow velocity fluctuations. During water replenishment and / or water intake processes, the water pump is controlled based on the correlation model. The operating parameters of the actuator and / or heating element are adjusted in real time using a correlation model under dynamic operating conditions. During water intake, the actual flow rate obtained from the model and the user-set water volume can be used to accurately calculate and control the water intake time, solving the technical problem of inaccurate water intake. During water replenishment, the model can monitor the water level rise trend in real time. In the event of temporary loss of water level data, the model can predict the water level and ensure that the water pump is shut off in time when the target water level is reached, effectively preventing water overflow. Furthermore, regarding the water level shifting phenomenon mentioned in the background technology, the model can predict the water level drop to a specified position and control the water pump power to smoothly and gradually change, rather than switching instantaneously. At the same time, the heating element power is synchronously and appropriately adjusted according to the predicted flow rate change, avoiding the problems of instantaneous flow interruption and sudden flow changes. This eliminates the difficulties in controlling the heating element overheating, jetting, and water discharge caused by these issues, greatly improving the safety of the product and further enhancing the user experience.

[0009] Further, the real-time water level sequence is fitted to determine the correlation model between water level height and water level change time. Specifically, this includes: acquiring multiple water level height data pairs of the real-time water level sequence within the preset time period, each water level height data pair including the acquisition time and the water level height value corresponding to the acquisition time; performing linear fitting on the multiple water level height data pairs to determine the correlation model, wherein the correlation model includes a slope parameter representing the flow velocity and an intercept parameter representing the initial water level height.

[0010] By explicitly employing a linear fitting method to construct a model relating water level to time, and defining the physical meaning of the slope and intercept parameters in the model, a precise quantitative description of water flow dynamics is achieved. During the operation of a water purifier, water level changes are essentially a continuous, time-dependent process. However, existing technologies, relying on discrete point detection or fixed-sequence control, cannot capture this dynamic characteristic. This technical solution collects water level sequences within a preset time period, representing each data point as a binary pair of time and water level values, and then performs linear fitting. The slope parameter k is physically defined as the real-time flow velocity, with its sign distinguishing between water replenishment (k>0) and water intake (k<0) processes, and its absolute value representing the flow rate. The intercept parameter b corresponds to the baseline water level at the start of the fitting. This modeling method transforms the flow velocity variable, which is difficult to measure directly, into an explicit parameter obtainable through time-series data analysis, solving the flow velocity uncertainty problem caused by fluctuations in water source pressure, changes in pipeline resistance, and pump performance degradation in the background technology. By periodically updating the fitted model, flow rate changes can be dynamically tracked. For example, when the flow rate of the water purifier membrane module decreases due to long-term use, the slope parameter k obtained from the fitting will automatically decrease, truly reflecting the flow rate decay.

[0011] Furthermore, before performing linear fitting on the multiple water level height data pairs, the method further includes: detecting invalid values ​​for the water level height data pairs based on adjacent water level height values ​​corresponding to adjacent acquisition times; when there is an invalid water level height value in the water level height data pair, removing this water level height data pair from the real-time water level height sequence; and recording the corresponding invalid acquisition time so that, after determining the correlation model, the estimated water level height value corresponding to the invalid acquisition time can be determined based on the invalid acquisition time and the correlation model.

[0012] Ultrasonic water level sensors are susceptible to water surface fluctuations, bubble interference, and temporary signal loss in practical applications, leading to outliers or missing values ​​in the collected data. Directly fitting data sequences containing invalid values ​​will contaminate the model parameters. For example, a sudden change in water level caused by surface sloshing may cause the fitted line to deviate from the true trend, resulting in incorrect flow velocity calculations and erratic control commands. In the data preprocessing stage, invalid value detection identifies and removes outlier data pairs. In the model application stage, for the timestamps corresponding to the removed data points, a reliable correlation model is used to perform reverse calculations to fill in reasonable estimated water level values. Through invalid data detection and compensation, the robustness and reliability of the water level detection system under complex operating conditions are improved. This overcomes the problem of overall control interruption caused by a single point of data failure in traditional solutions, and avoids risks such as water overflow or heater burnout caused by temporary data loss.

[0013] Furthermore, according to the correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: receiving the user-set quantitative water intake parameters; determining the water intake flow rate based on the absolute value of the slope parameter in the correlation model corresponding to the water intake process; calculating the theoretical water intake time using the quantitative water intake parameters and the water intake flow rate; starting timing upon triggering the water intake signal; and controlling the water pump to stop when the actual water intake time reaches the theoretical water intake time, thereby stopping water intake.

[0014] By combining real-time flow rate measurement with user-defined parameters, high-precision dynamic quantitative water intake control is achieved, solving the problem of water intake deviation caused by the uncertainty of flow rate in traditional timed water intake methods. Through the mapping relationship between water intake time and water volume, the water intake flow rate extracted from the correlation model is used as a process variable to obtain the theoretical water intake time required to achieve the quantitative water intake parameters. Timing starts when the water intake signal is triggered and automatically terminates the pump operation when the actual water intake time is reached. This ensures that water intake accuracy no longer depends on the pump's calibrated flow rate or the stability of the pipeline pressure, but is calculated based on the real-time sensed actual flow rate. This solves the technical problem of inaccurate water intake and avoids the extra operation of repeated calibration of water intake by the user.

[0015] Furthermore, according to the correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: during the water intake process, real-time acquisition of water level data, wherein the water level data includes real-time collected water level data and / or estimated water level data obtained based on the correlation model; when the water level data is detected to drop to a preset water switching trigger threshold, the operating power of the water pump is controlled to decrease from a first power level to a second power level through a non-instantaneous gradual process, and the heating power of the heating element is adjusted to match, wherein the outlet flow rate corresponding to the second power level is less than the outlet flow rate corresponding to the first power level, and is the same as the target small pump operating flow rate.

[0016] By introducing power gradient and heat load linkage in multi-pump switching scenarios, the technical problem caused by sudden flow changes during water switching in instantaneous water purifiers is solved. When the water level drops to the water switching trigger threshold through real-time water level monitoring or model estimation, the main water pump power is controlled to gradually decrease from a high power level (corresponding to a large flow rate) to a low power level (corresponding to a small flow rate) along a preset slope. At the same time, based on the thermodynamic model, the change in heat load demand due to the flow reduction is predicted, and the heating element power is adjusted accordingly. This achieves a coordinated and gradual change in water and heat, breaking down the barrier of independent operation of the water and heat systems in traditional control. During the power reduction process, the water flow speed transitions smoothly, avoiding instantaneous flow interruption. The matching reduction of heating power ensures that the heat input per unit time and the heat carried away by the water flow remain balanced, avoiding the risk of local vaporization and jetting caused by heat accumulation. This not only solves product safety issues but also significantly improves the user experience, eliminating the sudden flow changes and temperature fluctuations during water switching, making the water dispensing process more stable and comfortable.

[0017] Furthermore, controlling the operating power of the water pump to decrease from a first power level to a second power level through a non-instantaneous gradual process specifically includes: using a preset first time interval as the adjustment cycle, gradually reducing the driving power value of the water pump according to a preset adjustment power step size, and after completing the power adjustment of each adjustment cycle, waiting for a preset first time period until the driving power value of the water pump reaches the second power level.

[0018] The adjustment cycle determines the frequency of power adjustments, the adjustment step size determines the magnitude of each power change, affecting the continuity of flow rate changes, and the settling time provides dynamic equilibrium time, allowing the water flow to re-establish a stable flow field after each power adjustment. By properly configuring these three parameters, a power reduction curve best suited to the specific product characteristics can be constructed, ensuring consistent control performance and providing flexible configuration space for adapting the product to different pump characteristics.

[0019] Furthermore, the heating power of the heating element is adjusted to be lowered in a matching manner, specifically including: determining the power reduction rate of the water pump during the adjustment period, so as to predict the predicted water flow change rate during the adjustment period based on the reduction rate; calculating the predicted heat demand to heat to the preset target heating temperature based on the predicted water flow change rate and the real-time water temperature in the insulation tank using thermodynamic formulas; determining the target heating power of the heating element based on the predicted heat demand, so as to synchronously reduce the heating power of the heating element to the target heating power during the adjustment period.

[0020] By using power prediction, synchronous matching between heating power and water flow changes is achieved. By monitoring the rate of decrease in water pump power, the trend of water flow changes within the future control cycle is predicted in advance. Then, the optimal heating power required to match the target water temperature is calculated in real time, ensuring that the adjustment of heating power and water flow changes are synchronized in time. This ensures that the heat flux on the surface of the instantaneous heating element is always matched with the cooling capacity, avoids local boiling caused by excess energy, and solves the problem of overheating and jetting of the heating element.

[0021] Furthermore, according to the correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: acquiring raw water temperature data in real time during the water replenishment process; determining the current water replenishment flow rate using the slope parameter in the correlation model; and determining the real-time matching heating power required to heat the water replenishment to the target heating temperature based on the current water replenishment flow rate, the raw water temperature data, and the preset target heating temperature, so as to control the heating element to perform water replenishment heating according to the real-time matching heating power.

[0022] By controlling the water-thermal coupling during the water replenishment process, dynamic matching of energy input and flow rate changes is achieved, optimizing system energy efficiency and thermal management performance. Traditional water purifiers typically employ fixed-power heating or independent temperature control strategies completely separate from water replenishment during the replenishment stage, leading to energy waste and temperature fluctuations. This technical solution uses the replenishment flow rate and raw water temperature as variables affecting heating power, calculating the optimal heating power in real time to ensure that the replenished water is precisely heated to the target temperature per unit time. This achieves on-demand energy allocation, saving energy compared to fixed-power heating, while also reducing heat loss due to overheating. By preheating the replenishment water, the temperature difference between the replenished cold water and the hot water in the tank is significantly reduced, alleviating the thermal circulation burden required for subsequent mixing and creating conditions for optimized operation of the circulation pump.

[0023] Furthermore, the method also includes: during the process of controlling the heating element to perform water replenishment heating according to the real-time matched heating power, obtaining a dynamically updated water replenishment flow rate; comparing the updated water replenishment flow rate with the current water replenishment flow rate to determine whether the flow rate deviation exceeds a preset allowable range; if the determination is yes, then updating the heating power of the heating element based on the updated water replenishment flow rate.

[0024] The introduction of flow rate monitoring and power adaptive correction during the water replenishment and heating process ensures the stability and reliability of water-heat synergy under various operating conditions. Although the initial heating power is calculated based on the current flow rate, the actual water replenishment flow rate may drift due to disturbances such as changes in water source pressure and changes in filter clogging. By continuously updating the water level fitting model, the latest water replenishment flow rate data is obtained and compared with the historical flow rate used to calculate the current heating power. When the deviation exceeds the preset tolerance range, the power is immediately recalculated to prevent energy waste due to excessive power or substandard water temperature due to insufficient power. This effectively addresses the dynamic characteristics of the domestic water environment, enabling the water-heat synergy control system to not only work under ideal conditions but also maintain optimal performance in real and complex environments.

[0025] Furthermore, the method also includes: monitoring the real-time water temperature in the insulation tank and comparing it with the target heating temperature; if the real-time water temperature reaches the target heating temperature, controlling the circulation pump to stop running or reduce its operating frequency so that the next water replenishment operation begins or the water temperature drops below the target heating temperature.

[0026] By optimizing the operation strategy of the circulating pump, system energy consumption and component wear are significantly reduced while ensuring water temperature uniformity, thus improving the long-term reliability and economy of the product. The operating logic of the circulating pump has been transformed from traditional timed or temperature difference-triggered operation to a variable operating mode based on actual heat demand. A temperature sensor continuously monitors the actual water temperature inside the insulation tank. When the target heating temperature is reached, it is determined that the hot water in the tank is in a uniform state or requires only minimal heat to maintain. At this point, the circulating pump is automatically controlled to enter a sleep or low-speed operation mode, avoiding the energy waste of the circulating pump continuing to operate under thermal equilibrium conditions in traditional solutions. For example, during low water usage periods at night, the circulating pump can be completely shut off for several hours, only restarting when the next water replenishment operation begins or the water temperature drops below the trigger temperature. This reduces the cumulative workload of the circulating pump's mechanical components, extends its service life, and lowers the maintenance costs throughout the product's lifecycle.

[0027] The above-described at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects: 1. By collecting real-time water level height sequences triggered by water replenishment and / or water intake signals, this technology solves the problem of continuous water level monitoring in existing technologies such as float switches. This technical solution collects data under the trigger of a clear water replenishment or water intake event, ensuring the efficiency and relevance of data collection. Collecting real-time water level height sequences means that dynamic water level data points over a period of time are obtained, rather than isolated, static instantaneous water level values. This provides a data foundation for subsequent analysis of water level change trends rather than just the current state, overcomes the limitations of point-based detection such as float switches, and realizes stepless and continuous water level detection. 2. By fitting real-time water level sequences, a correlation model between water level height and water level change time is determined. Through mathematical methods, the objective law of water level height change over time is extracted from discrete water level data points. This allows for dynamic measurement of real-time flow velocity, avoiding control errors caused by flow velocity fluctuations. During water replenishment and / or water intake processes, the operating parameters of the water pump and / or heating element are controlled based on the correlation model. Under dynamic operating conditions, the operating parameters of the actuators are adjusted in real time using the correlation model. During water intake, the water intake time can be accurately calculated and controlled based on the actual flow velocity obtained from the model and the user-set water volume, solving the technical problem of inaccurate water intake. During water replenishment, the water level rise trend can be monitored in real time based on the model. In the event of temporary loss of water level data, the model can predict the water level, ensuring that the water pump is shut off in time when the target water level is reached, effectively preventing water overflow. 3. Regarding the water diversion phenomenon during the water intake process mentioned in the background technology, the water level can be predicted to drop to a specified position based on the model, and the power of the water pump can be controlled to change smoothly and gradually, rather than switching instantaneously. At the same time, the power of the heating element can be adjusted synchronously and appropriately according to the predicted flow rate change, avoiding the problems of instantaneous flow interruption and sudden flow change. This eliminates the problems of overheating of the heating element, jetting, and difficulty in controlling water discharge caused by these issues, greatly improving the safety of product use and further enhancing the user experience. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 A flowchart illustrating a water level detection and control method for a water purifier's insulated tank, provided as an embodiment of this specification; Figure 2 A physical diagram of a water tank equipped with an integrated ultrasonic and temperature component, provided as an embodiment of this specification; Figure 3 This is a schematic diagram of the water circuit structure of a water purifier with an integrated ultrasonic and temperature component, provided as an embodiment of this specification. Detailed Implementation

[0029] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this specification.

[0030] This specification provides a water level detection and control method for a water purifier's insulation tank. It should be noted that the executing entity in this specification can be a server or any device with data processing capabilities. Figure 1 This is a flowchart illustrating a water level detection and control method for a water purifier's insulation tank, as provided in the embodiments of this specification. Figure 1 As shown, the main steps include the following: Step S101: Under the triggering of the water replenishment signal and / or water intake signal, the real-time water level height sequence of the insulation tank within a preset time is collected, the real-time water level height sequence is fitted, and the correlation model between water level height and water level change time is determined.

[0031] In one embodiment of this specification, the water level acquisition device is an integrated ultrasonic temperature sensor component, which simultaneously detects water level and water temperature through a single component.

[0032] Traditional water purifiers typically use a four-stage float to detect water level in their insulated tanks: low, medium, high, and overflow. The low level triggers protection when the tank is empty; the medium level determines if water needs to be added; the high level stops adding water; and the overflow level prevents overflow. To prevent the float rod from deforming and producing odors at high temperatures, this component is usually made of stainless steel, which is expensive. Additionally, to monitor the water temperature in the tank in real time, an NTC (Non-Conducting Temperature) module is required and fixed to the bottom of the tank. This data acquisition structure has the limitation of not being able to continuously detect water levels; it can only detect specific water levels.

[0033] Based on this, in one embodiment of this specification, the ultrasonic sensor and the temperature sensor are integrated into a single component, which can be called an ultrasonic and temperature integrated component, simultaneously realizing water level detection and water temperature detection. Figure 2 A physical diagram of a water tank equipped with an integrated ultrasonic and temperature component, provided as an embodiment of this specification, is shown below. Figure 2 As shown, the ultrasonic and temperature integrated component is installed at the bottom of the water tank, integrating the ultrasonic sensor and the temperature sensor to simultaneously detect water level and water temperature. Figure 3 This specification provides a schematic diagram of the water circuit structure of a water purifier with an integrated ultrasonic and temperature component, as shown in the embodiments.Figure 3 As shown, the water purifier includes at least a filter, a room temperature tank, an insulated tank, and a faucet. The filter delivers filtered water to the room temperature tank, which supplies water to the insulated tank via a cold water pump. The insulated tank then supplies insulated water to the faucet via a hot water pump. An integrated ultrasonic and temperature sensor is mounted on the insulated tank storing heated pure water. Specifically, the ultrasonic and temperature sensor is designed as a single module. Its ultrasonic transmitter / receiver probe is mounted perpendicular to the water surface at the center of the bottom of the insulated tank to ensure the sound wave path is perpendicular to the liquid surface, obtaining the strongest echo signal. The temperature sensing part (NTC) of the component contacts the tank wall or the internal water in a thermally conductive manner to directly measure the water temperature inside the tank. This installation method achieves simultaneous detection of two core physical quantities (water level and water temperature) at a single source point, replacing the separate float switch assembly and tank bottom NTC sensor in traditional solutions. Compared to traditional float-based detection, this method can detect continuous liquid levels, enabling quantitative water dispensing. It is more flexible and convenient than float-based detection at fixed water levels. Combined with the cross-sectional area of ​​the insulation tank, it can accurately measure the actual water output each time, achieving quantitative water dispensing even without a flow meter. However, the float needs to rise to a certain level to float, therefore the minimum detection level must be above the bottom of the insulation tank, while the maximum detection level must be below the top, significantly limiting the actual volume utilization. With an actual 2L volume, using a float only provides 1.5L of effective volume between the high and low water levels. However, using an ultrasonic sensor, with a small safety margin, allows for 95% of the volume to be used, increasing the effective volume from 75% to 95%. Therefore, for the same volume, the overall size of the unit can be significantly reduced.

[0034] The ultrasonic sensor in the embodiments of this specification can integrate a temperature sensor into the same component, reducing the number of parts, reducing assembly steps, and saving costs. The more water levels that need to be detected, the more floats are needed, and the higher the cost. However, the ultrasonic sensor is not affected by the number of water levels being detected, giving it a significant cost advantage. Furthermore, the float-based design has a complex manufacturing and assembly process, and minor damage is difficult to detect, leading to problems in the market such as internal reed switch breakage, float jamming, and floats being attracted by water films and not detaching. In contrast, the ultrasonic sensor is installed at the bottom, is easy to operate, has consistent parts, and effectively improves product reliability.

[0035] Furthermore, integrating real-time water level and temperature detection into a single component and applying it to the water purifier's insulation tank solves the technical shortcomings of independent data between water level and temperature sensors in traditional designs. It also addresses the issues of space occupation, complex installation, and data asynchrony associated with traditional separate sensors. By physically integrating the ultrasonic probe and temperature sensing element (such as an NTC) into the same housing and installing them in a specific location (such as the bottom) of the insulation tank, the hardware structure is simplified and reliability is improved. Simultaneously, it ensures that the water level and temperature signals originate from the same local water area within the tank and are completely synchronized in time. This provides a unified physical basis for subsequent data fusion processing, offering the following beneficial effects: First, by integrating hardware, the data source is unified and synchronized in time and space, enabling direct correlation and mutual calibration of detected physical quantities, real-time temperature compensation for ultrasonic ranging, and establishing an intrinsic correlation model between water level changes and temperature changes.

[0036] The propagation speed of ultrasound in water is related to water temperature. The temperature sensor in the integrated component can measure the water temperature in real time, providing accurate sound velocity compensation parameters for ultrasonic ranging, thus ensuring the absolute accuracy of water level data. Under dynamic operating conditions, the water temperature data can be correlated with the rate of water level change (slope parameter) detected by ultrasound. For example, the flow rate of cold water injected during water replenishment (reflected by the slope of the water level rise) directly affects the temperature drop gradient inside the tank; during water extraction or heating, the water flow rate and heating power jointly affect the temperature rise and fall. The integrated component enables the simultaneous capture of changes in two key parameters, thus not only knowing "how much the water level has changed," but also combining "how the temperature has changed accordingly" to more accurately infer and verify the authenticity of the water flow state, and even identify abnormal operating conditions, such as false water level signals caused by airlock.

[0037] Secondly, the integrated components enable real-time analysis of the dynamic thermal mixing state during the water replenishment process. During replenishment, when cold water is added to the insulation tank, the water temperature inside the tank drops due to mixing. Traditional single temperature sensors can only sense the result of mixing, not the process itself. By simultaneously acquiring water level data (reflecting the amount of cold water injected) and temperature data (reflecting the degree of mixing), the real-time temperature and its gradient of the mixed water in the tank at any replenishment moment can be accurately calculated. This allows for proactive control of the temperature drop in the insulation tank, rather than a passive response, significantly improving the stability and response speed of water temperature control. During water intake and heating maintenance, the optimal instantaneous heating power required to maintain the outlet water temperature can be calculated by combining the water intake flow rate (water level drop slope) and real-time water temperature, enabling on-demand heating and avoiding energy waste. In complex transitional conditions such as water transfer, synchronized water level and temperature data provide crucial input for predicting heat demand and achieving smooth synchronous adjustment of water flow and heating power, fundamentally preventing phenomena such as jetting.

[0038] Third, by integrating real-time water level detection and real-time temperature detection into a single component, closed-loop coordinated control of the three parameters—water level, temperature, and power—is achieved. The integrated component provides homogeneous water level change parameters and temperature data, which, together with the heating power control command, form a ternary coupled optimization system. Based on the real-time water level change slope (flow velocity) and instantaneous water temperature, the optimal heating power can be dynamically calculated and controlled, ensuring precise matching of energy input with flow rate and heat load. During water intake, this integrated data is also used to achieve a smooth transition of water flow and heat during water transfer. This control strategy, combining tank water temperature, water level change, and heating power, achieves a transformation from water volume control and temperature control to precise energy flow management, ultimately realizing a comprehensive technical effect of improved energy efficiency, enhanced safety, and optimized user experience.

[0039] When using an integrated ultrasonic temperature sensor for water level detection, ultrasonic waves are emitted from the bottom of the water tank, reflected by the water surface, and then received. The current water level is calculated by measuring the time between emission and reception. If there are significant fluctuations in water replenishment, the water surface may become unstable, leading to data loss. Therefore, the water replenishment pipeline is optimized by placing the inlet of the heating tank at the bottom and installing a baffle to reduce water surface fluctuations during replenishment and improve the accuracy of water level measurement. For temperature detection, the temperature sensor (NTC) is placed inside the component and contacts the water through the outer casing to sense the water temperature. The sensing principle is the same as existing sensor components, and will not be described further in this specification.

[0040] In one embodiment of this specification, triggered by a water replenishment signal and / or a water intake signal, a real-time water level sequence of the insulated tank within a preset time period is collected. The water replenishment signal can be triggered by the user through the user interface on the water purifier, or it can be automatically triggered based on the internal logic of the water purifier, such as when the water level is below a low water level threshold. The water intake signal is triggered by the user through the user interface. Upon triggering the water replenishment signal and / or the water intake signal, a data acquisition command is sent to the ultrasonic temperature sensor integrated component at the bottom of the water tank, driving the ultrasonic sensor to emit ultrasonic pulses of a specific frequency. The ultrasonic pulses pass through the water body and reach the water-air interface (i.e., the liquid surface), where they are reflected back and captured. The time difference from transmission to reception is accurately measured by the timing circuit built into the control board, and the absolute height of the current liquid level relative to the bottom of the water tank is calculated based on the propagation speed of sound waves at a specific water temperature. The propagation speed of sound waves at a specific water temperature can be obtained by using the calibrated propagation speed after calibrating the normal temperature propagation speed with real-time water temperature. The water temperature is measured in real time using an NTC temperature sensor integrated in the component, and the normal temperature propagation speed is compensated and calibrated by measuring the water level in real time to obtain the calibrated propagation speed, thereby obtaining a real-time water level height value.

[0041] The above data collection process is repeated at a fixed high-frequency sampling period, such as once per second or once every 0.5 seconds, for a preset duration to obtain a real-time water level height sequence. This real-time water level height sequence is a dataset containing multiple water level height measurements arranged in chronological order. It should be noted that the preset time cannot be too long, to prevent the water level from reaching the required level for water intake and / or replenishment before fitting the model, nor can it be too short, to prevent insufficient data in the water level height sequence to fit an accurate correlation model. Therefore, the preset time can be dynamically determined based on a combination of minimum data volume requirements and event-driven early triggering, as detailed below: The preset time is set as a dynamically achievable time window. First, a basic lower limit for the time window is set. This lower limit is determined based on the minimum number of valid data points required to build the correlation model. Specifically, the lower limit is determined by the minimum number of valid data points and the height data acquisition cycle. The lower limit can be used directly, or a value no less than this lower limit can be set according to requirements. For example, when the fitting method is based on least squares linear fitting, at least two non-overlapping data points are needed to stably solve for the slope parameter k and intercept parameter b. However, to overcome fluctuations in single-point data and ensure model reliability, at least five valid data points are usually required. The more valid data points, the better the model reliability. In the example of five valid data points, the initial value of the preset time should at least cover the time required to complete five valid ultrasonic water level acquisitions. For example, if the acquisition cycle is once per second, the initial preset time can be set to 5 seconds; if it is once every 0.5 seconds, the initial preset time can be set to 2.5 seconds.

[0042] However, to prevent response delays caused by rigidly waiting for a fixed time window to end during rapid water level changes—for example, during rapid water replenishment, the water level may have reached the high water level threshold, but the preset time has not yet ended, leading to the risk of overflow—two conditions are continuously monitored after the real-time water level height sequence is collected. Fitting is performed as soon as either condition is met. The first condition is reaching the preset time window length (e.g., five seconds), ensuring the model has a sufficient data foundation. The second condition is detecting that the real-time water level height has entered the preset control critical zone. For example, during water replenishment, when the real-time collected water level height value is in the warning range above the middle water level threshold but below the high water level threshold, fitting is immediately performed using all currently collected data (even if the amount is less than the ideal value). This dynamic value acquisition method ensures that there is sufficient data to establish an accurate correlation model under normal conditions, while also ensuring that the system prioritizes response speed and intervenes in control in a timely manner when operating conditions change drastically, thus achieving an optimal balance between model accuracy and system real-time performance.

[0043] The method involves acquiring real-time water level height sequences, fitting these sequences to determine a correlation model between water level height and water level change time. Before performing linear fitting on multiple water level height data pairs, the method further includes: detecting invalid values ​​for water level height data pairs based on adjacent water level height values ​​corresponding to adjacent acquisition times; when an invalid water level height value exists in a data pair, that data pair is removed from the real-time water level height sequence; and recording the corresponding invalid acquisition time so that, after determining the correlation model, the estimated water level height value corresponding to the invalid acquisition time can be determined based on the invalid acquisition time and the correlation model.

[0044] In the actual operation of water purifiers, especially instantaneous water purifiers, the liquid surface inside the insulated tank is not a static plane. During water replenishment, the incoming water flow impacts the liquid surface, causing turbulence and waves. During water extraction, especially at high flow rates, eddies form inside the tank. Furthermore, tiny air bubbles that may precipitate in the water and vibrations of the device itself can interfere with the detection process of the ultrasonic sensor installed at the bottom. These interferences can cause distortion of the ultrasonic echo signal or errors in time interpretation, introducing abnormal and invalid data points into the periodically collected real-time water level height sequence. Examples include instantaneous jumps in water level values ​​or static values ​​that deviate significantly from the actual water level. If this noisy data sequence is directly used for linear fitting, the fitted results will have significant deviations, thus affecting subsequent parameter control processes.

[0045] To address the aforementioned technical issues, in one embodiment of this specification, after acquiring the real-time water level height sequence and before executing the fitting algorithm, invalid value detection is performed on water level height data pairs based on adjacent water level height values ​​corresponding to adjacent acquisition times. A sliding data window is maintained in memory, continuously storing several newly acquired water level height data pairs (each data pair contains a precise timestamp and a corresponding water level height value). The detection logic is based on a core physical principle: within an extremely short time interval, due to the incompressibility of water and the physical inertia of the system, a step-like change in water level is impossible. Therefore, the difference between the currently acquired water level height value and the water level height value of the previous valid sampling point is calculated, and its absolute value is taken to obtain the height difference. Simultaneously, a preset maximum reasonable change threshold is obtained. This maximum reasonable change threshold is derived based on numerous experiments and physical models, comprehensively considering the maximum theoretical flow rate of the water pump, the cross-sectional area of ​​the water tank, and the sampling period, defining a theoretical upper limit for water level change within a single sampling period. If the height difference exceeds the maximum reasonable change threshold, the current data pair is determined to be invalid; if the height difference does not exceed the maximum reasonable change threshold, the current data pair is determined to be valid.

[0046] When invalid water level values ​​exist in a water level data pair, the pair is removed from the real-time water level sequence to ensure that outlier data points are not included in subsequent fitting calculations. Simultaneously, the corresponding invalid acquisition time is recorded, accurately noting the acquisition timestamp of this invalid data point. After determining the correlation model, the estimated water level value corresponding to the invalid acquisition time is determined based on the invalid acquisition time and the correlation model. After invalid data is removed, the recorded invalid acquisition timestamp is substituted into the fitted reliable correlation model for calculation, providing an estimated water level value for the time corresponding to the invalid acquisition timestamp, thus ensuring the continuity and integrity of the water level monitoring data stream.

[0047] In the data preprocessing stage, invalid value detection is performed to identify and remove abnormal data pairs. In the model application stage, invalid data detection and compensation improve the robustness and reliability of the water level detection system under complex working conditions, overcoming the problem of overall control interruption caused by single-point data failure in traditional solutions, and avoiding risks such as water overflow or dry burning of the heating element caused by temporary data loss. By actively removing deviating invalid values, it is ensured that the fitted correlation model truly reflects the physical change law of water level, improving the accuracy and reliability of the calculated flow velocity and water level values. For the timestamps corresponding to the removed data points, the established reliable correlation model is used for reverse calculation to fill in reasonable estimated water level values. By using the reliable model to estimate data at invalid times, information interruption caused by single-point data loss is overcome. Even under disturbed working conditions, a continuous and reasonable water level reference can still be obtained, avoiding false protection (such as misjudgment of dry burning) or control logic interruption that may be caused by instantaneous data loss.

[0048] The real-time water level sequence was then fitted to determine the correlation model between water level height and water level change time, specifically including: Multiple water level height data pairs of the real-time water level height sequence are acquired within the preset time period. Each water level height data pair includes the acquisition time and the water level height value corresponding to the acquisition time. The acquisition time is usually recorded in the form of a relative timestamp. For example, the time origin is taken as the start time of the fitting calculation (t=0), the first acquisition is recorded as t1=1 (second), the second as t2=2 (second), and so on, thus forming a linear time coordinate axis. The corresponding water level height value is the absolute height value expressed in length units after sound speed and temperature compensation.

[0049] Next, linear fitting is performed on multiple water level height data pairs to determine the correlation model. This correlation model includes a slope parameter representing the flow velocity and an intercept parameter representing the initial water level height. Assuming the cross-sectional area of ​​the insulated tank is a constant cylindrical shape, the inflow or outflow volume per unit time is uniform, theoretically making the change in water level height over time linear. In one embodiment of this specification, the least squares method is preferably used for linear fitting. The least squares method is a mathematical optimization technique that finds the best function match for the data by minimizing the sum of squared errors, and is widely used in curve fitting and regression analysis. The goal of the least squares method is to find an optimal linear equation for data pairs distributed as scattered points in a coordinate system, minimizing the sum of squared deviations between all actually observed water level height values ​​and their corresponding estimated values ​​on this line. This is accomplished by solving a set of canonical equations based on the statistical characteristics of the data points. The calculation process first requires calculating the average value of all time coordinates and the average value of all water level heights. Then, the sum of squares of the time series and the sum of the products of time and water level height are calculated. Finally, the slope and intercept of the straight line are solved using a defined formula. Ultimately, this fitting process determines the correlation model, which includes a slope parameter representing the flow velocity and an intercept parameter representing the initial water level height. The slope parameter has a clear physical meaning. Since its unit is height / time, and the cross-sectional area of ​​the insulated tank is a known fixed value, the volumetric flow velocity can be directly converted using a formula. Therefore, the slope parameter directly and linearly characterizes the water flow velocity, and its sign indicates the flow direction: positive for water replenishment and negative for water intake. The physical meaning of the intercept parameter is the water level height calculated by the model backtracking at the beginning of the fitting time window (t=0), representing the initial state on which this fitting is based.

[0050] By employing a linear fitting method to construct a model of the relationship between water level and time, and defining the physical meaning of the slope and intercept parameters in the model, a precise quantitative description of water flow dynamics is achieved. During the operation of a water purifier, water level changes are essentially a continuous process related to time. However, existing technologies, relying on discrete point detection or fixed time-series control, cannot capture this dynamic characteristic. This technical solution collects water level sequences within a preset time period, representing each data point as a binary pair of time and water level values, and then performs linear fitting. The slope parameter k is physically defined as the real-time flow velocity, with its sign distinguishing between water replenishment (k>0) and water intake (k<0) processes, and its absolute value representing the flow rate. The intercept parameter b corresponds to the baseline water level at the start of the fitting. This modeling method transforms the flow velocity variable, which is difficult to measure directly, into an explicit parameter obtainable through time-series data analysis, solving the flow velocity uncertainty problem caused by fluctuations in water source pressure, changes in pipeline resistance, and pump performance degradation in the background technology. By periodically updating the fitted model, flow rate changes can be dynamically tracked. For example, when the flow rate of the water purifier membrane module decreases due to long-term use, the slope parameter k obtained from the fitting will automatically decrease, truly reflecting the flow rate decay.

[0051] Step S102: During the water replenishment or water intake process of the heat preservation tank, the operating parameters of the water pump and / or heating element are controlled according to the correlation model.

[0052] During the water dispensing process, the user inputs their desired water volume (e.g., 300 ml) through the water purifier's human-machine interface (such as a touchscreen, buttons, or a connected mobile application), which becomes the user-defined quantitative water dispensing parameter. The water dispensing flow rate is determined by the absolute value of the slope parameter in the correlation model corresponding to the water dispensing process. During dispensing, the water level continuously decreases, and the slope parameter becomes negative; its absolute value is then recorded. Since the insulated tank is designed as a straight cylinder with a uniform cross-sectional area, its cross-sectional area is a known fixed value. Therefore, the actual water dispensing flow rate can be obtained during the dispensing process. Using the quantitative water dispensing parameter and the actual water dispensing flow rate, the theoretical water dispensing time is calculated using the ratio of the water volume dispensed according to the quantitative water dispensing parameter to the water dispensing flow rate.

[0053] After obtaining the theoretical water extraction time, a timer starts upon triggering a water extraction signal. When the actual water extraction time reaches the theoretical time, the water pump is stopped to cease water extraction. A high-precision timer is activated upon triggering the water extraction signal and accumulates the actual water extraction time from zero. Simultaneously, the control board maintains the water pump (typically a high-flow pump driving the hot water flow) at its rated power. During the water extraction process, the actual water extraction time is continuously compared with the calculated theoretical time. Once the actual water extraction time reaches the theoretical time, a stop command is immediately generated, cutting off the power to the water pump or disabling it via the drive circuit, stopping the pump and ending the water extraction process. This method achieves high-precision quantitative water output control without relying on an external flow meter, solely through built-in ultrasonic water level detection and intelligent algorithms.

[0054] By combining real-time flow rate measurement with user-defined parameters, high-precision dynamic quantitative water intake control is achieved, solving the problem of water intake deviation caused by the uncertainty of flow rate in traditional timed water intake methods. Through the mapping relationship between water intake time and water volume, the water intake flow rate extracted from the correlation model is used as a process variable to obtain the theoretical water intake time required to achieve the quantitative water intake parameters. Timing starts when the water intake signal is triggered and automatically terminates the pump operation when the actual water intake time is reached. This ensures that water intake accuracy no longer depends on the pump's calibrated flow rate or the stability of the pipeline pressure, but is calculated based on the real-time sensed actual flow rate. This solves the technical problem of inaccurate water intake and avoids the extra operation of repeated calibration of water intake by the user.

[0055] In the water dispensing process of instant water purifiers, to achieve different modes such as quickly filling a cup of water and dispensing water in a fine, small flow rate, a high-flow-rate pump and a low-flow-rate pump are usually configured. Traditional control schemes generally adopt an instantaneous switching strategy when switching water flow from the high-flow-rate pump to the low-flow-rate pump. First, the pump's drive power and its corresponding water flow rate change abruptly, causing a brief but potentially malfunction-inducing momentary interruption or severe flow rate change. For the downstream instant heating element, its power is usually not adjusted at this moment and still maintains the high power required to match the high flow rate. The amount of water flowing through the heating element decreases sharply, while the heat received per unit area on its surface does not decrease accordingly. This inevitably causes the surface temperature of the heating element to spike instantly, enough to instantly vaporize any remaining water on its surface, generating steam that is ejected from the outlet. Second, from a user experience perspective, the sudden change from a strong to a weak water flow creates a negative perception of machine instability. At the same time, the drastic change in flow rate also greatly interferes with the stability of the water temperature control system, potentially causing fluctuations in the outlet water temperature.

[0056] Based on this, the embodiments in this specification introduce power gradual change and heat load linkage in multi-pump switching scenarios, which solves the technical problem caused by sudden flow changes during the water switching process of instantaneous water purifiers. The specific implementation process is as follows: During water intake, water level data is acquired in real time. This includes real-time collected water level data and / or estimated water level data based on a correlation model. Real-time collected water level data refers to directly collecting physical measurements after invalid value detection and cleaning. Estimated water level data is a logically calculated value based on a fitted correlation model, substituted with time, when sensor data is temporarily lost due to extreme conditions such as violent water surface fluctuations. Dual-path data protection is provided to ensure reliable water level status information at all times.

[0057] Next, the relationship between the water level data and the preset water transition trigger threshold is determined. The water transition trigger threshold is a water level value pre-calibrated experimentally and stored in the system's non-volatile memory, indicating that the water intake process is about to transition from a high-flow-rate phase to a low-flow-rate phase. The continuously acquired water level data is compared with this threshold. When the water level data is detected to drop to the preset water transition trigger threshold, the operating power of the water pump is controlled to decrease from a first power level to a second power level through a non-instantaneous gradual process. The heating power of the heating element is also adjusted to match this decrease. The outlet flow rate corresponding to the second power level is lower than that corresponding to the first power level, but the same as the operating flow rate of the target small pump. For the control of the water pump power, the first power level corresponds to the rated operating power of the high-flow-rate water pump to ensure initial rapid water output, while the second power level corresponds to the stable operating power of the target small pump. The design goal is to ensure that the outlet flow rate after the switch is exactly the same as the flow rate when the small pump operates independently, thereby achieving seamless functional substitution.

[0058] When real-time water level monitoring or model estimation detects a drop in water level to the water switching trigger threshold, the main water pump power is controlled to gradually decrease from a high power level (corresponding to a large flow rate) to a low power level (corresponding to a small flow rate) along a preset slope. Simultaneously, based on the thermodynamic model's prediction of the heat load change caused by the flow reduction, the heating element power is adjusted accordingly, achieving a gradual change in water and heat coordination. During the power reduction process, the water flow velocity transitions smoothly, avoiding instantaneous flow interruptions. The matching reduction of heating power ensures that the heat input per unit time remains balanced with the heat carried away by the water flow, avoiding the risk of localized vaporization and jetting caused by heat accumulation. This not only solves product safety issues but also significantly improves the user experience, eliminating sudden changes in water flow and temperature fluctuations during water switching, making the water intake process more stable and comfortable.

[0059] In the above process, the operating power of the water pump is controlled to decrease from the first power level to the second power level through a non-instantaneous gradual process. Specifically, this is achieved by: using a preset first time interval as the adjustment cycle, gradually reducing the driving power value of the water pump according to a preset adjustment power step size, and waiting for a preset first time period after completing the power adjustment of each adjustment cycle until the driving power value of the water pump reaches the second power level.

[0060] Specifically, the adjustment cycle is first determined by a set first time interval, which sets the execution frequency of the power adjustment command. The value of this interval must balance control smoothness and system response speed. Simultaneously, a preset power adjustment step size is set, defining the maximum allowable reduction in pump drive power within each adjustment cycle. This specific value can be obtained through experimental testing to ensure subtle power changes and avoid perceptible impacts on water flow. The specific reduction process is as follows: The control device (such as an MCU) reads the current pump drive power value, i.e., the first power level, from its memory or registers. Then, at the start of each timer-triggered adjustment cycle, the pump drive power value is gradually reduced by subtracting one power adjustment step size from the current power value, calculating a new target power command. This new power command is applied to the pump's motor drive circuit via a digital-to-analog converter or PWM controller, thereby actually changing the pump's speed and output flow rate. Next, after completing the power adjustment for each adjustment cycle, a preset first time period is waited for a stabilization window. During this period, further power adjustments are paused to alleviate the mechanical inertia of the water pump and allow the water flow in the pipeline to re-establish a stable flow state under the new power setting, until the water pump's drive power value is detected to reach the second power level. At this point, the water pump operates smoothly in the preset low power state, and its outlet flow rate matches the operating conditions of the target small pump.

[0061] The adjustment cycle determines the frequency of power adjustments, the adjustment step size determines the magnitude of each power change, affecting the continuity of flow rate changes, and the settling time provides dynamic equilibrium time, allowing the water flow to re-establish a stable flow field after each power adjustment. By properly configuring these three parameters, a power reduction curve best suited to the specific product characteristics can be constructed, ensuring consistent control performance and providing flexible configuration space for adapting the product to different pump characteristics.

[0062] As the water pump power is reduced, the heating power of the heating element is also adjusted accordingly, specifically including: A clear correspondence is established between pump power and outlet flow velocity during system calibration. Therefore, the power decrease rate can be used to predict the predicted flow rate change within the adjustment period. The pump power decrease rate represents the rate of change of pump power over time. This rate can be determined by monitoring the pump control signal, calculated as the ratio of the power decrease value within a preset time period to the corresponding time interval. Based on the decrease rate, the predicted flow rate change within the adjustment period can be predicted. Since pump power and flow velocity are usually positively correlated, the flow rate change can be derived from the power decrease rate.

[0063] A pre-established model relating pump power to outlet flow rate is stored in the system's non-volatile memory. This model is derived during product design or production calibration by experimentally measuring the stable outlet flow rate produced by the pump under different drive powers, thus creating a calibration curve from power to flow rate. In actual operation, this model is used to query the sensitivity of the outlet flow rate to changes in pump power near the current power operating point; that is, the amount of flow rate change caused by a unit power change. This sensitivity coefficient is a parameter obtained from the slope of the calibration curve. Next, the calculated power decrease rate is multiplied by the sensitivity coefficient retrieved from the power-flow rate model to obtain the predicted flow rate, representing the expected change in outlet flow rate per unit time within the current adjustment period. Physically, this means that, based on the current rate of power decrease and the pump's ability to convert power into flow, the flow rate will decrease synchronously at the predicted rate.

[0064] Finally, the predicted rate of change in water flow is used to extrapolate the future flow state. For example, it can be inferred that at the end of the next adjustment cycle, the outflow velocity will change from the current actual value to the current value plus the product of the predicted rate of change in water flow and the duration of the adjustment cycle. This future flow velocity is calculated through prediction.

[0065] Using thermodynamic formulas, based on the predicted water flow rate and the real-time water temperature in the insulation tank, the predicted heat demand for heating to the preset target heating temperature is calculated. The required temperature difference is calculated using the current water temperature measured in real-time by a temperature sensor and the user-set or system-default target heating temperature. Simultaneously, combining the predicted future water flow rate with the inherent physical constants of water such as specific heat capacity and density, the theoretical heat required to heat the water flowing through the heating element to the target temperature per unit time under future operating conditions is calculated using the thermodynamic energy conservation formula; this is the predicted heat demand. Based on the predicted heat demand, the target heating power of the heating element is determined. During the adjustment cycle, the heating power of the heating element is synchronously adjusted to the target heating power, generating a corresponding control signal to drive the power actuator of the heating element, ensuring its output power matches the calculated target heating power. This process is repeated in each adjustment cycle, dynamically correcting the heating power based on the latest prediction results. This ensures that throughout the water transfer phase, the heat supply and the heat demand carried away by the water flow remain precisely and in real-time balanced, achieving water-heat linkage and matching adjustment.

[0066] By using power prediction, synchronous matching between heating power and water flow changes is achieved. By monitoring the rate of decrease in water pump power, the trend of water flow changes within the future control cycle is predicted in advance. Then, the optimal heating power required to match the target water temperature is calculated in real time, ensuring that the adjustment of heating power and water flow changes are synchronized in time. This ensures that the heat flux on the surface of the instantaneous heating element is always matched with the cooling capacity, avoids local boiling caused by excess energy, and solves the problem of overheating and jetting of the heating element.

[0067] In the operation of instant water purifiers, traditional control schemes either use a fixed heating power during the water replenishment period, ignoring changes in water volume and temperature, or completely disconnect heating control from the water replenishment process, only starting circulation heating after replenishment is complete. Fixed-power heating cannot achieve precise energy matching when faced with varying water flow rates and raw water temperatures. When the water flow rate is fast or the raw water temperature is low, the fixed power may not be sufficient to heat the water to the target temperature in time, causing an overall drop in water temperature within the tank and resulting in temperature fluctuations for the user. Conversely, when the water flow rate is slow or the raw water temperature is high, the fixed power is excessive, leading to unnecessary energy waste and potentially accelerating scale formation due to localized overheating. The mode of heating only after replenishment results in users having to wait a long time for the desired hot water, and the circulation pump needs to operate for an extended period to mix the hot and cold water, increasing pump wear and energy consumption.

[0068] Based on this, the embodiments of this specification control the operating parameters of the water pump and / or heating element according to the correlation model during the water replenishment process, specifically through the following methods: During the water replenishment process, the raw water temperature data is acquired in real time through a temperature sensor installed on the water replenishment path. This sensor is integrated into an ultrasonic temperature sensor assembly and is used to measure the temperature of the unheated raw water about to enter the insulation tank. The resistance value or voltage signal of the sensor is periodically read by an analog-to-digital converter and converted into a precise temperature value according to the sensor's characteristic parameter table. The raw water temperature data reflects the initial temperature difference required to raise the water to the target temperature.

[0069] The current water replenishment flow rate is determined by the slope parameter in the correlation model. During the water replenishment process, water level sequences are continuously collected by ultrasonic sensors and fitted with straight lines to generate a dynamically updated correlation model. In this model, the slope parameter is positive, physically representing the linear velocity of the water level rise. Since the insulated tank is designed as a straight cylinder with a constant cross-sectional area, the volume of water replenished per unit time, i.e., the current water replenishment flow rate, can be calculated instantaneously by multiplying the water level linear velocity by the cross-sectional area of ​​the tank. This current water replenishment flow rate is a dynamic value that accurately reflects flow fluctuations caused by factors such as changes in inlet water pressure and the degree of filter clogging.

[0070] Based on the current water supply flow rate, raw water temperature data, and the preset target heating temperature, the real-time matching heating power required to heat the water to the target temperature is determined, so that the heating element can be controlled to heat the water according to the real-time matching heating power. First, the difference between the target heating temperature and the raw water temperature is calculated. This temperature difference represents the amount of heat that each unit mass of water needs to absorb. Then, combined with the current water supply flow rate (i.e., the mass of water supplied per unit time), the total heat required to heat all the continuously supplied cold water to the target temperature per unit time is calculated, which is the real-time matching heating power. The above calculation process essentially performs a precise dynamic matching between the heater's power output and the heat load of the supplied water.

[0071] The calculated real-time matching heating power value is converted into specific control commands. If the heating element uses PWM control, the power value is converted into a corresponding PWM signal duty cycle; if it uses analog voltage regulation control, it is converted into a specific output voltage command. The control command is sent to the heating element's drive circuit, thereby immediately adjusting the actual output power of the heating element to operate at the real-time matching heating power. In this way, it is ensured that at every moment of water replenishment, the input energy is precisely used to heat the currently replenished cold water, achieving optimal energy efficiency and stable water temperature control.

[0072] By controlling the water-thermal coupling during the water replenishment process, dynamic matching of energy input and flow rate changes is achieved, optimizing system energy efficiency and thermal management performance. Traditional water purifiers typically employ fixed-power heating or independent temperature control strategies completely separate from water replenishment during the replenishment stage, leading to energy waste and temperature fluctuations. This technical solution uses the replenishment flow rate and raw water temperature as variables affecting heating power, calculating the optimal heating power in real time to ensure that the replenished water is precisely heated to the target temperature per unit time. This achieves on-demand energy allocation, saving energy compared to fixed-power heating, while also reducing heat loss due to overheating. By preheating the replenishment water, the temperature difference between the replenished cold water and the hot water in the tank is significantly reduced, alleviating the thermal circulation burden required for subsequent mixing and creating conditions for optimized operation of the circulation pump.

[0073] In the actual working environment of a water purifier, the flow rate during the water replenishment process is not constant. Fluctuations in water source pressure, the start and stop of other water usage points in the pipeline network, and the increasing degree of clogging of the filter over time all cause the water replenishment flow rate to change dynamically within the replenishment cycle. The real-time matching heating power initially calculated based on the water replenishment flow rate at a certain moment will gradually deviate from the optimal value as the actual flow rate changes. If the system lacks an effective tracking and correction mechanism, this deviation will lead to two adverse situations: when the actual flow rate is higher than the calculated flow rate, the heating power will be relatively insufficient, and the water temperature in the replenishment tank will be lower than the target temperature, thus lowering the overall water temperature, affecting the user experience of the next water dispensing, and possibly forcing the circulation pump to work more frequently and for longer periods to reheat the mixed water, increasing energy consumption and wear; conversely, when the actual flow rate is lower than the initial flow rate, the heating power will be relatively excessive, resulting in wasted electricity, and may also cause localized overheating in areas with slow water flow.

[0074] During the process of controlling the heating element to perform water replenishment heating according to the real-time matched heating power, the dynamically updated water replenishment flow rate is obtained. Here, the updated water replenishment flow rate refers to the updated water level flow rate obtained after updating the correlation model with the newly collected water level height data during the water replenishment process.

[0075] The updated makeup water flow rate is compared with the current makeup water flow rate to determine if the flow rate deviation exceeds the preset allowable range. The current makeup water flow rate refers to the flow rate value used in the last calculation of the real-time matching heating power. The relative or absolute deviation between the updated and current makeup water flow rates is calculated. The preset allowable range is a threshold set through engineering trade-offs to prevent the system from overreacting to small, insignificant flow rate fluctuations, thereby maintaining control stability. This allowable range can be a percentage, such as a few percent of historical flow rate values, or a fixed flow difference. The calculated deviation is then checked to see if it exceeds this allowable range. If it does, the heating power of the heating element is updated based on the updated makeup water flow rate, triggering a recalculation of the heating power. This process is consistent with the initial calculation of the real-time matching heating power, but uses the latest updated makeup water flow rate, real-time sampled raw water temperature data (which is also continuously updated), and the unchanged preset target heating temperature. Based on these latest parameters, the thermodynamic calculation is re-executed to obtain a heating power value that precisely matches the current operating conditions. Subsequently, a new drive command is generated to adjust the operating power of the heating element to this newly calculated value, ensuring that the heating power can track the changes in the water replenishment flow rate, thereby maintaining the accuracy of energy input at the highest level throughout the entire water replenishment period.

[0076] The introduction of flow rate monitoring and power adaptive correction during the water replenishment and heating process ensures the stability and reliability of water-heat synergy under various operating conditions. Although the initial heating power is calculated based on the current flow rate, the actual water replenishment flow rate may drift due to disturbances such as changes in water source pressure and changes in filter clogging. By continuously updating the water level fitting model, the latest water replenishment flow rate data is obtained and compared with the historical flow rate used to calculate the current heating power. When the deviation exceeds the preset tolerance range, the power is immediately recalculated to prevent energy waste due to excessive power or substandard water temperature due to insufficient power. This effectively addresses the dynamic characteristics of the domestic water environment, enabling the water-heat synergy control system to not only work under ideal conditions but also maintain optimal performance in real and complex environments.

[0077] In storage-type instant hot water systems, the circulating pump's function is to promote water circulation within the insulated tank, eliminating temperature stratification, ensuring uniform water temperature, and rapidly providing consistent hot water to users. However, under conventional control strategies, circulating pumps often operate on a timed basis or are triggered by a fixed temperature difference. This causes them to periodically start and run even after the water temperature in the tank has reached the target temperature, performing many unnecessary and ineffective cycles. This continuous or frequent operation not only directly consumes additional electrical energy, contradicting the current trend of pursuing high energy efficiency in home appliances, but also exacerbates the wear and tear on the circulating pump's mechanical components, thus shortening the pump's lifespan and affecting the long-term reliability of the product.

[0078] Based on this, in one embodiment of this specification, the real-time water temperature inside the insulation tank is monitored, reflecting the overall thermal state of the water in the tank. Simultaneously, the target heating temperature set by the user or the system default is read; this temperature is the baseline value that needs to be maintained. The real-time water temperature is compared with the target heating temperature. If the real-time water temperature reaches the target heating temperature, the circulation pump is controlled to stop operating or reduce its operating frequency, so that the next water replenishment operation begins or the water temperature drops below the target heating temperature.

[0079] When it is determined that the current real-time water temperature is at or above the target heating temperature, it means that the water temperature inside the tank has reached an ideal state of uniformity and sufficient heat. Therefore, a control command will be generated to stop the circulation pump or reduce its operating frequency. Stopping the circulation pump means completely cutting off the drive signal supplied to the circulation pump motor, causing it to stop rotating completely, achieving zero energy consumption and zero wear. Reducing the operating frequency is usually applicable to circulation pumps driven by frequency converters, lowering their operating frequency from a high mixing frequency to an extremely low frequency that maintains basic circulation, significantly reducing their speed, flow rate, noise, and power consumption.

[0080] The system controls the circulation pump to stop or reduce its operating frequency until the next water replenishment operation begins or the water temperature drops below the target heating temperature, setting clear exit conditions for the circulation pump's hibernation or low-speed operation. When a water replenishment signal is detected, it indicates that ambient temperature pure water will be injected into the insulation tank, causing a localized drop in water temperature and severe temperature stratification. In this case, the circulation pump is activated (or restored to full speed) to quickly mix the cold and hot water, preventing users from receiving water at an insufficient temperature. The water temperature dropping below the target heating temperature means that during non-replenishment periods, due to environmental heat loss, the water temperature in the insulation tank will slowly decrease over time, falling below the preset target heating temperature tolerance range. In this situation, the circulation pump also needs to be restarted to work with the heating system for thermal circulation, restoring the water temperature to a uniform level and returning to the set value. These intelligent triggering conditions ensure that the circulation pump can rest to the maximum extent when mixing is not needed, and can immediately resume operation when mixing is required, perfectly balancing the contradictions between energy saving, noise reduction, durability, and user experience.

[0081] By optimizing the operation strategy of the circulating pump, system energy consumption and component wear are significantly reduced while ensuring water temperature uniformity, thus improving the long-term reliability and economy of the product. A temperature sensor continuously monitors the real-time water temperature inside the insulation tank. When the target heating temperature is reached, it indicates that the hot water in the tank is in a uniform state or requires only minimal heat to maintain. At this point, the circulating pump is automatically controlled to enter a sleep or low-speed operation mode. This avoids the energy waste of the circulating pump continuing to run under thermal equilibrium conditions, as is common in traditional solutions. For example, during low water usage periods at night, the circulating pump can be completely shut off for several hours, only restarting when the next water replenishment operation begins or the water temperature drops below the trigger temperature. This reduces the cumulative workload on the circulating pump's mechanical components, extends its service life, and lowers the maintenance costs throughout the product's lifecycle.

[0082] The above-mentioned at least one technical solution adopted in the embodiments of this specification can achieve the following beneficial effects: Real-time water level height sequences are collected under the trigger of water replenishment signals and / or water intake signals, solving the problem of continuous water level monitoring in existing technologies such as float switches. This technical solution collects data under the trigger of a clear water replenishment or water intake event, ensuring the efficiency and relevance of data collection. Collecting real-time water level height sequences means that dynamic water level data points over a period of time are obtained, rather than isolated, static instantaneous water level values. This provides a data foundation for subsequent analysis of water level change trends rather than just the current state, overcoming the limitations of point-based detection such as float switches, and achieving stepless and continuous water level detection. Fitting the real-time water level height sequence determines the correlation model between water level height and water level change time. Through mathematical methods, the objective law of water level height change over time is extracted from discrete water level data points, allowing dynamic measurement of real-time flow velocity and avoiding control errors caused by flow velocity fluctuations. This is particularly beneficial during water replenishment and / or water intake processes. During the process, the operating parameters of the water pump and / or heating element are controlled based on the correlation model. Under dynamic operating conditions, the operating parameters of the actuator are adjusted in real time using the correlation model. When drawing water, the water drawing time can be accurately calculated and controlled based on the actual flow rate obtained from the model and the user-set water volume, solving the technical problem of inaccurate water drawing volume. When replenishing water, the water level rise trend can be monitored in real time based on the model. In the event of temporary loss of water level data, the water level can be predicted through the model, ensuring that the water pump is shut off in time when the target water level is reached, effectively preventing water overflow. Regarding the water level shifting phenomenon mentioned in the background technology, the water level can be predicted to drop to a specified position based on the model, and the water pump power can be controlled to change smoothly and gradually, rather than switching instantaneously. At the same time, the heating element power is adjusted synchronously and appropriately based on the predicted flow rate change, avoiding the problems of instantaneous flow interruption and sudden flow change, eliminating the difficulties in controlling the heating element overheating and jetting and water discharge caused by these issues, greatly improving the safety of product use, and further enhancing the user experience.

[0083] Those skilled in the art will understand that embodiments of this specification can be provided as methods, systems, or computer program products. Therefore, this specification may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this specification may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0085] The above are merely one or more embodiments of this specification and are not intended to limit this specification. Various modifications and variations can be made to the one or more embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of one or more embodiments of this specification should be included within the scope of the claims of this specification.

Claims

1. A method for detecting and controlling the water level in a water purifier's insulation tank, characterized in that, The method includes: Triggered by a water replenishment signal and / or a water intake signal, the real-time water level height sequence of the insulated tank is collected within a preset time. The real-time water level height sequence is fitted to determine the correlation model between the water level height and the water level change time. During the water replenishment or water intake process of the insulated tank, the operating parameters of the water pump and / or heating element are controlled according to the correlation model.

2. The water level detection and control method for a water purifier insulation tank according to claim 1, characterized in that, Fitting the real-time water level sequence to determine the correlation model between water level height and water level change time specifically includes: Acquire multiple pairs of water level height data for the real-time water level height sequence within the preset time period, each pair of water level height data including the acquisition time and the water level height value corresponding to the acquisition time; A linear fit is performed on the multiple water level height data pairs to determine the correlation model, wherein the correlation model includes a slope parameter representing the flow velocity and an intercept parameter representing the initial water level height.

3. The water level detection and control method for a water purifier insulation tank according to claim 2, characterized in that, Before performing linear fitting on the plurality of water level height data pairs, the method further includes: Invalid value detection is performed on the water level height data pairs based on the adjacent water level height values ​​corresponding to adjacent collection times; When an invalid water level value exists in a pair of water level height data, the pair of water level height data is removed from the real-time water level height sequence. Record the corresponding invalid data collection time so that, after determining the correlation model, the estimated water level height value corresponding to the invalid data collection time can be determined based on the invalid data collection time and the correlation model.

4. The water level detection and control method for a water purifier insulation tank according to claim 1, characterized in that, Based on the aforementioned correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: Receive the user-defined quantitative water intake parameters and determine the water intake flow rate based on the absolute value of the slope parameter in the correlation model corresponding to the water intake process; The theoretical water extraction time is calculated using the quantitative water extraction parameters and the water extraction flow rate. The timing starts when the water intake signal is triggered, and when the actual water intake time reaches the theoretical water intake time, the water pump is controlled to stop, so as to stop water intake.

5. The water level detection and control method for a water purifier insulation tank according to claim 1, characterized in that, Based on the aforementioned correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: During the water intake process, water level data is acquired in real time, including real-time collected water level data and / or estimated water level data obtained based on the correlation model. When the water level is detected to drop to a preset water switching trigger threshold, the operating power of the water pump is controlled to decrease from a first power level to a second power level through a non-instantaneous gradual process, and the heating power of the heating element is adjusted to match. The water flow rate corresponding to the second power level is less than the water flow rate corresponding to the first power level, and is the same as the operating flow rate of the target small pump.

6. The water level detection and control method for a water purifier insulation tank according to claim 5, characterized in that, Controlling the operating power of the water pump to decrease from a first power level to a second power level through a non-instantaneous gradual process specifically includes: With a preset first time interval as the adjustment cycle, the driving power value of the water pump is gradually reduced according to a preset adjustment power step size. After completing the power adjustment of each adjustment cycle, a preset first time period is waited until the driving power value of the water pump reaches the second power level.

7. The water level detection and control method for a water purifier insulation tank according to claim 6, characterized in that, The heating power of the heating element is adjusted to a lower level for matching purposes, specifically including: Determine the rate of power decrease of the water pump during the adjustment period, and predict the rate of change of water flow during the adjustment period based on the rate of decrease; Using thermodynamic formulas, based on the predicted water flow rate and the real-time water temperature inside the insulation tank, the predicted heat required to heat to the preset target heating temperature is calculated. Based on the predicted heat demand, the target heating power of the heating element is determined, so that the heating power of the heating element is synchronously reduced to the target heating power during the adjustment period.

8. The water level detection and control method for a water purifier insulation tank according to claim 1, characterized in that, Based on the aforementioned correlation model, the operating parameters of the water pump and / or heating element are controlled, specifically including: During the water replenishment process, the raw water temperature data is acquired in real time; The current water replenishment flow rate is determined using the slope parameter in the aforementioned correlation model; Based on the current water supply flow rate, the raw water temperature data, and the preset target heating temperature, the real-time matching heating power required to heat the water supply to the target heating temperature is determined, so as to control the heating element to perform water supply heating according to the real-time matching heating power.

9. The water level detection and control method for a water purifier insulation tank according to claim 8, characterized in that, The method further includes: During the process of controlling the heating element to perform water replenishment heating according to the real-time matched heating power, the dynamically updated water replenishment flow rate is obtained; The updated water supply flow rate is compared with the current water supply flow rate to determine whether the flow rate deviation exceeds a preset allowable range. If the determination is yes, then the heating power of the heating element is updated based on the updated water replenishment flow rate.

10. A method for detecting and controlling the water level in a water purifier's insulation tank according to claim 8, characterized in that, The method further includes: Monitor the real-time water temperature inside the insulation tank and compare it with the target heating temperature; If the real-time water temperature reaches the target heating temperature, the circulating pump is controlled to stop running or reduce its operating frequency so that the next water replenishment operation can begin or the water temperature drops below the target heating temperature.

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